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Vol. 51 N° 50 - Décembre 2012 [texte imprimé] . - 2013 . - p. 16165–16530 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierAlkoxycarbonylation of industrially relevant anilines using Zn4O(O2CCH3)6 as catalyst / Elisenda Reixach in Industrial & engineering chemistry research, Vol. 51 N° 50 (Décembre 2012)
Titre : Alkoxycarbonylation of industrially relevant anilines using Zn4O(O2CCH3)6 as catalyst Type de document : texte imprimé Auteurs : Elisenda Reixach, Auteur ; Robert M. Haak, Auteur ; Stefan Wershofen, Auteur Année de publication : 2013 Article en page(s) : pp. 16165-16170 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Résumé : An efficient procedure is presented for the alkooycarbonylation of industrially important amines using environmentally friendly alkyl carbonates as reagents and Zn4O(OAc)6 as catalyst. Aromatic amines in particular (thirteen examples) consistently give high yields (up to 98%), regardless of the electronic properties of the substituents or the ring substitution pattern. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732142
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16165-16170[article] Alkoxycarbonylation of industrially relevant anilines using Zn4O(O2CCH3)6 as catalyst [texte imprimé] / Elisenda Reixach, Auteur ; Robert M. Haak, Auteur ; Stefan Wershofen, Auteur . - 2013 . - pp. 16165-16170.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16165-16170
Mots-clés : Catalyst Résumé : An efficient procedure is presented for the alkooycarbonylation of industrially important amines using environmentally friendly alkyl carbonates as reagents and Zn4O(OAc)6 as catalyst. Aromatic amines in particular (thirteen examples) consistently give high yields (up to 98%), regardless of the electronic properties of the substituents or the ring substitution pattern. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732142 Exemplaires
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Titre : Combined advanced oxidation processes and aerobic biological treatment for synthetic fatliquor used in tanneries Type de document : texte imprimé Auteurs : Chitra Kalyanaraman, Auteur ; Sri Bala Kameswari Kanchinadham, Auteur ; L. Vidya Devi, Auteur Année de publication : 2013 Article en page(s) : pp. 16171-16181 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Leather industry Tannery Biological treatment Aerobe Oxidation Résumé : The use of synthetic oils, fats, and fatliquors in the leather industry has become popular due to their superiority in terms of high emulsifying power when compared to natural oil based fatliquor. Compared to natural oil based fatliquor, the quantity required is lesser and the leather is not unduly loaded with fats and oils to achieve specific softness. Generally, synthetic fatliquors are prepared from paraffins and are made emulsifiable by sulphochlorination to produce chlorinated paraffin sulphonates. Due to the inherent nature of synthetic fatliquor and its low BODS/COD ratio of 0.077, it is adsorbed over the microbes and reduces the efficiency of the aerobic treatment unit in the treatment plants. Hence the aim of the present study was to evaluate the environment friendliness of synthetic fatliquors containing chlorinated paraffin sulphonates, by undertaking aerobic biodegradation studies at the same operating conditions maintained in the tannery effluent treatment plants, viz., f/m ratio of 0.15 and hydraulic retention time (HRT) of one day. Considering the nature of the compounds present in the synthetic fatliquors, the biodegradability of the fatliquor was sought to be improved by adopting advanced oxidation processes (AOPs) like UV/H2O2 and Fenton's reagent as pretreatment. AOP pretreatment of UV/H2O2 and Fenton's reagent improves the BOD5/ COD ratio of synthetic fatliquor from 0.077 to 0.3 and 0.37 and the biodegradable organics are effectively degraded in the aerobic reactor. UV/H2O2 pretreated synthetic fatliquor produced biochemical oxygen demand (BODS) and chemical oxygen demand (COD) of 45 and 330 mg/L in the aerobic reactor and Fenton's reagent pretreated fatliquor produced BOD5 and COD of 28 and 240 mg/L in the aerobic treated effluent. It was evident from FT-IR analysis that the chlorinated paraffin sulfonates are degraded efficiently in the batch reactor after AOP pretreatment and short chain chlorinated compounds and carboxylic acids presence are observed in the operating conditions maintained in the batch aerobic reactors. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732143
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16171-16181[article] Combined advanced oxidation processes and aerobic biological treatment for synthetic fatliquor used in tanneries [texte imprimé] / Chitra Kalyanaraman, Auteur ; Sri Bala Kameswari Kanchinadham, Auteur ; L. Vidya Devi, Auteur . - 2013 . - pp. 16171-16181.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16171-16181
Mots-clés : Leather industry Tannery Biological treatment Aerobe Oxidation Résumé : The use of synthetic oils, fats, and fatliquors in the leather industry has become popular due to their superiority in terms of high emulsifying power when compared to natural oil based fatliquor. Compared to natural oil based fatliquor, the quantity required is lesser and the leather is not unduly loaded with fats and oils to achieve specific softness. Generally, synthetic fatliquors are prepared from paraffins and are made emulsifiable by sulphochlorination to produce chlorinated paraffin sulphonates. Due to the inherent nature of synthetic fatliquor and its low BODS/COD ratio of 0.077, it is adsorbed over the microbes and reduces the efficiency of the aerobic treatment unit in the treatment plants. Hence the aim of the present study was to evaluate the environment friendliness of synthetic fatliquors containing chlorinated paraffin sulphonates, by undertaking aerobic biodegradation studies at the same operating conditions maintained in the tannery effluent treatment plants, viz., f/m ratio of 0.15 and hydraulic retention time (HRT) of one day. Considering the nature of the compounds present in the synthetic fatliquors, the biodegradability of the fatliquor was sought to be improved by adopting advanced oxidation processes (AOPs) like UV/H2O2 and Fenton's reagent as pretreatment. AOP pretreatment of UV/H2O2 and Fenton's reagent improves the BOD5/ COD ratio of synthetic fatliquor from 0.077 to 0.3 and 0.37 and the biodegradable organics are effectively degraded in the aerobic reactor. UV/H2O2 pretreated synthetic fatliquor produced biochemical oxygen demand (BODS) and chemical oxygen demand (COD) of 45 and 330 mg/L in the aerobic reactor and Fenton's reagent pretreated fatliquor produced BOD5 and COD of 28 and 240 mg/L in the aerobic treated effluent. It was evident from FT-IR analysis that the chlorinated paraffin sulfonates are degraded efficiently in the batch reactor after AOP pretreatment and short chain chlorinated compounds and carboxylic acids presence are observed in the operating conditions maintained in the batch aerobic reactors. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732143 Exemplaires
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Titre : Hydrotalcite-supported platinum nanoparticles prepared by a green synthesis method for selective oxidation of glycerol in water using molecular oxygen Type de document : texte imprimé Auteurs : Duangta Tongsakul, Auteur ; Shun Nishimura, Auteur ; Chuchaat Thammacharoen, Auteur Année de publication : 2013 Article en page(s) : pp. 16182-16187 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oxidation Nanoparticle Résumé : Hydrotalcite-supported platinum nanoparticles (Pt NPs/HT) prepared by the immobilization method with soluble starch as a reducing and a stabilizing agent were applied as catalysts for the selective oxidation of glycerol using atmospheric molecular oxygen as an oxidant in water. The Pt NPs/HT catalyst achieved a high selectivity (68%) toward glyceric acid (GA) in base-free aqueous solution. The catalyst was removed from the solution by simple filtration after the reaction and could be reused up to three times with a high selectivity (71% in third recycled). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732144
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16182-16187[article] Hydrotalcite-supported platinum nanoparticles prepared by a green synthesis method for selective oxidation of glycerol in water using molecular oxygen [texte imprimé] / Duangta Tongsakul, Auteur ; Shun Nishimura, Auteur ; Chuchaat Thammacharoen, Auteur . - 2013 . - pp. 16182-16187.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16182-16187
Mots-clés : Oxidation Nanoparticle Résumé : Hydrotalcite-supported platinum nanoparticles (Pt NPs/HT) prepared by the immobilization method with soluble starch as a reducing and a stabilizing agent were applied as catalysts for the selective oxidation of glycerol using atmospheric molecular oxygen as an oxidant in water. The Pt NPs/HT catalyst achieved a high selectivity (68%) toward glyceric acid (GA) in base-free aqueous solution. The catalyst was removed from the solution by simple filtration after the reaction and could be reused up to three times with a high selectivity (71% in third recycled). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732144 Exemplaires
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Titre : Facile preparation of nanocryptomelane and its application in the treatment of aqueous solutions containing basic fuchsin Type de document : texte imprimé Auteurs : Wei Xu, Auteur ; Zifeng Deng, Auteur ; Guangming Li, Auteur Année de publication : 2013 Article en page(s) : pp. 16188-16195 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aqueous solution Preparation Résumé : Cryptomelane nanomaterials were synthesized by a facile redox―reflux method. The physicochemical properties of these composites were studied in detail using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, laser Raman spectroscopy, thennogravimetric analysis (TGA), and N, adsorption-desorption techniques. The catalytic activities of nanocryptomelane were evaluated through treatment of aqueous solutions that contained basic fuchsin. In the case of basic fuchsin, the catalytic activity of synthetic nanocryptomelane was much higher than that of natural cryptomelane. Moreover, synthetic nanocryptomelane shows high stability and recyclability, has a high specific surface area, and is rich in mesopores. It could be anticipated that the specific surface area of the material had an obvious effect on the degradation of basic fuchsin. Kinetic studies indicated that the reaction follows the Langmuir―Hinshelwood model. The catalytic activities were found to be primarily correlated with the specific surface area. Overall, cryptomelane nanomaterials have great potential in the treatment of dye-containing wastewater. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732145
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16188-16195[article] Facile preparation of nanocryptomelane and its application in the treatment of aqueous solutions containing basic fuchsin [texte imprimé] / Wei Xu, Auteur ; Zifeng Deng, Auteur ; Guangming Li, Auteur . - 2013 . - pp. 16188-16195.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16188-16195
Mots-clés : Aqueous solution Preparation Résumé : Cryptomelane nanomaterials were synthesized by a facile redox―reflux method. The physicochemical properties of these composites were studied in detail using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, laser Raman spectroscopy, thennogravimetric analysis (TGA), and N, adsorption-desorption techniques. The catalytic activities of nanocryptomelane were evaluated through treatment of aqueous solutions that contained basic fuchsin. In the case of basic fuchsin, the catalytic activity of synthetic nanocryptomelane was much higher than that of natural cryptomelane. Moreover, synthetic nanocryptomelane shows high stability and recyclability, has a high specific surface area, and is rich in mesopores. It could be anticipated that the specific surface area of the material had an obvious effect on the degradation of basic fuchsin. Kinetic studies indicated that the reaction follows the Langmuir―Hinshelwood model. The catalytic activities were found to be primarily correlated with the specific surface area. Overall, cryptomelane nanomaterials have great potential in the treatment of dye-containing wastewater. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732145 Exemplaires
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Titre : Rheology of poly(acrylic acid) : A model study Type de document : texte imprimé Auteurs : Yuchen Wang, Auteur ; Richard A. Pethrick, Auteur ; Nicholas E. Hudson, Auteur Année de publication : 2013 Article en page(s) : pp 16196–16208 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Rheology Résumé : In this study, we examine the rheological characteristics of poly(acrylic acid) (PAA) polymers in aqueous solutions at 20 °C using various techniques. We also develop a model to simulate the rheological behavior of the polymer solutions, because, in some applications, the polymer is required to be dispersed within a short period of time, during which high-shear mixing is commonly used to achieve the necessary level of homogeneity. The model, which involves consideration of reptation, relaxation of the chains by slippage or loop relaxation, and normal Rouse dynamics, is appropriately adapted to reflect the structural changes of the polymer molecules and then used to identify possible relationships between molecular structure and viscoplastic behavior. The simple theory for flexible polymers is modified to include the possibility of complex formation by association between neighboring polymer molecules. We conclude that, although the model is sensitive to the average molar mass of the polymer, additional and more extensive high-shear-rate data are required to explore fully the validity of the Rouse description. However, the scaling of the viscosity by the addition of an increased friction factor provides a reasonable description of the short-range motions observed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie302313a
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp 16196–16208[article] Rheology of poly(acrylic acid) : A model study [texte imprimé] / Yuchen Wang, Auteur ; Richard A. Pethrick, Auteur ; Nicholas E. Hudson, Auteur . - 2013 . - pp 16196–16208.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp 16196–16208
Mots-clés : Rheology Résumé : In this study, we examine the rheological characteristics of poly(acrylic acid) (PAA) polymers in aqueous solutions at 20 °C using various techniques. We also develop a model to simulate the rheological behavior of the polymer solutions, because, in some applications, the polymer is required to be dispersed within a short period of time, during which high-shear mixing is commonly used to achieve the necessary level of homogeneity. The model, which involves consideration of reptation, relaxation of the chains by slippage or loop relaxation, and normal Rouse dynamics, is appropriately adapted to reflect the structural changes of the polymer molecules and then used to identify possible relationships between molecular structure and viscoplastic behavior. The simple theory for flexible polymers is modified to include the possibility of complex formation by association between neighboring polymer molecules. We conclude that, although the model is sensitive to the average molar mass of the polymer, additional and more extensive high-shear-rate data are required to explore fully the validity of the Rouse description. However, the scaling of the viscosity by the addition of an increased friction factor provides a reasonable description of the short-range motions observed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie302313a Exemplaires
