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Electrochemical oxidation of the sulfide ion in synthetic geothermal brines in batch cells using coke electrodes / Keegan Rankin in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6261–6266 Titre : Electrochemical oxidation of the sulfide ion in synthetic geothermal brines in batch cells using coke electrodes Type de document : texte imprimé Auteurs : Keegan Rankin, Auteur ; Dorin Bejan, Auteur ; Nigel J. Bunce, Auteur Année de publication : 2010 Article en page(s) : pp. 6261–6266 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oxidation Ion Electrodes Résumé : The oxidation of the sulfide ion occurs efficiently in batch cells at massive coke electrodes. At all currents studied, the products included a low yield of elemental sulfur, which deposited on the anode; the yields of sulfate were also low, except at the highest current. The remaining products were soluble organosulfur species, indicating that the coke anodes acted sacrificially. The reaction displayed unusual kinetic behavior with respect to the disappearance of sulfide: a two-stage reaction was observed in which the loss of sulfide was faster in the early stages of reaction, while elemental sulfur deposited on the anode. A subsequent slower current-controlled reaction was associated with the formation of the remaining products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901511a [article] Electrochemical oxidation of the sulfide ion in synthetic geothermal brines in batch cells using coke electrodes [texte imprimé] / Keegan Rankin, Auteur ; Dorin Bejan, Auteur ; Nigel J. Bunce, Auteur . - 2010 . - pp. 6261–6266. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6261–6266 Mots-clés : Oxidation Ion Electrodes Résumé : The oxidation of the sulfide ion occurs efficiently in batch cells at massive coke electrodes. At all currents studied, the products included a low yield of elemental sulfur, which deposited on the anode; the yields of sulfate were also low, except at the highest current. The remaining products were soluble organosulfur species, indicating that the coke anodes acted sacrificially. The reaction displayed unusual kinetic behavior with respect to the disappearance of sulfide: a two-stage reaction was observed in which the loss of sulfide was faster in the early stages of reaction, while elemental sulfur deposited on the anode. A subsequent slower current-controlled reaction was associated with the formation of the remaining products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901511a

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Gas chromatographic − mass spectrometric analysis of chemically derivatized hexahydrotriazine - based hydrogen sulfide scavengers / Grahame N. Taylor in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6267-6269 Titre : Gas chromatographic − mass spectrometric analysis of chemically derivatized hexahydrotriazine - based hydrogen sulfide scavengers : Part II Type de document : texte imprimé Auteurs : Grahame N. Taylor, Auteur ; Ron Matherly, Auteur Année de publication : 2010 Article en page(s) : pp. 6267-6269 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogen sulfides Résumé : A gas chromatography−mass spectrometry method of assaying various thiadiazines and dithiazines in laboratory and field fluids is described. This method also involves the tris-trifluoroacetylation of anhydrous 5-(hydroxyethyl)dithiazine, which unexpectedly yields a novel derivative. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040378 [article] Gas chromatographic − mass spectrometric analysis of chemically derivatized hexahydrotriazine - based hydrogen sulfide scavengers : Part II [texte imprimé] / Grahame N. Taylor, Auteur ; Ron Matherly, Auteur . - 2010 . - pp. 6267-6269. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6267-6269 Mots-clés : Hydrogen sulfides Résumé : A gas chromatography−mass spectrometry method of assaying various thiadiazines and dithiazines in laboratory and field fluids is described. This method also involves the tris-trifluoroacetylation of anhydrous 5-(hydroxyethyl)dithiazine, which unexpectedly yields a novel derivative. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040378

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Synthesis of lactic acid by alkaline hydrothermal conversion of glycerol at high glycerol concentration / Camilo A. Ramirez-Lopez in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6270–6278 Titre : Synthesis of lactic acid by alkaline hydrothermal conversion of glycerol at high glycerol concentration Type de document : texte imprimé Auteurs : Camilo A. Ramirez-Lopez, Auteur ; José R. Ochoa-Gomez, Auteur ; Maria Fernandez-Santos, Auteur Année de publication : 2010 Article en page(s) : pp. 6270–6278 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : lactic acid Hydrothermal Résumé : The synthesis of lactic acid by alkaline hydrothermal conversion of glycerol at high glycerol concentrations under autogenous pressure is described. Temperature (250−290 °C), NaOH/glycerol molar ratio (1.1−1.75), glycerol concentration (2.5−3.5 M), and reaction time (30−250 min) have been the variables studied with temperature and NaOH/glycerol molar ratio having the major influence. An 84.5% lactic acid (as sodium lactate) yield is obtained at 280 °C and 90 min with a 2.5 M glycerol concentration and a 1.1 NaOH/glycerol molar ratio. The same yield is obtained starting from crude glycerol from biodiesel production as raw material. Sodium acrylate, oxalate and formate, and sodium carbonate have been identified as the main byproducts with carbonate being the major one. Several conversion routes based on the experimental results are proposed. A process for lactic acid separation based on electrodialysis is outlined. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001586 [article] Synthesis of lactic acid by alkaline hydrothermal conversion of glycerol at high glycerol concentration [texte imprimé] / Camilo A. Ramirez-Lopez, Auteur ; José R. Ochoa-Gomez, Auteur ; Maria Fernandez-Santos, Auteur . - 2010 . - pp. 6270–6278. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6270–6278 Mots-clés : lactic acid Hydrothermal Résumé : The synthesis of lactic acid by alkaline hydrothermal conversion of glycerol at high glycerol concentrations under autogenous pressure is described. Temperature (250−290 °C), NaOH/glycerol molar ratio (1.1−1.75), glycerol concentration (2.5−3.5 M), and reaction time (30−250 min) have been the variables studied with temperature and NaOH/glycerol molar ratio having the major influence. An 84.5% lactic acid (as sodium lactate) yield is obtained at 280 °C and 90 min with a 2.5 M glycerol concentration and a 1.1 NaOH/glycerol molar ratio. The same yield is obtained starting from crude glycerol from biodiesel production as raw material. Sodium acrylate, oxalate and formate, and sodium carbonate have been identified as the main byproducts with carbonate being the major one. Several conversion routes based on the experimental results are proposed. A process for lactic acid separation based on electrodialysis is outlined. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001586

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Addition of surfactant tween 80 in coating solutions for making mesoporous pure silica zeolite MFI low - k films / Hsin - Yan Lu in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6279–6286 Titre : Addition of surfactant tween 80 in coating solutions for making mesoporous pure silica zeolite MFI low - k films Type de document : texte imprimé Auteurs : Hsin - Yan Lu, Auteur ; Chin - Lin Teng, Auteur ; Chun-Wei Yu, Auteur Année de publication : 2010 Article en page(s) : pp. 6279–6286 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mesoporous Zeolite Résumé : A mesoporous pure-silica-zeolite (PSZ) MFI low dielectric (k) film with smooth surface morphology was successfully synthesized using a centrifuged coating solution composed of a solution with PSZ MFI nanoparticles and surfactant Tween 80. The zeolite nanoparticles were prepared using TEOS as the silica source through a two-stage hydrothermal process. Both the k value and the mechanical strength of the film were strongly affected by the weight ratio of Tween 80 to TEOS and by the hydrothermal period of the second stage. When a higher weight ratio of Tween 80 to TEOS was employed, a lower k value and mechanical strength were obtained. A film coated from a solution prepared under optimal experimental conditions possessed an ultra low k value of 1.83, a hardness of 1.39 GPa, an elastic module of 12.3 GPa, and a leakage current of 1.35 × 10−7 A/cm2, all of which met the needs of the integrated circuits (IC) industry. Moreover, the occurrence of electrical degradation of electronic devices could be minimized because only few pores in the film exceeded 5 nm. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100203e [article] Addition of surfactant tween 80 in coating solutions for making mesoporous pure silica zeolite MFI low - k films [texte imprimé] / Hsin - Yan Lu, Auteur ; Chin - Lin Teng, Auteur ; Chun-Wei Yu, Auteur . - 2010 . - pp. 6279–6286. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6279–6286 Mots-clés : Mesoporous Zeolite Résumé : A mesoporous pure-silica-zeolite (PSZ) MFI low dielectric (k) film with smooth surface morphology was successfully synthesized using a centrifuged coating solution composed of a solution with PSZ MFI nanoparticles and surfactant Tween 80. The zeolite nanoparticles were prepared using TEOS as the silica source through a two-stage hydrothermal process. Both the k value and the mechanical strength of the film were strongly affected by the weight ratio of Tween 80 to TEOS and by the hydrothermal period of the second stage. When a higher weight ratio of Tween 80 to TEOS was employed, a lower k value and mechanical strength were obtained. A film coated from a solution prepared under optimal experimental conditions possessed an ultra low k value of 1.83, a hardness of 1.39 GPa, an elastic module of 12.3 GPa, and a leakage current of 1.35 × 10−7 A/cm2, all of which met the needs of the integrated circuits (IC) industry. Moreover, the occurrence of electrical degradation of electronic devices could be minimized because only few pores in the film exceeded 5 nm. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100203e

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The Determination of sodium silicate composition using ATR FT - IR / James S. Falcone in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6287-6290 Titre : The Determination of sodium silicate composition using ATR FT - IR Type de document : texte imprimé Auteurs : James S. Falcone, Auteur ; Jonathan L. Bass, Auteur ; Maria Angelella, Auteur Année de publication : 2010 Article en page(s) : pp. 6287-6290 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Sodium silicate Résumé : A procedure that measures both the silica concentration and the ratio of silica to alkali content of the commercially important sodium silicate solutions using an ATR FT-IR spectrophotomer has been developed. The accuracy and precision have been found to be equal to or better than the commonly used measures via titrimetry and density determination. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1002747 [article] The Determination of sodium silicate composition using ATR FT - IR [texte imprimé] / James S. Falcone, Auteur ; Jonathan L. Bass, Auteur ; Maria Angelella, Auteur . - 2010 . - pp. 6287-6290. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6287-6290 Mots-clés : Sodium silicate Résumé : A procedure that measures both the silica concentration and the ratio of silica to alkali content of the commercially important sodium silicate solutions using an ATR FT-IR spectrophotomer has been developed. The accuracy and precision have been found to be equal to or better than the commonly used measures via titrimetry and density determination. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1002747

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Effects of macromolecular compatibilizers containing epoxy groups on the properties of linear low - density polyethylene / magnesium hydroxide composites / Zhen Yang in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp.6291–6301 Titre : Effects of macromolecular compatibilizers containing epoxy groups on the properties of linear low - density polyethylene / magnesium hydroxide composites Type de document : texte imprimé Auteurs : Zhen Yang, Auteur ; Chengang Zhou, Auteur ; Jun Cai, Auteur Année de publication : 2010 Article en page(s) : pp.6291–6301 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Macromolecular Hydroxide Résumé : The effects of two kinds of macromolecular compatibilizers, poly(ethylene-co-glycidyl methacrylate) (PE-co-PGMA) and poly(ethylene-co-methyl acrylate-co-glycidyl methacrylate) (PE-co-PMA-co-PGMA), both containing epoxy groups, on the properties of linear low-density polyethylene (LLDPE)/magnesium hydroxide (MH) composites were studied in this work. On the basis of the experimental results from the mechanical test, thermal stability analysis, and scanning electron microscopy (SEM) observation, both PE-co-PGMA and PE-co-PMA-co-PGMA were demonstrated to be efficient compatibilizers. In order to investigate the compatibilization mechanism, further characterization by particle size and a particle size distribution analyzer, SEM-energy dispersive X-ray spectroscopy (EDX), and attenuated total reflection-Fourier transform infrared (ATR-FTIR) were carried out, respectively. It was found that the epoxy groups on the compatibilizers played a very important role in modification of the LLDPE/MH system. The compatibilizers conglutinated tightly on the surface of MH though ring-open reactions between the epoxy group and hydroxyl of MH; furthermore, the long organic chains of compatibilizers entwisted with LLDPE through van der Waals force. The fracture morphology observation of LLDPE/MH composites also showed that MH particles were closely united with polymer matrix through the compatibilizers. Therefore, the compatibility between MH and LLDPE was enhanced, which improved the final performances of the LLDPE/MH composites further. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100610j [article] Effects of macromolecular compatibilizers containing epoxy groups on the properties of linear low - density polyethylene / magnesium hydroxide composites [texte imprimé] / Zhen Yang, Auteur ; Chengang Zhou, Auteur ; Jun Cai, Auteur . - 2010 . - pp.6291–6301. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp.6291–6301 Mots-clés : Macromolecular Hydroxide Résumé : The effects of two kinds of macromolecular compatibilizers, poly(ethylene-co-glycidyl methacrylate) (PE-co-PGMA) and poly(ethylene-co-methyl acrylate-co-glycidyl methacrylate) (PE-co-PMA-co-PGMA), both containing epoxy groups, on the properties of linear low-density polyethylene (LLDPE)/magnesium hydroxide (MH) composites were studied in this work. On the basis of the experimental results from the mechanical test, thermal stability analysis, and scanning electron microscopy (SEM) observation, both PE-co-PGMA and PE-co-PMA-co-PGMA were demonstrated to be efficient compatibilizers. In order to investigate the compatibilization mechanism, further characterization by particle size and a particle size distribution analyzer, SEM-energy dispersive X-ray spectroscopy (EDX), and attenuated total reflection-Fourier transform infrared (ATR-FTIR) were carried out, respectively. It was found that the epoxy groups on the compatibilizers played a very important role in modification of the LLDPE/MH system. The compatibilizers conglutinated tightly on the surface of MH though ring-open reactions between the epoxy group and hydroxyl of MH; furthermore, the long organic chains of compatibilizers entwisted with LLDPE through van der Waals force. The fracture morphology observation of LLDPE/MH composites also showed that MH particles were closely united with polymer matrix through the compatibilizers. Therefore, the compatibility between MH and LLDPE was enhanced, which improved the final performances of the LLDPE/MH composites further. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100610j

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Kinetics of isothermal nicotine adsorption from the aqueous solution onto the USY zeolite / Natasa Lazarevic in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6302-6308 Titre : Kinetics of isothermal nicotine adsorption from the aqueous solution onto the USY zeolite Type de document : texte imprimé Auteurs : Natasa Lazarevic, Auteur ; Jelena Jovanovic, Auteur ; Milutin Jevremovic, Auteur Année de publication : 2010 Article en page(s) : pp. 6302-6308 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Zeolite Aqueous solution Adsorption Kinetics Résumé : The kinetics of isothermal adsorption of nicotine from an aqueous solution onto hydrophobic zeolite type USY was investigated. The adsorption isotherms of nicotine on zeolite type USY were measured in the temperature range from 298 to 322 K. Specific shape parameters of the adsorption degree curves were determined. The changes in the specific shape parameters of the adsorption degree curves with temperature and the kinetic parameters of nicotine adsorption (Ea, In A) were determined. The kinetic model of nicotine adsorption, [I - (1 - α)1/2] = kt, was established by using the model-fitting method. It was found that the nicotine adsorption was a kinetically controlled process which was determined by the rate of bidimensional movement of the boundary layer of the adsorption phase. Nicotine is most probably chemisorbed onto the acidic centers of zeolite type USY. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040383 [article] Kinetics of isothermal nicotine adsorption from the aqueous solution onto the USY zeolite [texte imprimé] / Natasa Lazarevic, Auteur ; Jelena Jovanovic, Auteur ; Milutin Jevremovic, Auteur . - 2010 . - pp. 6302-6308. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6302-6308 Mots-clés : Zeolite Aqueous solution Adsorption Kinetics Résumé : The kinetics of isothermal adsorption of nicotine from an aqueous solution onto hydrophobic zeolite type USY was investigated. The adsorption isotherms of nicotine on zeolite type USY were measured in the temperature range from 298 to 322 K. Specific shape parameters of the adsorption degree curves were determined. The changes in the specific shape parameters of the adsorption degree curves with temperature and the kinetic parameters of nicotine adsorption (Ea, In A) were determined. The kinetic model of nicotine adsorption, [I - (1 - α)1/2] = kt, was established by using the model-fitting method. It was found that the nicotine adsorption was a kinetically controlled process which was determined by the rate of bidimensional movement of the boundary layer of the adsorption phase. Nicotine is most probably chemisorbed onto the acidic centers of zeolite type USY. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040383

