Dépouillements

Arvind Varma / Massimo Morbidelli in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8957–8959 Titre : Arvind Varma : Educator, Researcher and Leader Type de document : texte imprimé Auteurs : Massimo Morbidelli, Auteur ; Bala Subramaniam, Auteur Année de publication : 2009 Article en page(s) : p. 8957–8959 Note générale : Engineering Chemistry Langues : Anglais (eng) Mots-clés : Arvind Varma -- Educator, Researcher and Leader En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801563q [article] Arvind Varma : Educator, Researcher and Leader [texte imprimé] / Massimo Morbidelli, Auteur ; Bala Subramaniam, Auteur . - 2009 . - p. 8957–8959. Engineering Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8957–8959 Mots-clés : Arvind Varma -- Educator, Researcher and Leader En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801563q

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Petroleum residue upgradation via visbreaking / Jyeshtharaj B. Joshi in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8960–8988 Titre : Petroleum residue upgradation via visbreaking : a review Type de document : texte imprimé Auteurs : Jyeshtharaj B. Joshi, Auteur ; Aniruddha B. Pandit, Auteur ; Rohit P. Kulkarni, Auteur Année de publication : 2009 Article en page(s) : p. 8960–8988 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Petroleum residue Upgradation Visbreaking Résumé : World petroleum residue processing capacity has reached about 810 MMTPA. In the present petroleum refining scenario, the viability of a petroleum refinery strongly depends on the flexibility of processing heavy crudes and, in turn, heavy residues. Visbreaking is one of the major residue upgrading processes and constitutes about 33% of the total residue processing capacity. In the present communication, the published literature pertaining to the visbreaking process has been extensively analyzed and a state-of-the-art review has been written that includes the following: (i) the effect of feed properties on fuel oil stability; (ii) reaction pathways, mechanism, and kinetics; (iii) parametric sensitivity of the operating variables such as temperature, pressure, and residence time; (iv) different visbreaker designs, viz. coil visbreaker, coil-soaker visbreaker, soaker with internals, and high conversion soaker; (v) coking and fouling; (vi) estimation of design parameters, viz. gas holdup in high-pressure bubble column (soaker), gas holdup in sectionalized bubble column (soaker with internals), liquid-phase mixing and axial mixing in high-pressure bubble column, liquid-phase mixing and axial mixing in sectionalized bubble column, and weeping; and (vii) mathematical modeling of visbreaker, which mainly includes the coil and the soaker. An attempt has been made to get the aforementioned aspects together in a coherent manner so that the information is available at a glance and is expected to be useful to researchers and practicing refiners. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0710871#afn1 [article] Petroleum residue upgradation via visbreaking : a review [texte imprimé] / Jyeshtharaj B. Joshi, Auteur ; Aniruddha B. Pandit, Auteur ; Rohit P. Kulkarni, Auteur . - 2009 . - p. 8960–8988. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8960–8988 Mots-clés : Petroleum residue Upgradation Visbreaking Résumé : World petroleum residue processing capacity has reached about 810 MMTPA. In the present petroleum refining scenario, the viability of a petroleum refinery strongly depends on the flexibility of processing heavy crudes and, in turn, heavy residues. Visbreaking is one of the major residue upgrading processes and constitutes about 33% of the total residue processing capacity. In the present communication, the published literature pertaining to the visbreaking process has been extensively analyzed and a state-of-the-art review has been written that includes the following: (i) the effect of feed properties on fuel oil stability; (ii) reaction pathways, mechanism, and kinetics; (iii) parametric sensitivity of the operating variables such as temperature, pressure, and residence time; (iv) different visbreaker designs, viz. coil visbreaker, coil-soaker visbreaker, soaker with internals, and high conversion soaker; (v) coking and fouling; (vi) estimation of design parameters, viz. gas holdup in high-pressure bubble column (soaker), gas holdup in sectionalized bubble column (soaker with internals), liquid-phase mixing and axial mixing in high-pressure bubble column, liquid-phase mixing and axial mixing in sectionalized bubble column, and weeping; and (vii) mathematical modeling of visbreaker, which mainly includes the coil and the soaker. An attempt has been made to get the aforementioned aspects together in a coherent manner so that the information is available at a glance and is expected to be useful to researchers and practicing refiners. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0710871#afn1

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Complex srruO3-Pt and LaRuO3-Pt catalysts for direct alcohol fuel cells / Aidong Lan in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8989–8994 Titre : Complex srruO3-Pt and LaRuO3-Pt catalysts for direct alcohol fuel cells Type de document : texte imprimé Auteurs : Aidong Lan, Auteur ; Mukasyan, Alexander S., Auteur Année de publication : 2009 Article en page(s) : p. 8989–8994 Note générale : Engineering Chemistry Langues : Anglais (eng) Mots-clés : Complex SrRuO3 -- Pt and LaRuO3 Catalysts for Direct Alcohol Fuel Cells Résumé : Using energy efficient and rapid solution combustion synthesis technique, a variety of complex, i.e., perovskites/platinum (ABO3/Pt), catalysts were synthesized. A high-throughput NuVant system was used for testing these compositions as an anode catalyst for electrooxidation of methanol and ethanol in the conditions close to those for direct alcohol fuel cells. It was found that a variety of ABO3/Pt compositions with Ru at B-site, prepared directly in the combustion wave, exhibit comparable performance with Pt−Ru alloy. It is important that these bifunctional catalysts contain much less platinum than that used in standard ones. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8000698 [article] Complex srruO3-Pt and LaRuO3-Pt catalysts for direct alcohol fuel cells [texte imprimé] / Aidong Lan, Auteur ; Mukasyan, Alexander S., Auteur . - 2009 . - p. 8989–8994. Engineering Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8989–8994 Mots-clés : Complex SrRuO3 -- Pt and LaRuO3 Catalysts for Direct Alcohol Fuel Cells Résumé : Using energy efficient and rapid solution combustion synthesis technique, a variety of complex, i.e., perovskites/platinum (ABO3/Pt), catalysts were synthesized. A high-throughput NuVant system was used for testing these compositions as an anode catalyst for electrooxidation of methanol and ethanol in the conditions close to those for direct alcohol fuel cells. It was found that a variety of ABO3/Pt compositions with Ru at B-site, prepared directly in the combustion wave, exhibit comparable performance with Pt−Ru alloy. It is important that these bifunctional catalysts contain much less platinum than that used in standard ones. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8000698

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Microstructured mesh contactor for asymmetric transfer hydrogenation with simultaneous stripping / M. Zanfir in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8995–9005 Titre : Microstructured mesh contactor for asymmetric transfer hydrogenation with simultaneous stripping : modeling and experiments Type de document : texte imprimé Auteurs : M. Zanfir, Auteur ; X. Sun, Auteur ; A. Gavriilidis, Auteur Année de publication : 2009 Article en page(s) : p. 8995–9005 Note générale : Engineering Chemistry Langues : Anglais (eng) Mots-clés : Mesh Contactor for Asymmetric -- Modeling and Experiments Résumé : A two-dimensional model for a mesh contactor utilized for acetone stripping from binary mixtures acetone−isopropanol with nitrogen as inert gas, as well as for asymmetric transfer hydrogenation of acetophenone with isopropanol as the hydrogen donor in the presence of a homogeneous catalyst and simultaneous acetone removal by stripping has been formulated and solved. Experiments have been performed with a microstructured mesh contactor that consists of parallel metal plates, gaskets, and a microstructured mesh so that passages for gas and liquid phases are formed. The model gives good agreement with experimental data for both acetone removal from a binary mixture and asymmetric transfer of hydrogenation. Theoretical and experimental investigations show that the amount of acetone removed from the liquid phase is strongly dependent on the ratio of inlet gas to liquid flowrate. For a higher ratio, more efficient acetone removal from the liquid phase is achieved. If dry nitrogen is used as a stripping agent, simultaneous evaporation of acetone and isopropanol results in significant solvent depletion of the liquid phase. In this case, the gas phase becomes saturated with solvent (isopropanol) near the reactor entrance. Due to efficient removal of acetone produced as byproduct during the reaction, reaction time in the mesh reactor can be significantly decreased as compared to a laboratory batch reactor. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071653s [article] Microstructured mesh contactor for asymmetric transfer hydrogenation with simultaneous stripping : modeling and experiments [texte imprimé] / M. Zanfir, Auteur ; X. Sun, Auteur ; A. Gavriilidis, Auteur . - 2009 . - p. 8995–9005. Engineering Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8995–9005 Mots-clés : Mesh Contactor for Asymmetric -- Modeling and Experiments Résumé : A two-dimensional model for a mesh contactor utilized for acetone stripping from binary mixtures acetone−isopropanol with nitrogen as inert gas, as well as for asymmetric transfer hydrogenation of acetophenone with isopropanol as the hydrogen donor in the presence of a homogeneous catalyst and simultaneous acetone removal by stripping has been formulated and solved. Experiments have been performed with a microstructured mesh contactor that consists of parallel metal plates, gaskets, and a microstructured mesh so that passages for gas and liquid phases are formed. The model gives good agreement with experimental data for both acetone removal from a binary mixture and asymmetric transfer of hydrogenation. Theoretical and experimental investigations show that the amount of acetone removed from the liquid phase is strongly dependent on the ratio of inlet gas to liquid flowrate. For a higher ratio, more efficient acetone removal from the liquid phase is achieved. If dry nitrogen is used as a stripping agent, simultaneous evaporation of acetone and isopropanol results in significant solvent depletion of the liquid phase. In this case, the gas phase becomes saturated with solvent (isopropanol) near the reactor entrance. Due to efficient removal of acetone produced as byproduct during the reaction, reaction time in the mesh reactor can be significantly decreased as compared to a laboratory batch reactor. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071653s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Kinetic modeling of NOx storage/Reduction on Pt/BaO/Al2O3 monolith catalysts / L. Cao in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9006–9017 Titre : Kinetic modeling of NOx storage/Reduction on Pt/BaO/Al2O3 monolith catalysts Type de document : texte imprimé Auteurs : L. Cao, Auteur ; J. L. Ratts, Auteur ; A. Yezerets, Auteur ; N. W. Currier, Auteur Année de publication : 2009 Article en page(s) : p. 9006–9017 Note générale : Engineering Chemistry Langues : Anglais (eng) Mots-clés : Kinetic Modeling of NOx Storage -- Reduction on Pt BaO Al2O3 Monolith Catalysts Résumé : A balance of the complexity of the reactor model and the chemical reaction mechanism has to be made in order to predict the dynamic nature of NOx storage/reduction processes in real time. In this work, a one-dimensional, two-phase model is used to simulate the transient behavior of a monolithic Pt/BaO/Al2O3 catalyst for NOx storage/reduction. The following aspects of the process are discussed: (i) kinetics of NO and NO2 adsorption on BaO sites, (ii) effects of CO2 and H2O on NO/NO2 adsorption, and (iii) reduction of surface nitrates using H2. NOx adsorption with excess oxygen involves two kinetic routes, namely, NO2 disproportionation and direct NO adsorption, both of which form nitrates on the catalyst at 300 °C. A model with two time scales was found to be necessary to describe NO2 adsorption on the 20 wt % BaO catalyst. The model and parameters required to fit the NOx breakthrough curves suggest that CO2 and H2O in the feed reduce the number of sites for NO adsorption by changing the surface morphology of the Ba phase. The rate constants for both fast and slow NO2 uptake are decreased in the presence of CO2 and H2O, but the total capacity remains the same. Under reaction conditions, H2 reduction of surface NOx is limited by the supply of the reductant; that is, the rate of surface NOx removal is limited by the flux of inlet H2. NH3 serves as the reducing intermediate/H carrier during the H2 reduction process. The confined reduction front moving along the channel localizes the heat generation, thus leading to a surface temperature in the reduction front about 35 °C higher than the inlet gas temperature for our reaction conditions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001809 [article] Kinetic modeling of NOx storage/Reduction on Pt/BaO/Al2O3 monolith catalysts [texte imprimé] / L. Cao, Auteur ; J. L. Ratts, Auteur ; A. Yezerets, Auteur ; N. W. Currier, Auteur . - 2009 . - p. 9006–9017. Engineering Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9006–9017 Mots-clés : Kinetic Modeling of NOx Storage -- Reduction on Pt BaO Al2O3 Monolith Catalysts Résumé : A balance of the complexity of the reactor model and the chemical reaction mechanism has to be made in order to predict the dynamic nature of NOx storage/reduction processes in real time. In this work, a one-dimensional, two-phase model is used to simulate the transient behavior of a monolithic Pt/BaO/Al2O3 catalyst for NOx storage/reduction. The following aspects of the process are discussed: (i) kinetics of NO and NO2 adsorption on BaO sites, (ii) effects of CO2 and H2O on NO/NO2 adsorption, and (iii) reduction of surface nitrates using H2. NOx adsorption with excess oxygen involves two kinetic routes, namely, NO2 disproportionation and direct NO adsorption, both of which form nitrates on the catalyst at 300 °C. A model with two time scales was found to be necessary to describe NO2 adsorption on the 20 wt % BaO catalyst. The model and parameters required to fit the NOx breakthrough curves suggest that CO2 and H2O in the feed reduce the number of sites for NO adsorption by changing the surface morphology of the Ba phase. The rate constants for both fast and slow NO2 uptake are decreased in the presence of CO2 and H2O, but the total capacity remains the same. Under reaction conditions, H2 reduction of surface NOx is limited by the supply of the reductant; that is, the rate of surface NOx removal is limited by the flux of inlet H2. NH3 serves as the reducing intermediate/H carrier during the H2 reduction process. The confined reduction front moving along the channel localizes the heat generation, thus leading to a surface temperature in the reduction front about 35 °C higher than the inlet gas temperature for our reaction conditions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001809

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Modeling and simulation of a downer-Type HS-FCC unit / Abdullah A. Shaikh in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9018–9024 Titre : Modeling and simulation of a downer-Type HS-FCC unit Type de document : texte imprimé Auteurs : Abdullah A. Shaikh, Auteur ; Eid M. Al-Mutairi, Auteur ; Takashi Ino, Auteur Année de publication : 2009 Article en page(s) : p. 9018–9024 Note générale : Engineering Chemistry Langues : Anglais (eng) Mots-clés : Modeling and Simulation of a Downer -- Type HS-FCC Unit Résumé : Mathematical models and simulations of an integrated downer−regenerator FCC unit are presented. The models describe the steady-state nonisothermal behavior of the interdependent heavy oil cracking downflow reactor and catalyst regeneration fluidized-bed reactor. The models are rooted in four-lump cracking reaction kinetics and complete combustion kinetics for the regenerator reactions. Simulations results for the downer-type unit are partially validated against data collected in a 0.1−0.3 b/day pilot plant that was operated in the high-severity mode. The results are fairly reasonable especially in regard to predicting the performance of the cracking reactor. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800060y [article] Modeling and simulation of a downer-Type HS-FCC unit [texte imprimé] / Abdullah A. Shaikh, Auteur ; Eid M. Al-Mutairi, Auteur ; Takashi Ino, Auteur . - 2009 . - p. 9018–9024. Engineering Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9018–9024 Mots-clés : Modeling and Simulation of a Downer -- Type HS-FCC Unit Résumé : Mathematical models and simulations of an integrated downer−regenerator FCC unit are presented. The models describe the steady-state nonisothermal behavior of the interdependent heavy oil cracking downflow reactor and catalyst regeneration fluidized-bed reactor. The models are rooted in four-lump cracking reaction kinetics and complete combustion kinetics for the regenerator reactions. Simulations results for the downer-type unit are partially validated against data collected in a 0.1−0.3 b/day pilot plant that was operated in the high-severity mode. The results are fairly reasonable especially in regard to predicting the performance of the cracking reactor. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800060y

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Multiplicity and stability of chemical reactors with evaporative cooling / Manuel Z. Solórzano in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9025–9039 Titre : Multiplicity and stability of chemical reactors with evaporative cooling Type de document : texte imprimé Auteurs : Manuel Z. Solórzano, Auteur ; W. Harmon Ray, Auteur Année de publication : 2009 Article en page(s) : p. 9025–9039 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : chemical reactors evaporative cooling Résumé : This work characterizes the dynamic behavior of reactors with evaporative cooling. The process under consideration is a continuous stirred tank reactor used to carry out an exothermic irreversible first-order reaction with heat removal through the wall as well as by partial evaporation of the reacting liquid followed by return of the condensate to the reactor. Bifurcation analysis is used to classify the stability character and the types of multiplicity and oscillatory behavior to be expected. A variety of practical situations is examined, including cases of volatile reactant, volatile or nonvolatile product (liquid or solid), and volatile solvent. For a fixed vapor flowrate to the condenser, the dynamic structure of reactors with evaporative cooling is qualitatively similar to the case with wall cooling alone. Other cases show significantly different structures. Cases with five steady states and two regions of three steady states are found with evaporative cooling operation, and for some conditions even seven steady states may be possible. A rich variety of dynamic behavior is predicted. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800044b [article] Multiplicity and stability of chemical reactors with evaporative cooling [texte imprimé] / Manuel Z. Solórzano, Auteur ; W. Harmon Ray, Auteur . - 2009 . - p. 9025–9039. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9025–9039 Mots-clés : chemical reactors evaporative cooling Résumé : This work characterizes the dynamic behavior of reactors with evaporative cooling. The process under consideration is a continuous stirred tank reactor used to carry out an exothermic irreversible first-order reaction with heat removal through the wall as well as by partial evaporation of the reacting liquid followed by return of the condensate to the reactor. Bifurcation analysis is used to classify the stability character and the types of multiplicity and oscillatory behavior to be expected. A variety of practical situations is examined, including cases of volatile reactant, volatile or nonvolatile product (liquid or solid), and volatile solvent. For a fixed vapor flowrate to the condenser, the dynamic structure of reactors with evaporative cooling is qualitatively similar to the case with wall cooling alone. Other cases show significantly different structures. Cases with five steady states and two regions of three steady states are found with evaporative cooling operation, and for some conditions even seven steady states may be possible. A rich variety of dynamic behavior is predicted. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800044b

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Parametric study of solid-Phase axial heat conduction in thermally integrated microchannel networks / Angela Moreno in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9040–9054 Titre : Parametric study of solid-Phase axial heat conduction in thermally integrated microchannel networks Type de document : texte imprimé Auteurs : Angela Moreno, Auteur ; Kevin Murphy, Auteur ; Benjamin A. Wilhite, Auteur Année de publication : 2009 Article en page(s) : p. 9040–9054 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Parametric Study of Solid-Phase Axial Heat Conduction in Thermally Integrated Microchannel Networks Résumé : A parametric study is presented to highlight design challenges of thermally integrated microchannel networks for portable chemistry and/or fuels reforming. One-dimensional modeling analysis of heat transfer in a two-fluid system is presented for the case of (i) two nonreacting fluids (heat exchanger), (ii) a single exothermic reacting fluid and a second nonreacting fluid (regenerative combustor), and (iii) one exothermic reacting fluid and a second endothermic reacting fluid (heat exchanger reactor). In each case, the influence of solid-phase thermal conductivity and thermal packaging upon thermal efficiency, reaction conversion, and steady-state multiplicity is investigated. Results demonstrate the importance of both packaging and solid-phase axial thermal conduction upon system performance, with optimal performance obtained using low thermal conductivity substrates. Modeling analysis predicts steady-state multiplicity when employing low thermal conductivity materials, illustrating the need for future detailed stability analysis. Lastly, simplified mechanical analysis is presented to illustrate the value of coupled thermomechanical analysis. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001638 [article] Parametric study of solid-Phase axial heat conduction in thermally integrated microchannel networks [texte imprimé] / Angela Moreno, Auteur ; Kevin Murphy, Auteur ; Benjamin A. Wilhite, Auteur . - 2009 . - p. 9040–9054. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9040–9054 Mots-clés : Parametric Study of Solid-Phase Axial Heat Conduction in Thermally Integrated Microchannel Networks Résumé : A parametric study is presented to highlight design challenges of thermally integrated microchannel networks for portable chemistry and/or fuels reforming. One-dimensional modeling analysis of heat transfer in a two-fluid system is presented for the case of (i) two nonreacting fluids (heat exchanger), (ii) a single exothermic reacting fluid and a second nonreacting fluid (regenerative combustor), and (iii) one exothermic reacting fluid and a second endothermic reacting fluid (heat exchanger reactor). In each case, the influence of solid-phase thermal conductivity and thermal packaging upon thermal efficiency, reaction conversion, and steady-state multiplicity is investigated. Results demonstrate the importance of both packaging and solid-phase axial thermal conduction upon system performance, with optimal performance obtained using low thermal conductivity substrates. Modeling analysis predicts steady-state multiplicity when employing low thermal conductivity materials, illustrating the need for future detailed stability analysis. Lastly, simplified mechanical analysis is presented to illustrate the value of coupled thermomechanical analysis. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001638

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Novelties of solid-Liquid phase transfer catalyzed synthesis of triclosan from potassium 2,4-Dichlorophenolate and 2,5-Dichlorophenol / Ganapati D. Yadav in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9055–9060 Titre : Novelties of solid-Liquid phase transfer catalyzed synthesis of triclosan from potassium 2,4-Dichlorophenolate and 2,5-Dichlorophenol Type de document : texte imprimé Auteurs : Ganapati D. Yadav, Auteur ; Bhavana G. Motirale, Auteur Année de publication : 2009 Article en page(s) : p. 9055–9060 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Solid−  Liquid Phase Catalyzed Synthesis of Triclosan from Potassium Résumé : Triclosan is a broad-spectrum bacteriostat and an antimicrobial agent popularly used in hygiene and health care products. The current paper presents a cost-effective and simpler process of synthesis of triclosan from 2,5-dichlorophenol and potassium 2,4-dichlorophenolate by using p-xylene as a solvent under solid−liquid phase transfer catalysis (S−L PTC), at 120 °C. It leads to 100% selectivity of the product in comparison with a liquid−liquid PTC process. A novel mathematical model is developed to determine simultaneously the rate constant and anion exchange equilibrium constant from the same set of data. This will be helpful in reactor design and scale-up. The activation energy and Gibbs free energy for a combined ion exchange and partitioning of ion pairs are calculated. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800191k [article] Novelties of solid-Liquid phase transfer catalyzed synthesis of triclosan from potassium 2,4-Dichlorophenolate and 2,5-Dichlorophenol [texte imprimé] / Ganapati D. Yadav, Auteur ; Bhavana G. Motirale, Auteur . - 2009 . - p. 9055–9060. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9055–9060 Mots-clés : Solid−  Liquid Phase Catalyzed Synthesis of Triclosan from Potassium Résumé : Triclosan is a broad-spectrum bacteriostat and an antimicrobial agent popularly used in hygiene and health care products. The current paper presents a cost-effective and simpler process of synthesis of triclosan from 2,5-dichlorophenol and potassium 2,4-dichlorophenolate by using p-xylene as a solvent under solid−liquid phase transfer catalysis (S−L PTC), at 120 °C. It leads to 100% selectivity of the product in comparison with a liquid−liquid PTC process. A novel mathematical model is developed to determine simultaneously the rate constant and anion exchange equilibrium constant from the same set of data. This will be helpful in reactor design and scale-up. The activation energy and Gibbs free energy for a combined ion exchange and partitioning of ion pairs are calculated. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800191k

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Polymerizations in the Presence of vaporization / Manojkumar Ramteke in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9061–9071 Titre : Polymerizations in the Presence of vaporization : experimental results on nylon-6 Type de document : texte imprimé Auteurs : Manojkumar Ramteke, Auteur ; Santosh K. Gupta, Auteur Année de publication : 2009 Article en page(s) : p. 9061–9071 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Polymerizations Vaporization Results on Nylon-6 Résumé : This study deals with the hydrolytic step-growth polymerization of ε-caprolactam to produce nylon-6 in a semibatch reactor at near industrial conditions. ε-caprolactam is polymerized in a 1.6 L stainless steel reactor at three different initial water concentrations, 4.43% (by mass), 2.52%, and 3.45%, respectively. During the polymerization, the values of the temperature and the pressure are controlled and recorded. Samples of the liquid reaction mass are taken from the reactor at different times and analyzed. The monomer conversions are obtained gravimetrically (in terms of water extractibles) as well as by using gas chromatography. The samples are also analyzed for the degree of polymerization using amide and acid end-group concentrations. The parameters are tuned using one set of data with genetic algorithm. The tuned parameters are then used to predict the second set of data. In the simulation, the poly-NRTL model is used to describe the vapor−liquid equilibria. The simulated values match well with the experimental values. The tuned model gives reasonably good results. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800287d [article] Polymerizations in the Presence of vaporization : experimental results on nylon-6 [texte imprimé] / Manojkumar Ramteke, Auteur ; Santosh K. Gupta, Auteur . - 2009 . - p. 9061–9071. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9061–9071 Mots-clés : Polymerizations Vaporization Results on Nylon-6 Résumé : This study deals with the hydrolytic step-growth polymerization of ε-caprolactam to produce nylon-6 in a semibatch reactor at near industrial conditions. ε-caprolactam is polymerized in a 1.6 L stainless steel reactor at three different initial water concentrations, 4.43% (by mass), 2.52%, and 3.45%, respectively. During the polymerization, the values of the temperature and the pressure are controlled and recorded. Samples of the liquid reaction mass are taken from the reactor at different times and analyzed. The monomer conversions are obtained gravimetrically (in terms of water extractibles) as well as by using gas chromatography. The samples are also analyzed for the degree of polymerization using amide and acid end-group concentrations. The parameters are tuned using one set of data with genetic algorithm. The tuned parameters are then used to predict the second set of data. In the simulation, the poly-NRTL model is used to describe the vapor−liquid equilibria. The simulated values match well with the experimental values. The tuned model gives reasonably good results. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800287d

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Economic and environmental impact analyses of solid acid catalyzed isoparaffin/Olefin alkylation in supercritical carbon dioxide / Kening Gong in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9072–9080 Titre : Economic and environmental impact analyses of solid acid catalyzed isoparaffin/Olefin alkylation in supercritical carbon dioxide Type de document : texte imprimé Auteurs : Kening Gong, Auteur ; Steve Chafin, Auteur ; Kent Pennybaker, Auteur Année de publication : 2009 Article en page(s) : p. 9072–9080 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Economic and Environmental Analyses of Solid Acid Catalyzed Isoparaffin Supercritical Carbon Dioxide Résumé : HYSYS-based process simulation was accomplished for a recently reported 1-butene + isobutane alkylation concept that employs SiO2-supported Nafion catalyst in dense CO2 media to obtain stable C8 alkylates production (solid acid/CO2 process). Semiquantitative economic and environmental impact assessments were conducted for this novel process design along with comparative assessments for a conventional sulfuric acid catalyzed alkylation process (at equivalent production capacities). The simulations are commercial scale and are based on available data and reasonable process assumptions. The total capital investment of the solid acid/CO2 process is approximately 20−30% higher than that of the sulfuric acid process. Sensitivity analysis shows that, if the olefin space velocity can be increased by a factor of 4 from the base-case value while maintaining the same C8 alkylate productivity, the total capital investments along with the utility and chemical costs would be nearly the same for both processes. The environmental impact assessment shows that the conventional sulfuric acid process has a 3.9 times higher adverse environmental impact potential than the solid acid/CO2 process. For the sulfuric acid process, the major contributors to the environmental impact are acid rain (66%) and inhalation toxicity (32%). The main pollution comes from the SO2 emissions during sulfuric acid regeneration (53%) and acid leakage in the alkylation unit (10%). For the solid acid/CO2 process, the major contributors to the environmental impact are inhalation toxicity (83%), global warming (10%), and acid rain (6%). For the solid acid/CO2 process, the main pollution sources are fugitive emissions. This evaluation illustrates the advantages and shortcomings of the novel process and provides rational research guidance. For example, the analyses established performance targets, such as catalyst activity and operating pressure, for the solid acid/CO2 process to be commercially viable. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800399s [article] Economic and environmental impact analyses of solid acid catalyzed isoparaffin/Olefin alkylation in supercritical carbon dioxide [texte imprimé] / Kening Gong, Auteur ; Steve Chafin, Auteur ; Kent Pennybaker, Auteur . - 2009 . - p. 9072–9080. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9072–9080 Mots-clés : Economic and Environmental Analyses of Solid Acid Catalyzed Isoparaffin Supercritical Carbon Dioxide Résumé : HYSYS-based process simulation was accomplished for a recently reported 1-butene + isobutane alkylation concept that employs SiO2-supported Nafion catalyst in dense CO2 media to obtain stable C8 alkylates production (solid acid/CO2 process). Semiquantitative economic and environmental impact assessments were conducted for this novel process design along with comparative assessments for a conventional sulfuric acid catalyzed alkylation process (at equivalent production capacities). The simulations are commercial scale and are based on available data and reasonable process assumptions. The total capital investment of the solid acid/CO2 process is approximately 20−30% higher than that of the sulfuric acid process. Sensitivity analysis shows that, if the olefin space velocity can be increased by a factor of 4 from the base-case value while maintaining the same C8 alkylate productivity, the total capital investments along with the utility and chemical costs would be nearly the same for both processes. The environmental impact assessment shows that the conventional sulfuric acid process has a 3.9 times higher adverse environmental impact potential than the solid acid/CO2 process. For the sulfuric acid process, the major contributors to the environmental impact are acid rain (66%) and inhalation toxicity (32%). The main pollution comes from the SO2 emissions during sulfuric acid regeneration (53%) and acid leakage in the alkylation unit (10%). For the solid acid/CO2 process, the major contributors to the environmental impact are inhalation toxicity (83%), global warming (10%), and acid rain (6%). For the solid acid/CO2 process, the main pollution sources are fugitive emissions. This evaluation illustrates the advantages and shortcomings of the novel process and provides rational research guidance. For example, the analyses established performance targets, such as catalyst activity and operating pressure, for the solid acid/CO2 process to be commercially viable. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800399s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Ionic liquid as catalyst for solid-Liquid Phase transfer catalyzed synthesis of p-Nitrodiphenyl ether / Ganapati D. Yadav in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9081–9089 Titre : Ionic liquid as catalyst for solid-Liquid Phase transfer catalyzed synthesis of p-Nitrodiphenyl ether Type de document : texte imprimé Auteurs : Ganapati D. Yadav, Auteur ; Bhavana G. Motirale, Auteur Année de publication : 2009 Article en page(s) : p. 9081–9089 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Synthesis of p-Nitrodiphenyl Ethe Résumé : The novelties of solid−liquid phase transfer catalyzed synthesis of p-nitrodiphenyl ether from p-nitrochlorobenzene and potassium phenoxide were studied in detail with ionic liquids as phase transfer catalysts among others. Tetradecyl(trihexyl)phosphonium bromide was found to be the best catalyst leading to 100% selectivity toward the desired product p-nitrodiphenyl ether. Ionic liquids offer excellent conversions and selectivity, stability at high temperatures, and reusability in this reaction. A mathematical model was developed to study the kinetics of the reaction and used to extract both the rate constant and ion-exchange equilibrium constant. The contribution of the uncatalyzed reaction was also considered in this model. The activation energy and Gibb’s free energy for a combined ion exchange were also calculated. Microwave irradiation was also employed as an effective alternative to conventional heating. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800340j [article] Ionic liquid as catalyst for solid-Liquid Phase transfer catalyzed synthesis of p-Nitrodiphenyl ether [texte imprimé] / Ganapati D. Yadav, Auteur ; Bhavana G. Motirale, Auteur . - 2009 . - p. 9081–9089. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9081–9089 Mots-clés : Synthesis of p-Nitrodiphenyl Ethe Résumé : The novelties of solid−liquid phase transfer catalyzed synthesis of p-nitrodiphenyl ether from p-nitrochlorobenzene and potassium phenoxide were studied in detail with ionic liquids as phase transfer catalysts among others. Tetradecyl(trihexyl)phosphonium bromide was found to be the best catalyst leading to 100% selectivity toward the desired product p-nitrodiphenyl ether. Ionic liquids offer excellent conversions and selectivity, stability at high temperatures, and reusability in this reaction. A mathematical model was developed to study the kinetics of the reaction and used to extract both the rate constant and ion-exchange equilibrium constant. The contribution of the uncatalyzed reaction was also considered in this model. The activation energy and Gibb’s free energy for a combined ion exchange were also calculated. Microwave irradiation was also employed as an effective alternative to conventional heating. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800340j

