Nos Abonnements
Ressources Électroniques
|
[n° ou bulletin]
[n° ou bulletin]
Vol. 49 N° 1 - Janvier 2010 [texte imprimé] . - 2010 . - p. 1-442 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
|
Exemplaires
| Code-barres | Cote | Support | Localisation | Section | Disponibilité |
|---|---|---|---|---|---|
| aucun exemplaire | |||||
|
Dépouillements
Ajouter le résultat dans votre panierEvaluation of the topography of surface sized eucalyptus based papers / Isabel Moutinho in Industrial & engineering chemistry research, Vol. 49 N° 1 (Janvier 2010)
Titre : Evaluation of the topography of surface sized eucalyptus based papers Type de document : texte imprimé Auteurs : Isabel Moutinho, Auteur ; Petri Ihalainen, Auteur ; Margarida Figueiredo, Auteur Année de publication : 2010 Article en page(s) : pp. 1–5 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Evaluation--Topography--Surface--Sized Eucalyptus--Based Papers Résumé : The surface properties of paper depend not only on the fibrous matrix but also on the final treatment of the paper surface. The present work compares paper samples with two different surface sizing treatments by using AFM and profilometry to assess topography and roughness parameters as well as to evaluate the spreading of the sizing formulation and to estimate sizing agent particle sizes. The results were confronted with dynamic light scattering measurements regarding particle size. This work shows that AFM is a valuable technique to visualize and quantify the effects of sizing on the paper surface. Due to the small amount of surface sizing applied, no significant differences between the surface sized samples and the reference sample (without surface treatment) could be detected in terms of the surface roughness parameters. Nonetheless, those of sample B1 are systematically smaller than those of sample A1. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900677y
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 1–5[article] Evaluation of the topography of surface sized eucalyptus based papers [texte imprimé] / Isabel Moutinho, Auteur ; Petri Ihalainen, Auteur ; Margarida Figueiredo, Auteur . - 2010 . - pp. 1–5.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 1–5
Mots-clés : Evaluation--Topography--Surface--Sized Eucalyptus--Based Papers Résumé : The surface properties of paper depend not only on the fibrous matrix but also on the final treatment of the paper surface. The present work compares paper samples with two different surface sizing treatments by using AFM and profilometry to assess topography and roughness parameters as well as to evaluate the spreading of the sizing formulation and to estimate sizing agent particle sizes. The results were confronted with dynamic light scattering measurements regarding particle size. This work shows that AFM is a valuable technique to visualize and quantify the effects of sizing on the paper surface. Due to the small amount of surface sizing applied, no significant differences between the surface sized samples and the reference sample (without surface treatment) could be detected in terms of the surface roughness parameters. Nonetheless, those of sample B1 are systematically smaller than those of sample A1. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900677y Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Structure of Monoethanolamine and Diethanolamine carbamates in aqueous solutions determined by high-energy X-ray scattering Type de document : texte imprimé Année de publication : 2010 Article en page(s) : pp. 6–13 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Structure--Monoethanolamine--Diethanolamine--Carbamates--Aqueous--Solutions--Determined--High-Energy X-ray--Scattering Résumé : A more detailed understanding of interactions between amine solution and carbon dioxide (CO2) is required for economical capture and recovery of CO2 emitted from thermal power plants. In order to investigate the molecular structure of the carbamate molecules which originate from CO2 gas, a high-energy X-ray scattering method was applied to monoethanolamine and diethanolamine aqueous solutions with several concentrations of CO2. Distinct peaks attributable to C−O (0.126 nm) and O···O (0.223 nm) interactions within the carbamate molecule were found in the difference distribution function derived from observed interference functions. To our knowledge, this is the first observation of the CO2−captured molecule. The experimental difference distribution functions were well reproduced by theoretical difference distribution functions evaluated from information obtained from NMR and computer conformation analysis. The present results indicate that the X-ray scattering method can contribute to the structural analysis of amine−H2O−CO2 systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9009556
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 6–13[article] Structure of Monoethanolamine and Diethanolamine carbamates in aqueous solutions determined by high-energy X-ray scattering [texte imprimé] . - 2010 . - pp. 6–13.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 6–13
Mots-clés : Structure--Monoethanolamine--Diethanolamine--Carbamates--Aqueous--Solutions--Determined--High-Energy X-ray--Scattering Résumé : A more detailed understanding of interactions between amine solution and carbon dioxide (CO2) is required for economical capture and recovery of CO2 emitted from thermal power plants. In order to investigate the molecular structure of the carbamate molecules which originate from CO2 gas, a high-energy X-ray scattering method was applied to monoethanolamine and diethanolamine aqueous solutions with several concentrations of CO2. Distinct peaks attributable to C−O (0.126 nm) and O···O (0.223 nm) interactions within the carbamate molecule were found in the difference distribution function derived from observed interference functions. To our knowledge, this is the first observation of the CO2−captured molecule. The experimental difference distribution functions were well reproduced by theoretical difference distribution functions evaluated from information obtained from NMR and computer conformation analysis. The present results indicate that the X-ray scattering method can contribute to the structural analysis of amine−H2O−CO2 systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9009556 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Computational fluid dynamics simulation and experimental investigation : study of two-phase liquid−liquid flow in a vertical taylor−couette contactor Type de document : texte imprimé Auteurs : Mayur J. Sathe, Auteur ; Sandesh S. Deshmukh, Auteur ; Jyeshtharaj B. Joshi, Auteur Année de publication : 2010 Article en page(s) : pp. 14–28 Langues : Anglais (eng) Mots-clés : study--two-phase--liquid− liquid--flow--vertical--taylor− couette--contactor ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900185z
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 14–28[article] Computational fluid dynamics simulation and experimental investigation : study of two-phase liquid−liquid flow in a vertical taylor−couette contactor [texte imprimé] / Mayur J. Sathe, Auteur ; Sandesh S. Deshmukh, Auteur ; Jyeshtharaj B. Joshi, Auteur . - 2010 . - pp. 14–28.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 14–28
Mots-clés : study--two-phase--liquid− liquid--flow--vertical--taylor− couette--contactor ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900185z Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Kinetic modeling of methanol-to-olefin reaction over ZSM-5 in fluid bed Type de document : texte imprimé Auteurs : Mads Kaarsholm, Auteur ; Banafsheh Rafii, Auteur ; Finn Joensen, Auteur Année de publication : 2010 Article en page(s) : pp. 29–38 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetic Modeling of Methanol-to-Olefin Reaction over ZSM-5 in Fluid Bed Résumé : The methanol to olefins reaction has been studied in a small scale fluidized bed reactor over a phosphorus modified ZSM-5 catalyst. The product distribution was relatively insensitive to either feed rate or inlet gas composition. It was more sensitive to temperature with a significant increase in light olefins when the temperature was increased from 400 to 550 °C. A model based on the hydrocarbon pool mechanism is proposed in which olefins form through reversible reactions with a high molecular weight hydrocarbon species in catalyst pores and intersections. Agreement between the model and the product distribution of the olefinic species is good throughout the temperature interval investigated. Further experimental work is required to adequately characterize the paraffin and C6+ fractions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900341t
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 29–38[article] Kinetic modeling of methanol-to-olefin reaction over ZSM-5 in fluid bed [texte imprimé] / Mads Kaarsholm, Auteur ; Banafsheh Rafii, Auteur ; Finn Joensen, Auteur . - 2010 . - pp. 29–38.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 29–38
Mots-clés : Kinetic Modeling of Methanol-to-Olefin Reaction over ZSM-5 in Fluid Bed Résumé : The methanol to olefins reaction has been studied in a small scale fluidized bed reactor over a phosphorus modified ZSM-5 catalyst. The product distribution was relatively insensitive to either feed rate or inlet gas composition. It was more sensitive to temperature with a significant increase in light olefins when the temperature was increased from 400 to 550 °C. A model based on the hydrocarbon pool mechanism is proposed in which olefins form through reversible reactions with a high molecular weight hydrocarbon species in catalyst pores and intersections. Agreement between the model and the product distribution of the olefinic species is good throughout the temperature interval investigated. Further experimental work is required to adequately characterize the paraffin and C6+ fractions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900341t Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : A kinetic model for the selective catalytic reduction of NOx with NH3 over an fe−zeolite catalyst Type de document : texte imprimé Auteurs : Hanna Sjövall, Auteur ; Richard J. Blint, Auteur ; Ashok Gopinath, Auteur Année de publication : 2010 Article en page(s) : pp. 39–52 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : A Kinetic Model for the Selective Catalytic Reduction of NOx with NH3 over an Fe− zeolite Catalyst Résumé : The selective catalytic reduction of NOx with ammonia over an Fe−zeolite catalyst was investigated experimentally and a transient kinetic model was developed. The model includes reactions that describe ammonia storage and oxidation, NO oxidation, selective catalytic reduction (SCR) of NO and NO2, formation of N2O, ammonia inhibition and ammonium nitrate formation. The model can account for a broad range of experimental conditions in the presence of H2O, CO2, and O2 at temperatures from 150 to 650 °C. The catalyst stores ammonia at temperatures up to 400 °C and shows ammonia oxidation activity from 350 °C. The catalyst is also active for the oxidation of NO to NO2 and the oxidation reaches equilibrium at 500 °C. The SCR of NO is already active at 150 °C and the introduction of equal amounts of NO and NO2 greatly enhances the conversion of NOx at temperatures up to 300 °C. The formation of N2O is negligible if small fractions of NO2 are fed to the reactor, but a significant amount of N2O is formed at high NO2 to NO ratios. An ammonia inhibition on the SCR of NO is observed at 200 °C. This kinetic model contains 12 reactions and is able to describe the experimental results well. The model was validated using short transient experiments and experimental conditions not used in the parameter estimation and predicted these new conditions adequately. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9003464
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 39–52[article] A kinetic model for the selective catalytic reduction of NOx with NH3 over an fe−zeolite catalyst [texte imprimé] / Hanna Sjövall, Auteur ; Richard J. Blint, Auteur ; Ashok Gopinath, Auteur . - 2010 . - pp. 39–52.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 39–52
Mots-clés : A Kinetic Model for the Selective Catalytic Reduction of NOx with NH3 over an Fe− zeolite Catalyst Résumé : The selective catalytic reduction of NOx with ammonia over an Fe−zeolite catalyst was investigated experimentally and a transient kinetic model was developed. The model includes reactions that describe ammonia storage and oxidation, NO oxidation, selective catalytic reduction (SCR) of NO and NO2, formation of N2O, ammonia inhibition and ammonium nitrate formation. The model can account for a broad range of experimental conditions in the presence of H2O, CO2, and O2 at temperatures from 150 to 650 °C. The catalyst stores ammonia at temperatures up to 400 °C and shows ammonia oxidation activity from 350 °C. The catalyst is also active for the oxidation of NO to NO2 and the oxidation reaches equilibrium at 500 °C. The SCR of NO is already active at 150 °C and the introduction of equal amounts of NO and NO2 greatly enhances the conversion of NOx at temperatures up to 300 °C. The formation of N2O is negligible if small fractions of NO2 are fed to the reactor, but a significant amount of N2O is formed at high NO2 to NO ratios. An ammonia inhibition on the SCR of NO is observed at 200 °C. This kinetic model contains 12 reactions and is able to describe the experimental results well. The model was validated using short transient experiments and experimental conditions not used in the parameter estimation and predicted these new conditions adequately. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9003464 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Pure hydrogen production from pyrolysis oil using the steam−iron process : Effects of temperature and iron oxide conversion in the reduction Type de document : texte imprimé Auteurs : M. F. Bleeker, Auteur ; H. J. Veringa, Auteur ; S. R. A. Kersten, Auteur Année de publication : 2010 Article en page(s) : pp. 53–64 Note générale : Indusrtial chemistry Langues : Anglais (eng) Mots-clés : Pure Hydrogen Production from Pyrolysis Oil Using the Steam− Iron Process: Effects of Temperature and Iron Oxide Conversion in Reduction Résumé : In the steam−iron process, relatively pure hydrogen can be produced from pyrolysis oil in a redox cycle with iron oxides. Experiments in a fluidized bed showed that the hydrogen production from pyrolysis oil increases with increasing temperature during reduction. The experimental hydrogen production at nearly 1000 °C with noncatalytic (blast furnace) and catalytic (ammonia synthesis) iron oxide was found to be 1.39 and 1.82 Nm3 of H2/kg of dry oil, respectively. However, this high hydrogen production could be achieved only when a low relative conversion (α) of the iron oxide in the reduction was maintained (about 7%). It was found in all experiments that the reduction rate decreased strongly with increasing relative conversion of the iron oxide [at 800 °C, the relative conversion rate (dα/dt) decreased from 3.0 × 10−4 s−1 at α = 0.6% to 8.8 × 10−6 s−1 at α = 10.0%]. The gasification of pyrolysis oil over an iron oxide bed results in an increased carbon-to-gas conversion compared to gasification over a sand bed. Near-complete gasification of oil is achieved when temperatures above 900 °C are applied in a fluidized-bed setup containing iron oxide. A lumped reaction path scheme is proposed for char formation in pyrolysis oil gasification. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900530d
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 53–64[article] Pure hydrogen production from pyrolysis oil using the steam−iron process : Effects of temperature and iron oxide conversion in the reduction [texte imprimé] / M. F. Bleeker, Auteur ; H. J. Veringa, Auteur ; S. R. A. Kersten, Auteur . - 2010 . - pp. 53–64.