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Continuous Acetone Ammoximation over TS-1 in a Tubular Membrane Reactor / Zhaohui Li in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6309–6316 Titre : Continuous Acetone Ammoximation over TS-1 in a Tubular Membrane Reactor Type de document : texte imprimé Auteurs : Zhaohui Li, Auteur ; Rizhi Chen, Auteur ; Weihong Xing, Auteur Année de publication : 2010 Article en page(s) : pp. 6309–6316 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Tubular membrane reactor Résumé : A new tubular membrane reactor based on tubular metallic membrane is developed, which can solve the problem concerning in situ separation of catalyst from the reaction mixture and make the production process continuous. In this article, the feasibility of continuous ammoximation of acetone to acetone oxime over titanium silicalites-1 (TS-1) in the tubular membrane reactor was investigated. It has demonstrated that the tubular membrane reactor system can maintain a more long-term steady production of acetone oxime than that of a side-stream ceramic membrane reactor and has a higher productivity than the batch reactor. The effects of operation conditions (stirring rate, residence time, temperature, catalyst concentration, molar ratio of NH3/acetone, H2O2/acetone, and t-butanol/acetone) on the performances of the reaction system were examined via single factor experiments. Results show that the operation conditions greatly affect the conversion, selectivity of acetone ammoximation, and the filtration resistance. The acetone conversion is >94.5% and the acetone oxime selectivity remains stable at 98% in a 30-h continuous run. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901912e [article] Continuous Acetone Ammoximation over TS-1 in a Tubular Membrane Reactor [texte imprimé] / Zhaohui Li, Auteur ; Rizhi Chen, Auteur ; Weihong Xing, Auteur . - 2010 . - pp. 6309–6316. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6309–6316 Mots-clés : Tubular membrane reactor Résumé : A new tubular membrane reactor based on tubular metallic membrane is developed, which can solve the problem concerning in situ separation of catalyst from the reaction mixture and make the production process continuous. In this article, the feasibility of continuous ammoximation of acetone to acetone oxime over titanium silicalites-1 (TS-1) in the tubular membrane reactor was investigated. It has demonstrated that the tubular membrane reactor system can maintain a more long-term steady production of acetone oxime than that of a side-stream ceramic membrane reactor and has a higher productivity than the batch reactor. The effects of operation conditions (stirring rate, residence time, temperature, catalyst concentration, molar ratio of NH3/acetone, H2O2/acetone, and t-butanol/acetone) on the performances of the reaction system were examined via single factor experiments. Results show that the operation conditions greatly affect the conversion, selectivity of acetone ammoximation, and the filtration resistance. The acetone conversion is >94.5% and the acetone oxime selectivity remains stable at 98% in a 30-h continuous run. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901912e

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Low - temperature selective catalytic reduction of NO with urea supported on pitch - based spherical activated carbon / Zhi Wang in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6317-6322 Titre : Low - temperature selective catalytic reduction of NO with urea supported on pitch - based spherical activated carbon Type de document : texte imprimé Auteurs : Zhi Wang, Auteur ; Yanli Wang, Auteur ; Dengjun Wang, Auteur Année de publication : 2010 Article en page(s) : pp. 6317-6322 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Activated carbon Selective catalytic reduction Low temperature Résumé : Urea as a reducing agent supported on pitch-based spherical activated carbon (PSAC) was studied for NO reduction at low temperatures (30−90 °C). The results showed that PSAC with 8 wt % urea loading exhibited high activity in the selective catalytic reduction (SCR) of NO at 30 °C. The SCR activity decreased markedly when urea loading was increased above 8 wt % due to pore plugging, which restricted the adsorption of gas phase reactants on PSAC, although the NOx removal period was extended. A low reaction temperature was favorable for NO reduction on account of the increased NO adsorption on PSAC. It was found that the SCR activity was improved by increasing NO or O2 concentration in the feed gas, owing to the enhanced NO oxidation by O2 to NO2, which was then reduced by urea to form N2. Increasing space velocity not only decreased the SCR activity but also shortened the NOx removal period. More than 85% NOx conversion for 55 h could be achieved over PSAC with 8 wt % urea loading at 30 °C under the conditions of 500 ppmv NO, 21 vol % O2, and a space velocity of 2000 h−1. Furthermore, PSAC showed a superior hydrodynamic property, and the pressure drop ratio of PSAC to a commercial granule activated carbon with the equivalent particle size was about 35% with the apparent air flow velocity in a range of 0.120.51 m/s. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040385 [article] Low - temperature selective catalytic reduction of NO with urea supported on pitch - based spherical activated carbon [texte imprimé] / Zhi Wang, Auteur ; Yanli Wang, Auteur ; Dengjun Wang, Auteur . - 2010 . - pp. 6317-6322. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6317-6322 Mots-clés : Activated carbon Selective catalytic reduction Low temperature Résumé : Urea as a reducing agent supported on pitch-based spherical activated carbon (PSAC) was studied for NO reduction at low temperatures (30−90 °C). The results showed that PSAC with 8 wt % urea loading exhibited high activity in the selective catalytic reduction (SCR) of NO at 30 °C. The SCR activity decreased markedly when urea loading was increased above 8 wt % due to pore plugging, which restricted the adsorption of gas phase reactants on PSAC, although the NOx removal period was extended. A low reaction temperature was favorable for NO reduction on account of the increased NO adsorption on PSAC. It was found that the SCR activity was improved by increasing NO or O2 concentration in the feed gas, owing to the enhanced NO oxidation by O2 to NO2, which was then reduced by urea to form N2. Increasing space velocity not only decreased the SCR activity but also shortened the NOx removal period. More than 85% NOx conversion for 55 h could be achieved over PSAC with 8 wt % urea loading at 30 °C under the conditions of 500 ppmv NO, 21 vol % O2, and a space velocity of 2000 h−1. Furthermore, PSAC showed a superior hydrodynamic property, and the pressure drop ratio of PSAC to a commercial granule activated carbon with the equivalent particle size was about 35% with the apparent air flow velocity in a range of 0.120.51 m/s. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040385

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Partial hydrogenation of soybean oil in a piston oscillating monolith reactor / Yogesh G. Waghmare in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6323–6331 Titre : Partial hydrogenation of soybean oil in a piston oscillating monolith reactor Type de document : texte imprimé Auteurs : Yogesh G. Waghmare, Auteur ; Alan G. Bussard, Auteur ; Robert V. Forest, Auteur Année de publication : 2010 Article en page(s) : pp. 6323–6331 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogenation Soybean Oil Résumé : The partial hydrogenation of soybean oil was carried out in a novel piston oscillating monolith reactor (POMR). POMR performance was studied under the application of low frequency (0−17.5 Hz) and amplitude (2.5 mm) vibrations at 110 °C and 0.41 MPa H2 using a Pd/Al2O3 monolith catalyst. Results show observed rate improvements of up to 220% for 17.5 Hz, 2.5 mm piston oscillations over low frequency pulsing conditions. For comparison purposes, the reaction was also carried out in a stirred tank reactor using the monolith catalyst. The POMR showed better activity at an equivalent power per unit volume when compared to a stirred tank. With the monolith catalyst, both external and internal mass transfer limitations exist. Using standard diffusion-reaction calculations and measurements over a range of particle sizes it was shown that the vibrations improve external mass transfer rates as well as internal transport within the washcoat. The POMR showed equal or better serial pathway selectivity than a stirred tank, except at the highest frequency, but gave higher trans fatty acid formation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902000e [article] Partial hydrogenation of soybean oil in a piston oscillating monolith reactor [texte imprimé] / Yogesh G. Waghmare, Auteur ; Alan G. Bussard, Auteur ; Robert V. Forest, Auteur . - 2010 . - pp. 6323–6331. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6323–6331 Mots-clés : Hydrogenation Soybean Oil Résumé : The partial hydrogenation of soybean oil was carried out in a novel piston oscillating monolith reactor (POMR). POMR performance was studied under the application of low frequency (0−17.5 Hz) and amplitude (2.5 mm) vibrations at 110 °C and 0.41 MPa H2 using a Pd/Al2O3 monolith catalyst. Results show observed rate improvements of up to 220% for 17.5 Hz, 2.5 mm piston oscillations over low frequency pulsing conditions. For comparison purposes, the reaction was also carried out in a stirred tank reactor using the monolith catalyst. The POMR showed better activity at an equivalent power per unit volume when compared to a stirred tank. With the monolith catalyst, both external and internal mass transfer limitations exist. Using standard diffusion-reaction calculations and measurements over a range of particle sizes it was shown that the vibrations improve external mass transfer rates as well as internal transport within the washcoat. The POMR showed equal or better serial pathway selectivity than a stirred tank, except at the highest frequency, but gave higher trans fatty acid formation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902000e

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Predicting the multipollutant performance of utility SCR systems / Stephen Niksa in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6332–6341 Titre : Predicting the multipollutant performance of utility SCR systems Type de document : texte imprimé Auteurs : Stephen Niksa, Auteur ; April Freeman Sibley, Auteur Année de publication : 2010 Article en page(s) : pp. 6332–6341 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst material composition Résumé : This analysis relates catalyst material composition and bimodal pore size characteristics in a direct, quantitative way to the reactivities for simultaneous NO reduction, Hg0 oxidation, and SO3 production along utility selective catalytic reduction (SCR) reactors. SCR monoliths sustain two chemically distinct regions. In the inlet region, strong NH3 adsorption minimizes the coverage of chlorinated and sulfated surface sites, so NO reduction inhibits Hg0 and SO2 oxidation. Once the NH3 has been consumed, however, the chlorinated surface coverage surges by orders of magnitude, and the Hg0 oxidation rate rapidly increases, even while the HCl concentration in the gas phase remains uniform. Ammonia inhibition also eliminates the benefit of the rapid film mass transfer at the SCR inlet from promoting Hg0 oxidation. In many cases, the Hg0 oxidation rate becomes limited by film transport soon after the Hg0 begins to oxidize, so that none of the catalyst internal surface area is utilized. Shifting the pore size distribution toward macropores in a final catalyst stage appears to be an effective means for directly enhancing Hg0 oxidation. The predictions were validated with pilot-scale data to demonstrate the crucial impact of NH3 inhibition on SCR performance and with full-scale data for catalysts from a single vendor to show quantitative consistency across broad ranges of coal Cl content, gas hourly space velocity (GHSV), NH3/NO ratio, and catalyst specifications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020599 [article] Predicting the multipollutant performance of utility SCR systems [texte imprimé] / Stephen Niksa, Auteur ; April Freeman Sibley, Auteur . - 2010 . - pp. 6332–6341. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6332–6341 Mots-clés : Catalyst material composition Résumé : This analysis relates catalyst material composition and bimodal pore size characteristics in a direct, quantitative way to the reactivities for simultaneous NO reduction, Hg0 oxidation, and SO3 production along utility selective catalytic reduction (SCR) reactors. SCR monoliths sustain two chemically distinct regions. In the inlet region, strong NH3 adsorption minimizes the coverage of chlorinated and sulfated surface sites, so NO reduction inhibits Hg0 and SO2 oxidation. Once the NH3 has been consumed, however, the chlorinated surface coverage surges by orders of magnitude, and the Hg0 oxidation rate rapidly increases, even while the HCl concentration in the gas phase remains uniform. Ammonia inhibition also eliminates the benefit of the rapid film mass transfer at the SCR inlet from promoting Hg0 oxidation. In many cases, the Hg0 oxidation rate becomes limited by film transport soon after the Hg0 begins to oxidize, so that none of the catalyst internal surface area is utilized. Shifting the pore size distribution toward macropores in a final catalyst stage appears to be an effective means for directly enhancing Hg0 oxidation. The predictions were validated with pilot-scale data to demonstrate the crucial impact of NH3 inhibition on SCR performance and with full-scale data for catalysts from a single vendor to show quantitative consistency across broad ranges of coal Cl content, gas hourly space velocity (GHSV), NH3/NO ratio, and catalyst specifications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020599

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Formation of H2 and H2O2 in a water - spray gliding arc nonthermal plasma reactor / R. Burlica in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6342–6349 Titre : Formation of H2 and H2O2 in a water - spray gliding arc nonthermal plasma reactor Type de document : texte imprimé Auteurs : R. Burlica, Auteur ; K.-Y. Shih, Auteur ; B. R. Locke, Auteur Année de publication : 2010 Article en page(s) : pp. 6342–6349 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Plasma Reactor nonthermal Résumé : The formation rates and energy yields of H2 and H2O2 from pure water exposed to a nonthermal pulsed plasma-gliding arc reactor equipped with a spray nozzle were determined. Both H2 and H2O2 formation rates were the highest with the argon carrier where the maximum energy yields were 13 and 81 g/kWh, respectively. Both H2O2 and H2 were suppressed with carrier gases (air and nitrogen) where significant amounts of nitrates are formed. The energy yields of H2 and H2O2 with the argon carrier gas in the present work are higher than previously reported microwave plasma, corona, and AC gliding arc. The results for H2 are very close to an ideal quenching limit of 45% of thermodynamic limitations, thereby suggesting that the presence of water droplets in the plasma enhance energy yield through enhanced quenching of radicals and reactions that destroy the desired molecular products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100038g [article] Formation of H2 and H2O2 in a water - spray gliding arc nonthermal plasma reactor [texte imprimé] / R. Burlica, Auteur ; K.-Y. Shih, Auteur ; B. R. Locke, Auteur . - 2010 . - pp. 6342–6349. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6342–6349 Mots-clés : Plasma Reactor nonthermal Résumé : The formation rates and energy yields of H2 and H2O2 from pure water exposed to a nonthermal pulsed plasma-gliding arc reactor equipped with a spray nozzle were determined. Both H2 and H2O2 formation rates were the highest with the argon carrier where the maximum energy yields were 13 and 81 g/kWh, respectively. Both H2O2 and H2 were suppressed with carrier gases (air and nitrogen) where significant amounts of nitrates are formed. The energy yields of H2 and H2O2 with the argon carrier gas in the present work are higher than previously reported microwave plasma, corona, and AC gliding arc. The results for H2 are very close to an ideal quenching limit of 45% of thermodynamic limitations, thereby suggesting that the presence of water droplets in the plasma enhance energy yield through enhanced quenching of radicals and reactions that destroy the desired molecular products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100038g

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Reactive distillation for fischer - tropsch synthesis / Seethamraju Srinivas in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6350–6361 Titre : Reactive distillation for fischer - tropsch synthesis : feasible solution space Type de document : texte imprimé Auteurs : Seethamraju Srinivas, Auteur ; Sanjay M. Mahajani, Auteur ; Ranjan K. Malik, Auteur Année de publication : 2010 Article en page(s) : pp. 6350–6361 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reactive Distillation Résumé : Fischer−Tropsch synthesis can be advantageously carried out in reactive distillation (RD) mode. Parametric studies like the effect of reflux ratio, pressure, etc. have been reported in our earlier work [Srinivas et al. Ind. Eng. Chem. Res. 2009, 48, 4719−4730] using Aspen Plus. As an extension of this work, multiparameter sensitivity analysis is performed on a simple RD configuration without side-draws or side-coolers in Aspen Plus, retaining the kinetic and thermodynamic models used previously. A feasible solution space in terms of reflux ratio, pressure, and total catalyst loading is identified and possible reasons for the bounds observed are provided. Changes in the column configuration toward various objectives like maximum conversion, maximum gasoline yield, or selectivity, etc. are also investigated. Regions of interest corresponding to different objectives are represented on a Da−reflux ratio plot. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100106u?journalCode=iecred [article] Reactive distillation for fischer - tropsch synthesis : feasible solution space [texte imprimé] / Seethamraju Srinivas, Auteur ; Sanjay M. Mahajani, Auteur ; Ranjan K. Malik, Auteur . - 2010 . - pp. 6350–6361. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6350–6361 Mots-clés : Reactive Distillation Résumé : Fischer−Tropsch synthesis can be advantageously carried out in reactive distillation (RD) mode. Parametric studies like the effect of reflux ratio, pressure, etc. have been reported in our earlier work [Srinivas et al. Ind. Eng. Chem. Res. 2009, 48, 4719−4730] using Aspen Plus. As an extension of this work, multiparameter sensitivity analysis is performed on a simple RD configuration without side-draws or side-coolers in Aspen Plus, retaining the kinetic and thermodynamic models used previously. A feasible solution space in terms of reflux ratio, pressure, and total catalyst loading is identified and possible reasons for the bounds observed are provided. Changes in the column configuration toward various objectives like maximum conversion, maximum gasoline yield, or selectivity, etc. are also investigated. Regions of interest corresponding to different objectives are represented on a Da−reflux ratio plot. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100106u?journalCode=iecred

