[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9913–9917

Titre :	Solubility Parameters for Nine Ionic Liquids
Type de document :	texte imprimé
Auteurs :	Brian Yoo, Auteur ; Waheed Afzal, Auteur ; John M. Prausnitz, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9913–9917
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ionic  liquids
Résumé :	Solubility parameters are useful for estimating solubilities of solutes in ionic liquids when no solubility data are available. Solubility parameters are reported for nine ionic liquids; they were obtained from solubility data for a variety of solutes. The ionic liquids are 1-butyl,3-methylimidazolium hydrogen sulfate, 1-ethyl,3-methylimidazolium acetate, 1-methyl,3-trimethylsylilimidazolium chloride, 4-methyl,n-butylpyridinium tetrafluoroborate, ethylammonium nitrate, 1-ethyl,3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-methyl,3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl,3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 1-ethyl,3-methylimidazolium ethylsulfate.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300588s

[article] Solubility Parameters for Nine Ionic Liquids [texte imprimé] / Brian Yoo, Auteur ; Waheed Afzal, Auteur ; John M. Prausnitz, Auteur . - 2012 . - pp. 9913–9917.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9913–9917

Mots-clés :	Ionic  liquids
Résumé :	Solubility parameters are useful for estimating solubilities of solutes in ionic liquids when no solubility data are available. Solubility parameters are reported for nine ionic liquids; they were obtained from solubility data for a variety of solutes. The ionic liquids are 1-butyl,3-methylimidazolium hydrogen sulfate, 1-ethyl,3-methylimidazolium acetate, 1-methyl,3-trimethylsylilimidazolium chloride, 4-methyl,n-butylpyridinium tetrafluoroborate, ethylammonium nitrate, 1-ethyl,3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-methyl,3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl,3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 1-ethyl,3-methylimidazolium ethylsulfate.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300588s

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9906-9912

Titre :	Statistical approach to constructing predictive models for thermal resistance based on operating conditions
Type de document :	texte imprimé
Auteurs :	Hiromasa Kaneko, Auteur ; Susumu Inasawa, Auteur ; Nagisa Morimoto, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9906-9912
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Operating  conditions  Forecast  model
Résumé :	We have constructed statistical models that predict thermal resistance after fouling layer formation in a heat exchanger, in which a slurry of stearic acid in toluene was cooled. Chemoinformatics was used, and the initial rate of increase in thermal resistance (dU―1/dt) was calculated from experimental conditions such as coolant flow rate and the degree of supersaturation. We then constructed models for thermal resistance at a steady state using calculated values of dU―1/dt and experimental conditions. Our model gives a good correlation with the experimental results. The contribution of operating conditions to fouling layer formation was discussed semiquantitatively on the basis of linear regression coefficients that were obtained from our model. Because only operating conditions and set values were used as input, our approach is very practical for prediction of thermal resistance given certain operating conditions.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184969

[article] Statistical approach to constructing predictive models for thermal resistance based on operating conditions [texte imprimé] / Hiromasa Kaneko, Auteur ; Susumu Inasawa, Auteur ; Nagisa Morimoto, Auteur . - 2012 . - pp. 9906-9912.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9906-9912

Mots-clés :	Operating  conditions  Forecast  model
Résumé :	We have constructed statistical models that predict thermal resistance after fouling layer formation in a heat exchanger, in which a slurry of stearic acid in toluene was cooled. Chemoinformatics was used, and the initial rate of increase in thermal resistance (dU―1/dt) was calculated from experimental conditions such as coolant flow rate and the degree of supersaturation. We then constructed models for thermal resistance at a steady state using calculated values of dU―1/dt and experimental conditions. Our model gives a good correlation with the experimental results. The contribution of operating conditions to fouling layer formation was discussed semiquantitatively on the basis of linear regression coefficients that were obtained from our model. Because only operating conditions and set values were used as input, our approach is very practical for prediction of thermal resistance given certain operating conditions.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184969

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9894-9905

Titre :	Nonionic surfactant for enhanced oil recovery from carbonates : Adsorption kinetics and equilibrium
Type de document :	texte imprimé
Auteurs :	Mohammad Ali Ahmadi, Auteur ; Sohrab Zendehboudi, Auteur ; Ali Shafiei, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9894-9905
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetics  Adsorption  Non  ionic  surfactant
Résumé :	Around 40% of the current world conventional oil production comes from carbonate reservoirs, dominantly mature and declining giant oilfields. Tertiary oil production methods as part of an Enhanced Oil Recovery (EOR) scheme are inevitable after primary and secondary oil production. The goal of surfactant flooding is to reduce the mobility ratio by lowering the interfacial tension between oil and water and mobilizing the residual oil. This paper highlights adsorption kinetics and equilibrium of Glycyrrhiza Glabra, a novel surfactant, in aqueous solutions for EOR and reservoir stimulation purposes. A conductivity technique was used to assess adsorption of the surfactant in the aqueous phase. Batch experimental runs were also performed at various temperatures to understand the effect of adsorbate dose on the sorption efficiency. The adsorption kinetics was experimentally investigated at room temperature (27 °C) by monitoring the uptake of the Glycyrrhiza Glabra as a function of time. The adsorption data were examined using different adsorption equilibrium and kinetic models. The Langmuir isotherm suits the equilibrium data very well. A pseudo-second order kinetic model can satisfactorily estimate the kinetics of the surfactant adsorption on carbonates. Results obtained from this research can help in selecting appropriate surfactants for design of EOR schemes and reservoir stimulation plans for carbonate reservoirs.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184968

[article] Nonionic surfactant for enhanced oil recovery from carbonates : Adsorption kinetics and equilibrium [texte imprimé] / Mohammad Ali Ahmadi, Auteur ; Sohrab Zendehboudi, Auteur ; Ali Shafiei, Auteur . - 2012 . - pp. 9894-9905.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9894-9905

Mots-clés :	Kinetics  Adsorption  Non  ionic  surfactant
Résumé :	Around 40% of the current world conventional oil production comes from carbonate reservoirs, dominantly mature and declining giant oilfields. Tertiary oil production methods as part of an Enhanced Oil Recovery (EOR) scheme are inevitable after primary and secondary oil production. The goal of surfactant flooding is to reduce the mobility ratio by lowering the interfacial tension between oil and water and mobilizing the residual oil. This paper highlights adsorption kinetics and equilibrium of Glycyrrhiza Glabra, a novel surfactant, in aqueous solutions for EOR and reservoir stimulation purposes. A conductivity technique was used to assess adsorption of the surfactant in the aqueous phase. Batch experimental runs were also performed at various temperatures to understand the effect of adsorbate dose on the sorption efficiency. The adsorption kinetics was experimentally investigated at room temperature (27 °C) by monitoring the uptake of the Glycyrrhiza Glabra as a function of time. The adsorption data were examined using different adsorption equilibrium and kinetic models. The Langmuir isotherm suits the equilibrium data very well. A pseudo-second order kinetic model can satisfactorily estimate the kinetics of the surfactant adsorption on carbonates. Results obtained from this research can help in selecting appropriate surfactants for design of EOR schemes and reservoir stimulation plans for carbonate reservoirs.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184968

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9886-9893

Titre :	Estimation of thermal conductivity of ionic liquids using a perceptron neural network
Type de document :	texte imprimé
Auteurs :	Ali Zeinolabedini Hezave, Auteur ; Sona Raeissi, Auteur ; Mostafa Lashkarbolooki, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9886-9893
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Neural  network  Ionic  liquid  Thermal  conductivity
Résumé :	On the basis of an artificial neural network (ANN), a model is proposed to predict the thermal conductivity of pure ionic liquids. A total of 209 data points from 21 different ionic liquids was used to train and test the proposed network. The optimum number of hidden layers was determined to be 1, with 13 neurons in the hidden layer and logarithmic―sigmoid and purelin functions as the transfer functions in the hidden and output layers, respectively. The results obtained reveal that the proposed network is able to correlate and predict the thermal conductivity of all of the pure ionic liquids with an overall absolute mean relative deviation percent (MARD %) of 0.5% and mean square error (MSE) of 1.2 × 10―6 The optimized network was also compared with literature correlations and a predictive group contribution method. The results indicate the rather good accuracy of the proposed neural network compared to the previously proposed literature methods.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184967

