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Vol. 51 N° 13 - Avril 2012 [texte imprimé] . - 2012 . - p. 4769-5116 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierSystematic assessment of the influence of hydrogen peroxide dosage on caffeine degradation by the photo - fenton process / Evelyn Yamal-Turbay in Industrial & engineering chemistry research, Vol. 51 N° 13 (Avril 2012)
Titre : Systematic assessment of the influence of hydrogen peroxide dosage on caffeine degradation by the photo - fenton process Type de document : texte imprimé Auteurs : Evelyn Yamal-Turbay, Auteur ; Moisès Graells, Auteur ; Montserrat Pérez-Moya, Auteur Année de publication : 2012 Article en page(s) : pp. 4770–4778 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrogen peroxide Photo fnton process Résumé : Caffeine degradation performance via photo-Fenton treatment was investigated under different dosage conditions. Experiments were planned according to a design of experiments to characterize hydrogen peroxide dosage protocols. Fenton reagent loads were first determined after a preliminary study. The addition of a fixed hydrogen peroxide load was controlled by an initial load fraction and the span of the continuous flow producing the total load. The experiments were carried out using 12 L solution samples of commercial coffee (300 mg L–1, approximately 17 mg L–1 of caffeine). Hence, HPLC data revealed that all treatments completely removed caffeine from samples, while TOC monitoring revealed reductions of up to 70%. Using reaction conversion as a performance index, the methodological approach presented enabled a comparison of dosage protocols and determination of those producing enhanced results. For the particular case addressed, the operation scheme that most increased treatment performance produced a conversion which was 25% higher than that obtained without dosage. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202256k
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4770–4778[article] Systematic assessment of the influence of hydrogen peroxide dosage on caffeine degradation by the photo - fenton process [texte imprimé] / Evelyn Yamal-Turbay, Auteur ; Moisès Graells, Auteur ; Montserrat Pérez-Moya, Auteur . - 2012 . - pp. 4770–4778.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4770–4778
Mots-clés : Hydrogen peroxide Photo fnton process Résumé : Caffeine degradation performance via photo-Fenton treatment was investigated under different dosage conditions. Experiments were planned according to a design of experiments to characterize hydrogen peroxide dosage protocols. Fenton reagent loads were first determined after a preliminary study. The addition of a fixed hydrogen peroxide load was controlled by an initial load fraction and the span of the continuous flow producing the total load. The experiments were carried out using 12 L solution samples of commercial coffee (300 mg L–1, approximately 17 mg L–1 of caffeine). Hence, HPLC data revealed that all treatments completely removed caffeine from samples, while TOC monitoring revealed reductions of up to 70%. Using reaction conversion as a performance index, the methodological approach presented enabled a comparison of dosage protocols and determination of those producing enhanced results. For the particular case addressed, the operation scheme that most increased treatment performance produced a conversion which was 25% higher than that obtained without dosage. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202256k Exemplaires
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Titre : A preliminary study of the preparation of a KBr - doped ZnO nanoparticle and its photocatalytic performance on the removal of oil from oily sewage Type de document : texte imprimé Auteurs : Yanxiu Liu, Auteur ; Hua Song, Auteur ; Qiuhong Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 4779–4782 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photocatalytic Oily sewage Résumé : A novel photocatalytic composite material KBr-doped ZnO was prepared using the sol–gel method. The KBr-doped ZnO was characterized using powder X-ray diffraction (XRD) and BET surface area measurements. As-prepared KBr-doped ZnO exhibited higher photocatalytic activity when compared to the pure ZnO on the removal of oil from oily sewage with a 300W UV lamp as lighting source. Experiments indicated that parameters such as calcining temperature, KBr doping amounts, dosages of catalyst, and pH value have great influence in the photocatalysis reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202313w
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4779–4782[article] A preliminary study of the preparation of a KBr - doped ZnO nanoparticle and its photocatalytic performance on the removal of oil from oily sewage [texte imprimé] / Yanxiu Liu, Auteur ; Hua Song, Auteur ; Qiuhong Zhang, Auteur . - 2012 . - pp. 4779–4782.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4779–4782
Mots-clés : Photocatalytic Oily sewage Résumé : A novel photocatalytic composite material KBr-doped ZnO was prepared using the sol–gel method. The KBr-doped ZnO was characterized using powder X-ray diffraction (XRD) and BET surface area measurements. As-prepared KBr-doped ZnO exhibited higher photocatalytic activity when compared to the pure ZnO on the removal of oil from oily sewage with a 300W UV lamp as lighting source. Experiments indicated that parameters such as calcining temperature, KBr doping amounts, dosages of catalyst, and pH value have great influence in the photocatalysis reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202313w Exemplaires
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Titre : Thermodynamics of phase and chemical equilibrium in the processes of biodiesel fuel synthesis in subcritical and supercritical methanol Type de document : texte imprimé Auteurs : Vladimir Anikeev, Auteur ; Denis Stepanov, Auteur ; Anna Yermakova, Auteur Année de publication : 2012 Article en page(s) : pp. 4783–4796 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamic Chemical Equilibrium Methanol Résumé : Thermodynamic data (critical parameters, enthalpy, entropy) were calculated for the monoglycerides, diglycerides, and triglycerides of fatty acids (palmitic, oleic and linoleic), free fatty acids, and methyl esters of fatty acids, which are involved in the transesterification of vegetable oils with lower alcohols. Phase diagrams of the reaction mixtures were calculated and reaction conditions providing supercritical state of the reaction mixture were selected for transesterification of triglycerides in various lower alcohols. Chemical equilibrium of the methanol transesterification of simple and mixed fatty acid triglycerides was studied in a wide range of temperatures, pressures, and ratios of initial components, including the region of supercritical state of the reaction mixture. Calculation of the phase equilibrium and equilibrium composition of the reaction products obtained by transesterification of triglycerides with lower alcohols allowed choosing the optimal reaction conditions for practical application. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202379u
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4783–4796[article] Thermodynamics of phase and chemical equilibrium in the processes of biodiesel fuel synthesis in subcritical and supercritical methanol [texte imprimé] / Vladimir Anikeev, Auteur ; Denis Stepanov, Auteur ; Anna Yermakova, Auteur . - 2012 . - pp. 4783–4796.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4783–4796
Mots-clés : Thermodynamic Chemical Equilibrium Methanol Résumé : Thermodynamic data (critical parameters, enthalpy, entropy) were calculated for the monoglycerides, diglycerides, and triglycerides of fatty acids (palmitic, oleic and linoleic), free fatty acids, and methyl esters of fatty acids, which are involved in the transesterification of vegetable oils with lower alcohols. Phase diagrams of the reaction mixtures were calculated and reaction conditions providing supercritical state of the reaction mixture were selected for transesterification of triglycerides in various lower alcohols. Chemical equilibrium of the methanol transesterification of simple and mixed fatty acid triglycerides was studied in a wide range of temperatures, pressures, and ratios of initial components, including the region of supercritical state of the reaction mixture. Calculation of the phase equilibrium and equilibrium composition of the reaction products obtained by transesterification of triglycerides with lower alcohols allowed choosing the optimal reaction conditions for practical application. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202379u Exemplaires
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Titre : Synthesis, characterization, and thermodynamic properties of the rare earth coordination complex [Sm(C6H4NO2)2·C9H6NO] Type de document : texte imprimé Auteurs : Hui-Wen Gu, Auteur ; Sheng-Xiong Xiao, Auteur ; Hang-Ying Xiao, Auteur Année de publication : 2012 Article en page(s) : pp. 4797–4803 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamic properties Résumé : This article reports the synthesis and thermodynamic properties of a novel rare earth coordination complex, samarium chloride hexahydrate (SmCl3·6H2O) with nicotinic acid (C6H5NO2) and 8-hydroxylquinoline (C9H7NO), whose composition and structure were characterized by elemental analysis, molar conductance, thermogravimetric analysis (TG–DTG), UV spectroscopy, IR spectroscopy, and X-ray powder diffraction. During the process of coordination, C6H5NO2 was bidentate-coordinated with the rare earth ion (Sm3+) through an acidic group that was formed by removing the proton; the hydroxyl oxygen atom and heterocyclic nitrogen atom of C9H6NO– formed a chelate ring with Sm3+ for coordination. The X-ray powder diffraction pattern demonstrated that the crystal type of [Sm(C6H4NO2)2·C9H6NO] is similar to that of C5H11NO2, with the cell parameters a = 5.426 nm, b = 22.105 nm, and c = 5.277 nm. At a constant temperature of 298.15 K, the dissolution enthalpies of the reactants and products of the coordination reaction in the optimized calorimetric solvent were determined with an advanced solution–reaction isoperibol microcalorimeter. The standard molar enthalpy change of the coordination reaction was determined to be ΔrHmΘ = (167.49 ± 0.39) kJ·mol–1. The standard molar enthalpy of formation of the title complex, [Sm(C6H4NO2)2·C9H6NO], was estimated to be ΔfHmΘ[Sm(C6H4NO2)2·C9H6NO(s), 298.15 K] = −(1483.4 ± 2.4) kJ·mol–1, from a combination of the experimental values of enthalpies of dissolution and some other auxiliary thermodynamic data through a designed thermochemical cycle based on a supposed chemical reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202891s
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4797–4803[article] Synthesis, characterization, and thermodynamic properties of the rare earth coordination complex [Sm(C6H4NO2)2·C9H6NO] [texte imprimé] / Hui-Wen Gu, Auteur ; Sheng-Xiong Xiao, Auteur ; Hang-Ying Xiao, Auteur . - 2012 . - pp. 4797–4803.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4797–4803
Mots-clés : Thermodynamic properties Résumé : This article reports the synthesis and thermodynamic properties of a novel rare earth coordination complex, samarium chloride hexahydrate (SmCl3·6H2O) with nicotinic acid (C6H5NO2) and 8-hydroxylquinoline (C9H7NO), whose composition and structure were characterized by elemental analysis, molar conductance, thermogravimetric analysis (TG–DTG), UV spectroscopy, IR spectroscopy, and X-ray powder diffraction. During the process of coordination, C6H5NO2 was bidentate-coordinated with the rare earth ion (Sm3+) through an acidic group that was formed by removing the proton; the hydroxyl oxygen atom and heterocyclic nitrogen atom of C9H6NO– formed a chelate ring with Sm3+ for coordination. The X-ray powder diffraction pattern demonstrated that the crystal type of [Sm(C6H4NO2)2·C9H6NO] is similar to that of C5H11NO2, with the cell parameters a = 5.426 nm, b = 22.105 nm, and c = 5.277 nm. At a constant temperature of 298.15 K, the dissolution enthalpies of the reactants and products of the coordination reaction in the optimized calorimetric solvent were determined with an advanced solution–reaction isoperibol microcalorimeter. The standard molar enthalpy change of the coordination reaction was determined to be ΔrHmΘ = (167.49 ± 0.39) kJ·mol–1. The standard molar enthalpy of formation of the title complex, [Sm(C6H4NO2)2·C9H6NO], was estimated to be ΔfHmΘ[Sm(C6H4NO2)2·C9H6NO(s), 298.15 K] = −(1483.4 ± 2.4) kJ·mol–1, from a combination of the experimental values of enthalpies of dissolution and some other auxiliary thermodynamic data through a designed thermochemical cycle based on a supposed chemical reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202891s Exemplaires
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Titre : Kinetic study on the selective production of 2 - (Hydroxybenzyl) - 4 - methylphenol from organosolv lignin in a mixture of supercritical water and p - cresol Type de document : texte imprimé Auteurs : Seiichi Takami, Auteur ; Kazuhide Okuda, Auteur ; Xin Man, Auteur Année de publication : 2012 Article en page(s) : pp. 4804–4808 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetic Organosolv lignin Résumé : We have realized chemical recovery of a phenolic compound, 2-(hydroxy-benzyl)-4-methyl-phenol (BMP), from organosolv lignin without forming char in a mixture of supercritical water and p-cresol (Okuda, K.; et al. J. Phys.: Condens. Matter2004, 16, S1325). In this paper, we evaluated the reaction rate constants of the depolymerization process of organosolv lignin using Monte Carlo simulation. We also evaluated the formation and decomposition rate of BMP based on the proposed reaction scheme. The obtained reaction rate constants gave insight into the mechanism why the mixture of supercritical water and p-cresol suppressed the formation of char. They also suggested the reaction path for the formation of BMP. In addition, these reaction rate constants enable the design and optimization of the chemical recovery processes to realize the highest yield. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200211n
