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Experimental and kinetic study of iow temperature selective catalytic reduction of NO with NH3 over the V2O5/AC catalyst / Zhigang Lei in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5360-5368 Titre : Experimental and kinetic study of iow temperature selective catalytic reduction of NO with NH3 over the V2O5/AC catalyst Type de document : texte imprimé Auteurs : Zhigang Lei, Auteur ; Aibin Long, Auteur ; Cuiping Wen, Auteur Année de publication : 2011 Article en page(s) : pp. 5360-5368 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst  Selective  catalytic  reduction  Low  temperature  Kinetics Résumé : Selective catalytic reduction (SCR) of NO (nitric oxide) by NH3 (ammonia) at temperatures of393-523 K over AC (activated carbon) supported V2O5 (vanadium pentoxide) was investigated in this work. The V2O5/AC catalyst was prepared by the pore volume impregnation method. The intrinsic kinetics for this catalyst was first measured in the absence of internal and external diffusions in a fixed-bed microreactor. Then, five intrinsic kinetic models, i.e. the Eley-Rideal model, the Langmuir―Hinshelwood model, the Mars-van Krevelen model, the first-order model, and the power-rate law model, were applied to correlate the experimental data. Among them, the Eley-Rideal model is the most accurate, and the Langmuir-Hinshelwood model is unfeasible for describing SCR of NO by NH3 over the V2O5/AC catalyst. Therefore, the SCR of NO with NH3 over V2O5/AC is likely to Follow the Eley-Rideal mechanism in light ofintrinsic kinetic measurements. Finally, the kinetic equations were incorporated into a 3D mathematical model for monolithic honeycomb reactor, and it was found that the Eley-Rideal model is more suitable and can provide useful information for future application in the actual industrial plants. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128658 [article] Experimental and kinetic study of iow temperature selective catalytic reduction of NO with NH3 over the V2O5/AC catalyst [texte imprimé] / Zhigang Lei, Auteur ; Aibin Long, Auteur ; Cuiping Wen, Auteur . - 2011 . - pp. 5360-5368. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5360-5368 Mots-clés : Catalyst  Selective  catalytic  reduction  Low  temperature  Kinetics Résumé : Selective catalytic reduction (SCR) of NO (nitric oxide) by NH3 (ammonia) at temperatures of393-523 K over AC (activated carbon) supported V2O5 (vanadium pentoxide) was investigated in this work. The V2O5/AC catalyst was prepared by the pore volume impregnation method. The intrinsic kinetics for this catalyst was first measured in the absence of internal and external diffusions in a fixed-bed microreactor. Then, five intrinsic kinetic models, i.e. the Eley-Rideal model, the Langmuir―Hinshelwood model, the Mars-van Krevelen model, the first-order model, and the power-rate law model, were applied to correlate the experimental data. Among them, the Eley-Rideal model is the most accurate, and the Langmuir-Hinshelwood model is unfeasible for describing SCR of NO by NH3 over the V2O5/AC catalyst. Therefore, the SCR of NO with NH3 over V2O5/AC is likely to Follow the Eley-Rideal mechanism in light ofintrinsic kinetic measurements. Finally, the kinetic equations were incorporated into a 3D mathematical model for monolithic honeycomb reactor, and it was found that the Eley-Rideal model is more suitable and can provide useful information for future application in the actual industrial plants. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128658

Extension of the UNIFAC model for ionic liquids / Zhigang Lei in Industrial & engineering chemistry research, Vol. 51 N° 37 (Septembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12135–12144 Titre : Extension of the UNIFAC model for ionic liquids Type de document : texte imprimé Auteurs : Zhigang Lei, Auteur ; Chengna Dai, Auteur ; Xing Liu, Auteur Année de publication : 2012 Article en page(s) : pp. 12135–12144 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Extension  Ionic  Liquids Résumé : The UNIFAC model has recently become very popular for ionic liquids (ILs) because of its applicability for prediction of thermodynamic properties. This work is a continuation of our studies on the extension of group parameters of the UNIFAC model to systems with ILs. The new IL groups for 33 main groups and 53 subgroups were added into the current UNIFAC parameter matrix. The parameters of group surface area and volume for ILs were obtained by the COSMO calculation, while the group binary interaction parameters, anm and amn, were obtained by means of correlating the activity coefficients of solutes at infinite dilution in ILs at different temperatures exhaustively collected from literature by the end of 2011. The predicted results of UNIFAC model are more accurate than those of the COSMO-RS model so that it can be used for identifying the general relationship between molecular structure of ILs and separation performance for the separation of liquid mixtures with ILs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301159v [article] Extension of the UNIFAC model for ionic liquids [texte imprimé] / Zhigang Lei, Auteur ; Chengna Dai, Auteur ; Xing Liu, Auteur . - 2012 . - pp. 12135–12144. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12135–12144 Mots-clés : Extension  Ionic  Liquids Résumé : The UNIFAC model has recently become very popular for ionic liquids (ILs) because of its applicability for prediction of thermodynamic properties. This work is a continuation of our studies on the extension of group parameters of the UNIFAC model to systems with ILs. The new IL groups for 33 main groups and 53 subgroups were added into the current UNIFAC parameter matrix. The parameters of group surface area and volume for ILs were obtained by the COSMO calculation, while the group binary interaction parameters, anm and amn, were obtained by means of correlating the activity coefficients of solutes at infinite dilution in ILs at different temperatures exhaustively collected from literature by the end of 2011. The predicted results of UNIFAC model are more accurate than those of the COSMO-RS model so that it can be used for identifying the general relationship between molecular structure of ILs and separation performance for the separation of liquid mixtures with ILs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301159v