[article] Estimation of thermal conductivity of ionic liquids using a perceptron neural network [texte imprimé] / Ali Zeinolabedini Hezave, Auteur ; Sona Raeissi, Auteur ; Mostafa Lashkarbolooki, Auteur . - 2012 . - pp. 9886-9893.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9886-9893

Mots-clés :	Neural  network  Ionic  liquid  Thermal  conductivity
Résumé :	On the basis of an artificial neural network (ANN), a model is proposed to predict the thermal conductivity of pure ionic liquids. A total of 209 data points from 21 different ionic liquids was used to train and test the proposed network. The optimum number of hidden layers was determined to be 1, with 13 neurons in the hidden layer and logarithmic―sigmoid and purelin functions as the transfer functions in the hidden and output layers, respectively. The results obtained reveal that the proposed network is able to correlate and predict the thermal conductivity of all of the pure ionic liquids with an overall absolute mean relative deviation percent (MARD %) of 0.5% and mean square error (MSE) of 1.2 × 10―6 The optimized network was also compared with literature correlations and a predictive group contribution method. The results indicate the rather good accuracy of the proposed neural network compared to the previously proposed literature methods.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184967

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9875-9885

Titre :	Modeling CO2 solubility in aqueous N - methyldiethanolamine solution by electrolyte modified peng – robinson plus association equation of state
Type de document :	texte imprimé
Auteurs :	Ali T. Zoghi, Auteur ; Farzaneh Feyzi, Auteur ; Mohammad R. Dehghani, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9875-9885
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic  properties  Equations  of  state  Electrolyte  Solubility  Carbon  dioxide  Modeling
Résumé :	In the present work, the electrolyte equation of state proposed by Huttenhuis et al. [Fluid Phase Equilibria 2008, 264, 99―112] is improved to describe the solubility of carbon dioxide in aqueous solutions of N-methyldiethanolamine (MDEA) in wide ranges of concentration, pressure, temperature, and acid gas loading. The molecular part of the equation is based on the modified Peng―Robinson Plus Association equation of state (mPR-CPA EoS) proposed by Zoghi et al. [J. Pet. Sci. Eng. 2011, 78, 109―118]. To account for the presence of ions, three contributions are added to the mPR-CPA EoS to describe short-range interactions, long-range interactions, and the Born term. The same EoS is used for both vapor and liquid phases. A consistent database including 567 experimental data points is utilized in this study. In the first step of modeling the parameters of the EoS have been tuned by regression to the vapor pressure and saturated liquid density experimental data for associating pure components (i.e., water and MDEA). In the next step, the vapor―liquid equilibrium calculations were carried out for adjusting the molecular binary interaction parameters. These parameters are optimized for binary subsystems including H2O―CO2, CO2― MDEA, and H2O―MDEA. Finally, the binary interaction parameters between ionic and molecular species are tuned via the simultaneous vapor—liquid and chemical reaction equilibrium calculations. The results show that the proposed model is able to improve the precision of prediction of the solubility of CO2 in aqueous MDEA solution by more than 6.7% in comparison with that of Huttenhuis et al. [Fluid Phase Equilibria 2008, 264, 99―112] in a wide range of pressures, temperatures, acid gas loadings, and aqueous MDEA concentrations.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184966

[article] Modeling CO2 solubility in aqueous N - methyldiethanolamine solution by electrolyte modified peng – robinson plus association equation of state [texte imprimé] / Ali T. Zoghi, Auteur ; Farzaneh Feyzi, Auteur ; Mohammad R. Dehghani, Auteur . - 2012 . - pp. 9875-9885.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9875-9885

Mots-clés :	Thermodynamic  properties  Equations  of  state  Electrolyte  Solubility  Carbon  dioxide  Modeling
Résumé :	In the present work, the electrolyte equation of state proposed by Huttenhuis et al. [Fluid Phase Equilibria 2008, 264, 99―112] is improved to describe the solubility of carbon dioxide in aqueous solutions of N-methyldiethanolamine (MDEA) in wide ranges of concentration, pressure, temperature, and acid gas loading. The molecular part of the equation is based on the modified Peng―Robinson Plus Association equation of state (mPR-CPA EoS) proposed by Zoghi et al. [J. Pet. Sci. Eng. 2011, 78, 109―118]. To account for the presence of ions, three contributions are added to the mPR-CPA EoS to describe short-range interactions, long-range interactions, and the Born term. The same EoS is used for both vapor and liquid phases. A consistent database including 567 experimental data points is utilized in this study. In the first step of modeling the parameters of the EoS have been tuned by regression to the vapor pressure and saturated liquid density experimental data for associating pure components (i.e., water and MDEA). In the next step, the vapor―liquid equilibrium calculations were carried out for adjusting the molecular binary interaction parameters. These parameters are optimized for binary subsystems including H2O―CO2, CO2― MDEA, and H2O―MDEA. Finally, the binary interaction parameters between ionic and molecular species are tuned via the simultaneous vapor—liquid and chemical reaction equilibrium calculations. The results show that the proposed model is able to improve the precision of prediction of the solubility of CO2 in aqueous MDEA solution by more than 6.7% in comparison with that of Huttenhuis et al. [Fluid Phase Equilibria 2008, 264, 99―112] in a wide range of pressures, temperatures, acid gas loadings, and aqueous MDEA concentrations.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184966

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9867-9874

Titre :	Temperature enhancement of zinc and iron separation from chromium(III) passivation baths by emulsion pertraction technology
Type de document :	texte imprimé
Auteurs :	Nazely Diban, Auteur ; Veronica Garcia, Auteur ; Francisco Alguacil, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9867-9874
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Emulsion  Passivation
Résumé :	This work reports the influence of the temperature on the selective removal of zinc and iron from a chromium(III) passivation bath by emulsion pertraction technology using Cyanex 272 as extractant and hollow fiber membrane contactors. The results indicate that the kinetics of the separation was largely influenced by the temperature in the range 10—40 °C. The viscosity of the organic liquid phase was measured at different temperatures and extractant concentrations, and the results were fitted to the Riedel and Grunberg and Nissan correlations. The improvement observed from 20 to 40 °C was explained by the increase in the diffusion coefficient of the zinc and iron organometallic complexes through the liquid membrane. However, the remarkably slower zinc and iron separation rates observed at 10 °C in comparison with those at 20—40 °C were attributed to a shift in the driving force due to an endothermic change of the interfacial extraction reaction. The equilibrium parameters at 10 and 20―40 °C were estimated by fitting the experimental kinetic results to the proposed mathematical model. Thus, this work addresses the thermal character of equilibrium and its relevant influence on the separation kinetics of reactive membrane systems.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184965

[article] Temperature enhancement of zinc and iron separation from chromium(III) passivation baths by emulsion pertraction technology [texte imprimé] / Nazely Diban, Auteur ; Veronica Garcia, Auteur ; Francisco Alguacil, Auteur . - 2012 . - pp. 9867-9874.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9867-9874