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

A rationale for monod's biochemical growth kinetics / Doraiswami Ramkrishna in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9090–9098 Titre : A rationale for monod's biochemical growth kinetics Type de document : texte imprimé Auteurs : Doraiswami Ramkrishna, Auteur ; Hyun-Seob Song, Auteur Année de publication : 2009 Article en page(s) : p. 9090–9098 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Biochemical Growth Kinetics Résumé : A rationale is presented for Monod′s biochemical kinetics which has hitherto been viewed as purely empirical. It is shown here that this expression, which continues to be used by modelers of biochemical processes, has indeed an origin that relates to the detailed treatment of metabolism. This rationale originates from the resolution of the metabolic network into so-called elementary modes and assumes steady state for every metabolite in each elementary mode. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800905d [article] A rationale for monod's biochemical growth kinetics [texte imprimé] / Doraiswami Ramkrishna, Auteur ; Hyun-Seob Song, Auteur . - 2009 . - p. 9090–9098. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9090–9098 Mots-clés : Biochemical Growth Kinetics Résumé : A rationale is presented for Monod′s biochemical kinetics which has hitherto been viewed as purely empirical. It is shown here that this expression, which continues to be used by modelers of biochemical processes, has indeed an origin that relates to the detailed treatment of metabolism. This rationale originates from the resolution of the metabolic network into so-called elementary modes and assumes steady state for every metabolite in each elementary mode. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800905d

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Configurational biomimetic imprinting for protein recognition / Nicole M. Bergmann in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9099–9107 Titre : Configurational biomimetic imprinting for protein recognition : structural characteristics of recognitive hydrogels Type de document : texte imprimé Auteurs : Nicole M. Bergmann, Auteur ; Nicholas A. Peppas, Auteur Année de publication : 2009 Article en page(s) : p. 9099–9107 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Biomimetic Hydrogels Structural Characteristics of Recognitive Résumé : Using a configurational biomimetic imprinting technique, we prepared a family of molecularly imprinting polyacrylamide polymers with recognition for the template protein chicken egg white lysozyme in aqueous solution. We showed the formation of a network with specific recognitive sites for the template. To determine the overall macroscopic properties of protein-imprinted gel, we utilized a variety of tools. When gels were examined using scanning electron microscopy, definite morphological differences were observed between the CBIP polymers and the controls. Additionally, Fourier transform infrared spectroscopy determined that the presence of template had no effect upon the overall gel composition, whereas differential scanning calorimetry showed no significant change in the molecular weight between cross-links between CBIP polymers and nonimprinted polymers. Using these results, a theory of gel formation was proposed to try to elucidate gel formation in the presence of a macromolecule. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071270u [article] Configurational biomimetic imprinting for protein recognition : structural characteristics of recognitive hydrogels [texte imprimé] / Nicole M. Bergmann, Auteur ; Nicholas A. Peppas, Auteur . - 2009 . - p. 9099–9107. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9099–9107 Mots-clés : Biomimetic Hydrogels Structural Characteristics of Recognitive Résumé : Using a configurational biomimetic imprinting technique, we prepared a family of molecularly imprinting polyacrylamide polymers with recognition for the template protein chicken egg white lysozyme in aqueous solution. We showed the formation of a network with specific recognitive sites for the template. To determine the overall macroscopic properties of protein-imprinted gel, we utilized a variety of tools. When gels were examined using scanning electron microscopy, definite morphological differences were observed between the CBIP polymers and the controls. Additionally, Fourier transform infrared spectroscopy determined that the presence of template had no effect upon the overall gel composition, whereas differential scanning calorimetry showed no significant change in the molecular weight between cross-links between CBIP polymers and nonimprinted polymers. Using these results, a theory of gel formation was proposed to try to elucidate gel formation in the presence of a macromolecule. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071270u

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Emulsion texture and stability / Youngsun Kong in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9108–9114 Titre : Emulsion texture and stability : role of surfactant micellar interactions in the presence of proteins Type de document : texte imprimé Auteurs : Youngsun Kong, Auteur ; Alex Nikolov, Auteur ; Darsh Wasan, Auteur Année de publication : 2009 Article en page(s) : p. 9108–9114 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Texture and Stability Role of Surfactant Micellar Presence Proteins Résumé : This article presents the results of our recent research on the texture and stability of oil-in-water emulsions containing sucrose ester and proteins. We used both the direct microscopic imaging and nondestructive back-light scattering (Kossel diffraction) techniques to evaluate the emulsion texture and the energy barrier between droplets for two different emulsifier compositions with and without the proteins present. The microinterferometric method employing our capillary force balance was used to study the stability of the confined thin film (containing surfactant micelles and proteins) between two droplets. In addition to the film stability, we also measured the second virial coefficient of the micellar solutions with and without protein and assessed the intermicellar interaction and related it to the stabilities of the emulsions prepared using two different emulsifier compositions. The effect of protein on the oil-in-water emulsion stability was also assessed and was found to lead to the depletion attraction between droplets, resulting in a less stable emulsion. The results offer new insight into the understanding of how the micellar interactions in the presence of proteins affect emulsion texture and stability. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001815 [article] Emulsion texture and stability : role of surfactant micellar interactions in the presence of proteins [texte imprimé] / Youngsun Kong, Auteur ; Alex Nikolov, Auteur ; Darsh Wasan, Auteur . - 2009 . - p. 9108–9114. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9108–9114 Mots-clés : Texture and Stability Role of Surfactant Micellar Presence Proteins Résumé : This article presents the results of our recent research on the texture and stability of oil-in-water emulsions containing sucrose ester and proteins. We used both the direct microscopic imaging and nondestructive back-light scattering (Kossel diffraction) techniques to evaluate the emulsion texture and the energy barrier between droplets for two different emulsifier compositions with and without the proteins present. The microinterferometric method employing our capillary force balance was used to study the stability of the confined thin film (containing surfactant micelles and proteins) between two droplets. In addition to the film stability, we also measured the second virial coefficient of the micellar solutions with and without protein and assessed the intermicellar interaction and related it to the stabilities of the emulsions prepared using two different emulsifier compositions. The effect of protein on the oil-in-water emulsion stability was also assessed and was found to lead to the depletion attraction between droplets, resulting in a less stable emulsion. The results offer new insight into the understanding of how the micellar interactions in the presence of proteins affect emulsion texture and stability. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001815

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Determining the accuracy of classical force fields for ionic liquids / Manish S. Kelkar in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9115–9126 Titre : Determining the accuracy of classical force fields for ionic liquids : atomistic simulation of the thermodynamic and transport properties of 1-Ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]) and its mixtures with water Type de document : texte imprimé Auteurs : Manish S. Kelkar, Auteur ; Wei Shi, Auteur ; Edward J. Anthony, Auteur Année de publication : 2009 Article en page(s) : p. 9115–9126 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Accuracy of classical Ionic liquids Atomistic simulation the thermodynamic Résumé : The ability of simple classical force fields to predict the structure and density of ionic liquids is now well-established. However, it is less clear how accurate such force fields are for a range of other pure and mixture properties of ionic liquids. In this work, a single classical force field is used to compute a wide range of thermodynamic and transport properties for the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]). In addition to liquid densities, the volumetric expansivity, heat capacity, enthalpy of vaporization, rotational relaxation time, self-diffusivity, shear viscosity, and thermal conductivity are computed at various temperatures for the pure ionic liquid. The density, excess molar volume, enthalpy of mixing, partial molar enthalpy, water solubility as a function of partial pressure, rotational relaxation time, self-diffusivity, shear viscosity, and thermal conductivity are also computed for mixtures that contain different concentrations of water at various temperatures. The agreement between simulations and experiment is fair for most properties, although deviations in enthalpy of mixing, viscosity, and self-diffusivity are often large. It is shown that much of the error for mixtures with water likely is due to neglect of the water polarizability, which results in too strong of an attraction between water and the [EtSO4] anion. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800843u#auth-fn1 [article] Determining the accuracy of classical force fields for ionic liquids : atomistic simulation of the thermodynamic and transport properties of 1-Ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]) and its mixtures with water [texte imprimé] / Manish S. Kelkar, Auteur ; Wei Shi, Auteur ; Edward J. Anthony, Auteur . - 2009 . - p. 9115–9126. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9115–9126 Mots-clés : Accuracy of classical Ionic liquids Atomistic simulation the thermodynamic Résumé : The ability of simple classical force fields to predict the structure and density of ionic liquids is now well-established. However, it is less clear how accurate such force fields are for a range of other pure and mixture properties of ionic liquids. In this work, a single classical force field is used to compute a wide range of thermodynamic and transport properties for the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]). In addition to liquid densities, the volumetric expansivity, heat capacity, enthalpy of vaporization, rotational relaxation time, self-diffusivity, shear viscosity, and thermal conductivity are computed at various temperatures for the pure ionic liquid. The density, excess molar volume, enthalpy of mixing, partial molar enthalpy, water solubility as a function of partial pressure, rotational relaxation time, self-diffusivity, shear viscosity, and thermal conductivity are also computed for mixtures that contain different concentrations of water at various temperatures. The agreement between simulations and experiment is fair for most properties, although deviations in enthalpy of mixing, viscosity, and self-diffusivity are often large. It is shown that much of the error for mixtures with water likely is due to neglect of the water polarizability, which results in too strong of an attraction between water and the [EtSO4] anion. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800843u#auth-fn1

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Preparation of hydrotalcite thin films using an electrophoretic technique / Tae Wook Kim in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9127–9132 Titre : Preparation of hydrotalcite thin films using an electrophoretic technique Type de document : texte imprimé Auteurs : Tae Wook Kim, Auteur ; Muhammad Sahimi, Auteur ; Theodore T. Tsotsis, Auteur Année de publication : 2009 Article en page(s) : p. 9127–9132 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Preparation of Hydrotalcite Electrophoretic Technique Résumé : Electrophoretic deposition (EPD) was utilized as a new method for the preparation of hydrotalcite (HT) thin films. The films were deposited on macroporous alumina substrates and on alumina substrates that had been previously coated by conventional dip-coating techniques using slurries of HT colloidal particles. Their permeation properties were investigated by single- and mixed-gas permeation tests, and the films were shown to be permselective toward CO2, which is consistent with prior studies of these materials, which show them to be effective CO2 adsorbents. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071446s [article] Preparation of hydrotalcite thin films using an electrophoretic technique [texte imprimé] / Tae Wook Kim, Auteur ; Muhammad Sahimi, Auteur ; Theodore T. Tsotsis, Auteur . - 2009 . - p. 9127–9132. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9127–9132 Mots-clés : Preparation of Hydrotalcite Electrophoretic Technique Résumé : Electrophoretic deposition (EPD) was utilized as a new method for the preparation of hydrotalcite (HT) thin films. The films were deposited on macroporous alumina substrates and on alumina substrates that had been previously coated by conventional dip-coating techniques using slurries of HT colloidal particles. Their permeation properties were investigated by single- and mixed-gas permeation tests, and the films were shown to be permselective toward CO2, which is consistent with prior studies of these materials, which show them to be effective CO2 adsorbents. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071446s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Investigation of the Porosity Variation during Chromatographic Experiments / Nicola Forrer in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9133–9140 Titre : Investigation of the Porosity Variation during Chromatographic Experiments Type de document : texte imprimé Auteurs : Nicola Forrer, Auteur ; Olga Kartachova, Auteur ; Alessandro Butté, Auteur Année de publication : 2009 Article en page(s) : p. 9133–9140 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Investigation of the Porosity Variation during Chromatographic Experiments Résumé : Poly(vinyl pyrrolidone) tracers are used to investigate the porosity variation on ion-exchange materials. The porosity was measured as a function of the salt concentration in the mobile phase and of the amount of protein adsorbed on the material. Immunoglobulin G (IgG) and human serum albumin (HSA) are selected as proteins. Two materials with different pore size distributions were investigated. The surface of both resins is functionalized with tentacles that carry a terminal ionic group. In both materials, a small increase of the accessible porosity was observed for increasing salt concentrations. A larger effect was observed in the presence of protein adsorption. The accessible porosity decreases quickly as the amount of adsorbed proteins increases. The decrease in porosity due to the HSA adsorption is smaller than the decrease caused by IgG. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800131t [article] Investigation of the Porosity Variation during Chromatographic Experiments [texte imprimé] / Nicola Forrer, Auteur ; Olga Kartachova, Auteur ; Alessandro Butté, Auteur . - 2009 . - p. 9133–9140. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9133–9140 Mots-clés : Investigation of the Porosity Variation during Chromatographic Experiments Résumé : Poly(vinyl pyrrolidone) tracers are used to investigate the porosity variation on ion-exchange materials. The porosity was measured as a function of the salt concentration in the mobile phase and of the amount of protein adsorbed on the material. Immunoglobulin G (IgG) and human serum albumin (HSA) are selected as proteins. Two materials with different pore size distributions were investigated. The surface of both resins is functionalized with tentacles that carry a terminal ionic group. In both materials, a small increase of the accessible porosity was observed for increasing salt concentrations. A larger effect was observed in the presence of protein adsorption. The accessible porosity decreases quickly as the amount of adsorbed proteins increases. The decrease in porosity due to the HSA adsorption is smaller than the decrease caused by IgG. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800131t

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Forced convection heat transfer in power law liquids from a pair of cylinders in tandem arrangement / Rahul C. Patil in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9141–9164 Titre : Forced convection heat transfer in power law liquids from a pair of cylinders in tandem arrangement Type de document : texte imprimé Auteurs : Rahul C. Patil, Auteur ; Ram P. Bharti, Auteur ; Rajendra P. Chhabra, Auteur Année de publication : 2009 Article en page(s) : p. 9141–9164 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Power Law Liquids Pair of Cylinders Résumé : Forced convection heat transfer characteristics for the flow of incompressible power law fluids over a pair of cylinders (of equal diameters) in tandem arrangement has been studied in the two-dimensional, steady cross-flow regime. The field equations have been solved using a finite volume method based solver (FLUENT 6.2) over the ranges of conditions as follows: power law index (0.2 ≤ n ≤ 1.8), Reynolds number (1 ≤ Re ≤ 40), Prandtl number (1 ≤ Pr ≤ 100), and the gap ratio between the two cylinders (2 ≤ G ≤ 10). Extensive results on the isotherm patterns, centerline temperature profiles, and local and average Nusselt numbers have been presented in detail, for the two commonly used thermal boundary conditions, namely, constant temperature or constant heat flux prescribed on the surface of the two cylinders. While the upstream cylinder shows characteristics similar to an isolated cylinder, the downstream cylinder displays a complex dependence on the relevant dimensionless parameters. As expected, at large values of the gap ratio (G), the behavior of the downstream cylinder approaches that of a single cylinder, thereby suggesting no or weak interference between the two cylinders. Depending upon the values of G and n, both the wake interference and power-law rheology influence the heat transfer characteristics to varying extents. Generally, the upstream cylinder shows higher values of the average Nusselt number than the downstream cylinder. On the other hand, the average Nusselt number for both cylinders is seen to be smaller than that for a single cylinder under otherwise identical conditions. With reference to Newtonian fluids, the shear-thinning behavior promotes heat transfer, whereas shear-thickening lowers it. Finally, simple predictive correlations are developed to estimate the value of the average Nusselt number or the j-factor in a new application. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie7017178 [article] Forced convection heat transfer in power law liquids from a pair of cylinders in tandem arrangement [texte imprimé] / Rahul C. Patil, Auteur ; Ram P. Bharti, Auteur ; Rajendra P. Chhabra, Auteur . - 2009 . - p. 9141–9164. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9141–9164 Mots-clés : Power Law Liquids Pair of Cylinders Résumé : Forced convection heat transfer characteristics for the flow of incompressible power law fluids over a pair of cylinders (of equal diameters) in tandem arrangement has been studied in the two-dimensional, steady cross-flow regime. The field equations have been solved using a finite volume method based solver (FLUENT 6.2) over the ranges of conditions as follows: power law index (0.2 ≤ n ≤ 1.8), Reynolds number (1 ≤ Re ≤ 40), Prandtl number (1 ≤ Pr ≤ 100), and the gap ratio between the two cylinders (2 ≤ G ≤ 10). Extensive results on the isotherm patterns, centerline temperature profiles, and local and average Nusselt numbers have been presented in detail, for the two commonly used thermal boundary conditions, namely, constant temperature or constant heat flux prescribed on the surface of the two cylinders. While the upstream cylinder shows characteristics similar to an isolated cylinder, the downstream cylinder displays a complex dependence on the relevant dimensionless parameters. As expected, at large values of the gap ratio (G), the behavior of the downstream cylinder approaches that of a single cylinder, thereby suggesting no or weak interference between the two cylinders. Depending upon the values of G and n, both the wake interference and power-law rheology influence the heat transfer characteristics to varying extents. Generally, the upstream cylinder shows higher values of the average Nusselt number than the downstream cylinder. On the other hand, the average Nusselt number for both cylinders is seen to be smaller than that for a single cylinder under otherwise identical conditions. With reference to Newtonian fluids, the shear-thinning behavior promotes heat transfer, whereas shear-thickening lowers it. Finally, simple predictive correlations are developed to estimate the value of the average Nusselt number or the j-factor in a new application. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie7017178

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Lattice Boltzmann Simulation of Two-Fluid Model Equations / Krishnan Sankaranarayanan in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9165–9173 Titre : Lattice Boltzmann Simulation of Two-Fluid Model Equations Type de document : texte imprimé Auteurs : Krishnan Sankaranarayanan, Auteur ; Sankaran Sundaresan, Auteur Année de publication : 2009 Article en page(s) : p. 9165–9173 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Lattice Boltzmann Simulation of Two-Fluid Model Equations Résumé : An implicit lattice Boltzmann equation to simulate the locally averaged flow behavior of disperse two-phase mixtures is presented. Using a multiscale expansion technique, it is shown that these equations reduce to the widely used two-fluid model for flows of such suspensions. The viability of the lattice Boltzmann approach is demonstrated through illustrative examples. The lattice Boltzmann scheme is easy to program and it parallelizes readily. It is suggested that this approach may serve as an attractive alternative to conventional approaches to solving the two-fluid model equations. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800283b [article] Lattice Boltzmann Simulation of Two-Fluid Model Equations [texte imprimé] / Krishnan Sankaranarayanan, Auteur ; Sankaran Sundaresan, Auteur . - 2009 . - p. 9165–9173. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9165–9173 Mots-clés : Lattice Boltzmann Simulation of Two-Fluid Model Equations Résumé : An implicit lattice Boltzmann equation to simulate the locally averaged flow behavior of disperse two-phase mixtures is presented. Using a multiscale expansion technique, it is shown that these equations reduce to the widely used two-fluid model for flows of such suspensions. The viability of the lattice Boltzmann approach is demonstrated through illustrative examples. The lattice Boltzmann scheme is easy to program and it parallelizes readily. It is suggested that this approach may serve as an attractive alternative to conventional approaches to solving the two-fluid model equations. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800283b

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Experimental and numerical studies of water droplet impact on a porous surface in the film-Boiling regime / Zhao Yu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9174–9182 Titre : Experimental and numerical studies of water droplet impact on a porous surface in the film-Boiling regime Type de document : texte imprimé Auteurs : Zhao Yu, Auteur ; Fei Wang, Auteur ; L.-S. Fan, Auteur Année de publication : 2009 Article en page(s) : p. 9174–9182 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Experimental and Numerical Studies Water Droplet Film-Boiling Regime Résumé : An experimental and numerical study of the water droplet in collision with a porous surface in the film-boiling regime is reported. The porous substrate with a porosity of 34% and pore size of 76 nm is heated to 300 °C, and the motion of the droplet is recorded by a high-speed digital camera. A new three-dimensional (3-D) numerical model is developed to account for the transport phenomenon both inside and outside the porous media, by coupling the flow field with the heat and mass transfer process. The vapor layer model is used as a subgrid model to calculate the induced vapor pressure in the narrow region between the droplet and the surface. The vapor mass transfer is modeled considering the vapor generation and transport mechanisms in different domains. Direct numerical simulation is performed under the same conditions as the experiment, and the simulation results for the droplet behavior are in good agreement with the experimental results. The collision of a water droplet on the porous surface shows similar features to those on nonporous surfaces in the film-boiling regime, probably because of the small pore size of the material used in the current study. However, the droplet has a longer residence time, and it also seems to be less stable on the porous surface. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800479r [article] Experimental and numerical studies of water droplet impact on a porous surface in the film-Boiling regime [texte imprimé] / Zhao Yu, Auteur ; Fei Wang, Auteur ; L.-S. Fan, Auteur . - 2009 . - p. 9174–9182. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9174–9182 Mots-clés : Experimental and Numerical Studies Water Droplet Film-Boiling Regime Résumé : An experimental and numerical study of the water droplet in collision with a porous surface in the film-boiling regime is reported. The porous substrate with a porosity of 34% and pore size of 76 nm is heated to 300 °C, and the motion of the droplet is recorded by a high-speed digital camera. A new three-dimensional (3-D) numerical model is developed to account for the transport phenomenon both inside and outside the porous media, by coupling the flow field with the heat and mass transfer process. The vapor layer model is used as a subgrid model to calculate the induced vapor pressure in the narrow region between the droplet and the surface. The vapor mass transfer is modeled considering the vapor generation and transport mechanisms in different domains. Direct numerical simulation is performed under the same conditions as the experiment, and the simulation results for the droplet behavior are in good agreement with the experimental results. The collision of a water droplet on the porous surface shows similar features to those on nonporous surfaces in the film-boiling regime, probably because of the small pore size of the material used in the current study. However, the droplet has a longer residence time, and it also seems to be less stable on the porous surface. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800479r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Ethylbenzene dehydrogenation into styrene / Jae Won Lee in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9183–9194 Titre : Ethylbenzene dehydrogenation into styrene : kinetic modeling and reactor simulation Type de document : texte imprimé Auteurs : Jae Won Lee, Auteur ; Gilbert F. Froment, Auteur Année de publication : 2009 Article en page(s) : p. 9183–9194 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Ethylbenzene Dehydrogenation into Styrene Kinetic Modeling and Reactor Simulation Résumé : A set of intrinsic rate equations based on the Hougen—Watson formalism was derived for the dehydrogenation of ethylbenzene into styrene on a commercial potassium-promoted iron catalyst. The model discrimination and parameter estimation was based on an extensive set of experiments that were conducted in a tubular reactor. Experimental data were obtained for a range of temperatures, space times, and feed molar ratios of steam to ethylbenzene, styrene to ethylbenzene, and hydrogen to ethylbenzene. All the estimated parameters satisfied the statistical tests and physicochemical criteria, and the kinetic model yielded an excellent fit of the experimental data. The model was applied in the simulation of the dehydrogenation in industrial multibed adiabatic reactors with either axial or radial flow and accounting also for thermal radical-type reactions, internal diffusion limitations, coke formation, and gasification. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071098u [article] Ethylbenzene dehydrogenation into styrene : kinetic modeling and reactor simulation [texte imprimé] / Jae Won Lee, Auteur ; Gilbert F. Froment, Auteur . - 2009 . - p. 9183–9194. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9183–9194 Mots-clés : Ethylbenzene Dehydrogenation into Styrene Kinetic Modeling and Reactor Simulation Résumé : A set of intrinsic rate equations based on the Hougen—Watson formalism was derived for the dehydrogenation of ethylbenzene into styrene on a commercial potassium-promoted iron catalyst. The model discrimination and parameter estimation was based on an extensive set of experiments that were conducted in a tubular reactor. Experimental data were obtained for a range of temperatures, space times, and feed molar ratios of steam to ethylbenzene, styrene to ethylbenzene, and hydrogen to ethylbenzene. All the estimated parameters satisfied the statistical tests and physicochemical criteria, and the kinetic model yielded an excellent fit of the experimental data. The model was applied in the simulation of the dehydrogenation in industrial multibed adiabatic reactors with either axial or radial flow and accounting also for thermal radical-type reactions, internal diffusion limitations, coke formation, and gasification. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071098u

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Anomalous crystal growth on TiO2 thin film induced by the AFM tip / Yao Bin in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9195–9200 Titre : Anomalous crystal growth on TiO2 thin film induced by the AFM tip Type de document : texte imprimé Auteurs : Yao Bin, Auteur ; King Lun Yeung, Auteur Année de publication : 2009 Article en page(s) : p. 9195–9200 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Crystal Growth on TiO2 Induced by the AFM Tip Résumé : Tip-induced nucleation and crystallization have been observed in polymer thin films. This work shows for the first time that it is possible to induce a rapid crystal growth on amorphous inorganic thin film using the AFM tip. The force applied on the AFM tip exerts an enormous pressure on the surface of an amorphous titania thin film. The movement of the tip displaced the spin-coated titania sol and deformed the film. The V-shaped grooves left by the passage of the tip measured 65 nm in width and penetrated 5 nm into the 15 nm thick film. Heat treatment in air at 723 K crystallizes the TiO2. Large TiO2 crystallized on the grooves compared to the surrounding film indicating an anomalous rapid crystal growth. It is speculated that the enormous tip pressure caused a local densification and structural rearrangement of the titania that presage nucleation resulting in a faster crystallization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071181h [article] Anomalous crystal growth on TiO2 thin film induced by the AFM tip [texte imprimé] / Yao Bin, Auteur ; King Lun Yeung, Auteur . - 2009 . - p. 9195–9200. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9195–9200 Mots-clés : Crystal Growth on TiO2 Induced by the AFM Tip Résumé : Tip-induced nucleation and crystallization have been observed in polymer thin films. This work shows for the first time that it is possible to induce a rapid crystal growth on amorphous inorganic thin film using the AFM tip. The force applied on the AFM tip exerts an enormous pressure on the surface of an amorphous titania thin film. The movement of the tip displaced the spin-coated titania sol and deformed the film. The V-shaped grooves left by the passage of the tip measured 65 nm in width and penetrated 5 nm into the 15 nm thick film. Heat treatment in air at 723 K crystallizes the TiO2. Large TiO2 crystallized on the grooves compared to the surrounding film indicating an anomalous rapid crystal growth. It is speculated that the enormous tip pressure caused a local densification and structural rearrangement of the titania that presage nucleation resulting in a faster crystallization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071181h

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Reaction of finasteride intermediate with benzeneseleninic anhydride / Ch. Suchitra in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9201–9205 Titre : Reaction of finasteride intermediate with benzeneseleninic anhydride : an in-Depth study Type de document : texte imprimé Auteurs : Ch. Suchitra, Auteur ; Kalyani Maitra, Auteur ; Dilip Raut, Auteur Année de publication : 2009 Article en page(s) : p. 9201–9205 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Finasteride Intermediate Benzeneseleninic Anhydride In-Depth Study Résumé : One of the intermediates of finasteride was oxidized by the reaction of benzeneseleninic (BS) anhydride in refluxing toluene for 16 h. Sometimes, the desired product was obtained, and sometimes, there was no yield or very low yield at the end of the reaction time. To obtain a better understanding of such variations, laboratory syntheses were conducted with commercial BS anhydride, pure BS anhydride, pure BS acid, and mixtures of anhydride and acid samples. During the reaction, the intermediate reaction masses were analyzed by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) at predetermined times and correlated with differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) samples. The DSC and XRPD data indicated that commercial BS anhydride samples did not always consist of the pure anhydride form. When the BS acid was present in the anhydride sample, the reaction rate was lower than that of the pure BS anhydride sample. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800530c [article] Reaction of finasteride intermediate with benzeneseleninic anhydride : an in-Depth study [texte imprimé] / Ch. Suchitra, Auteur ; Kalyani Maitra, Auteur ; Dilip Raut, Auteur . - 2009 . - p. 9201–9205. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9201–9205 Mots-clés : Finasteride Intermediate Benzeneseleninic Anhydride In-Depth Study Résumé : One of the intermediates of finasteride was oxidized by the reaction of benzeneseleninic (BS) anhydride in refluxing toluene for 16 h. Sometimes, the desired product was obtained, and sometimes, there was no yield or very low yield at the end of the reaction time. To obtain a better understanding of such variations, laboratory syntheses were conducted with commercial BS anhydride, pure BS anhydride, pure BS acid, and mixtures of anhydride and acid samples. During the reaction, the intermediate reaction masses were analyzed by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) at predetermined times and correlated with differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) samples. The DSC and XRPD data indicated that commercial BS anhydride samples did not always consist of the pure anhydride form. When the BS acid was present in the anhydride sample, the reaction rate was lower than that of the pure BS anhydride sample. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800530c

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

New protein-Based hydrogel with superabsorbing properties / A. Pourjavadi in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9206–9213 Titre : New protein-Based hydrogel with superabsorbing properties : effect of monomer ratio on swelling behavior and kinetics Type de document : texte imprimé Auteurs : A. Pourjavadi, Auteur ; H. Salimi, Auteur Année de publication : 2009 Article en page(s) : p. 9206–9213 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : New Protein-Based Hydrogel Superabsorbing Properties Monomer Ratio on Swelling Behavior and Kinetics Résumé : In this paper we report an efficient synthesis of hydrolyzed collagen-g-poly(sodium acrylate-co-2-hydroxyethyl acrylate) hydrogel through chemical cross-linking by graft copolymerization of these two monomers onto the protein backbone in the presence of a cross-linker. Infrared spectroscopy and thermogravimetric analysis (TGA) were carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). To investigate the effect of monomer ratio on swelling behavior in various media three hydrogels with different acrylic acid/2-hydroxyethyl acrylate (AA/HEA) weight ratios were synthesized and swelling capacity was assessed. Moreover, the swelling of hydrogels were measured in solutions with pH ranging 1 to 12, and additionally, the swelling kinetics of the synthesized hydrogels were studied. The absorbency under load (AUL) of hydrogel was also investigated by using an AUL tester at various applied pressures. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002478 [article] New protein-Based hydrogel with superabsorbing properties : effect of monomer ratio on swelling behavior and kinetics [texte imprimé] / A. Pourjavadi, Auteur ; H. Salimi, Auteur . - 2009 . - p. 9206–9213. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9206–9213 Mots-clés : New Protein-Based Hydrogel Superabsorbing Properties Monomer Ratio on Swelling Behavior and Kinetics Résumé : In this paper we report an efficient synthesis of hydrolyzed collagen-g-poly(sodium acrylate-co-2-hydroxyethyl acrylate) hydrogel through chemical cross-linking by graft copolymerization of these two monomers onto the protein backbone in the presence of a cross-linker. Infrared spectroscopy and thermogravimetric analysis (TGA) were carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). To investigate the effect of monomer ratio on swelling behavior in various media three hydrogels with different acrylic acid/2-hydroxyethyl acrylate (AA/HEA) weight ratios were synthesized and swelling capacity was assessed. Moreover, the swelling of hydrogels were measured in solutions with pH ranging 1 to 12, and additionally, the swelling kinetics of the synthesized hydrogels were studied. The absorbency under load (AUL) of hydrogel was also investigated by using an AUL tester at various applied pressures. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002478