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Zinc acetates as efficient catalysts for the synthesis of bis - isocyanate precursors / Elisenda Reixach in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6362-6366 Titre : Zinc acetates as efficient catalysts for the synthesis of bis - isocyanate precursors Type de document : texte imprimé Auteurs : Elisenda Reixach, Auteur ; Nuria Bonet, Auteur ; F. Xavier Rius-Ruiz, Auteur Année de publication : 2010 Article en page(s) : pp. 6362-6366 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Precursor Catalyst Résumé : Anhydrous and hydrated zinc acetates were found to efficiently catalyze alkoxycarbonylation of the aromatic diamines 2,4-toluenediamine (2,4-TDA) and 4,4'-diphenylmethane diamine (4,4'-MDA) with diethyl and dimethyl carbonate, providing the desired bis-carbamates in yields from 93 to 98%. Driving these reactions to completion required temperatures of ca. 190 °C for 2,4-TDA and ca. 180 °C for 4,4'-MDA, and alkyl carbonate-to-substrate molar ratios of 25 :1 to 30:1. Higher catalyst loadings were required for 2,4-TDA (2.5 mol %) than for 4,4'-MDA (I mol %). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040390 [article] Zinc acetates as efficient catalysts for the synthesis of bis - isocyanate precursors [texte imprimé] / Elisenda Reixach, Auteur ; Nuria Bonet, Auteur ; F. Xavier Rius-Ruiz, Auteur . - 2010 . - pp. 6362-6366. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6362-6366 Mots-clés : Precursor Catalyst Résumé : Anhydrous and hydrated zinc acetates were found to efficiently catalyze alkoxycarbonylation of the aromatic diamines 2,4-toluenediamine (2,4-TDA) and 4,4'-diphenylmethane diamine (4,4'-MDA) with diethyl and dimethyl carbonate, providing the desired bis-carbamates in yields from 93 to 98%. Driving these reactions to completion required temperatures of ca. 190 °C for 2,4-TDA and ca. 180 °C for 4,4'-MDA, and alkyl carbonate-to-substrate molar ratios of 25 :1 to 30:1. Higher catalyst loadings were required for 2,4-TDA (2.5 mol %) than for 4,4'-MDA (I mol %). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040390

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Kinetic modeling of hemicellulose hydrolysis from triticale straw in a pressurized low polarity water flow - through reactor / Carl Pronyk in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6367–6375 Titre : Kinetic modeling of hemicellulose hydrolysis from triticale straw in a pressurized low polarity water flow - through reactor Type de document : texte imprimé Auteurs : Carl Pronyk, Auteur ; Giuseppe Mazza, Auteur Année de publication : 2010 Article en page(s) : pp. 6367–6375 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetic Hydrolysis Résumé : Two classic and one modified kinetic models were used to study the hydrolysis of triticale straw using pressurized low-polarity water (PLPW) in a flow-through reactor. Results indicated that for these experiments hemicellulose did not follow a biphasic reaction pathway. High yields of 72% were achieved at 170 °C, but these decreased to 60% at 150 °C and only 13% at 130 °C. The kinetics were controlled more by increases in temperature than flow rate in the reactor. Increases in flow rate reduced the overall hemicellulose yields but increased the portion extracted as oligomers. The kinetic rate constants when plotted as an Arrhenius-type temperature relationship displayed a dependency with flow rate. Curvature in the Arrhenius plots of the kinetic rate constants was due to differences in acetic acid formation with temperature. A modified monophasic kinetic model which incorporated reactor geometry and fluid flow was successful at modeling the yield of xylo-oligomers and monomers in PLPW. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003625 [article] Kinetic modeling of hemicellulose hydrolysis from triticale straw in a pressurized low polarity water flow - through reactor [texte imprimé] / Carl Pronyk, Auteur ; Giuseppe Mazza, Auteur . - 2010 . - pp. 6367–6375. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6367–6375 Mots-clés : Kinetic Hydrolysis Résumé : Two classic and one modified kinetic models were used to study the hydrolysis of triticale straw using pressurized low-polarity water (PLPW) in a flow-through reactor. Results indicated that for these experiments hemicellulose did not follow a biphasic reaction pathway. High yields of 72% were achieved at 170 °C, but these decreased to 60% at 150 °C and only 13% at 130 °C. The kinetics were controlled more by increases in temperature than flow rate in the reactor. Increases in flow rate reduced the overall hemicellulose yields but increased the portion extracted as oligomers. The kinetic rate constants when plotted as an Arrhenius-type temperature relationship displayed a dependency with flow rate. Curvature in the Arrhenius plots of the kinetic rate constants was due to differences in acetic acid formation with temperature. A modified monophasic kinetic model which incorporated reactor geometry and fluid flow was successful at modeling the yield of xylo-oligomers and monomers in PLPW. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003625

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Transformation of toluene and 1 , 2 , 4 - trimethylbenzene over ZSM - 5 and mordenite catalysts / S. M. Waziri in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6376–6387 Titre : Transformation of toluene and 1 , 2 , 4 - trimethylbenzene over ZSM - 5 and mordenite catalysts : A comprehensive kinetic model with reversibility Type de document : texte imprimé Auteurs : S. M. Waziri, Auteur ; A. M. Aitani, Auteur ; Al-Khattaf, S., Auteur Année de publication : 2010 Article en page(s) : pp. 6376–6387 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalytic transformations toluene Résumé : The catalytic transformations of toluene, 1,2,4-trimethylbenzene (TMB), and an equimolar mixture of the two compounds were investigated over H-mordenite and H-ZSM-5 catalysts. A series of experiments were conducted in a riser simulator over a temperature range of 300−400 °C and reaction times of 5−20 s. The influence of reaction conditions on variation of 1,2,4-TMB conversion, toluene conversion, para- to ortho-xylene ratio, xylenes to TMB isomers ratio, 1,3,5-TMB to 1,2,3-TMB ratio, and xylenes to benzene ratio were discussed. The study also includes the development of comprehensive kinetic models for isomerization, disproportionation, and transalkylation reactions of 1,2,4-TMB and toluene. The models account for reversibility of the isomerization reaction based on values of temperature dependent thermodynamic equilibrium constants. Catalysts deactivation was modeled using an activity decay function based on time-on-stream (TOS). The developed models gave a good match with experimental data based on a statistically significant estimate of the kinetic parameters in the models. For the 1,2,4-TMB reaction and transalkylation of 1,2,4-TMB with toluene, the apparent activation energy over H-ZSM-5 was higher than that over H-mordenite (i.e., Eapp,(H-ZSM-5) > Eapp,(H-Mordenite)) while the reverse order was observed for the toluene reaction over the two catalysts. A simple correlation that gives accurate representation of the temperature dependency of thermodynamic equilibrium compositions of TMB isomers was also reported. Note de contenu : Industrial chemistry ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100527x [article] Transformation of toluene and 1 , 2 , 4 - trimethylbenzene over ZSM - 5 and mordenite catalysts : A comprehensive kinetic model with reversibility [texte imprimé] / S. M. Waziri, Auteur ; A. M. Aitani, Auteur ; Al-Khattaf, S., Auteur . - 2010 . - pp. 6376–6387. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6376–6387 Mots-clés : Catalytic transformations toluene Résumé : The catalytic transformations of toluene, 1,2,4-trimethylbenzene (TMB), and an equimolar mixture of the two compounds were investigated over H-mordenite and H-ZSM-5 catalysts. A series of experiments were conducted in a riser simulator over a temperature range of 300−400 °C and reaction times of 5−20 s. The influence of reaction conditions on variation of 1,2,4-TMB conversion, toluene conversion, para- to ortho-xylene ratio, xylenes to TMB isomers ratio, 1,3,5-TMB to 1,2,3-TMB ratio, and xylenes to benzene ratio were discussed. The study also includes the development of comprehensive kinetic models for isomerization, disproportionation, and transalkylation reactions of 1,2,4-TMB and toluene. The models account for reversibility of the isomerization reaction based on values of temperature dependent thermodynamic equilibrium constants. Catalysts deactivation was modeled using an activity decay function based on time-on-stream (TOS). The developed models gave a good match with experimental data based on a statistically significant estimate of the kinetic parameters in the models. For the 1,2,4-TMB reaction and transalkylation of 1,2,4-TMB with toluene, the apparent activation energy over H-ZSM-5 was higher than that over H-mordenite (i.e., Eapp,(H-ZSM-5) > Eapp,(H-Mordenite)) while the reverse order was observed for the toluene reaction over the two catalysts. A simple correlation that gives accurate representation of the temperature dependency of thermodynamic equilibrium compositions of TMB isomers was also reported. Note de contenu : Industrial chemistry ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100527x

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Effect of surface substrate roughness and of chelating agent on the microstructure and mechanical properties of electroless processed brass coatings / Abel Hurtado-Macias in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6388-6393 Titre : Effect of surface substrate roughness and of chelating agent on the microstructure and mechanical properties of electroless processed brass coatings Type de document : texte imprimé Auteurs : Abel Hurtado-Macias, Auteur ; Carlos Dominguez-Rios, Auteur ; Juan Munoz-Saldana, Auteur Année de publication : 2010 Article en page(s) : pp. 6388-6393 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mechanical properties Microstructure Chelating agent Roughness Résumé : Brass coatings were deposited by electroless process on zamak-5 alloy substrates with various degrees of polishing and different concentrations of chelating agent in the chemical baths, in which the Cu complexing agent was varied in a wide range of compositions. The effect of Rochelle salt content as well as the substrate roughness on the microstructure and mechanical properties of the prepared coatings was addressed. A two-layer structure is formed during the deposition process having stoichiometric composition corresponding to CuZn and Cu5Zn8 for the top and bottom layer, respectively, and also CuZn5 was detected. The CuZn stoichiometric top layer showed invariably higher hardness. Polishing of the substrate leads to coatings with coarse-grained microstructure and higher surface hardness. It is found that both the chelating agent and the substrate roughness influence the microstructure and mechanical properties of the coatings, and higher chelating agent concentrations and smoother substrates produce higher densities and therefore better mechanical properties. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040393 [article] Effect of surface substrate roughness and of chelating agent on the microstructure and mechanical properties of electroless processed brass coatings [texte imprimé] / Abel Hurtado-Macias, Auteur ; Carlos Dominguez-Rios, Auteur ; Juan Munoz-Saldana, Auteur . - 2010 . - pp. 6388-6393. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6388-6393 Mots-clés : Mechanical properties Microstructure Chelating agent Roughness Résumé : Brass coatings were deposited by electroless process on zamak-5 alloy substrates with various degrees of polishing and different concentrations of chelating agent in the chemical baths, in which the Cu complexing agent was varied in a wide range of compositions. The effect of Rochelle salt content as well as the substrate roughness on the microstructure and mechanical properties of the prepared coatings was addressed. A two-layer structure is formed during the deposition process having stoichiometric composition corresponding to CuZn and Cu5Zn8 for the top and bottom layer, respectively, and also CuZn5 was detected. The CuZn stoichiometric top layer showed invariably higher hardness. Polishing of the substrate leads to coatings with coarse-grained microstructure and higher surface hardness. It is found that both the chelating agent and the substrate roughness influence the microstructure and mechanical properties of the coatings, and higher chelating agent concentrations and smoother substrates produce higher densities and therefore better mechanical properties. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040393

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Evaluation of immobilized enzyme in a high - surface - area biofuel cell electrode made of redox - polymer - grafted carbon black / Takanori Tamaki in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6394-6398 Titre : Evaluation of immobilized enzyme in a high - surface - area biofuel cell electrode made of redox - polymer - grafted carbon black Type de document : texte imprimé Auteurs : Takanori Tamaki, Auteur ; Atsushi Hiraide, Auteur ; Faizly B. Asmat, Auteur Année de publication : 2010 Article en page(s) : pp. 6394-6398 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon black Electrodes Surface area Immobilized enzyme Résumé : The current density of biofuel cell needs to be increased by 2 orders of magnitude to reach 10-1 A cm-2, which is the required density for portable energy devices. Model calculations have suggested that high-surface-area biofuel cell electrodes can achieve the required current density. However, experimental current density has amounted to only about 10-3 A cm-2 because of low enzyme surface coverage. In this study, we investigated the low surface coverage of glucose oxidase (GOD) in a high-surface-area biofuel cell electrode made of redox-polymer-grafted carbon black. Three possible explanations were considered: (i) low total amount of GOD, (ii) poor contact between GOD and mediator in the redox polymer, and (iii) deactivation of GOD. Among them, iii was found to be the main problem. Reducing this deactivation is the key for achieving a current density of approximately 10-1 A cm-2. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040394 [article] Evaluation of immobilized enzyme in a high - surface - area biofuel cell electrode made of redox - polymer - grafted carbon black [texte imprimé] / Takanori Tamaki, Auteur ; Atsushi Hiraide, Auteur ; Faizly B. Asmat, Auteur . - 2010 . - pp. 6394-6398. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6394-6398 Mots-clés : Carbon black Electrodes Surface area Immobilized enzyme Résumé : The current density of biofuel cell needs to be increased by 2 orders of magnitude to reach 10-1 A cm-2, which is the required density for portable energy devices. Model calculations have suggested that high-surface-area biofuel cell electrodes can achieve the required current density. However, experimental current density has amounted to only about 10-3 A cm-2 because of low enzyme surface coverage. In this study, we investigated the low surface coverage of glucose oxidase (GOD) in a high-surface-area biofuel cell electrode made of redox-polymer-grafted carbon black. Three possible explanations were considered: (i) low total amount of GOD, (ii) poor contact between GOD and mediator in the redox polymer, and (iii) deactivation of GOD. Among them, iii was found to be the main problem. Reducing this deactivation is the key for achieving a current density of approximately 10-1 A cm-2. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040394

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Synergetic effect of dual compatibilizers on in situ formed poly (lactic acid) / soy protein composites / Bo Liu in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6399-6406 Titre : Synergetic effect of dual compatibilizers on in situ formed poly (lactic acid) / soy protein composites Type de document : texte imprimé Auteurs : Bo Liu, Auteur ; Jiang, Long, Auteur ; Hongzhi Liu, Auteur Année de publication : 2010 Article en page(s) : pp. 6399-6406 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Composite material In situ Synergism Résumé : In this work, biobased poly(lactic acid) (PLA)/soy protein concentrate (SPC) composites were prepared by twin screw extrusion and injection molding. Poly(2-ethyl-2-oxamline) (PEOX) and polymeric methylene diphenyl diisocyanate (pMDI) were used sequentially as compatibilization agents to improve phase morphology and interfacial bonding. Properties of the PLA/SPC composites were significantly improved by the application of PEOX and pMDI. The SPC phase was refined and stretched into fine threads during processing under the compatibilization effect of PEOX. With only 0.5 part pMDI, the tensile strength of PLA/SPC composite increased significantly to approach that of pure PLA. With I part pMDI, the tensile strength was 6% higher than that of the neat PLA. Scanning electron micrographs evidenced enhanced interfacial adhesion between the two phases. Dynamic mechanical analysis tests revealed that the presence of pMDI enhanced the storage modulus of the composite, especially at temperatures above the glass-transition temperature of PLA, due to the strong interactions between the PLA and SPC phases after pMDI compatibilization. The compatibilized PLA/SPC blends also exhibited significantly reduced water uptakes. Fourier Transform Infrared Spectroscopy confirmed the occurrence of PLA grafting onto SPC molecules through pMDI compatibilization. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040395 [article] Synergetic effect of dual compatibilizers on in situ formed poly (lactic acid) / soy protein composites [texte imprimé] / Bo Liu, Auteur ; Jiang, Long, Auteur ; Hongzhi Liu, Auteur . - 2010 . - pp. 6399-6406. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6399-6406 Mots-clés : Composite material In situ Synergism Résumé : In this work, biobased poly(lactic acid) (PLA)/soy protein concentrate (SPC) composites were prepared by twin screw extrusion and injection molding. Poly(2-ethyl-2-oxamline) (PEOX) and polymeric methylene diphenyl diisocyanate (pMDI) were used sequentially as compatibilization agents to improve phase morphology and interfacial bonding. Properties of the PLA/SPC composites were significantly improved by the application of PEOX and pMDI. The SPC phase was refined and stretched into fine threads during processing under the compatibilization effect of PEOX. With only 0.5 part pMDI, the tensile strength of PLA/SPC composite increased significantly to approach that of pure PLA. With I part pMDI, the tensile strength was 6% higher than that of the neat PLA. Scanning electron micrographs evidenced enhanced interfacial adhesion between the two phases. Dynamic mechanical analysis tests revealed that the presence of pMDI enhanced the storage modulus of the composite, especially at temperatures above the glass-transition temperature of PLA, due to the strong interactions between the PLA and SPC phases after pMDI compatibilization. The compatibilized PLA/SPC blends also exhibited significantly reduced water uptakes. Fourier Transform Infrared Spectroscopy confirmed the occurrence of PLA grafting onto SPC molecules through pMDI compatibilization. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040395

