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Vol. 49 N° 10 - Mai 2010 [texte imprimé] . - 2010 . - p. 4475-5026 : ill. ; 28 cm. Chemical engineering Langues : Français (fre)
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Ajouter le résultat dans votre panierReview of water network design methods with literature annotations / Jacek Jezowski in Industrial & engineering chemistry research, Vol. 49 N° 10 (Mai 2010)
Titre : Review of water network design methods with literature annotations Type de document : texte imprimé Auteurs : Jacek Jezowski, Auteur Année de publication : 2010 Article en page(s) : pp. 4475–4516 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Water Network Résumé : The designing of heat exchanger networks (HENs), mass exchanger networks (MENs), and water networks (WNs) is a major topic of process system engineering. The WN problem is most recent, and although the seminal work was published in 1980, the real development should be dated from 1994. Increasing public concern on scarce water resources, together with stringent regulations on wastewater discharge, has caused a great number of publications in recent years. Despite noticeable achievements in the topic, there is still a need for robust flexible approaches that will find wider application in practice. This review provides the reader with literature annotations on the WN problem from the year 1980 and follows the format of an earlier HEN review paper [Furman, K. C.; Sahinidis, N. V. A critical revue and annotated bibliography for heat exchanger network synthesis in the 20th century. Ind. Eng. Chem. Res. 2002, 41, 2335−2370]. An analysis of the WN problem formulation also is given, together with an overview of solution techniques. Statistics and classifications of the literature annotations are provided. Finally, thoughts on the direction of future research are presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901632w
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4475–4516[article] Review of water network design methods with literature annotations [texte imprimé] / Jacek Jezowski, Auteur . - 2010 . - pp. 4475–4516.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4475–4516
Mots-clés : Water Network Résumé : The designing of heat exchanger networks (HENs), mass exchanger networks (MENs), and water networks (WNs) is a major topic of process system engineering. The WN problem is most recent, and although the seminal work was published in 1980, the real development should be dated from 1994. Increasing public concern on scarce water resources, together with stringent regulations on wastewater discharge, has caused a great number of publications in recent years. Despite noticeable achievements in the topic, there is still a need for robust flexible approaches that will find wider application in practice. This review provides the reader with literature annotations on the WN problem from the year 1980 and follows the format of an earlier HEN review paper [Furman, K. C.; Sahinidis, N. V. A critical revue and annotated bibliography for heat exchanger network synthesis in the 20th century. Ind. Eng. Chem. Res. 2002, 41, 2335−2370]. An analysis of the WN problem formulation also is given, together with an overview of solution techniques. Statistics and classifications of the literature annotations are provided. Finally, thoughts on the direction of future research are presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901632w Exemplaires
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Titre : Preparation and characterization of waterborne hyperbranched polyurethane - urea and their hybrid coatings Type de document : texte imprimé Auteurs : Pion Florian, Auteur ; Kishore K. Jena, Auteur ; Shaik Allauddin, Auteur Année de publication : 2010 Article en page(s) : pp. 4517–4527 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Waterborne Hybrid Coatings Résumé : A series of novel waterborne hyperbranched polyurethane-urea (WHBPU) were prepared with different chain extenders (diamine, diol, and siloxane) by a systematic reaction process. Initially, the hyperbranched polyester polyol was prepared by reacting polytetramethyleneglycol (PTMG)-1000 with 2,2-bis(hydroxymethyl) propionic acid (DMPA) in a molar ratio of 1:14 (3rd generation) at 160 °C by one pot synthesis. This was reacted with an adduct of isophorone diisocyanate (IPDI) and DMPA with NCO:OH mole ratio of 1.6:1. Then 50% of free NCO in these prepolymers was reacted with three different chain extenders (diol, diamine and APTES). This reaction mixture was neutralized with triethyl amine and another 50% of free NCO was chain extended with isophorone diamine during water dispersion. The obtained polyester was characterized with Fourier transform-infrared spectroscopy (FT-IR), 1H and 13C NMR, respectively. The properties of WHBPU and their hybrid coatings were studied by FT-IR, 1H NMR, thermogravimetric analyzer (TGA), dynamic mechanical, and thermal analyzer (DMTA), and the contact angle measurement. TGA and DMTA results confirmed that these coatings have good thermal and mechanical properties. The onset degradation temperature of the WHBPU without APTES starts in between 200 and 250 °C, whereas the APTES chain extended WHBPU starts at 250 °C. Tg of WHBPU without APTES varies between 106 and 126 °C, while 129 °C for APTES chain extended WHBPU. The conditions for the reproducible preparation of suitable products have been found and optimized. They enable the tuning of their properties according to the intended use. The aim of the prepared WHBPU films is long-term use as thermal and mechanical resistant systems. Along with these property APTES cross-linked system, the hydrophobic silica-rich surface is likely to be inhibited the hybrid films upon exposure to an aqueous environment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900840g
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4517–4527[article] Preparation and characterization of waterborne hyperbranched polyurethane - urea and their hybrid coatings [texte imprimé] / Pion Florian, Auteur ; Kishore K. Jena, Auteur ; Shaik Allauddin, Auteur . - 2010 . - pp. 4517–4527.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4517–4527
Mots-clés : Waterborne Hybrid Coatings Résumé : A series of novel waterborne hyperbranched polyurethane-urea (WHBPU) were prepared with different chain extenders (diamine, diol, and siloxane) by a systematic reaction process. Initially, the hyperbranched polyester polyol was prepared by reacting polytetramethyleneglycol (PTMG)-1000 with 2,2-bis(hydroxymethyl) propionic acid (DMPA) in a molar ratio of 1:14 (3rd generation) at 160 °C by one pot synthesis. This was reacted with an adduct of isophorone diisocyanate (IPDI) and DMPA with NCO:OH mole ratio of 1.6:1. Then 50% of free NCO in these prepolymers was reacted with three different chain extenders (diol, diamine and APTES). This reaction mixture was neutralized with triethyl amine and another 50% of free NCO was chain extended with isophorone diamine during water dispersion. The obtained polyester was characterized with Fourier transform-infrared spectroscopy (FT-IR), 1H and 13C NMR, respectively. The properties of WHBPU and their hybrid coatings were studied by FT-IR, 1H NMR, thermogravimetric analyzer (TGA), dynamic mechanical, and thermal analyzer (DMTA), and the contact angle measurement. TGA and DMTA results confirmed that these coatings have good thermal and mechanical properties. The onset degradation temperature of the WHBPU without APTES starts in between 200 and 250 °C, whereas the APTES chain extended WHBPU starts at 250 °C. Tg of WHBPU without APTES varies between 106 and 126 °C, while 129 °C for APTES chain extended WHBPU. The conditions for the reproducible preparation of suitable products have been found and optimized. They enable the tuning of their properties according to the intended use. The aim of the prepared WHBPU films is long-term use as thermal and mechanical resistant systems. Along with these property APTES cross-linked system, the hydrophobic silica-rich surface is likely to be inhibited the hybrid films upon exposure to an aqueous environment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900840g Exemplaires
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Titre : Mechanistic insights into copper removal by pyrolytic tire char through equilibrium studies Type de document : texte imprimé Auteurs : Augustine Quek, Auteur ; Xiu-Song Zhao, Auteur ; Rajasekhar Balasubramanian, Auteur Année de publication : 2010 Article en page(s) : pp. 4528–4534 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : adsorptive Copper Résumé : This study showed that copper(II) can be removed from aqueous solution by activated pyrolytic tire char in three mechanistically distinct ways. On the basis of equilibrium studies, the mechanisms involved in the adsorptive removal of copper(II), namely, precipitation, surface adsorption, and pore diffusion, were elucidated. Precipitation of copper(II) resulted from changes in the solution pH to neutral levels. This was attributed to amphoteric zinc oxide on the char surface, formed during production of the pyrolytic char. Surface adsorption was revealed by X-ray photoelectron spectroscopy data, which showed a significant increase in copper(II) on the char surface after shaking in the copper solution. This surface adsorption took place despite the relatively low surface area and porosity of the char. However, some cracks and fissures were found to exist in the char that can trap small species such as copper ions. These trapped copper species were partially recovered by microwave-assisted acid digestion of the char. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901289e
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4528–4534[article] Mechanistic insights into copper removal by pyrolytic tire char through equilibrium studies [texte imprimé] / Augustine Quek, Auteur ; Xiu-Song Zhao, Auteur ; Rajasekhar Balasubramanian, Auteur . - 2010 . - pp. 4528–4534.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4528–4534
Mots-clés : adsorptive Copper Résumé : This study showed that copper(II) can be removed from aqueous solution by activated pyrolytic tire char in three mechanistically distinct ways. On the basis of equilibrium studies, the mechanisms involved in the adsorptive removal of copper(II), namely, precipitation, surface adsorption, and pore diffusion, were elucidated. Precipitation of copper(II) resulted from changes in the solution pH to neutral levels. This was attributed to amphoteric zinc oxide on the char surface, formed during production of the pyrolytic char. Surface adsorption was revealed by X-ray photoelectron spectroscopy data, which showed a significant increase in copper(II) on the char surface after shaking in the copper solution. This surface adsorption took place despite the relatively low surface area and porosity of the char. However, some cracks and fissures were found to exist in the char that can trap small species such as copper ions. These trapped copper species were partially recovered by microwave-assisted acid digestion of the char. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901289e Exemplaires
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Titre : Decomposition of epoxy resin in supercritical isopropanol Type de document : texte imprimé Auteurs : Guozhan Jiang, Auteur ; Stephen J. Pickering, Auteur ; Edward H. Lester, Auteur Année de publication : 2010 Article en page(s) : pp. 4535–4541 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Isopropanol Hydroxide Résumé : This paper reports the decomposition of an amine-cured bisphenol A diglycidyl ether (DGEBA) epoxy resin in supercritical isopropanol in a flow reactor with and without potassium hydroxide (KOH). The decomposition process was monitored by the change of the refractive index of the exit solution with time. The product distribution was analyzed using gas chromatography−mass spectroscopy (GC-MS) and compared with those obtained from the decomposition in supercritical 1-butanol and pyrolysis processes. This study indicated that thermolysis played a key role in cleaving the chemical bonds of the epoxy resin, and that supercritical isopropanol reduced char formation, because of the rapid removal of the primary decomposition products from the reaction zone to lessen secondary reactions. KOH reduced the initial decomposition temperature of the epoxy resin, but it also promoted the Guerbet reaction of isopropanol to form complex alcohols. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901542z
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4535–4541[article] Decomposition of epoxy resin in supercritical isopropanol [texte imprimé] / Guozhan Jiang, Auteur ; Stephen J. Pickering, Auteur ; Edward H. Lester, Auteur . - 2010 . - pp. 4535–4541.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4535–4541
Mots-clés : Isopropanol Hydroxide Résumé : This paper reports the decomposition of an amine-cured bisphenol A diglycidyl ether (DGEBA) epoxy resin in supercritical isopropanol in a flow reactor with and without potassium hydroxide (KOH). The decomposition process was monitored by the change of the refractive index of the exit solution with time. The product distribution was analyzed using gas chromatography−mass spectroscopy (GC-MS) and compared with those obtained from the decomposition in supercritical 1-butanol and pyrolysis processes. This study indicated that thermolysis played a key role in cleaving the chemical bonds of the epoxy resin, and that supercritical isopropanol reduced char formation, because of the rapid removal of the primary decomposition products from the reaction zone to lessen secondary reactions. KOH reduced the initial decomposition temperature of the epoxy resin, but it also promoted the Guerbet reaction of isopropanol to form complex alcohols. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901542z Exemplaires
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Titre : Boehmite Dissolution Model Based on Simulant Data Type de document : texte imprimé Auteurs : Renee L. Russell, Auteur ; Reid A. Peterson, Auteur Année de publication : 2010 Article en page(s) : pp. 4542–4545 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Boehmite Waste Treatment Résumé : Several of the Hanford waste tanks contain significant quantities of boehmite. This boehmite will be dissolved through caustic leaching as part of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) currently under construction. Therefore, it is important to fully understand the nature of this dissolution process so that caustic leaching can be effectively deployed on the Hanford tank wastes. This research determined the impact of aluminate ion on the dissolution kinetics of boehmite. In addition, other parameters that impact boehmite dissolution, such reaction temperature, were also assessed and used to develop a semiempirical model of the boehmite dissolution process. A shrinking core model was used to fit data from a series of boehmite dissolution tests with an additional term added to account for the approach to saturation. This revised model provided an adequate fit to the experimental data; however, a superior fit to the experimental data was obtained when a term was added to represent the number of dissolution sites available at the start of the reaction. These results suggest that boehmite will dissolve significantly slower as gibbsite dissolves and adds aluminate to the solution. Practically, these results indicate that the blending of wastes with gibbsite and boehmite will ultimately result in either more caustic or more time required to achieve the same fraction of boehmite dissolution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901841g
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4542–4545[article] Boehmite Dissolution Model Based on Simulant Data [texte imprimé] / Renee L. Russell, Auteur ; Reid A. Peterson, Auteur . - 2010 . - pp. 4542–4545.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4542–4545
Mots-clés : Boehmite Waste Treatment Résumé : Several of the Hanford waste tanks contain significant quantities of boehmite. This boehmite will be dissolved through caustic leaching as part of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) currently under construction. Therefore, it is important to fully understand the nature of this dissolution process so that caustic leaching can be effectively deployed on the Hanford tank wastes. This research determined the impact of aluminate ion on the dissolution kinetics of boehmite. In addition, other parameters that impact boehmite dissolution, such reaction temperature, were also assessed and used to develop a semiempirical model of the boehmite dissolution process. A shrinking core model was used to fit data from a series of boehmite dissolution tests with an additional term added to account for the approach to saturation. This revised model provided an adequate fit to the experimental data; however, a superior fit to the experimental data was obtained when a term was added to represent the number of dissolution sites available at the start of the reaction. These results suggest that boehmite will dissolve significantly slower as gibbsite dissolves and adds aluminate to the solution. Practically, these results indicate that the blending of wastes with gibbsite and boehmite will ultimately result in either more caustic or more time required to achieve the same fraction of boehmite dissolution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901841g Exemplaires
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Titre : Novel slow - release multielement compound fertilizer with hydroscopicity and moisture preservation Type de document : texte imprimé Auteurs : Boli Ni, Auteur ; Mingzhu Liu, Auteur ; Shaoyu Lü, Auteur Année de publication : 2010 Article en page(s) : pp.4546–4552 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydroscopicity Résumé : To improve the utilization of fertilizer and water resources at the same time, a novel slow-release multielement compound fertilizer (SMF) with the function of water retention was prepared. The fertilizer nutrients (11.3% N, 9.6% P2O5, 6.1% K2O, and 0.76% Cu) were entrapped in the alginate matrix granules, and the sodium alginate-g-ploy(acrylic acid) (SA-g-PAA) superabsorbent polymer was used as a coating material. The structural and chemical characteristics of the product as well as its efficiency in slowing nutrient release and water evaporation in soil were examined. The degradation of the SA-g-PAA coating was assessed by examining the weight loss with incubation time in soil. Additionally, the nutrient release mechanism was proposed and the diffusional exponent n was calculated. These studies showed that the product with good slow-release and water-retention properties, being partially degradable in nature, could be expected to have wide potential applications in modern agriculture and horticulture. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019769
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp.4546–4552[article] Novel slow - release multielement compound fertilizer with hydroscopicity and moisture preservation [texte imprimé] / Boli Ni, Auteur ; Mingzhu Liu, Auteur ; Shaoyu Lü, Auteur . - 2010 . - pp.4546–4552.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp.4546–4552
Mots-clés : Hydroscopicity Résumé : To improve the utilization of fertilizer and water resources at the same time, a novel slow-release multielement compound fertilizer (SMF) with the function of water retention was prepared. The fertilizer nutrients (11.3% N, 9.6% P2O5, 6.1% K2O, and 0.76% Cu) were entrapped in the alginate matrix granules, and the sodium alginate-g-ploy(acrylic acid) (SA-g-PAA) superabsorbent polymer was used as a coating material. The structural and chemical characteristics of the product as well as its efficiency in slowing nutrient release and water evaporation in soil were examined. The degradation of the SA-g-PAA coating was assessed by examining the weight loss with incubation time in soil. Additionally, the nutrient release mechanism was proposed and the diffusional exponent n was calculated. These studies showed that the product with good slow-release and water-retention properties, being partially degradable in nature, could be expected to have wide potential applications in modern agriculture and horticulture. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019769 Exemplaires
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Titre : New amines for CO2 capture. III. effect of alkyl chain length between amine functions on polyamines degradation Type de document : texte imprimé Auteurs : Helene Lepaumier, Auteur ; Sandrine Martin, Auteur Année de publication : 2010 Article en page(s) : pp. 4553-4560 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon dioxide Résumé : This study examines degradation of five tertiary polyamines (di- and triamines) in the presence of CO2 or O2. They were chosen to identify the impact of alkyl chain length between amine functions. Degradation of aqueous amine solutions was evaluated at 140 °C under CO2 or air pressure (2 MPa) in stainless steel batch reactors for 15 days. At the end of the run, most degradation products were identified by gas chromatography (GC)/mass spectrometry; amounts of remaining amine and its degradation products were determined with a quantitative GC method. The main degradation mechanisms are proposed, and some structure−properties relationships are established. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797443
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4553-4560[article] New amines for CO2 capture. III. effect of alkyl chain length between amine functions on polyamines degradation [texte imprimé] / Helene Lepaumier, Auteur ; Sandrine Martin, Auteur . - 2010 . - pp. 4553-4560.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4553-4560
Mots-clés : Carbon dioxide Résumé : This study examines degradation of five tertiary polyamines (di- and triamines) in the presence of CO2 or O2. They were chosen to identify the impact of alkyl chain length between amine functions. Degradation of aqueous amine solutions was evaluated at 140 °C under CO2 or air pressure (2 MPa) in stainless steel batch reactors for 15 days. At the end of the run, most degradation products were identified by gas chromatography (GC)/mass spectrometry; amounts of remaining amine and its degradation products were determined with a quantitative GC method. The main degradation mechanisms are proposed, and some structure−properties relationships are established. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797443 Exemplaires
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Titre : Catalytic hydrodechlorination of 4 - chlorophenol in an aqueous solution with Pd/Ni catalyst and formic acid Type de document : texte imprimé Auteurs : Shu Wang, Auteur ; Bo Yang, Auteur ; Tingting Zhang, Auteur Année de publication : 2010 Article en page(s) : pp. 4561–4565 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aqueous solution Catalyst Formic acid Résumé : Palladized foam nickel (Pd/Ni) catalyst was prepared by replacement deposition and employed to hydrodechlorinate 4-chlorophenol (4-CP) with formic acid (FA). 4-CP was rapidly transformed to phenol by means of hydrogenolysis. Major factors that may influence the 4-CP conversion rate, including the Pd loading amount, FA dosage, and solution pH value, were investigated. A moderate Pd loading amount (1.0 wt %), an excess of FA dosage (FA/4-CP ratio of 51.4:1), and a relatively low pH (4.0) were found to be the optimal operational conditions under which 4-CP was degraded up to 96.2% within 2 h and the catalytic activity of Pd/Ni reduced negligibly after three recycles. The dechlorination pathway is postulated as follows: (1) HCOOH (or HCOO−) decomposed on Pd particles with atomic hydrogen ([H]) generated; (2) [H] served as the direct reducing agent in the hydrodechlorination of 4-CP adsorbed on both Pd particles and Ni substrate, through the radical mechanism. Pd/Ni is found to be a promising catalyst in the elimination of organochlorines. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005194
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4561–4565[article] Catalytic hydrodechlorination of 4 - chlorophenol in an aqueous solution with Pd/Ni catalyst and formic acid [texte imprimé] / Shu Wang, Auteur ; Bo Yang, Auteur ; Tingting Zhang, Auteur . - 2010 . - pp. 4561–4565.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4561–4565
Mots-clés : Aqueous solution Catalyst Formic acid Résumé : Palladized foam nickel (Pd/Ni) catalyst was prepared by replacement deposition and employed to hydrodechlorinate 4-chlorophenol (4-CP) with formic acid (FA). 4-CP was rapidly transformed to phenol by means of hydrogenolysis. Major factors that may influence the 4-CP conversion rate, including the Pd loading amount, FA dosage, and solution pH value, were investigated. A moderate Pd loading amount (1.0 wt %), an excess of FA dosage (FA/4-CP ratio of 51.4:1), and a relatively low pH (4.0) were found to be the optimal operational conditions under which 4-CP was degraded up to 96.2% within 2 h and the catalytic activity of Pd/Ni reduced negligibly after three recycles. The dechlorination pathway is postulated as follows: (1) HCOOH (or HCOO−) decomposed on Pd particles with atomic hydrogen ([H]) generated; (2) [H] served as the direct reducing agent in the hydrodechlorination of 4-CP adsorbed on both Pd particles and Ni substrate, through the radical mechanism. Pd/Ni is found to be a promising catalyst in the elimination of organochlorines. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005194 Exemplaires
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Titre : Control - based modeling and simulation of the chemical - looping combustion process Type de document : texte imprimé Auteurs : S. Balaji, Auteur ; Jovan Ilic, Auteur ; B. Erik Ydstie, Auteur Année de publication : 2010 Article en page(s) : pp. 4566–4575 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chemical looping combustion Résumé : In this study, we develop a model for the chemical-looping combustion system with a goal of determining the system behavior and the effect of important physical and operating parameters. We propose a model based on system invariants under thermodynamic equilibrium to obtain a computationally inexpensive model that can be utilized for advanced control studies. The system is represented by coupling the mole and energy balances of the system invariants along with the population balance of the particles and the shrinking-core mechanism. The model results are validated based on the experimental data from the literature. The simulated results show that the model is flexible enough to be used for different types of gaseous fuels and metal oxides. In the area of looping combustion, this work is the first in the proposal of a control-oriented model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901540m
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4566–4575[article] Control - based modeling and simulation of the chemical - looping combustion process [texte imprimé] / S. Balaji, Auteur ; Jovan Ilic, Auteur ; B. Erik Ydstie, Auteur . - 2010 . - pp. 4566–4575.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4566–4575
Mots-clés : Chemical looping combustion Résumé : In this study, we develop a model for the chemical-looping combustion system with a goal of determining the system behavior and the effect of important physical and operating parameters. We propose a model based on system invariants under thermodynamic equilibrium to obtain a computationally inexpensive model that can be utilized for advanced control studies. The system is represented by coupling the mole and energy balances of the system invariants along with the population balance of the particles and the shrinking-core mechanism. The model results are validated based on the experimental data from the literature. The simulated results show that the model is flexible enough to be used for different types of gaseous fuels and metal oxides. In the area of looping combustion, this work is the first in the proposal of a control-oriented model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901540m Exemplaires
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Titre : Multiple microcapillary reactor for organic synthesis Type de document : texte imprimé Auteurs : Christian H. Hornung, Auteur ; Bart Hallmark, Auteur ; Marcus Baumann, Auteur Année de publication : 2010 Article en page(s) : pp. 4576–4582 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microcapillary reactor Résumé : This paper presents process characteristics and proof of concept reactions for a newly developed microreactor system, termed the Cambridge Disc Microreactor (CDM), using plastic microcapillary flow discs (MFDs). These flat reactor discs were constructed from a flexible, temperature resilient, solvent resistant fluoropolymer microcapillary film (MCF) comprising 10 parallel capillary channels with mean hydraulic diameters typically between 150 and 400 μm. The MFDs were heated inside the microreactor via conductive heat transfer from two heated surfaces, which were in contact with the flat outer surfaces of the disc. This allowed continuous flow processing of liquid phase reactions through the reactor at elevated temperatures and pressures at a precisely controlled residence time. The process characteristics of the reactor system were established experimentally by investigating the hydraulic response and the temperature profile or modeled analytically such that the residence time characteristics inside the device could be predicted. A series of organic chemical reactions, namely electrophilic fluorination and the formation of various mono- and bicyclic heteroaromatic compounds, were conducted in the system at temperatures between 110 and 120 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901674h
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4576–4582[article] Multiple microcapillary reactor for organic synthesis [texte imprimé] / Christian H. Hornung, Auteur ; Bart Hallmark, Auteur ; Marcus Baumann, Auteur . - 2010 . - pp. 4576–4582.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4576–4582
Mots-clés : Microcapillary reactor Résumé : This paper presents process characteristics and proof of concept reactions for a newly developed microreactor system, termed the Cambridge Disc Microreactor (CDM), using plastic microcapillary flow discs (MFDs). These flat reactor discs were constructed from a flexible, temperature resilient, solvent resistant fluoropolymer microcapillary film (MCF) comprising 10 parallel capillary channels with mean hydraulic diameters typically between 150 and 400 μm. The MFDs were heated inside the microreactor via conductive heat transfer from two heated surfaces, which were in contact with the flat outer surfaces of the disc. This allowed continuous flow processing of liquid phase reactions through the reactor at elevated temperatures and pressures at a precisely controlled residence time. The process characteristics of the reactor system were established experimentally by investigating the hydraulic response and the temperature profile or modeled analytically such that the residence time characteristics inside the device could be predicted. A series of organic chemical reactions, namely electrophilic fluorination and the formation of various mono- and bicyclic heteroaromatic compounds, were conducted in the system at temperatures between 110 and 120 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901674h Exemplaires
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Titre : Topological criteria to safely optimize hazardous chemical processes involving consecutive reactions Type de document : texte imprimé Auteurs : Sabrina Copelli, Auteur ; Marco Derudi, Auteur ; Renato Rota, Auteur Année de publication : 2010 Article en page(s) : pp. 4583–4593 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chemical Processes Résumé : Safe operating conditions, for strongly exothermic chemical systems involving multiple reactions, are particularly critical to be obtained, because of the complex interactions between selectivity and safety constraints. In this work, new criteria, which are useful for isoperibolic semibatch processes involving consecutive reactions and based on the topology of a particular phase space, are presented. Such criteria are able to detect both the runaway boundary and the so-called “quick onset, fair conversion, smooth temperature profile” (QFS) operating region by performing a topological analysis of the phase space of the system of ordinary differential equations (ODEs) that describe the analyzed process. Moreover, a safe optimization procedure, the objective of which is to obtain the optimum values both of the dosing time of the dosed reactant and the initial reactor temperature, based on such criteria, has been developed. Finally, such a set of optimum operating parameters has been validated through a comparison with experimental data from published literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901679q
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4583–4593[article] Topological criteria to safely optimize hazardous chemical processes involving consecutive reactions [texte imprimé] / Sabrina Copelli, Auteur ; Marco Derudi, Auteur ; Renato Rota, Auteur . - 2010 . - pp. 4583–4593.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4583–4593
Mots-clés : Chemical Processes Résumé : Safe operating conditions, for strongly exothermic chemical systems involving multiple reactions, are particularly critical to be obtained, because of the complex interactions between selectivity and safety constraints. In this work, new criteria, which are useful for isoperibolic semibatch processes involving consecutive reactions and based on the topology of a particular phase space, are presented. Such criteria are able to detect both the runaway boundary and the so-called “quick onset, fair conversion, smooth temperature profile” (QFS) operating region by performing a topological analysis of the phase space of the system of ordinary differential equations (ODEs) that describe the analyzed process. Moreover, a safe optimization procedure, the objective of which is to obtain the optimum values both of the dosing time of the dosed reactant and the initial reactor temperature, based on such criteria, has been developed. Finally, such a set of optimum operating parameters has been validated through a comparison with experimental data from published literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901679q Exemplaires
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Titre : Oxidative desulfurization I : peroxyformic acid oxidation of benzothiophene and dibenzothiophene Type de document : texte imprimé Auteurs : Paolo De Filippis, Auteur ; Marco Scarsella, Auteur ; Nicola Verdone, Auteur Année de publication : 2010 Article en page(s) : pp. 4594–4600 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Peroxyformic acid Oxidation Résumé : Oxidative desulfurization routes appear among the most promising methods for obtaining ultralow-sulfur diesel fuels requested worldwide by environmental legislation. In this work, the oxidation kinetic of benzo- and dibenzothiophene with the oxidizing system constituted by hydrogen peroxide and formic acid was studied in isothermal conditions at 40 °C. Since the oxidation occurs in a heterophasic system, both physical and chemical phenomena play an important rule. The aim of this work was to interpret the obtained experimental conversions with a model able to capture the influence of both mass transfer and chemical kinetics. The results allowed verification that the oxidation reaction occurs in the slow liquid−liquid reaction regime and chemical kinetics is the controlling step. The identified values of the intrinsic kinetic constants for the oxidation of benzo- and dibenzothiophene are 2.255 × 10−1 and 1.206 × 100 m3 kmol−1 s−1, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9017622
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4594–4600[article] Oxidative desulfurization I : peroxyformic acid oxidation of benzothiophene and dibenzothiophene [texte imprimé] / Paolo De Filippis, Auteur ; Marco Scarsella, Auteur ; Nicola Verdone, Auteur . - 2010 . - pp. 4594–4600.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4594–4600
Mots-clés : Peroxyformic acid Oxidation Résumé : Oxidative desulfurization routes appear among the most promising methods for obtaining ultralow-sulfur diesel fuels requested worldwide by environmental legislation. In this work, the oxidation kinetic of benzo- and dibenzothiophene with the oxidizing system constituted by hydrogen peroxide and formic acid was studied in isothermal conditions at 40 °C. Since the oxidation occurs in a heterophasic system, both physical and chemical phenomena play an important rule. The aim of this work was to interpret the obtained experimental conversions with a model able to capture the influence of both mass transfer and chemical kinetics. The results allowed verification that the oxidation reaction occurs in the slow liquid−liquid reaction regime and chemical kinetics is the controlling step. The identified values of the intrinsic kinetic constants for the oxidation of benzo- and dibenzothiophene are 2.255 × 10−1 and 1.206 × 100 m3 kmol−1 s−1, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9017622 Exemplaires
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Titre : Vegetable oil deacidification by amberlyst : study of the catalyst lifetime and a suitable reactor configuration Type de document : texte imprimé Auteurs : C. Pirola, Auteur ; C. L. Bianchi, Auteur ; D. C. Boffito, Auteur Année de publication : 2010 Article en page(s) : pp. 4601–4606 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Résumé : Deacidification of crude vegetable oils containing high amounts of free fatty acids is the first step toward low-cost biodiesel production. In order to lower the acid content, the most popular method is based on an esterification process carried out with methanol and using Amberlysts as solid acid heterogeneous catalysts. This process was deeply investigated in recent years with good results. At the moment, the lifetime of the catalyst is the most crucial issue in industrial applications. With the aim of investigating this aspect, 90 consecutive batch deacidification runs, each lasting 6 h, were conducted using crude palm oil or soybean oil as a feedstock and Amberlyst 46 as a catalyst. At the end of the recycles, a decrease of activity of about 25% was observed, probably ascribed to some fragmentation of the catalyst’s particles, with a loss of active material, caused by the mechanical stress occurring in the batch reactor. The same reaction was also conducted in both continuous and semicontinuous catalytic packed-bed reactors, in order to immobilize the catalyst so as to prevent mechanical stress. A catalytic packed-bed reactor needs to be fed with a homogeneous methanol/vegetable oil emulsion: the results obtained with a traditional mechanical stirring and with an emulsificator were compared. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901980c
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4601–4606[article] Vegetable oil deacidification by amberlyst : study of the catalyst lifetime and a suitable reactor configuration [texte imprimé] / C. Pirola, Auteur ; C. L. Bianchi, Auteur ; D. C. Boffito, Auteur . - 2010 . - pp. 4601–4606.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4601–4606
Mots-clés : Catalyst Résumé : Deacidification of crude vegetable oils containing high amounts of free fatty acids is the first step toward low-cost biodiesel production. In order to lower the acid content, the most popular method is based on an esterification process carried out with methanol and using Amberlysts as solid acid heterogeneous catalysts. This process was deeply investigated in recent years with good results. At the moment, the lifetime of the catalyst is the most crucial issue in industrial applications. With the aim of investigating this aspect, 90 consecutive batch deacidification runs, each lasting 6 h, were conducted using crude palm oil or soybean oil as a feedstock and Amberlyst 46 as a catalyst. At the end of the recycles, a decrease of activity of about 25% was observed, probably ascribed to some fragmentation of the catalyst’s particles, with a loss of active material, caused by the mechanical stress occurring in the batch reactor. The same reaction was also conducted in both continuous and semicontinuous catalytic packed-bed reactors, in order to immobilize the catalyst so as to prevent mechanical stress. A catalytic packed-bed reactor needs to be fed with a homogeneous methanol/vegetable oil emulsion: the results obtained with a traditional mechanical stirring and with an emulsificator were compared. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901980c Exemplaires
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Titre : Hydroxylation of phenol by hydrogen peroxide catalyzed by copper(II) and Iron(III) complexes : the structure of the ligand and the selectivity of ortho - hydroxylation Type de document : texte imprimé Auteurs : Edward A. Karakhanov, Auteur ; Anton L. Maximov, Auteur ; Yulia S. Kardasheva, Auteur Année de publication : 2010 Article en page(s) : pp. 4607–4613 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydroxylation Hydrogen Résumé : A number of complexes of copper(II) and iron(III) with different N,N and N,O ligands were tested as catalysts for the hydroxylation of phenol to dihydroxybenzene by hydrogen peroxide for the purpose of achieving a high catechol selectivity. Cu(II) complexes were demonstrated to give a high selectivity on catechol. The best selectivity was found for Cu(II) complex with 2,6-dihydroxypiridine. The best conditions for the selective formation of catechol were the reaction time of 15 min and a ratio of 2,6-dihydroxypiridine to copper greater than 3 (65 °C). The concentration of phenol and the reaction time had a dramatic influence on the catechol yield and selectivity for most selective catalysts. At high concentrations and reaction times, both the catechol yield and selectivity decreased, with tars being formed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902040m
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4607–4613[article] Hydroxylation of phenol by hydrogen peroxide catalyzed by copper(II) and Iron(III) complexes : the structure of the ligand and the selectivity of ortho - hydroxylation [texte imprimé] / Edward A. Karakhanov, Auteur ; Anton L. Maximov, Auteur ; Yulia S. Kardasheva, Auteur . - 2010 . - pp. 4607–4613.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4607–4613
Mots-clés : Hydroxylation Hydrogen Résumé : A number of complexes of copper(II) and iron(III) with different N,N and N,O ligands were tested as catalysts for the hydroxylation of phenol to dihydroxybenzene by hydrogen peroxide for the purpose of achieving a high catechol selectivity. Cu(II) complexes were demonstrated to give a high selectivity on catechol. The best selectivity was found for Cu(II) complex with 2,6-dihydroxypiridine. The best conditions for the selective formation of catechol were the reaction time of 15 min and a ratio of 2,6-dihydroxypiridine to copper greater than 3 (65 °C). The concentration of phenol and the reaction time had a dramatic influence on the catechol yield and selectivity for most selective catalysts. At high concentrations and reaction times, both the catechol yield and selectivity decreased, with tars being formed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902040m Exemplaires
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Titre : Study of propane dehydrogenation to propylene in an integrated fluidized bed reactor using Pt - Sn /Al - SAPO - 34 novel catalyst Type de document : texte imprimé Auteurs : Zeeshan Nawaz, Auteur ; Yue Chu, Auteur ; Wei, Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 4614–4619 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Résumé : Direct propane dehydrogenation is the most economical route to propylene, but very complex due to endothermic reaction requirements, equilibrium limitations, stereochemistry, and engineering constraints. The state of the art idea of bimodal particle (gas−solid−solid) fluidization was applied, in order to overcome alkane dehydrogenation reaction barriers in a fluidized bed technology. In this study, the propane dehydrogenation reaction was studied in an integrated fluidized bed reactor, using Pt-Sn/Al-SAPO-34 novel catalyst at 590 °C. The results of fixed bed microreactor and integrated bimodal particle fluidized bed reactors were compared and parametrically characterized. The results showed that the propylene selectivity is over 95%, with conversion between 31 and 24%. This significant enhancement is by using novel bimodal particle fluidization system, owing to uniform heat transfer throughout the reactor and transfer coke from principal catalyst to secondary catalyst, which increases principal catalyst’s stability. Experimental investigation reveals that the novel Pt-Sn/Al-SAPO-34 catalyst and proposed intensified design of fluidized bed reactor is a promising opportunity for direct propane dehydrogenation to propylene, with both economic and operational benefit. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902043w
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4614–4619[article] Study of propane dehydrogenation to propylene in an integrated fluidized bed reactor using Pt - Sn /Al - SAPO - 34 novel catalyst [texte imprimé] / Zeeshan Nawaz, Auteur ; Yue Chu, Auteur ; Wei, Yang, Auteur . - 2010 . - pp. 4614–4619.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4614–4619
Mots-clés : Catalyst Résumé : Direct propane dehydrogenation is the most economical route to propylene, but very complex due to endothermic reaction requirements, equilibrium limitations, stereochemistry, and engineering constraints. The state of the art idea of bimodal particle (gas−solid−solid) fluidization was applied, in order to overcome alkane dehydrogenation reaction barriers in a fluidized bed technology. In this study, the propane dehydrogenation reaction was studied in an integrated fluidized bed reactor, using Pt-Sn/Al-SAPO-34 novel catalyst at 590 °C. The results of fixed bed microreactor and integrated bimodal particle fluidized bed reactors were compared and parametrically characterized. The results showed that the propylene selectivity is over 95%, with conversion between 31 and 24%. This significant enhancement is by using novel bimodal particle fluidization system, owing to uniform heat transfer throughout the reactor and transfer coke from principal catalyst to secondary catalyst, which increases principal catalyst’s stability. Experimental investigation reveals that the novel Pt-Sn/Al-SAPO-34 catalyst and proposed intensified design of fluidized bed reactor is a promising opportunity for direct propane dehydrogenation to propylene, with both economic and operational benefit. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902043w Exemplaires
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Titre : Application of artificial neural networks for estimation of the reaction rate in methanol dehydration Type de document : texte imprimé Auteurs : Peyvand Valeh-e-Sheyda, Auteur ; Farhooman, Fereydoon, Auteur ; Gholamreza Moradi, Auteur Année de publication : 2010 Article en page(s) : pp. 4620–4626 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Artificial neural networks Methanol Résumé : In this paper, the artificial neural network has been applied to estimate the reaction rate of methanol dehydration in dimethyl ether synthesis. The multilayer feed forward neural network with three inputs and one output has been trained with different algorithms and different numbers of neurons in the hidden layer. Two thirds of all training data are used for training of the network and the rest are used for testing of the generalization of the network. The accuracy of the proposed model was found to agree well with the experimental results over a wide range of experimental conditions. The results clearly depict that the neural network is a powerful tool to estimate the reaction rate and the designed neural network can be used instead of approximate and complex analytical equations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020705
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4620–4626[article] Application of artificial neural networks for estimation of the reaction rate in methanol dehydration [texte imprimé] / Peyvand Valeh-e-Sheyda, Auteur ; Farhooman, Fereydoon, Auteur ; Gholamreza Moradi, Auteur . - 2010 . - pp. 4620–4626.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4620–4626
Mots-clés : Artificial neural networks Methanol Résumé : In this paper, the artificial neural network has been applied to estimate the reaction rate of methanol dehydration in dimethyl ether synthesis. The multilayer feed forward neural network with three inputs and one output has been trained with different algorithms and different numbers of neurons in the hidden layer. Two thirds of all training data are used for training of the network and the rest are used for testing of the generalization of the network. The accuracy of the proposed model was found to agree well with the experimental results over a wide range of experimental conditions. The results clearly depict that the neural network is a powerful tool to estimate the reaction rate and the designed neural network can be used instead of approximate and complex analytical equations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020705 Exemplaires
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Titre : Analysis of gaseous and liquid products from pressurized pyrolysis of flax straw in a fixed bed reactor Type de document : texte imprimé Auteurs : Mohammad Shahed Hasan Khan Tushar, Auteur ; Nader Mahinpey, Auteur ; Pulikesi Murugan, Auteur Année de publication : 2010 Article en page(s) : pp. 4627–4632 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas Liquid Résumé : Pyrolysis of flax straw was investigated under a nitrogen atmosphere using a tubular reactor at different pressures, ranging from 10 to 40 psi. The effects of pressure on the pyrolysis yields and the products obtained (gas, liquid, char) have been analyzed. The gaseous products were analyzed by online GC, and the bio-oils were characterized by gas chromatography/mass spectrometry (GC/MS). Scanning electron microscopy (SEM) was used to view the char surfaces in order to characterize the char and validate the presence of porosity. As the pyrolysis pressure increased, the yield of char and liquid decreased while the gas products increased. The gas products were mainly CO, H2, CO2, CH4, and C3’s. The bio-oils were mostly composed of phenolic compounds, carboxylic acids, and furfural. The pH and the density of the bio-oil revealed a moderate increase with increasing pressure. The SEM study confirms the porous nature of the char. Overall, bio-oil production was maximized at 10 psi; however, char and hydrogen production was maximized at 20 psi. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902036v
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4627–4632[article] Analysis of gaseous and liquid products from pressurized pyrolysis of flax straw in a fixed bed reactor [texte imprimé] / Mohammad Shahed Hasan Khan Tushar, Auteur ; Nader Mahinpey, Auteur ; Pulikesi Murugan, Auteur . - 2010 . - pp. 4627–4632.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4627–4632
Mots-clés : Gas Liquid Résumé : Pyrolysis of flax straw was investigated under a nitrogen atmosphere using a tubular reactor at different pressures, ranging from 10 to 40 psi. The effects of pressure on the pyrolysis yields and the products obtained (gas, liquid, char) have been analyzed. The gaseous products were analyzed by online GC, and the bio-oils were characterized by gas chromatography/mass spectrometry (GC/MS). Scanning electron microscopy (SEM) was used to view the char surfaces in order to characterize the char and validate the presence of porosity. As the pyrolysis pressure increased, the yield of char and liquid decreased while the gas products increased. The gas products were mainly CO, H2, CO2, CH4, and C3’s. The bio-oils were mostly composed of phenolic compounds, carboxylic acids, and furfural. The pH and the density of the bio-oil revealed a moderate increase with increasing pressure. The SEM study confirms the porous nature of the char. Overall, bio-oil production was maximized at 10 psi; however, char and hydrogen production was maximized at 20 psi. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902036v Exemplaires
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Titre : Novel recuperative configuration for coupling of methanol dehydration to dimethyl ether with cyclohexane dehydrogenation to benzene Type de document : texte imprimé Auteurs : Mohammad Farsi, Auteur ; Mohammad H. Khademi, Auteur ; Abdolhosein Jahanmiri, Auteur Année de publication : 2010 Article en page(s) : pp. 4633–4643 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Methanol Résumé : Coupling energy intensive endothermic reaction systems with suitable exothermic reactions improves the thermal efficiency of processes and reduces the size of reactors. One type of reactor suitable for such a type of coupling is the recuperative reactor. In this work, the catalytic methanol dehydration to dimethyl ether (DME) is coupled with the catalytic dehydrogenation of cyclohexane to benzene in a simulated integrated reactor formed of two fixed beds separated by a wall, where heat is transferred across the surface of tube. A steady state heterogeneous model of the two fixed beds predicts the performance of this novel configuration. The cocurrent mode is investigated, and the simulation results are compared with corresponding predictions for an industrial adiabatic methanol dehydration fixed-bed reactor operated at the same feed conditions. In this coupled reactor, benzene and hydrogen are also produced as additional valuable products in a favorable manner and autothermality is achieved within the reactor. This novel configuration can decrease the temperature of methanol dehydration reaction in the second half of the reactor and shift the thermodynamic equilibrium. Therefore, the methanol conversion and DME mole fraction increase by 1.82% and 1.6%, respectively. The influence of inlet temperature and the molar flow rate of exothermic and endothermic stream on reactor behavior is investigated. The results suggest that coupling of these reactions could be feasible and beneficial. An experimental proof-of-concept is needed to establish the validity and safe operation of the novel reactor. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000086
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4633–4643[article] Novel recuperative configuration for coupling of methanol dehydration to dimethyl ether with cyclohexane dehydrogenation to benzene [texte imprimé] / Mohammad Farsi, Auteur ; Mohammad H. Khademi, Auteur ; Abdolhosein Jahanmiri, Auteur . - 2010 . - pp. 4633–4643.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4633–4643
Mots-clés : Methanol Résumé : Coupling energy intensive endothermic reaction systems with suitable exothermic reactions improves the thermal efficiency of processes and reduces the size of reactors. One type of reactor suitable for such a type of coupling is the recuperative reactor. In this work, the catalytic methanol dehydration to dimethyl ether (DME) is coupled with the catalytic dehydrogenation of cyclohexane to benzene in a simulated integrated reactor formed of two fixed beds separated by a wall, where heat is transferred across the surface of tube. A steady state heterogeneous model of the two fixed beds predicts the performance of this novel configuration. The cocurrent mode is investigated, and the simulation results are compared with corresponding predictions for an industrial adiabatic methanol dehydration fixed-bed reactor operated at the same feed conditions. In this coupled reactor, benzene and hydrogen are also produced as additional valuable products in a favorable manner and autothermality is achieved within the reactor. This novel configuration can decrease the temperature of methanol dehydration reaction in the second half of the reactor and shift the thermodynamic equilibrium. Therefore, the methanol conversion and DME mole fraction increase by 1.82% and 1.6%, respectively. The influence of inlet temperature and the molar flow rate of exothermic and endothermic stream on reactor behavior is investigated. The results suggest that coupling of these reactions could be feasible and beneficial. An experimental proof-of-concept is needed to establish the validity and safe operation of the novel reactor. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000086 Exemplaires
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Titre : Adsorption and photocatalytic degradation kinetics of gaseous cyclohexane in an annular fluidized bed photocatalytic reactor Type de document : texte imprimé Auteurs : Qijin Geng, Auteur ; Qingjie Guo, Auteur ; Xuehai Yue, Auteur Année de publication : 2010 Article en page(s) : pp. 4644–4652 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics Photocatalytic Résumé : The adsorption and photocatalytic degradation kinetics of gaseous cyclohexane using nano-titania agglomerates were investigated in an annular fluidized bed photocatalytic reactor (AFBPR). A series of adsorption and photocatalytic degradation kinetic equations were developed to explore the relationship of adsorption/degradation efficiency and operating variables based on Langmuir adsorption law and photocatalytic elementary reactions. The adsorption equilibrium constant, adsorption active sites, and apparent reaction rate coefficient of cyclohexane were determined by linear regression analysis with variation of gas velocity and relative humidity (RH). It has been demonstrated that the initial concentration, RH, and gas velocity have obviously influenced the adsorption/photocatalytic degradation efficiency and corresponding kinetic parameters. In the adsorption process, the variation of adsorption sites and adsorption efficiency with gas velocity indicated that the adsorption controlling step was related to gas velocity. In the photocatalytic degradation process, the relationship of photocatalytic degradation efficiency and RH indicates that the water molecule played a promotion role in photocatalytic degradation of cyclohexane below a humidity inflection point, while it played an inhibition role in photocatalytic degradation of cyclohexane after this point. In addition, the optimal operating conditions were determined according to the maximum degradation efficiency with respect to RH at 20% and the fluidization number at 1.62. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100114e
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4644–4652[article] Adsorption and photocatalytic degradation kinetics of gaseous cyclohexane in an annular fluidized bed photocatalytic reactor [texte imprimé] / Qijin Geng, Auteur ; Qingjie Guo, Auteur ; Xuehai Yue, Auteur . - 2010 . - pp. 4644–4652.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4644–4652
Mots-clés : Kinetics Photocatalytic Résumé : The adsorption and photocatalytic degradation kinetics of gaseous cyclohexane using nano-titania agglomerates were investigated in an annular fluidized bed photocatalytic reactor (AFBPR). A series of adsorption and photocatalytic degradation kinetic equations were developed to explore the relationship of adsorption/degradation efficiency and operating variables based on Langmuir adsorption law and photocatalytic elementary reactions. The adsorption equilibrium constant, adsorption active sites, and apparent reaction rate coefficient of cyclohexane were determined by linear regression analysis with variation of gas velocity and relative humidity (RH). It has been demonstrated that the initial concentration, RH, and gas velocity have obviously influenced the adsorption/photocatalytic degradation efficiency and corresponding kinetic parameters. In the adsorption process, the variation of adsorption sites and adsorption efficiency with gas velocity indicated that the adsorption controlling step was related to gas velocity. In the photocatalytic degradation process, the relationship of photocatalytic degradation efficiency and RH indicates that the water molecule played a promotion role in photocatalytic degradation of cyclohexane below a humidity inflection point, while it played an inhibition role in photocatalytic degradation of cyclohexane after this point. In addition, the optimal operating conditions were determined according to the maximum degradation efficiency with respect to RH at 20% and the fluidization number at 1.62. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100114e Exemplaires
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Titre : Experimental assessment on the enzymatic hydrolysis of hydrothermally pretreated eucalyptus globulus wood Type de document : texte imprimé Auteurs : Aloia Romaní, Auteur ; Gil Garrote, Auteur ; Jose Luis Alonso, Auteur Année de publication : 2010 Article en page(s) : pp. 4653–4663 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Enzymatic hydrolysis. Résumé : Hydrothermal processing of Eucalyptus globulus wood was evaluated as a pretreatment for bioethanol manufacture, to assess the effects caused by the severity of wood solubilization, composition of liquors, and spent solid and suceptibility of substrates toward enzymatic hydrolysis. A factorial design was employed to assess the hydrolysis kinetics of spent solids. The liquor to solid ratio (6−20 g/g) and the enzyme to substrate ratio (8−28 FPU/g) were considered as independent variables. Generalized empirical models suitable for predicting glucose concentrations were developed. Using selected substrates and hydrolysis conditions (LSR = 6 g/g, ESR = 28 FPU/g), media containing more than 82 g glucose/L were obtained (with cellulose-to-glucose conversions of 75−80%), whereas cellulose-to-glucose conversions of 80−100% were obtained under a variety of experimental conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100154m
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4653–4663[article] Experimental assessment on the enzymatic hydrolysis of hydrothermally pretreated eucalyptus globulus wood [texte imprimé] / Aloia Romaní, Auteur ; Gil Garrote, Auteur ; Jose Luis Alonso, Auteur . - 2010 . - pp. 4653–4663.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4653–4663
Mots-clés : Enzymatic hydrolysis. Résumé : Hydrothermal processing of Eucalyptus globulus wood was evaluated as a pretreatment for bioethanol manufacture, to assess the effects caused by the severity of wood solubilization, composition of liquors, and spent solid and suceptibility of substrates toward enzymatic hydrolysis. A factorial design was employed to assess the hydrolysis kinetics of spent solids. The liquor to solid ratio (6−20 g/g) and the enzyme to substrate ratio (8−28 FPU/g) were considered as independent variables. Generalized empirical models suitable for predicting glucose concentrations were developed. Using selected substrates and hydrolysis conditions (LSR = 6 g/g, ESR = 28 FPU/g), media containing more than 82 g glucose/L were obtained (with cellulose-to-glucose conversions of 75−80%), whereas cellulose-to-glucose conversions of 80−100% were obtained under a variety of experimental conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100154m Exemplaires
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Titre : Hydrogenation of nitrobenzene to aniline over silica gel supported nickel catalysts Type de document : texte imprimé Auteurs : Junhua Wang, Auteur ; Zhenle Yuan, Auteur ; Renfeng Nie, Auteur Année de publication : 2010 Article en page(s) : pp. 4664–4669 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Silica gel Catalysts Résumé : Nanosized silica gel supported Ni catalysts that have average Ni particle size of 3.7, 11.4, and 11.8 nm were prepared by facile impregnation of different Ni precursors and used for hydrogenation of nitrobenzene (NB). These catalysts were characterized by N2 adsorption, X-ray diffraction, and transmission electron microscopy. It was found that Ni dispersed highly on the surface of silica gel in the catalyst prepared via Ni(en)3(NO3)2, and the detected average Ni particle size was 3.7 nm. On the 3.7 nm sized Ni catalyst, the selectivity of aniline (AN) reached 99% with a 100% conversion of NB in 5.5 h at 90 °C, 1.0 MPa, and NB:Ni = 305 (mole ratio). But, the activities of 11.8 nm sized Ni catalysts and commercial Raney Ni catalyst are quite lower. The reaction network and mechanism of NB hydrogenation on 3.7 nm sized Ni catalyst were discussed on the basis of products distributions at different temperatures and pressures. The calculated activation energy of NB hydrogenation on Ni-5/SiO2-EN catalyst is 54.5 kJ/mol in 70−90 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1002069
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4664–4669[article] Hydrogenation of nitrobenzene to aniline over silica gel supported nickel catalysts [texte imprimé] / Junhua Wang, Auteur ; Zhenle Yuan, Auteur ; Renfeng Nie, Auteur . - 2010 . - pp. 4664–4669.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4664–4669
Mots-clés : Silica gel Catalysts Résumé : Nanosized silica gel supported Ni catalysts that have average Ni particle size of 3.7, 11.4, and 11.8 nm were prepared by facile impregnation of different Ni precursors and used for hydrogenation of nitrobenzene (NB). These catalysts were characterized by N2 adsorption, X-ray diffraction, and transmission electron microscopy. It was found that Ni dispersed highly on the surface of silica gel in the catalyst prepared via Ni(en)3(NO3)2, and the detected average Ni particle size was 3.7 nm. On the 3.7 nm sized Ni catalyst, the selectivity of aniline (AN) reached 99% with a 100% conversion of NB in 5.5 h at 90 °C, 1.0 MPa, and NB:Ni = 305 (mole ratio). But, the activities of 11.8 nm sized Ni catalysts and commercial Raney Ni catalyst are quite lower. The reaction network and mechanism of NB hydrogenation on 3.7 nm sized Ni catalyst were discussed on the basis of products distributions at different temperatures and pressures. The calculated activation energy of NB hydrogenation on Ni-5/SiO2-EN catalyst is 54.5 kJ/mol in 70−90 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1002069 Exemplaires
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Titre : A Detailed study on the negative effect of residual sodium on the performance of Ni/ZnO adsorbent for diesel fuel desulfurization Type de document : texte imprimé Auteurs : Lichun Huang, Auteur ; Zhangfeng Qin, Auteur ; Guofu Wang, Auteur Année de publication : 2010 Article en page(s) : pp. 4670-4675 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Desulfurization Diesel fuel Résumé : Desulfurization of diesel fuel was conducted via reactive adsorption over a coprecipitated Ni/ZnO adsorbent. A negative effect of the residual sodium in Ni/ZnO adsorbent on its adsorption performance was observed. The desulfurization ability of Ni/ZnO adsorbent is markedly weakened with the increase in the residual sodium content. This negative effect can be attributed to the fact that the residual sodium decreases the adsorbent surface area and pore volume, suppresses the interaction between Ni and ZnO, and leads to an increase in the crystallite size of the active species. Moreover, the residual sodium is enriched on the adsorbent surface upon calcination and reduction treatment, which may promote the formation of the catalytically inactive Ni-Zn and NaZn(OH)3 species. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797458
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4670-4675[article] A Detailed study on the negative effect of residual sodium on the performance of Ni/ZnO adsorbent for diesel fuel desulfurization [texte imprimé] / Lichun Huang, Auteur ; Zhangfeng Qin, Auteur ; Guofu Wang, Auteur . - 2010 . - pp. 4670-4675.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4670-4675
Mots-clés : Desulfurization Diesel fuel Résumé : Desulfurization of diesel fuel was conducted via reactive adsorption over a coprecipitated Ni/ZnO adsorbent. A negative effect of the residual sodium in Ni/ZnO adsorbent on its adsorption performance was observed. The desulfurization ability of Ni/ZnO adsorbent is markedly weakened with the increase in the residual sodium content. This negative effect can be attributed to the fact that the residual sodium decreases the adsorbent surface area and pore volume, suppresses the interaction between Ni and ZnO, and leads to an increase in the crystallite size of the active species. Moreover, the residual sodium is enriched on the adsorbent surface upon calcination and reduction treatment, which may promote the formation of the catalytically inactive Ni-Zn and NaZn(OH)3 species. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797458 Exemplaires
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Titre : Improved prediction of offset ink setting rates based on experimental data and filtration equations Type de document : texte imprimé Auteurs : Hanna Koivula, Auteur ; Douglas Bousfield, Auteur ; Martti Toivakka, Auteur Année de publication : 2010 Article en page(s) : pp. 4676–4681 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Filtration Equations Résumé : The setting rates of inks on paper influence the printing operation and the quality of the final product. Although much work has been reported on the effect of the coating structure on setting rates, much less work has been done understanding the ink parameters, especially the influence of emulsification. A series of four papers were tested with three inks. The inks were characterized in terms of printing properties, rheology, and their filtration behavior. The filtration rate is used to obtain a permeability value of the ink filtercake. The value of the maximum tack was determined to be more dependent on the smoothness of the paper tested than on the type of ink. The dynamics and magnitude of the tack test were dependent on the ink viscosity, but viscosity alone does not explain the results. The measured ink filtercake permeabilities are different between the ink types by a factor of 2. The setting rate is found to be primarily a function of the viscosity of the oil used in the ink, rather than a function of the pigment and resin system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9014028
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4676–4681[article] Improved prediction of offset ink setting rates based on experimental data and filtration equations [texte imprimé] / Hanna Koivula, Auteur ; Douglas Bousfield, Auteur ; Martti Toivakka, Auteur . - 2010 . - pp. 4676–4681.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4676–4681
Mots-clés : Filtration Equations Résumé : The setting rates of inks on paper influence the printing operation and the quality of the final product. Although much work has been reported on the effect of the coating structure on setting rates, much less work has been done understanding the ink parameters, especially the influence of emulsification. A series of four papers were tested with three inks. The inks were characterized in terms of printing properties, rheology, and their filtration behavior. The filtration rate is used to obtain a permeability value of the ink filtercake. The value of the maximum tack was determined to be more dependent on the smoothness of the paper tested than on the type of ink. The dynamics and magnitude of the tack test were dependent on the ink viscosity, but viscosity alone does not explain the results. The measured ink filtercake permeabilities are different between the ink types by a factor of 2. The setting rate is found to be primarily a function of the viscosity of the oil used in the ink, rather than a function of the pigment and resin system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9014028 Exemplaires
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Titre : Detecting and monitoring industrial scale formation using an intrinsic exposed - core optical fiber sensor Type de document : texte imprimé Auteurs : Martijn Boerkamp, Auteur ; David W. Lamb, Auteur ; Peter G. Lye, Auteur Année de publication : 2010 Article en page(s) : pp. 4682-4686 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fiber optic sensors Scale formation Surveillance Résumé : Measurements of heterogeneous crystallization (scaling) have been performed using an intrinsic exposed-core optical fiber sensor (IECOFS). The IECOFS showed several advantages over the conventional techniques of scale detection: turbidity and electrical conductivity, including insensitivity to the presence of suspended crystals caused by homogeneous crystallization and the ability to monitor scale deposition under continuous supply conditions. Calibration of the IECOFS, to quantify scale deposited on a given surface, and the limitations of the technique are also presented. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797460
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4682-4686[article] Detecting and monitoring industrial scale formation using an intrinsic exposed - core optical fiber sensor [texte imprimé] / Martijn Boerkamp, Auteur ; David W. Lamb, Auteur ; Peter G. Lye, Auteur . - 2010 . - pp. 4682-4686.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4682-4686
Mots-clés : Fiber optic sensors Scale formation Surveillance Résumé : Measurements of heterogeneous crystallization (scaling) have been performed using an intrinsic exposed-core optical fiber sensor (IECOFS). The IECOFS showed several advantages over the conventional techniques of scale detection: turbidity and electrical conductivity, including insensitivity to the presence of suspended crystals caused by homogeneous crystallization and the ability to monitor scale deposition under continuous supply conditions. Calibration of the IECOFS, to quantify scale deposited on a given surface, and the limitations of the technique are also presented. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797460 Exemplaires
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Titre : Sulfur - functionalization of porous silica particles and application to mercury vapor sorption Type de document : texte imprimé Auteurs : Noah D. Meeks, Auteur ; Stephen Rankin, Auteur ; Dibakar Bhattacharyya, Auteur Année de publication : 2010 Article en page(s) : pp. 4687–4693 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Porous Silica Particles Résumé : Silanol (SiOH) groups on silica particle surfaces undergo silylation reactions with organosilane molecules to give functionalized particles, which are used in many applications. The determination of the extent of this reaction is important for proper design of functionalized materials, depending upon the application. Two types of porous silica particles (206 and 484 m2 g−1; 9.6 and 2.9 nm average pore diameter, respectively), and colloidal silica (Ludox) with a nonporous base particle of 22 nm diameter, were functionalized with sulfur-containing silanes, 3-mercaptopropyl trimethoxy silane (MPTMS), and bis[3-(triethoxysilyl) propyl]-tetrasulfide (S4). Maximum extent of functionalization was determined with S4 using Fourier transform infrared spectrometry (FTIR), thermogravimetric analysis (TGA), and total S analysis. For the two types of porous silica particles, FTIR indicated that 54 and 17% of the silanol groups were functionalized with S4, and TGA indicated that the functionalized particles were 12 and 11 mass % MPTMS, respectively. These results were independently confirmed with total sulfur analysis. Extents of functionalization were determined for varying the silane structure on the same silica particle. MPTMS reacted with 38% of functional groups, while S4 reacted with 17%; the mass % of silane is the same regardless of silane structure on the same silica particle. Characterization by DSC indicated a glass transition occurs in the silane layer of the S4-functionalized silica at about 85 °C, but not in the MPTMS functionalized particles. Finally, mercury sorption breakthrough curves indicate the pore characteristics of the S4 functionalized samples. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901580k
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4687–4693[article] Sulfur - functionalization of porous silica particles and application to mercury vapor sorption [texte imprimé] / Noah D. Meeks, Auteur ; Stephen Rankin, Auteur ; Dibakar Bhattacharyya, Auteur . - 2010 . - pp. 4687–4693.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4687–4693
Mots-clés : Porous Silica Particles Résumé : Silanol (SiOH) groups on silica particle surfaces undergo silylation reactions with organosilane molecules to give functionalized particles, which are used in many applications. The determination of the extent of this reaction is important for proper design of functionalized materials, depending upon the application. Two types of porous silica particles (206 and 484 m2 g−1; 9.6 and 2.9 nm average pore diameter, respectively), and colloidal silica (Ludox) with a nonporous base particle of 22 nm diameter, were functionalized with sulfur-containing silanes, 3-mercaptopropyl trimethoxy silane (MPTMS), and bis[3-(triethoxysilyl) propyl]-tetrasulfide (S4). Maximum extent of functionalization was determined with S4 using Fourier transform infrared spectrometry (FTIR), thermogravimetric analysis (TGA), and total S analysis. For the two types of porous silica particles, FTIR indicated that 54 and 17% of the silanol groups were functionalized with S4, and TGA indicated that the functionalized particles were 12 and 11 mass % MPTMS, respectively. These results were independently confirmed with total sulfur analysis. Extents of functionalization were determined for varying the silane structure on the same silica particle. MPTMS reacted with 38% of functional groups, while S4 reacted with 17%; the mass % of silane is the same regardless of silane structure on the same silica particle. Characterization by DSC indicated a glass transition occurs in the silane layer of the S4-functionalized silica at about 85 °C, but not in the MPTMS functionalized particles. Finally, mercury sorption breakthrough curves indicate the pore characteristics of the S4 functionalized samples. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901580k Exemplaires
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Titre : Study on deactivation of zinc - based sorbents for hot gas desulfurization Type de document : texte imprimé Auteurs : No-Kuk Park, Auteur ; Tae Jin Lee, Auteur ; Si Ok Ryu, Auteur Année de publication : 2010 Article en page(s) : pp. 4694–4699 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas Desulfurization Résumé : The possible reasons that were associated with the reduction of zinc oxide and the deposition of elemental Zn on the zinc-based sorbent surfaces were proposed in this study and examined by monitoring chemical reactivity and physical/chemical properties of the sorbents during the multicyclic tests with the aid of various diagnostics in order to investigate the deactivation of the sorbents that was observed in previous works. The reactivity of the sorbents was investigated using a temperature programmed technique (TPT) with a thermal gravimetric analyzer (TGA). From our experiments, the undesirable features due to the reduction of ZnO that was caused by the reducing components in the gasified coal gas were observed in the chemical reactivity and sorbent properties. In the investigation of the migration of elemental Zn onto the sorbent surface, elemental Zn accumulated on the surface of the sorbents rather than the zinc vaporization. It might have caused the deactivation of the zinc-based sorbents. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9017463
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4694–4699[article] Study on deactivation of zinc - based sorbents for hot gas desulfurization [texte imprimé] / No-Kuk Park, Auteur ; Tae Jin Lee, Auteur ; Si Ok Ryu, Auteur . - 2010 . - pp. 4694–4699.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4694–4699
Mots-clés : Gas Desulfurization Résumé : The possible reasons that were associated with the reduction of zinc oxide and the deposition of elemental Zn on the zinc-based sorbent surfaces were proposed in this study and examined by monitoring chemical reactivity and physical/chemical properties of the sorbents during the multicyclic tests with the aid of various diagnostics in order to investigate the deactivation of the sorbents that was observed in previous works. The reactivity of the sorbents was investigated using a temperature programmed technique (TPT) with a thermal gravimetric analyzer (TGA). From our experiments, the undesirable features due to the reduction of ZnO that was caused by the reducing components in the gasified coal gas were observed in the chemical reactivity and sorbent properties. In the investigation of the migration of elemental Zn onto the sorbent surface, elemental Zn accumulated on the surface of the sorbents rather than the zinc vaporization. It might have caused the deactivation of the zinc-based sorbents. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9017463 Exemplaires
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Titre : Sorption of Cd(II), Pb(II), Cu(II), and Zn(II) complexes with nitrilotris(Methylenephosphonic) acid on polystyrene anion exchangers Type de document : texte imprimé Auteurs : Marcin Siek, Auteur ; Dorota Kolodynska, Auteur ; Zbigniew Hubicki, Auteur Année de publication : 2010 Article en page(s) : pp. 4700–4709 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Anion exchangers Résumé : The performance of the polystyrene anion exchangers Lewatit MonoPlus M 500, Lewatit MonoPlus M 600, Lewatit MonoPlus MP 500, Lewatit MonoPlus MP 64, and Lewatit MP 62 as well as Amberlyst A 21 was investigated for their further application in purification of wastewaters containing nitrilotris(methylenephosphonic acid) (NTMP) and heavy metal ions. The comparison involved evaluation of the sorption/desorption behavior of NTMP complexes of Cd(II), Pb(II), Cu(II), and Zn(II) on the resins with different basicity of functional groups. The batch method, in which a fixed amount of anion exchanger was contacted with the sample solution for increasing periods of time and the amount of metal ion remaining in the solution measured as a function of the elapsed time, was used to obtain information on the kinetics of species formed in the presence of added complexing agent. The effects of pH, metal(II) ion and ligand concentration, and their molar ratio on the sorption as well as type of functional groups of the anion exchangers used were determined. The sorption data were fitted to various models to obtain certain constants related to the sorption phenomena. The effect of the regeneration solution was also investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901748k
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4700–4709[article] Sorption of Cd(II), Pb(II), Cu(II), and Zn(II) complexes with nitrilotris(Methylenephosphonic) acid on polystyrene anion exchangers [texte imprimé] / Marcin Siek, Auteur ; Dorota Kolodynska, Auteur ; Zbigniew Hubicki, Auteur . - 2010 . - pp. 4700–4709.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4700–4709
Mots-clés : Anion exchangers Résumé : The performance of the polystyrene anion exchangers Lewatit MonoPlus M 500, Lewatit MonoPlus M 600, Lewatit MonoPlus MP 500, Lewatit MonoPlus MP 64, and Lewatit MP 62 as well as Amberlyst A 21 was investigated for their further application in purification of wastewaters containing nitrilotris(methylenephosphonic acid) (NTMP) and heavy metal ions. The comparison involved evaluation of the sorption/desorption behavior of NTMP complexes of Cd(II), Pb(II), Cu(II), and Zn(II) on the resins with different basicity of functional groups. The batch method, in which a fixed amount of anion exchanger was contacted with the sample solution for increasing periods of time and the amount of metal ion remaining in the solution measured as a function of the elapsed time, was used to obtain information on the kinetics of species formed in the presence of added complexing agent. The effects of pH, metal(II) ion and ligand concentration, and their molar ratio on the sorption as well as type of functional groups of the anion exchangers used were determined. The sorption data were fitted to various models to obtain certain constants related to the sorption phenomena. The effect of the regeneration solution was also investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901748k Exemplaires
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Titre : Comparative study of ultrasound stimulation and conventional heating methods on the preparation of nanosized γ - Al2O3 Type de document : texte imprimé Auteurs : Abhijit Majhi, Auteur ; G. Pugazhenthi, Auteur ; Anupam Shukla, Auteur Année de publication : 2010 Article en page(s) : pp. 4710–4719 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanosized Résumé : This work addresses the advantages of the ultrasound stimulation method over the conventional heating method for the preparation of nanosized γ-Al2O3. The γ-Al2O3 obtained by calcination of boehmite at 600 °C is derived from the inexpensive aluminum chloride salt by the precipitation route. Thermal evolution, phase transformation, surface area, and particle size distribution of the boehmite and γ-Al2O3 are characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared analysis (FT-IR), nitrogen adsorption−desorption isothermal data, and dynamic light scattering analysis (DLS). The γ-Al2O3 prepared by ultrasound stimulation has higher surface area (256 m2 g−1), bigger pore diameter (6.06 nm) and larger cumulative pore volume (0.388 cm3 g−1) than the conventional heating method (surface area, pore diameter, and pore volume of 219 m2 g−1, 5.61 nm, 0.307 cm3 g−1, respectively), which are even higher than the value reported in the literature for γ-Al2O3 synthesized at 100 °C for 24 h aging (pore diameter of 4.27 nm and pore volume of 0.26 cm3 g−1). The sonication applied during the aging of boehmite sol reduces the crystallite size (or particle size) and increases the porosity. The boehmite and γ-Al2O3 obtained by sonication have the highest porosity of 46% and 59%, respectively, without using any structure directing agent. The crystallite size calculated from XRD analysis using Scherrer’s equation is found to be 2.32 and 3.13 nm for boehmite and γ-Al2O3 obtained by ultrasound stimulation, respectively, which is due to the formation of microjets during sonication. The particle size analysis result reveals the formation of nanosized γ-Al2O3 particles by ultrasonication with a mean particle size of 51 nm. In conclusion, the boehmite and γ-Al2O3 prepared by ultrasound stimulation are better than the samples synthesized by the conventional method. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901857q
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4710–4719[article] Comparative study of ultrasound stimulation and conventional heating methods on the preparation of nanosized γ - Al2O3 [texte imprimé] / Abhijit Majhi, Auteur ; G. Pugazhenthi, Auteur ; Anupam Shukla, Auteur . - 2010 . - pp. 4710–4719.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4710–4719
Mots-clés : Nanosized Résumé : This work addresses the advantages of the ultrasound stimulation method over the conventional heating method for the preparation of nanosized γ-Al2O3. The γ-Al2O3 obtained by calcination of boehmite at 600 °C is derived from the inexpensive aluminum chloride salt by the precipitation route. Thermal evolution, phase transformation, surface area, and particle size distribution of the boehmite and γ-Al2O3 are characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared analysis (FT-IR), nitrogen adsorption−desorption isothermal data, and dynamic light scattering analysis (DLS). The γ-Al2O3 prepared by ultrasound stimulation has higher surface area (256 m2 g−1), bigger pore diameter (6.06 nm) and larger cumulative pore volume (0.388 cm3 g−1) than the conventional heating method (surface area, pore diameter, and pore volume of 219 m2 g−1, 5.61 nm, 0.307 cm3 g−1, respectively), which are even higher than the value reported in the literature for γ-Al2O3 synthesized at 100 °C for 24 h aging (pore diameter of 4.27 nm and pore volume of 0.26 cm3 g−1). The sonication applied during the aging of boehmite sol reduces the crystallite size (or particle size) and increases the porosity. The boehmite and γ-Al2O3 obtained by sonication have the highest porosity of 46% and 59%, respectively, without using any structure directing agent. The crystallite size calculated from XRD analysis using Scherrer’s equation is found to be 2.32 and 3.13 nm for boehmite and γ-Al2O3 obtained by ultrasound stimulation, respectively, which is due to the formation of microjets during sonication. The particle size analysis result reveals the formation of nanosized γ-Al2O3 particles by ultrasonication with a mean particle size of 51 nm. In conclusion, the boehmite and γ-Al2O3 prepared by ultrasound stimulation are better than the samples synthesized by the conventional method. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901857q Exemplaires
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Titre : Improving the resistance of sulfur dyes to oxidation Type de document : texte imprimé Auteurs : Wenlong Zhou, Auteur ; Yiqi Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 4720–4725 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Sulfur Oxidation Résumé : A method that substantially improves the oxidative bleaching resistance of sulfur dyed textiles is reported. Sulfur dyes are known for their poor bleaching resistance due to the sensitivity of the sulfur linkages to oxidation. This disadvantage severely prohibits the broad application of sulfur dyes because of the existence of the activated oxidative bleaching agents in many commercial detergents. In this study, 1% (w/w) of lanthanum triacetate was applied to sulfur dyed cotton fabrics via a simple padding procedure to chemically stabilize the sulfur linkages. The treatment could render sulfur dyed cotton fabrics a reduction in color changes of about 50% after laundering with detergent containing a bleaching agent, an improvement in strength retention of almost 100% after aging and an improvement in staining resistance of at least 0.5-class for about 1/3 of the sulfur dyes examined. These improvements were proved durable to repeated launderings. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901901r
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4720–4725[article] Improving the resistance of sulfur dyes to oxidation [texte imprimé] / Wenlong Zhou, Auteur ; Yiqi Yang, Auteur . - 2010 . - pp. 4720–4725.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4720–4725
Mots-clés : Sulfur Oxidation Résumé : A method that substantially improves the oxidative bleaching resistance of sulfur dyed textiles is reported. Sulfur dyes are known for their poor bleaching resistance due to the sensitivity of the sulfur linkages to oxidation. This disadvantage severely prohibits the broad application of sulfur dyes because of the existence of the activated oxidative bleaching agents in many commercial detergents. In this study, 1% (w/w) of lanthanum triacetate was applied to sulfur dyed cotton fabrics via a simple padding procedure to chemically stabilize the sulfur linkages. The treatment could render sulfur dyed cotton fabrics a reduction in color changes of about 50% after laundering with detergent containing a bleaching agent, an improvement in strength retention of almost 100% after aging and an improvement in staining resistance of at least 0.5-class for about 1/3 of the sulfur dyes examined. These improvements were proved durable to repeated launderings. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901901r Exemplaires
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Titre : Comparison of methods to obtain micropore size distributions of carbonaceous materials from CO2 adsorption based on the dubinin − radushkevich isotherm Type de document : texte imprimé Auteurs : Moisés L. Pinto, Auteur ; Ana S. Mestre, Auteur ; Ana P. Carvalho, Auteur Année de publication : 2010 Article en page(s) : pp. 4726-4730 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Carbon dioxide Particle size distribution Microporosity Résumé : Micropore size distributions of various carbonaceous materials were obtained using two methods based on the Dubinin-Radushkevich equation and the relationship between the characteristic parameter of this equation and the pore width. One method was the well-known Dubinin-Radushkevich-Stoeckli (DRS) equation, and the other method used the integral adsorption equation without assuming a mathematical distribution for dw0/dE0. These methods were applied to carbon dioxide adsorption data on four activated carbons and eight chars to obtain micropore size distributions. Significant differences were found between the results obtained by the two methods. The DRS method gives an average of the distribution obtained by the method using the integral adsorption equation, because the latter is not constrained to a particular preassumed shape. The results reveal that the differences are more significant for the analysis of adsorption data on chars than on activated carbons. This was attributed to the fact that a less-homogeneous pore structure is expected to exist on chars than on activated carbons that cannot be described by the DRS method and can be described by the method based on the integral adsorption equation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797466
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4726-4730[article] Comparison of methods to obtain micropore size distributions of carbonaceous materials from CO2 adsorption based on the dubinin − radushkevich isotherm [texte imprimé] / Moisés L. Pinto, Auteur ; Ana S. Mestre, Auteur ; Ana P. Carvalho, Auteur . - 2010 . - pp. 4726-4730.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4726-4730
Mots-clés : Adsorption Carbon dioxide Particle size distribution Microporosity Résumé : Micropore size distributions of various carbonaceous materials were obtained using two methods based on the Dubinin-Radushkevich equation and the relationship between the characteristic parameter of this equation and the pore width. One method was the well-known Dubinin-Radushkevich-Stoeckli (DRS) equation, and the other method used the integral adsorption equation without assuming a mathematical distribution for dw0/dE0. These methods were applied to carbon dioxide adsorption data on four activated carbons and eight chars to obtain micropore size distributions. Significant differences were found between the results obtained by the two methods. The DRS method gives an average of the distribution obtained by the method using the integral adsorption equation, because the latter is not constrained to a particular preassumed shape. The results reveal that the differences are more significant for the analysis of adsorption data on chars than on activated carbons. This was attributed to the fact that a less-homogeneous pore structure is expected to exist on chars than on activated carbons that cannot be described by the DRS method and can be described by the method based on the integral adsorption equation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797466 Exemplaires
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Titre : Superstructure optimization in heat exchanger network (HEN) synthesis using modular simulators and a genetic algorithm framework Type de document : texte imprimé Auteurs : Roghayeh Lotfi, Auteur ; Ramin B. Boozarjomehry, Auteur Année de publication : 2010 Article en page(s) : pp. 4731-4737 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Genetic algorithm Heat exchanger Meshed network Optimization Superstructure Résumé : Heat exchanger network synthesis (HENS) is one of the most efficient process integration tools to save energy in chemical plants. In this work, a new optimization framework is proposed for the synthesis of HENS, based on a genetic algorithm (GA) coupled with a commercial process simulator through the ActiveX capability of the simulator. The use of GA provides a robust search in complex and nonconvex spaces of mathematical problems, while the use of a simulator facilitates the formulation of rigorous models for different alternatives. To include the most common heat exchanger structures in the model, a promising superstructure has been used. Allowing nonisothermal mixing of streams in the new simulation-based approach leads to the discovery of truly optimal network configurations. The performance of the proposed approach is demonstrated using some case studies, and the obtained solutions are compared with those available in the literature. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797467
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4731-4737[article] Superstructure optimization in heat exchanger network (HEN) synthesis using modular simulators and a genetic algorithm framework [texte imprimé] / Roghayeh Lotfi, Auteur ; Ramin B. Boozarjomehry, Auteur . - 2010 . - pp. 4731-4737.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4731-4737
Mots-clés : Genetic algorithm Heat exchanger Meshed network Optimization Superstructure Résumé : Heat exchanger network synthesis (HENS) is one of the most efficient process integration tools to save energy in chemical plants. In this work, a new optimization framework is proposed for the synthesis of HENS, based on a genetic algorithm (GA) coupled with a commercial process simulator through the ActiveX capability of the simulator. The use of GA provides a robust search in complex and nonconvex spaces of mathematical problems, while the use of a simulator facilitates the formulation of rigorous models for different alternatives. To include the most common heat exchanger structures in the model, a promising superstructure has been used. Allowing nonisothermal mixing of streams in the new simulation-based approach leads to the discovery of truly optimal network configurations. The performance of the proposed approach is demonstrated using some case studies, and the obtained solutions are compared with those available in the literature. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797467 Exemplaires
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Titre : Development of a novel soft sensor using a local model network with an adaptive subtractive clustering approach Type de document : texte imprimé Auteurs : Tian-Hong Pan, Auteur ; David Shan-Hill Wong, Auteur ; Shi-Shang Jang, Auteur Année de publication : 2010 Article en page(s) : pp. 4738–4747 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heat Exchanger Genetic Algorithm Résumé : In this study, using data-driven methods, we develop a soft senor based on a multiple local model for a nonlinear industrial process. The soft sensor is based on a novel learning algorithm, which uses online subtractive clustering to recursively update the structure and parameters of a local model network. We also propose rules for updating the centers and local model coefficients of existing clusters, for generating new clusters and new models as well as for merging existing clusters and their corresponding models. As an industrial example, the proposed algorithm is applied to an o-xylene purification column, and it is shown that it is possible to track dynamic trends and compactly accumulate operating experiences. The performance of the proposed approach is compared with that of adaptive principal component regression, adaptive linear models based on key variables selection, fixed partial least-squares, and radial basic function neural network. The results demonstrate the effectiveness of the proposed modeling approach. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901098w
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4738–4747[article] Development of a novel soft sensor using a local model network with an adaptive subtractive clustering approach [texte imprimé] / Tian-Hong Pan, Auteur ; David Shan-Hill Wong, Auteur ; Shi-Shang Jang, Auteur . - 2010 . - pp. 4738–4747.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4738–4747
Mots-clés : Heat Exchanger Genetic Algorithm Résumé : In this study, using data-driven methods, we develop a soft senor based on a multiple local model for a nonlinear industrial process. The soft sensor is based on a novel learning algorithm, which uses online subtractive clustering to recursively update the structure and parameters of a local model network. We also propose rules for updating the centers and local model coefficients of existing clusters, for generating new clusters and new models as well as for merging existing clusters and their corresponding models. As an industrial example, the proposed algorithm is applied to an o-xylene purification column, and it is shown that it is possible to track dynamic trends and compactly accumulate operating experiences. The performance of the proposed approach is compared with that of adaptive principal component regression, adaptive linear models based on key variables selection, fixed partial least-squares, and radial basic function neural network. The results demonstrate the effectiveness of the proposed modeling approach. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901098w Exemplaires
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Titre : Control of Re - startup of anaerobic USBF reactors after short stops Type de document : texte imprimé Auteurs : Carlos García-Diéguez, Auteur ; Francisco Molina, Auteur ; Eugenio Fernández, Auteur Année de publication : 2010 Article en page(s) : pp. 4748–4755 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Anaerobic wastewater treatment Résumé : In this work, a previously developed variable gain controller (VGC) was applied for automatic control of re-startup and an organic overload in an anaerobic wastewater treatment (AWT) plant treating winery wastewater. The experiments for testing the automatic re-startup, and later organic overload, were conducted at 37 ± 2 °C in a hybrid upflow sludge bed-filter (USBF) pilot-scale reactor fully monitored with a liquid volume of 1.15 m3. The validation of the system was performed by simulation with Anaerobic Digestion Model No. 1 (ADM1) and experimentally by closed-loop control of the USBF reactor. It was determined that the time required for the re-startup of the AWT plant after short programmed stop periods (one month) could be greatly reduced, in comparison with the manual procedure, using this control system (only two days are needed). The organic-loading rate reached a value of 12 kg COD/(m3 d), with an initial chemical oxygen demand (COD) concentration in the influent of 8 kg COD/m3. To test the controller for the management of an organic overload, a COD increase of a 50% was applied. The control system decreased the feed flow rate and allowed process stability to be recovered after the organic overload. One of the advantages of this controller is its suitability for maintaining a high effluent quality by controlling H2 concentration in the biogas. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901164t
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4748–4755[article] Control of Re - startup of anaerobic USBF reactors after short stops [texte imprimé] / Carlos García-Diéguez, Auteur ; Francisco Molina, Auteur ; Eugenio Fernández, Auteur . - 2010 . - pp. 4748–4755.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4748–4755
Mots-clés : Anaerobic wastewater treatment Résumé : In this work, a previously developed variable gain controller (VGC) was applied for automatic control of re-startup and an organic overload in an anaerobic wastewater treatment (AWT) plant treating winery wastewater. The experiments for testing the automatic re-startup, and later organic overload, were conducted at 37 ± 2 °C in a hybrid upflow sludge bed-filter (USBF) pilot-scale reactor fully monitored with a liquid volume of 1.15 m3. The validation of the system was performed by simulation with Anaerobic Digestion Model No. 1 (ADM1) and experimentally by closed-loop control of the USBF reactor. It was determined that the time required for the re-startup of the AWT plant after short programmed stop periods (one month) could be greatly reduced, in comparison with the manual procedure, using this control system (only two days are needed). The organic-loading rate reached a value of 12 kg COD/(m3 d), with an initial chemical oxygen demand (COD) concentration in the influent of 8 kg COD/m3. To test the controller for the management of an organic overload, a COD increase of a 50% was applied. The control system decreased the feed flow rate and allowed process stability to be recovered after the organic overload. One of the advantages of this controller is its suitability for maintaining a high effluent quality by controlling H2 concentration in the biogas. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901164t Exemplaires
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Titre : Thermohydraulic simulation of heat exchanger networks Type de document : texte imprimé Auteurs : Viviane B. G. Tavares, Auteur ; Eduardo M. Queiroz, Auteur ; André L. H. Costa, Auteur Année de publication : 2010 Article en page(s) : pp. 4756–4765 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heat exchanger networks Résumé : This paper presents a simulation scheme of heat exchanger networks considering thermal and hydraulic effects simultaneously. The determination of network temperatures is carried out together with the evaluation of flow rates and pressures along the network, considering head losses in heat exchangers and associated piping. The model encompasses two systems of equations: a network hydraulic model, composed by a nonlinear system of mass balances and fluid flow equations, and an energy model, represented by a linear system of energy balances and heat exchanger equations. The mathematical structure is based on a matrix representation of the network. The proposed model allows a more realistic analysis of heat exchanger networks where flow rates are constrained by limitations of hydraulic facilities. The utilization of the simulation scheme is illustrated by the analysis of a cooling water system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901275z
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4756–4765[article] Thermohydraulic simulation of heat exchanger networks [texte imprimé] / Viviane B. G. Tavares, Auteur ; Eduardo M. Queiroz, Auteur ; André L. H. Costa, Auteur . - 2010 . - pp. 4756–4765.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4756–4765
Mots-clés : Heat exchanger networks Résumé : This paper presents a simulation scheme of heat exchanger networks considering thermal and hydraulic effects simultaneously. The determination of network temperatures is carried out together with the evaluation of flow rates and pressures along the network, considering head losses in heat exchangers and associated piping. The model encompasses two systems of equations: a network hydraulic model, composed by a nonlinear system of mass balances and fluid flow equations, and an energy model, represented by a linear system of energy balances and heat exchanger equations. The mathematical structure is based on a matrix representation of the network. The proposed model allows a more realistic analysis of heat exchanger networks where flow rates are constrained by limitations of hydraulic facilities. The utilization of the simulation scheme is illustrated by the analysis of a cooling water system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901275z Exemplaires
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Titre : Integrated gasification combined cycle dynamic model : H2S absorption/stripping, water − gas shift reactors, and CO2 absorption/stripping Type de document : texte imprimé Auteurs : Patrick J. Robinson, Auteur ; William L. Luyben, Auteur Année de publication : 2010 Article en page(s) : pp. 4766–4781 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dynamic Gas Absorption Résumé : Gasification could potentially emerge as the premier unit operation in the energy and chemical industries. In the future, plants are predicted to be a hybrid between power and chemical with the ability to handle unavoidable swings in both power demand and biomass feed composition without a loss of efficiency. The coupling of a power plant with a chemical plant provides an additional control degree of freedom, which fundamentally improves the controllability of the process. The coupling of an integrated gasification combined cycle (IGCC) power plant with a methanol chemical plant handles swings in power demand by diverting hydrogen gas from a combustion turbine and syn gas from the gasifier to a methanol plant for the production of an easily stored, hydrogen-consuming liquid product. This paper presents an extension of the dynamic gasifier model, which uses a high-molecular weight hydrocarbon (with a 1:1 hydrogen to carbon ratio) as a pseudo-biomass feed stock. Using this gasifier model, the downstream units of a typical IGCC can be modeled in the widely used process simulator Aspen Dynamics. Dynamic simulations of the H2S absorption/stripping unit, water−gas shift (WGS) reactors, and CO2 absorption/stripping unit are essential for the development of stable and agile plantwide control structures of this hybrid power/chemical plant. Because of the high pressure of the system, hydrogen sulfide is removed by means of physical absorption. SELEXOL (a mixture of the dimethyl ethers of polyethylene glycol) is used to achieve a gas purity of less than 5 ppm H2S. This desulfurized synthesis gas is sent to two water−gas shift reactors that convert a total of 99% of carbon monoxide to hydrogen. Physical absorption of carbon dioxide with Selexol produces a hydrogen-rich stream (90 mol % H2) to be fed into combustion turbines or to a methanol plant. Steady-state economic designs and plantwide control structures are developed in this paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901549s
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4766–4781[article] Integrated gasification combined cycle dynamic model : H2S absorption/stripping, water − gas shift reactors, and CO2 absorption/stripping [texte imprimé] / Patrick J. Robinson, Auteur ; William L. Luyben, Auteur . - 2010 . - pp. 4766–4781.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4766–4781
Mots-clés : Dynamic Gas Absorption Résumé : Gasification could potentially emerge as the premier unit operation in the energy and chemical industries. In the future, plants are predicted to be a hybrid between power and chemical with the ability to handle unavoidable swings in both power demand and biomass feed composition without a loss of efficiency. The coupling of a power plant with a chemical plant provides an additional control degree of freedom, which fundamentally improves the controllability of the process. The coupling of an integrated gasification combined cycle (IGCC) power plant with a methanol chemical plant handles swings in power demand by diverting hydrogen gas from a combustion turbine and syn gas from the gasifier to a methanol plant for the production of an easily stored, hydrogen-consuming liquid product. This paper presents an extension of the dynamic gasifier model, which uses a high-molecular weight hydrocarbon (with a 1:1 hydrogen to carbon ratio) as a pseudo-biomass feed stock. Using this gasifier model, the downstream units of a typical IGCC can be modeled in the widely used process simulator Aspen Dynamics. Dynamic simulations of the H2S absorption/stripping unit, water−gas shift (WGS) reactors, and CO2 absorption/stripping unit are essential for the development of stable and agile plantwide control structures of this hybrid power/chemical plant. Because of the high pressure of the system, hydrogen sulfide is removed by means of physical absorption. SELEXOL (a mixture of the dimethyl ethers of polyethylene glycol) is used to achieve a gas purity of less than 5 ppm H2S. This desulfurized synthesis gas is sent to two water−gas shift reactors that convert a total of 99% of carbon monoxide to hydrogen. Physical absorption of carbon dioxide with Selexol produces a hydrogen-rich stream (90 mol % H2) to be fed into combustion turbines or to a methanol plant. Steady-state economic designs and plantwide control structures are developed in this paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901549s Exemplaires
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Titre : Nonlinear model predictive control : a self - adaptive approach Type de document : texte imprimé Auteurs : Ivan Dones, Auteur ; Flavio Manenti, Auteur ; Heinz A. Preisig, Auteur Année de publication : 2010 Article en page(s) : pp. 4782–4791 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dynamic models Predictive Control Résumé : Model predictive control (MPC) is an online application based on dynamic models. Its application faces two major obstacles: (i) computational constraints and (ii) the need to accurately simulate the process by a model that properly predicts how the plant will behave in the future.
Implementation of MPC is not always possible in large-scale or industrial applications due to the computational complexity of MPC and to the dimensionality of the models. To facilitate MPC implementations, this paper proposes a self-adaptive approach based on simplified (or reduced-order) nonlinear models. The proposed methodology yields an MPC that adjusts the dimension of the model according to both the current process conditions and the control objectives. The self-adaptive approach is described and validated on an industrial case study, a C4-splitter.ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901693w
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4782–4791[article] Nonlinear model predictive control : a self - adaptive approach [texte imprimé] / Ivan Dones, Auteur ; Flavio Manenti, Auteur ; Heinz A. Preisig, Auteur . - 2010 . - pp. 4782–4791.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4782–4791
Mots-clés : Dynamic models Predictive Control Résumé : Model predictive control (MPC) is an online application based on dynamic models. Its application faces two major obstacles: (i) computational constraints and (ii) the need to accurately simulate the process by a model that properly predicts how the plant will behave in the future.
Implementation of MPC is not always possible in large-scale or industrial applications due to the computational complexity of MPC and to the dimensionality of the models. To facilitate MPC implementations, this paper proposes a self-adaptive approach based on simplified (or reduced-order) nonlinear models. The proposed methodology yields an MPC that adjusts the dimension of the model according to both the current process conditions and the control objectives. The self-adaptive approach is described and validated on an industrial case study, a C4-splitter.ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901693w Exemplaires
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Titre : Nonlinear probabilistic monitoring based on the gaussian process latent variable model Type de document : texte imprimé Auteurs : Zhiqiang Ge, Auteur ; Zhihuan Song, Auteur Année de publication : 2010 Article en page(s) : pp. 4792–4799 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nonlinear probabilistic Gaussian process Résumé : For probabilistic interpretation and monitoring performance enhancement in noisy processes, the probabilistic principal component analysis (PPCA) method has recently been introduced into the monitoring area. However, PPCA is restricted in linear processes. This paper first gives a new interpretation of PPCA through the Gaussian process manner. Then a new nonlinear probabilistic monitoring method is proposed, which is developed upon the Gaussian process latent variable model. Different from the traditional PPCA method, the new approach can successfully extract the nonlinear relationship between process variables. Furthermore, it exhibits more detailed information of uncertainty for process data, through which the operation condition and the fault behavior can be interpreted more easily. Two case studies are provided to show the efficiency of the proposed method. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019402
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4792–4799[article] Nonlinear probabilistic monitoring based on the gaussian process latent variable model [texte imprimé] / Zhiqiang Ge, Auteur ; Zhihuan Song, Auteur . - 2010 . - pp. 4792–4799.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4792–4799
Mots-clés : Nonlinear probabilistic Gaussian process Résumé : For probabilistic interpretation and monitoring performance enhancement in noisy processes, the probabilistic principal component analysis (PPCA) method has recently been introduced into the monitoring area. However, PPCA is restricted in linear processes. This paper first gives a new interpretation of PPCA through the Gaussian process manner. Then a new nonlinear probabilistic monitoring method is proposed, which is developed upon the Gaussian process latent variable model. Different from the traditional PPCA method, the new approach can successfully extract the nonlinear relationship between process variables. Furthermore, it exhibits more detailed information of uncertainty for process data, through which the operation condition and the fault behavior can be interpreted more easily. Two case studies are provided to show the efficiency of the proposed method. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019402 Exemplaires
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Titre : System identification and nonlinear model predictive control of a solid oxide fuel cell Type de document : texte imprimé Auteurs : Debangsu Bhattacharyya, Auteur ; Raghunathan Rengaswamy, Auteur Année de publication : 2010 Article en page(s) : pp. 4800–4808 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nonlinear system Oxide fuel cell Résumé : Solid oxide fuel cells (SOFCs) are high temperature fuel cells with a strong potential for stationary power house applications. However, considerable challenges need to be overcome to connect these cells to the power grid. The fluctuating grid demand has to be met without sacrificing the cell efficiency and causing structural/material damage to the system. This requirement coupled with fast and highly nonlinear transients of the transport variables results in a challenging control problem. This paper is on synthesizing a controller that can address some of these challenges. For using in the model predictive controller (MPC), input−output models are identified from the data generated by a detailed dynamic model. A traditional SISO control and a novel MIMO control are considered here. In the SISO control problem, power is the controlled variable (CV) and H2 flow is the manipulated variable (MV). In the MIMO control problem, power and the utilization factor (UF) of the fuel are the CVs while voltage and the flow of H2 are the MVs. The identification study shows that the nonlinear NAARX models with properly chosen cross terms can improve the model performance significantly in a MIMO problem. The results from the control study indicate that a well-tuned proportional−integral−derivative (PID) controller is sufficient for the single input single output (SISO) power control of a tubular SOFC. It also shows that the mutiple input multiple output (MIMO) control of power and the UF is highly interactive and necessitates a nonlinear model predictive controller (NMPC). Without using any additional hardware such as an ultracapacitor or battery pack, the designed NMPC could satisfy a step change in load with acceptable overshoot in power and the UF. A well-tuned PID controller is found to perform poorly for the MIMO problem. On the basis of these findings, future work will focus on the development of nonlinear predictive control approaches for stack-level control of tubular solid oxide fuel cells. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020254
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4800–4808[article] System identification and nonlinear model predictive control of a solid oxide fuel cell [texte imprimé] / Debangsu Bhattacharyya, Auteur ; Raghunathan Rengaswamy, Auteur . - 2010 . - pp. 4800–4808.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4800–4808
Mots-clés : Nonlinear system Oxide fuel cell Résumé : Solid oxide fuel cells (SOFCs) are high temperature fuel cells with a strong potential for stationary power house applications. However, considerable challenges need to be overcome to connect these cells to the power grid. The fluctuating grid demand has to be met without sacrificing the cell efficiency and causing structural/material damage to the system. This requirement coupled with fast and highly nonlinear transients of the transport variables results in a challenging control problem. This paper is on synthesizing a controller that can address some of these challenges. For using in the model predictive controller (MPC), input−output models are identified from the data generated by a detailed dynamic model. A traditional SISO control and a novel MIMO control are considered here. In the SISO control problem, power is the controlled variable (CV) and H2 flow is the manipulated variable (MV). In the MIMO control problem, power and the utilization factor (UF) of the fuel are the CVs while voltage and the flow of H2 are the MVs. The identification study shows that the nonlinear NAARX models with properly chosen cross terms can improve the model performance significantly in a MIMO problem. The results from the control study indicate that a well-tuned proportional−integral−derivative (PID) controller is sufficient for the single input single output (SISO) power control of a tubular SOFC. It also shows that the mutiple input multiple output (MIMO) control of power and the UF is highly interactive and necessitates a nonlinear model predictive controller (NMPC). Without using any additional hardware such as an ultracapacitor or battery pack, the designed NMPC could satisfy a step change in load with acceptable overshoot in power and the UF. A well-tuned PID controller is found to perform poorly for the MIMO problem. On the basis of these findings, future work will focus on the development of nonlinear predictive control approaches for stack-level control of tubular solid oxide fuel cells. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020254 Exemplaires
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Titre : Improving the performance of generalized predictive control for nonlinear processes Type de document : texte imprimé Auteurs : Ma'moun Abu-Ayyad, Auteur ; Rickey Dubay, Auteur Année de publication : 2010 Article en page(s) : pp. 4809–4816 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nonlinear Processes Résumé : This paper presents a unique method for improving the performance of the generalized predictive control (GPC) algorithm for controlling nonlinear systems which can be extended to other forms of predictive controllers. This method is termed adaptive generalized predictive control (AGPC) which uses a multidimensional workspace of the nonlinear plant to recalculate the controller parameters every sampling instant. This results in a more accurate process prediction and improved closed-loop performance over the original GPC algorithm. The AGPC controller was tested in simulation, and its control performance was compared to GPC on several nonlinear plants with different degrees of nonlinearity. Practical testing and comparisons were performed on a steel cylinder temperature control system. Simulation and experimental results show that the adaptive generalized predictive controller provided improved closed-loop performance over GPC. The formulation of the multidimensional workspace can be readily applied to other advanced control strategies making the methodology generic. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100133k
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4809–4816[article] Improving the performance of generalized predictive control for nonlinear processes [texte imprimé] / Ma'moun Abu-Ayyad, Auteur ; Rickey Dubay, Auteur . - 2010 . - pp. 4809–4816.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4809–4816
Mots-clés : Nonlinear Processes Résumé : This paper presents a unique method for improving the performance of the generalized predictive control (GPC) algorithm for controlling nonlinear systems which can be extended to other forms of predictive controllers. This method is termed adaptive generalized predictive control (AGPC) which uses a multidimensional workspace of the nonlinear plant to recalculate the controller parameters every sampling instant. This results in a more accurate process prediction and improved closed-loop performance over the original GPC algorithm. The AGPC controller was tested in simulation, and its control performance was compared to GPC on several nonlinear plants with different degrees of nonlinearity. Practical testing and comparisons were performed on a steel cylinder temperature control system. Simulation and experimental results show that the adaptive generalized predictive controller provided improved closed-loop performance over GPC. The formulation of the multidimensional workspace can be readily applied to other advanced control strategies making the methodology generic. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100133k Exemplaires
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Titre : Recovery of germanium from aqueous solutions by ion - exchange extraction of its catechol complex Type de document : texte imprimé Auteurs : Fátima Arroyo Torralvo, Auteur ; Constantino Fernández-Pereira, Auteur ; Maria C. Campanario, Auteur Année de publication : 2010 Article en page(s) : pp. 4817–4823 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ion exchange Aqueous solution Résumé : The paper is concerned with the recovery of germanium from dilute aqueous solutions. The method is based on the sorption of the selective complex formed by catechol with germanium onto low-cost anionic resins. Experimental investigations were undertaken using conventional quaternary ammonium macroporous resins: Amberlite IRA-900 and IRA-958. The influence of pH, metal concentration, and amounts of resin and catechol on the sorption capacity were investigated. For a proper set of experiments, a statistical technique such as a response surface methodology (RSM) has been used. For the investigation of the exchange equilibrium, the experimental data were analyzed using the Langmuir, Freundlich and Dubinin−Radushkevich equations, the Freundlich isotherm in general constituting a better fit. The uptake of the germanium complex by the ion-exchange resins was reversed by acid and neutral solutions. The results obtained showed better performance for IRA-900 than IRA-958, measured in terms of global recovery yields (retention and elution). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797476
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4817–4823[article] Recovery of germanium from aqueous solutions by ion - exchange extraction of its catechol complex [texte imprimé] / Fátima Arroyo Torralvo, Auteur ; Constantino Fernández-Pereira, Auteur ; Maria C. Campanario, Auteur . - 2010 . - pp. 4817–4823.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4817–4823
Mots-clés : Ion exchange Aqueous solution Résumé : The paper is concerned with the recovery of germanium from dilute aqueous solutions. The method is based on the sorption of the selective complex formed by catechol with germanium onto low-cost anionic resins. Experimental investigations were undertaken using conventional quaternary ammonium macroporous resins: Amberlite IRA-900 and IRA-958. The influence of pH, metal concentration, and amounts of resin and catechol on the sorption capacity were investigated. For a proper set of experiments, a statistical technique such as a response surface methodology (RSM) has been used. For the investigation of the exchange equilibrium, the experimental data were analyzed using the Langmuir, Freundlich and Dubinin−Radushkevich equations, the Freundlich isotherm in general constituting a better fit. The uptake of the germanium complex by the ion-exchange resins was reversed by acid and neutral solutions. The results obtained showed better performance for IRA-900 than IRA-958, measured in terms of global recovery yields (retention and elution). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797476 Exemplaires
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Titre : Double - skinned forward osmosis membranes for reducing internal concentration polarization within the porous sublayer Type de document : texte imprimé Auteurs : Kai Yu Wang, Auteur ; Rui Chin Ong, Auteur ; Tai-Shung Chung, Auteur Année de publication : 2010 Article en page(s) : pp. 4824–4831 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Osmosis Membranes Résumé : A scheme to fabricate forward osmosis membranes comprising a highly porous sublayer sandwiched between two selective skin layers via phase inversion was proposed. One severe deficiency of existing composite and asymmetric membranes used in forward osmosis is the presence of unfavorable internal concentration polarization within the porous support layer that hinders both (i) separation (salt flux) and (ii) the performance (water flux). The double skin layers of the tailored membrane may mitigate the internal concentration polarization by preventing the salt and other solutes in the draw solution from penetrating into the membrane porous support. The prototype double-skinned cellulose acetate membrane displayed a water flux of 48.2 L·m−2·h−1 and lower reverse salt transport of 6.5 g·m−2·h−1 using 5.0 M MgCl2 as the draw solution in a forward osmosis process performed at 22 °C. This can be attributed to the effective salt rejection by the double skin layers and the low water transport resistance within the porous support layer. The prospects of utilizing the double-selective layer membranes may have potential application in forward osmosis for desalination. This study may help pave the way to improve the membrane design for the forward osmosis process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901592d
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4824–4831[article] Double - skinned forward osmosis membranes for reducing internal concentration polarization within the porous sublayer [texte imprimé] / Kai Yu Wang, Auteur ; Rui Chin Ong, Auteur ; Tai-Shung Chung, Auteur . - 2010 . - pp. 4824–4831.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4824–4831
Mots-clés : Osmosis Membranes Résumé : A scheme to fabricate forward osmosis membranes comprising a highly porous sublayer sandwiched between two selective skin layers via phase inversion was proposed. One severe deficiency of existing composite and asymmetric membranes used in forward osmosis is the presence of unfavorable internal concentration polarization within the porous support layer that hinders both (i) separation (salt flux) and (ii) the performance (water flux). The double skin layers of the tailored membrane may mitigate the internal concentration polarization by preventing the salt and other solutes in the draw solution from penetrating into the membrane porous support. The prototype double-skinned cellulose acetate membrane displayed a water flux of 48.2 L·m−2·h−1 and lower reverse salt transport of 6.5 g·m−2·h−1 using 5.0 M MgCl2 as the draw solution in a forward osmosis process performed at 22 °C. This can be attributed to the effective salt rejection by the double skin layers and the low water transport resistance within the porous support layer. The prospects of utilizing the double-selective layer membranes may have potential application in forward osmosis for desalination. This study may help pave the way to improve the membrane design for the forward osmosis process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901592d Exemplaires
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Titre : Comparison of traditional and structured adsorbents for CO2 separation by vacuum - swing dsorption Type de document : texte imprimé Auteurs : Fateme Rezaei, Auteur ; Alessandra Mosca, Auteur ; Paul Webley, Auteur Année de publication : 2010 Article en page(s) : pp. 4832–4841 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas separation processes Adsorbents Résumé : The development of structured adsorbents with attractive characteristics is an important step in the improvement of adsorption-based gas-separation processes. The improved features of structured adsorbents include lower energy consumption, higher throughput, and superior recovery and purity of product because of the even flow distribution, very low mass-transfer resistance, and low pressure drop in combination with a reasonable adsorption capacity. This study examines the vacuum-swing adsorption (VSA) CO2 separation performance of structured adsorbents in the form of thin NaX films grown on the walls of ceramic cordierite monoliths, and the results are compared with NaX pellets. Adsorption equilibrium and dynamic properties are explored experimentally. The CO2 breakthrough front for the NaX film grown on the 400 cells/in.2 (cpsi) monolith was close to ideal and indicated that axial dispersion was very small and that the mass-transfer resistance in the film was very low. The breakthrough front for the structured adsorbent with 400 cpsi was sharper than that for the structured adsorbent with 900 cpsi and only shifted to shorter breakthrough times because of the lower amount of zeolite and higher effective diffusivity of the former sample. In addition, the CO2 breakthrough fronts for the 400 and 900 cpsi structured adsorbents were both sharper than the breakthrough front for NaX beads. This indicates that the flow distribution in the structured adsorbents is more even and that the mass-transfer resistance in the film is very low because of the small film thickness and high effective diffusivity for CO2 in the NaX film. Experimental data were used to obtain overall mass-transfer linear-driving-force constants, which were subsequently used in a numerical simulation program to estimate the performance of the adsorbents for CO2/N2 separation in a VSA process. It was found that the recovery of structured adsorbents was superior to that of a packed bed because of the much shorter mass-transfer zone. The purity, on the other hand, was not as high as that obtained with a packed bed because of excessive voidage in the structured adsorbents. Increased cell density or improved zeolite loading of the structured adsorbents would improve the CO2 purity without sacrificing recovery for the structured adsorbents, and this represents a path forward to improved VSA performance for CO2 capture. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016545
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4832–4841[article] Comparison of traditional and structured adsorbents for CO2 separation by vacuum - swing dsorption [texte imprimé] / Fateme Rezaei, Auteur ; Alessandra Mosca, Auteur ; Paul Webley, Auteur . - 2010 . - pp. 4832–4841.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4832–4841
Mots-clés : Gas separation processes Adsorbents Résumé : The development of structured adsorbents with attractive characteristics is an important step in the improvement of adsorption-based gas-separation processes. The improved features of structured adsorbents include lower energy consumption, higher throughput, and superior recovery and purity of product because of the even flow distribution, very low mass-transfer resistance, and low pressure drop in combination with a reasonable adsorption capacity. This study examines the vacuum-swing adsorption (VSA) CO2 separation performance of structured adsorbents in the form of thin NaX films grown on the walls of ceramic cordierite monoliths, and the results are compared with NaX pellets. Adsorption equilibrium and dynamic properties are explored experimentally. The CO2 breakthrough front for the NaX film grown on the 400 cells/in.2 (cpsi) monolith was close to ideal and indicated that axial dispersion was very small and that the mass-transfer resistance in the film was very low. The breakthrough front for the structured adsorbent with 400 cpsi was sharper than that for the structured adsorbent with 900 cpsi and only shifted to shorter breakthrough times because of the lower amount of zeolite and higher effective diffusivity of the former sample. In addition, the CO2 breakthrough fronts for the 400 and 900 cpsi structured adsorbents were both sharper than the breakthrough front for NaX beads. This indicates that the flow distribution in the structured adsorbents is more even and that the mass-transfer resistance in the film is very low because of the small film thickness and high effective diffusivity for CO2 in the NaX film. Experimental data were used to obtain overall mass-transfer linear-driving-force constants, which were subsequently used in a numerical simulation program to estimate the performance of the adsorbents for CO2/N2 separation in a VSA process. It was found that the recovery of structured adsorbents was superior to that of a packed bed because of the much shorter mass-transfer zone. The purity, on the other hand, was not as high as that obtained with a packed bed because of excessive voidage in the structured adsorbents. Increased cell density or improved zeolite loading of the structured adsorbents would improve the CO2 purity without sacrificing recovery for the structured adsorbents, and this represents a path forward to improved VSA performance for CO2 capture. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016545 Exemplaires
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Titre : Transformation of monohydrate into anhydrous form of risedronate monosodium in methanol − water mixture Type de document : texte imprimé Auteurs : Thi Nhat Phuong Nguyen, Auteur ; Kwang-Joo Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 4842–4849 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Monohydrate Methanol Résumé : The transformation of a monohydrate into an anhydrous form of risedronate monosodium (RS) in a methanol and water mixture was investigated. The phase transformation was detected by monitoring the number of particles, particle size, and shape. At the same time, polymorphic forms of crystals were identified by various offline techniques such as XRPD, TGA, and DSC. The kinetics of phase transformation was found to be controlled by three-dimensional nuclear growth. The reaction of water in the solvent mixture was a main factor determining the stability of anhydrate and monohydrate forms. The time required for phase transformation was strongly affected by temperature and agitation rate. The phase transformation could be successfully determined in real time by using an in situ particle measurement system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901677n
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4842–4849[article] Transformation of monohydrate into anhydrous form of risedronate monosodium in methanol − water mixture [texte imprimé] / Thi Nhat Phuong Nguyen, Auteur ; Kwang-Joo Kim, Auteur . - 2010 . - pp. 4842–4849.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4842–4849
Mots-clés : Monohydrate Methanol Résumé : The transformation of a monohydrate into an anhydrous form of risedronate monosodium (RS) in a methanol and water mixture was investigated. The phase transformation was detected by monitoring the number of particles, particle size, and shape. At the same time, polymorphic forms of crystals were identified by various offline techniques such as XRPD, TGA, and DSC. The kinetics of phase transformation was found to be controlled by three-dimensional nuclear growth. The reaction of water in the solvent mixture was a main factor determining the stability of anhydrate and monohydrate forms. The time required for phase transformation was strongly affected by temperature and agitation rate. The phase transformation could be successfully determined in real time by using an in situ particle measurement system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901677n Exemplaires
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Titre : Liquid − liquid equilibrium of mixtures of imidazolium - based ionic liquids with propanediols or glycerol Type de document : texte imprimé Auteurs : Carlos A. S. Trindade, Auteur ; Zoran P. Visak, Auteur ; Rafat Bogel-Lukasik, Auteur Année de publication : 2010 Article en page(s) : pp. 4850-4857 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic liquid Phase equilibrium Liquid Résumé : In this work, liquid-liquid equilibria (LLE) of solutions of imidazolium-based ionic liquids-with either bistriflamide ([Cnmim][NTf2], n = 2 and n = 10) or triflate anions ([C2mim][OTf]), with 1-propanol, 1,2-propanediol, 1,3-propanediol, and glycerol (1,2,3-propanetdol)-were studied. The obtained phase diagrams show a remarkable difference in solvation properties between ionic liquids with NTf2 or OTf anions toward the aforementioned alcohols: although [C2mim][NTf2] constantly exhibited partial miscibility, [C2mim][OTf was always completely miscible. This divergence is likely to be related to the distinct abilities of NTf2 and OTf anions toward hydrogen bonding. It was also found that the shorter cation alkyl chain in the [Cnmim][NTf2] ionic liquids provided better solubility with both propanediols and glycerol. In addition, the solubility of 1,3-propanediol in both [C2mim][NTf2] and [C10mim][NTf2] was much lower than that of 1,2-propanediol From the application point of view, the present results show that mixtures of [C2mim][NTf2] and [C2mim][OTf ionic liquids may achieve the separation of 1,3-propanediol from glycerol. The LLE experimental results were correlated using a model based on the Peng-Robinson equation of state (PR EoS) combined with th ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797480
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4850-4857[article] Liquid − liquid equilibrium of mixtures of imidazolium - based ionic liquids with propanediols or glycerol [texte imprimé] / Carlos A. S. Trindade, Auteur ; Zoran P. Visak, Auteur ; Rafat Bogel-Lukasik, Auteur . - 2010 . - pp. 4850-4857.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4850-4857
Mots-clés : Ionic liquid Phase equilibrium Liquid Résumé : In this work, liquid-liquid equilibria (LLE) of solutions of imidazolium-based ionic liquids-with either bistriflamide ([Cnmim][NTf2], n = 2 and n = 10) or triflate anions ([C2mim][OTf]), with 1-propanol, 1,2-propanediol, 1,3-propanediol, and glycerol (1,2,3-propanetdol)-were studied. The obtained phase diagrams show a remarkable difference in solvation properties between ionic liquids with NTf2 or OTf anions toward the aforementioned alcohols: although [C2mim][NTf2] constantly exhibited partial miscibility, [C2mim][OTf was always completely miscible. This divergence is likely to be related to the distinct abilities of NTf2 and OTf anions toward hydrogen bonding. It was also found that the shorter cation alkyl chain in the [Cnmim][NTf2] ionic liquids provided better solubility with both propanediols and glycerol. In addition, the solubility of 1,3-propanediol in both [C2mim][NTf2] and [C10mim][NTf2] was much lower than that of 1,2-propanediol From the application point of view, the present results show that mixtures of [C2mim][NTf2] and [C2mim][OTf ionic liquids may achieve the separation of 1,3-propanediol from glycerol. The LLE experimental results were correlated using a model based on the Peng-Robinson equation of state (PR EoS) combined with th ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797480 Exemplaires
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Titre : Effects of coagulation bath temperature on the separation performance and antifouling property of poly(ether sulfone) ultrafiltration membranes Type de document : texte imprimé Auteurs : Jinming Peng, Auteur ; Su, Yanlei, Auteur ; Wenjuan Chen, Auteur Année de publication : 2010 Article en page(s) : pp. 4858-4864 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Membrane separation Ultrafiltration Flocculation Coagulation Résumé : Poly(ether sulfone) (PES) ultrafiltration membranes are fabricated via nonsolvent-induced phase separation by blending with hydrophilic homopolymer additive poly(ethylene glycol) (PEG) or amphiphilic block copolymer Pluronic F127. The effects of coagulation bath temperature (CBT) on membrane structure, separation performance, and antifouling property are investigated in detail. All the membranes display an asymmetric morphology. PES/PEG membranes possess only fingerlike pores of support layer, while there is a spongelike sublayer between skin layer and the fingerlike pores for PES/Pluronic F127 membranes. The thickness of the spongelike sublayer for PES/Pluronic F127 membranes is remarkablely decreased with the increase of CBT. For all the membranes, pure water flux increases substantially with the increase of CBT. The rejection of PES/PEG membrane for bovine serum albumin (BSA) is above 95%. However, the rejection of PES/Pluronic F127 membrane for BSA molecules is decreased sharply form 95.3% to 10.2% with the increase of CBT from 20 to 60 °C. At higher CBT, the antifouling capabilities of PES/Pluronic F127 membranes are slightly weakened mainly because of the lower surface coverage of amphiphilic copolymer. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797481
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4858-4864[article] Effects of coagulation bath temperature on the separation performance and antifouling property of poly(ether sulfone) ultrafiltration membranes [texte imprimé] / Jinming Peng, Auteur ; Su, Yanlei, Auteur ; Wenjuan Chen, Auteur . - 2010 . - pp. 4858-4864.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4858-4864
Mots-clés : Membrane separation Ultrafiltration Flocculation Coagulation Résumé : Poly(ether sulfone) (PES) ultrafiltration membranes are fabricated via nonsolvent-induced phase separation by blending with hydrophilic homopolymer additive poly(ethylene glycol) (PEG) or amphiphilic block copolymer Pluronic F127. The effects of coagulation bath temperature (CBT) on membrane structure, separation performance, and antifouling property are investigated in detail. All the membranes display an asymmetric morphology. PES/PEG membranes possess only fingerlike pores of support layer, while there is a spongelike sublayer between skin layer and the fingerlike pores for PES/Pluronic F127 membranes. The thickness of the spongelike sublayer for PES/Pluronic F127 membranes is remarkablely decreased with the increase of CBT. For all the membranes, pure water flux increases substantially with the increase of CBT. The rejection of PES/PEG membrane for bovine serum albumin (BSA) is above 95%. However, the rejection of PES/Pluronic F127 membrane for BSA molecules is decreased sharply form 95.3% to 10.2% with the increase of CBT from 20 to 60 °C. At higher CBT, the antifouling capabilities of PES/Pluronic F127 membranes are slightly weakened mainly because of the lower surface coverage of amphiphilic copolymer. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797481 Exemplaires
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Titre : Taylor vortex effect on phase transformation of guanosine 5 - monophosphate in drowning - out crystallization Type de document : texte imprimé Auteurs : Anh-Tuan Nguyen, Auteur Année de publication : 2010 Article en page(s) : pp 4865–4872 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Monophosphate Crystallization Résumé : A continuous Couette−Taylor (CT) crystallizer exploiting a Taylor vortex was developed to promote the phase transformation of guanosine 5-monophosphate (GMP). In drowning-out crystallization, amorphous GMP is initially generated and then transformed into hydrate GMP crystals via the consecutive dissolution of the amorphous GMP and nucleation and growth of hydrate GMP crystals. Because of the intensive mixing of the Taylor vortex, the dissolution of the amorphous GMP and growth of the hydrate GMP crystals were both markedly promoted, allowing the phase transformation to be completed within a mean residence time of 5 min, even with a high GMP feed concentration of 150 g/L and moderate rotation speed of 300 rpm This result was at least 5 times faster than the phase transformation in a mixed suspension, mixed product removal (MSMPR) crystallizer under the same crystallization conditions. The phase transformation efficiency of the Taylor vortex over the turbulent eddy in the MSMPR crystallizer was explained in terms of the effectiveness of the turbulence for the mass transfer at the solid−liquid interface. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901932t
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp 4865–4872[article] Taylor vortex effect on phase transformation of guanosine 5 - monophosphate in drowning - out crystallization [texte imprimé] / Anh-Tuan Nguyen, Auteur . - 2010 . - pp 4865–4872.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp 4865–4872
Mots-clés : Monophosphate Crystallization Résumé : A continuous Couette−Taylor (CT) crystallizer exploiting a Taylor vortex was developed to promote the phase transformation of guanosine 5-monophosphate (GMP). In drowning-out crystallization, amorphous GMP is initially generated and then transformed into hydrate GMP crystals via the consecutive dissolution of the amorphous GMP and nucleation and growth of hydrate GMP crystals. Because of the intensive mixing of the Taylor vortex, the dissolution of the amorphous GMP and growth of the hydrate GMP crystals were both markedly promoted, allowing the phase transformation to be completed within a mean residence time of 5 min, even with a high GMP feed concentration of 150 g/L and moderate rotation speed of 300 rpm This result was at least 5 times faster than the phase transformation in a mixed suspension, mixed product removal (MSMPR) crystallizer under the same crystallization conditions. The phase transformation efficiency of the Taylor vortex over the turbulent eddy in the MSMPR crystallizer was explained in terms of the effectiveness of the turbulence for the mass transfer at the solid−liquid interface. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901932t Exemplaires
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Titre : Development of a treated laterite for arsenic adsorption : effects of treatment parameters Type de document : texte imprimé Auteurs : Abhijit Maiti, Auteur ; Jayanta Kumar Basu, Auteur ; Sirshendu De, Auteur Année de publication : 2010 Article en page(s) : pp. 4873–4886 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Arsenic adsorbent Résumé : A porous and efficient arsenic adsorbent (specific surface area, 181 ± 4 m2/g; pore volume, 0.35 ± 0.01 mL/g) is prepared from raw laterite by acid followed by alkali treatment. FTIR, XRD, SEM-EDAX, HRTEM, and a surface area analyzer are used for detailed characterization of treated materials. Adsorption of arsenic on treated laterite (TL) using arsenic spiked distilled water and contaminated groundwater (CGW) is studied in the batch and fixed-bed column modes. The Langmuir isotherm fits better to the experimental data compared to the Freundlich isotherm. The Langmuir maximum capacities of As(V) and As(III) on the best-performing treated material are found to be 24.8 ± 3.9 and 8.0 ± 1.4 mg/g, respectively. Arsenic adsorption on TL follows pseudo-second-order kinetics. The Langmuir maximum adsorptions of arsenic on raw laterite and TL using CGW as the total arsenic are found to be 0.11 ± 0.01 and 7.5 ± 0.4 mg/g, respectively. In the fixed-bed column run, the 6.5 cm TL bed is capable to produce 3000 times the bed volume of treated water with an effluent arsenic concentration ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100612u
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4873–4886[article] Development of a treated laterite for arsenic adsorption : effects of treatment parameters [texte imprimé] / Abhijit Maiti, Auteur ; Jayanta Kumar Basu, Auteur ; Sirshendu De, Auteur . - 2010 . - pp. 4873–4886.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4873–4886
Mots-clés : Arsenic adsorbent Résumé : A porous and efficient arsenic adsorbent (specific surface area, 181 ± 4 m2/g; pore volume, 0.35 ± 0.01 mL/g) is prepared from raw laterite by acid followed by alkali treatment. FTIR, XRD, SEM-EDAX, HRTEM, and a surface area analyzer are used for detailed characterization of treated materials. Adsorption of arsenic on treated laterite (TL) using arsenic spiked distilled water and contaminated groundwater (CGW) is studied in the batch and fixed-bed column modes. The Langmuir isotherm fits better to the experimental data compared to the Freundlich isotherm. The Langmuir maximum capacities of As(V) and As(III) on the best-performing treated material are found to be 24.8 ± 3.9 and 8.0 ± 1.4 mg/g, respectively. Arsenic adsorption on TL follows pseudo-second-order kinetics. The Langmuir maximum adsorptions of arsenic on raw laterite and TL using CGW as the total arsenic are found to be 0.11 ± 0.01 and 7.5 ± 0.4 mg/g, respectively. In the fixed-bed column run, the 6.5 cm TL bed is capable to produce 3000 times the bed volume of treated water with an effluent arsenic concentration ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100612u Exemplaires
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Titre : Effects of CO2 on a High Performance Hollow-Fiber Membrane for Natural Gas Purification Type de document : texte imprimé Auteurs : Imona C. Omole, Auteur ; Ryan T. Adams, Auteur ; Stephen J. Miller, Auteur Année de publication : 2010 Article en page(s) : pp. 4887–4896 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Natural Gas Fiber Résumé : A 6FDA-based, cross-linkable polyimide was characterized in the form of a defect-free asymmetric hollow-fiber membrane. The novel membrane was cross-linked at various temperatures and tested for natural gas purification in the presence of high CO2 partial pressures. The cross-linked membrane material shows high intrinsic separation performance for CO2 and CH4 (selectivity 49, CO2 permeability 161 barrer, with a feed at 65 psia, 35 °C, and 10% CO2). Cross-linked asymmetric hollow-fiber membranes made from the material show good resistance to CO2-induced plasticization. Carbon dioxide partial pressures as high as 400 psia were employed, and the membrane was shown to be promisingly stable under these aggressive conditions. The performance of the membrane was also analyzed using the dual-mode sorption/transport model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100084s#afn1
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4887–4896[article] Effects of CO2 on a High Performance Hollow-Fiber Membrane for Natural Gas Purification [texte imprimé] / Imona C. Omole, Auteur ; Ryan T. Adams, Auteur ; Stephen J. Miller, Auteur . - 2010 . - pp. 4887–4896.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4887–4896
Mots-clés : Natural Gas Fiber Résumé : A 6FDA-based, cross-linkable polyimide was characterized in the form of a defect-free asymmetric hollow-fiber membrane. The novel membrane was cross-linked at various temperatures and tested for natural gas purification in the presence of high CO2 partial pressures. The cross-linked membrane material shows high intrinsic separation performance for CO2 and CH4 (selectivity 49, CO2 permeability 161 barrer, with a feed at 65 psia, 35 °C, and 10% CO2). Cross-linked asymmetric hollow-fiber membranes made from the material show good resistance to CO2-induced plasticization. Carbon dioxide partial pressures as high as 400 psia were employed, and the membrane was shown to be promisingly stable under these aggressive conditions. The performance of the membrane was also analyzed using the dual-mode sorption/transport model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100084s#afn1 Exemplaires
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Titre : Choice of low temperature salt for a resorption refrigerator Type de document : texte imprimé Auteurs : H. S. Bao, Auteur ; R.G. Oliveira, Auteur ; R.Z. Wang, Auteur Année de publication : 2010 Article en page(s) : pp. 4897–4903 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mass refrigerant Résumé : Three bench-scale resorption systems were compared with respect to the degree of conversion, the specific cooling power, and the influence of the working condition on the temperature equilibrium drop. The mass of refrigerant that reacted during specified periods of each working condition studied was assessed gravimetrically. The three systems had MnCl2 in the main reactor, and they were designed to provide a cooling effect at 0 and at −5 °C. However, each system had a different salt (BaCl2, NaBr, or NH4Cl) in the reactor employed for cold production. The system with NH4Cl was the most suitable for cold production at the temperatures indicated above, whereas the system with BaCl2 was not suitable to operate at these levels of cooling production. Thus, we designed and manufactured a larger resorption system and assessed the feasibility of using this system to refrigerate a 33 L cold box, with two temperature zones. When the ambient temperature was 30 °C, the air temperature in the bottom of the cold box could be kept below 0 °C for 5 h, while the temperature of the upper zone remained below 6 °C for about 2.5 h. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901575k
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4897–4903[article] Choice of low temperature salt for a resorption refrigerator [texte imprimé] / H. S. Bao, Auteur ; R.G. Oliveira, Auteur ; R.Z. Wang, Auteur . - 2010 . - pp. 4897–4903.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4897–4903
Mots-clés : Mass refrigerant Résumé : Three bench-scale resorption systems were compared with respect to the degree of conversion, the specific cooling power, and the influence of the working condition on the temperature equilibrium drop. The mass of refrigerant that reacted during specified periods of each working condition studied was assessed gravimetrically. The three systems had MnCl2 in the main reactor, and they were designed to provide a cooling effect at 0 and at −5 °C. However, each system had a different salt (BaCl2, NaBr, or NH4Cl) in the reactor employed for cold production. The system with NH4Cl was the most suitable for cold production at the temperatures indicated above, whereas the system with BaCl2 was not suitable to operate at these levels of cooling production. Thus, we designed and manufactured a larger resorption system and assessed the feasibility of using this system to refrigerate a 33 L cold box, with two temperature zones. When the ambient temperature was 30 °C, the air temperature in the bottom of the cold box could be kept below 0 °C for 5 h, while the temperature of the upper zone remained below 6 °C for about 2.5 h. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901575k Exemplaires
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Titre : Product Design : a Transdermal Patch Containing a Traditional Chinese Medicinal Tincture Type de document : texte imprimé Auteurs : Yuen S. Cheng, Auteur ; Ka M. Ng, Auteur ; Christianto Wibowo, Auteur Année de publication : 2010 Article en page(s) : pp. 4904–4913 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Transdermal Patch Résumé : The traditional Chinese medicinal tincture is inconvenient to use and has strong herbal smells. It is highly desirable to convert such a tincture product into a transdermal patch. This study aims to design such a transdermal patch using an integrative approach. The tasks of market study, product design, prototyping, and process design were considered. Specifically, customers’ needs were collected from market study to identify the quality factors of the new product, which were, in turn, translated into the basic product configuration and technical specifications. Compatibility tests and diffusion experiments were carried out for material screening and performance testing. The procedure for fabricating the transdermal patch was also developed. Finally, a manufacturing process was proposed based on the laboratory-scale fabrication procedure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901554s
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4904–4913[article] Product Design : a Transdermal Patch Containing a Traditional Chinese Medicinal Tincture [texte imprimé] / Yuen S. Cheng, Auteur ; Ka M. Ng, Auteur ; Christianto Wibowo, Auteur . - 2010 . - pp. 4904–4913.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4904–4913
Mots-clés : Transdermal Patch Résumé : The traditional Chinese medicinal tincture is inconvenient to use and has strong herbal smells. It is highly desirable to convert such a tincture product into a transdermal patch. This study aims to design such a transdermal patch using an integrative approach. The tasks of market study, product design, prototyping, and process design were considered. Specifically, customers’ needs were collected from market study to identify the quality factors of the new product, which were, in turn, translated into the basic product configuration and technical specifications. Compatibility tests and diffusion experiments were carried out for material screening and performance testing. The procedure for fabricating the transdermal patch was also developed. Finally, a manufacturing process was proposed based on the laboratory-scale fabrication procedure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901554s Exemplaires
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Titre : Integral Equation Theory for Gas Sorption and Swelling of Glassy Atactic Polystyrene Type de document : texte imprimé Auteurs : Qinzhi Xu, Auteur ; Jianguo Mi, Auteur ; Chongli Zhong, Auteur Année de publication : 2010 Article en page(s) : pp. 4914–4922 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas Sorption Résumé : On the basis of the polymer reference interaction site model (PRISM), a theoretical approach was proposed to describe gas solubilities in atactic polystyrene (aPS) melt. In the PRISM, our recently developed multisite semiflexible model was applied to derive intramolecular correlation functions. The intermolecular correlation functions for gas−gas and gas−aPS were obtained and further applied to calculate the excess chemical potential of gas−aPS system. The solubility coefficients of a wide range of gases in aPS were predicted at low pressure. These predictions are in good agreement with the experimental data. Particularly, the sorption curves of CO2 in aPS under high pressures were calculated, and the reasonable results were obtained. These results demonstrate that the theoretical model is reliable to describe the sorption properties of small molecules in aPS chain. On the basis of the CO2 sorption isotherms, the swelling of aPS under high pressure were also discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901728p
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4914–4922[article] Integral Equation Theory for Gas Sorption and Swelling of Glassy Atactic Polystyrene [texte imprimé] / Qinzhi Xu, Auteur ; Jianguo Mi, Auteur ; Chongli Zhong, Auteur . - 2010 . - pp. 4914–4922.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4914–4922
Mots-clés : Gas Sorption Résumé : On the basis of the polymer reference interaction site model (PRISM), a theoretical approach was proposed to describe gas solubilities in atactic polystyrene (aPS) melt. In the PRISM, our recently developed multisite semiflexible model was applied to derive intramolecular correlation functions. The intermolecular correlation functions for gas−gas and gas−aPS were obtained and further applied to calculate the excess chemical potential of gas−aPS system. The solubility coefficients of a wide range of gases in aPS were predicted at low pressure. These predictions are in good agreement with the experimental data. Particularly, the sorption curves of CO2 in aPS under high pressures were calculated, and the reasonable results were obtained. These results demonstrate that the theoretical model is reliable to describe the sorption properties of small molecules in aPS chain. On the basis of the CO2 sorption isotherms, the swelling of aPS under high pressure were also discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901728p Exemplaires
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Titre : Integral Equation Theory for Gas Sorption and Swelling of Glassy Atactic Polystyrene Type de document : texte imprimé Année de publication : 2010 Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010)[article] Integral Equation Theory for Gas Sorption and Swelling of Glassy Atactic Polystyrene [texte imprimé] . - 2010.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010)Exemplaires
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Titre : Using an adaptive parameter method for process simulation of nonideal systems Type de document : texte imprimé Auteurs : Laura A. Pellegrini, Auteur ; Simone Gamba, Auteur ; Stefania Moioli, Auteur Année de publication : 2010 Article en page(s) : pp. 4923–4932 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Process Simulation Nonideal Systems Résumé : A thermodynamic model of the / class of methods that can be easily used with commercial process simulators is proposed. The vapor−liquid equilibrium (VLE) is calculated by means of a Redlich−Kwong-type equation of state (EoS) that uses modified Huron−Vidal mixing rules with activity coefficients: the activity coefficients are derived from the NRTL model whose parameters are evaluated by fitting VLE data of binary mixtures. By means of the Aspen PLUS process simulator, a comparison is made between the performances of both the proposed method with user-created adaptive parameters that can be forced into the simulator database and the Predictive−Soave−Redlich−Kwong (PSRK) method that uses UNIFAC to compute the excess free energy. The ethanol−water separation by extractive distillation is analyzed to point out how an incorrect prediction of the azeotrope can lead to underestimation of the overall process energy requirement. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901773q
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4923–4932[article] Using an adaptive parameter method for process simulation of nonideal systems [texte imprimé] / Laura A. Pellegrini, Auteur ; Simone Gamba, Auteur ; Stefania Moioli, Auteur . - 2010 . - pp. 4923–4932.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4923–4932
Mots-clés : Process Simulation Nonideal Systems Résumé : A thermodynamic model of the / class of methods that can be easily used with commercial process simulators is proposed. The vapor−liquid equilibrium (VLE) is calculated by means of a Redlich−Kwong-type equation of state (EoS) that uses modified Huron−Vidal mixing rules with activity coefficients: the activity coefficients are derived from the NRTL model whose parameters are evaluated by fitting VLE data of binary mixtures. By means of the Aspen PLUS process simulator, a comparison is made between the performances of both the proposed method with user-created adaptive parameters that can be forced into the simulator database and the Predictive−Soave−Redlich−Kwong (PSRK) method that uses UNIFAC to compute the excess free energy. The ethanol−water separation by extractive distillation is analyzed to point out how an incorrect prediction of the azeotrope can lead to underestimation of the overall process energy requirement. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901773q Exemplaires
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Titre : Time variations of macrostickies and extractable stickies concentrations in deinking Type de document : texte imprimé Auteurs : Donald MacNeil, Auteur ; Ruben Miranda, Auteur ; M. Concepcion Monte, Auteur Année de publication : 2010 Article en page(s) : pp. 4933–4939 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Macrostickies Résumé : The stickies content, both macrostickies and stickies extractable in a solvent, was determined for samples taken at short time intervals from deinking lines, producing deinked pulp for newsprint production. The study was carried out at three mills on different continents, with each having a different source of recycled paper as raw material. The short-term variations in extractable stickies in the incoming raw material were quite extreme, with differences of 100% being seen within hours. Despite this, the final deinked pulp contained fewer sudden variations and had no correlation to the incoming stickies content. While the raw material appeared to affect the incoming stickies content, a well-optimized deinking line was able to buffer the raw material variability, and the final stickies content was more dependent on the deinking process. This result was seen for the two mills examined for this phenomenon, despite a different raw material supply. Macrostickies were found to exhibit the same tendencies, although with smaller and less sudden variations. However, the variations of macrostickies and extractable stickies never correlated, even when both were measured for the same pulp fraction, thus confirming that solvent extraction is not an appropriate method for the determination of macrostickies and is more a reflection of microstickies. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9018098
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4933–4939[article] Time variations of macrostickies and extractable stickies concentrations in deinking [texte imprimé] / Donald MacNeil, Auteur ; Ruben Miranda, Auteur ; M. Concepcion Monte, Auteur . - 2010 . - pp. 4933–4939.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4933–4939
Mots-clés : Macrostickies Résumé : The stickies content, both macrostickies and stickies extractable in a solvent, was determined for samples taken at short time intervals from deinking lines, producing deinked pulp for newsprint production. The study was carried out at three mills on different continents, with each having a different source of recycled paper as raw material. The short-term variations in extractable stickies in the incoming raw material were quite extreme, with differences of 100% being seen within hours. Despite this, the final deinked pulp contained fewer sudden variations and had no correlation to the incoming stickies content. While the raw material appeared to affect the incoming stickies content, a well-optimized deinking line was able to buffer the raw material variability, and the final stickies content was more dependent on the deinking process. This result was seen for the two mills examined for this phenomenon, despite a different raw material supply. Macrostickies were found to exhibit the same tendencies, although with smaller and less sudden variations. However, the variations of macrostickies and extractable stickies never correlated, even when both were measured for the same pulp fraction, thus confirming that solvent extraction is not an appropriate method for the determination of macrostickies and is more a reflection of microstickies. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9018098 Exemplaires
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Titre : An efficient numerical method for solving a model describing crystallization of polymorphs Type de document : texte imprimé Auteurs : Shamsul Qamar, Auteur ; Saima Noor, Auteur ; Andreas Seidel - Morgenstern, Auteur Année de publication : 2010 Article en page(s) : pp. 4940–4947 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystallization Polymorphs Résumé : Polymorphism, in which a chemical compound exhibits different crystal forms or structures, has significant influence on the processing and storage of some crystalline powders in pharmaceutical industry. Different crystal structures, the so-called polymorphs, have different physical and chemical properties, such as crystal morphology, solubility, and color. These properties can have profound effect on the performance of products. This fact has motivated several researchers in this field to analyze, simulate, and control the crystallization of polymorphs. In this article, an efficient and accurate numerical method is introduced for solving a model describing crystallization of polymorphs. The proposed method has two parts. In the first part, a coupled system of ordinary differential equations of moments and the solute concentration is numerically solved in the time domain of interest. The resulting values are used to get the discrete growth and nucleation rates in the same time domain. In the second part, these discrete values along with the initial crystal size distribution (CSD) are used to construct the final CSD. The method is applied to a model describing crystallization of polymorphs of l-glutamic acid. For a validation, the results of the proposed technique are compared with those from the finite volume schemes. The numerical results demonstrate the potential of our scheme for the simulation of current model with high efficiency and accuracy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9018353
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4940–4947[article] An efficient numerical method for solving a model describing crystallization of polymorphs [texte imprimé] / Shamsul Qamar, Auteur ; Saima Noor, Auteur ; Andreas Seidel - Morgenstern, Auteur . - 2010 . - pp. 4940–4947.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4940–4947
Mots-clés : Crystallization Polymorphs Résumé : Polymorphism, in which a chemical compound exhibits different crystal forms or structures, has significant influence on the processing and storage of some crystalline powders in pharmaceutical industry. Different crystal structures, the so-called polymorphs, have different physical and chemical properties, such as crystal morphology, solubility, and color. These properties can have profound effect on the performance of products. This fact has motivated several researchers in this field to analyze, simulate, and control the crystallization of polymorphs. In this article, an efficient and accurate numerical method is introduced for solving a model describing crystallization of polymorphs. The proposed method has two parts. In the first part, a coupled system of ordinary differential equations of moments and the solute concentration is numerically solved in the time domain of interest. The resulting values are used to get the discrete growth and nucleation rates in the same time domain. In the second part, these discrete values along with the initial crystal size distribution (CSD) are used to construct the final CSD. The method is applied to a model describing crystallization of polymorphs of l-glutamic acid. For a validation, the results of the proposed technique are compared with those from the finite volume schemes. The numerical results demonstrate the potential of our scheme for the simulation of current model with high efficiency and accuracy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9018353 Exemplaires
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Titre : Integration of operational planning and medium - term scheduling for large - scale industrial batch plants under demand and processing time uncertainty Type de document : texte imprimé Auteurs : Peter M. Verderame, Auteur ; Christodoulos A. Floudas, Auteur Année de publication : 2010 Article en page(s) : pp. 4948–4965 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Operational Planning Résumé : Operational planning, medium-term scheduling, and short-term scheduling are closely related activities. Despite prior advances, the effective integration of planning and scheduling under demand and processing time uncertainty remains a challenging problem, especially for large-scale industrial processes. To address this issue, a novel framework for the integration of planning and scheduling under demand due date and amount uncertainty, as well as batch processing time uncertainty is proposed. Both the robust operational planning with production disaggregation model and the operational conditional value-at-risk planning with production disaggregation model have been successfully interfaced with an industrially validated medium-term scheduling model by means of a rolling horizon framework used in conjunction with a novel feedback loop. Demand uncertainty is taken into account at the planning level, processing time uncertainty is addressed within the selected scheduling model, and a novel feedback loop allows for the two-way interaction between the planning and scheduling levels. An industrial case study has been conducted for a large-scale multipurpose and multiproduct batch plant capable of producing hundreds of products over a time horizon of 3 months in order to demonstrate the viability of the proposed approach. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901973e
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4948–4965[article] Integration of operational planning and medium - term scheduling for large - scale industrial batch plants under demand and processing time uncertainty [texte imprimé] / Peter M. Verderame, Auteur ; Christodoulos A. Floudas, Auteur . - 2010 . - pp. 4948–4965.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4948–4965
Mots-clés : Operational Planning Résumé : Operational planning, medium-term scheduling, and short-term scheduling are closely related activities. Despite prior advances, the effective integration of planning and scheduling under demand and processing time uncertainty remains a challenging problem, especially for large-scale industrial processes. To address this issue, a novel framework for the integration of planning and scheduling under demand due date and amount uncertainty, as well as batch processing time uncertainty is proposed. Both the robust operational planning with production disaggregation model and the operational conditional value-at-risk planning with production disaggregation model have been successfully interfaced with an industrially validated medium-term scheduling model by means of a rolling horizon framework used in conjunction with a novel feedback loop. Demand uncertainty is taken into account at the planning level, processing time uncertainty is addressed within the selected scheduling model, and a novel feedback loop allows for the two-way interaction between the planning and scheduling levels. An industrial case study has been conducted for a large-scale multipurpose and multiproduct batch plant capable of producing hundreds of products over a time horizon of 3 months in order to demonstrate the viability of the proposed approach. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901973e Exemplaires
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Titre : Application of a group contribution equation of state for the thermodynamic modeling of gas + ionic liquid mixtures Type de document : texte imprimé Auteurs : Maria Dolores Bermejo, Auteur ; David Méndez, Auteur ; Angel Martin, Auteur Année de publication : 2010 Article en page(s) : pp. 4966–4973 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas Ionic Liquid Résumé : The group contribution equation of state (GC-EoS) is used to describe the phase behavior of gas + ionic liquid mixtures. With this equation, by application of the group contribution concept, if the parameters of the characteristic functional group of a family of ionic liquids are calculated using experimental data of a reduced number of ionic liquids of the family, then the phase behavior of all ionic liquids of the same family can be predicted. With this work, the parameter table of the GC-EoS is extended to systems that are comprised of an ionic liquid of the methylimidazolium bis[(trifluoromethyl)sulfonyl]imide family [−mim][Tf2N] and a gas (H2, CO, C2H4, O2, SO2, CH3OH, N2O, or Xe). Furthermore, a compilation of all GC-EoS parameters for gas + ionic liquid systems currently available in the literature is presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901989f
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4966–4973[article] Application of a group contribution equation of state for the thermodynamic modeling of gas + ionic liquid mixtures [texte imprimé] / Maria Dolores Bermejo, Auteur ; David Méndez, Auteur ; Angel Martin, Auteur . - 2010 . - pp. 4966–4973.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4966–4973
Mots-clés : Gas Ionic Liquid Résumé : The group contribution equation of state (GC-EoS) is used to describe the phase behavior of gas + ionic liquid mixtures. With this equation, by application of the group contribution concept, if the parameters of the characteristic functional group of a family of ionic liquids are calculated using experimental data of a reduced number of ionic liquids of the family, then the phase behavior of all ionic liquids of the same family can be predicted. With this work, the parameter table of the GC-EoS is extended to systems that are comprised of an ionic liquid of the methylimidazolium bis[(trifluoromethyl)sulfonyl]imide family [−mim][Tf2N] and a gas (H2, CO, C2H4, O2, SO2, CH3OH, N2O, or Xe). Furthermore, a compilation of all GC-EoS parameters for gas + ionic liquid systems currently available in the literature is presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901989f Exemplaires
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Titre : Pressure drop as a simple method for locating phase transitions in continuous flow high pressure reactors Type de document : texte imprimé Auteurs : Geoffrey R. Akien, Auteur ; Ryan A. Skilton, Auteur ; Martyn Poliakoff, Auteur Année de publication : 2010 Article en page(s) : pp. 4974-4980 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reactor Continuous process Phase transitions Hydrodynamics Pressure drop Résumé : This paper describes the use of the pressure drop across a packed column to locate phase transitions in highpressure fluids in continuous flow. The pressure drop method yields data that can be used to locate phase transitions objectively, and an example of an automated searching algorithm is demonstrated as a proof of concept. Finally, we demonstrate the ability of the pressure drop method to be applied in operando to a hydrogenation reaction. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797493
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4974-4980[article] Pressure drop as a simple method for locating phase transitions in continuous flow high pressure reactors [texte imprimé] / Geoffrey R. Akien, Auteur ; Ryan A. Skilton, Auteur ; Martyn Poliakoff, Auteur . - 2010 . - pp. 4974-4980.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4974-4980
Mots-clés : Reactor Continuous process Phase transitions Hydrodynamics Pressure drop Résumé : This paper describes the use of the pressure drop across a packed column to locate phase transitions in highpressure fluids in continuous flow. The pressure drop method yields data that can be used to locate phase transitions objectively, and an example of an automated searching algorithm is demonstrated as a proof of concept. Finally, we demonstrate the ability of the pressure drop method to be applied in operando to a hydrogenation reaction. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22797493 Exemplaires
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Titre : Solubilities of NaCl, KCl, LiCl, and LiBr in methanol, ethanol, acetone, and mixed solvents and correlation using the LIQUAC model Type de document : texte imprimé Auteurs : Miyi Li, Auteur ; Dana Constantinescu, Auteur ; Wang, Lisheng, Auteur Année de publication : 2010 Article en page(s) : pp. 4981–4988 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solubilities Water Methanol Résumé : The solubilities of NaCl, KCl, LiCl, and LiBr in pure methanol, ethanol, and acetone were measured over a temperature range from 293.15 to 333.15 K. Furthermore salt solubilities in the mixed solvents (water + methanol, water + ethanol, water + acetone, methanol + ethanol, methanol + acetone, ethanol + acetone) were determined at 313.15 K. For a few systems solubility data are reported for the first time. In a few cases a comparison with published data stored in the Dortmund Data Bank (DDB)(1) showed disagreement. The LIQUAC model was used to correlate the experimental data. The calculated salt solubilities are in good agreement with the experimental results for the systems NaCl + water + methanol and KCl + water + methanol. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100027c
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4981–4988[article] Solubilities of NaCl, KCl, LiCl, and LiBr in methanol, ethanol, acetone, and mixed solvents and correlation using the LIQUAC model [texte imprimé] / Miyi Li, Auteur ; Dana Constantinescu, Auteur ; Wang, Lisheng, Auteur . - 2010 . - pp. 4981–4988.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4981–4988
Mots-clés : Solubilities Water Methanol Résumé : The solubilities of NaCl, KCl, LiCl, and LiBr in pure methanol, ethanol, and acetone were measured over a temperature range from 293.15 to 333.15 K. Furthermore salt solubilities in the mixed solvents (water + methanol, water + ethanol, water + acetone, methanol + ethanol, methanol + acetone, ethanol + acetone) were determined at 313.15 K. For a few systems solubility data are reported for the first time. In a few cases a comparison with published data stored in the Dortmund Data Bank (DDB)(1) showed disagreement. The LIQUAC model was used to correlate the experimental data. The calculated salt solubilities are in good agreement with the experimental results for the systems NaCl + water + methanol and KCl + water + methanol. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100027c Exemplaires
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Titre : An empirical modification of classical mixing rule for the cohesive parameter : the triple interactions in binary systems considered Type de document : texte imprimé Auteurs : Ilya Polishuk, Auteur Année de publication : 2010 Article en page(s) : pp. 4989–4994 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Binary Systems Résumé : The proposed mixing rule can be formally interpreted as an approach considering the triple cohesive interactions of a part of the molecules in a mixture as follows: a = k∑i=12∑j=12xixjaij(1 − kij(T)) + (1 − κ)∑i=12∑j=12∑k=12xixjxkaijk, where kij(T) and κ are the system-dependent adjustable parameters. Regardless of its possible theoretical justification, the proposed mixing rule is equivalent to the classical mixing rule with the composition-dependent adjustable parameter kij(T), and this dependence follows the regularities typically required for an accurate modeling of experimental data. This study demonstrates that the proposed mixing rule allows an accurate description of the entire thermodynamic phase space involving liquid−liquid−vapor equilibria, vapor−liquid equilibria, and the high pressure liquid−liquid equilibria. However in some complex cases it still may not cancel a need of evaluating the binary parameter l12. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100138h
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4989–4994[article] An empirical modification of classical mixing rule for the cohesive parameter : the triple interactions in binary systems considered [texte imprimé] / Ilya Polishuk, Auteur . - 2010 . - pp. 4989–4994.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4989–4994
Mots-clés : Binary Systems Résumé : The proposed mixing rule can be formally interpreted as an approach considering the triple cohesive interactions of a part of the molecules in a mixture as follows: a = k∑i=12∑j=12xixjaij(1 − kij(T)) + (1 − κ)∑i=12∑j=12∑k=12xixjxkaijk, where kij(T) and κ are the system-dependent adjustable parameters. Regardless of its possible theoretical justification, the proposed mixing rule is equivalent to the classical mixing rule with the composition-dependent adjustable parameter kij(T), and this dependence follows the regularities typically required for an accurate modeling of experimental data. This study demonstrates that the proposed mixing rule allows an accurate description of the entire thermodynamic phase space involving liquid−liquid−vapor equilibria, vapor−liquid equilibria, and the high pressure liquid−liquid equilibria. However in some complex cases it still may not cancel a need of evaluating the binary parameter l12. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100138h Exemplaires
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Titre : Phenomenological simulation model for the prediction of hydrodynamic parameters of an internal loop airlift reactor Type de document : texte imprimé Auteurs : Ragupathy Prabhu Arunkumar, Auteur ; Karuppan Muthukumar, Auteur Année de publication : 2010 Article en page(s) : pp. 4995–5000 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrodynamic Loop airlift reactor Résumé : Airlift reactors are pneumatically agitated reactors finding wide applications in chemical and biotechnology industries as well as in the treatment of wastewater. The design and scale-up of an airlift reactor is difficult and largely based on empirical approaches. The bubble size, distribution, and concentration are important parameters that influence the gas holdup and interfacial area. However, the influence of bubble size and distribution are not taken into account by any of the empirical correlations. In the present investigation, a phenomenological approach has been developed to predict the gas holdup in an internal loop airlift reactor. This approach considers the effect of bubble dynamics such as bubble breakup and bubble coalescence in the column and employs a population balance approach to determine bubble concentration in the column. From the knowledge of number and size of the bubbles, gas holdup in the reactor was obtained. A reasonably good agreement was observed between the simulation model predictions and the experimental data reported in the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900713v
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4995–5000[article] Phenomenological simulation model for the prediction of hydrodynamic parameters of an internal loop airlift reactor [texte imprimé] / Ragupathy Prabhu Arunkumar, Auteur ; Karuppan Muthukumar, Auteur . - 2010 . - pp. 4995–5000.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4995–5000
Mots-clés : Hydrodynamic Loop airlift reactor Résumé : Airlift reactors are pneumatically agitated reactors finding wide applications in chemical and biotechnology industries as well as in the treatment of wastewater. The design and scale-up of an airlift reactor is difficult and largely based on empirical approaches. The bubble size, distribution, and concentration are important parameters that influence the gas holdup and interfacial area. However, the influence of bubble size and distribution are not taken into account by any of the empirical correlations. In the present investigation, a phenomenological approach has been developed to predict the gas holdup in an internal loop airlift reactor. This approach considers the effect of bubble dynamics such as bubble breakup and bubble coalescence in the column and employs a population balance approach to determine bubble concentration in the column. From the knowledge of number and size of the bubbles, gas holdup in the reactor was obtained. A reasonably good agreement was observed between the simulation model predictions and the experimental data reported in the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900713v Exemplaires
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Titre : General intercalation of poly(oxyalkylene) − amidoacids for anionic and cationic layered clays Type de document : texte imprimé Auteurs : Yi-Lin Liao, Auteur ; Chih-Wei Chiu, Auteur ; Jiang-Jen Lin, Auteur Année de publication : 2010 Article en page(s) : pp. 5001–5005 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic clays Hydroxides Résumé : The same poly(oxyalkylene)−amidoacids (POA−amidoacid) were incorporated into two different types of ionic clays, anionic layered-double-hydroxides (Mg−Al LDH), and cationic montmorillonite (MMT). Conventionally, the intercalation is an ionic exchange reaction, i.e. anionic organic salts for LDH and cationic salts for MMT. The successful intercalation using the neutral species of POA−amidoacid implies the existence of a new mechanism for clay intercalation. We prepared the POA−amidoacid from the reaction of maleic anhydride and poly(oxyalkylene)−diamine (POA−amine) with different hydrophobic and hydrophilic POA-backbones of 600−4200 molecular weight. The intercalation has resulted in the expansion of the clay basal spacing from 7.8 to 63 Å for LDH and from 12.4 to 51 Å for MMT, with a high Bragg’s regularity of XRD analyses. It appears that the driving force for the intercalation and organic incorporation into the silicate interlayer galleries is dissimilar to the counterion exchange but involving noncovalent bonding between amidoacid functionalities and ≡SiOH species in clay. The intercalation without ionic exchange reaction is effective for generating new clay hybrids with thermal responsiveness in water. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901136u
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 5001–5005[article] General intercalation of poly(oxyalkylene) − amidoacids for anionic and cationic layered clays [texte imprimé] / Yi-Lin Liao, Auteur ; Chih-Wei Chiu, Auteur ; Jiang-Jen Lin, Auteur . - 2010 . - pp. 5001–5005.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 5001–5005
Mots-clés : Ionic clays Hydroxides Résumé : The same poly(oxyalkylene)−amidoacids (POA−amidoacid) were incorporated into two different types of ionic clays, anionic layered-double-hydroxides (Mg−Al LDH), and cationic montmorillonite (MMT). Conventionally, the intercalation is an ionic exchange reaction, i.e. anionic organic salts for LDH and cationic salts for MMT. The successful intercalation using the neutral species of POA−amidoacid implies the existence of a new mechanism for clay intercalation. We prepared the POA−amidoacid from the reaction of maleic anhydride and poly(oxyalkylene)−diamine (POA−amine) with different hydrophobic and hydrophilic POA-backbones of 600−4200 molecular weight. The intercalation has resulted in the expansion of the clay basal spacing from 7.8 to 63 Å for LDH and from 12.4 to 51 Å for MMT, with a high Bragg’s regularity of XRD analyses. It appears that the driving force for the intercalation and organic incorporation into the silicate interlayer galleries is dissimilar to the counterion exchange but involving noncovalent bonding between amidoacid functionalities and ≡SiOH species in clay. The intercalation without ionic exchange reaction is effective for generating new clay hybrids with thermal responsiveness in water. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901136u Exemplaires
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Titre : Periodic thermal behavior of porous media under oscillating flow conditions Type de document : texte imprimé Auteurs : Margaritis Kostoglou, Auteur Année de publication : 2010 Article en page(s) : pp. 5006–5011 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermal Behavior Résumé : In the present work an analytical study of the heat transfer in an oscillating flow through a porous medium is performed using a two equation model. The previous analysis performed [Byun et al. Int. J. Heat Mass Transfer 2006, 49, 5081−5085] is extended to include an arbitrary velocity magnitude and arbitrary oscillation pattern of the flow. Using asymptotic analysis with respect to several dimensionless parameters, the limits of validity of the analytical solution based on the previous approach [Byun et al. Int. J. Heat Mass Transfer 2006, 49, 5081−5085] are assessed. A new analytical solution is derived for the case of thermal equilibrium between solid and fluid. Several asymptotic results existing in the literature [Byun et al. Int. J. Heat Mass Transfer 2006, 49, 5081−5085; Klein and Eigenberger Int. J. Heat Mass Transfer 2001, 44, 3535−3563] are compared with the findings of the present work. This work completes the analytical study of the particular mathematical problem, previously advanced [Byun et al. Int. J. Heat Mass Transfer 2006, 49, 5081−5085; Klein and Eigenberger Int. J. Heat Mass Transfer 2001, 44, 3535−3563]. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9014638
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 5006–5011[article] Periodic thermal behavior of porous media under oscillating flow conditions [texte imprimé] / Margaritis Kostoglou, Auteur . - 2010 . - pp. 5006–5011.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 5006–5011
Mots-clés : Thermal Behavior Résumé : In the present work an analytical study of the heat transfer in an oscillating flow through a porous medium is performed using a two equation model. The previous analysis performed [Byun et al. Int. J. Heat Mass Transfer 2006, 49, 5081−5085] is extended to include an arbitrary velocity magnitude and arbitrary oscillation pattern of the flow. Using asymptotic analysis with respect to several dimensionless parameters, the limits of validity of the analytical solution based on the previous approach [Byun et al. Int. J. Heat Mass Transfer 2006, 49, 5081−5085] are assessed. A new analytical solution is derived for the case of thermal equilibrium between solid and fluid. Several asymptotic results existing in the literature [Byun et al. Int. J. Heat Mass Transfer 2006, 49, 5081−5085; Klein and Eigenberger Int. J. Heat Mass Transfer 2001, 44, 3535−3563] are compared with the findings of the present work. This work completes the analytical study of the particular mathematical problem, previously advanced [Byun et al. Int. J. Heat Mass Transfer 2006, 49, 5081−5085; Klein and Eigenberger Int. J. Heat Mass Transfer 2001, 44, 3535−3563]. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9014638 Exemplaires
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Titre : Ionic Liquids as Vulcanization Accelerators Type de document : texte imprimé Auteurs : Juliusz Pernak, Auteur ; Filip Walkiewicz, Auteur ; Magdalena Maciejewska, Auteur Année de publication : 2010 Article en page(s) : pp. 5012–5017 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic liquids Résumé : The synthesis, physical properties, and antimicrobial activity of imidazolium, benzalkonium, and phosphonium ionic liquids with 2-mercaptobenzothiazolate has been studied. Synthesized ionic liquids were used as acceleration agents in the vulcanization of rubber. Use of synthesized salts allows to reduce amount of 2-mercaptobenzothiazole, which is commonly used in vulcanization but is an allergenic agent. We obtain in our research shorter vulcanization time, no loss of mechanical properties of rubber, and reduction of the allergen from 56 to 87% in comparison with the vulcanization without ILs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100151n
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 5012–5017[article] Ionic Liquids as Vulcanization Accelerators [texte imprimé] / Juliusz Pernak, Auteur ; Filip Walkiewicz, Auteur ; Magdalena Maciejewska, Auteur . - 2010 . - pp. 5012–5017.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 5012–5017
Mots-clés : Ionic liquids Résumé : The synthesis, physical properties, and antimicrobial activity of imidazolium, benzalkonium, and phosphonium ionic liquids with 2-mercaptobenzothiazolate has been studied. Synthesized ionic liquids were used as acceleration agents in the vulcanization of rubber. Use of synthesized salts allows to reduce amount of 2-mercaptobenzothiazole, which is commonly used in vulcanization but is an allergenic agent. We obtain in our research shorter vulcanization time, no loss of mechanical properties of rubber, and reduction of the allergen from 56 to 87% in comparison with the vulcanization without ILs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100151n Exemplaires
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Titre : Vaporization enthalpy of pure refrigerants : comparative study of eighteen correlations Type de document : texte imprimé Auteurs : A. Mulero, Auteur ; M. I. Parra, Auteur ; K. K. Park, Auteur Année de publication : 2010 Article en page(s) : pp. 5018–5026 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Vaporization Refrigerants Résumé : In this work, the performance and accuracy of 18 correlations for the vaporization enthalpy of 48 pure substances is studied. Forty-six of these substances are refrigerants, and two (hexane and heptane) could be used in refrigerant mixtures. Seven of the correlations include 2 adjustable coefficients for every fluid, whereas the other 11 have three coefficients. Some of these correlations are classical expressions, but others have been proposed recently or have been slightly modified or extended for this study. In all the cases, we consider the normal boiling point as a constraint, and then the input parameters are the critical temperature, and the temperature and vaporization enthalpy at the normal boiling point. The data and input properties were taken from both the DIPPR (1968 data) and the NIST databases (10 650 data). Thus, as a first step, we have studied the possible differences between these data. The results showed that the correlation recently proposed by Park gives the lowest mean average percentage deviations for both two-coefficient and three-coefficient models. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901015f
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 5018–5026[article] Vaporization enthalpy of pure refrigerants : comparative study of eighteen correlations [texte imprimé] / A. Mulero, Auteur ; M. I. Parra, Auteur ; K. K. Park, Auteur . - 2010 . - pp. 5018–5026.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 5018–5026
Mots-clés : Vaporization Refrigerants Résumé : In this work, the performance and accuracy of 18 correlations for the vaporization enthalpy of 48 pure substances is studied. Forty-six of these substances are refrigerants, and two (hexane and heptane) could be used in refrigerant mixtures. Seven of the correlations include 2 adjustable coefficients for every fluid, whereas the other 11 have three coefficients. Some of these correlations are classical expressions, but others have been proposed recently or have been slightly modified or extended for this study. In all the cases, we consider the normal boiling point as a constraint, and then the input parameters are the critical temperature, and the temperature and vaporization enthalpy at the normal boiling point. The data and input properties were taken from both the DIPPR (1968 data) and the NIST databases (10 650 data). Thus, as a first step, we have studied the possible differences between these data. The results showed that the correlation recently proposed by Park gives the lowest mean average percentage deviations for both two-coefficient and three-coefficient models. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901015f Exemplaires
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