Indusrtial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 53–64
Mots-clés : Pure Hydrogen Production from Pyrolysis Oil Using the Steam− Iron Process: Effects of Temperature and Iron Oxide Conversion in Reduction Résumé : In the steam−iron process, relatively pure hydrogen can be produced from pyrolysis oil in a redox cycle with iron oxides. Experiments in a fluidized bed showed that the hydrogen production from pyrolysis oil increases with increasing temperature during reduction. The experimental hydrogen production at nearly 1000 °C with noncatalytic (blast furnace) and catalytic (ammonia synthesis) iron oxide was found to be 1.39 and 1.82 Nm3 of H2/kg of dry oil, respectively. However, this high hydrogen production could be achieved only when a low relative conversion (α) of the iron oxide in the reduction was maintained (about 7%). It was found in all experiments that the reduction rate decreased strongly with increasing relative conversion of the iron oxide [at 800 °C, the relative conversion rate (dα/dt) decreased from 3.0 × 10−4 s−1 at α = 0.6% to 8.8 × 10−6 s−1 at α = 10.0%]. The gasification of pyrolysis oil over an iron oxide bed results in an increased carbon-to-gas conversion compared to gasification over a sand bed. Near-complete gasification of oil is achieved when temperatures above 900 °C are applied in a fluidized-bed setup containing iron oxide. A lumped reaction path scheme is proposed for char formation in pyrolysis oil gasification. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900530d Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Calcium-incorporated mesoporous aluminosilicates : synthesis, characterization, and applications to the condensation of long-chain fatty acid with long-chain amine and alcohol Type de document : texte imprimé Auteurs : Ayyamperumal Sakthivel, Auteur ; Kenichi Komura, Auteur ; Shing-Jong Huang, Auteur Année de publication : 2010 Article en page(s) : pp. 65–71 Note générale : Indusrtial chemistry Langues : Anglais (eng) Mots-clés : Calcium-Incorporated Mesoporous Aluminosilicates: Synthesis, Characterization, and Applications to the Condensation of Long-Chain Fatty Acid with Amine Alcohol Résumé : A comprehensive study on a series of highly stable calcium containing mesoporous aluminosilicate molecular sieves (CaAlMMSH) having different acidic properties has been made by varying the Si/Ca ratio in synthesis gels. The structural, physical, and porous properties of these microporous/mesoporous composite materials were characterized by X-ray diffraction, N2 adsorption/desorption isotherm measurements, solid-state 27Al and 29Si magic angle spinning NMR, and variable-temperature hyperpolarized 129Xe NMR, Fourier transform infrared (FTIR) and diffuse reflectance FTIR spectroscopies. As compared to the parent AlMMSH materials, the incorporation of excessive amount of calcium tends to result in an overall increase in acid amount while at the expense of strong acid sites. The CaAlMMSH materials were found to have superior catalytic activities than AlMMSH in the amidation of palmitic acid with N-hexadecylamine. However, no significant enhancement in catalytic activity for the esterification of palmitic acid with cetyl alcohol was observed upon introducing calcium onto the AlMMSH materials. Such discrepancies were ascribed to variations in available acid sties and coking in the two different condensations reaction over the CaAlMMSH materials as catalysts. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900641u
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 65–71[article] Calcium-incorporated mesoporous aluminosilicates : synthesis, characterization, and applications to the condensation of long-chain fatty acid with long-chain amine and alcohol [texte imprimé] / Ayyamperumal Sakthivel, Auteur ; Kenichi Komura, Auteur ; Shing-Jong Huang, Auteur . - 2010 . - pp. 65–71.
Indusrtial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 65–71
Mots-clés : Calcium-Incorporated Mesoporous Aluminosilicates: Synthesis, Characterization, and Applications to the Condensation of Long-Chain Fatty Acid with Amine Alcohol Résumé : A comprehensive study on a series of highly stable calcium containing mesoporous aluminosilicate molecular sieves (CaAlMMSH) having different acidic properties has been made by varying the Si/Ca ratio in synthesis gels. The structural, physical, and porous properties of these microporous/mesoporous composite materials were characterized by X-ray diffraction, N2 adsorption/desorption isotherm measurements, solid-state 27Al and 29Si magic angle spinning NMR, and variable-temperature hyperpolarized 129Xe NMR, Fourier transform infrared (FTIR) and diffuse reflectance FTIR spectroscopies. As compared to the parent AlMMSH materials, the incorporation of excessive amount of calcium tends to result in an overall increase in acid amount while at the expense of strong acid sites. The CaAlMMSH materials were found to have superior catalytic activities than AlMMSH in the amidation of palmitic acid with N-hexadecylamine. However, no significant enhancement in catalytic activity for the esterification of palmitic acid with cetyl alcohol was observed upon introducing calcium onto the AlMMSH materials. Such discrepancies were ascribed to variations in available acid sties and coking in the two different condensations reaction over the CaAlMMSH materials as catalysts. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900641u Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Reaction mechanism and in situ ATR spectroscopic studies of the 1-decene ozonolysis in micro- and semibatch reactors Type de document : texte imprimé Auteurs : Norbert Steinfeldt, Auteur ; Ursula Bentrup, Auteur ; Klaus Jähnisch, Auteur Année de publication : 2010 Article en page(s) : pp. 72–80 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reaction Mechanism and in Situ ATR Spectroscopic Studies of the 1-Decene Ozonolysis Micro- Semibatch Reactors Résumé : The ozonolysis of 1-decene (1) was performed in a falling film microreactor and in a semibatch reactor using different solvents (CH2Cl2, CH3OH, or a mixture of both). The main products of ozonolysis were 3-octyl-1,2,4-trioxolane (7) in CH2Cl2 and 1-hydroperoxy-1-methoxynonane (8) in CH3OH or in a CH2Cl2/CH3OH mixture. In both cases the selectivities were higher than 70% and almost independent of 1-decene conversion and reaction temperature. The ozonolysis proceeds mainly via the cleavage of the primary ozonide into the long-chain carbonyl oxide (6) and formaldehyde (4). Besides off-line analysis in situ ATR-FTIR spectroscopic measurements using a diamond ATR probe were applied to follow the reaction progress. Integral intensities of characteristic IR bands correlate well with quantitative results obtained from gas chromatography/high-performance liquid chromatography analysis. Thus, in situ ATR proved to be a suitable method for fast and real-time monitoring of liquid-phase reactions even in the presence of unstable or explosive intermediates like ozonides and/or hydroperoxides. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900726s
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 72–80[article] Reaction mechanism and in situ ATR spectroscopic studies of the 1-decene ozonolysis in micro- and semibatch reactors [texte imprimé] / Norbert Steinfeldt, Auteur ; Ursula Bentrup, Auteur ; Klaus Jähnisch, Auteur . - 2010 . - pp. 72–80.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 72–80
Mots-clés : Reaction Mechanism and in Situ ATR Spectroscopic Studies of the 1-Decene Ozonolysis Micro- Semibatch Reactors Résumé : The ozonolysis of 1-decene (1) was performed in a falling film microreactor and in a semibatch reactor using different solvents (CH2Cl2, CH3OH, or a mixture of both). The main products of ozonolysis were 3-octyl-1,2,4-trioxolane (7) in CH2Cl2 and 1-hydroperoxy-1-methoxynonane (8) in CH3OH or in a CH2Cl2/CH3OH mixture. In both cases the selectivities were higher than 70% and almost independent of 1-decene conversion and reaction temperature. The ozonolysis proceeds mainly via the cleavage of the primary ozonide into the long-chain carbonyl oxide (6) and formaldehyde (4). Besides off-line analysis in situ ATR-FTIR spectroscopic measurements using a diamond ATR probe were applied to follow the reaction progress. Integral intensities of characteristic IR bands correlate well with quantitative results obtained from gas chromatography/high-performance liquid chromatography analysis. Thus, in situ ATR proved to be a suitable method for fast and real-time monitoring of liquid-phase reactions even in the presence of unstable or explosive intermediates like ozonides and/or hydroperoxides. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900726s Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Catalytic deoxygenation of water : preparation, deactivation, and regeneration of palladium on a resin catalyst Type de document : texte imprimé Auteurs : Martín S. Gross, Auteur ; María L. Pisarello, Auteur ; Karina A. Pierpauli, Auteur Année de publication : 2010 Article en page(s) : pp. 81–88 Note générale : Industrail chemistry Langues : Anglais (eng) Mots-clés : Catalytic--Deoxygenation--Water--Preparation--Deactivation--Regeneration--Palladium--Resin Catalyst Résumé : Oxygen dissolved in water is a cause of corrosion in heating installations. On the other hand, in the production of beverages such as beer, it leads to the oxidation of organic matter, decreasing the quality of the product. Therefore, its content must be substantially reduced.
In this work, the catalytic deoxygenation of water using a palladium catalyst is studied. The catalyst consists of palladium ion-exchanged on a weak-basic macroporous resin. This work addresses the catalytic deactivation and regeneration of this type of catalyst, comparing results obtained in the laboratory with those obtained from an industrial reactor used to deoxygenate water for beer production. Two deactivation mechanisms are observed: (i) In the short term, the deposition of organic material (humic acids) coming with the water is responsible for activity lost; (ii) in the long term, the cause of the irreversible deactivation is the palladium leaching that occurs during the cleaning-in-place procedure, which is carried out with sodium hydroxide solution at 60 °C. This deactivation occurs in the presence of dissolved oxygen and is strongly favored by the presence of chlorine in the water. This study indicates the conditions necessary to regenerate the catalyst and to largely improve the stability during operation−regeneration cycles.ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007369
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 81–88[article] Catalytic deoxygenation of water : preparation, deactivation, and regeneration of palladium on a resin catalyst [texte imprimé] / Martín S. Gross, Auteur ; María L. Pisarello, Auteur ; Karina A. Pierpauli, Auteur . - 2010 . - pp. 81–88.
Industrail chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 81–88
Mots-clés : Catalytic--Deoxygenation--Water--Preparation--Deactivation--Regeneration--Palladium--Resin Catalyst Résumé : Oxygen dissolved in water is a cause of corrosion in heating installations. On the other hand, in the production of beverages such as beer, it leads to the oxidation of organic matter, decreasing the quality of the product. Therefore, its content must be substantially reduced.
In this work, the catalytic deoxygenation of water using a palladium catalyst is studied. The catalyst consists of palladium ion-exchanged on a weak-basic macroporous resin. This work addresses the catalytic deactivation and regeneration of this type of catalyst, comparing results obtained in the laboratory with those obtained from an industrial reactor used to deoxygenate water for beer production. Two deactivation mechanisms are observed: (i) In the short term, the deposition of organic material (humic acids) coming with the water is responsible for activity lost; (ii) in the long term, the cause of the irreversible deactivation is the palladium leaching that occurs during the cleaning-in-place procedure, which is carried out with sodium hydroxide solution at 60 °C. This deactivation occurs in the presence of dissolved oxygen and is strongly favored by the presence of chlorine in the water. This study indicates the conditions necessary to regenerate the catalyst and to largely improve the stability during operation−regeneration cycles.ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007369 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Kinetic models for the coke combustion on deactivated ZSM-5/MOR derived from n-heptane cracking Type de document : texte imprimé Auteurs : Ning Zhu, Auteur ; Yuan-yuan Liu, Auteur ; Yang Wang, Auteur Année de publication : 2010 Article en page(s) : pp. 89–93 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetic Models--Coke--Combustion--Deactivated--ZSM-5/MOR--Derived from n-Heptane--Cracking Résumé : The combustion behavior of coked H−ZSM-5/H−mordenite (ZSM-5/MOR) derived from catalytic cracking of n-heptane with and without water steam has been studied by thermogravimetric analysis (TGA). Catalytic cracking under vapor atmosphere with a water−oil ratio of 2 at 650 °C created only one type of coke deposit on the catalyst. On the other hand, two types of coke can be found on the coked catalyst deactivated by catalytic cracking without water steam. These results indicated different combustion kinetic models of different types of coke. A one-coke combustion model for the regeneration of coked catalyst obtained under water steam and a two-coke combustion model for the regeneration of coked catalyst derived without water steam were conducted by using TGA, respectively. Finally, the relationship between the C/H ratios and activation energies in the combustion kinetic models were investigated by ultimate analysis. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900855y
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 89–93[article] Kinetic models for the coke combustion on deactivated ZSM-5/MOR derived from n-heptane cracking [texte imprimé] / Ning Zhu, Auteur ; Yuan-yuan Liu, Auteur ; Yang Wang, Auteur . - 2010 . - pp. 89–93.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 89–93
Mots-clés : Kinetic Models--Coke--Combustion--Deactivated--ZSM-5/MOR--Derived from n-Heptane--Cracking Résumé : The combustion behavior of coked H−ZSM-5/H−mordenite (ZSM-5/MOR) derived from catalytic cracking of n-heptane with and without water steam has been studied by thermogravimetric analysis (TGA). Catalytic cracking under vapor atmosphere with a water−oil ratio of 2 at 650 °C created only one type of coke deposit on the catalyst. On the other hand, two types of coke can be found on the coked catalyst deactivated by catalytic cracking without water steam. These results indicated different combustion kinetic models of different types of coke. A one-coke combustion model for the regeneration of coked catalyst obtained under water steam and a two-coke combustion model for the regeneration of coked catalyst derived without water steam were conducted by using TGA, respectively. Finally, the relationship between the C/H ratios and activation energies in the combustion kinetic models were investigated by ultimate analysis. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900855y Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Catalytic partial oxidation pilot plant study Type de document : texte imprimé Auteurs : Vasilis Papavassiliou, Auteur ; Perry Pacouloute, Auteur ; KT Wu, Auteur Année de publication : 2010 Article en page(s) : pp. 94–103 Note générale : Industrail chemistry Langues : Anglais (eng) Mots-clés : Catalytic--Partial--Oxidation--Pilot--Plant--Study Résumé : A new high-pressure catalytic partial oxidation reactor was developed for high-pressure production of synthesis gas from natural gas and pure oxygen, and the integration of the new reactor with the gas to liquids process was investigated. The experimental work was performed at Praxair’s laboratory, process design and economic estimates were performed by Foster Wheeler, and theoretical simulations were preformed by University of Delaware. The reactor system was based on a millisecond contact time mixer capable of delivering a fuel-oxygen mixture to the catalyst without onset of homogeneous reactions. Significant differences were observed between high- and low-pressure operation. With proper mixer and catalyst bed design the system was able to operate stably at pressures up to 18 bar with performance comparable to low-pressure operation. Process economic analysis predicted a small economic advantage for a catalytic partial oxidation reactor compared to conventional technology. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900872r
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 94–103[article] Catalytic partial oxidation pilot plant study [texte imprimé] / Vasilis Papavassiliou, Auteur ; Perry Pacouloute, Auteur ; KT Wu, Auteur . - 2010 . - pp. 94–103.
