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Vol. 51 N° 19 - Mai 2012 [texte imprimé] . - 2012 . - p. 6599-6990 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierHydrotreating of phenolic compounds separated from bio - oil to alcohols / Jianhua Guo in Industrial & engineering chemistry research, Vol. 51 N° 19 (Mai 2012)
Titre : Hydrotreating of phenolic compounds separated from bio - oil to alcohols Type de document : texte imprimé Auteurs : Jianhua Guo, Auteur ; Renxiang Ruan, Auteur ; Ying Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 6599-6604 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrotreating Résumé : Phenolic compounds in bio-oil are not stable and difficult to be upgraded to ideal fuels. In this study, simulated bio-oil as well as phenolic compounds separated from bio-oil by glycerol-assisted distillation were hydrotreated by Ru/SBA-15 catalyst and completely converted into C3 to C10 alcohols at mild conditions, which could be a feasible way to transfer the phenolic compounds in bio-oil or other real systems from lignin decomposition into high heating-value liquid fuel or fuel additives. The stability of the Ru/SBA-15 catalyst was also investigated. It was found that Ru/SBA-15 was stable with phenolic compounds in the simulated bio-oil but not in a real one. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900211
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6599-6604[article] Hydrotreating of phenolic compounds separated from bio - oil to alcohols [texte imprimé] / Jianhua Guo, Auteur ; Renxiang Ruan, Auteur ; Ying Zhang, Auteur . - 2012 . - pp. 6599-6604.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6599-6604
Mots-clés : Hydrotreating Résumé : Phenolic compounds in bio-oil are not stable and difficult to be upgraded to ideal fuels. In this study, simulated bio-oil as well as phenolic compounds separated from bio-oil by glycerol-assisted distillation were hydrotreated by Ru/SBA-15 catalyst and completely converted into C3 to C10 alcohols at mild conditions, which could be a feasible way to transfer the phenolic compounds in bio-oil or other real systems from lignin decomposition into high heating-value liquid fuel or fuel additives. The stability of the Ru/SBA-15 catalyst was also investigated. It was found that Ru/SBA-15 was stable with phenolic compounds in the simulated bio-oil but not in a real one. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900211 Exemplaires
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Titre : Supersaturation - controlled synthesis of dicalcium phosphate dihydrate and nanocrystalline calcium - deficient hydroxyapatite Type de document : texte imprimé Auteurs : F. Lagno, Auteur ; S.D.F. Rocha, Auteur ; L. Katsarou, Auteur Année de publication : 2012 Article en page(s) : pp. 6605-6612 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydroxyapatite Supersaturation Résumé : The homogeneous and seed-assisted precipitation of dicalcium phosphate dihydrate (DCPD or brushite) and hydroxyapatite (HAP) under controlled supersaturation regimes in chloride media at room temperature (22 °C) is investigated. Prior to their reactive crystallization the metastable zones of precipitation for the two calcium orthophosphates were determined. The effects of supersaturation, reaction time, and seeding on the stoichiometry and crystallinity of these compounds were studied. Acidified solutions (pH ≈ 2.0) of NaH2PO4 (2-90 mmol/L) and CaCl2 (2-150 mmol/L) were mixed in order to get Ca to P molar ratios in initial solution of 1.0 or 1.67 (the stoichiometric ratios for dicalcium phosphate dihydrate and hydroxyapatite).The supersaturation in solution was built up by the slow addition of 100 mmol/L NaOH solution. In seed-assisted precipitation tests (Ca/P = 1) the metastable calcium phosphate solution (37.5 mmol/L) was neutralized until the precipitation pH of 5 was reached and 10 g/L of seed was added. The homogeneous precipitation of DCPD at pH 5.4 was fast and equilibrium was reached in 30 min. In the presence of seed, the precipitation rate was slower due to reduced supersaturation. Even so, in both cases well crystalline plate-like crystals matching the stoichiometry of brushite were produced. Calcium-deficient hydroxyapatite with nanocrystalline structure (nanocrystallite size ∼20 nm) was produced at pH 7.6 under controlled supersaturation. The homogeneously produced material consisted of irregularly shaped agglomerates of the order of 5―15 μm while the product obtained by seed-assisted precipitation was in the form of rather coarse (ca. 20―30 μm) and dense spheroids. The highest Ca:P ratio material (Ca:P = 1.58) was obtained with seed-assisted precipitation at a slow addition rate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900212
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6605-6612[article] Supersaturation - controlled synthesis of dicalcium phosphate dihydrate and nanocrystalline calcium - deficient hydroxyapatite [texte imprimé] / F. Lagno, Auteur ; S.D.F. Rocha, Auteur ; L. Katsarou, Auteur . - 2012 . - pp. 6605-6612.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6605-6612
Mots-clés : Hydroxyapatite Supersaturation Résumé : The homogeneous and seed-assisted precipitation of dicalcium phosphate dihydrate (DCPD or brushite) and hydroxyapatite (HAP) under controlled supersaturation regimes in chloride media at room temperature (22 °C) is investigated. Prior to their reactive crystallization the metastable zones of precipitation for the two calcium orthophosphates were determined. The effects of supersaturation, reaction time, and seeding on the stoichiometry and crystallinity of these compounds were studied. Acidified solutions (pH ≈ 2.0) of NaH2PO4 (2-90 mmol/L) and CaCl2 (2-150 mmol/L) were mixed in order to get Ca to P molar ratios in initial solution of 1.0 or 1.67 (the stoichiometric ratios for dicalcium phosphate dihydrate and hydroxyapatite).The supersaturation in solution was built up by the slow addition of 100 mmol/L NaOH solution. In seed-assisted precipitation tests (Ca/P = 1) the metastable calcium phosphate solution (37.5 mmol/L) was neutralized until the precipitation pH of 5 was reached and 10 g/L of seed was added. The homogeneous precipitation of DCPD at pH 5.4 was fast and equilibrium was reached in 30 min. In the presence of seed, the precipitation rate was slower due to reduced supersaturation. Even so, in both cases well crystalline plate-like crystals matching the stoichiometry of brushite were produced. Calcium-deficient hydroxyapatite with nanocrystalline structure (nanocrystallite size ∼20 nm) was produced at pH 7.6 under controlled supersaturation. The homogeneously produced material consisted of irregularly shaped agglomerates of the order of 5―15 μm while the product obtained by seed-assisted precipitation was in the form of rather coarse (ca. 20―30 μm) and dense spheroids. The highest Ca:P ratio material (Ca:P = 1.58) was obtained with seed-assisted precipitation at a slow addition rate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900212 Exemplaires
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Titre : Facile method for determination of amine speciation in CO2 capture solutions Type de document : texte imprimé Auteurs : Naser S. Matin, Auteur ; Joseph E. Remias, Auteur ; James K. Neathery, Auteur Année de publication : 2012 Article en page(s) : pp. 6613–6618 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Amine Capture solutions Résumé : A simple and quantitatively reliable method for determination of amine speciation is introduced. The method employs three experimental methods that should be readily accessible. The results for CO2 loaded aqueous solutions of 30 wt % monoethanolamine (MEA) are used for demonstration of the method and show promising agreement with the more complicated spectroscopic methods reported in the literature. The measurements were done at ambient temperature and atmospheric pressure, since theoretical calculations and experimental data from the open literature revealed no considerable difference in speciation at different temperatures. The procedure is based on acid and base titration of the CO2 loaded amine solution along with the determination of total CO2 loading. The quantitative results for the different species concentration in the example MEA solution is in agreement with other available spectroscopic methods, mainly NMR, particularly for the free amine, carbamate, and protonated amine concentrations. Aspen Plus was also used for further assessment of the experimental data. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300230k
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6613–6618[article] Facile method for determination of amine speciation in CO2 capture solutions [texte imprimé] / Naser S. Matin, Auteur ; Joseph E. Remias, Auteur ; James K. Neathery, Auteur . - 2012 . - pp. 6613–6618.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6613–6618
Mots-clés : Amine Capture solutions Résumé : A simple and quantitatively reliable method for determination of amine speciation is introduced. The method employs three experimental methods that should be readily accessible. The results for CO2 loaded aqueous solutions of 30 wt % monoethanolamine (MEA) are used for demonstration of the method and show promising agreement with the more complicated spectroscopic methods reported in the literature. The measurements were done at ambient temperature and atmospheric pressure, since theoretical calculations and experimental data from the open literature revealed no considerable difference in speciation at different temperatures. The procedure is based on acid and base titration of the CO2 loaded amine solution along with the determination of total CO2 loading. The quantitative results for the different species concentration in the example MEA solution is in agreement with other available spectroscopic methods, mainly NMR, particularly for the free amine, carbamate, and protonated amine concentrations. Aspen Plus was also used for further assessment of the experimental data. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300230k Exemplaires
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Titre : Cyclic imide dioximes : Formation and hydrolytic stability Type de document : texte imprimé Auteurs : Sung Ok Kang, Auteur ; Sinisa Vukovic, Auteur ; Radu Custelcean, Auteur Année de publication : 2012 Article en page(s) : pp. 6619-6624 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Stability Résumé : Poly(acrylamidoximes) play an important role in the uranium extraction from seawater. The present work reports solution studies of simple analogues to address the formation and stability of two binding sites present in these polymers, open-chain amidoximes and cyclic imide dioximes, including: (1) conditions that maximize the formation of the cyclic form, (2) the existence of a base-induced conversion from open-chain to cyclic form, and (3) degadation under acid and base conditions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900214
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6619-6624[article] Cyclic imide dioximes : Formation and hydrolytic stability [texte imprimé] / Sung Ok Kang, Auteur ; Sinisa Vukovic, Auteur ; Radu Custelcean, Auteur . - 2012 . - pp. 6619-6624.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6619-6624
Mots-clés : Stability Résumé : Poly(acrylamidoximes) play an important role in the uranium extraction from seawater. The present work reports solution studies of simple analogues to address the formation and stability of two binding sites present in these polymers, open-chain amidoximes and cyclic imide dioximes, including: (1) conditions that maximize the formation of the cyclic form, (2) the existence of a base-induced conversion from open-chain to cyclic form, and (3) degadation under acid and base conditions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900214 Exemplaires
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Titre : Complete reduction of polychlorinated biphenyls by acid - etched steel wool in supercritical carbon dioxide Type de document : texte imprimé Auteurs : Yun-Chieh Chen, Auteur ; Weisheng Liao, Auteur ; Hwa-Kwang Yak, Auteur Année de publication : 2012 Article en page(s) : pp. 6625-6630 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Supercritical state Carbon dioxide Steel Résumé : Inexpensive household steel wool was used as a reducing agent for the reductive dechlorination of polychlorinated biphenyls (PCBs) in supercritical carbon dioxide (scCO2). Untreated steel wool does not produce significant results. Steel wool treated with 6 N HCl, however, showed complete reduction of the PCBs (Aroclor 1254) used. Scanning electron microscopy (SEM) reveals the formation of nanoscale pits (nanopits) on the surface of steel wool after etching with HCl. These nanopits are responsible for the high efficiency of the hydrodechlorination process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900215