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Synthesis and characterization of hyperbranched polyurethane hybrids using tetraethoxysilane (TEOS) as cross-Linker / Kishore K. Jena in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9214–9224 Titre : Synthesis and characterization of hyperbranched polyurethane hybrids using tetraethoxysilane (TEOS) as cross-Linker Type de document : texte imprimé Auteurs : Kishore K. Jena, Auteur ; K. V. S. N. Raju, Auteur Année de publication : 2009 Article en page(s) : p. 9214–9224 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Hyperbranched Polyurethane Résumé : Organic−inorganic hybrid coatings were derived from a hydroxyl-terminated hyperbranched polyester, 3-isocyanatopropyl triethoxysilane (ISPTES), and then cross-linked with various percentages of SiO2. This system was able to cross-link by hydrolysis of a tetraethoxysilane group in room temperature and humid conditions and then at 120 °C for 12−14 h, forming a three-dimensional hybrid structure, where the organic and inorganic phases were bonded covalently. The main focus of this work was to study the change of properties of the coating with SiO2 modification. These hybrid coatings were also characterized by using NMR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamical mechanical thermal analyzer (DMTA), thermal analysis (TGA), and tensile strength. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800884y [article] Synthesis and characterization of hyperbranched polyurethane hybrids using tetraethoxysilane (TEOS) as cross-Linker [texte imprimé] / Kishore K. Jena, Auteur ; K. V. S. N. Raju, Auteur . - 2009 . - p. 9214–9224. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9214–9224 Mots-clés : Hyperbranched Polyurethane Résumé : Organic−inorganic hybrid coatings were derived from a hydroxyl-terminated hyperbranched polyester, 3-isocyanatopropyl triethoxysilane (ISPTES), and then cross-linked with various percentages of SiO2. This system was able to cross-link by hydrolysis of a tetraethoxysilane group in room temperature and humid conditions and then at 120 °C for 12−14 h, forming a three-dimensional hybrid structure, where the organic and inorganic phases were bonded covalently. The main focus of this work was to study the change of properties of the coating with SiO2 modification. These hybrid coatings were also characterized by using NMR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamical mechanical thermal analyzer (DMTA), thermal analysis (TGA), and tensile strength. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800884y

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Variability of the rocket propellants RP-1, RP-2, and TS-5 / Lisa Starkey Ott in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9225–9233 Titre : Variability of the rocket propellants RP-1, RP-2, and TS-5 : application of a composition- and enthalpy-explicit distillation curve method† Type de document : texte imprimé Auteurs : Lisa Starkey Ott, Auteur ; Amelia B. Hadler, Auteur ; Thomas J. Bruno, Auteur Année de publication : 2009 Article en page(s) : p. 9225–9233 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Rocket Propellants Application of a Composition Résumé : We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This method is a significant improvement over current approaches, featuring a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and an assessment of the energy content of each distillate fraction, among other features. The most significant modification is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to the measurement of a wide variety of fluids, including hydrocarbons, gasoline, jet fuel, diesel fuels (both petroleum-derived and biodiesel), and crude oils. In this paper, we present the application of the technique to representative batches of the rocket propellants RP-1, RP-2, and TS-5. We not only present the distillation curves but also utilize the composition-explicit information to characterize distillate cuts in terms of composition and available energy content. The measure we use for the fluid energy content is the composite enthalpy of combustion for each component selected for identification in each distillate fraction. Overall, the distillation curves and enthalpy data for all three fluids are remarkably similar. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800988u [article] Variability of the rocket propellants RP-1, RP-2, and TS-5 : application of a composition- and enthalpy-explicit distillation curve method† [texte imprimé] / Lisa Starkey Ott, Auteur ; Amelia B. Hadler, Auteur ; Thomas J. Bruno, Auteur . - 2009 . - p. 9225–9233. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9225–9233 Mots-clés : Rocket Propellants Application of a Composition Résumé : We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This method is a significant improvement over current approaches, featuring a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and an assessment of the energy content of each distillate fraction, among other features. The most significant modification is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to the measurement of a wide variety of fluids, including hydrocarbons, gasoline, jet fuel, diesel fuels (both petroleum-derived and biodiesel), and crude oils. In this paper, we present the application of the technique to representative batches of the rocket propellants RP-1, RP-2, and TS-5. We not only present the distillation curves but also utilize the composition-explicit information to characterize distillate cuts in terms of composition and available energy content. The measure we use for the fluid energy content is the composite enthalpy of combustion for each component selected for identification in each distillate fraction. Overall, the distillation curves and enthalpy data for all three fluids are remarkably similar. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800988u

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Selective conversion of D-fructose to 5-hydroxymethylfurfural by ion-exchange resin in acetone/dimethyl sulfoxide solvent mixtures / Xinhua Qi in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9234–9239 Titre : Selective conversion of D-fructose to 5-hydroxymethylfurfural by ion-exchange resin in acetone/dimethyl sulfoxide solvent mixtures Type de document : texte imprimé Auteurs : Xinhua Qi, Auteur ; Masaru Watanabe, Auteur ; Taku M. Aida, Auteur Année de publication : 2009 Article en page(s) : p. 9234–9239 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Selective Conversion D-Fructose to 5 Hydroxymethylfurfural Dimethyl sulfoxide Résumé : Catalytic dehydration of D-fructose to 5-Hydroxymethylfurfural (5-HMF) in acetone/dimethyl sulfoxide solvent mixtures was studied in the presence of a strong acidic cation-exchange resin catalyst (DOWEX 50WX8−100) by microwave heating. The addition of acetone to the dimethyl sulfoxide (DMSO) solvent promoted the formation of 5-HMF from D-fructose. For a D-fructose conversion of 97.9%, the 5-HMF selectivity was 91.7% for a 20-min reaction time in 70:30 (w/w) acetone/DMSO solvent mixtures. Concentrations as high as 10 wt % D-fructose were studied, for which it was found that 5-HMF yields of 82.1% for a reaction time of 10 min could be obtained. The stability of the ion-exchange resin used as the catalyst was confirmed. Compared to pure DMSO solvent, the combination of low-boiling-point acetone with DMSO used as the reaction medium not only gives highly selective 5-HMF formation, but also improves the separation efficiency and reduces environmental risk. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801016s [article] Selective conversion of D-fructose to 5-hydroxymethylfurfural by ion-exchange resin in acetone/dimethyl sulfoxide solvent mixtures [texte imprimé] / Xinhua Qi, Auteur ; Masaru Watanabe, Auteur ; Taku M. Aida, Auteur . - 2009 . - p. 9234–9239. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9234–9239 Mots-clés : Selective Conversion D-Fructose to 5 Hydroxymethylfurfural Dimethyl sulfoxide Résumé : Catalytic dehydration of D-fructose to 5-Hydroxymethylfurfural (5-HMF) in acetone/dimethyl sulfoxide solvent mixtures was studied in the presence of a strong acidic cation-exchange resin catalyst (DOWEX 50WX8−100) by microwave heating. The addition of acetone to the dimethyl sulfoxide (DMSO) solvent promoted the formation of 5-HMF from D-fructose. For a D-fructose conversion of 97.9%, the 5-HMF selectivity was 91.7% for a 20-min reaction time in 70:30 (w/w) acetone/DMSO solvent mixtures. Concentrations as high as 10 wt % D-fructose were studied, for which it was found that 5-HMF yields of 82.1% for a reaction time of 10 min could be obtained. The stability of the ion-exchange resin used as the catalyst was confirmed. Compared to pure DMSO solvent, the combination of low-boiling-point acetone with DMSO used as the reaction medium not only gives highly selective 5-HMF formation, but also improves the separation efficiency and reduces environmental risk. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801016s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Selective catalytic reduction of NOx / Sounak Roy in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9240–9247 Titre : Selective catalytic reduction of NOx : mechanistic perspectives on the role of base metal and noble metal ion substitution Type de document : texte imprimé Auteurs : Sounak Roy, Auteur ; A. Marimuthu, Auteur ; Parag A. Deshpande, Auteur Année de publication : 2009 Article en page(s) : p. 9240–9247 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : NOx Catalytic Reduction Noble Metal Ion Substitution Résumé : Selective catalytic reduction (SCR) of NO by NH3 in presence of excess oxygen is an industrially and environmentally important reaction. Determining a suitable catalyst substituted with noble metals or base metal ions with a suitable reaction mechanism is important. In this study, ionically substituted Mn and Pd in TiO2 catalysts were synthesized by the solution combustion technique and examined for SCR activity. A seven-step reaction mechanism was proposed to incorporate the role of NH3 oxidation in the SCR reaction that shows minima in the NO concentration profile. Both modeling and experimental results show that the reduction of NO in SCR condition follows the order Ti0.9Mn0.1O2-δ > Ti0.89Mn0.1Pd0.01O2-δ > Ti0.99Pd0.01O2-δ. However, the hydrogen uptake study showed that the noble metal ion (Pd2+) substituted TiO2 has better reducibility than the base metal ion (Mn3+) substituted TiO2. The rate of ammonia oxidation by different catalysts followed the reverse order such as that of NO reduction. This clearly indicates that catalysts with higher reducibility and that which exhibit higher rates of ammonia oxidation have poor SCR activity. Thus, the base metal ion substitution is better than noble metal ion substitution for SCR. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8010879#afn2 [article] Selective catalytic reduction of NOx : mechanistic perspectives on the role of base metal and noble metal ion substitution [texte imprimé] / Sounak Roy, Auteur ; A. Marimuthu, Auteur ; Parag A. Deshpande, Auteur . - 2009 . - p. 9240–9247. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9240–9247 Mots-clés : NOx Catalytic Reduction Noble Metal Ion Substitution Résumé : Selective catalytic reduction (SCR) of NO by NH3 in presence of excess oxygen is an industrially and environmentally important reaction. Determining a suitable catalyst substituted with noble metals or base metal ions with a suitable reaction mechanism is important. In this study, ionically substituted Mn and Pd in TiO2 catalysts were synthesized by the solution combustion technique and examined for SCR activity. A seven-step reaction mechanism was proposed to incorporate the role of NH3 oxidation in the SCR reaction that shows minima in the NO concentration profile. Both modeling and experimental results show that the reduction of NO in SCR condition follows the order Ti0.9Mn0.1O2-δ > Ti0.89Mn0.1Pd0.01O2-δ > Ti0.99Pd0.01O2-δ. However, the hydrogen uptake study showed that the noble metal ion (Pd2+) substituted TiO2 has better reducibility than the base metal ion (Mn3+) substituted TiO2. The rate of ammonia oxidation by different catalysts followed the reverse order such as that of NO reduction. This clearly indicates that catalysts with higher reducibility and that which exhibit higher rates of ammonia oxidation have poor SCR activity. Thus, the base metal ion substitution is better than noble metal ion substitution for SCR. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8010879#afn2

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Direct deoxy-liquefaction of poplar leaves to biopetroleum with two kinds of catalysts / Libin Wu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9248–9255 Titre : Direct deoxy-liquefaction of poplar leaves to biopetroleum with two kinds of catalysts Type de document : texte imprimé Auteurs : Libin Wu, Auteur ; Shipeng Guo, Auteur ; Chao Wang, Auteur Année de publication : 2009 Article en page(s) : p. 9248–9255 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Deoxy-Liquefaction Biopetroleum Kinds of Catalysts Résumé : The objective of this study was to investigate the direct deoxy-liquefaction of poplar leaves with two kinds of catalysts (T203, Z409). The optimum conditions were found to be at a temperature of 623 K with 3% T203 and 5% Z409. The effect of these catalysts on the products was investigated, and the obtained results were compared with similar experiments without catalyst. The oil yield of 10.18% was obtained without catalyst and reached 12.22% with 3% T203. Higher oil yield of 16.18% was observed when 5% Z409 was used. The relative contents of hydrocarbons (alkanes and aromatics) were high to 42.91 and 55.89% when using 3% T203 and 5% Z409 as catalysts, and some light alkanes such as C7H16 and C8H18 were also detected in the oil. The most striking characteristics of the oils were that H/C > 1.75, oxygen content 44.33 MJ kg−1. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801129b [article] Direct deoxy-liquefaction of poplar leaves to biopetroleum with two kinds of catalysts [texte imprimé] / Libin Wu, Auteur ; Shipeng Guo, Auteur ; Chao Wang, Auteur . - 2009 . - p. 9248–9255. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9248–9255 Mots-clés : Deoxy-Liquefaction Biopetroleum Kinds of Catalysts Résumé : The objective of this study was to investigate the direct deoxy-liquefaction of poplar leaves with two kinds of catalysts (T203, Z409). The optimum conditions were found to be at a temperature of 623 K with 3% T203 and 5% Z409. The effect of these catalysts on the products was investigated, and the obtained results were compared with similar experiments without catalyst. The oil yield of 10.18% was obtained without catalyst and reached 12.22% with 3% T203. Higher oil yield of 16.18% was observed when 5% Z409 was used. The relative contents of hydrocarbons (alkanes and aromatics) were high to 42.91 and 55.89% when using 3% T203 and 5% Z409 as catalysts, and some light alkanes such as C7H16 and C8H18 were also detected in the oil. The most striking characteristics of the oils were that H/C > 1.75, oxygen content 44.33 MJ kg−1. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801129b

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Modeling of the deactivation of CaO in a carbonate loop at high temperatures of calcination / Belén Gonzalez in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9256–9262 Titre : Modeling of the deactivation of CaO in a carbonate loop at high temperatures of calcination Type de document : texte imprimé Auteurs : Belén Gonzalez, Auteur ; Gemma Grasa, Auteur ; Monica Alonso, Auteur Année de publication : 2009 Article en page(s) : p. 9256–9262 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : CaO Carbonate Loop High Temperatures of Calcination Résumé : Calcium oxide is being proposed as a regenerable sorbent for CO2 at high temperatures via a carbonation/calcination loop. It is well-known that natural sorbents lose their capacity to capture CO2 as the number of the carbonation/calcination cycles increases. The equations proposed in the literature to describe this decay are limited to moderate calcination temperatures (typically well below 950 °C). This work studies the effect of the calcination temperature and calcination time when the temperatures exceed 950 °C. Such high regeneration temperatures are necessary in some of the most efficient processes proposed, and they are shown to strongly affect sorbent performance. We propose a model to describe maximum sorbent conversion as a function of the number of cycles, the calcination temperature, and the calcination time. This model combines existing knowledge about the decay of sorbent activity under moderate calcination temperatures with the effect of sintering in each cycle. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009318 [article] Modeling of the deactivation of CaO in a carbonate loop at high temperatures of calcination [texte imprimé] / Belén Gonzalez, Auteur ; Gemma Grasa, Auteur ; Monica Alonso, Auteur . - 2009 . - p. 9256–9262. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9256–9262 Mots-clés : CaO Carbonate Loop High Temperatures of Calcination Résumé : Calcium oxide is being proposed as a regenerable sorbent for CO2 at high temperatures via a carbonation/calcination loop. It is well-known that natural sorbents lose their capacity to capture CO2 as the number of the carbonation/calcination cycles increases. The equations proposed in the literature to describe this decay are limited to moderate calcination temperatures (typically well below 950 °C). This work studies the effect of the calcination temperature and calcination time when the temperatures exceed 950 °C. Such high regeneration temperatures are necessary in some of the most efficient processes proposed, and they are shown to strongly affect sorbent performance. We propose a model to describe maximum sorbent conversion as a function of the number of cycles, the calcination temperature, and the calcination time. This model combines existing knowledge about the decay of sorbent activity under moderate calcination temperatures with the effect of sintering in each cycle. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009318

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Equilibrium calculation of gaseous reactive systems with simultaneous species adsorption / Li, Mingheng in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9263–9271 Titre : Equilibrium calculation of gaseous reactive systems with simultaneous species adsorption Type de document : texte imprimé Auteurs : Li, Mingheng, Auteur Année de publication : 2009 Article en page(s) : p. 9263–9271 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Gaseous Reactive Systems Species Adsorption Résumé : This work focuses on the calculation of chemical equilibrium in a gaseous reactive system with simultaneous single or multiple species adsorption under isothermal and isobaric conditions. Two different algorithms are developed, following the minimization of Gibbs free energy and the concept of equilibrium constant, respectively. In either case, the problem formulation is converted to a set of nonlinear algebraic equations that are solved using the Newton−Raphson scheme. An example of steam reforming of ethanol with simultaneous CO2 adsorption is used to illustrate the proposed approaches. It is shown that at T = 500 °C and P = 5 bar, the CO2 removal ratio should exceed 40% to achieve a decent enhancement in hydrogen production and purity. An integrated process that combines the endothermic reforming and the exothermic combustion of CH4 from the off-gas supplemented with simultaneous CO2 adsorption in the reforming process yields a theoretical maximum overall conversion rate of 86.3% (the corresponding H2 purity out of the reformer is 89.4% on a wet basis, or 96.2% on a dry basis) with little or no external heat supply. The analysis in this work is potentially useful in the design and optimization of adsorption-enhanced reforming reactors for hydrogen generation and other applicable reactive systems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800408m [article] Equilibrium calculation of gaseous reactive systems with simultaneous species adsorption [texte imprimé] / Li, Mingheng, Auteur . - 2009 . - p. 9263–9271. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9263–9271 Mots-clés : Gaseous Reactive Systems Species Adsorption Résumé : This work focuses on the calculation of chemical equilibrium in a gaseous reactive system with simultaneous single or multiple species adsorption under isothermal and isobaric conditions. Two different algorithms are developed, following the minimization of Gibbs free energy and the concept of equilibrium constant, respectively. In either case, the problem formulation is converted to a set of nonlinear algebraic equations that are solved using the Newton−Raphson scheme. An example of steam reforming of ethanol with simultaneous CO2 adsorption is used to illustrate the proposed approaches. It is shown that at T = 500 °C and P = 5 bar, the CO2 removal ratio should exceed 40% to achieve a decent enhancement in hydrogen production and purity. An integrated process that combines the endothermic reforming and the exothermic combustion of CH4 from the off-gas supplemented with simultaneous CO2 adsorption in the reforming process yields a theoretical maximum overall conversion rate of 86.3% (the corresponding H2 purity out of the reformer is 89.4% on a wet basis, or 96.2% on a dry basis) with little or no external heat supply. The analysis in this work is potentially useful in the design and optimization of adsorption-enhanced reforming reactors for hydrogen generation and other applicable reactive systems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800408m

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Dual active-site mechanism for dry methane reforming over Ni/La2O3 produced from laNiO3 perovskite / Germán Sierra Gallego in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9272–9278 Titre : Dual active-site mechanism for dry methane reforming over Ni/La2O3 produced from laNiO3 perovskite Type de document : texte imprimé Auteurs : Germán Sierra Gallego, Auteur ; Catherine Batiot-Dupeyrat, Auteur ; Joël Barrault, Auteur Année de publication : 2009 Article en page(s) : p. 9272–9278 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Dry Methane LaNiO3 Perovskite Résumé : The kinetic behavior of the Ni/La2O3 catalyst obtained from the LaNiO3 perovskite in the reforming reaction of methane with carbon dioxide was investigated as function of temperature and CH4 and CO2 partial pressure. A rate reaction equation was developed including for the first time the presence of two active sites in this type of catalyst: the metallic nickel particles and the La2O3 which is the metal support. This kinetic model fits very well the experimental data, and the rate expression predicts better the rate of methane conversion than the models which incorporate only the metallic cluster as the active sites. X-ray photoelectron spectroscopy (XPS) of the catalyst after reaction suggests that Ni particles are partially covered by La2O2CO3 species which are formed by interaction of La2O3 with CO2. Catalytic activity occurs at the Ni−La2O2CO3 interface, while the oxycarbonate species participate directly by reacting with deposited carbon, thus restoring the activity of the Ni sites at the interface. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800281t [article] Dual active-site mechanism for dry methane reforming over Ni/La2O3 produced from laNiO3 perovskite [texte imprimé] / Germán Sierra Gallego, Auteur ; Catherine Batiot-Dupeyrat, Auteur ; Joël Barrault, Auteur . - 2009 . - p. 9272–9278. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9272–9278 Mots-clés : Dry Methane LaNiO3 Perovskite Résumé : The kinetic behavior of the Ni/La2O3 catalyst obtained from the LaNiO3 perovskite in the reforming reaction of methane with carbon dioxide was investigated as function of temperature and CH4 and CO2 partial pressure. A rate reaction equation was developed including for the first time the presence of two active sites in this type of catalyst: the metallic nickel particles and the La2O3 which is the metal support. This kinetic model fits very well the experimental data, and the rate expression predicts better the rate of methane conversion than the models which incorporate only the metallic cluster as the active sites. X-ray photoelectron spectroscopy (XPS) of the catalyst after reaction suggests that Ni particles are partially covered by La2O2CO3 species which are formed by interaction of La2O3 with CO2. Catalytic activity occurs at the Ni−La2O2CO3 interface, while the oxycarbonate species participate directly by reacting with deposited carbon, thus restoring the activity of the Ni sites at the interface. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800281t

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Use of coal as fuel for chemical-looping combustion with ni-based oxygen carrier / Zhengping Gao in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9279–9287 Titre : Use of coal as fuel for chemical-looping combustion with ni-based oxygen carrier Type de document : texte imprimé Auteurs : Zhengping Gao, Auteur ; Laihong Shen, Auteur ; Jun Xiao, Auteur Année de publication : 2009 Article en page(s) : p. 9279–9287 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Coal as Fuel Oxygen Carrier Résumé : Chemical-looping combustion is an indirect combustion technology with inherent separation of the greenhouse gas CO2. The feasibility of using NiO as an oxygen carrier during chemical-looping combustion of coal has been investigated experimentally at 800−960 °C in the present work. The experiments were carried out in a fluidized bed, where the steam acted as the gasification−fluidization medium. Coal gasification and the reaction of oxygen carrier with the water gas take place simultaneously in the reactor. The oxygen carrier particles exhibit high reactivity above 900 °C, and the dry basis concentration of CO2 in the exit gas of the reactor is nearly 95%. The flue gas composition as a function of the reactor temperature and cyclic reduction number is discussed. At 800−960 °C, the dry basis concentration of CO2 in the flue gas presents a monotonously increasing trend, whereas the dry basis concentration of CO, H2, and CH4 decreases monotonously. The concentrations of CO2, CO, H2, and CH4 in the flue gas as a function of cyclic reduction number present a para-curve characteristic at 900 °C. With the increase of cyclic reduction number, the dry basis concentration of CO2 decreases remarkably, while the dry basis concentrations of CO, H2, and CH4 increase rapidly. Moreover, the peak value of H2 concentration is less than that of CO. The performance of the NiO-based oxygen carriers was also evaluated using an X-ray diffractometer and a scanning electron microscope to characterize the solid residues of oxygen carrier. The results indicate that NiO is one of the suitable oxygen carriers for chemical-looping combustion of coal En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800850p [article] Use of coal as fuel for chemical-looping combustion with ni-based oxygen carrier [texte imprimé] / Zhengping Gao, Auteur ; Laihong Shen, Auteur ; Jun Xiao, Auteur . - 2009 . - p. 9279–9287. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9279–9287 Mots-clés : Coal as Fuel Oxygen Carrier Résumé : Chemical-looping combustion is an indirect combustion technology with inherent separation of the greenhouse gas CO2. The feasibility of using NiO as an oxygen carrier during chemical-looping combustion of coal has been investigated experimentally at 800−960 °C in the present work. The experiments were carried out in a fluidized bed, where the steam acted as the gasification−fluidization medium. Coal gasification and the reaction of oxygen carrier with the water gas take place simultaneously in the reactor. The oxygen carrier particles exhibit high reactivity above 900 °C, and the dry basis concentration of CO2 in the exit gas of the reactor is nearly 95%. The flue gas composition as a function of the reactor temperature and cyclic reduction number is discussed. At 800−960 °C, the dry basis concentration of CO2 in the flue gas presents a monotonously increasing trend, whereas the dry basis concentration of CO, H2, and CH4 decreases monotonously. The concentrations of CO2, CO, H2, and CH4 in the flue gas as a function of cyclic reduction number present a para-curve characteristic at 900 °C. With the increase of cyclic reduction number, the dry basis concentration of CO2 decreases remarkably, while the dry basis concentrations of CO, H2, and CH4 increase rapidly. Moreover, the peak value of H2 concentration is less than that of CO. The performance of the NiO-based oxygen carriers was also evaluated using an X-ray diffractometer and a scanning electron microscope to characterize the solid residues of oxygen carrier. The results indicate that NiO is one of the suitable oxygen carriers for chemical-looping combustion of coal En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800850p

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

FCC catalysts / Vassilis A. Tsiatouras in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9288–9296 Titre : FCC catalysts : cu(II)-exchanged USY-type. stability, dealumination, and acid sites after thermal and hydrothermal treatment before and after vanadium impregnation Type de document : texte imprimé Auteurs : Vassilis A. Tsiatouras, Auteur ; Nicholaos P. Evmiridis, Auteur Année de publication : 2009 Article en page(s) : p. 9288–9296 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : FCC Catalysts Hydrothermal Résumé : NaH-USY, H-USY, and Cu(II)-exchanged NaH-USY samples prepared were studied for ion-exchange mass balance, framework aluminum microenvironments (FAl-MEs), and number and strength of acid sites (AS) generated by the increase of the Cu(II)-exchange after thermal treatment (500 °C) and lost under hydrothermal treatment conditions in the presence and in the absence of V species. From the data obtained, conclusions were drawn that (a) the nature and number of Cu(II) species exchanged enter FAl-MEs which can compensate their charge, (b) the strength and number of generated AS in CuNaH-USY samples after thermal treatment is related to the nature and number of Cu(II) species accommodated in the corresponding FAl-MEs, (c) the AS lost during the hydrothermal treatment depend on the nature of counterion involved, and (d) in the presence of V species, an extra loss, restricted to strong AS, takes place. Differences of lost AS and structure−stability during hydrothermal treatment in the presence and absence of V species give evidence of V catalytic action and support the implication of the nature of counterion species for the degree of structure breakdown. These findings lead to the proposed reaction pathway for the chemistry of V detrimental effect. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8008605 [article] FCC catalysts : cu(II)-exchanged USY-type. stability, dealumination, and acid sites after thermal and hydrothermal treatment before and after vanadium impregnation [texte imprimé] / Vassilis A. Tsiatouras, Auteur ; Nicholaos P. Evmiridis, Auteur . - 2009 . - p. 9288–9296. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9288–9296 Mots-clés : FCC Catalysts Hydrothermal Résumé : NaH-USY, H-USY, and Cu(II)-exchanged NaH-USY samples prepared were studied for ion-exchange mass balance, framework aluminum microenvironments (FAl-MEs), and number and strength of acid sites (AS) generated by the increase of the Cu(II)-exchange after thermal treatment (500 °C) and lost under hydrothermal treatment conditions in the presence and in the absence of V species. From the data obtained, conclusions were drawn that (a) the nature and number of Cu(II) species exchanged enter FAl-MEs which can compensate their charge, (b) the strength and number of generated AS in CuNaH-USY samples after thermal treatment is related to the nature and number of Cu(II) species accommodated in the corresponding FAl-MEs, (c) the AS lost during the hydrothermal treatment depend on the nature of counterion involved, and (d) in the presence of V species, an extra loss, restricted to strong AS, takes place. Differences of lost AS and structure−stability during hydrothermal treatment in the presence and absence of V species give evidence of V catalytic action and support the implication of the nature of counterion species for the degree of structure breakdown. These findings lead to the proposed reaction pathway for the chemistry of V detrimental effect. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8008605

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Simulation of internal concentration profiles in a multimetallic ion exchange process / Nikolay Tikhonov in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9297–9303 Titre : Simulation of internal concentration profiles in a multimetallic ion exchange process Type de document : texte imprimé Auteurs : Nikolay Tikhonov, Auteur ; Federico Mijangos, Auteur ; Andreei Dautov, Auteur Année de publication : 2009 Article en page(s) : p. 9297–9303 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Simulation of internal Ion exchange process Résumé : The kinetics of heavy metal uptake—copper and cobalt against sodium—by chelating resins was analyzed experimentally by measuring the internal concentration profiles inside a single bead. Metal concentration profiles inside the particles at different reaction times were measured using an energy dispersive X-ray (SEM-EDX) coupled to a scanning electron microscope. This technique provided a line scan along diametrical positions, yielding the metal concentration profiles needed in order to build mathematical models for the simultaneous uptake of copper and cobalt. This process is described by means of a mathematical model which uses the Nernst−Planck equation for diffusion and takes into account relevant physical and chemical effects. The diffusion model proposed here takes into account the mobility of ions through the macroporous ion exchanger and the corresponding electric field generated by the diffusion of ions with dissimilar diffusivities. The estimated diffusion coefficients are discussed in terms of the mobility of a single metal and the contribution of its co-ion. The dynamic behavior of a system composed of two intraparticular phases is correctly described by this diffusion model, including the nonmonotonous tendencies which are not associated with the different values of the diffusion coefficient. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800648v#afn1 [article] Simulation of internal concentration profiles in a multimetallic ion exchange process [texte imprimé] / Nikolay Tikhonov, Auteur ; Federico Mijangos, Auteur ; Andreei Dautov, Auteur . - 2009 . - p. 9297–9303. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9297–9303 Mots-clés : Simulation of internal Ion exchange process Résumé : The kinetics of heavy metal uptake—copper and cobalt against sodium—by chelating resins was analyzed experimentally by measuring the internal concentration profiles inside a single bead. Metal concentration profiles inside the particles at different reaction times were measured using an energy dispersive X-ray (SEM-EDX) coupled to a scanning electron microscope. This technique provided a line scan along diametrical positions, yielding the metal concentration profiles needed in order to build mathematical models for the simultaneous uptake of copper and cobalt. This process is described by means of a mathematical model which uses the Nernst−Planck equation for diffusion and takes into account relevant physical and chemical effects. The diffusion model proposed here takes into account the mobility of ions through the macroporous ion exchanger and the corresponding electric field generated by the diffusion of ions with dissimilar diffusivities. The estimated diffusion coefficients are discussed in terms of the mobility of a single metal and the contribution of its co-ion. The dynamic behavior of a system composed of two intraparticular phases is correctly described by this diffusion model, including the nonmonotonous tendencies which are not associated with the different values of the diffusion coefficient. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800648v#afn1