Industrail chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 94–103
Mots-clés : Catalytic--Partial--Oxidation--Pilot--Plant--Study Résumé : A new high-pressure catalytic partial oxidation reactor was developed for high-pressure production of synthesis gas from natural gas and pure oxygen, and the integration of the new reactor with the gas to liquids process was investigated. The experimental work was performed at Praxair’s laboratory, process design and economic estimates were performed by Foster Wheeler, and theoretical simulations were preformed by University of Delaware. The reactor system was based on a millisecond contact time mixer capable of delivering a fuel-oxygen mixture to the catalyst without onset of homogeneous reactions. Significant differences were observed between high- and low-pressure operation. With proper mixer and catalyst bed design the system was able to operate stably at pressures up to 18 bar with performance comparable to low-pressure operation. Process economic analysis predicted a small economic advantage for a catalytic partial oxidation reactor compared to conventional technology. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900872r Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Hydrothermal conversion of biomass. II. : conversion of wood, pyrolysis oil, and glucose in hot compressed water Type de document : texte imprimé Auteurs : Dragan Knežević, Auteur ; Wim van Swaaij, Auteur ; Sascha Kersten, Auteur Année de publication : 2010 Article en page(s) : pp. 104–112 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrothermal--Conversion--Biomass--Conversion--Pyrolysis Oil--Glucose--Hot Compressed--Water Résumé : In part I of this work, hydrothermal conversion (HTC) of glucose has been studied. In this part II of the study, the investigation is extended to two other feedstocks: wood and pyrolysis oil. The effects of residence time (0−60 min) and feedstock concentration (0−45 wt %) on product yields are studied at 350 °C. For all three investigated feedstocks: (i) oil, char, and gas are formed with two distinct rates (fast rates in the first 10 min, followed by slow rates after this time), (ii) deoxygenation proceeds via both dehydration and decarboxylation. Dehydration is an initial reaction (first 5 min) and leads to undesired lowering of the H/C ratio of the oil product. Two types of char have clearly been identified for HTC of wood: primary char (nonliquefied remainder of biomass) and secondary char (polymerization product). Only a small amount of primary char is formed, while at longer residence times, typically practiced in pilot and demonstration plants, the majority of char is produced in polymerization reactions in the liquid phase (reaction order > 1). Several catalysts have been tested for their ability to increase decarboxylation yield and reduce char formation. The Ru/TiO2 catalyst is able to convert WSIS (char) to gas, while leaving the oil product practically unaltered with respect to composition and yield. Visual observations have revealed that a single liquid phase appears to exist at the HTC reaction conditions and that phase splitting into an oil and a water phase occurs in the temperature range of 180−220 °C. The engineering reaction path model, proposed for glucose in part I of this work, is extended for use with solid biomass and pyrolysis oil. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900964u
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 104–112[article] Hydrothermal conversion of biomass. II. : conversion of wood, pyrolysis oil, and glucose in hot compressed water [texte imprimé] / Dragan Knežević, Auteur ; Wim van Swaaij, Auteur ; Sascha Kersten, Auteur . - 2010 . - pp. 104–112.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 104–112
Mots-clés : Hydrothermal--Conversion--Biomass--Conversion--Pyrolysis Oil--Glucose--Hot Compressed--Water Résumé : In part I of this work, hydrothermal conversion (HTC) of glucose has been studied. In this part II of the study, the investigation is extended to two other feedstocks: wood and pyrolysis oil. The effects of residence time (0−60 min) and feedstock concentration (0−45 wt %) on product yields are studied at 350 °C. For all three investigated feedstocks: (i) oil, char, and gas are formed with two distinct rates (fast rates in the first 10 min, followed by slow rates after this time), (ii) deoxygenation proceeds via both dehydration and decarboxylation. Dehydration is an initial reaction (first 5 min) and leads to undesired lowering of the H/C ratio of the oil product. Two types of char have clearly been identified for HTC of wood: primary char (nonliquefied remainder of biomass) and secondary char (polymerization product). Only a small amount of primary char is formed, while at longer residence times, typically practiced in pilot and demonstration plants, the majority of char is produced in polymerization reactions in the liquid phase (reaction order > 1). Several catalysts have been tested for their ability to increase decarboxylation yield and reduce char formation. The Ru/TiO2 catalyst is able to convert WSIS (char) to gas, while leaving the oil product practically unaltered with respect to composition and yield. Visual observations have revealed that a single liquid phase appears to exist at the HTC reaction conditions and that phase splitting into an oil and a water phase occurs in the temperature range of 180−220 °C. The engineering reaction path model, proposed for glucose in part I of this work, is extended for use with solid biomass and pyrolysis oil. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900964u Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Studies on kinetics and reuse of spent liquor in the TEMPO-mediated selective oxidation of mechanical pulp Type de document : texte imprimé Auteurs : Lianshan Mao, Auteur ; Pu Ma, Auteur ; Kweinam Law, Auteur Année de publication : 2010 Article en page(s) : pp. 113–116 Note générale : Industrail chemistry Langues : Anglais (eng) Mots-clés : Studies--kinetics--reuse--spent--liquor--TEMPO-mediated selective--oxidation--mechanical pulp Résumé : The kinetics and reuse of spent liquor in the TEMPO-mediated oxidation of mechanical pulp have been studied. It was found that the oxidation reaction of the mechanical pulp by the 2,2,6,6-tetramethyl piperidine-1-oxyl radical (TEMPO)−NaBr−NaOCl system can be approximately described by first-order kinetics with respect to TEMPO and NaBr. In the concentration range used, the rate constant k is directly proportional to the concentration of TEMPO and NaBr, whereas the concentration of NaOCl determines the end of conversion of the primary alcohol groups on the mechanical pulp into carboxylic acid groups. It was also found that the spent reaction liquor can be recycled and reused with reinforced addition of NaOCl without additional TEMPO and NaBr and remains effective in generating carboxylic acid groups on mechanical pulp. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901039r
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 113–116[article] Studies on kinetics and reuse of spent liquor in the TEMPO-mediated selective oxidation of mechanical pulp [texte imprimé] / Lianshan Mao, Auteur ; Pu Ma, Auteur ; Kweinam Law, Auteur . - 2010 . - pp. 113–116.
Industrail chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 113–116
Mots-clés : Studies--kinetics--reuse--spent--liquor--TEMPO-mediated selective--oxidation--mechanical pulp Résumé : The kinetics and reuse of spent liquor in the TEMPO-mediated oxidation of mechanical pulp have been studied. It was found that the oxidation reaction of the mechanical pulp by the 2,2,6,6-tetramethyl piperidine-1-oxyl radical (TEMPO)−NaBr−NaOCl system can be approximately described by first-order kinetics with respect to TEMPO and NaBr. In the concentration range used, the rate constant k is directly proportional to the concentration of TEMPO and NaBr, whereas the concentration of NaOCl determines the end of conversion of the primary alcohol groups on the mechanical pulp into carboxylic acid groups. It was also found that the spent reaction liquor can be recycled and reused with reinforced addition of NaOCl without additional TEMPO and NaBr and remains effective in generating carboxylic acid groups on mechanical pulp. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901039r Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Application of random-pore model to SO2 capture by lime Type de document : texte imprimé Auteurs : H. Ale Ebrahim, Auteur Année de publication : 2010 Article en page(s) : pp. 117–122 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Application--Random-Pore--Model--SO2 Capture--Lime Résumé : Flue gas desulfurization by lime (CaO) is widely used for coal-based power plants. The incomplete conversion of CaO poses a significant problem for such systems. An interesting method for increasing the pore radius of lime by a weak acid has been presented in the literature as a means to solve this problem. In this article, the random-pore model was applied to model the above experimental work successfully. Therefore, the effect of the CaO pore size distribution on the final conversion for SO2 removal can be predicted by this model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901077b
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 117–122[article] Application of random-pore model to SO2 capture by lime [texte imprimé] / H. Ale Ebrahim, Auteur . - 2010 . - pp. 117–122.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 117–122
Mots-clés : Application--Random-Pore--Model--SO2 Capture--Lime Résumé : Flue gas desulfurization by lime (CaO) is widely used for coal-based power plants. The incomplete conversion of CaO poses a significant problem for such systems. An interesting method for increasing the pore radius of lime by a weak acid has been presented in the literature as a means to solve this problem. In this article, the random-pore model was applied to model the above experimental work successfully. Therefore, the effect of the CaO pore size distribution on the final conversion for SO2 removal can be predicted by this model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901077b Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Olefin production by catalytic transformation of crude bio-oil in a two-step process Type de document : texte imprimé Auteurs : Ana G. Gayubo, Auteur ; Beatriz Valle, Auteur ; Andrés T. Aguayo, Auteur Année de publication : 2010 Article en page(s) : pp. 123–131 Note générale : Industrail chemistry Langues : Anglais (eng) Mots-clés : Olefin--Production--Catalytic--Transformation--Crude--Bio-Oil----Two-Step Process Résumé : The valorization of crude bio-oil by catalytic transformation into hydrocarbons has been carried out in an online two-step (thermal-catalytic) process. The deposition of pyrolytic lignin, formed by polymerization of biomass-derived products, is enhanced in the thermal step. Volatiles are processed in a fluidized bed reactor with a catalyst that is hydrothermally stable and selective for olefin production, which has been based on a HZSM-5 zeolite. A study has been made of the effect of operating conditions (methanol content in the feed of bio-oil/methanol, temperature, space time, and time on stream) on bio-oil conversion, product lump yields and the selectivity of each individual C2−C4 olefin. These conditions also have a significant effect on deactivation, which is attributed to coke deposited on the catalyst. The TPO curves of coke combustion identify two fractions: one of thermal origin (pyrolytic lignin) and the other of catalytic origin, whose formation depends on the concentration of oxygenates in the reaction medium. A feed with 50 wt % of methanol, at 500 °C, with space time of 0.371 (g of catalyst) h (g of methanol)−1 allows a 94 wt % conversion of the bio-oil in the feed, with a selectivity of C2−C4 olefins of 48 wt % (50 wt % is propene) and low yields of CO and CO2 (its formation is attenuated by cofeeding methanol). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901204n
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 123–131[article] Olefin production by catalytic transformation of crude bio-oil in a two-step process [texte imprimé] / Ana G. Gayubo, Auteur ; Beatriz Valle, Auteur ; Andrés T. Aguayo, Auteur . - 2010 . - pp. 123–131.
Industrail chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 123–131
Mots-clés : Olefin--Production--Catalytic--Transformation--Crude--Bio-Oil----Two-Step Process Résumé : The valorization of crude bio-oil by catalytic transformation into hydrocarbons has been carried out in an online two-step (thermal-catalytic) process. The deposition of pyrolytic lignin, formed by polymerization of biomass-derived products, is enhanced in the thermal step. Volatiles are processed in a fluidized bed reactor with a catalyst that is hydrothermally stable and selective for olefin production, which has been based on a HZSM-5 zeolite. A study has been made of the effect of operating conditions (methanol content in the feed of bio-oil/methanol, temperature, space time, and time on stream) on bio-oil conversion, product lump yields and the selectivity of each individual C2−C4 olefin. These conditions also have a significant effect on deactivation, which is attributed to coke deposited on the catalyst. The TPO curves of coke combustion identify two fractions: one of thermal origin (pyrolytic lignin) and the other of catalytic origin, whose formation depends on the concentration of oxygenates in the reaction medium. A feed with 50 wt % of methanol, at 500 °C, with space time of 0.371 (g of catalyst) h (g of methanol)−1 allows a 94 wt % conversion of the bio-oil in the feed, with a selectivity of C2−C4 olefins of 48 wt % (50 wt % is propene) and low yields of CO and CO2 (its formation is attenuated by cofeeding methanol). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901204n Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Effect of polymer granules on the electrostatic behavior in gas−solid fluidized beds Type de document : texte imprimé Auteurs : Xianbo Yu, Auteur ; Wei Li, Auteur ; Yi Xu, Auteur Année de publication : 2010 Article en page(s) : pp. 132–139 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Effect--Polymer Granules--Electrostatic--Gas− Solid--Fluidized Beds Résumé : Granules polymers electrostatic behavior in a fluidized bed can be complicated by the differences in catalyst residue and surface properties among them. Electrically charged particles cling together in large aggregates and adhere to the wall of the apparatus. Polymer particles with the same chemical composition but different sizes would have their own special contributions to the generation of static charges. It is improtant to understand polymer particles role on electrostatic charge generation and dissipation. Experiments are carried out in a gas−solid fluidized bed with nitrogen as the fluidization gas to determine the relationship between the electrostatic charge level and the size of the polyethylene granule. By measuring the electrostatic potentials at different bed axial heights, it is found that the electric field inside the bed is significantly influenced by the size, weight fractions, and catalyst residue of added granular polyethylene. Consequently, an impact factor of granules (Fb) is proposed to study the influence of particle size and the weight percent of the residual catalyst to the electrostatic potentials. And it is found that the greater the degree of fineness of the granules, the more percentage of the residual catalyst in the particles, which results in the stronger affect on the electrostatic behavior in the fluidized bed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8017077
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 132–139[article] Effect of polymer granules on the electrostatic behavior in gas−solid fluidized beds [texte imprimé] / Xianbo Yu, Auteur ; Wei Li, Auteur ; Yi Xu, Auteur . - 2010 . - pp. 132–139.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 132–139
Mots-clés : Effect--Polymer Granules--Electrostatic--Gas− Solid--Fluidized Beds Résumé : Granules polymers electrostatic behavior in a fluidized bed can be complicated by the differences in catalyst residue and surface properties among them. Electrically charged particles cling together in large aggregates and adhere to the wall of the apparatus. Polymer particles with the same chemical composition but different sizes would have their own special contributions to the generation of static charges. It is improtant to understand polymer particles role on electrostatic charge generation and dissipation. Experiments are carried out in a gas−solid fluidized bed with nitrogen as the fluidization gas to determine the relationship between the electrostatic charge level and the size of the polyethylene granule. By measuring the electrostatic potentials at different bed axial heights, it is found that the electric field inside the bed is significantly influenced by the size, weight fractions, and catalyst residue of added granular polyethylene. Consequently, an impact factor of granules (Fb) is proposed to study the influence of particle size and the weight percent of the residual catalyst to the electrostatic potentials. And it is found that the greater the degree of fineness of the granules, the more percentage of the residual catalyst in the particles, which results in the stronger affect on the electrostatic behavior in the fluidized bed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8017077 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : High throughput methodology for continuous preparation of hydroxyapatite nanoparticles in a microporous tube-in-tube microchannel reactor Type de document : texte imprimé Auteurs : Qing Yang, Auteur ; Jie-Xin Wang, Auteur ; Lei Shao, Auteur Année de publication : 2010 Article en page(s) : pp. 140–147 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Throughput--Methodology--Continuous--Hydroxyapatite--Nanoparticles--Microporous--Tube-in-Tube--Microchannel Reactor Résumé : A microporous tube-in-tube microchannel reactor (MTMCR) was successfully adopted to prepare hydroxyapatite (HAP) nanoparticles. The rodlike HAP nanoparticles with a mean size of 58 nm, a specific surface area of 49.32 m2/g, and a narrow size distribution were obtained in an MTMCR under a high throughput of 3 L/min. The mean particle size sharply decreased with increasing the continuous phase flow rate, while first decreased and subsequently increased with increasing the dispersed phase flow rate and the reactant concentration. The extension of the mixing distance led to the initial rapid and following slight decrease of the mean particle size. The size of HAP nanoparticles was also strongly dependent on the micropore size on the surface of inner tube. Small micropore size was beneficial for producing small particles. For comparison, HAP nanoparticles were also prepared in a stirred tank reactor (STR) and a T-junction microchannel reactor (TMCR), clearly exhibiting the advantages of the MTMCR over the STR and TMCR due to the achievement of uniformly smaller HAP nanoparticles and a high throughput for industrial production. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005436
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 140–147[article] High throughput methodology for continuous preparation of hydroxyapatite nanoparticles in a microporous tube-in-tube microchannel reactor [texte imprimé] / Qing Yang, Auteur ; Jie-Xin Wang, Auteur ; Lei Shao, Auteur . - 2010 . - pp. 140–147.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 140–147