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6625-6630[article] Complete reduction of polychlorinated biphenyls by acid - etched steel wool in supercritical carbon dioxide [texte imprimé] / Yun-Chieh Chen, Auteur ; Weisheng Liao, Auteur ; Hwa-Kwang Yak, Auteur . - 2012 . - pp. 6625-6630.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6625-6630
Mots-clés : Supercritical state Carbon dioxide Steel Résumé : Inexpensive household steel wool was used as a reducing agent for the reductive dechlorination of polychlorinated biphenyls (PCBs) in supercritical carbon dioxide (scCO2). Untreated steel wool does not produce significant results. Steel wool treated with 6 N HCl, however, showed complete reduction of the PCBs (Aroclor 1254) used. Scanning electron microscopy (SEM) reveals the formation of nanoscale pits (nanopits) on the surface of steel wool after etching with HCl. These nanopits are responsible for the high efficiency of the hydrodechlorination process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900215 Exemplaires
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Titre : A statistical approach to microkinetic analysis Type de document : texte imprimé Auteurs : Pieter van Helden, Auteur ; Jan-Albert van den Berg, Auteur ; Roelof L. J. Coetzer, Auteur Année de publication : 2012 Article en page(s) : pp. 6631–6640 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microkinetic Analysis Résumé : An in-depth understanding of fundamental heterogeneous catalysis can be obtained by the use of Microkinetic Analysis of the elementary reaction steps. Unfortunately, for complex reaction networks, the sheer number of parameters present in such models can make the interpretation and deeper understanding of such microkinetic models very difficult. In this work, a Microkinetic Analysis Methodology, which incorporates statistical methods, is demonstrated, with application to a typical set of fundamental catalytic reactions. A uniform statistical experimental design is implemented, varying a selection of parameters within the microkinetic model. The responses of the simulated model are fitted to construct approximation models. We illustrate the extension of some known methods in order to successfully implement the proposed methodology, such as Kriging approximation models applied to additive log-ratio transformations of the surface coverage compositions, as well as a multivariate scaled EIGF criterion to iteratively improve the global model fit. We demonstrate that the methodology yields statistical approximation models that are capable of yielding accurate predictions of the complete parameter space. The proposed methodology can be applied to any number of microkinetic model parameters of interest. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2013086
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6631–6640[article] A statistical approach to microkinetic analysis [texte imprimé] / Pieter van Helden, Auteur ; Jan-Albert van den Berg, Auteur ; Roelof L. J. Coetzer, Auteur . - 2012 . - pp. 6631–6640.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6631–6640
Mots-clés : Microkinetic Analysis Résumé : An in-depth understanding of fundamental heterogeneous catalysis can be obtained by the use of Microkinetic Analysis of the elementary reaction steps. Unfortunately, for complex reaction networks, the sheer number of parameters present in such models can make the interpretation and deeper understanding of such microkinetic models very difficult. In this work, a Microkinetic Analysis Methodology, which incorporates statistical methods, is demonstrated, with application to a typical set of fundamental catalytic reactions. A uniform statistical experimental design is implemented, varying a selection of parameters within the microkinetic model. The responses of the simulated model are fitted to construct approximation models. We illustrate the extension of some known methods in order to successfully implement the proposed methodology, such as Kriging approximation models applied to additive log-ratio transformations of the surface coverage compositions, as well as a multivariate scaled EIGF criterion to iteratively improve the global model fit. We demonstrate that the methodology yields statistical approximation models that are capable of yielding accurate predictions of the complete parameter space. The proposed methodology can be applied to any number of microkinetic model parameters of interest. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2013086 Exemplaires
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Titre : Heterogeneous selective oxidation of sulfides with H2O2 catalyzed by ionic liquid - based polyoxometalate salts Type de document : texte imprimé Auteurs : Pingping Zhao, Auteur ; Mingjue Zhang, Auteur ; Yajing Wu, Auteur Année de publication : 2012 Article en page(s) : pp. 6641-6647 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic liquid Catalytic reaction Hydrogen peroxide Oxidation Résumé : A group of ionic liquid (LL)-based polyoxometalate (POM) salts were prepared via anion-exchange of imidazolium LL precursors tethered by different carbon chain alkyls with various Keggin POMs. The resultant imidazolium POM salts were tested as the catalysts for oxidation of sulfides with aqueous H2O2. For understanding the POM salt-catalyzed oxidation of sulfides, catalyst compositions, substrates, and reaction conditions were changed. The results show that the imidazolium POM salts are very active and selective heterogeneous catalysts for oxidations of sulfides, adding the advantages of convenient recovery, steady reuse, simple preparation, and flexible composition. Characterizations by Fourier transform infrared (FT-IR), ultraviolet-visible (UV―vis), X-ray diffraction (XRD), and elemental analysis further reveal that the heterogeneous nature of the oxidation processes associates with the good crystallinities of the butyl- and hexyl-functionalized imidazolium POM salts and the hydrogen bonding networks among cations and anions. The POM salts' excellent performances arise from the promoted redox property of the POM-anions by the intramolecular charge transfer from the IL-cations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900217
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6641-6647[article] Heterogeneous selective oxidation of sulfides with H2O2 catalyzed by ionic liquid - based polyoxometalate salts [texte imprimé] / Pingping Zhao, Auteur ; Mingjue Zhang, Auteur ; Yajing Wu, Auteur . - 2012 . - pp. 6641-6647.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6641-6647
Mots-clés : Ionic liquid Catalytic reaction Hydrogen peroxide Oxidation Résumé : A group of ionic liquid (LL)-based polyoxometalate (POM) salts were prepared via anion-exchange of imidazolium LL precursors tethered by different carbon chain alkyls with various Keggin POMs. The resultant imidazolium POM salts were tested as the catalysts for oxidation of sulfides with aqueous H2O2. For understanding the POM salt-catalyzed oxidation of sulfides, catalyst compositions, substrates, and reaction conditions were changed. The results show that the imidazolium POM salts are very active and selective heterogeneous catalysts for oxidations of sulfides, adding the advantages of convenient recovery, steady reuse, simple preparation, and flexible composition. Characterizations by Fourier transform infrared (FT-IR), ultraviolet-visible (UV―vis), X-ray diffraction (XRD), and elemental analysis further reveal that the heterogeneous nature of the oxidation processes associates with the good crystallinities of the butyl- and hexyl-functionalized imidazolium POM salts and the hydrogen bonding networks among cations and anions. The POM salts' excellent performances arise from the promoted redox property of the POM-anions by the intramolecular charge transfer from the IL-cations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900217 Exemplaires
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Titre : Study of the relationship between framework cation levels of Y zeolites and behavior during calcination, steaming, and n - heptane cracking processes Type de document : texte imprimé Auteurs : Bashir Y. Al-Zaidi, Auteur ; Richard J. Holmes, Auteur ; Arthur A. Garforth, Auteur Année de publication : 2012 Article en page(s) : pp. 6648-6657 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Cracking Calcining Zeolite Résumé : The synthesis process and production of forms of the Y zeolite (i.e., NaY, NH4Y, HY, and USY) have been studied in depth, in order to investigate the thermal stability of the Y structure throughout calcination, steaming, and cracking processes. The results indicate that an increase in the cation content within the Y framework during calcination and/or steaming processes led to an increase in the catalyst stability and a reduction in the rate of any associated dehydroxylation reactions. It was also found that the presence of sodium ions hindered the extraction of Al atoms from the crystal lattice structure during the steaming treatment, which minimized partial and/or entire structural collapse at high temperatures. Finally, enhancements in the distribution of the acid sites, and an increase in the activity and selectivity of the produced USY catalysts during n-C7 cracking reactions, have also been observed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900218
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6648-6657[article] Study of the relationship between framework cation levels of Y zeolites and behavior during calcination, steaming, and n - heptane cracking processes [texte imprimé] / Bashir Y. Al-Zaidi, Auteur ; Richard J. Holmes, Auteur ; Arthur A. Garforth, Auteur . - 2012 . - pp. 6648-6657.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6648-6657
Mots-clés : Cracking Calcining Zeolite Résumé : The synthesis process and production of forms of the Y zeolite (i.e., NaY, NH4Y, HY, and USY) have been studied in depth, in order to investigate the thermal stability of the Y structure throughout calcination, steaming, and cracking processes. The results indicate that an increase in the cation content within the Y framework during calcination and/or steaming processes led to an increase in the catalyst stability and a reduction in the rate of any associated dehydroxylation reactions. It was also found that the presence of sodium ions hindered the extraction of Al atoms from the crystal lattice structure during the steaming treatment, which minimized partial and/or entire structural collapse at high temperatures. Finally, enhancements in the distribution of the acid sites, and an increase in the activity and selectivity of the produced USY catalysts during n-C7 cracking reactions, have also been observed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900218 Exemplaires
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Titre : Removal of thiophenic sulfurs using an extractive oxidative desulfurization process with three New phosphotungstate catalysts Type de document : texte imprimé Auteurs : Hongxing Zhang, Auteur ; Jiajun Gao, Auteur ; Hong Meng, Auteur Année de publication : 2012 Article en page(s) : pp. 6658–6665 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thiophenic sulfurs Desulfurization process Résumé : Three Keggin-type phosphotungstates, i.e. [C5H5NH]3PW12O40, [C4H6N2H]3PW12O40·3C4H6N2 and [(C4H9)4N]3PW12O40, were synthesized and characterized by elemental analysis, X-ray diffraction, and infrared spectra, meanwhile their catalysis in an extractive catalytic oxidative desulfurization process was studied with ionic liquid (IL) as extractant and H2O2 as oxidant. The main factors affecting the desulfurization process were investigated, including temperature, hydrophobicity of IL, and variety of S-compounds, as well as the amount of catalyst, IL, and H2O2. Under the optimal conditions, the S-content of DBT oil can be decreased from 1000 to 2 ppm. A new interpretation is proposed for the current process, in which IL is assumed as a reaction phase, and the amount of the extracted S-compound and the peroxidized catalyst wherein greatly affect the desulfurization rate. Besides, the IL with the dissolved catalyst can be reused many times and regenerated easily. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3004545