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Titre : Elimination of the emerging contaminants amitriptyline hydrochloride, methyl salicylate, and 2-phenoxyethanol in ultrapure water and secondary effluents by photolytic and radicalary pathways Type de document : texte imprimé Auteurs : Francisco J. Real, Auteur ; F. Javier Benitez, Auteur ; Juan L. Acero, Auteur Année de publication : 2013 Article en page(s) : pp. 16209-16215 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ultrapure water High purity Pollution Résumé : Chemical degradation of the pharmaceuticals and personal care products (PPCPs) amitriptyline hydrochloride, methyl salicylate, and 2-phenoxyethanol by means of several advanced oxidation processes, including 254 nm UV radiation and Fenton's reagent, has been studied in different water matrixes, such as ultrapure (UP) and surface waters and two secondary effluents from wastewater treatment plants. The influence of the operating variables on the elimination of these compounds in UP water was established, and kinetic parameters for their degradation, such as quantum yields along a pH range of 3―11 and second-order rate constants for their oxidation by hydroxyl radicals, were determined. Specifically, for the reactions of oxidation of the three PPCPs with hydroxyl radicals, the use of a competition kinetic model in Fenton's reagent experiments allowed evaluation of their rate constants, whose values were (10.3 ± 0.3) × 109 M―1·s―1 for amitriptyline hydrochloride, (7.1 ± 0.1) × 109 M―1·s―1 for methyl salicylate, and (4.3 ± 0.1) × 109 M―1·s―1 for 2-phenoxyethanol. Furthermore, the simultaneous oxidation of these selected PPCPs in three different water systems (surface water from a reservoir and two secondary effluents) was studied, and the influence of the operating conditions on the removal efficiency was established. Finally, a kinetic model was proposed for the prediction of the elimination of these compounds by UV radiation and a UV/H2O2 system in these water matrixes, with theoretical results that agreed well with the experimental ones. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=2673214
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16209-16215[article] Elimination of the emerging contaminants amitriptyline hydrochloride, methyl salicylate, and 2-phenoxyethanol in ultrapure water and secondary effluents by photolytic and radicalary pathways [texte imprimé] / Francisco J. Real, Auteur ; F. Javier Benitez, Auteur ; Juan L. Acero, Auteur . - 2013 . - pp. 16209-16215.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16209-16215
Mots-clés : Ultrapure water High purity Pollution Résumé : Chemical degradation of the pharmaceuticals and personal care products (PPCPs) amitriptyline hydrochloride, methyl salicylate, and 2-phenoxyethanol by means of several advanced oxidation processes, including 254 nm UV radiation and Fenton's reagent, has been studied in different water matrixes, such as ultrapure (UP) and surface waters and two secondary effluents from wastewater treatment plants. The influence of the operating variables on the elimination of these compounds in UP water was established, and kinetic parameters for their degradation, such as quantum yields along a pH range of 3―11 and second-order rate constants for their oxidation by hydroxyl radicals, were determined. Specifically, for the reactions of oxidation of the three PPCPs with hydroxyl radicals, the use of a competition kinetic model in Fenton's reagent experiments allowed evaluation of their rate constants, whose values were (10.3 ± 0.3) × 109 M―1·s―1 for amitriptyline hydrochloride, (7.1 ± 0.1) × 109 M―1·s―1 for methyl salicylate, and (4.3 ± 0.1) × 109 M―1·s―1 for 2-phenoxyethanol. Furthermore, the simultaneous oxidation of these selected PPCPs in three different water systems (surface water from a reservoir and two secondary effluents) was studied, and the influence of the operating conditions on the removal efficiency was established. Finally, a kinetic model was proposed for the prediction of the elimination of these compounds by UV radiation and a UV/H2O2 system in these water matrixes, with theoretical results that agreed well with the experimental ones. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=2673214 Exemplaires
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Titre : Low-cost Fe-based oxygen carrier materials for the iG-CLC process with coal. 1 Type de document : texte imprimé Auteurs : T. Mendiara, Auteur ; R. Perez, Auteur ; A. Abad, Auteur Année de publication : 2013 Article en page(s) : pp. 16216-16229 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Coal Résumé : Different low-cost materials, especially Fe-based minerals or industrial residues, have been tested as carriers for iG-CLC. This work presents a methodology for the comparison of potential oxygen carriers. The methodology is based on results obtained in a batch fluidized bed reactor. The experiments were designed so that estimated solids inventory in the fuel reactor could be calculated for each oxygen carrier at different conditions and later compared. In the present paper, which is the first of a series of two, experimental results for different Fe-based materials were obtained. The second paper focuses on the evaluation and the comparison of the carriers based on these experimental results. In the present work, the performance of two iron minerals (hematite based and copper ferrite) is analyzed and compared to the behavior of ilmenite and a bauxite waste. The performance of a highly reactive synthetic Fe-based material is evaluated for comparison. In the TGA, the reactivity of the different materials to H2, CO, CH4, and O2 was studied. In the experiments in a fluidized bed, several O/C molar ratios were used to evaluate its effect on char gasification rate and combustion efficiency of the gasification products. The char gasification rate decreased when the O/C molar ratio decreased as the concentration of H2 and CO in the bed increased and high levels of these gases inhibit char gasification. With no inhibitory effect, the char gasification rate was very similar. Both the bauxite waste and the hematite based mineral were able to bum the gasification products with high combustion efficiencies, comparable to those obtained in the same conditions using the synthetic Fe-based material. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732148
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16216-16229[article] Low-cost Fe-based oxygen carrier materials for the iG-CLC process with coal. 1 [texte imprimé] / T. Mendiara, Auteur ; R. Perez, Auteur ; A. Abad, Auteur . - 2013 . - pp. 16216-16229.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16216-16229
Mots-clés : Coal Résumé : Different low-cost materials, especially Fe-based minerals or industrial residues, have been tested as carriers for iG-CLC. This work presents a methodology for the comparison of potential oxygen carriers. The methodology is based on results obtained in a batch fluidized bed reactor. The experiments were designed so that estimated solids inventory in the fuel reactor could be calculated for each oxygen carrier at different conditions and later compared. In the present paper, which is the first of a series of two, experimental results for different Fe-based materials were obtained. The second paper focuses on the evaluation and the comparison of the carriers based on these experimental results. In the present work, the performance of two iron minerals (hematite based and copper ferrite) is analyzed and compared to the behavior of ilmenite and a bauxite waste. The performance of a highly reactive synthetic Fe-based material is evaluated for comparison. In the TGA, the reactivity of the different materials to H2, CO, CH4, and O2 was studied. In the experiments in a fluidized bed, several O/C molar ratios were used to evaluate its effect on char gasification rate and combustion efficiency of the gasification products. The char gasification rate decreased when the O/C molar ratio decreased as the concentration of H2 and CO in the bed increased and high levels of these gases inhibit char gasification. With no inhibitory effect, the char gasification rate was very similar. Both the bauxite waste and the hematite based mineral were able to bum the gasification products with high combustion efficiencies, comparable to those obtained in the same conditions using the synthetic Fe-based material. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732148 Exemplaires
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Titre : Low-Cost Fe-Based Oxygen Carrier Materials for the iG-CLC Process with Coal. 2 Type de document : texte imprimé Auteurs : A. Abad, Auteur ; A. Cuadrat, Auteur ; T. Mendiara, Auteur Année de publication : 2013 Article en page(s) : pp. 16230-16241 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Coal Résumé : In order to compare potential oxygen carriers for the iG-CLC with coal a methodology was developed from results obtained in a batch fluidized reactor. The methodology is based on the solids inventory in the fuel reactor. The solids inventory values will be used for comparison purposes among different materials rather than for design purposes. In a companion paper, experiments with different types of Fe-based oxygen carriers were presented. Based on these experimental results, the present paper proposes two theoretical approaches for a fast evaluation of different materials as potential oxygen carriers for the iG-CLC process with different fuels. The methodology is focused on the study of the gasification of the char generated in the process after the devolatilization of the corresponding solid fuel and the subsequent combustion of the gasification products. Considering the results of carbon capture and combustion efficiency, the adequacy of the material can be evaluated. Four different Fe-based materials are tested in this work: ilmenite, bauxite waste, a mineral based on hematite, and a synthetic material. Based on the results obtained, the bauxite waste and the hematite mineral present the best performance for iG-CLC. As a rough estimation, an inventory around 1600 kg/MWtb will be needed using any of the above materials to achieve carbon captures above 0.93 and combustion efficiencies of 0.99 at 1000 °C. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732149
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16230-16241[article] Low-Cost Fe-Based Oxygen Carrier Materials for the iG-CLC Process with Coal. 2 [texte imprimé] / A. Abad, Auteur ; A. Cuadrat, Auteur ; T. Mendiara, Auteur . - 2013 . - pp. 16230-16241.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16230-16241
Mots-clés : Coal Résumé : In order to compare potential oxygen carriers for the iG-CLC with coal a methodology was developed from results obtained in a batch fluidized reactor. The methodology is based on the solids inventory in the fuel reactor. The solids inventory values will be used for comparison purposes among different materials rather than for design purposes. In a companion paper, experiments with different types of Fe-based oxygen carriers were presented. Based on these experimental results, the present paper proposes two theoretical approaches for a fast evaluation of different materials as potential oxygen carriers for the iG-CLC process with different fuels. The methodology is focused on the study of the gasification of the char generated in the process after the devolatilization of the corresponding solid fuel and the subsequent combustion of the gasification products. Considering the results of carbon capture and combustion efficiency, the adequacy of the material can be evaluated. Four different Fe-based materials are tested in this work: ilmenite, bauxite waste, a mineral based on hematite, and a synthetic material. Based on the results obtained, the bauxite waste and the hematite mineral present the best performance for iG-CLC. As a rough estimation, an inventory around 1600 kg/MWtb will be needed using any of the above materials to achieve carbon captures above 0.93 and combustion efficiencies of 0.99 at 1000 °C. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732149 Exemplaires
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Titre : Axial solids holdup distribution in a liquid–solid circulating fluidized bed : Effect of the liquid distributor, method of operation, and viscosity of the fluidizing media Type de document : texte imprimé Auteurs : Vidyasagar Shilapuram, Auteur ; P. S. T. Sai, Auteur Année de publication : 2013 Article en page(s) : pp. 16242-16250 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Viscosity Circulating fluidized bed Fluidization Holdup Résumé : While the choice of the location of the liquid distributor in a liquid―solid circulating fluidized bed is application dependent, three different methods exist for operating the riser in the circulating fluidization regime. Experiments were conducted to study the effect of the location of the liquid distributor, method of operation, liquid viscosity, and solids inventory on the axial solids holdup distribution in the circulating fluidized bed regime. The results show that the location of the liquid distributor has a significant effect on axial solids holdup, and the axial solids holdups obtained by the three methods of operation are different under identical conditions. The variation of the axial solids holdup distribution with liquid viscosity with a solid inventory of 0.15 m was different from that with both 0.25 and 0.35 m solid inventories. There is significant interaction of the solids inventory and liquid viscosity on the axial solids holdup distribution. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732150
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16242-16250[article] Axial solids holdup distribution in a liquid–solid circulating fluidized bed : Effect of the liquid distributor, method of operation, and viscosity of the fluidizing media [texte imprimé] / Vidyasagar Shilapuram, Auteur ; P. S. T. Sai, Auteur . - 2013 . - pp. 16242-16250.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16242-16250
Mots-clés : Viscosity Circulating fluidized bed Fluidization Holdup Résumé : While the choice of the location of the liquid distributor in a liquid―solid circulating fluidized bed is application dependent, three different methods exist for operating the riser in the circulating fluidization regime. Experiments were conducted to study the effect of the location of the liquid distributor, method of operation, liquid viscosity, and solids inventory on the axial solids holdup distribution in the circulating fluidized bed regime. The results show that the location of the liquid distributor has a significant effect on axial solids holdup, and the axial solids holdups obtained by the three methods of operation are different under identical conditions. The variation of the axial solids holdup distribution with liquid viscosity with a solid inventory of 0.15 m was different from that with both 0.25 and 0.35 m solid inventories. There is significant interaction of the solids inventory and liquid viscosity on the axial solids holdup distribution. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732150 Exemplaires
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Titre : Axial solids holdup distribution in a liquid–solid circulating fluidized bed : Effect of the liquid distributor, method of operation, and viscosity of the fluidizing media Type de document : texte imprimé Auteurs : Vidyasagar Shilapuram, Auteur ; P. S. T. Sai, Auteur Année de publication : 2013 Article en page(s) : pp. 16242-16250 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Viscosity Circulating fluidized bed Fluidization Holdup Résumé : While the choice of the location of the liquid distributor in a liquid―solid circulating fluidized bed is application dependent, three different methods exist for operating the riser in the circulating fluidization regime. Experiments were conducted to study the effect of the location of the liquid distributor, method of operation, liquid viscosity, and solids inventory on the axial solids holdup distribution in the circulating fluidized bed regime. The results show that the location of the liquid distributor has a significant effect on axial solids holdup, and the axial solids holdups obtained by the three methods of operation are different under identical conditions. The variation of the axial solids holdup distribution with liquid viscosity with a solid inventory of 0.15 m was different from that with both 0.25 and 0.35 m solid inventories. There is significant interaction of the solids inventory and liquid viscosity on the axial solids holdup distribution. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732150
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16242-16250[article] Axial solids holdup distribution in a liquid–solid circulating fluidized bed : Effect of the liquid distributor, method of operation, and viscosity of the fluidizing media [texte imprimé] / Vidyasagar Shilapuram, Auteur ; P. S. T. Sai, Auteur . - 2013 . - pp. 16242-16250.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16242-16250
Mots-clés : Viscosity Circulating fluidized bed Fluidization Holdup Résumé : While the choice of the location of the liquid distributor in a liquid―solid circulating fluidized bed is application dependent, three different methods exist for operating the riser in the circulating fluidization regime. Experiments were conducted to study the effect of the location of the liquid distributor, method of operation, liquid viscosity, and solids inventory on the axial solids holdup distribution in the circulating fluidized bed regime. The results show that the location of the liquid distributor has a significant effect on axial solids holdup, and the axial solids holdups obtained by the three methods of operation are different under identical conditions. The variation of the axial solids holdup distribution with liquid viscosity with a solid inventory of 0.15 m was different from that with both 0.25 and 0.35 m solid inventories. There is significant interaction of the solids inventory and liquid viscosity on the axial solids holdup distribution. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732150 Exemplaires