Mots-clés : Throughput--Methodology--Continuous--Hydroxyapatite--Nanoparticles--Microporous--Tube-in-Tube--Microchannel Reactor Résumé : A microporous tube-in-tube microchannel reactor (MTMCR) was successfully adopted to prepare hydroxyapatite (HAP) nanoparticles. The rodlike HAP nanoparticles with a mean size of 58 nm, a specific surface area of 49.32 m2/g, and a narrow size distribution were obtained in an MTMCR under a high throughput of 3 L/min. The mean particle size sharply decreased with increasing the continuous phase flow rate, while first decreased and subsequently increased with increasing the dispersed phase flow rate and the reactant concentration. The extension of the mixing distance led to the initial rapid and following slight decrease of the mean particle size. The size of HAP nanoparticles was also strongly dependent on the micropore size on the surface of inner tube. Small micropore size was beneficial for producing small particles. For comparison, HAP nanoparticles were also prepared in a stirred tank reactor (STR) and a T-junction microchannel reactor (TMCR), clearly exhibiting the advantages of the MTMCR over the STR and TMCR due to the achievement of uniformly smaller HAP nanoparticles and a high throughput for industrial production. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005436 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Development of a closed form nonlinear predictive control law based on a class of wiener models Type de document : texte imprimé Auteurs : Shraddha Deshpande, Auteur ; Sachin C. Patwardhan, Auteur ; Ravi Methekar, Auteur Année de publication : 2010 Article en page(s) : pp. 148–165 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Development--Closed--Nonlinear--Predictive--Control--Class--Wiener Models Résumé : Nonlinear model predictive control (NMPC) is increasingly being used for controlling microscale and system-on-chip devices, which exhibit complex and very fast dynamics. For effective control of such systems it is necessary to develop computationally efficient approaches for solving the NMPC problem. In this work, a Wiener type model has been used for capturing dynamics of multivariable nonlinear systems with fading memory. The resulting discrete nonlinear state space model is used to generate multistep predictions and formulate an unconstrained NMPC problem. A closed form solution to this problem is constructed analytically using the theory of solutions of quadratic operator polynomials. The effectiveness of the resulting quadratic control law is demonstrated by conducting simulation studies on a proton exchange membrane fuel cell (PEMFC) system, which exhibits fast dynamics and input multiplicity behavior. The quadratic control law is expected to control the PEMFC at its optimum (singular) operating point. The proposed laws achieve a fast and smooth transition from a suboptimal operating point to the optimum operating point with significantly small computation time. The proposed law is also found to be robust in the face of moderate perturbation in the unmeasured disturbances. The simulation results are validated by conducting experimental studies on a single cell PEMFC system and a benchmark heater−mixer setup that exhibits input multiplicity behavior. Through the experimental studies, we demonstrate that the proposed quadratic control law is able to operate the system at a singular operating point and establish the feasibility of employing the proposed control law for systems with very fast dynamics. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801284b
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 148–165[article] Development of a closed form nonlinear predictive control law based on a class of wiener models [texte imprimé] / Shraddha Deshpande, Auteur ; Sachin C. Patwardhan, Auteur ; Ravi Methekar, Auteur . - 2010 . - pp. 148–165.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 148–165
Mots-clés : Development--Closed--Nonlinear--Predictive--Control--Class--Wiener Models Résumé : Nonlinear model predictive control (NMPC) is increasingly being used for controlling microscale and system-on-chip devices, which exhibit complex and very fast dynamics. For effective control of such systems it is necessary to develop computationally efficient approaches for solving the NMPC problem. In this work, a Wiener type model has been used for capturing dynamics of multivariable nonlinear systems with fading memory. The resulting discrete nonlinear state space model is used to generate multistep predictions and formulate an unconstrained NMPC problem. A closed form solution to this problem is constructed analytically using the theory of solutions of quadratic operator polynomials. The effectiveness of the resulting quadratic control law is demonstrated by conducting simulation studies on a proton exchange membrane fuel cell (PEMFC) system, which exhibits fast dynamics and input multiplicity behavior. The quadratic control law is expected to control the PEMFC at its optimum (singular) operating point. The proposed laws achieve a fast and smooth transition from a suboptimal operating point to the optimum operating point with significantly small computation time. The proposed law is also found to be robust in the face of moderate perturbation in the unmeasured disturbances. The simulation results are validated by conducting experimental studies on a single cell PEMFC system and a benchmark heater−mixer setup that exhibits input multiplicity behavior. Through the experimental studies, we demonstrate that the proposed quadratic control law is able to operate the system at a singular operating point and establish the feasibility of employing the proposed control law for systems with very fast dynamics. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801284b Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Extended interval-based mixed integer nonlinear programming superstructure synthesis of heat and mass exchanger networks Type de document : texte imprimé Auteurs : Adeniyi J. Isafiade, Auteur ; Duncan M. Fraser, Auteur Année de publication : 2010 Article en page(s) : pp. 166–179 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Extended--Interval-Based--Integer--Nonlinear--Programming--Superstructure--Synthesis--Heat and Mass--Exchanger Networks Résumé : In this paper we present a method for extending the interval-based mixed integer nonlinear programming superstructure (IBMS) model of Isafiade and Fraser [Chem. Eng. Res. Des. 2008, 86, 245−257; 909−924] for heat and mass exchanger networks synthesis to handle split streams going through two or more exchangers in series. A major shortcoming of the IBMS generation approach is that only parallel heat/mass exchange can take place for split streams. Individual split stream branches cannot exchange heat/mass in more than one exchanger since split streams must be mixed immediately after exchanging heat/mass in order to define the next interval boundary temperature/composition. A major deficiency of this is the tendency for the search space to be reduced thereby limiting the number of possible network configurations which can be generated. A method for overcoming this shortcoming is presented in this paper. The approach involves splitting every stream into subsuperstructures just before it enters into the parent superstructure and subsequently mixing the split streams while exiting the subsuperstructures. The new method has been applied to literature example problems to demonstrate its benefits. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801823n
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 166–179[article] Extended interval-based mixed integer nonlinear programming superstructure synthesis of heat and mass exchanger networks [texte imprimé] / Adeniyi J. Isafiade, Auteur ; Duncan M. Fraser, Auteur . - 2010 . - pp. 166–179.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 166–179
Mots-clés : Extended--Interval-Based--Integer--Nonlinear--Programming--Superstructure--Synthesis--Heat and Mass--Exchanger Networks Résumé : In this paper we present a method for extending the interval-based mixed integer nonlinear programming superstructure (IBMS) model of Isafiade and Fraser [Chem. Eng. Res. Des. 2008, 86, 245−257; 909−924] for heat and mass exchanger networks synthesis to handle split streams going through two or more exchangers in series. A major shortcoming of the IBMS generation approach is that only parallel heat/mass exchange can take place for split streams. Individual split stream branches cannot exchange heat/mass in more than one exchanger since split streams must be mixed immediately after exchanging heat/mass in order to define the next interval boundary temperature/composition. A major deficiency of this is the tendency for the search space to be reduced thereby limiting the number of possible network configurations which can be generated. A method for overcoming this shortcoming is presented in this paper. The approach involves splitting every stream into subsuperstructures just before it enters into the parent superstructure and subsequently mixing the split streams while exiting the subsuperstructures. The new method has been applied to literature example problems to demonstrate its benefits. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801823n Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Online phase length optimization for a sequencing batch reactor by means of the hotelling’s T2 statistic Type de document : texte imprimé Auteurs : Kris Villez, Auteur ; Christian Rosén, Auteur ; Eline D’hooge, Auteur Année de publication : 2010 Article en page(s) : pp. 180–188 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Online--Length--Optimization--Sequencing--Batch--Reactor--Means--Hotelling’s T2--Statistic Résumé : Wastewater treatment systems have, over the past decades, been subjects for optimization and control research. One of the most intricate problems faced is that direct measurements of the variables of interest are seldom available. A large part of research has therefore been aimed at the extraction of suitable information from indirect measurements such as dissolved oxygen, pH, and oxidation reduction potential (ORP). Even if relatively complex tools, such as neural networks and fuzzy logic, have been used to conceive control laws, advantage is seldom taken of such tools with respect to development of the actual control algorithm. In this paper, a simple yet effective tool is presented that allows the detection of a desired process state by means of the Hotelling’s T2 statistic. The detection tool is generic in nature and is thereby applicable to any process where a certain desired state is to be detected by means of measured variables reflecting the targeted state. Its advantages over formerly proposed control strategies are discussed, and the precautions that were taken to render its application robust are presented. It is shown by means of a laboratory-scale sequencing batch reactor (SBR) setup for nutrient removal from wastewater that the proposed controller allows one to detect the targeted endogenous state and that its application leads to effective optimization of the overall system performance. More specifically, the length of the optimized phase is reduced by 41% of its original default length and a reduction of 5% is estimated for the expected energy consumption by the aeration system. In addition, effluent concentrations of total nitrogen and nitrate nitrogen are estimated to be lower by 30 and 25%, respectively. This is attributed to the gained length of the anoxic phase subsequent to the aerobic phase. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801907n
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 180–188[article] Online phase length optimization for a sequencing batch reactor by means of the hotelling’s T2 statistic [texte imprimé] / Kris Villez, Auteur ; Christian Rosén, Auteur ; Eline D’hooge, Auteur . - 2010 . - pp. 180–188.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 180–188
Mots-clés : Online--Length--Optimization--Sequencing--Batch--Reactor--Means--Hotelling’s T2--Statistic Résumé : Wastewater treatment systems have, over the past decades, been subjects for optimization and control research. One of the most intricate problems faced is that direct measurements of the variables of interest are seldom available. A large part of research has therefore been aimed at the extraction of suitable information from indirect measurements such as dissolved oxygen, pH, and oxidation reduction potential (ORP). Even if relatively complex tools, such as neural networks and fuzzy logic, have been used to conceive control laws, advantage is seldom taken of such tools with respect to development of the actual control algorithm. In this paper, a simple yet effective tool is presented that allows the detection of a desired process state by means of the Hotelling’s T2 statistic. The detection tool is generic in nature and is thereby applicable to any process where a certain desired state is to be detected by means of measured variables reflecting the targeted state. Its advantages over formerly proposed control strategies are discussed, and the precautions that were taken to render its application robust are presented. It is shown by means of a laboratory-scale sequencing batch reactor (SBR) setup for nutrient removal from wastewater that the proposed controller allows one to detect the targeted endogenous state and that its application leads to effective optimization of the overall system performance. More specifically, the length of the optimized phase is reduced by 41% of its original default length and a reduction of 5% is estimated for the expected energy consumption by the aeration system. In addition, effluent concentrations of total nitrogen and nitrate nitrogen are estimated to be lower by 30 and 25%, respectively. This is attributed to the gained length of the anoxic phase subsequent to the aerobic phase. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801907n Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Temperature control of the BTX divided-wall column Type de document : texte imprimé Auteurs : Hao Ling, Auteur Année de publication : 2010 Article en page(s) : pp. 189–203 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Temperature--BTX Divided-Wall--Column Résumé : The control of a divided-wall column is more difficult than the control of a conventional two-column separation sequence for the separation of ternary mixtures because there is more interaction among control loops. In a previous paper, a control structure using four composition loops was shown to provide effective control of the purities of the three product streams and also achieve minimum energy consumption for both feed flow rate and feed composition disturbances. The numerical example studied the separation of benzene, toluene, and o-xylene. The four manipulated variables were reflux flow rate (R), side-stream flow rate (S), reboiler heat input (QR), and liquid split (βL) at the top of the wall. In this paper we explore the use of temperatures to avoid expensive and high-maintenance composition analyzers. Two types of temperature control structures are studied. In the first, three temperatures located in the main column and one temperature on the prefractionator side of the wall are used to adjust the four manipulated variables. Feed flow rate disturbances are well handled with this structure, but product purities start to deviate significantly from their desired values for feed composition changes greater than about 10%. In the second control structure, four differential temperature control loops are used. Performance is improved and disturbances of 20% in feed composition are well handled with only small deviations in product purities. This structure also handles large changes in column operating pressure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900125w
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 189–203[article] Temperature control of the BTX divided-wall column [texte imprimé] / Hao Ling, Auteur . - 2010 . - pp. 189–203.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 189–203
Mots-clés : Temperature--BTX Divided-Wall--Column Résumé : The control of a divided-wall column is more difficult than the control of a conventional two-column separation sequence for the separation of ternary mixtures because there is more interaction among control loops. In a previous paper, a control structure using four composition loops was shown to provide effective control of the purities of the three product streams and also achieve minimum energy consumption for both feed flow rate and feed composition disturbances. The numerical example studied the separation of benzene, toluene, and o-xylene. The four manipulated variables were reflux flow rate (R), side-stream flow rate (S), reboiler heat input (QR), and liquid split (βL) at the top of the wall. In this paper we explore the use of temperatures to avoid expensive and high-maintenance composition analyzers. Two types of temperature control structures are studied. In the first, three temperatures located in the main column and one temperature on the prefractionator side of the wall are used to adjust the four manipulated variables. Feed flow rate disturbances are well handled with this structure, but product purities start to deviate significantly from their desired values for feed composition changes greater than about 10%. In the second control structure, four differential temperature control loops are used. Performance is improved and disturbances of 20% in feed composition are well handled with only small deviations in product purities. This structure also handles large changes in column operating pressure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900125w Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Systematic statistical-based approach for product design : application to disinfectant formulations Type de document : texte imprimé Auteurs : Navid Omidbakhsh, Auteur ; Thomas A. Duever, Auteur ; Ali Elkamel, Auteur Année de publication : 2010 Article en page(s) : pp. 204–209 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Systematic--statistical-based--approach--product--design--application--disinfectant--formulations Résumé : Product formulation development is a difficult and challenging task. The challenges include modeling complex systems and chemicals. Various tests are performed, often on a trial and error basis, to evaluate the performance of the prototypes in the product development process. These tests can be very expensive and time-consuming. A methodology is presented to shorten the product development time and reduce the costs given a database of historical data. It is based on augmenting the existing data set through designed experiments. An empirical model is first developed by analyzing the augmented data set using least-squares regression analysis. The model is then inverted by using an optimization technique, and the product formulation can be predicted on the basis of the desired product specifications. An iterative, sequential approach is employed in which the knowledge gained at each stage is applied in a systematic manner to design further experiments so that the future efforts will need fewer trials. This methodology is illustrated by a case study of disinfectant formulations and is proven to be superior to conventional formulation design methods. These disinfectant formulations consist of primarily water and small amounts of surfactants, oxidizing agents, chelating agents, pH buffers, and pH adjusters and consequently the resulting products are clear liquids. Although the methodology is illustrated on disinfectant product development, it is introduced in this paper in a general way and can be implemented in other applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900196u
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 204–209[article] Systematic statistical-based approach for product design : application to disinfectant formulations [texte imprimé] / Navid Omidbakhsh, Auteur ; Thomas A. Duever, Auteur ; Ali Elkamel, Auteur . - 2010 . - pp. 204–209.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 204–209