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6658–6665[article] Removal of thiophenic sulfurs using an extractive oxidative desulfurization process with three New phosphotungstate catalysts [texte imprimé] / Hongxing Zhang, Auteur ; Jiajun Gao, Auteur ; Hong Meng, Auteur . - 2012 . - pp. 6658–6665.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6658–6665
Mots-clés : Thiophenic sulfurs Desulfurization process Résumé : Three Keggin-type phosphotungstates, i.e. [C5H5NH]3PW12O40, [C4H6N2H]3PW12O40·3C4H6N2 and [(C4H9)4N]3PW12O40, were synthesized and characterized by elemental analysis, X-ray diffraction, and infrared spectra, meanwhile their catalysis in an extractive catalytic oxidative desulfurization process was studied with ionic liquid (IL) as extractant and H2O2 as oxidant. The main factors affecting the desulfurization process were investigated, including temperature, hydrophobicity of IL, and variety of S-compounds, as well as the amount of catalyst, IL, and H2O2. Under the optimal conditions, the S-content of DBT oil can be decreased from 1000 to 2 ppm. A new interpretation is proposed for the current process, in which IL is assumed as a reaction phase, and the amount of the extracted S-compound and the peroxidized catalyst wherein greatly affect the desulfurization rate. Besides, the IL with the dissolved catalyst can be reused many times and regenerated easily. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3004545 Exemplaires
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Titre : Esterification of acrylic acid with different alcohols catalyzed by zirconia supported tungstophosphoric acid Type de document : texte imprimé Auteurs : Emine Sert, Auteur ; Ferhan Sami Atalay, Auteur Année de publication : 2012 Article en page(s) : pp. 6666-6671 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalytic reaction Esterification Résumé : The liquid phase esterification of acrylic acid with different alcohols (butanol, iso-butanol, or hexanol) was investigated in a batch reactor with zirconia supported tungstophosphoric acid (TPA) as heterogeneous catalyst. The prepared catalysts with different TPA loadings (20, 25, and 30 wt %) and calcination temperatures (550, 650, and 750 °C) were characterized by nitrogen adsorption studies, X-ray diffraction (XRD), and thermogravimetric analysis (TGA) techniques. In addition, acidity measurements were performed by potentiometric titration with n-butylamine. The activitiy of catalysts strongly dependent on the acidic characteristic of the catalysts. The most active catalyst, 25 wt % TPA, calcined at 650 °C, gave more than 33%, 31%, and 27% conversions of acrylic acid for butyl, iso-butyl, and hexyl acrylate synthesis, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900220
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6666-6671[article] Esterification of acrylic acid with different alcohols catalyzed by zirconia supported tungstophosphoric acid [texte imprimé] / Emine Sert, Auteur ; Ferhan Sami Atalay, Auteur . - 2012 . - pp. 6666-6671.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6666-6671
Mots-clés : Catalytic reaction Esterification Résumé : The liquid phase esterification of acrylic acid with different alcohols (butanol, iso-butanol, or hexanol) was investigated in a batch reactor with zirconia supported tungstophosphoric acid (TPA) as heterogeneous catalyst. The prepared catalysts with different TPA loadings (20, 25, and 30 wt %) and calcination temperatures (550, 650, and 750 °C) were characterized by nitrogen adsorption studies, X-ray diffraction (XRD), and thermogravimetric analysis (TGA) techniques. In addition, acidity measurements were performed by potentiometric titration with n-butylamine. The activitiy of catalysts strongly dependent on the acidic characteristic of the catalysts. The most active catalyst, 25 wt % TPA, calcined at 650 °C, gave more than 33%, 31%, and 27% conversions of acrylic acid for butyl, iso-butyl, and hexyl acrylate synthesis, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900220 Exemplaires
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Titre : Evaluating the effects of precious metal distribution along a monolith - supported catalyst for CO oxidation Type de document : texte imprimé Auteurs : Suad M. Al Adwani, Auteur ; Joao Soares, Auteur ; William S. Epling, Auteur Année de publication : 2012 Article en page(s) : pp. 6672–6679 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Metal Catalyst Oxidation Résumé : Zone-coated diesel oxidation catalysts (DOCs) can be used to obtain overall improved performance in oxidation reaction extents. However, why this occurs and under what conditions an impact is expected are unknown. In order to demonstrate why these catalysts work better than their standard counterparts and how significant the improved performance is, the CO oxidation performance over a series of Pt–Pd/Al2O3 catalysts, each with a different distribution of precious metal down the length, while maintaining equivalent totals of precious metal, was modeled. Simulations with different flow rates, ramp rates, steady-state temperatures at the end of the ramp rate, different total precious metal loadings, and CO inlet values were compared. In terms of light off, at conversions less than 50%, the most significant differences were noted when the temperature was ramped to just at the CO oxidation light-off point, with catalysts containing more precious metal at the downstream portions leading to better light-off conversion performance. However, in terms of cumulative emissions over a long period of time, a “front-loaded” design proved best. These results are readily explained by decreased CO poisoning and the propagation of the exothermic heat from the front to the rear of the catalyst. Also, although the trends were the same, regardless of change in the parameter, the impact of different distributions was more apparent under conditions where a catalyst would be challenged, i.e., at low temperature ramp rates, higher CO inlet concentrations, and lower amounts of total catalyst used. At higher ramp rates, the input heat from the entering gas stream played an increasingly important role, relative to conduction associated with the exotherm, dampening the effects of the catalyst distribution. Therefore, although catalysts that are zone-coated with precious metals, or any active sites, could prove better in terms of performance than homogeneously distributed active site catalysts, this improvement is only significant under certain reaction conditions and thus application of these catalysts may not be appropriate for all drive cycles or applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202969u
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6672–6679[article] Evaluating the effects of precious metal distribution along a monolith - supported catalyst for CO oxidation [texte imprimé] / Suad M. Al Adwani, Auteur ; Joao Soares, Auteur ; William S. Epling, Auteur . - 2012 . - pp. 6672–6679.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6672–6679
Mots-clés : Metal Catalyst Oxidation Résumé : Zone-coated diesel oxidation catalysts (DOCs) can be used to obtain overall improved performance in oxidation reaction extents. However, why this occurs and under what conditions an impact is expected are unknown. In order to demonstrate why these catalysts work better than their standard counterparts and how significant the improved performance is, the CO oxidation performance over a series of Pt–Pd/Al2O3 catalysts, each with a different distribution of precious metal down the length, while maintaining equivalent totals of precious metal, was modeled. Simulations with different flow rates, ramp rates, steady-state temperatures at the end of the ramp rate, different total precious metal loadings, and CO inlet values were compared. In terms of light off, at conversions less than 50%, the most significant differences were noted when the temperature was ramped to just at the CO oxidation light-off point, with catalysts containing more precious metal at the downstream portions leading to better light-off conversion performance. However, in terms of cumulative emissions over a long period of time, a “front-loaded” design proved best. These results are readily explained by decreased CO poisoning and the propagation of the exothermic heat from the front to the rear of the catalyst. Also, although the trends were the same, regardless of change in the parameter, the impact of different distributions was more apparent under conditions where a catalyst would be challenged, i.e., at low temperature ramp rates, higher CO inlet concentrations, and lower amounts of total catalyst used. At higher ramp rates, the input heat from the entering gas stream played an increasingly important role, relative to conduction associated with the exotherm, dampening the effects of the catalyst distribution. Therefore, although catalysts that are zone-coated with precious metals, or any active sites, could prove better in terms of performance than homogeneously distributed active site catalysts, this improvement is only significant under certain reaction conditions and thus application of these catalysts may not be appropriate for all drive cycles or applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202969u Exemplaires
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Titre : Thermal and kinetic analysis of the process of thermochemical decomposition of phosphogypsum with CO and additives Type de document : texte imprimé Auteurs : Liping Ma, Auteur ; Yalei Du, Auteur ; Xuekui Niu, Auteur Année de publication : 2012 Article en page(s) : pp. 6680-6685 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Additive Kinetics Résumé : Phosphogypsum (PG) is a waste byproduct from the processing of phosphate rock by the "wet add method" of fertilizer production. One of the main methods for reusing PG is to decompose and recycle Ca and sulfur contained in it. However, the decomposition reaction process is very complex because of its complicated contents, and very high temperature is needed for the reaction. In this paper, to decrease the reaction temperature, CO as a main reducer and some additives were added in the decomposition process. Results show that the decomposition temperature will decrease from 1000 to 809 °C with pure CO. When CaCl2 is used as an additive, the decomposition temperature can decrease to 790 °C, and at the same time the reaction rate will be increased, the main product being CaS at this condition. The thermal and kinetic action of this process has also been discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900222
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6680-6685[article] Thermal and kinetic analysis of the process of thermochemical decomposition of phosphogypsum with CO and additives [texte imprimé] / Liping Ma, Auteur ; Yalei Du, Auteur ; Xuekui Niu, Auteur . - 2012 . - pp. 6680-6685.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6680-6685
Mots-clés : Additive Kinetics Résumé : Phosphogypsum (PG) is a waste byproduct from the processing of phosphate rock by the "wet add method" of fertilizer production. One of the main methods for reusing PG is to decompose and recycle Ca and sulfur contained in it. However, the decomposition reaction process is very complex because of its complicated contents, and very high temperature is needed for the reaction. In this paper, to decrease the reaction temperature, CO as a main reducer and some additives were added in the decomposition process. Results show that the decomposition temperature will decrease from 1000 to 809 °C with pure CO. When CaCl2 is used as an additive, the decomposition temperature can decrease to 790 °C, and at the same time the reaction rate will be increased, the main product being CaS at this condition. The thermal and kinetic action of this process has also been discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900222 Exemplaires