Mots-clés :	Emulsion  Passivation
Résumé :	This work reports the influence of the temperature on the selective removal of zinc and iron from a chromium(III) passivation bath by emulsion pertraction technology using Cyanex 272 as extractant and hollow fiber membrane contactors. The results indicate that the kinetics of the separation was largely influenced by the temperature in the range 10—40 °C. The viscosity of the organic liquid phase was measured at different temperatures and extractant concentrations, and the results were fitted to the Riedel and Grunberg and Nissan correlations. The improvement observed from 20 to 40 °C was explained by the increase in the diffusion coefficient of the zinc and iron organometallic complexes through the liquid membrane. However, the remarkably slower zinc and iron separation rates observed at 10 °C in comparison with those at 20—40 °C were attributed to a shift in the driving force due to an endothermic change of the interfacial extraction reaction. The equilibrium parameters at 10 and 20―40 °C were estimated by fitting the experimental kinetic results to the proposed mathematical model. Thus, this work addresses the thermal character of equilibrium and its relevant influence on the separation kinetics of reactive membrane systems.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184965

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9858-9866

Titre :	Comparative characterization of lignins extracted from cotton stalk based on complete dissolution in different systems
Type de document :	texte imprimé
Auteurs :	Lingyan Meng, Auteur ; Sumin Kang, Auteur ; Xueming Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9858-9866
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dissolution  Extract
Résumé :	A method for the isolation of lignin in high purity from cotton stalk is presented in this study. Lignin fractions were obtained by dissolution of ball-milled cotton stalk in lithium chloride/dimethylacetamide (LiCl/DMAc), tetrabutylammonium fluoride/dimethylsulfoxide (TBAF/DMSO), lithium chloride/N-methyl-2-pyrrolidone (LiCl/NMP), NaOH/urea/H2O, NaOH/thiourea/H2O, and 1-allyl-3-methylimidazolium chloride/dimethylsulfoxide ([Amim]Cl/DMSO) followed by precipitation in the course of which lignin and carbohydrate fractions were separated. Structural elucidation of the lignin fractions was investigated by sugar analysis, FT-IR, and 1D/2D NMR spectroscopy. The results showed that the separated lignin fractions possessed higher purities and molecular weights than MWL. 1D/2D NMR spectra demonstrated that guaiacyl (G) and syringyl (S) units were predominant in the lignin fractions, and a small amount of p-hydroxyphenyl (H) unit was also detected. Moreover, the separated lignin fractions consisted mainly of β-O-4' aryl ether linkages (0.36―0.61/Ar), followed by resinol (0.05—0.08/Ar) and phenylcoumaran structures (0.03—0.05/Ar). In consideration of the relatively high yield and purity and limited structural changes, isolation of lignin from ball-milled materials by complete dissolution in [Amim]Cl/DMSO provided us a more effective approach as compared with the other systems.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184964

[article] Comparative characterization of lignins extracted from cotton stalk based on complete dissolution in different systems [texte imprimé] / Lingyan Meng, Auteur ; Sumin Kang, Auteur ; Xueming Zhang, Auteur . - 2012 . - pp. 9858-9866.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9858-9866

Mots-clés :	Dissolution  Extract
Résumé :	A method for the isolation of lignin in high purity from cotton stalk is presented in this study. Lignin fractions were obtained by dissolution of ball-milled cotton stalk in lithium chloride/dimethylacetamide (LiCl/DMAc), tetrabutylammonium fluoride/dimethylsulfoxide (TBAF/DMSO), lithium chloride/N-methyl-2-pyrrolidone (LiCl/NMP), NaOH/urea/H2O, NaOH/thiourea/H2O, and 1-allyl-3-methylimidazolium chloride/dimethylsulfoxide ([Amim]Cl/DMSO) followed by precipitation in the course of which lignin and carbohydrate fractions were separated. Structural elucidation of the lignin fractions was investigated by sugar analysis, FT-IR, and 1D/2D NMR spectroscopy. The results showed that the separated lignin fractions possessed higher purities and molecular weights than MWL. 1D/2D NMR spectra demonstrated that guaiacyl (G) and syringyl (S) units were predominant in the lignin fractions, and a small amount of p-hydroxyphenyl (H) unit was also detected. Moreover, the separated lignin fractions consisted mainly of β-O-4' aryl ether linkages (0.36―0.61/Ar), followed by resinol (0.05—0.08/Ar) and phenylcoumaran structures (0.03—0.05/Ar). In consideration of the relatively high yield and purity and limited structural changes, isolation of lignin from ball-milled materials by complete dissolution in [Amim]Cl/DMSO provided us a more effective approach as compared with the other systems.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184964

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9850-9857

Titre :	Effect of the alcohol cosolvent in the removal of caffeine by activated carbons
Type de document :	texte imprimé
Auteurs :	Ana S. Mestre, Auteur ; Susana C. R. Marques, Auteur ; Ana P. Carvalho, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9850-9857
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Activated  carbon  Cosolvent
Résumé :	The effect of the addition of methanol and 2-propanol as cosolvents on the caffeine adsorption onto activated carbons was evaluated by both kinetic and equilibrium studies. The kinetic results presented a good adjustment to the pseudo-second-order kinetic model and reveal that the alcohol cosolvent has a double negative effect on caffeine adsorption: it enhances caffeine's solubility lowering its affinity toward the adsorbent and it seems to compete with caffeine for the adsorption active sites. The change in the isotherm shape from L to F type, when the mixture 2-propanol/water was used, was justified in terms of the higher interaction between the caffeine and 2-propanol molecules. This solvent presents the most similar Hansen three-dimensional solubility parameters when compared to the ones of caffeine. The overall adsorption results point out that when the sample with acidic surface chemistry is used, the water adsorption is favored and consequently the effect of the cosolvent is less marked and is mainly explained by the solubility. For the carbons with basic surfaces the addition of the alcohol cosolvent reflects in the adsorption mechanism due to the competitive adsorption of the alcohol, especially when the cosolvent is 2-propanol.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184963

[article] Effect of the alcohol cosolvent in the removal of caffeine by activated carbons [texte imprimé] / Ana S. Mestre, Auteur ; Susana C. R. Marques, Auteur ; Ana P. Carvalho, Auteur . - 2012 . - pp. 9850-9857.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9850-9857

Mots-clés :	Activated  carbon  Cosolvent
Résumé :	The effect of the addition of methanol and 2-propanol as cosolvents on the caffeine adsorption onto activated carbons was evaluated by both kinetic and equilibrium studies. The kinetic results presented a good adjustment to the pseudo-second-order kinetic model and reveal that the alcohol cosolvent has a double negative effect on caffeine adsorption: it enhances caffeine's solubility lowering its affinity toward the adsorbent and it seems to compete with caffeine for the adsorption active sites. The change in the isotherm shape from L to F type, when the mixture 2-propanol/water was used, was justified in terms of the higher interaction between the caffeine and 2-propanol molecules. This solvent presents the most similar Hansen three-dimensional solubility parameters when compared to the ones of caffeine. The overall adsorption results point out that when the sample with acidic surface chemistry is used, the water adsorption is favored and consequently the effect of the cosolvent is less marked and is mainly explained by the solubility. For the carbons with basic surfaces the addition of the alcohol cosolvent reflects in the adsorption mechanism due to the competitive adsorption of the alcohol, especially when the cosolvent is 2-propanol.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184963

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9835-9849

Titre :	Improved performance of a simulated moving bed process by a recycling method in the partial - discard strategy
Type de document :	texte imprimé
Auteurs :	Kyung Min Kim, Auteur ; Hyeon-Hui Lee, Auteur ; Chang-Ha Lee, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9835-9849
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Recycling  Simulated  moving  bed
Résumé :	The recycling partial-discard (RPD) strategy was developed to improve the performance of simulated moving bed (SMB) chromatography in partial-discard (PD) strategy by a simulation study. In the RPD operation, each discarded product portion of extract and raffinate is recycled as part of the feed. This strategy was applied to a binary mixture with a nonlinear isotherm in a four-zone SMB with two columns per zone. The two additional operating variables, recycle length (RL) and recycle flowrate (RF), were suggested for the RPD strategy in order to determine the time duration and flowrate of the recycle feed. Compared to those of the PD operation, extract and raffinate with higher purities can be produced from the RPD operation. Simultaneously, the losses in the other performance parameters (recovery, productivity, and eluent consumption) stemming from the PD operation could be favorably reduced by controlling the recycle length and recycle ratio in the RPD operation. The two variables, RL and RF, in the RPD operation played key roles in the improvement and trade-off of SMB performance parameters (purity, recovery, productivity, and eluent consumption).
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184962