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Titre : Hydrodynamics of liquid–liquid dispersion in an advanced-flow reactor Type de document : texte imprimé Auteurs : Maria José Nieves-Remacha, Auteur ; Amol A. Kulkarni, Auteur ; Klavs F. Jensen, Auteur Année de publication : 2013 Article en page(s) : pp 16251–16262 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrodynamics Mass transfer Résumé : Hydrodynamics and mass transfer of immiscible liquid–liquid flows are explored in an Advanced-Flow Reactor (AFR). These systems are emerging as one of the major commercial systems for small scale continuous flow chemistry, and characterization of the transport phenomena is critical for reaction implementation. With hexane/water as a model system, we use flow visualization techniques to determine drop size distribution, hexane holdup, and specific interfacial areas for a phase flow rate range of 10–80 mL/min. The complex geometry of the AFR with its continuously changing cross section along the flow path and strategically placed obstacles creates pressure changes that cause drop breakup and enhance mass transfer. Observations show that a wide range of average drop size (0.33–1.3 mm) can be achieved in the AFR depending upon the inlet flow rates and inlet composition. Pressure drop measurements are performed to estimate the power consumption and are used to compare the efficiency of AFR with conventional liquid–liquid contactors. The analysis shows that, similar to microreactors, the AFR can provide specific interfacial areas (1000–10 000 m–1) and overall mass transfer coefficients (1.9–41 s–1) a few orders of magnitude larger than conventional stirred tank reactors and also the static mixers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301821k
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp 16251–16262[article] Hydrodynamics of liquid–liquid dispersion in an advanced-flow reactor [texte imprimé] / Maria José Nieves-Remacha, Auteur ; Amol A. Kulkarni, Auteur ; Klavs F. Jensen, Auteur . - 2013 . - pp 16251–16262.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp 16251–16262
Mots-clés : Hydrodynamics Mass transfer Résumé : Hydrodynamics and mass transfer of immiscible liquid–liquid flows are explored in an Advanced-Flow Reactor (AFR). These systems are emerging as one of the major commercial systems for small scale continuous flow chemistry, and characterization of the transport phenomena is critical for reaction implementation. With hexane/water as a model system, we use flow visualization techniques to determine drop size distribution, hexane holdup, and specific interfacial areas for a phase flow rate range of 10–80 mL/min. The complex geometry of the AFR with its continuously changing cross section along the flow path and strategically placed obstacles creates pressure changes that cause drop breakup and enhance mass transfer. Observations show that a wide range of average drop size (0.33–1.3 mm) can be achieved in the AFR depending upon the inlet flow rates and inlet composition. Pressure drop measurements are performed to estimate the power consumption and are used to compare the efficiency of AFR with conventional liquid–liquid contactors. The analysis shows that, similar to microreactors, the AFR can provide specific interfacial areas (1000–10 000 m–1) and overall mass transfer coefficients (1.9–41 s–1) a few orders of magnitude larger than conventional stirred tank reactors and also the static mixers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301821k Exemplaires
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Titre : Kinetics study of the ketalization reaction of cyclohexanone with glycol using bronsted acidic ionic liquids as catalysts Type de document : texte imprimé Auteurs : Duan-Jian Tao, Auteur ; Zhang-Min Li, Auteur ; Zheng Cheng, Auteur Année de publication : 2013 Article en page(s) : pp. 16263-16269 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Ionic liquid Kinetics Résumé : It is remarkable that Brønsted acidic ionic liquids (BALLS) have several unique advantages in the acid-catalysis reaction, which avoids the technical issues raised from mineral acids. The kinetics for the ketalization of cyclohexanone with glycol using BAILs as catalysts was therefore studied for the first time. The effects of various parameters such as kind of BAILs, temperature, catalyst loading, and molar ratio of the reactants on the conversion of cyclohexanone were examined in detail, and a pseudohomogeneous (PH) kinetic model was used successfully to correlate the experimental data in the temperature range from 313.15 to 343.15 K. The kinetic parameters such as reaction rate constant, activation energy, and chemical equilibrium constant then were proposed and utilized to interpret the catalytic activities of the BAILs catalysts. It was also validated from the comparison of catalytic performance among the BAILs, H2SO4, and solid resin that the BAILs were considered to be environmentally friendly and high efficient catalysts, and were suggested to replace mineral and solid acids in the synthesis of ketal. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732152
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16263-16269[article] Kinetics study of the ketalization reaction of cyclohexanone with glycol using bronsted acidic ionic liquids as catalysts [texte imprimé] / Duan-Jian Tao, Auteur ; Zhang-Min Li, Auteur ; Zheng Cheng, Auteur . - 2013 . - pp. 16263-16269.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16263-16269
Mots-clés : Catalyst Ionic liquid Kinetics Résumé : It is remarkable that Brønsted acidic ionic liquids (BALLS) have several unique advantages in the acid-catalysis reaction, which avoids the technical issues raised from mineral acids. The kinetics for the ketalization of cyclohexanone with glycol using BAILs as catalysts was therefore studied for the first time. The effects of various parameters such as kind of BAILs, temperature, catalyst loading, and molar ratio of the reactants on the conversion of cyclohexanone were examined in detail, and a pseudohomogeneous (PH) kinetic model was used successfully to correlate the experimental data in the temperature range from 313.15 to 343.15 K. The kinetic parameters such as reaction rate constant, activation energy, and chemical equilibrium constant then were proposed and utilized to interpret the catalytic activities of the BAILs catalysts. It was also validated from the comparison of catalytic performance among the BAILs, H2SO4, and solid resin that the BAILs were considered to be environmentally friendly and high efficient catalysts, and were suggested to replace mineral and solid acids in the synthesis of ketal. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732152 Exemplaires
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Titre : Design and fabrication of a high-throughput microreactor and its evaluation for highly exothermic reactions Type de document : texte imprimé Auteurs : Nageswara Rao Peela, Auteur ; Ivan C. Lee, Auteur ; Dionisios G. Vlachos, Auteur Année de publication : 2013 Article en page(s) : pp. 16270–16277 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microreactor Résumé : The effect of distributor and channel positions on flow uniformity in a high-throughput reactor is studied using a COMSOL MULTIPHYSICS, CFD package. The best design is subsequently fabricated and evaluated for propane total oxidation reaction at low conversions. Comparison of our design with a literature design is also presented. The results indicate that the conical distributor performs significantly better in terms of flow uniformity as compared to the commonly used disc shaped distributor. The flow uniformity is improved when the central channel is removed from the design, indicating that the channel arrangement also affects the flow uniformity. The experimental results on flow uniformity are in good agreement with simulation. The deviation in conversion of propane from channel to channel is within experimental error, indicating that the reactor can reliably screen catalysts and deliver kinetics. A half a dozen catalysts were tested for complete propane oxidation using the developed technology. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie302093u
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16270–16277[article] Design and fabrication of a high-throughput microreactor and its evaluation for highly exothermic reactions [texte imprimé] / Nageswara Rao Peela, Auteur ; Ivan C. Lee, Auteur ; Dionisios G. Vlachos, Auteur . - 2013 . - pp. 16270–16277.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16270–16277
Mots-clés : Microreactor Résumé : The effect of distributor and channel positions on flow uniformity in a high-throughput reactor is studied using a COMSOL MULTIPHYSICS, CFD package. The best design is subsequently fabricated and evaluated for propane total oxidation reaction at low conversions. Comparison of our design with a literature design is also presented. The results indicate that the conical distributor performs significantly better in terms of flow uniformity as compared to the commonly used disc shaped distributor. The flow uniformity is improved when the central channel is removed from the design, indicating that the channel arrangement also affects the flow uniformity. The experimental results on flow uniformity are in good agreement with simulation. The deviation in conversion of propane from channel to channel is within experimental error, indicating that the reactor can reliably screen catalysts and deliver kinetics. A half a dozen catalysts were tested for complete propane oxidation using the developed technology. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie302093u Exemplaires
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Titre : Autothermal partial oxidation of glycerol to syngas over Pt-, LaMnO3-, and Pt/LaMnO3-coated monoliths Type de document : texte imprimé Auteurs : Shih-Kang Liu, Auteur ; Yu-Chuan Lin, Auteur Année de publication : 2013 Article en page(s) : pp. 16278-16287 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Monolithic construction Synthesis gas Partial oxidation Résumé : Glycerol and glycerol/water solution were converted to syngas over Pt-, LaMnO3-, and Pt/LaMnO3-coated monoliths under autothermal partial oxidation. XRD and SEM were used to characterize the phase compositions and surface morphologies of freshly prepared and postreaction catalysts. A continuous fixed-bed design, without an upstream vaporizer or external heat supply, was operated at millisecond contact times. Among the catalysts used in this study, Pt was the least reactive, and its activity was found to be reduced by sintering. Pt also tended to produce nonequilibrium products such as ethylene and acetaldehyde in fuel-rich environments. In contrast, LaMnO3 was found to favor glycerol combustion, producing fewer minor products and generating sufficient heat to sustain autothermal operations in fuel- and steam-rich regimes. Pt supported on LaMnO3 showed a synergistic effect of Pt sintering suppression and a broad H2/CO distribution in the resulting syngas. This effect can be correlated to the interaction between Pt and LaMnO3. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732154
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16278-16287[article] Autothermal partial oxidation of glycerol to syngas over Pt-, LaMnO3-, and Pt/LaMnO3-coated monoliths [texte imprimé] / Shih-Kang Liu, Auteur ; Yu-Chuan Lin, Auteur . - 2013 . - pp. 16278-16287.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16278-16287
Mots-clés : Monolithic construction Synthesis gas Partial oxidation Résumé : Glycerol and glycerol/water solution were converted to syngas over Pt-, LaMnO3-, and Pt/LaMnO3-coated monoliths under autothermal partial oxidation. XRD and SEM were used to characterize the phase compositions and surface morphologies of freshly prepared and postreaction catalysts. A continuous fixed-bed design, without an upstream vaporizer or external heat supply, was operated at millisecond contact times. Among the catalysts used in this study, Pt was the least reactive, and its activity was found to be reduced by sintering. Pt also tended to produce nonequilibrium products such as ethylene and acetaldehyde in fuel-rich environments. In contrast, LaMnO3 was found to favor glycerol combustion, producing fewer minor products and generating sufficient heat to sustain autothermal operations in fuel- and steam-rich regimes. Pt supported on LaMnO3 showed a synergistic effect of Pt sintering suppression and a broad H2/CO distribution in the resulting syngas. This effect can be correlated to the interaction between Pt and LaMnO3. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732154 Exemplaires
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Titre : Effective and intrinsic kinetics of the two-phase alkylation of i-paraffins with olefins using chloroaluminate ionic liquids as catalyst Type de document : texte imprimé Auteurs : Stephan Josef Aschauer, Auteur ; Andreas Jess, Auteur Année de publication : 2013 Article en page(s) : pp. 16288-16298 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Ionic liquid Alkylation Kinetics Résumé : Acidic ionic liquids (IL) are attractive alternative catalysts in refinery alkylation of i-paraffins with light olefins, but the intrinsic kinetics and influence of mass transfer on the effective kinetics in this biphasic system is still unknown. Solubility measurements were conducted (largely with neutral, nonacidic ILs) using mixtures of i-hexane/2-hexene and i-pentane/ 2-pentene, respectively, to determine the Nernst partition coefficient and thus the maximum concentration of olefms and paraffins in the IL. Thereafter, kinetic studies were carried out both in a stirred and nonstirred batch reactor using i-hexane/ 1-hexene and i-pentane/1-pentene. In the static system, the concentration profile of the particular olefin in the organic phase was measured. The experimental results are in good agreement with the simulation based on the interplay of the chemical reaction in the ionic liquid as well as of the external and internal mass transfer to the interface and into the IL. The effective reaction rate of alkylation is proportional to the interfacial surface area between organic and IL phase: The intrinsic chemical reaction is very fast which leads to a strong mass transfer limitation of the olefin into the IL phase. Hence, the effectiveness (compared to utilization of the entire IL phase) is very low, and the alkylation reaction takes place in a very thin layer with a thickness of only around 5 μm. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732155
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16288-16298[article] Effective and intrinsic kinetics of the two-phase alkylation of i-paraffins with olefins using chloroaluminate ionic liquids as catalyst [texte imprimé] / Stephan Josef Aschauer, Auteur ; Andreas Jess, Auteur . - 2013 . - pp. 16288-16298.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16288-16298
Mots-clés : Catalyst Ionic liquid Alkylation Kinetics Résumé : Acidic ionic liquids (IL) are attractive alternative catalysts in refinery alkylation of i-paraffins with light olefins, but the intrinsic kinetics and influence of mass transfer on the effective kinetics in this biphasic system is still unknown. Solubility measurements were conducted (largely with neutral, nonacidic ILs) using mixtures of i-hexane/2-hexene and i-pentane/ 2-pentene, respectively, to determine the Nernst partition coefficient and thus the maximum concentration of olefms and paraffins in the IL. Thereafter, kinetic studies were carried out both in a stirred and nonstirred batch reactor using i-hexane/ 1-hexene and i-pentane/1-pentene. In the static system, the concentration profile of the particular olefin in the organic phase was measured. The experimental results are in good agreement with the simulation based on the interplay of the chemical reaction in the ionic liquid as well as of the external and internal mass transfer to the interface and into the IL. The effective reaction rate of alkylation is proportional to the interfacial surface area between organic and IL phase: The intrinsic chemical reaction is very fast which leads to a strong mass transfer limitation of the olefin into the IL phase. Hence, the effectiveness (compared to utilization of the entire IL phase) is very low, and the alkylation reaction takes place in a very thin layer with a thickness of only around 5 μm. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732155 Exemplaires