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

A new coated catalyst for the production of diacetone alcohol via catalytic distillation / Greg P. Dechaine in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9304–9313 Titre : A new coated catalyst for the production of diacetone alcohol via catalytic distillation Type de document : texte imprimé Auteurs : Greg P. Dechaine, Auteur ; Flora T. T. Ng, Auteur Année de publication : 2009 Article en page(s) : p. 9304–9313 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : New coated catalystCatalytic distillation Résumé : A method has been developed for the production of catalytically active coated ceramic distillation saddles for use in catalytic distillation (CD) columns. A thin layer of magnesium acetate was applied to ceramic Norton saddles using a sol−gel dip-coating method. The magnesium acetate coating was converted to the catalytically active magnesium oxide (MgO) via a temperature-ramped calcination program. The kinetic performance of the MgO-coated saddles for the aldol condensation of acetone was determined in a batch reactor and a batch CD column. Although the coated saddles provided lower yields to DAA than Amberlite IRA-900 ion exchange resins in a batch reactor, their improved mass transfer characteristics provided higher yields than the same ion exchange resins held inside fiberglass bags in a CD column at low flow rates. The coated saddles also showed significant improvements in selectivity to DAA compared to the resin catalysts for the aldol condensation reaction carried out both in the batch reactor and in the CD column. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800009u [article] A new coated catalyst for the production of diacetone alcohol via catalytic distillation [texte imprimé] / Greg P. Dechaine, Auteur ; Flora T. T. Ng, Auteur . - 2009 . - p. 9304–9313. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9304–9313 Mots-clés : New coated catalystCatalytic distillation Résumé : A method has been developed for the production of catalytically active coated ceramic distillation saddles for use in catalytic distillation (CD) columns. A thin layer of magnesium acetate was applied to ceramic Norton saddles using a sol−gel dip-coating method. The magnesium acetate coating was converted to the catalytically active magnesium oxide (MgO) via a temperature-ramped calcination program. The kinetic performance of the MgO-coated saddles for the aldol condensation of acetone was determined in a batch reactor and a batch CD column. Although the coated saddles provided lower yields to DAA than Amberlite IRA-900 ion exchange resins in a batch reactor, their improved mass transfer characteristics provided higher yields than the same ion exchange resins held inside fiberglass bags in a CD column at low flow rates. The coated saddles also showed significant improvements in selectivity to DAA compared to the resin catalysts for the aldol condensation reaction carried out both in the batch reactor and in the CD column. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800009u

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Propane dehydrogenation over Pt-Sn-K/γ-Al2O3 cCatalyst in a two-zone fluidized bed reactor / M. Pilar Lobera in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9314–9320 Titre : Propane dehydrogenation over Pt-Sn-K/γ-Al2O3 cCatalyst in a two-zone fluidized bed reactor Type de document : texte imprimé Auteurs : M. Pilar Lobera, Auteur ; Carlos Téllez, Auteur ; Javier Herguido, Auteur Année de publication : 2009 Article en page(s) : p. 9314–9320 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Propane dehydrogenation Pt−  Sn−  K/γ  -Al2O3 Catalyst in a Two-Zone fluidized bed reactor Résumé : A two-zone fluidized bed reactor (TZFBR) is employed for propane dehydrogenation over a Pt−Sn−K/γ-Al2O3 catalyst. This type of reactor constitutes an alternative to the use of two separate reactors with solid circulation between them or of a single reactor with periodic operation and allows continuous operation with in situ catalyst regeneration. The effect of the main TZFBR operating variables is studied and the reactor performance compared with results obtained in other works using Pt−Sn based catalysts, showing that a steady state is reached with similar selectivity to that reported in the literature for other reactors which suffer the problem of catalyst deactivation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800848c [article] Propane dehydrogenation over Pt-Sn-K/γ-Al2O3 cCatalyst in a two-zone fluidized bed reactor [texte imprimé] / M. Pilar Lobera, Auteur ; Carlos Téllez, Auteur ; Javier Herguido, Auteur . - 2009 . - p. 9314–9320. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9314–9320 Mots-clés : Propane dehydrogenation Pt−  Sn−  K/γ  -Al2O3 Catalyst in a Two-Zone fluidized bed reactor Résumé : A two-zone fluidized bed reactor (TZFBR) is employed for propane dehydrogenation over a Pt−Sn−K/γ-Al2O3 catalyst. This type of reactor constitutes an alternative to the use of two separate reactors with solid circulation between them or of a single reactor with periodic operation and allows continuous operation with in situ catalyst regeneration. The effect of the main TZFBR operating variables is studied and the reactor performance compared with results obtained in other works using Pt−Sn based catalysts, showing that a steady state is reached with similar selectivity to that reported in the literature for other reactors which suffer the problem of catalyst deactivation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800848c

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Hydrolysis of microcrystalline cellulose in subcritical and supercritical water in a continuous flow reactor / Sandeep Kumar in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9321–9329 Titre : Hydrolysis of microcrystalline cellulose in subcritical and supercritical water in a continuous flow reactor Type de document : texte imprimé Auteurs : Sandeep Kumar, Auteur ; Gupta, Ram B., Auteur Année de publication : 2009 Article en page(s) : p. 9321–9329 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Hydrolysis Microcrystalline cellulose Supercritical water Flow reactor Résumé : For cellulosic ethanol production, efficient hydrolysis of crystalline cellulose to easily fermentable sugars is important. The focus of this study is to maximize the yield of cellulose hydrolysis in subcritical and supercritical water at practically achievable reaction times. Microcrystalline cellulose is treated with subcritical and supercritical water in a temperature range of 302−405 °C, at a pressure of 27.6 MPa, and residence times of 2.5−8.1 s. Cellulose−water slurry of 2.7 wt % after mixing with preheated water is rapidly heated to the reaction temperature and then the reaction product is rapidly cooled in a continuous reactor. Cellulose partially dissolves in subcritical water at 302 °C and completely dissolves at 330 °C. About 65% of cellulose converts to the oligomers and monomers at 335 °C in 4.8 s and also at 354 °C in 3.5 s. Upon increase in the reaction time or temperature to supercritical region, oligomers and monomers partially degrade to glycoaldehyde dimer, d-fructose, 1,3-dihydroxyacetone dimer, anhydroglucose, 5-HMF, and furfural. The effect of temperature, pressure, and reaction time on formation of various products is studied. In addition, the effect of a base catalyst, K2CO3, is examined. The catalyst increases cellulose gasification in the temperature range studied (302−333 °C). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801102j [article] Hydrolysis of microcrystalline cellulose in subcritical and supercritical water in a continuous flow reactor [texte imprimé] / Sandeep Kumar, Auteur ; Gupta, Ram B., Auteur . - 2009 . - p. 9321–9329. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9321–9329 Mots-clés : Hydrolysis Microcrystalline cellulose Supercritical water Flow reactor Résumé : For cellulosic ethanol production, efficient hydrolysis of crystalline cellulose to easily fermentable sugars is important. The focus of this study is to maximize the yield of cellulose hydrolysis in subcritical and supercritical water at practically achievable reaction times. Microcrystalline cellulose is treated with subcritical and supercritical water in a temperature range of 302−405 °C, at a pressure of 27.6 MPa, and residence times of 2.5−8.1 s. Cellulose−water slurry of 2.7 wt % after mixing with preheated water is rapidly heated to the reaction temperature and then the reaction product is rapidly cooled in a continuous reactor. Cellulose partially dissolves in subcritical water at 302 °C and completely dissolves at 330 °C. About 65% of cellulose converts to the oligomers and monomers at 335 °C in 4.8 s and also at 354 °C in 3.5 s. Upon increase in the reaction time or temperature to supercritical region, oligomers and monomers partially degrade to glycoaldehyde dimer, d-fructose, 1,3-dihydroxyacetone dimer, anhydroglucose, 5-HMF, and furfural. The effect of temperature, pressure, and reaction time on formation of various products is studied. In addition, the effect of a base catalyst, K2CO3, is examined. The catalyst increases cellulose gasification in the temperature range studied (302−333 °C). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801102j

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Structure and properties of blend films prepared from castor oil-based polyurethane/soy protein derivative / Dagang Liu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9330–9336 Titre : Structure and properties of blend films prepared from castor oil-based polyurethane/soy protein derivative Type de document : texte imprimé Auteurs : Dagang Liu, Auteur ; Huafeng Tian, Auteur ; Lina Zhang, Auteur Année de publication : 2009 Article en page(s) : p. 9330–9336 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Blend films Castor oil-based polyurethane Soy protein Résumé : We successfully prepared a series of transparent blend films from castor oil-based polyurethane (PU) and p-phenylene diamine soy protein (PDSP). The miscibility, morphology, and properties of the blend films were investigated with Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical thermal analysis, scanning electron microscopy, moisture adsorption, thermal degradation, and tensile testing. The results revealed that the PDSP exhibited certain miscibility with PU varied its content from 10 to 80 wt % and also showed the strong hydrogen-bond and chemical cross-linking interactions lied between PU and PDSP. With an increase in the PU content, the elongation at break, thermal stability, and water resistance were improved whereas the tensile strength and Young’s modulus decreased. It is worth noting that modified soy protein could be blended with hydrophobic polyurethane to obtain the blend films having good mechanical properties and optical transmittance. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009632 [article] Structure and properties of blend films prepared from castor oil-based polyurethane/soy protein derivative [texte imprimé] / Dagang Liu, Auteur ; Huafeng Tian, Auteur ; Lina Zhang, Auteur . - 2009 . - p. 9330–9336. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9330–9336 Mots-clés : Blend films Castor oil-based polyurethane Soy protein Résumé : We successfully prepared a series of transparent blend films from castor oil-based polyurethane (PU) and p-phenylene diamine soy protein (PDSP). The miscibility, morphology, and properties of the blend films were investigated with Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical thermal analysis, scanning electron microscopy, moisture adsorption, thermal degradation, and tensile testing. The results revealed that the PDSP exhibited certain miscibility with PU varied its content from 10 to 80 wt % and also showed the strong hydrogen-bond and chemical cross-linking interactions lied between PU and PDSP. With an increase in the PU content, the elongation at break, thermal stability, and water resistance were improved whereas the tensile strength and Young’s modulus decreased. It is worth noting that modified soy protein could be blended with hydrophobic polyurethane to obtain the blend films having good mechanical properties and optical transmittance. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009632

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Characterization of solid deposits formed from short durations of jet fuel degradation / Ramya Venkataraman in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9337–9350 Titre : Characterization of solid deposits formed from short durations of jet fuel degradation : carbonaceous solids Type de document : texte imprimé Auteurs : Ramya Venkataraman, Auteur ; Semih Eser, Auteur Année de publication : 2009 Article en page(s) : p. 9337–9350 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Solid deposits Jet fuel Carbonaceous solids Résumé : The deposits formed after short durations of pyrolytic degradation consist of carbonaceous solids growing on metal sulfide particles. Carbonaceous solids contain amorphous films and uniformly sized spheroids. Close association of the carbonaceous film with the sulfide particles suggests that it was produced by a heterogeneous process similar to chemical vapor deposition (CVD), while the morphology of the spheroidal deposits suggests that they were formed by homogeneous nucleation and growth in the fluid phase. Thermal stressing on an alumina-coated SS316 surface and reducing the sulfur content of the jet fuel from 0.10 to 0.01 wt % inhibited metal sulfide formation on the surface. This consequently inhibited the growth of film deposits but not the nature or amount of fluid-phase deposits. These results have shown that the sulfur content of jet fuel and the substrate composition control the heterogeneous carbon deposition. These parameters do not affect the nucleation and growth of the fluid-phase deposits. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8010066 [article] Characterization of solid deposits formed from short durations of jet fuel degradation : carbonaceous solids [texte imprimé] / Ramya Venkataraman, Auteur ; Semih Eser, Auteur . - 2009 . - p. 9337–9350. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9337–9350 Mots-clés : Solid deposits Jet fuel Carbonaceous solids Résumé : The deposits formed after short durations of pyrolytic degradation consist of carbonaceous solids growing on metal sulfide particles. Carbonaceous solids contain amorphous films and uniformly sized spheroids. Close association of the carbonaceous film with the sulfide particles suggests that it was produced by a heterogeneous process similar to chemical vapor deposition (CVD), while the morphology of the spheroidal deposits suggests that they were formed by homogeneous nucleation and growth in the fluid phase. Thermal stressing on an alumina-coated SS316 surface and reducing the sulfur content of the jet fuel from 0.10 to 0.01 wt % inhibited metal sulfide formation on the surface. This consequently inhibited the growth of film deposits but not the nature or amount of fluid-phase deposits. These results have shown that the sulfur content of jet fuel and the substrate composition control the heterogeneous carbon deposition. These parameters do not affect the nucleation and growth of the fluid-phase deposits. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8010066

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Characterization of solid deposits formed from jet fuel degradation under pyrolytic conditions / Ramya Venkataraman in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9351–9360 Titre : Characterization of solid deposits formed from jet fuel degradation under pyrolytic conditions : metal sulfides Type de document : texte imprimé Auteurs : Ramya Venkataraman, Auteur ; Semih Eser, Auteur Année de publication : 2009 Article en page(s) : p. 9351–9360 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Solid deposits Jet fuel Metal sulfides Résumé : Reaction of the organic sulfur compounds in Jet A with Fe- and Ni-based alloy substrates under pyrolytic conditions formed significant amounts of metal sulfides. Pyrrhotite (Fe(1−x)S) and heazlewoodite (Ni3S2) were formed on SS316 and Inconel 600 surfaces, respectively, in the short duration experiments. After extended periods of thermal stressing, an additional crystal phase, pentlandite (Fe,Ni)9S8, was also observed on both surfaces. The lack of FeS2 (pyrite) formation over extended periods of stressing indicates that the amount of sulfur reacting with the substrates decreased with the increasing thermal stressing time. A focused ion beam (FIB)/SEM analysis showed that the metal sulfide formation can extend up to 2 μm depth from the surface in 2 h of thermal stressing. The formation of metal sulfides on alloy surfaces degrades the alloy surfaces and affects solid carbon deposition from jet fuel. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801007r [article] Characterization of solid deposits formed from jet fuel degradation under pyrolytic conditions : metal sulfides [texte imprimé] / Ramya Venkataraman, Auteur ; Semih Eser, Auteur . - 2009 . - p. 9351–9360. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9351–9360 Mots-clés : Solid deposits Jet fuel Metal sulfides Résumé : Reaction of the organic sulfur compounds in Jet A with Fe- and Ni-based alloy substrates under pyrolytic conditions formed significant amounts of metal sulfides. Pyrrhotite (Fe(1−x)S) and heazlewoodite (Ni3S2) were formed on SS316 and Inconel 600 surfaces, respectively, in the short duration experiments. After extended periods of thermal stressing, an additional crystal phase, pentlandite (Fe,Ni)9S8, was also observed on both surfaces. The lack of FeS2 (pyrite) formation over extended periods of stressing indicates that the amount of sulfur reacting with the substrates decreased with the increasing thermal stressing time. A focused ion beam (FIB)/SEM analysis showed that the metal sulfide formation can extend up to 2 μm depth from the surface in 2 h of thermal stressing. The formation of metal sulfides on alloy surfaces degrades the alloy surfaces and affects solid carbon deposition from jet fuel. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801007r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Rheological study of epoxy systems blended with poly(ether sulfone) of different molecular weights / Yingfeng Yu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9361–9369 Titre : Rheological study of epoxy systems blended with poly(ether sulfone) of different molecular weights Type de document : texte imprimé Auteurs : Yingfeng Yu, Auteur ; Minghai Wang, Auteur ; David Foix, Auteur Année de publication : 2009 Article en page(s) : p. 9361–9369 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Rheological study Epoxy systems ether sulfone Résumé : In this work, the rheological behavior and structural transitions in poly(ether sulfone) (PES)-modified epoxy systems during phase separation were studied by rheometry instrument, scanning electronic microscopy, time-resolved light scattering, and differential scanning calorimetry. The molecular weight and concentration of PES have profound effects on rheological behavior of modified epoxy systems. It was found that the evolution of complex viscosity is closely connected to the molecular weight of PES. Blends with higher molecular weight PES tend to have a lower conversion at the onset of phase separation and show quicker increase of viscosity with curing process. The complex viscosity exhibits an exponential growing process during phase separation at various temperatures. The relaxation time of rheological growth depends on both molecular weight of PES and test frequency. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800845p#afn1 [article] Rheological study of epoxy systems blended with poly(ether sulfone) of different molecular weights [texte imprimé] / Yingfeng Yu, Auteur ; Minghai Wang, Auteur ; David Foix, Auteur . - 2009 . - p. 9361–9369. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9361–9369 Mots-clés : Rheological study Epoxy systems ether sulfone Résumé : In this work, the rheological behavior and structural transitions in poly(ether sulfone) (PES)-modified epoxy systems during phase separation were studied by rheometry instrument, scanning electronic microscopy, time-resolved light scattering, and differential scanning calorimetry. The molecular weight and concentration of PES have profound effects on rheological behavior of modified epoxy systems. It was found that the evolution of complex viscosity is closely connected to the molecular weight of PES. Blends with higher molecular weight PES tend to have a lower conversion at the onset of phase separation and show quicker increase of viscosity with curing process. The complex viscosity exhibits an exponential growing process during phase separation at various temperatures. The relaxation time of rheological growth depends on both molecular weight of PES and test frequency. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800845p#afn1

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Use of new branched cationic polyacrylamides to improve retention and drainage in papermaking / Elisabete Antunes in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9370–9375 Titre : Use of new branched cationic polyacrylamides to improve retention and drainage in papermaking Type de document : texte imprimé Auteurs : Elisabete Antunes, Auteur ; Fernando A.P. Garcia, Auteur ; Paulo Ferreira, Auteur Année de publication : 2009 Article en page(s) : p. 9370–9375 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Polyacrylamides Improve retention Papermaking Résumé : Cationic polyacrylamides of very high molecular weight and with different charge densities and degrees of branching have been investigated as retention aids for papermaking. The effects of polymer charge density and polymer branching on drainage and retention of a suspension containing fibers and precipitated calcium carbonate have been correlated with flocs properties. Additionally, the effects of flocculant dosage and contact time with the furnish were investigated. Results show that polymers of medium charge density are more adequate to be used as retention aids since lower drainage time and higher filler retention are obtained at short contact time and low flocculant dosage. The branched polymers exhibited better performance than the linear polymers: drainage performance is significantly improved because highly branched polymers produce small flocs with a more open structure. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801216t [article] Use of new branched cationic polyacrylamides to improve retention and drainage in papermaking [texte imprimé] / Elisabete Antunes, Auteur ; Fernando A.P. Garcia, Auteur ; Paulo Ferreira, Auteur . - 2009 . - p. 9370–9375. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9370–9375 Mots-clés : Polyacrylamides Improve retention Papermaking Résumé : Cationic polyacrylamides of very high molecular weight and with different charge densities and degrees of branching have been investigated as retention aids for papermaking. The effects of polymer charge density and polymer branching on drainage and retention of a suspension containing fibers and precipitated calcium carbonate have been correlated with flocs properties. Additionally, the effects of flocculant dosage and contact time with the furnish were investigated. Results show that polymers of medium charge density are more adequate to be used as retention aids since lower drainage time and higher filler retention are obtained at short contact time and low flocculant dosage. The branched polymers exhibited better performance than the linear polymers: drainage performance is significantly improved because highly branched polymers produce small flocs with a more open structure. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801216t

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Anion effect on Cu2+ adsorption on NH2-MCM-41 / Koon Fung Lam in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9376–9383 Titre : Anion effect on Cu2+ adsorption on NH2-MCM-41 Type de document : texte imprimé Auteurs : Koon Fung Lam, Auteur ; Xinqing Chen, Auteur ; Gordon McKay, Auteur Année de publication : 2009 Article en page(s) : p. 9376–9383 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Anion affect Cu2+ adsorption NH2-MCM-41 Résumé : The anion effect was investigated for the copper adsorption on NH2-MCM-41 from Cu(NO3)2 and CuSO4 solutions. The copper adsorption was higher and faster in the presence of SO42− anion compared to NO3−. The MCM-41 possesses well-ordered mesopores that are readily accessible and a uniform surface that is amenable to the attachment of the chemical moieties for creating tailored adsorption sites. The adsorption sites on NH2-MCM-41 were created by grafting aminopropyls on MCM-41, and the random deposition resulted in a site distribution best described by the Freundlich equation. The majority of the adsorption sites (i.e., up to 70%) are readily accessible to Cu2+ adsorption. The remaining sites were only accessible in the presence of SO42−. Evidence showed that the SO42− anion affects the adsorption by interacting with the dissolved copper to form [CuSO4]0 species, coadsorbing with Cu2+ to form stable complexes, and may even indirectly react with the weakly acidic silanol groups to liberate aminopropyls for more Cu2+ adsorption. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701748b [article] Anion effect on Cu2+ adsorption on NH2-MCM-41 [texte imprimé] / Koon Fung Lam, Auteur ; Xinqing Chen, Auteur ; Gordon McKay, Auteur . - 2009 . - p. 9376–9383. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9376–9383 Mots-clés : Anion affect Cu2+ adsorption NH2-MCM-41 Résumé : The anion effect was investigated for the copper adsorption on NH2-MCM-41 from Cu(NO3)2 and CuSO4 solutions. The copper adsorption was higher and faster in the presence of SO42− anion compared to NO3−. The MCM-41 possesses well-ordered mesopores that are readily accessible and a uniform surface that is amenable to the attachment of the chemical moieties for creating tailored adsorption sites. The adsorption sites on NH2-MCM-41 were created by grafting aminopropyls on MCM-41, and the random deposition resulted in a site distribution best described by the Freundlich equation. The majority of the adsorption sites (i.e., up to 70%) are readily accessible to Cu2+ adsorption. The remaining sites were only accessible in the presence of SO42−. Evidence showed that the SO42− anion affects the adsorption by interacting with the dissolved copper to form [CuSO4]0 species, coadsorbing with Cu2+ to form stable complexes, and may even indirectly react with the weakly acidic silanol groups to liberate aminopropyls for more Cu2+ adsorption. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701748b

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Chemical vapor synthesis and characterization of nanosized WC-Co composite powder and post-treatment / Taegong Ryu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9384–9388 Titre : Chemical vapor synthesis and characterization of nanosized WC-Co composite powder and post-treatment Type de document : texte imprimé Auteurs : Taegong Ryu, Auteur ; Hong Yong Sohn, Auteur ; Kyu Sup Hwang, Auteur Année de publication : 2009 Article en page(s) : p. 9384–9388 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Chemical vapor WC-Co composite Résumé : Nanosized WC−Co composite powders were produced by a chemical vapor synthesis (CVS) process. The reactions of vaporized chlorides (WCl6 and CoCl2) with methane−hydrogen mixtures produced nanosized WC−Co composite powder, which sometimes contained W2C or W phase. The effects of reactant concentrations, WCl6 volatilizer temperature, and H2 to CH4 molar ratio in the feed stream were investigated. The produced powder was heat-treated under hydrogen to fully carburize all tungsten carbide phases to WC and reduce carbon content down to nearly stoichiometric levels. Finally, WC−Co composite powders of particle size less than 70 nm with 0−3% excess carbon were obtained. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800322y [article] Chemical vapor synthesis and characterization of nanosized WC-Co composite powder and post-treatment [texte imprimé] / Taegong Ryu, Auteur ; Hong Yong Sohn, Auteur ; Kyu Sup Hwang, Auteur . - 2009 . - p. 9384–9388. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9384–9388 Mots-clés : Chemical vapor WC-Co composite Résumé : Nanosized WC−Co composite powders were produced by a chemical vapor synthesis (CVS) process. The reactions of vaporized chlorides (WCl6 and CoCl2) with methane−hydrogen mixtures produced nanosized WC−Co composite powder, which sometimes contained W2C or W phase. The effects of reactant concentrations, WCl6 volatilizer temperature, and H2 to CH4 molar ratio in the feed stream were investigated. The produced powder was heat-treated under hydrogen to fully carburize all tungsten carbide phases to WC and reduce carbon content down to nearly stoichiometric levels. Finally, WC−Co composite powders of particle size less than 70 nm with 0−3% excess carbon were obtained. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800322y

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Structure and properties of soy protein plastics with ε-caprolactone/glycerol as binary plasticizers / Pu Chen in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9389–9395 Titre : Structure and properties of soy protein plastics with ε-caprolactone/glycerol as binary plasticizers Type de document : texte imprimé Auteurs : Pu Chen, Auteur ; Huafeng Tian, Auteur ; Lina Zhang, Auteur Année de publication : 2009 Article en page(s) : p. 9389–9395 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Properties soy protein plastics ε  -Caprolactone Binary plasticizers Résumé : We successfully prepared a series of soy protein isolate (SPI) plastics with ε-caprolactone (CL)/glycerol binary plasticizers via extrusion and compression-molding. The chemical reactions among SPI, CL, and glycerol as well as the influence of CL/glycerol content on the microstructure, thermal degradation, and mechanical properties have been investigated using Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis-Fourier transform infrared spectroscopy (TGA-FTIR), and mechanical tests. The results of FTIR, SEM, DSC, and DMTA revealed that CL reacted with protein and glycerol molecules under high-temperature, high-shear, and high-pressure conditions. When the CL content was low (less than 25 wt %), the CL added to the protein matrix was dispersed mainly in the glycerol-rich domains and reacted with glycerol. However, at a higher concentration, the CL predominated in the protein-rich domains and reacted with protein molecules. The chemical reactions led to a significant increase in glass transition and mechanical relaxation temperatures of the glycerol-rich and protein-rich domains. Accordingly, the chemical reactions retarded the volatilization of glycerol and the release of NH3 and CO2 and elevated the tensile strength, Young’s modulus, and the water resistance of the soy protein plastic sheets. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800371f#afn1 [article] Structure and properties of soy protein plastics with ε-caprolactone/glycerol as binary plasticizers [texte imprimé] / Pu Chen, Auteur ; Huafeng Tian, Auteur ; Lina Zhang, Auteur . - 2009 . - p. 9389–9395. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9389–9395 Mots-clés : Properties soy protein plastics ε  -Caprolactone Binary plasticizers Résumé : We successfully prepared a series of soy protein isolate (SPI) plastics with ε-caprolactone (CL)/glycerol binary plasticizers via extrusion and compression-molding. The chemical reactions among SPI, CL, and glycerol as well as the influence of CL/glycerol content on the microstructure, thermal degradation, and mechanical properties have been investigated using Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis-Fourier transform infrared spectroscopy (TGA-FTIR), and mechanical tests. The results of FTIR, SEM, DSC, and DMTA revealed that CL reacted with protein and glycerol molecules under high-temperature, high-shear, and high-pressure conditions. When the CL content was low (less than 25 wt %), the CL added to the protein matrix was dispersed mainly in the glycerol-rich domains and reacted with glycerol. However, at a higher concentration, the CL predominated in the protein-rich domains and reacted with protein molecules. The chemical reactions led to a significant increase in glass transition and mechanical relaxation temperatures of the glycerol-rich and protein-rich domains. Accordingly, the chemical reactions retarded the volatilization of glycerol and the release of NH3 and CO2 and elevated the tensile strength, Young’s modulus, and the water resistance of the soy protein plastic sheets. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800371f#afn1

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

One-part geopolymer mixes from geothermal silica and sodium aluminate / Ailar Hajimohammadi in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p.9396–9405 Titre : One-part geopolymer mixes from geothermal silica and sodium aluminate Type de document : texte imprimé Auteurs : Ailar Hajimohammadi, Auteur ; John L. Provis, Auteur ; Jannie S. J. van Deventer, Auteur Année de publication : 2009 Article en page(s) : p.9396–9405 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Geopolymer mixes Geothermal Silica and sodium aluminate Résumé : In geopolymer technology, silicate solutions are frequently used as alkali activators to dissolve the solid aluminosilicate precursor and aid in binder formation. These corrosive and often viscous solutions are not user-friendly and would be difficult to use for bulk production. Developing geopolymers as a one-part mixture (“just add water”), similar to Portland cement, increases their commercial viability. Here, for the first time, the geopolymer system consisting of geothermal silica and solid sodium aluminate (providing the solid silica, alkali, and alumina sources) is studied. The effects of water content, high early silica, and high early alumina in the formation of one-part mix geopolymers are also investigated. This system demonstrates that making geopolymers from solid sources by “just adding water” is possible. XRD shows that the formulation with less water has an unexpected greater extent of crystallinity. It is also observed that a high early Al concentration inhibits geopolymerization, while a high early Si concentration enhances the reaction. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8006825 [article] One-part geopolymer mixes from geothermal silica and sodium aluminate [texte imprimé] / Ailar Hajimohammadi, Auteur ; John L. Provis, Auteur ; Jannie S. J. van Deventer, Auteur . - 2009 . - p.9396–9405. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p.9396–9405 Mots-clés : Geopolymer mixes Geothermal Silica and sodium aluminate Résumé : In geopolymer technology, silicate solutions are frequently used as alkali activators to dissolve the solid aluminosilicate precursor and aid in binder formation. These corrosive and often viscous solutions are not user-friendly and would be difficult to use for bulk production. Developing geopolymers as a one-part mixture (“just add water”), similar to Portland cement, increases their commercial viability. Here, for the first time, the geopolymer system consisting of geothermal silica and solid sodium aluminate (providing the solid silica, alkali, and alumina sources) is studied. The effects of water content, high early silica, and high early alumina in the formation of one-part mix geopolymers are also investigated. This system demonstrates that making geopolymers from solid sources by “just adding water” is possible. XRD shows that the formulation with less water has an unexpected greater extent of crystallinity. It is also observed that a high early Al concentration inhibits geopolymerization, while a high early Si concentration enhances the reaction. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8006825