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Titre : Modeling studies on lean NOx reduction by a sequence of LNT – SCR bricks Type de document : texte imprimé Auteurs : Arun S. Kota, Auteur ; Dan Luss, Auteur ; Vemuri Balakotaiah, Auteur Année de publication : 2012 Article en page(s) : pp. 6686–6696 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : NOx Selective catalytic reduction Résumé : Several experimental studies have been conducted to determine the NOx reduction by a series of LNT (lean NOx trap) and SCR (selective catalytic reduction) catalytic bricks. An important goal is to minimize the required precious metal loading in the LNT while keeping the NOx emission below a specified level. We present a mathematical model of this system using hydrogen as the reductant. Simulations are used to determine the influence of the architecture of the LNT–SCR bricks, nonuniform precious metal loading in the LNT bricks, and the cycle time at temperatures in the range of 200–350 °C. The simulations lead to the following observations: (a) Low temperature reduction is the limiting step in the optimization of precious group metal (PGM) loading in LNT. (b) The NOx conversion increases as the number of the sequential bricks (with total length fixed) increase and reaches an asymptotic limit. From a practical point of view, there is little incentive in using more than two sequential pairs. (c) Nonuniform precious metal loading of the LNT bricks results in only a minor improvement in the deNOx performance. (d) The cycle time has a significant impact on the NOx conversion. In the simulated example, the NOx conversion at low temperatures is increased by about 15–20% by reducing the cycle time by a factor of 2. (e) Even at low temperature operation, diffusional limitations in the washcoat are most likely to be important in the LNT but not in the SCR operation. The NOx conversion and ammonia selectivity are reduced when washcoat diffusion is dominant in the LNT. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300190c
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6686–6696[article] Modeling studies on lean NOx reduction by a sequence of LNT – SCR bricks [texte imprimé] / Arun S. Kota, Auteur ; Dan Luss, Auteur ; Vemuri Balakotaiah, Auteur . - 2012 . - pp. 6686–6696.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6686–6696
Mots-clés : NOx Selective catalytic reduction Résumé : Several experimental studies have been conducted to determine the NOx reduction by a series of LNT (lean NOx trap) and SCR (selective catalytic reduction) catalytic bricks. An important goal is to minimize the required precious metal loading in the LNT while keeping the NOx emission below a specified level. We present a mathematical model of this system using hydrogen as the reductant. Simulations are used to determine the influence of the architecture of the LNT–SCR bricks, nonuniform precious metal loading in the LNT bricks, and the cycle time at temperatures in the range of 200–350 °C. The simulations lead to the following observations: (a) Low temperature reduction is the limiting step in the optimization of precious group metal (PGM) loading in LNT. (b) The NOx conversion increases as the number of the sequential bricks (with total length fixed) increase and reaches an asymptotic limit. From a practical point of view, there is little incentive in using more than two sequential pairs. (c) Nonuniform precious metal loading of the LNT bricks results in only a minor improvement in the deNOx performance. (d) The cycle time has a significant impact on the NOx conversion. In the simulated example, the NOx conversion at low temperatures is increased by about 15–20% by reducing the cycle time by a factor of 2. (e) Even at low temperature operation, diffusional limitations in the washcoat are most likely to be important in the LNT but not in the SCR operation. The NOx conversion and ammonia selectivity are reduced when washcoat diffusion is dominant in the LNT. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300190c Exemplaires
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Titre : Effect of rubber – filler interaction on transport of aromatic liquids through high density polyethylene / ethylene propylene diene terpolymer rubber blends Type de document : texte imprimé Auteurs : Anil Kumar P. V., Auteur ; K. T. Varughese, Auteur ; Sabu Thomas, Auteur Année de publication : 2012 Article en page(s) : pp. 6697–6704 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : High density Transport process Filler Résumé : The sorption and transport of four aromatic hydrocarbons through dynamically vulcanized high density polyethylene/ethylene propylene diene terpolymer rubber blends filled with carbon black and that filled with silica at the same loading have been investigated in the temperature range of 28–58 °C by an equilibrium swelling technique . Blends loaded with high abrasion furnace (HAF) black and those with silica of same loading have been used. The silica-incorporated blends sorbed a higher amount of aromatic solvents compared with the HAF filled blends. This has been explained in terms of the differences in the interaction between the filler particles and the blend components. The swelling coefficient, diffusion coefficient, and molar mass between cross-links have been computed to complement the experimental observations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900224
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6697–6704[article] Effect of rubber – filler interaction on transport of aromatic liquids through high density polyethylene / ethylene propylene diene terpolymer rubber blends [texte imprimé] / Anil Kumar P. V., Auteur ; K. T. Varughese, Auteur ; Sabu Thomas, Auteur . - 2012 . - pp. 6697–6704.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6697–6704
Mots-clés : High density Transport process Filler Résumé : The sorption and transport of four aromatic hydrocarbons through dynamically vulcanized high density polyethylene/ethylene propylene diene terpolymer rubber blends filled with carbon black and that filled with silica at the same loading have been investigated in the temperature range of 28–58 °C by an equilibrium swelling technique . Blends loaded with high abrasion furnace (HAF) black and those with silica of same loading have been used. The silica-incorporated blends sorbed a higher amount of aromatic solvents compared with the HAF filled blends. This has been explained in terms of the differences in the interaction between the filler particles and the blend components. The swelling coefficient, diffusion coefficient, and molar mass between cross-links have been computed to complement the experimental observations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900224 Exemplaires
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Titre : Rheology of carbon nanotubes – filled poly(vinylidene fluoride) composites Type de document : texte imprimé Auteurs : Defeng Wu, Auteur ; Jianghong Wang, Auteur ; Ming Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 6705–6713 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Rheology Carbon nanotubes Résumé : The carbon nanotubes (CNTs)–filled poly(vinylidene fluoride) (PVDF) composites (PCTs) were prepared by melt compounding for rheological study. The steady and oscillatory flow behaviors were then explored. The results show that the presence of CNTs enhances the pseudoplastic flow accompanied by the increased flow activation energy. However, the linear flow region is not sensitive to the temperature whether driven by shear rate or by strain. During oscillatory shear flow, the solid-like response is attributed to the percolation of CNTs, but the formation of a percolated CNT network is temperature-dependent, and the percolation threshold values reduce with an increase of temperature. The two-phase viscoelastic model was then used to further describe the linear responses of composites, aiming at relating hierarchical structures of the CNTs to flow behaviors of the composites. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024454
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6705–6713[article] Rheology of carbon nanotubes – filled poly(vinylidene fluoride) composites [texte imprimé] / Defeng Wu, Auteur ; Jianghong Wang, Auteur ; Ming Zhang, Auteur . - 2012 . - pp. 6705–6713.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6705–6713
Mots-clés : Rheology Carbon nanotubes Résumé : The carbon nanotubes (CNTs)–filled poly(vinylidene fluoride) (PVDF) composites (PCTs) were prepared by melt compounding for rheological study. The steady and oscillatory flow behaviors were then explored. The results show that the presence of CNTs enhances the pseudoplastic flow accompanied by the increased flow activation energy. However, the linear flow region is not sensitive to the temperature whether driven by shear rate or by strain. During oscillatory shear flow, the solid-like response is attributed to the percolation of CNTs, but the formation of a percolated CNT network is temperature-dependent, and the percolation threshold values reduce with an increase of temperature. The two-phase viscoelastic model was then used to further describe the linear responses of composites, aiming at relating hierarchical structures of the CNTs to flow behaviors of the composites. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024454 Exemplaires
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Titre : Corrosion behavior of carbon steel at typical positions of an amine - based CO2 capture pilot plant Type de document : texte imprimé Auteurs : Jubao Gao, Auteur ; Shujuan Wang, Auteur ; Chenchen Sun, Auteur Année de publication : 2012 Article en page(s) : pp. 6714-6721 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pilot plant Carbon dioxide steel Corrosion Résumé : Corrosion tests of carbon steel at six typical positions in a CO2 capture pilot plant using amine-based solvent were conducted with simulated flue gas ( 12 vol % CO2, 18 vol % O2 and 214 ppm SO2). A weight-loss method was used to determine the corrosion rates for about 400 h of experiment. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to analyze the morphology and compositions of the coupon surface and cross section. The corrosion products on the sample's surface and cross section were analyzed with X-ray diffraction and Raman spectroscopy, respectively. Experimental and theoretical analyses show that the higher corrosion rates among these positions were present at the bottom of the absorber and rich liquid outlet of the rich-lean heat exchanger. The double-layer structure of the corrosion products with different colors was obviously observed on the cross sectional surface of the coupons at the absorber bottom and the stripper inlet. The corrosion products in the inner layer are mainly composed of hematite (a-Fe2O3) and magnetite (Fe3O4) with traces of goethite (a-FeOOH), while the outer layer mainly consists of siderite (FeCO3). The inner corrosion products, including a-Fe2O3, Fe3O4, and a-FeOOH, may come from the decomposition of FeCO3 in the amine-H2O―CO2―O2―SO2 system. An addition of SO2 yields large amounts of hydrogen ion and dissolved oxygen which may induce a higher corrosion rate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900226
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6714-6721[article] Corrosion behavior of carbon steel at typical positions of an amine - based CO2 capture pilot plant [texte imprimé] / Jubao Gao, Auteur ; Shujuan Wang, Auteur ; Chenchen Sun, Auteur . - 2012 . - pp. 6714-6721.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6714-6721
Mots-clés : Pilot plant Carbon dioxide steel Corrosion Résumé : Corrosion tests of carbon steel at six typical positions in a CO2 capture pilot plant using amine-based solvent were conducted with simulated flue gas ( 12 vol % CO2, 18 vol % O2 and 214 ppm SO2). A weight-loss method was used to determine the corrosion rates for about 400 h of experiment. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to analyze the morphology and compositions of the coupon surface and cross section. The corrosion products on the sample's surface and cross section were analyzed with X-ray diffraction and Raman spectroscopy, respectively. Experimental and theoretical analyses show that the higher corrosion rates among these positions were present at the bottom of the absorber and rich liquid outlet of the rich-lean heat exchanger. The double-layer structure of the corrosion products with different colors was obviously observed on the cross sectional surface of the coupons at the absorber bottom and the stripper inlet. The corrosion products in the inner layer are mainly composed of hematite (a-Fe2O3) and magnetite (Fe3O4) with traces of goethite (a-FeOOH), while the outer layer mainly consists of siderite (FeCO3). The inner corrosion products, including a-Fe2O3, Fe3O4, and a-FeOOH, may come from the decomposition of FeCO3 in the amine-H2O―CO2―O2―SO2 system. An addition of SO2 yields large amounts of hydrogen ion and dissolved oxygen which may induce a higher corrosion rate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900226 Exemplaires