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Titre : Gas–liquid reactive crystallization kinetics of hydromagnesite in the MgCl2–CO2–NH3–H2O system : Its potential in CO2 sequestration Type de document : texte imprimé Auteurs : Daoguang Wang, Auteur ; Zhibao Li, Auteur Année de publication : 2013 Article en page(s) : pp. 16299-16310 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon dioxide Kinetics Chemical precipitation Résumé : The reactive crystallization kinetics of hydromagnesite in the MgCl2―CO2―NH3―H2O system, which plays an important role in a new approach to sequester CO2 with saline sea/lake brines, was systematically investigated by the MSMPR (mixed-suspension-mixed-product removal) crystallization method. The temperature effect on the crystallization of magnesium carbonate hydrates in the system was first investigated batchwise. The optimum temperature of 353.2 K for precipitation of the regular spherical hydromagnesite with good filterability was selected for kinetic study. The supersaturation of hydromagnesite was experimentally tested, and the activity coefficients of aqueous species were strictly calculated by the Pitzer model embedded in the Aspen Plus platform. The nucleation and growth rate and agglomeration kernel were determined by moments analysis based on the PSD (particle size distribution) of crystals in volume coordinates. The corresponding kinetic parameters in three empirical equations were then estimated by linear regression. The resulting volume growth rate order of 2.30 means that surface integration is dominant in the volume growth of hydromagnesite. A simplified process for the new sequestration approach was finally constructed. The value of hydromagnesite as carbonated product was assessed considering the scale-up and costs of such a process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732156
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16299-16310[article] Gas–liquid reactive crystallization kinetics of hydromagnesite in the MgCl2–CO2–NH3–H2O system : Its potential in CO2 sequestration [texte imprimé] / Daoguang Wang, Auteur ; Zhibao Li, Auteur . - 2013 . - pp. 16299-16310.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16299-16310
Mots-clés : Carbon dioxide Kinetics Chemical precipitation Résumé : The reactive crystallization kinetics of hydromagnesite in the MgCl2―CO2―NH3―H2O system, which plays an important role in a new approach to sequester CO2 with saline sea/lake brines, was systematically investigated by the MSMPR (mixed-suspension-mixed-product removal) crystallization method. The temperature effect on the crystallization of magnesium carbonate hydrates in the system was first investigated batchwise. The optimum temperature of 353.2 K for precipitation of the regular spherical hydromagnesite with good filterability was selected for kinetic study. The supersaturation of hydromagnesite was experimentally tested, and the activity coefficients of aqueous species were strictly calculated by the Pitzer model embedded in the Aspen Plus platform. The nucleation and growth rate and agglomeration kernel were determined by moments analysis based on the PSD (particle size distribution) of crystals in volume coordinates. The corresponding kinetic parameters in three empirical equations were then estimated by linear regression. The resulting volume growth rate order of 2.30 means that surface integration is dominant in the volume growth of hydromagnesite. A simplified process for the new sequestration approach was finally constructed. The value of hydromagnesite as carbonated product was assessed considering the scale-up and costs of such a process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732156 Exemplaires
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Titre : Artificial neural networks, optimization and kinetic modeling of amoxicillin degradation in photo-fenton process using aluminum pillared montmorillonite-supported ferrioxalate catalyst Type de document : texte imprimé Auteurs : O. B. Ayodele, Auteur ; H. S. Auta, Auteur ; N. Md Nor, Auteur Année de publication : 2013 Article en page(s) : pp. 16311-16319 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Modeling Catalyst Montmorillonite Fenton reaction PhotooxidationKinetic model Optimization Neural network Résumé : An artificial neural network (ANN) was applied to study the hierarchy of significance of process variables affecting the degradation of amoxicillin (AMX) in a heterogeneous photo-Fenton process. Catalyst and H2O2 dosages were found to be the most significant variables followed by degradation time and concentration of AMX. The significant variables were optimized and the optimum condition to achieve degradation of 97.87% of 40 ppm AMX was 21.54% excess H2O2 dosage, 2.24 g of catalyst in 10 min. A mathematical model (MM) for the degradation of AMX was developed on the basis of the combined results of the ANN and the optimization studies. The MM result showed that increases in both catalyst and H2O2 dosage enhanced the rate of AMX degradation as shown by the rate constants evaluated from the model. The highest rate constant at the optimum conditions was 122 M―1 S―1. These results provided invaluable insights into the catalytic degradation of AMX in photo-Fenton process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732157
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16311-16319[article] Artificial neural networks, optimization and kinetic modeling of amoxicillin degradation in photo-fenton process using aluminum pillared montmorillonite-supported ferrioxalate catalyst [texte imprimé] / O. B. Ayodele, Auteur ; H. S. Auta, Auteur ; N. Md Nor, Auteur . - 2013 . - pp. 16311-16319.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16311-16319
Mots-clés : Modeling Catalyst Montmorillonite Fenton reaction PhotooxidationKinetic model Optimization Neural network Résumé : An artificial neural network (ANN) was applied to study the hierarchy of significance of process variables affecting the degradation of amoxicillin (AMX) in a heterogeneous photo-Fenton process. Catalyst and H2O2 dosages were found to be the most significant variables followed by degradation time and concentration of AMX. The significant variables were optimized and the optimum condition to achieve degradation of 97.87% of 40 ppm AMX was 21.54% excess H2O2 dosage, 2.24 g of catalyst in 10 min. A mathematical model (MM) for the degradation of AMX was developed on the basis of the combined results of the ANN and the optimization studies. The MM result showed that increases in both catalyst and H2O2 dosage enhanced the rate of AMX degradation as shown by the rate constants evaluated from the model. The highest rate constant at the optimum conditions was 122 M―1 S―1. These results provided invaluable insights into the catalytic degradation of AMX in photo-Fenton process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732157 Exemplaires
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Titre : Gas–liquid effective interfacial area in a rotating packed bed Type de document : texte imprimé Auteurs : Yong Luo, Auteur ; Guang-Wen Chu, Auteur ; Hai-Kui Zou, Auteur Année de publication : 2013 Article en page(s) : pp. 16320–16325 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas Liquid Résumé : Stainless steel wire mesh packing is widely used for experimental and industrial applications in rotating packed beds (RPBs) for gas–liquid contacting because it has a higher mass-transfer performance than other conventional packings. In this work, the gas–liquid effective interfacial area of a conventional RPB was studied with eight types of stainless steel wire mesh packings, consisting of four different stainless steel fibers. Gas–liquid chemisorption with CO2 in NaOH solution was employed to measure the effective interfacial area for all types of packings with different rotational speeds and gas–liquid ratios. An empirical correlation that takes the effects of the fiber diameter and opening size of the wire mesh into consideration was proposed for the calculation of the gas–liquid effective interfacial area of stainless steel wire mesh packings in a conventional RPB. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie302531j
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16320–16325[article] Gas–liquid effective interfacial area in a rotating packed bed [texte imprimé] / Yong Luo, Auteur ; Guang-Wen Chu, Auteur ; Hai-Kui Zou, Auteur . - 2013 . - pp. 16320–16325.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16320–16325
Mots-clés : Gas Liquid Résumé : Stainless steel wire mesh packing is widely used for experimental and industrial applications in rotating packed beds (RPBs) for gas–liquid contacting because it has a higher mass-transfer performance than other conventional packings. In this work, the gas–liquid effective interfacial area of a conventional RPB was studied with eight types of stainless steel wire mesh packings, consisting of four different stainless steel fibers. Gas–liquid chemisorption with CO2 in NaOH solution was employed to measure the effective interfacial area for all types of packings with different rotational speeds and gas–liquid ratios. An empirical correlation that takes the effects of the fiber diameter and opening size of the wire mesh into consideration was proposed for the calculation of the gas–liquid effective interfacial area of stainless steel wire mesh packings in a conventional RPB. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie302531j Exemplaires
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Titre : Transparent epoxy acrylate resin nanocomposites reinforced with cellulose nanocrystals Type de document : texte imprimé Auteurs : Haifeng Pan, Auteur ; Lei Song, Auteur ; Liyan Ma, Auteur Année de publication : 2013 Article en page(s) : pp. 16326-16332 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanocrystal Nanocomposite Résumé : A series of nanocomposites based on cellulose nanocrystals (CNCs) and epoxy acrylate resin (EA) were prepared using solution casting followed by UV curing. The microstructure of the CNCs and nanocomposites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The thermal behavior and dynamic mechanical properties of the nanocomposites were determined using dynamical mechanical analysis (DMA) and thermogravimetric analysis (TGA). The transparency of the nanocomposite films was examined by UV―vis transmission spectroscopy. TGA results showed that the thermal stability of EA was affected slightly after incorporation of CNCs. The results from DMA showed that the storage modulus of nanocomposites improved over the entire temperature range compared to pure EA derived from the reinforcing effect of the CNCs. The glass transition temperature of nanocomposites was increased with the increase of CNC loading levels. The ultraviolet-visible spectra of the films showed no obvious absorbance over a range of 400—800 nm, which revealed that the films were transparent. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732159
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16326-16332[article] Transparent epoxy acrylate resin nanocomposites reinforced with cellulose nanocrystals [texte imprimé] / Haifeng Pan, Auteur ; Lei Song, Auteur ; Liyan Ma, Auteur . - 2013 . - pp. 16326-16332.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16326-16332
Mots-clés : Nanocrystal Nanocomposite Résumé : A series of nanocomposites based on cellulose nanocrystals (CNCs) and epoxy acrylate resin (EA) were prepared using solution casting followed by UV curing. The microstructure of the CNCs and nanocomposites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The thermal behavior and dynamic mechanical properties of the nanocomposites were determined using dynamical mechanical analysis (DMA) and thermogravimetric analysis (TGA). The transparency of the nanocomposite films was examined by UV―vis transmission spectroscopy. TGA results showed that the thermal stability of EA was affected slightly after incorporation of CNCs. The results from DMA showed that the storage modulus of nanocomposites improved over the entire temperature range compared to pure EA derived from the reinforcing effect of the CNCs. The glass transition temperature of nanocomposites was increased with the increase of CNC loading levels. The ultraviolet-visible spectra of the films showed no obvious absorbance over a range of 400—800 nm, which revealed that the films were transparent. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732159 Exemplaires
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Titre : Effects of morphology and Zr doping on structural, optical, and photocatalytic properties of ZnO nanostructures Type de document : texte imprimé Auteurs : N. Clament Sagaya Selvam, Auteur ; J. Judith Vijaya, Auteur ; L. John Kennedy, Auteur Année de publication : 2013 Article en page(s) : pp. 16333-16345 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanostructure Photocatalysis Doping Morphology Résumé : ZnO nanomaterials with different morphologies such as nanoflakes, spherical nanoparticles (SNPs), and nanorods have been synthesized via a simple low temperature coprecipitation method. The concentration of the capping agent is a key factor in the morphological control of ZnO nanostructures. Triton X-100 micelles were found to be single molecules at low concentration but spherical and rod-like shaped micellar aggregation at higher concentrations. The formation of different morphologies of ZnO was confirmed by HR-SEM and HR-TEM. XRD data showed the formation of single-phase ZnO with the wurtzite crystal structure. The influence of Zr contents on the structure, morphology, absorption, emission, and photocatalytic activity of ZnO SNPs was investigated systematically. The influence of the ZnO morphologies on the photocatalytic degradation (PCD) of resorcinol as a model reaction is evaluated and discussed in terms of particle size, surface area, crystal growth habits, and oxygen defects. The results indicated that the particle size is an important factor for the PCD, and thus, the 1.5 wt % Zr- doped ZnO SNPs show superior performance toward PCD of resorcinol than other samples due to the small particle size distribution. Furthermore, the effect of different photocatalytic reaction parameters on the resulting PCD efficiency of ZnO SNPs was investigated. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732160
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16333-16345[article] Effects of morphology and Zr doping on structural, optical, and photocatalytic properties of ZnO nanostructures [texte imprimé] / N. Clament Sagaya Selvam, Auteur ; J. Judith Vijaya, Auteur ; L. John Kennedy, Auteur . - 2013 . - pp. 16333-16345.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16333-16345
Mots-clés : Nanostructure Photocatalysis Doping Morphology Résumé : ZnO nanomaterials with different morphologies such as nanoflakes, spherical nanoparticles (SNPs), and nanorods have been synthesized via a simple low temperature coprecipitation method. The concentration of the capping agent is a key factor in the morphological control of ZnO nanostructures. Triton X-100 micelles were found to be single molecules at low concentration but spherical and rod-like shaped micellar aggregation at higher concentrations. The formation of different morphologies of ZnO was confirmed by HR-SEM and HR-TEM. XRD data showed the formation of single-phase ZnO with the wurtzite crystal structure. The influence of Zr contents on the structure, morphology, absorption, emission, and photocatalytic activity of ZnO SNPs was investigated systematically. The influence of the ZnO morphologies on the photocatalytic degradation (PCD) of resorcinol as a model reaction is evaluated and discussed in terms of particle size, surface area, crystal growth habits, and oxygen defects. The results indicated that the particle size is an important factor for the PCD, and thus, the 1.5 wt % Zr- doped ZnO SNPs show superior performance toward PCD of resorcinol than other samples due to the small particle size distribution. Furthermore, the effect of different photocatalytic reaction parameters on the resulting PCD efficiency of ZnO SNPs was investigated. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732160 Exemplaires