[article] Improved performance of a simulated moving bed process by a recycling method in the partial - discard strategy [texte imprimé] / Kyung Min Kim, Auteur ; Hyeon-Hui Lee, Auteur ; Chang-Ha Lee, Auteur . - 2012 . - pp. 9835-9849.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9835-9849

Mots-clés :	Recycling  Simulated  moving  bed
Résumé :	The recycling partial-discard (RPD) strategy was developed to improve the performance of simulated moving bed (SMB) chromatography in partial-discard (PD) strategy by a simulation study. In the RPD operation, each discarded product portion of extract and raffinate is recycled as part of the feed. This strategy was applied to a binary mixture with a nonlinear isotherm in a four-zone SMB with two columns per zone. The two additional operating variables, recycle length (RL) and recycle flowrate (RF), were suggested for the RPD strategy in order to determine the time duration and flowrate of the recycle feed. Compared to those of the PD operation, extract and raffinate with higher purities can be produced from the RPD operation. Simultaneously, the losses in the other performance parameters (recovery, productivity, and eluent consumption) stemming from the PD operation could be favorably reduced by controlling the recycle length and recycle ratio in the RPD operation. The two variables, RL and RF, in the RPD operation played key roles in the improvement and trade-off of SMB performance parameters (purity, recovery, productivity, and eluent consumption).
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184962

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9825-9834

Titre :	A Modeling framework for railcar fleet sizing in the chemical industry
Type de document :	texte imprimé
Auteurs :	Myun-Seok Cheon, Auteur ; Kevin C. Furman, Auteur ; Timothy, D. Shaffer, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9825-9834
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Chemical  industry  Modeling
Résumé :	This paper tackles a railcar fleet sizing optimization problem in the chemical industry. In some sectors of the chemical industry, railcars are used not only as a means of transportation but also as storage space; thus, it is necessary to consider inventory in the determination of the optimal fleet size. Because of the long lifespans of railcars, this problem is formulated as a long-term capacity expansion problem considering various economic factors. A mixed-integer programming approach to modeling and solving this problem is proposed and a substantial improvement is demonstrated, compared to existing rule-based methods.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184961

[article] A Modeling framework for railcar fleet sizing in the chemical industry [texte imprimé] / Myun-Seok Cheon, Auteur ; Kevin C. Furman, Auteur ; Timothy, D. Shaffer, Auteur . - 2012 . - pp. 9825-9834.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9825-9834

Mots-clés :	Chemical  industry  Modeling
Résumé :	This paper tackles a railcar fleet sizing optimization problem in the chemical industry. In some sectors of the chemical industry, railcars are used not only as a means of transportation but also as storage space; thus, it is necessary to consider inventory in the determination of the optimal fleet size. Because of the long lifespans of railcars, this problem is formulated as a long-term capacity expansion problem considering various economic factors. A mixed-integer programming approach to modeling and solving this problem is proposed and a substantial improvement is demonstrated, compared to existing rule-based methods.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184961

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9812-9824

Titre :	Recursive fault detection and isolation approaches of time - varying processes
Type de document :	texte imprimé
Auteurs :	Lamiaa M. Elshenawy, Auteur ; Hamdi. A. Awad, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9812-9824
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Time  varying  system  Failure  detection
Résumé :	Recursive principal component analysis (RPCA) has gained significant attention as a monitoring tool for time-varying systems in recent years. The contribution of this article is the development of numerically efficient and memory-saving recursive fault detection and isolation (FDI) approaches for time-varying processes. The proposed approaches incorporate a recursive PCA based on a first-order perturbation (RPCA-FOP) analysis procedure and two recursive fault isolation methods. The proposed recursive fault isolation methods are the (i) recursive partial decomposition contribution (RPDC) and (ii) recursive diagonal contribution (RDC) methods. Four types of sensor faults, including bias, drifting, precision degradation, and complete failure, are simulated to test the proposed approaches. The utility of the proposed FDI approaches is demonstrated using a nonisothermal continuous stirred tank reactor (CSTR) system.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184960

[article] Recursive fault detection and isolation approaches of time - varying processes [texte imprimé] / Lamiaa M. Elshenawy, Auteur ; Hamdi. A. Awad, Auteur . - 2012 . - pp. 9812-9824.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9812-9824

Mots-clés :	Time  varying  system  Failure  detection
Résumé :	Recursive principal component analysis (RPCA) has gained significant attention as a monitoring tool for time-varying systems in recent years. The contribution of this article is the development of numerically efficient and memory-saving recursive fault detection and isolation (FDI) approaches for time-varying processes. The proposed approaches incorporate a recursive PCA based on a first-order perturbation (RPCA-FOP) analysis procedure and two recursive fault isolation methods. The proposed recursive fault isolation methods are the (i) recursive partial decomposition contribution (RPDC) and (ii) recursive diagonal contribution (RDC) methods. Four types of sensor faults, including bias, drifting, precision degradation, and complete failure, are simulated to test the proposed approaches. The utility of the proposed FDI approaches is demonstrated using a nonisothermal continuous stirred tank reactor (CSTR) system.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184960

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9803-9811

Titre :	Process simulation based on experimental investigations for 3 - methylthiophene alkylation with isobutylene in a reactive distillation column
Type de document :	texte imprimé
Auteurs :	Yu Liu, Auteur ; Bolun Yang, Auteur ; Shasha Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9803-9811
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Distillation  column  Distillation  with  reaction  Alkylation
Résumé :	A new approach that substitutes the original two-step olefinic alkylation of thiophenic sulfur (OATS) technology with a reactive distillation (RD) column was proposed to remove sulfur compounds from fluid catalytic cracking (FCC) gasoline. 3-Methylthiophene (3MT) and isobutylene (IB) were designated as the model compounds for sulfide and olefin, respectively; NKC-9 cation exchange resin mixed with the 2 mm × 2 mm θ ring packing was used as the catalyst bed. The process parameters such as feed composition, molar ratio of 3MT to IB, and reflux ratio were investigated experimentally in the RD column. Simulation for this process was carried out by using the equilibrium stage model—the RADFRAC module of Aspen Plus. The multicomponent vapor―liquid equilibria were predicted by an UNIQUAC method, and the kinetics model that is essential in the RD process was obtained from our previous work. The key design factors (e.g., number of reactive and nonreactive stages, location of feed stage, column pressure, mass ratio of distillate to feed, and catalyst weight) were optimized. The theoretical calculations from the equilibrium stage model matched well with the experimental results. Optimization of the process revealed that applying RD technology into OATS process offers higher alkylation selectivity and better catalytic stability, and the sulfur content in FCC gasoline declined by more than 99%.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184959

[article] Process simulation based on experimental investigations for 3 - methylthiophene alkylation with isobutylene in a reactive distillation column [texte imprimé] / Yu Liu, Auteur ; Bolun Yang, Auteur ; Shasha Li, Auteur . - 2012 . - pp. 9803-9811.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9803-9811