Mots-clés : Systematic--statistical-based--approach--product--design--application--disinfectant--formulations Résumé : Product formulation development is a difficult and challenging task. The challenges include modeling complex systems and chemicals. Various tests are performed, often on a trial and error basis, to evaluate the performance of the prototypes in the product development process. These tests can be very expensive and time-consuming. A methodology is presented to shorten the product development time and reduce the costs given a database of historical data. It is based on augmenting the existing data set through designed experiments. An empirical model is first developed by analyzing the augmented data set using least-squares regression analysis. The model is then inverted by using an optimization technique, and the product formulation can be predicted on the basis of the desired product specifications. An iterative, sequential approach is employed in which the knowledge gained at each stage is applied in a systematic manner to design further experiments so that the future efforts will need fewer trials. This methodology is illustrated by a case study of disinfectant formulations and is proven to be superior to conventional formulation design methods. These disinfectant formulations consist of primarily water and small amounts of surfactants, oxidizing agents, chelating agents, pH buffers, and pH adjusters and consequently the resulting products are clear liquids. Although the methodology is illustrated on disinfectant product development, it is introduced in this paper in a general way and can be implemented in other applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900196u Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Plantwide control for throughput maximization : a case study Type de document : texte imprimé Auteurs : Rahul Kanodia, Auteur ; Nitin Kaistha, Auteur Année de publication : 2010 Article en page(s) : pp. 210–221 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Plantwide Control--Throughput--Maximization--Case Study Résumé : The impact of the basic plantwide regulatory control structure on maximizing the throughput using an explicit optimizing controller is quantitatively evaluated for a simple process module. The module consists of the reaction A + B → C occurring in a continuously stirred tank reactor followed by a distillation column separating the product from the recycled unreacted reactants. The column vapor boilup hitting a maximum acts as the bottleneck constraint limiting the throughput due to column flooding. Through an evaluation of reasonable plantwide control structures, the location of the throughput manipulator, the composition analyzer for overall component inventory balancing and the “local” column reflux management policy are shown to significantly affect the maximum throughput. Quantitative results show that locating the throughput manipulator close to and where possible at the bottleneck constraint reduces the throughput derating necessary due to disturbances. Designing the plantwide regulatory control system to minimize the process variability propagated into the bottleneck constraint emerges as the key heuristic from the case study. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900366r
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 210–221[article] Plantwide control for throughput maximization : a case study [texte imprimé] / Rahul Kanodia, Auteur ; Nitin Kaistha, Auteur . - 2010 . - pp. 210–221.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 210–221
Mots-clés : Plantwide Control--Throughput--Maximization--Case Study Résumé : The impact of the basic plantwide regulatory control structure on maximizing the throughput using an explicit optimizing controller is quantitatively evaluated for a simple process module. The module consists of the reaction A + B → C occurring in a continuously stirred tank reactor followed by a distillation column separating the product from the recycled unreacted reactants. The column vapor boilup hitting a maximum acts as the bottleneck constraint limiting the throughput due to column flooding. Through an evaluation of reasonable plantwide control structures, the location of the throughput manipulator, the composition analyzer for overall component inventory balancing and the “local” column reflux management policy are shown to significantly affect the maximum throughput. Quantitative results show that locating the throughput manipulator close to and where possible at the bottleneck constraint reduces the throughput derating necessary due to disturbances. Designing the plantwide regulatory control system to minimize the process variability propagated into the bottleneck constraint emerges as the key heuristic from the case study. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900366r Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Resiliency issues in integration of scheduling and control Type de document : texte imprimé Auteurs : Kishalay Mitra, Auteur ; Ravindra D. Gudi, Auteur ; Sachin C. Patwardhan, Auteur Année de publication : 2010 Article en page(s) : pp. 222–235 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Resiliency--Issues--Integration--Scheduling--Control Résumé : Integration of scheduling and control in process manufacturing systems has traditionally resulted in greater coordination between the different layers of hierarchy in optimization and control. However, the effectiveness of this coordination as well as the overall responsiveness of the manufacturing system could be greatly improved if such integration explicitly accounts for parametric variations at each of the layers. This paper proposes an approach to the problem of robust integration of the scheduling and control layers in an uncertainty analysis framework so as to yield robust manufacturing systems that can perform well in the presence of the parametric variations. The uncertainty analysis is performed here using different uncertainty approaches such as the chance constrained programming, fuzzy mathematical programming, and robust optimization. In this paper, we propose to analyze the impact of the uncertainty on the different manufacturing objectives in a multiobjective Pareto sense. The deterministic integrated scheduling and control model taken from published work [Flores-Tlacuahuac, A.; Grossmann, I. E. Ind. Eng. Chem. Res. 2006, 45, 6698] forms the basis of our work toward addressing the uncertainty issues. We demonstrate the development of improved and robust integration of the scheduling and control tasks using the proposed frameworks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900380s
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 222–235[article] Resiliency issues in integration of scheduling and control [texte imprimé] / Kishalay Mitra, Auteur ; Ravindra D. Gudi, Auteur ; Sachin C. Patwardhan, Auteur . - 2010 . - pp. 222–235.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 222–235
Mots-clés : Resiliency--Issues--Integration--Scheduling--Control Résumé : Integration of scheduling and control in process manufacturing systems has traditionally resulted in greater coordination between the different layers of hierarchy in optimization and control. However, the effectiveness of this coordination as well as the overall responsiveness of the manufacturing system could be greatly improved if such integration explicitly accounts for parametric variations at each of the layers. This paper proposes an approach to the problem of robust integration of the scheduling and control layers in an uncertainty analysis framework so as to yield robust manufacturing systems that can perform well in the presence of the parametric variations. The uncertainty analysis is performed here using different uncertainty approaches such as the chance constrained programming, fuzzy mathematical programming, and robust optimization. In this paper, we propose to analyze the impact of the uncertainty on the different manufacturing objectives in a multiobjective Pareto sense. The deterministic integrated scheduling and control model taken from published work [Flores-Tlacuahuac, A.; Grossmann, I. E. Ind. Eng. Chem. Res. 2006, 45, 6698] forms the basis of our work toward addressing the uncertainty issues. We demonstrate the development of improved and robust integration of the scheduling and control tasks using the proposed frameworks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900380s Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : State−time−space superstructure-based MINLP formulation for batch water-allocation network design Type de document : texte imprimé Auteurs : Li-Juan Li, Auteur ; Rui-Jie Zhou, Auteur ; Hong-Guang Dong, Auteur Année de publication : 2010 Article en page(s) : pp. 236–251 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : State− Time− Space--Superstructure-Based--MINLP--Formulation--Batch Water-Allocation--Network Design Résumé : The mathematical technique presented in this work deals with one step design of single- and multicontaminant batch water-allocation network (WAN), where batch production, water-reuse subsystems, and wastewater-treatment subsystems are all taken into account. In the first place, a flexible schedule model combining the merits of discrete and continuous time formulations is introduced to integrate batch production and WAN. Then, two novel state−time−space (STS) superstructures incorporating all basic elements (i.e., states, tasks, equipment, and time) are adopted to capture all production schemes and batch WAN configurations. Specifically, by adding novel components in the original superstructure, a series of optimal network structures with multistage splitting and mixing options which have never been contained within previous superstructure can be easily generated. Finally, a reliable optimization strategy, where deterministic and stochastic searching techniques are combined, is suggested to deal with the resulting mixed integer nonlinear programming (MINLP) model. Two illustrative examples are presented to demonstrate the effectiveness of the proposed approach. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900427b
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 236–251[article] State−time−space superstructure-based MINLP formulation for batch water-allocation network design [texte imprimé] / Li-Juan Li, Auteur ; Rui-Jie Zhou, Auteur ; Hong-Guang Dong, Auteur . - 2010 . - pp. 236–251.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 236–251
Mots-clés : State− Time− Space--Superstructure-Based--MINLP--Formulation--Batch Water-Allocation--Network Design Résumé : The mathematical technique presented in this work deals with one step design of single- and multicontaminant batch water-allocation network (WAN), where batch production, water-reuse subsystems, and wastewater-treatment subsystems are all taken into account. In the first place, a flexible schedule model combining the merits of discrete and continuous time formulations is introduced to integrate batch production and WAN. Then, two novel state−time−space (STS) superstructures incorporating all basic elements (i.e., states, tasks, equipment, and time) are adopted to capture all production schemes and batch WAN configurations. Specifically, by adding novel components in the original superstructure, a series of optimal network structures with multistage splitting and mixing options which have never been contained within previous superstructure can be easily generated. Finally, a reliable optimization strategy, where deterministic and stochastic searching techniques are combined, is suggested to deal with the resulting mixed integer nonlinear programming (MINLP) model. Two illustrative examples are presented to demonstrate the effectiveness of the proposed approach. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900427b Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Efficient recursive principal component analysis algorithms for process monitoring Type de document : texte imprimé Auteurs : Lamiaa M. Elshenawy, Auteur ; Shen Yin, Auteur ; Amol S. Naik, Auteur Année de publication : 2010 Article en page(s) : pp. 252–259 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Efficient Recursive Principal Component Analysis Algorithms for Process Monitoring Résumé : Principal component analysis (PCA) has been successfully applied in large scale process monitoring. However, classical PCA has some drawbacks: one of these aspects is the inability to deal with parameter-varying processes, where it interprets the natural changes in the process as faults, resulting in numerous false alarms. These false alarms threaten the credibility of the monitoring system. Therefore, recursive PCA (RPCA) algorithms are recommended. The most important challenge faced by these algorithms is the high computation costs, due to repeated eigenvalue decomposition (EVD) or singular value decomposition (SVD). Motivated by this issue, we present two RPCA algorithms that will greatly reduce the computation cost. The first algorithm is based on first-order perturbation analysis (FOP), which is a rank-one update of the eigenvalues and their corresponding eigenvectors of a sample covariance matrix. The second one is based on the data projection method (DPM), which is a simple and reliable approach for adaptive subspace tracking. The effectiveness of the presented RPCA algorithms is evaluated with an application of monitoring a nonisothermal continuous stirred tank reactor (CSTR) system. The results show the efficiency of these approaches compared to the classical PCA. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900720w
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 252–259[article] Efficient recursive principal component analysis algorithms for process monitoring [texte imprimé] / Lamiaa M. Elshenawy, Auteur ; Shen Yin, Auteur ; Amol S. Naik, Auteur . - 2010 . - pp. 252–259.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 252–259
Mots-clés : Efficient Recursive Principal Component Analysis Algorithms for Process Monitoring Résumé : Principal component analysis (PCA) has been successfully applied in large scale process monitoring. However, classical PCA has some drawbacks: one of these aspects is the inability to deal with parameter-varying processes, where it interprets the natural changes in the process as faults, resulting in numerous false alarms. These false alarms threaten the credibility of the monitoring system. Therefore, recursive PCA (RPCA) algorithms are recommended. The most important challenge faced by these algorithms is the high computation costs, due to repeated eigenvalue decomposition (EVD) or singular value decomposition (SVD). Motivated by this issue, we present two RPCA algorithms that will greatly reduce the computation cost. The first algorithm is based on first-order perturbation analysis (FOP), which is a rank-one update of the eigenvalues and their corresponding eigenvectors of a sample covariance matrix. The second one is based on the data projection method (DPM), which is a simple and reliable approach for adaptive subspace tracking. The effectiveness of the presented RPCA algorithms is evaluated with an application of monitoring a nonisothermal continuous stirred tank reactor (CSTR) system. The results show the efficiency of these approaches compared to the classical PCA. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900720w Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Operational planning of large-scale industrial batch plants under demand due date and amount uncertainty : II. conditional value-at-risk framework Type de document : texte imprimé Auteurs : Peter M. Verderame, Auteur ; Christodoulos A. Floudas, Auteur Année de publication : 2010 Article en page(s) : pp. 260–275 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Operational Planning of Large-Scale Industrial Batch Plants under Demand Due Date and Amount Uncertainty: II. Conditional Value-at-Risk Framework Résumé : A novel framework based on conditional value-at-risk theory has been applied to the problem of operational planning for large-scale industrial batch plants under demand due date and amount uncertainty. The nominal planning with production disaggregation model has been extended by means of conditional value-at-risk theory to address the objectives of providing a daily production profile that not only is a tight upper bound on the production capacity of the plant but also is immune to the various forms of demand uncertainty. An industrial case study was conducted to demonstrate the viability of the proposed approach, which involves the novel application of conditional value-at-risk theory to the problem of operational planning under demand due date and amount uncertainty. A comparative study that juxtaposes the proposed operational planning model and the robust operational planning with production disaggregation model presented in part I of this series of articles (Verderame and Floudas Ind. Eng. Chem. Res. 2009, 48, 7214) is introduced as well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900925k
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 260–275[article] Operational planning of large-scale industrial batch plants under demand due date and amount uncertainty : II. conditional value-at-risk framework [texte imprimé] / Peter M. Verderame, Auteur ; Christodoulos A. Floudas, Auteur . - 2010 . - pp. 260–275.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 260–275
Mots-clés : Operational Planning of Large-Scale Industrial Batch Plants under Demand Due Date and Amount Uncertainty: II. Conditional Value-at-Risk Framework Résumé : A novel framework based on conditional value-at-risk theory has been applied to the problem of operational planning for large-scale industrial batch plants under demand due date and amount uncertainty. The nominal planning with production disaggregation model has been extended by means of conditional value-at-risk theory to address the objectives of providing a daily production profile that not only is a tight upper bound on the production capacity of the plant but also is immune to the various forms of demand uncertainty. An industrial case study was conducted to demonstrate the viability of the proposed approach, which involves the novel application of conditional value-at-risk theory to the problem of operational planning under demand due date and amount uncertainty. A comparative study that juxtaposes the proposed operational planning model and the robust operational planning with production disaggregation model presented in part I of this series of articles (Verderame and Floudas Ind. Eng. Chem. Res. 2009, 48, 7214) is introduced as well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900925k Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Supply chain optimization for refinery with considerations of operation mode changeover and yield fluctuations Type de document : texte imprimé Auteurs : Jiali Yang, Auteur ; Haijie Gu, Auteur ; Gang Rong, Auteur Année de publication : 2010 Article en page(s) : pp. 276–287 Note générale : Industrail chemistry Langues : Anglais (eng) Mots-clés : Supply--Chain--Optimization--Refinery--Considerations--Operation--Changeover--Yield Fluctuations Résumé : Stochastic programming is employed to achieve optimization for the multiperiod supply chain problem in a refinery with multiple operation modes under the uncertainty of product yields. With dramatic fluctuations of product yields at the beginning of operation mode changeover, the product yields tends to stabilize after the changeover is finished. Markov chain is utilized here to describe the dynamic characteristic of product yield fluctuations. The distribution of yield fluctuation in each period is usually unknown since it depends on the decision variable of operation mode changeover. Therefore, the resulting chance constrained programming is more complicated than general situations where the distribution characteristic of stochastic variable is known in each period. This problem can be solved by the big-M method and by transforming chance constrained inequalities into a group of equivalent deterministic inequalities. This method provides a universal approach for similar chance constrained programming in which the distribution of stochastic variable depends on binary decision variables. Case studies show that the proposed modeling and solving approach can provide an effective decision-making guidance that balances confidence level and economic interests for supply chain optimization problems with multiple operation modes under yield uncertainty. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900968x
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 276–287[article] Supply chain optimization for refinery with considerations of operation mode changeover and yield fluctuations [texte imprimé] / Jiali Yang, Auteur ; Haijie Gu, Auteur ; Gang Rong, Auteur . - 2010 . - pp. 276–287.