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Titre : Solvent free generation of open and skinless foam in poly (l - lactic acid) / poly (d,l - lactic acid) blends using carbon dioxide Type de document : texte imprimé Auteurs : Xia Liao, Auteur ; Arghavan V. Nawaby, Auteur Année de publication : 2012 Article en page(s) : pp. 6722-6730 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon dioxide Foam Résumé : Foams generated via carbon dioxide (CO2) processing typically exhibit a solid skin layer on the exterior surface and a closed-pore structure with limited interconnectivity in the core section thus limiting its application for biomedical intent. By controlling the properties of poly(L-lactic acid)/poly(D,L-lactic acid) (PLLA/PDLLA) blends and using CO2 with specific processing parameters, skinless foams with interconnected porous structure were prepared in this work using only CO2 as a physical foaming agent, which overcome the necessity to use organic solvents and solid porogens. The crystallization behaviors and sorption kinetics of PLLA and its blends were studied. Addition of PDLLA reduces the crystallinity of PLLA/PDLLA blends while treated with CO2 as compared to neat PLLA. The solubility and diffusion coefficients of CO2 in PLLA and its blends were found to be similar. Furthermore, the effect of PLLA/PDLLA blend ratio and CO2 treatment conditions on the foam morphologies was investigated. Through fine parameter control, well interconnected pore structures with a porous surface were generated. Results indicated that by controlling the physical properties of samples combined with optimizing CO2 foaming process, it is indeed possible to create biodegradable interconnected porous structures for potential biomedical applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900227
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6722-6730[article] Solvent free generation of open and skinless foam in poly (l - lactic acid) / poly (d,l - lactic acid) blends using carbon dioxide [texte imprimé] / Xia Liao, Auteur ; Arghavan V. Nawaby, Auteur . - 2012 . - pp. 6722-6730.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6722-6730
Mots-clés : Carbon dioxide Foam Résumé : Foams generated via carbon dioxide (CO2) processing typically exhibit a solid skin layer on the exterior surface and a closed-pore structure with limited interconnectivity in the core section thus limiting its application for biomedical intent. By controlling the properties of poly(L-lactic acid)/poly(D,L-lactic acid) (PLLA/PDLLA) blends and using CO2 with specific processing parameters, skinless foams with interconnected porous structure were prepared in this work using only CO2 as a physical foaming agent, which overcome the necessity to use organic solvents and solid porogens. The crystallization behaviors and sorption kinetics of PLLA and its blends were studied. Addition of PDLLA reduces the crystallinity of PLLA/PDLLA blends while treated with CO2 as compared to neat PLLA. The solubility and diffusion coefficients of CO2 in PLLA and its blends were found to be similar. Furthermore, the effect of PLLA/PDLLA blend ratio and CO2 treatment conditions on the foam morphologies was investigated. Through fine parameter control, well interconnected pore structures with a porous surface were generated. Results indicated that by controlling the physical properties of samples combined with optimizing CO2 foaming process, it is indeed possible to create biodegradable interconnected porous structures for potential biomedical applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900227 Exemplaires
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Titre : Zeta potential and slip coefficient measurements of hydrophobic polymer surfaces exploiting a microchannel Type de document : texte imprimé Auteurs : Hung Mok Park, Auteur Année de publication : 2012 Article en page(s) : pp. 6731-6744 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrokinetic potential Résumé : The surface charge and wettability of polymer surfaces are important properties that affect various physicochemical properties such as adhesion, hydrophilicity, and swelling. The zeta potential gives information of the ions distribution at the electric double layer (EDL), and the Navier slip coefficient is also an important indicator of the wettability of surfaces. In the present investigation, a technique is devised to measure the zeta potential and the slip coefficient of polymer surfaces nondestructively exploiting electrokinetic flows in a microchannel, which is formed by combining a probe cell and a macroscopic polymer surface under consideration. By measuring zeta potential and volumetric flow rate of electroosmotic flow at various bulk ionic concentration, one can estimate the zeta potential and slip coefficient accurately even under significant experimental errors in the measurement of streaming potential and volumetric flow rate. The method devised in the present investigation may be employed to estimate zeta potential and slip coefficient of various polymeric surfaces, which are important characterizing various physicochemical properties of polymers. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900228
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6731-6744[article] Zeta potential and slip coefficient measurements of hydrophobic polymer surfaces exploiting a microchannel [texte imprimé] / Hung Mok Park, Auteur . - 2012 . - pp. 6731-6744.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6731-6744
Mots-clés : Electrokinetic potential Résumé : The surface charge and wettability of polymer surfaces are important properties that affect various physicochemical properties such as adhesion, hydrophilicity, and swelling. The zeta potential gives information of the ions distribution at the electric double layer (EDL), and the Navier slip coefficient is also an important indicator of the wettability of surfaces. In the present investigation, a technique is devised to measure the zeta potential and the slip coefficient of polymer surfaces nondestructively exploiting electrokinetic flows in a microchannel, which is formed by combining a probe cell and a macroscopic polymer surface under consideration. By measuring zeta potential and volumetric flow rate of electroosmotic flow at various bulk ionic concentration, one can estimate the zeta potential and slip coefficient accurately even under significant experimental errors in the measurement of streaming potential and volumetric flow rate. The method devised in the present investigation may be employed to estimate zeta potential and slip coefficient of various polymeric surfaces, which are important characterizing various physicochemical properties of polymers. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900228 Exemplaires
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Titre : Pilot plant scale synthesis of CNS : Influence of the operating conditions Type de document : texte imprimé Auteurs : Vicente Jiménez, Auteur ; Alfredo Muñoz, Auteur ; Paula Sánchez, Auteur Année de publication : 2012 Article en page(s) : pp. 6745-6752 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Operating conditions Pilot plant scale Résumé : The present work was an in-depth study related to synthesis of carbon nanospheres (CNSs) at different scales (lab and pilot) with the end goal to economize the production of these materials on a large scale. Synthesis of large amounts of CNSs relies on the careful control of the operating conditions such as space velocity (helium flow rate), hydsocarbon (benzene) content in feed stream, and synthesis time. The alteration of these variables caused important changes in both the yield and properties of the obtained materials. In general, characterization results of the synthesized CNSs demonstrated that they showed low BET surface area and pore volume values typical of spherical geometrical bodies, good thermal stability, and good crystallinity. Normally, CNSs are presented as conglomerates as consequence of the accretion via the carbon atoms at the edge of the "curling" graphitic flakes. Finally, results demonstrated a successful scale up, obtaining a CNSs yield at pilot scale considerably superior (factor of 3.9) to that obtained at laboratory scale. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900229
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6745-6752[article] Pilot plant scale synthesis of CNS : Influence of the operating conditions [texte imprimé] / Vicente Jiménez, Auteur ; Alfredo Muñoz, Auteur ; Paula Sánchez, Auteur . - 2012 . - pp. 6745-6752.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6745-6752
Mots-clés : Operating conditions Pilot plant scale Résumé : The present work was an in-depth study related to synthesis of carbon nanospheres (CNSs) at different scales (lab and pilot) with the end goal to economize the production of these materials on a large scale. Synthesis of large amounts of CNSs relies on the careful control of the operating conditions such as space velocity (helium flow rate), hydsocarbon (benzene) content in feed stream, and synthesis time. The alteration of these variables caused important changes in both the yield and properties of the obtained materials. In general, characterization results of the synthesized CNSs demonstrated that they showed low BET surface area and pore volume values typical of spherical geometrical bodies, good thermal stability, and good crystallinity. Normally, CNSs are presented as conglomerates as consequence of the accretion via the carbon atoms at the edge of the "curling" graphitic flakes. Finally, results demonstrated a successful scale up, obtaining a CNSs yield at pilot scale considerably superior (factor of 3.9) to that obtained at laboratory scale. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900229 Exemplaires
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Titre : Highly transparent and multifunctional polymer nanohybrid film with superhigh ZnO content synthesized by a bulk polymerization method Type de document : texte imprimé Auteurs : Hai-Tao Liu, Auteur ; Xiao - Fei Zeng, Auteur ; Hong Zhao, Auteur Année de publication : 2012 Article en page(s) : pp. 6753-6759 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Polymerization Résumé : Highly transparent and multifunctional ZnO/poly(n-butyl methacrylate) (ZnO/PBMA) nanohybrid films with superhigh contents of ZnO nanoparticles (NPs) were synthesized by a bulk polymerization method. The structure; morphology; and optical, mechanical, and thermal properties of the obtained nanohybrid films were studied. ZnO NPs were dispersed uniformly and retained their original size (4―6 nm) in the PBMA matrix without any aggregation. The ZnO/PBMA nanohybrid films allowed more than 90% of visible light at 550 nm to pass and maintained almost the same high transparency as pure PBMA film even when the ZnO NP content was as high as 60 wt %. The nanohybrid films embedded with ZnO NPs exhibited significantly enhanced multifunctional performance, including excellent UV-shielding properties, good thermal stability, high surface hardness, and desired flexibility. In particular, the coefficient of thermal expansion (CTE) of the nanohybrid films dearly decreased to 193 from 325 ppm/K for pure PBMA below the glass transition temperature (Tg) and strikingly decreased from 5378 to 1373 ppm/K after the glass transition. The ZnO/polymer nanohybrids synthesized in this work are promising for the fabrication of optical devices with high transparency, such as flexible displays, optical filters, and flexible solar cells. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900230
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6753-6759[article] Highly transparent and multifunctional polymer nanohybrid film with superhigh ZnO content synthesized by a bulk polymerization method [texte imprimé] / Hai-Tao Liu, Auteur ; Xiao - Fei Zeng, Auteur ; Hong Zhao, Auteur . - 2012 . - pp. 6753-6759.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6753-6759