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The Erosion − corrosion inhibition of AISI 431 martensitic stainless steel in 2.0 M H2SO4 solution using N - alkyl quaternary ammonium salts as inhibitors / R. Fuchs-Godec in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6407-6415 Titre : The Erosion − corrosion inhibition of AISI 431 martensitic stainless steel in 2.0 M H2SO4 solution using N - alkyl quaternary ammonium salts as inhibitors Type de document : texte imprimé Auteurs : R. Fuchs-Godec, Auteur Année de publication : 2010 Article en page(s) : pp. 6407-6415 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Stainless steel Corrosion inhibition Erosion corrosion Résumé : Electrochemical measurements were performed to explore the influence of cationic surfactants on the corrosion inhibition in the moving fluid with and without abrasive particles. The surfactants of the type of N-alkyl quaternary ammonium salts with different chain length (myristyltrimethylammonium bromide, chloride MTABr, MTAC1 and trioctylmethylammonium bromide, chloride TOMABr, TOMACI) were used as corrosion inhibitors for martensitic stainless steel type AISI 431 in 2 M H2SO4 solution. The polarization data showed that both surfactants used in this study acted as mixed type inhibitors, adsorbing on the stainless steel surface in agreement with the Flory—Huggins adsorption isotherm. Good inhibitory properties were achieved, only when the concentration of added surfactants exceeded their CMC values. It seems that the moving medium makes it difficult for the surfactants to adsorb on the metal surface, even when no abrasive particles are added. The number of -CH2 groups (clustered chain surfactants) had shown a significant effect on the inhibition efficiency of the investigated system. The inhibitory action of n-alkyl quaternary ammonium salts in 2.0 M H2SO4 mainly results from the physical (electrostatic) adsorption of the N-alkyl ammonium ions on the negatively charged surface of stainless steel. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040396 [article] The Erosion − corrosion inhibition of AISI 431 martensitic stainless steel in 2.0 M H2SO4 solution using N - alkyl quaternary ammonium salts as inhibitors [texte imprimé] / R. Fuchs-Godec, Auteur . - 2010 . - pp. 6407-6415. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6407-6415 Mots-clés : Stainless steel Corrosion inhibition Erosion corrosion Résumé : Electrochemical measurements were performed to explore the influence of cationic surfactants on the corrosion inhibition in the moving fluid with and without abrasive particles. The surfactants of the type of N-alkyl quaternary ammonium salts with different chain length (myristyltrimethylammonium bromide, chloride MTABr, MTAC1 and trioctylmethylammonium bromide, chloride TOMABr, TOMACI) were used as corrosion inhibitors for martensitic stainless steel type AISI 431 in 2 M H2SO4 solution. The polarization data showed that both surfactants used in this study acted as mixed type inhibitors, adsorbing on the stainless steel surface in agreement with the Flory—Huggins adsorption isotherm. Good inhibitory properties were achieved, only when the concentration of added surfactants exceeded their CMC values. It seems that the moving medium makes it difficult for the surfactants to adsorb on the metal surface, even when no abrasive particles are added. The number of -CH2 groups (clustered chain surfactants) had shown a significant effect on the inhibition efficiency of the investigated system. The inhibitory action of n-alkyl quaternary ammonium salts in 2.0 M H2SO4 mainly results from the physical (electrostatic) adsorption of the N-alkyl ammonium ions on the negatively charged surface of stainless steel. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040396

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Enhanced electrical properties of transparent carbon nanotube / binder hybrid thin films / Joong Tark Han in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6416-6421 Titre : Enhanced electrical properties of transparent carbon nanotube / binder hybrid thin films : effects of the silane sol and the bundle size of the carbon nanotubes Type de document : texte imprimé Auteurs : Joong Tark Han, Auteur ; Sun Young Kim, Auteur ; Jun Suk Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 6416-6421 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thin film Binders Electrical properties Résumé : We report the effects of intermolecular interactions at the few-walled carbon nanotubes (FWNTs)/binder interface and the bundle size of the acid-treated FWNTs on the electrical properties of FWNTs/silane sol hybrid films. The bundle size of the FWNTs was successfully controlled by using acid treatment; assembled bundle structures due to hydrogen bonding were observed only for FWNTs functionalized with hydroxyl groups (FWNTs-OH). It was also confirmed by measuring the UV absorbance that the FWNTs-OH even form bundled structures in the solution state. Tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTMS) sols were used to manipulate the intermolecular interactions between the nanotubes and binder. We found that the hybridization of relatively large bundled FWNTs with TEOS sol unfavorable to hydrophobic nanotube surfaces enhanced the electrical properties of thin films prepared by spray coating. Moreover, the Raman spectrum of the bundled FWNTs-OH is not affected by the silane sol, whereas the D-to-G ratio and the G band position of the unbundled FWNTs-COOH is noticeably influenced by the silane sol. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040397 [article] Enhanced electrical properties of transparent carbon nanotube / binder hybrid thin films : effects of the silane sol and the bundle size of the carbon nanotubes [texte imprimé] / Joong Tark Han, Auteur ; Sun Young Kim, Auteur ; Jun Suk Kim, Auteur . - 2010 . - pp. 6416-6421. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6416-6421 Mots-clés : Thin film Binders Electrical properties Résumé : We report the effects of intermolecular interactions at the few-walled carbon nanotubes (FWNTs)/binder interface and the bundle size of the acid-treated FWNTs on the electrical properties of FWNTs/silane sol hybrid films. The bundle size of the FWNTs was successfully controlled by using acid treatment; assembled bundle structures due to hydrogen bonding were observed only for FWNTs functionalized with hydroxyl groups (FWNTs-OH). It was also confirmed by measuring the UV absorbance that the FWNTs-OH even form bundled structures in the solution state. Tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTMS) sols were used to manipulate the intermolecular interactions between the nanotubes and binder. We found that the hybridization of relatively large bundled FWNTs with TEOS sol unfavorable to hydrophobic nanotube surfaces enhanced the electrical properties of thin films prepared by spray coating. Moreover, the Raman spectrum of the bundled FWNTs-OH is not affected by the silane sol, whereas the D-to-G ratio and the G band position of the unbundled FWNTs-COOH is noticeably influenced by the silane sol. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040397

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Effect of cross - linking fiber joints on the tensile and fracture behavior of paper / Andrew T. Horvath in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6422–6431 Titre : Effect of cross - linking fiber joints on the tensile and fracture behavior of paper Type de document : texte imprimé Auteurs : Andrew T. Horvath, Auteur ; Robert Pelton, Auteur ; Per Tomas Larsson, Auteur Année de publication : 2010 Article en page(s) : pp. 6422–6431 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fracture properties paper Résumé : The tensile and fracture properties of cross-linked paper were investigated at low and high relative humidity by cross-linking the joints formed between fibers. Cationic acetal dextran served as a model cross-linking agent, as it can be prepared to adsorb specifically to the fiber surface. Thus, cross-linking occurs only in the joints between fibers. The kinetics of hydrolysis was investigated to optimize the stock preparation, such that the resulting aldehyde groups react as the paper is dried. The effect of the cross-link density on the tensile and fracture properties was studied by varying the amount of acetal groups adsorbed to the pulp fibers. At low humidity, cross-linking improved the tensile and fracture properties of paper, although lower cross-link densities yielded better properties. Cross-linking was not effective at high relative humidty, as the tensile strength and stiffness were not improved. However, the fracture properties were significantly improved. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100334z [article] Effect of cross - linking fiber joints on the tensile and fracture behavior of paper [texte imprimé] / Andrew T. Horvath, Auteur ; Robert Pelton, Auteur ; Per Tomas Larsson, Auteur . - 2010 . - pp. 6422–6431. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6422–6431 Mots-clés : Fracture properties paper Résumé : The tensile and fracture properties of cross-linked paper were investigated at low and high relative humidity by cross-linking the joints formed between fibers. Cationic acetal dextran served as a model cross-linking agent, as it can be prepared to adsorb specifically to the fiber surface. Thus, cross-linking occurs only in the joints between fibers. The kinetics of hydrolysis was investigated to optimize the stock preparation, such that the resulting aldehyde groups react as the paper is dried. The effect of the cross-link density on the tensile and fracture properties was studied by varying the amount of acetal groups adsorbed to the pulp fibers. At low humidity, cross-linking improved the tensile and fracture properties of paper, although lower cross-link densities yielded better properties. Cross-linking was not effective at high relative humidty, as the tensile strength and stiffness were not improved. However, the fracture properties were significantly improved. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100334z

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Production of coated papers with improved properties by using a water - soluble chitosan derivative / Susana C. M. Fernandes in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6432–6438 Titre : Production of coated papers with improved properties by using a water - soluble chitosan derivative Type de document : texte imprimé Auteurs : Susana C. M. Fernandes, Auteur ; Carmen S. R. Freire, Auteur ; Armando J. D. Silvestre, Auteur Année de publication : 2010 Article en page(s) : pp. 6432–6438 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Production Papers Chitosan derivative Résumé : Eucalyptus globulus-based paper sheets were coated with chitosan and a water-soluble chitosan derivative on a pilot-size press machine. Different coating weights were attained by the deposition of 1−5 coating layers. The morphological, mechanical, barrier, and optical properties as well as the paper aging and inkjet print quality of the ensuing coated papers were investigated and assessed. In general, both chitosan and water-soluble chitosan coatings had a positive impact on the final properties of the coated papers, which was quite dependent on the number of deposited chitosan layers. The results obtained also showed that the water-soluble chitosan-coated papers presented superior optical properties and printability and better results on aging measurements than chitosan-coated papers. Therefore, the use of water-soluble chitosan derivatives on paper coating processes represents an interesting and sustainable strategy for the development of new functional paper materials or for the improvement of the end-user properties of paper products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100573z [article] Production of coated papers with improved properties by using a water - soluble chitosan derivative [texte imprimé] / Susana C. M. Fernandes, Auteur ; Carmen S. R. Freire, Auteur ; Armando J. D. Silvestre, Auteur . - 2010 . - pp. 6432–6438. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6432–6438 Mots-clés : Production Papers Chitosan derivative Résumé : Eucalyptus globulus-based paper sheets were coated with chitosan and a water-soluble chitosan derivative on a pilot-size press machine. Different coating weights were attained by the deposition of 1−5 coating layers. The morphological, mechanical, barrier, and optical properties as well as the paper aging and inkjet print quality of the ensuing coated papers were investigated and assessed. In general, both chitosan and water-soluble chitosan coatings had a positive impact on the final properties of the coated papers, which was quite dependent on the number of deposited chitosan layers. The results obtained also showed that the water-soluble chitosan-coated papers presented superior optical properties and printability and better results on aging measurements than chitosan-coated papers. Therefore, the use of water-soluble chitosan derivatives on paper coating processes represents an interesting and sustainable strategy for the development of new functional paper materials or for the improvement of the end-user properties of paper products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100573z

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Flowrate targeting algorithm for interplant resource conservation network. Part 1 / Irene M. L. Chew in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp 6439–6455 Titre : Flowrate targeting algorithm for interplant resource conservation network. Part 1 : unassisted integration scheme Type de document : texte imprimé Auteurs : Irene M. L. Chew, Auteur ; Dominic C. Y. Foo, Auteur ; Denny K. S. Ng, Auteur Année de publication : 2010 Article en page(s) : pp 6439–6455 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Algorithm Resource conservation network Résumé : This paper is part 1 of a series describing a new algorithm for targeting minimum fresh resource and waste flow rates for an interplant resource conservation network (IPRCN). The IPRCN enables the reuse of the excess process sources among different networks, which reduces the consumption of fresh resource and generation of waste simultaneously. Four hypothetical examples are presented to illustrate both concentration- and property-based utility gas and water integration problems. In addition, the proposed targeting algorithm is adapted in the synthesis of total resource network, where the minimum regeneration and waste treatment flow rates can be targeted prior to the detailed design of an IPRCN. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901802m [article] Flowrate targeting algorithm for interplant resource conservation network. Part 1 : unassisted integration scheme [texte imprimé] / Irene M. L. Chew, Auteur ; Dominic C. Y. Foo, Auteur ; Denny K. S. Ng, Auteur . - 2010 . - pp 6439–6455. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp 6439–6455 Mots-clés : Algorithm Resource conservation network Résumé : This paper is part 1 of a series describing a new algorithm for targeting minimum fresh resource and waste flow rates for an interplant resource conservation network (IPRCN). The IPRCN enables the reuse of the excess process sources among different networks, which reduces the consumption of fresh resource and generation of waste simultaneously. Four hypothetical examples are presented to illustrate both concentration- and property-based utility gas and water integration problems. In addition, the proposed targeting algorithm is adapted in the synthesis of total resource network, where the minimum regeneration and waste treatment flow rates can be targeted prior to the detailed design of an IPRCN. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901802m

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Flowrate targeting algorithm for interplant resource conservation network. Part 2 / Irene M. L. Chew in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6456–6468 Titre : Flowrate targeting algorithm for interplant resource conservation network. Part 2 : assisted integration scheme Type de document : texte imprimé Auteurs : Irene M. L. Chew, Auteur ; Dominic C. Y. Foo, Auteur ; Raymond R. Tan, Auteur Année de publication : 2010 Article en page(s) : pp. 6456–6468 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Algorithm Resource conservation network Résumé : Part 1 of the series (Chew, I. M. L.; Foo, D. C. Y.; Ng, D. K. S.; Tan, R. R. Flowrate Targeting Algorithm for Interplant Resource Conservation Network. Part 1: Unassisted Integration Scheme. Ind. Eng. Chem. Res. DOI: 10.1021/ie901802m.) proposes a systematic three-step targeting algorithm for unassisted integration scheme for interplant resource conservation network (IPRCN), where cross-plant streams within the pinch region can be used to achieve minimum resource flow rate targets. However, the unassisted scheme does not hold true for all cases. Part 2 of the series explores additional material recovery to be realized by sending cross-plant streams outside the pinch region. This is known as the assisted integration scheme. Appropriate identification of waste streams as the cross-plant streams is an important step in locating the minimum flow rate targets for these cases. The effect of pinch shifting and the generation of new waste streams are also investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901804z [article] Flowrate targeting algorithm for interplant resource conservation network. Part 2 : assisted integration scheme [texte imprimé] / Irene M. L. Chew, Auteur ; Dominic C. Y. Foo, Auteur ; Raymond R. Tan, Auteur . - 2010 . - pp. 6456–6468. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6456–6468 Mots-clés : Algorithm Resource conservation network Résumé : Part 1 of the series (Chew, I. M. L.; Foo, D. C. Y.; Ng, D. K. S.; Tan, R. R. Flowrate Targeting Algorithm for Interplant Resource Conservation Network. Part 1: Unassisted Integration Scheme. Ind. Eng. Chem. Res. DOI: 10.1021/ie901802m.) proposes a systematic three-step targeting algorithm for unassisted integration scheme for interplant resource conservation network (IPRCN), where cross-plant streams within the pinch region can be used to achieve minimum resource flow rate targets. However, the unassisted scheme does not hold true for all cases. Part 2 of the series explores additional material recovery to be realized by sending cross-plant streams outside the pinch region. This is known as the assisted integration scheme. Appropriate identification of waste streams as the cross-plant streams is an important step in locating the minimum flow rate targets for these cases. The effect of pinch shifting and the generation of new waste streams are also investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901804z