Industrail chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 276–287
Mots-clés : Supply--Chain--Optimization--Refinery--Considerations--Operation--Changeover--Yield Fluctuations Résumé : Stochastic programming is employed to achieve optimization for the multiperiod supply chain problem in a refinery with multiple operation modes under the uncertainty of product yields. With dramatic fluctuations of product yields at the beginning of operation mode changeover, the product yields tends to stabilize after the changeover is finished. Markov chain is utilized here to describe the dynamic characteristic of product yield fluctuations. The distribution of yield fluctuation in each period is usually unknown since it depends on the decision variable of operation mode changeover. Therefore, the resulting chance constrained programming is more complicated than general situations where the distribution characteristic of stochastic variable is known in each period. This problem can be solved by the big-M method and by transforming chance constrained inequalities into a group of equivalent deterministic inequalities. This method provides a universal approach for similar chance constrained programming in which the distribution of stochastic variable depends on binary decision variables. Case studies show that the proposed modeling and solving approach can provide an effective decision-making guidance that balances confidence level and economic interests for supply chain optimization problems with multiple operation modes under yield uncertainty. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900968x Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Comparison of control strategies for dividing-wall columns Type de document : texte imprimé Auteurs : Ruben C. van Diggelen, Auteur ; Anton A. Kiss, Auteur ; Arnold W. Heemink, Auteur Année de publication : 2010 Article en page(s) : pp. 288–307 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Comparison--Control--Strategies--Dividing-Wall--Columns Résumé : Conventional ternary separations progressed via thermally coupled columns such as Petlyuk configuration to a novel design that integrates two distillation columns into one shell—a setup known today as dividing-wall column (DWC). The DWC concept is a major breakthrough in distillation technology, as it brings significant reduction in the capital invested as well as savings in the operating costs. However, the integration of two columns into one shell leads also to changes in the operating mode and ultimately in the controllability of the system. Although much of the literature focuses on the control of binary distillation columns, there are just a few studies on the controllability of DWC. In this work we explore the DWC control issues and make a comparison of various control strategies based on PID loops, within a multiloop framework (DB/LSV, DV/LSB, LB/DSV, LV/DSB) versus more advanced controllers such as LQG/LQR, GMC, and high order controllers obtained by H∞ controller synthesis and μ-synthesis. The controllers are applied to a dividing-wall column used in an industrial case study—the ternary separation of benzene−toluene−xylene. The performances of these control strategies and the dynamic response of the DWC is investigated in terms of product composition and flow rates, for various persistent disturbances in the feed flow rate and composition. Significantly shorter settling times can be achieved using the advanced controllers based on LQG/LQR, H∞ controller synthesis, and μ-synthesis. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010673
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 288–307[article] Comparison of control strategies for dividing-wall columns [texte imprimé] / Ruben C. van Diggelen, Auteur ; Anton A. Kiss, Auteur ; Arnold W. Heemink, Auteur . - 2010 . - pp. 288–307.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 288–307
Mots-clés : Comparison--Control--Strategies--Dividing-Wall--Columns Résumé : Conventional ternary separations progressed via thermally coupled columns such as Petlyuk configuration to a novel design that integrates two distillation columns into one shell—a setup known today as dividing-wall column (DWC). The DWC concept is a major breakthrough in distillation technology, as it brings significant reduction in the capital invested as well as savings in the operating costs. However, the integration of two columns into one shell leads also to changes in the operating mode and ultimately in the controllability of the system. Although much of the literature focuses on the control of binary distillation columns, there are just a few studies on the controllability of DWC. In this work we explore the DWC control issues and make a comparison of various control strategies based on PID loops, within a multiloop framework (DB/LSV, DV/LSB, LB/DSV, LV/DSB) versus more advanced controllers such as LQG/LQR, GMC, and high order controllers obtained by H∞ controller synthesis and μ-synthesis. The controllers are applied to a dividing-wall column used in an industrial case study—the ternary separation of benzene−toluene−xylene. The performances of these control strategies and the dynamic response of the DWC is investigated in terms of product composition and flow rates, for various persistent disturbances in the feed flow rate and composition. Significantly shorter settling times can be achieved using the advanced controllers based on LQG/LQR, H∞ controller synthesis, and μ-synthesis. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010673 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Optimal startup/shutdown operating policies with a recombinant strain continuously stirred bioreactor Type de document : texte imprimé Auteurs : Letizia Luperini-Enciso, Auteur ; Holda Purón-Zepeda, Auteur ; Lorena Pedraza-Segura, Auteur Année de publication : 2010 Article en page(s) : pp. 308–316 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Optimal--Startup--Shutdown--Operating--Policies--Recombinant--Strain--Continuously--Stirred--Bioreactor Résumé : In this work dynamic optimal startup and shutdown policies were computed and validated in an experimental lab-scale continuous bioreactor. Using the theoretical optimal profile, a reduction in the startup time was achieved when compared to simple steplike changes in the manipulated variables. Therefore, the use of optimal startup policies led to raw material savings. To test the optimal startup policies, two operating points were selected. Experiments were run at these conditions to fit kinetic rate constants leading to a reliable model representation of the addressed biosystem. The practical implementation of theoretical optimization results is not a trivial task, and this is a major contribution of the present work. This is true especially for the optimal dynamic shutdown results that are not, up to our best knowledge, reported in the open literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901138p
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 308–316[article] Optimal startup/shutdown operating policies with a recombinant strain continuously stirred bioreactor [texte imprimé] / Letizia Luperini-Enciso, Auteur ; Holda Purón-Zepeda, Auteur ; Lorena Pedraza-Segura, Auteur . - 2010 . - pp. 308–316.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 308–316
Mots-clés : Optimal--Startup--Shutdown--Operating--Policies--Recombinant--Strain--Continuously--Stirred--Bioreactor Résumé : In this work dynamic optimal startup and shutdown policies were computed and validated in an experimental lab-scale continuous bioreactor. Using the theoretical optimal profile, a reduction in the startup time was achieved when compared to simple steplike changes in the manipulated variables. Therefore, the use of optimal startup policies led to raw material savings. To test the optimal startup policies, two operating points were selected. Experiments were run at these conditions to fit kinetic rate constants leading to a reliable model representation of the addressed biosystem. The practical implementation of theoretical optimization results is not a trivial task, and this is a major contribution of the present work. This is true especially for the optimal dynamic shutdown results that are not, up to our best knowledge, reported in the open literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901138p Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Dynamics of an industrial fluidized-Bed granulator for urea production Type de document : texte imprimé Auteurs : Diego E. Bertín, Auteur ; Juliana Pina, Auteur ; Verónica Bucalá, Auteur Année de publication : 2010 Article en page(s) : pp. 317–326 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dynamics--Industrial--Fluidized-Bed--Granulator--Urea Production Résumé : Granulation is one of the fundamental operations in particulate processing; however, there is still need to provide insight into the complex dynamic state behavior of these units. The unsteady state of an industrial multichamber fluidized-bed granulator for urea production, with variable mass holdup, is studied under different imposed step changes in key operating variables. For the assayed disturbances, the unit dynamics is considerably slow. In fact, many important state variables (e.g., bed height, pressure drop, solid mass flow, etc.) required more than 1 h to achieve the new steady state. The observed nonsteady behavior indicates the need of an efficient control to return the system rapidly to the desired operational point. The discharge area, fluidization air flow rate, and temperature were determined to be the more appropriate manipulative variables, for granulator stability control purposes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901155a
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 317–326[article] Dynamics of an industrial fluidized-Bed granulator for urea production [texte imprimé] / Diego E. Bertín, Auteur ; Juliana Pina, Auteur ; Verónica Bucalá, Auteur . - 2010 . - pp. 317–326.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 317–326
Mots-clés : Dynamics--Industrial--Fluidized-Bed--Granulator--Urea Production Résumé : Granulation is one of the fundamental operations in particulate processing; however, there is still need to provide insight into the complex dynamic state behavior of these units. The unsteady state of an industrial multichamber fluidized-bed granulator for urea production, with variable mass holdup, is studied under different imposed step changes in key operating variables. For the assayed disturbances, the unit dynamics is considerably slow. In fact, many important state variables (e.g., bed height, pressure drop, solid mass flow, etc.) required more than 1 h to achieve the new steady state. The observed nonsteady behavior indicates the need of an efficient control to return the system rapidly to the desired operational point. The discharge area, fluidization air flow rate, and temperature were determined to be the more appropriate manipulative variables, for granulator stability control purposes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901155a Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Complex column design by application of column profile map techniques : sharp-split petlyuk column design Type de document : texte imprimé Auteurs : Simon T. Holland, Auteur ; Ronald Abbas, Auteur ; Diane Hildebrandt, Auteur Année de publication : 2010 Article en page(s) : pp. 327–349 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Complex--Column--Design--Application--Column Profile--Map Techniques--Sharp-Split--Petlyuk--Column Design Résumé : Currently employed short-cut design techniques have a tendency to be configuration-specific. Few can be applied to complex distillation configurations. In this work, we will demonstrate, in detail, the use of column profile maps (CPMs) for the comprehensive analysis and design of complex distillation systems by applying the CPM technique to the design of the fully thermally coupled (Petlyuk) distillation column at sharp-split conditions. It is shown that, for set product composition specifications and a set reflux ratio, only a small region of key parameters (vapor and liquid split ratios) result in feasible separations. These results—and, hence, the CPM design procedure—are validated by the work of Halvorsen in his 2001 Ph.D. thesis. It is also shown that the minimum reflux solution can be found using this methodology. The results are valid for all zeotropic separation syntheses. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801752r
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 327–349[article] Complex column design by application of column profile map techniques : sharp-split petlyuk column design [texte imprimé] / Simon T. Holland, Auteur ; Ronald Abbas, Auteur ; Diane Hildebrandt, Auteur . - 2010 . - pp. 327–349.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 327–349
Mots-clés : Complex--Column--Design--Application--Column Profile--Map Techniques--Sharp-Split--Petlyuk--Column Design Résumé : Currently employed short-cut design techniques have a tendency to be configuration-specific. Few can be applied to complex distillation configurations. In this work, we will demonstrate, in detail, the use of column profile maps (CPMs) for the comprehensive analysis and design of complex distillation systems by applying the CPM technique to the design of the fully thermally coupled (Petlyuk) distillation column at sharp-split conditions. It is shown that, for set product composition specifications and a set reflux ratio, only a small region of key parameters (vapor and liquid split ratios) result in feasible separations. These results—and, hence, the CPM design procedure—are validated by the work of Halvorsen in his 2001 Ph.D. thesis. It is also shown that the minimum reflux solution can be found using this methodology. The results are valid for all zeotropic separation syntheses. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801752r Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Extended ponchon−savarit method for graphically analyzing and designing lnternally heat-lntegrated distillation columns Type de document : texte imprimé Auteurs : Tsung-Jen Ho, Auteur ; Chi-Tsung Huang, Auteur ; Liang-Sun Lee, Auteur Année de publication : 2010 Article en page(s) : pp. 350–358 Langues : Anglais (eng) Mots-clés : Extended--Ponchon− Savarit--Method--Graphically--Analyzing--Designing--Internally Heat-Integrated--Distillation Columns Résumé : The heat-integrated distillation column, generally called HIDiC, applies the principle of internal heat integration between the rectifying section and the stripping section of a distillation column by increasing the temperature of the rectifying section with a compressor. In this work, a theoretical stage-to-stage study of a HIDiC based on the Ponchon−Savarit method is performed. Several HIDiC design variables, such as the number of theoretical stages, reboiler (or preheater) duty, minimum overall internal heat-transfer rate, and configuration, can easily be interpreted in the Ponchon−Savarit (Hxy) diagram. Such an approach brings new insights into and better understanding of the features of HIDiC. A preliminary (or shortcut) HIDiC design procedure using Hxy diagrams is also proposed. The obvious advantages are that the proposed method allows the direct design of a HIDiC and avoids trial-and-error design using a commercial simulator. In addition, the proposed graphical method can foresee possible pinch points before requiring use of a rigorous simulator. Furthermore, the proposed graphical estimation of internal stages of a HIDiC is applied to a binary methanol−water system and compared to the rigorous simulation results obtained using Aspen Plus. Moreover, the McCabe−Thiele diagram of the HIDiC is also drawn using the extended Ponchon−Savarit method and presented in this study. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005468
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 350–358[article] Extended ponchon−savarit method for graphically analyzing and designing lnternally heat-lntegrated distillation columns [texte imprimé] / Tsung-Jen Ho, Auteur ; Chi-Tsung Huang, Auteur ; Liang-Sun Lee, Auteur . - 2010 . - pp. 350–358.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 350–358