Mots-clés :	Distillation  column  Distillation  with  reaction  Alkylation
Résumé :	A new approach that substitutes the original two-step olefinic alkylation of thiophenic sulfur (OATS) technology with a reactive distillation (RD) column was proposed to remove sulfur compounds from fluid catalytic cracking (FCC) gasoline. 3-Methylthiophene (3MT) and isobutylene (IB) were designated as the model compounds for sulfide and olefin, respectively; NKC-9 cation exchange resin mixed with the 2 mm × 2 mm θ ring packing was used as the catalyst bed. The process parameters such as feed composition, molar ratio of 3MT to IB, and reflux ratio were investigated experimentally in the RD column. Simulation for this process was carried out by using the equilibrium stage model—the RADFRAC module of Aspen Plus. The multicomponent vapor―liquid equilibria were predicted by an UNIQUAC method, and the kinetics model that is essential in the RD process was obtained from our previous work. The key design factors (e.g., number of reactive and nonreactive stages, location of feed stage, column pressure, mass ratio of distillate to feed, and catalyst weight) were optimized. The theoretical calculations from the equilibrium stage model matched well with the experimental results. Optimization of the process revealed that applying RD technology into OATS process offers higher alkylation selectivity and better catalytic stability, and the sulfur content in FCC gasoline declined by more than 99%.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184959

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9790-9802

Titre :	Analysis of Local Recycle for Membrane Pervaporation Systems
Type de document :	texte imprimé
Auteurs :	Anton Santoso, Auteur ; Yu, Cheng-Ching, Auteur ; Jeffrey D. Ward, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9790-9802
Note générale :	Industrial chemoistry
Langues :	Anglais (eng)
Mots-clés :	Membrane  separation  Pervaporation
Résumé :	We present an analysis of local recycle in membrane pervaporation processes. Local recycle (reheating and recycling part of the retentate from a membrane unit back to the inlet) can mitigate the problem of temperature drop in pervaporation units. The excess fluid acts as a thermal carrier, increasing the temperature. However, a trade-off occurs because this recycle also decreases the concentration of the more permeable species on the retentate side of the membrane. We present a method based on dimensional analysis that can be used to quickly determine whether local recycle around a single membrane unit is desirable. We show that membrane modules can be classified into one of three types: local recycle is not desirable, local recycle is desirable with an intermediate recycle ratio, and local recycle is desirable with the maximum possible recycle ratio. The method is illustrated using three case studies, two of which are based on hybrid distillation/pervaporation processes. The results indicate that the correct application of internal recycle can significantly improve efficiency and reduce cost.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184958

[article] Analysis of Local Recycle for Membrane Pervaporation Systems [texte imprimé] / Anton Santoso, Auteur ; Yu, Cheng-Ching, Auteur ; Jeffrey D. Ward, Auteur . - 2012 . - pp. 9790-9802.
Industrial chemoistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9790-9802

Mots-clés :	Membrane  separation  Pervaporation
Résumé :	We present an analysis of local recycle in membrane pervaporation processes. Local recycle (reheating and recycling part of the retentate from a membrane unit back to the inlet) can mitigate the problem of temperature drop in pervaporation units. The excess fluid acts as a thermal carrier, increasing the temperature. However, a trade-off occurs because this recycle also decreases the concentration of the more permeable species on the retentate side of the membrane. We present a method based on dimensional analysis that can be used to quickly determine whether local recycle around a single membrane unit is desirable. We show that membrane modules can be classified into one of three types: local recycle is not desirable, local recycle is desirable with an intermediate recycle ratio, and local recycle is desirable with the maximum possible recycle ratio. The method is illustrated using three case studies, two of which are based on hybrid distillation/pervaporation processes. The results indicate that the correct application of internal recycle can significantly improve efficiency and reduce cost.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184958

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9783-9789

Titre :	Local model - based predictive control for spatially - distributed systems based on linear programming
Type de document :	texte imprimé
Auteurs :	Mengling Wang, Auteur ; Yang Zhang, Auteur ; Hongbo Shi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9783-9789
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Mathematical  programming  Linear  programming  Predictive  controlModeling
Résumé :	A local model-based predictive control strategy based on linear programming is proposed for partial differential equation descriptions unknown spatially distributed systems (SDSs). First, the interval type-2 T-S fuzzy based local modeling approach is developed to estimate the dynamics of the SDS based on the input—output data. On the basis of the local IT2 T-S fuzzy model, the local model-based predictive controller is designed to obtain local controlled outputs through minimizing the local optimization objective. Finally, the global controlled outputs are obtained by a linear programming method, where the deviations of the spatial temporal outputs from their spatial set points over the prediction horizon are considered as the optimal objective. The accuracy and efficiency of the proposed methodologies are tested in the simulation case.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184957

[article] Local model - based predictive control for spatially - distributed systems based on linear programming [texte imprimé] / Mengling Wang, Auteur ; Yang Zhang, Auteur ; Hongbo Shi, Auteur . - 2012 . - pp. 9783-9789.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9783-9789

Mots-clés :	Mathematical  programming  Linear  programming  Predictive  controlModeling
Résumé :	A local model-based predictive control strategy based on linear programming is proposed for partial differential equation descriptions unknown spatially distributed systems (SDSs). First, the interval type-2 T-S fuzzy based local modeling approach is developed to estimate the dynamics of the SDS based on the input—output data. On the basis of the local IT2 T-S fuzzy model, the local model-based predictive controller is designed to obtain local controlled outputs through minimizing the local optimization objective. Finally, the global controlled outputs are obtained by a linear programming method, where the deviations of the spatial temporal outputs from their spatial set points over the prediction horizon are considered as the optimal objective. The accuracy and efficiency of the proposed methodologies are tested in the simulation case.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184957

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9777–9782

Titre :	Influence of eucalyptus globulus kraft pulping severity on the rheological properties of gel - like cellulose pulp dispersions in castor oil
Type de document :	texte imprimé
Auteurs :	N. Nunez, Auteur ; J. E. Martin-Alfonso, Auteur ; M. E. Eugenio, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9777–9782
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dispersion  Rheological  properties  Paper  industry  Pulping
Résumé :	The development of some cellulose pulp gel-like dispersions in castor oil with application as biodegradable lubricants was explored in this work by analyzing the effect that Kraft cellulosic pulp cooking conditions exerts on the rheological properties and mechanical stability of these formulations. With this aim, Eucalyptus globulus cellulosic pulps were obtained by increasing the pulping time at the maximum temperature, yielding H factors ranging from 150 to 500. Gel-like dispersions of cellulosic pulps in castor oil were prepared and characterized from a rheological point of view. Small-amplitude oscillatory shear (SAOS) measurements and some standard mechanical tests, usually performed on commercial lubricating greases, were carried out in order to evaluate the lubricant performance of these dispersions. In general, the values of linear viscoelastic functions increase with the H factor. Cellulose pulps submitted to lower H factors provides gel-like dispersions with SAOS functions values more similar to those found in traditional lubricating greases. Results were explained attending to a balance between the cellulose polymerization degree and lignin and α-cellulose contents, all of them affected by the H factor applied. An empirical correlation between these variables and both the plateau modulus and the loss of consistency has been proposed to predict the rheological behavior and mechanical stability of gel-like cellulose pulp dispersions in castor oil.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184956

[article] Influence of eucalyptus globulus kraft pulping severity on the rheological properties of gel - like cellulose pulp dispersions in castor oil [texte imprimé] / N. Nunez, Auteur ; J. E. Martin-Alfonso, Auteur ; M. E. Eugenio, Auteur . - 2012 . - pp. 9777–9782.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9777–9782

Mots-clés :	Dispersion  Rheological  properties  Paper  industry  Pulping
Résumé :	The development of some cellulose pulp gel-like dispersions in castor oil with application as biodegradable lubricants was explored in this work by analyzing the effect that Kraft cellulosic pulp cooking conditions exerts on the rheological properties and mechanical stability of these formulations. With this aim, Eucalyptus globulus cellulosic pulps were obtained by increasing the pulping time at the maximum temperature, yielding H factors ranging from 150 to 500. Gel-like dispersions of cellulosic pulps in castor oil were prepared and characterized from a rheological point of view. Small-amplitude oscillatory shear (SAOS) measurements and some standard mechanical tests, usually performed on commercial lubricating greases, were carried out in order to evaluate the lubricant performance of these dispersions. In general, the values of linear viscoelastic functions increase with the H factor. Cellulose pulps submitted to lower H factors provides gel-like dispersions with SAOS functions values more similar to those found in traditional lubricating greases. Results were explained attending to a balance between the cellulose polymerization degree and lignin and α-cellulose contents, all of them affected by the H factor applied. An empirical correlation between these variables and both the plateau modulus and the loss of consistency has been proposed to predict the rheological behavior and mechanical stability of gel-like cellulose pulp dispersions in castor oil.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184956

