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Vol. 51 N° 38 - Septembre 2012 [texte imprimé] . - 2012 . - p. 12155–12556 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierNew insights into the gelation behavior of polyethyleneimine cross - linking partially hydrolyzed polyacrylamide gels / Jia Hu in Industrial & engineering chemistry research, Vol. 51 N° 38 (Septembre 2012)
Titre : New insights into the gelation behavior of polyethyleneimine cross - linking partially hydrolyzed polyacrylamide gels Type de document : texte imprimé Auteurs : Jia Hu, Auteur ; Jin-Zhou Zhao, Auteur ; Fa-Yang Jin, Auteur Année de publication : 2012 Article en page(s) : pp. 12155–12166 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gelation Résumé : Using polymer gel is still the mainstream technique of the chemical method for water shut-off in mature oilfield development. The gelation performance of polyethyleneimine (PEI) cross-linking partially hydrolyzed polyacrylamide (HPAM) gel was systematically investigated in this paper by using three types of molecular weight (Mw) HPAM. Results show that the gelant solution (the fluid solution of cross-linker and polymer that exists before gelation) can slightly gel even at room temperature and form a rudimentary 3D network structure for protecting the subsequent gelling. The main factors, including HPAM, PEI concentrations, HPAM Mw, and total dissolved solids (TDS) to affect the gelation performance are also discussed. The gelation time is around 18–72 h at 65 °C, which is much longer than the commonly used chromium(III)-acetate cross-linking HPAM gel system. The gelation performance of the PEI/HPAM gel system is improved after flowing through porous media and shows the adverse law for a porous media sheared chromium(III)-acetate or phenol-formaldehyde cross-linking HPAM gel system. Atomic force microscopy (AFM) scanning results show that the microstructure of PEI/HPAM gel distributes a lot of cavities. Compared to the original premature gel (code B), the cavities are more uniform and regular after flowing through porous media. In addition, this study revealed that the presence of free oxygen in the uniform cavities of the weak cross-linked gel after flowing through porous media can accelerate the oxidation reaction to produce a darker brown gel. It also discusses how these new findings will affect the application of the gel system in the oil field. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399664
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12155–12166[article] New insights into the gelation behavior of polyethyleneimine cross - linking partially hydrolyzed polyacrylamide gels [texte imprimé] / Jia Hu, Auteur ; Jin-Zhou Zhao, Auteur ; Fa-Yang Jin, Auteur . - 2012 . - pp. 12155–12166.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12155–12166
Mots-clés : Gelation Résumé : Using polymer gel is still the mainstream technique of the chemical method for water shut-off in mature oilfield development. The gelation performance of polyethyleneimine (PEI) cross-linking partially hydrolyzed polyacrylamide (HPAM) gel was systematically investigated in this paper by using three types of molecular weight (Mw) HPAM. Results show that the gelant solution (the fluid solution of cross-linker and polymer that exists before gelation) can slightly gel even at room temperature and form a rudimentary 3D network structure for protecting the subsequent gelling. The main factors, including HPAM, PEI concentrations, HPAM Mw, and total dissolved solids (TDS) to affect the gelation performance are also discussed. The gelation time is around 18–72 h at 65 °C, which is much longer than the commonly used chromium(III)-acetate cross-linking HPAM gel system. The gelation performance of the PEI/HPAM gel system is improved after flowing through porous media and shows the adverse law for a porous media sheared chromium(III)-acetate or phenol-formaldehyde cross-linking HPAM gel system. Atomic force microscopy (AFM) scanning results show that the microstructure of PEI/HPAM gel distributes a lot of cavities. Compared to the original premature gel (code B), the cavities are more uniform and regular after flowing through porous media. In addition, this study revealed that the presence of free oxygen in the uniform cavities of the weak cross-linked gel after flowing through porous media can accelerate the oxidation reaction to produce a darker brown gel. It also discusses how these new findings will affect the application of the gel system in the oil field. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399664 Exemplaires
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Titre : Electrochemical deammonification of synthetic swine wastewater Type de document : texte imprimé Auteurs : Luis A. Diaz, Auteur ; Gerardine G. Botte, Auteur Année de publication : 2012 Article en page(s) : pp. 12167–12172 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Vertebrata Mammalia Ungulata Artiodactyla Waste water Swine Résumé : The ammonia electrolysis process, which presents as only products nitrogen and hydrogen fuel, was evaluated for the deammonification of wastewater. The effects of cell voltage, pH, and flow rate were analyzed for single pass ammonia electro-oxidation of synthetic swine wastewater. A surface response analysis was performed to obtain quadratic models that predict the NH3 conversion and hydrogen (H2) production where pH was identified as the variable with the most statistic significance to explain changes in ammonia conversion with hydrogen production. NH3 conversions above 80% and specific energy consumption under 3 kW·h kg―1 of NH3, without considering the energy that can be obtained from the H2 produced, show that the ammonia electrolysis technology has promising potential for the deammonification of wastewater with less energy consumption than the conventional nitrification/denitrification process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399665
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12167–12172[article] Electrochemical deammonification of synthetic swine wastewater [texte imprimé] / Luis A. Diaz, Auteur ; Gerardine G. Botte, Auteur . - 2012 . - pp. 12167–12172.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12167–12172
Mots-clés : Vertebrata Mammalia Ungulata Artiodactyla Waste water Swine Résumé : The ammonia electrolysis process, which presents as only products nitrogen and hydrogen fuel, was evaluated for the deammonification of wastewater. The effects of cell voltage, pH, and flow rate were analyzed for single pass ammonia electro-oxidation of synthetic swine wastewater. A surface response analysis was performed to obtain quadratic models that predict the NH3 conversion and hydrogen (H2) production where pH was identified as the variable with the most statistic significance to explain changes in ammonia conversion with hydrogen production. NH3 conversions above 80% and specific energy consumption under 3 kW·h kg―1 of NH3, without considering the energy that can be obtained from the H2 produced, show that the ammonia electrolysis technology has promising potential for the deammonification of wastewater with less energy consumption than the conventional nitrification/denitrification process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399665 Exemplaires
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Titre : Controlled release of urea encapsulated by Starch - g - poly (vinyl acetate) Type de document : texte imprimé Auteurs : Yongsheng Niu, Auteur ; Hongchun Li, Auteur Année de publication : 2012 Article en page(s) : pp. 12173–12177 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Membrane encapsulated urea Résumé : A new type of slow-release membrane-encapsulated urea fertilizer was prepared with starch-g-poly(vinyl acetate) (St-g-PVAc) as a biodegradable carrier material. By solution casting and washing rapidly with water the urea was individually encapsulated within the starch matrix modified by vinyl acetate through in situ graft-copolymerization. St-g-PVAc, which exhibits relatively low swellability, was synthesized by the reaction of starch and VAc in the presence of K2S2O8 as the initiator. The chemical structure of the St-g-PVAc and St-g-PVAc/urea composite film was confirmed by FTIR. The release behavior of urea encapsulated in the films was studied. The experimental results indicated that the introduction of hydrophobic PVAc reduced the swellability of the starch matrix; the urea nitrogen slow-release time can reach 28 h in water. The St-g-PVAc/urea composite films could biodegrade in the soil environment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301684p
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12173–12177[article] Controlled release of urea encapsulated by Starch - g - poly (vinyl acetate) [texte imprimé] / Yongsheng Niu, Auteur ; Hongchun Li, Auteur . - 2012 . - pp. 12173–12177.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12173–12177
Mots-clés : Membrane encapsulated urea Résumé : A new type of slow-release membrane-encapsulated urea fertilizer was prepared with starch-g-poly(vinyl acetate) (St-g-PVAc) as a biodegradable carrier material. By solution casting and washing rapidly with water the urea was individually encapsulated within the starch matrix modified by vinyl acetate through in situ graft-copolymerization. St-g-PVAc, which exhibits relatively low swellability, was synthesized by the reaction of starch and VAc in the presence of K2S2O8 as the initiator. The chemical structure of the St-g-PVAc and St-g-PVAc/urea composite film was confirmed by FTIR. The release behavior of urea encapsulated in the films was studied. The experimental results indicated that the introduction of hydrophobic PVAc reduced the swellability of the starch matrix; the urea nitrogen slow-release time can reach 28 h in water. The St-g-PVAc/urea composite films could biodegrade in the soil environment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301684p Exemplaires
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Titre : In-situ cure and cure kinetic analysis of a liquid rubber modified epoxy resin Type de document : texte imprimé Auteurs : Raju Thomas, Auteur ; Christophe Sinturel, Auteur ; Jurgen Pionteck, Auteur Année de publication : 2012 Article en page(s) : pp. 12178–12191 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics In situ Résumé : The in-situ cure and cure kinetics of an epoxy resin based on diglycidyl ether of bisphenol A (DGEBA) polymerized with an anhydride hardener and its mixtures with a liquid polybutadiene rubber having hydroxyl functionality (HTPB) were studied using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) in an isothermal mode. The cure reaction was monitored in-situ by FTIR spectroscopy by observing variation in intensity of epoxy, anhydride, and ester bands. The cure reaction mechanisms by which the network structure of epoxy was developed were discussed. Isothermal mode DSC measurements were performed at selected temperatures. The reaction followed an autocatalytic mechanism, and kinetic analysis was done by a phenomenological model developed by Kamal. Good fits were obtained between the autocatalytic model and the experimental data up to the vitrification state. Afterward, the reaction became diffusion controlled. The reaction during the later stages of cure was explained by introducing a diffusion factor, which agreed well with the kinetic data. The nature of the developing morphology of modified epoxies was analyzed by optical microscopy (OM) and small angle laser light scattering (SALLS) technique. The ultimate morphology of the cured blends was analyzed using scanning electron microscopy (SEM). The cure kinetics has been correlated with the developed morphology to get insight into the mechanism of reaction-induced microphase separation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399667
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12178–12191[article] In-situ cure and cure kinetic analysis of a liquid rubber modified epoxy resin [texte imprimé] / Raju Thomas, Auteur ; Christophe Sinturel, Auteur ; Jurgen Pionteck, Auteur . - 2012 . - pp. 12178–12191.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12178–12191
Mots-clés : Kinetics In situ Résumé : The in-situ cure and cure kinetics of an epoxy resin based on diglycidyl ether of bisphenol A (DGEBA) polymerized with an anhydride hardener and its mixtures with a liquid polybutadiene rubber having hydroxyl functionality (HTPB) were studied using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) in an isothermal mode. The cure reaction was monitored in-situ by FTIR spectroscopy by observing variation in intensity of epoxy, anhydride, and ester bands. The cure reaction mechanisms by which the network structure of epoxy was developed were discussed. Isothermal mode DSC measurements were performed at selected temperatures. The reaction followed an autocatalytic mechanism, and kinetic analysis was done by a phenomenological model developed by Kamal. Good fits were obtained between the autocatalytic model and the experimental data up to the vitrification state. Afterward, the reaction became diffusion controlled. The reaction during the later stages of cure was explained by introducing a diffusion factor, which agreed well with the kinetic data. The nature of the developing morphology of modified epoxies was analyzed by optical microscopy (OM) and small angle laser light scattering (SALLS) technique. The ultimate morphology of the cured blends was analyzed using scanning electron microscopy (SEM). The cure kinetics has been correlated with the developed morphology to get insight into the mechanism of reaction-induced microphase separation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399667 Exemplaires
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Titre : Kinetics of hardwood carbohydrate degradation during kraft pulp cooking Type de document : texte imprimé Auteurs : Ricardo B. Santos, Auteur ; Hasan Jameel, Auteur ; Hou-min Chang, Auteur Année de publication : 2012 Article en page(s) : pp. 12192-12198 Note générale : industrial chemistry Langues : Anglais (eng) Mots-clés : Hardwood Kinetics Résumé : Most of the studies on hardwood carbohydrate degradation focus upon the understanding of carbohydrate behavior of a single wood species. These studies tend to determine the activation energies associated with the three different cooking phases and for the different reactions that participate in carbohydrate degradation. In the current study, a variety of hardwood species were comprehensively characterized and the kinetics of carbohydrate degradation was studied. The kinetics of glucan, xylan, and total carbohydrate dissolution during the bulk phase of the kraft pulping process were investigated. A wide range of carbohydrate dissolution rates was obtained and correlated to chemical features and delignification rates for nine different hardwood species. It was determined that carbohydrate dissolution was dependent upon the rate of delignification. Species with high carbohydrate dissolution also presented high lignin removal rates. Our results indicate that the presence of lignin carbohydrate complexes positively influences pulping process selectivity during the bulk reaction phase. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399668
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12192-12198[article] Kinetics of hardwood carbohydrate degradation during kraft pulp cooking [texte imprimé] / Ricardo B. Santos, Auteur ; Hasan Jameel, Auteur ; Hou-min Chang, Auteur . - 2012 . - pp. 12192-12198.
industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12192-12198
Mots-clés : Hardwood Kinetics Résumé : Most of the studies on hardwood carbohydrate degradation focus upon the understanding of carbohydrate behavior of a single wood species. These studies tend to determine the activation energies associated with the three different cooking phases and for the different reactions that participate in carbohydrate degradation. In the current study, a variety of hardwood species were comprehensively characterized and the kinetics of carbohydrate degradation was studied. The kinetics of glucan, xylan, and total carbohydrate dissolution during the bulk phase of the kraft pulping process were investigated. A wide range of carbohydrate dissolution rates was obtained and correlated to chemical features and delignification rates for nine different hardwood species. It was determined that carbohydrate dissolution was dependent upon the rate of delignification. Species with high carbohydrate dissolution also presented high lignin removal rates. Our results indicate that the presence of lignin carbohydrate complexes positively influences pulping process selectivity during the bulk reaction phase. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399668 Exemplaires
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Titre : Biodiesel production via transesterification of soybean oil using acid catalyst in CO2 expanded methanol liquid Type de document : texte imprimé Auteurs : Zhen Ma, Auteur ; Zi-Yang Shang, Auteur ; En-Jun Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 12199–12204 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biodiesel Soybean oil Catalyst Résumé : The transesterification of soybean oil and methanol to prepare biodiesel using H2SO4 and solid acid (NaHSO4) as catalysts was conducted in CO2-expanded liquids (CXLs). The aim of adding CO2 in the system is to intensify the reaction, and then to shorten the reaction time and decrease the methanol consumption in the traditional acid catalysis method or decrease the high temperature and pressure in the supercritical methanol method. The parameters affecting the fatty acid methyl esters (FAME) yield, such as pressure, temperature, and the molar ratio of methanol to soybean oil (M/O ratio), as well as catalyst amount were investigated. The results indicated that a complete oil conversion happened at 10 MPa, 70 °C (reaction time 6 h) and 80 °C (reaction time 4 h) with M/O ratio of 12:1, and H2SO4 amount of 4%, while for NaHSO4 catalytic reactions, the FAME yield was 80.94% after 6 h at 10 MPa, 90 °C, and the M/O ratio 9:1, NaHSO4 amount of 5% (based on oil weight). The underlying reasons why CO2 enhances the transesterification of oil and methanol were highlighted. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3011929
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12199–12204[article] Biodiesel production via transesterification of soybean oil using acid catalyst in CO2 expanded methanol liquid [texte imprimé] / Zhen Ma, Auteur ; Zi-Yang Shang, Auteur ; En-Jun Wang, Auteur . - 2012 . - pp. 12199–12204.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12199–12204
Mots-clés : Biodiesel Soybean oil Catalyst Résumé : The transesterification of soybean oil and methanol to prepare biodiesel using H2SO4 and solid acid (NaHSO4) as catalysts was conducted in CO2-expanded liquids (CXLs). The aim of adding CO2 in the system is to intensify the reaction, and then to shorten the reaction time and decrease the methanol consumption in the traditional acid catalysis method or decrease the high temperature and pressure in the supercritical methanol method. The parameters affecting the fatty acid methyl esters (FAME) yield, such as pressure, temperature, and the molar ratio of methanol to soybean oil (M/O ratio), as well as catalyst amount were investigated. The results indicated that a complete oil conversion happened at 10 MPa, 70 °C (reaction time 6 h) and 80 °C (reaction time 4 h) with M/O ratio of 12:1, and H2SO4 amount of 4%, while for NaHSO4 catalytic reactions, the FAME yield was 80.94% after 6 h at 10 MPa, 90 °C, and the M/O ratio 9:1, NaHSO4 amount of 5% (based on oil weight). The underlying reasons why CO2 enhances the transesterification of oil and methanol were highlighted. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3011929 Exemplaires
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Titre : Effect of support acidity on liquid - phase hydrogenation of benzene to cyclohexene over Ru – B/ZrO2 catalysts Type de document : texte imprimé Auteurs : Gongbing Zhou, Auteur ; Jianliang Liu, Auteur ; Xiaohe Tan, Auteur Année de publication : 2012 Article en page(s) : pp. 12205-12213 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Hydrogenation Liquid phase Acidity Résumé : Ru–B/ZrO2 catalysts using monoclinic, amorphous, and tetragonal ZrO2 as supports were prepared and used for liquid-phase hydrogenation of benzene to cyclohexene. It is identified that both the Lewis acid sites and the Brønsted acid sites existed on monoclinic ZrO2 (ZrO2-M), while there were only Lewis acid sites on amorphous (ZrO2-A) and tetragonal ZrO2 (ZrO2-T). The amount of acid sites on ZrO2-T was the lowest. In liquid-phase hydrogenation of benzene to cyclohexene, the Ru–B/ZrO2-T catalyst exhibited the highest selectivity and yield of cyclohexene, with the maximum yield of cyclohexene being 47%. These results suggest that for ZrO2-supported Ru–B catalysts, the lower was the amount of acid sites on ZrO2, the higher was the selectivity to cyclohexene. Also, the presence of the Brønsted acid sites on ZrO2 is probably adverse to the selectivity toward cyclohexene. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399670
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12205-12213[article] Effect of support acidity on liquid - phase hydrogenation of benzene to cyclohexene over Ru – B/ZrO2 catalysts [texte imprimé] / Gongbing Zhou, Auteur ; Jianliang Liu, Auteur ; Xiaohe Tan, Auteur . - 2012 . - pp. 12205-12213.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12205-12213
Mots-clés : Catalyst Hydrogenation Liquid phase Acidity Résumé : Ru–B/ZrO2 catalysts using monoclinic, amorphous, and tetragonal ZrO2 as supports were prepared and used for liquid-phase hydrogenation of benzene to cyclohexene. It is identified that both the Lewis acid sites and the Brønsted acid sites existed on monoclinic ZrO2 (ZrO2-M), while there were only Lewis acid sites on amorphous (ZrO2-A) and tetragonal ZrO2 (ZrO2-T). The amount of acid sites on ZrO2-T was the lowest. In liquid-phase hydrogenation of benzene to cyclohexene, the Ru–B/ZrO2-T catalyst exhibited the highest selectivity and yield of cyclohexene, with the maximum yield of cyclohexene being 47%. These results suggest that for ZrO2-supported Ru–B catalysts, the lower was the amount of acid sites on ZrO2, the higher was the selectivity to cyclohexene. Also, the presence of the Brønsted acid sites on ZrO2 is probably adverse to the selectivity toward cyclohexene. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399670 Exemplaires
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Titre : Deactivation of external acid sites of h-mordenite by modification with lanthanide oxides for the isopropylation of biphenyl and the cracking of 1,3,5-triisopropylbenzene and cumene Type de document : texte imprimé Auteurs : Chokkalingam Anand, Auteur ; Ikuyo Toyama, Auteur ; Hiroshi Tamada, Auteur Année de publication : 2012 Article en page(s) : pp. 12214–12221 Note générale : Indusrial chemistry Langues : Anglais (eng) Mots-clés : Lanthanide oxides Isopropylation Résumé : The modification of H-mordenite (MOR) with lanthanide oxides La2O3, CeO2, Pr2O3, Sm2O3, Dy2O3, and Yb2O3 was examined for the deactivation of external acid sites and confirmed in the cracking of 1,3,5-triisopropylbenzene (TIPB) and cumene (IPB) and in the isopropylation of biphenyl (BP). The cracking of TIPB, which cannot enter the pores of MOR, shows that external acid sites were effectively deactivated by the modification of MOR with the lanthanide oxides in small amounts. Only the cracking of IPB over CeO2-modified MOR exhibited excellent catalytic activities, even at a 30 wt % metal loading, whereas the activities of other lanthanide oxide-modified MORs rapidly decreased as the loadings were increased because pore entrances became choked. The isomerization of 4,4′-diisopropylbiphenyl (4,4′-DIPB) during the isopropylation of BP at high temperatures such as 300 °C was also effectively prevented by the modification of MOR with the lanthanide oxides. Particularly, CeO2-modified MOR remained highly active even at a 30 wt % loading. Other lanthanide oxides can deactivate the isomerization of 4,4′-DIPB at 5–10 wt % loadings without significant loss of the activities at 300 °C, while the activity was rapidly lost as the loading amount was increased. The physicochemical properties of lanthanide oxide-modified MORs indicate that the lanthanide oxides modify the surface properties of MOR. The amounts of N2, o-xylene, and NH3 adsorbed on MORs mostly remained high after CeO2 modification; however, they rapidly decreased when loadings of the other oxides increased. These results show that CeO2 remains the open pores at high loadings; however, the other oxides reduce the size of pore entrances as the loading is increased. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301362e
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12214–12221[article] Deactivation of external acid sites of h-mordenite by modification with lanthanide oxides for the isopropylation of biphenyl and the cracking of 1,3,5-triisopropylbenzene and cumene [texte imprimé] / Chokkalingam Anand, Auteur ; Ikuyo Toyama, Auteur ; Hiroshi Tamada, Auteur . - 2012 . - pp. 12214–12221.
Indusrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12214–12221
Mots-clés : Lanthanide oxides Isopropylation Résumé : The modification of H-mordenite (MOR) with lanthanide oxides La2O3, CeO2, Pr2O3, Sm2O3, Dy2O3, and Yb2O3 was examined for the deactivation of external acid sites and confirmed in the cracking of 1,3,5-triisopropylbenzene (TIPB) and cumene (IPB) and in the isopropylation of biphenyl (BP). The cracking of TIPB, which cannot enter the pores of MOR, shows that external acid sites were effectively deactivated by the modification of MOR with the lanthanide oxides in small amounts. Only the cracking of IPB over CeO2-modified MOR exhibited excellent catalytic activities, even at a 30 wt % metal loading, whereas the activities of other lanthanide oxide-modified MORs rapidly decreased as the loadings were increased because pore entrances became choked. The isomerization of 4,4′-diisopropylbiphenyl (4,4′-DIPB) during the isopropylation of BP at high temperatures such as 300 °C was also effectively prevented by the modification of MOR with the lanthanide oxides. Particularly, CeO2-modified MOR remained highly active even at a 30 wt % loading. Other lanthanide oxides can deactivate the isomerization of 4,4′-DIPB at 5–10 wt % loadings without significant loss of the activities at 300 °C, while the activity was rapidly lost as the loading amount was increased. The physicochemical properties of lanthanide oxide-modified MORs indicate that the lanthanide oxides modify the surface properties of MOR. The amounts of N2, o-xylene, and NH3 adsorbed on MORs mostly remained high after CeO2 modification; however, they rapidly decreased when loadings of the other oxides increased. These results show that CeO2 remains the open pores at high loadings; however, the other oxides reduce the size of pore entrances as the loading is increased. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301362e Exemplaires
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Titre : Monolithic stirrer reactor : Performance in the partial hydrogenation of sunflower oil Type de document : texte imprimé Auteurs : Diego E. Boldrini, Auteur ; Jhon F. Sánchez M., Auteur ; Tonetto, Gabriela M., Auteur Année de publication : 2012 Article en page(s) : pp. 12222-12232 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogenation Reactor Agitator Monolithic construction Résumé : In the present paper, the performance of monolithic catalysts obtained from a catalytic converter was analyzed in the partial hydrogenation of sunflower oil. The monoliths were reimpregnated with palladium and installed as a blade in a monolithic stirrer reactor. The use of this type of reactor was explored in the reaction at 373 K and 413 kPa, analyzing the effect variables such as stirrer speed, hydrogen supply, and stirrer design on the catalyst activity and selectivity to trans-isomers and saturated product. The volumetric gas–liquid and liquid–solid mass transfer coefficients were calculated, and the influence of the stirrer speed was examined. Estimations of the Carberry numbers and Weisz–Prater modulus were used for establishing the presence or absence of mass transfer resistances. The performance of the catalyst was studied in consecutive tests, and different procedures for catalyst regeneration were applied. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399672
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12222-12232[article] Monolithic stirrer reactor : Performance in the partial hydrogenation of sunflower oil [texte imprimé] / Diego E. Boldrini, Auteur ; Jhon F. Sánchez M., Auteur ; Tonetto, Gabriela M., Auteur . - 2012 . - pp. 12222-12232.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12222-12232
Mots-clés : Hydrogenation Reactor Agitator Monolithic construction Résumé : In the present paper, the performance of monolithic catalysts obtained from a catalytic converter was analyzed in the partial hydrogenation of sunflower oil. The monoliths were reimpregnated with palladium and installed as a blade in a monolithic stirrer reactor. The use of this type of reactor was explored in the reaction at 373 K and 413 kPa, analyzing the effect variables such as stirrer speed, hydrogen supply, and stirrer design on the catalyst activity and selectivity to trans-isomers and saturated product. The volumetric gas–liquid and liquid–solid mass transfer coefficients were calculated, and the influence of the stirrer speed was examined. Estimations of the Carberry numbers and Weisz–Prater modulus were used for establishing the presence or absence of mass transfer resistances. The performance of the catalyst was studied in consecutive tests, and different procedures for catalyst regeneration were applied. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399672 Exemplaires
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Titre : Modeling and experimental studies on phase and chemical equilibria in high - pressure methanol synthesis Type de document : texte imprimé Auteurs : Joost G. Van Bennekom, Auteur ; Jozef G.M. Winkelman, Auteur ; Robertus H. Venderbosch, Auteur Année de publication : 2012 Article en page(s) : pp. 12233–12243 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chemical equilibria Résumé : A solution method was developed to calculate the simultaneous phase and chemical equilibria in high-pressure methanol synthesis (P = 20 MPa, 463 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3017362
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12233–12243[article] Modeling and experimental studies on phase and chemical equilibria in high - pressure methanol synthesis [texte imprimé] / Joost G. Van Bennekom, Auteur ; Jozef G.M. Winkelman, Auteur ; Robertus H. Venderbosch, Auteur . - 2012 . - pp. 12233–12243.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12233–12243
Mots-clés : Chemical equilibria Résumé : A solution method was developed to calculate the simultaneous phase and chemical equilibria in high-pressure methanol synthesis (P = 20 MPa, 463 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3017362 Exemplaires
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Titre : Density functional theory study of methane oxidation and reforming on Pt(111) and Pt(211) Type de document : texte imprimé Auteurs : Ying Chen, Auteur ; Dionisios G. Vlachos, Auteur Année de publication : 2012 Article en page(s) : pp. 12244–12252 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Methane Oxidation Résumé : The activation barriers of elementary-like reactions pertaining to the oxidation and reforming of methane on Pt(111) and Pt(211) surfaces have been calculated using periodic density functional theory (DFT) calculations. We have investigated the adsorption of CHx(x=1–3)OH and CHx(x=1–3)O, all the O and OH-assisted dehydrogenation reactions of CHx(x=1–4), all the C–O bond coupling reactions forming C1 oxygenates, and their subsequent dehydrogenation. It has been found that (i) COH and CHO are the most stable C1 oxygenates on Pt(111) and Pt(211), repectively; (ii) In the presence of O on Pt(211), oxidative dehydrogenation of CH by O is more kinetically favorable than the pyrolytic CH dehydrogenation; (iii) CO can be generated by oxidation of C with a low reaction barrier on Pt(211); (iv) The reactions involving OH and the dehydrogenation of CHx(x=1–3)OH and CHx(x=1–3)O appear to be secondary reaction pathways on Pt. Based on the activation barriers, we conclude that the major reaction pathways on Pt(111) and Pt(211) are CH4 (g) → CH3ad → CH2ad → CHad → Cad, Cad + Oad → COad and CH4 (g) → CH3ad → CH2ad → CHad, CHad + Oad → Cad, CHad + Oad → COad, respectively. Low coordination sites, such as steps, exhibit lower barriers for pyrolytic dehydrogenation except for the reaction CH2ad + * → CHad + Had that is preferred on terraces. In addition, they are lower barrier sites in the oxidation of C and CH and, thus, are expected to play a key role in partial and total oxidation of methane. In methane steam reforming, OHad may play a role only in the last step of C oxidation and certainly in the water-gas shift reaction, and, thus, this process consists of nearly decoupled methane catalytic pyrolysis and water-gas shift reactions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301792g