Mots-clés : Extended--Ponchon− Savarit--Method--Graphically--Analyzing--Designing--Internally Heat-Integrated--Distillation Columns Résumé : The heat-integrated distillation column, generally called HIDiC, applies the principle of internal heat integration between the rectifying section and the stripping section of a distillation column by increasing the temperature of the rectifying section with a compressor. In this work, a theoretical stage-to-stage study of a HIDiC based on the Ponchon−Savarit method is performed. Several HIDiC design variables, such as the number of theoretical stages, reboiler (or preheater) duty, minimum overall internal heat-transfer rate, and configuration, can easily be interpreted in the Ponchon−Savarit (Hxy) diagram. Such an approach brings new insights into and better understanding of the features of HIDiC. A preliminary (or shortcut) HIDiC design procedure using Hxy diagrams is also proposed. The obvious advantages are that the proposed method allows the direct design of a HIDiC and avoids trial-and-error design using a commercial simulator. In addition, the proposed graphical method can foresee possible pinch points before requiring use of a rigorous simulator. Furthermore, the proposed graphical estimation of internal stages of a HIDiC is applied to a binary methanol−water system and compared to the rigorous simulation results obtained using Aspen Plus. Moreover, the McCabe−Thiele diagram of the HIDiC is also drawn using the extended Ponchon−Savarit method and presented in this study. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005468 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Adsorption of CO2-containing gas mixtures over amine-bearing pore-expanded MCM-41 silica : application for gas purification Type de document : texte imprimé Auteurs : Youssef Belmabkhout, Auteur ; Rodrigo Serna-Guerrero, Auteur ; Abdelhamid Sayari, Auteur Année de publication : 2010 Article en page(s) : pp. 359–365 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption--CO2-Containing--Gas Mixtures--Amine-Bearing--Pore-Expanded--MCM-41 Silica: Application for Gas Purification Résumé : Adsorption of CO2 on triamine-grafted pore-expanded mesoporous silica, TRI-PE-MCM-41, was investigated from very low pressure to 1 bar at four temperatures (298, 308, 318, 328 K) using gravimetric measurements. TRI-PE-MCM-41 exhibited one of the highest equilibrium capacities compared to other typical CO2 adsorbents such as zeolites, activated carbons, and metal−organic frameworks (MOFs). In contrast, under the same pressure and temperature conditions, TRI-PE-MCM-41 exhibited very small uptakes of N2, CH4, H2, and O2. Column-breakthrough measurements of CO2 in mixtures with other species showed exceedingly high selectivity of CO2 over N2, CH4, H2, and O2 even at very low CO2 concentrations, indicating that TRI-PE-MCM-41 is suitable adsorbent for gas purification applications. Moreover, water vapor was found to have a beneficial effect on CO2 adsorption capacity even at very low CO2 partial pressure, e.g. 400 ppm, without adverse effect on CO2 selectivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900837t
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 359–365[article] Adsorption of CO2-containing gas mixtures over amine-bearing pore-expanded MCM-41 silica : application for gas purification [texte imprimé] / Youssef Belmabkhout, Auteur ; Rodrigo Serna-Guerrero, Auteur ; Abdelhamid Sayari, Auteur . - 2010 . - pp. 359–365.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 359–365
Mots-clés : Adsorption--CO2-Containing--Gas Mixtures--Amine-Bearing--Pore-Expanded--MCM-41 Silica: Application for Gas Purification Résumé : Adsorption of CO2 on triamine-grafted pore-expanded mesoporous silica, TRI-PE-MCM-41, was investigated from very low pressure to 1 bar at four temperatures (298, 308, 318, 328 K) using gravimetric measurements. TRI-PE-MCM-41 exhibited one of the highest equilibrium capacities compared to other typical CO2 adsorbents such as zeolites, activated carbons, and metal−organic frameworks (MOFs). In contrast, under the same pressure and temperature conditions, TRI-PE-MCM-41 exhibited very small uptakes of N2, CH4, H2, and O2. Column-breakthrough measurements of CO2 in mixtures with other species showed exceedingly high selectivity of CO2 over N2, CH4, H2, and O2 even at very low CO2 concentrations, indicating that TRI-PE-MCM-41 is suitable adsorbent for gas purification applications. Moreover, water vapor was found to have a beneficial effect on CO2 adsorption capacity even at very low CO2 partial pressure, e.g. 400 ppm, without adverse effect on CO2 selectivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900837t Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Composite membranes based on a selective chitosan−poly(ethylene glycol) hybrid layer : synthesis, characterization, and performance in oil−water purification Type de document : texte imprimé Auteurs : Bryan D. McCloskey, Auteur ; Hao Ju, Auteur ; Benny D. Freeman, Auteur Année de publication : 2010 Article en page(s) : pp. 366–373 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Composite--Membranes--Selective--Chitosan-Poly(ethylene glycol)--Hybrid Layer--Synthesis--Characterization--Performance--Oil-Water Purification Résumé : A series of poly(ethylene glycol) diglycidyl ether−cross-linked chitosan (chi−PEG hybrid) films were prepared to elucidate their potential as fouling-resistant ultrafiltration (UF) membrane coating layers. Water permeability increased as the poly(ethylene glycol) diglycidyl ether to chitosan ratio in the prepolymerization mixture increased due to increased porosity in the polymer matrix resulting from phase separation during polymerization. Composite membranes for oil−water emulsion filtration were prepared by coating an optimized member of the chi−PEG hybrid family onto a commercial polysulfone ultrafiltration membrane. Scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared spectroscopy (FTIR), and pure water permeance measurements indicated that, depending on the concentration of chitosan in the coating solution, the coating layer thickness could be controlled, so water permeance could be optimized. These composite membranes exhibited water flux values more than 5 times higher than that of uncoated membranes after 1 day of oily water crossflow filtration, indicating that the hydrophilic polymer coating significantly enhanced the fouling resistance of the underlying polysulfone membrane. The organic rejection of the coated membranes was also slightly higher than that of the uncoated polysulfone membranes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901197u
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 366–373[article] Composite membranes based on a selective chitosan−poly(ethylene glycol) hybrid layer : synthesis, characterization, and performance in oil−water purification [texte imprimé] / Bryan D. McCloskey, Auteur ; Hao Ju, Auteur ; Benny D. Freeman, Auteur . - 2010 . - pp. 366–373.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 366–373
Mots-clés : Composite--Membranes--Selective--Chitosan-Poly(ethylene glycol)--Hybrid Layer--Synthesis--Characterization--Performance--Oil-Water Purification Résumé : A series of poly(ethylene glycol) diglycidyl ether−cross-linked chitosan (chi−PEG hybrid) films were prepared to elucidate their potential as fouling-resistant ultrafiltration (UF) membrane coating layers. Water permeability increased as the poly(ethylene glycol) diglycidyl ether to chitosan ratio in the prepolymerization mixture increased due to increased porosity in the polymer matrix resulting from phase separation during polymerization. Composite membranes for oil−water emulsion filtration were prepared by coating an optimized member of the chi−PEG hybrid family onto a commercial polysulfone ultrafiltration membrane. Scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared spectroscopy (FTIR), and pure water permeance measurements indicated that, depending on the concentration of chitosan in the coating solution, the coating layer thickness could be controlled, so water permeance could be optimized. These composite membranes exhibited water flux values more than 5 times higher than that of uncoated membranes after 1 day of oily water crossflow filtration, indicating that the hydrophilic polymer coating significantly enhanced the fouling resistance of the underlying polysulfone membrane. The organic rejection of the coated membranes was also slightly higher than that of the uncoated polysulfone membranes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901197u Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Integrated model for financial risk management in refinery planning Type de document : texte imprimé Auteurs : Jeongho Park, Auteur ; Sunwon Park, Auteur ; Choamun Yun, Auteur Année de publication : 2010 Article en page(s) : pp. 374–380 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Integrated--Financial--Risk--Management--Planning Résumé : An integrated model based on two-stage stochastic programming is developed for operational planning and financial risk management of a refinery. Downside risk, which rationally quantifies financial risk, is selected as the objective function to be minimized. Subsequently, the contract sizes and the operational plan are optimized on the basis of the developed model and the price scenarios. A case study shows that financial risk can be substantially reduced by diversifying suppliers with spot contracts and by cross-hedging with futures contracts. The former approach is particularly effective for low-target profits, whereas the latter is effective for relatively high-target profits. Furthermore, the target profit is closely related to risk propensity. A high-target profit set in a refinery reflects risk-taking behavior, whereas a low-target profit indicates a risk-averse attitude. The developed model is beneficial for refineries because it aids in decision-making on operational and financial strategies. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9000713
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 374–380[article] Integrated model for financial risk management in refinery planning [texte imprimé] / Jeongho Park, Auteur ; Sunwon Park, Auteur ; Choamun Yun, Auteur . - 2010 . - pp. 374–380.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 374–380
Mots-clés : Integrated--Financial--Risk--Management--Planning Résumé : An integrated model based on two-stage stochastic programming is developed for operational planning and financial risk management of a refinery. Downside risk, which rationally quantifies financial risk, is selected as the objective function to be minimized. Subsequently, the contract sizes and the operational plan are optimized on the basis of the developed model and the price scenarios. A case study shows that financial risk can be substantially reduced by diversifying suppliers with spot contracts and by cross-hedging with futures contracts. The former approach is particularly effective for low-target profits, whereas the latter is effective for relatively high-target profits. Furthermore, the target profit is closely related to risk propensity. A high-target profit set in a refinery reflects risk-taking behavior, whereas a low-target profit indicates a risk-averse attitude. The developed model is beneficial for refineries because it aids in decision-making on operational and financial strategies. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9000713 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Rolling horizon approach for dynamic parallel machine scheduling problem with release times Type de document : texte imprimé Auteurs : Lixin Tang, Auteur ; Shujun Jiang, Auteur ; Jiyin Liu, Auteur Année de publication : 2010 Article en page(s) : pp. 381–389 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Rolling Horizon Approach for Dynamic Parallel Machine Scheduling Problem with Release Times Résumé : In this paper, we study a dynamic parallel machine scheduling problem with release times, where the release times and processing times of jobs may change during the production process due to uncertainties. The problem is different from classical scheduling problems in the deterministic environment where all information of jobs is known at the beginning of the scheduling horizon and will not change during the operations throughout the whole horizon. In practice, there are often unpredictable events causing dynamic changes in job release times and/or processing times. Traditional optimization methods cannot solve the dynamic scheduling problem directly even though they have been successful in solving the static version of the problem. A model predictive control (MPC) strategy based rolling horizon approach is applied to tackle the dynamic parallel machine scheduling problem with the objective of minimizing the total weighted completion times of jobs, the energy consumption due to job waiting, and the total deviation of actual job completion times from those in the original schedule. When the MPC is applied to the problem, the rolling horizon approach allows applying a Lagrangian relaxation (LR) algorithm to solve the model of the scheduling problem in a rolling fashion. Computational experiments are carried out comparing the proposed method with the passive adjustment method often adopted by human schedulers. The result shows that the proposed method yields significantly better results, with 11.72% improvement on average. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900206m
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 381–389[article] Rolling horizon approach for dynamic parallel machine scheduling problem with release times [texte imprimé] / Lixin Tang, Auteur ; Shujun Jiang, Auteur ; Jiyin Liu, Auteur . - 2010 . - pp. 381–389.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 381–389
Mots-clés : Rolling Horizon Approach for Dynamic Parallel Machine Scheduling Problem with Release Times Résumé : In this paper, we study a dynamic parallel machine scheduling problem with release times, where the release times and processing times of jobs may change during the production process due to uncertainties. The problem is different from classical scheduling problems in the deterministic environment where all information of jobs is known at the beginning of the scheduling horizon and will not change during the operations throughout the whole horizon. In practice, there are often unpredictable events causing dynamic changes in job release times and/or processing times. Traditional optimization methods cannot solve the dynamic scheduling problem directly even though they have been successful in solving the static version of the problem. A model predictive control (MPC) strategy based rolling horizon approach is applied to tackle the dynamic parallel machine scheduling problem with the objective of minimizing the total weighted completion times of jobs, the energy consumption due to job waiting, and the total deviation of actual job completion times from those in the original schedule. When the MPC is applied to the problem, the rolling horizon approach allows applying a Lagrangian relaxation (LR) algorithm to solve the model of the scheduling problem in a rolling fashion. Computational experiments are carried out comparing the proposed method with the passive adjustment method often adopted by human schedulers. The result shows that the proposed method yields significantly better results, with 11.72% improvement on average. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900206m Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Anomalous enhancement of interphase transport rates by nanoparticles : effect of magnetic iron oxide on gas−liquid mass transfer Type de document : texte imprimé Auteurs : Srinivas Komati, Auteur ; Akkihebbal K. Suresh, Auteur Année de publication : 2010 Article en page(s) : pp. 390–405 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Anomalous--Enhancement--Interphase--Transport--Nanoparticles--Magnetic--Iron Oxide--Gas− Liquid--Mass Transfer Résumé : In this paper, we examine the effect of magnetic iron oxide nanoparticles on gas−liquid mass transfer rates. Carbon dioxide and oxygen are the gases absorbed, into a variety of reactive and nonreactive liquids. Experiments have been carried out in a wetted wall column (where the hydrodynamics can be rigorously modeled) and in a capillary tube (with the liquid phase being quiescent). In the case of absorption with reaction, studies have been conducted in several absorption regimes, representing different levels of transport limitations. The experiments convincingly demonstrate that the liquid phase mass transfer coefficients are significantly enhanced in the presence of nanoparticles in the region of concentration gradients, the extent of enhancement depending on the volume fraction of solid particles in the fluid, and on the particle size scaled with respect to the depth of penetration of the diffusing solute. A modified Sherwood number has been identified, based on the traditional theories of interphase mass transfer, as the dominant parameter which determines the magnitude of the mass transfer intensification effect at a given particle holdup, and a correlation has been derived for the enhancement, which explains not only the data obtained in this work, but also data from the literature. The enhancement effect, having been observed in the presence and absence of reaction and flow, points to the fundamental molecular-level transport processes being influenced by the nanoparticles, but the exact mechanisms remain to be established. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900302z