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Multiobjective optimization of a porous ceramic membrane reactor for oxidative coupling of methane / Mohammad R. Quddus in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6469–6481 Titre : Multiobjective optimization of a porous ceramic membrane reactor for oxidative coupling of methane Type de document : texte imprimé Auteurs : Mohammad R. Quddus, Auteur ; Yan Zhang, Auteur ; Ajay K. Ray, Auteur Année de publication : 2010 Article en page(s) : pp. 6469–6481 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Optimization Porous ceramic membrane Résumé : Multiobjective optimization of a porous ceramic membrane reactor for oxidative coupling of methane has been studied with the elitist nondominated sorting genetic algorithm with jumping genes (NSGA-II-aJG). A mathematical model was first developed and “tuned” using some experimental results available in the literature. A parametric sensitivity analysis was carried out on the experimentally verified model to systematically investigate the effects of the process parameters on the performance of the membrane reactor. Several two objective optimization problems were performed at both operating and design stages using NSGA-II-aJG. Significant performance improvement in terms of C2 yield and selectivity could be achieved when rigorous optimization was performed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900971p [article] Multiobjective optimization of a porous ceramic membrane reactor for oxidative coupling of methane [texte imprimé] / Mohammad R. Quddus, Auteur ; Yan Zhang, Auteur ; Ajay K. Ray, Auteur . - 2010 . - pp. 6469–6481. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6469–6481 Mots-clés : Optimization Porous ceramic membrane Résumé : Multiobjective optimization of a porous ceramic membrane reactor for oxidative coupling of methane has been studied with the elitist nondominated sorting genetic algorithm with jumping genes (NSGA-II-aJG). A mathematical model was first developed and “tuned” using some experimental results available in the literature. A parametric sensitivity analysis was carried out on the experimentally verified model to systematically investigate the effects of the process parameters on the performance of the membrane reactor. Several two objective optimization problems were performed at both operating and design stages using NSGA-II-aJG. Significant performance improvement in terms of C2 yield and selectivity could be achieved when rigorous optimization was performed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900971p

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Mixed - integer linear programming monolithic formulations for lot - sizing and scheduling of single - stage batch facilities / Pablo A. Marchetti in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6482–6498 Titre : Mixed - integer linear programming monolithic formulations for lot - sizing and scheduling of single - stage batch facilities Type de document : texte imprimé Auteurs : Pablo A. Marchetti, Auteur ; Carlos A. Méndez, Auteur ; Jaime Cerdá, Auteur Année de publication : 2010 Article en page(s) : pp. 6482–6498 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Linear programming Monolithic formulations Résumé : This paper presents a pair of mixed-integer linear programming (MILP) continuous-time formulations for the simultaneous lot-sizing and scheduling of single-stage multiproduct batch facilities. Both approaches can handle multiple customer orders per product at different due dates as well as variable processing times. To match product demands, several batches can be allocated to a single requirement and, at the same time, a single batch may be used to satisfy multiple orders. Through a novel procedure, a predefined set of batches for each order with enough elements to guarantee optimality is generated. The two proposed formulations deal with batch sequencing decisions in a different manner. One of them rigorously arranges individual batches assigned to the same unit, while the other sequences clusters of batches sharing the same product and due date, and processed in the same equipment item. Grouping batches into clusters seeks to reduce the number of product changeovers. The final contents of clusters are model decisions. Powerful symmetry breaking constraints based on allocation variables to avoid redundant solutions were also developed. Three cases studies involving up to 56 batches have been solved. The two formulations provide very good results at quite competitive CPU times when compared with prior monolithic techniques. Moreover, the approximate cluster-based method was able to solve very large problems in an efficient manner. It was validated by comparing its results with the ones provided by the rigorous model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100054h [article] Mixed - integer linear programming monolithic formulations for lot - sizing and scheduling of single - stage batch facilities [texte imprimé] / Pablo A. Marchetti, Auteur ; Carlos A. Méndez, Auteur ; Jaime Cerdá, Auteur . - 2010 . - pp. 6482–6498. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6482–6498 Mots-clés : Linear programming Monolithic formulations Résumé : This paper presents a pair of mixed-integer linear programming (MILP) continuous-time formulations for the simultaneous lot-sizing and scheduling of single-stage multiproduct batch facilities. Both approaches can handle multiple customer orders per product at different due dates as well as variable processing times. To match product demands, several batches can be allocated to a single requirement and, at the same time, a single batch may be used to satisfy multiple orders. Through a novel procedure, a predefined set of batches for each order with enough elements to guarantee optimality is generated. The two proposed formulations deal with batch sequencing decisions in a different manner. One of them rigorously arranges individual batches assigned to the same unit, while the other sequences clusters of batches sharing the same product and due date, and processed in the same equipment item. Grouping batches into clusters seeks to reduce the number of product changeovers. The final contents of clusters are model decisions. Powerful symmetry breaking constraints based on allocation variables to avoid redundant solutions were also developed. Three cases studies involving up to 56 batches have been solved. The two formulations provide very good results at quite competitive CPU times when compared with prior monolithic techniques. Moreover, the approximate cluster-based method was able to solve very large problems in an efficient manner. It was validated by comparing its results with the ones provided by the rigorous model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100054h

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Rigorous separation design. 1. / Seon B. Kim in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6499–6513 Titre : Rigorous separation design. 1. : multicomponent mixtures, nonideal mixtures, and prefractionating column networks Type de document : texte imprimé Auteurs : Seon B. Kim, Auteur ; Gerardo J. Ruiz, Auteur ; Andreas A. Linninger, Auteur Année de publication : 2010 Article en page(s) : pp. 6499–6513 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Separation networks Résumé : Currently, there is a lack of reliable computational methods to automatically synthesize separation networks within specific product targets. Computational methods exploring the combinatorial wealth of different separation configurations, while simultaneously selecting feasible or detecting globally optimal operating conditions, are not available for problems of practical size. In this paper, we extend the minimum bubble point distance algorithm embedded in the temperature collocation methodology to rigorously design complex networks to separate nonideal multicomponent mixtures into products of desired purity using heat-integrated prefractionating columns. Our employed inverse design procedure enables the systematic design of physically realizable separations for mixtures with a large number of species. The computer procedure robustly converges to the desired purity targets, unless the desired purity target is thermodynamically impossible to realize. The algorithm also rapidly identifies infeasible specifications without fail. Finally, synthesized networks were validated with AspenPlus matching exactly the inverse design results with the target purity. The rigorous flowsheet design combined with validation of the networks with commercial flowsheet simulators enables the systematic design of energy-efficient separation networks. The methodology is ready to address currently unresolved design problems such as the computer-aided design of energy-efficient separations, the design of biorefineries, or new process designs for carbon sequestration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000532 [article] Rigorous separation design. 1. : multicomponent mixtures, nonideal mixtures, and prefractionating column networks [texte imprimé] / Seon B. Kim, Auteur ; Gerardo J. Ruiz, Auteur ; Andreas A. Linninger, Auteur . - 2010 . - pp. 6499–6513. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6499–6513 Mots-clés : Separation networks Résumé : Currently, there is a lack of reliable computational methods to automatically synthesize separation networks within specific product targets. Computational methods exploring the combinatorial wealth of different separation configurations, while simultaneously selecting feasible or detecting globally optimal operating conditions, are not available for problems of practical size. In this paper, we extend the minimum bubble point distance algorithm embedded in the temperature collocation methodology to rigorously design complex networks to separate nonideal multicomponent mixtures into products of desired purity using heat-integrated prefractionating columns. Our employed inverse design procedure enables the systematic design of physically realizable separations for mixtures with a large number of species. The computer procedure robustly converges to the desired purity targets, unless the desired purity target is thermodynamically impossible to realize. The algorithm also rapidly identifies infeasible specifications without fail. Finally, synthesized networks were validated with AspenPlus matching exactly the inverse design results with the target purity. The rigorous flowsheet design combined with validation of the networks with commercial flowsheet simulators enables the systematic design of energy-efficient separation networks. The methodology is ready to address currently unresolved design problems such as the computer-aided design of energy-efficient separations, the design of biorefineries, or new process designs for carbon sequestration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000532

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Dissolution of cobalt from CoO / A l 2O3 catalyst with mineral acids / Ilhem Boukerche in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6514–6520 Titre : Dissolution of cobalt from CoO / A l 2O3 catalyst with mineral acids Type de document : texte imprimé Auteurs : Ilhem Boukerche, Auteur ; Naima Habbache, Auteur ; Nadia Alane, Auteur Année de publication : 2010 Article en page(s) : pp. 6514–6520 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Mineral acids Résumé : In this study, the dissolution of CoO from CoO/Al2O3 catalyst with HCl, H2SO4, and HNO3 solutions was investigated in a batch reactor employing parameters that were expected to affect the dissolution rate of cobalt, such as stirring speed, temperature, and acid concentration. It was found that 99.82% of cobalt was dissolved after 4 h with HCl at 2 M, 75 °C, and a liquid-to-solid ratio (l/s) of 100 mL/g, while only 31.96% and 13.57% cobalt dissolutions were reached with H2SO4 and HNO3, respectively, under the same operation conditions. The difference in dissolution rates was due to the presence of different anions (Cl−, NO3−, and HSO4−) involved in the surface reactions. Dissolution kinetic of cobalt was examined according to a heterogeneous model. It was found that the dissolution rate was controlled by surface chemical processes in all cases. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901444y [article] Dissolution of cobalt from CoO / A l 2O3 catalyst with mineral acids [texte imprimé] / Ilhem Boukerche, Auteur ; Naima Habbache, Auteur ; Nadia Alane, Auteur . - 2010 . - pp. 6514–6520. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6514–6520 Mots-clés : Catalyst Mineral acids Résumé : In this study, the dissolution of CoO from CoO/Al2O3 catalyst with HCl, H2SO4, and HNO3 solutions was investigated in a batch reactor employing parameters that were expected to affect the dissolution rate of cobalt, such as stirring speed, temperature, and acid concentration. It was found that 99.82% of cobalt was dissolved after 4 h with HCl at 2 M, 75 °C, and a liquid-to-solid ratio (l/s) of 100 mL/g, while only 31.96% and 13.57% cobalt dissolutions were reached with H2SO4 and HNO3, respectively, under the same operation conditions. The difference in dissolution rates was due to the presence of different anions (Cl−, NO3−, and HSO4−) involved in the surface reactions. Dissolution kinetic of cobalt was examined according to a heterogeneous model. It was found that the dissolution rate was controlled by surface chemical processes in all cases. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901444y

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Batch distillation in a batch stripper with a side withdrawal for purification of heat - unstable compounds / Xianbao Cui in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6521–6529 Titre : Batch distillation in a batch stripper with a side withdrawal for purification of heat - unstable compounds Type de document : texte imprimé Auteurs : Xianbao Cui, Auteur ; Xiaokai Zhang, Auteur ; Ying Zhang, Auteur Année de publication : 2010 Article en page(s) : pp. 6521–6529 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Distillation process Résumé : Batch distillation in a batch stripper with a side withdrawal (BSS) for the purification of heat-unstable compounds from light and heavy impurities was investigated. The batch distillation process was simulated by a dimensionless dynamic model and optimized by simulated annealing algorithm. Batch distillation in a BSS was compared with that in a batch stripper (BS) for the purification of heat-unstable compounds with different types of degradation reactions. The recovery of heat-unstable compounds in a BSS is larger than that in a BS, especially in the case of the heat-unstable compound converting to a heavy impurity. Compared with batch distillation in a batch rectifier with a side withdrawal (BRS), batch distillation in a BSS is more suitable for purification of heat-unstable compounds that convert to a light impurity. The effects of operational and design parameters for batch distillation in a BSS were discussed according to the simulation results, such as the temperature in the top storage vessel, the location of the side withdrawal stage, the holdup in the reboiler, the reboiler ratio, and the side reflux ratio. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901558c [article] Batch distillation in a batch stripper with a side withdrawal for purification of heat - unstable compounds [texte imprimé] / Xianbao Cui, Auteur ; Xiaokai Zhang, Auteur ; Ying Zhang, Auteur . - 2010 . - pp. 6521–6529. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6521–6529 Mots-clés : Distillation process Résumé : Batch distillation in a batch stripper with a side withdrawal (BSS) for the purification of heat-unstable compounds from light and heavy impurities was investigated. The batch distillation process was simulated by a dimensionless dynamic model and optimized by simulated annealing algorithm. Batch distillation in a BSS was compared with that in a batch stripper (BS) for the purification of heat-unstable compounds with different types of degradation reactions. The recovery of heat-unstable compounds in a BSS is larger than that in a BS, especially in the case of the heat-unstable compound converting to a heavy impurity. Compared with batch distillation in a batch rectifier with a side withdrawal (BRS), batch distillation in a BSS is more suitable for purification of heat-unstable compounds that convert to a light impurity. The effects of operational and design parameters for batch distillation in a BSS were discussed according to the simulation results, such as the temperature in the top storage vessel, the location of the side withdrawal stage, the holdup in the reboiler, the reboiler ratio, and the side reflux ratio. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901558c

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Gas permeation behavior of pebax - 1657 nanocomposite membrane incorporated with multiwalled carbon nanotubes / R. Surya Murali in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6530–6538 Titre : Gas permeation behavior of pebax - 1657 nanocomposite membrane incorporated with multiwalled carbon nanotubes Type de document : texte imprimé Auteurs : R. Surya Murali, Auteur ; S. Sridhar, Auteur ; T. Sankarshana, Auteur Année de publication : 2010 Article en page(s) : pp. 6530–6538 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon nanotubes Gaz Résumé : Incorporation of multiwalled carbon nanotubes (MWNT) on the gas permeation properties of H2, CO2, O2, and N2 gases in poly(ether-block-amide) (Pebax-1657) membrane has been investigated. Pebax-1657 was dissolved in the ethanol−water mixture and cast on an ultraporous polyethersulfone substrate followed by complete solvent evaporation. Nanocomposite membranes were prepared by dispersion of MWNT in concentrations of 0−5% of polymer weight in the Pebax solutions with sonication for 2 h to ensure uniformity. Cross-linking was carried out in hexane medium using 2,4-toluylene diisocyanate (TDI). The permeabilities of pure gases were measured at room temperature, and the ideal selectivities were determined at pressures varying from 1−3 MPa using an indigenously built high-pressure gas separation manifold. For neat Pebax membrane, high permeabilities of 55.8 and 32.1 barrers were observed for CO2 and H2 gases, respectively, whereas that of N2 was as low as 1.4 barrers. The selectivity of cross-linked 2% MWNT Pebax membrane was enhanced from 83.2 to 162 with increasing feed pressure (1−3 MPa) for the CO2/N2 gas pair, whereas the corresponding values for H2/N2 and O2/N2 systems were found to be in the range 82.5−90 and 7.1−6.8, respectively. The membranes were characterized by scanning electron microscopy (SEM) to study surface and cross-sectional morphologies. Fourier transform infrared (FT-IR), wide-angle X-ray diffraction (WAXD), and ion exchange capacity (IEC) studies were carried out to determine the effect of MWNT incorporation on intermolecular interactions, degree of crystallinity, and extent of cross-linking, respectively. Fractional free volume (FFV) calculations based on density measurements were conducted along with water sorption studies to explain permeation behavior. The use of modified block copolymer membranes provides a means for separation of CO2 from N2 in power plants, H2 recycle from ammonia purge gas, O2 enrichment from air for medical applications, and CO2 removal from water-gas shift reaction to improve H2 yield. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016495 [article] Gas permeation behavior of pebax - 1657 nanocomposite membrane incorporated with multiwalled carbon nanotubes [texte imprimé] / R. Surya Murali, Auteur ; S. Sridhar, Auteur ; T. Sankarshana, Auteur . - 2010 . - pp. 6530–6538. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6530–6538 Mots-clés : Carbon nanotubes Gaz Résumé : Incorporation of multiwalled carbon nanotubes (MWNT) on the gas permeation properties of H2, CO2, O2, and N2 gases in poly(ether-block-amide) (Pebax-1657) membrane has been investigated. Pebax-1657 was dissolved in the ethanol−water mixture and cast on an ultraporous polyethersulfone substrate followed by complete solvent evaporation. Nanocomposite membranes were prepared by dispersion of MWNT in concentrations of 0−5% of polymer weight in the Pebax solutions with sonication for 2 h to ensure uniformity. Cross-linking was carried out in hexane medium using 2,4-toluylene diisocyanate (TDI). The permeabilities of pure gases were measured at room temperature, and the ideal selectivities were determined at pressures varying from 1−3 MPa using an indigenously built high-pressure gas separation manifold. For neat Pebax membrane, high permeabilities of 55.8 and 32.1 barrers were observed for CO2 and H2 gases, respectively, whereas that of N2 was as low as 1.4 barrers. The selectivity of cross-linked 2% MWNT Pebax membrane was enhanced from 83.2 to 162 with increasing feed pressure (1−3 MPa) for the CO2/N2 gas pair, whereas the corresponding values for H2/N2 and O2/N2 systems were found to be in the range 82.5−90 and 7.1−6.8, respectively. The membranes were characterized by scanning electron microscopy (SEM) to study surface and cross-sectional morphologies. Fourier transform infrared (FT-IR), wide-angle X-ray diffraction (WAXD), and ion exchange capacity (IEC) studies were carried out to determine the effect of MWNT incorporation on intermolecular interactions, degree of crystallinity, and extent of cross-linking, respectively. Fractional free volume (FFV) calculations based on density measurements were conducted along with water sorption studies to explain permeation behavior. The use of modified block copolymer membranes provides a means for separation of CO2 from N2 in power plants, H2 recycle from ammonia purge gas, O2 enrichment from air for medical applications, and CO2 removal from water-gas shift reaction to improve H2 yield. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016495

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Negative rejection of NaCl in ultrafiltration of aqueous solution of NaCl and KCl using sodalite octahydrate zeolite − clay charged ultrafiltration membrane / Fasil Qayoom Mir in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6539–6546 Titre : Negative rejection of NaCl in ultrafiltration of aqueous solution of NaCl and KCl using sodalite octahydrate zeolite − clay charged ultrafiltration membrane Type de document : texte imprimé Auteurs : Fasil Qayoom Mir, Auteur ; Anupam Shukla, Auteur Année de publication : 2010 Article en page(s) : pp. 6539–6546 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aqueous solution Zéolithe Résumé : Permeation of mixed salt solution through charged membrane is a complex process, and depending upon electrostatic interaction among different types of ions and wall charges, complex separation behaviors such as negative rejection of a salt in the mixture have been observed for such systems. Negative rejection of a salt in an aqueous mixture of salts has been observed for nanofiltration membranes that have very small pores (pore diameter 1 nm). We report in this work studies on separation of mixed salt solutions of NaCl and KCl using a charge ultrafiltration membrane of large pore size (pore diameter 15−92 nm) whose preparation is described elsewhere [Workneh, S.; Shukla, A. J. Membr. Sci. 2008, 309, 189]. At a low total concentration of electrolytes in the feed (0.01 M), when the effective exclusion of co-ions occurs inside the membrane, negative rejection of NaCl is obtained. It is found that irrespective of the composition of the salt mixture used in this work, the magnitude of negative observed rejection increases with pressure initially but beyond a certain pressure its magnitude decreases by a small amount. It is also found that as the NaCl composition is increased the magnitude of negative observed rejection first increases but beyond a value of 60% NaCl it decreases for all the pressure differences used in this work. Simulated values of the intrinsic rejection coefficient, however, are found to increase monotonically with pressure, indicating that the maximum in magnitude of observed negative rejection is due to concentration polarization. With variation in feed composition the intrinsic rejection shows a trend similar to the observed rejection. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901775v [article] Negative rejection of NaCl in ultrafiltration of aqueous solution of NaCl and KCl using sodalite octahydrate zeolite − clay charged ultrafiltration membrane [texte imprimé] / Fasil Qayoom Mir, Auteur ; Anupam Shukla, Auteur . - 2010 . - pp. 6539–6546. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6539–6546 Mots-clés : Aqueous solution Zéolithe Résumé : Permeation of mixed salt solution through charged membrane is a complex process, and depending upon electrostatic interaction among different types of ions and wall charges, complex separation behaviors such as negative rejection of a salt in the mixture have been observed for such systems. Negative rejection of a salt in an aqueous mixture of salts has been observed for nanofiltration membranes that have very small pores (pore diameter 1 nm). We report in this work studies on separation of mixed salt solutions of NaCl and KCl using a charge ultrafiltration membrane of large pore size (pore diameter 15−92 nm) whose preparation is described elsewhere [Workneh, S.; Shukla, A. J. Membr. Sci. 2008, 309, 189]. At a low total concentration of electrolytes in the feed (0.01 M), when the effective exclusion of co-ions occurs inside the membrane, negative rejection of NaCl is obtained. It is found that irrespective of the composition of the salt mixture used in this work, the magnitude of negative observed rejection increases with pressure initially but beyond a certain pressure its magnitude decreases by a small amount. It is also found that as the NaCl composition is increased the magnitude of negative observed rejection first increases but beyond a value of 60% NaCl it decreases for all the pressure differences used in this work. Simulated values of the intrinsic rejection coefficient, however, are found to increase monotonically with pressure, indicating that the maximum in magnitude of observed negative rejection is due to concentration polarization. With variation in feed composition the intrinsic rejection shows a trend similar to the observed rejection. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901775v

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Extraction of aleuritic acid from seedlac and purification by reactive adsorption on functionalized polymers / Shobha K. Nagappayya in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6547–6553 Titre : Extraction of aleuritic acid from seedlac and purification by reactive adsorption on functionalized polymers Type de document : texte imprimé Auteurs : Shobha K. Nagappayya, Auteur ; Vilas G. Gaikar, Auteur Année de publication : 2010 Article en page(s) : pp. 6547–6553 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aleuritic acid Polymers Résumé : Reactive extraction of aleuritic acid from seedlac was carried out at different NaOH concentrations and temperatures. A mathematical model was proposed for the hydrolysis of seedlac considering the breaking of ester linkages at any position along the length of the polymeric chain. Recovery and purification of aleuritic acid from the product mixture was further achieved by reactive adsorption using weakly basic polymeric resin containing tertiary amino group as the functional group. Aleuritic acid was recovered by continuous column studies with 92% yield and 94% purity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902061e [article] Extraction of aleuritic acid from seedlac and purification by reactive adsorption on functionalized polymers [texte imprimé] / Shobha K. Nagappayya, Auteur ; Vilas G. Gaikar, Auteur . - 2010 . - pp. 6547–6553. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6547–6553 Mots-clés : Aleuritic acid Polymers Résumé : Reactive extraction of aleuritic acid from seedlac was carried out at different NaOH concentrations and temperatures. A mathematical model was proposed for the hydrolysis of seedlac considering the breaking of ester linkages at any position along the length of the polymeric chain. Recovery and purification of aleuritic acid from the product mixture was further achieved by reactive adsorption using weakly basic polymeric resin containing tertiary amino group as the functional group. Aleuritic acid was recovered by continuous column studies with 92% yield and 94% purity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902061e

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Synergistic Solvent Impregnated Resin for Adsorptive Separation of Lithium Ion / Kenta Onishi in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6554–6558 Titre : Synergistic Solvent Impregnated Resin for Adsorptive Separation of Lithium Ion Type de document : texte imprimé Auteurs : Kenta Onishi, Auteur ; Takahide Nakamura, Auteur ; Syouhei Nishihama, Auteur Année de publication : 2010 Article en page(s) : pp. 6554–6558 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solvent Adsorption Résumé : A novel synergistic solvent impregnated resin (SIR), containing both 1-phenyl-1,3-tetradecanedione (C11phβDK) and tri-n-octylphosphine oxide (TOPO), was used for the selective adsorption of Li+ in aqueous chloride media. The extractants have a synergistic effect on the ability of the SIR system to adsorb Li+ ion with high selectivity relative to Na+ and K+. The extent of adsorption of Li+ is increased with an increase in the amount of TOPO impregnated in the SIR. Li+ can be effectively separated from a solution containing a high concentration of Na+ by column chromatography using a column packed with SIR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100145d [article] Synergistic Solvent Impregnated Resin for Adsorptive Separation of Lithium Ion [texte imprimé] / Kenta Onishi, Auteur ; Takahide Nakamura, Auteur ; Syouhei Nishihama, Auteur . - 2010 . - pp. 6554–6558. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6554–6558 Mots-clés : Solvent Adsorption Résumé : A novel synergistic solvent impregnated resin (SIR), containing both 1-phenyl-1,3-tetradecanedione (C11phβDK) and tri-n-octylphosphine oxide (TOPO), was used for the selective adsorption of Li+ in aqueous chloride media. The extractants have a synergistic effect on the ability of the SIR system to adsorb Li+ ion with high selectivity relative to Na+ and K+. The extent of adsorption of Li+ is increased with an increase in the amount of TOPO impregnated in the SIR. Li+ can be effectively separated from a solution containing a high concentration of Na+ by column chromatography using a column packed with SIR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100145d

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Parametric studies on radiation grafting of polymeric sorbents for recovery of heavy metals from seawater / T. L. Prasad in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6559–6565 Titre : Parametric studies on radiation grafting of polymeric sorbents for recovery of heavy metals from seawater Type de document : texte imprimé Auteurs : T. L. Prasad, Auteur ; P. K. Tewari, Auteur ; D. Sathiyamoorthy, Auteur Année de publication : 2010 Article en page(s) : pp. 6559–6565 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Radiation grafting polymeric Résumé : Uranium and vanadium are valuable trace metals in seawater. The economic viability of recovery of these metals depends on development of efficient sorbents. The radiation induced graft polymerization technique was adopted in this study to prepare metal chelate embedded polymers in sheet form in order to investigate the recovery the heavy metals from seawater, using different nonwoven substrate materials. In order to obtain more direct information on the grafting levels, the parametric studies to see the influence of cumulative dose, retention time in air, surrounding atmosphere, and reaction temperature on grafting yields were investigated using different electron beam energies. The grafted sorbents were verified by infrared spectroscopic measurements, and thermal properties were analyzed by scanning calorimetric methods. Metal sorption characteristics for uranium and vanadium were evaluated through in-field trials at seawaters of the Andaman and Nicobar Islands, Indian Ocean, and Arabian Sea along Indian coastal lines. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100326q [article] Parametric studies on radiation grafting of polymeric sorbents for recovery of heavy metals from seawater [texte imprimé] / T. L. Prasad, Auteur ; P. K. Tewari, Auteur ; D. Sathiyamoorthy, Auteur . - 2010 . - pp. 6559–6565. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6559–6565 Mots-clés : Radiation grafting polymeric Résumé : Uranium and vanadium are valuable trace metals in seawater. The economic viability of recovery of these metals depends on development of efficient sorbents. The radiation induced graft polymerization technique was adopted in this study to prepare metal chelate embedded polymers in sheet form in order to investigate the recovery the heavy metals from seawater, using different nonwoven substrate materials. In order to obtain more direct information on the grafting levels, the parametric studies to see the influence of cumulative dose, retention time in air, surrounding atmosphere, and reaction temperature on grafting yields were investigated using different electron beam energies. The grafted sorbents were verified by infrared spectroscopic measurements, and thermal properties were analyzed by scanning calorimetric methods. Metal sorption characteristics for uranium and vanadium were evaluated through in-field trials at seawaters of the Andaman and Nicobar Islands, Indian Ocean, and Arabian Sea along Indian coastal lines. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100326q

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Experimental and theoretical studies of a dividing - wall column used for the recovery of high - purity products / Gerit Niggemann in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6566–6577 Titre : Experimental and theoretical studies of a dividing - wall column used for the recovery of high - purity products Type de document : texte imprimé Auteurs : Gerit Niggemann, Auteur ; Christoph Hiller, Auteur ; Georg Fieg, Auteur Année de publication : 2010 Article en page(s) : pp. 6566–6577 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dividing wall columns. Résumé : Although dividing-wall columns are now well established in industrial practice, their complex hydraulics is not well understood, and open literature does not provide any quantitative information in this respect. This study aims to provide the missing knowledge. Hence, a pilot plant was built to separate a ternary mixture of fatty alcohols into high-purity products of 99 wt %. A model was established to simulate this separation process. It could successfully describe the experiments quantitatively and even account for the self-adjustment of the vapor splits. A case study with the validated model highlighted the strong influence of the heat transfer across the vertical partition wall on hydrodynamics and vapor distribution. These aspects are of special interest for the design and scale-up of dividing-wall columns. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003416 [article] Experimental and theoretical studies of a dividing - wall column used for the recovery of high - purity products [texte imprimé] / Gerit Niggemann, Auteur ; Christoph Hiller, Auteur ; Georg Fieg, Auteur . - 2010 . - pp. 6566–6577. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6566–6577 Mots-clés : Dividing wall columns. Résumé : Although dividing-wall columns are now well established in industrial practice, their complex hydraulics is not well understood, and open literature does not provide any quantitative information in this respect. This study aims to provide the missing knowledge. Hence, a pilot plant was built to separate a ternary mixture of fatty alcohols into high-purity products of 99 wt %. A model was established to simulate this separation process. It could successfully describe the experiments quantitatively and even account for the self-adjustment of the vapor splits. A case study with the validated model highlighted the strong influence of the heat transfer across the vertical partition wall on hydrodynamics and vapor distribution. These aspects are of special interest for the design and scale-up of dividing-wall columns. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003416

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Equilibrium distribution model of betaine between surfactant micelles and water / Maria O. Ruiz in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6578–6586 Titre : Equilibrium distribution model of betaine between surfactant micelles and water : application to a micellar - enhanced ultrafiltration process Type de document : texte imprimé Auteurs : Maria O. Ruiz, Auteur ; José M. Benito, Auteur ; Beatriz Barriuso, Auteur Année de publication : 2010 Article en page(s) : pp. 6578–6586 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ultrafiltration process Résumé : The aim of this work was to determine the optimal surfactant concentration and operating conditions for betaine recovery from aqueous solutions by micellar-enhanced ultrafiltration (MEUF). Initial centrifugal ultrafiltration experiments with commercial 5 kDa cutoff polyethersulfone membranes showed that optimal betaine extraction was achieved with 200 mol/m3 of sodium dodecyl sulfate (SDS) as surfactant, at pH 1, with phosphoric acid for pH adjustment. The degree of betaine extraction increased with SDS concentration but remained constant with increasing betaine concentration for a given initial SDS concentration. The equilibrium distribution constants, KS, of betaine between SDS micelles and water were determined assuming a theoretical pseudophase separation model. Continuous MEUF with a 5 kDa cutoff TiO2 tubular ceramic membrane was performed in order to concentrate the micellar solution. Complete rejection of the micelles by the membrane was observed, resulting in 54% of the betaine and 99% of the SDS in micellar form, in agreement with the values estimated using the proposed theoretical model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100485w [article] Equilibrium distribution model of betaine between surfactant micelles and water : application to a micellar - enhanced ultrafiltration process [texte imprimé] / Maria O. Ruiz, Auteur ; José M. Benito, Auteur ; Beatriz Barriuso, Auteur . - 2010 . - pp. 6578–6586. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6578–6586 Mots-clés : Ultrafiltration process Résumé : The aim of this work was to determine the optimal surfactant concentration and operating conditions for betaine recovery from aqueous solutions by micellar-enhanced ultrafiltration (MEUF). Initial centrifugal ultrafiltration experiments with commercial 5 kDa cutoff polyethersulfone membranes showed that optimal betaine extraction was achieved with 200 mol/m3 of sodium dodecyl sulfate (SDS) as surfactant, at pH 1, with phosphoric acid for pH adjustment. The degree of betaine extraction increased with SDS concentration but remained constant with increasing betaine concentration for a given initial SDS concentration. The equilibrium distribution constants, KS, of betaine between SDS micelles and water were determined assuming a theoretical pseudophase separation model. Continuous MEUF with a 5 kDa cutoff TiO2 tubular ceramic membrane was performed in order to concentrate the micellar solution. Complete rejection of the micelles by the membrane was observed, resulting in 54% of the betaine and 99% of the SDS in micellar form, in agreement with the values estimated using the proposed theoretical model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100485w

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Changes in gas - transport properties with the phase structure of blends containing styrene − butadiene − styrene triblock copolymer and poly (2,6 - dimethyl - 1,4 - phenylene oxide) / K. W. Song in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6587–6592 Titre : Changes in gas - transport properties with the phase structure of blends containing styrene − butadiene − styrene triblock copolymer and poly (2,6 - dimethyl - 1,4 - phenylene oxide) Type de document : texte imprimé Auteurs : K. W. Song, Auteur ; K. R. Ka, Auteur ; C. K. Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 6587–6592 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas transport properties Résumé : Blend films prepared from styrene−butadiene−styrene triblock copolymer (SBS) and poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) in various compositions were examined to explore their application as gas separation membranes. PPO formed a single-phase mixture with hard styrene segments in SBS regardless of the blend composition. Therefore, an increase in the hard-phase volume with PPO blending resulted in phase structure changes: As the PPO content in the blend increased, the hard phase that was dispersed in the matrix formed by butadiene soft segments was converted into a continuous lamellar structure and finally formed a matrix of the blend by phase inversion. A decrease in the gas permeability and an increase in the gas selectivity were observed with increasing PPO content. The continuous soft phase was changed to the discrete phase in blends containing between 40 and 50 wt % PPO. As a result, an abrupt decrease in the gas permeability was observed at around these blend compositions. Permeability coefficients showed a small decrease as the upstream gas pressure increased when the hard phase formed a matrix, whereas they were not changed regardless of the upstream gas pressure when the soft segments formed the continuous phase. Plasticization caused by a polar penetrant was not observed in the SBS/PPO blend membranes. Our results show that blend films exhibiting desired gas permselectivity can be fabricated by controlling the phase-separated structure of SBS/PPO blends. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100565q [article] Changes in gas - transport properties with the phase structure of blends containing styrene − butadiene − styrene triblock copolymer and poly (2,6 - dimethyl - 1,4 - phenylene oxide) [texte imprimé] / K. W. Song, Auteur ; K. R. Ka, Auteur ; C. K. Kim, Auteur . - 2010 . - pp. 6587–6592. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6587–6592 Mots-clés : Gas transport properties Résumé : Blend films prepared from styrene−butadiene−styrene triblock copolymer (SBS) and poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) in various compositions were examined to explore their application as gas separation membranes. PPO formed a single-phase mixture with hard styrene segments in SBS regardless of the blend composition. Therefore, an increase in the hard-phase volume with PPO blending resulted in phase structure changes: As the PPO content in the blend increased, the hard phase that was dispersed in the matrix formed by butadiene soft segments was converted into a continuous lamellar structure and finally formed a matrix of the blend by phase inversion. A decrease in the gas permeability and an increase in the gas selectivity were observed with increasing PPO content. The continuous soft phase was changed to the discrete phase in blends containing between 40 and 50 wt % PPO. As a result, an abrupt decrease in the gas permeability was observed at around these blend compositions. Permeability coefficients showed a small decrease as the upstream gas pressure increased when the hard phase formed a matrix, whereas they were not changed regardless of the upstream gas pressure when the soft segments formed the continuous phase. Plasticization caused by a polar penetrant was not observed in the SBS/PPO blend membranes. Our results show that blend films exhibiting desired gas permselectivity can be fabricated by controlling the phase-separated structure of SBS/PPO blends. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100565q

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High - temperature CO2 capture on Li6Zr2O7 / Xian-Sheng Yin in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6593–6598 Titre : High - temperature CO2 capture on Li6Zr2O7 : experimental and modeling studies Type de document : texte imprimé Auteurs : Xian-Sheng Yin, Auteur ; Miao Song, Auteur ; Qin-Hui Zhang, Auteur Année de publication : 2010 Article en page(s) : pp. 6593–6598 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : CO2 Adsorption monoclinic phase Résumé : The properties of CO2 adsorption on monoclinic-phase Li6Zr2O7 (m-Li6Zr2O7) in low CO2 concentration stream are studied and compared with tetragonal-phase Li2ZrO3 (t-Li2ZrO3) using thermogravimetric analysis. The results indicate that because of the higher lithium content, about 86.7% capacity can be preserved for m-Li6Zr2O7 (at 1023 K) as the CO2 partial pressure decreases from 1.0 to 0.1 bar, whereas only about 3.5% capacity is preserved for t-Li2ZrO3 (at 848 K). The multicycle test of m-Li6Zr2O7 in 10% CO2 stream exhibits effective performance of CO2 uptake and release, though the capacity reduces gradually. Further, on the basis of the proposed adsorption pathway, a double exponential model is used to simulate the CO2 adsorption processes on m-Li6Zr2O7 with the activation energy of 22.684 and 56.084 kJ/mol for CO2 and Li+ diffusion, respectively, indicating the Li+ diffusion is the limiting step in the adsorption process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100710x [article] High - temperature CO2 capture on Li6Zr2O7 : experimental and modeling studies [texte imprimé] / Xian-Sheng Yin, Auteur ; Miao Song, Auteur ; Qin-Hui Zhang, Auteur . - 2010 . - pp. 6593–6598. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6593–6598 Mots-clés : CO2 Adsorption monoclinic phase Résumé : The properties of CO2 adsorption on monoclinic-phase Li6Zr2O7 (m-Li6Zr2O7) in low CO2 concentration stream are studied and compared with tetragonal-phase Li2ZrO3 (t-Li2ZrO3) using thermogravimetric analysis. The results indicate that because of the higher lithium content, about 86.7% capacity can be preserved for m-Li6Zr2O7 (at 1023 K) as the CO2 partial pressure decreases from 1.0 to 0.1 bar, whereas only about 3.5% capacity is preserved for t-Li2ZrO3 (at 848 K). The multicycle test of m-Li6Zr2O7 in 10% CO2 stream exhibits effective performance of CO2 uptake and release, though the capacity reduces gradually. Further, on the basis of the proposed adsorption pathway, a double exponential model is used to simulate the CO2 adsorption processes on m-Li6Zr2O7 with the activation energy of 22.684 and 56.084 kJ/mol for CO2 and Li+ diffusion, respectively, indicating the Li+ diffusion is the limiting step in the adsorption process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100710x

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Simultaneous momentum, mass, and energy transfer analysis of a distillation sieve tray using CFD techniques / Dirceu Martins in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6599–6611 Titre : Simultaneous momentum, mass, and energy transfer analysis of a distillation sieve tray using CFD techniques : prediction of efficiencies Type de document : texte imprimé Auteurs : Dirceu Martins, Auteur ; Antonio A. C. Barros, Auteur ; Maria R. Wolf Maciel, Auteur Année de publication : 2010 Article en page(s) : pp. 6599–6611 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Prediction Computational fluid dynamics Perforated trayDistillation Energy transfer Momentum. Résumé : Conventional models for distillation columns are based on equilibrium and nonequilibrium stage concepts. Although equilibrium and nonequilibrium stage models provide useful results, they neglect the fluid dynamics phenomena by assuming a perfect mixture on the plates in each phase. However, the flow pattern on a distillation tray is of great importance in terms of the mass and energy transfer mechanisms, and this influence can only be analyzed by carrying out a fluid dynamics study. The main objective of this study is to obtain experimental data of clear liquid height in a distillation sieve tray apparatus operating with air and water, and to apply a computational fluid dynamics (CFD) model in a Eulerian−Eulerian framework for gas−liquid flows that is able to predict the momentum, mass, and thermal phenomena of multiphase flows. A two-phase, three-dimensional and transient model with chemical species, energy, and momentum conservation balances was applied to predict the volume fraction, velocity, pressure, temperature, and concentration fields of two-phase flows on distillation sieve trays. The mathematical model was applied in the CFD commercial code for numerical studies, with the construction of a particular numerical grid and with its own subroutines in Fortran language for the closure equations of the model. The hydrodynamic model was compared with experimental data and presented good agreement. The results of the model show the volume fraction, velocity, temperature, and concentration profiles as a function of time and the position on the distillation sieve tray. The model implemented in this study allows direct application to predict efficiencies in distillation plates, more specifically point, plate, component, and global efficiencies. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040416 [article] Simultaneous momentum, mass, and energy transfer analysis of a distillation sieve tray using CFD techniques : prediction of efficiencies [texte imprimé] / Dirceu Martins, Auteur ; Antonio A. C. Barros, Auteur ; Maria R. Wolf Maciel, Auteur . - 2010 . - pp. 6599–6611. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6599–6611 Mots-clés : Prediction Computational fluid dynamics Perforated trayDistillation Energy transfer Momentum. Résumé : Conventional models for distillation columns are based on equilibrium and nonequilibrium stage concepts. Although equilibrium and nonequilibrium stage models provide useful results, they neglect the fluid dynamics phenomena by assuming a perfect mixture on the plates in each phase. However, the flow pattern on a distillation tray is of great importance in terms of the mass and energy transfer mechanisms, and this influence can only be analyzed by carrying out a fluid dynamics study. The main objective of this study is to obtain experimental data of clear liquid height in a distillation sieve tray apparatus operating with air and water, and to apply a computational fluid dynamics (CFD) model in a Eulerian−Eulerian framework for gas−liquid flows that is able to predict the momentum, mass, and thermal phenomena of multiphase flows. A two-phase, three-dimensional and transient model with chemical species, energy, and momentum conservation balances was applied to predict the volume fraction, velocity, pressure, temperature, and concentration fields of two-phase flows on distillation sieve trays. The mathematical model was applied in the CFD commercial code for numerical studies, with the construction of a particular numerical grid and with its own subroutines in Fortran language for the closure equations of the model. The hydrodynamic model was compared with experimental data and presented good agreement. The results of the model show the volume fraction, velocity, temperature, and concentration profiles as a function of time and the position on the distillation sieve tray. The model implemented in this study allows direct application to predict efficiencies in distillation plates, more specifically point, plate, component, and global efficiencies. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23040416

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Two - dimensional property distributions, ohmic losses, and power consumption within a fuel cell polymer electrolyte membrane / Venkateshwar R. Devulapalli in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6612–6621 Titre : Two - dimensional property distributions, ohmic losses, and power consumption within a fuel cell polymer electrolyte membrane Type de document : texte imprimé Auteurs : Venkateshwar R. Devulapalli, Auteur ; Aaron V. Phoenix, Auteur Année de publication : 2010 Article en page(s) : pp. 6612–6621 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Polymer electrolyte membrane Résumé : The average and localized water content, current, ohmic loss, and power consumption distributions within a Nafion 117 polymer electrolyte membrane (PEM) were modeled in two dimensions to determine the influence of the cathodic flowfield plate on the properties and performance of a fuel cell. The membrane model was decoupled from the cathode and anode by using fixed, assumed anodic boundary conditions and cathodic boundary conditions from literature indicative of operation at three channel:land configurations (1:1, 2:1, and 4:1) and three nominal cathode overpotentials (NCOs) (0.3, 0.5, and 0.7 V). The results suggested that a 1:1 configuration maintained the membrane in a more-hydrated state that was better able to moderate changes in ohmic loss and power consumption due to changes in the NCO. Detailed distributions within the membrane showed complex anisotropy, including the existence of localized maxima along anodic boundaries, cathodic boundaries, and even along both anodic and cathodic boundaries under the same operating conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901711y [article] Two - dimensional property distributions, ohmic losses, and power consumption within a fuel cell polymer electrolyte membrane [texte imprimé] / Venkateshwar R. Devulapalli, Auteur ; Aaron V. Phoenix, Auteur . - 2010 . - pp. 6612–6621. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6612–6621 Mots-clés : Polymer electrolyte membrane Résumé : The average and localized water content, current, ohmic loss, and power consumption distributions within a Nafion 117 polymer electrolyte membrane (PEM) were modeled in two dimensions to determine the influence of the cathodic flowfield plate on the properties and performance of a fuel cell. The membrane model was decoupled from the cathode and anode by using fixed, assumed anodic boundary conditions and cathodic boundary conditions from literature indicative of operation at three channel:land configurations (1:1, 2:1, and 4:1) and three nominal cathode overpotentials (NCOs) (0.3, 0.5, and 0.7 V). The results suggested that a 1:1 configuration maintained the membrane in a more-hydrated state that was better able to moderate changes in ohmic loss and power consumption due to changes in the NCO. Detailed distributions within the membrane showed complex anisotropy, including the existence of localized maxima along anodic boundaries, cathodic boundaries, and even along both anodic and cathodic boundaries under the same operating conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901711y

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Heat transfer characteristics of falling film process on coated division tubes / Qunchang Wang in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6622–6629 Titre : Heat transfer characteristics of falling film process on coated division tubes : effect of the surface configurations Type de document : texte imprimé Auteurs : Qunchang Wang, Auteur ; Xuehu Ma, Auteur ; Zhong Lan, Auteur Année de publication : 2010 Article en page(s) : pp. 6622–6629 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heat transfer Résumé : In general, mixing of solution could refresh the interface of bulk liquid, and hence lead to the more efficient heat transfer within the liquid film. By using the high speed video camera and thermal imaging technique, the flow patterns and heat transfer characteristics of liquid film on coated division tubes, on which the hydrophobically coated regions and the bare regions presented alternately, were investigated experimentally. Flow visualization revealed that the minimum wetting rate increases with the increase in the effective contact angle of this surface. The cumulative liquid ring was observed at the boundary of bare region and coated region. The fluctuations of liquid film temperature were measured at different liquid film mass flow rates and the initial fluid temperatures. The temperature fluctuation periods on the coated division tube increased with the decrease of flow rate and initial liquid temperature. The liquid film surface temperature on the coated division tubes was higher than that on the uncoated bare tube at the same falling film position; that is, the heat transfer in the liquid film on the coated division tube was more efficient than that on the uncoated bare tube. The disturbance of falling liquid film was strengthened from the existence of the coated region, resulting in stronger mixing that drove the liquid particles from the internal of the liquid film to the interface, which greatly contributed to the enhancement of heat and mass transfer. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9018676 [article] Heat transfer characteristics of falling film process on coated division tubes : effect of the surface configurations [texte imprimé] / Qunchang Wang, Auteur ; Xuehu Ma, Auteur ; Zhong Lan, Auteur . - 2010 . - pp. 6622–6629. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6622–6629 Mots-clés : Heat transfer Résumé : In general, mixing of solution could refresh the interface of bulk liquid, and hence lead to the more efficient heat transfer within the liquid film. By using the high speed video camera and thermal imaging technique, the flow patterns and heat transfer characteristics of liquid film on coated division tubes, on which the hydrophobically coated regions and the bare regions presented alternately, were investigated experimentally. Flow visualization revealed that the minimum wetting rate increases with the increase in the effective contact angle of this surface. The cumulative liquid ring was observed at the boundary of bare region and coated region. The fluctuations of liquid film temperature were measured at different liquid film mass flow rates and the initial fluid temperatures. The temperature fluctuation periods on the coated division tube increased with the decrease of flow rate and initial liquid temperature. The liquid film surface temperature on the coated division tubes was higher than that on the uncoated bare tube at the same falling film position; that is, the heat transfer in the liquid film on the coated division tube was more efficient than that on the uncoated bare tube. The disturbance of falling liquid film was strengthened from the existence of the coated region, resulting in stronger mixing that drove the liquid particles from the internal of the liquid film to the interface, which greatly contributed to the enhancement of heat and mass transfer. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9018676

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Dynamic simulation and optimization of a urea granulation circuit / Ivana M. Cotabarren in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6630–6640 Titre : Dynamic simulation and optimization of a urea granulation circuit Type de document : texte imprimé Auteurs : Ivana M. Cotabarren, Auteur ; Diego Bertín, Auteur ; José Romagnoli, Auteur Année de publication : 2010 Article en page(s) : pp. 6630–6640 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Granulation circuit Résumé : A dynamic model for a complete urea granulation circuit is presented in this work. The flowsheet includes a fluidized bed granulator, a cooling unit, a vibrating double-deck screen, and a double-roll crusher. This contribution is based on mathematical models for all the equipments, some of them previous validated against industrial data. All the units are modeled by means of the population balance equation (PBE). In addition, the granulator energy and mass balances for urea and air (used as a cooling medium and fluidization agent) are solved simultaneously with the PBE to properly represent the unit dynamics. Furthermore, mass, energy, and population balances are developed for the cooler. The individual units are successfully integrated under the gPROMS Model Builder Environment, which allows one to have a powerful tool for the circuit simulation and optimization. A sensitivity analysis is performed by running several dynamic and steady-state gPROMS simulations in order to evaluate the influence of different operating variables on the particle size distributions and mass flow rates of the circuit streams, as well as the mass holdup and thermal conditions in the granulator and cooler. The results indicate that both screen deck apertures, together with the crusher lower gap, are the variables that most affect the circuit performance. The circuit stability is also analyzed. Finally, different optimization scenarios are carried out to determine the values of the selected manipulated variables that maximize production on specification, minimize the recycle fraction, and allow a plant revamping. The urea granulation process simulator (including mass, energy, and population balances) constitutes a powerful tool to study the circuit responses under different disturbances, determine the optimal combination of operating and design variables in order to meet the production requirements and explore new process flow diagrams. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901885x [article] Dynamic simulation and optimization of a urea granulation circuit [texte imprimé] / Ivana M. Cotabarren, Auteur ; Diego Bertín, Auteur ; José Romagnoli, Auteur . - 2010 . - pp. 6630–6640. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6630–6640 Mots-clés : Granulation circuit Résumé : A dynamic model for a complete urea granulation circuit is presented in this work. The flowsheet includes a fluidized bed granulator, a cooling unit, a vibrating double-deck screen, and a double-roll crusher. This contribution is based on mathematical models for all the equipments, some of them previous validated against industrial data. All the units are modeled by means of the population balance equation (PBE). In addition, the granulator energy and mass balances for urea and air (used as a cooling medium and fluidization agent) are solved simultaneously with the PBE to properly represent the unit dynamics. Furthermore, mass, energy, and population balances are developed for the cooler. The individual units are successfully integrated under the gPROMS Model Builder Environment, which allows one to have a powerful tool for the circuit simulation and optimization. A sensitivity analysis is performed by running several dynamic and steady-state gPROMS simulations in order to evaluate the influence of different operating variables on the particle size distributions and mass flow rates of the circuit streams, as well as the mass holdup and thermal conditions in the granulator and cooler. The results indicate that both screen deck apertures, together with the crusher lower gap, are the variables that most affect the circuit performance. The circuit stability is also analyzed. Finally, different optimization scenarios are carried out to determine the values of the selected manipulated variables that maximize production on specification, minimize the recycle fraction, and allow a plant revamping. The urea granulation process simulator (including mass, energy, and population balances) constitutes a powerful tool to study the circuit responses under different disturbances, determine the optimal combination of operating and design variables in order to meet the production requirements and explore new process flow diagrams. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901885x

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Experimental study of mass transfer in membrane absorption process using membranes with different porosities / Zhang, Weidong in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6641–6648 Titre : Experimental study of mass transfer in membrane absorption process using membranes with different porosities Type de document : texte imprimé Auteurs : Zhang, Weidong, Auteur ; Li Jiang, Auteur ; Geng Chen, Auteur Année de publication : 2010 Article en page(s) : pp. 6641–6648 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mass transfer Membrane absorption Résumé : Experimental study has been carried out to investigate the mass transfer behavior when carbon dioxide (CO2) is absorbed through microporous membranes with different porosities. Deionized water and sodium hydroxide (NaOH) aqueous solutions are chosen as absorbents. The effects of membrane porosity, absorbent pH value, and liquid velocity on mass transfer are studied. The effect of membrane porosity on mass transfer depends on both the absorbent pH value and liquid velocity. In the case of low pH values (7−11) in absorbent, membrane porosity almost has no effect on mass transfer at relatively lower liquid velocity, namely, the mass transfer coefficients based on the whole membrane area remain almost the same at different membrane porosities; the effect of membrane porosity on mass transfer becomes obvious with the increasing liquid velocity. Contrarily, as the absorbent pH value increases to 12 or 13, the influence of porosity on mass transfer coefficient becomes significant at varied liquid velocity. The modified mass transfer correlations are obtained with consideration of the effect of porosity over a varying membrane porosity range. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001026 [article] Experimental study of mass transfer in membrane absorption process using membranes with different porosities [texte imprimé] / Zhang, Weidong, Auteur ; Li Jiang, Auteur ; Geng Chen, Auteur . - 2010 . - pp. 6641–6648. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6641–6648 Mots-clés : Mass transfer Membrane absorption Résumé : Experimental study has been carried out to investigate the mass transfer behavior when carbon dioxide (CO2) is absorbed through microporous membranes with different porosities. Deionized water and sodium hydroxide (NaOH) aqueous solutions are chosen as absorbents. The effects of membrane porosity, absorbent pH value, and liquid velocity on mass transfer are studied. The effect of membrane porosity on mass transfer depends on both the absorbent pH value and liquid velocity. In the case of low pH values (7−11) in absorbent, membrane porosity almost has no effect on mass transfer at relatively lower liquid velocity, namely, the mass transfer coefficients based on the whole membrane area remain almost the same at different membrane porosities; the effect of membrane porosity on mass transfer becomes obvious with the increasing liquid velocity. Contrarily, as the absorbent pH value increases to 12 or 13, the influence of porosity on mass transfer coefficient becomes significant at varied liquid velocity. The modified mass transfer correlations are obtained with consideration of the effect of porosity over a varying membrane porosity range. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001026

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Flow of newtonian and power - law fluids past an elliptical cylinder / P. Koteswara Rao in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6649–6661 Titre : Flow of newtonian and power - law fluids past an elliptical cylinder : A numerical study Type de document : texte imprimé Auteurs : P. Koteswara Rao, Auteur ; Akhilesh K. Sahu, Auteur ; R. P. Chhabra, Auteur Année de publication : 2010 Article en page(s) : pp. 6649–6661 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Numerical simulations Elliptical cylinders Résumé : Extensive numerical simulations of the 2-D laminar flow of power-law fluids over elliptical cylinders with different aspect ratios have been carried out to establish the conditions for the onset of wake formation and the onset of vortex shedding. The continuity and momentum equations were solved numerically using FLUENT (version 6.3.26). The influence of the power-law index (0.3 ≤ n ≤ 1.8) and the aspect ratio (E = b/a; 0.2 ≤ E ≤ 5) of the cylinder on the critical values of the Reynolds number denoting the onsets of flow separation and vortex shedding are presented. For shear-thinning (n 1). Also, the values of the Strouhal number (Stc) and the time-average drag coefficient (C̅D) corresponding to the cessation of the steady-flow regime are presented. Velocity vector plots denoting the flow separation and vorticity profiles showing the vortex shedding are also included. The delineation of different flow regimes also helps identify the range of validity of some of the results on flow and heat transfer available in the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100251w [article] Flow of newtonian and power - law fluids past an elliptical cylinder : A numerical study [texte imprimé] / P. Koteswara Rao, Auteur ; Akhilesh K. Sahu, Auteur ; R. P. Chhabra, Auteur . - 2010 . - pp. 6649–6661. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6649–6661 Mots-clés : Numerical simulations Elliptical cylinders Résumé : Extensive numerical simulations of the 2-D laminar flow of power-law fluids over elliptical cylinders with different aspect ratios have been carried out to establish the conditions for the onset of wake formation and the onset of vortex shedding. The continuity and momentum equations were solved numerically using FLUENT (version 6.3.26). The influence of the power-law index (0.3 ≤ n ≤ 1.8) and the aspect ratio (E = b/a; 0.2 ≤ E ≤ 5) of the cylinder on the critical values of the Reynolds number denoting the onsets of flow separation and vortex shedding are presented. For shear-thinning (n 1). Also, the values of the Strouhal number (Stc) and the time-average drag coefficient (C̅D) corresponding to the cessation of the steady-flow regime are presented. Velocity vector plots denoting the flow separation and vorticity profiles showing the vortex shedding are also included. The delineation of different flow regimes also helps identify the range of validity of some of the results on flow and heat transfer available in the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100251w

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Extension of GMA equation of state to long - chain alkanes using group contribution method / Majid Moosavi in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6662–6669 Titre : Extension of GMA equation of state to long - chain alkanes using group contribution method Type de document : texte imprimé Auteurs : Majid Moosavi, Auteur Année de publication : 2010 Article en page(s) : pp. 6662–6669 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Equation Alkanes Résumé : In this work, the group contribution method has been applied in combination with the Goharshadi−Morsali−Abbaspour (GMA) equation of state (EoS) to calculate the density of n-alkanes and their binary and ternary mixtures. Each normal alkane has been considered as a hypothetical mixture of methyl and methylene groups in which the interaction potential between each pair is assumed to be the average effective pair potential (AEPP). The GMA EoS has been modified for n-alkanes according to the group contribution method (GCM), and the new regularity is called GCM−GMA EoS. Propane, n-butane, and n-hexane have been used as basic compounds to investigate the contribution of each carbonic (methyl and methylene) group in the new EoS parameters. The calculated parameters along with GCM−GMA EoS have been used to calculate the density of n-alkanes and their binary and ternary mixtures at different temperatures, pressures, and compositions. The results in the prediction of density show good agreement with experimental data. To show the ability of this equation of state in the prediction of density, the calculated densities of some liquid mixtures have been compared with those computed from original GMA EoS according to mixing and combining rules and also with the COSTALD method. The GCM-GMA EoS have been also compared with four cubic equations of state, namely, RM (Riazi-Mansoori), RK (Redlich-Kwong), SRK (Soave-Redlich-Kwong), and PR (Peng-Rabinson). The results show that the group contribution method gives better results than other methods. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100515r [article] Extension of GMA equation of state to long - chain alkanes using group contribution method [texte imprimé] / Majid Moosavi, Auteur . - 2010 . - pp. 6662–6669. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6662–6669 Mots-clés : Equation Alkanes Résumé : In this work, the group contribution method has been applied in combination with the Goharshadi−Morsali−Abbaspour (GMA) equation of state (EoS) to calculate the density of n-alkanes and their binary and ternary mixtures. Each normal alkane has been considered as a hypothetical mixture of methyl and methylene groups in which the interaction potential between each pair is assumed to be the average effective pair potential (AEPP). The GMA EoS has been modified for n-alkanes according to the group contribution method (GCM), and the new regularity is called GCM−GMA EoS. Propane, n-butane, and n-hexane have been used as basic compounds to investigate the contribution of each carbonic (methyl and methylene) group in the new EoS parameters. The calculated parameters along with GCM−GMA EoS have been used to calculate the density of n-alkanes and their binary and ternary mixtures at different temperatures, pressures, and compositions. The results in the prediction of density show good agreement with experimental data. To show the ability of this equation of state in the prediction of density, the calculated densities of some liquid mixtures have been compared with those computed from original GMA EoS according to mixing and combining rules and also with the COSTALD method. The GCM-GMA EoS have been also compared with four cubic equations of state, namely, RM (Riazi-Mansoori), RK (Redlich-Kwong), SRK (Soave-Redlich-Kwong), and PR (Peng-Rabinson). The results show that the group contribution method gives better results than other methods. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100515r

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Conversion of benzylic bromides to benzaldehydes using sodium nitrate as an oxidant / K. Kulangiappar in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6670–6673 Titre : Conversion of benzylic bromides to benzaldehydes using sodium nitrate as an oxidant Type de document : texte imprimé Auteurs : K. Kulangiappar, Auteur ; M. Anbu Kulandainathan, Auteur ; T. Raju, Auteur Année de publication : 2010 Article en page(s) : pp. 6670–6673 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Sodium nitrate Oxidant Résumé : A simple and effective approach for the synthesis of benzaldehydes from benzylic bromides is reported using sodium nitrate as an oxidant with 10% sodium hydroxide. Benzyl bromide is oxidized to benzaldehyde in 91% yield with 98% conversion at 120 °C, whereas 82% of benzyl alcohol is obtained at a temperature of 80 °C in 80 min with 20% sodium nitrate solution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901986g [article] Conversion of benzylic bromides to benzaldehydes using sodium nitrate as an oxidant [texte imprimé] / K. Kulangiappar, Auteur ; M. Anbu Kulandainathan, Auteur ; T. Raju, Auteur . - 2010 . - pp. 6670–6673. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6670–6673 Mots-clés : Sodium nitrate Oxidant Résumé : A simple and effective approach for the synthesis of benzaldehydes from benzylic bromides is reported using sodium nitrate as an oxidant with 10% sodium hydroxide. Benzyl bromide is oxidized to benzaldehyde in 91% yield with 98% conversion at 120 °C, whereas 82% of benzyl alcohol is obtained at a temperature of 80 °C in 80 min with 20% sodium nitrate solution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901986g

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Covalently anchored polymer immobilized Co(II) phthalocyanine as efficient catalyst for oxidation of mercaptans using molecular oxygen as oxidant / Jomy K. Joseph in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6674–6677 Titre : Covalently anchored polymer immobilized Co(II) phthalocyanine as efficient catalyst for oxidation of mercaptans using molecular oxygen as oxidant Type de document : texte imprimé Auteurs : Jomy K. Joseph, Auteur ; Suman L. Jain, Auteur ; Bir Sain, Auteur Année de publication : 2010 Article en page(s) : pp. 6674–6677 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Oxidation Résumé : The present paper describes the covalent immobilization of cobalt phthalocyanine “MEROX catalyst” to polystyrene resin via sulfonamide linkage and its catalytic activity for the oxidation of mercaptans to disulfides using molecular oxygen as an oxidant under alkaline conditions. Polymer-supported cobalt phthalocyanine, wherein the catalyst is chemically bounded to the support which prevents the leaching of the catalyst/ligand, can readily be recovered from the reaction mixture and reused for several runs without significant decrease in catalytic activity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100351s [article] Covalently anchored polymer immobilized Co(II) phthalocyanine as efficient catalyst for oxidation of mercaptans using molecular oxygen as oxidant [texte imprimé] / Jomy K. Joseph, Auteur ; Suman L. Jain, Auteur ; Bir Sain, Auteur . - 2010 . - pp. 6674–6677. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6674–6677 Mots-clés : Catalyst Oxidation Résumé : The present paper describes the covalent immobilization of cobalt phthalocyanine “MEROX catalyst” to polystyrene resin via sulfonamide linkage and its catalytic activity for the oxidation of mercaptans to disulfides using molecular oxygen as an oxidant under alkaline conditions. Polymer-supported cobalt phthalocyanine, wherein the catalyst is chemically bounded to the support which prevents the leaching of the catalyst/ligand, can readily be recovered from the reaction mixture and reused for several runs without significant decrease in catalytic activity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100351s

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Combined influence of fluorinated solvent and base in friedel − crafts reaction of toluene and CO2 / Pradip Munshi in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp 6678–6682 Titre : Combined influence of fluorinated solvent and base in friedel − crafts reaction of toluene and CO2 Type de document : texte imprimé Auteurs : Pradip Munshi, Auteur ; Eric J. Beckman, Auteur ; Sudhakar Padmanabhan, Auteur Année de publication : 2010 Article en page(s) : pp 6678–6682 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reaction Toluene Résumé : As disclosed in preceding studies [Munshi and Beckman Ind. Eng. Chem. Res. 2009, 48, 1059−1062 and Beckman and Munshi US Patent 7,271,286, 2007], aluminum chloride is superior among Lewis acids in making p-toluic acid from toluene and 6.9 MPa CO2 offering 80% stoichiometric yield, with respect to Al2Cl6, and 98% selectivity at 80 °C in 18 h. Attempts to improve the efficiency resulted in the finding that H+ exchange between HCl and Tol-COOAl2Cl5 is the key step in making the reaction catalytic. Introduction of a base complemented by a fluorinated solvent can only bring Al2Cl6 into catalytic cycle, provided pKa[Tol-COOH] > pKa[BH+] > pKa[HCl]. Efficiency of the reaction depends upon the nature of the fluorinated solvents and reaction parameters employed. Turnover number of 7.87 for p-toluic acid in 6 h is obtained employing 2.68 mmol quinoxaline, 15 mL 1,3,5-tris(trifluoromethyl)benzene, and 2.68 mmol of Al2Cl6 and CO2 at a pressure of 6.9 MPa CO2 and 100 °C. The base and fluorinated solvent could be recyclable and reused. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100533c [article] Combined influence of fluorinated solvent and base in friedel − crafts reaction of toluene and CO2 [texte imprimé] / Pradip Munshi, Auteur ; Eric J. Beckman, Auteur ; Sudhakar Padmanabhan, Auteur . - 2010 . - pp 6678–6682. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp 6678–6682 Mots-clés : Reaction Toluene Résumé : As disclosed in preceding studies [Munshi and Beckman Ind. Eng. Chem. Res. 2009, 48, 1059−1062 and Beckman and Munshi US Patent 7,271,286, 2007], aluminum chloride is superior among Lewis acids in making p-toluic acid from toluene and 6.9 MPa CO2 offering 80% stoichiometric yield, with respect to Al2Cl6, and 98% selectivity at 80 °C in 18 h. Attempts to improve the efficiency resulted in the finding that H+ exchange between HCl and Tol-COOAl2Cl5 is the key step in making the reaction catalytic. Introduction of a base complemented by a fluorinated solvent can only bring Al2Cl6 into catalytic cycle, provided pKa[Tol-COOH] > pKa[BH+] > pKa[HCl]. Efficiency of the reaction depends upon the nature of the fluorinated solvents and reaction parameters employed. Turnover number of 7.87 for p-toluic acid in 6 h is obtained employing 2.68 mmol quinoxaline, 15 mL 1,3,5-tris(trifluoromethyl)benzene, and 2.68 mmol of Al2Cl6 and CO2 at a pressure of 6.9 MPa CO2 and 100 °C. The base and fluorinated solvent could be recyclable and reused. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100533c

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