Mots-clés : Polymerization Résumé : Highly transparent and multifunctional ZnO/poly(n-butyl methacrylate) (ZnO/PBMA) nanohybrid films with superhigh contents of ZnO nanoparticles (NPs) were synthesized by a bulk polymerization method. The structure; morphology; and optical, mechanical, and thermal properties of the obtained nanohybrid films were studied. ZnO NPs were dispersed uniformly and retained their original size (4―6 nm) in the PBMA matrix without any aggregation. The ZnO/PBMA nanohybrid films allowed more than 90% of visible light at 550 nm to pass and maintained almost the same high transparency as pure PBMA film even when the ZnO NP content was as high as 60 wt %. The nanohybrid films embedded with ZnO NPs exhibited significantly enhanced multifunctional performance, including excellent UV-shielding properties, good thermal stability, high surface hardness, and desired flexibility. In particular, the coefficient of thermal expansion (CTE) of the nanohybrid films dearly decreased to 193 from 325 ppm/K for pure PBMA below the glass transition temperature (Tg) and strikingly decreased from 5378 to 1373 ppm/K after the glass transition. The ZnO/polymer nanohybrids synthesized in this work are promising for the fabrication of optical devices with high transparency, such as flexible displays, optical filters, and flexible solar cells. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900230 Exemplaires
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Titre : Bi2O2CO3 / BiOI photocatalysts with heterojunctions highly efficient for visible - light treatment of dye - containing wastewater Type de document : texte imprimé Auteurs : Lang Chen, Auteur ; Shuang-Feng Yin, Auteur ; Sheng-Lian Luo, Auteur Année de publication : 2012 Article en page(s) : pp. 6760-6768 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Waste water Dyes Visible radiation Photocatalysis Catalyst Résumé : Bi2O2CO3/BiOI composites were fabricated at room temperature for the first time by a facile method. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (UV―vis DRS), and nitrogen adsorption-desorption techniques were employed to characterize the physiochemical properties of the composites. The photocatalytic activities of Bi2O2CO3, BiOI, and Bi2O2CO3/BiOI were evaluated through the photocleaning of wastewater which contained rhodamine-B, methylene blue, crystal violet, or a mixture of them under visible-light irradiation (λ ≥ 420 nm). The photocatalytic activity of Bi2O2CO3/BiOI is much higher than that of its components. Moreover, the composite shows good photostability and recyclability. The excellent catalytic efficiency of the Bi2O2CO3/BiOI composite is deduced closely related to Bi2O2CO3/BiOI heterojunctions whose presence is generally regarded to be a favorable factor for the separation of photogenerated electrons and holes. Moreover, ·OH was found to be the main active species for the photocatalytic interactions. The catalyst shows potential application in the treatment of dye-containing wastewater. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900231
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6760-6768[article] Bi2O2CO3 / BiOI photocatalysts with heterojunctions highly efficient for visible - light treatment of dye - containing wastewater [texte imprimé] / Lang Chen, Auteur ; Shuang-Feng Yin, Auteur ; Sheng-Lian Luo, Auteur . - 2012 . - pp. 6760-6768.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6760-6768
Mots-clés : Waste water Dyes Visible radiation Photocatalysis Catalyst Résumé : Bi2O2CO3/BiOI composites were fabricated at room temperature for the first time by a facile method. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (UV―vis DRS), and nitrogen adsorption-desorption techniques were employed to characterize the physiochemical properties of the composites. The photocatalytic activities of Bi2O2CO3, BiOI, and Bi2O2CO3/BiOI were evaluated through the photocleaning of wastewater which contained rhodamine-B, methylene blue, crystal violet, or a mixture of them under visible-light irradiation (λ ≥ 420 nm). The photocatalytic activity of Bi2O2CO3/BiOI is much higher than that of its components. Moreover, the composite shows good photostability and recyclability. The excellent catalytic efficiency of the Bi2O2CO3/BiOI composite is deduced closely related to Bi2O2CO3/BiOI heterojunctions whose presence is generally regarded to be a favorable factor for the separation of photogenerated electrons and holes. Moreover, ·OH was found to be the main active species for the photocatalytic interactions. The catalyst shows potential application in the treatment of dye-containing wastewater. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900231 Exemplaires
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Titre : A comparative theoretical and computational study on robust counterpart optimization : II. Probabilistic guarantees on constraint satisfaction Type de document : texte imprimé Auteurs : Zukui Li, Auteur ; Qiuhua Tang, Auteur ; Christodoulos A. Floudas, Auteur Année de publication : 2012 Article en page(s) : pp. 6760-6768 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Optimization Résumé : Probabilislic guarantees on constraint satisfaction for robust counterpart optimization are studied in this paper. The robust counterpart optimization formulations studied are derived from box, ellipsoidal, polyhedrai, "interval+ellipsoidal", and "interval+polyhedral" uncertainty sets (Li, Z.; Ding, R.; Floudas, CA A Comparative Theoretical and Computational Study on Robust Counterpart Optimization: L Robust Linear and Robust Mixed Integer Linear Optimization. Ind. Eng. Chem. Res. 2011, 50, 10567). For those robust counterpart optimization formulations, their corresponding probability bounds on constraint satisfaction are derived for different types of uncertainty characteristic (i.e., bounded or unbounded uncertainty, with or without detailed probability distribution information). The findings of this work extend the results in the literature and provide greater flexibility for robust optimization practitioners in choosing tighter probability bounds so as to find less conservative robust solutions. Extensive numerical studies are performed to compare the tightness of the different probability bounds and the conservatism of different robust counterpart optimization formulations. Guiding rules for the selection of robust counterpart optimization models and for the determination of the size of the uncertainty set are discussed. Applications in production planning and process scheduling problems are presented. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900232
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6760-6768[article] A comparative theoretical and computational study on robust counterpart optimization : II. Probabilistic guarantees on constraint satisfaction [texte imprimé] / Zukui Li, Auteur ; Qiuhua Tang, Auteur ; Christodoulos A. Floudas, Auteur . - 2012 . - pp. 6760-6768.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6760-6768
Mots-clés : Optimization Résumé : Probabilislic guarantees on constraint satisfaction for robust counterpart optimization are studied in this paper. The robust counterpart optimization formulations studied are derived from box, ellipsoidal, polyhedrai, "interval+ellipsoidal", and "interval+polyhedral" uncertainty sets (Li, Z.; Ding, R.; Floudas, CA A Comparative Theoretical and Computational Study on Robust Counterpart Optimization: L Robust Linear and Robust Mixed Integer Linear Optimization. Ind. Eng. Chem. Res. 2011, 50, 10567). For those robust counterpart optimization formulations, their corresponding probability bounds on constraint satisfaction are derived for different types of uncertainty characteristic (i.e., bounded or unbounded uncertainty, with or without detailed probability distribution information). The findings of this work extend the results in the literature and provide greater flexibility for robust optimization practitioners in choosing tighter probability bounds so as to find less conservative robust solutions. Extensive numerical studies are performed to compare the tightness of the different probability bounds and the conservatism of different robust counterpart optimization formulations. Guiding rules for the selection of robust counterpart optimization models and for the determination of the size of the uncertainty set are discussed. Applications in production planning and process scheduling problems are presented. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900232 Exemplaires
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Titre : Sensor network design for optimal process operation based on data reconciliation Type de document : texte imprimé Auteurs : M. Nabil, Auteur ; Sridharakumar Narasimhan, Auteur Année de publication : 2012 Article en page(s) : pp. 6789-6797 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Data reconciliation Design Résumé : The fundamental problem in optimal sensor network design is choosing a set of important or strategic process variables to be measured. An optimization formulation for sensor network design that relates process economics and data reconciliation is proposed. To address this, an economic quantity is defined to quantify the loss of operational profit caused due to measurement uncertainty. The resulting analytical expression that quantifies the loss is shown to be the sum of weighted error variances of the reconciled estimates obtained from reconciliation. The final formulation is a mixed integer cone program that can be solved to obtain a globally optimal sensor network The effect of the process economics, capital cost, and marginal utility of additional sensors is illustrated using case studies. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900233
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6789-6797[article] Sensor network design for optimal process operation based on data reconciliation [texte imprimé] / M. Nabil, Auteur ; Sridharakumar Narasimhan, Auteur . - 2012 . - pp. 6789-6797.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6789-6797
Mots-clés : Data reconciliation Design Résumé : The fundamental problem in optimal sensor network design is choosing a set of important or strategic process variables to be measured. An optimization formulation for sensor network design that relates process economics and data reconciliation is proposed. To address this, an economic quantity is defined to quantify the loss of operational profit caused due to measurement uncertainty. The resulting analytical expression that quantifies the loss is shown to be the sum of weighted error variances of the reconciled estimates obtained from reconciliation. The final formulation is a mixed integer cone program that can be solved to obtain a globally optimal sensor network The effect of the process economics, capital cost, and marginal utility of additional sensors is illustrated using case studies. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900233 Exemplaires
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Titre : Integration design of heat exchanger networks into membrane distillation systems to save energy Type de document : texte imprimé Auteurs : Yanyue Lu, Auteur ; Junghui Chen, Auteur Année de publication : 2012 Article en page(s) : pp. 6798-6810 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Membrane separation distillation Heat exchanger Meshed network Design Résumé : Membrane distillation requires a lower operation temperature than other separation processes. It is also able to use low-grade thermal energy. In this study, an integrated design method that utilizes a membrane distillation (MD) system to produce pure water is presented. This method is the integration of the heat exchanger network (HEN) into the MD system, and it uses the waste heat from HEN as the energy source of the MD process so as to greatly reduce the water cost. In this proposed method, a multistage MD system is designed to generate the optimal system structure and operating conditions. Then the output and input MD streams are merged into the existing HEN so that the energy cost of pure water can be determined by redesigning the HEN with the trans-shipment models. The efficiency of the proposed method is demonstrated through an industrial case. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900234
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6798-6810[article] Integration design of heat exchanger networks into membrane distillation systems to save energy [texte imprimé] / Yanyue Lu, Auteur ; Junghui Chen, Auteur . - 2012 . - pp. 6798-6810.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6798-6810