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 390–405[article] Anomalous enhancement of interphase transport rates by nanoparticles : effect of magnetic iron oxide on gas−liquid mass transfer [texte imprimé] / Srinivas Komati, Auteur ; Akkihebbal K. Suresh, Auteur . - 2010 . - pp. 390–405.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 390–405
Mots-clés : Anomalous--Enhancement--Interphase--Transport--Nanoparticles--Magnetic--Iron Oxide--Gas− Liquid--Mass Transfer Résumé : In this paper, we examine the effect of magnetic iron oxide nanoparticles on gas−liquid mass transfer rates. Carbon dioxide and oxygen are the gases absorbed, into a variety of reactive and nonreactive liquids. Experiments have been carried out in a wetted wall column (where the hydrodynamics can be rigorously modeled) and in a capillary tube (with the liquid phase being quiescent). In the case of absorption with reaction, studies have been conducted in several absorption regimes, representing different levels of transport limitations. The experiments convincingly demonstrate that the liquid phase mass transfer coefficients are significantly enhanced in the presence of nanoparticles in the region of concentration gradients, the extent of enhancement depending on the volume fraction of solid particles in the fluid, and on the particle size scaled with respect to the depth of penetration of the diffusing solute. A modified Sherwood number has been identified, based on the traditional theories of interphase mass transfer, as the dominant parameter which determines the magnitude of the mass transfer intensification effect at a given particle holdup, and a correlation has been derived for the enhancement, which explains not only the data obtained in this work, but also data from the literature. The enhancement effect, having been observed in the presence and absence of reaction and flow, points to the fundamental molecular-level transport processes being influenced by the nanoparticles, but the exact mechanisms remain to be established. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900302z Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : New parametric model to correlate the gibbs excess function and other thermodynamic properties of multicomponent systems : application to binary systems Type de document : texte imprimé Auteurs : Juan Ortega, Auteur ; Fernando Espiau, Auteur Année de publication : 2010 Article en page(s) : pp. 406–421 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Parametric--Correlate--Gibbs Excess--Function--Thermodynamic--Multicomponent--Systems--Application--Binary Systems Résumé : A new empirical mathematical model for the Gibbs excess function, gE = ψ(p,T,x), is presented for a multicomponent system. Dependence on the composition is achieved through the so-called active fraction, zi, which, in turn, is related to the molar fraction xi of the components of a solution and a parameter kij, the determination of which is also indicated. The efficacy of the model in relation to its extension of application is discussed, considering various cases and three possible ways to calculate the parameter kij. This produces different versions of the model for data correlation the advantages of which are discussed. The model proposed for the Gibbs excess function adopts the following generic expression, gE(P,T,x) = z(x)[1 − z(x)]∑i=0gi(P,T)zi where gi(P,T) = gi1 + gi2P2 + gi3PT + gi4/T + gi5T2, which can be applied to a general case of vapor−liquid equilibrium with variation of the three main variables xi, p, and T, or by considering the experimental values for two important situations, isobaric and isothermal, which are also studied here. Other mixing properties are obtained via mathematical derivation, and a simultaneous correlation is carried out on several of them. The model has been applied to various binary systems for which experimental data are available in the literature and over a wide range of p and T. The results obtained can be considered acceptable. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900898t
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 406–421[article] New parametric model to correlate the gibbs excess function and other thermodynamic properties of multicomponent systems : application to binary systems [texte imprimé] / Juan Ortega, Auteur ; Fernando Espiau, Auteur . - 2010 . - pp. 406–421.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 406–421
Mots-clés : Parametric--Correlate--Gibbs Excess--Function--Thermodynamic--Multicomponent--Systems--Application--Binary Systems Résumé : A new empirical mathematical model for the Gibbs excess function, gE = ψ(p,T,x), is presented for a multicomponent system. Dependence on the composition is achieved through the so-called active fraction, zi, which, in turn, is related to the molar fraction xi of the components of a solution and a parameter kij, the determination of which is also indicated. The efficacy of the model in relation to its extension of application is discussed, considering various cases and three possible ways to calculate the parameter kij. This produces different versions of the model for data correlation the advantages of which are discussed. The model proposed for the Gibbs excess function adopts the following generic expression, gE(P,T,x) = z(x)[1 − z(x)]∑i=0gi(P,T)zi where gi(P,T) = gi1 + gi2P2 + gi3PT + gi4/T + gi5T2, which can be applied to a general case of vapor−liquid equilibrium with variation of the three main variables xi, p, and T, or by considering the experimental values for two important situations, isobaric and isothermal, which are also studied here. Other mixing properties are obtained via mathematical derivation, and a simultaneous correlation is carried out on several of them. The model has been applied to various binary systems for which experimental data are available in the literature and over a wide range of p and T. The results obtained can be considered acceptable. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900898t Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Agglomeration effects on the drying and dehydration stability of pharmaceutical acicular hydrate : carbamazepine dihydrate Type de document : texte imprimé Auteurs : Ji Yi Khoo, Auteur ; Jerry Y. Y. Heng, Auteur ; Daryl R. Williams, Auteur Année de publication : 2010 Article en page(s) : pp. 422–427 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Agglomeration--Effects--Drying--Dehydration--Stability--Pharmaceutical--Acicular--Hydrate--Carbamazepine--Dihydrate Résumé : The effects of agglomeration on the dehydration kinetics and stability of carbamazepine dihydrate were investigated and are reported here. The prepared dihydrate agglomerates were sieved into six particle size distributions, ranging from 75 to ∼1800 μm, prior to gravimetric dehydration studies. It was concluded that when these agglomerates exceed a critical agglomerates size, they then retain an excess amount of physically adsorbed (unbound) water relative to the smaller agglomerate sizes. Specifically, agglomerates with particle diameter >1400 μm held up to 57.2 wt % of unbound water, residing within the funicular regime of moisture saturation. These larger agglomerates exhibit a distinct and densely packed particle structure, leading to a relatively more stable dihydrate, having a lower critical humidity of 20% RH (0.0039 kgwater/kgair) at 25 °C, than those agglomerates without inclusion of unbound water. This work demonstrates that the moisture stability performance of agglomerated solids is dependent both on the intrinsic water sorption properties of the component materials as well as the local microstructure that evolves within the agglomerated solids. Furthermore, this work also demonstrates that the moisture stability of a solid state form can be strongly influenced by local particle microstructure, which thus provides another strategy for improving moisture stability of formulated products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9011968
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 422–427[article] Agglomeration effects on the drying and dehydration stability of pharmaceutical acicular hydrate : carbamazepine dihydrate [texte imprimé] / Ji Yi Khoo, Auteur ; Jerry Y. Y. Heng, Auteur ; Daryl R. Williams, Auteur . - 2010 . - pp. 422–427.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 422–427
Mots-clés : Agglomeration--Effects--Drying--Dehydration--Stability--Pharmaceutical--Acicular--Hydrate--Carbamazepine--Dihydrate Résumé : The effects of agglomeration on the dehydration kinetics and stability of carbamazepine dihydrate were investigated and are reported here. The prepared dihydrate agglomerates were sieved into six particle size distributions, ranging from 75 to ∼1800 μm, prior to gravimetric dehydration studies. It was concluded that when these agglomerates exceed a critical agglomerates size, they then retain an excess amount of physically adsorbed (unbound) water relative to the smaller agglomerate sizes. Specifically, agglomerates with particle diameter >1400 μm held up to 57.2 wt % of unbound water, residing within the funicular regime of moisture saturation. These larger agglomerates exhibit a distinct and densely packed particle structure, leading to a relatively more stable dihydrate, having a lower critical humidity of 20% RH (0.0039 kgwater/kgair) at 25 °C, than those agglomerates without inclusion of unbound water. This work demonstrates that the moisture stability performance of agglomerated solids is dependent both on the intrinsic water sorption properties of the component materials as well as the local microstructure that evolves within the agglomerated solids. Furthermore, this work also demonstrates that the moisture stability of a solid state form can be strongly influenced by local particle microstructure, which thus provides another strategy for improving moisture stability of formulated products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9011968 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Statistical approximation of the iInverse problem in multivariate population balance modeling Type de document : texte imprimé Auteurs : Andreas Braumann, Auteur ; Peter L. W. Man, Auteur ; Markus Kraft, Auteur Année de publication : 2010 Article en page(s) : pp. 428–438 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Statistical--Approximation--Inverse--Problem--Multivariate--Population--Balance--Modeling Résumé : This paper deals with the estimation of model parameters and their uncertainties encountered in granulation modeling. The outcome of a multivariate, detailed population balance model of a high shear granulation process is locally approximated in the parameter space by first and second order response surfaces, allowing a fast computation of the model response. The response surfaces are used in three different objective functions—moment matching, expected least-squares, and expected weighted least-squares—in order to estimate ranges for the rate constants for particle coalescence, particle compaction, particle breakage, and reaction, which appear as free parameters in the granulation model. First, second-order response surfaces for the population balance model are constructed and used as approximations of the model in the objective functions for the numerical solution of the inverse problem. Second, the choice of objective function is investigated. It is found that the uncertainties of the model predictions differ for the three objective functions only slightly. The estimates for the intervals of the model parameters either overlap or are very close. However, the moment matching objective function is recommended because the number of estimated parameters and experimental data sets can be chosen independently. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901230u
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 428–438[article] Statistical approximation of the iInverse problem in multivariate population balance modeling [texte imprimé] / Andreas Braumann, Auteur ; Peter L. W. Man, Auteur ; Markus Kraft, Auteur . - 2010 . - pp. 428–438.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 428–438
Mots-clés : Statistical--Approximation--Inverse--Problem--Multivariate--Population--Balance--Modeling Résumé : This paper deals with the estimation of model parameters and their uncertainties encountered in granulation modeling. The outcome of a multivariate, detailed population balance model of a high shear granulation process is locally approximated in the parameter space by first and second order response surfaces, allowing a fast computation of the model response. The response surfaces are used in three different objective functions—moment matching, expected least-squares, and expected weighted least-squares—in order to estimate ranges for the rate constants for particle coalescence, particle compaction, particle breakage, and reaction, which appear as free parameters in the granulation model. First, second-order response surfaces for the population balance model are constructed and used as approximations of the model in the objective functions for the numerical solution of the inverse problem. Second, the choice of objective function is investigated. It is found that the uncertainties of the model predictions differ for the three objective functions only slightly. The estimates for the intervals of the model parameters either overlap or are very close. However, the moment matching objective function is recommended because the number of estimated parameters and experimental data sets can be chosen independently. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901230u Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Extension of an artificial neural network algorithm for estimating sulfur content of sour gases at elevated temperatures and pressures Type de document : texte imprimé Auteurs : Mehdi Mehrpooya, Auteur ; Amir H. Mohammadi, Auteur ; Dominique Richon, Auteur Année de publication : 2010 Article en page(s) : pp. 439–442 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Extension--Artificial--Neural--Network--Algorithm--Estimating--Sulfur--Gases--Elevated--Temperatures--Pressures Résumé : In this communication, we report an extended artificial neural network algorithm to estimate sulfur content of sour/acid gases. The main advantage of this algorithm is that it eliminates any need for characterization parameters, due to the tendency of sulfurs to react, required in thermodynamic models. To develop this tool, reliable experimental data found in the literature on sulfur content of various gases are used. To estimate the sulfur content of a gas, the information on temperature, pressure, gravity of acid gas free gas, and the concentrations of hydrogen sulfide and carbon dioxide in the gas are required. The developed algorithm is then used to predict independent experimental data (not used in its development). It is shown that the artificial neural network algorithm can be used as an efficient tool to estimate sulfur content of various gases. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900399b
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 439–442[article] Extension of an artificial neural network algorithm for estimating sulfur content of sour gases at elevated temperatures and pressures [texte imprimé] / Mehdi Mehrpooya, Auteur ; Amir H. Mohammadi, Auteur ; Dominique Richon, Auteur . - 2010 . - pp. 439–442.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 439–442
Mots-clés : Extension--Artificial--Neural--Network--Algorithm--Estimating--Sulfur--Gases--Elevated--Temperatures--Pressures Résumé : In this communication, we report an extended artificial neural network algorithm to estimate sulfur content of sour/acid gases. The main advantage of this algorithm is that it eliminates any need for characterization parameters, due to the tendency of sulfurs to react, required in thermodynamic models. To develop this tool, reliable experimental data found in the literature on sulfur content of various gases are used. To estimate the sulfur content of a gas, the information on temperature, pressure, gravity of acid gas free gas, and the concentrations of hydrogen sulfide and carbon dioxide in the gas are required. The developed algorithm is then used to predict independent experimental data (not used in its development). It is shown that the artificial neural network algorithm can be used as an efficient tool to estimate sulfur content of various gases. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900399b Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