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

New insights into the interactions of CO2 with amine-functionalized silica / Rodrigo Serna-Guerrero in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9406–9412 Titre : New insights into the interactions of CO2 with amine-functionalized silica Type de document : texte imprimé Auteurs : Rodrigo Serna-Guerrero, Auteur ; Enshirah Da’na, Auteur ; Abdelhamid Sayari, Auteur Année de publication : 2009 Article en page(s) : p. 9406–9412 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Interactions of CO2 Amine-functionalized silica Résumé : The CO2−amine chemistry in gas−solid processes was investigated under both humid and dry conditions using aminopropyl-grafted pore-expanded MCM-41 silica (MONO-PE-MCM-41). To draw accurate conclusions, a set of conditions had to be met including (i) the use of an adsorbent with open pore structure and readily accessible adsorption sites, e.g. MONO-PE-MCM-41 with a mean pore size of 7.2 nm; (ii) the CO2 concentration in the feed should be high enough to achieve saturation via chemisorption, but low enough to avoid any additional physisorption, e.g., 5% CO2 in N2; (iii) the use of a reliable method for the accurate measurement of CO2/N ratio. Under such conditions, the obtained CO2/N ratios were reminiscent of those obtained in the CO2 scrubbing process using ethanolamine solutions. Under dry conditions, the CO2/N ratio was close to 0.5, consistent with the formation of carbamate. Streams with relative humidity (RH) of 27, 61, and 74% were studied as well. As RH in the feed increased, CO2/N ratio increased from 0.57 to 0.88, in line with the gradual formation of bicarbonate. As for the determination of CO2/N ratio under dry conditions, both thermogravimetry (TG) and mass spectrometry (MS) were suitable, whereas in the presence of moisture, TG was found to drastically underestimate the CO2 uptake. The seemingly disparate CO2/N ratios reported in the literature for various propylamine-bearing adsorbents were rationalized on the basis of the adsorbent pore structure and/or the experimental conditions used. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801186g [article] New insights into the interactions of CO2 with amine-functionalized silica [texte imprimé] / Rodrigo Serna-Guerrero, Auteur ; Enshirah Da’na, Auteur ; Abdelhamid Sayari, Auteur . - 2009 . - p. 9406–9412. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9406–9412 Mots-clés : Interactions of CO2 Amine-functionalized silica Résumé : The CO2−amine chemistry in gas−solid processes was investigated under both humid and dry conditions using aminopropyl-grafted pore-expanded MCM-41 silica (MONO-PE-MCM-41). To draw accurate conclusions, a set of conditions had to be met including (i) the use of an adsorbent with open pore structure and readily accessible adsorption sites, e.g. MONO-PE-MCM-41 with a mean pore size of 7.2 nm; (ii) the CO2 concentration in the feed should be high enough to achieve saturation via chemisorption, but low enough to avoid any additional physisorption, e.g., 5% CO2 in N2; (iii) the use of a reliable method for the accurate measurement of CO2/N ratio. Under such conditions, the obtained CO2/N ratios were reminiscent of those obtained in the CO2 scrubbing process using ethanolamine solutions. Under dry conditions, the CO2/N ratio was close to 0.5, consistent with the formation of carbamate. Streams with relative humidity (RH) of 27, 61, and 74% were studied as well. As RH in the feed increased, CO2/N ratio increased from 0.57 to 0.88, in line with the gradual formation of bicarbonate. As for the determination of CO2/N ratio under dry conditions, both thermogravimetry (TG) and mass spectrometry (MS) were suitable, whereas in the presence of moisture, TG was found to drastically underestimate the CO2 uptake. The seemingly disparate CO2/N ratios reported in the literature for various propylamine-bearing adsorbents were rationalized on the basis of the adsorbent pore structure and/or the experimental conditions used. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801186g

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

On the use of net present value in investment capacity planning models / Miguel Bagajewicz in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9413–9416 Titre : On the use of net present value in investment capacity planning models Type de document : texte imprimé Auteurs : Miguel Bagajewicz, Auteur Année de publication : 2009 Article en page(s) : p. 9413–9416 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Capacity planning Investment Résumé : Net present value has been widely used in several investment planning models. This article examines the validity of this objective function, discusses its merits, and also provides some simple alternatives. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071008l [article] On the use of net present value in investment capacity planning models [texte imprimé] / Miguel Bagajewicz, Auteur . - 2009 . - p. 9413–9416. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9413–9416 Mots-clés : Capacity planning Investment Résumé : Net present value has been widely used in several investment planning models. This article examines the validity of this objective function, discusses its merits, and also provides some simple alternatives. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071008l

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

L-shaped bONUS algorithm with application to water pollutant trading / Yogendra N. Shastri in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9417–9425 Titre : L-shaped bONUS algorithm with application to water pollutant trading Type de document : texte imprimé Auteurs : Yogendra N. Shastri, Auteur ; Urmila M. Diwekar, Auteur Année de publication : 2009 Article en page(s) : p. 9417–9425 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Algorithm Water pollutant Résumé : Applications of optimization in the field of process systems engineering often involve dealing with nonlinearity and uncertainty, necessitating the solution of stochastic nonlinear programming (SNLP) problems. However, the existing algorithms to solve such problems suffer from various limitations. The L-shaped BONUS algorithm, which is an integration of the BONUS (Better Optimization of Nonlinear Uncertain Systems) algorithm and the sampling-based L-shaped method, has been recently proposed to overcome some of these problems. It is shown to have desirable computational properties. This work further investigates the properties of the algorithm by applying it to the environmental problem of pollutant (nutrient) trading in the Christina River Basin. With environmental concerns being heightened, pollution abatement-related decisions are important for industry, making efficient solution techniques invaluable. The results confirm the computational efficiency of the L-shaped BONUS algorithm. Simultaneously, interesting aspects of the environmental trading problem are also explored, pointing toward the scope of implementing stochastic programming techniques for better decision making in the field of industrial ecology. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0710263 [article] L-shaped bONUS algorithm with application to water pollutant trading [texte imprimé] / Yogendra N. Shastri, Auteur ; Urmila M. Diwekar, Auteur . - 2009 . - p. 9417–9425. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9417–9425 Mots-clés : Algorithm Water pollutant Résumé : Applications of optimization in the field of process systems engineering often involve dealing with nonlinearity and uncertainty, necessitating the solution of stochastic nonlinear programming (SNLP) problems. However, the existing algorithms to solve such problems suffer from various limitations. The L-shaped BONUS algorithm, which is an integration of the BONUS (Better Optimization of Nonlinear Uncertain Systems) algorithm and the sampling-based L-shaped method, has been recently proposed to overcome some of these problems. It is shown to have desirable computational properties. This work further investigates the properties of the algorithm by applying it to the environmental problem of pollutant (nutrient) trading in the Christina River Basin. With environmental concerns being heightened, pollution abatement-related decisions are important for industry, making efficient solution techniques invaluable. The results confirm the computational efficiency of the L-shaped BONUS algorithm. Simultaneously, interesting aspects of the environmental trading problem are also explored, pointing toward the scope of implementing stochastic programming techniques for better decision making in the field of industrial ecology. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0710263

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Effect analysis from dynamic regulation of vacuum pressure in an adiabatic batch crystallizer using data and image acquisition / Eusebio Bolaños-Reynoso in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9426–9436 Titre : Effect analysis from dynamic regulation of vacuum pressure in an adiabatic batch crystallizer using data and image acquisition Type de document : texte imprimé Auteurs : Eusebio Bolaños-Reynoso, Auteur ; Omar Xaca-Xaca, Auteur ; José Alvarez-Ramírez, Auteur Année de publication : 2009 Article en page(s) : p. 9426–9436 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Effect analysis Dynamic regulation Vacuum pressure Adiabatic Résumé : The effect of dynamic regulation of vacuum pressure was analyzed in an adiabatic batch crystallizer using data and image acquisition, virtual instruments, and supervisor control to obtain a controlled vacuum pressure, confirming that the process follows programmed routes in the central computer to obtain both programmed vacuum pressure and cooling dynamic profiles inside the crystallizer (direct design approach). The dynamical regulation profile of vacuum pressure called “adiabatic natural cooling” was able to originate an abrupt cooling effect by adiabatic evaporation inside of the crystallizer (e.g., natural cooling in batch crystallizers operated to atmospheric pressure), benefiting the seeded crystal growth from cane sugar until it reached a size of 732.7 μm (% volume). In turn, the increase in crystal growth, formed mass, and the available supersaturation depletion in the system, contribute to final molasses reduction. From a process dynamics viewpoint, the use of dynamic regulation profiles of vacuum pressure reduces batch time and energy consumption (steam) in the process operation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071594i [article] Effect analysis from dynamic regulation of vacuum pressure in an adiabatic batch crystallizer using data and image acquisition [texte imprimé] / Eusebio Bolaños-Reynoso, Auteur ; Omar Xaca-Xaca, Auteur ; José Alvarez-Ramírez, Auteur . - 2009 . - p. 9426–9436. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9426–9436 Mots-clés : Effect analysis Dynamic regulation Vacuum pressure Adiabatic Résumé : The effect of dynamic regulation of vacuum pressure was analyzed in an adiabatic batch crystallizer using data and image acquisition, virtual instruments, and supervisor control to obtain a controlled vacuum pressure, confirming that the process follows programmed routes in the central computer to obtain both programmed vacuum pressure and cooling dynamic profiles inside the crystallizer (direct design approach). The dynamical regulation profile of vacuum pressure called “adiabatic natural cooling” was able to originate an abrupt cooling effect by adiabatic evaporation inside of the crystallizer (e.g., natural cooling in batch crystallizers operated to atmospheric pressure), benefiting the seeded crystal growth from cane sugar until it reached a size of 732.7 μm (% volume). In turn, the increase in crystal growth, formed mass, and the available supersaturation depletion in the system, contribute to final molasses reduction. From a process dynamics viewpoint, the use of dynamic regulation profiles of vacuum pressure reduces batch time and energy consumption (steam) in the process operation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071594i

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Autothermal reforming of gasoline for fuel cell applications / Yongyou Hu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9437–9446 Titre : Autothermal reforming of gasoline for fuel cell applications : a control-oriented dynamic model Type de document : texte imprimé Auteurs : Yongyou Hu, Auteur ; Donald J. Chmielewski, Auteur Année de publication : 2009 Article en page(s) : p. 9437–9446 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Autothermal Fuel cell Applications Control-oriented dynamic Résumé : In this work, we develop a control-oriented, reduced order dynamic model of an autothermal reforming (ATR) reactor. The targeted application is within the on-board fuel-processing unit of a fuel cell vehicle. A previous effort has illustrated that a predictive-type controller may be required to achieve desired performance within this application. The objective of the current effort is to determine the existence of a reduced order model with enough speed and accuracy to meet the online computational demands of a predictive controller. Central to the model development is an approximation of reaction rates that achieve reasonable accuracy near the inlet while preserving the overall energy balance. The resulting scheme converts a partial differential equation model into a set of ordinary differential/algebraic equations and achieves nearly a 4 orders of magnitude improvement in computational speed while preserving most of the nonlinear characteristics of the original system. Such results give clear indication that the hurdle of computational viability can be overcome and opens the door for further development of a predictive controller for the ATR application. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800209k [article] Autothermal reforming of gasoline for fuel cell applications : a control-oriented dynamic model [texte imprimé] / Yongyou Hu, Auteur ; Donald J. Chmielewski, Auteur . - 2009 . - p. 9437–9446. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9437–9446 Mots-clés : Autothermal Fuel cell Applications Control-oriented dynamic Résumé : In this work, we develop a control-oriented, reduced order dynamic model of an autothermal reforming (ATR) reactor. The targeted application is within the on-board fuel-processing unit of a fuel cell vehicle. A previous effort has illustrated that a predictive-type controller may be required to achieve desired performance within this application. The objective of the current effort is to determine the existence of a reduced order model with enough speed and accuracy to meet the online computational demands of a predictive controller. Central to the model development is an approximation of reaction rates that achieve reasonable accuracy near the inlet while preserving the overall energy balance. The resulting scheme converts a partial differential equation model into a set of ordinary differential/algebraic equations and achieves nearly a 4 orders of magnitude improvement in computational speed while preserving most of the nonlinear characteristics of the original system. Such results give clear indication that the hurdle of computational viability can be overcome and opens the door for further development of a predictive controller for the ATR application. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800209k

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Fault diagnosis based on signed digraph combined with dynamic kernel PLS and SVR / Ning Lu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9447–9456 Titre : Fault diagnosis based on signed digraph combined with dynamic kernel PLS and SVR Type de document : texte imprimé Auteurs : Ning Lu, Auteur ; Xiong Wang, Auteur Année de publication : 2009 Article en page(s) : p. 9447–9456 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Signed digraph Dynamic kernel PLS and SVR Résumé : The signed digraph (SDG) method for fault diagnosis, which is one of the model-based methods, has been widely applied in the chemical industry in recent years. However, how to elicit appropriate thresholds for SDG is a very difficult problem. This study presents a new hybrid method combining SDG with dynamic kernel partial least-squares (DKPLS) and support vector regression (SVR) for fault diagnosis. Using the relationships of each variable in SDG, a series of DKPLS-SVR models are built to estimate the values of the measured variables in process. The difference between the estimation and the measured value can determine the qualitative status of the variable, and then the fault can be diagnosed by SDG reasoning. Therefore, the threshold of each measured variable does not need to be decided in advance. The method can also overcome the limited availability of using the KPLS method alone in identifying the root cause. To verify the performance of the proposed method, its application is illustrated on the Tennessee Eastman (TE) challenge process. Through case studies, the proposed method demonstrates a good diagnosis capability compared with previous hybrid methods. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009457 [article] Fault diagnosis based on signed digraph combined with dynamic kernel PLS and SVR [texte imprimé] / Ning Lu, Auteur ; Xiong Wang, Auteur . - 2009 . - p. 9447–9456. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9447–9456 Mots-clés : Signed digraph Dynamic kernel PLS and SVR Résumé : The signed digraph (SDG) method for fault diagnosis, which is one of the model-based methods, has been widely applied in the chemical industry in recent years. However, how to elicit appropriate thresholds for SDG is a very difficult problem. This study presents a new hybrid method combining SDG with dynamic kernel partial least-squares (DKPLS) and support vector regression (SVR) for fault diagnosis. Using the relationships of each variable in SDG, a series of DKPLS-SVR models are built to estimate the values of the measured variables in process. The difference between the estimation and the measured value can determine the qualitative status of the variable, and then the fault can be diagnosed by SDG reasoning. Therefore, the threshold of each measured variable does not need to be decided in advance. The method can also overcome the limited availability of using the KPLS method alone in identifying the root cause. To verify the performance of the proposed method, its application is illustrated on the Tennessee Eastman (TE) challenge process. Through case studies, the proposed method demonstrates a good diagnosis capability compared with previous hybrid methods. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009457

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Strategies to achieve a uniform cell structure with a high void fraction in advanced structural foam molding / John W. S. Lee in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9457–9464 Titre : Strategies to achieve a uniform cell structure with a high void fraction in advanced structural foam molding Type de document : texte imprimé Auteurs : John W. S. Lee, Auteur ; Jing Wang, Auteur ; Jae D. Yoon, Auteur Année de publication : 2009 Article en page(s) : p. 9457–9464 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Achieve a uniform cell structure High void Structural foam molding Résumé : Structural foams offer numerous advantages over their solid counterparts, including greater geometrical accuracy, the absence of sink marks on the final product’s surface, lower weight (and, by extension, the need for less material), and a higher stiffness-to-weight ratio. The possibility of achieving a suitable void fraction in structural foams using conventional structural foam molding methods, however, has been of limited success; these methods allow for little control and typically yield large voids and a nonuniform cell structure. This article reports on our use of an advanced structural foam molding machine to achieve a uniform cell structure with a high void fraction. We studied the following processing parameters: injection flow rate, blowing agent content, and melt temperature. The pressure profile inside the mold cavity under various processing conditions was also investigated to elucidate cell nucleation and growth behaviors. By optimizing all processing conditions, we achieved a uniform cell structure and a very high void fraction (over 40%). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0707016 [article] Strategies to achieve a uniform cell structure with a high void fraction in advanced structural foam molding [texte imprimé] / John W. S. Lee, Auteur ; Jing Wang, Auteur ; Jae D. Yoon, Auteur . - 2009 . - p. 9457–9464. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9457–9464 Mots-clés : Achieve a uniform cell structure High void Structural foam molding Résumé : Structural foams offer numerous advantages over their solid counterparts, including greater geometrical accuracy, the absence of sink marks on the final product’s surface, lower weight (and, by extension, the need for less material), and a higher stiffness-to-weight ratio. The possibility of achieving a suitable void fraction in structural foams using conventional structural foam molding methods, however, has been of limited success; these methods allow for little control and typically yield large voids and a nonuniform cell structure. This article reports on our use of an advanced structural foam molding machine to achieve a uniform cell structure with a high void fraction. We studied the following processing parameters: injection flow rate, blowing agent content, and melt temperature. The pressure profile inside the mold cavity under various processing conditions was also investigated to elucidate cell nucleation and growth behaviors. By optimizing all processing conditions, we achieved a uniform cell structure and a very high void fraction (over 40%). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0707016

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Selection of controlled variables / Eduardo Shigueo Hori in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9465–9471 Titre : Selection of controlled variables : maximum gain rule and combination of measurements Type de document : texte imprimé Auteurs : Eduardo Shigueo Hori, Auteur ; Sigurd Skogestad, Auteur Année de publication : 2009 Article en page(s) : p. 9465–9471 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Selection variables Gain rule Combination of measurements Résumé : The appropriate selection of controlled variables is one of the most important tasks in plantwide control. In this paper, we consider the selection of secondary temperature measurements for indirect composition control of distillation columns. The maximum gain rule (maximize minimum singular value of scaled gain matrix) is compared to the exact local method, and it is found that the gain rule should be used with care for ill-conditioned plants like distillation columns. We also consider the use of optimal combinations of measurements to further reduce the effect of disturbances and implementation errors. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0711978 [article] Selection of controlled variables : maximum gain rule and combination of measurements [texte imprimé] / Eduardo Shigueo Hori, Auteur ; Sigurd Skogestad, Auteur . - 2009 . - p. 9465–9471. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9465–9471 Mots-clés : Selection variables Gain rule Combination of measurements Résumé : The appropriate selection of controlled variables is one of the most important tasks in plantwide control. In this paper, we consider the selection of secondary temperature measurements for indirect composition control of distillation columns. The maximum gain rule (maximize minimum singular value of scaled gain matrix) is compared to the exact local method, and it is found that the gain rule should be used with care for ill-conditioned plants like distillation columns. We also consider the use of optimal combinations of measurements to further reduce the effect of disturbances and implementation errors. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0711978

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Design and control of the side reactor configuration for production of ethyl acetate / Reui-Chiang Tsai in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9472–9484 Titre : Design and control of the side reactor configuration for production of ethyl acetate Type de document : texte imprimé Auteurs : Reui-Chiang Tsai, Auteur ; Jian Kai Cheng, Auteur ; Hsiao-Ping Huang, Auteur Année de publication : 2009 Article en page(s) : p. 9472–9484 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Design and control Side reactor configuration Production of ethyl acetate Résumé : Despite some potential advantages of reactive distillation (RD), reactive distillation may suffer from maintenance/design problems such as catalyst deactivation/replacement and equipment design. In this work, an alternative design, a side reactor configuration, is sought and the process of interest is production of ethyl acetate via esterification. The reactive distillation study by Tang et al. (2005) reveals that almost 90% conversion takes place in the column base of the RD. This naturally suggests a coupled reactor/distillation configuration where all of the catalyst is packed in the bottoms base, denoted as single-reactive tray reactive distillation (RD-SRT). This mitigates the maintenance problem associated with conventional RD. However, simulation results show that, with the same amount of catalyst loading, the SRT configuration cannot achieve the same performance as the RD (∼93% conversion). Another alternative is adding external reactors to the SRT, and this is termed the side reactor configuration (SRC). A systematic design procedure is devised for the SRC design, and the objective function to be minimized is the total annual cost (TAC). The results show that the TAC of the SRC only increases by 5% as compared to that of the RD. A plantwide control structure is developed followed by process identification and controller tuning. The results show that reasonable control performance can be achieved using simple temperature control for the feed flow rate and feed composition disturbances. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071648o [article] Design and control of the side reactor configuration for production of ethyl acetate [texte imprimé] / Reui-Chiang Tsai, Auteur ; Jian Kai Cheng, Auteur ; Hsiao-Ping Huang, Auteur . - 2009 . - p. 9472–9484. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9472–9484 Mots-clés : Design and control Side reactor configuration Production of ethyl acetate Résumé : Despite some potential advantages of reactive distillation (RD), reactive distillation may suffer from maintenance/design problems such as catalyst deactivation/replacement and equipment design. In this work, an alternative design, a side reactor configuration, is sought and the process of interest is production of ethyl acetate via esterification. The reactive distillation study by Tang et al. (2005) reveals that almost 90% conversion takes place in the column base of the RD. This naturally suggests a coupled reactor/distillation configuration where all of the catalyst is packed in the bottoms base, denoted as single-reactive tray reactive distillation (RD-SRT). This mitigates the maintenance problem associated with conventional RD. However, simulation results show that, with the same amount of catalyst loading, the SRT configuration cannot achieve the same performance as the RD (∼93% conversion). Another alternative is adding external reactors to the SRT, and this is termed the side reactor configuration (SRC). A systematic design procedure is devised for the SRC design, and the objective function to be minimized is the total annual cost (TAC). The results show that the TAC of the SRC only increases by 5% as compared to that of the RD. A plantwide control structure is developed followed by process identification and controller tuning. The results show that reasonable control performance can be achieved using simple temperature control for the feed flow rate and feed composition disturbances. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071648o

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Synthesis of direct and indirect interplant water network / Irene Mei Leng Chew in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9485–9496 Titre : Synthesis of direct and indirect interplant water network Type de document : texte imprimé Auteurs : Irene Mei Leng Chew, Auteur ; Raymond Tan, Auteur ; Denny Kok Sum Ng, Auteur Année de publication : 2009 Article en page(s) : p. 9485–9496 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Water network Résumé : To date, most work on water network synthesis has been focusing on a single water network. The increase of public awareness toward industrial ecology has inspired new research into interplant water integration (IPWI). In this context, each water network may be grouped according to the geographical location of the water-using processes or as different plants operated by different business entities. Water source(s) from one network may be reused/recycled to sink(s) in another network. In this work, two different IPWI schemes, that is, “direct” and “indirect” integration are analyzed using mathematical optimization techniques. In the former, water from different networks is integrated directly via cross-plant pipeline(s). A mixed integer linear program (MILP) model is formulated and solved to achieve a globally optimal solution. In the latter, water from different networks is integrated indirectly via a centralized utility hub. The centralized utility hub serves to collect and redistribute water to the individual plants, and may even function as a shared water regeneration unit. For the indirect integration scheme, a mixed integer nonlinear program (MINLP) is formulated and solved using a relaxation linearization technique to obtain an optimal solution. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800072r#afn1 [article] Synthesis of direct and indirect interplant water network [texte imprimé] / Irene Mei Leng Chew, Auteur ; Raymond Tan, Auteur ; Denny Kok Sum Ng, Auteur . - 2009 . - p. 9485–9496. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9485–9496 Mots-clés : Water network Résumé : To date, most work on water network synthesis has been focusing on a single water network. The increase of public awareness toward industrial ecology has inspired new research into interplant water integration (IPWI). In this context, each water network may be grouped according to the geographical location of the water-using processes or as different plants operated by different business entities. Water source(s) from one network may be reused/recycled to sink(s) in another network. In this work, two different IPWI schemes, that is, “direct” and “indirect” integration are analyzed using mathematical optimization techniques. In the former, water from different networks is integrated directly via cross-plant pipeline(s). A mixed integer linear program (MILP) model is formulated and solved to achieve a globally optimal solution. In the latter, water from different networks is integrated indirectly via a centralized utility hub. The centralized utility hub serves to collect and redistribute water to the individual plants, and may even function as a shared water regeneration unit. For the indirect integration scheme, a mixed integer nonlinear program (MINLP) is formulated and solved using a relaxation linearization technique to obtain an optimal solution. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800072r#afn1

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Nonlinear characterization of pressure fluctuations in fluidized beds / Reza Zarghami in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9497–9507 Titre : Nonlinear characterization of pressure fluctuations in fluidized beds Type de document : texte imprimé Auteurs : Reza Zarghami, Auteur ; Navid Mostoufi, Auteur ; Rahmat Sotudeh-Gharebagh, Auteur Année de publication : 2009 Article en page(s) : p. 9497–9507 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Pressure fluctuations Fluidized beds Résumé : Nonlinear time series analysis techniques were applied to predict pressure fluctuation data in fluidized beds in two different hydrodynamic states. The method of delays was used to reconstruct the state space attractor to carry out analysis in the reconstructed state space. The state space reconstruction parameters, i.e., time delay and embedding dimension, were determined and the results shown that their values were different for various types of methods introduced in the literature. Chaotic behavior and predictability of fluidized system were determined by introducing two nonlinear dynamic invariants, correlation dimension and entropy, in different ways. The traditional linear autoregression method and state space based prediction methods (SSBPMs), i.e., nearest neighbors and locally linear, and global linear methods, were applied to predict the pressure fluctuation signals. The quality of prediction was assessed by comparison of the predicted data with its original benchmark. In addition, the dynamic invariants of measured and predicted attractor of the pressure signals were compared. The results showed that SSBPMs are preferred to the traditional linear methods. Finally, a continuous uncertainty band of pressure signals of single and multiple bubble regimes for the prediction methods was presented. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800460f [article] Nonlinear characterization of pressure fluctuations in fluidized beds [texte imprimé] / Reza Zarghami, Auteur ; Navid Mostoufi, Auteur ; Rahmat Sotudeh-Gharebagh, Auteur . - 2009 . - p. 9497–9507. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9497–9507 Mots-clés : Pressure fluctuations Fluidized beds Résumé : Nonlinear time series analysis techniques were applied to predict pressure fluctuation data in fluidized beds in two different hydrodynamic states. The method of delays was used to reconstruct the state space attractor to carry out analysis in the reconstructed state space. The state space reconstruction parameters, i.e., time delay and embedding dimension, were determined and the results shown that their values were different for various types of methods introduced in the literature. Chaotic behavior and predictability of fluidized system were determined by introducing two nonlinear dynamic invariants, correlation dimension and entropy, in different ways. The traditional linear autoregression method and state space based prediction methods (SSBPMs), i.e., nearest neighbors and locally linear, and global linear methods, were applied to predict the pressure fluctuation signals. The quality of prediction was assessed by comparison of the predicted data with its original benchmark. In addition, the dynamic invariants of measured and predicted attractor of the pressure signals were compared. The results showed that SSBPMs are preferred to the traditional linear methods. Finally, a continuous uncertainty band of pressure signals of single and multiple bubble regimes for the prediction methods was presented. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800460f

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Model migration with inclusive similarity for development of a new process model / Junde Lu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9508–9516 Titre : Model migration with inclusive similarity for development of a new process model Type de document : texte imprimé Auteurs : Junde Lu, Auteur ; Furong Gao, Auteur Année de publication : 2009 Article en page(s) : p. 9508–9516 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Model migration Résumé : In the processing industries, operating conditions change to meet the requirements of the market and customers. Under different operating conditions, data-based process modeling must be repeated for the development of a new process model. Obviously, this is inefficient and uneconomical. Effective use and adaptation of the existing process model can reduce the number of experiments in the development of a new process model, resulting in savings of time, cost, and effort. In this paper, a particular process similarity, inclusive similarity, is discussed in detail. A model migration strategy for processes with this type of similarity is developed to model a new process by taking advantage of existing models and data from the new process. The new model is built by aggregating the existing models using a bagging algorithm. As an illustrated example, the development of a new soft-sensor model for online prediction of melt-flow length for new mold geometry for an injection molding process is demonstrated by taking advantage of existing models for different molds. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800595a [article] Model migration with inclusive similarity for development of a new process model [texte imprimé] / Junde Lu, Auteur ; Furong Gao, Auteur . - 2009 . - p. 9508–9516. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9508–9516 Mots-clés : Model migration Résumé : In the processing industries, operating conditions change to meet the requirements of the market and customers. Under different operating conditions, data-based process modeling must be repeated for the development of a new process model. Obviously, this is inefficient and uneconomical. Effective use and adaptation of the existing process model can reduce the number of experiments in the development of a new process model, resulting in savings of time, cost, and effort. In this paper, a particular process similarity, inclusive similarity, is discussed in detail. A model migration strategy for processes with this type of similarity is developed to model a new process by taking advantage of existing models and data from the new process. The new model is built by aggregating the existing models using a bagging algorithm. As an illustrated example, the development of a new soft-sensor model for online prediction of melt-flow length for new mold geometry for an injection molding process is demonstrated by taking advantage of existing models for different molds. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800595a

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Distribution of electrostatic potential in a gas-solid fluidized bed and measurement of bed level / Wang Fang in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9517–9526 Titre : Distribution of electrostatic potential in a gas-solid fluidized bed and measurement of bed level Type de document : texte imprimé Auteurs : Wang Fang, Auteur ; Wang Jingdai, Auteur ; Yongrong Yang, Auteur Année de publication : 2009 Article en page(s) : p. 9517–9526 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Electrostatic potential Gas-solid fluidized Bed level Résumé : A theory on the electrostatic charge distribution in gas−solid fluidized beds was proposed. It consists of an interpretation of the causes of bipolar charging, the charging mechanisms in the fluidized bed, and the relationship between charge distribution and particle-size distribution in fluidized beds. Experiments were performed in a three-dimensional column gas−solid fluidized bed to measure the electrostatic charge distribution. It was found that the electric field inside the bed was nonuniform. If there was a distinct interface between the dilute and dense phases, the voltage polarity would reverse near the bed level, resulting in a Z-shaped axial profile of potential. The heights where voltage polarity reversal happened rose with the increase of gas velocity and static bed height. It was also found that the electrostatic voltage rose with increasing radial distances from the axis of the column. To sum up, the voltage at any axial cross section of the bed showed double saddles, with bed level as the interface. Accordingly, three special zones to be emphasized were identified: distributor, stagnant, and bed level zones, of which the latter two have high voltages and are more readily disturbed by particle/wall adhesion and even wall sheets. Based on the characteristics of axial profile of electrostatic potential in the fluidized bed, a new technique that could successfully predict bed level was developed. Good agreement was observed between visual measurements of bed level and predictions by the electrostatic method, with maximum relative error of 4.08% and mean relative error of 2.02%. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800805t [article] Distribution of electrostatic potential in a gas-solid fluidized bed and measurement of bed level [texte imprimé] / Wang Fang, Auteur ; Wang Jingdai, Auteur ; Yongrong Yang, Auteur . - 2009 . - p. 9517–9526. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9517–9526 Mots-clés : Electrostatic potential Gas-solid fluidized Bed level Résumé : A theory on the electrostatic charge distribution in gas−solid fluidized beds was proposed. It consists of an interpretation of the causes of bipolar charging, the charging mechanisms in the fluidized bed, and the relationship between charge distribution and particle-size distribution in fluidized beds. Experiments were performed in a three-dimensional column gas−solid fluidized bed to measure the electrostatic charge distribution. It was found that the electric field inside the bed was nonuniform. If there was a distinct interface between the dilute and dense phases, the voltage polarity would reverse near the bed level, resulting in a Z-shaped axial profile of potential. The heights where voltage polarity reversal happened rose with the increase of gas velocity and static bed height. It was also found that the electrostatic voltage rose with increasing radial distances from the axis of the column. To sum up, the voltage at any axial cross section of the bed showed double saddles, with bed level as the interface. Accordingly, three special zones to be emphasized were identified: distributor, stagnant, and bed level zones, of which the latter two have high voltages and are more readily disturbed by particle/wall adhesion and even wall sheets. Based on the characteristics of axial profile of electrostatic potential in the fluidized bed, a new technique that could successfully predict bed level was developed. Good agreement was observed between visual measurements of bed level and predictions by the electrostatic method, with maximum relative error of 4.08% and mean relative error of 2.02%. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800805t