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Titre : Structural change of bitumen in the recycling process by using rheology and NMR Type de document : texte imprimé Auteurs : Luigi Filippelli, Auteur ; Luigi Gentile, Auteur ; Cesare Oliviero Rossi, Auteur Année de publication : 2013 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Rheology Résumé : The mechanical properties of bitumen are the result of the chemical composition and arrangement of the molecular structures (phases present). The loss of elasticity of the bitumen with aging is mainly due to the oxidation of aromatic compounds and resins. This work deals with the recycling process of bitumen, by following the changes in the bitumen structure. Fresh, aged, and doped recycled bitumens were investigated. Rheology and nuclear magnetic resonance were used to monitor the differences between the bitumens and the role of the additives. As a novel approach to the understanding of the colloidal nature of the bitumen, an inverse Laplace transform of the NMR spin-echo decay (T2) was applied. The results indicate that the rejuvenating additives have little influence on the solid–liquid transition. However, they help to restructure the aged bitumen, thus facilitating workability at a lower temperature. Two-dimensional maps of the structure distributions were reconstructed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301899v
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012)[article] Structural change of bitumen in the recycling process by using rheology and NMR [texte imprimé] / Luigi Filippelli, Auteur ; Luigi Gentile, Auteur ; Cesare Oliviero Rossi, Auteur . - 2013.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012)
Mots-clés : Rheology Résumé : The mechanical properties of bitumen are the result of the chemical composition and arrangement of the molecular structures (phases present). The loss of elasticity of the bitumen with aging is mainly due to the oxidation of aromatic compounds and resins. This work deals with the recycling process of bitumen, by following the changes in the bitumen structure. Fresh, aged, and doped recycled bitumens were investigated. Rheology and nuclear magnetic resonance were used to monitor the differences between the bitumens and the role of the additives. As a novel approach to the understanding of the colloidal nature of the bitumen, an inverse Laplace transform of the NMR spin-echo decay (T2) was applied. The results indicate that the rejuvenating additives have little influence on the solid–liquid transition. However, they help to restructure the aged bitumen, thus facilitating workability at a lower temperature. Two-dimensional maps of the structure distributions were reconstructed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301899v Exemplaires
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Titre : Synthesis of heavy tungsten alloy by thermal technique Type de document : texte imprimé Auteurs : K. S. Abdel Halim, Auteur ; M. Bram, Auteur ; H. P. Buchkremer, Auteur Année de publication : 2013 Article en page(s) : pp. 16354–16360 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermal Technique Résumé : Heavy tungsten alloy with composition 93W:3Ni:2Fe:2Co was successfully prepared through gaseous reduction technique. Starting from tungsten, nickel, iron, and cobalt oxides, a mixture of these oxide powders was reduced by treatment in hydrogen. The course of reduction was followed up by measuring the weight loss as a function of time in the temperature range of 850–1000 °C. Afterward, samples were subjected to sintering process in reducing atmosphere (Ar/4% H2) at different temperatures (1300–1500 °C) and dwell times (30, 90 min) to investigate the microstructural changes occurring during sintering. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the reduced samples. The microhardness of the sintered samples was measured and correlated to sintering temperature and dwell time. It was found that the heavy tungsten alloy can be synthesized from metal oxide at reduction temperatures above 850 °C. The reduction rate increased with temperature. The values of the apparent activation energy were calculated from Arrhenius plots and correlated with the reduction mechanism. Considering the activation energy values, the course of reduction is most likely controlled by interfacial chemical reaction mechanisms. With increase of sintering temperature and dwell time, transition from solid-state diffusion to liquid-phase sintering took place, which led to rapid densification of the alloy together with formation of tungsten solid phase. Increase of densification was also coupled with increase of hardness. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301947e
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16354–16360[article] Synthesis of heavy tungsten alloy by thermal technique [texte imprimé] / K. S. Abdel Halim, Auteur ; M. Bram, Auteur ; H. P. Buchkremer, Auteur . - 2013 . - pp. 16354–16360.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16354–16360
Mots-clés : Thermal Technique Résumé : Heavy tungsten alloy with composition 93W:3Ni:2Fe:2Co was successfully prepared through gaseous reduction technique. Starting from tungsten, nickel, iron, and cobalt oxides, a mixture of these oxide powders was reduced by treatment in hydrogen. The course of reduction was followed up by measuring the weight loss as a function of time in the temperature range of 850–1000 °C. Afterward, samples were subjected to sintering process in reducing atmosphere (Ar/4% H2) at different temperatures (1300–1500 °C) and dwell times (30, 90 min) to investigate the microstructural changes occurring during sintering. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the reduced samples. The microhardness of the sintered samples was measured and correlated to sintering temperature and dwell time. It was found that the heavy tungsten alloy can be synthesized from metal oxide at reduction temperatures above 850 °C. The reduction rate increased with temperature. The values of the apparent activation energy were calculated from Arrhenius plots and correlated with the reduction mechanism. Considering the activation energy values, the course of reduction is most likely controlled by interfacial chemical reaction mechanisms. With increase of sintering temperature and dwell time, transition from solid-state diffusion to liquid-phase sintering took place, which led to rapid densification of the alloy together with formation of tungsten solid phase. Increase of densification was also coupled with increase of hardness. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301947e Exemplaires
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Titre : Nanostructured ZnO thin films for optical, electrical, and photoelectrochemical applications from a new Zn complex Type de document : texte imprimé Auteurs : Muhammad Shahid, Auteur ; Mazhar Hamid, Auteur ; Asif A. Tahir, Auteur Année de publication : 2013 Article en page(s) : pp. 16361–16368 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thin film Résumé : New hexanuclear zinc complex, Zn6(OAc)8(μ-O)2(dmae)4 (1) (OAc = acetato, dmae = N,N-dimethyl aminoethanolato) has been synthesized and characterized by its melting point, elemental analysis, Fourier transform infrared spectroscopy, atmospheric-pressure chemical-ionization mass spectrometry, thermal gravimetric analysis, and single crystal X-ray analysis. The complex (1) crystallizes in the monoclinic space group C2/c. The high solubility of complex (1) in organic solvents such as alcohol, THF, and toluene and low decomposition temperature as compared to Zn(OAc)2 make it a promising single source candidate for the deposition of nanostructured ZnO thin films by aerosol-assisted chemical vapor deposition. Films with various nanostructures, morphology, and crystallographic orientation have been deposited by controlling the deposition temperature. The deposited films have been characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analysis. The optical characterization of ZnO films deposited on the FTO substrate show a direct band gap of 3.31 eV, and the photoelectrochemical study revealed that the photocurrent onset is at about −0.32 V, whereas no photocurrent saturation was observed. The I–V measurements designated the deposited films as ohmic semiconductors. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732163
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16361–16368[article] Nanostructured ZnO thin films for optical, electrical, and photoelectrochemical applications from a new Zn complex [texte imprimé] / Muhammad Shahid, Auteur ; Mazhar Hamid, Auteur ; Asif A. Tahir, Auteur . - 2013 . - pp. 16361–16368.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16361–16368
Mots-clés : Thin film Résumé : New hexanuclear zinc complex, Zn6(OAc)8(μ-O)2(dmae)4 (1) (OAc = acetato, dmae = N,N-dimethyl aminoethanolato) has been synthesized and characterized by its melting point, elemental analysis, Fourier transform infrared spectroscopy, atmospheric-pressure chemical-ionization mass spectrometry, thermal gravimetric analysis, and single crystal X-ray analysis. The complex (1) crystallizes in the monoclinic space group C2/c. The high solubility of complex (1) in organic solvents such as alcohol, THF, and toluene and low decomposition temperature as compared to Zn(OAc)2 make it a promising single source candidate for the deposition of nanostructured ZnO thin films by aerosol-assisted chemical vapor deposition. Films with various nanostructures, morphology, and crystallographic orientation have been deposited by controlling the deposition temperature. The deposited films have been characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analysis. The optical characterization of ZnO films deposited on the FTO substrate show a direct band gap of 3.31 eV, and the photoelectrochemical study revealed that the photocurrent onset is at about −0.32 V, whereas no photocurrent saturation was observed. The I–V measurements designated the deposited films as ohmic semiconductors. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732163 Exemplaires
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Titre : Synthesis, crystallization kinetics, and morphology of novel biodegradable poly(butylene succinate-co-hexamethylene succinate) copolyesters Type de document : texte imprimé Auteurs : Guyu Wang, Auteur ; Zhaobin Qiu, Auteur Année de publication : 2013 Article en page(s) : pp. 16369-16376 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Morphology Kinetics Crystallization Résumé : Biodegradable poly(butylene succinate) and a series of poly(butylene succinate-co- hexamethylene succinate) (P(BS-co-HS)) with hexamethylene succinate (HS) comonomer composition ranging from 14 to 35 mol % were prepared in the present work via a two-stage melt polycondensation method. Basic thermal behaviors, crystal structure, isothermal melt crystallization kinetics, and spherultic morphology and growth of P(BS-co-HS) copolyesters with different HS composition were studied in detail with various techniques and compared with those of neat PBS. With respect to neat PBS, the glass transition temperature of P(BS-co-HS) decreases slightly, while the melting point temperature and equilibrium melting point temperature of P(BS-co-HS) are reduced significantly with an increase in the HS composition. Both neat PBS and P(BS-co-HS) have the same crystal structure; however, the crystallinity values are slightly smaller in P(BS-co-HS) than in neat PES. The overall isothermal melt crystallization kinetics of neat PBS and P(BS-co-HS) were studied in a wide crystallization temperature range and analyzed by the Avrami equation. The experimental results indicate that the crystallization mechanism remains unchanged for both neat PBS and P(BS-co-HS); however, the overall crystallization rates of P(BS-co-HS) decrease with increasing HS composition and crystallization temperature. The spherulitic morphology of neat PBS and P(BS-co-HS) were also investigated in a wide crystallization temperature range; moreover, the spherulitic growth rates of P(BS-co-HS) also decrease with increasing HS content and crystallization temperature. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732164
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16369-16376[article] Synthesis, crystallization kinetics, and morphology of novel biodegradable poly(butylene succinate-co-hexamethylene succinate) copolyesters [texte imprimé] / Guyu Wang, Auteur ; Zhaobin Qiu, Auteur . - 2013 . - pp. 16369-16376.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16369-16376
Mots-clés : Morphology Kinetics Crystallization Résumé : Biodegradable poly(butylene succinate) and a series of poly(butylene succinate-co- hexamethylene succinate) (P(BS-co-HS)) with hexamethylene succinate (HS) comonomer composition ranging from 14 to 35 mol % were prepared in the present work via a two-stage melt polycondensation method. Basic thermal behaviors, crystal structure, isothermal melt crystallization kinetics, and spherultic morphology and growth of P(BS-co-HS) copolyesters with different HS composition were studied in detail with various techniques and compared with those of neat PBS. With respect to neat PBS, the glass transition temperature of P(BS-co-HS) decreases slightly, while the melting point temperature and equilibrium melting point temperature of P(BS-co-HS) are reduced significantly with an increase in the HS composition. Both neat PBS and P(BS-co-HS) have the same crystal structure; however, the crystallinity values are slightly smaller in P(BS-co-HS) than in neat PES. The overall isothermal melt crystallization kinetics of neat PBS and P(BS-co-HS) were studied in a wide crystallization temperature range and analyzed by the Avrami equation. The experimental results indicate that the crystallization mechanism remains unchanged for both neat PBS and P(BS-co-HS); however, the overall crystallization rates of P(BS-co-HS) decrease with increasing HS composition and crystallization temperature. The spherulitic morphology of neat PBS and P(BS-co-HS) were also investigated in a wide crystallization temperature range; moreover, the spherulitic growth rates of P(BS-co-HS) also decrease with increasing HS content and crystallization temperature. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732164 Exemplaires
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Titre : Investigation on a novel fly ash based calcium silicate filler : Effect of particle size on paper properties Type de document : texte imprimé Auteurs : Shunxi Song, Auteur ; Meiyun Zhang, Auteur ; Zhibin He, Auteur Année de publication : 2013 Article en page(s) : pp. 16377–16384 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fly ash Particle Résumé : Value-added utilization of fly ash has recently gained a strong interest. As a solid waste, fly ash can be used as a paper filler, and the recent innovation on the production of high-brightness fly ash products further facilitated such applications. This work reports the results on using the novel fly ash based fillers in the paper making process, with a focus on the effect of filler particle size. In comparison with ground calcium carbonate (GCC) commonly used as paper fillers, the original fly ash based calcium silicate filler (FACS) has a larger particle size (27.6 μm), a much lower true density (1.3–1.4 g/cm3), a higher specific surface area (121 m2/g), and a similar brightness (91% ISO). FACS exhibits porous, aggregated, and needle-like morphologies based on the results of scanning electron microscope image analysis. Ball milling decreased the particle size, broadened the particle size distribution, and improved the brightness while changing its morphology. The paper bulk increased dramatically when the original FACS was used due to its large particle size and narrow particle size distribution. With ball milling, the paper bulk and porosity decreased with decreasing particle size at the same filler content, while the tensile index increased. In addition, the ball milled FACS-filled paper had better light scattering coefficient and brightness than the GCC-filled paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3028813
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16377–16384[article] Investigation on a novel fly ash based calcium silicate filler : Effect of particle size on paper properties [texte imprimé] / Shunxi Song, Auteur ; Meiyun Zhang, Auteur ; Zhibin He, Auteur . - 2013 . - pp. 16377–16384.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16377–16384
Mots-clés : Fly ash Particle Résumé : Value-added utilization of fly ash has recently gained a strong interest. As a solid waste, fly ash can be used as a paper filler, and the recent innovation on the production of high-brightness fly ash products further facilitated such applications. This work reports the results on using the novel fly ash based fillers in the paper making process, with a focus on the effect of filler particle size. In comparison with ground calcium carbonate (GCC) commonly used as paper fillers, the original fly ash based calcium silicate filler (FACS) has a larger particle size (27.6 μm), a much lower true density (1.3–1.4 g/cm3), a higher specific surface area (121 m2/g), and a similar brightness (91% ISO). FACS exhibits porous, aggregated, and needle-like morphologies based on the results of scanning electron microscope image analysis. Ball milling decreased the particle size, broadened the particle size distribution, and improved the brightness while changing its morphology. The paper bulk increased dramatically when the original FACS was used due to its large particle size and narrow particle size distribution. With ball milling, the paper bulk and porosity decreased with decreasing particle size at the same filler content, while the tensile index increased. In addition, the ball milled FACS-filled paper had better light scattering coefficient and brightness than the GCC-filled paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3028813 Exemplaires
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Titre : Analysis of the thermal efficiency limit of the steam methane reforming process Type de document : texte imprimé Auteurs : X. D. Peng, Auteur Année de publication : 2013 Article en page(s) : pp. 16385–16392 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reforming process Résumé : The thermal efficiency limit of the steam methane reforming (SMR) process is analyzed on the basis of energy balance and pinch analysis. The composite heat exchange curves of the SMR process are characterized by internal pinches. These internal pinches determine the process efficiency limit. An analytical solution for the process efficiency limit is derived from energy balance across the composite heat exchange curves. The solution can be used to calculate the process efficiency limit for any given set of reaction and process conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3002843
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16385–16392[article] Analysis of the thermal efficiency limit of the steam methane reforming process [texte imprimé] / X. D. Peng, Auteur . - 2013 . - pp. 16385–16392.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16385–16392
Mots-clés : Reforming process Résumé : The thermal efficiency limit of the steam methane reforming (SMR) process is analyzed on the basis of energy balance and pinch analysis. The composite heat exchange curves of the SMR process are characterized by internal pinches. These internal pinches determine the process efficiency limit. An analytical solution for the process efficiency limit is derived from energy balance across the composite heat exchange curves. The solution can be used to calculate the process efficiency limit for any given set of reaction and process conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3002843 Exemplaires
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Titre : Dynamics and control of reactive distillation under multiple steady states based on a nonlinear wave theory Type de document : texte imprimé Auteurs : Bo-kyung Kim, Auteur ; Myungwan Han, Auteur Année de publication : 2013 Article en page(s) : pp. 16393–16409 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Distillation Dynamics Résumé : Reactive distillation, which combines reaction and distillation in a single vessel, is receiving increasing attention because of its great potential for use in process intensification. The superposition of reaction and separation in a single processing unit can introduce new patterns of dynamic behavior such as multiplicity and oscillation. Acetic acid was effectively recovered from its dilute aqueous solution in the form of methyl acetate by reactive distillation. The reactive distillation column converting the acetic acid to the methyl acetate was highly nonlinear and showed steady-state multiplicity under certain conditions. The dynamic behavior of the column under multiple steady states was demonstrated to be well explained by nonlinear wave propagation theory. If the maximum conversion was obtained under the condition where the multiplicity appears, then a conventional control scheme could not deal with the control difficulty due to the multiplicity. A profile position control scheme based on wave propagation theory was proposed for the control of the column under multiple steady states, and the performance of the proposed controller was compared with that of conventional controllers. The proposed control scheme using profile positions as controlled variables was shown to give an excellent performance for the control of the reaction conversion and product purity in the reactive distillation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300923y
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16393–16409[article] Dynamics and control of reactive distillation under multiple steady states based on a nonlinear wave theory [texte imprimé] / Bo-kyung Kim, Auteur ; Myungwan Han, Auteur . - 2013 . - pp. 16393–16409.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16393–16409
Mots-clés : Distillation Dynamics Résumé : Reactive distillation, which combines reaction and distillation in a single vessel, is receiving increasing attention because of its great potential for use in process intensification. The superposition of reaction and separation in a single processing unit can introduce new patterns of dynamic behavior such as multiplicity and oscillation. Acetic acid was effectively recovered from its dilute aqueous solution in the form of methyl acetate by reactive distillation. The reactive distillation column converting the acetic acid to the methyl acetate was highly nonlinear and showed steady-state multiplicity under certain conditions. The dynamic behavior of the column under multiple steady states was demonstrated to be well explained by nonlinear wave propagation theory. If the maximum conversion was obtained under the condition where the multiplicity appears, then a conventional control scheme could not deal with the control difficulty due to the multiplicity. A profile position control scheme based on wave propagation theory was proposed for the control of the column under multiple steady states, and the performance of the proposed controller was compared with that of conventional controllers. The proposed control scheme using profile positions as controlled variables was shown to give an excellent performance for the control of the reaction conversion and product purity in the reactive distillation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300923y Exemplaires
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Titre : Improvements in the design of the ammonia synthesis process implementing counter current gas permeation modules Type de document : texte imprimé Auteurs : Carlos Daniel Fischer, Auteur ; Oscar Alberto Iribarren, Auteur Année de publication : 2013 Article en page(s) : pp. 16410–16418 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Membrane separation Gaseous permeation Countercurrent flowDesign Résumé : This paper explores mass exchanging the outlet and inlet streams of the reactor, following a design heuristic proposed by Fischer and Iribarren in Industrial and Engineering Chemistry Research2011, 50 (11), 6849–6859 within the Hierarchical Process Design Procedure by J. M. Douglas in Conceptual Design of Chemical Processes, McGraw-Hill, 1988. When applied to the ammonia synthesis process, this design methodology generated a process alternative different from that previously proposed by other authors, resorting to ceramic membrane counter current gas permeation units to perform the mass exchange of hydrogen. This alternative design is shown to produce a reduction of the gas recycle stream (hydrogen and nitrogen) of up to an interesting 8.40%, reducing recompression associated costs. However, as the present cost of zeolite membranes is still high and their hydrogen–nitrogen selectivity moderate, in the optimal economical solution, the net annual income amounted to 4.56%, corresponding to U.S. $817,793/year savings. The heuristic was used again at a later refinement stage, yielding an appreciable percent reduction in the cost of recovering hydrogen from the purge. As gas permeation technology (and hydrogen permeation, in particular) is a very active R&D area, we hope that the results of this paper bring some attention to this novel (concentration driven) counter current application for gas permeation modules, apart from the presently more widespread (pressure driven) cross-flow application. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732168
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16410–16418[article] Improvements in the design of the ammonia synthesis process implementing counter current gas permeation modules [texte imprimé] / Carlos Daniel Fischer, Auteur ; Oscar Alberto Iribarren, Auteur . - 2013 . - pp. 16410–16418.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16410–16418
Mots-clés : Membrane separation Gaseous permeation Countercurrent flowDesign Résumé : This paper explores mass exchanging the outlet and inlet streams of the reactor, following a design heuristic proposed by Fischer and Iribarren in Industrial and Engineering Chemistry Research2011, 50 (11), 6849–6859 within the Hierarchical Process Design Procedure by J. M. Douglas in Conceptual Design of Chemical Processes, McGraw-Hill, 1988. When applied to the ammonia synthesis process, this design methodology generated a process alternative different from that previously proposed by other authors, resorting to ceramic membrane counter current gas permeation units to perform the mass exchange of hydrogen. This alternative design is shown to produce a reduction of the gas recycle stream (hydrogen and nitrogen) of up to an interesting 8.40%, reducing recompression associated costs. However, as the present cost of zeolite membranes is still high and their hydrogen–nitrogen selectivity moderate, in the optimal economical solution, the net annual income amounted to 4.56%, corresponding to U.S. $817,793/year savings. The heuristic was used again at a later refinement stage, yielding an appreciable percent reduction in the cost of recovering hydrogen from the purge. As gas permeation technology (and hydrogen permeation, in particular) is a very active R&D area, we hope that the results of this paper bring some attention to this novel (concentration driven) counter current application for gas permeation modules, apart from the presently more widespread (pressure driven) cross-flow application. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732168 Exemplaires
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Titre : Adjoint transfer matrix based decoupling control for multivariable processes Type de document : texte imprimé Auteurs : Yuling Shen, Auteur ; Youxian Sun, Auteur ; Shaoyuan Li, Auteur Année de publication : 2013 Article en page(s) : pp. 16419-16426 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Multivariable system Résumé : In this paper, a novel decoupling control scheme based on adjoint matrix is proposed. By introducing the concept of characteristic sequence, the characteristic sequence of both the adjoint transfer matrix and the determinant transfer function are derived from that of original process transfer matrix. The adjoint transfer matrix and determinant transfer function are then determined. Finally, the adjoint matrix is selected as a decoupler, and the decentralized controller is designed for the determinant transfer function. The effectiveness of the proposed design approach is verified by three multivariable industrial processes, which shows that it results in better overall performance compared with other methods. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732169
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16419-16426[article] Adjoint transfer matrix based decoupling control for multivariable processes [texte imprimé] / Yuling Shen, Auteur ; Youxian Sun, Auteur ; Shaoyuan Li, Auteur . - 2013 . - pp. 16419-16426.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16419-16426
Mots-clés : Multivariable system Résumé : In this paper, a novel decoupling control scheme based on adjoint matrix is proposed. By introducing the concept of characteristic sequence, the characteristic sequence of both the adjoint transfer matrix and the determinant transfer function are derived from that of original process transfer matrix. The adjoint transfer matrix and determinant transfer function are then determined. Finally, the adjoint matrix is selected as a decoupler, and the decentralized controller is designed for the determinant transfer function. The effectiveness of the proposed design approach is verified by three multivariable industrial processes, which shows that it results in better overall performance compared with other methods. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732169 Exemplaires
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Titre : Economic optimum design of the heterogeneous azeotropic dehydration of ethanol Type de document : texte imprimé Auteurs : William L. Luyben, Auteur Année de publication : 2013 Article en page(s) : pp. 16427–16432 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heterogeneous azeotropic Résumé : Several processes are available for the important operation of dehydrating ethanol/water mixtures to concentrations above the azeotrope (90 mol %). Heterogeneous azeotropic distillation has been studied using several entrainers: benzene, cyclohexane, isooctane, ethylene glycol, etc. A pioneering paper by Ryan and Doherty [Ryan, P. J.; Doherty, M. F. Design optimization of ternary heterogeneous azeotropic distillation sequences. AIChE J.1989, 35, 1592–1601.] explored several alternative process configurations and concluded that the three-column flowsheet with a preconcentrator (beer still), an azeotropic column, and a recovery column was the economic optimum. They used approximate ternary diagram methods. It appears that they arbitrarily assumed a beer still distillate composition with an ethanol concentration of about 88 mol %, which is quite close to the azeotropic composition of 90 mol %. Energy consumption in the beer still increases as its distillate composition gets closer to the azeotrope. On the other hand, energy consumption in the azeotropic-recovery column section of the process decreases as the feed to this section becomes richer in ethanol. It appears that this fundamental trade-off has not been studied in the literature. This paper examines quantitatively, using rigorous simulations, how this design parameter affects the energy and capital investment of the entire system. The focus is the distillate composition trade-off. The example used is the heterogeneous azeotropic distillation process, but the same issue applies in any of the other methods (such as extractive distillation) in which a preconcentrator column is used. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3020878
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16427–16432[article] Economic optimum design of the heterogeneous azeotropic dehydration of ethanol [texte imprimé] / William L. Luyben, Auteur . - 2013 . - pp. 16427–16432.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16427–16432
Mots-clés : Heterogeneous azeotropic Résumé : Several processes are available for the important operation of dehydrating ethanol/water mixtures to concentrations above the azeotrope (90 mol %). Heterogeneous azeotropic distillation has been studied using several entrainers: benzene, cyclohexane, isooctane, ethylene glycol, etc. A pioneering paper by Ryan and Doherty [Ryan, P. J.; Doherty, M. F. Design optimization of ternary heterogeneous azeotropic distillation sequences. AIChE J.1989, 35, 1592–1601.] explored several alternative process configurations and concluded that the three-column flowsheet with a preconcentrator (beer still), an azeotropic column, and a recovery column was the economic optimum. They used approximate ternary diagram methods. It appears that they arbitrarily assumed a beer still distillate composition with an ethanol concentration of about 88 mol %, which is quite close to the azeotropic composition of 90 mol %. Energy consumption in the beer still increases as its distillate composition gets closer to the azeotrope. On the other hand, energy consumption in the azeotropic-recovery column section of the process decreases as the feed to this section becomes richer in ethanol. It appears that this fundamental trade-off has not been studied in the literature. This paper examines quantitatively, using rigorous simulations, how this design parameter affects the energy and capital investment of the entire system. The focus is the distillate composition trade-off. The example used is the heterogeneous azeotropic distillation process, but the same issue applies in any of the other methods (such as extractive distillation) in which a preconcentrator column is used. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3020878 Exemplaires
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Titre : Solvent extraction equilibrium of zinc from nitrate solutions with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester Type de document : texte imprimé Auteurs : Chaitanya R. Adhikari, Auteur ; Hirokazu Narita, Auteur Année de publication : 2013 Article en page(s) : pp. 16433-16437 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solvent extraction Résumé : The solvent extraction equilibrium of zinc with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPNA) in an alkane diluent, Shellsol D70, was studied at a constant ionic strength of 1 mol/L from nitrate solutions considering the correction of the extractant nonideality in the organic phase by Alstad's method. On the basis of the slope analysis of the obtained data, a molar ratio of 1:2 for the zinc to the EHPNA dimer in the extracted complex was indicated. Apparent extraction equilibrium constants obtained at each temperature from 283 to 323 K showed the endothermic nature of the extraction reaction and gave the apparent standard enthalpy and entropy changes. These two constants enable the calculation of the zinc distribution ratio at each temperature which correlates the experimental data with good accuracy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732171
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16433-16437[article] Solvent extraction equilibrium of zinc from nitrate solutions with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester [texte imprimé] / Chaitanya R. Adhikari, Auteur ; Hirokazu Narita, Auteur . - 2013 . - pp. 16433-16437.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16433-16437
Mots-clés : Solvent extraction Résumé : The solvent extraction equilibrium of zinc with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPNA) in an alkane diluent, Shellsol D70, was studied at a constant ionic strength of 1 mol/L from nitrate solutions considering the correction of the extractant nonideality in the organic phase by Alstad's method. On the basis of the slope analysis of the obtained data, a molar ratio of 1:2 for the zinc to the EHPNA dimer in the extracted complex was indicated. Apparent extraction equilibrium constants obtained at each temperature from 283 to 323 K showed the endothermic nature of the extraction reaction and gave the apparent standard enthalpy and entropy changes. These two constants enable the calculation of the zinc distribution ratio at each temperature which correlates the experimental data with good accuracy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732171 Exemplaires
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Titre : Microemulsion extraction of gold(III) from hydrochloric acid medium using ionic liquid as surfactant and extractant Type de document : texte imprimé Auteurs : Yu Tong, Auteur ; Lu Han, Auteur ; Yanzhao Yang, Auteur Année de publication : 2013 Article en page(s) : pp. 16438–16443 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microemulsion Ionic Liquid Résumé : A microemulsion consisting of cyclohexane, n-hexanol, hydrochloric acid solution, and the ionic liquid 1-n-tetradecyl-3-methylimidazolium bromide ([C14mim]Br) was investigated for Au(III) extraction. In the extraction system, [C14mim]Br bears double functions of surfactant and extractant. The anion-exchange mechanism of Au(III) extraction by [C14mim]Br was confirmed by the method of continuous variation and infrared spectrum analysis. The effects of extraction time and various material concentrations were examined for Au(III) extraction. Under optimum conditions, almost all the Au(III) in hydrochloric acid solution was extracted to the microemulsion phase, which also has high selectivity for Au(III) over some metals (Cu(II), Cd(II), Co(II), Ni(II), Sb(III), Fe(III), Al(III), and Sn(IV)). Therefore, the extraction of Au(III) by the [C14mim]Br/cyclohexane/n-hexanol/HCl microemulsion is an efficient and effective approach with high selectivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301644t
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16438–16443[article] Microemulsion extraction of gold(III) from hydrochloric acid medium using ionic liquid as surfactant and extractant [texte imprimé] / Yu Tong, Auteur ; Lu Han, Auteur ; Yanzhao Yang, Auteur . - 2013 . - pp. 16438–16443.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16438–16443
Mots-clés : Microemulsion Ionic Liquid Résumé : A microemulsion consisting of cyclohexane, n-hexanol, hydrochloric acid solution, and the ionic liquid 1-n-tetradecyl-3-methylimidazolium bromide ([C14mim]Br) was investigated for Au(III) extraction. In the extraction system, [C14mim]Br bears double functions of surfactant and extractant. The anion-exchange mechanism of Au(III) extraction by [C14mim]Br was confirmed by the method of continuous variation and infrared spectrum analysis. The effects of extraction time and various material concentrations were examined for Au(III) extraction. Under optimum conditions, almost all the Au(III) in hydrochloric acid solution was extracted to the microemulsion phase, which also has high selectivity for Au(III) over some metals (Cu(II), Cd(II), Co(II), Ni(II), Sb(III), Fe(III), Al(III), and Sn(IV)). Therefore, the extraction of Au(III) by the [C14mim]Br/cyclohexane/n-hexanol/HCl microemulsion is an efficient and effective approach with high selectivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301644t Exemplaires
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Titre : Esterification of Acrylic Acid and n-Butanol in a Pilot-Scale Reactive Distillation Column—Experimental Investigation, Model Validation, and Process Analysis Type de document : texte imprimé Auteurs : Alexander Niesbach, Auteur ; Ron Fuhrmeister, Auteur ; Tobias Keller, Auteur Année de publication : 2013 Article en page(s) : pp. 16444-16456 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Modeling Distillation column with reactionEsterification Résumé : Due to a high risk of polymerization and complex thermodynamic behavior of the chemical system, the current production process for n-butyl acrylate synthesis is cost-intensive and challenging. Reactive distillation integrates chemical reactions and distillation into one unit at the same time and is one of the best-known examples of process intensification. To facilitate industrial application of this concept for the production of n-butyl acrylate, reliable experimental data are required. This article presents an experimental and theoretical investigation of the synthesis of n-butyl acrylate using reactive distillation. Experiments were conducted in a pilot-scale reactive distillation column, and the decisive operational parameters were varied. To predict the experimental results, a nonequilibrium-stage model was applied and the model was validated using the experimental data. The validated model was then used to perform a process analysis, showing trends in the conversion of acrylic acid and n-butanol and the purity of n-butyl acrylate that can be used for prospective optimization studies. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732173
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16444-16456[article] Esterification of Acrylic Acid and n-Butanol in a Pilot-Scale Reactive Distillation Column—Experimental Investigation, Model Validation, and Process Analysis [texte imprimé] / Alexander Niesbach, Auteur ; Ron Fuhrmeister, Auteur ; Tobias Keller, Auteur . - 2013 . - pp. 16444-16456.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16444-16456
Mots-clés : Modeling Distillation column with reactionEsterification Résumé : Due to a high risk of polymerization and complex thermodynamic behavior of the chemical system, the current production process for n-butyl acrylate synthesis is cost-intensive and challenging. Reactive distillation integrates chemical reactions and distillation into one unit at the same time and is one of the best-known examples of process intensification. To facilitate industrial application of this concept for the production of n-butyl acrylate, reliable experimental data are required. This article presents an experimental and theoretical investigation of the synthesis of n-butyl acrylate using reactive distillation. Experiments were conducted in a pilot-scale reactive distillation column, and the decisive operational parameters were varied. To predict the experimental results, a nonequilibrium-stage model was applied and the model was validated using the experimental data. The validated model was then used to perform a process analysis, showing trends in the conversion of acrylic acid and n-butanol and the purity of n-butyl acrylate that can be used for prospective optimization studies. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732173 Exemplaires
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Titre : In situ platinum recovery and color removal from organosilicon streams Type de document : texte imprimé Auteurs : He Bai, Auteur Année de publication : 2013 Article en page(s) : pp. 16457–16466 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Organosilicon Streams Résumé : Resource limitations, increased demand, and the high cost of precious metals (e.g., platinum) have led to the focus on recovery of platinum from organosilicon hydrosilylation streams as a potentially important source of cost savings in the organosilicon industry. In this work, in situ fixed-bed adsorption technology is demonstrated to be an effective platinum recovery and product color removal process. With the in situ Pt recovery process and using a functionalized silica gel scavenging material, a Pt recovery greater than 90% can be obtained both from silane distillation heavy wastes (with initial Pt concentration of around 50 ppm) and from organosilicon products (with initial Pt concentration of around 5 ppm), with suitable temperature and residence time. Long-term bed volume (BV) experiments were also carried out, and very high BV operations of the corresponding streams could be achieved, still with reasonably high Pt recovery at the end of the long-term run, and a Pt loading of about 2% could be obtained on scavengers. In addition, after Pt removal, the organosilicon products showed much reduced color, which is preferable for industrial applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3020318
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16457–16466[article] In situ platinum recovery and color removal from organosilicon streams [texte imprimé] / He Bai, Auteur . - 2013 . - pp. 16457–16466.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16457–16466
Mots-clés : Organosilicon Streams Résumé : Resource limitations, increased demand, and the high cost of precious metals (e.g., platinum) have led to the focus on recovery of platinum from organosilicon hydrosilylation streams as a potentially important source of cost savings in the organosilicon industry. In this work, in situ fixed-bed adsorption technology is demonstrated to be an effective platinum recovery and product color removal process. With the in situ Pt recovery process and using a functionalized silica gel scavenging material, a Pt recovery greater than 90% can be obtained both from silane distillation heavy wastes (with initial Pt concentration of around 50 ppm) and from organosilicon products (with initial Pt concentration of around 5 ppm), with suitable temperature and residence time. Long-term bed volume (BV) experiments were also carried out, and very high BV operations of the corresponding streams could be achieved, still with reasonably high Pt recovery at the end of the long-term run, and a Pt loading of about 2% could be obtained on scavengers. In addition, after Pt removal, the organosilicon products showed much reduced color, which is preferable for industrial applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3020318 Exemplaires
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Titre : Nonlinear analysis of chaotic time series in a natural circulation boiling loop Type de document : texte imprimé Auteurs : Arnab Karmakar, Auteur ; Swapan Paruya, Auteur Année de publication : 2013 Article en page(s) : pp. 16467-16481 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Boiling Time series Résumé : The present study reports chaotic flow oscillations observed in a natural circulation boiling loop. The periodic oscillations of wall temperature (thermal oscillations) initiate at a certain condition of heat flux and inlet subcooling in addition to geysering instability and pressure-drop oscillations. We observed that boiling regime changes from nucleate boiling to transition boiling as a result of decrease in inlet subcooling and increase in heat flux. The thermal oscillations are strongly coupled with pressure-drop oscillations. Nonlinear analysis of the time series of loop flow rate at various heater power and inlet subcooling have been carried out using statistical analysis, fast Fourier transform (FFT), time delay embedding for attractor reconstruction, autocorrelation, and correlation dimension. The analysis confirms that the oscillations are more chaotic at relatively low heater power and high inlet subcooling. The complexity of the oscillations strongly depends on boiling heat transfer regime. Our observations and analysis have been supported by other relevant experiments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732175
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16467-16481[article] Nonlinear analysis of chaotic time series in a natural circulation boiling loop [texte imprimé] / Arnab Karmakar, Auteur ; Swapan Paruya, Auteur . - 2013 . - pp. 16467-16481.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16467-16481
Mots-clés : Boiling Time series Résumé : The present study reports chaotic flow oscillations observed in a natural circulation boiling loop. The periodic oscillations of wall temperature (thermal oscillations) initiate at a certain condition of heat flux and inlet subcooling in addition to geysering instability and pressure-drop oscillations. We observed that boiling regime changes from nucleate boiling to transition boiling as a result of decrease in inlet subcooling and increase in heat flux. The thermal oscillations are strongly coupled with pressure-drop oscillations. Nonlinear analysis of the time series of loop flow rate at various heater power and inlet subcooling have been carried out using statistical analysis, fast Fourier transform (FFT), time delay embedding for attractor reconstruction, autocorrelation, and correlation dimension. The analysis confirms that the oscillations are more chaotic at relatively low heater power and high inlet subcooling. The complexity of the oscillations strongly depends on boiling heat transfer regime. Our observations and analysis have been supported by other relevant experiments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732175 Exemplaires
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Titre : Homogeneous fluidization of geldart D particles in a gas–solid fluidized bed with a frame impeller Type de document : texte imprimé Auteurs : Ying Han, Auteur ; Jia-Jun Wang, Auteur ; Xue-Ping Gu, Auteur Année de publication : 2013 Article en page(s) : pp 16482–16487 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Particles Gas solid Résumé : The influence of agitation of a frame impeller on the fluidization performance of Geldart D particles is experimentally and numerically studied in a gas–solid stirred fluidized bed, using a three-dimensional (3D) unsteady computational fluid dynamics (CFD) simulation. The bed pressure drops obtained from simulations are in reasonable agreement with those measured with pressure transducers, which validates the CFD models. The experimental results of the pressure fluctuation and the simulated ones of the solid volume fraction distribution show that Geldart D particles can perform homogeneous fluidization in the presence of the impeller. The homogeneous fluidization regime expands as the minimum bubbling velocity increases with the agitation speed while the minimum fluidizing velocity remains unaffected. In addition, the uniformity of particle velocities that are distributed in the entire fluidized bed is also improved by the agitation of the frame impeller. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301574q
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp 16482–16487[article] Homogeneous fluidization of geldart D particles in a gas–solid fluidized bed with a frame impeller [texte imprimé] / Ying Han, Auteur ; Jia-Jun Wang, Auteur ; Xue-Ping Gu, Auteur . - 2013 . - pp 16482–16487.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp 16482–16487
Mots-clés : Particles Gas solid Résumé : The influence of agitation of a frame impeller on the fluidization performance of Geldart D particles is experimentally and numerically studied in a gas–solid stirred fluidized bed, using a three-dimensional (3D) unsteady computational fluid dynamics (CFD) simulation. The bed pressure drops obtained from simulations are in reasonable agreement with those measured with pressure transducers, which validates the CFD models. The experimental results of the pressure fluctuation and the simulated ones of the solid volume fraction distribution show that Geldart D particles can perform homogeneous fluidization in the presence of the impeller. The homogeneous fluidization regime expands as the minimum bubbling velocity increases with the agitation speed while the minimum fluidizing velocity remains unaffected. In addition, the uniformity of particle velocities that are distributed in the entire fluidized bed is also improved by the agitation of the frame impeller. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301574q Exemplaires
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Titre : Comparative study of the triboelectric charging behavior of powders using a nonintrusive approach Type de document : texte imprimé Auteurs : Jin W. Kwek, Auteur ; M. Jeyabalasingam, Auteur ; Wai K. Ng, Auteur Année de publication : 2013 Article en page(s) : pp. 16488-16494 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Powder Comparative study Résumé : Powder processing operations such as blending or pneumatic transport can potentially induce triboelectric charging with subsequent agglomeration. Traditionally the charging behavior is investigated using a Faraday cage. In this paper, an alternative nonintrusive probe connected to a voltmeter for comparative triboelectric charging studies of sieved pharmaceutically relevant materials such as α-lactose monohydrate (ALM) and adipic acid (AA) on acetal surfaces under controlled environmental conditions was explored. The probe was verified using standard voltages with determination in the positioning limits for effective measurements between probe and surface. Results obtained with the probe were found to be in good agreement with the Faraday cage method. A greater incidence of particle-to-wall adhesions in smaller sized AA particles led to a reduction in initial surface specific potential while the higher quantity of fines in the ALM larger sieve fractions could be the major contributing factor in the reduced surface specific potential. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732177
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16488-16494[article] Comparative study of the triboelectric charging behavior of powders using a nonintrusive approach [texte imprimé] / Jin W. Kwek, Auteur ; M. Jeyabalasingam, Auteur ; Wai K. Ng, Auteur . - 2013 . - pp. 16488-16494.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16488-16494
Mots-clés : Powder Comparative study Résumé : Powder processing operations such as blending or pneumatic transport can potentially induce triboelectric charging with subsequent agglomeration. Traditionally the charging behavior is investigated using a Faraday cage. In this paper, an alternative nonintrusive probe connected to a voltmeter for comparative triboelectric charging studies of sieved pharmaceutically relevant materials such as α-lactose monohydrate (ALM) and adipic acid (AA) on acetal surfaces under controlled environmental conditions was explored. The probe was verified using standard voltages with determination in the positioning limits for effective measurements between probe and surface. Results obtained with the probe were found to be in good agreement with the Faraday cage method. A greater incidence of particle-to-wall adhesions in smaller sized AA particles led to a reduction in initial surface specific potential while the higher quantity of fines in the ALM larger sieve fractions could be the major contributing factor in the reduced surface specific potential. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732177 Exemplaires
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Titre : Hydrodynamics of gas–liquid cocurrent flows in micropacked beds—wall visualization study Type de document : texte imprimé Auteurs : Ali Faridkhou, Auteur ; Faïçal Larachi, Auteur Année de publication : 2013 Article en page(s) : pp. 16495–16504 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrodynamics Gas Liquid Résumé : An inverted microscopy technique was implemented to scrutinize the wall-region hydrodynamics of gas–liquid cocurrent flows in micropacked beds. Digital image analysis enabled characterization of two contiguous flow regimes, hysteresis, and transition thereof. Low- and high-interaction regimes featuring, respectively, slow and rapid displacements of gas–liquid boundary were identified. The onset of regime changeover was delineated by distinguishing the fluctuating behavior in time of characteristic lengths extracted from the areas occupied by gas and liquid in the field of view. A Charpentier and Favier flow regime map demarcating low and high interaction regimes in conventional macroscale trickle beds was elaborated for the sake of comparison of micropacked bed transitions for three different gas–liquid systems (air–water, argon–water, and argon–sucrose solution). The flow regime map suggests that micropacked bed transition occurs at considerably lower L/G values. Manifestation of hysteresis in micropacked beds was apprehended via pressure drop measurements and wetting fraction determination both in imbibition and drainage modes. In agreement with macroscale packed bed observations, the drainage branch revealed a larger pressure drop and wetting fraction compared with the imbibition branch for the same set of bed and fluid flow rates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301709x
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16495–16504[article] Hydrodynamics of gas–liquid cocurrent flows in micropacked beds—wall visualization study [texte imprimé] / Ali Faridkhou, Auteur ; Faïçal Larachi, Auteur . - 2013 . - pp. 16495–16504.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16495–16504
Mots-clés : Hydrodynamics Gas Liquid Résumé : An inverted microscopy technique was implemented to scrutinize the wall-region hydrodynamics of gas–liquid cocurrent flows in micropacked beds. Digital image analysis enabled characterization of two contiguous flow regimes, hysteresis, and transition thereof. Low- and high-interaction regimes featuring, respectively, slow and rapid displacements of gas–liquid boundary were identified. The onset of regime changeover was delineated by distinguishing the fluctuating behavior in time of characteristic lengths extracted from the areas occupied by gas and liquid in the field of view. A Charpentier and Favier flow regime map demarcating low and high interaction regimes in conventional macroscale trickle beds was elaborated for the sake of comparison of micropacked bed transitions for three different gas–liquid systems (air–water, argon–water, and argon–sucrose solution). The flow regime map suggests that micropacked bed transition occurs at considerably lower L/G values. Manifestation of hysteresis in micropacked beds was apprehended via pressure drop measurements and wetting fraction determination both in imbibition and drainage modes. In agreement with macroscale packed bed observations, the drainage branch revealed a larger pressure drop and wetting fraction compared with the imbibition branch for the same set of bed and fluid flow rates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301709x Exemplaires
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Titre : A Predictive model for vapor solubility and volume dilation in glassy polymers Type de document : texte imprimé Auteurs : Matteo Minelli, Auteur ; Ferruccio Doghieri, Auteur Année de publication : 2013 Article en page(s) : pp. 16505-16516 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solubility Forecast model Résumé : The nonequilibrium lattice fluid (NELF) model is here implemented with a simplified relation for bulk rheological behavior of glassy polymers, to obtain a predictive model for pseudoequilibrium solute content and volume dilation induced by swelling agents. The rheological model discussed in this work is ultimately used to derive a relation for the pseudoequilibrium volume of the polymeric system as a function of temperature and solute fugacity. The model makes use of two nonequilibrium parameters which, in turn, can be determined through the analysis of nonequilibrium pVT properties of the polymeric species. The predictive ability of the new model for solubility and volume swelling was tested by means of the comparison of model predictions and correlations with experimental data, available in the literature, for different polymer/penetrant pairs. The results obtained from the comparison allow one to conclude that the model is not just useful to describe the swelling effect of penetrants but also to recognize conditions at which plasticization by solute species induces a glass to rubber transition in the polymeric system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732179
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16505-16516[article] A Predictive model for vapor solubility and volume dilation in glassy polymers [texte imprimé] / Matteo Minelli, Auteur ; Ferruccio Doghieri, Auteur . - 2013 . - pp. 16505-16516.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16505-16516
Mots-clés : Solubility Forecast model Résumé : The nonequilibrium lattice fluid (NELF) model is here implemented with a simplified relation for bulk rheological behavior of glassy polymers, to obtain a predictive model for pseudoequilibrium solute content and volume dilation induced by swelling agents. The rheological model discussed in this work is ultimately used to derive a relation for the pseudoequilibrium volume of the polymeric system as a function of temperature and solute fugacity. The model makes use of two nonequilibrium parameters which, in turn, can be determined through the analysis of nonequilibrium pVT properties of the polymeric species. The predictive ability of the new model for solubility and volume swelling was tested by means of the comparison of model predictions and correlations with experimental data, available in the literature, for different polymer/penetrant pairs. The results obtained from the comparison allow one to conclude that the model is not just useful to describe the swelling effect of penetrants but also to recognize conditions at which plasticization by solute species induces a glass to rubber transition in the polymeric system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732179 Exemplaires
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Titre : Measurements and correlations of diffusivities of nitrous oxide and carbon dioxide in monoethanolamine + water by laminar liquid jet Type de document : texte imprimé Auteurs : Jiru Ying, Auteur ; Dag A. Eimer, Auteur Année de publication : 2013 Article en page(s) : pp. 16517-16524 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Liquid jet Carbon dioxide Diffusion coefficien Correlation analysis Résumé : The molecular diffusivities of nitrous oxide (N2O) with aqueous monoethanolamine (MEA) solutions up to 12 M were studied over a temperature range from 298.15 to 333.15 K under atmospheric pressure using a laminar liquid jet absorber. The diffusivities of CO2 in aqueous MEA solutions were calculated by the "N2O analogy" method. A simple and effective thermal control technique was used to control the temperatures of gas and liquid in the laminar liquid jet absorber. The rates of absorption were determined by measuring the flow of gas needed to replace the gas absorbed. The results showed that the diffusivities of both N2O and CO2 into aqueous MEA solution decrease with the increase of the concentration of MEA, and increase with an increase of the temperature of the solution. The relationship between the diffusivity and the viscosity of the solution roughly agrees with the modified Stokes-Einstein equation, but an exponent mathematical model was employed to simulate the diffusivity data and shows a better agreement between data and model for the diffusivity of N2O and CO2 in the monoethanolamine + water system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732180
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16517-16524[article] Measurements and correlations of diffusivities of nitrous oxide and carbon dioxide in monoethanolamine + water by laminar liquid jet [texte imprimé] / Jiru Ying, Auteur ; Dag A. Eimer, Auteur . - 2013 . - pp. 16517-16524.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16517-16524
Mots-clés : Liquid jet Carbon dioxide Diffusion coefficien Correlation analysis Résumé : The molecular diffusivities of nitrous oxide (N2O) with aqueous monoethanolamine (MEA) solutions up to 12 M were studied over a temperature range from 298.15 to 333.15 K under atmospheric pressure using a laminar liquid jet absorber. The diffusivities of CO2 in aqueous MEA solutions were calculated by the "N2O analogy" method. A simple and effective thermal control technique was used to control the temperatures of gas and liquid in the laminar liquid jet absorber. The rates of absorption were determined by measuring the flow of gas needed to replace the gas absorbed. The results showed that the diffusivities of both N2O and CO2 into aqueous MEA solution decrease with the increase of the concentration of MEA, and increase with an increase of the temperature of the solution. The relationship between the diffusivity and the viscosity of the solution roughly agrees with the modified Stokes-Einstein equation, but an exponent mathematical model was employed to simulate the diffusivity data and shows a better agreement between data and model for the diffusivity of N2O and CO2 in the monoethanolamine + water system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732180 Exemplaires
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Titre : Comparison between ethanol and diethyl carbonate as ethylating agents for ethyl octyl ether synthesis over acidic ion-exchange resins Type de document : texte imprimé Auteurs : Jordi Guilera, Auteur ; Roger Bringue, Auteur ; Eliana Ramirez, Auteur Année de publication : 2013 Article en page(s) : pp. 16525-16530 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ion exchange resin Résumé : Direct addition of bioethanol to diesel reduces the quality of commercial blends. An alternative way to introduce bioethanol into diesel is as linear ether such as ethyl octyl ether (EOE). EOE synthesis by I-octanol (OcOH) reaction with ethanol (EtOH) or diethyl carbonate (DEC) over acidic ion-exchange resins has been studied in a 100-mL batch reactor (130― 150 °C, 25 bar). The main drawback for ethylating OcOH in both reaction systems is the loss of ethyl groups by diethyl ether formation. In OcOH excess, selectivity to EOE with respect to EtOH and to DEC was found to be similar (58―59%) when the ethylating agent was entirely consumed. However, the initial reaction rate of EOE formation from DEC is lower, due to the formation of ethyl octyl carbonate as reaction intermediate. Accordingly, EtOH showed to be more interesting ethylating agent to produce a synthetic biofuel such as EOE over acidic ion-exchange resins. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732181
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16525-16530[article] Comparison between ethanol and diethyl carbonate as ethylating agents for ethyl octyl ether synthesis over acidic ion-exchange resins [texte imprimé] / Jordi Guilera, Auteur ; Roger Bringue, Auteur ; Eliana Ramirez, Auteur . - 2013 . - pp. 16525-16530.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16525-16530
Mots-clés : Ion exchange resin Résumé : Direct addition of bioethanol to diesel reduces the quality of commercial blends. An alternative way to introduce bioethanol into diesel is as linear ether such as ethyl octyl ether (EOE). EOE synthesis by I-octanol (OcOH) reaction with ethanol (EtOH) or diethyl carbonate (DEC) over acidic ion-exchange resins has been studied in a 100-mL batch reactor (130― 150 °C, 25 bar). The main drawback for ethylating OcOH in both reaction systems is the loss of ethyl groups by diethyl ether formation. In OcOH excess, selectivity to EOE with respect to EtOH and to DEC was found to be similar (58―59%) when the ethylating agent was entirely consumed. However, the initial reaction rate of EOE formation from DEC is lower, due to the formation of ethyl octyl carbonate as reaction intermediate. Accordingly, EtOH showed to be more interesting ethylating agent to produce a synthetic biofuel such as EOE over acidic ion-exchange resins. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26732181 Exemplaires
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