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9769–9776

Titre :	Halogen - free flame - retardant flexible polyurethane foam with a novel nitrogen – phosphorus flame retardant
Type de document :	texte imprimé
Auteurs :	Ming-Jun Chen, Auteur ; Zhu-Bao Shao, Auteur ; Xiu-Li Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9769–9776
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Halogen  Nitrogen
Résumé :	A novel nitrogen–phosphorus flame retardant, 2-carboxyethyl(phenyl)phosphinic acid melamine salt (CMA), was synthesized by the reaction of 2-carboxyethyl(phenyl)phosphinic acid with melamine in aqueous solution, and it was characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), inductively coupled plasma-atomic emission spectrometry (ICP-AES), elemental analysis, and thermogravimetric analysis (TGA). Halogen-free flame-retardant flexible polyurethane foams (FPUF) were prepared successfully by using CMA as a flame retardant. The effects of CMA content on the mechanical, thermal, and flame-retardant properties of FPUF were investigated by tensile test, TGA, limiting oxygen index (LOI), flame propagation test (Cal T.B. 117A-Part I standard), and cone calorimeter. The foam morphology of FPUF was studied via scanning electron microscopy (SEM). The results showed that CMA endowed FPUF with good flame-retardant properties. FPUF containing only 12 wt % CMA can pass Cal T.B. 117A-Part I standard, and its LOI value was increased from 18.2 (for FPUF without CMA) to 24.1. Particularly, the addition of CMA almost did not decrease the mechanical properties of the resulting flame-retardant FPUFs.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301004d

[article] Halogen - free flame - retardant flexible polyurethane foam with a novel nitrogen – phosphorus flame retardant [texte imprimé] / Ming-Jun Chen, Auteur ; Zhu-Bao Shao, Auteur ; Xiu-Li Wang, Auteur . - 2012 . - pp. 9769–9776.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9769–9776

Mots-clés :	Halogen  Nitrogen
Résumé :	A novel nitrogen–phosphorus flame retardant, 2-carboxyethyl(phenyl)phosphinic acid melamine salt (CMA), was synthesized by the reaction of 2-carboxyethyl(phenyl)phosphinic acid with melamine in aqueous solution, and it was characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), inductively coupled plasma-atomic emission spectrometry (ICP-AES), elemental analysis, and thermogravimetric analysis (TGA). Halogen-free flame-retardant flexible polyurethane foams (FPUF) were prepared successfully by using CMA as a flame retardant. The effects of CMA content on the mechanical, thermal, and flame-retardant properties of FPUF were investigated by tensile test, TGA, limiting oxygen index (LOI), flame propagation test (Cal T.B. 117A-Part I standard), and cone calorimeter. The foam morphology of FPUF was studied via scanning electron microscopy (SEM). The results showed that CMA endowed FPUF with good flame-retardant properties. FPUF containing only 12 wt % CMA can pass Cal T.B. 117A-Part I standard, and its LOI value was increased from 18.2 (for FPUF without CMA) to 24.1. Particularly, the addition of CMA almost did not decrease the mechanical properties of the resulting flame-retardant FPUFs.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301004d

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9760-9768

Titre :	Synthesis and characterization of all acrylic block copolymer / clay nanocomposites prepared via surface initiated atom transfer radical polymerization (SI - ATRP)
Type de document :	texte imprimé
Auteurs :	Dhruba J. Haloi, Auteur ; Souvik Ata, Auteur ; Nikhil K. Singha, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9760-9768
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Polymerization  Nanocomposite
Résumé :	Surface initiated polymerization (SIP) is an emerging powerful tool to modify and tailor the surface properties of nanoparticles. Among different methods of SIP, surface initiated atom transfer radical polymerization (SI-ATRP) has several strategic advantages over other methods of polymerizations. This investigation reports the preparation and characterization of poly(2-ethylhexyl acrylate) (PEHA)/clay nanocomposite from nanoclay surface via SI-ATRP and poly(2-ethylhexyl acrylate)-block-poly(methyl methacrylate) (PEHA-b-PMMA)/clay nanocomposite via conventional ATRP. To carry out SI-ATRP, the nanoclay (Cloisite Na+) surface was first modified by incorporating an ATRP initiator (2-bromopropionyl bromide) to nanoclay surface via a grafting reaction. The prepared bromo-functionalized nanoclay (Clay—Br) was then used to carry out SI-ATRP of 2-ethylhexyl acrylate (EHA) at 90 °C using CuBr as catalyst in combination with N, N, N', N", N"- pentamethyl diethylenetriamine (PMDETA) as the ligand. The macroinitiator (clay-PEHA-Br) was used to prepare PEHA-b-PMMA/clay nanocomposites via conventional ATRP using the same reaction conditions as SI-ATRP of EHA. A series of PEHA-b-PMMA/ clay nanocomposites were prepared via ATRP. The prepared PEHA/clay nanocomposites and PEHA-b-PMMA/clay nanocomposites were characterized by WAXD and TEM analyses. DSC analysis of PEHA-b-PMMA/clay nanocomposites showed two Tg values corresponding to two blocks present in the block copolymers. TGA analysis was also carried out to study the thermal stability of PEHA/clay nanocomposites and PEHA-b-PMMA/clay nanocomposites at different nanoclay loading. The chemical structure and molecular weights of the prepared polymers were analyzed by Fourier transform infrared (FT-IR), 1H NMR, and gel permeation chromatography (GPC) analyses.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184954

[article] Synthesis and characterization of all acrylic block copolymer / clay nanocomposites prepared via surface initiated atom transfer radical polymerization (SI - ATRP) [texte imprimé] / Dhruba J. Haloi, Auteur ; Souvik Ata, Auteur ; Nikhil K. Singha, Auteur . - 2012 . - pp. 9760-9768.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9760-9768

Mots-clés :	Polymerization  Nanocomposite
Résumé :	Surface initiated polymerization (SIP) is an emerging powerful tool to modify and tailor the surface properties of nanoparticles. Among different methods of SIP, surface initiated atom transfer radical polymerization (SI-ATRP) has several strategic advantages over other methods of polymerizations. This investigation reports the preparation and characterization of poly(2-ethylhexyl acrylate) (PEHA)/clay nanocomposite from nanoclay surface via SI-ATRP and poly(2-ethylhexyl acrylate)-block-poly(methyl methacrylate) (PEHA-b-PMMA)/clay nanocomposite via conventional ATRP. To carry out SI-ATRP, the nanoclay (Cloisite Na+) surface was first modified by incorporating an ATRP initiator (2-bromopropionyl bromide) to nanoclay surface via a grafting reaction. The prepared bromo-functionalized nanoclay (Clay—Br) was then used to carry out SI-ATRP of 2-ethylhexyl acrylate (EHA) at 90 °C using CuBr as catalyst in combination with N, N, N', N", N"- pentamethyl diethylenetriamine (PMDETA) as the ligand. The macroinitiator (clay-PEHA-Br) was used to prepare PEHA-b-PMMA/clay nanocomposites via conventional ATRP using the same reaction conditions as SI-ATRP of EHA. A series of PEHA-b-PMMA/ clay nanocomposites were prepared via ATRP. The prepared PEHA/clay nanocomposites and PEHA-b-PMMA/clay nanocomposites were characterized by WAXD and TEM analyses. DSC analysis of PEHA-b-PMMA/clay nanocomposites showed two Tg values corresponding to two blocks present in the block copolymers. TGA analysis was also carried out to study the thermal stability of PEHA/clay nanocomposites and PEHA-b-PMMA/clay nanocomposites at different nanoclay loading. The chemical structure and molecular weights of the prepared polymers were analyzed by Fourier transform infrared (FT-IR), 1H NMR, and gel permeation chromatography (GPC) analyses.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184954