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Mass transfer rates from oscillating bubbles in bubble columns operating with viscous fluids / Mariano Martin in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9527–9536 Titre : Mass transfer rates from oscillating bubbles in bubble columns operating with viscous fluids Type de document : texte imprimé Auteurs : Mariano Martin, Auteur ; Francisco J. Montes, Auteur ; Miguel A. Galán, Auteur Année de publication : 2009 Article en page(s) : p. 9527–9536 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Transfer rates Bubble columns Viscous fluids Résumé : In spite of the work on bubble columns, their design and scale-up is still a difficult task due to the lack of understanding of bubble dispersions and mass transfer mechanisms. Even less known are viscous or non-Newtonian fluids. Therefore, a theoretical model for predicting the volumetric mass transfer coefficient, kLa, in bubble columns operating with viscous fluids has been proposed. The model consists of a population balance coupled with a theoretical equation for the Sherwood number for oscillating bubbles, considering the effect of liquid viscosity on both. Experimental results for Newtonian and non-Newtonian viscous liquids from the literature are used to validate the model. Bubble dispersions have been simulated with good agreement using the Weber critical number, Wec, as a parameter to account for the effect of liquid viscosity, which increases bubble stability. A correlation between the liquid viscosity and Wec has also been proposed. The mass transfer resistance is calculated taking into account the hydrodynamic processes involving bubbles (collisions, breakup, coalescence, detachment) because they provide initial oscillation amplitudes. However, bubble oscillation decays in viscous liquids because the oscillating energy is absorbed as viscous dissipation. Good agreement is found between the experimental and the predicted kLa when considering that bubble oscillations do not decay completely by viscous dissipation due to the continuous bubble collisions, breakup, and coalescence. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801077s [article] Mass transfer rates from oscillating bubbles in bubble columns operating with viscous fluids [texte imprimé] / Mariano Martin, Auteur ; Francisco J. Montes, Auteur ; Miguel A. Galán, Auteur . - 2009 . - p. 9527–9536. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9527–9536 Mots-clés : Transfer rates Bubble columns Viscous fluids Résumé : In spite of the work on bubble columns, their design and scale-up is still a difficult task due to the lack of understanding of bubble dispersions and mass transfer mechanisms. Even less known are viscous or non-Newtonian fluids. Therefore, a theoretical model for predicting the volumetric mass transfer coefficient, kLa, in bubble columns operating with viscous fluids has been proposed. The model consists of a population balance coupled with a theoretical equation for the Sherwood number for oscillating bubbles, considering the effect of liquid viscosity on both. Experimental results for Newtonian and non-Newtonian viscous liquids from the literature are used to validate the model. Bubble dispersions have been simulated with good agreement using the Weber critical number, Wec, as a parameter to account for the effect of liquid viscosity, which increases bubble stability. A correlation between the liquid viscosity and Wec has also been proposed. The mass transfer resistance is calculated taking into account the hydrodynamic processes involving bubbles (collisions, breakup, coalescence, detachment) because they provide initial oscillation amplitudes. However, bubble oscillation decays in viscous liquids because the oscillating energy is absorbed as viscous dissipation. Good agreement is found between the experimental and the predicted kLa when considering that bubble oscillations do not decay completely by viscous dissipation due to the continuous bubble collisions, breakup, and coalescence. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801077s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Parametric study of the CaO-Ca12Al14O33 synthesis with respect to high CO2 sorption capacity and stability on multicycle operation / Christina S. Martavaltzi in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9537–9543 Titre : Parametric study of the CaO-Ca12Al14O33 synthesis with respect to high CO2 sorption capacity and stability on multicycle operation Type de document : texte imprimé Auteurs : Christina S. Martavaltzi, Auteur ; Angeliki A. Lemonidou, Auteur Année de publication : 2009 Article en page(s) : p. 9537–9543 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Parametric study CaO−  Ca12Al14O33 CO2 Sorption capacity Résumé : This study focuses on the effect of various parameters of the synthesis procedure of the CO2 sorbent—CaO−Ca12Al14O33 derived from calcium acetate—on the CO2 sorption ability and lifetime. The synthesis procedure consists of the calcination of the acetate CaO precursor (step 1), the precipitation of the CaO with aluminum nitrates (step 2), followed by calcination at 500 °C for nitrates removal (step 3) and the calcination at 900 °C for the synthesis of Ca12Al14O33 (step 4). It has been shown, by employing TGA, that the applied difference in the calcination conditions (900 °C/2 h, 850 °C/1 h, 750 °C/0.5 h,) for the decomposition of the CaO acetate precursor (step 1) is not adequate to affect the sorption fixation and stability results. On the other hand calcination history of the precipitate and the addition of water in between the two calcination steps (nitrates removal and Ca12Al14O33 synthesis reaction) are of high importance for ensuring sorption capacities higher than 6.5 mol CO2/kg of sorbent in the first cycle. SEM observations showed that the addition of water after calcination at 500 °C (step 3) accounts for the generation of the regular hexagonal crystalloids of Ca(OH)2 which transforms in a porous network during calcination at 900 °C. It was also demonstrated that the quantity of CO2 molecules retained increases with decreasing aging time of the precipitate as a result of higher surface area (smaller crystal size) of the as-synthesized samples. The sorbent with the lower binder content (CaO/Ca12Al14O33 = 85:15) showed the prospective higher capacity (45% weight increase) in the first cycle but also a fair stability on repetitive sorption−desorption cycles. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800882d [article] Parametric study of the CaO-Ca12Al14O33 synthesis with respect to high CO2 sorption capacity and stability on multicycle operation [texte imprimé] / Christina S. Martavaltzi, Auteur ; Angeliki A. Lemonidou, Auteur . - 2009 . - p. 9537–9543. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9537–9543 Mots-clés : Parametric study CaO−  Ca12Al14O33 CO2 Sorption capacity Résumé : This study focuses on the effect of various parameters of the synthesis procedure of the CO2 sorbent—CaO−Ca12Al14O33 derived from calcium acetate—on the CO2 sorption ability and lifetime. The synthesis procedure consists of the calcination of the acetate CaO precursor (step 1), the precipitation of the CaO with aluminum nitrates (step 2), followed by calcination at 500 °C for nitrates removal (step 3) and the calcination at 900 °C for the synthesis of Ca12Al14O33 (step 4). It has been shown, by employing TGA, that the applied difference in the calcination conditions (900 °C/2 h, 850 °C/1 h, 750 °C/0.5 h,) for the decomposition of the CaO acetate precursor (step 1) is not adequate to affect the sorption fixation and stability results. On the other hand calcination history of the precipitate and the addition of water in between the two calcination steps (nitrates removal and Ca12Al14O33 synthesis reaction) are of high importance for ensuring sorption capacities higher than 6.5 mol CO2/kg of sorbent in the first cycle. SEM observations showed that the addition of water after calcination at 500 °C (step 3) accounts for the generation of the regular hexagonal crystalloids of Ca(OH)2 which transforms in a porous network during calcination at 900 °C. It was also demonstrated that the quantity of CO2 molecules retained increases with decreasing aging time of the precipitate as a result of higher surface area (smaller crystal size) of the as-synthesized samples. The sorbent with the lower binder content (CaO/Ca12Al14O33 = 85:15) showed the prospective higher capacity (45% weight increase) in the first cycle but also a fair stability on repetitive sorption−desorption cycles. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800882d

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Recovery of petroleum ether from solanesol extracting solution through vacuum hydrophilic membrane distillation / Xin Y. Qu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9544–9551 Titre : Recovery of petroleum ether from solanesol extracting solution through vacuum hydrophilic membrane distillation Type de document : texte imprimé Auteurs : Xin Y. Qu, Auteur ; Lin Zhang, Auteur ; De S. Tang, Auteur Année de publication : 2009 Article en page(s) : p. 9544–9551 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Recovery of petroleum ether Solanesol Membrane distillation Résumé : The objective of this work is to study the feasibility of vacuum membrane distillation (VMD) by hydrophilic membranes to recover petroleum ether from the extracting solution of solanesol. Being different from the traditional membrane distillation (MD) process, hydrophilic membranes were used to avoid the membrane wetting for the nonaqueous solutions. The VMD performances of polyvinylidene fluoride (PVDF) membrane and two kinds of polyacrylonitrile (PAN) membranes with different structures were compared in the process of recovering petroleum ether. The results showed that good solvent flux (>15 kg/m2 h) and solanesol rejection (>98%) for the PAN membranes were obtained, indicating that PAN membranes had considerable potential use in this area, while the PVDF membrane was not appropriate for the nonaqueous solution system because of membrane wetting. The effects of operation conditions on VMD performances of the two PAN membranes were investigated, and it was found that high-feed temperatures, low-downstream pressures enhanced the permeate flux for both membranes, and the flux of PAN1 membrane decreased more obviously than that of PAN2 membrane under high-feed concentration because of its larger pore size. General models including Knudsen and viscous flows were proposed, and a good agreement between the experimental and the theoretical fluxes was obtained. Additionally, temperature and concentration polarizations were proved to have an obvious influence on mass transport of PAN1 membrane. It was advisable to work at the downstream pressure of 20 kPa, the feed temperature of 30 °C, and the feed flow rate of 27.5 mL/s to obtain favorable results for PAN2 membrane. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071499%2B [article] Recovery of petroleum ether from solanesol extracting solution through vacuum hydrophilic membrane distillation [texte imprimé] / Xin Y. Qu, Auteur ; Lin Zhang, Auteur ; De S. Tang, Auteur . - 2009 . - p. 9544–9551. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9544–9551 Mots-clés : Recovery of petroleum ether Solanesol Membrane distillation Résumé : The objective of this work is to study the feasibility of vacuum membrane distillation (VMD) by hydrophilic membranes to recover petroleum ether from the extracting solution of solanesol. Being different from the traditional membrane distillation (MD) process, hydrophilic membranes were used to avoid the membrane wetting for the nonaqueous solutions. The VMD performances of polyvinylidene fluoride (PVDF) membrane and two kinds of polyacrylonitrile (PAN) membranes with different structures were compared in the process of recovering petroleum ether. The results showed that good solvent flux (>15 kg/m2 h) and solanesol rejection (>98%) for the PAN membranes were obtained, indicating that PAN membranes had considerable potential use in this area, while the PVDF membrane was not appropriate for the nonaqueous solution system because of membrane wetting. The effects of operation conditions on VMD performances of the two PAN membranes were investigated, and it was found that high-feed temperatures, low-downstream pressures enhanced the permeate flux for both membranes, and the flux of PAN1 membrane decreased more obviously than that of PAN2 membrane under high-feed concentration because of its larger pore size. General models including Knudsen and viscous flows were proposed, and a good agreement between the experimental and the theoretical fluxes was obtained. Additionally, temperature and concentration polarizations were proved to have an obvious influence on mass transport of PAN1 membrane. It was advisable to work at the downstream pressure of 20 kPa, the feed temperature of 30 °C, and the feed flow rate of 27.5 mL/s to obtain favorable results for PAN2 membrane. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071499%2B

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Ammonium removal from municipal landfill leachate by clinoptilolite bed columns / D. Karadag in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9552–9557 Titre : Ammonium removal from municipal landfill leachate by clinoptilolite bed columns : breakthrough modeling and error analysis Type de document : texte imprimé Auteurs : D. Karadag, Auteur ; E. Akkaya, Auteur ; A. Demir, Auteur Année de publication : 2009 Article en page(s) : p. 9552–9557 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Ammonium removal Landfill leachate Breakthrough modeling Résumé : In this study, a clinoptilolite bed column system was used to remove ammonium from municipal landfill leachate. Laboratory-scale column experiments were conducted in upflow fixed-bed and fluidized-bed modes with different ammonium concentrations. Ammonium removal was managed mainly by Ca2+ and K+ cations of clinoptilolite, and higher treatment performances were obtained at lower flow rates. On the other hand, higher effluent volumes and removal rates were produced by lower ammonium concentrations, and increased expansion ratios in the fluidized-bed column reduced the treatment efficiency. The sum of normalized errors (SNE) procedure was applied using five different error functions to model the experimental data. The Clark and Yoon−Nelson kinetic models were applied to column data to predict the breakthrough data, and the results indicated that the Clark model is better for modeling the experimental data. Ammonia stripping was investigated as a pretreatment step to obtain lower ammonium concentrations in the effluent. With a 12-h aeration time at pH 12, the ammonium concentration of leachate was decreased from about 3000 to below 400 mg/L. These results indicate that combining ammonia stripping and an upflow fixed-bed system is feasible in reducing higher ammonium concentrations to satisfactory levels. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800434e [article] Ammonium removal from municipal landfill leachate by clinoptilolite bed columns : breakthrough modeling and error analysis [texte imprimé] / D. Karadag, Auteur ; E. Akkaya, Auteur ; A. Demir, Auteur . - 2009 . - p. 9552–9557. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9552–9557 Mots-clés : Ammonium removal Landfill leachate Breakthrough modeling Résumé : In this study, a clinoptilolite bed column system was used to remove ammonium from municipal landfill leachate. Laboratory-scale column experiments were conducted in upflow fixed-bed and fluidized-bed modes with different ammonium concentrations. Ammonium removal was managed mainly by Ca2+ and K+ cations of clinoptilolite, and higher treatment performances were obtained at lower flow rates. On the other hand, higher effluent volumes and removal rates were produced by lower ammonium concentrations, and increased expansion ratios in the fluidized-bed column reduced the treatment efficiency. The sum of normalized errors (SNE) procedure was applied using five different error functions to model the experimental data. The Clark and Yoon−Nelson kinetic models were applied to column data to predict the breakthrough data, and the results indicated that the Clark model is better for modeling the experimental data. Ammonia stripping was investigated as a pretreatment step to obtain lower ammonium concentrations in the effluent. With a 12-h aeration time at pH 12, the ammonium concentration of leachate was decreased from about 3000 to below 400 mg/L. These results indicate that combining ammonia stripping and an upflow fixed-bed system is feasible in reducing higher ammonium concentrations to satisfactory levels. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800434e

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Adsorption and competitive adsorption on zeolites of nitrophenol compounds present in wastewater / Bachar Koubaissy in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9558–9565 Titre : Adsorption and competitive adsorption on zeolites of nitrophenol compounds present in wastewater Type de document : texte imprimé Auteurs : Bachar Koubaissy, Auteur ; Guy Joly, Auteur ; Patrick Magnoux, Auteur Année de publication : 2009 Article en page(s) : p. 9558–9565 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Competitive adsorption Zeolites Nitrophenol compounds Résumé : This work investigates the removal of various nitrophenolic compounds (ortho-nitrophenol (ONP), para-nitrophenol (PNP), meta-nitrophenol (MNP), and 2,4-dinitrophenol (2,4-DNP)) from aqueous solution using hydrophobic FAU zeolites. The adsorption equilibrium of nitrophenols from aqueous solutions by FAU can be well-described using the Fowler−Guggenheim equation. The relative affinity of nitrophenols toward the FAU is dependent on the pH solution and on the pollutant solubility in water. Their sorption capacity is in the following order: ONP > 2.4-DNP > PNP > MNP. In binary mixtures, the most important parameter that governs the adsorption in zeolites seems to be the solubility of pollutants in water. Thus, the less-soluble compound (in this case, ONP) was adsorbed more easily than the other components present in the binary mixture. Finally, hydrophobic FAU zeolite seems to be an efficient adsorbent; it is able to be easily regenerated under air or by solvent leaching, through retention of these initial adsorption properties. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001777 [article] Adsorption and competitive adsorption on zeolites of nitrophenol compounds present in wastewater [texte imprimé] / Bachar Koubaissy, Auteur ; Guy Joly, Auteur ; Patrick Magnoux, Auteur . - 2009 . - p. 9558–9565. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9558–9565 Mots-clés : Competitive adsorption Zeolites Nitrophenol compounds Résumé : This work investigates the removal of various nitrophenolic compounds (ortho-nitrophenol (ONP), para-nitrophenol (PNP), meta-nitrophenol (MNP), and 2,4-dinitrophenol (2,4-DNP)) from aqueous solution using hydrophobic FAU zeolites. The adsorption equilibrium of nitrophenols from aqueous solutions by FAU can be well-described using the Fowler−Guggenheim equation. The relative affinity of nitrophenols toward the FAU is dependent on the pH solution and on the pollutant solubility in water. Their sorption capacity is in the following order: ONP > 2.4-DNP > PNP > MNP. In binary mixtures, the most important parameter that governs the adsorption in zeolites seems to be the solubility of pollutants in water. Thus, the less-soluble compound (in this case, ONP) was adsorbed more easily than the other components present in the binary mixture. Finally, hydrophobic FAU zeolite seems to be an efficient adsorbent; it is able to be easily regenerated under air or by solvent leaching, through retention of these initial adsorption properties. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001777

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Preparation and evaluation of cellulose adsorbents for hydrophobic charge induction chromatography / Hai-Feng Xia in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9566–9572 Titre : Preparation and evaluation of cellulose adsorbents for hydrophobic charge induction chromatography Type de document : texte imprimé Auteurs : Hai-Feng Xia, Auteur ; Dong-Qiang Lin, Auteur ; Li-Ping Wang, Auteur Année de publication : 2009 Article en page(s) : p. 9566–9572 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Evaluation of cellulose adsorbents Charge induction chromatography Résumé : Hydrophobic charge induction chromatography (HCIC) has been proven to be an efficient technique for antibody purification. Several HCIC adsorbents were prepared with macroporous cellulose−tungsten carbide composite beads (Cell-TuC) as the matrix. First, the cellulose beads were activated by allyl bromide (AB) or divinyl sulfone (DVS), and then they were coupled with three types of mercaptoheterocyclic groups—4-mercapto-ethyl-pyridine hydrochloride (MEP), 2-mercapto-1-methyl-imidazole (MMI), and 2-mercapto-benzimidazole (MBI)—as the HCIC ligands. Four types of HCIC adsorbents were obtained, labeled Cell-TuC-AB-MEP, Cell-TuC-DVS-MEP, Cell-TuC-DVS-MMI, and Cell-TuC-DVS-MBI. The activation and coupling conditions were optimized for high ligand density. The isotherm adsorption of immunoglobulin of egg yolk (IgY) on four HCIC adsorbents were investigated. High adsorption capacities of IgY could be obtained for all four adsorbents at pH 7, and low adsorption of IgY at pH 4 and of bovine serum albumin (BSA) at pH 7 was observed, which indicates that the HCIC adsorbents prepared have a potential application for antibody purification. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800662r [article] Preparation and evaluation of cellulose adsorbents for hydrophobic charge induction chromatography [texte imprimé] / Hai-Feng Xia, Auteur ; Dong-Qiang Lin, Auteur ; Li-Ping Wang, Auteur . - 2009 . - p. 9566–9572. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9566–9572 Mots-clés : Evaluation of cellulose adsorbents Charge induction chromatography Résumé : Hydrophobic charge induction chromatography (HCIC) has been proven to be an efficient technique for antibody purification. Several HCIC adsorbents were prepared with macroporous cellulose−tungsten carbide composite beads (Cell-TuC) as the matrix. First, the cellulose beads were activated by allyl bromide (AB) or divinyl sulfone (DVS), and then they were coupled with three types of mercaptoheterocyclic groups—4-mercapto-ethyl-pyridine hydrochloride (MEP), 2-mercapto-1-methyl-imidazole (MMI), and 2-mercapto-benzimidazole (MBI)—as the HCIC ligands. Four types of HCIC adsorbents were obtained, labeled Cell-TuC-AB-MEP, Cell-TuC-DVS-MEP, Cell-TuC-DVS-MMI, and Cell-TuC-DVS-MBI. The activation and coupling conditions were optimized for high ligand density. The isotherm adsorption of immunoglobulin of egg yolk (IgY) on four HCIC adsorbents were investigated. High adsorption capacities of IgY could be obtained for all four adsorbents at pH 7, and low adsorption of IgY at pH 4 and of bovine serum albumin (BSA) at pH 7 was observed, which indicates that the HCIC adsorbents prepared have a potential application for antibody purification. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800662r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Recovery of lemon essential oil, lemon wax, and diatomaceous earth from the filter cake of the lemon essential oil dewaxing process at pilot-plant scale / Carlos A. Correa in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9573–9580 Titre : Recovery of lemon essential oil, lemon wax, and diatomaceous earth from the filter cake of the lemon essential oil dewaxing process at pilot-plant scale Type de document : texte imprimé Auteurs : Carlos A. Correa, Auteur ; Mónica B. Gramajo de Doz, Auteur ; Carlos M. Bonatti, Auteur Année de publication : 2009 Article en page(s) : p. 9573–9580 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Essential oil, lemon wax Résumé : A pilot-plant scale unit suitable for recovery of lemon essential oil, lemon wax, and diatomaceous earth that exists in the waste filter cake arising from the dewaxing process of the cold-pressed lemon essential oil has been developed for batch operation, using a steam stripping process. It includes steam-distillation of the essential oil contained in the filter cake followed by its liquid−liquid separation from water, cooling and decantation of the nonvolatile residue that remains inside the stripper, and manual separation of lemon wax and diatomaceous earth. Mass and energy balances of the process were also made, which allow for the calculation of the time to exhaust the oil and the consumed vapor required to extract one kilogram of essential oil. The experimental results show that this process is suitable for the separation of these “three components” of the filter cake at pilot-plant scale, minimizing the environment contamination. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie7017355 [article] Recovery of lemon essential oil, lemon wax, and diatomaceous earth from the filter cake of the lemon essential oil dewaxing process at pilot-plant scale [texte imprimé] / Carlos A. Correa, Auteur ; Mónica B. Gramajo de Doz, Auteur ; Carlos M. Bonatti, Auteur . - 2009 . - p. 9573–9580. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9573–9580 Mots-clés : Essential oil, lemon wax Résumé : A pilot-plant scale unit suitable for recovery of lemon essential oil, lemon wax, and diatomaceous earth that exists in the waste filter cake arising from the dewaxing process of the cold-pressed lemon essential oil has been developed for batch operation, using a steam stripping process. It includes steam-distillation of the essential oil contained in the filter cake followed by its liquid−liquid separation from water, cooling and decantation of the nonvolatile residue that remains inside the stripper, and manual separation of lemon wax and diatomaceous earth. Mass and energy balances of the process were also made, which allow for the calculation of the time to exhaust the oil and the consumed vapor required to extract one kilogram of essential oil. The experimental results show that this process is suitable for the separation of these “three components” of the filter cake at pilot-plant scale, minimizing the environment contamination. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie7017355

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

A novel reactive distillation process for the indirect hydration of cyclohexene to cyclohexanol using a reactive entrainer / Frank Steyer in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9581–9587 Titre : A novel reactive distillation process for the indirect hydration of cyclohexene to cyclohexanol using a reactive entrainer Type de document : texte imprimé Auteurs : Frank Steyer, Auteur ; Hannsjorg Freund, Auteur ; Kai Sundmacher, Auteur Année de publication : 2009 Article en page(s) : p. 9581–9587 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Reactive distillation Cyclohexene Cyclohexanol Résumé : In the conventional process for cyclohexanol production, large amounts of energy are consumed and a considerable quantity of side products is formed. In addition, the process is inherently unsafe. The alternative process of cyclohexene direct hydration requires large amounts of catalyst to overcome kinetic limitations. This publication shows the feasibility of a new route from cyclohexene to cyclohexanol by means of reactive distillation using formic acid as a reactive entrainer. This allows overcoming kinetic limitations with moderate amounts of catalyst and makes large-scale cyclohexanol production by reactive distillation an interesting alternative. The suggested coupled reactive distillation process allows producing cyclohexanol in an inherently safe and energetically advantageous way without incurring significant amounts of side products. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800303k [article] A novel reactive distillation process for the indirect hydration of cyclohexene to cyclohexanol using a reactive entrainer [texte imprimé] / Frank Steyer, Auteur ; Hannsjorg Freund, Auteur ; Kai Sundmacher, Auteur . - 2009 . - p. 9581–9587. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9581–9587 Mots-clés : Reactive distillation Cyclohexene Cyclohexanol Résumé : In the conventional process for cyclohexanol production, large amounts of energy are consumed and a considerable quantity of side products is formed. In addition, the process is inherently unsafe. The alternative process of cyclohexene direct hydration requires large amounts of catalyst to overcome kinetic limitations. This publication shows the feasibility of a new route from cyclohexene to cyclohexanol by means of reactive distillation using formic acid as a reactive entrainer. This allows overcoming kinetic limitations with moderate amounts of catalyst and makes large-scale cyclohexanol production by reactive distillation an interesting alternative. The suggested coupled reactive distillation process allows producing cyclohexanol in an inherently safe and energetically advantageous way without incurring significant amounts of side products. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800303k

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Synthesis and characterization of Mg-Al-CO3 layered double hydroxide for CO2 adsorption / Ulka Sharma in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9588–9595 Titre : Synthesis and characterization of Mg-Al-CO3 layered double hydroxide for CO2 adsorption Type de document : texte imprimé Auteurs : Ulka Sharma, Auteur ; Beena Tyagi, Auteur ; Raksh V. Jasra, Auteur Année de publication : 2009 Article en page(s) : p. 9588–9595 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Characterization of Mg−  Al−  CO3 Hydroxide for CO2 Résumé : A series of Mg−Al−CO3 layered double hydroxide (LDH) samples have been synthesized by conventional precipitation and coprecipitation methods. The effect of various synthetic parameters, such as cation molar ratio, mode of addition of magnesium and aluminum precursors, addition temperature, agitation, and drying conditions, on the structural, textural, and thermal behavior of the samples has been studied. These properties were correlated with the CO2 adsorption capacity of the samples. The Mg−Al−CO3 LDH sample prepared with optimized synthetic parameters has shown the higher CO2 adsorption capacity (22 cm3/g). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800365t [article] Synthesis and characterization of Mg-Al-CO3 layered double hydroxide for CO2 adsorption [texte imprimé] / Ulka Sharma, Auteur ; Beena Tyagi, Auteur ; Raksh V. Jasra, Auteur . - 2009 . - p. 9588–9595. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9588–9595 Mots-clés : Characterization of Mg−  Al−  CO3 Hydroxide for CO2 Résumé : A series of Mg−Al−CO3 layered double hydroxide (LDH) samples have been synthesized by conventional precipitation and coprecipitation methods. The effect of various synthetic parameters, such as cation molar ratio, mode of addition of magnesium and aluminum precursors, addition temperature, agitation, and drying conditions, on the structural, textural, and thermal behavior of the samples has been studied. These properties were correlated with the CO2 adsorption capacity of the samples. The Mg−Al−CO3 LDH sample prepared with optimized synthetic parameters has shown the higher CO2 adsorption capacity (22 cm3/g). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800365t

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Modeling of the phase equilibrium for aqueous solutions of brij 58 surfactant and three salts / Masumeh Foroutan in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9596–9600 Titre : Modeling of the phase equilibrium for aqueous solutions of brij 58 surfactant and three salts Type de document : texte imprimé Auteurs : Masumeh Foroutan, Auteur ; Maryam Mohammadlou, Auteur Année de publication : 2009 Article en page(s) : p. 9596–9600 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Equilibrium Three salts Résumé : The osmotic virial model and the Flory−Huggins model, with the Debye−Huckel equation as an electrostatic term, have been used to correlate the liquid−liquid equilibrium data for an aqueous solution of polyoxyethylene cetyl ether surfactant (abbreviated as Brij 58) and three inorganic salts (containing NH4H2PO4, (NH4)2HPO4, and Brij58−KH2PO4) at 298.15 K. The results have shown that the maximum absolute deviation from experimental data is less than 0.6% and 1.4% for the osmotic virial model and the Flory−Huggins theory, respectively. These models are in good agreement with experimental data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800467y [article] Modeling of the phase equilibrium for aqueous solutions of brij 58 surfactant and three salts [texte imprimé] / Masumeh Foroutan, Auteur ; Maryam Mohammadlou, Auteur . - 2009 . - p. 9596–9600. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9596–9600 Mots-clés : Equilibrium Three salts Résumé : The osmotic virial model and the Flory−Huggins model, with the Debye−Huckel equation as an electrostatic term, have been used to correlate the liquid−liquid equilibrium data for an aqueous solution of polyoxyethylene cetyl ether surfactant (abbreviated as Brij 58) and three inorganic salts (containing NH4H2PO4, (NH4)2HPO4, and Brij58−KH2PO4) at 298.15 K. The results have shown that the maximum absolute deviation from experimental data is less than 0.6% and 1.4% for the osmotic virial model and the Flory−Huggins theory, respectively. These models are in good agreement with experimental data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800467y

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Optimized design of recycle chromatography for separation of a single component from a ternary mixture / Ju Weon Lee in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9601–9610 Titre : Optimized design of recycle chromatography for separation of a single component from a ternary mixture Type de document : texte imprimé Auteurs : Ju Weon Lee, Auteur ; Phillip C. Wankat, Auteur Année de publication : 2009 Article en page(s) : p. 9601–9610 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Optimized design Chromatography Ternary mixture Résumé : Recycle chromatographic systems were designed to isolate one component from a ternary mixture. Since the concentrations of the dilute ternary mixtures studied (phenols, amino acids, and benzenes) were all in the linear range of isotherms, the Lapidus−Amundson equation was used to predict the broadening of elution bands caused by axial dispersion and mass-transfer resistance. Optimum operating conditions were designed to isolate the target solutes with over 99% purity and yield. Compared to complete ternary separation, recycle chromatography for separation of a single component required significantly less solvent and had higher productivity. For the amino acid system the optimum column length and mobile-phase velocity which had maximum productivity were determined with different sizes of adsorbent particle. When large particles were used, longer columns and faster mobile-phase velocities were needed to obtain maximum productivity as compared with small particle sizes. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800583p [article] Optimized design of recycle chromatography for separation of a single component from a ternary mixture [texte imprimé] / Ju Weon Lee, Auteur ; Phillip C. Wankat, Auteur . - 2009 . - p. 9601–9610. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9601–9610 Mots-clés : Optimized design Chromatography Ternary mixture Résumé : Recycle chromatographic systems were designed to isolate one component from a ternary mixture. Since the concentrations of the dilute ternary mixtures studied (phenols, amino acids, and benzenes) were all in the linear range of isotherms, the Lapidus−Amundson equation was used to predict the broadening of elution bands caused by axial dispersion and mass-transfer resistance. Optimum operating conditions were designed to isolate the target solutes with over 99% purity and yield. Compared to complete ternary separation, recycle chromatography for separation of a single component required significantly less solvent and had higher productivity. For the amino acid system the optimum column length and mobile-phase velocity which had maximum productivity were determined with different sizes of adsorbent particle. When large particles were used, longer columns and faster mobile-phase velocities were needed to obtain maximum productivity as compared with small particle sizes. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800583p