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12244–12252[article] Density functional theory study of methane oxidation and reforming on Pt(111) and Pt(211) [texte imprimé] / Ying Chen, Auteur ; Dionisios G. Vlachos, Auteur . - 2012 . - pp. 12244–12252.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12244–12252
Mots-clés : Methane Oxidation Résumé : The activation barriers of elementary-like reactions pertaining to the oxidation and reforming of methane on Pt(111) and Pt(211) surfaces have been calculated using periodic density functional theory (DFT) calculations. We have investigated the adsorption of CHx(x=1–3)OH and CHx(x=1–3)O, all the O and OH-assisted dehydrogenation reactions of CHx(x=1–4), all the C–O bond coupling reactions forming C1 oxygenates, and their subsequent dehydrogenation. It has been found that (i) COH and CHO are the most stable C1 oxygenates on Pt(111) and Pt(211), repectively; (ii) In the presence of O on Pt(211), oxidative dehydrogenation of CH by O is more kinetically favorable than the pyrolytic CH dehydrogenation; (iii) CO can be generated by oxidation of C with a low reaction barrier on Pt(211); (iv) The reactions involving OH and the dehydrogenation of CHx(x=1–3)OH and CHx(x=1–3)O appear to be secondary reaction pathways on Pt. Based on the activation barriers, we conclude that the major reaction pathways on Pt(111) and Pt(211) are CH4 (g) → CH3ad → CH2ad → CHad → Cad, Cad + Oad → COad and CH4 (g) → CH3ad → CH2ad → CHad, CHad + Oad → Cad, CHad + Oad → COad, respectively. Low coordination sites, such as steps, exhibit lower barriers for pyrolytic dehydrogenation except for the reaction CH2ad + * → CHad + Had that is preferred on terraces. In addition, they are lower barrier sites in the oxidation of C and CH and, thus, are expected to play a key role in partial and total oxidation of methane. In methane steam reforming, OHad may play a role only in the last step of C oxidation and certainly in the water-gas shift reaction, and, thus, this process consists of nearly decoupled methane catalytic pyrolysis and water-gas shift reactions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301792g Exemplaires
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Titre : Kinetics of glycerol dehydration with WO3/TiO2 in supercritical water Type de document : texte imprimé Auteurs : Makoto Akizuki, Auteur ; Yoshito Oshima, Auteur Année de publication : 2012 Article en page(s) : pp. 12253–12257 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics Dehydration glycerol Résumé : Dehydration of glycerol on TiO2 and WO3/TiO2 in supercritical water at 400 °C and 33 MPa was examined using a fixed bed flow reactor. The structure of TiO2 was changed from anatase type to rutile type in supercritical water, and addition of WO3 to TiO2 suppressed the change of structure. Main products were acrolein and acetaldehyde. In the reaction on TiO2, a large amount of propionic acid was also produced. The reaction route was proposed on the basis of the products distribution from glycerol and intermediate products. From kinetic analysis, the reaction route could explain the experimental data well. Because of high water density, degradation of acrolein to acetaldehyde is favorable in supercritical water. Reaction rate for dehydration of glycerol to acrolein considerably increased with an increase in WO3 content of the catalyst, and this dependence is attributed to higher surface area and stronger acidity of WO3/TiO2 catalysts. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301823f
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12253–12257[article] Kinetics of glycerol dehydration with WO3/TiO2 in supercritical water [texte imprimé] / Makoto Akizuki, Auteur ; Yoshito Oshima, Auteur . - 2012 . - pp. 12253–12257.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12253–12257
Mots-clés : Kinetics Dehydration glycerol Résumé : Dehydration of glycerol on TiO2 and WO3/TiO2 in supercritical water at 400 °C and 33 MPa was examined using a fixed bed flow reactor. The structure of TiO2 was changed from anatase type to rutile type in supercritical water, and addition of WO3 to TiO2 suppressed the change of structure. Main products were acrolein and acetaldehyde. In the reaction on TiO2, a large amount of propionic acid was also produced. The reaction route was proposed on the basis of the products distribution from glycerol and intermediate products. From kinetic analysis, the reaction route could explain the experimental data well. Because of high water density, degradation of acrolein to acetaldehyde is favorable in supercritical water. Reaction rate for dehydration of glycerol to acrolein considerably increased with an increase in WO3 content of the catalyst, and this dependence is attributed to higher surface area and stronger acidity of WO3/TiO2 catalysts. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301823f Exemplaires
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Titre : Synthesis and properties of biodegradable poly (butylene succinate - co - diethylene glycol succinate) copolymers Type de document : texte imprimé Auteurs : Jian-Bing Zeng, Auteur ; Cai-Li Huang, Auteur ; Ling Jiao, Auteur Année de publication : 2012 Article en page(s) : pp. 12258–12265 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Properties biodegradable Résumé : Diethylene glycol was incorporated into poly(butylene succinate) (PBS) to form biodegradable poly(butylene succinate-co-diethylene glycol succinate) (P(BS-co-DEGS)) copolymer through a two-step procedure of esterification and polycondensation from succinic acid with 1,4-butanediol and diethylene glycol. The chemical structure of P(BS-co-DEGS) was confirmed by proton nuclear magnetic resonance spectroscopy (1H NMR). The effect of incorporated DEGS content on the molecular weight, thermal properties, crystallization behaviors, and hydrophilicity of the copolymers was investigated by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), thermogravimetry analysis (TGA), and water contact angle. The mechanical properties and hydrolytic degradation behaviors of P(BS-co-DEGS) were also studied. The results suggest that with an increase of DEGS content, the crystallizability and degree of crystallinity of the copolymers decreased, while the crystal structure kept unchanged; the thermal stability of the copolymers hardly changed, while the hydrophilicity and hydrolytic degradation rate increased. The tensile modulus decreased, but the elongation at break increased and the tensile strength increased first and then decreased with an increase of DEGS. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300133a
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12258–12265[article] Synthesis and properties of biodegradable poly (butylene succinate - co - diethylene glycol succinate) copolymers [texte imprimé] / Jian-Bing Zeng, Auteur ; Cai-Li Huang, Auteur ; Ling Jiao, Auteur . - 2012 . - pp. 12258–12265.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12258–12265
Mots-clés : Properties biodegradable Résumé : Diethylene glycol was incorporated into poly(butylene succinate) (PBS) to form biodegradable poly(butylene succinate-co-diethylene glycol succinate) (P(BS-co-DEGS)) copolymer through a two-step procedure of esterification and polycondensation from succinic acid with 1,4-butanediol and diethylene glycol. The chemical structure of P(BS-co-DEGS) was confirmed by proton nuclear magnetic resonance spectroscopy (1H NMR). The effect of incorporated DEGS content on the molecular weight, thermal properties, crystallization behaviors, and hydrophilicity of the copolymers was investigated by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), thermogravimetry analysis (TGA), and water contact angle. The mechanical properties and hydrolytic degradation behaviors of P(BS-co-DEGS) were also studied. The results suggest that with an increase of DEGS content, the crystallizability and degree of crystallinity of the copolymers decreased, while the crystal structure kept unchanged; the thermal stability of the copolymers hardly changed, while the hydrophilicity and hydrolytic degradation rate increased. The tensile modulus decreased, but the elongation at break increased and the tensile strength increased first and then decreased with an increase of DEGS. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300133a Exemplaires
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Titre : Mesoporous zirconium phosphonate hybrid material as adsorbent to heavy metal ions Type de document : texte imprimé Auteurs : Yunjie Jia, Auteur ; Yuejuan Zhang, Auteur ; Ruiwei Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 12266-12273 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Metal ion Heavy metal Résumé : A new kind of inorganic―organic hybrid zirconium phosphonate material (NTAZP) with mesoporous structure was synthesized using nitrilotris(methylene)-triphosphonic acid (ATMP) and zirconium dichloride oxide octahydrate. The sample possesses a spherical morphology, and the spheres are composed of lobular lamellae. The lobular lamellae have the structure of a worm-like mesoporous (about 2.7 nm) framework and a high surface area (about 160.4 m2/g), which were characterized by SEM, TEM, N2 sorption, XRD, TG-DTA, elemental analysis, TOC (total organic carbon), XPS, and FT-IR spectroscopy techniques. The as-prepared NTAZP was used as adsorbent for the efficient removal of heavy metal ions (e.g., Pb2+, Cu2+, and Cd2+). Our results indicate that the material has good prospects for application as an adsorbent in wastewater processing. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399677
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12266-12273[article] Mesoporous zirconium phosphonate hybrid material as adsorbent to heavy metal ions [texte imprimé] / Yunjie Jia, Auteur ; Yuejuan Zhang, Auteur ; Ruiwei Wang, Auteur . - 2012 . - pp. 12266-12273.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12266-12273
Mots-clés : Metal ion Heavy metal Résumé : A new kind of inorganic―organic hybrid zirconium phosphonate material (NTAZP) with mesoporous structure was synthesized using nitrilotris(methylene)-triphosphonic acid (ATMP) and zirconium dichloride oxide octahydrate. The sample possesses a spherical morphology, and the spheres are composed of lobular lamellae. The lobular lamellae have the structure of a worm-like mesoporous (about 2.7 nm) framework and a high surface area (about 160.4 m2/g), which were characterized by SEM, TEM, N2 sorption, XRD, TG-DTA, elemental analysis, TOC (total organic carbon), XPS, and FT-IR spectroscopy techniques. The as-prepared NTAZP was used as adsorbent for the efficient removal of heavy metal ions (e.g., Pb2+, Cu2+, and Cd2+). Our results indicate that the material has good prospects for application as an adsorbent in wastewater processing. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399677 Exemplaires
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Titre : Behavior of CaO/CuO based composite in a combined calcium and copper chemical looping process Type de document : texte imprimé Auteurs : Changlei Qin, Auteur ; Junjun Yin, Auteur ; Wenqiang Liu, Auteur Année de publication : 2012 Article en page(s) : pp. 12274–12281 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chemical looping combustion Résumé : Integration of chemical looping combustion into calcium looping is an attractive approach to solving the problem of energy requirement for the regeneration of CaO-based sorbent. In this work, the behavior of MgO supported CaO/CuO composite in the new combined process (CaCuCL) was investigated. The composite was prepared via a simple wet mixing method and measured via a thermogravimetric analyzer for its chemical performance. It appears that the component of Cu/CuO has a significant influence on the cyclic performance of CaO, which is probably caused by the “wrapping” of Cu/CuO outside, due to its low melting point. However, this negative effect can be greatly reduced by using appropriate operating conditions in the successive reactions. When tested for 68 cycles, all synthetic sorbents showed good reactivity and stability of the Cu/CuO component, although loss-in-capacity of CaO was stilled observed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300677s
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12274–12281[article] Behavior of CaO/CuO based composite in a combined calcium and copper chemical looping process [texte imprimé] / Changlei Qin, Auteur ; Junjun Yin, Auteur ; Wenqiang Liu, Auteur . - 2012 . - pp. 12274–12281.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12274–12281
Mots-clés : Chemical looping combustion Résumé : Integration of chemical looping combustion into calcium looping is an attractive approach to solving the problem of energy requirement for the regeneration of CaO-based sorbent. In this work, the behavior of MgO supported CaO/CuO composite in the new combined process (CaCuCL) was investigated. The composite was prepared via a simple wet mixing method and measured via a thermogravimetric analyzer for its chemical performance. It appears that the component of Cu/CuO has a significant influence on the cyclic performance of CaO, which is probably caused by the “wrapping” of Cu/CuO outside, due to its low melting point. However, this negative effect can be greatly reduced by using appropriate operating conditions in the successive reactions. When tested for 68 cycles, all synthetic sorbents showed good reactivity and stability of the Cu/CuO component, although loss-in-capacity of CaO was stilled observed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300677s Exemplaires
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Titre : Hansen solubility parameters for octahedral oligomeric silsesquioxanes Type de document : texte imprimé Auteurs : Andrew J. Guenthner, Auteur ; Kevin R. Lamison, Auteur ; Lisa M. Lubin, Auteur Année de publication : 2012 Article en page(s) : pp. 12282-12293 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solubility Résumé : The Hansen Solubility Parameters (HSP) for several polyhedral oligomeric silsesquioxane (POSS) compounds were successfully determined, demonstrating the applicability of the HSP approach for selected types of organic―inorganic compounds. As commonly practiced with organic polymers, a set of simple "pass/fail" tests for complete solubility at a fixed concentration (100 mg/mL) was conducted for an array of five octameric POSS compounds, octa(phenethyl), octa(styrenyl), octa(isobutyl), octakis(hexafluoroisobutyl), and (1-naphthyl)heptaphenyl), and 45 test solvents. Group contributions for the octameric POSS cage were determined using three different approaches, which produced similar results. The best cage contribution estimate for the dispersive, polar, and hydrogen-bonding components δD, δP, and δH of the total volubility parameter was determined to be δD = 22 (J/cc)1/2, δP = 19 (J/cc)1/2, and δH = 15 (J/cc)1/2, with an estimated uncertainty of approximately 5 (J/cc)1/2. The utility of the HSP approach was demonstrated by successfully identifying mixtures of poor solvents that provided significantly enhanced solubility for octa(isobutyl) POSS, and by successfully estimating the HSP of octakis(trifluoropropyl) POSS from group contributions derived solely from aromatic POSS compounds. ISSN : 0888 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399679
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12282-12293[article] Hansen solubility parameters for octahedral oligomeric silsesquioxanes [texte imprimé] / Andrew J. Guenthner, Auteur ; Kevin R. Lamison, Auteur ; Lisa M. Lubin, Auteur . - 2012 . - pp. 12282-12293.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12282-12293
Mots-clés : Solubility Résumé : The Hansen Solubility Parameters (HSP) for several polyhedral oligomeric silsesquioxane (POSS) compounds were successfully determined, demonstrating the applicability of the HSP approach for selected types of organic―inorganic compounds. As commonly practiced with organic polymers, a set of simple "pass/fail" tests for complete solubility at a fixed concentration (100 mg/mL) was conducted for an array of five octameric POSS compounds, octa(phenethyl), octa(styrenyl), octa(isobutyl), octakis(hexafluoroisobutyl), and (1-naphthyl)heptaphenyl), and 45 test solvents. Group contributions for the octameric POSS cage were determined using three different approaches, which produced similar results. The best cage contribution estimate for the dispersive, polar, and hydrogen-bonding components δD, δP, and δH of the total volubility parameter was determined to be δD = 22 (J/cc)1/2, δP = 19 (J/cc)1/2, and δH = 15 (J/cc)1/2, with an estimated uncertainty of approximately 5 (J/cc)1/2. The utility of the HSP approach was demonstrated by successfully identifying mixtures of poor solvents that provided significantly enhanced solubility for octa(isobutyl) POSS, and by successfully estimating the HSP of octakis(trifluoropropyl) POSS from group contributions derived solely from aromatic POSS compounds. ISSN : 0888 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399679 Exemplaires