Mots-clés : Membrane separation distillation Heat exchanger Meshed network Design Résumé : Membrane distillation requires a lower operation temperature than other separation processes. It is also able to use low-grade thermal energy. In this study, an integrated design method that utilizes a membrane distillation (MD) system to produce pure water is presented. This method is the integration of the heat exchanger network (HEN) into the MD system, and it uses the waste heat from HEN as the energy source of the MD process so as to greatly reduce the water cost. In this proposed method, a multistage MD system is designed to generate the optimal system structure and operating conditions. Then the output and input MD streams are merged into the existing HEN so that the energy cost of pure water can be determined by redesigning the HEN with the trans-shipment models. The efficiency of the proposed method is demonstrated through an industrial case. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900234 Exemplaires
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Titre : Probabilistic PCA - based spatiotemporal multimodeling for nonlinear distributed parameter processes Type de document : texte imprimé Auteurs : Chenkun Qi, Auteur ; Han-Xiong, Li, Auteur Année de publication : 2012 Article en page(s) : pp. 6811–6822 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Probabilistic Résumé : Many industrial processes are nonlinear distributed parameter systems (DPSs). Data-based spatiotemporal modeling is required for analysis and control when the first-principles model is unknown. Because a DPS is infinite-dimensional and time–space coupled, a low-order model is necessary for prediction and control in practice. For low-order modeling, traditional principal component analysis (PCA) is often used for dimension reduction and time–space separation. However, it is a linear method and leads to only one set of fixed spatial basis functions. Therefore, it might not be always effective for nonlinear systems. In this study, a spatiotemporal multimodeling approach is proposed for unknown nonlinear DPSs. First, multimodel decomposition is performed, where probabilistic PCA (PPCA) is used to obtain multiple sets of spatial basis functions from the experimental data by maximizing a likelihood function. Using these multiple sets of PCA spatial bases for time–space separation, the high-dimensionality spatiotemporal data can be reduced to multiple sets of low-dimensionality temporal series. Then, multiple low-order neural models can be easily established to model these local dynamics. Finally, the original spatiotemporal dynamics can be reconstructed by multimodel synthesis. Because the proposed spatiotemporal modeling approach involves a multimodeling mechanism, it can achieve better performance than the traditional PCA-based single-modeling for nonlinear DPSs, which is demonstrated by numerical simulations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202613t
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6811–6822[article] Probabilistic PCA - based spatiotemporal multimodeling for nonlinear distributed parameter processes [texte imprimé] / Chenkun Qi, Auteur ; Han-Xiong, Li, Auteur . - 2012 . - pp. 6811–6822.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6811–6822
Mots-clés : Probabilistic Résumé : Many industrial processes are nonlinear distributed parameter systems (DPSs). Data-based spatiotemporal modeling is required for analysis and control when the first-principles model is unknown. Because a DPS is infinite-dimensional and time–space coupled, a low-order model is necessary for prediction and control in practice. For low-order modeling, traditional principal component analysis (PCA) is often used for dimension reduction and time–space separation. However, it is a linear method and leads to only one set of fixed spatial basis functions. Therefore, it might not be always effective for nonlinear systems. In this study, a spatiotemporal multimodeling approach is proposed for unknown nonlinear DPSs. First, multimodel decomposition is performed, where probabilistic PCA (PPCA) is used to obtain multiple sets of spatial basis functions from the experimental data by maximizing a likelihood function. Using these multiple sets of PCA spatial bases for time–space separation, the high-dimensionality spatiotemporal data can be reduced to multiple sets of low-dimensionality temporal series. Then, multiple low-order neural models can be easily established to model these local dynamics. Finally, the original spatiotemporal dynamics can be reconstructed by multimodel synthesis. Because the proposed spatiotemporal modeling approach involves a multimodeling mechanism, it can achieve better performance than the traditional PCA-based single-modeling for nonlinear DPSs, which is demonstrated by numerical simulations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202613t Exemplaires
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Titre : An efficient multiperiod MINLP model for optimal planning of offshore oil and gas field infrastructure Type de document : texte imprimé Auteurs : Vijay Gupta, Auteur ; Ignacio E. Grossmann, Auteur Année de publication : 2012 Article en page(s) : pp. 6823-6840 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mathematical programming Planning Modeling Mixed integer Non linear Résumé : In this paper, we present an efficient strategic/tactical planning model for offshore oilfield development problem that is fairly generic and can be extended to include other complexities. The proposed multiperiod nonconvex MINLP (mixed integer nonlinear programming) model for multifield site includes three components (oil, water, and gas) explicitly in the formulation using higher order polynomials, avoiding bilinear and other nonlinear terms. With the objective of maximizing total NPV for long-term planning horizon, the model involves decisions related to FPSO (floating production, storage, and offloading) installation and expansion, field―FPSO connections, well drilling, and production rates in each time period. The model can be solved effectively with DICOPT for realistic instances and gives good quality solutions. Furthermore, it can be reformulated into an MILP after piecewise linearization and exact linearization techniques that can be solved globally in an efficient way. Solutions of realistic instances involving 10 fields, 3 FPSOs, 84 wells, and 20 years planning horizon are reported, as well as comparisons between the computational performance of the proposed MINLP and MILP formulations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900236
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6823-6840[article] An efficient multiperiod MINLP model for optimal planning of offshore oil and gas field infrastructure [texte imprimé] / Vijay Gupta, Auteur ; Ignacio E. Grossmann, Auteur . - 2012 . - pp. 6823-6840.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6823-6840
Mots-clés : Mathematical programming Planning Modeling Mixed integer Non linear Résumé : In this paper, we present an efficient strategic/tactical planning model for offshore oilfield development problem that is fairly generic and can be extended to include other complexities. The proposed multiperiod nonconvex MINLP (mixed integer nonlinear programming) model for multifield site includes three components (oil, water, and gas) explicitly in the formulation using higher order polynomials, avoiding bilinear and other nonlinear terms. With the objective of maximizing total NPV for long-term planning horizon, the model involves decisions related to FPSO (floating production, storage, and offloading) installation and expansion, field―FPSO connections, well drilling, and production rates in each time period. The model can be solved effectively with DICOPT for realistic instances and gives good quality solutions. Furthermore, it can be reformulated into an MILP after piecewise linearization and exact linearization techniques that can be solved globally in an efficient way. Solutions of realistic instances involving 10 fields, 3 FPSOs, 84 wells, and 20 years planning horizon are reported, as well as comparisons between the computational performance of the proposed MINLP and MILP formulations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900236 Exemplaires
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Titre : Optimization, kinetics, and thermodynamics in the extraction process of puerarin by decompressing inner ebullition Type de document : texte imprimé Auteurs : Xiaoguang Chen, Auteur ; Tengyou Wei, Auteur ; Mengwei Peng, Auteur Année de publication : 2012 Article en page(s) : pp. 6841–6846 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics Thermodynamics Résumé : Decompressing inner ebullition (DIE) is a novel method and it can achieve a rapid extraction at lower temperature for active constituents of medical plants. In this work, DIE was employed to extract puerarin from puerarin lobata (Willd.) Ohwi (PLO). The extraction conditions were investigated according single factor analysis. Experiment results showed that the extraction yield of puerarin reached a maximum value when the ethanol mass concentration in the aqueous solution immersing the PLO was 60%, the amount of ethanol solution for premaceration and of water for extraction were 1.6 and 10 mL·g–1 of PLO, respectively, the operation gauge pressure was −0.084 MPa, and the extraction temperature was 50 °C. Under the optimal conditions, the extraction kinetics of DIE was studied. The mass transfer coefficient of DIE ranged between 0.09 and 0.13 s–1, which is 183 times greater than that of ultrasonic assistant extraction under the same conditions, and its extraction activation energy ΔE is 10.86 kJ·mol–1. Also, the thermodynamics properties in the extraction process of DIE at 50 °C were also calculated, the enthalpy change ΔH is 58.76 kJ·mol–1, the entropy change ΔS is 224.50 J·mol–1·K–1, and Gibbs free energy ΔG is −13.73 kJ·mol–1, respectively. The extraction of DIE belongs to a spontaneous process with endothermic and entropy increasing. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2020153
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6841–6846[article] Optimization, kinetics, and thermodynamics in the extraction process of puerarin by decompressing inner ebullition [texte imprimé] / Xiaoguang Chen, Auteur ; Tengyou Wei, Auteur ; Mengwei Peng, Auteur . - 2012 . - pp. 6841–6846.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6841–6846
Mots-clés : Kinetics Thermodynamics Résumé : Decompressing inner ebullition (DIE) is a novel method and it can achieve a rapid extraction at lower temperature for active constituents of medical plants. In this work, DIE was employed to extract puerarin from puerarin lobata (Willd.) Ohwi (PLO). The extraction conditions were investigated according single factor analysis. Experiment results showed that the extraction yield of puerarin reached a maximum value when the ethanol mass concentration in the aqueous solution immersing the PLO was 60%, the amount of ethanol solution for premaceration and of water for extraction were 1.6 and 10 mL·g–1 of PLO, respectively, the operation gauge pressure was −0.084 MPa, and the extraction temperature was 50 °C. Under the optimal conditions, the extraction kinetics of DIE was studied. The mass transfer coefficient of DIE ranged between 0.09 and 0.13 s–1, which is 183 times greater than that of ultrasonic assistant extraction under the same conditions, and its extraction activation energy ΔE is 10.86 kJ·mol–1. Also, the thermodynamics properties in the extraction process of DIE at 50 °C were also calculated, the enthalpy change ΔH is 58.76 kJ·mol–1, the entropy change ΔS is 224.50 J·mol–1·K–1, and Gibbs free energy ΔG is −13.73 kJ·mol–1, respectively. The extraction of DIE belongs to a spontaneous process with endothermic and entropy increasing. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2020153 Exemplaires