Liquid−liquid extraction of low-concentration aniline from aqueous solutions with salts / Xiaohua Wu in Industrial & engineering chemistry research, Vol. 49 N° 6 (Mars 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 6 (Mars 2010) . - pp. 2581–2588 Titre : Liquid−liquid extraction of low-concentration aniline from aqueous solutions with salts Type de document : texte imprimé Auteurs : Xiaohua Wu, Auteur ; Zhigang Lei, Auteur ; Qunsheng Li, Auteur Année de publication : 2010 Article en page(s) : pp. 2581–2588 Note générale : Idustrial Chemistry Langues : Anglais (eng) Mots-clés : Liquid  Extraction  Low-Concentration  Aniline  Aqueous  Solutions  Salts Résumé : The focus of this work was to concentrate aniline at low concentration from water samples using liquid−liquid extraction with salts. The salts included inorganic solid salts and ionic liquids and were added to the system of water + aniline + MTBE (methyl tert-butyl ether) to intensify the conventional liquid−liquid extraction process. The influence of such factors as extraction time, initial aqueous aniline concentration, phase volume ratio, and extraction temperature on the extraction process was investigated to determine the optimum extraction conditions. It was found that the salting effect of K2CO3 on aniline and water is the highest among all of the salts investigated, whereas the imidazolium-based ionic liquids do not bring about a good extraction efficiency as expected. The complex formation and interaction force of the systems containing salts were determined using FTIR (Fourier transform infrared) spectrometry and density functional theory (DFT). This work also tries to explain the separation mechanism by means of the Hofmeister series and quantum chemistry. ISSN : 0885-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012979 [article] Liquid−liquid extraction of low-concentration aniline from aqueous solutions with salts [texte imprimé] / Xiaohua Wu, Auteur ; Zhigang Lei, Auteur ; Qunsheng Li, Auteur . - 2010 . - pp. 2581–2588. Idustrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 6 (Mars 2010) . - pp. 2581–2588 Mots-clés : Liquid  Extraction  Low-Concentration  Aniline  Aqueous  Solutions  Salts Résumé : The focus of this work was to concentrate aniline at low concentration from water samples using liquid−liquid extraction with salts. The salts included inorganic solid salts and ionic liquids and were added to the system of water + aniline + MTBE (methyl tert-butyl ether) to intensify the conventional liquid−liquid extraction process. The influence of such factors as extraction time, initial aqueous aniline concentration, phase volume ratio, and extraction temperature on the extraction process was investigated to determine the optimum extraction conditions. It was found that the salting effect of K2CO3 on aniline and water is the highest among all of the salts investigated, whereas the imidazolium-based ionic liquids do not bring about a good extraction efficiency as expected. The complex formation and interaction force of the systems containing salts were determined using FTIR (Fourier transform infrared) spectrometry and density functional theory (DFT). This work also tries to explain the separation mechanism by means of the Hofmeister series and quantum chemistry. ISSN : 0885-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012979

Selection of ionic liquids as entrainers for the separation of ethyl acetate and ethanol / Qunsheng Li in Industrial & engineering chemistry research, Vol. 48 N° 19 (Octobre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 19 (Octobre 2009) . - pp. 9006–9012 Titre : Selection of ionic liquids as entrainers for the separation of ethyl acetate and ethanol Type de document : texte imprimé Auteurs : Qunsheng Li, Auteur ; Jiguo Zhang, Auteur ; Zhigang Lei, Auteur Année de publication : 2009 Article en page(s) : pp. 9006–9012 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Ionic  liquidsMolecular  structures  Vapor−liquid  equilibrium Résumé : This work tries to explore the relation between molecular structures of ionic liquids (ILs) as entrainers and separation performance on ethyl acetate (1) and ethanol (2). The vapor−liquid equilibrium (VLE) data have been measured for ethyl acetate (1) + ethanol (2) containing ILs at 101.32 kPa. The ionic liquids investigated were 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]+[BF4]−) and 1-methyl-3-octylimidazolium tetrafluoroborate ([OMIM]+[BF4]−), as well as 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]+[BF4]−) that has been studied in our previous work. All the ILs could give rise to the salting-out effect. It was found that, at low IL concentration, the separation ability of ILs is in the order [EMIM]+[BF4]− > [BMIM]+[BF4]− > [OMIM]+[BF4]−, while at high IL concentration (x3 = 0.10−0.30) the separation ability of ILs is in the order [OMIM]+[BF4]− > [EMIM]+[BF4]− > [BMIM]+[BF4]− due to the difference of polarity of the three ILs and demixing effect. [EMIM]+[triflate]− was included as entrainer and compared with the tetrafluoroborate-based ILs. The measured ternary data were correlated using the NRTL model. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8017127 [article] Selection of ionic liquids as entrainers for the separation of ethyl acetate and ethanol [texte imprimé] / Qunsheng Li, Auteur ; Jiguo Zhang, Auteur ; Zhigang Lei, Auteur . - 2009 . - pp. 9006–9012. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 19 (Octobre 2009) . - pp. 9006–9012 Mots-clés : Ionic  liquidsMolecular  structures  Vapor−liquid  equilibrium Résumé : This work tries to explore the relation between molecular structures of ionic liquids (ILs) as entrainers and separation performance on ethyl acetate (1) and ethanol (2). The vapor−liquid equilibrium (VLE) data have been measured for ethyl acetate (1) + ethanol (2) containing ILs at 101.32 kPa. The ionic liquids investigated were 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]+[BF4]−) and 1-methyl-3-octylimidazolium tetrafluoroborate ([OMIM]+[BF4]−), as well as 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]+[BF4]−) that has been studied in our previous work. All the ILs could give rise to the salting-out effect. It was found that, at low IL concentration, the separation ability of ILs is in the order [EMIM]+[BF4]− > [BMIM]+[BF4]− > [OMIM]+[BF4]−, while at high IL concentration (x3 = 0.10−0.30) the separation ability of ILs is in the order [OMIM]+[BF4]− > [EMIM]+[BF4]− > [BMIM]+[BF4]− due to the difference of polarity of the three ILs and demixing effect. [EMIM]+[triflate]− was included as entrainer and compared with the tetrafluoroborate-based ILs. The measured ternary data were correlated using the NRTL model. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8017127

Selective catalytic reduction for NO removal / Zhigang Lei in Industrial & engineering chemistry research, Vol. 50 N° 10 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp 5942–5951 Titre : Selective catalytic reduction for NO removal : comparison of transfer and reaction performances among monolith catalysts Type de document : texte imprimé Auteurs : Zhigang Lei, Auteur ; Cuiping Wen, Auteur ; Jie Zhang, Auteur Année de publication : 2011 Article en page(s) : pp 5942–5951 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Monolith  catalysts Résumé : One of the available technologies that can effectively control the emission of NOx is the selective catalytic reduction (SCR) of NOx with ammonia (NH3). Monolith catalysts are widely used in this technology due to their unique advantages that they offer, like low pressure drop, high external geometric surface area, and resistance to deposition of carbon, dust, and metals from combustion process. But the configuration of monolith catalysts has prominent influence on transfer and reaction performances of SCR for NO removal. This work tries to provide an easy-to-read and comprehensive comparison of momentum transfer, heat transfer, mass transfer, and reaction performance between two types of monolith catalysts with five kinds of channel shapes for SCR for NO removal, and to address the issues specific to SCR applications as to (i) whether or not monolith catalysts can improve the transfer and reaction performances compared to traditional pellet packed-bed reactors; (ii) which type of monolith catalysts and (iii) which kind of channel shapes for each type are optimum from the viewpoint of chemical reaction engineering. It was found that monolith catalysts have a much lower pressure drop and higher effectiveness factor than traditional pellet packed-bed reactors, and a coating catalyst seems more suitable than an extruded catalyst for SCR for NO removal. Although a round channel brings the best heat and mass transfer, a triangle-shaped channel of coating catalyst possesses the highest NOx conversion due to the chemical reaction being the controlling step. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102206x [article] Selective catalytic reduction for NO removal : comparison of transfer and reaction performances among monolith catalysts [texte imprimé] / Zhigang Lei, Auteur ; Cuiping Wen, Auteur ; Jie Zhang, Auteur . - 2011 . - pp 5942–5951. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp 5942–5951 Mots-clés : Monolith  catalysts Résumé : One of the available technologies that can effectively control the emission of NOx is the selective catalytic reduction (SCR) of NOx with ammonia (NH3). Monolith catalysts are widely used in this technology due to their unique advantages that they offer, like low pressure drop, high external geometric surface area, and resistance to deposition of carbon, dust, and metals from combustion process. But the configuration of monolith catalysts has prominent influence on transfer and reaction performances of SCR for NO removal. This work tries to provide an easy-to-read and comprehensive comparison of momentum transfer, heat transfer, mass transfer, and reaction performance between two types of monolith catalysts with five kinds of channel shapes for SCR for NO removal, and to address the issues specific to SCR applications as to (i) whether or not monolith catalysts can improve the transfer and reaction performances compared to traditional pellet packed-bed reactors; (ii) which type of monolith catalysts and (iii) which kind of channel shapes for each type are optimum from the viewpoint of chemical reaction engineering. It was found that monolith catalysts have a much lower pressure drop and higher effectiveness factor than traditional pellet packed-bed reactors, and a coating catalyst seems more suitable than an extruded catalyst for SCR for NO removal. Although a round channel brings the best heat and mass transfer, a triangle-shaped channel of coating catalyst possesses the highest NOx conversion due to the chemical reaction being the controlling step. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102206x