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Titre : Crystallization and coarsening kinetics of rutile phase in modified Ti - bearing blast furnace slag Type de document : texte imprimé Auteurs : Zhang Wu, Auteur ; Zhang Li, Auteur ; Zhang Ju-hua, Auteur Année de publication : 2012 Article en page(s) : pp. 12294-12298 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Blast furnace slag Slag Kinetics Crystallization Résumé : Crystallization and coarsening kinetics of nonisothermal precipitation process of rutile in modified Ti-bearing blast furnace slag were discussed. The modified slag was analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) and EDX. The experimental results showed that the cooling rate has an important effect on precipitation of the rutile phase. Low cooling rate is in favor of the increase in the volume fraction of rutile phase in Ti-bearing blast furnace slag and the growth of rutile phase. The volume fraction of rutile phase was approximately described by JMAK equation. The experiential expression of average crystal radius for rutile phase was also obtained. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399680
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12294-12298[article] Crystallization and coarsening kinetics of rutile phase in modified Ti - bearing blast furnace slag [texte imprimé] / Zhang Wu, Auteur ; Zhang Li, Auteur ; Zhang Ju-hua, Auteur . - 2012 . - pp. 12294-12298.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12294-12298
Mots-clés : Blast furnace slag Slag Kinetics Crystallization Résumé : Crystallization and coarsening kinetics of nonisothermal precipitation process of rutile in modified Ti-bearing blast furnace slag were discussed. The modified slag was analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) and EDX. The experimental results showed that the cooling rate has an important effect on precipitation of the rutile phase. Low cooling rate is in favor of the increase in the volume fraction of rutile phase in Ti-bearing blast furnace slag and the growth of rutile phase. The volume fraction of rutile phase was approximately described by JMAK equation. The experiential expression of average crystal radius for rutile phase was also obtained. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399680 Exemplaires
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Titre : Poly(acrylic acid)/clay thin films assembled by layer - by - layer deposition for improving the flame retardancy properties of cotton Type de document : texte imprimé Auteurs : Guobo Huang, Auteur ; Huading Liang, Auteur ; Xu Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 12299-12309 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Flame Thin film Résumé : A flame-retardant poly(acrylic acid) (FR-PAA) was prepared by copolymerization of N-(2-(5,5-dimethyl-1,3,2- dioxaphosphinyl-2-ylamino)-ethylacetamide-2-propenyl acid (DPEPA) and acrylic acid and used to fabricate various FR-PAA/ montmorillonite (MMT) thin films via layer-by-layer (LbL) deposition as a flame-retardant coating system for cotton fabric. Thermogravimetric analysis (TGA) indicated that treatment of FR-PAA/MMT thin films improved the thermal stability of cotton fabric. Cone calorimeter testing showed that the cotton fabrics coated with the FR-PAA/MMT thin films had less flammability with lower peak heat release rate (PHRR), lower total heat release (THR), and lower average mass loss rate (AMLR). In addition, scanning electronic microscopy (SEM) demonstrated that the surface of the fabrics coated with FR-PAA/ MMT films after combustion was covered by a layer of continuous and compact char. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399681
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12299-12309[article] Poly(acrylic acid)/clay thin films assembled by layer - by - layer deposition for improving the flame retardancy properties of cotton [texte imprimé] / Guobo Huang, Auteur ; Huading Liang, Auteur ; Xu Wang, Auteur . - 2012 . - pp. 12299-12309.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12299-12309
Mots-clés : Flame Thin film Résumé : A flame-retardant poly(acrylic acid) (FR-PAA) was prepared by copolymerization of N-(2-(5,5-dimethyl-1,3,2- dioxaphosphinyl-2-ylamino)-ethylacetamide-2-propenyl acid (DPEPA) and acrylic acid and used to fabricate various FR-PAA/ montmorillonite (MMT) thin films via layer-by-layer (LbL) deposition as a flame-retardant coating system for cotton fabric. Thermogravimetric analysis (TGA) indicated that treatment of FR-PAA/MMT thin films improved the thermal stability of cotton fabric. Cone calorimeter testing showed that the cotton fabrics coated with the FR-PAA/MMT thin films had less flammability with lower peak heat release rate (PHRR), lower total heat release (THR), and lower average mass loss rate (AMLR). In addition, scanning electronic microscopy (SEM) demonstrated that the surface of the fabrics coated with FR-PAA/ MMT films after combustion was covered by a layer of continuous and compact char. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399681 Exemplaires
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Titre : Role of ligand acidity in chelating adsorption and desorption of metal salts Type de document : texte imprimé Auteurs : Katri Laatikainen, Auteur ; Markku Laatikainen, Auteur ; Catherine Branger, Auteur Année de publication : 2012 Article en page(s) : pp. 12310-12320 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Desorption Adsorption Acidity Ligand Résumé : A method is proposed to establish useful operation conditions for solid separation of materials having different acidities. The effect of ligand acidity on competitive adsorption and desorption of metal salts was studied by using copper sulfate and sulfuric acid as model electrolytes. Adsorption equilibria with four commercial N-donor chelating adsorbents, WP-1 (functional group branched poly(ethyleneimine)), CuWRAM (functional group 2-(aminomethyl)pyridine), Reillex HP (functional group poly(4-vinylpyridine)), and Dowex M 4195 (functional group bis-2-(pyridylmethyl)amine) were measured using potentiometric and batch uptake methods. Moreover, formation of the complexes in the solid phase was studied with reflection UV―vis spectroscopy. Experimental data were correlated with a nonideal competitive adsorption (NICA) model, and the obtained parameters were used in mapping the operation conditions for the studied adsorbents. Acidity of the adsorbents was proved to increase in the order WP-1 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399682
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12310-12320[article] Role of ligand acidity in chelating adsorption and desorption of metal salts [texte imprimé] / Katri Laatikainen, Auteur ; Markku Laatikainen, Auteur ; Catherine Branger, Auteur . - 2012 . - pp. 12310-12320.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12310-12320
Mots-clés : Desorption Adsorption Acidity Ligand Résumé : A method is proposed to establish useful operation conditions for solid separation of materials having different acidities. The effect of ligand acidity on competitive adsorption and desorption of metal salts was studied by using copper sulfate and sulfuric acid as model electrolytes. Adsorption equilibria with four commercial N-donor chelating adsorbents, WP-1 (functional group branched poly(ethyleneimine)), CuWRAM (functional group 2-(aminomethyl)pyridine), Reillex HP (functional group poly(4-vinylpyridine)), and Dowex M 4195 (functional group bis-2-(pyridylmethyl)amine) were measured using potentiometric and batch uptake methods. Moreover, formation of the complexes in the solid phase was studied with reflection UV―vis spectroscopy. Experimental data were correlated with a nonideal competitive adsorption (NICA) model, and the obtained parameters were used in mapping the operation conditions for the studied adsorbents. Acidity of the adsorbents was proved to increase in the order WP-1 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399682 Exemplaires
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Titre : Friction between a steel ball and a steel flat lubricated by MoS2 particles suspended in hexadecane at 150 °C Type de document : texte imprimé Auteurs : Manimunda Praveena, Auteur ; Vikram Jayaram, Auteur ; Sanjay K. Biswas, Auteur Année de publication : 2012 Article en page(s) : pp. 12321-12328 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Steel Friction Résumé : A steel ball was slid on a steel flat lubricated by molybdenum disulfide (MoS2) particles suspended in hexadecane oil at 150 °C. The friction data is compared with that obtained when the ball was slid on the flat sprayed apriori with nominally dry MoS2 particles. The friction in the dry experiment was found to increase with temperature while the friction in wet condition was found to decrease with increasing temperature. Micro-Raman and Fourier transform IR spectroscopy are used to explore the roles of environmental moisture and chemical degadation of oil on the formation of antifriction film on the steel substrate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399683
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12321-12328[article] Friction between a steel ball and a steel flat lubricated by MoS2 particles suspended in hexadecane at 150 °C [texte imprimé] / Manimunda Praveena, Auteur ; Vikram Jayaram, Auteur ; Sanjay K. Biswas, Auteur . - 2012 . - pp. 12321-12328.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12321-12328
Mots-clés : Steel Friction Résumé : A steel ball was slid on a steel flat lubricated by molybdenum disulfide (MoS2) particles suspended in hexadecane oil at 150 °C. The friction data is compared with that obtained when the ball was slid on the flat sprayed apriori with nominally dry MoS2 particles. The friction in the dry experiment was found to increase with temperature while the friction in wet condition was found to decrease with increasing temperature. Micro-Raman and Fourier transform IR spectroscopy are used to explore the roles of environmental moisture and chemical degadation of oil on the formation of antifriction film on the steel substrate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399683 Exemplaires
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Titre : Plasticization of [C12MIM] [PF6] ionic liquid on foaming performance of poly(methyl methacrylate) in supercritical CO2 Type de document : texte imprimé Auteurs : Fang-fang Tong, Auteur ; Xu Hong, Auteur ; Jian Yu, Auteur Année de publication : 2012 Article en page(s) : pp. 12329–12336 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic liquid Résumé : A series of poly(methyl methacrylate) (PMMA)/1-dodecyl-3-methylimidazolium hexafluorophosphate ionic liquid ([C12MIM][PF6]) blends were prepared by melt blending. The compatibility of blends was verified by scanning electron microscopy and differential scanning calorimetry. The introduction of [C12MIM][PF6] decreased the glass transition temperature of the blends due to its plasticization effect and increased the diffusivity of CO2 without significantly affecting the CO2 solubility. These blends were foamed with supercritical CO2 as the blowing agent via a pressure-quenching process. The foaming conditions are divided into three regions according to the main morphological difference of foams. At relatively low temperatures and pressures, neat PMMA could not be foamed, while the addition of [C12MIM][PF6] facilitated the formation of cells. By increasing temperature or pressure, neat PMMA foams were obtained with wide cell size distribution, while the blend foams were formed with narrowed cell size distribution and increased cell size. At high temperatures and pressures, neat PMMA was foamed with narrow cell size distribution and high cell density, while the major effect of [C12MIM][PF6] was to increase the cell size. These results indicated that the plasticization effect and the low surface energy of [C12MIM][PF6] accounted for the differences on the cell morphology between neat PMMA and the blend foams. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301409h
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12329–12336[article] Plasticization of [C12MIM] [PF6] ionic liquid on foaming performance of poly(methyl methacrylate) in supercritical CO2 [texte imprimé] / Fang-fang Tong, Auteur ; Xu Hong, Auteur ; Jian Yu, Auteur . - 2012 . - pp. 12329–12336.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12329–12336
Mots-clés : Ionic liquid Résumé : A series of poly(methyl methacrylate) (PMMA)/1-dodecyl-3-methylimidazolium hexafluorophosphate ionic liquid ([C12MIM][PF6]) blends were prepared by melt blending. The compatibility of blends was verified by scanning electron microscopy and differential scanning calorimetry. The introduction of [C12MIM][PF6] decreased the glass transition temperature of the blends due to its plasticization effect and increased the diffusivity of CO2 without significantly affecting the CO2 solubility. These blends were foamed with supercritical CO2 as the blowing agent via a pressure-quenching process. The foaming conditions are divided into three regions according to the main morphological difference of foams. At relatively low temperatures and pressures, neat PMMA could not be foamed, while the addition of [C12MIM][PF6] facilitated the formation of cells. By increasing temperature or pressure, neat PMMA foams were obtained with wide cell size distribution, while the blend foams were formed with narrowed cell size distribution and increased cell size. At high temperatures and pressures, neat PMMA was foamed with narrow cell size distribution and high cell density, while the major effect of [C12MIM][PF6] was to increase the cell size. These results indicated that the plasticization effect and the low surface energy of [C12MIM][PF6] accounted for the differences on the cell morphology between neat PMMA and the blend foams. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301409h Exemplaires
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Titre : Coordinative adsorption of thiophene with metallic silver / adsorbent cotton prepared via aqueous In situ reduction for desulfurization Type de document : texte imprimé Auteurs : Shuo Ai, Auteur ; Hong Sui, Auteur ; Hong Li, Auteur Année de publication : 2012 Article en page(s) : pp. 12337–12343 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Metallic Silver Adsorbent Desulfurization Résumé : Selective adsorption has demonstrated minimal influence on the quality of aromatics-containing fuels. Considering the exposed surface of fibers for mass transfer, metallic silver was supported on adsorbent cotton fibers via an aqueous reduction–dehydration method with virtues such as extra low silver loading (0.2 wt %), facile preparation, low energy consumption, and no toxic emissions. On the basis of adsorption tests, thermogravimetric analysis (TGA)/differential thermal analysis (DTA) and energy-dispersive X-ray spectroscopy (ESEM-EDX), it is confirmed that the active component of adsorption is Ag0 instead of Ag+. It is attributed to the distinct polarities of thiophene–octane (model oil) and AgNO3. Model oil (500 ppmw sulfur) was pressed into an adsorption column without solvent for degassing. Temperature and retention time dependencies on capacity were investigated below 60 °C and at flow rates of 0.2 and 0.3 mL/min. The adsorption is substantially coordinative reaction. Higher capacities were determined at 50 °C in 2 h with an average sulfur removal of 27.6%, and sulfur removal declined at temperatures above 60 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301503h
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12337–12343[article] Coordinative adsorption of thiophene with metallic silver / adsorbent cotton prepared via aqueous In situ reduction for desulfurization [texte imprimé] / Shuo Ai, Auteur ; Hong Sui, Auteur ; Hong Li, Auteur . - 2012 . - pp. 12337–12343.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12337–12343
Mots-clés : Metallic Silver Adsorbent Desulfurization Résumé : Selective adsorption has demonstrated minimal influence on the quality of aromatics-containing fuels. Considering the exposed surface of fibers for mass transfer, metallic silver was supported on adsorbent cotton fibers via an aqueous reduction–dehydration method with virtues such as extra low silver loading (0.2 wt %), facile preparation, low energy consumption, and no toxic emissions. On the basis of adsorption tests, thermogravimetric analysis (TGA)/differential thermal analysis (DTA) and energy-dispersive X-ray spectroscopy (ESEM-EDX), it is confirmed that the active component of adsorption is Ag0 instead of Ag+. It is attributed to the distinct polarities of thiophene–octane (model oil) and AgNO3. Model oil (500 ppmw sulfur) was pressed into an adsorption column without solvent for degassing. Temperature and retention time dependencies on capacity were investigated below 60 °C and at flow rates of 0.2 and 0.3 mL/min. The adsorption is substantially coordinative reaction. Higher capacities were determined at 50 °C in 2 h with an average sulfur removal of 27.6%, and sulfur removal declined at temperatures above 60 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301503h Exemplaires
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Titre : Thermoreversible Poly(isopropyl lactate diol) - based polyurethane hydrogels : Effect of isocyanate on some physical properties Type de document : texte imprimé Auteurs : Luiza M. Gradinaru, Auteur ; Constantin Ciobanu, Auteur ; Stelian Vlad, Auteur Année de publication : 2012 Article en page(s) : pp. 12344-12354 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Physical properties Résumé : A series of polyurethanes were synthesized from poly(isopropyl lactate)diol, poly(ethylene oxide)― poly(propylene oxide)―poly(ethylene oxide) triblock copolymer, and different aliphatic diisocyanates. The chemical structure and molecular characteristics were investigated by 1H NMR, FT-IR, and GPC analysis. The effect of the isocyanate moiety on the polymer properties was studied. The wetting properties were evaluated from the contact angle determination. The obtained water-soluble polyurethanes present very low critical micelle concentration as determined by surface tension measurements. Aqueous solutions of these polyurethanes underwent a sol―gel―sol transition in a certain range of temperature, as a function of their chemical composition. The gelation for aqueous polyurethane solutions has been also realized under isothermal condition, and the viscoelastic properties of the hydrogels at 37 °C were investigated. The chemical structure of the diisocyanates influences the gelation process as well as the properties of the polyurethane hydrogels. These polyurethane properties might aid in devising new theoretical and practical approaches in many areas, such as pharmacology and materials fabrication. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399686
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12344-12354[article] Thermoreversible Poly(isopropyl lactate diol) - based polyurethane hydrogels : Effect of isocyanate on some physical properties [texte imprimé] / Luiza M. Gradinaru, Auteur ; Constantin Ciobanu, Auteur ; Stelian Vlad, Auteur . - 2012 . - pp. 12344-12354.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12344-12354
Mots-clés : Physical properties Résumé : A series of polyurethanes were synthesized from poly(isopropyl lactate)diol, poly(ethylene oxide)― poly(propylene oxide)―poly(ethylene oxide) triblock copolymer, and different aliphatic diisocyanates. The chemical structure and molecular characteristics were investigated by 1H NMR, FT-IR, and GPC analysis. The effect of the isocyanate moiety on the polymer properties was studied. The wetting properties were evaluated from the contact angle determination. The obtained water-soluble polyurethanes present very low critical micelle concentration as determined by surface tension measurements. Aqueous solutions of these polyurethanes underwent a sol―gel―sol transition in a certain range of temperature, as a function of their chemical composition. The gelation for aqueous polyurethane solutions has been also realized under isothermal condition, and the viscoelastic properties of the hydrogels at 37 °C were investigated. The chemical structure of the diisocyanates influences the gelation process as well as the properties of the polyurethane hydrogels. These polyurethane properties might aid in devising new theoretical and practical approaches in many areas, such as pharmacology and materials fabrication. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399686 Exemplaires
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Titre : Thin films of intumescent flame retardant - polyacrylamide and exfoliated graphene oxide fabricated via layer - by - layer assembly for improving flame retardant properties of cotton fabric Type de document : texte imprimé Auteurs : Guobo Huang, Auteur ; Jianguo Yang, Auteur ; Jianrong Gao, Auteur Année de publication : 2012 Article en page(s) : pp. 12355-12366 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Flame retardant Thin film Résumé : A novel intumescent flame retardant-polyacrylamide (IFR-PAM) was prepared by the copolymerization of N1-(5,5-dimethyl-1,3,2-dioxaphosphinyl-2-yl)-acrylamide (DPAA) and acrylamide and was used to prepare various IFR-PAM/ graphene oxide (GO) thin films via layer-by-layer (LbL) assembly as a flame retardant coating system for cotton fabric Films assembled with IFR-PAM and GO nanosheets show linear growth as a function of the number of bilayer deposited. Higher hydrophobe DPAA content of IFR-PAM results in much thicker assemblies due to hydrophobic association. The results from X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electronic microscopy (SEM) indicate that the IFR-PAM/ GO ultrathin films with high homogeneity and orientation are formed by LbL assembly driven by hydrogen interaction. The thermogravimetric analysis (TGA) results indicate that the IFR-PAM/GO coating improves the thermal stability of cotton fabric. Cone calorimeter testing shows that the IFR-PAM/GO-coated fabrics become less flammable with lower peak heat release rate (PHRR) and longer time to ignition (TTI). SEM images demonstrate that the surface of the IFR-PAM/GO-coated fabrics is covered by a layer of continuous and compact char after combustion. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399687
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12355-12366[article] Thin films of intumescent flame retardant - polyacrylamide and exfoliated graphene oxide fabricated via layer - by - layer assembly for improving flame retardant properties of cotton fabric [texte imprimé] / Guobo Huang, Auteur ; Jianguo Yang, Auteur ; Jianrong Gao, Auteur . - 2012 . - pp. 12355-12366.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12355-12366
Mots-clés : Flame retardant Thin film Résumé : A novel intumescent flame retardant-polyacrylamide (IFR-PAM) was prepared by the copolymerization of N1-(5,5-dimethyl-1,3,2-dioxaphosphinyl-2-yl)-acrylamide (DPAA) and acrylamide and was used to prepare various IFR-PAM/ graphene oxide (GO) thin films via layer-by-layer (LbL) assembly as a flame retardant coating system for cotton fabric Films assembled with IFR-PAM and GO nanosheets show linear growth as a function of the number of bilayer deposited. Higher hydrophobe DPAA content of IFR-PAM results in much thicker assemblies due to hydrophobic association. The results from X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electronic microscopy (SEM) indicate that the IFR-PAM/ GO ultrathin films with high homogeneity and orientation are formed by LbL assembly driven by hydrogen interaction. The thermogravimetric analysis (TGA) results indicate that the IFR-PAM/GO coating improves the thermal stability of cotton fabric. Cone calorimeter testing shows that the IFR-PAM/GO-coated fabrics become less flammable with lower peak heat release rate (PHRR) and longer time to ignition (TTI). SEM images demonstrate that the surface of the IFR-PAM/GO-coated fabrics is covered by a layer of continuous and compact char after combustion. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399687 Exemplaires
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Titre : Catalytic effects of nickel (Cobalt or Zinc) acetates on thermal and flammability properties of polypropylene-modified lignin composites Type de document : texte imprimé Auteurs : Youming Yu, Auteur ; Ping’an Song, Auteur ; Chunde Jin, Auteur Année de publication : 2012 Article en page(s) : pp. 12367-12374 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Composite material Flammability Catalytic reaction Résumé : Previous work has demonstrated that functionalized lignin (PN-lignin) was shown to enhance thermal stability and flame retardancy of polypropylene (PP). To further strength these effects, nickel (cobalt or zinc) acetates were introduced into PP/PN-lignin systems in the present work. Thermogravimetric analysis demonstrates that adding 2 wt % nickel acetate (Ni(Ac)2) catalytically degrades PP/PN-lignin but significantly increases the char residues in both N2 and air conditions. For instance, the presence of Ni2+ reduced the initial degradation temperature (T,) by ∼13 °C but doubled the char residue in the N2 condition relative to those of PP/PN-lignin. In comparison, the addition of cobalt or zinc acetate has little effect on thermal properties and char residues of PP/PN-lignin. Cone calorimeter results indicate that although the presence of Ni(Ac)2 shortens slightly the time to ignition (tign) from ∼38 s to ∼31 s, it reduces the peak heat release rate (PHRR) from 380 kW/m2 to 330 kW/m2, suggesting a further improved flame retardancy of PP/PN-lignin. Moreover, the addition of Ni(Ac)2 significantly increases char residue by ∼44%. Limited oxygen index (LOI) measurements show that adding Ni(Ac)2 increases the LOI value from 22 for PP/PN-lignin (17.5 for pure PP) up to 26, also indicating a better flame retardancy. Unlike Ni(Ac)2, cobalt or zinc acetate still has no obvious effect on flame retardancy. Char residue analysis shows that not only does Ni(Ac)2 participate in the char-forming process of PN-lignin by itself but its degradation products, NiO and Ni(0), also promote the carbonization through the catalytic action of the PP matrix, both of which are primarily responsible for the enhanced flame retardancy of the PP/PN-lignin system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399688
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12367-12374[article] Catalytic effects of nickel (Cobalt or Zinc) acetates on thermal and flammability properties of polypropylene-modified lignin composites [texte imprimé] / Youming Yu, Auteur ; Ping’an Song, Auteur ; Chunde Jin, Auteur . - 2012 . - pp. 12367-12374.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12367-12374
Mots-clés : Composite material Flammability Catalytic reaction Résumé : Previous work has demonstrated that functionalized lignin (PN-lignin) was shown to enhance thermal stability and flame retardancy of polypropylene (PP). To further strength these effects, nickel (cobalt or zinc) acetates were introduced into PP/PN-lignin systems in the present work. Thermogravimetric analysis demonstrates that adding 2 wt % nickel acetate (Ni(Ac)2) catalytically degrades PP/PN-lignin but significantly increases the char residues in both N2 and air conditions. For instance, the presence of Ni2+ reduced the initial degradation temperature (T,) by ∼13 °C but doubled the char residue in the N2 condition relative to those of PP/PN-lignin. In comparison, the addition of cobalt or zinc acetate has little effect on thermal properties and char residues of PP/PN-lignin. Cone calorimeter results indicate that although the presence of Ni(Ac)2 shortens slightly the time to ignition (tign) from ∼38 s to ∼31 s, it reduces the peak heat release rate (PHRR) from 380 kW/m2 to 330 kW/m2, suggesting a further improved flame retardancy of PP/PN-lignin. Moreover, the addition of Ni(Ac)2 significantly increases char residue by ∼44%. Limited oxygen index (LOI) measurements show that adding Ni(Ac)2 increases the LOI value from 22 for PP/PN-lignin (17.5 for pure PP) up to 26, also indicating a better flame retardancy. Unlike Ni(Ac)2, cobalt or zinc acetate still has no obvious effect on flame retardancy. Char residue analysis shows that not only does Ni(Ac)2 participate in the char-forming process of PN-lignin by itself but its degradation products, NiO and Ni(0), also promote the carbonization through the catalytic action of the PP matrix, both of which are primarily responsible for the enhanced flame retardancy of the PP/PN-lignin system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399688 Exemplaires
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Titre : Discriminating between critical and noncritical disturbances in (Bio)chemical batch processes using multimodel fault detection and end - quality prediction Type de document : texte imprimé Auteurs : Geert Gins, Auteur ; Jef Vanlaer, Auteur ; Jan F. M. Van Impe, Auteur Année de publication : 2012 Article en page(s) : pp. 12375–12385 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biochemical batch processes Résumé : This paper proposes a novel multimodel methodology for discriminating between critical and noncritical process disturbances in (bio)chemical batch processes, in addition to providing online prediction of batch-end quality. A multivariate multiway partial least squares (MPLS) or multiway principal component analysis (MPCA) model monitoring all available measurements is coupled with an MPLS or MPCA model monitoring only those measurements influencing the final product quality. Hence, process disturbances are labeled critical or noncritical, depending on whether they impact final quality and require immediate attention. This avoids unnecessary control actions or even early batch terminations for noncritical disturbances. The presented approach is illustrated on a simulated industrial-scale penicillin production process. On the basis of extensive simulation results, it is concluded that the proposed methodology discriminates between critical (according to a hypothesis test with 0.05 significance level) and noncritical disturbances. In addition, accurate online estimations of the batch-end product quality are provided. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202386p
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12375–12385[article] Discriminating between critical and noncritical disturbances in (Bio)chemical batch processes using multimodel fault detection and end - quality prediction [texte imprimé] / Geert Gins, Auteur ; Jef Vanlaer, Auteur ; Jan F. M. Van Impe, Auteur . - 2012 . - pp. 12375–12385.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12375–12385
Mots-clés : Biochemical batch processes Résumé : This paper proposes a novel multimodel methodology for discriminating between critical and noncritical process disturbances in (bio)chemical batch processes, in addition to providing online prediction of batch-end quality. A multivariate multiway partial least squares (MPLS) or multiway principal component analysis (MPCA) model monitoring all available measurements is coupled with an MPLS or MPCA model monitoring only those measurements influencing the final product quality. Hence, process disturbances are labeled critical or noncritical, depending on whether they impact final quality and require immediate attention. This avoids unnecessary control actions or even early batch terminations for noncritical disturbances. The presented approach is illustrated on a simulated industrial-scale penicillin production process. On the basis of extensive simulation results, it is concluded that the proposed methodology discriminates between critical (according to a hypothesis test with 0.05 significance level) and noncritical disturbances. In addition, accurate online estimations of the batch-end product quality are provided. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202386p Exemplaires
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Titre : Model - based framework for the analysis of failure consequences in a freeze - drying process Type de document : texte imprimé Auteurs : Davide Fissore, Auteur ; Roberto Pisano, Auteur ; Antonello A. Barresi, Auteur Année de publication : 2012 Article en page(s) : pp. 12386-12397 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Freeze drying Modeling Résumé : This paper shows how mathematical modeling can be used to assess the effect of process failures on product quality during the freeze-drying of pharmaceutical and biotech products. In particular, the model is used to calculate the product temperature response after an unexpected variation in the temperature of the heat transfer fluid and/or in the chamber pressure. Here a monodimensional model is used as it requires a limited number of parameters, which are the heat transfer coefficient and the product resistance to vapor flow. In this paper, the problem of determination of model parameters is addressed, with emphasis on the nonuniformity of the batch and on the uncertainty of the method of measurement used. The heat transfer coefficient was determined by gravimetric method, while the product resistance to vapor flow was measured by a weighing device placed directly in the chamber. Results obtained by the above devices agreed with the values estimated by the pressure rise test technique. This paper also shows how mathematical modeling can be used to calculate the probability that product temperature is maintained below its limit value, as well as to estimate the new duration for the primary drying. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399690
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12386-12397[article] Model - based framework for the analysis of failure consequences in a freeze - drying process [texte imprimé] / Davide Fissore, Auteur ; Roberto Pisano, Auteur ; Antonello A. Barresi, Auteur . - 2012 . - pp. 12386-12397.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12386-12397
Mots-clés : Freeze drying Modeling Résumé : This paper shows how mathematical modeling can be used to assess the effect of process failures on product quality during the freeze-drying of pharmaceutical and biotech products. In particular, the model is used to calculate the product temperature response after an unexpected variation in the temperature of the heat transfer fluid and/or in the chamber pressure. Here a monodimensional model is used as it requires a limited number of parameters, which are the heat transfer coefficient and the product resistance to vapor flow. In this paper, the problem of determination of model parameters is addressed, with emphasis on the nonuniformity of the batch and on the uncertainty of the method of measurement used. The heat transfer coefficient was determined by gravimetric method, while the product resistance to vapor flow was measured by a weighing device placed directly in the chamber. Results obtained by the above devices agreed with the values estimated by the pressure rise test technique. This paper also shows how mathematical modeling can be used to calculate the probability that product temperature is maintained below its limit value, as well as to estimate the new duration for the primary drying. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399690 Exemplaires
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Titre : Controller design for MIMO processes based on simple decoupled equivalent transfer functions and simplified decoupler Type de document : texte imprimé Auteurs : C. Rajapandiyan, Auteur ; M. Chidambaram, Auteur Année de publication : 2012 Article en page(s) : pp. 12398-12410 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Transfer function Design Résumé : A method for the independent design of proportional-integral/proportional-integral derivative (PI/PID) controllers is proposed based on the equivalent transfer function (ETF) model of the individual loops and the simplified decoupler matrix. It is shown that the conventional effective open-loop transfer function (EOTF, derived from the dynamic relative gain array (DRGA)) is equivalent to the ETF (derived from the relative normalized gain array (RNGA) and relative average residence time array (RARTA)). This relation is used to approximate the decoupled process models as ETF models. The simplified decoupler is shown to decompose the multiloop systems into independent loops (multi-single loop systems) with the ETFs as the resulting decoupled process model The concept of the ETF (perfect control approximation) is validated by introducing the decoupler. Based on the corresponding ETFs, the decentralized PI controllers are designed using the simplified internal model control (SIMC) method. Three simulation examples of multi-input multi-output (MIMO) process models are considered to demonstrate the simplicity and effectiveness of the proposed method. The performance of the proposed control system is compared with the ideal, normalized, inverted decoupling, and centralized control systems. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399691
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12398-12410[article] Controller design for MIMO processes based on simple decoupled equivalent transfer functions and simplified decoupler [texte imprimé] / C. Rajapandiyan, Auteur ; M. Chidambaram, Auteur . - 2012 . - pp. 12398-12410.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12398-12410
Mots-clés : Transfer function Design Résumé : A method for the independent design of proportional-integral/proportional-integral derivative (PI/PID) controllers is proposed based on the equivalent transfer function (ETF) model of the individual loops and the simplified decoupler matrix. It is shown that the conventional effective open-loop transfer function (EOTF, derived from the dynamic relative gain array (DRGA)) is equivalent to the ETF (derived from the relative normalized gain array (RNGA) and relative average residence time array (RARTA)). This relation is used to approximate the decoupled process models as ETF models. The simplified decoupler is shown to decompose the multiloop systems into independent loops (multi-single loop systems) with the ETFs as the resulting decoupled process model The concept of the ETF (perfect control approximation) is validated by introducing the decoupler. Based on the corresponding ETFs, the decentralized PI controllers are designed using the simplified internal model control (SIMC) method. Three simulation examples of multi-input multi-output (MIMO) process models are considered to demonstrate the simplicity and effectiveness of the proposed method. The performance of the proposed control system is compared with the ideal, normalized, inverted decoupling, and centralized control systems. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399691 Exemplaires
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Titre : Influence of the top impeller diameter on the gas dispersion in a sparged multi - impeller stirred tank Type de document : texte imprimé Auteurs : Yuyun Bao, Auteur ; Jie Yang, Auteur ; Lei Chen, Auteur Année de publication : 2012 Article en page(s) : pp. 12411-12420 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Stirred vessel Dispersion Agitator Résumé : The impeller configuration with a hollow half-elliptical blade dispersing turbine below two up-pumping wide-blade hydrofoils, identified as HEDT+2WHU and recommended in previous work, was used in this study. The effect of the top impeller diameter, ranging from 0.33T to 0.50T, on gas―liquid flow in a stirred tank of 0.48 m diameter was investigated by experimental and CFD methods. Power consumption, total gas holdup, and local void fraction were measured for the impeller configurations with different top impeller diameters. Results show that while the ratio of top impeller diameter to tank diameter (Dtop/T) increases from 0.33 to 0.50, the relative power demand (RPD) in a gas―liquid system decreases slightly. The increase of total gas holdup with rising gas flow rate becomes less evident as Dtop/T increases from 0.33 to 0.50. Local void fractions at the measurement points above the height of 0.8T increase significantly with the increase of top impeller diameter. When Dtop/T = 0.50, there is an extremely large voidage of about 50% just above the top impeller. The maximum voidage decreases with the decrease of top impeller diameter and almost disappears when Dtop/T = 0.33. CFD simulation based on the two-fluid model along with the population balance model (PBM) was used to investigate the effect of top impeller diameter on the gas―liquid flows. The power consumption, total gas holdup, and local void fraction predicted by the CFD approach were in reasonably good agreement with the experimental data. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399692
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12411-12420[article] Influence of the top impeller diameter on the gas dispersion in a sparged multi - impeller stirred tank [texte imprimé] / Yuyun Bao, Auteur ; Jie Yang, Auteur ; Lei Chen, Auteur . - 2012 . - pp. 12411-12420.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12411-12420
Mots-clés : Stirred vessel Dispersion Agitator Résumé : The impeller configuration with a hollow half-elliptical blade dispersing turbine below two up-pumping wide-blade hydrofoils, identified as HEDT+2WHU and recommended in previous work, was used in this study. The effect of the top impeller diameter, ranging from 0.33T to 0.50T, on gas―liquid flow in a stirred tank of 0.48 m diameter was investigated by experimental and CFD methods. Power consumption, total gas holdup, and local void fraction were measured for the impeller configurations with different top impeller diameters. Results show that while the ratio of top impeller diameter to tank diameter (Dtop/T) increases from 0.33 to 0.50, the relative power demand (RPD) in a gas―liquid system decreases slightly. The increase of total gas holdup with rising gas flow rate becomes less evident as Dtop/T increases from 0.33 to 0.50. Local void fractions at the measurement points above the height of 0.8T increase significantly with the increase of top impeller diameter. When Dtop/T = 0.50, there is an extremely large voidage of about 50% just above the top impeller. The maximum voidage decreases with the decrease of top impeller diameter and almost disappears when Dtop/T = 0.33. CFD simulation based on the two-fluid model along with the population balance model (PBM) was used to investigate the effect of top impeller diameter on the gas―liquid flows. The power consumption, total gas holdup, and local void fraction predicted by the CFD approach were in reasonably good agreement with the experimental data. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399692 Exemplaires
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Titre : Fixed - bed and stirred - tank studies of manganese sorption by calcite limestone Type de document : texte imprimé Auteurs : Adarlene M. Silva, Auteur ; Fabrício C. M. Cordeiro, Auteur ; Emannoelle C. Cunha, Auteur Année de publication : 2012 Article en page(s) : pp. 12421-12429 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Sorption Stirred vessel Fixed bed Résumé : This study addressed manganese removal from mine waters in a stirred tank as well as fixed-bed experiments. Manganese sorption on limestone is described by pseudo first-order kinetics. Equilibrium sorption was modeled by the Langmuir isotherm, and limestone showed maximum manganese uptakes ranging from 0.92 mg/g in the absence of sulfate to 1.08 mg/g in the presence of 600 mg/L of the species. Fixed-bed testing showed limestone uptakes that increased with the flow rate at low manganese concentration (1.5 mg/L) but decreased for mine water containing 15 mgMn/L. The Thomas model was fitted to breakthrough curves to determine the characteristic design parameters of the column. The maximum uptake was 46.85 mg/L-bed for a 15 mg/L manganese solution at 1 mL/min, and sulfate did not affect the manganese sorption. The solid residues obtained during the removal process were characterized, and the presence of manganese carbonate (MnCO3) on the limestone surface was confirmed by IR during the experiments with mine water. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399693
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12421-12429[article] Fixed - bed and stirred - tank studies of manganese sorption by calcite limestone [texte imprimé] / Adarlene M. Silva, Auteur ; Fabrício C. M. Cordeiro, Auteur ; Emannoelle C. Cunha, Auteur . - 2012 . - pp. 12421-12429.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12421-12429
Mots-clés : Sorption Stirred vessel Fixed bed Résumé : This study addressed manganese removal from mine waters in a stirred tank as well as fixed-bed experiments. Manganese sorption on limestone is described by pseudo first-order kinetics. Equilibrium sorption was modeled by the Langmuir isotherm, and limestone showed maximum manganese uptakes ranging from 0.92 mg/g in the absence of sulfate to 1.08 mg/g in the presence of 600 mg/L of the species. Fixed-bed testing showed limestone uptakes that increased with the flow rate at low manganese concentration (1.5 mg/L) but decreased for mine water containing 15 mgMn/L. The Thomas model was fitted to breakthrough curves to determine the characteristic design parameters of the column. The maximum uptake was 46.85 mg/L-bed for a 15 mg/L manganese solution at 1 mL/min, and sulfate did not affect the manganese sorption. The solid residues obtained during the removal process were characterized, and the presence of manganese carbonate (MnCO3) on the limestone surface was confirmed by IR during the experiments with mine water. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399693 Exemplaires
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Titre : Novel copper - exchanged titanosilicate adsorbent for low temperature H2S removal Type de document : texte imprimé Auteurs : Sabereh Rezaei, Auteur ; Aida Tavana, Auteur ; James A. Sawada, Auteur Année de publication : 2012 Article en page(s) : pp. 12430-12434 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogen sulfides Low temperature Résumé : The H2S removal capacity of copper loaded on a number of titanosilicate supports was investigated. Copper supported on Engelhard Titanosilicate-2 (Cu-ETS-2) has been found to be a superior H2S scavenger for maintaining H2S levels below 0.5 ppm because of its high cation exchange capacity and copper dispersion. Cu-ETS-2 demonstrated higher utilization at room temperature when compared to fully developed commercial H2S adsorbents. In addition it was found that the adsorption capacity of Cu-ETS-2 is maintained over a wide range of activation temperatures. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399694
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12430-12434[article] Novel copper - exchanged titanosilicate adsorbent for low temperature H2S removal [texte imprimé] / Sabereh Rezaei, Auteur ; Aida Tavana, Auteur ; James A. Sawada, Auteur . - 2012 . - pp. 12430-12434.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12430-12434
Mots-clés : Hydrogen sulfides Low temperature Résumé : The H2S removal capacity of copper loaded on a number of titanosilicate supports was investigated. Copper supported on Engelhard Titanosilicate-2 (Cu-ETS-2) has been found to be a superior H2S scavenger for maintaining H2S levels below 0.5 ppm because of its high cation exchange capacity and copper dispersion. Cu-ETS-2 demonstrated higher utilization at room temperature when compared to fully developed commercial H2S adsorbents. In addition it was found that the adsorption capacity of Cu-ETS-2 is maintained over a wide range of activation temperatures. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399694 Exemplaires
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Titre : Batch distillation : The forward and inverse problems Type de document : texte imprimé Auteurs : O. Samimi Abianeh, Auteur ; C. P. Chen, Auteur ; Ramon L. Cerro, Auteur Année de publication : 2012 Article en page(s) : pp. 12435-12448 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Inverse problem Distillation Batchwise Résumé : There are two basic theoretical and computational problems associated with batch distillation. The forward or direct problem consists on generating the distillation curve of a given mixture. This is an old problem, but new results are presented here to relate mathematical properties of the distillation curve with the physicochemical properties of the molecular species present in the mixture. The inverse problem consists of, given a distillation curve, finding a surrogate mixture that would accurately represent experimental data. There is more than one solution to the reverse problem because there are theoretically an infinite number of mixtures that will present very similar experimental distillation curves. The method developed in this paper requires the same number of molecular species in the surrogate mixture as the points of the distillation curve that will be matched precisely. The choice of exact points to match on the distillation curve allows to conform a square system of equations where the number of equations is equal to the number of unknowns. Other points of the distillation curve are satisfied within a prescribed small error tolerance. A surrogate mixture for gasoline was developed as an example. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399695
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12435-12448[article] Batch distillation : The forward and inverse problems [texte imprimé] / O. Samimi Abianeh, Auteur ; C. P. Chen, Auteur ; Ramon L. Cerro, Auteur . - 2012 . - pp. 12435-12448.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12435-12448
Mots-clés : Inverse problem Distillation Batchwise Résumé : There are two basic theoretical and computational problems associated with batch distillation. The forward or direct problem consists on generating the distillation curve of a given mixture. This is an old problem, but new results are presented here to relate mathematical properties of the distillation curve with the physicochemical properties of the molecular species present in the mixture. The inverse problem consists of, given a distillation curve, finding a surrogate mixture that would accurately represent experimental data. There is more than one solution to the reverse problem because there are theoretically an infinite number of mixtures that will present very similar experimental distillation curves. The method developed in this paper requires the same number of molecular species in the surrogate mixture as the points of the distillation curve that will be matched precisely. The choice of exact points to match on the distillation curve allows to conform a square system of equations where the number of equations is equal to the number of unknowns. Other points of the distillation curve are satisfied within a prescribed small error tolerance. A surrogate mixture for gasoline was developed as an example. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399695 Exemplaires
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Titre : Adsorption Behavior of Metal–Organic Frameworks for Thiophenic Sulfur from Diesel Oil Type de document : texte imprimé Auteurs : Hong - Xing Zhang, Auteur ; Hong-Liang Huang, Auteur ; Chun-Xi Li, Auteur Année de publication : 2012 Article en page(s) : pp. 12449-12455 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Résumé : Four metal―organic frameworks (MOFs) are synthesized using two different metal centers and two different organic ligands, viz., Cu3[C6H3(CO2)3]2 (Cu-BTC), Cu[O2C―C6H4―CO2] (Cu-BDC), Cr(OH)[O2C―C6H4―CO2] (Cr-BDC), and Cr3F(H2O)3O[C6H3(CO2)3]2 (Cr-BTC). Their adsorption behaviors for thiophenic sulfurs in model diesel oils are systematically investigated at mild temperatures and follow the order Cu-BTC > Cr-BDC > Cr-BTC ≫ Cu-BDC. Meanwhile, the adsorption capacity of different sulfur compounds follows the order dibenzothiophene (DBT) > benzothiophene (BT) > 3-methylthiophene (3-MT). The MOFs adsorption mechanism is regarded as a combined effect of many factors involving appropriate framework structure, suitable pore size and shape, and exposed Lewis acid site matching the S-compound to be adsorbed. The difference in adsorptive activity among the organosulfurs is mainly ascribed to their π-electron number and the electron density on the S-atom. Finally, the used MOF can be easily regenerated by solvent washing and recycled at least five times. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399696
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12449-12455[article] Adsorption Behavior of Metal–Organic Frameworks for Thiophenic Sulfur from Diesel Oil [texte imprimé] / Hong - Xing Zhang, Auteur ; Hong-Liang Huang, Auteur ; Chun-Xi Li, Auteur . - 2012 . - pp. 12449-12455.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12449-12455
Mots-clés : Adsorption Résumé : Four metal―organic frameworks (MOFs) are synthesized using two different metal centers and two different organic ligands, viz., Cu3[C6H3(CO2)3]2 (Cu-BTC), Cu[O2C―C6H4―CO2] (Cu-BDC), Cr(OH)[O2C―C6H4―CO2] (Cr-BDC), and Cr3F(H2O)3O[C6H3(CO2)3]2 (Cr-BTC). Their adsorption behaviors for thiophenic sulfurs in model diesel oils are systematically investigated at mild temperatures and follow the order Cu-BTC > Cr-BDC > Cr-BTC ≫ Cu-BDC. Meanwhile, the adsorption capacity of different sulfur compounds follows the order dibenzothiophene (DBT) > benzothiophene (BT) > 3-methylthiophene (3-MT). The MOFs adsorption mechanism is regarded as a combined effect of many factors involving appropriate framework structure, suitable pore size and shape, and exposed Lewis acid site matching the S-compound to be adsorbed. The difference in adsorptive activity among the organosulfurs is mainly ascribed to their π-electron number and the electron density on the S-atom. Finally, the used MOF can be easily regenerated by solvent washing and recycled at least five times. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399696 Exemplaires
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Titre : Uncommon Crop Residues as Ni(II) and Cd(II) Biosorbents Type de document : texte imprimé Auteurs : Maria L. Correa, Auteur ; Jorge A. Velasquez, Auteur ; German C. Quintana, Auteur Année de publication : 2012 Article en page(s) : pp. 12456–12462 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biosorbents Résumé : Four residues of uncommon crops—Coffea arabica fruit endocarp, coconut fruit endocarp, Eichhornia crassipes weed (EC), and Guadua angustifolia plant—and a commercial activated carbon (CA) are evaluated as Ni(II) and Cd(II) biosorbents. These materials are chosen for their abundance and economic importance in Colombia. Surface functional groups containing oxygen, such as carboxylic, lactonic, and phenolic, are quantified using the Boehm’s method. The Ni(II) and Cd(II) adsorption are determined from dose curves. The highest removal percentage is obtained using EC: 74.31% and 95.77% for Ni(II) and Cd(II), respectively. The equilibrium isotherms are constructed at 28 °C and pH 6.6. The results are adjusted to the Langmuir model by nonlinear regression, showing a good fit, with R2 above 95%. The highest maximum adsorption capacity (XmL) is found with EC: 17.47 mg Ni(II)/g EC and 32.82 mg Cd(II)/g EC. The trend in the estimated XmL values is found to be consistent with their contents of total acidic surface functional groups. It is concluded that these lignocellulosic materials, without chemical and physic treatment, behave similarly or even equal to the CA. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301156y
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12456–12462[article] Uncommon Crop Residues as Ni(II) and Cd(II) Biosorbents [texte imprimé] / Maria L. Correa, Auteur ; Jorge A. Velasquez, Auteur ; German C. Quintana, Auteur . - 2012 . - pp. 12456–12462.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12456–12462
Mots-clés : Biosorbents Résumé : Four residues of uncommon crops—Coffea arabica fruit endocarp, coconut fruit endocarp, Eichhornia crassipes weed (EC), and Guadua angustifolia plant—and a commercial activated carbon (CA) are evaluated as Ni(II) and Cd(II) biosorbents. These materials are chosen for their abundance and economic importance in Colombia. Surface functional groups containing oxygen, such as carboxylic, lactonic, and phenolic, are quantified using the Boehm’s method. The Ni(II) and Cd(II) adsorption are determined from dose curves. The highest removal percentage is obtained using EC: 74.31% and 95.77% for Ni(II) and Cd(II), respectively. The equilibrium isotherms are constructed at 28 °C and pH 6.6. The results are adjusted to the Langmuir model by nonlinear regression, showing a good fit, with R2 above 95%. The highest maximum adsorption capacity (XmL) is found with EC: 17.47 mg Ni(II)/g EC and 32.82 mg Cd(II)/g EC. The trend in the estimated XmL values is found to be consistent with their contents of total acidic surface functional groups. It is concluded that these lignocellulosic materials, without chemical and physic treatment, behave similarly or even equal to the CA. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301156y Exemplaires
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Titre : Optimizing argon recovery : Membrane separation of carbon monoxide at high concentrations via the water gas shift Type de document : texte imprimé Auteurs : Thomas Harlacher, Auteur ; Marco Scholz, Auteur ; Thomas Melin, Auteur Année de publication : 2012 Article en page(s) : pp. 12463-12470 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Water gas Membrane separation Optimization Résumé : This paper investigates the feasibility of separating carbon monoxide at high concentrations from argon in silicon carbide production by using five commercial polymer membranes. Single gas and mixed gas experiments are reported and compared to module simulation. Three possible process routes with a membrane gas separation incorporated were studied: direct CO removal, methanation, and the water gas shift reaction. The latter proved to be the most promising membrane process route. While a polyether-based Polyactive (PEO) membrane separated CO2 best, polyimide membranes (PI) could separate both CO2 and H2 from argon but required a 10-time greater membrane area. In conclusion, carbon monoxide can be effectively separated from argon in the percentage concentration range via the water gas shift reaction and subsequent separation of the resulting CO2 and H2 using both cited membranes. However, since there was a trade-off between separation performance and required membrane area, future membrane processes should comprise both PEO and PI to ensure optimal argon recovery. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399698
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12463-12470[article] Optimizing argon recovery : Membrane separation of carbon monoxide at high concentrations via the water gas shift [texte imprimé] / Thomas Harlacher, Auteur ; Marco Scholz, Auteur ; Thomas Melin, Auteur . - 2012 . - pp. 12463-12470.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12463-12470
Mots-clés : Water gas Membrane separation Optimization Résumé : This paper investigates the feasibility of separating carbon monoxide at high concentrations from argon in silicon carbide production by using five commercial polymer membranes. Single gas and mixed gas experiments are reported and compared to module simulation. Three possible process routes with a membrane gas separation incorporated were studied: direct CO removal, methanation, and the water gas shift reaction. The latter proved to be the most promising membrane process route. While a polyether-based Polyactive (PEO) membrane separated CO2 best, polyimide membranes (PI) could separate both CO2 and H2 from argon but required a 10-time greater membrane area. In conclusion, carbon monoxide can be effectively separated from argon in the percentage concentration range via the water gas shift reaction and subsequent separation of the resulting CO2 and H2 using both cited membranes. However, since there was a trade-off between separation performance and required membrane area, future membrane processes should comprise both PEO and PI to ensure optimal argon recovery. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399698 Exemplaires
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Titre : Treatment of effluents issued from agro - food industries by liquid – liquid extraction of malic and lactic acids using Tri - n - octylamine and Tri - n - butyl phosphate Type de document : texte imprimé Auteurs : Abdallah Labbaci, Auteur ; Mustapha Douani, Auteur ; Joël Albet, Auteur Année de publication : 2012 Article en page(s) : pp. 12471-12478 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Liquid liquid extraction Food industry Résumé : The principal objective of this study is to develop new methods for recovery of the acids malic and lactic present in the distilling effluents of the wine industry by solvents. The information about the influence of the factors which govern the thermodynamic equilibrium of all coexistent phases in the aqueous medium of extraction is the essential step. This approach is at the base of the choice of suitable solvent taking into account its selectivity of extraction with respect to the acids lactic and malic. The experimental study showed that the better extents are obtained when the composition of solvent corresponds to 15% (v/v) TOA, 18% (v/v) 1-decanol, and 67% (v/v) n-dodecane. The malic percentage of acid extracted is 80%, whereas that of the lactic acid is 53.6%. This last solvent exhibits an excellent extraction efficiency of the malic acid comparatively to lactic acid. The system extractant-diluent (TBP, n-dodecane) extracts the lactic acid in a way much more selective from the solution, with a percentage of extraction exceeding 54%. Comparatively to results obtained by the ternary mixture (TOA, 1-decanol, and n-dodecane), the separation is more satisfactory using the first system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399699
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12471-12478[article] Treatment of effluents issued from agro - food industries by liquid – liquid extraction of malic and lactic acids using Tri - n - octylamine and Tri - n - butyl phosphate [texte imprimé] / Abdallah Labbaci, Auteur ; Mustapha Douani, Auteur ; Joël Albet, Auteur . - 2012 . - pp. 12471-12478.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12471-12478
Mots-clés : Liquid liquid extraction Food industry Résumé : The principal objective of this study is to develop new methods for recovery of the acids malic and lactic present in the distilling effluents of the wine industry by solvents. The information about the influence of the factors which govern the thermodynamic equilibrium of all coexistent phases in the aqueous medium of extraction is the essential step. This approach is at the base of the choice of suitable solvent taking into account its selectivity of extraction with respect to the acids lactic and malic. The experimental study showed that the better extents are obtained when the composition of solvent corresponds to 15% (v/v) TOA, 18% (v/v) 1-decanol, and 67% (v/v) n-dodecane. The malic percentage of acid extracted is 80%, whereas that of the lactic acid is 53.6%. This last solvent exhibits an excellent extraction efficiency of the malic acid comparatively to lactic acid. The system extractant-diluent (TBP, n-dodecane) extracts the lactic acid in a way much more selective from the solution, with a percentage of extraction exceeding 54%. Comparatively to results obtained by the ternary mixture (TOA, 1-decanol, and n-dodecane), the separation is more satisfactory using the first system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399699 Exemplaires
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Titre : Activity coefficients of organic solutes at Infinite dilution in the ionic liquids. 2. : Organic solutes in 1-hexyl-3-methylimidazolium nitrate and gas–liquid partitioning and interfacial adsorption using gas–liquid chromatography Type de document : texte imprimé Auteurs : Jiang Kan, Auteur ; Li-Sheng Wang, Auteur ; Xin-Xin Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 12479–12487 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic liquids Adsorption Gas liquid Résumé : This paper reports activity coefficients at infinite dilution for a series of organic solutes in the ionic liquid 1-hexyl-3-methylimidazolium nitrate by gas–liquid chromatography at different temperatures between 313.15 and 363.15 K. The contribution of gas–liquid partitioning and interfacial adsorption to the retention mechanism was estimated by changing the loading of ionic liquid in stationary phase, and the influence of different loading of ionic liquid on the experimental values of activity coefficients at infinite dilution was discussed. The partial molar excess enthalpies at infinite dilution and the solubility parameters of ionic liquid were also calculated from the experimental values of activity coefficients at infinite dilution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301591j
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12479–12487[article] Activity coefficients of organic solutes at Infinite dilution in the ionic liquids. 2. : Organic solutes in 1-hexyl-3-methylimidazolium nitrate and gas–liquid partitioning and interfacial adsorption using gas–liquid chromatography [texte imprimé] / Jiang Kan, Auteur ; Li-Sheng Wang, Auteur ; Xin-Xin Wang, Auteur . - 2012 . - pp. 12479–12487.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12479–12487
Mots-clés : Ionic liquids Adsorption Gas liquid Résumé : This paper reports activity coefficients at infinite dilution for a series of organic solutes in the ionic liquid 1-hexyl-3-methylimidazolium nitrate by gas–liquid chromatography at different temperatures between 313.15 and 363.15 K. The contribution of gas–liquid partitioning and interfacial adsorption to the retention mechanism was estimated by changing the loading of ionic liquid in stationary phase, and the influence of different loading of ionic liquid on the experimental values of activity coefficients at infinite dilution was discussed. The partial molar excess enthalpies at infinite dilution and the solubility parameters of ionic liquid were also calculated from the experimental values of activity coefficients at infinite dilution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301591j Exemplaires
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Titre : Investigation on the aerodynamic field distribution in an entrained - flow gasifier by two - stage oxygen Type de document : texte imprimé Auteurs : Junjie Fan, Auteur ; Zhongxiao Zhang, Auteur ; Quanhai An, Auteur Année de publication : 2012 Article en page(s) : pp. 12488-12496 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aerodynamic Gasifier Résumé : In this paper, a full scale cold model of 500 t/d entrained-flow gasifier by two-stage oxygen was used to analyze the distribution characteristics of the aerodynamic field in the gasifier. The realizable k―ε turbulent model was adopted to simulate the three-dimensional turbulent flow field with the SIMPLE (semi-implicit method for pressure-linked equations) algorithm for the gasifier. The effects of side injecting velocity, position, number of nozzles, and group mode on aerodynamic field distributions were analyzed. The results show that the numerical simulation data are well-matched with the experiment data. The simulated results are acceptable and can present a foundation for the future design, assessment, and further optimization of the entrained-flow gasifier by two-stage oxygen. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202444h
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12488-12496[article] Investigation on the aerodynamic field distribution in an entrained - flow gasifier by two - stage oxygen [texte imprimé] / Junjie Fan, Auteur ; Zhongxiao Zhang, Auteur ; Quanhai An, Auteur . - 2012 . - pp. 12488-12496.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12488-12496
Mots-clés : Aerodynamic Gasifier Résumé : In this paper, a full scale cold model of 500 t/d entrained-flow gasifier by two-stage oxygen was used to analyze the distribution characteristics of the aerodynamic field in the gasifier. The realizable k―ε turbulent model was adopted to simulate the three-dimensional turbulent flow field with the SIMPLE (semi-implicit method for pressure-linked equations) algorithm for the gasifier. The effects of side injecting velocity, position, number of nozzles, and group mode on aerodynamic field distributions were analyzed. The results show that the numerical simulation data are well-matched with the experiment data. The simulated results are acceptable and can present a foundation for the future design, assessment, and further optimization of the entrained-flow gasifier by two-stage oxygen. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202444h Exemplaires
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Titre : Artificial neural network and neuro - fuzzy methodology for phase distribution modeling of a liquid – solid circulating fluidized bed riser Type de document : texte imprimé Auteurs : Shaikh A. Razzak, Auteur ; Syed M. Rahman, Auteur ; Mohammad M. Hossain, Auteur Année de publication : 2012 Article en page(s) : pp. 12497–12508 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Neural network Liquid solid Résumé : Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) modeling techniques are applied to study the radial and axial solids holdup distributions in a liquid–solid circulating fluidized bed (LSCFB) system. The modeling process is based on the experiments that were conducted using 500 μm size glass beads as solid phase. The radial nonuniformity of the solids holdup is observed under different superficial liquid velocities at superficial solids velocity of 0.95 cm/s and auxiliary liquid velocity of 1.4 cm/s at four axial locations (H = 1.0, 2.0, 3.0, and 3.8 m above the distributor). The effects of different operating parameters such as auxiliary and primary liquid velocities and superficial solids velocity on radial phase distribution in different axial positions of the riser are considered in the model development and analysis. The adequacy of the developed models is investigated by comparing the model predicted and experimental solids holdup data obtained from the pilot scale LSCFB reactor. Radial nonuniformity of the solids holdup is observed under different superficial liquid velocities at superficial solids velocity of 0.95 cm/s and auxiliary liquid velocities of 1.4 cm/s at four axial locations (H = 1, 2, 3, and 3.8 m above the distributor). The cross-sectional average solids holdup in axial directions is compared to the output of the two models. The model outputs show good agreements with the experimental data and reasonable trends of phase distributions. The correlation coefficient values of the predicted output and the experimental data are 0.95 and 0.96 for ANFIS and ANN models, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301746y
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12497–12508[article] Artificial neural network and neuro - fuzzy methodology for phase distribution modeling of a liquid – solid circulating fluidized bed riser [texte imprimé] / Shaikh A. Razzak, Auteur ; Syed M. Rahman, Auteur ; Mohammad M. Hossain, Auteur . - 2012 . - pp. 12497–12508.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12497–12508
Mots-clés : Neural network Liquid solid Résumé : Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) modeling techniques are applied to study the radial and axial solids holdup distributions in a liquid–solid circulating fluidized bed (LSCFB) system. The modeling process is based on the experiments that were conducted using 500 μm size glass beads as solid phase. The radial nonuniformity of the solids holdup is observed under different superficial liquid velocities at superficial solids velocity of 0.95 cm/s and auxiliary liquid velocity of 1.4 cm/s at four axial locations (H = 1.0, 2.0, 3.0, and 3.8 m above the distributor). The effects of different operating parameters such as auxiliary and primary liquid velocities and superficial solids velocity on radial phase distribution in different axial positions of the riser are considered in the model development and analysis. The adequacy of the developed models is investigated by comparing the model predicted and experimental solids holdup data obtained from the pilot scale LSCFB reactor. Radial nonuniformity of the solids holdup is observed under different superficial liquid velocities at superficial solids velocity of 0.95 cm/s and auxiliary liquid velocities of 1.4 cm/s at four axial locations (H = 1, 2, 3, and 3.8 m above the distributor). The cross-sectional average solids holdup in axial directions is compared to the output of the two models. The model outputs show good agreements with the experimental data and reasonable trends of phase distributions. The correlation coefficient values of the predicted output and the experimental data are 0.95 and 0.96 for ANFIS and ANN models, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301746y Exemplaires
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Titre : Production and evaluation of floating photocatalytic composite particles formed using pickering emulsions and membrane emulsification Type de document : texte imprimé Auteurs : Richard G. Holdich, Auteur ; Idil Yilmaz Ipek, Auteur ; Manal Lazrigh, Auteur Année de publication : 2012 Article en page(s) : pp. 12509–12516 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Photocatalytic Membrane emulsification Résumé : Floating photocatalytic composite particles were created by injecting a lipid (sunflower oil or liquefied cocoa butter) into an aqueous suspension of TiO2 nanoparticles using the process of membrane emulsification to control the (Pickering) emulsion size. The composite particle median diameters were controlled in a range from 80 to 300 μm. The composite particles floated in water and possessed photocatalytic activity, which was further enhanced by chemically incorporating silver particles into the TiO2 shell. The cocoa butter-based composite particles proved more robust and were not affected by the UV photocatalytic process. Using a combination of cocoa butter and hexane, for the core of the particles, it was possible to generate composite TiO2 and lipid particles with 36 mg of TiO2 per gram of particle. Optimal dye decolorization was achieved with a particle surface coverage of between 60 and 80%. Complete surface coverage resulted in a reduced reaction rate due possibly to reflection of the UV light. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3001748
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12509–12516[article] Production and evaluation of floating photocatalytic composite particles formed using pickering emulsions and membrane emulsification [texte imprimé] / Richard G. Holdich, Auteur ; Idil Yilmaz Ipek, Auteur ; Manal Lazrigh, Auteur . - 2012 . - pp. 12509–12516.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12509–12516
Mots-clés : Photocatalytic Membrane emulsification Résumé : Floating photocatalytic composite particles were created by injecting a lipid (sunflower oil or liquefied cocoa butter) into an aqueous suspension of TiO2 nanoparticles using the process of membrane emulsification to control the (Pickering) emulsion size. The composite particle median diameters were controlled in a range from 80 to 300 μm. The composite particles floated in water and possessed photocatalytic activity, which was further enhanced by chemically incorporating silver particles into the TiO2 shell. The cocoa butter-based composite particles proved more robust and were not affected by the UV photocatalytic process. Using a combination of cocoa butter and hexane, for the core of the particles, it was possible to generate composite TiO2 and lipid particles with 36 mg of TiO2 per gram of particle. Optimal dye decolorization was achieved with a particle surface coverage of between 60 and 80%. Complete surface coverage resulted in a reduced reaction rate due possibly to reflection of the UV light. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3001748 Exemplaires
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Titre : Morphological differentiation and crystal growth form of friedel’s salt originated from pozzolan and portland cement Type de document : texte imprimé Auteurs : Rafael Talero, Auteur ; Lidia Trusilewicz, Auteur Année de publication : 2012 Article en page(s) : pp. 12517–12529 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Morphological comparison Friedel’s salt Résumé : This paper has a scientific–technical character and deals with morphological comparison of Friedel’s salt (Fs), which is a compound that is originated from two routes: C3A phase of Portland cement (PC) and Al2O3r– (reactive alumina) of pozzolans. The reaction courses are contrasted and the role of reactive components is discussed in detail. The results show a great difference in morphology of the Fs, relative to the function of its origin, which is directly related to its very different formation rate: Friedel’s salt of rapid formation (Fs-rf) or Friedel’s salt of slow formation (Fs-lf). The reactive alumina (Al2O3r–) component of pozzolans is found to be involved in the direct, nondirect, and, above all, indirect stimulation of the C3A phase of ordinary Portland cement (OPC) saline hydration, because of its high, fast, and early pozzolanic activity. For this reason, its pozzolanic activity is justifiably classified more as specific than generic, intensifying the formation of Fs from the C3A origin of OPC. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301671z
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12517–12529[article] Morphological differentiation and crystal growth form of friedel’s salt originated from pozzolan and portland cement [texte imprimé] / Rafael Talero, Auteur ; Lidia Trusilewicz, Auteur . - 2012 . - pp. 12517–12529.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12517–12529
Mots-clés : Morphological comparison Friedel’s salt Résumé : This paper has a scientific–technical character and deals with morphological comparison of Friedel’s salt (Fs), which is a compound that is originated from two routes: C3A phase of Portland cement (PC) and Al2O3r– (reactive alumina) of pozzolans. The reaction courses are contrasted and the role of reactive components is discussed in detail. The results show a great difference in morphology of the Fs, relative to the function of its origin, which is directly related to its very different formation rate: Friedel’s salt of rapid formation (Fs-rf) or Friedel’s salt of slow formation (Fs-lf). The reactive alumina (Al2O3r–) component of pozzolans is found to be involved in the direct, nondirect, and, above all, indirect stimulation of the C3A phase of ordinary Portland cement (OPC) saline hydration, because of its high, fast, and early pozzolanic activity. For this reason, its pozzolanic activity is justifiably classified more as specific than generic, intensifying the formation of Fs from the C3A origin of OPC. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301671z Exemplaires
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Titre : Combined application of in Situ FBRM, ATR-FTIR, and raman on polymorphism transformation monitoring during the cooling crystallization Type de document : texte imprimé Auteurs : Yingying Zhao, Auteur ; Junsheng Yuan, Auteur ; Zhiyong Ji, Auteur Année de publication : 2012 Article en page(s) : pp. 12530-12536 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystallization Cooling Surveillance Polymorphism In situ Résumé : This study evaluates the potential use of the FBRM, ATR-FTIR, and Raman for on line detection of polymorphic transformation of carbamazepine (CBZ) during the cooling crystallization. Changes in solution concentration as a function of time were quantified from the ATR-FTIR data. A new quantitative method of polymorphs ratio was developed using Raman spectroscopy for in situ monitoring during a solution-mediated transformation of carbamazepine from form II to form III in 1-propanol. The polymorphic forms initially crystallized from solution, in the absence of seeds, could be clearly identified by FBRM and showed good agreement with results of microscopic images. Furthermore, the kinetics of the conversion of carbamazepine from metastable form to the stable form at different cooling rates could be readily followed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399705
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12530-12536[article] Combined application of in Situ FBRM, ATR-FTIR, and raman on polymorphism transformation monitoring during the cooling crystallization [texte imprimé] / Yingying Zhao, Auteur ; Junsheng Yuan, Auteur ; Zhiyong Ji, Auteur . - 2012 . - pp. 12530-12536.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12530-12536
Mots-clés : Crystallization Cooling Surveillance Polymorphism In situ Résumé : This study evaluates the potential use of the FBRM, ATR-FTIR, and Raman for on line detection of polymorphic transformation of carbamazepine (CBZ) during the cooling crystallization. Changes in solution concentration as a function of time were quantified from the ATR-FTIR data. A new quantitative method of polymorphs ratio was developed using Raman spectroscopy for in situ monitoring during a solution-mediated transformation of carbamazepine from form II to form III in 1-propanol. The polymorphic forms initially crystallized from solution, in the absence of seeds, could be clearly identified by FBRM and showed good agreement with results of microscopic images. Furthermore, the kinetics of the conversion of carbamazepine from metastable form to the stable form at different cooling rates could be readily followed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399705 Exemplaires
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Titre : Computational design of new refrigerant fluids based on environmental, safety, and thermodynamic characteristics Type de document : texte imprimé Auteurs : Andrei Kazakov, Auteur ; Mark O. McLinden, Auteur ; Michael Frenkel, Auteur Année de publication : 2012 Article en page(s) : pp. 12537-12548 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Safety Refrigerant fluid Design Résumé : We present a systematic search for new classes of refrigerants that would possess low values of global warming potential (GWP), along with low- to moderate flammability and suitable thermodynamic characteristics. We have developed new methods for estimating, solely from the molecular structure, the radiative efficiency (RE, a measure of radiative climate forcing) and atmospheric lifetime; the combination of RE and lifetime yields an estimate of the GWP. We also developed an estimate of the lower flammability limit (LFL) based on the enthalpy of formation. These estimation techniques, along with a previously developed technique for estimating critical temperature (Tc), are applied to a library of over 56000 candidate molecules. We select fluids with GWP 0.1 kg·m―3. Filters for toxicity and chemical stability based on functional groups are also applied to arrive at 1234 candidates for further study. The candidates that would be suitable for use in present types of refrigeration equipment (those having critical temperatures less than 400 K) are dominated by halogenated alkenes; additional chemical classes, including halogenated ethers and cyclic compounds, are identified among fluids with higher critical temperatures. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399706
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12537-12548[article] Computational design of new refrigerant fluids based on environmental, safety, and thermodynamic characteristics [texte imprimé] / Andrei Kazakov, Auteur ; Mark O. McLinden, Auteur ; Michael Frenkel, Auteur . - 2012 . - pp. 12537-12548.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12537-12548
Mots-clés : Safety Refrigerant fluid Design Résumé : We present a systematic search for new classes of refrigerants that would possess low values of global warming potential (GWP), along with low- to moderate flammability and suitable thermodynamic characteristics. We have developed new methods for estimating, solely from the molecular structure, the radiative efficiency (RE, a measure of radiative climate forcing) and atmospheric lifetime; the combination of RE and lifetime yields an estimate of the GWP. We also developed an estimate of the lower flammability limit (LFL) based on the enthalpy of formation. These estimation techniques, along with a previously developed technique for estimating critical temperature (Tc), are applied to a library of over 56000 candidate molecules. We select fluids with GWP 0.1 kg·m―3. Filters for toxicity and chemical stability based on functional groups are also applied to arrive at 1234 candidates for further study. The candidates that would be suitable for use in present types of refrigeration equipment (those having critical temperatures less than 400 K) are dominated by halogenated alkenes; additional chemical classes, including halogenated ethers and cyclic compounds, are identified among fluids with higher critical temperatures. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399706 Exemplaires
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Titre : Solubility of hydrogen sulfide in aqueous solutions of N-methyldiethanolamine and piperazine Type de document : texte imprimé Auteurs : Dirk Speyer, Auteur ; Arne Böttger, Auteur ; Maurer, Gerd, Auteur Année de publication : 2012 Article en page(s) : pp. 12549-12556 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aqueous solution Hydrogen sulfides Solubility Résumé : The solubility of hydrogen sulfide in an aqueous mixture of 2,2'-methyliminodiethanol (N-methyldiethanolamine, [CAS 105-59-9], MDEA) and 1,4-diazacyclohexane (piperazine, [CAS 110-85-0], PIPH2) was measured over a wide range of gas-loadings (stoichiometric molar ratios of hydrogen sulfide to (MDEA + PIPH2) between about 0.014 and 1.67) at three temperatures (about 313 K, 353 K, and 393 K) by headspace gas chromatography as well as by a synthetic gas solubility method. The molality of MDEA in the aqueous mixture was about 4.5 mol·(kg water)―1 and that of PIPH2 about 1.6 mol·(kg water)―1. The headspace gas chromatography technique was applied in the low pressure range (partial pressure of H2S between 0.64 and 125.7 kPa, stoichiometric molar ratio of H2S to (MDEA + PIPH2) between about 0.014 and 0.73). The synthetic method was applied in the high pressure range (total pressure between 0.2 and 5.5 MPa, stoichiometric molar ratio of H2S to (MDEA + PIPH2) between about about 0.51 and 1.67). The new experimental results are compared to prediction results from a thermodynamic model that was parametrized using only experimental results for the solubility of H2S data in the aqueous solution of the single amines in the high pressure range. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399707
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12549-12556[article] Solubility of hydrogen sulfide in aqueous solutions of N-methyldiethanolamine and piperazine [texte imprimé] / Dirk Speyer, Auteur ; Arne Böttger, Auteur ; Maurer, Gerd, Auteur . - 2012 . - pp. 12549-12556.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12549-12556
Mots-clés : Aqueous solution Hydrogen sulfides Solubility Résumé : The solubility of hydrogen sulfide in an aqueous mixture of 2,2'-methyliminodiethanol (N-methyldiethanolamine, [CAS 105-59-9], MDEA) and 1,4-diazacyclohexane (piperazine, [CAS 110-85-0], PIPH2) was measured over a wide range of gas-loadings (stoichiometric molar ratios of hydrogen sulfide to (MDEA + PIPH2) between about 0.014 and 1.67) at three temperatures (about 313 K, 353 K, and 393 K) by headspace gas chromatography as well as by a synthetic gas solubility method. The molality of MDEA in the aqueous mixture was about 4.5 mol·(kg water)―1 and that of PIPH2 about 1.6 mol·(kg water)―1. The headspace gas chromatography technique was applied in the low pressure range (partial pressure of H2S between 0.64 and 125.7 kPa, stoichiometric molar ratio of H2S to (MDEA + PIPH2) between about 0.014 and 0.73). The synthetic method was applied in the high pressure range (total pressure between 0.2 and 5.5 MPa, stoichiometric molar ratio of H2S to (MDEA + PIPH2) between about about 0.51 and 1.67). The new experimental results are compared to prediction results from a thermodynamic model that was parametrized using only experimental results for the solubility of H2S data in the aqueous solution of the single amines in the high pressure range. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26399707 Exemplaires
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