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Adsorbate-induced expansion of silicalite-1 crystals / Stephanie G. Sorenson in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9611–9616 Titre : Adsorbate-induced expansion of silicalite-1 crystals Type de document : texte imprimé Auteurs : Stephanie G. Sorenson, Auteur ; Joseph R. Smyth, Auteur ; Milan Kocirik, Auteur Année de publication : 2009 Article en page(s) : p. 9611–9616 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Induced expansion Silicalite-1 crystals Résumé : Optical microscopy and XRD measurements show that silicalite-1 crystals expand when C4−C8 alkanes and i-butane adsorb in the MFI structure at room temperature. The c-direction linear expansion was 0.20−0.45%, and was measured with XRD and optical microscopy for 200 μm crystals. n-Pentane, n-hexane, and n-heptane had the maximum linear expansion of approximately 0.54% in the b-direction, and n-hexane and n-heptane had the maximum volume expansion of 1.2%. In contrast, benzene did not cause a significant change in the unit cell volume. The a-direction expanded least for the molecules studied except i-butane. n-Hexane expanded the silicalite-1 crystal more at 180 K than at room temperature. Crystal expansion due to n-alkane adsorption decreased the size of defects in a polycrystalline MFI membrane, and changes in the fluxes of i-octane through defects were measured by transient permeation. Loadings as low as 0.5 molecule/unit cell decreased the flux through defects at 358−473 K, but benzene had no effect. Higher loadings increased crystal expansion and decreased the defect size more. Crystal expansion was reversible. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800630g [article] Adsorbate-induced expansion of silicalite-1 crystals [texte imprimé] / Stephanie G. Sorenson, Auteur ; Joseph R. Smyth, Auteur ; Milan Kocirik, Auteur . - 2009 . - p. 9611–9616. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9611–9616 Mots-clés : Induced expansion Silicalite-1 crystals Résumé : Optical microscopy and XRD measurements show that silicalite-1 crystals expand when C4−C8 alkanes and i-butane adsorb in the MFI structure at room temperature. The c-direction linear expansion was 0.20−0.45%, and was measured with XRD and optical microscopy for 200 μm crystals. n-Pentane, n-hexane, and n-heptane had the maximum linear expansion of approximately 0.54% in the b-direction, and n-hexane and n-heptane had the maximum volume expansion of 1.2%. In contrast, benzene did not cause a significant change in the unit cell volume. The a-direction expanded least for the molecules studied except i-butane. n-Hexane expanded the silicalite-1 crystal more at 180 K than at room temperature. Crystal expansion due to n-alkane adsorption decreased the size of defects in a polycrystalline MFI membrane, and changes in the fluxes of i-octane through defects were measured by transient permeation. Loadings as low as 0.5 molecule/unit cell decreased the flux through defects at 358−473 K, but benzene had no effect. Higher loadings increased crystal expansion and decreased the defect size more. Crystal expansion was reversible. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800630g

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Deep desulfurization of diesel feedstock by selective adsorption of refractory sulfur compounds / Alain Favre-Reguillon in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9617–9622 Titre : Deep desulfurization of diesel feedstock by selective adsorption of refractory sulfur compounds Type de document : texte imprimé Auteurs : Alain Favre-Reguillon, Auteur ; Marc Sévignon, Auteur ; Muriel Rocault, Auteur Année de publication : 2009 Article en page(s) : p. 9617–9622 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Deep desulfurization Diesel feedstock Refractory sulfur compounds Résumé : Adsorptive desulfurization was studied using straight-run gas oil (SRGO) with various sulfur contents (390 and 60 ppm S). Immobilization of electron-poor molecules (π-acceptors) on macroporous resins was achieved in three steps starting from commercially available poly(styrene-co-divinylbenzene) beads. Influence of the temperature on adsorption was studied, and the process was examined on the basis of breakthrough curves. The regeneration of the support was studied using fixed-bed technology and was efficiently performed with toluene as the solvent. The extracted compounds were easily recovered after evaporation of the toluene and the affinity of the resins toward alkyldibenzothiophenes was confirmed by GC-FPD analysis. On the basis of these preliminary experimental results, a new concept is proposed for ultradeep desulfurization of SRGO. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801065z [article] Deep desulfurization of diesel feedstock by selective adsorption of refractory sulfur compounds [texte imprimé] / Alain Favre-Reguillon, Auteur ; Marc Sévignon, Auteur ; Muriel Rocault, Auteur . - 2009 . - p. 9617–9622. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9617–9622 Mots-clés : Deep desulfurization Diesel feedstock Refractory sulfur compounds Résumé : Adsorptive desulfurization was studied using straight-run gas oil (SRGO) with various sulfur contents (390 and 60 ppm S). Immobilization of electron-poor molecules (π-acceptors) on macroporous resins was achieved in three steps starting from commercially available poly(styrene-co-divinylbenzene) beads. Influence of the temperature on adsorption was studied, and the process was examined on the basis of breakthrough curves. The regeneration of the support was studied using fixed-bed technology and was efficiently performed with toluene as the solvent. The extracted compounds were easily recovered after evaporation of the toluene and the affinity of the resins toward alkyldibenzothiophenes was confirmed by GC-FPD analysis. On the basis of these preliminary experimental results, a new concept is proposed for ultradeep desulfurization of SRGO. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801065z

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Engineering pharmaceutical fine particles of budesonide for dry powder inhalation (DPI) / Ting-Ting Hu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9623–9627 Titre : Engineering pharmaceutical fine particles of budesonide for dry powder inhalation (DPI) Type de document : texte imprimé Auteurs : Ting-Ting Hu, Auteur ; Hong Zhao, Auteur ; Li-Chuan Jiang, Auteur Année de publication : 2009 Article en page(s) : p. 9623–9627 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Engineering pharmaceutical Fine particles Dry powder Résumé : Budesonide, as one of the inhaled glucocorticosteroids, is widely used in the treatment of asthma by pulmonary delivery. The purpose of this study was to prepare ultra-fine budesonide particles by antisolvent precipitation for dry powder inhalation. Both methanol and acetone were used to make the budesonide solution, and water was chosen as the antisolvent to induce precipitation. Hydroxypropyl cellulose and tyloxapol were added as the stabilizers. The results revealed that crystals of rectangular shape could be obtained from an acetone−water system while elliptic particles were obtained from a methanol−water system. They both had a flaky morphology, no more than 5 µm in length and 300 nm in thickness, and were formed into agglomerates. When the stabilizers were present, uniform spindle or ellipsoidal particles less than 5 µm in diameter could be prepared. All the prepared particles had the same crystalline structure as the commercial budesonide product, as assessed by X-ray diffraction. In vitro evaluation with an Aerolizer inhaler and a multistage liquid impinger (MSLI) showed that the flaky particles had better aerosol performance, because they both achieved a FPFemitted value of over 69%. However, the spindle or ellipsoidal particles had poor dispersibility, because of FPFemitted values of 23 ± 2% and 26 ± 3%, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0715052 [article] Engineering pharmaceutical fine particles of budesonide for dry powder inhalation (DPI) [texte imprimé] / Ting-Ting Hu, Auteur ; Hong Zhao, Auteur ; Li-Chuan Jiang, Auteur . - 2009 . - p. 9623–9627. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9623–9627 Mots-clés : Engineering pharmaceutical Fine particles Dry powder Résumé : Budesonide, as one of the inhaled glucocorticosteroids, is widely used in the treatment of asthma by pulmonary delivery. The purpose of this study was to prepare ultra-fine budesonide particles by antisolvent precipitation for dry powder inhalation. Both methanol and acetone were used to make the budesonide solution, and water was chosen as the antisolvent to induce precipitation. Hydroxypropyl cellulose and tyloxapol were added as the stabilizers. The results revealed that crystals of rectangular shape could be obtained from an acetone−water system while elliptic particles were obtained from a methanol−water system. They both had a flaky morphology, no more than 5 µm in length and 300 nm in thickness, and were formed into agglomerates. When the stabilizers were present, uniform spindle or ellipsoidal particles less than 5 µm in diameter could be prepared. All the prepared particles had the same crystalline structure as the commercial budesonide product, as assessed by X-ray diffraction. In vitro evaluation with an Aerolizer inhaler and a multistage liquid impinger (MSLI) showed that the flaky particles had better aerosol performance, because they both achieved a FPFemitted value of over 69%. However, the spindle or ellipsoidal particles had poor dispersibility, because of FPFemitted values of 23 ± 2% and 26 ± 3%, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0715052

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Asymmetric Aldol Addition by oligopeptide immobilized on magnetic particles through an lonic liquids spacer / Yangyang Jiang in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9628–9635 Titre : Asymmetric Aldol Addition by oligopeptide immobilized on magnetic particles through an lonic liquids spacer Type de document : texte imprimé Auteurs : Yangyang Jiang, Auteur ; Chen, Guo, Auteur ; Hansong Xia, Auteur Année de publication : 2009 Article en page(s) : p. 9628–9635 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Oligopeptide Magnetic particles Ionic liquids spacer Résumé : In this work, oligopeptide was covalently bonded on the surface of magnetic particles through an ionic liquids spacer. When ionic liquids containing bulky cations with strong H-bonding ability or having hydrophobic anions were used, the yield and enantioselectivity of aldol reaction were enhanced greatly. Introducing an ionic liquids spacer between the oligopeptide and magnetic resin decreased the minimum number of amino acids for optimizing the efficiency of aldol addition. Varying the amino acid sequence of the oligopeptide showed limited effect on the yield and enantioselectivity; however, introducing a series of lysine groups on the terminal of the oligopeptide, close to the imidazolium ring, would significantly increase the output. The magnetite-loaded oligopeptide had a broader substrate range for ketone donor but restricted the enantioselectivity of aldehyde acceptor than the free oligopeptide. The combinative unit served as a recyclable catalyst for aldol addition of ketone and aldehyde, and its catalytic efficiency and selectivity can be finely designed by the characteristics of each part of the catalyst. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0712131 [article] Asymmetric Aldol Addition by oligopeptide immobilized on magnetic particles through an lonic liquids spacer [texte imprimé] / Yangyang Jiang, Auteur ; Chen, Guo, Auteur ; Hansong Xia, Auteur . - 2009 . - p. 9628–9635. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9628–9635 Mots-clés : Oligopeptide Magnetic particles Ionic liquids spacer Résumé : In this work, oligopeptide was covalently bonded on the surface of magnetic particles through an ionic liquids spacer. When ionic liquids containing bulky cations with strong H-bonding ability or having hydrophobic anions were used, the yield and enantioselectivity of aldol reaction were enhanced greatly. Introducing an ionic liquids spacer between the oligopeptide and magnetic resin decreased the minimum number of amino acids for optimizing the efficiency of aldol addition. Varying the amino acid sequence of the oligopeptide showed limited effect on the yield and enantioselectivity; however, introducing a series of lysine groups on the terminal of the oligopeptide, close to the imidazolium ring, would significantly increase the output. The magnetite-loaded oligopeptide had a broader substrate range for ketone donor but restricted the enantioselectivity of aldehyde acceptor than the free oligopeptide. The combinative unit served as a recyclable catalyst for aldol addition of ketone and aldehyde, and its catalytic efficiency and selectivity can be finely designed by the characteristics of each part of the catalyst. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0712131

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

CO2 permeability of polystyrene nanocomposites and nanocomposite foams / Zhihua Guo in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9636–9643 Titre : CO2 permeability of polystyrene nanocomposites and nanocomposite foams Type de document : texte imprimé Auteurs : Zhihua Guo, Auteur ; L. James Lee, Auteur ; David L. Tomasko, Auteur Année de publication : 2009 Article en page(s) : p. 9636–9643 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : CO2 permeability Polystyrene Nanocomposite Résumé : Steady state permeability coefficients P of carbon dioxide (CO2) in polystyrene (PS) and PS nanocomposites and their corresponding foams at 0.10 MPa (gauge pressure) and three different temperatures were measured. Permeability coefficients of foams are about 1 order of magnitude higher than those of corresponding plates. Three PS nanocomposites were used: PS + 5% 20A (treated nanoclay provided by Southern Clay), PS + 5% CNFs (carbon nanofibers), and PS + 5% MHABS (nanoclay treated with 2-methacryloyloxyethylhexadecyldimethylammonium bromide). For both plates and foams, the permeability coefficient decreases considerably with addition of nanoparticles. Foam structure is shown to play a more important role than nanoparticles in determining the permeability coefficient values for nanocomposite foams. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8000088 [article] CO2 permeability of polystyrene nanocomposites and nanocomposite foams [texte imprimé] / Zhihua Guo, Auteur ; L. James Lee, Auteur ; David L. Tomasko, Auteur . - 2009 . - p. 9636–9643. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9636–9643 Mots-clés : CO2 permeability Polystyrene Nanocomposite Résumé : Steady state permeability coefficients P of carbon dioxide (CO2) in polystyrene (PS) and PS nanocomposites and their corresponding foams at 0.10 MPa (gauge pressure) and three different temperatures were measured. Permeability coefficients of foams are about 1 order of magnitude higher than those of corresponding plates. Three PS nanocomposites were used: PS + 5% 20A (treated nanoclay provided by Southern Clay), PS + 5% CNFs (carbon nanofibers), and PS + 5% MHABS (nanoclay treated with 2-methacryloyloxyethylhexadecyldimethylammonium bromide). For both plates and foams, the permeability coefficient decreases considerably with addition of nanoparticles. Foam structure is shown to play a more important role than nanoparticles in determining the permeability coefficient values for nanocomposite foams. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8000088

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Inactivation of bacteria in oil-field reinjection water by pulsed electric field (PEF) process / Qing Xin in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9644–9650 Titre : Inactivation of bacteria in oil-field reinjection water by pulsed electric field (PEF) process Type de document : texte imprimé Auteurs : Qing Xin, Auteur ; Xingwang Zhang, Auteur ; Lecheng Lei, Auteur Année de publication : 2009 Article en page(s) : p. 9644–9650 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Inactivation of bacteria Oil-Field Reinjection water Résumé : Microbial pollution commonly causes serious pipe corrosion in oil-field reinjection water systems. As an alternative and environmentally friendly inactivation technology, the pulsed electric field (PEF) process is employed to inactivate microorganisms in oil-field reinjection water. The effects on inactivation of process parameters including electric field strength, process temperature, initial bacteria concentration, and conductivity were investigated. The results showed that electric field intensity is the most important parameter in PEF inactivation. After a 20-min treatment, the inactivation efficiency was a 2.8 log reduction for saprophytic bacteria, a 3.6 log reduction for iron bacteria, and a 3.9 log reduction for sulfate-reducing bacteria. Transmission electron microscopy observations of the bacteria confirmed that PEF technology can lead to severe surface damage and rupture to the cells. Moreover, a possible mechanism of inactivation is discussed and used to explain the influence of process parameters on PEF treatment. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8000524 [article] Inactivation of bacteria in oil-field reinjection water by pulsed electric field (PEF) process [texte imprimé] / Qing Xin, Auteur ; Xingwang Zhang, Auteur ; Lecheng Lei, Auteur . - 2009 . - p. 9644–9650. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9644–9650 Mots-clés : Inactivation of bacteria Oil-Field Reinjection water Résumé : Microbial pollution commonly causes serious pipe corrosion in oil-field reinjection water systems. As an alternative and environmentally friendly inactivation technology, the pulsed electric field (PEF) process is employed to inactivate microorganisms in oil-field reinjection water. The effects on inactivation of process parameters including electric field strength, process temperature, initial bacteria concentration, and conductivity were investigated. The results showed that electric field intensity is the most important parameter in PEF inactivation. After a 20-min treatment, the inactivation efficiency was a 2.8 log reduction for saprophytic bacteria, a 3.6 log reduction for iron bacteria, and a 3.9 log reduction for sulfate-reducing bacteria. Transmission electron microscopy observations of the bacteria confirmed that PEF technology can lead to severe surface damage and rupture to the cells. Moreover, a possible mechanism of inactivation is discussed and used to explain the influence of process parameters on PEF treatment. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8000524

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Response surface methodology for optimization of lipase production by an immobilized newly isolated penicillium sp. / Elisangela Wolski ; Elisangele Menusi ; Marcio Mazutti in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9651–9657 Titre : Response surface methodology for optimization of lipase production by an immobilized newly isolated penicillium sp. Type de document : texte imprimé Auteurs : Elisangela Wolski, Auteur ; Elisangele Menusi, Auteur ; Marcio Mazutti, Auteur Année de publication : 2009 Article en page(s) : p. 9651–9657 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Surface methodology Lipase production Penicillium sp Résumé : This work reports the use of response surface methodology to optimize the lipase production by submerged fermentation using immobilized cells of a newly isolated Penicillium sp. For this, experimental designs were employed to evaluate the best condition for microorganism immobilization. The optimum experimental conditions for immobilized microorganisms were determined as 2.5% (w/v) of calcium alginate, 0.2% (w/v) of CaCl2, and 1.5% (v/v) of glutaraldehyde and 6 h of curing time, yielding a lipase activity as high as 20.96 U/mL in 120 h of fermentation. The activity obtained is higher than those observed with free cells of this microorganism and comparable to results presented in the literature for lipase production with immobilized cells from several microorganisms. The crude enzymatic extract presented optimum pH and temperature of 7.0 and 37 °C, respectively, and maintained its activity for 60 days storage at −10 °C. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800658j [article] Response surface methodology for optimization of lipase production by an immobilized newly isolated penicillium sp. [texte imprimé] / Elisangela Wolski, Auteur ; Elisangele Menusi, Auteur ; Marcio Mazutti, Auteur . - 2009 . - p. 9651–9657. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9651–9657 Mots-clés : Surface methodology Lipase production Penicillium sp Résumé : This work reports the use of response surface methodology to optimize the lipase production by submerged fermentation using immobilized cells of a newly isolated Penicillium sp. For this, experimental designs were employed to evaluate the best condition for microorganism immobilization. The optimum experimental conditions for immobilized microorganisms were determined as 2.5% (w/v) of calcium alginate, 0.2% (w/v) of CaCl2, and 1.5% (v/v) of glutaraldehyde and 6 h of curing time, yielding a lipase activity as high as 20.96 U/mL in 120 h of fermentation. The activity obtained is higher than those observed with free cells of this microorganism and comparable to results presented in the literature for lipase production with immobilized cells from several microorganisms. The crude enzymatic extract presented optimum pH and temperature of 7.0 and 37 °C, respectively, and maintained its activity for 60 days storage at −10 °C. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800658j

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Volume-explicit equation of state for fused hard sphere chain fluids / Saidu M. Waziri in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9658–9662 Titre : Volume-explicit equation of state for fused hard sphere chain fluids Type de document : texte imprimé Auteurs : Saidu M. Waziri, Auteur ; Esam Z. Hamad, Auteur Année de publication : 2009 Article en page(s) : p. 9658–9662 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Volume-explicit equation Chain fluids Résumé : An extension of a volume-explicit equation of state for chains of tangent hard spheres to chains of fused hard spheres and their mixtures is presented. The extension was achieved by the use of a simple relationship between number of segments and nonsphericity parameter. A comparison of compressibility factors calculated using the extended equation with corresponding simulation data for hard dumbbell systems at various elongations and for fused long chains molecules and their mixtures has shown that the extended equation is reasonably accurate. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800755s [article] Volume-explicit equation of state for fused hard sphere chain fluids [texte imprimé] / Saidu M. Waziri, Auteur ; Esam Z. Hamad, Auteur . - 2009 . - p. 9658–9662. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9658–9662 Mots-clés : Volume-explicit equation Chain fluids Résumé : An extension of a volume-explicit equation of state for chains of tangent hard spheres to chains of fused hard spheres and their mixtures is presented. The extension was achieved by the use of a simple relationship between number of segments and nonsphericity parameter. A comparison of compressibility factors calculated using the extended equation with corresponding simulation data for hard dumbbell systems at various elongations and for fused long chains molecules and their mixtures has shown that the extended equation is reasonably accurate. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800755s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Calculation of solubility parameter using perturbed-chain SAFT and cubic-plus-association equations of state / Zhi-Yong Zeng in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9663–9669 Titre : Calculation of solubility parameter using perturbed-chain SAFT and cubic-plus-association equations of state Type de document : texte imprimé Auteurs : Zhi-Yong Zeng, Auteur ; Yuan-Yuan Xu, Auteur ; Wang Li-jun, Auteur Année de publication : 2009 Article en page(s) : p. 9663–9669 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Solubility Pparameter Perturbed-Chain Association equations of state Résumé : Starting from the original definition of the solubility parameter, two models are developed to calculate the solubility parameter utilizing Perturbed-Chain SAFT and Cubic-Plus-Association equations of state, respectively. C3∼C12 n-alkanes and C1∼C5 1-alcohols,which represent the nonassociative and associative compounds, respectively, were investigated mainly over wide ranges of temperature and pressure. Solubility parameters calculated by two models are in good agreement with Hansen solubility parameters (HSP) and the results of Monte Carlo simulation for all of these selected molecules. It is also found that the solubility parameter increases monotonically with increasing pressure, and decreases with increasing temperature for all of these studied molecules. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800811f [article] Calculation of solubility parameter using perturbed-chain SAFT and cubic-plus-association equations of state [texte imprimé] / Zhi-Yong Zeng, Auteur ; Yuan-Yuan Xu, Auteur ; Wang Li-jun, Auteur . - 2009 . - p. 9663–9669. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9663–9669 Mots-clés : Solubility Pparameter Perturbed-Chain Association equations of state Résumé : Starting from the original definition of the solubility parameter, two models are developed to calculate the solubility parameter utilizing Perturbed-Chain SAFT and Cubic-Plus-Association equations of state, respectively. C3∼C12 n-alkanes and C1∼C5 1-alcohols,which represent the nonassociative and associative compounds, respectively, were investigated mainly over wide ranges of temperature and pressure. Solubility parameters calculated by two models are in good agreement with Hansen solubility parameters (HSP) and the results of Monte Carlo simulation for all of these selected molecules. It is also found that the solubility parameter increases monotonically with increasing pressure, and decreases with increasing temperature for all of these studied molecules. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800811f

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Factors that determine the performance of carbon fuels in the direct carbon fuel cell / Xiang Li in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9670–9677 Titre : Factors that determine the performance of carbon fuels in the direct carbon fuel cell Type de document : texte imprimé Auteurs : Xiang Li, Auteur ; Zhong Hua Zhu, Auteur ; Roland De Marco, Auteur Année de publication : 2009 Article en page(s) : p. 9670–9677 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Carbon fuels Résumé : The direct carbon fuel cell (DCFC) is a promising power generation device, which has a much higher efficiency (80%) and a lower emission than conventional coal-fired power plants. In this study, different commercial carbon fuels including activated carbon (AC), carbon black (CB220 and CB660), and graphitic carbon (GC) were tested in DCFC at 600−800 °C. The relationship between the intrinsic properties of carbon fuels and their electrochemical performance in the DCFC was analyzed. It is found that a desirable carbon fuel for DCFC should have high mesoporous surface area and rich oxygen-containing surface groups. The anodic performance of the DCFC may also be improved by small carbon particle size, fast stirring rates, and high cell temperatures. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800891m [article] Factors that determine the performance of carbon fuels in the direct carbon fuel cell [texte imprimé] / Xiang Li, Auteur ; Zhong Hua Zhu, Auteur ; Roland De Marco, Auteur . - 2009 . - p. 9670–9677. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9670–9677 Mots-clés : Carbon fuels Résumé : The direct carbon fuel cell (DCFC) is a promising power generation device, which has a much higher efficiency (80%) and a lower emission than conventional coal-fired power plants. In this study, different commercial carbon fuels including activated carbon (AC), carbon black (CB220 and CB660), and graphitic carbon (GC) were tested in DCFC at 600−800 °C. The relationship between the intrinsic properties of carbon fuels and their electrochemical performance in the DCFC was analyzed. It is found that a desirable carbon fuel for DCFC should have high mesoporous surface area and rich oxygen-containing surface groups. The anodic performance of the DCFC may also be improved by small carbon particle size, fast stirring rates, and high cell temperatures. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800891m

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Molecular thermodynamic model of multicomponent chainlike fluid mixtures based on a Lattice model / Qin Xin in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9678–9686 Titre : Molecular thermodynamic model of multicomponent chainlike fluid mixtures based on a Lattice model Type de document : texte imprimé Auteurs : Qin Xin, Auteur ; Changjun Peng, Auteur ; Honglai Liu, Auteur Année de publication : 2009 Article en page(s) : p. 9678–9686 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Thermodynamic Fluid mixtures Lattice model Résumé : The molecular thermodynamic model of polymer solutions based on a close-packed lattice model presented in a previous work has been generally extended to multicomponent chainlike fluid mixtures. The Helmholtz function of mixing contains three terms, i.e., the contribution of athermal mixing of polymer chains, which is calculated by Guggenheim’s theory; the contribution of nearest-neighbor interactions between monomers, which is calculated by Yang et al.’s model of the Helmholtz function of mixing for a multicomponent Ising lattice; and the contribution of the formation of polymer chains from monomers, which is obtained according to the sticky-point theory of Cummings, Zhou, and Stell. The liquid−liquid phase equilibria of ternary chainlike mixtures predicted by this model are in good agreement with Monte Carlo simulation results and superior to the results calculated by Flory−Huggins (FH) theory and revised Freed theory (RFT) obviously. This model not only can describe types 1−3 phase separations of Treybal classification satisfactorily, but can also correlate well the coexistence curves of binary polymer blends systems with an upper critical solution temperature (UCST) or a lower critical solution temperature (LCST). Meanwhile, model parameters correlated from the binary system can be further extended to predict the corresponding liquid−liquid equilibrium of ternary mixtures, including systems of ionic liquids. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800924r [article] Molecular thermodynamic model of multicomponent chainlike fluid mixtures based on a Lattice model [texte imprimé] / Qin Xin, Auteur ; Changjun Peng, Auteur ; Honglai Liu, Auteur . - 2009 . - p. 9678–9686. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9678–9686 Mots-clés : Thermodynamic Fluid mixtures Lattice model Résumé : The molecular thermodynamic model of polymer solutions based on a close-packed lattice model presented in a previous work has been generally extended to multicomponent chainlike fluid mixtures. The Helmholtz function of mixing contains three terms, i.e., the contribution of athermal mixing of polymer chains, which is calculated by Guggenheim’s theory; the contribution of nearest-neighbor interactions between monomers, which is calculated by Yang et al.’s model of the Helmholtz function of mixing for a multicomponent Ising lattice; and the contribution of the formation of polymer chains from monomers, which is obtained according to the sticky-point theory of Cummings, Zhou, and Stell. The liquid−liquid phase equilibria of ternary chainlike mixtures predicted by this model are in good agreement with Monte Carlo simulation results and superior to the results calculated by Flory−Huggins (FH) theory and revised Freed theory (RFT) obviously. This model not only can describe types 1−3 phase separations of Treybal classification satisfactorily, but can also correlate well the coexistence curves of binary polymer blends systems with an upper critical solution temperature (UCST) or a lower critical solution temperature (LCST). Meanwhile, model parameters correlated from the binary system can be further extended to predict the corresponding liquid−liquid equilibrium of ternary mixtures, including systems of ionic liquids. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800924r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

QSPR study of critical micelle concentrations of nonionic surfactants / Alan R. Katritzky in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9687–9695 Titre : QSPR study of critical micelle concentrations of nonionic surfactants Type de document : texte imprimé Auteurs : Alan R. Katritzky, Auteur ; Liliana M. Pacureanu, Auteur ; Svetoslav H. Slavov, Auteur Année de publication : 2009 Article en page(s) : p. 9687–9695 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Nonionic surfactants Résumé : Linear and nonlinear predictive models are derived for a data set of 162 nonionic surfactants. The descriptors in the derived models relate to the molecular shape and size and to the presence of heteroatoms participating in donor−acceptor and dipole−dipole interactions. Steric hindrance in the hydrophobic area also plays an important role in micellization. The derived linear and nonlinear QSPR models could be useful to predict the CMCs of broad classes of nonionic surfactants. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800954k [article] QSPR study of critical micelle concentrations of nonionic surfactants [texte imprimé] / Alan R. Katritzky, Auteur ; Liliana M. Pacureanu, Auteur ; Svetoslav H. Slavov, Auteur . - 2009 . - p. 9687–9695. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9687–9695 Mots-clés : Nonionic surfactants Résumé : Linear and nonlinear predictive models are derived for a data set of 162 nonionic surfactants. The descriptors in the derived models relate to the molecular shape and size and to the presence of heteroatoms participating in donor−acceptor and dipole−dipole interactions. Steric hindrance in the hydrophobic area also plays an important role in micellization. The derived linear and nonlinear QSPR models could be useful to predict the CMCs of broad classes of nonionic surfactants. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800954k

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Experimental investigation into the production behavior of methane hydrate in porous sediment with hot brine stimulation / Xiao-Sen Li in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9696–9702 Titre : Experimental investigation into the production behavior of methane hydrate in porous sediment with hot brine stimulation Type de document : texte imprimé Auteurs : Xiao-Sen Li, Auteur ; Li-Hua Wan, Auteur ; Gang Li, Auteur Année de publication : 2009 Article en page(s) : p. 9696–9702 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Experimental investigation Methane hydrate Porous sediment Hot brine stimulation Résumé : The gas production behavior from methane hydrate in porous sediment by injecting the brine with the salinity of 0−24 wt % and the temperature of −1 to 130 °C was investigated in a one-dimensional experimental apparatus. The results show that the gas production process consists of three periods: the free gas production, the hydrate dissociation, and the general gas reservoir production. The hydrate dissociation accompanies the temperature decrease with the injection of the brine (NaCl solution), and the dissociation duration is shortened with the increase of the salinity. With the injection of hot brine, instantaneous hydrate dissociation rate also increases with the increase of the salinity. However, while the NaCl concentration is beyond a certain value, the rate has no longer continued increasing. Thermal efficiency and energy ratio for the hydrate production can be enhanced by injecting hot brine, and the enhanced effectiveness is quite good with the injection of high salinity at lower temperature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009582 [article] Experimental investigation into the production behavior of methane hydrate in porous sediment with hot brine stimulation [texte imprimé] / Xiao-Sen Li, Auteur ; Li-Hua Wan, Auteur ; Gang Li, Auteur . - 2009 . - p. 9696–9702. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9696–9702 Mots-clés : Experimental investigation Methane hydrate Porous sediment Hot brine stimulation Résumé : The gas production behavior from methane hydrate in porous sediment by injecting the brine with the salinity of 0−24 wt % and the temperature of −1 to 130 °C was investigated in a one-dimensional experimental apparatus. The results show that the gas production process consists of three periods: the free gas production, the hydrate dissociation, and the general gas reservoir production. The hydrate dissociation accompanies the temperature decrease with the injection of the brine (NaCl solution), and the dissociation duration is shortened with the increase of the salinity. With the injection of hot brine, instantaneous hydrate dissociation rate also increases with the increase of the salinity. However, while the NaCl concentration is beyond a certain value, the rate has no longer continued increasing. Thermal efficiency and energy ratio for the hydrate production can be enhanced by injecting hot brine, and the enhanced effectiveness is quite good with the injection of high salinity at lower temperature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009582