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9750-9759

Titre :	Influence of TEMPO - mediated oxidation on properties of hemp fibers
Type de document :	texte imprimé
Auteurs :	Jovana Milanovic, Auteur ; Mirjana Kostic, Auteur ; Predrag Milanovic, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9750-9759
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Oxidation
Résumé :	Hemp fibers are a very interesting natural material for textile and technical applications, but some of these applications require improved and/or specific fiber properties. In order to modify hemp fibers for obtaining high added value products, hemp fibers were oxidized with sodium hypochlorite and a catalytic amount of sodium bromide and 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO), under various conditions. The oxidized hemp fibers were analyzed and characterized in terms of chemical composition (lignin and hemicelluloses) and weight loss, fineness, introduced functional groups, sorption (moisture sorption, water retention values, iodine sorption), and mechanical properties (tenacity and elongation). Applied TEMPO-mediated oxidation has been very efficient for simultaneous removal of noncellulosic substances (reduction of lignin content up to 1.95%) and introduction of surface functional groups, i.e., aldehyde (up to 0.415 mmol/g) and carboxyl groups (up to 0.815 mmol/g). The oxidized hemp fibers were finer, with a lower content of lignin and hemicelluloses and with improved water uptake properties.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184953

[article] Influence of TEMPO - mediated oxidation on properties of hemp fibers [texte imprimé] / Jovana Milanovic, Auteur ; Mirjana Kostic, Auteur ; Predrag Milanovic, Auteur . - 2012 . - pp. 9750-9759.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9750-9759

Mots-clés :	Oxidation
Résumé :	Hemp fibers are a very interesting natural material for textile and technical applications, but some of these applications require improved and/or specific fiber properties. In order to modify hemp fibers for obtaining high added value products, hemp fibers were oxidized with sodium hypochlorite and a catalytic amount of sodium bromide and 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO), under various conditions. The oxidized hemp fibers were analyzed and characterized in terms of chemical composition (lignin and hemicelluloses) and weight loss, fineness, introduced functional groups, sorption (moisture sorption, water retention values, iodine sorption), and mechanical properties (tenacity and elongation). Applied TEMPO-mediated oxidation has been very efficient for simultaneous removal of noncellulosic substances (reduction of lignin content up to 1.95%) and introduction of surface functional groups, i.e., aldehyde (up to 0.415 mmol/g) and carboxyl groups (up to 0.815 mmol/g). The oxidized hemp fibers were finer, with a lower content of lignin and hemicelluloses and with improved water uptake properties.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184953

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9742-9749

Titre :	Polymerization of ethylene over rac - Et(1 - indenyl)2ZrCl2/MAO catalyst supported on pseudo - inverse opal silica particles
Type de document :	texte imprimé
Auteurs :	Sang Yool Lee, Auteur ; Kyu Yong Choi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9742-9749
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst  support  Polymerization
Résumé :	The polymerization of ethylene with rac-Et(1-indenyl)2ZrCl2/MAO catalyst supported on ultraporous and spherical pseudo-inverse opal silica (PIOS) particles with unique morphology is reported. The novel silica particles with an inverse opal-like structure provide wide-open pore and surface structures favorable for the catalyst deposition and monomer access with minimal intraparticle diffusion resistance. The metallocene catalyst supported on the PIOS support exhibited very high initial catalyst activity and longer catalyst lifetime compared with conventional silica-supported catalysts. The experimental data that show the effects of support geometry on the catalytic activity, catalyst particle fragmentation, polymer particle morphology, and polymer molecular weight distribution in ethylene polymerization are presented.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184952

[article] Polymerization of ethylene over rac - Et(1 - indenyl)2ZrCl2/MAO catalyst supported on pseudo - inverse opal silica particles [texte imprimé] / Sang Yool Lee, Auteur ; Kyu Yong Choi, Auteur . - 2012 . - pp. 9742-9749.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9742-9749

Mots-clés :	Catalyst  support  Polymerization
Résumé :	The polymerization of ethylene with rac-Et(1-indenyl)2ZrCl2/MAO catalyst supported on ultraporous and spherical pseudo-inverse opal silica (PIOS) particles with unique morphology is reported. The novel silica particles with an inverse opal-like structure provide wide-open pore and surface structures favorable for the catalyst deposition and monomer access with minimal intraparticle diffusion resistance. The metallocene catalyst supported on the PIOS support exhibited very high initial catalyst activity and longer catalyst lifetime compared with conventional silica-supported catalysts. The experimental data that show the effects of support geometry on the catalytic activity, catalyst particle fragmentation, polymer particle morphology, and polymer molecular weight distribution in ethylene polymerization are presented.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184952

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9733-9741

Titre :	Backmixing characterization of a bubble column with short venturi throats by multipoint internal tracer injections
Type de document :	texte imprimé
Auteurs :	Zi-Bin Huang, Auteur ; Zhen-Min Cheng, Auteur ; Jian-Ding Chen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9733-9741
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Tracers  Venturi  Bubble  column  Backmixing
Résumé :	In reduction of liquid backmixing in bubble columns, Wu et al. [Wu, Y; Cheng, Z. M.; Huang, Z. B. Backmixing reduction of a bubble column by interruption of the global liquid circulation. Ind. Eng. Chem. Res. 2009, 48, 6558― 6563] have shown that the backmixing could be substantially reduced by interrupting the global liquid circulation using four identical short Venturi throats (SVTs). Considering the advantages of such structures, it is necessary to further investigate the backmixing characteristics of a bubble column with SVTs. In the present work, a multipoint tracer injection and detection device was employed to enhance the insight into where and how the liquid tracer was backmixed in different stages of a 50-cm diameter column. Tracer response profiles were measured to track the liquid backmixing trajectory in different stages at various operating conditions. The results showed that the backmixing of the column was sensitive to the throat diameter of SVTs. Based on the observed physical phenomena, a tanks-in-series with backflow (TISB) model was adopted to interpret the tracer experiment data, which shows an excellent agreement between the prediction and experimental measurements.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184951

[article] Backmixing characterization of a bubble column with short venturi throats by multipoint internal tracer injections [texte imprimé] / Zi-Bin Huang, Auteur ; Zhen-Min Cheng, Auteur ; Jian-Ding Chen, Auteur . - 2012 . - pp. 9733-9741.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9733-9741

Mots-clés :	Tracers  Venturi  Bubble  column  Backmixing
Résumé :	In reduction of liquid backmixing in bubble columns, Wu et al. [Wu, Y; Cheng, Z. M.; Huang, Z. B. Backmixing reduction of a bubble column by interruption of the global liquid circulation. Ind. Eng. Chem. Res. 2009, 48, 6558― 6563] have shown that the backmixing could be substantially reduced by interrupting the global liquid circulation using four identical short Venturi throats (SVTs). Considering the advantages of such structures, it is necessary to further investigate the backmixing characteristics of a bubble column with SVTs. In the present work, a multipoint tracer injection and detection device was employed to enhance the insight into where and how the liquid tracer was backmixed in different stages of a 50-cm diameter column. Tracer response profiles were measured to track the liquid backmixing trajectory in different stages at various operating conditions. The results showed that the backmixing of the column was sensitive to the throat diameter of SVTs. Based on the observed physical phenomena, a tanks-in-series with backflow (TISB) model was adopted to interpret the tracer experiment data, which shows an excellent agreement between the prediction and experimental measurements.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184951