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4804–4808[article] Kinetic study on the selective production of 2 - (Hydroxybenzyl) - 4 - methylphenol from organosolv lignin in a mixture of supercritical water and p - cresol [texte imprimé] / Seiichi Takami, Auteur ; Kazuhide Okuda, Auteur ; Xin Man, Auteur . - 2012 . - pp. 4804–4808.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4804–4808
Mots-clés : Kinetic Organosolv lignin Résumé : We have realized chemical recovery of a phenolic compound, 2-(hydroxy-benzyl)-4-methyl-phenol (BMP), from organosolv lignin without forming char in a mixture of supercritical water and p-cresol (Okuda, K.; et al. J. Phys.: Condens. Matter2004, 16, S1325). In this paper, we evaluated the reaction rate constants of the depolymerization process of organosolv lignin using Monte Carlo simulation. We also evaluated the formation and decomposition rate of BMP based on the proposed reaction scheme. The obtained reaction rate constants gave insight into the mechanism why the mixture of supercritical water and p-cresol suppressed the formation of char. They also suggested the reaction path for the formation of BMP. In addition, these reaction rate constants enable the design and optimization of the chemical recovery processes to realize the highest yield. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200211n Exemplaires
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Titre : Thermal effects in the absorption of pure CO2 into aqueous solutions of 2 - Methyl - amino - ethanol Type de document : texte imprimé Auteurs : Rafael Pacheco, Auteur ; Antonio Sanchez, Auteur ; Maria Dolores La Rubia, Auteur Année de publication : 2012 Article en page(s) : pp. 4809–4818 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Absorption Aqueous solutions Résumé : The process of pure CO2 absorption by aqueous solutions of 2-methyl-amino-ethanol (MAE) has been studied in relation to the thermal effects of the operation. This study evaluates the consequences of heat effects during absorption and chemical reaction. The experiments were performed in a stirred tank reactor operated in batches with respect to the gas–liquid phases, having a plane interfacial area. The working variables considered were the alkanolamine concentration within the interval 0.1–2.0 kmol/m3 and the temperature in the range 288–313 K. From the results, it is deduced that the CO2 absorption at high pressures in aqueous MAE solutions, occur in the instantaneous reaction regime with high interface temperature. An expression is proposed to relate the experimental results to the initial concentration of alkanolamine and at the same time enable the determination of the interfacial temperature (Ts). In relation to temperature in the bulk liquid phase (TB), increases (Ts – TB) close to 43 K were determined in the experiments performed at high concentrations and in the highest temperature series. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201035y
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4809–4818[article] Thermal effects in the absorption of pure CO2 into aqueous solutions of 2 - Methyl - amino - ethanol [texte imprimé] / Rafael Pacheco, Auteur ; Antonio Sanchez, Auteur ; Maria Dolores La Rubia, Auteur . - 2012 . - pp. 4809–4818.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4809–4818
Mots-clés : Absorption Aqueous solutions Résumé : The process of pure CO2 absorption by aqueous solutions of 2-methyl-amino-ethanol (MAE) has been studied in relation to the thermal effects of the operation. This study evaluates the consequences of heat effects during absorption and chemical reaction. The experiments were performed in a stirred tank reactor operated in batches with respect to the gas–liquid phases, having a plane interfacial area. The working variables considered were the alkanolamine concentration within the interval 0.1–2.0 kmol/m3 and the temperature in the range 288–313 K. From the results, it is deduced that the CO2 absorption at high pressures in aqueous MAE solutions, occur in the instantaneous reaction regime with high interface temperature. An expression is proposed to relate the experimental results to the initial concentration of alkanolamine and at the same time enable the determination of the interfacial temperature (Ts). In relation to temperature in the bulk liquid phase (TB), increases (Ts – TB) close to 43 K were determined in the experiments performed at high concentrations and in the highest temperature series. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201035y Exemplaires
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Titre : Kinetics and mechanistic investigation of decarboxylation for the oxidation of levofloxacin by chloroamine - T in acidic medium Type de document : texte imprimé Auteurs : Aftab Aslam Parwaz Khan, Auteur ; Abdullah M. Asiri, Auteur ; Naved Azum, Auteur Année de publication : 2012 Article en page(s) : pp. 4819–4824 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetics Decarboxylation Résumé : The mechanistic investigation of oxidation of levofloxacin (LF) has been studied by chloramine-T(CAT) in aqueous perchloric acid medium at 25 °C. The reaction followed first-order kinetics with respect to [CAT], [LF], and [H+] in their lower concentrations range, tending to zero-order at their higher concentrations. First-order kinetics with respect to [CAT] was observed for the oxidation of levofloxacin. An increase in perchloric acid concentration increased the rate of reaction. The effect of added products, ionic strength, and dielectric constant of the medium was studied on the rate of reaction. The main products were identified by spot test, FT-IR, and NMR. A mechanism was proposed on the basis of experimental results. The activation parameters with respect to the slow step of the mechanism was evaluated, and the thermodynamic parameters were also determined and discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202483c
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4819–4824[article] Kinetics and mechanistic investigation of decarboxylation for the oxidation of levofloxacin by chloroamine - T in acidic medium [texte imprimé] / Aftab Aslam Parwaz Khan, Auteur ; Abdullah M. Asiri, Auteur ; Naved Azum, Auteur . - 2012 . - pp. 4819–4824.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4819–4824
Mots-clés : Kinetics Decarboxylation Résumé : The mechanistic investigation of oxidation of levofloxacin (LF) has been studied by chloramine-T(CAT) in aqueous perchloric acid medium at 25 °C. The reaction followed first-order kinetics with respect to [CAT], [LF], and [H+] in their lower concentrations range, tending to zero-order at their higher concentrations. First-order kinetics with respect to [CAT] was observed for the oxidation of levofloxacin. An increase in perchloric acid concentration increased the rate of reaction. The effect of added products, ionic strength, and dielectric constant of the medium was studied on the rate of reaction. The main products were identified by spot test, FT-IR, and NMR. A mechanism was proposed on the basis of experimental results. The activation parameters with respect to the slow step of the mechanism was evaluated, and the thermodynamic parameters were also determined and discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202483c Exemplaires
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Titre : Kinetic and equilibrium profiles of adsorptive recovery of thorium (IV) from aqueous solutions using poly (methacrylic acid) grafted cellulose / bentonite superabsorbent composite Type de document : texte imprimé Auteurs : T. S. Anirudhan, Auteur ; Padmajan S. Suchithra, Auteur ; P. Senan, Auteur Année de publication : 2012 Article en page(s) : pp. 4825–4836 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetic Aqueous solutions Résumé : The removal and recovery of thorium(IV) [Th(IV)] ions from aqueous solutions were investigated using poly(methacrylic acid)-grafted-cellulose/bentonite (PMAA-g-Cell/Bent) superabsorbent composite through batch adsorption experiments. Surface characterizations of the adsorbent were investigated. The adsorbent showed significant Th(IV) removal (>99.7%) at pH 5.0. The influence of coexisting ions on the adsorption of Th(IV) was studied. Mass transfer aspects of Th(IV) adsorption onto PMAA-g-Cell/Bent were evaluated. The Sips adsorption isotherm described the adsorption data very well, with a maximum adsorption capacity of 188.1 mg/g. Thermodynamic parameters such as standard enthalpy (ΔH°), standard entropy (ΔS°), standard free energy (ΔG°), activation energy (Ea), isosteric enthalpy (ΔHx), and entropy (ΔSx) were calculated. Tests with a seawater sample revealed the effectiveness of PMAA-g-Cell/Bent for adsorptive removal of Th(IV) from aqueous solutions. Desorption experiments showed that 0.1 M HNO3 can effectively desorb adsorbed thorium ions with a contact time of 3 h. A single stage batch reactor is designed for commercial applicability of the adsorbent. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202538q
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4825–4836[article] Kinetic and equilibrium profiles of adsorptive recovery of thorium (IV) from aqueous solutions using poly (methacrylic acid) grafted cellulose / bentonite superabsorbent composite [texte imprimé] / T. S. Anirudhan, Auteur ; Padmajan S. Suchithra, Auteur ; P. Senan, Auteur . - 2012 . - pp. 4825–4836.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4825–4836
Mots-clés : Kinetic Aqueous solutions Résumé : The removal and recovery of thorium(IV) [Th(IV)] ions from aqueous solutions were investigated using poly(methacrylic acid)-grafted-cellulose/bentonite (PMAA-g-Cell/Bent) superabsorbent composite through batch adsorption experiments. Surface characterizations of the adsorbent were investigated. The adsorbent showed significant Th(IV) removal (>99.7%) at pH 5.0. The influence of coexisting ions on the adsorption of Th(IV) was studied. Mass transfer aspects of Th(IV) adsorption onto PMAA-g-Cell/Bent were evaluated. The Sips adsorption isotherm described the adsorption data very well, with a maximum adsorption capacity of 188.1 mg/g. Thermodynamic parameters such as standard enthalpy (ΔH°), standard entropy (ΔS°), standard free energy (ΔG°), activation energy (Ea), isosteric enthalpy (ΔHx), and entropy (ΔSx) were calculated. Tests with a seawater sample revealed the effectiveness of PMAA-g-Cell/Bent for adsorptive removal of Th(IV) from aqueous solutions. Desorption experiments showed that 0.1 M HNO3 can effectively desorb adsorbed thorium ions with a contact time of 3 h. A single stage batch reactor is designed for commercial applicability of the adsorbent. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202538q Exemplaires
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Titre : Synthesis of lactide from alkyl lactate via a prepolymer route Type de document : texte imprimé Auteurs : Pravin P. Upare, Auteur ; Young Kyu Hwang, Auteur ; Jong-San Chang, Auteur Année de publication : 2012 Article en page(s) : pp. 4837–4842 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Lactic acid Prepolymer Résumé : Poly(lactic acid) is a biodegradable polymer that has enormous potential for use as a replacement for some petroleum-based materials. However, the properties of this polymer depend strongly on the quality of the lactide monomer from which it is often synthesized. In this work, lactide was synthesized from alkyl lactate via a prepolymer route, and the reaction kinetics was compared with lactide synthesis from lactic acid. A number of different parameters were investigated in order to obtain the highest possible yield of lactide, as well as to achieve l-isomer selectivity. Among the various acid catalysts tested, Sn(Oct)2 was found to be the most effective for L-lactide selectivity as well as for producing a high oligomer yield from the alkyl lactate. The effect of the alkyl group length of the starting materials was investigated with the highest lactide yield being obtained from ethyl lactate, over methyl and butyl lactate. The deoligomerization reaction was also studied in detail. It was found that an oligomer with a molecular weight of 600–800 g/mol gave the highest lactide yield. The optimum depolymerization temperature for the oligomer with a molecular weight of 1274 g/mol was shown to be 180 °C, as above this temperature, the reaction rate of oligomerization for heavy residue was much faster than that of deoligomerization for crude lactide, which resulted in a lower lactide yield. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202714n
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4837–4842[article] Synthesis of lactide from alkyl lactate via a prepolymer route [texte imprimé] / Pravin P. Upare, Auteur ; Young Kyu Hwang, Auteur ; Jong-San Chang, Auteur . - 2012 . - pp. 4837–4842.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4837–4842
Mots-clés : Lactic acid Prepolymer Résumé : Poly(lactic acid) is a biodegradable polymer that has enormous potential for use as a replacement for some petroleum-based materials. However, the properties of this polymer depend strongly on the quality of the lactide monomer from which it is often synthesized. In this work, lactide was synthesized from alkyl lactate via a prepolymer route, and the reaction kinetics was compared with lactide synthesis from lactic acid. A number of different parameters were investigated in order to obtain the highest possible yield of lactide, as well as to achieve l-isomer selectivity. Among the various acid catalysts tested, Sn(Oct)2 was found to be the most effective for L-lactide selectivity as well as for producing a high oligomer yield from the alkyl lactate. The effect of the alkyl group length of the starting materials was investigated with the highest lactide yield being obtained from ethyl lactate, over methyl and butyl lactate. The deoligomerization reaction was also studied in detail. It was found that an oligomer with a molecular weight of 600–800 g/mol gave the highest lactide yield. The optimum depolymerization temperature for the oligomer with a molecular weight of 1274 g/mol was shown to be 180 °C, as above this temperature, the reaction rate of oligomerization for heavy residue was much faster than that of deoligomerization for crude lactide, which resulted in a lower lactide yield. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202714n Exemplaires
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Titre : Response Surface Modeling and Optimization of CO Hydrogenation for Higher Liquid Hydrocarbon Using Cu–Co–Cr + ZSM-5 Bifunctional Catalyst Type de document : texte imprimé Auteurs : Pravakar Mohanty, Auteur ; Sachchit Majhi, Auteur ; J.N. Sahu, Auteur Année de publication : 2012 Article en page(s) : pp. 4843–4853 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization Hydrogenation Hydrocarbon Résumé : This paper represents an extensive statistical analysis of the combined effects of operating variables (temperature, pressure, reaction time, and H2/CO flow rate) toward CO-hydrogenation for liquid hydrocarbon which was performed in a fixed bed benchtop reactor system, by means of response surface methodology (RSM). The application of RSM in conjunction with a central composite rotatable design (CCRD) was used for modeling and optimizing the performance of a multivariable FT-synthesis process using bifunctional CuO–CoO–Cr2O3 + ZSM-5 catalyst. The CuO–CoO–Cr2O3 catalyst was synthesized by a coprecipitation method, and its physiochemical characterization was done by using Brunauer–Emmett–Teller, temperature-programmed reduction, thermogravimetric analysis, X-ray diffraction, and transmission electron mocroscopy techniques. Through this work a 50 full factorial (CCRD) experimental design was employed. Maximum CO conversion was predicted and experimentally validated to determine optimum conditions that allow improvement of the performance of the catalyst for a long run time of 120 h. The optimum values of CO conversion, temperature, pressure, and (H2/CO) molar ratio were found to be 64.3%, 310 ± 4 °C, 33–36 bar, and 1.0, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202866q
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4843–4853[article] Response Surface Modeling and Optimization of CO Hydrogenation for Higher Liquid Hydrocarbon Using Cu–Co–Cr + ZSM-5 Bifunctional Catalyst [texte imprimé] / Pravakar Mohanty, Auteur ; Sachchit Majhi, Auteur ; J.N. Sahu, Auteur . - 2012 . - pp. 4843–4853.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4843–4853
Mots-clés : Optimization Hydrogenation Hydrocarbon Résumé : This paper represents an extensive statistical analysis of the combined effects of operating variables (temperature, pressure, reaction time, and H2/CO flow rate) toward CO-hydrogenation for liquid hydrocarbon which was performed in a fixed bed benchtop reactor system, by means of response surface methodology (RSM). The application of RSM in conjunction with a central composite rotatable design (CCRD) was used for modeling and optimizing the performance of a multivariable FT-synthesis process using bifunctional CuO–CoO–Cr2O3 + ZSM-5 catalyst. The CuO–CoO–Cr2O3 catalyst was synthesized by a coprecipitation method, and its physiochemical characterization was done by using Brunauer–Emmett–Teller, temperature-programmed reduction, thermogravimetric analysis, X-ray diffraction, and transmission electron mocroscopy techniques. Through this work a 50 full factorial (CCRD) experimental design was employed. Maximum CO conversion was predicted and experimentally validated to determine optimum conditions that allow improvement of the performance of the catalyst for a long run time of 120 h. The optimum values of CO conversion, temperature, pressure, and (H2/CO) molar ratio were found to be 64.3%, 310 ± 4 °C, 33–36 bar, and 1.0, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202866q Exemplaires
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Titre : Kinetic modeling of nitrate reduction catalyzed by Pd – Cu supported on carbon nanotubes Type de document : texte imprimé Auteurs : Olivia Salomé G. P. Soares, Auteur ; Xiaolei Fan, Auteur ; José J. M. Orfao, Auteur Année de publication : 2012 Article en page(s) : pp. 4854–4860 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalysts Liquid phase Nanotubes Résumé : New catalysts for liquid phase nitrate reduction were recently synthesized using multiwalled carbon nanotubes as a support. The most promising catalyst (1%Pd–1%Cu/CNT) was used in this kinetic study. The catalyst experimentally showed high selectivity to nitrogen, between 80 and 89%. A mechanistic model was applied to experimental data to show that the reason for high selectivity is due to the enhanced mass transfer near the catalyst surface promoted by the use of a structured support. The experimental selectivity is close to the maximum selectivity predicted for this catalytic system at the best operating conditions and in the absence of any mass transfer limitations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202957v
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4854–4860[article] Kinetic modeling of nitrate reduction catalyzed by Pd – Cu supported on carbon nanotubes [texte imprimé] / Olivia Salomé G. P. Soares, Auteur ; Xiaolei Fan, Auteur ; José J. M. Orfao, Auteur . - 2012 . - pp. 4854–4860.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4854–4860
Mots-clés : Catalysts Liquid phase Nanotubes Résumé : New catalysts for liquid phase nitrate reduction were recently synthesized using multiwalled carbon nanotubes as a support. The most promising catalyst (1%Pd–1%Cu/CNT) was used in this kinetic study. The catalyst experimentally showed high selectivity to nitrogen, between 80 and 89%. A mechanistic model was applied to experimental data to show that the reason for high selectivity is due to the enhanced mass transfer near the catalyst surface promoted by the use of a structured support. The experimental selectivity is close to the maximum selectivity predicted for this catalytic system at the best operating conditions and in the absence of any mass transfer limitations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202957v Exemplaires
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Titre : Heterogeneous catalytic generation of hydrogen from formic acid under pressurized aqueous conditions Type de document : texte imprimé Auteurs : Siu-Wa Ting, Auteur ; Chaoquan Hu, Auteur ; Jayasree K. Pulleri, Auteur Année de publication : 2012 Article en page(s) : pp. 4861–4867 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst hydrogen Aqueous solution Résumé : PtRuBiOx/C catalyst has shown the promise for catalyzing CO-free hydrogen generation from formic acid in aqueous solution at room temperature and atmospheric pressure. In order to produce hydrogen at moderate-pressure to feed into a fuel cell stack, postgeneration compression is needed to overcome the flow resistance. In the present study, liquid formic acid decomposition over the PtRuBiOx/C catalyst was investigated at temperatures ranging from 80 to 140 °C and pressure up to 350 psi. It was found that the selectivity of the catalyst for formic acid decomposition remained almost 100%, and a complete conversion of formic acid could be achieved in several hours, which is significantly shorter than that at ambient conditions. The overall activation energy was also found to be 78 kJ·mol–1 under present conditions. The increase from the previously determined value of 37 kJ/mol at open atmosphere pressure was due to carbon dioxide release beyond saturation at elevated pressures. Furthermore, the stability of the catalyst was confirmed by performing a series of repeated runs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2030079
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4861–4867[article] Heterogeneous catalytic generation of hydrogen from formic acid under pressurized aqueous conditions [texte imprimé] / Siu-Wa Ting, Auteur ; Chaoquan Hu, Auteur ; Jayasree K. Pulleri, Auteur . - 2012 . - pp. 4861–4867.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4861–4867
Mots-clés : Catalyst hydrogen Aqueous solution Résumé : PtRuBiOx/C catalyst has shown the promise for catalyzing CO-free hydrogen generation from formic acid in aqueous solution at room temperature and atmospheric pressure. In order to produce hydrogen at moderate-pressure to feed into a fuel cell stack, postgeneration compression is needed to overcome the flow resistance. In the present study, liquid formic acid decomposition over the PtRuBiOx/C catalyst was investigated at temperatures ranging from 80 to 140 °C and pressure up to 350 psi. It was found that the selectivity of the catalyst for formic acid decomposition remained almost 100%, and a complete conversion of formic acid could be achieved in several hours, which is significantly shorter than that at ambient conditions. The overall activation energy was also found to be 78 kJ·mol–1 under present conditions. The increase from the previously determined value of 37 kJ/mol at open atmosphere pressure was due to carbon dioxide release beyond saturation at elevated pressures. Furthermore, the stability of the catalyst was confirmed by performing a series of repeated runs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2030079 Exemplaires
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Titre : Catalytic oxidative desulfurization of fuel by H2O2 in situ produced via oxidation of 2 - propanol Type de document : texte imprimé Auteurs : Hong - Xing Zhang, Auteur ; Jia-jun Gao, Auteur ; Hong Meng, Auteur Année de publication : 2012 Article en page(s) : pp. 4868–4874 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalytic oxidative Résumé : A novel integrated process is proposed for the catalytic oxidative desulfurization of fuel oil, in which the oxidant H2O2 is in situ generated by oxidizing 2-propanol with oxygen, and its feasibility is evaluated in terms of the S-conversion of 3-methylthiophene (3-MT), benzothiophene (BT), and dibenzothiophene (DBT) in octane under varying conditions. The catalysis of [π-C5H5NC16H33]3[PW4O16] is found to be much superior to H3PW12O40 and [(C4H9)4N]3[PW12O40] due to its good dispersivity in oil and adsorptivity for S-compounds. Some influencing factors for the S-conversion were studied, viz., time, temperature, various S-compounds, and the amount of 2-propanol, initiator, oxygen, and catalyst. All factors that favor the production of the 2-propanol radicals affect the desulfurization rate remarkably. Both BT and DBT can be removed efficiently at mild conditions (1.4 MPa O2, 90 °C) in 6 h with S-conversion above 96%, and the resulting sulfones can be separated via settling or filtration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300035c
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4868–4874[article] Catalytic oxidative desulfurization of fuel by H2O2 in situ produced via oxidation of 2 - propanol [texte imprimé] / Hong - Xing Zhang, Auteur ; Jia-jun Gao, Auteur ; Hong Meng, Auteur . - 2012 . - pp. 4868–4874.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4868–4874
Mots-clés : Catalytic oxidative Résumé : A novel integrated process is proposed for the catalytic oxidative desulfurization of fuel oil, in which the oxidant H2O2 is in situ generated by oxidizing 2-propanol with oxygen, and its feasibility is evaluated in terms of the S-conversion of 3-methylthiophene (3-MT), benzothiophene (BT), and dibenzothiophene (DBT) in octane under varying conditions. The catalysis of [π-C5H5NC16H33]3[PW4O16] is found to be much superior to H3PW12O40 and [(C4H9)4N]3[PW12O40] due to its good dispersivity in oil and adsorptivity for S-compounds. Some influencing factors for the S-conversion were studied, viz., time, temperature, various S-compounds, and the amount of 2-propanol, initiator, oxygen, and catalyst. All factors that favor the production of the 2-propanol radicals affect the desulfurization rate remarkably. Both BT and DBT can be removed efficiently at mild conditions (1.4 MPa O2, 90 °C) in 6 h with S-conversion above 96%, and the resulting sulfones can be separated via settling or filtration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300035c Exemplaires
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Titre : Enhanced investigation of CO methanation over Ni/Al2O3 catalysts for synthetic natural gas production Type de document : texte imprimé Auteurs : Dacheng Hu, Auteur ; Jiajian Gao, Auteur ; Yuan Ping, Auteur Année de publication : 2012 Article en page(s) : pp. 4875–4886 Note générale : Chimie indutsrielle Langues : Anglais (eng) Mots-clés : Natural gas Résumé : CO methanation reaction over the Ni/Al2O3 catalysts for synthetic natural gas production was systematically investigated by tuning a number of parameters, including using different commercial Al2O3 supports and varying NiO and MgO loading, calcination temperature, space velocity, H2/CO ratio, reaction pressure, and time, respectively. The catalytic performance was greatly influenced by the above-mentioned parameters. Briefly, a large surface area of the Al2O3 support, a moderate interaction between Ni and the support Al2O3, a proper Ni content (20 wt %), and a relatively low calcination temperature (400 °C) promoted the formation of small NiO particles and reducible β-type NiO species, which led to high catalytic activities and strong resistance to the carbon deposition, while addition of a small amount of MgO (2 wt %) could improve the catalyst stability by reducing the carbon deposition; other optimized conditions that enhanced the catalytic performance included high reaction pressure (3.0 MPa), high H2/CO ratio (≥3:1), low space velocity, and addition of quartz sand as the diluting agent in catalyst bed. The best catalyst combination was 20–40 wt % of NiO supported on a commercial Al2O3 (S4) with addition of 2–4 wt % of MgO, calcined at 400–500 °C and run at a reaction pressure of 3.0 MPa. On this catalyst, 100% of CO conversion could be achieved within a wide range of reaction temperature (300–550 °C), and the CH4 selectivity increased with increasing temperature and reached 96.5% at a relatively low temperature of 350 °C. These results will be very helpful to develop highly efficient Ni-based catalysts for the methanation reaction, to optimize the reaction process, and to better understand the above reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300049f
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4875–4886[article] Enhanced investigation of CO methanation over Ni/Al2O3 catalysts for synthetic natural gas production [texte imprimé] / Dacheng Hu, Auteur ; Jiajian Gao, Auteur ; Yuan Ping, Auteur . - 2012 . - pp. 4875–4886.
Chimie indutsrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4875–4886
Mots-clés : Natural gas Résumé : CO methanation reaction over the Ni/Al2O3 catalysts for synthetic natural gas production was systematically investigated by tuning a number of parameters, including using different commercial Al2O3 supports and varying NiO and MgO loading, calcination temperature, space velocity, H2/CO ratio, reaction pressure, and time, respectively. The catalytic performance was greatly influenced by the above-mentioned parameters. Briefly, a large surface area of the Al2O3 support, a moderate interaction between Ni and the support Al2O3, a proper Ni content (20 wt %), and a relatively low calcination temperature (400 °C) promoted the formation of small NiO particles and reducible β-type NiO species, which led to high catalytic activities and strong resistance to the carbon deposition, while addition of a small amount of MgO (2 wt %) could improve the catalyst stability by reducing the carbon deposition; other optimized conditions that enhanced the catalytic performance included high reaction pressure (3.0 MPa), high H2/CO ratio (≥3:1), low space velocity, and addition of quartz sand as the diluting agent in catalyst bed. The best catalyst combination was 20–40 wt % of NiO supported on a commercial Al2O3 (S4) with addition of 2–4 wt % of MgO, calcined at 400–500 °C and run at a reaction pressure of 3.0 MPa. On this catalyst, 100% of CO conversion could be achieved within a wide range of reaction temperature (300–550 °C), and the CH4 selectivity increased with increasing temperature and reached 96.5% at a relatively low temperature of 350 °C. These results will be very helpful to develop highly efficient Ni-based catalysts for the methanation reaction, to optimize the reaction process, and to better understand the above reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300049f Exemplaires
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Titre : Efficient Degradation of an antibiotic norfloxacin in aqueous solution via a simulated solar - light - mediated Bi2WO6 process Type de document : texte imprimé Auteurs : Meijuan Chen, Auteur ; Wei Chu, Auteur Année de publication : 2012 Article en page(s) : pp. 4887–4893 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Adsorption Norfloxacin Aqueous solution Résumé : A simulated solar-light-mediated bismuth tungstate process (SSL/Bi2WO6) was employed to degrade norfloxacin photocatalytically. The effects of environmental parameters, including catalyst dosage, probe concentration, and solution pH, on the process performance were investigated systematically. Under weak alkaline conditions, an optimal decay performance that can be attributed to the beneficial effect of hydroxyl ions was obtained. The reaction rationale and related constants were determined by the Langmuir–Hinshelwood (LH) model, combined with the experimental results. Our results showed that the adsorption of norfloxacin onto Bi2WO6 benefited the SSL/Bi2WO6 process, and the Bi2WO6 maximum adsorption capacity was 3.20× 10–3 mmol/g. In the SSL/Bi2WO6 process, the degradation of norfloxacin was accompanied by the decomposition of germicidal group and benzene ring, as well as gradual generation of inorganic ions of NH4+ and F–. Furthermore, the toxicity of initial norfloxacin solution was efficiently eliminated by this SSL/Bi2WO6 process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300146h
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4887–4893[article] Efficient Degradation of an antibiotic norfloxacin in aqueous solution via a simulated solar - light - mediated Bi2WO6 process [texte imprimé] / Meijuan Chen, Auteur ; Wei Chu, Auteur . - 2012 . - pp. 4887–4893.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4887–4893
Mots-clés : Adsorption Norfloxacin Aqueous solution Résumé : A simulated solar-light-mediated bismuth tungstate process (SSL/Bi2WO6) was employed to degrade norfloxacin photocatalytically. The effects of environmental parameters, including catalyst dosage, probe concentration, and solution pH, on the process performance were investigated systematically. Under weak alkaline conditions, an optimal decay performance that can be attributed to the beneficial effect of hydroxyl ions was obtained. The reaction rationale and related constants were determined by the Langmuir–Hinshelwood (LH) model, combined with the experimental results. Our results showed that the adsorption of norfloxacin onto Bi2WO6 benefited the SSL/Bi2WO6 process, and the Bi2WO6 maximum adsorption capacity was 3.20× 10–3 mmol/g. In the SSL/Bi2WO6 process, the degradation of norfloxacin was accompanied by the decomposition of germicidal group and benzene ring, as well as gradual generation of inorganic ions of NH4+ and F–. Furthermore, the toxicity of initial norfloxacin solution was efficiently eliminated by this SSL/Bi2WO6 process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300146h Exemplaires
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Titre : Sour corrosion of C110 steel and its influence by galvanic couple and stress Type de document : texte imprimé Auteurs : Chengqiang Ren, Auteur ; Dezhi Zeng, Auteur ; Jianhui Lin, Auteur Année de publication : 2012 Article en page(s) : pp. 4894–4904 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Metals sour gas Résumé : Combinational metals of casing or tubing string have been extensively used in deep sour gas wells because of their corrosion resistance and low costs. C110 carbon steel and G3 alloy connected by a thread joint under different stresses represent a typical application of dissimilar metals in such a case. Around the contact part, complex corrosion can occur, including general, galvanic, and stress corrosion. To evaluate such corrosion, simulation experiments were conducted. Three specimens involving (1) a single piece of C110, (2) a galvanic couple of G3 alloy and C110, and (3) an elastic- and plastic-stressed C110 were separately placed in a high-pressure and high-temperature (HPHT) autoclave containing brine water and dissolved H2S, CO2, and elemental sulfur. After corrosion at 120 °C and 65 MPa for seven days, the specimens were examined by various methods, including weight loss, potential dynamic polarization, electrochemical impendence spectroscopy (EIS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectrometry (XPS). The experimental results showed that sour corrosion of C110 in the vapor is similar to that in solution. The galvanic effect on C110 corrosion by G3 was not evident based on the measurement of the limited increment of corrosion rate. Slower acceleration for corrosion was also observed for C110 when elastic stress was applied. However, plastic deformation significantly stimulated the corrosion rate of C110. The yield strain was found to change the polarization behavior of the anode and the performance of the corrosion scale. The corrosion mechanism is discussed in detail based on an analysis of the surface morphology, composition, and electrochemical performance of the scale, together with theories of the supercritical state, semiconductors, and mechano-electrochemistry. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2018492
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4894–4904[article] Sour corrosion of C110 steel and its influence by galvanic couple and stress [texte imprimé] / Chengqiang Ren, Auteur ; Dezhi Zeng, Auteur ; Jianhui Lin, Auteur . - 2012 . - pp. 4894–4904.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4894–4904
Mots-clés : Metals sour gas Résumé : Combinational metals of casing or tubing string have been extensively used in deep sour gas wells because of their corrosion resistance and low costs. C110 carbon steel and G3 alloy connected by a thread joint under different stresses represent a typical application of dissimilar metals in such a case. Around the contact part, complex corrosion can occur, including general, galvanic, and stress corrosion. To evaluate such corrosion, simulation experiments were conducted. Three specimens involving (1) a single piece of C110, (2) a galvanic couple of G3 alloy and C110, and (3) an elastic- and plastic-stressed C110 were separately placed in a high-pressure and high-temperature (HPHT) autoclave containing brine water and dissolved H2S, CO2, and elemental sulfur. After corrosion at 120 °C and 65 MPa for seven days, the specimens were examined by various methods, including weight loss, potential dynamic polarization, electrochemical impendence spectroscopy (EIS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectrometry (XPS). The experimental results showed that sour corrosion of C110 in the vapor is similar to that in solution. The galvanic effect on C110 corrosion by G3 was not evident based on the measurement of the limited increment of corrosion rate. Slower acceleration for corrosion was also observed for C110 when elastic stress was applied. However, plastic deformation significantly stimulated the corrosion rate of C110. The yield strain was found to change the polarization behavior of the anode and the performance of the corrosion scale. The corrosion mechanism is discussed in detail based on an analysis of the surface morphology, composition, and electrochemical performance of the scale, together with theories of the supercritical state, semiconductors, and mechano-electrochemistry. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2018492 Exemplaires
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Titre : Studies on the continuous precipitation of silver nanoparticles Type de document : texte imprimé Auteurs : Kan-Sen Chou, Auteur ; Yu-Chun Chang, Auteur ; Lien-Hua Chiu, Auteur Année de publication : 2012 Article en page(s) : pp. 4905–4910 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Silver nanoparticles Sodium borohydride Résumé : The continuous precipitation of silver nanoparticles was performed at room temperature using sodium borohydride (NaBH4) as the reducing agent. The effects of the concentration of the silver precursor (i.e., silver nitrate), the quantity of dispersing polymer [poly(vinyl pyrrolidone), PVP], and the flow rates of the reacting solutions on the resulting particle size and its distribution were investigated and are reported herein. Particles with average sizes ranging from 13 to 130 nm were obtained. Our results show that there is an optimal flow rate for each precursor concentration to obtain a uniform size distribution of the silver nanoparticles. This phenomenon can be explained in terms of the sequence of mixing, reaction, supersaturation generation and subsequent nucleation, growth, and agglomeration steps. Size control was mainly achieved through the use of PVP/AgNO3 weight ratios ranging from 0.05 to 1.5. Other properties such as residual PVP quantity and boron and sodium contamination are also reported here for several representative samples. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202032h
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4905–4910[article] Studies on the continuous precipitation of silver nanoparticles [texte imprimé] / Kan-Sen Chou, Auteur ; Yu-Chun Chang, Auteur ; Lien-Hua Chiu, Auteur . - 2012 . - pp. 4905–4910.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4905–4910
Mots-clés : Silver nanoparticles Sodium borohydride Résumé : The continuous precipitation of silver nanoparticles was performed at room temperature using sodium borohydride (NaBH4) as the reducing agent. The effects of the concentration of the silver precursor (i.e., silver nitrate), the quantity of dispersing polymer [poly(vinyl pyrrolidone), PVP], and the flow rates of the reacting solutions on the resulting particle size and its distribution were investigated and are reported herein. Particles with average sizes ranging from 13 to 130 nm were obtained. Our results show that there is an optimal flow rate for each precursor concentration to obtain a uniform size distribution of the silver nanoparticles. This phenomenon can be explained in terms of the sequence of mixing, reaction, supersaturation generation and subsequent nucleation, growth, and agglomeration steps. Size control was mainly achieved through the use of PVP/AgNO3 weight ratios ranging from 0.05 to 1.5. Other properties such as residual PVP quantity and boron and sodium contamination are also reported here for several representative samples. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202032h Exemplaires
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Titre : Evaluation of ideal adsorbed solution theory as a tool for the design of metal – organic framework materials Type de document : texte imprimé Auteurs : Naomi F. Cessford, Auteur ; Nigel A. Seaton, Auteur ; Tina Duren, Auteur Année de publication : 2012 Article en page(s) : pp.4911–4921 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Meta organic Adsorption Mixtures gases Résumé : As a class of porous materials, metal–organic frameworks (MOFs) show promise for the adsorption-based separation of mixtures of gases. The design of any process involving selective adsorption requires knowledge of mixture adsorption isotherms. Ideal adsorbed solution theory (IAST) predicts mixture adsorption equilibria using only single-component data, thereby minimizing the need for experimental adsorption data. In this work we perform a systematic study of the applicability of IAST to MOFs by using grand canonical Monte Carlo (GCMC) simulations to investigate the suitability of IAST for the prediction of the adsorption of mixtures of molecules of differing sizes, asphericities, and polarities in a range of structurally different MOFs. We show that IAST is generally accurate for MOFs. Where we find IAST is less accurate, deviations result from both mixture effects, in the form of nonidealities in the adsorbed phase, and characteristics of the adsorbent structures. In terms of the MOF structure, departures from IAST are a consequence of heterogeneities both on the scale of the unit cell and on shorter length scales, whereby competition for adsorption sites has a strong influence. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202219w
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp.4911–4921[article] Evaluation of ideal adsorbed solution theory as a tool for the design of metal – organic framework materials [texte imprimé] / Naomi F. Cessford, Auteur ; Nigel A. Seaton, Auteur ; Tina Duren, Auteur . - 2012 . - pp.4911–4921.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp.4911–4921
Mots-clés : Meta organic Adsorption Mixtures gases Résumé : As a class of porous materials, metal–organic frameworks (MOFs) show promise for the adsorption-based separation of mixtures of gases. The design of any process involving selective adsorption requires knowledge of mixture adsorption isotherms. Ideal adsorbed solution theory (IAST) predicts mixture adsorption equilibria using only single-component data, thereby minimizing the need for experimental adsorption data. In this work we perform a systematic study of the applicability of IAST to MOFs by using grand canonical Monte Carlo (GCMC) simulations to investigate the suitability of IAST for the prediction of the adsorption of mixtures of molecules of differing sizes, asphericities, and polarities in a range of structurally different MOFs. We show that IAST is generally accurate for MOFs. Where we find IAST is less accurate, deviations result from both mixture effects, in the form of nonidealities in the adsorbed phase, and characteristics of the adsorbent structures. In terms of the MOF structure, departures from IAST are a consequence of heterogeneities both on the scale of the unit cell and on shorter length scales, whereby competition for adsorption sites has a strong influence. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202219w Exemplaires
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Titre : Controllable synthesis of hexagonal, bullet - like ZnO microstructures and nanorod arrays and their photocatalytic property Type de document : texte imprimé Auteurs : Limin Song, Auteur ; Shujuan Zhang, Auteur ; Xiaoqing Wu, Auteur Année de publication : 2012 Article en page(s) : pp. 4922–4926 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photocatalytic Property Microstructure Résumé : Hexagonal, bullet-like ZnO microstructures and nanorod arrays have been prepared successfully by a simple hydrothermal method without surfactants. The structure and composition of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrum (EDS), infrared spectrum (IR), and UV–vis diffusive reflectance spectrum (UV–vis). The as-synthesized bullet-like ZnO has hexagonal microstructures with an average diameter of about 10 μm and a length of 30 μm. The obtained ZnO nanorod arrays are highly oriented. Their average diameter is around 50–100 nm, and their length is about 1 μm. In the present work, the effect of concentration, heating temperature, and time on the morphology of ZnO structures was studied experimentally, and their formation was discussed in detail. The photocatalytic degradation of methylene blue (MB) was also investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202253a
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4922–4926[article] Controllable synthesis of hexagonal, bullet - like ZnO microstructures and nanorod arrays and their photocatalytic property [texte imprimé] / Limin Song, Auteur ; Shujuan Zhang, Auteur ; Xiaoqing Wu, Auteur . - 2012 . - pp. 4922–4926.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4922–4926
Mots-clés : Photocatalytic Property Microstructure Résumé : Hexagonal, bullet-like ZnO microstructures and nanorod arrays have been prepared successfully by a simple hydrothermal method without surfactants. The structure and composition of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrum (EDS), infrared spectrum (IR), and UV–vis diffusive reflectance spectrum (UV–vis). The as-synthesized bullet-like ZnO has hexagonal microstructures with an average diameter of about 10 μm and a length of 30 μm. The obtained ZnO nanorod arrays are highly oriented. Their average diameter is around 50–100 nm, and their length is about 1 μm. In the present work, the effect of concentration, heating temperature, and time on the morphology of ZnO structures was studied experimentally, and their formation was discussed in detail. The photocatalytic degradation of methylene blue (MB) was also investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202253a Exemplaires
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Titre : Direct growth of aligned carbon nanotubes on quartz fibers for structural epoxy composites Type de document : texte imprimé Auteurs : Lei Jin, Auteur ; Ling Zhang, Auteur ; Danhua Su, Auteur Année de publication : 2012 Article en page(s) : pp. 4927–4933 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon Nanotubes Quartz fiber Résumé : We developed an approach to prepare the multilayered 3D composites where aligned multiwalled carbon nanotubes (MWCNTs) were grown on the surface of quartz fiber cloths (QFCs) by chemical vapor deposition method. The morphologies of the MWCNTs-QFCs preforms were analyzed by field emission scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis. The results showed that the growth of high yield and uniform alignment of MWCNTs on the surface of QFCs could be controlled by the process. The unique MWCNTs-QFCs preforms, when served as connecting bridges for structural epoxy composites, demonstrated a significant enhancement of the interlaminar shear strength and electrical conductivity along in-plane and out-of-plane directions when compared to QFCs/epoxy composites without MWCNTs, making the MWCNTs-QFCs reinforcements meaningful in structural composites. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202306v
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4927–4933[article] Direct growth of aligned carbon nanotubes on quartz fibers for structural epoxy composites [texte imprimé] / Lei Jin, Auteur ; Ling Zhang, Auteur ; Danhua Su, Auteur . - 2012 . - pp. 4927–4933.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4927–4933
Mots-clés : Carbon Nanotubes Quartz fiber Résumé : We developed an approach to prepare the multilayered 3D composites where aligned multiwalled carbon nanotubes (MWCNTs) were grown on the surface of quartz fiber cloths (QFCs) by chemical vapor deposition method. The morphologies of the MWCNTs-QFCs preforms were analyzed by field emission scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis. The results showed that the growth of high yield and uniform alignment of MWCNTs on the surface of QFCs could be controlled by the process. The unique MWCNTs-QFCs preforms, when served as connecting bridges for structural epoxy composites, demonstrated a significant enhancement of the interlaminar shear strength and electrical conductivity along in-plane and out-of-plane directions when compared to QFCs/epoxy composites without MWCNTs, making the MWCNTs-QFCs reinforcements meaningful in structural composites. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202306v Exemplaires
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Titre : Carbon nanotubes supported mono - and bimetallic Pt and Ru catalysts for selective hydrogenation of phenylacetylene Type de document : texte imprimé Auteurs : Chuang Li, Auteur ; Zhengfeng Shao, Auteur ; Min Pang, Auteur Année de publication : 2012 Article en page(s) : pp. 4934–4941 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanoparticle Carbon nanotubes Résumé : Deposition of Pt, Ru, Pt–Ru alloy, Ru@Pt, and Pt@Ru nanoparticles onto carbon nanotubes (CNTs) has been achieved by chemical reduction of the corresponding RuCl3·3H2O and/or H2PtCl6·6H2O by ethylene glycol in the presence of NaOH. The as-prepared catalysts were characterized by X-ray diffraction, H2-temperature programmed reduction, H2-temperature programmed desorption, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. Liquid-phase selective hydrogenation of phenylacetylene was used as a probe reaction to evaluate their catalytic performances. The as-prepared Pt, Ru, Pt–Ru alloy, Ru@Pt, and Pt@Ru nanoparticles fell in the range of 1.5–3.0 nm in diameter, and were uniformly dispersed on the CNTs. All the bimetallic catalysts displayed the characteristic diffraction peaks due to a Pt face-centered cubic structure, but the 2θ values were shifted to slightly higher ones, indicating the formation of alloy or core–shell structures. XPS analysis revealed that the catalysts contained mostly Pt(0) and Ru(0), with traces of Pt(II), Pt(IV), and Ru(IV). The Pt@Ru/CNTs and Ru@Pt/CNTs core–shell catalysts showed different catalytic properties in selective hydrogenation of phenylacetylene from the Pt–Ru alloy and the mixed monometallic samples with the correspondingly identical composition. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202342a
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4934–4941[article] Carbon nanotubes supported mono - and bimetallic Pt and Ru catalysts for selective hydrogenation of phenylacetylene [texte imprimé] / Chuang Li, Auteur ; Zhengfeng Shao, Auteur ; Min Pang, Auteur . - 2012 . - pp. 4934–4941.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4934–4941
Mots-clés : Nanoparticle Carbon nanotubes Résumé : Deposition of Pt, Ru, Pt–Ru alloy, Ru@Pt, and Pt@Ru nanoparticles onto carbon nanotubes (CNTs) has been achieved by chemical reduction of the corresponding RuCl3·3H2O and/or H2PtCl6·6H2O by ethylene glycol in the presence of NaOH. The as-prepared catalysts were characterized by X-ray diffraction, H2-temperature programmed reduction, H2-temperature programmed desorption, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. Liquid-phase selective hydrogenation of phenylacetylene was used as a probe reaction to evaluate their catalytic performances. The as-prepared Pt, Ru, Pt–Ru alloy, Ru@Pt, and Pt@Ru nanoparticles fell in the range of 1.5–3.0 nm in diameter, and were uniformly dispersed on the CNTs. All the bimetallic catalysts displayed the characteristic diffraction peaks due to a Pt face-centered cubic structure, but the 2θ values were shifted to slightly higher ones, indicating the formation of alloy or core–shell structures. XPS analysis revealed that the catalysts contained mostly Pt(0) and Ru(0), with traces of Pt(II), Pt(IV), and Ru(IV). The Pt@Ru/CNTs and Ru@Pt/CNTs core–shell catalysts showed different catalytic properties in selective hydrogenation of phenylacetylene from the Pt–Ru alloy and the mixed monometallic samples with the correspondingly identical composition. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202342a Exemplaires
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Titre : Preparation and performance evaluation of nanokaolinite - particle - based polyacrylonitrile mixed - matrix membranes Type de document : texte imprimé Auteurs : R. Saranya, Auteur ; G. Arthanareeswaran, Auteur ; S. Sakthivelu, Auteur Année de publication : 2012 Article en page(s) : pp. 4942–4951 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanokaolinite particles Résumé : The synergistic effects of polyacrylonitrile (PAN) and nanokaolinite particles were studied using PAN/nanokaolinite mixed-matrix membranes (MMMs). Nanokaolinite was obtained from naturally available kaolin clay by an intercalation/exfoliation method. The kaolinite nanoparticles were added in varying compositions from 2.5 to 10 wt % at an increment of 2.5 wt % to PAN in the presence of the solvent N,N′-dimethylformamide (DMF). The uniform dispersion of nanokaolinite in the PAN matrix was achieved with the help of ultrasonication. The PAN/nanokaolinite material was characterized by attenuated-total-reflectance-infrared (ATR-IR) spectroscopy. Contact-angle measurements showed increased hydrophilicity due to the nanokaolinite addition that, in turn, helped reduce membrane fouling. Thermal stability and miscibility were characterized using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The pure-water permeability flux increased from 122.8 to 264.93 L m–2 h–1 with increasing nanokaolinite concentration from 0 to 7.5 wt %. Rejection studies using protein showed an improved rejection efficiency of 92.7%, which is higher than that of the neat PAN membrane. PAN/nanokaolinite MMMs were also investigated in the separation of synthetic rhodamine B dye with and without the macroligand poly(diallyldimethylammonium chloride) (PDDA) for which the dye removal efficiency and flux were compared. Nanokaolinite-based MMMs are an inexpensive material and provide enhanced properties such as porosity, hydrophilicity, thermal stability, rejection, and productivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300026s
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4942–4951[article] Preparation and performance evaluation of nanokaolinite - particle - based polyacrylonitrile mixed - matrix membranes [texte imprimé] / R. Saranya, Auteur ; G. Arthanareeswaran, Auteur ; S. Sakthivelu, Auteur . - 2012 . - pp. 4942–4951.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4942–4951
Mots-clés : Nanokaolinite particles Résumé : The synergistic effects of polyacrylonitrile (PAN) and nanokaolinite particles were studied using PAN/nanokaolinite mixed-matrix membranes (MMMs). Nanokaolinite was obtained from naturally available kaolin clay by an intercalation/exfoliation method. The kaolinite nanoparticles were added in varying compositions from 2.5 to 10 wt % at an increment of 2.5 wt % to PAN in the presence of the solvent N,N′-dimethylformamide (DMF). The uniform dispersion of nanokaolinite in the PAN matrix was achieved with the help of ultrasonication. The PAN/nanokaolinite material was characterized by attenuated-total-reflectance-infrared (ATR-IR) spectroscopy. Contact-angle measurements showed increased hydrophilicity due to the nanokaolinite addition that, in turn, helped reduce membrane fouling. Thermal stability and miscibility were characterized using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The pure-water permeability flux increased from 122.8 to 264.93 L m–2 h–1 with increasing nanokaolinite concentration from 0 to 7.5 wt %. Rejection studies using protein showed an improved rejection efficiency of 92.7%, which is higher than that of the neat PAN membrane. PAN/nanokaolinite MMMs were also investigated in the separation of synthetic rhodamine B dye with and without the macroligand poly(diallyldimethylammonium chloride) (PDDA) for which the dye removal efficiency and flux were compared. Nanokaolinite-based MMMs are an inexpensive material and provide enhanced properties such as porosity, hydrophilicity, thermal stability, rejection, and productivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300026s Exemplaires
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Titre : Polyacrylonitrile / silica nanospheres with three - dimensional interpenetrating network structure and their application for removal of Pb (II) from water Type de document : texte imprimé Auteurs : Qingchun Zhao, Auteur ; Tian Cao, Auteur Année de publication : 2012 Article en page(s) : pp. 4952–4957 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanospheres Thermogravimetric analysis Adsorption Aqueous solutions Résumé : Polyacrylonitrile/silica nanospheres with three-dimensional interpenetrating network structure have been synthesized via emulsion polymerization method using 0.08 g azobisisbutyronitrile (AIBN) as initiator, 5 g acrylonitrile, and 5 g γ-methacryloxypropyl trimethoxy silane as monomer, 0.85 g dodecylbenzene sulfate as emulsifier at 60 °C for 10 h. The composition and morphology of the obtained nanospheres were investigated by infrared spectrum, thermogravimetric analysis, and scanning electron microscopy, respectively. The obtained polyacrylonitrile/silica nanospheres were used to investigate adsorption Pb(II) from aqueous solutions. The research results display that composite material has high adsorption capacity at optimum pH = 5. The maximum adsorption capacity was 0.108 mmol/g within 300 min at 25 °C. The pseudo-first-order equation and the pseudo-second-order equation are applied to analyze the experimental data. Adsorption behavior for Pb(II) onto nanospheres belongs to the pseudo-second-order kinetic model, and the adsorption process is a chemical process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3000024
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4952–4957[article] Polyacrylonitrile / silica nanospheres with three - dimensional interpenetrating network structure and their application for removal of Pb (II) from water [texte imprimé] / Qingchun Zhao, Auteur ; Tian Cao, Auteur . - 2012 . - pp. 4952–4957.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4952–4957
Mots-clés : Nanospheres Thermogravimetric analysis Adsorption Aqueous solutions Résumé : Polyacrylonitrile/silica nanospheres with three-dimensional interpenetrating network structure have been synthesized via emulsion polymerization method using 0.08 g azobisisbutyronitrile (AIBN) as initiator, 5 g acrylonitrile, and 5 g γ-methacryloxypropyl trimethoxy silane as monomer, 0.85 g dodecylbenzene sulfate as emulsifier at 60 °C for 10 h. The composition and morphology of the obtained nanospheres were investigated by infrared spectrum, thermogravimetric analysis, and scanning electron microscopy, respectively. The obtained polyacrylonitrile/silica nanospheres were used to investigate adsorption Pb(II) from aqueous solutions. The research results display that composite material has high adsorption capacity at optimum pH = 5. The maximum adsorption capacity was 0.108 mmol/g within 300 min at 25 °C. The pseudo-first-order equation and the pseudo-second-order equation are applied to analyze the experimental data. Adsorption behavior for Pb(II) onto nanospheres belongs to the pseudo-second-order kinetic model, and the adsorption process is a chemical process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3000024 Exemplaires
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Titre : Tuning a soft sensor’s bias update term. 1. : The open - loop case Type de document : texte imprimé Auteurs : Yuri A. W. Shardt, Auteur ; Biao Huang, Auteur Année de publication : 2012 Article en page(s) : pp. 4958–4967 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Process variables Measuring Sensor systems Résumé : The difficulty in measuring certain types of process variables rapidly has encouraged the use of soft sensors, which can determine the values of difficult to measure process variables based on easily available secondary process variables. A bias update term that allows the system to take into consideration disturbances in the system is often included in such soft sensor systems. The first part of this two-part series considers the bias update for the open-loop situation, including the ideal case, the case where there is measurement delay, the case with multirate sampling, and the case where there is a combination of measurement delay and multirate sampling. Proposed tuning rules are provided for all cases in order to obtain optimal open-loop tracking of the quality variable, especially in the presence of slow or drifting disturbances. Simulation and experimental validation of the results is presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201456z
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4958–4967[article] Tuning a soft sensor’s bias update term. 1. : The open - loop case [texte imprimé] / Yuri A. W. Shardt, Auteur ; Biao Huang, Auteur . - 2012 . - pp. 4958–4967.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4958–4967
Mots-clés : Process variables Measuring Sensor systems Résumé : The difficulty in measuring certain types of process variables rapidly has encouraged the use of soft sensors, which can determine the values of difficult to measure process variables based on easily available secondary process variables. A bias update term that allows the system to take into consideration disturbances in the system is often included in such soft sensor systems. The first part of this two-part series considers the bias update for the open-loop situation, including the ideal case, the case where there is measurement delay, the case with multirate sampling, and the case where there is a combination of measurement delay and multirate sampling. Proposed tuning rules are provided for all cases in order to obtain optimal open-loop tracking of the quality variable, especially in the presence of slow or drifting disturbances. Simulation and experimental validation of the results is presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201456z Exemplaires
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Titre : Tuning a soft sensor’s bias update term. 2. : The closed - loop case Type de document : texte imprimé Auteurs : Yuri A. W. Shardt, Auteur ; Biao Huang, Auteur Année de publication : 2012 Article en page(s) : pp. 4968–4981 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Process variables measuring Sampling Résumé : The difficulty in measuring certain types of process variables rapidly has encouraged the use of soft sensors, which can determine the values of difficult to measure process variables based on easily available secondary process variables. A bias update term that allows the system to take into consideration disturbances in the system is often included in such soft sensor systems. In the second part of this two-part series, an investigation of the bias update term in closed-loop operation in the presence of a drifting (integrating) disturbance for the ideal case, the case where there is measurement delay, the case with multirate sampling, and the case where there is a combination of measurement delay and multirate sampling is considered. Proposed tuning rules are provided for all cases in order to obtain optimal closed-loop tracking of the controller. Simulation and experimental validation of the results is also presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2014586
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4968–4981[article] Tuning a soft sensor’s bias update term. 2. : The closed - loop case [texte imprimé] / Yuri A. W. Shardt, Auteur ; Biao Huang, Auteur . - 2012 . - pp. 4968–4981.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4968–4981
Mots-clés : Process variables measuring Sampling Résumé : The difficulty in measuring certain types of process variables rapidly has encouraged the use of soft sensors, which can determine the values of difficult to measure process variables based on easily available secondary process variables. A bias update term that allows the system to take into consideration disturbances in the system is often included in such soft sensor systems. In the second part of this two-part series, an investigation of the bias update term in closed-loop operation in the presence of a drifting (integrating) disturbance for the ideal case, the case where there is measurement delay, the case with multirate sampling, and the case where there is a combination of measurement delay and multirate sampling is considered. Proposed tuning rules are provided for all cases in order to obtain optimal closed-loop tracking of the controller. Simulation and experimental validation of the results is also presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2014586 Exemplaires
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Titre : Optimal design and decision for combined steam reforming process with dry methane reforming to reuse CO2 as a raw material Type de document : texte imprimé Auteurs : Youngsub Lim, Auteur ; Chul-Jin Lee, Auteur ; Yeong Su Jeong, Auteur Année de publication : 2012 Article en page(s) : pp. 4982-4989 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Raw materials Carbon dioxide Reuse Steam reforming Optimal design Résumé : Carbon dioxide (CO2) conversion technology has been estimated as a potentially practical solution for global warming problems although it still has some weaknesses such as cost and energy consumption. In this study, a combined steam reforming process with dry methane reforming process for the CO2 treatment was investigated. Because the dry methane reforming process could generate synthesis gas from carbon dioxide, it could decrease the CO2 emissions from the existing steam reforming process. Models for the steam reforming process and the combined process were developed and extended mitigation cost was suggested to evaluate CO2 reduction of the overall process. The combined process could reduce net CO2 emission by 67% compared with the reference steam reforming process, and the extended mitigation cost of the combined process ranged from 21 to 26.5 (US$/CO2 ton) according to the change of the cost for CO2 transportation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777937
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4982-4989[article] Optimal design and decision for combined steam reforming process with dry methane reforming to reuse CO2 as a raw material [texte imprimé] / Youngsub Lim, Auteur ; Chul-Jin Lee, Auteur ; Yeong Su Jeong, Auteur . - 2012 . - pp. 4982-4989.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4982-4989
Mots-clés : Raw materials Carbon dioxide Reuse Steam reforming Optimal design Résumé : Carbon dioxide (CO2) conversion technology has been estimated as a potentially practical solution for global warming problems although it still has some weaknesses such as cost and energy consumption. In this study, a combined steam reforming process with dry methane reforming process for the CO2 treatment was investigated. Because the dry methane reforming process could generate synthesis gas from carbon dioxide, it could decrease the CO2 emissions from the existing steam reforming process. Models for the steam reforming process and the combined process were developed and extended mitigation cost was suggested to evaluate CO2 reduction of the overall process. The combined process could reduce net CO2 emission by 67% compared with the reference steam reforming process, and the extended mitigation cost of the combined process ranged from 21 to 26.5 (US$/CO2 ton) according to the change of the cost for CO2 transportation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777937 Exemplaires
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Titre : An adaptive vapor recompression scheme for a ternary batch distillation with a side withdrawal Type de document : texte imprimé Auteurs : G. Uday Bhaskar Babu, Auteur ; Etendra K. Pal, Auteur ; Amiya K. Jana, Auteur Année de publication : 2012 Article en page(s) : pp. 4990–4997 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Batch distillation Adaptive vapor Résumé : Batch distillation is known to be less energy efficient than its continuous counterpart. However, it has received renewed interest last years owing to the flexibility it offers. In an effort to reduce energy consumption, a batch distillation with a side withdrawal (BDS) was proposed recently. In this contribution, we first construct the fundamental model for an unsteady state BDS process and simulate the column to derive an operational policy. Although the representative process was proved as an energy efficient scheme, in order to improve further the thermodynamic efficiency of the BDS structure, we propose an adaptive vapor recompression mechanism that considers the top vapor recompression with a variable speed. Apart from the compression ratio (CR), the other two manipulated variables involved are the external heat input to the reboiler through steam and the flow rate of overhead vapor entering the compressor. It is investigated that the two manipulated variables are required to adapt simultaneously throughout the batch operation; one is the CR and another one is either the heat input to the still or the overhead vapor rate. Finally, the influence of the adaptive vapor recompression scheme on the energetic and economic aspects is evaluated through intensive comparison against the conventional stand alone column. The proposed adaptive vapor recompression strategy appears overwhelmingly superior to its conventional counterpart in terms of thermal efficiency and economic performance. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201413p
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4990–4997[article] An adaptive vapor recompression scheme for a ternary batch distillation with a side withdrawal [texte imprimé] / G. Uday Bhaskar Babu, Auteur ; Etendra K. Pal, Auteur ; Amiya K. Jana, Auteur . - 2012 . - pp. 4990–4997.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4990–4997
Mots-clés : Batch distillation Adaptive vapor Résumé : Batch distillation is known to be less energy efficient than its continuous counterpart. However, it has received renewed interest last years owing to the flexibility it offers. In an effort to reduce energy consumption, a batch distillation with a side withdrawal (BDS) was proposed recently. In this contribution, we first construct the fundamental model for an unsteady state BDS process and simulate the column to derive an operational policy. Although the representative process was proved as an energy efficient scheme, in order to improve further the thermodynamic efficiency of the BDS structure, we propose an adaptive vapor recompression mechanism that considers the top vapor recompression with a variable speed. Apart from the compression ratio (CR), the other two manipulated variables involved are the external heat input to the reboiler through steam and the flow rate of overhead vapor entering the compressor. It is investigated that the two manipulated variables are required to adapt simultaneously throughout the batch operation; one is the CR and another one is either the heat input to the still or the overhead vapor rate. Finally, the influence of the adaptive vapor recompression scheme on the energetic and economic aspects is evaluated through intensive comparison against the conventional stand alone column. The proposed adaptive vapor recompression strategy appears overwhelmingly superior to its conventional counterpart in terms of thermal efficiency and economic performance. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201413p Exemplaires
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Titre : Hybrid compressor model for optimal operation of compressed dry air system in LCD production industry Type de document : texte imprimé Auteurs : Kiwook Song, Auteur ; Changhyun Jeong, Auteur ; Jiyeon Nam, Auteur Année de publication : 2012 Article en page(s) : pp. 4998-5002 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production Modeling Compressor Résumé : Compressed dry air (CDA) is a widely used utility in liquid crystal display (LCD) production industry usually utilized as an air knife and an air curtain for room and glass cleaning to prohibit particles from entering the chamber. CDA is consumed in various sites of the production line and demand for CDA fluctuates largely from moment to moment. Therefore, it is common to supply compressed air with a number of small-capacity compressors rather than few large-capacity ones. To find an optimal operating strategy of such a compressor network, a first hybrid modeling technique of an ideal model and an empirical model is used to predict the efficiency and power consumption of each compressor. Ideal compression work is calculated using thermodynamic equation with slight modification. An artificial neural network is configured to predict the efficiency. Then, actual power consumption of each compressor is given by the ratio of ideal work to efficiency. Then, optimization procedure is applied to search optimal operating configuration. The proposed method is applied to LCD production industry to show good prediction accuracy. Energy saving of total compression work is achieved by optimization scenario of segregating full-load and part-load compressor group. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777939
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4998-5002[article] Hybrid compressor model for optimal operation of compressed dry air system in LCD production industry [texte imprimé] / Kiwook Song, Auteur ; Changhyun Jeong, Auteur ; Jiyeon Nam, Auteur . - 2012 . - pp. 4998-5002.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 4998-5002
Mots-clés : Production Modeling Compressor Résumé : Compressed dry air (CDA) is a widely used utility in liquid crystal display (LCD) production industry usually utilized as an air knife and an air curtain for room and glass cleaning to prohibit particles from entering the chamber. CDA is consumed in various sites of the production line and demand for CDA fluctuates largely from moment to moment. Therefore, it is common to supply compressed air with a number of small-capacity compressors rather than few large-capacity ones. To find an optimal operating strategy of such a compressor network, a first hybrid modeling technique of an ideal model and an empirical model is used to predict the efficiency and power consumption of each compressor. Ideal compression work is calculated using thermodynamic equation with slight modification. An artificial neural network is configured to predict the efficiency. Then, actual power consumption of each compressor is given by the ratio of ideal work to efficiency. Then, optimization procedure is applied to search optimal operating configuration. The proposed method is applied to LCD production industry to show good prediction accuracy. Energy saving of total compression work is achieved by optimization scenario of segregating full-load and part-load compressor group. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777939 Exemplaires
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Titre : Modeling studies of a cylindrical polymer electrolyte membrane fuel cell cathode Type de document : texte imprimé Auteurs : Srinivasarao Modekurti, Auteur ; Brian Bullecks, Auteur ; Debangsu Bhattacharyya, Auteur Année de publication : 2012 Article en page(s) : pp. 5003–5010 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Polymer electrolyte Fuel cells Résumé : Traditional polymer electrolyte membrane fuel cells (PEMFCs) are planar. High cost and low gravimetric and volumetric power densities are two major issues with the planar design. To improve the gravimetric and volumetric power densities of the PEMFCs and to reduce the cost, a novel cylindrical PEMFC design has been developed. The performance of the air-breathing cylindrical PEMFC is found to be superior to a state-of-the-art planar cell in the high current density region. To understand the effect of various design parameters and operating conditions on the performance of the cylindrical PEMFC, two-dimensional, two-phase, steady-state models of the cylindrical cell for both air-breathing and pressurized conditions have been developed in this work. The developed model of the air-breathing cylindrical PEMFC is validated with in-house experimental data. Experiments were conducted with hydrogen on the anode side and air on the cathode side. The cathode catalyst layer is modeled using spherical agglomerate characterization. With the developed model, the effects of various operating and design parameters on the performance of the cell are studied. These studies show that the performance of the cylindrical cell can be further improved by optimizing these parameters. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2028359
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5003–5010[article] Modeling studies of a cylindrical polymer electrolyte membrane fuel cell cathode [texte imprimé] / Srinivasarao Modekurti, Auteur ; Brian Bullecks, Auteur ; Debangsu Bhattacharyya, Auteur . - 2012 . - pp. 5003–5010.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5003–5010
Mots-clés : Polymer electrolyte Fuel cells Résumé : Traditional polymer electrolyte membrane fuel cells (PEMFCs) are planar. High cost and low gravimetric and volumetric power densities are two major issues with the planar design. To improve the gravimetric and volumetric power densities of the PEMFCs and to reduce the cost, a novel cylindrical PEMFC design has been developed. The performance of the air-breathing cylindrical PEMFC is found to be superior to a state-of-the-art planar cell in the high current density region. To understand the effect of various design parameters and operating conditions on the performance of the cylindrical PEMFC, two-dimensional, two-phase, steady-state models of the cylindrical cell for both air-breathing and pressurized conditions have been developed in this work. The developed model of the air-breathing cylindrical PEMFC is validated with in-house experimental data. Experiments were conducted with hydrogen on the anode side and air on the cathode side. The cathode catalyst layer is modeled using spherical agglomerate characterization. With the developed model, the effects of various operating and design parameters on the performance of the cell are studied. These studies show that the performance of the cylindrical cell can be further improved by optimizing these parameters. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2028359 Exemplaires
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Titre : Two - stage VPSA process for CO2 capture from flue gas using activated carbon beads Type de document : texte imprimé Auteurs : Chunzhi Shen, Auteur ; Zhen Liu, Auteur ; Ping Li, Auteur Année de publication : 2012 Article en page(s) : pp. 5011–5021 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flue gas Vacuum Swing Adsorption Résumé : Carbon dioxide removal from flue gas with a two-stage vacuum pressure swing adsorption (VPSA) process, which uses activated carbon (AC) beads as the adsorbent, was investigated both theoretically and experimentally. First, single-column VPSA experiments were studied for CO2/N2 separation with high CO2 feed concentration. Then, a two-stage VPSA process composed two columns for each stage was designed, and the effects of different parameters were investigated. The first-stage VPSA unit operates with a four-step Skarstrom cycle, which includes feed pressurization, adsorption, blowdown, and counter-current purge with N2. For the second-stage VPSA process, a cycle with feed pressurization, adsorption, pressure equalization, blowdown and pressure equalization was employed. With the proposed two-stage VPSA process, a CO2 purity of 95.3% was obtained with 74.4% recovery. The total specific power consumption of the two-stage VPSA process is 723.6 kJ/kg-CO2, while the unit productivity is 0.85 mol-CO2/kg·h. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202097y
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5011–5021[article] Two - stage VPSA process for CO2 capture from flue gas using activated carbon beads [texte imprimé] / Chunzhi Shen, Auteur ; Zhen Liu, Auteur ; Ping Li, Auteur . - 2012 . - pp. 5011–5021.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5011–5021
Mots-clés : Flue gas Vacuum Swing Adsorption Résumé : Carbon dioxide removal from flue gas with a two-stage vacuum pressure swing adsorption (VPSA) process, which uses activated carbon (AC) beads as the adsorbent, was investigated both theoretically and experimentally. First, single-column VPSA experiments were studied for CO2/N2 separation with high CO2 feed concentration. Then, a two-stage VPSA process composed two columns for each stage was designed, and the effects of different parameters were investigated. The first-stage VPSA unit operates with a four-step Skarstrom cycle, which includes feed pressurization, adsorption, blowdown, and counter-current purge with N2. For the second-stage VPSA process, a cycle with feed pressurization, adsorption, pressure equalization, blowdown and pressure equalization was employed. With the proposed two-stage VPSA process, a CO2 purity of 95.3% was obtained with 74.4% recovery. The total specific power consumption of the two-stage VPSA process is 723.6 kJ/kg-CO2, while the unit productivity is 0.85 mol-CO2/kg·h. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202097y Exemplaires
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Titre : Systematic investigation of particle segregation in binary fluidized beds with and without multilayer horizontal baffles Type de document : texte imprimé Auteurs : Yongmin Zhang, Auteur ; Haibo Wang, Auteur ; Lili Chen, Auteur Année de publication : 2012 Article en page(s) : pp. 5022-5036 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Baffle Multiple layer Fluidized bed Fluidization Segregation Résumé : Particle segregation was systematically studied in a binary fluidized bed of inner diameter 0.286 m with fine FCC and coarse millet particles as flotsam and jetsam, respectively. Segregation efficiencies of both flotsam and jetsam, axial and radial fraction profiles were studied and analyzed systematically. A new developed horizontal baffle was examined to see its effects on particles segregation. Experimental results showed that the baffle-free bed could only get high-purity flotsam particles at very low gas velocities. However, both nearly pure jetsam and flotsam particles were obtainable at much higher gas velocities after four layers of new baffle are installed. A wider operating range suitable for particle segregation and greater axial fraction gradients were found in the baffled bed, further proving the baffle's effect on promoting particle segregation. This enables the baffled bed to be a promising continuous particle classifier in industry. Further analysis demonstrated that reduced bubble size, improve bubble flow distribution, and suppressed solid mixing are the intrinsic causes. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777942
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5022-5036[article] Systematic investigation of particle segregation in binary fluidized beds with and without multilayer horizontal baffles [texte imprimé] / Yongmin Zhang, Auteur ; Haibo Wang, Auteur ; Lili Chen, Auteur . - 2012 . - pp. 5022-5036.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5022-5036
Mots-clés : Baffle Multiple layer Fluidized bed Fluidization Segregation Résumé : Particle segregation was systematically studied in a binary fluidized bed of inner diameter 0.286 m with fine FCC and coarse millet particles as flotsam and jetsam, respectively. Segregation efficiencies of both flotsam and jetsam, axial and radial fraction profiles were studied and analyzed systematically. A new developed horizontal baffle was examined to see its effects on particles segregation. Experimental results showed that the baffle-free bed could only get high-purity flotsam particles at very low gas velocities. However, both nearly pure jetsam and flotsam particles were obtainable at much higher gas velocities after four layers of new baffle are installed. A wider operating range suitable for particle segregation and greater axial fraction gradients were found in the baffled bed, further proving the baffle's effect on promoting particle segregation. This enables the baffled bed to be a promising continuous particle classifier in industry. Further analysis demonstrated that reduced bubble size, improve bubble flow distribution, and suppressed solid mixing are the intrinsic causes. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777942 Exemplaires
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Titre : Kinetics study on the liquid entrapment and melt transport of static and falling - film melt crystallization Type de document : texte imprimé Auteurs : Xiaobin Jiang, Auteur ; Baohong Hou, Auteur ; Yingying Zhao, Auteur Année de publication : 2012 Article en page(s) : pp. 5037-5044 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Melt crystallization Falling film Transport process Kinetics Résumé : Experiments were carried out to study the kinetics of crystal growth and the sweating process in two kinds of melt crystallization modes: static melt crystallization (SMC) and falling-film melt crystallization (FFMC). The system utilized in this paper was hyperpure phosphoric acid with water and trace amounts of metal ions as impurities. The kinetic experimental data of crystal growth, liquid entrapment, and the melt-transport process were well fitted by power function equations (R2 > 0.947). The fractal and porous media theories were introduced to improve the model of melt transport and explain the difference between the two modes. The separation efficiencies of SMC and FFMC on different ion impurities were compared. The SMC mode separated calcium and ferrum ions with higher efficiency than the FFMC mode, while the FFMC mode separated sodium and magnesium ions better than the SMC mode. A combined operation mode was suggested to prepare hyperpure phosphoric acid in industrial applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777943
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5037-5044[article] Kinetics study on the liquid entrapment and melt transport of static and falling - film melt crystallization [texte imprimé] / Xiaobin Jiang, Auteur ; Baohong Hou, Auteur ; Yingying Zhao, Auteur . - 2012 . - pp. 5037-5044.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5037-5044
Mots-clés : Melt crystallization Falling film Transport process Kinetics Résumé : Experiments were carried out to study the kinetics of crystal growth and the sweating process in two kinds of melt crystallization modes: static melt crystallization (SMC) and falling-film melt crystallization (FFMC). The system utilized in this paper was hyperpure phosphoric acid with water and trace amounts of metal ions as impurities. The kinetic experimental data of crystal growth, liquid entrapment, and the melt-transport process were well fitted by power function equations (R2 > 0.947). The fractal and porous media theories were introduced to improve the model of melt transport and explain the difference between the two modes. The separation efficiencies of SMC and FFMC on different ion impurities were compared. The SMC mode separated calcium and ferrum ions with higher efficiency than the FFMC mode, while the FFMC mode separated sodium and magnesium ions better than the SMC mode. A combined operation mode was suggested to prepare hyperpure phosphoric acid in industrial applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777943 Exemplaires
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Titre : Removal of atenolol and isoproturon in aqueous solutions by adsorption in a fixed - bed column Type de document : texte imprimé Auteurs : José Luis Sotelo, Auteur ; Gabriel Ovejero, Auteur ; Araceli Rodríguez, Auteur Année de publication : 2012 Article en page(s) : pp. 5045–5055 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Atenolol Isoproturon Adsorption Résumé : In this work, the removal of a β-blocker, atenolol, and a pesticide, isoproturon, from aqueous solutions by adsorption on granular activated carbon fixed-bed columns has been studied. The effect of important operation parameters on breakthrough curves as column length (Z = 1.0–3.0 cm), initial concentration of atenolol or isoproturon (C0 = 50.0–500.0 μg·L–1), and volumetric flow rate (Q = 1.5 mL·min–1) was studied. Breakthrough time of the bed was found to increase with an increase in the value of the column length, and with a decrease in the value of initial concentration or flow rate. Mathematical models, as Bohart–Adams, Thomas, Yoon–Nelson, and Clark were applied to the experimental data for the prediction of the breakthrough curves, and to determine the characteristic parameters of the bed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300334q
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5045–5055[article] Removal of atenolol and isoproturon in aqueous solutions by adsorption in a fixed - bed column [texte imprimé] / José Luis Sotelo, Auteur ; Gabriel Ovejero, Auteur ; Araceli Rodríguez, Auteur . - 2012 . - pp. 5045–5055.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5045–5055
Mots-clés : Atenolol Isoproturon Adsorption Résumé : In this work, the removal of a β-blocker, atenolol, and a pesticide, isoproturon, from aqueous solutions by adsorption on granular activated carbon fixed-bed columns has been studied. The effect of important operation parameters on breakthrough curves as column length (Z = 1.0–3.0 cm), initial concentration of atenolol or isoproturon (C0 = 50.0–500.0 μg·L–1), and volumetric flow rate (Q = 1.5 mL·min–1) was studied. Breakthrough time of the bed was found to increase with an increase in the value of the column length, and with a decrease in the value of initial concentration or flow rate. Mathematical models, as Bohart–Adams, Thomas, Yoon–Nelson, and Clark were applied to the experimental data for the prediction of the breakthrough curves, and to determine the characteristic parameters of the bed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300334q Exemplaires
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Titre : Liquid – liquid two - phase flow patterns in a serpentine microchannel Type de document : texte imprimé Auteurs : P. S. Sarkar, Auteur ; Singh, K. K., Auteur ; K. T. Shenoy, Auteur Année de publication : 2012 Article en page(s) : pp.5056–5066 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Phase flow Microchannel Résumé : Liquid–liquid two-phase flow patterns in a serpentine glass microchannel have been studied using a camera with very high shutter speed. The phase system is equilibrated water−succinic acid−n-butanol system. Observed flow patterns have been classified into seven different types: slug flow, slug and droplet flow, droplet flow, unstable annular flow, annular flow, annular dispersed flow, and fully dispersed flow. Two different ways of introducing the aqueous and organic phases into the microchannel have been studied. Flow regime maps are presented and discussed. Voronoi diagrams of the flow regime maps are also presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201590f
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp.5056–5066[article] Liquid – liquid two - phase flow patterns in a serpentine microchannel [texte imprimé] / P. S. Sarkar, Auteur ; Singh, K. K., Auteur ; K. T. Shenoy, Auteur . - 2012 . - pp.5056–5066.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp.5056–5066
Mots-clés : Phase flow Microchannel Résumé : Liquid–liquid two-phase flow patterns in a serpentine glass microchannel have been studied using a camera with very high shutter speed. The phase system is equilibrated water−succinic acid−n-butanol system. Observed flow patterns have been classified into seven different types: slug flow, slug and droplet flow, droplet flow, unstable annular flow, annular flow, annular dispersed flow, and fully dispersed flow. Two different ways of introducing the aqueous and organic phases into the microchannel have been studied. Flow regime maps are presented and discussed. Voronoi diagrams of the flow regime maps are also presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201590f Exemplaires
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Titre : Condensation of acetol and acetic acid vapor and nitrogen using sprayed aqueous liquid Type de document : texte imprimé Auteurs : Leland C. Dickey, Auteur ; Akwasi A. Boateng, Auteur ; Neil M. Goldberg, Auteur Année de publication : 2012 Article en page(s) : pp. 5067–5072 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Condensation Acetol Acetic Acid Résumé : A cellulose-derived fraction of biomass pyrolysis vapor was simulated by evaporating acetol and acetic acid with heated nitrogen. After generating the vapor/nitrogen mixture, it was superheated in a tube oven and condensed by contact with an aqueous mist created by an ultrasonic spray nozzle. The rates of condensation and fractions of vapor condensed were determined for various fluid flow rates to estimate liquid flow rates necessary to obtain complete acetol vapor condensation. The effect of noncondensible gas on the condensation was determined by varying the ratio of nitrogen to acetol vapor. For standard conditions, no effect of nitrogen content on rate was seen for vapor contents greater than 10 mol %, which would include any practical fast pyrolysis vapor. Increasing the concentration of condensed vapor in the aqueous solution spray, up to 30 wt %, had little effect on the condensation rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2017465
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5067–5072[article] Condensation of acetol and acetic acid vapor and nitrogen using sprayed aqueous liquid [texte imprimé] / Leland C. Dickey, Auteur ; Akwasi A. Boateng, Auteur ; Neil M. Goldberg, Auteur . - 2012 . - pp. 5067–5072.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5067–5072
Mots-clés : Condensation Acetol Acetic Acid Résumé : A cellulose-derived fraction of biomass pyrolysis vapor was simulated by evaporating acetol and acetic acid with heated nitrogen. After generating the vapor/nitrogen mixture, it was superheated in a tube oven and condensed by contact with an aqueous mist created by an ultrasonic spray nozzle. The rates of condensation and fractions of vapor condensed were determined for various fluid flow rates to estimate liquid flow rates necessary to obtain complete acetol vapor condensation. The effect of noncondensible gas on the condensation was determined by varying the ratio of nitrogen to acetol vapor. For standard conditions, no effect of nitrogen content on rate was seen for vapor contents greater than 10 mol %, which would include any practical fast pyrolysis vapor. Increasing the concentration of condensed vapor in the aqueous solution spray, up to 30 wt %, had little effect on the condensation rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2017465 Exemplaires
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Titre : Multiphase equilibrium calculations from soave equation of state with chang - twu / UNIFAC mixing rules for mixtures containing water, alcohols, and esters Type de document : texte imprimé Auteurs : Gui-Bing Hong, Auteur ; Cheng-Ting Hsieh, Auteur ; Ho-mu Lin, Auteur Année de publication : 2012 Article en page(s) : pp. 5073–5081 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamic properties Mixing rule Equations of state Multiphase equilibrium Résumé : Various versions of the Soave–Redlich–Kwong (SRK) equation of state incorporating different mixing rules were applied to calculate vapor–liquid equilibrium (VLE), liquid–liquid equilibrium (LLE), and vapor–liquid–liquid equilibrium (VLLE) properties for the systems containing water, alcohols, and esters. The calculated results showed that the SRK equation with the T-type α function and the Chung–Twu (CT) mixing rules embedded in the UNIFAC–Lyngby model (SRK-T/CT–UNIFAC– Lyngby) not only predicts accurately the VLE properties of the constituent binaries but also represents the ternary LLE and VLLE phase behavior reasonably well. Using this model, the vapor pressure data of the pure constituent components are the only required property for the phase equilibrium calculations. REFERENCE : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777947
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5073–5081[article] Multiphase equilibrium calculations from soave equation of state with chang - twu / UNIFAC mixing rules for mixtures containing water, alcohols, and esters [texte imprimé] / Gui-Bing Hong, Auteur ; Cheng-Ting Hsieh, Auteur ; Ho-mu Lin, Auteur . - 2012 . - pp. 5073–5081.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5073–5081
Mots-clés : Thermodynamic properties Mixing rule Equations of state Multiphase equilibrium Résumé : Various versions of the Soave–Redlich–Kwong (SRK) equation of state incorporating different mixing rules were applied to calculate vapor–liquid equilibrium (VLE), liquid–liquid equilibrium (LLE), and vapor–liquid–liquid equilibrium (VLLE) properties for the systems containing water, alcohols, and esters. The calculated results showed that the SRK equation with the T-type α function and the Chung–Twu (CT) mixing rules embedded in the UNIFAC–Lyngby model (SRK-T/CT–UNIFAC– Lyngby) not only predicts accurately the VLE properties of the constituent binaries but also represents the ternary LLE and VLLE phase behavior reasonably well. Using this model, the vapor pressure data of the pure constituent components are the only required property for the phase equilibrium calculations. REFERENCE : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777947 Exemplaires
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Titre : Measurement and correlation of the solubilities of 2 - [(6- Oxido - 6H - dibenz [c,e] [1,2] oxaphosphorin - 6 - yl) methyl] butanedioic acid in selected solvents Type de document : texte imprimé Auteurs : Xian-Zhao Shao, Auteur ; Li-Sheng Wang, Auteur ; Mi-Yi Li, Auteur Année de publication : 2012 Article en page(s) : pp. 5082–5089 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solubility Correlation analysis Résumé : The solubilities of 2-[(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)methyl]butanedioic acid (DDP) in selected solvents were measured by a static analytic method. The measurements were carried out over the temperature range from 293 to 353 K in methanol, ethanol, 1-propanol, tetrahydrofuran, 1,4-dioxane, ethyl acetate, toluene, benzene, and cyclohexane. Several commonly used thermodynamic models, including the empirical equation and the Scatchard–Hildebrand, Wilson, nonrandom two-liquid, and UNIQUAC equations, were applied to correlate the experimental solubility data. The binary interaction parameters of the above models were found to have a linear dependence on the temperature, and the coefficients were regressed. It was found that all of these models can satisfactorily reproduce the experimental data and the UNIQUAC equation can provide the best correlation results with an overall relative standard deviation of 1.52%. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777948
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5082–5089[article] Measurement and correlation of the solubilities of 2 - [(6- Oxido - 6H - dibenz [c,e] [1,2] oxaphosphorin - 6 - yl) methyl] butanedioic acid in selected solvents [texte imprimé] / Xian-Zhao Shao, Auteur ; Li-Sheng Wang, Auteur ; Mi-Yi Li, Auteur . - 2012 . - pp. 5082–5089.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5082–5089
Mots-clés : Solubility Correlation analysis Résumé : The solubilities of 2-[(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)methyl]butanedioic acid (DDP) in selected solvents were measured by a static analytic method. The measurements were carried out over the temperature range from 293 to 353 K in methanol, ethanol, 1-propanol, tetrahydrofuran, 1,4-dioxane, ethyl acetate, toluene, benzene, and cyclohexane. Several commonly used thermodynamic models, including the empirical equation and the Scatchard–Hildebrand, Wilson, nonrandom two-liquid, and UNIQUAC equations, were applied to correlate the experimental solubility data. The binary interaction parameters of the above models were found to have a linear dependence on the temperature, and the coefficients were regressed. It was found that all of these models can satisfactorily reproduce the experimental data and the UNIQUAC equation can provide the best correlation results with an overall relative standard deviation of 1.52%. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777948 Exemplaires
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Titre : The gibbs – helmholtz equation and the thermodynamic consistency of chemical absorption data Type de document : texte imprimé Auteurs : Paul M. Mathias, Auteur ; John P. O’Connell, Auteur Année de publication : 2012 Article en page(s) : pp. 5090–5097 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamic Chemical absorption Résumé : The Gibbs–Helmholtz (G-H) equation connects vapor–liquid equilibrium (VLE) and calorimetric data. If experimental measurements for the heat of solution are not available, they may be estimated through the G-H equation. Further, if both VLE and heat-of-solution data are available, their mutual thermodynamic consistency can be evaluated through the G-H equation, to develop the most accurate and reliable model. This kind of analysis is particularly useful for chemical-absorption systems, such as the capture of CO2 using aqueous solutions of amines, where regeneration energies are significant. In this work, the G-H equation is derived to unambiguously relate the commonly used form to the rigorous and general form, including for systems where phase equilibrium is accompanied by chemical reactions in any phase. The effect of approximations and the range of applicability of the common G-H equation are first applied to data generated for a simple VLE system by an equation of state, with different reliability found for the vapor and liquid phases. Next, consistency is evaluated for many VLE and calorimetric data for CO2 absorption in aqueous MEA (monoethanolamine). It is shown that some VLE and/or calorimetric data sets are likely to be in error and that the experimental VLE and CO2 heat of solution at the highest temperatures are currently uncertain. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202668k
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5090–5097[article] The gibbs – helmholtz equation and the thermodynamic consistency of chemical absorption data [texte imprimé] / Paul M. Mathias, Auteur ; John P. O’Connell, Auteur . - 2012 . - pp. 5090–5097.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5090–5097
Mots-clés : Thermodynamic Chemical absorption Résumé : The Gibbs–Helmholtz (G-H) equation connects vapor–liquid equilibrium (VLE) and calorimetric data. If experimental measurements for the heat of solution are not available, they may be estimated through the G-H equation. Further, if both VLE and heat-of-solution data are available, their mutual thermodynamic consistency can be evaluated through the G-H equation, to develop the most accurate and reliable model. This kind of analysis is particularly useful for chemical-absorption systems, such as the capture of CO2 using aqueous solutions of amines, where regeneration energies are significant. In this work, the G-H equation is derived to unambiguously relate the commonly used form to the rigorous and general form, including for systems where phase equilibrium is accompanied by chemical reactions in any phase. The effect of approximations and the range of applicability of the common G-H equation are first applied to data generated for a simple VLE system by an equation of state, with different reliability found for the vapor and liquid phases. Next, consistency is evaluated for many VLE and calorimetric data for CO2 absorption in aqueous MEA (monoethanolamine). It is shown that some VLE and/or calorimetric data sets are likely to be in error and that the experimental VLE and CO2 heat of solution at the highest temperatures are currently uncertain. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202668k Exemplaires
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Titre : Checking liquid - liquid plait point conditions and their application in ternary systems Type de document : texte imprimé Auteurs : A. Marcilla, Auteur ; M. D. Serrano, Auteur ; Juan A. Reyes-Labarta, Auteur Année de publication : 2012 Article en page(s) : pp. 5098-5102 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ternary system Surveillance Résumé : This work reviews the thermodynamic criteria for incipient immiscibility at the plait point in ternary systems, and also shows its application to singular LL equilibria, such as different type 3 ternary systems (Treybal classification), where an inadequate use of the criteria could yield to ambiguities. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777950
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5098-5102[article] Checking liquid - liquid plait point conditions and their application in ternary systems [texte imprimé] / A. Marcilla, Auteur ; M. D. Serrano, Auteur ; Juan A. Reyes-Labarta, Auteur . - 2012 . - pp. 5098-5102.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5098-5102
Mots-clés : Ternary system Surveillance Résumé : This work reviews the thermodynamic criteria for incipient immiscibility at the plait point in ternary systems, and also shows its application to singular LL equilibria, such as different type 3 ternary systems (Treybal classification), where an inadequate use of the criteria could yield to ambiguities. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777950 Exemplaires
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Titre : Computation of upper flash point of chemical compounds using a chemical structure - based model Type de document : texte imprimé Auteurs : Farhad Gharagheizi, Auteur ; Poorandokht Ilani-Kashkouli, Auteur ; Seyyed Alireza Mirkhani, Auteur Année de publication : 2012 Article en page(s) : pp. 5103-5107 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling Chemical structure compound Résumé : In this communication, a quantitative structure-property relationship (QSPR) is presented for an estimation of the upper flash point of pure compounds. The model is a multilinear equation that has eight parameters. All the parameters are solely computed based on chemical structure. To develop this model, more than 3000 parameters were evaluated using the Genetic Algorithm Multivariate Linear Regression (GA-MLR) method to select the most statistically effective ones. The maximum average absolute relative deviation (mARD), ARD, squared correlation coefficient, and root mean squares of error of the model from database (DIPPR 801) values for 1294 pure compounds are 2S.76%, 3.56%, 0.95, and 17.42 K, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777951
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5103-5107[article] Computation of upper flash point of chemical compounds using a chemical structure - based model [texte imprimé] / Farhad Gharagheizi, Auteur ; Poorandokht Ilani-Kashkouli, Auteur ; Seyyed Alireza Mirkhani, Auteur . - 2012 . - pp. 5103-5107.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5103-5107
Mots-clés : Modeling Chemical structure compound Résumé : In this communication, a quantitative structure-property relationship (QSPR) is presented for an estimation of the upper flash point of pure compounds. The model is a multilinear equation that has eight parameters. All the parameters are solely computed based on chemical structure. To develop this model, more than 3000 parameters were evaluated using the Genetic Algorithm Multivariate Linear Regression (GA-MLR) method to select the most statistically effective ones. The maximum average absolute relative deviation (mARD), ARD, squared correlation coefficient, and root mean squares of error of the model from database (DIPPR 801) values for 1294 pure compounds are 2S.76%, 3.56%, 0.95, and 17.42 K, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25777951 Exemplaires
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Titre : Thermodynamics of mixtures containing oxaalkanes. 7. : Random mixing in ether + CCl4 systems Type de document : texte imprimé Auteurs : Juan Antonio Gonzalez, Auteur ; Isaias García de la Fuente, Auteur ; José Carlos Cobos, Auteur Année de publication : 2012 Article en page(s) : pp. 5108-5116 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamics Mixing Résumé : Mixtures of a linear or cyclic ether + CCl4 have been studied using the Flory model and the Kirkwood-Buff integrals formalism. The relative variation of the molar excess enthalpy, HEm, along the homologous series of the investigated systems was investigated in terms of the contributions to HEm from the breaking of the ether-ether and CCl4-CCl4 interactions upon mixing and the formation of ether-CCl4 interactions. For CH3(CH2)u-l(CH2CH2O)v(CH2)u-lCH3 + CCl4 mixtures, an increase in u (v = 0) leads to a weakening of interactions between unlike molecules. In contrast, an increase in v (u fixed) or cyclization leads to stronger interactions between unlike molecules. For acetal mixtures, proximity effects weaken this type of interaction. From the application of the two models, it is shown that the structure of the mixtures is close to that of random mixing. Erroneously, strong orientational effects are predicted by the Flory model for 1,3-dioxolane or 1,3-dioxane + CCl4 systems, but this is because the theory cannot describe asymmetric HEm curves when the mixture compounds have similar values for Vi (molar volume) and for V*i (reduction parameter for volume). The Flory results on the excess molar volumes are discussed in terms of the interactional, curvature, and P* contributions to this excess function. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300094e
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5108-5116[article] Thermodynamics of mixtures containing oxaalkanes. 7. : Random mixing in ether + CCl4 systems [texte imprimé] / Juan Antonio Gonzalez, Auteur ; Isaias García de la Fuente, Auteur ; José Carlos Cobos, Auteur . - 2012 . - pp. 5108-5116.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5108-5116
Mots-clés : Thermodynamics Mixing Résumé : Mixtures of a linear or cyclic ether + CCl4 have been studied using the Flory model and the Kirkwood-Buff integrals formalism. The relative variation of the molar excess enthalpy, HEm, along the homologous series of the investigated systems was investigated in terms of the contributions to HEm from the breaking of the ether-ether and CCl4-CCl4 interactions upon mixing and the formation of ether-CCl4 interactions. For CH3(CH2)u-l(CH2CH2O)v(CH2)u-lCH3 + CCl4 mixtures, an increase in u (v = 0) leads to a weakening of interactions between unlike molecules. In contrast, an increase in v (u fixed) or cyclization leads to stronger interactions between unlike molecules. For acetal mixtures, proximity effects weaken this type of interaction. From the application of the two models, it is shown that the structure of the mixtures is close to that of random mixing. Erroneously, strong orientational effects are predicted by the Flory model for 1,3-dioxolane or 1,3-dioxane + CCl4 systems, but this is because the theory cannot describe asymmetric HEm curves when the mixture compounds have similar values for Vi (molar volume) and for V*i (reduction parameter for volume). The Flory results on the excess molar volumes are discussed in terms of the interactional, curvature, and P* contributions to this excess function. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300094e Exemplaires
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Titre : Liquid – liquid two - phase flow patterns in a serpentine microchannel Type de document : texte imprimé Auteurs : P. S. Sarkar, Auteur ; Singh, K. K., Auteur ; K. T. Shenoy, Auteur Année de publication : 2012 Article en page(s) : pp. 5056–5066 Note générale : Chimie industrielle Langues : Anglais (eng) Résumé : Liquid–liquid two-phase flow patterns in a serpentine glass microchannel have been studied using a camera with very high shutter speed. The phase system is equilibrated water−succinic acid−n-butanol system. Observed flow patterns have been classified into seven different types: slug flow, slug and droplet flow, droplet flow, unstable annular flow, annular flow, annular dispersed flow, and fully dispersed flow. Two different ways of introducing the aqueous and organic phases into the microchannel have been studied. Flow regime maps are presented and discussed. Voronoi diagrams of the flow regime maps are also presented.
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5056–5066[article] Liquid – liquid two - phase flow patterns in a serpentine microchannel [texte imprimé] / P. S. Sarkar, Auteur ; Singh, K. K., Auteur ; K. T. Shenoy, Auteur . - 2012 . - pp. 5056–5066.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 13 (Avril 2012) . - pp. 5056–5066
Résumé : Liquid–liquid two-phase flow patterns in a serpentine glass microchannel have been studied using a camera with very high shutter speed. The phase system is equilibrated water−succinic acid−n-butanol system. Observed flow patterns have been classified into seven different types: slug flow, slug and droplet flow, droplet flow, unstable annular flow, annular flow, annular dispersed flow, and fully dispersed flow. Two different ways of introducing the aqueous and organic phases into the microchannel have been studied. Flow regime maps are presented and discussed. Voronoi diagrams of the flow regime maps are also presented. Exemplaires
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