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

High solid-flux concurrent conveying flow realized by coupling a moving bed to the bottom section of a riser / Xinhua Liu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9703–9708 Titre : High solid-flux concurrent conveying flow realized by coupling a moving bed to the bottom section of a riser Type de document : texte imprimé Auteurs : Xinhua Liu, Auteur ; Xin Cui, Auteur ; Guang Sun, Auteur Année de publication : 2009 Article en page(s) : p. 9703–9708 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Solid-flux Moving bed Résumé : Gasification of coal and biomass is in pursuit of the technologies based on dual bed combination and a high-density transport bed. Dual fluidized bed gasification (DFBG) relies on rapidly circulated particles between its combustor and gasifier to provide the endothermic heat required by the gasification. High-density transport bed gasification (HTBG) has to work with a high solid flux and a high particle density inside its gasifier so as to increase the heat reserve in the bed and to suppress tar evolution there. The idea of coupling a moving bed to the bottom section of the riser of a circulating fluidized bed (CFB) was proposed to realize the desired high solid-flux conveying flow inside the riser. Experiments in a 12-m high and 90 mm i.d. riser of the newly configured CFB demonstrated that at superficial gas velocities of about 9.6 m/s, a solid circulation rate as high as 370 kg/(m2 s) and an average solid holdup of about 0.12 in the bottom section of the riser were readily achieved simultaneously for the silica sand particles of 378 μm in Sauter mean diameter. Parametric investigation further clarified that the solid circulation rate and the local solid holdup at the riser bottom of the newly configured CFB were highly dependent on the moving bed aeration and the primary gas velocity of the riser, whereas changing the solid inventory in the system did not greatly affect those two variables. Adoption of a secondary air injection into the riser enabled adjustment of the solid circulation rate within a certain range, showing essentially a complementary means for controlling the gas−solid flow inside the riser of the newly configured CFB. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801041g [article] High solid-flux concurrent conveying flow realized by coupling a moving bed to the bottom section of a riser [texte imprimé] / Xinhua Liu, Auteur ; Xin Cui, Auteur ; Guang Sun, Auteur . - 2009 . - p. 9703–9708. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9703–9708 Mots-clés : Solid-flux Moving bed Résumé : Gasification of coal and biomass is in pursuit of the technologies based on dual bed combination and a high-density transport bed. Dual fluidized bed gasification (DFBG) relies on rapidly circulated particles between its combustor and gasifier to provide the endothermic heat required by the gasification. High-density transport bed gasification (HTBG) has to work with a high solid flux and a high particle density inside its gasifier so as to increase the heat reserve in the bed and to suppress tar evolution there. The idea of coupling a moving bed to the bottom section of the riser of a circulating fluidized bed (CFB) was proposed to realize the desired high solid-flux conveying flow inside the riser. Experiments in a 12-m high and 90 mm i.d. riser of the newly configured CFB demonstrated that at superficial gas velocities of about 9.6 m/s, a solid circulation rate as high as 370 kg/(m2 s) and an average solid holdup of about 0.12 in the bottom section of the riser were readily achieved simultaneously for the silica sand particles of 378 μm in Sauter mean diameter. Parametric investigation further clarified that the solid circulation rate and the local solid holdup at the riser bottom of the newly configured CFB were highly dependent on the moving bed aeration and the primary gas velocity of the riser, whereas changing the solid inventory in the system did not greatly affect those two variables. Adoption of a secondary air injection into the riser enabled adjustment of the solid circulation rate within a certain range, showing essentially a complementary means for controlling the gas−solid flow inside the riser of the newly configured CFB. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801041g

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Stoichiometry of sulfite oxidation by oxygen during the determination of the volumetric mass transfer coefficient / Edgardo M. Contreras in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9709–9714 Titre : Stoichiometry of sulfite oxidation by oxygen during the determination of the volumetric mass transfer coefficient Type de document : texte imprimé Auteurs : Edgardo M. Contreras, Auteur Année de publication : 2009 Article en page(s) : p. 9709–9714 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Stoichiometry Oxidation Oxygen Résumé : The aim of this work was to study the effect of the initial sulfite concentration on the stoichiometric coefficient of sulfite oxidation. A combined method based on the oxidation of sulfite by oxygen in the presence of cobalt(II) (0.5 mM) as catalyst was used to determine the volumetric mass transfer coefficient (kLa) and the oxygen consumption (OC) due to sulfite oxidation. Results demonstrated that the dissolved oxygen (DO) probe response constant (ksensor) was not dependent on the DO concentration or the agitation speed; obtained ksensor values were high enough to not interfere with DO or OC measurements. Using the reaction time to sulfite depletion method, volumetric mass transfer coefficient (kLa) yielded a linear increase as a function of the initial sulfite concentration. On the contrary, from the saturation phase of DO curves, an almost constant kLa value was obtained in accordance to constant air flow rate and agitation conditions that were used in the experiments. The observed stoichiometric coefficient (OC/S0) at high initial sulfite concentrations or low kLa values was lower than the theoretical one, suggesting that the formation of elemental sulfur becomes significant at these conditions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801079e [article] Stoichiometry of sulfite oxidation by oxygen during the determination of the volumetric mass transfer coefficient [texte imprimé] / Edgardo M. Contreras, Auteur . - 2009 . - p. 9709–9714. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9709–9714 Mots-clés : Stoichiometry Oxidation Oxygen Résumé : The aim of this work was to study the effect of the initial sulfite concentration on the stoichiometric coefficient of sulfite oxidation. A combined method based on the oxidation of sulfite by oxygen in the presence of cobalt(II) (0.5 mM) as catalyst was used to determine the volumetric mass transfer coefficient (kLa) and the oxygen consumption (OC) due to sulfite oxidation. Results demonstrated that the dissolved oxygen (DO) probe response constant (ksensor) was not dependent on the DO concentration or the agitation speed; obtained ksensor values were high enough to not interfere with DO or OC measurements. Using the reaction time to sulfite depletion method, volumetric mass transfer coefficient (kLa) yielded a linear increase as a function of the initial sulfite concentration. On the contrary, from the saturation phase of DO curves, an almost constant kLa value was obtained in accordance to constant air flow rate and agitation conditions that were used in the experiments. The observed stoichiometric coefficient (OC/S0) at high initial sulfite concentrations or low kLa values was lower than the theoretical one, suggesting that the formation of elemental sulfur becomes significant at these conditions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801079e

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Batch and dynamic flow biosorption potential of agaricus bisporus/thuja orientalis biomass mixture for decolorization of RR45 dye / Tamer Akar in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9715–9723 Titre : Batch and dynamic flow biosorption potential of agaricus bisporus/thuja orientalis biomass mixture for decolorization of RR45 dye Type de document : texte imprimé Auteurs : Tamer Akar, Auteur ; Burcu Anilan, Auteur ; Zerrin Kaynak, Auteur Année de publication : 2009 Article en page(s) : p. 9715–9723 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Batch and dynamic Biosorption Agaricus bisporus Thuja Biomass Résumé : This work reports the batch and dynamic flow biosorption conditions for Reactive Red 45 dye using Agaricus bisporus/Thuja orientalis biomass mixture (ABTOC). Experiments were performed to determine optimum pH, biomass amount, contact time, temperature, dye concentration, and flow rate. The applicability of different kinetic and isotherm models for the biosorption process was evaluated. Biosorption showed a highly pH dependent profile. Under optimized batch conditions up to 93.04% dye could be removed from solution in a relatively short time. Kinetic experiments suggest that the biosorption process followed the pseudo-second-order model in comparison to intraparticle diffusion and the pseudo-first-order models. Thermodynamic data confirm that the biosorption process is spontaneous and endothermic in nature. Besides, the highest regression coefficient (r2 ≈ 1) for the Langmuir model indicates the monolayer coverage of biomass by RR45 dye molecules (qmax = 108.90 mg g−1). Column studies showed that ABTOC effectively removes RR45 dye with a maximum biosorption yield of ∼100%. ABTOC was able to give nearly 96% dye removal in the presence of Na+, K+, Mg2+, Ca2+, Pb2+, Ni2+, Cu2+, and Cd2+ ions. Our results revealed that ABTOC could be employed as an effective and low-cost alternative biosorbent material for removal of reactive textile dyes from contaminated effluents. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8007874 [article] Batch and dynamic flow biosorption potential of agaricus bisporus/thuja orientalis biomass mixture for decolorization of RR45 dye [texte imprimé] / Tamer Akar, Auteur ; Burcu Anilan, Auteur ; Zerrin Kaynak, Auteur . - 2009 . - p. 9715–9723. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9715–9723 Mots-clés : Batch and dynamic Biosorption Agaricus bisporus Thuja Biomass Résumé : This work reports the batch and dynamic flow biosorption conditions for Reactive Red 45 dye using Agaricus bisporus/Thuja orientalis biomass mixture (ABTOC). Experiments were performed to determine optimum pH, biomass amount, contact time, temperature, dye concentration, and flow rate. The applicability of different kinetic and isotherm models for the biosorption process was evaluated. Biosorption showed a highly pH dependent profile. Under optimized batch conditions up to 93.04% dye could be removed from solution in a relatively short time. Kinetic experiments suggest that the biosorption process followed the pseudo-second-order model in comparison to intraparticle diffusion and the pseudo-first-order models. Thermodynamic data confirm that the biosorption process is spontaneous and endothermic in nature. Besides, the highest regression coefficient (r2 ≈ 1) for the Langmuir model indicates the monolayer coverage of biomass by RR45 dye molecules (qmax = 108.90 mg g−1). Column studies showed that ABTOC effectively removes RR45 dye with a maximum biosorption yield of ∼100%. ABTOC was able to give nearly 96% dye removal in the presence of Na+, K+, Mg2+, Ca2+, Pb2+, Ni2+, Cu2+, and Cd2+ ions. Our results revealed that ABTOC could be employed as an effective and low-cost alternative biosorbent material for removal of reactive textile dyes from contaminated effluents. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8007874

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Mechanism analysis on the two-phase flow characteristics in coalescence-dispersion pulsed-sieve-plate extraction columns / Tang Xiaojin in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9724–9727 Titre : Mechanism analysis on the two-phase flow characteristics in coalescence-dispersion pulsed-sieve-plate extraction columns Type de document : texte imprimé Auteurs : Tang Xiaojin, Auteur ; Guangsheng Luo, Auteur ; Wang Jiading, Auteur Année de publication : 2009 Article en page(s) : p. 9724–9727 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Mechanism analysis Flow characteristics Pulsed-Sieve Résumé : To investigate the influence of drop breakage and drop coalescence, a mechanism analysis of the liquid−liquid two-phase flow characteristics in the coalescence−dispersion pulsed-sieve-plate extraction column (CDPSEC) is performed. According to the experimental results, the operation of CDPSEC can be divided by a turning point into two regions: the drop breakage control region with higher holdup of the dispersed phase and the drop coalescence control region with lower holdup. The size of the maximum droplet in CDPSEC is estimated. It was found that, in the drop coalescence control region, droplets coalesce under the coalescence plate to produce the new large droplets, and the influence of drop coalescence is stronger than that of drop breakage. At the turning point, the new large droplets reach the maximum droplets and no larger droplets can be produced. From this point on, in the drop breakage control region, the droplets are so large that they break up into small droplets. Drop breakage becomes the main flow characteristic instead of drop coalescence. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002792 [article] Mechanism analysis on the two-phase flow characteristics in coalescence-dispersion pulsed-sieve-plate extraction columns [texte imprimé] / Tang Xiaojin, Auteur ; Guangsheng Luo, Auteur ; Wang Jiading, Auteur . - 2009 . - p. 9724–9727. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9724–9727 Mots-clés : Mechanism analysis Flow characteristics Pulsed-Sieve Résumé : To investigate the influence of drop breakage and drop coalescence, a mechanism analysis of the liquid−liquid two-phase flow characteristics in the coalescence−dispersion pulsed-sieve-plate extraction column (CDPSEC) is performed. According to the experimental results, the operation of CDPSEC can be divided by a turning point into two regions: the drop breakage control region with higher holdup of the dispersed phase and the drop coalescence control region with lower holdup. The size of the maximum droplet in CDPSEC is estimated. It was found that, in the drop coalescence control region, droplets coalesce under the coalescence plate to produce the new large droplets, and the influence of drop coalescence is stronger than that of drop breakage. At the turning point, the new large droplets reach the maximum droplets and no larger droplets can be produced. From this point on, in the drop breakage control region, the droplets are so large that they break up into small droplets. Drop breakage becomes the main flow characteristic instead of drop coalescence. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002792

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Automated generation of phase diagrams for binary systems with azeotropic behavior / Martín Cismondi in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9728–9743 Titre : Automated generation of phase diagrams for binary systems with azeotropic behavior Type de document : texte imprimé Auteurs : Martín Cismondi, Auteur ; Michael L. Michelsen, Auteur ; Marcelo S. Zabaloy, Auteur Année de publication : 2009 Article en page(s) : p. 9728–9743 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Automated generation Diagrams Azeotropic behavior Résumé : In this work, we propose a computational strategy and methods for the automated calculation of complete loci of homogeneous azeotropy of binary mixtures and the related Pxy and Txy diagrams for models of the equation-of-state (EOS) type. The strategy consists of first finding the system’s azeotropic end points (AEPs). These can exist on vapor−liquid (VL) critical lines (CAEPs), on liquid−liquid−vapor (LLV) lines (HAEPs), and on pure-compound vapor pressure lines (PAEPs). Next, for the chosen binary system, we generate one or two azeotropic lines. Each of these lines has, as its starting point, one of the previously identified AEPs. We calculate the azeotropic lines using a numerical continuation method that solves the nonlinear azeotropic system of equations under a range of conditions and efficiently tracks entire azeotropic curves. We have integrated our strategy for calculating azeotropic lines into a general algorithm for the single-run computation of binary global phase equilibrium diagrams (GPEDs). GPEDs are defined by pure-compound, critical, LLV, and azeotropic lines. We implemented this general algorithm in the computer program GPEC (Global Phase Equilibrium Calculations), which makes it possible to evaluate, at a glance, the behavior of a given model−parameter values combination, for a chosen model and binary system. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002914 [article] Automated generation of phase diagrams for binary systems with azeotropic behavior [texte imprimé] / Martín Cismondi, Auteur ; Michael L. Michelsen, Auteur ; Marcelo S. Zabaloy, Auteur . - 2009 . - p. 9728–9743. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9728–9743 Mots-clés : Automated generation Diagrams Azeotropic behavior Résumé : In this work, we propose a computational strategy and methods for the automated calculation of complete loci of homogeneous azeotropy of binary mixtures and the related Pxy and Txy diagrams for models of the equation-of-state (EOS) type. The strategy consists of first finding the system’s azeotropic end points (AEPs). These can exist on vapor−liquid (VL) critical lines (CAEPs), on liquid−liquid−vapor (LLV) lines (HAEPs), and on pure-compound vapor pressure lines (PAEPs). Next, for the chosen binary system, we generate one or two azeotropic lines. Each of these lines has, as its starting point, one of the previously identified AEPs. We calculate the azeotropic lines using a numerical continuation method that solves the nonlinear azeotropic system of equations under a range of conditions and efficiently tracks entire azeotropic curves. We have integrated our strategy for calculating azeotropic lines into a general algorithm for the single-run computation of binary global phase equilibrium diagrams (GPEDs). GPEDs are defined by pure-compound, critical, LLV, and azeotropic lines. We implemented this general algorithm in the computer program GPEC (Global Phase Equilibrium Calculations), which makes it possible to evaluate, at a glance, the behavior of a given model−parameter values combination, for a chosen model and binary system. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002914

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Fast liquid jet mixing in millimeter channels with various multislits designs / Zhe Liu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9744–9753 Titre : Fast liquid jet mixing in millimeter channels with various multislits designs Type de document : texte imprimé Auteurs : Zhe Liu, Auteur ; Yi Cheng, Auteur ; Yong Jin, Auteur Année de publication : 2009 Article en page(s) : p. 9744–9753 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Liquid jet Millimeter channels Résumé : The jet flow mixers in which fluids are mixed in the confined millimeter-sized channels were further studied to better understand the fast liquid mixing process and the means to intensify the mixing performance. Four mixer designs with different modifications on the local configuration for adjusted contact mode between liquids were investigated by visualizing the mixing processes using planar laser-induced fluorescence (PLIF) technique. A large amount of experiments with various operating conditions were carried out for all the four designs. The common feature in all the cases was that the two liquids can be mixed well in milliseconds, where the momentum ratio between the bulk and the jet flows played a significant role in the mixing performance. The results also demonstrated that the contact mode between the two liquids had a great effect on the mixing performance. By dividing the side-jet liquid stream into several smaller aperture-jets, the mixing process can be clearly improved, which can be attributed to the increased contact area and the higher velocity difference between the two liquids. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800344p [article] Fast liquid jet mixing in millimeter channels with various multislits designs [texte imprimé] / Zhe Liu, Auteur ; Yi Cheng, Auteur ; Yong Jin, Auteur . - 2009 . - p. 9744–9753. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9744–9753 Mots-clés : Liquid jet Millimeter channels Résumé : The jet flow mixers in which fluids are mixed in the confined millimeter-sized channels were further studied to better understand the fast liquid mixing process and the means to intensify the mixing performance. Four mixer designs with different modifications on the local configuration for adjusted contact mode between liquids were investigated by visualizing the mixing processes using planar laser-induced fluorescence (PLIF) technique. A large amount of experiments with various operating conditions were carried out for all the four designs. The common feature in all the cases was that the two liquids can be mixed well in milliseconds, where the momentum ratio between the bulk and the jet flows played a significant role in the mixing performance. The results also demonstrated that the contact mode between the two liquids had a great effect on the mixing performance. By dividing the side-jet liquid stream into several smaller aperture-jets, the mixing process can be clearly improved, which can be attributed to the increased contact area and the higher velocity difference between the two liquids. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800344p

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Heat-transfer performance of a liquid-liquid microdispersed system / Kai Wang in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9754–9758 Titre : Heat-transfer performance of a liquid-liquid microdispersed system Type de document : texte imprimé Auteurs : Kai Wang, Auteur ; Yangcheng Lu, Auteur ; Huawei Shao, Auteur Année de publication : 2009 Article en page(s) : p. 9754–9758 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Performance Liquid-liquid Microdispersed system Résumé : In this work, the heat-transfer performance of liquid−liquid microdispersed systems was tested for the first time with a microdispersion contactor named a membrane dispersion minicontactor and octane/water as the working system. The volumetric heat-transfer coefficients ranging from 5 to 25 MW/(m3·°C) were obtained, which were 15−20 times higher than that of the conventional dispersion heat-transfer methods. The heat-transfer Murphree efficiencies, defined to evaluate the heat-transfer performance, reached 85−99% for the microdispersed system with residence times less than 0.1 s. By introducing the two parameters of Ca number and oil volumetric fraction, a semiempirical model for predicting the volumetric heat-transfer coefficient has been developed, which fits the experimental results very well. Furthermore, the similarity between the heat and mass transfer in the microdispersed system was demonstrated. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005484 [article] Heat-transfer performance of a liquid-liquid microdispersed system [texte imprimé] / Kai Wang, Auteur ; Yangcheng Lu, Auteur ; Huawei Shao, Auteur . - 2009 . - p. 9754–9758. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9754–9758 Mots-clés : Performance Liquid-liquid Microdispersed system Résumé : In this work, the heat-transfer performance of liquid−liquid microdispersed systems was tested for the first time with a microdispersion contactor named a membrane dispersion minicontactor and octane/water as the working system. The volumetric heat-transfer coefficients ranging from 5 to 25 MW/(m3·°C) were obtained, which were 15−20 times higher than that of the conventional dispersion heat-transfer methods. The heat-transfer Murphree efficiencies, defined to evaluate the heat-transfer performance, reached 85−99% for the microdispersed system with residence times less than 0.1 s. By introducing the two parameters of Ca number and oil volumetric fraction, a semiempirical model for predicting the volumetric heat-transfer coefficient has been developed, which fits the experimental results very well. Furthermore, the similarity between the heat and mass transfer in the microdispersed system was demonstrated. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005484

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Flow patterns and transitions of a novel annular spouted bed with multiple air nozzles / Guoxin Hu in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9759–9766 Titre : Flow patterns and transitions of a novel annular spouted bed with multiple air nozzles Type de document : texte imprimé Auteurs : Guoxin Hu, Auteur ; Xiwu Gong, Auteur ; Bingnan Wei, Auteur Année de publication : 2009 Article en page(s) : p. 9759–9766 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Flow patterns Transitions Air nozzles Résumé : Experimental study on the flow patterns and transitions in a novel annular spouted bed with multiple air nozzles was carried out. Three distinct stable flow patterns, i.e. internal jet, jet-spouting, and fully developed spouting were identified. Two transitional flow patterns and flow instabilities, single internal jet, single jet-spouting, and bubbling or slugging were found. Schematic diagrams and typical flow pattern images obtained by a digital charge-coupled display (CCD) camera were presented for classifying these flow patterns. Experimental results show that the internal jet or jet-spouting is easier to occur for forward nozzles than for angle nozzles with the increasing of spouting gas velocity. Due to the interaction of spouting gases from different nozzles, the turbulent exchange or mixing of particles among the nozzles in the fully developed spouting state can be observed distinctly. The total bed pressure drop varied with the spouting gas velocity increases, as a result of the transition of flow pattern. Typical flow pattern map at various static bed heights and spouting gas velocity were plotted for describing the transitions between flow patterns. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800733n [article] Flow patterns and transitions of a novel annular spouted bed with multiple air nozzles [texte imprimé] / Guoxin Hu, Auteur ; Xiwu Gong, Auteur ; Bingnan Wei, Auteur . - 2009 . - p. 9759–9766. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9759–9766 Mots-clés : Flow patterns Transitions Air nozzles Résumé : Experimental study on the flow patterns and transitions in a novel annular spouted bed with multiple air nozzles was carried out. Three distinct stable flow patterns, i.e. internal jet, jet-spouting, and fully developed spouting were identified. Two transitional flow patterns and flow instabilities, single internal jet, single jet-spouting, and bubbling or slugging were found. Schematic diagrams and typical flow pattern images obtained by a digital charge-coupled display (CCD) camera were presented for classifying these flow patterns. Experimental results show that the internal jet or jet-spouting is easier to occur for forward nozzles than for angle nozzles with the increasing of spouting gas velocity. Due to the interaction of spouting gases from different nozzles, the turbulent exchange or mixing of particles among the nozzles in the fully developed spouting state can be observed distinctly. The total bed pressure drop varied with the spouting gas velocity increases, as a result of the transition of flow pattern. Typical flow pattern map at various static bed heights and spouting gas velocity were plotted for describing the transitions between flow patterns. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800733n

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

An empirical correlation of drag coefficient for a single bubble rising in non-newtonian liquids / Zhang, Li. in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9767–9772 Titre : An empirical correlation of drag coefficient for a single bubble rising in non-newtonian liquids Type de document : texte imprimé Auteurs : Zhang, Li., Auteur ; Chao Yang, Auteur ; Zai-Sha Mao, Auteur Année de publication : 2009 Article en page(s) : p. 9767–9772 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Empirical correlation Drag coefficient Non-Newtonian liquids Résumé : The motion of a single bubble rising unsteadily and steadily in a quiescent non-Newtonian liquid was investigated experimentally. By using a charged coupled device camera to follow the rising bubble, the sequences of the recorded frames were digitized and analyzed using image analysis software, and the measurements of the acceleration and steady motion of bubbles were obtained. Using the experimental data, we proposed an empirical correlation to predict the total drag coefficient calculated from the accelerating motion to the steady motion with the added mass force and history force included. This correlation is an extension of our previous work with non-Newtonian fluids. This new correlation represents very well the experimental data of the total drag force in a wide range covering both unsteady accelerating motion and steady motion in non-Newtonian fluids. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8010319 [article] An empirical correlation of drag coefficient for a single bubble rising in non-newtonian liquids [texte imprimé] / Zhang, Li., Auteur ; Chao Yang, Auteur ; Zai-Sha Mao, Auteur . - 2009 . - p. 9767–9772. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9767–9772 Mots-clés : Empirical correlation Drag coefficient Non-Newtonian liquids Résumé : The motion of a single bubble rising unsteadily and steadily in a quiescent non-Newtonian liquid was investigated experimentally. By using a charged coupled device camera to follow the rising bubble, the sequences of the recorded frames were digitized and analyzed using image analysis software, and the measurements of the acceleration and steady motion of bubbles were obtained. Using the experimental data, we proposed an empirical correlation to predict the total drag coefficient calculated from the accelerating motion to the steady motion with the added mass force and history force included. This correlation is an extension of our previous work with non-Newtonian fluids. This new correlation represents very well the experimental data of the total drag force in a wide range covering both unsteady accelerating motion and steady motion in non-Newtonian fluids. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8010319

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Fluidization characteristics of binary mixtures of biomass and quartz sand in an acoustic fluidized bed / Chongdian Si in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9773–9782 Titre : Fluidization characteristics of binary mixtures of biomass and quartz sand in an acoustic fluidized bed Type de document : texte imprimé Auteurs : Chongdian Si, Auteur ; Qingjie Guo, Auteur Année de publication : 2009 Article en page(s) : p. 9773–9782 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Fluidization characteristics Binary mixtures Biomass Quartz sand Acoustic fluidized bed Résumé : The fluidization behaviors of binary mixtures of biomass and quartz sand were investigated in an acoustic bubbling fluidized bed. Two kinds of biomass particles, sawdust and wheat stalk, were employed in this test. The experiments indicated that the addition of quartz sand can improve the fluidization quality of biomass. The minimum fluidization velocity of the mixtures increased with increasing biomass content in the mixtures. A new correlation was developed for predicting the minimum fluidization velocity of different binary mixtures. The minimum fluidization velocity decreased with increasing sound pressure level and had a minimum value over the sound frequency range of 100−200 Hz. Such an acoustic fluidized bed operated in a stable or unstable fluidization regime depending on the operating conditions. According to the slope of a plot of standard deviations, unstable fluidization can be expected if the slope is greater than 50, and stable fluidization can be expected if the value is less than or equal to 50. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801070z [article] Fluidization characteristics of binary mixtures of biomass and quartz sand in an acoustic fluidized bed [texte imprimé] / Chongdian Si, Auteur ; Qingjie Guo, Auteur . - 2009 . - p. 9773–9782. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9773–9782 Mots-clés : Fluidization characteristics Binary mixtures Biomass Quartz sand Acoustic fluidized bed Résumé : The fluidization behaviors of binary mixtures of biomass and quartz sand were investigated in an acoustic bubbling fluidized bed. Two kinds of biomass particles, sawdust and wheat stalk, were employed in this test. The experiments indicated that the addition of quartz sand can improve the fluidization quality of biomass. The minimum fluidization velocity of the mixtures increased with increasing biomass content in the mixtures. A new correlation was developed for predicting the minimum fluidization velocity of different binary mixtures. The minimum fluidization velocity decreased with increasing sound pressure level and had a minimum value over the sound frequency range of 100−200 Hz. Such an acoustic fluidized bed operated in a stable or unstable fluidization regime depending on the operating conditions. According to the slope of a plot of standard deviations, unstable fluidization can be expected if the slope is greater than 50, and stable fluidization can be expected if the value is less than or equal to 50. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801070z

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Applying an experimental design to improve the characteristics of microcapsules containing phase change materials for fabric uses / Luz Sánchez in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9783–9790 Titre : Applying an experimental design to improve the characteristics of microcapsules containing phase change materials for fabric uses Type de document : texte imprimé Auteurs : Luz Sánchez, Auteur ; Engracia Lacasa, Auteur ; Manuel Carmona, Auteur Année de publication : 2009 Article en page(s) : p. 9783–9790 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Experimental design Characteristics of microcapsules Fabric uses Résumé : Microcapsules with a high amount of PRS paraffin wax encapsulated and narrow size distribution were prepared by a Shirasu porous glass (SPG) emulsification technique and a subsequent suspensionlike polymerization process. An experimental design approach, based on a central composite design, was used to determine quantitatively the effect of RepSol-YPF Paraffin (PRS) paraffin wax/styrene mass ratio (PRS/St), percentage of polyvinylpyrrolidone/styrene mass ratio (% PVP/St), and water/styrene mass ratio (H2O/St) on the phase change material (PCM) microcapsules properties. The % PVP/St mass ratio was the most important parameter affecting the particle size distribution. The thermal energy storage of microcapsules increases with the PRS/St mass ratio used. The following synthesis conditions, mass ratios PRS/St of 1.02, % PVP/St of 9.43, and H2O/St of 8.23, allowed the the proper main particle size in number (4.80 μm) for fabrics applications containing the maximum phase change material encapsulated with a latent heat of 102.42 J/g to be achieved. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801107e [article] Applying an experimental design to improve the characteristics of microcapsules containing phase change materials for fabric uses [texte imprimé] / Luz Sánchez, Auteur ; Engracia Lacasa, Auteur ; Manuel Carmona, Auteur . - 2009 . - p. 9783–9790. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9783–9790 Mots-clés : Experimental design Characteristics of microcapsules Fabric uses Résumé : Microcapsules with a high amount of PRS paraffin wax encapsulated and narrow size distribution were prepared by a Shirasu porous glass (SPG) emulsification technique and a subsequent suspensionlike polymerization process. An experimental design approach, based on a central composite design, was used to determine quantitatively the effect of RepSol-YPF Paraffin (PRS) paraffin wax/styrene mass ratio (PRS/St), percentage of polyvinylpyrrolidone/styrene mass ratio (% PVP/St), and water/styrene mass ratio (H2O/St) on the phase change material (PCM) microcapsules properties. The % PVP/St mass ratio was the most important parameter affecting the particle size distribution. The thermal energy storage of microcapsules increases with the PRS/St mass ratio used. The following synthesis conditions, mass ratios PRS/St of 1.02, % PVP/St of 9.43, and H2O/St of 8.23, allowed the the proper main particle size in number (4.80 μm) for fabrics applications containing the maximum phase change material encapsulated with a latent heat of 102.42 J/g to be achieved. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801107e

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

A comparative study of ZnO-CuO-Al2O3/SiO2-Al2O3 composite and hybrid catalysts for direct synthesis of dimethyl ether from syngas / Sajo P. Naik in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9791–9794 Titre : A comparative study of ZnO-CuO-Al2O3/SiO2-Al2O3 composite and hybrid catalysts for direct synthesis of dimethyl ether from syngas Type de document : texte imprimé Auteurs : Sajo P. Naik, Auteur ; Hao Du, Auteur ; Haijun Wan, Auteur Année de publication : 2009 Article en page(s) : p. 9791–9794 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Comparative study ZnO−  CuO−  Al2O3/SiO2−  Al2O3 Dimethyl ether Syngas Résumé : Two different strategies for the preparation of active dimethyl ether catalysts are evaluated using CuO−ZnO−Al2O3 and SiO2−Al2O3 as methanol synthesis and methanol dehydration catalysts components, respectively. Composite catalysts are prepared by mixing of the two freshly precipitated catalyst precursors and by coprecipitation methods, whereas hybrid catalysts are prepared by mechanical mixing of the two calcined catalyst components by grinding. Composite catalysts are partially deactivated during the catalyst preparation or calcination stages and therefore exhibit much lower activity, as compared to the hybrid catalysts toward syngas conversions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801437c [article] A comparative study of ZnO-CuO-Al2O3/SiO2-Al2O3 composite and hybrid catalysts for direct synthesis of dimethyl ether from syngas [texte imprimé] / Sajo P. Naik, Auteur ; Hao Du, Auteur ; Haijun Wan, Auteur . - 2009 . - p. 9791–9794. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9791–9794 Mots-clés : Comparative study ZnO−  CuO−  Al2O3/SiO2−  Al2O3 Dimethyl ether Syngas Résumé : Two different strategies for the preparation of active dimethyl ether catalysts are evaluated using CuO−ZnO−Al2O3 and SiO2−Al2O3 as methanol synthesis and methanol dehydration catalysts components, respectively. Composite catalysts are prepared by mixing of the two freshly precipitated catalyst precursors and by coprecipitation methods, whereas hybrid catalysts are prepared by mechanical mixing of the two calcined catalyst components by grinding. Composite catalysts are partially deactivated during the catalyst preparation or calcination stages and therefore exhibit much lower activity, as compared to the hybrid catalysts toward syngas conversions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801437c

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire