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Vol. 47 n°22 - Novembre 2008 [texte imprimé] . - 2008 . - p. 8517-8956 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierToward a sustainable chemical industry / Maaike C. Kroon ; Dap Hartmann in Industrial & engineering chemistry research, Vol. 47 n°22 (Novembre 2008)
Titre : Toward a sustainable chemical industry : cyclic innovation applied to ionic liquid-based technology Type de document : texte imprimé Auteurs : Maaike C. Kroon, Auteur ; Dap Hartmann, Auteur Année de publication : 2008 Article en page(s) : p.8517–8525 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chemical Industry En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800370t
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p.8517–8525[article] Toward a sustainable chemical industry : cyclic innovation applied to ionic liquid-based technology [texte imprimé] / Maaike C. Kroon, Auteur ; Dap Hartmann, Auteur . - 2008 . - p.8517–8525.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p.8517–8525
Mots-clés : Chemical Industry En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800370t Exemplaires
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Titre : Electrosynthesis of Potassium Permanganate in a Cation Exchange Membrane Cell Type de document : texte imprimé Auteurs : K. Subramanian, Auteur ; K. G. Gomathi, Auteur ; K. Asokan, Auteur Année de publication : 2008 Article en page(s) : p. 8526–8532 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Potassium Permanganate Electrosynthesis Résumé : Potassium permanganate is produced by the electro-oxidation of alkaline potassium manganate in a divided electrolytic cell. A filter press type flow electrolyzer has been designed, fabricated, and operated with perfluoro sulfonic acid based cation exchange membrane Nafion 417, precious metal/precious metal oxide coated titanium anode, and stainless steel cathode. Optimum process parameters are evaluated and reported. Performance characteristics of coated titanium anodes are compared with conventional nickel anodes, to fix the most suitable one for the job on hand. Anode materials have been electrochemically characterized by potentiodynamic studies in alkaline potassium manganate solution. Transport properties of the membrane Nafion 417 for K+ ions and water molecules are studied using a small membrane cell operating on batch mode. It has been estimated that each K+ ion transported across the membrane carries with it 1.5 to 1.7 water molecules. The anolyte contains K2MnO4 and KOH. Studies reveal that the relative current efficiency value for electro-oxidation of manganate and the competing anodic oxygen evolution may have a direct bearing on the source of K+ ion transported across the cation exchange membrane. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800240m
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8526–8532[article] Electrosynthesis of Potassium Permanganate in a Cation Exchange Membrane Cell [texte imprimé] / K. Subramanian, Auteur ; K. G. Gomathi, Auteur ; K. Asokan, Auteur . - 2008 . - p. 8526–8532.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8526–8532
Mots-clés : Potassium Permanganate Electrosynthesis Résumé : Potassium permanganate is produced by the electro-oxidation of alkaline potassium manganate in a divided electrolytic cell. A filter press type flow electrolyzer has been designed, fabricated, and operated with perfluoro sulfonic acid based cation exchange membrane Nafion 417, precious metal/precious metal oxide coated titanium anode, and stainless steel cathode. Optimum process parameters are evaluated and reported. Performance characteristics of coated titanium anodes are compared with conventional nickel anodes, to fix the most suitable one for the job on hand. Anode materials have been electrochemically characterized by potentiodynamic studies in alkaline potassium manganate solution. Transport properties of the membrane Nafion 417 for K+ ions and water molecules are studied using a small membrane cell operating on batch mode. It has been estimated that each K+ ion transported across the membrane carries with it 1.5 to 1.7 water molecules. The anolyte contains K2MnO4 and KOH. Studies reveal that the relative current efficiency value for electro-oxidation of manganate and the competing anodic oxygen evolution may have a direct bearing on the source of K+ ion transported across the cation exchange membrane. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800240m Exemplaires
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Titre : Initial degradation rate of p-Nitrophenol in aqueous solution by fenton reaction Type de document : texte imprimé Auteurs : Meng-Wen Chang, Auteur ; Tai-Shang Chen, Auteur ; Jia-Ming Chern, Auteur Année de publication : 2008 Article en page(s) : p. 8533–8541 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : p-Nitrophenol Résumé : Because of environmental concern, wastewater containing nitrophenols must be treated before it is allowed to discharge. In addition to traditional treatment methods, advanced oxidation processes (AOPs) using a powerful hydroxyl radical to decompose organic pollutants in wastewater receive great attraction. Among the many AOPs to degrade nitrophenols, the Fenton reaction was proven to be the most effective and the least expensive method, and the resultant solutions treated by the Fenton reagent were not toxic. However, owing to the complicated mechanism involved in the Fenton reaction, an oversimplified first-order rate equation or empirical rate laws were usually used to model the Fenton reaction. Such oversimplified or empirical kinetics cannot be used confidently in the design and operation of large-scale Fenton processes. A series of experiments were carried out to determine the initial decomposition rates of p-nitrophenol (PNP) at varying initial ferrous ion, hydrogen peroxide, and PNP concentrations. The PNP decomposition rate equations for two proposed mechanisms were derived by the general rate methodology. The rate equation resulting from the reaction mechanism involving the PNP reaction with both hydroxyl and hydroperoxy radicals fits the experimental data well. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003013
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8533–8541[article] Initial degradation rate of p-Nitrophenol in aqueous solution by fenton reaction [texte imprimé] / Meng-Wen Chang, Auteur ; Tai-Shang Chen, Auteur ; Jia-Ming Chern, Auteur . - 2008 . - p. 8533–8541.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8533–8541
Mots-clés : p-Nitrophenol Résumé : Because of environmental concern, wastewater containing nitrophenols must be treated before it is allowed to discharge. In addition to traditional treatment methods, advanced oxidation processes (AOPs) using a powerful hydroxyl radical to decompose organic pollutants in wastewater receive great attraction. Among the many AOPs to degrade nitrophenols, the Fenton reaction was proven to be the most effective and the least expensive method, and the resultant solutions treated by the Fenton reagent were not toxic. However, owing to the complicated mechanism involved in the Fenton reaction, an oversimplified first-order rate equation or empirical rate laws were usually used to model the Fenton reaction. Such oversimplified or empirical kinetics cannot be used confidently in the design and operation of large-scale Fenton processes. A series of experiments were carried out to determine the initial decomposition rates of p-nitrophenol (PNP) at varying initial ferrous ion, hydrogen peroxide, and PNP concentrations. The PNP decomposition rate equations for two proposed mechanisms were derived by the general rate methodology. The rate equation resulting from the reaction mechanism involving the PNP reaction with both hydroxyl and hydroperoxy radicals fits the experimental data well. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003013 Exemplaires
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Titre : Influence of lignin structural features on eucalyptus globulus kraft pulping Type de document : texte imprimé Auteurs : Anderson Guerra, Auteur ; Juan Pedro Elissetche, Auteur Année de publication : 2008 Article en page(s) : p. 8542–8549 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Eucalyptus Kraft Pulping Résumé : Clones of Eucalyptus globulus Labill. (5- to 7-year-old), from a common geographic area, were evaluated for chemical pulping easiness. Significant variations were observed in the pulp yield and specific wood consumption to produce pulps with similar kappa numbers, as well as in the strength properties of the resulting kraft pulps. Comprehensive lignin analyses were undertaken in an attempt to rationalize the observed differences in these clones’ pulping performance. While lignin content did not correlate with pulp yield, the data reported here provides evidence of the influence of lignin features on the pulping response of different eucalyptus clones. Significant correlations were observed between pulp yield and specific wood consumption and the content of syringyl-type arylglycerol-β-aryl structures (β-O-4 linkages). Furthermore, eucalyptus woods with a greater content of uncondensed β-O-4 linkages were found to require more PFI revolutions to obtain pulps with a given drainability. In contrast, no relationship between pulping efficiency and the other lignin structural features evaluated was apparent, including syringyl/guaiacyl ratio (S/G), total aliphatic and phenolic hydroxyl groups, syringyl and guaiacyl units bearing free phenolic hydroxyls, and the erythro-to-threo ratio of β-O-4 structures. These findings support the use of the content of syringyl-type arylglycerol-β-aryl structures as a selection parameter in clonal breeding programs for pulpwood production. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800320d
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8542–8549[article] Influence of lignin structural features on eucalyptus globulus kraft pulping [texte imprimé] / Anderson Guerra, Auteur ; Juan Pedro Elissetche, Auteur . - 2008 . - p. 8542–8549.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8542–8549
Mots-clés : Eucalyptus Kraft Pulping Résumé : Clones of Eucalyptus globulus Labill. (5- to 7-year-old), from a common geographic area, were evaluated for chemical pulping easiness. Significant variations were observed in the pulp yield and specific wood consumption to produce pulps with similar kappa numbers, as well as in the strength properties of the resulting kraft pulps. Comprehensive lignin analyses were undertaken in an attempt to rationalize the observed differences in these clones’ pulping performance. While lignin content did not correlate with pulp yield, the data reported here provides evidence of the influence of lignin features on the pulping response of different eucalyptus clones. Significant correlations were observed between pulp yield and specific wood consumption and the content of syringyl-type arylglycerol-β-aryl structures (β-O-4 linkages). Furthermore, eucalyptus woods with a greater content of uncondensed β-O-4 linkages were found to require more PFI revolutions to obtain pulps with a given drainability. In contrast, no relationship between pulping efficiency and the other lignin structural features evaluated was apparent, including syringyl/guaiacyl ratio (S/G), total aliphatic and phenolic hydroxyl groups, syringyl and guaiacyl units bearing free phenolic hydroxyls, and the erythro-to-threo ratio of β-O-4 structures. These findings support the use of the content of syringyl-type arylglycerol-β-aryl structures as a selection parameter in clonal breeding programs for pulpwood production. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800320d Exemplaires
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Titre : Reduction of nitrite by ultrasound-dispersed nanoscale zero-valent iron particles Type de document : texte imprimé Auteurs : Feng Liang, Auteur ; Jing Fan, Auteur ; Yanhui Guo, Auteur Année de publication : 2008 Article en page(s) : p. 8550–8554 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nitrite Ultrasound Iron Résumé : This research focuses on the removal of nitrite by ultrasound-dispersed nanoscale zerovalent iron (NZVI) particles. The factors affecting the removal of nitrite, namely, the length of ultrasonication time, the dosage of NZVI, the initial nitrite concentration, the temperature, and the solution pH, were investigated. Kinetics studies revealed that the denitrification process is a pseudo-first-order reaction with respect to the concentration of nitrite under the given experimental conditions. The derived activation energy of NZVI-based nitrite reduction is 31.44 kJ·mol−1. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003946
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8550–8554[article] Reduction of nitrite by ultrasound-dispersed nanoscale zero-valent iron particles [texte imprimé] / Feng Liang, Auteur ; Jing Fan, Auteur ; Yanhui Guo, Auteur . - 2008 . - p. 8550–8554.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8550–8554
Mots-clés : Nitrite Ultrasound Iron Résumé : This research focuses on the removal of nitrite by ultrasound-dispersed nanoscale zerovalent iron (NZVI) particles. The factors affecting the removal of nitrite, namely, the length of ultrasonication time, the dosage of NZVI, the initial nitrite concentration, the temperature, and the solution pH, were investigated. Kinetics studies revealed that the denitrification process is a pseudo-first-order reaction with respect to the concentration of nitrite under the given experimental conditions. The derived activation energy of NZVI-based nitrite reduction is 31.44 kJ·mol−1. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003946 Exemplaires
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Titre : Mathematical model for predicting gel Point in the process of manufacturing alkyd resins Type de document : texte imprimé Auteurs : M. A. B. Prashantha, Auteur ; J. K. Premachandra, Auteur ; A. D. U. S. Amarasinghe, Auteur Année de publication : 2008 Article en page(s) : p. 8555–8560 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mathematical Manufacturing Alkyd Résumé : A mathematical model for the prediction of gel formation in the synthesis of alkyd resins is developed. The probability of developing linear polymer molecules is related to the average functionality, Fav. A statistical factor φ is introduced to represent the probability of having free OH groups in the backbone of a linear alkyd molecule. Factor φ increases from 0 to a maximum of φmax when the acid value decreases from AVinitial to AVmax during the polymerization. Branch generation in alkyd molecules becomes significant only after the acid value is reached, AVmax, and it continues until a gel is formed. At φmax, the average functionality (Fav(max)) and the acid value (AVmax) are calculated in terms of the number of moles of OH groups, number of moles of COOH groups, and total number of molecules per unit mass at the beginning of polymerization. The acid value at the gel point, AVgel, is then calculated using the values of Fav(max) and AVmax. The predicted acid values using the new model are in good agreement with the actual data reported for polyesterification in the synthesis of alkyd resins. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005534
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8555–8560[article] Mathematical model for predicting gel Point in the process of manufacturing alkyd resins [texte imprimé] / M. A. B. Prashantha, Auteur ; J. K. Premachandra, Auteur ; A. D. U. S. Amarasinghe, Auteur . - 2008 . - p. 8555–8560.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8555–8560
Mots-clés : Mathematical Manufacturing Alkyd Résumé : A mathematical model for the prediction of gel formation in the synthesis of alkyd resins is developed. The probability of developing linear polymer molecules is related to the average functionality, Fav. A statistical factor φ is introduced to represent the probability of having free OH groups in the backbone of a linear alkyd molecule. Factor φ increases from 0 to a maximum of φmax when the acid value decreases from AVinitial to AVmax during the polymerization. Branch generation in alkyd molecules becomes significant only after the acid value is reached, AVmax, and it continues until a gel is formed. At φmax, the average functionality (Fav(max)) and the acid value (AVmax) are calculated in terms of the number of moles of OH groups, number of moles of COOH groups, and total number of molecules per unit mass at the beginning of polymerization. The acid value at the gel point, AVgel, is then calculated using the values of Fav(max) and AVmax. The predicted acid values using the new model are in good agreement with the actual data reported for polyesterification in the synthesis of alkyd resins. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005534 Exemplaires
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Titre : Synthesis of environmentally friendly calcium oleate detergent Type de document : texte imprimé Auteurs : Yonglei Wang, Auteur ; Wumanjiang Eli, Auteur ; Yuanfeng Liu, Auteur Année de publication : 2008 Article en page(s) : p. 8561–8565 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : calcium oleate Ca(OH)2 detergent Résumé : This article discusses a method for synthesizing an environmentally friendly calcium oleate detergent using vegetable oil instead of mineral oil as the raw material. Reaction conditions including the molar ratio of total lime [Ca(OH)2 and CaO] to oleic acid, the molar ratio of Ca(OH)2 to CaO, the carbonation temperature, the amount of methanol, the molar ratio of water to CaO, the gas flow rate of CO2, and the molar ratio of injected CO2 to total lime [Ca(OH)2 and CaO] were optimized. Using the optimized conditions, a high-alkali calcium oleate solution with a total base number (TBN) of 376 mg of KOH/g and an overbased calcium oleate solution with a value of TBN = 420 mg of KOH/g could be obtained. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800679a
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8561–8565[article] Synthesis of environmentally friendly calcium oleate detergent [texte imprimé] / Yonglei Wang, Auteur ; Wumanjiang Eli, Auteur ; Yuanfeng Liu, Auteur . - 2008 . - p. 8561–8565.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8561–8565
Mots-clés : calcium oleate Ca(OH)2 detergent Résumé : This article discusses a method for synthesizing an environmentally friendly calcium oleate detergent using vegetable oil instead of mineral oil as the raw material. Reaction conditions including the molar ratio of total lime [Ca(OH)2 and CaO] to oleic acid, the molar ratio of Ca(OH)2 to CaO, the carbonation temperature, the amount of methanol, the molar ratio of water to CaO, the gas flow rate of CO2, and the molar ratio of injected CO2 to total lime [Ca(OH)2 and CaO] were optimized. Using the optimized conditions, a high-alkali calcium oleate solution with a total base number (TBN) of 376 mg of KOH/g and an overbased calcium oleate solution with a value of TBN = 420 mg of KOH/g could be obtained. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800679a Exemplaires
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Titre : Spectroscopic characterization of linseed oil based polymers Type de document : texte imprimé Auteurs : Vinay Sharma, Auteur ; J. S. Banait, Auteur ; P. P. Kundu, Auteur Année de publication : 2008 Article en page(s) : p. 8566–8571 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Linseed Oil Based Polymers Résumé : Linseed oil based polymers from cationic and thermal polymerizations have been investigated quantitatively through 1H NMR and FTIR spectroscopic analysis. The solubility of the samples ranges from 22 to 37% for cationic samples and from 4.23 to 53% for thermal samples. The content of the grafted linseed oil calculated from 1H NMR results ranges from 22.9 to 43.0% and from 0 to 10% for cationic and thermal samples. The grafted linseed oil contents from FTIR are 18.2−45.4% and 0−10.7% for cationic and thermal samples. The values obtained through quantitative 1H NMR and FTIR spectroscopic analysis methods are consistent and can be applied to other polymers also. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800415z
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8566–8571[article] Spectroscopic characterization of linseed oil based polymers [texte imprimé] / Vinay Sharma, Auteur ; J. S. Banait, Auteur ; P. P. Kundu, Auteur . - 2008 . - p. 8566–8571.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8566–8571
Mots-clés : Linseed Oil Based Polymers Résumé : Linseed oil based polymers from cationic and thermal polymerizations have been investigated quantitatively through 1H NMR and FTIR spectroscopic analysis. The solubility of the samples ranges from 22 to 37% for cationic samples and from 4.23 to 53% for thermal samples. The content of the grafted linseed oil calculated from 1H NMR results ranges from 22.9 to 43.0% and from 0 to 10% for cationic and thermal samples. The grafted linseed oil contents from FTIR are 18.2−45.4% and 0−10.7% for cationic and thermal samples. The values obtained through quantitative 1H NMR and FTIR spectroscopic analysis methods are consistent and can be applied to other polymers also. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800415z Exemplaires
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Titre : Multiscale modeling and solution multiplicity in catalytic pellet reactors Type de document : texte imprimé Auteurs : Kedar Kulkarni, Auteur ; Jeonghwa Moon, Auteur ; Libin Zhang, Auteur Année de publication : 2008 Article en page(s) : p. 8572–8581 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pellet Reactors Résumé : Transport and reaction phenomena in catalytic pellet reactors are often difficult to analyze because of coupling between heat and mass transport occurring at different space and time scales. To calculate the reactor concentrations and temperatures, it is necessary to account for the species reaction and transport occurring in the reactor bulk at the macroscopic level as well as the catalyst pellets at the microscopic level. The resulting approach yields a large system of nonlinear partial differential equations with multiple scales and solutions that are difficult to find numerically. In addition, the catalyst pellets may operate in multiple steady states for identical conditions. Conventional computational methods may entirely miss the multiplicity phenomenon at the catalyst pellet level and, as a result, may not correctly predict overall reactor yields. In this paper, we introduce two numerical techniques to address multiple scales and multiplicity in heterogeneous reaction models. The first method expands existing bisection with “shooting”; the second global method deploys orthogonal collocation over finite elements with niche evolutionary algorithms. We also propose a new multiscale method entitled effectiveness factor maps to expedite and simplify the numerical effort to solve transport and reaction phenomena at different length scales. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003978
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8572–8581[article] Multiscale modeling and solution multiplicity in catalytic pellet reactors [texte imprimé] / Kedar Kulkarni, Auteur ; Jeonghwa Moon, Auteur ; Libin Zhang, Auteur . - 2008 . - p. 8572–8581.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8572–8581
Mots-clés : Pellet Reactors Résumé : Transport and reaction phenomena in catalytic pellet reactors are often difficult to analyze because of coupling between heat and mass transport occurring at different space and time scales. To calculate the reactor concentrations and temperatures, it is necessary to account for the species reaction and transport occurring in the reactor bulk at the macroscopic level as well as the catalyst pellets at the microscopic level. The resulting approach yields a large system of nonlinear partial differential equations with multiple scales and solutions that are difficult to find numerically. In addition, the catalyst pellets may operate in multiple steady states for identical conditions. Conventional computational methods may entirely miss the multiplicity phenomenon at the catalyst pellet level and, as a result, may not correctly predict overall reactor yields. In this paper, we introduce two numerical techniques to address multiple scales and multiplicity in heterogeneous reaction models. The first method expands existing bisection with “shooting”; the second global method deploys orthogonal collocation over finite elements with niche evolutionary algorithms. We also propose a new multiscale method entitled effectiveness factor maps to expedite and simplify the numerical effort to solve transport and reaction phenomena at different length scales. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003978 Exemplaires
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Titre : Study on the FCC process of a novel riser−downer coupling reactor (III) : industrial trial and CFD modeling Type de document : texte imprimé Auteurs : Fei Liu, Auteur ; Wei Fei, Auteur ; Guoliang Li, Auteur Année de publication : 2008 Article en page(s) : p. 8582–8587 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Industrial Trial CFD Modeling Résumé : Industrial trials detailed in a riser−downer coupling reactor proposed for the fluid catalytic cracking (FCC) process are presented in this paper. The trials are based on the fundamental research of hydrodynamics, mixing behaviors, and laboratory-scale hot experiments described in our previous investigations. Compared with the riser reactor with the same feeds and catalyst, the LPG and propylene yield increased by 8.15 and 4.30 wt %, respectively. The gasoline octane number likewise reached 94.8 with 28 wt % olefin content. However, dry gas is significantly suppressed, and the coke has little change in yield even with the increased catalyst to oil ratio. With some gasoline recycling, the LPG and propylene yield increased by 11.45 and 5.06 wt %, respectively, and the olefin content in gasoline significantly decreased to 22 wt %; the high octane number (95.4) is maintained. The computational fluid dynamics (CFD) coupled with a 6-lump kinetic model is also applied to simulate the FCC process for the industrial trials. The yield of propylene and butylene and the temperature profile along the axis direction demonstrated consistency between the simulation results and the experimental data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800645y
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8582–8587[article] Study on the FCC process of a novel riser−downer coupling reactor (III) : industrial trial and CFD modeling [texte imprimé] / Fei Liu, Auteur ; Wei Fei, Auteur ; Guoliang Li, Auteur . - 2008 . - p. 8582–8587.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8582–8587
Mots-clés : Industrial Trial CFD Modeling Résumé : Industrial trials detailed in a riser−downer coupling reactor proposed for the fluid catalytic cracking (FCC) process are presented in this paper. The trials are based on the fundamental research of hydrodynamics, mixing behaviors, and laboratory-scale hot experiments described in our previous investigations. Compared with the riser reactor with the same feeds and catalyst, the LPG and propylene yield increased by 8.15 and 4.30 wt %, respectively. The gasoline octane number likewise reached 94.8 with 28 wt % olefin content. However, dry gas is significantly suppressed, and the coke has little change in yield even with the increased catalyst to oil ratio. With some gasoline recycling, the LPG and propylene yield increased by 11.45 and 5.06 wt %, respectively, and the olefin content in gasoline significantly decreased to 22 wt %; the high octane number (95.4) is maintained. The computational fluid dynamics (CFD) coupled with a 6-lump kinetic model is also applied to simulate the FCC process for the industrial trials. The yield of propylene and butylene and the temperature profile along the axis direction demonstrated consistency between the simulation results and the experimental data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800645y Exemplaires
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Titre : Combination of V2O5/WO3 - TiO2, Fe - ZSM5, and Cu - ZSM5 Catalysts for the selective catalytic reduction of nitric oxide with ammonia Type de document : texte imprimé Auteurs : Oliver Krocher, Auteur ; Martin Elsener, Auteur Année de publication : 2008 Article en page(s) : p. 8588–8593 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : V2O5/WO3− TiO2,Fe− ZSM5,Cu− ZSM5 Résumé : Cordierite monoliths coated with V2O5/WO3−TiO2, Fe−ZSM5, and Cu−ZSM5 catalysts were combined to investigate the possibility of combining the advantages of the different single catalysts for the selective catalytic reduction of nitric oxide with ammonia (NO SCR) while minimizing their drawbacks. Selected combinations of two of the three above-mentioned catalysts were connected in series such that the volume of each catalyst was halved in order to maintain the total space velocity constant. The combinations V2O5/WO3−TiO2 followed by Fe−ZSM5 and the reversed catalyst order achieved markedly lower NOx reduction efficiencies (DeNOx) than the pure vanadia-based catalyst. Fe−ZSM5 applied downstream of V2O5/WO3−TiO2 did not reduce the N2O formed over the V-based catalyst at temperatures above 450 °C, as expected from the known N2O decomposition and N2O SCR activities of Fe−ZSM5. When V2O5/WO3−TiO2 was mounted downstream of Fe−ZSM5, ammonia slip was observed even at small NOx reduction efficiencies. The combination of Fe−ZSM5 and Cu−ZSM5 showed high activities at temperatures from 200 to 700 °C with small N2O formation, similar to pure Fe−ZSM5. V2O5/WO3−TiO2 combined with Cu−ZSM5 showed slightly higher activity at lower temperatures than V2O5/WO3−TiO2 only. At temperatures above 350 °C potential ammonia excess was selectively oxidized to nitrogen; in other words, Cu−ZSM5 functions as a selective catalyst for ammonia oxidation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800951a
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8588–8593[article] Combination of V2O5/WO3 - TiO2, Fe - ZSM5, and Cu - ZSM5 Catalysts for the selective catalytic reduction of nitric oxide with ammonia [texte imprimé] / Oliver Krocher, Auteur ; Martin Elsener, Auteur . - 2008 . - p. 8588–8593.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8588–8593
Mots-clés : V2O5/WO3− TiO2,Fe− ZSM5,Cu− ZSM5 Résumé : Cordierite monoliths coated with V2O5/WO3−TiO2, Fe−ZSM5, and Cu−ZSM5 catalysts were combined to investigate the possibility of combining the advantages of the different single catalysts for the selective catalytic reduction of nitric oxide with ammonia (NO SCR) while minimizing their drawbacks. Selected combinations of two of the three above-mentioned catalysts were connected in series such that the volume of each catalyst was halved in order to maintain the total space velocity constant. The combinations V2O5/WO3−TiO2 followed by Fe−ZSM5 and the reversed catalyst order achieved markedly lower NOx reduction efficiencies (DeNOx) than the pure vanadia-based catalyst. Fe−ZSM5 applied downstream of V2O5/WO3−TiO2 did not reduce the N2O formed over the V-based catalyst at temperatures above 450 °C, as expected from the known N2O decomposition and N2O SCR activities of Fe−ZSM5. When V2O5/WO3−TiO2 was mounted downstream of Fe−ZSM5, ammonia slip was observed even at small NOx reduction efficiencies. The combination of Fe−ZSM5 and Cu−ZSM5 showed high activities at temperatures from 200 to 700 °C with small N2O formation, similar to pure Fe−ZSM5. V2O5/WO3−TiO2 combined with Cu−ZSM5 showed slightly higher activity at lower temperatures than V2O5/WO3−TiO2 only. At temperatures above 350 °C potential ammonia excess was selectively oxidized to nitrogen; in other words, Cu−ZSM5 functions as a selective catalyst for ammonia oxidation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800951a Exemplaires
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Titre : Simple procedure for interpreting hydrotreating kinetic data Type de document : texte imprimé Auteurs : K. T. Kam Ezra, Auteur ; Hamza Al-Bazzaz, Auteur ; Jamal Al-Fadhli, Auteur Année de publication : 2008 Article en page(s) : p. 8594–8601 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrotreating Résumé : A simple procedure is developed to determine the apparent rate constants, reaction orders, and activation energies of various hydrotreating reactions, such as the hydrodesulfurization (HDS), hydrodemetalation (HDM), hydrodenitrogenation (HDN), and asphaltene cracking (HDAsph) of hydrotreating catalysts loaded in multiple-reactor fixed bed units. The procedure is derived from the basic kinetic and engineering principles. The only required input parameters are the sulfur, vanadium, nickel, nitrogen, and asphaltenes contents in the feedstock and products, reaction temperatures, and liquid hourly space velocity (LHSV). These parameters are normally available from laboratories performing the kinetic studies. Since there is no correlation coefficient in the developed kinetic expression, the apparent reaction rate constant and activation energy for various hydrotreating reactions can be determined directly once the optimum value of the reaction order has been identified. To demonstrate how the procedure works, it has been applied to calculate the kinetic values published in the open literature. Excellent agreements are obtained. The procedure is further verified with kinetic parameters from experiments undertaken in our pilot plants. In some cases, kinetic values which were unable to be determined in our pervious studies can now be obtained. The overall absolute average deviation (AAD) is less than 10%. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002705
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8594–8601[article] Simple procedure for interpreting hydrotreating kinetic data [texte imprimé] / K. T. Kam Ezra, Auteur ; Hamza Al-Bazzaz, Auteur ; Jamal Al-Fadhli, Auteur . - 2008 . - p. 8594–8601.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8594–8601
Mots-clés : Hydrotreating Résumé : A simple procedure is developed to determine the apparent rate constants, reaction orders, and activation energies of various hydrotreating reactions, such as the hydrodesulfurization (HDS), hydrodemetalation (HDM), hydrodenitrogenation (HDN), and asphaltene cracking (HDAsph) of hydrotreating catalysts loaded in multiple-reactor fixed bed units. The procedure is derived from the basic kinetic and engineering principles. The only required input parameters are the sulfur, vanadium, nickel, nitrogen, and asphaltenes contents in the feedstock and products, reaction temperatures, and liquid hourly space velocity (LHSV). These parameters are normally available from laboratories performing the kinetic studies. Since there is no correlation coefficient in the developed kinetic expression, the apparent reaction rate constant and activation energy for various hydrotreating reactions can be determined directly once the optimum value of the reaction order has been identified. To demonstrate how the procedure works, it has been applied to calculate the kinetic values published in the open literature. Excellent agreements are obtained. The procedure is further verified with kinetic parameters from experiments undertaken in our pilot plants. In some cases, kinetic values which were unable to be determined in our pervious studies can now be obtained. The overall absolute average deviation (AAD) is less than 10%. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8002705 Exemplaires
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Titre : Simultaneous ammonia and toluene decomposition on tungsten-based catalysts for hot gas cleanup Type de document : texte imprimé Auteurs : Sourabh S. Pansare, Auteur ; James G. Goodwin, Auteur ; Santosh Gangwal, Auteur Année de publication : 2008 Article en page(s) : p. 8602–8611 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ammonia Toluene Catalysts Gas cleanup Résumé : The current paper reports the results of a study of the simultaneous decomposition of NH3 and toluene on sulfur tolerant nonconventional tungsten-based catalysts [tungsten carbide (WC) and tungstated zirconia (WZ)] at temperatures En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800525c
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8602–8611[article] Simultaneous ammonia and toluene decomposition on tungsten-based catalysts for hot gas cleanup [texte imprimé] / Sourabh S. Pansare, Auteur ; James G. Goodwin, Auteur ; Santosh Gangwal, Auteur . - 2008 . - p. 8602–8611.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8602–8611
Mots-clés : Ammonia Toluene Catalysts Gas cleanup Résumé : The current paper reports the results of a study of the simultaneous decomposition of NH3 and toluene on sulfur tolerant nonconventional tungsten-based catalysts [tungsten carbide (WC) and tungstated zirconia (WZ)] at temperatures En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800525c Exemplaires
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Titre : Textural and structural analyses of industrial raney nickel catalyst Type de document : texte imprimé Auteurs : Cristiane B. Rodella, Auteur ; Guinther Kellermann, Auteur ; Maria Suzana P. Francisco, Auteur ; Maura H. Jordao, Auteur Année de publication : 2008 Article en page(s) : p. 8612–8618 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nickel Catalyst Résumé : In this work, the influence of the temperature (60, 80, and 110 °C) in the production of Raney Ni catalysts was addressed. The catalysts were obtained by alkaline leaching of a Ni−Al alloy, and both the Ni−Al alloy and the leaching process that was evaluated were provided by an industrial partner. The physical−chemical properties of the catalysts were investigated by X-ray diffraction (XRD), scanning and transmission electron microscopies (FEG-SEM and TEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption, and small-angle X-ray scattering (SAXS) techniques. In particular, a comparison between SAXS and N2 adsorption results about the textural properties is discussed. The three Raney Ni catalysts presented the typical highly porous metallic nickel structure. The analysis of the surface, however, suggested the presence of major contributions of NiO, Ni(OH)2/Ni2O3, and Ni−O−Al species in all samples and the presence of Ni0 for the samples produced at 60 and 80 °C. The two samples prepared at lower temperatures presented similar characteristics: crystalline domains of 50 and 60 Å, BET specific surface area of 58 and 65 m2 g−1, and porosity of 0.100 and 0.107 cm3 g−1, respectively. These properties appear to be more interesting for catalytic purposes than the characteristics of the catalyst prepared at 110 °C: mean crystalline size of 100 Å, BET specific surface area of 51 m2 g−1, and pore volume of the 0.097 cm3 g−1. A higher concentration of Al species, about 80 atom %, however, was also observed on the surface of the catalysts produced at 60 and 80 °C. The larger pores found in the catalyst produced at 110 °C may have facilitated the removal of the Al species during the washing process and are probably related to the larger Ni crystalline domains in this sample. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800543t
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8612–8618[article] Textural and structural analyses of industrial raney nickel catalyst [texte imprimé] / Cristiane B. Rodella, Auteur ; Guinther Kellermann, Auteur ; Maria Suzana P. Francisco, Auteur ; Maura H. Jordao, Auteur . - 2008 . - p. 8612–8618.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8612–8618
Mots-clés : Nickel Catalyst Résumé : In this work, the influence of the temperature (60, 80, and 110 °C) in the production of Raney Ni catalysts was addressed. The catalysts were obtained by alkaline leaching of a Ni−Al alloy, and both the Ni−Al alloy and the leaching process that was evaluated were provided by an industrial partner. The physical−chemical properties of the catalysts were investigated by X-ray diffraction (XRD), scanning and transmission electron microscopies (FEG-SEM and TEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption, and small-angle X-ray scattering (SAXS) techniques. In particular, a comparison between SAXS and N2 adsorption results about the textural properties is discussed. The three Raney Ni catalysts presented the typical highly porous metallic nickel structure. The analysis of the surface, however, suggested the presence of major contributions of NiO, Ni(OH)2/Ni2O3, and Ni−O−Al species in all samples and the presence of Ni0 for the samples produced at 60 and 80 °C. The two samples prepared at lower temperatures presented similar characteristics: crystalline domains of 50 and 60 Å, BET specific surface area of 58 and 65 m2 g−1, and porosity of 0.100 and 0.107 cm3 g−1, respectively. These properties appear to be more interesting for catalytic purposes than the characteristics of the catalyst prepared at 110 °C: mean crystalline size of 100 Å, BET specific surface area of 51 m2 g−1, and pore volume of the 0.097 cm3 g−1. A higher concentration of Al species, about 80 atom %, however, was also observed on the surface of the catalysts produced at 60 and 80 °C. The larger pores found in the catalyst produced at 110 °C may have facilitated the removal of the Al species during the washing process and are probably related to the larger Ni crystalline domains in this sample. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800543t Exemplaires
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Titre : Ball mill-assisted dechlorination of flexible and rigid poly(vinyl chloride) in NaOH/EG solution Type de document : texte imprimé Auteurs : Tomohito Kameda, Auteur ; Masahiko Ono, Auteur ; Guido Grause, Auteur ; Tadaaki Mizoguchi, Auteur Année de publication : 2008 Article en page(s) : p. 8619–8624 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dechlorination vinyl chloride NaOH/EG Résumé : Both flexible and rigid forms of poly(vinyl chloride) (PVC) were effectively dechlorinated in NaOH/ethylene glycol (EG) solution during ball mill pulverization. The high degree of dechlorination obtained was attributed to the increased surface area of the crushed PVC particles and the resulting enhancement of contact between the PVC and dissolved hydroxide ions. The common additives diisononyl phthalate and CaCO3 were easily separated from the PVC bulk during the dechlorination reaction. The reaction proceeded under chemical control, with degrees of dechlorination for both flexible and rigid PVC increasing with temperature with apparent activation energies of 110 and 80 kJ/mol, respectively. This reaction was accurately represented by a modified shrinking-core model. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8006819
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8619–8624[article] Ball mill-assisted dechlorination of flexible and rigid poly(vinyl chloride) in NaOH/EG solution [texte imprimé] / Tomohito Kameda, Auteur ; Masahiko Ono, Auteur ; Guido Grause, Auteur ; Tadaaki Mizoguchi, Auteur . - 2008 . - p. 8619–8624.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8619–8624
Mots-clés : Dechlorination vinyl chloride NaOH/EG Résumé : Both flexible and rigid forms of poly(vinyl chloride) (PVC) were effectively dechlorinated in NaOH/ethylene glycol (EG) solution during ball mill pulverization. The high degree of dechlorination obtained was attributed to the increased surface area of the crushed PVC particles and the resulting enhancement of contact between the PVC and dissolved hydroxide ions. The common additives diisononyl phthalate and CaCO3 were easily separated from the PVC bulk during the dechlorination reaction. The reaction proceeded under chemical control, with degrees of dechlorination for both flexible and rigid PVC increasing with temperature with apparent activation energies of 110 and 80 kJ/mol, respectively. This reaction was accurately represented by a modified shrinking-core model. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8006819 Exemplaires
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Titre : Development of a micropyrolyzer for enhanced Isotope ratio measurement Type de document : texte imprimé Auteurs : Jianli Hu, Auteur ; Robert A. Dagle, Auteur ; Bradley R. Johnson, Auteur ; Helen W. Kreuzer, Auteur Année de publication : 2008 Article en page(s) : p. 8625–8630 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Micropyrolyzer Résumé : This paper presents design, fabrication, and testing of a microscale ceramic reactor for the pyrolysis of organic compounds. One application for this pyrolysis reactor is to convert the oxygen and hydrogen atoms in organic compounds to CO and H2 for isotope ratio measurements in a continuous flow mode. Existing commercial pyrolyzers use high carrier gas flow rates (typically 80−100 mL/min) such that >95% of the CO and H2 produced from a given sample is vented before introduction into the mass spectrometer. We describe here the fabrication and testing of a microscale pyrolysis reactor designed to be compatible with existing isotope ratio mass spectrometers. The microreactor uses carrier gas flow rates of 3−5 mL/min, decreasing the proportion of the CO and H2 lost in venting and permitting analysis of samples 20−50 times smaller than can be analyzed with conventional pyrolysis reactors. Results have shown that organic compounds, such as 1-butanol, ethanol, and ethanolamine, can be fully decomposed to desired products CO and H2, at a temperature of 1200 °C, which is 200 °C lower than conventionally reported. Furthermore, we are able to eliminate undesired products such as methane and CO2 in the pyrolysis process. The proof-of-concept experimental results clearly demonstrate that the micropyrolyzer quantitatively converts organic compounds to gases suitable for isotope ratio analysis. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009236
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8625–8630[article] Development of a micropyrolyzer for enhanced Isotope ratio measurement [texte imprimé] / Jianli Hu, Auteur ; Robert A. Dagle, Auteur ; Bradley R. Johnson, Auteur ; Helen W. Kreuzer, Auteur . - 2008 . - p. 8625–8630.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8625–8630
Mots-clés : Micropyrolyzer Résumé : This paper presents design, fabrication, and testing of a microscale ceramic reactor for the pyrolysis of organic compounds. One application for this pyrolysis reactor is to convert the oxygen and hydrogen atoms in organic compounds to CO and H2 for isotope ratio measurements in a continuous flow mode. Existing commercial pyrolyzers use high carrier gas flow rates (typically 80−100 mL/min) such that >95% of the CO and H2 produced from a given sample is vented before introduction into the mass spectrometer. We describe here the fabrication and testing of a microscale pyrolysis reactor designed to be compatible with existing isotope ratio mass spectrometers. The microreactor uses carrier gas flow rates of 3−5 mL/min, decreasing the proportion of the CO and H2 lost in venting and permitting analysis of samples 20−50 times smaller than can be analyzed with conventional pyrolysis reactors. Results have shown that organic compounds, such as 1-butanol, ethanol, and ethanolamine, can be fully decomposed to desired products CO and H2, at a temperature of 1200 °C, which is 200 °C lower than conventionally reported. Furthermore, we are able to eliminate undesired products such as methane and CO2 in the pyrolysis process. The proof-of-concept experimental results clearly demonstrate that the micropyrolyzer quantitatively converts organic compounds to gases suitable for isotope ratio analysis. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009236 Exemplaires
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Titre : Esterification of long-chain acids and alcohols catalyzed by ferric chloride hexahydrate Type de document : texte imprimé Auteurs : Noboru Ieda, Auteur ; Kshudiram Mantri, Auteur ; Yasuyuki Miyata, Auteur ; Akiyoshi Ozaki, Auteur Année de publication : 2008 Article en page(s) : p. 8631–8638 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Acids Alcohols Catalyzed Hexahydrate Résumé : A variety of multivalent metal salt, many of them are hydrates, were screened as catalysts for the esterification of fatty acids and alcohols. These salts included chlorides, nitrates, sulfates, and acetates of Fe3+, Al3+, Ga3+, In3+, ZrO2+, HfO2+, Zn2+, Co2+, Ni2+, Mn3+, Cr3+, and Cu2+. Ferric salts, particularly, FeCl3·6H2O, were the most active among the salts screened. The esters of primary C10−C18 fatty acids and alcohols were obtained quantitatively from equimolar mixtures in the presence of FeCl3·6H2O (substrate/catalyst (S/C; mol/mol) = 200, reaction period = 6 h, in refluxing mesitylene). Esters of isostearic acid and C10–C18 fatty alcohols were obtained with large quantities and prolonged reaction periods. The esters of aromatic carboxylic acids with cetyl alcohol and bulky steroid alcohols, including cholesterol, with C8−C18 fatty acids, were obtained in high yield. The cationic cluster formed by hydrolysis of the ferric cation is proposed to be the catalytically active species. Such a catalysis is proposed to occur through the activation of the carboxylic acid by ligand exchange from water to the carboxylate moiety, followed by addition of the alcohol. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800957b
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8631–8638[article] Esterification of long-chain acids and alcohols catalyzed by ferric chloride hexahydrate [texte imprimé] / Noboru Ieda, Auteur ; Kshudiram Mantri, Auteur ; Yasuyuki Miyata, Auteur ; Akiyoshi Ozaki, Auteur . - 2008 . - p. 8631–8638.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8631–8638
Mots-clés : Acids Alcohols Catalyzed Hexahydrate Résumé : A variety of multivalent metal salt, many of them are hydrates, were screened as catalysts for the esterification of fatty acids and alcohols. These salts included chlorides, nitrates, sulfates, and acetates of Fe3+, Al3+, Ga3+, In3+, ZrO2+, HfO2+, Zn2+, Co2+, Ni2+, Mn3+, Cr3+, and Cu2+. Ferric salts, particularly, FeCl3·6H2O, were the most active among the salts screened. The esters of primary C10−C18 fatty acids and alcohols were obtained quantitatively from equimolar mixtures in the presence of FeCl3·6H2O (substrate/catalyst (S/C; mol/mol) = 200, reaction period = 6 h, in refluxing mesitylene). Esters of isostearic acid and C10–C18 fatty alcohols were obtained with large quantities and prolonged reaction periods. The esters of aromatic carboxylic acids with cetyl alcohol and bulky steroid alcohols, including cholesterol, with C8−C18 fatty acids, were obtained in high yield. The cationic cluster formed by hydrolysis of the ferric cation is proposed to be the catalytically active species. Such a catalysis is proposed to occur through the activation of the carboxylic acid by ligand exchange from water to the carboxylate moiety, followed by addition of the alcohol. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800957b Exemplaires
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Titre : Detoxification kinetic modeling for nonbiodegradable wastewaters : an ecotoxicity lumping approach Type de document : texte imprimé Auteurs : A. Santos, Auteur ; P. Yustos, Auteur ; S. Rodríguez, Auteur ; F. Vicente, Auteur Année de publication : 2008 Article en page(s) : p. 8639–8644 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Detoxification Nonbiodegradable Ecotoxicity Résumé : A lumped pseudokinetic model that is able to predict the toxicity change during the treatment of industrial wastewater as a function of the initial toxicity and temperature of the process is proposed. The original pollutant (or pollutant mixture), P, reacts to form a lumped intermediate species, I, which, in turn, reacts to form a nontoxic lumped species D. Therefore, only P and I in this serial scheme, P → I → D, are considered to contribute to the toxicity of the aqueous sample. The median effective nominal concentration of species I, EC50(I), is a fitting parameter in this lumping approach and gives an idea of the toxicity of the first organic intermediates generated, lumped as I. The model was successfully validated by analyzing the toxicity data obtained during the catalytic wet oxidation of phenolic solutions (with phenol, o-cresol, and p-cresol employed as pollutants) in a three-phase fixed-bed reactor. Moreover, the lumped kinetic model developed in a previous work for the mineralization of phenol was also validated by analyzing the total organic carbon (TOC) evolution data obtained with o-cresol and p-cresol as pollutants. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8010758
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8639–8644[article] Detoxification kinetic modeling for nonbiodegradable wastewaters : an ecotoxicity lumping approach [texte imprimé] / A. Santos, Auteur ; P. Yustos, Auteur ; S. Rodríguez, Auteur ; F. Vicente, Auteur . - 2008 . - p. 8639–8644.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8639–8644
Mots-clés : Detoxification Nonbiodegradable Ecotoxicity Résumé : A lumped pseudokinetic model that is able to predict the toxicity change during the treatment of industrial wastewater as a function of the initial toxicity and temperature of the process is proposed. The original pollutant (or pollutant mixture), P, reacts to form a lumped intermediate species, I, which, in turn, reacts to form a nontoxic lumped species D. Therefore, only P and I in this serial scheme, P → I → D, are considered to contribute to the toxicity of the aqueous sample. The median effective nominal concentration of species I, EC50(I), is a fitting parameter in this lumping approach and gives an idea of the toxicity of the first organic intermediates generated, lumped as I. The model was successfully validated by analyzing the toxicity data obtained during the catalytic wet oxidation of phenolic solutions (with phenol, o-cresol, and p-cresol employed as pollutants) in a three-phase fixed-bed reactor. Moreover, the lumped kinetic model developed in a previous work for the mineralization of phenol was also validated by analyzing the total organic carbon (TOC) evolution data obtained with o-cresol and p-cresol as pollutants. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8010758 Exemplaires
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Titre : Characterization and evaluation of catalytic dechlorination activity of Pd/Fe bimetallic nanoparticles Type de document : texte imprimé Auteurs : Xiangyu Wang, Auteur ; Chao Chen, Auteur ; Huiling Liu, Auteur ; Jun Ma, Auteur Année de publication : 2008 Article en page(s) : p. 8645–8651 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dechlorination Pd/Fe Résumé : Two kinds of Pd/Fe nanoparticles (NPs) (k-Pd/Fe NPs and p-Pd/Fe NPs) were prepared by using an aqueous solution of potassium hexachloropalladate and an ethanol solution of palladium acetate as palladization solution, respectively, through the chemical precipitation method, followed by drying in an oven under vacuum, and characterized systematically in terms of morphology (SEM), Pd loading (EDS), surface composition (XRF), specific surface area (BET), particle size (TEM), and crystal structure (XRD). Batch experiments were conducted to evaluate the catalytic dechlorination activity of the prepared Pd/Fe NPs. Evidence observed suggests that the activities of various kinds of particles used for dechlorination of chlorinated methanes including carbon tetrachloride (CT), chloroform (CF), and dichloromethane (DCM) followed the order p-Pd/Fe NPs > Fe NPs > k-Pd/Fe NPs > Micro-Fe (commercial microscale iron powder). This order was found to be dependent on the size, surface area, degree of Pd dispersion, and purity extent of metal particles. These results may provide better understanding of the effects of preparing and drying methods on the catalytic dechlorination activity of Pd/Fe NPs. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701762d
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8645–8651[article] Characterization and evaluation of catalytic dechlorination activity of Pd/Fe bimetallic nanoparticles [texte imprimé] / Xiangyu Wang, Auteur ; Chao Chen, Auteur ; Huiling Liu, Auteur ; Jun Ma, Auteur . - 2008 . - p. 8645–8651.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8645–8651
Mots-clés : Dechlorination Pd/Fe Résumé : Two kinds of Pd/Fe nanoparticles (NPs) (k-Pd/Fe NPs and p-Pd/Fe NPs) were prepared by using an aqueous solution of potassium hexachloropalladate and an ethanol solution of palladium acetate as palladization solution, respectively, through the chemical precipitation method, followed by drying in an oven under vacuum, and characterized systematically in terms of morphology (SEM), Pd loading (EDS), surface composition (XRF), specific surface area (BET), particle size (TEM), and crystal structure (XRD). Batch experiments were conducted to evaluate the catalytic dechlorination activity of the prepared Pd/Fe NPs. Evidence observed suggests that the activities of various kinds of particles used for dechlorination of chlorinated methanes including carbon tetrachloride (CT), chloroform (CF), and dichloromethane (DCM) followed the order p-Pd/Fe NPs > Fe NPs > k-Pd/Fe NPs > Micro-Fe (commercial microscale iron powder). This order was found to be dependent on the size, surface area, degree of Pd dispersion, and purity extent of metal particles. These results may provide better understanding of the effects of preparing and drying methods on the catalytic dechlorination activity of Pd/Fe NPs. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701762d Exemplaires
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Titre : Analysis of steady convective heating for molten materials processing within trapezoidal enclosures Type de document : texte imprimé Auteurs : Tanmay Basak, Auteur ; S. Roy, Auteur ; E. Natarajan, Auteur Année de publication : 2008 Article en page(s) : p. 8652–8666 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Convective Heating Résumé : Material processing involving natural convection within a trapezoidal enclosure for uniformly and nonuniformly heated bottom wall, insulated top wall, and isothermal sidewalls with inclination angle φ have been investigated. The penalty finite element method is used to obtain isotherm and streamline profiles for model liquids e.g. molten metal, salt water and olive oil. Parametric study for the wide range of Rayleigh number (Ra), 103 ≤ Ra ≤ 105 and Prandtl number (Pr) for model fluids with various tilt angles φ = 45°, 30°, and 0° have been obtained. Secondary circulations were observed during molten metal processing. Streamlines show that the strength of convection is larger for φ = 45° and flow intensities are also found to be larger for olive oil compared to molten metal and salt water. Heat transfer rates are shown via local and average Nusselt number plots. Local heat transfer rates are found to be relatively more for φ = 0° than those with φ = 45° and φ = 30°. Average Nusselt number plots show higher heat transfer rates for φ = 0° except for the nonuniform heating of the bottom wall with Pr = 0.015 (molten metal). Overall, less heat transfer rates are observed for molten metal processing. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800263c
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8652–8666[article] Analysis of steady convective heating for molten materials processing within trapezoidal enclosures [texte imprimé] / Tanmay Basak, Auteur ; S. Roy, Auteur ; E. Natarajan, Auteur . - 2008 . - p. 8652–8666.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8652–8666
Mots-clés : Convective Heating Résumé : Material processing involving natural convection within a trapezoidal enclosure for uniformly and nonuniformly heated bottom wall, insulated top wall, and isothermal sidewalls with inclination angle φ have been investigated. The penalty finite element method is used to obtain isotherm and streamline profiles for model liquids e.g. molten metal, salt water and olive oil. Parametric study for the wide range of Rayleigh number (Ra), 103 ≤ Ra ≤ 105 and Prandtl number (Pr) for model fluids with various tilt angles φ = 45°, 30°, and 0° have been obtained. Secondary circulations were observed during molten metal processing. Streamlines show that the strength of convection is larger for φ = 45° and flow intensities are also found to be larger for olive oil compared to molten metal and salt water. Heat transfer rates are shown via local and average Nusselt number plots. Local heat transfer rates are found to be relatively more for φ = 0° than those with φ = 45° and φ = 30°. Average Nusselt number plots show higher heat transfer rates for φ = 0° except for the nonuniform heating of the bottom wall with Pr = 0.015 (molten metal). Overall, less heat transfer rates are observed for molten metal processing. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800263c Exemplaires
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Titre : Performance enhancement of poly(lactic acid) and sugar beet pulp composites by improving interfacial adhesion and penetration Type de document : texte imprimé Auteurs : Feng Chen, Auteur ; LinShu Liu, Auteur ; Peter H. Cooke, Auteur ; Kevin B. Hicks, Auteur Année de publication : 2008 Article en page(s) : p. 8667–8675 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Poly(lactic acid) Résumé : Sugar beet pulp (SBP), the residue from the sugar extraction process, contains abundant dietary fibers and is mainly used for feedstuff. In this study, poly(lactic acid) (PLA) and SBP composites were prepared using a twin screw extruder. The phase structure, thermal properties, mechanical properties, and water absorption of the composites were studied. The molecular weight change of PLA in the composites was also studied. Polymeric diphenylmethane diisocyanate (pMDI) was used as a coupling agent and resulted in significant increases in mechanical properties and water resistance. The tensile strength of the PLA/SBP (70/30 w/w) composite was only 56.9% that of neat PLA, but it was increased to 80.3% with the addition of 0.5% pMDI and further increased to 93.8% at 2% pMDI. With 50% SBP and 2% pMDI, the tensile strength of the composite was 87.8% of that of neat PLA. The microstructure of the composites indicated that the addition of pMDI greatly improved the wettability of the SBP particles by PLA and increased the penetration of PLA into the porous SBP. Consequently, the failure of the composites in mechanical testing changed from extensive debonding without pMDI to progressive rupture of the SBP particles with pMDI. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800930j
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8667–8675[article] Performance enhancement of poly(lactic acid) and sugar beet pulp composites by improving interfacial adhesion and penetration [texte imprimé] / Feng Chen, Auteur ; LinShu Liu, Auteur ; Peter H. Cooke, Auteur ; Kevin B. Hicks, Auteur . - 2008 . - p. 8667–8675.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8667–8675
Mots-clés : Poly(lactic acid) Résumé : Sugar beet pulp (SBP), the residue from the sugar extraction process, contains abundant dietary fibers and is mainly used for feedstuff. In this study, poly(lactic acid) (PLA) and SBP composites were prepared using a twin screw extruder. The phase structure, thermal properties, mechanical properties, and water absorption of the composites were studied. The molecular weight change of PLA in the composites was also studied. Polymeric diphenylmethane diisocyanate (pMDI) was used as a coupling agent and resulted in significant increases in mechanical properties and water resistance. The tensile strength of the PLA/SBP (70/30 w/w) composite was only 56.9% that of neat PLA, but it was increased to 80.3% with the addition of 0.5% pMDI and further increased to 93.8% at 2% pMDI. With 50% SBP and 2% pMDI, the tensile strength of the composite was 87.8% of that of neat PLA. The microstructure of the composites indicated that the addition of pMDI greatly improved the wettability of the SBP particles by PLA and increased the penetration of PLA into the porous SBP. Consequently, the failure of the composites in mechanical testing changed from extensive debonding without pMDI to progressive rupture of the SBP particles with pMDI. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800930j Exemplaires
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Titre : Effects of coagulation conditions on properties of multifilament fibers based on dissolution of cellulose in NaOH/Urea aqueous solution Type de document : texte imprimé Auteurs : Yuan Mao, Auteur ; Lina Zhang, Auteur ; Jie Cai, Auteur ; Jinping Zhou, Auteur Année de publication : 2008 Article en page(s) : p. 8676–8683 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dissolution--Cellulose NaOH/Urea Aqueous Résumé : Effects of coagulation temperature, coagulants, and wet-spinning methods on structure and properties of novel regenerated cellulose (RC) fibers prepared from cellulose in 7.5 wt % NaOH/11 wt % urea aqueous solution on pilot scale spinning machine by one- and two-stage coagulation were investigated by tensile testing, optical microscopy, scanning electron micrograph, and wide-angle X-ray diffraction. The results indicated that H2SO4/Na2SO4 and H2SO4 aqueous solutions are potential coagulants for NaOH/urea system and fibers wet-spun from the two-stage coagulation obviously exhibited the better mechanical properties than those from the one-stage coagulation. The optimal coagulation conditions for two-stage coagulation are 10 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 5 wt % H2SO4 for the second bath or 5 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 10 wt % H2SO4 for the second bath. Moreover, the tensile strength of novel fibers increased with a drop in coagulation temperature. The diffusion rate between the coagulant and solvent plays a major role in determining the mechanical properties of the cellulose fibers. Our spinning process was quite different from that of the viscose process, in which orientation and coagulation proceed more or less simultaneously. The production method of this fiber wet-spun could be suitable in the wide range of coagulation conditions, compared to the viscose one. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800833w
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8676–8683[article] Effects of coagulation conditions on properties of multifilament fibers based on dissolution of cellulose in NaOH/Urea aqueous solution [texte imprimé] / Yuan Mao, Auteur ; Lina Zhang, Auteur ; Jie Cai, Auteur ; Jinping Zhou, Auteur . - 2008 . - p. 8676–8683.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8676–8683
Mots-clés : Dissolution--Cellulose NaOH/Urea Aqueous Résumé : Effects of coagulation temperature, coagulants, and wet-spinning methods on structure and properties of novel regenerated cellulose (RC) fibers prepared from cellulose in 7.5 wt % NaOH/11 wt % urea aqueous solution on pilot scale spinning machine by one- and two-stage coagulation were investigated by tensile testing, optical microscopy, scanning electron micrograph, and wide-angle X-ray diffraction. The results indicated that H2SO4/Na2SO4 and H2SO4 aqueous solutions are potential coagulants for NaOH/urea system and fibers wet-spun from the two-stage coagulation obviously exhibited the better mechanical properties than those from the one-stage coagulation. The optimal coagulation conditions for two-stage coagulation are 10 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 5 wt % H2SO4 for the second bath or 5 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 10 wt % H2SO4 for the second bath. Moreover, the tensile strength of novel fibers increased with a drop in coagulation temperature. The diffusion rate between the coagulant and solvent plays a major role in determining the mechanical properties of the cellulose fibers. Our spinning process was quite different from that of the viscose process, in which orientation and coagulation proceed more or less simultaneously. The production method of this fiber wet-spun could be suitable in the wide range of coagulation conditions, compared to the viscose one. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800833w Exemplaires
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Titre : Synthesis of PID tuning rule using the desired closed-loop response Type de document : texte imprimé Auteurs : Rames Chandra Panda, Auteur Année de publication : 2008 Article en page(s) : p. 8684–8692 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Industrial chemistry Résumé : Proportional−integral−derivative (PID) controllers are widely used in industry, because of their simple structure and ease in implementation. A tuning method based on the IMC−PID rule is synthesized for stable single-input−single-output systems. The controller transfer function is expanded, in the vicinity of zero in the complex plane, using a Laurent series, to derive analytical expressions for controller parameters. A tuning parameter is chosen to determine the stability of the response/closed-loop system. PID parameters are obtained for different types of processes, and related robustness issues are also discussed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800258c
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8684–8692[article] Synthesis of PID tuning rule using the desired closed-loop response [texte imprimé] / Rames Chandra Panda, Auteur . - 2008 . - p. 8684–8692.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8684–8692
Mots-clés : Industrial chemistry Résumé : Proportional−integral−derivative (PID) controllers are widely used in industry, because of their simple structure and ease in implementation. A tuning method based on the IMC−PID rule is synthesized for stable single-input−single-output systems. The controller transfer function is expanded, in the vicinity of zero in the complex plane, using a Laurent series, to derive analytical expressions for controller parameters. A tuning parameter is chosen to determine the stability of the response/closed-loop system. PID parameters are obtained for different types of processes, and related robustness issues are also discussed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800258c Exemplaires
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Titre : Integrated batch-to-batch control and within-batch online control for batch processes using two-step MPLS-based model structures Type de document : texte imprimé Auteurs : Junghui Chen, Auteur ; Kuen-Chi Lin, Auteur Année de publication : 2008 Article en page(s) : p. 8693–8703 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : MPLS-Based Model Résumé : A feedback profile tracking scheme is proposed for batch-to-batch and within-batch control of the end-point quality in batch processes. This new method is based on two-step multiway partial least squares (MPLS) models. The first-step MPLS model, called the quality MPLS, is used to relate the final qualities with the online measurements; the second one, called the measurement MPLS, can relate the online measurements with both the manipulated variables and the prior measured variables. Because the standard MPLS model embeds all process variables into a single input data block, the input variables can be adjusted only on the basis of target qualities at the end point. With the proposed method, the desired online measured variables along the time axis can be computed using the quality MPLS; then the operating input variables can be appropriately adjusted using the measurement MPLS to match the desired online measured variables at each time point and finally get the target qualities at the end-time point. Under these two-step MPLS model structures, the integrated control strategy is sequentially developed by combining batch-to-batch control with within-batch control. Also, the conventional double exponentially weighted moving average control method can be separately and directly applied to each input−output variable in the reduced space of the latent variables. It can gradually reduce the model errors for the model-plant mismatches between batches. The applications are discussed through a typical batch reactor to demonstrate the advantages of the proposed method in comparison with the conventional methods. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070803w
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8693–8703[article] Integrated batch-to-batch control and within-batch online control for batch processes using two-step MPLS-based model structures [texte imprimé] / Junghui Chen, Auteur ; Kuen-Chi Lin, Auteur . - 2008 . - p. 8693–8703.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8693–8703
Mots-clés : MPLS-Based Model Résumé : A feedback profile tracking scheme is proposed for batch-to-batch and within-batch control of the end-point quality in batch processes. This new method is based on two-step multiway partial least squares (MPLS) models. The first-step MPLS model, called the quality MPLS, is used to relate the final qualities with the online measurements; the second one, called the measurement MPLS, can relate the online measurements with both the manipulated variables and the prior measured variables. Because the standard MPLS model embeds all process variables into a single input data block, the input variables can be adjusted only on the basis of target qualities at the end point. With the proposed method, the desired online measured variables along the time axis can be computed using the quality MPLS; then the operating input variables can be appropriately adjusted using the measurement MPLS to match the desired online measured variables at each time point and finally get the target qualities at the end-time point. Under these two-step MPLS model structures, the integrated control strategy is sequentially developed by combining batch-to-batch control with within-batch control. Also, the conventional double exponentially weighted moving average control method can be separately and directly applied to each input−output variable in the reduced space of the latent variables. It can gradually reduce the model errors for the model-plant mismatches between batches. The applications are discussed through a typical batch reactor to demonstrate the advantages of the proposed method in comparison with the conventional methods. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070803w Exemplaires
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Titre : Dynamic control of a Column/Side-Reactor process Type de document : texte imprimé Auteurs : Devrim B. Kaymak, Auteur ; William L. Luyben, Auteur Année de publication : 2008 Article en page(s) : p. 8704–8712 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dynamic Control Résumé : If the temperature range suitable for reasonable chemical reaction kinetics does not match the temperature range suitable for vapor−liquid equilibrium, reactive columns are not economically attractive. One way to overcome this temperature mismatch is use a flowsheet that features a distillation column with multiple side reactors. The column operates at a pressure that gives temperatures favorable for separation, while the reactors operate at temperatures (and pressures) favorable for reaction kinetics. This paper discusses the controllability of a column/side-reactor process based on the steady-state design studied by Kaymak and Luyben.(1) The performances of two different control structures are explored. The first uses two temperature controllers, one with direct action and the other with reverse action. The second control structure uses an internal composition analyzer. One of the main conclusions is that the opposite actions of controllers in the two-temperature control structure result in a composition breakthrough that moves the column to a different operating condition. The composition and temperature controllers in the second structure have the same action and provide reasonably effective control. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701705m
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8704–8712[article] Dynamic control of a Column/Side-Reactor process [texte imprimé] / Devrim B. Kaymak, Auteur ; William L. Luyben, Auteur . - 2008 . - p. 8704–8712.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8704–8712
Mots-clés : Dynamic Control Résumé : If the temperature range suitable for reasonable chemical reaction kinetics does not match the temperature range suitable for vapor−liquid equilibrium, reactive columns are not economically attractive. One way to overcome this temperature mismatch is use a flowsheet that features a distillation column with multiple side reactors. The column operates at a pressure that gives temperatures favorable for separation, while the reactors operate at temperatures (and pressures) favorable for reaction kinetics. This paper discusses the controllability of a column/side-reactor process based on the steady-state design studied by Kaymak and Luyben.(1) The performances of two different control structures are explored. The first uses two temperature controllers, one with direct action and the other with reverse action. The second control structure uses an internal composition analyzer. One of the main conclusions is that the opposite actions of controllers in the two-temperature control structure result in a composition breakthrough that moves the column to a different operating condition. The composition and temperature controllers in the second structure have the same action and provide reasonably effective control. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701705m Exemplaires
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Titre : Dealing with irregular data in soft sensors : bayesian method and comparative study Type de document : texte imprimé Auteurs : Khatibisepehr Shima, Auteur ; Biao Huang, Auteur Année de publication : 2008 Article en page(s) : p. 8713–8723 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Irregular Data Résumé : The main challenge in developing soft sensors in process industry is the existence of irregularity of data, such as measurement noises, outliers, and missing data. This paper is concerned with a comparative study among various data-driven soft sensor algorithms and the Bayesian methods. The algorithms to be considered for a comparative study in this paper include ordinary least-squares, robust regression, error-in-variable methods, partial least-squares, and the Bayesian inference algorithms. Methods for handling irregular data are reviewed. An iterative Bayesian algorithm for handling measurement noise and outliers is proposed. Performance of the Bayesian methods is compared with other existing methods through simulations, a pilot-scale experiment, and an industrial application. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800386v
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8713–8723[article] Dealing with irregular data in soft sensors : bayesian method and comparative study [texte imprimé] / Khatibisepehr Shima, Auteur ; Biao Huang, Auteur . - 2008 . - p. 8713–8723.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8713–8723
Mots-clés : Irregular Data Résumé : The main challenge in developing soft sensors in process industry is the existence of irregularity of data, such as measurement noises, outliers, and missing data. This paper is concerned with a comparative study among various data-driven soft sensor algorithms and the Bayesian methods. The algorithms to be considered for a comparative study in this paper include ordinary least-squares, robust regression, error-in-variable methods, partial least-squares, and the Bayesian inference algorithms. Methods for handling irregular data are reviewed. An iterative Bayesian algorithm for handling measurement noise and outliers is proposed. Performance of the Bayesian methods is compared with other existing methods through simulations, a pilot-scale experiment, and an industrial application. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800386v Exemplaires
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Titre : Optimal design of mixed refrigerant cycles Type de document : texte imprimé Auteurs : Frank Del Nogal, Auteur ; Jin-Kuk Kim, Auteur ; Simon Perry, Auteur ; Robin Smith, Auteur Année de publication : 2008 Article en page(s) : p. 8724–8740 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : mixed refrigerant design Résumé : A new approach for the optimal design of mixed refrigerant cycles is presented. It is based on mathematical programming and offers significant improvements in relation to previous approaches. It includes multistage refrigerant compression, full enforcement of the minimum temperature difference in heat exchangers, simultaneous optimization of variables, consideration of capital costs, and the use of stochastic optimization (genetic algorithm) to overcome local optima. The approach can be applied to either single mixed refrigerant cycles or to systems consisting of two of these in cascade. The effectiveness of the method is illustrated by revisiting previously published liquified natural gas case studies, for which better and feasible solutions are produced, and which prove the importance of considering multistage compression and capital costs during optimization. The application of genetic algorithms in the design of mixed refrigerant cycles permits a greater confidence in the optimality of the results. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800515u
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8724–8740[article] Optimal design of mixed refrigerant cycles [texte imprimé] / Frank Del Nogal, Auteur ; Jin-Kuk Kim, Auteur ; Simon Perry, Auteur ; Robin Smith, Auteur . - 2008 . - p. 8724–8740.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8724–8740
Mots-clés : mixed refrigerant design Résumé : A new approach for the optimal design of mixed refrigerant cycles is presented. It is based on mathematical programming and offers significant improvements in relation to previous approaches. It includes multistage refrigerant compression, full enforcement of the minimum temperature difference in heat exchangers, simultaneous optimization of variables, consideration of capital costs, and the use of stochastic optimization (genetic algorithm) to overcome local optima. The approach can be applied to either single mixed refrigerant cycles or to systems consisting of two of these in cascade. The effectiveness of the method is illustrated by revisiting previously published liquified natural gas case studies, for which better and feasible solutions are produced, and which prove the importance of considering multistage compression and capital costs during optimization. The application of genetic algorithms in the design of mixed refrigerant cycles permits a greater confidence in the optimality of the results. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800515u Exemplaires
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Titre : Optimizing control of CSTR/distillation column processes with one material recycle Type de document : texte imprimé Auteurs : Hiroya Seki, Auteur ; Naka Yuji, Auteur Année de publication : 2008 Article en page(s) : p. 8741–8753 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : CSTR/Distillation Résumé : Control system design for recycle processes that are composed of a continuous stirred tank reactor (CSTR) and a distillation column is discussed. It is shown that the reflux ratio control, which has been known to serve as a self-optimizing control for the process with the elementary chemistry A → B, can be also applied to processes with more-general types of chemistry that involves side reactions. Using the self-optimizing control as the basis, control systems that seek economically optimal operations are hierarchically constructed for example processes with different types of process chemistry. Particularly, for a process that exhibits tradeoff between product yield and separation cost, a linear model predictive controller design example is given with simulation results. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800183a
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8741–8753[article] Optimizing control of CSTR/distillation column processes with one material recycle [texte imprimé] / Hiroya Seki, Auteur ; Naka Yuji, Auteur . - 2008 . - p. 8741–8753.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8741–8753
Mots-clés : CSTR/Distillation Résumé : Control system design for recycle processes that are composed of a continuous stirred tank reactor (CSTR) and a distillation column is discussed. It is shown that the reflux ratio control, which has been known to serve as a self-optimizing control for the process with the elementary chemistry A → B, can be also applied to processes with more-general types of chemistry that involves side reactions. Using the self-optimizing control as the basis, control systems that seek economically optimal operations are hierarchically constructed for example processes with different types of process chemistry. Particularly, for a process that exhibits tradeoff between product yield and separation cost, a linear model predictive controller design example is given with simulation results. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800183a Exemplaires
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Titre : Three-Dimensional fluid flow in the processing of fine fibers Type de document : texte imprimé Auteurs : William P. Klinzing, Auteur ; Ephraim M. Sparrow, Auteur Année de publication : 2008 Article en page(s) : p. 8754–8761 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Three-Dimensional fluid fibers Résumé : In this paper, a multidimensional numerical simulation has been used to investigate the creation of fine fiber by the melt-blown process. The problem involves highly complex fluid flow and convective heat transfer processes. The fine fiber is created by the use of high-velocity, obliquely impinging air jets whose high shear forces stretch a polymer extrudate in the partially fluid state. High-temperature air is used to maintain the fluidity of the polymeric material as it exits the die. The model which was developed and implemented for the simulation closely reflects the physical situation employed in the actual production of fine fibers. The actual configuration of fine fiber production is a linear array of orifices from which the partially fluid polymer emerges. The array contains inherent symmetries which enable the problem to be tractable. Notwithstanding this, the numerical simulation still required multimillions of control volumes to achieve results of practical relevance. The results of the simulation indicate that, contrary to physical intuition, the shear exerted by the airflow is relatively uniform around the circumference of a given fiber. Although the interfiber spacing is small, it does not promote unfavorable fiber-to-fiber interactions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800099f
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8754–8761[article] Three-Dimensional fluid flow in the processing of fine fibers [texte imprimé] / William P. Klinzing, Auteur ; Ephraim M. Sparrow, Auteur . - 2008 . - p. 8754–8761.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8754–8761
Mots-clés : Three-Dimensional fluid fibers Résumé : In this paper, a multidimensional numerical simulation has been used to investigate the creation of fine fiber by the melt-blown process. The problem involves highly complex fluid flow and convective heat transfer processes. The fine fiber is created by the use of high-velocity, obliquely impinging air jets whose high shear forces stretch a polymer extrudate in the partially fluid state. High-temperature air is used to maintain the fluidity of the polymeric material as it exits the die. The model which was developed and implemented for the simulation closely reflects the physical situation employed in the actual production of fine fibers. The actual configuration of fine fiber production is a linear array of orifices from which the partially fluid polymer emerges. The array contains inherent symmetries which enable the problem to be tractable. Notwithstanding this, the numerical simulation still required multimillions of control volumes to achieve results of practical relevance. The results of the simulation indicate that, contrary to physical intuition, the shear exerted by the airflow is relatively uniform around the circumference of a given fiber. Although the interfiber spacing is small, it does not promote unfavorable fiber-to-fiber interactions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800099f Exemplaires
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Titre : Stochastic combinatorial optimization approach to biopharmaceutical portfolio management Type de document : texte imprimé Auteurs : Edmund D. George, Auteur ; Suzanne S. Farid, Auteur Année de publication : 2008 Article en page(s) : p. 8762–8774 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biopharmaceutical Stochastic Résumé : Key strategic decisions in biopharmaceutical portfolio management include drug selection, activity scheduling, and third party involvement. Optimizing strategies is complicated by uncertainty, dependency relationships between decisions, and multiple objectives that may conflict. This paper presents the development of a stochastic combinatorial multiobjective optimization framework designed to address these issues. The framework simulates portfolio management strategies while harnessing Bayesian networks and evolutionary computation concertedly to characterize the probabilistic structure of superior decisions and evolve strategies to multiobjective optimality. This formulation is applied to a case study entailing a portfolio of five therapeutic antibody projects. Optimization was driven by two objectives that conflicted here: maximizing profitability and maximizing the probability of being profitable. Initial analysis of competing strategies along the Pareto optimal front indicated that strategies with clear differences in comprising decisions can compete with similar reward−risk profiles. Hence optimization yielded results that were not intuitive but instead suggested that flexibility between strategies can exist in such large-scale problems. A cluster analysis was used to identify the prevalence of broad and superior building blocks along the Pareto front. In-house development of drugs generally emerged as a preferred constituent of superior strategies which suggested a drive toward minimizing contracting fees, premiums, royalty charges, and losses in sales revenue to third parties; no budgetary constraints were imposed in this case study. It appeared that strategies for scheduling activities had the most overarching impact on performance. Strategies for portfolio structure appeared to have the greatest degree of flexibility relative to other strategic components. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003144
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8762–8774[article] Stochastic combinatorial optimization approach to biopharmaceutical portfolio management [texte imprimé] / Edmund D. George, Auteur ; Suzanne S. Farid, Auteur . - 2008 . - p. 8762–8774.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8762–8774
Mots-clés : Biopharmaceutical Stochastic Résumé : Key strategic decisions in biopharmaceutical portfolio management include drug selection, activity scheduling, and third party involvement. Optimizing strategies is complicated by uncertainty, dependency relationships between decisions, and multiple objectives that may conflict. This paper presents the development of a stochastic combinatorial multiobjective optimization framework designed to address these issues. The framework simulates portfolio management strategies while harnessing Bayesian networks and evolutionary computation concertedly to characterize the probabilistic structure of superior decisions and evolve strategies to multiobjective optimality. This formulation is applied to a case study entailing a portfolio of five therapeutic antibody projects. Optimization was driven by two objectives that conflicted here: maximizing profitability and maximizing the probability of being profitable. Initial analysis of competing strategies along the Pareto optimal front indicated that strategies with clear differences in comprising decisions can compete with similar reward−risk profiles. Hence optimization yielded results that were not intuitive but instead suggested that flexibility between strategies can exist in such large-scale problems. A cluster analysis was used to identify the prevalence of broad and superior building blocks along the Pareto front. In-house development of drugs generally emerged as a preferred constituent of superior strategies which suggested a drive toward minimizing contracting fees, premiums, royalty charges, and losses in sales revenue to third parties; no budgetary constraints were imposed in this case study. It appeared that strategies for scheduling activities had the most overarching impact on performance. Strategies for portfolio structure appeared to have the greatest degree of flexibility relative to other strategic components. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003144 Exemplaires
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Titre : Particle swarm optimization algorithm for a campaign planning problem in process industries Type de document : texte imprimé Auteurs : Lixin Tang, Auteur ; Ping Yan, Auteur Année de publication : 2008 Article en page(s) : p. 8775–8784 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : swarm algorithm Résumé : Campaign planning problem (CPP) is to determine the number and length of campaigns for different products over a planning horizon such that the setup and inventory holding costs are minimized. This problem can be found frequently in a multiproduct batch processing plant in the processing industry, such as chemical or pharmaceutical industries. This paper investigates a typical CPP and proposes a hybrid approach of heuristic and particle swarm optimization (PSO) algorithms where the PSO is applied to solve one subproblem with binary variables while the heuristic is applied to the other subproblem with remaining variables by fixing binary variables. As for the evaluation of particles, we take the whole objective function of the primal problem as a fitness function which can be calculated by solving the two subproblems. In implementing the PSO, by designing a “product-to-period” representation for a discrete particle, we redefine the particle position and velocity which are different from the standard PSO. Furthermore, a new strategy is developed to move a particle to the new position. To escape from local minima, a disturbance strategy is also introduced during the iteration process of the PSO. Computational results show that the proposed PSO may find optimal or near optimal solutions for the 180 instances generated randomly within a reasonable computational time. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800383y
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8775–8784[article] Particle swarm optimization algorithm for a campaign planning problem in process industries [texte imprimé] / Lixin Tang, Auteur ; Ping Yan, Auteur . - 2008 . - p. 8775–8784.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8775–8784
Mots-clés : swarm algorithm Résumé : Campaign planning problem (CPP) is to determine the number and length of campaigns for different products over a planning horizon such that the setup and inventory holding costs are minimized. This problem can be found frequently in a multiproduct batch processing plant in the processing industry, such as chemical or pharmaceutical industries. This paper investigates a typical CPP and proposes a hybrid approach of heuristic and particle swarm optimization (PSO) algorithms where the PSO is applied to solve one subproblem with binary variables while the heuristic is applied to the other subproblem with remaining variables by fixing binary variables. As for the evaluation of particles, we take the whole objective function of the primal problem as a fitness function which can be calculated by solving the two subproblems. In implementing the PSO, by designing a “product-to-period” representation for a discrete particle, we redefine the particle position and velocity which are different from the standard PSO. Furthermore, a new strategy is developed to move a particle to the new position. To escape from local minima, a disturbance strategy is also introduced during the iteration process of the PSO. Computational results show that the proposed PSO may find optimal or near optimal solutions for the 180 instances generated randomly within a reasonable computational time. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800383y Exemplaires
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Titre : Costs for rescheduling actions : a critical issue for reducing the gap between scheduling theory and practice Type de document : texte imprimé Auteurs : Kopanos, Georgios M., Auteur ; Elisabet Capon-Garcia, Auteur ; Antonio Espuna, Auteur ; Puigjaner, Luis, Auteur Année de publication : 2008 Article en page(s) : p. 8785–8795 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Scheduling Résumé : Rescheduling programmed tasks, when an unexpected event occurs, may affect the smooth operation of the plant if the initial schedule is not taken into account. This work addresses the penalty incurred by rescheduling actions and the optimization procedure to preserve schedule stability. To adjust the rescheduling process to the needs of the decision-maker, rescheduling costs are included to the initial objective function. Namely, unit reallocation and sequencing alterations are the sources of rescheduling costs. A mixed-integer linear programming (MILP) model for the simultaneous rescheduling of multiple operations that permits local reordering, unit reallocation, and accommodation of new orders, is considered. The need to consider rescheduling penalties in the optimization procedure is highlighted through several case studies. As a result, the production plant stability and efficiency are preserved, whereas the generation of pseudo-optimal schedules is avoided. In addition, the tradeoff between the original objective function optimization and the smooth operation of the plant is thoroughly examined. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005676
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8785–8795[article] Costs for rescheduling actions : a critical issue for reducing the gap between scheduling theory and practice [texte imprimé] / Kopanos, Georgios M., Auteur ; Elisabet Capon-Garcia, Auteur ; Antonio Espuna, Auteur ; Puigjaner, Luis, Auteur . - 2008 . - p. 8785–8795.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8785–8795
Mots-clés : Scheduling Résumé : Rescheduling programmed tasks, when an unexpected event occurs, may affect the smooth operation of the plant if the initial schedule is not taken into account. This work addresses the penalty incurred by rescheduling actions and the optimization procedure to preserve schedule stability. To adjust the rescheduling process to the needs of the decision-maker, rescheduling costs are included to the initial objective function. Namely, unit reallocation and sequencing alterations are the sources of rescheduling costs. A mixed-integer linear programming (MILP) model for the simultaneous rescheduling of multiple operations that permits local reordering, unit reallocation, and accommodation of new orders, is considered. The need to consider rescheduling penalties in the optimization procedure is highlighted through several case studies. As a result, the production plant stability and efficiency are preserved, whereas the generation of pseudo-optimal schedules is avoided. In addition, the tradeoff between the original objective function optimization and the smooth operation of the plant is thoroughly examined. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005676 Exemplaires
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Titre : The fixed-bed study of dye removal on chitosan beads at high pH Type de document : texte imprimé Auteurs : Dan Xu, Auteur ; San Hein, Auteur ; Sunsun Leslie Loo, Auteur ; Kean Wang, Auteur Année de publication : 2008 Article en page(s) : p. 8796–8800 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Beads High pH Résumé : Chitosan hydrogel beads were modified with ammonium sulfate to remove a dye (Acid Orange-7) in aqueous solutions at pH 8.2. The modified beads present much higher sorption capacity than the native beads in the basic solution. The sorption equilibrium was measured in a batch adsorber, and kinetics was investigated in a fixed bed rig. The breakthrough curves were found to be J-shaped in general and were modeled by the Wheeler−Jonas equation with a two-segmented approach. Analysis shows that the kinetics is controlled by film resistance and intraparticle diffusion in each segment, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800387z
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8796–8800[article] The fixed-bed study of dye removal on chitosan beads at high pH [texte imprimé] / Dan Xu, Auteur ; San Hein, Auteur ; Sunsun Leslie Loo, Auteur ; Kean Wang, Auteur . - 2008 . - p. 8796–8800.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8796–8800
Mots-clés : Beads High pH Résumé : Chitosan hydrogel beads were modified with ammonium sulfate to remove a dye (Acid Orange-7) in aqueous solutions at pH 8.2. The modified beads present much higher sorption capacity than the native beads in the basic solution. The sorption equilibrium was measured in a batch adsorber, and kinetics was investigated in a fixed bed rig. The breakthrough curves were found to be J-shaped in general and were modeled by the Wheeler−Jonas equation with a two-segmented approach. Analysis shows that the kinetics is controlled by film resistance and intraparticle diffusion in each segment, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800387z Exemplaires
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Titre : Selective extraction and identification of neutral nitrogen compounds contained in straight-run diesel feed Using chloride based ionic liquid Type de document : texte imprimé Auteurs : Li-Li Xie, Auteur ; Alain Favre-Reguillon, Auteur ; Stephane Pellet-Rostaing, Auteur ; Xu-Xu Wang, Auteur Année de publication : 2008 Article en page(s) : p. 8801–8807 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chloride Based Ionic Liquid Diesel Résumé : Extraction of neutral nitrogen-containing compounds (N-compounds) has been investigated with chloride based ionic liquids (ILs) with varying cation classes (imidazolium, pyridinium). ILs were first discriminated by their mutual solubility of ILs and model fuel. Low solubility of 1-butyl-3-methylimidazolinium chloride (BMImCl) and 1-octylpyridinium chloride (OcPyCl) in the model fuel was observed. The ILs were then evaluated using a synthetic solution with dibenzothiophene and carbazole as model compounds, and a high selectivity for N-compounds was found. BMImCl and OcPyCl were then evaluated using straight-run diesel feed, containing 13 400 ppm S and 105 ppm N. An extraction of up to 50% of the N-compounds was obtained in one step whereas the sulfur concentration reduction was only 5%. Both ILs can be regenerated using small amount of water. Extracted compounds could be then extracted using toluene. The major constituents were identified by GC-MS. Analysis of the extracted compounds emphasized the selectivity of the extraction process. Furthermore, refractory sulfur-containing compounds (S-compounds) and polyaromatics were also identified in the extract. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701704q
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8801–8807[article] Selective extraction and identification of neutral nitrogen compounds contained in straight-run diesel feed Using chloride based ionic liquid [texte imprimé] / Li-Li Xie, Auteur ; Alain Favre-Reguillon, Auteur ; Stephane Pellet-Rostaing, Auteur ; Xu-Xu Wang, Auteur . - 2008 . - p. 8801–8807.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8801–8807
Mots-clés : Chloride Based Ionic Liquid Diesel Résumé : Extraction of neutral nitrogen-containing compounds (N-compounds) has been investigated with chloride based ionic liquids (ILs) with varying cation classes (imidazolium, pyridinium). ILs were first discriminated by their mutual solubility of ILs and model fuel. Low solubility of 1-butyl-3-methylimidazolinium chloride (BMImCl) and 1-octylpyridinium chloride (OcPyCl) in the model fuel was observed. The ILs were then evaluated using a synthetic solution with dibenzothiophene and carbazole as model compounds, and a high selectivity for N-compounds was found. BMImCl and OcPyCl were then evaluated using straight-run diesel feed, containing 13 400 ppm S and 105 ppm N. An extraction of up to 50% of the N-compounds was obtained in one step whereas the sulfur concentration reduction was only 5%. Both ILs can be regenerated using small amount of water. Extracted compounds could be then extracted using toluene. The major constituents were identified by GC-MS. Analysis of the extracted compounds emphasized the selectivity of the extraction process. Furthermore, refractory sulfur-containing compounds (S-compounds) and polyaromatics were also identified in the extract. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701704q Exemplaires
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Titre : How Is effective enantioselectivity of immobilized enzyme in kinetic resolution of racemate affected in a fixed-bed reactor? Type de document : texte imprimé Auteurs : Hongwei Yu, Auteur ; Chi Bun Ching, Auteur Année de publication : 2008 Article en page(s) : p. 8808–8814 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Enantioselectivity Résumé : The purpose of this theoretical discussion is to help researchers understand how some parameters and reaction type (first-order and Michaelis−Menten kinetic) could impact effective enantioselectivity of enzyme in a fixed-bed reactor, including adsorption equilibrium constant (adsorption effect), Biot number, Peclet number, and bed length parameter. The theoretical analysis clearly derives that reaction rate is able to impact the effective enantioselectivity of enzyme through controlling the loading of enzyme on the solid support. In addition, adsorption phenomenon and reaction type have no effect on the effective enantioselectivity in a fixed-bed reactor. Among these parameters, Bi ( En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800429e
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8808–8814[article] How Is effective enantioselectivity of immobilized enzyme in kinetic resolution of racemate affected in a fixed-bed reactor? [texte imprimé] / Hongwei Yu, Auteur ; Chi Bun Ching, Auteur . - 2008 . - p. 8808–8814.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8808–8814
Mots-clés : Enantioselectivity Résumé : The purpose of this theoretical discussion is to help researchers understand how some parameters and reaction type (first-order and Michaelis−Menten kinetic) could impact effective enantioselectivity of enzyme in a fixed-bed reactor, including adsorption equilibrium constant (adsorption effect), Biot number, Peclet number, and bed length parameter. The theoretical analysis clearly derives that reaction rate is able to impact the effective enantioselectivity of enzyme through controlling the loading of enzyme on the solid support. In addition, adsorption phenomenon and reaction type have no effect on the effective enantioselectivity in a fixed-bed reactor. Among these parameters, Bi ( En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800429e Exemplaires
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Titre : Synthesis of multicomponent products separation sequences via stochastic GP method Type de document : texte imprimé Auteurs : Xiao-Hong Wang, Auteur ; Yu-Gang Li, Auteur Année de publication : 2008 Article en page(s) : p. 8815–8822 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Stochastic GP Method Résumé : This paper addresses the application of genetic programming (GP) to the synthesis of multicomponent products nonsharp distillation sequences, and the proposed method regards minimizing the annual total cost as an optimization objective and seeks the nonsharp separation optimal flow to give the major technological parameters of the important equipment which provide the accurate theoretical basis for actual production. In combination with the domain knowledge of chemical engineering, some evolutionary factors are improved, and a set of a special encoding method and solving strategy is proposed to deal with this kind of problem. The system structural variable is optimized by GP, and the continuous variable is optimized by the complex algorithm simultaneously. Because GP has the automatic searching function, the optimal solution can be automatically found including distillation, splitting, blending, and bypassing operations without any superstructures of nonsharp distillation sequences. Three illustrating examples are presented to demonstrate the effective computational strategies. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800610s
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8815–8822[article] Synthesis of multicomponent products separation sequences via stochastic GP method [texte imprimé] / Xiao-Hong Wang, Auteur ; Yu-Gang Li, Auteur . - 2008 . - p. 8815–8822.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8815–8822
Mots-clés : Stochastic GP Method Résumé : This paper addresses the application of genetic programming (GP) to the synthesis of multicomponent products nonsharp distillation sequences, and the proposed method regards minimizing the annual total cost as an optimization objective and seeks the nonsharp separation optimal flow to give the major technological parameters of the important equipment which provide the accurate theoretical basis for actual production. In combination with the domain knowledge of chemical engineering, some evolutionary factors are improved, and a set of a special encoding method and solving strategy is proposed to deal with this kind of problem. The system structural variable is optimized by GP, and the continuous variable is optimized by the complex algorithm simultaneously. Because GP has the automatic searching function, the optimal solution can be automatically found including distillation, splitting, blending, and bypassing operations without any superstructures of nonsharp distillation sequences. Three illustrating examples are presented to demonstrate the effective computational strategies. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800610s Exemplaires
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Titre : Improved absorption in gas−liquid systems by the addition of a low surface tension component in the gas and/or liquid phase Type de document : texte imprimé Auteurs : Nai-Hsuan Yang, Auteur ; Yi-Jen Chen, Auteur ; Chien-Chih Liao, Auteur ; Tsair-Wang Chung, Auteur Année de publication : 2008 Article en page(s) : p. 8823–8827 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas− Liquid Résumé : If a system uses the phenomenon of Marangoni convection, there will be more interfacial turbulence and this may dominate the mass transfer performance between the gas and liquid phases. Marangoni convection was applied in a gas−liquid contact device (dehumidifier) in this study to measure the effect of interfacial turbulence on the water vapor removal efficiency caused by adding a low surface tension component (99.5% ethanol) into the gas or liquid phase at room temperature. The differences in water vapor removal efficiency under different conditions with and without the addition of ethanol into the moist air or working solution (38−42 wt % aqueous lithium chloride solution) were observed. Since the Marangoni effect was more pronounced when the concentration of working solution was greater than a specific value, the trend line for water vapor removal efficiency in different solution concentrations was presented as a broken line in this study. The break in the trend line is the critical concentration of the working solution, and the value is about 40 wt % of aqueous lithium chloride solution. The experimental results show that addition of low surface tension ethanol into the gas phase was better than adding it into the liquid phase for the interfacial mass transfer performance in this gas−liquid contact device. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800316n
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8823–8827[article] Improved absorption in gas−liquid systems by the addition of a low surface tension component in the gas and/or liquid phase [texte imprimé] / Nai-Hsuan Yang, Auteur ; Yi-Jen Chen, Auteur ; Chien-Chih Liao, Auteur ; Tsair-Wang Chung, Auteur . - 2008 . - p. 8823–8827.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8823–8827
Mots-clés : Gas− Liquid Résumé : If a system uses the phenomenon of Marangoni convection, there will be more interfacial turbulence and this may dominate the mass transfer performance between the gas and liquid phases. Marangoni convection was applied in a gas−liquid contact device (dehumidifier) in this study to measure the effect of interfacial turbulence on the water vapor removal efficiency caused by adding a low surface tension component (99.5% ethanol) into the gas or liquid phase at room temperature. The differences in water vapor removal efficiency under different conditions with and without the addition of ethanol into the moist air or working solution (38−42 wt % aqueous lithium chloride solution) were observed. Since the Marangoni effect was more pronounced when the concentration of working solution was greater than a specific value, the trend line for water vapor removal efficiency in different solution concentrations was presented as a broken line in this study. The break in the trend line is the critical concentration of the working solution, and the value is about 40 wt % of aqueous lithium chloride solution. The experimental results show that addition of low surface tension ethanol into the gas phase was better than adding it into the liquid phase for the interfacial mass transfer performance in this gas−liquid contact device. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800316n Exemplaires
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Titre : Rag layers in oil sand froths Type de document : texte imprimé Auteurs : Mehrrad Saadatmand, Auteur ; Harvey W. Yarranton, Auteur ; Kevin Moran, Auteur Année de publication : 2008 Article en page(s) : p. 8828–8839 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : oil sand Résumé : During the settling stages in some oil sands froth treatments, a rag layer (an undesirable mixture of dispersed oil, water, and solids) can form at the water−oil interface. To investigate rag layer formation, oil sand froths were diluted with mixtures of toluene and heptane and the diluted froths were centrifuged in steps of increasing rpm. The volumes of oil phase, rag layer, free water, and sediment were measured after each step. The data obtained from the experiments were used for material balances to determine the composition of the rag layers. The size and properties of the rag layer solids were also measured. Two mechanisms were found to influence rag layer formation: slow coalescence of emulsified water between 1500 and 3000 rpm (200−1000 times gravity); trapping of fine intermediate to oil wet solids at higher rpm and residence times. The main process factors affecting rag formation appear to be the type of diluent and asphaltene precipitation. As well, higher quality oil sand produced much smaller rag layers. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800601r
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8828–8839[article] Rag layers in oil sand froths [texte imprimé] / Mehrrad Saadatmand, Auteur ; Harvey W. Yarranton, Auteur ; Kevin Moran, Auteur . - 2008 . - p. 8828–8839.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8828–8839
Mots-clés : oil sand Résumé : During the settling stages in some oil sands froth treatments, a rag layer (an undesirable mixture of dispersed oil, water, and solids) can form at the water−oil interface. To investigate rag layer formation, oil sand froths were diluted with mixtures of toluene and heptane and the diluted froths were centrifuged in steps of increasing rpm. The volumes of oil phase, rag layer, free water, and sediment were measured after each step. The data obtained from the experiments were used for material balances to determine the composition of the rag layers. The size and properties of the rag layer solids were also measured. Two mechanisms were found to influence rag layer formation: slow coalescence of emulsified water between 1500 and 3000 rpm (200−1000 times gravity); trapping of fine intermediate to oil wet solids at higher rpm and residence times. The main process factors affecting rag formation appear to be the type of diluent and asphaltene precipitation. As well, higher quality oil sand produced much smaller rag layers. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800601r Exemplaires
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Titre : New HIGEE-rotating zigzag bed and its mass transfer performance Type de document : texte imprimé Auteurs : Q.G. Wang, Auteur ; O. G. Xu, Auteur ; Z. C. Xu, Auteur ; J. B. Ji, Auteur Année de publication : 2008 Article en page(s) : p. 8840–8846 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : HIGEE-Rotating Zigzag Bed Résumé : To overcome the disadvantages of the rotating bed available in open literature, a novel kind of high gravity device-rotating zigzag bed (RZB) was developed, which exhibits many superior features owing to its unique rotor combining a rotational part with a stationary one. The outstanding characteristics of RZB are its capability of middle-feed and easily realizing multirotor configuration in one unit by simply installing multiple rotors along the same axis. Thus one unit of RZB can be applied to continuous distillation processes with a higher mass transfer capacity. A preliminary test of mass transfer performance of the RZB in a pilot-scale system using methanol−water was carried out in this study. Experimental results show its excellent mass transfer behavior with an acceptable pressure drop. Comparison with rotating packing bed (RPB) shows that RZB provides equivalent mass transfer efficiency to RPB but exhibits excellent operability with a higher turndown ratio than that of RPB. Comparison with valve tray indicates that the baffle efficiency of RZB is slightly lower than the plate efficiency of valve tray. But if the difference between the tray space and baffle space is taken into consideration, RZB provides much higher efficiency than that of valve tray. Therefore the RZB is a kind of high efficiency gas−liquid contactor and a promising alternative in chemical process industries. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801020u
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8840–8846[article] New HIGEE-rotating zigzag bed and its mass transfer performance [texte imprimé] / Q.G. Wang, Auteur ; O. G. Xu, Auteur ; Z. C. Xu, Auteur ; J. B. Ji, Auteur . - 2008 . - p. 8840–8846.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8840–8846
Mots-clés : HIGEE-Rotating Zigzag Bed Résumé : To overcome the disadvantages of the rotating bed available in open literature, a novel kind of high gravity device-rotating zigzag bed (RZB) was developed, which exhibits many superior features owing to its unique rotor combining a rotational part with a stationary one. The outstanding characteristics of RZB are its capability of middle-feed and easily realizing multirotor configuration in one unit by simply installing multiple rotors along the same axis. Thus one unit of RZB can be applied to continuous distillation processes with a higher mass transfer capacity. A preliminary test of mass transfer performance of the RZB in a pilot-scale system using methanol−water was carried out in this study. Experimental results show its excellent mass transfer behavior with an acceptable pressure drop. Comparison with rotating packing bed (RPB) shows that RZB provides equivalent mass transfer efficiency to RPB but exhibits excellent operability with a higher turndown ratio than that of RPB. Comparison with valve tray indicates that the baffle efficiency of RZB is slightly lower than the plate efficiency of valve tray. But if the difference between the tray space and baffle space is taken into consideration, RZB provides much higher efficiency than that of valve tray. Therefore the RZB is a kind of high efficiency gas−liquid contactor and a promising alternative in chemical process industries. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801020u Exemplaires
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Titre : Modeling phase equilibria of asymmetric mixtures using a group-contribution SAFT (GC-SAFT) with a kij correlation method based on London’s theory. 1. application to CO2 + n-Alkane, Methane + n-Alkane, and Ethane + n-Alkane systems Type de document : texte imprimé Auteurs : Dong Nguyen-Huynh, Auteur ; Jean-Philippe Passarello, Auteur ; Pascal Tobaly, Auteur Année de publication : 2008 Article en page(s) : p. 8847–8858 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : SAFT (GC-SAFT) kij Correlation CO2 + n-Alkane Methane Ethane Résumé : Here, a group contribution statistical associating fluid theory equation of state (SAFT EOS) (GC-SAFT) proposed earlier by our group (Tamouza et al., Fluid Phase Equilib. 2004, 222−223, 67−76) is extended to some asymmetric systems, using a method for correlating the kij binary parameters, using only pure compound parameters. The method is inspired by London’s theory of dispersive interactions and correlates the kij values to the “pseudo-ionization energies” of compounds i and j (denoted as Ji and Jj, respectively). A group contribution for the latter parameters is also proposed, in view of obtaining a more-predictive model. Correlation tests of phase equilibria are conducted on some CO2 + n-alkane systems. Using the parameters thus obtained, the phase envelopes of other CO2 + n-alkane systems, as well as methane + n-alkane and ethane + n-alkane systems, were fully predicted. Correlation and predictions are qualitatively and quantitatively satisfactory. The deviations are within 4%−5% (i.e., comparable to those obtained on previously investigated systems). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071643r
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8847–8858[article] Modeling phase equilibria of asymmetric mixtures using a group-contribution SAFT (GC-SAFT) with a kij correlation method based on London’s theory. 1. application to CO2 + n-Alkane, Methane + n-Alkane, and Ethane + n-Alkane systems [texte imprimé] / Dong Nguyen-Huynh, Auteur ; Jean-Philippe Passarello, Auteur ; Pascal Tobaly, Auteur . - 2008 . - p. 8847–8858.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8847–8858
Mots-clés : SAFT (GC-SAFT) kij Correlation CO2 + n-Alkane Methane Ethane Résumé : Here, a group contribution statistical associating fluid theory equation of state (SAFT EOS) (GC-SAFT) proposed earlier by our group (Tamouza et al., Fluid Phase Equilib. 2004, 222−223, 67−76) is extended to some asymmetric systems, using a method for correlating the kij binary parameters, using only pure compound parameters. The method is inspired by London’s theory of dispersive interactions and correlates the kij values to the “pseudo-ionization energies” of compounds i and j (denoted as Ji and Jj, respectively). A group contribution for the latter parameters is also proposed, in view of obtaining a more-predictive model. Correlation tests of phase equilibria are conducted on some CO2 + n-alkane systems. Using the parameters thus obtained, the phase envelopes of other CO2 + n-alkane systems, as well as methane + n-alkane and ethane + n-alkane systems, were fully predicted. Correlation and predictions are qualitatively and quantitatively satisfactory. The deviations are within 4%−5% (i.e., comparable to those obtained on previously investigated systems). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071643r Exemplaires
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Titre : Modeling Phase Equilibria of Asymmetric Mixtures Using a Group-Contribution SAFT (GC-SAFT) with a kij Correlation Method Based on Londonʼs Theory. 2. Application to Binary Mixtures Containing Aromatic Hydrocarbons, n-Alkanes, CO2, N2, and H2S Type de document : texte imprimé Auteurs : Dong Nguyen-Huynh, Auteur ; T. K. S. Tran, Auteur ; S. Tamouza, Auteur ; Jean-Philippe Passarello, Auteur Année de publication : 2008 Article en page(s) : p. 8859–8868 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : SAFT (GC-SAFT) kij Correlation Hydrocarbons n-Alkanes CO2 N2 H2S Résumé : A group-contribution statistical associating fluid theory equation of state (GC-SAFT EOS) that was proposed by Tamouza et al. [Tamouza et al. Fluid Phase Equilib. 2004, 222−223, 67−76], which was extended in the first part in this series of papers to the asymmetric systems CO2 + n-alkane, methane + n-alkane, and ethane + n-alkane, is further tested here on binary mixtures that contain aromatic hydrocarbons, n-alkanes, CO2, N2, and H2S. The method for correlating the binary interaction parameters (kij), which is inspired by Londonʼs theory of dispersive interactions, uses only pure compound adjustable parameters (“pseudo-ionization energies” of compounds i and j, denoted as Ji and Jj). A group contribution for the latter parameters also is used for n-alkane and alkyl benzene series. Numerous prediction tests on the aforementioned cited systems were performed in a systematic and comprehensive way. Predictions are both qualitatively and quantitatively satisfactory, within deviations (4%−5%) that are comparable to those obtained on previously investigated systems (n-alkane + n-alkane, n-alkane + aromatic, n-alkane + n-alkanol). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071644j
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8859–8868[article] Modeling Phase Equilibria of Asymmetric Mixtures Using a Group-Contribution SAFT (GC-SAFT) with a kij Correlation Method Based on Londonʼs Theory. 2. Application to Binary Mixtures Containing Aromatic Hydrocarbons, n-Alkanes, CO2, N2, and H2S [texte imprimé] / Dong Nguyen-Huynh, Auteur ; T. K. S. Tran, Auteur ; S. Tamouza, Auteur ; Jean-Philippe Passarello, Auteur . - 2008 . - p. 8859–8868.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8859–8868
Mots-clés : SAFT (GC-SAFT) kij Correlation Hydrocarbons n-Alkanes CO2 N2 H2S Résumé : A group-contribution statistical associating fluid theory equation of state (GC-SAFT EOS) that was proposed by Tamouza et al. [Tamouza et al. Fluid Phase Equilib. 2004, 222−223, 67−76], which was extended in the first part in this series of papers to the asymmetric systems CO2 + n-alkane, methane + n-alkane, and ethane + n-alkane, is further tested here on binary mixtures that contain aromatic hydrocarbons, n-alkanes, CO2, N2, and H2S. The method for correlating the binary interaction parameters (kij), which is inspired by Londonʼs theory of dispersive interactions, uses only pure compound adjustable parameters (“pseudo-ionization energies” of compounds i and j, denoted as Ji and Jj). A group contribution for the latter parameters also is used for n-alkane and alkyl benzene series. Numerous prediction tests on the aforementioned cited systems were performed in a systematic and comprehensive way. Predictions are both qualitatively and quantitatively satisfactory, within deviations (4%−5%) that are comparable to those obtained on previously investigated systems (n-alkane + n-alkane, n-alkane + aromatic, n-alkane + n-alkanol). En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071644j Exemplaires
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Titre : Integrating controlled random search into the Line-Up competition algorithm to solve unsteady operation problems Type de document : texte imprimé Auteurs : Daim-Yuang Sun, Auteur ; Pi-Min Lin, Auteur ; Shu-Ping Lin, Auteur Année de publication : 2008 Article en page(s) : p. 8869–8887 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Controlled Random Line-Up Algorithm Résumé : In this work, a line-up competition algorithm (LCA) is applied to solve the dynamic optimization problems derived from unsteady chemical systems. The problems are first converted ito nonlinear programming problems using the concept of control vector parametrization. The parameters embedded in the converted problems then are selected by LCA. To improve numerical accuracy, the normal (Gaussian) sampling policy is introduced to replace the uniform sampling policy used in basic LCA. Variable step input (VSI) and variable ramp input (VRI) are respectively considered to rebuild the control policy in solutions. Some typical examples are provided to demonstrate the robustness and efficiency of this modification. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009999
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8869–8887[article] Integrating controlled random search into the Line-Up competition algorithm to solve unsteady operation problems [texte imprimé] / Daim-Yuang Sun, Auteur ; Pi-Min Lin, Auteur ; Shu-Ping Lin, Auteur . - 2008 . - p. 8869–8887.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8869–8887
Mots-clés : Controlled Random Line-Up Algorithm Résumé : In this work, a line-up competition algorithm (LCA) is applied to solve the dynamic optimization problems derived from unsteady chemical systems. The problems are first converted ito nonlinear programming problems using the concept of control vector parametrization. The parameters embedded in the converted problems then are selected by LCA. To improve numerical accuracy, the normal (Gaussian) sampling policy is introduced to replace the uniform sampling policy used in basic LCA. Variable step input (VSI) and variable ramp input (VRI) are respectively considered to rebuild the control policy in solutions. Some typical examples are provided to demonstrate the robustness and efficiency of this modification. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009999 Exemplaires
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Titre : New cuprous adsorbent prepared by a bioreduction method for SO2 removal at low temperature Type de document : texte imprimé Auteurs : Lishan Jia, Auteur ; Hao Song, Auteur ; Qingbiao Li, Auteur ; Weiping Fang, Auteur Année de publication : 2008 Article en page(s) : p. 8888–8893 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Bioreduction Method SO2 Résumé : A new cuprous adsorbent was prepared by bioreduction method with biomass R08 and its desulfurization ability and regenerative property at low temperature were studied. The results indicated that the amount of SO2 adsorbed on the adsorbent was lower than that on Cu/γ-Al2O3 prepared by chemical method at low temperature; however, it can be easily regenerated and the regenerative adsorbent still has a good SO2 adsorption ability, higher than 87% of that in fresh adsorbent after six regenerations. XPS and FTIR analysis showed that biomass can reduce Cu2+ to Cu+ by aldose and keep the valence of copper exposed to O2 and H2O atmosphere. Furthermore, SO2 is adsorbed on the sorbent with chemical complexation bonds so that it can be desorbed by increasing temperature which is different from γ-Al2O3, Cu(II)/γ-Al2O3 and Cu(I)/γ-Al2O3 that sulfate species are formed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800059z
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8888–8893[article] New cuprous adsorbent prepared by a bioreduction method for SO2 removal at low temperature [texte imprimé] / Lishan Jia, Auteur ; Hao Song, Auteur ; Qingbiao Li, Auteur ; Weiping Fang, Auteur . - 2008 . - p. 8888–8893.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8888–8893
Mots-clés : Bioreduction Method SO2 Résumé : A new cuprous adsorbent was prepared by bioreduction method with biomass R08 and its desulfurization ability and regenerative property at low temperature were studied. The results indicated that the amount of SO2 adsorbed on the adsorbent was lower than that on Cu/γ-Al2O3 prepared by chemical method at low temperature; however, it can be easily regenerated and the regenerative adsorbent still has a good SO2 adsorption ability, higher than 87% of that in fresh adsorbent after six regenerations. XPS and FTIR analysis showed that biomass can reduce Cu2+ to Cu+ by aldose and keep the valence of copper exposed to O2 and H2O atmosphere. Furthermore, SO2 is adsorbed on the sorbent with chemical complexation bonds so that it can be desorbed by increasing temperature which is different from γ-Al2O3, Cu(II)/γ-Al2O3 and Cu(I)/γ-Al2O3 that sulfate species are formed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800059z Exemplaires
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Titre : Joule−Thomson inversion curves and third virial coefficients for pure fluids from molecular-based models Type de document : texte imprimé Auteurs : F. Castro-Marcano, Auteur ; C. G. Olivera-Fuentes, Auteur ; C. M. Colina, Auteur Année de publication : 2008 Article en page(s) : p. 8894–8905 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Joule− Thomson Curves Résumé : In this work, we present the application of the BACKONE, PC-SAFT, SAFT-VR, and soft-SAFT models to examine the impact of the accuracy of representation of third virial coefficients on the behavior of the correspondingly predicted Joule−Thomson inversion curve (JTIC). Calculations were performed for nonassociating fluids such as ethane and pentane, associating fluids such as alcohols, and quadrupolar fluids such as nitrogen and carbon dioxide. By taking advantage of the molecular nature of the models investigated, we were able to evaluate the separate contributions to the Helmholtz free energy. Nonassociating and quadrupolar fluids are mostly governed by the dispersion contribution, whereas, as expected, the association term plays a predominant role for associating compounds. We validated our previous findings that deviations from the correct shape of the JTIC at high temperatures directly reflect the inadequacies in the predicted third virial coefficients. Consequently, much attention should be dedicated to the reliable description of virial coefficients in building and testing any newly developed equation of state. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800651q
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8894–8905[article] Joule−Thomson inversion curves and third virial coefficients for pure fluids from molecular-based models [texte imprimé] / F. Castro-Marcano, Auteur ; C. G. Olivera-Fuentes, Auteur ; C. M. Colina, Auteur . - 2008 . - p. 8894–8905.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8894–8905
Mots-clés : Joule− Thomson Curves Résumé : In this work, we present the application of the BACKONE, PC-SAFT, SAFT-VR, and soft-SAFT models to examine the impact of the accuracy of representation of third virial coefficients on the behavior of the correspondingly predicted Joule−Thomson inversion curve (JTIC). Calculations were performed for nonassociating fluids such as ethane and pentane, associating fluids such as alcohols, and quadrupolar fluids such as nitrogen and carbon dioxide. By taking advantage of the molecular nature of the models investigated, we were able to evaluate the separate contributions to the Helmholtz free energy. Nonassociating and quadrupolar fluids are mostly governed by the dispersion contribution, whereas, as expected, the association term plays a predominant role for associating compounds. We validated our previous findings that deviations from the correct shape of the JTIC at high temperatures directly reflect the inadequacies in the predicted third virial coefficients. Consequently, much attention should be dedicated to the reliable description of virial coefficients in building and testing any newly developed equation of state. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800651q Exemplaires
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Titre : Determination of cellulose reactivity by using phosphitylation and quantitative 31P NMR spectroscopy Type de document : texte imprimé Auteurs : Ilari Filpponen, Auteur ; Dimitris S. Argyropoulos, Auteur Année de publication : 2008 Article en page(s) : p. 8906–8910 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Cellulose Phosphitylation Résumé : The phosphitylation of cellulose with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane [P(II)], is proposed as a means to determine its reactivity via an evaluation of its accessible hydroxyl groups. A variety of cellulose samples were subjected to this phosphitylation reaction, and the consumption of phosphitylation reagent was followed by quantitative 31P NMR spectroscopy. This consumption was found to be directly proportional to the amount of reactive hydroxyl groups on the cellulosic material. To further evaluate the quantitative reliability of this methodology, cellulose samples were subjected to a series of mechanical beating treatments, and the changes in the amount of accessible OH groups were evaluated. In addition, cellulose samples were equilibrated to various moisture contents, and their accessible OH groups were determined using the developed methodology. Both variables examined were found to affect the amount of reactive OH groups present on the samples with variations in the moisture content having a greater effect. For example, up to 6.5 mmol g−1, of accessible OH groups were found to be created within the highly refined samples at the highest moisture content. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800936x
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8906–8910[article] Determination of cellulose reactivity by using phosphitylation and quantitative 31P NMR spectroscopy [texte imprimé] / Ilari Filpponen, Auteur ; Dimitris S. Argyropoulos, Auteur . - 2008 . - p. 8906–8910.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8906–8910
Mots-clés : Cellulose Phosphitylation Résumé : The phosphitylation of cellulose with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane [P(II)], is proposed as a means to determine its reactivity via an evaluation of its accessible hydroxyl groups. A variety of cellulose samples were subjected to this phosphitylation reaction, and the consumption of phosphitylation reagent was followed by quantitative 31P NMR spectroscopy. This consumption was found to be directly proportional to the amount of reactive hydroxyl groups on the cellulosic material. To further evaluate the quantitative reliability of this methodology, cellulose samples were subjected to a series of mechanical beating treatments, and the changes in the amount of accessible OH groups were evaluated. In addition, cellulose samples were equilibrated to various moisture contents, and their accessible OH groups were determined using the developed methodology. Both variables examined were found to affect the amount of reactive OH groups present on the samples with variations in the moisture content having a greater effect. For example, up to 6.5 mmol g−1, of accessible OH groups were found to be created within the highly refined samples at the highest moisture content. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800936x Exemplaires
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Titre : Investigation of Interfacial Tensions for Carbon Dioxide Aqueous Solutions by Perturbed-Chain Statistical Associating Fluid Theory Combined with Density-Gradient Theory Type de document : texte imprimé Auteurs : Xiao-Sen Li, Auteur ; Jian-Min Liu, Auteur ; Dong Fu, Auteur Année de publication : 2008 Article en page(s) : p. 8911–8917 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon Dioxide Aqueous Solutions Perturbed-Chain Résumé : The perturbed-chain statistical associating fluid theory and density-gradient theory are used to construct an equation of state (EOS) applicable for the phase behaviors of carbon dioxide aqueous solutions. With the molecular parameters and influence parameters respectively regressed from bulk properties and surface tensions of pure fluids as input, both the bulk and interfacial properties of carbon dioxide aqueous solutions are satisfactorily correlated by adjusting the binary interaction parameter (kij). Our results show that the constructed EOS is able to describe the interfacial properties of carbon dioxide aqueous solutions in a wide temperature range, and illustrate the influences of temperature, pressure, and densities in each phase on the interfacial properties. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800959h
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8911–8917[article] Investigation of Interfacial Tensions for Carbon Dioxide Aqueous Solutions by Perturbed-Chain Statistical Associating Fluid Theory Combined with Density-Gradient Theory [texte imprimé] / Xiao-Sen Li, Auteur ; Jian-Min Liu, Auteur ; Dong Fu, Auteur . - 2008 . - p. 8911–8917.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8911–8917
Mots-clés : Carbon Dioxide Aqueous Solutions Perturbed-Chain Résumé : The perturbed-chain statistical associating fluid theory and density-gradient theory are used to construct an equation of state (EOS) applicable for the phase behaviors of carbon dioxide aqueous solutions. With the molecular parameters and influence parameters respectively regressed from bulk properties and surface tensions of pure fluids as input, both the bulk and interfacial properties of carbon dioxide aqueous solutions are satisfactorily correlated by adjusting the binary interaction parameter (kij). Our results show that the constructed EOS is able to describe the interfacial properties of carbon dioxide aqueous solutions in a wide temperature range, and illustrate the influences of temperature, pressure, and densities in each phase on the interfacial properties. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800959h Exemplaires
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Titre : Determination of CO2 minimum miscibility pressure from measured and predicted equilibrium interfacial tensions Type de document : texte imprimé Auteurs : Morteza Nobakht, Auteur ; Samane Moghadam, Auteur ; Yongan Gu, Auteur Année de publication : 2008 Article en page(s) : p. 8918–8925 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : CO2 Minimum Résumé : Accurate determination of the minimum miscibility pressure (MMP) of a crude oil−CO2 system at the actual reservoir temperature is required in order to determine whether CO2 flooding is immiscible or miscible under the actual reservoir pressure. The objective of this study is to determine the MMPs of a crude oil−CO2 system from its measured and predicted equilibrium interfacial tension (IFT) versus equilibrium pressure data at a constant temperature. In the experiment, first, the CO2 solubilities in the crude oil are measured under four different equilibrium pressures. Second, the equilibrium IFTs of the crude oil−CO2 system are measured at 12 different equilibrium pressures and a constant temperature of T = 27 °C by applying the axisymmetric drop shape analysis (ADSA) technique for the pendant drop case. The detailed experimental results show that the CO2 solubility in the crude oil is increased almost linearly with the equilibrium pressure. It is also found that the measured crude oil−CO2 equilibrium IFT is reduced almost linearly with the equilibrium pressure as long as it is lower than a threshold pressure. The measured equilibrium IFT versus equilibrium pressure data are used to determine the MMP of the crude oil−CO2 system by applying the so-called vanishing interfacial tension (VIT) technique. In addition, the equilibrium IFT versus equilibrium pressure data of the crude oil−CO2 system are predicted by using the parachor model and linear gradient theory (LGT) model, respectively. The predicted equilibrium IFT data from each model are also used to determine the MMP of the same crude oil−CO2 system. Comparison of the MMPs determined from the two equilibrium IFT prediction models and that determined from the measured equilibrium IFTs shows that the LGT model is suitable for determining the MMP of the crude oil−CO2 system. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800358g
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8918–8925[article] Determination of CO2 minimum miscibility pressure from measured and predicted equilibrium interfacial tensions [texte imprimé] / Morteza Nobakht, Auteur ; Samane Moghadam, Auteur ; Yongan Gu, Auteur . - 2008 . - p. 8918–8925.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8918–8925
Mots-clés : CO2 Minimum Résumé : Accurate determination of the minimum miscibility pressure (MMP) of a crude oil−CO2 system at the actual reservoir temperature is required in order to determine whether CO2 flooding is immiscible or miscible under the actual reservoir pressure. The objective of this study is to determine the MMPs of a crude oil−CO2 system from its measured and predicted equilibrium interfacial tension (IFT) versus equilibrium pressure data at a constant temperature. In the experiment, first, the CO2 solubilities in the crude oil are measured under four different equilibrium pressures. Second, the equilibrium IFTs of the crude oil−CO2 system are measured at 12 different equilibrium pressures and a constant temperature of T = 27 °C by applying the axisymmetric drop shape analysis (ADSA) technique for the pendant drop case. The detailed experimental results show that the CO2 solubility in the crude oil is increased almost linearly with the equilibrium pressure. It is also found that the measured crude oil−CO2 equilibrium IFT is reduced almost linearly with the equilibrium pressure as long as it is lower than a threshold pressure. The measured equilibrium IFT versus equilibrium pressure data are used to determine the MMP of the crude oil−CO2 system by applying the so-called vanishing interfacial tension (VIT) technique. In addition, the equilibrium IFT versus equilibrium pressure data of the crude oil−CO2 system are predicted by using the parachor model and linear gradient theory (LGT) model, respectively. The predicted equilibrium IFT data from each model are also used to determine the MMP of the same crude oil−CO2 system. Comparison of the MMPs determined from the two equilibrium IFT prediction models and that determined from the measured equilibrium IFTs shows that the LGT model is suitable for determining the MMP of the crude oil−CO2 system. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800358g Exemplaires
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Titre : Validation study of two continuum granular frictional flow theories Type de document : texte imprimé Auteurs : Sofiane Benyahia, Auteur Année de publication : 2008 Article en page(s) : p. 8926–8932 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : dilute flow Résumé : Granular kinetic theories are valid in both kinetic (dilute) flow regime and dense collisional (intermediate) flow regime. This is true as long as contacts between two colliding particles are instantaneous. Empirical theories derived from soil mechanics have been traditionally used in continuum modeling for dense granular flows dominated by enduring contact between particles. This study focuses on validating two continuum theories commonly used to model dense frictional granular flows. The first validation example is conducted for a granular bin discharge, and model predictions are compared with a well-known empirical correlation for the discharge rate. The second example involves a more detailed comparison of flow variables with predictions obtained using a discrete technique for granular flow in a simple shear cell. The frictional flow theory that is only activated at the quasi-static flow regime above maximum packing does not show accurate predictions. Better predictions are obtained using a frictional theory that extends in the intermediate flow regime below packing where both collisional and enduring contact between particles occur. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003557
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8926–8932[article] Validation study of two continuum granular frictional flow theories [texte imprimé] / Sofiane Benyahia, Auteur . - 2008 . - p. 8926–8932.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8926–8932
Mots-clés : dilute flow Résumé : Granular kinetic theories are valid in both kinetic (dilute) flow regime and dense collisional (intermediate) flow regime. This is true as long as contacts between two colliding particles are instantaneous. Empirical theories derived from soil mechanics have been traditionally used in continuum modeling for dense granular flows dominated by enduring contact between particles. This study focuses on validating two continuum theories commonly used to model dense frictional granular flows. The first validation example is conducted for a granular bin discharge, and model predictions are compared with a well-known empirical correlation for the discharge rate. The second example involves a more detailed comparison of flow variables with predictions obtained using a discrete technique for granular flow in a simple shear cell. The frictional flow theory that is only activated at the quasi-static flow regime above maximum packing does not show accurate predictions. Better predictions are obtained using a frictional theory that extends in the intermediate flow regime below packing where both collisional and enduring contact between particles occur. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8003557 Exemplaires
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Titre : Clathrate hydrate formation from cyclopentane-in-water emulsions Type de document : texte imprimé Auteurs : Masahiro Nakajima, Auteur ; Ryo Ohmura, Auteur ; Yasuhiko H. Mori, Auteur Année de publication : 2008 Article en page(s) : p. 8933–8939 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Clathrate Hydrate Résumé : This paper reports the experimental examinations of hydrate-forming cyclopentane-in-water emulsions as potential thermal energy storage media for air-conditioning systems. It was demonstrated that an adequately compounded cyclopentane/water/surfactant mixture formed a stable emulsion with the aid of continuous agitation and, through its cooling to ∼2 °C, turned into a bulky mass of granular hydrate crystals. The behavior of the hydrate formation was investigated by varying the amount and composition of the surfactant (or surfactant mixture) in the sample cyclopentane/water/surfactant mixture from run to run in order to determine the appropriate preparation of the mixture for efficient hydrate formation. Also performed were measurements of the effective heat of dissociation for the granular hydrate products obtained in the above hydrate-forming experiments. The measurements showed that the effective heat of dissociation can be as high as ∼93% of the intrinsic heat of dissociation of cyclopentane hydrate crystals, thereby indicating a sufficient potential of the cyclopentane-in-water emulsions as thermal energy storage media. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800949k
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8933–8939[article] Clathrate hydrate formation from cyclopentane-in-water emulsions [texte imprimé] / Masahiro Nakajima, Auteur ; Ryo Ohmura, Auteur ; Yasuhiko H. Mori, Auteur . - 2008 . - p. 8933–8939.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8933–8939
Mots-clés : Clathrate Hydrate Résumé : This paper reports the experimental examinations of hydrate-forming cyclopentane-in-water emulsions as potential thermal energy storage media for air-conditioning systems. It was demonstrated that an adequately compounded cyclopentane/water/surfactant mixture formed a stable emulsion with the aid of continuous agitation and, through its cooling to ∼2 °C, turned into a bulky mass of granular hydrate crystals. The behavior of the hydrate formation was investigated by varying the amount and composition of the surfactant (or surfactant mixture) in the sample cyclopentane/water/surfactant mixture from run to run in order to determine the appropriate preparation of the mixture for efficient hydrate formation. Also performed were measurements of the effective heat of dissociation for the granular hydrate products obtained in the above hydrate-forming experiments. The measurements showed that the effective heat of dissociation can be as high as ∼93% of the intrinsic heat of dissociation of cyclopentane hydrate crystals, thereby indicating a sufficient potential of the cyclopentane-in-water emulsions as thermal energy storage media. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800949k Exemplaires
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Titre : Solubility of ethylene in the presence of hydrogen in process solvents under polymerization conditions Type de document : texte imprimé Auteurs : G. Sivalingam, Auteur ; V. Natarajan, Auteur ; K. R. Sarma, Auteur ; U. Parasuveera, Auteur Année de publication : 2008 Article en page(s) : p. 8940–8946 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ethylene Hydrogen Solvents Polymerization Résumé : The concentration of ethylene in the solvent of slurry polymerization process is important as it determines the extent of reaction, reaction temperature, heat duty, and molecular weight. In the present study, gas liquid behavior of ethylene, in the presence and absence of hydrogen, was studied in two process solvents namely, hexane and Varsol at various process pressures and temperatures. Solubility of ethylene increases with increase in pressure and decreases with increase in temperature in both the solvents. Ethylene solubility decreases with increase in carbon number of solvent at identical conditions. The presence of hydrogen strongly influences the solubility of ethylene in hexane and varsol. The solubility of ethylene in hexane decreases in the presence of hydrogen compared to its binary solubility, while the presence of hydrogen increases the solubility of ethylene in varsol compared to its binary solubility. A heterogeneous thermodynamic model based on the Chao−Seader method was adopted for modeling the solubility of ethylene, in the presence and absence of hydrogen, in hexane and varsol. Chao−Seader method uses the Redlich−Kwong equation of state for vapor phase fugacity, Chao−Seader correlation for pure component/reference state fugacity, Scatchard−Hildebrand model for liquid activity coefficient, and Lee−Kesler method for molar volume, Gibbs free energy departure and enthalpy departure of the mixtures. The model could explain the ethylene solubility closely in both solvents with the presence and absence of hydrogen over the entire range of process conditions studied. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801236m
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8940–8946[article] Solubility of ethylene in the presence of hydrogen in process solvents under polymerization conditions [texte imprimé] / G. Sivalingam, Auteur ; V. Natarajan, Auteur ; K. R. Sarma, Auteur ; U. Parasuveera, Auteur . - 2008 . - p. 8940–8946.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8940–8946
Mots-clés : Ethylene Hydrogen Solvents Polymerization Résumé : The concentration of ethylene in the solvent of slurry polymerization process is important as it determines the extent of reaction, reaction temperature, heat duty, and molecular weight. In the present study, gas liquid behavior of ethylene, in the presence and absence of hydrogen, was studied in two process solvents namely, hexane and Varsol at various process pressures and temperatures. Solubility of ethylene increases with increase in pressure and decreases with increase in temperature in both the solvents. Ethylene solubility decreases with increase in carbon number of solvent at identical conditions. The presence of hydrogen strongly influences the solubility of ethylene in hexane and varsol. The solubility of ethylene in hexane decreases in the presence of hydrogen compared to its binary solubility, while the presence of hydrogen increases the solubility of ethylene in varsol compared to its binary solubility. A heterogeneous thermodynamic model based on the Chao−Seader method was adopted for modeling the solubility of ethylene, in the presence and absence of hydrogen, in hexane and varsol. Chao−Seader method uses the Redlich−Kwong equation of state for vapor phase fugacity, Chao−Seader correlation for pure component/reference state fugacity, Scatchard−Hildebrand model for liquid activity coefficient, and Lee−Kesler method for molar volume, Gibbs free energy departure and enthalpy departure of the mixtures. The model could explain the ethylene solubility closely in both solvents with the presence and absence of hydrogen over the entire range of process conditions studied. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801236m Exemplaires
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Titre : Process parameters and kinetics for the electrochemical generation of cerium(IV) methanesulphonate from cerium(III) methanesulphonate Type de document : texte imprimé Auteurs : Thasan Raju, Auteur ; C. Ahmed Basha, Auteur Année de publication : 2008 Article en page(s) : p. 8947–8952 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrochemical Cerium(IV) Methanesulphonate from Cerium(III) Résumé : To study and optimize the process parameters such as current density, temperature, concentration of cerium(III) methanesulphonate and methanesulphonic acid, and kinetics for the electrochemical generation of cerium(IV) methanesulphonate in aqueous methane sulfonic acid medium. A 97% current efficiency and conversion was achieved at 5 A/dm2 current density in 0.8 M cerium(III) methanesulphonate with 2 M methanesulphonic acid medium at 50 °C temperature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701727x
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8947–8952[article] Process parameters and kinetics for the electrochemical generation of cerium(IV) methanesulphonate from cerium(III) methanesulphonate [texte imprimé] / Thasan Raju, Auteur ; C. Ahmed Basha, Auteur . - 2008 . - p. 8947–8952.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8947–8952
Mots-clés : Electrochemical Cerium(IV) Methanesulphonate from Cerium(III) Résumé : To study and optimize the process parameters such as current density, temperature, concentration of cerium(III) methanesulphonate and methanesulphonic acid, and kinetics for the electrochemical generation of cerium(IV) methanesulphonate in aqueous methane sulfonic acid medium. A 97% current efficiency and conversion was achieved at 5 A/dm2 current density in 0.8 M cerium(III) methanesulphonate with 2 M methanesulphonic acid medium at 50 °C temperature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie701727x Exemplaires
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Titre : Measurement and correlation of solubility of diphenyl carbonate in alkanols Type de document : texte imprimé Auteurs : Dongwei Wei, Auteur ; Yanhong Pei, Auteur Année de publication : 2008 Article en page(s) : p. 8953–8956 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbonate Alkanols Résumé : In an equilibrium vessel, the solubility of diphenyl carbonate (DPC) in alkanols was measured in the temperature range of 283−338 K, using a method in which an excess amount of solute was equilibrated with the alkanol solution. The liquid concentrations of the investigated DPC in the saturated solution were analyzed by spectrophotometry. The solubility data have been correlated as functions of the temperature. Activity coefficients for DPC have been calculated by means of the Wilson, NRTL, and UNIQUAC equations and, with them, were correlated solubility data that were compared with the experimental data. The best correlation of the solubility data has been obtained by the Wilson equation, by which the average root-mean-square deviation of temperature for the seven systems is 1.72 K. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801263x
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8953–8956[article] Measurement and correlation of solubility of diphenyl carbonate in alkanols [texte imprimé] / Dongwei Wei, Auteur ; Yanhong Pei, Auteur . - 2008 . - p. 8953–8956.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8953–8956
Mots-clés : Carbonate Alkanols Résumé : In an equilibrium vessel, the solubility of diphenyl carbonate (DPC) in alkanols was measured in the temperature range of 283−338 K, using a method in which an excess amount of solute was equilibrated with the alkanol solution. The liquid concentrations of the investigated DPC in the saturated solution were analyzed by spectrophotometry. The solubility data have been correlated as functions of the temperature. Activity coefficients for DPC have been calculated by means of the Wilson, NRTL, and UNIQUAC equations and, with them, were correlated solubility data that were compared with the experimental data. The best correlation of the solubility data has been obtained by the Wilson equation, by which the average root-mean-square deviation of temperature for the seven systems is 1.72 K. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801263x Exemplaires
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