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9719-9732

Titre :	Formation of nitrogen oxides in flames of model biodiesel fuels
Type de document :	texte imprimé
Auteurs :	Qiyao Feng, Auteur ; Yang Lee Wang, Auteur ; Theodore T. Tsotsis, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9719-9732
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Fuel  Modeling  Flame
Résumé :	The nitrogen oxide formation characteristics of a class of model biodiesel fuels, namely fatty acid esters, were studied in both premixed and nonpremixed flames. The experiments were conducted in the opposed-jet configuration at atmospheric pressure and for various reactant concentrations. The measurements were performed using a quartz-probe sampling method. Flames of the model biodiesel fuels were determined to form significantly less nitrogen oxides when compared to the corresponding n-alkanes. Additional experimental studies were carried out in order to assess the effects of carbon number, type of ester group (methyl or ethyl), and the extent of saturation on the nitrogen oxide concentrations in flames of these model biodiesel fuels. Three recently developed chemical kinetic models were utilized in order to model the experiments and to investigate the relative contributions of the four different nitrogen oxide pathways to the nitrogen oxide formation in these flames as well as to provide insight into the differences that were determined experimentally in flames of the various model biodiesel fuels.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184950

[article] Formation of nitrogen oxides in flames of model biodiesel fuels [texte imprimé] / Qiyao Feng, Auteur ; Yang Lee Wang, Auteur ; Theodore T. Tsotsis, Auteur . - 2012 . - pp. 9719-9732.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9719-9732

Mots-clés :	Fuel  Modeling  Flame
Résumé :	The nitrogen oxide formation characteristics of a class of model biodiesel fuels, namely fatty acid esters, were studied in both premixed and nonpremixed flames. The experiments were conducted in the opposed-jet configuration at atmospheric pressure and for various reactant concentrations. The measurements were performed using a quartz-probe sampling method. Flames of the model biodiesel fuels were determined to form significantly less nitrogen oxides when compared to the corresponding n-alkanes. Additional experimental studies were carried out in order to assess the effects of carbon number, type of ester group (methyl or ethyl), and the extent of saturation on the nitrogen oxide concentrations in flames of these model biodiesel fuels. Three recently developed chemical kinetic models were utilized in order to model the experiments and to investigate the relative contributions of the four different nitrogen oxide pathways to the nitrogen oxide formation in these flames as well as to provide insight into the differences that were determined experimentally in flames of the various model biodiesel fuels.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26184950

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9713–9718

Titre :	Preparation of anhydrous magnesium chloride from magnesia
Type de document :	texte imprimé
Auteurs :	Zhimin Zhang, Auteur ; Xuchen Lu, Auteur ; Suping Yang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9713–9718
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Magnesium  Chloride
Résumé :	High-purity anhydrous magnesium chloride was prepared by using magnesia and ammonium chloride as reactants, alumina as covering agent. The process was characterized by X-ray diffraction and thermogravimetric and differential scanning calorimetry analysis. The reaction mechanism involved in the process was proposed and discussed. In addition, the effects of molar ratio of ammonium chloride to magnesia, thickness of the covering agent (alumina), reaction temperature, and reaction time on the purity of anhydrous magnesium chloride were investigated. The content of magnesia in anhydrous magnesium chloride was achieved 0.014% under the optimum conditions: ammonium chloride and magnesia with the molar ratio of NH4Cl:MgO = 5:1 were mixed evenly. Alumina with the thickness of 1.1 cm was used as a covering agent. The mixture was maintained at 450 °C for 1.5 h for the complete reaction, and then calcined at 700 °C for 0.5 h to obtain well-sintered anhydrous magnesium chloride.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300765u

[article] Preparation of anhydrous magnesium chloride from magnesia [texte imprimé] / Zhimin Zhang, Auteur ; Xuchen Lu, Auteur ; Suping Yang, Auteur . - 2012 . - pp. 9713–9718.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9713–9718

Mots-clés :	Magnesium  Chloride
Résumé :	High-purity anhydrous magnesium chloride was prepared by using magnesia and ammonium chloride as reactants, alumina as covering agent. The process was characterized by X-ray diffraction and thermogravimetric and differential scanning calorimetry analysis. The reaction mechanism involved in the process was proposed and discussed. In addition, the effects of molar ratio of ammonium chloride to magnesia, thickness of the covering agent (alumina), reaction temperature, and reaction time on the purity of anhydrous magnesium chloride were investigated. The content of magnesia in anhydrous magnesium chloride was achieved 0.014% under the optimum conditions: ammonium chloride and magnesia with the molar ratio of NH4Cl:MgO = 5:1 were mixed evenly. Alumina with the thickness of 1.1 cm was used as a covering agent. The mixture was maintained at 450 °C for 1.5 h for the complete reaction, and then calcined at 700 °C for 0.5 h to obtain well-sintered anhydrous magnesium chloride.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300765u

[article] 
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9705–9712

Titre :	Mechanistic features of ultrasound - assisted oxidative desulfurization of liquid fuels
Type de document :	texte imprimé
Auteurs :	Manohar Kumar Bolla, Auteur ; Hanif A. Choudhury, Auteur ; Vijayanand S. Moholkar, Auteur
Année de publication :	2012
Article en page(s) :	pp. 9705–9712
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ultrasound  Oxidative  Liquid  fuels
Résumé :	A new technology for the removal of sulfur compounds from liquid fuels is oxidative desulfurization. Although several studies have reported the enhancement effect of ultrasound irradiation on oxidative desulfurization, the exact mechanism underlying this enhancement is not known yet. In this study, we have addressed this issue with dual approach of coupling experiments with mathematical model for cavitation. Results of this study have given interesting revelation of interaction between mechanism of ultrasound, cavitation, and oxidation system. Isolation of cavitation phenomenon helps to increase the extent of oxidation. This effect is attributed to formation of hydrogen and carbon monoxide during transient collapse of cavitation bubbles due to thermal dissociation of hexane vapor entrapped in the bubble, which hamper the action of O species generated from the oxidation system. Transient cavitation itself does not give rise to radical formation, because of rather low temperature peaks reached during collapse. Therefore, cavitation does not enhance the oxidation process, but in fact, has an adverse effect on it. Current study has established that the beneficial effect of ultrasound on oxidative desulfurization system is merely of a physical nature (i.e., emulsification due to intense micromixing), with no involvement of a sonochemical effect.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300807a

[article] Mechanistic features of ultrasound - assisted oxidative desulfurization of liquid fuels [texte imprimé] / Manohar Kumar Bolla, Auteur ; Hanif A. Choudhury, Auteur ; Vijayanand S. Moholkar, Auteur . - 2012 . - pp. 9705–9712.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9705–9712

Mots-clés :	Ultrasound  Oxidative  Liquid  fuels
Résumé :	A new technology for the removal of sulfur compounds from liquid fuels is oxidative desulfurization. Although several studies have reported the enhancement effect of ultrasound irradiation on oxidative desulfurization, the exact mechanism underlying this enhancement is not known yet. In this study, we have addressed this issue with dual approach of coupling experiments with mathematical model for cavitation. Results of this study have given interesting revelation of interaction between mechanism of ultrasound, cavitation, and oxidation system. Isolation of cavitation phenomenon helps to increase the extent of oxidation. This effect is attributed to formation of hydrogen and carbon monoxide during transient collapse of cavitation bubbles due to thermal dissociation of hexane vapor entrapped in the bubble, which hamper the action of O species generated from the oxidation system. Transient cavitation itself does not give rise to radical formation, because of rather low temperature peaks reached during collapse. Therefore, cavitation does not enhance the oxidation process, but in fact, has an adverse effect on it. Current study has established that the beneficial effect of ultrasound on oxidative desulfurization system is merely of a physical nature (i.e., emulsification due to intense micromixing), with no involvement of a sonochemical effect.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300807a