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Titre : Dynamics of flocculation of lignocellulosic hydrolyzates by polymers Type de document : texte imprimé Auteurs : L. Rakesh Yasarla, Auteur ; Bandaru V. Ramarao, Auteur Année de publication : 2012 Article en page(s) : pp. 6847-6861 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Flocculation Résumé : Pretreatment of lignocellulosic materials involves the solubilization of heniicelluloses, small portions of the lignin, and such components. The hemicellulose solutions are hydrolyzed for downstream fermentation into biofuels or biomaterials. Hydrolyzates produced by pretreatment contain significant colloidal material that is anionically charged. Many of the compounds that are present in the hydrolyzates are inhibitory to fermentation and interfere with downstream separations. The flocculation of this colloidal material makes separations easier by sedimentation and can reduce the fouling tendencies of membranes. It can also reduce the toxicity of the hydrolyzates to fermentation micro-organisms. We studied the dynamics of flocculation of lignocellulosic hydrolyzates with a variety of flocculating agents: electrolytes (alum) and polymers (PEI, pDADMAC, CPAM). It was found that trivalent cations were the most effective suspension destabilizers among the electrolytes, while the cationic polymers could cause flocculation and also redispersion depending on their dosage levels. Flocculation reduced the hydrolyzates' turbidity from > 10000 to under 20. With PEI and pDADMAC, flocculation occurred rapidly when the zeta potential of the colloid was close to zero showing that charge neutralization is the significant destabilizing mechanism. At higher dosages, redispersion occurred indicating that patching is also important in flocculation. Flocculation by PEI was sensitive to pH (from hydrolyzate pH of 3 to 8) with increased dosage necessary at higher pH values. The cationicity of PEI is reduced at higher pH which results in loss of its effectiveness. On the other hand, the zeta potential was largely unaffected with CPAM dosage indicating the dominance of bridging flocculation. Floc sizes ranged up to 3 mm, depending on flocculant dose and pH. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900238
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6847-6861[article] Dynamics of flocculation of lignocellulosic hydrolyzates by polymers [texte imprimé] / L. Rakesh Yasarla, Auteur ; Bandaru V. Ramarao, Auteur . - 2012 . - pp. 6847-6861.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6847-6861
Mots-clés : Flocculation Résumé : Pretreatment of lignocellulosic materials involves the solubilization of heniicelluloses, small portions of the lignin, and such components. The hemicellulose solutions are hydrolyzed for downstream fermentation into biofuels or biomaterials. Hydrolyzates produced by pretreatment contain significant colloidal material that is anionically charged. Many of the compounds that are present in the hydrolyzates are inhibitory to fermentation and interfere with downstream separations. The flocculation of this colloidal material makes separations easier by sedimentation and can reduce the fouling tendencies of membranes. It can also reduce the toxicity of the hydrolyzates to fermentation micro-organisms. We studied the dynamics of flocculation of lignocellulosic hydrolyzates with a variety of flocculating agents: electrolytes (alum) and polymers (PEI, pDADMAC, CPAM). It was found that trivalent cations were the most effective suspension destabilizers among the electrolytes, while the cationic polymers could cause flocculation and also redispersion depending on their dosage levels. Flocculation reduced the hydrolyzates' turbidity from > 10000 to under 20. With PEI and pDADMAC, flocculation occurred rapidly when the zeta potential of the colloid was close to zero showing that charge neutralization is the significant destabilizing mechanism. At higher dosages, redispersion occurred indicating that patching is also important in flocculation. Flocculation by PEI was sensitive to pH (from hydrolyzate pH of 3 to 8) with increased dosage necessary at higher pH values. The cationicity of PEI is reduced at higher pH which results in loss of its effectiveness. On the other hand, the zeta potential was largely unaffected with CPAM dosage indicating the dominance of bridging flocculation. Floc sizes ranged up to 3 mm, depending on flocculant dose and pH. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900238 Exemplaires
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Titre : Kinetics and mechanism of tartrazine adsorption onto chitin and chitosan Type de document : texte imprimé Auteurs : Guilherme L. Dotto, Auteur ; Mery L. G. Vieira, Auteur ; Luiz A. A. Pinto, Auteur Année de publication : 2012 Article en page(s) : pp. 6862-6868 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Kinetics Résumé : In this work the kinetics and mechanisms of tartrazine adsorption onto chitin and chitosan were studied at different pH values (3, 5, 7, 9 and 11). Five models were employed to elucidate the adsorption kinetics. The adsorption mechanisms were verified by use of models based on mass transfer and elemental analysis. The adsorption capacity was increased with pH decrease, reaching maximum values at pH 3. The maximum values were 30 mg·g―1 and 350 mg·g―1 for chitin and chitosan, respectively. For both adsorbents a fast kinetic was observed, and the Avrami model was the more adequate to fitting the experimental data. Tartrazine adsorption onto chitin occurred only by film diffusion. In the chitosan case, adsorption occurred by film and intraparticle diffusion, however, intraparticle diffusion was the rate-limiting step. At pH 3, tartrazine adsorption onto chitin and chitosan occurred by chemical interactions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900239
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6862-6868[article] Kinetics and mechanism of tartrazine adsorption onto chitin and chitosan [texte imprimé] / Guilherme L. Dotto, Auteur ; Mery L. G. Vieira, Auteur ; Luiz A. A. Pinto, Auteur . - 2012 . - pp. 6862-6868.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6862-6868
Mots-clés : Adsorption Kinetics Résumé : In this work the kinetics and mechanisms of tartrazine adsorption onto chitin and chitosan were studied at different pH values (3, 5, 7, 9 and 11). Five models were employed to elucidate the adsorption kinetics. The adsorption mechanisms were verified by use of models based on mass transfer and elemental analysis. The adsorption capacity was increased with pH decrease, reaching maximum values at pH 3. The maximum values were 30 mg·g―1 and 350 mg·g―1 for chitin and chitosan, respectively. For both adsorbents a fast kinetic was observed, and the Avrami model was the more adequate to fitting the experimental data. Tartrazine adsorption onto chitin occurred only by film diffusion. In the chitosan case, adsorption occurred by film and intraparticle diffusion, however, intraparticle diffusion was the rate-limiting step. At pH 3, tartrazine adsorption onto chitin and chitosan occurred by chemical interactions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900239 Exemplaires
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Titre : Adsorptive removal of saturated and unsaturated fatty acids using Ion - exchange resins Type de document : texte imprimé Auteurs : Ganesh L. Maddikeri, Auteur ; Aniruddha B. Pandit, Auteur ; Parag R. Gogate, Auteur Année de publication : 2012 Article en page(s) : pp. 6869–6876 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Acids Ion exchange Résumé : One of the pretreatment approaches for decreasing the initial acid content of waste vegetable oil or nonedible oils with high initial free fatty acid content, with an objective of obtaining a suitable starting raw material for the production of biodiesel, is the adsorption of the free acids using ion-exchange resins. The present work deals with investigation of adsorption characteristics of saturated (stearic) and unsaturated (oleic) fatty acids on different ion exchange resins (polymeric strong (Indion 810) and weak (Indion 850 and Indion 860) anion exchange resins). The ion exchange resins contain tertiary or quaternary amino functional groups on the styrene-divinyl benzene copolymer matrix which can facilitate the adsorption of acids. Kinetic adsorption studies have been carried out initially to determine the contact time required to reach the adsorption equilibrium between fatty acid adsorbed on the resin and remaining fatty acid present in the oil. Equilibrium adsorption studies have been carried out at different temperatures viz. 293, 303, and 313 K. It has been observed that adsorption of saturated and unsaturated fatty acids increased with its concentration in the liquid at constant temperature and decreased with an increase in the temperature at constant concentration. Also, the adsorption equilibrium data have been found to be well described by the Freundlich type isotherm. The negative values of ΔG and ΔH showed that the adsorption of both saturated and unsaturated acids on the ion exchange resins was spontaneous and also exothermic. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3000562
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6869–6876[article] Adsorptive removal of saturated and unsaturated fatty acids using Ion - exchange resins [texte imprimé] / Ganesh L. Maddikeri, Auteur ; Aniruddha B. Pandit, Auteur ; Parag R. Gogate, Auteur . - 2012 . - pp. 6869–6876.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6869–6876
Mots-clés : Acids Ion exchange Résumé : One of the pretreatment approaches for decreasing the initial acid content of waste vegetable oil or nonedible oils with high initial free fatty acid content, with an objective of obtaining a suitable starting raw material for the production of biodiesel, is the adsorption of the free acids using ion-exchange resins. The present work deals with investigation of adsorption characteristics of saturated (stearic) and unsaturated (oleic) fatty acids on different ion exchange resins (polymeric strong (Indion 810) and weak (Indion 850 and Indion 860) anion exchange resins). The ion exchange resins contain tertiary or quaternary amino functional groups on the styrene-divinyl benzene copolymer matrix which can facilitate the adsorption of acids. Kinetic adsorption studies have been carried out initially to determine the contact time required to reach the adsorption equilibrium between fatty acid adsorbed on the resin and remaining fatty acid present in the oil. Equilibrium adsorption studies have been carried out at different temperatures viz. 293, 303, and 313 K. It has been observed that adsorption of saturated and unsaturated fatty acids increased with its concentration in the liquid at constant temperature and decreased with an increase in the temperature at constant concentration. Also, the adsorption equilibrium data have been found to be well described by the Freundlich type isotherm. The negative values of ΔG and ΔH showed that the adsorption of both saturated and unsaturated acids on the ion exchange resins was spontaneous and also exothermic. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3000562 Exemplaires
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Titre : Antimony(III) adsorption from aqueous solution using raw perlite and Mn - modified perlite : Equilibrium, thermodynamic, and kinetic studies Type de document : texte imprimé Auteurs : Ahmet Sari, Auteur ; Gungor Sahinoglu, Auteur ; Mustafa Tuzen, Auteur Année de publication : 2012 Article en page(s) : pp. 6877–6886 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Aqueous Solution Thermodynamic Kinetic Résumé : In this study, the adsorption potential of expanded perlite (EP) and manganese oxides-modified EP (Mn-MEP) for the removal of Sb(III) from aqueous solution were investigated. The influence of solution pH, adsorbent concentration, contact time and temperature on the Sb(III) adsorption were studied using the batch method. Modification of the surface of EP with 0.18 g of manganese oxide per gram EP showed an increase of 1.6-fold in its surface area. The raw EP and Mn-MEP samples with Sb(III) ions were characterized before and after the adsorption process using FT-IR and SEM analysis techniques. The monolayer adsorption capacity of EP and Mn-MEP for Sb(III) was found to be 54.4 and 76.5 mg g–1 at pH 4, respectively. The mean adsorption energy (6.3 kJ mol–1) calculated from the Dubinin–Radushkevich model indicated that the adsorption of Sb(III) onto Mn-MEP was physically carried out. After 10 times of adsorption/desorption cycles, the reusability of Mn-MEP decreased as slightly as 5% for adsorption and 7% for desorption. The calculated thermodynamic parameters (ΔGo, ΔHo, and ΔSo) showed that the adsorption was feasible, spontaneous, and exothermic. The kinetic parameters revealed that the adsorption of Sb(III) onto Mn-MEP followed well the pseudo-second-order kinetic model. In addition, from a practical viewpoint, Mn-MEP is a promising adsorbent for the removal of Sb(III) from aqueous solutions since it has large surface area, high adsorption capacity, easy availability, low-cost, and good reusability performance. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300243n
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6877–6886[article] Antimony(III) adsorption from aqueous solution using raw perlite and Mn - modified perlite : Equilibrium, thermodynamic, and kinetic studies [texte imprimé] / Ahmet Sari, Auteur ; Gungor Sahinoglu, Auteur ; Mustafa Tuzen, Auteur . - 2012 . - pp. 6877–6886.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6877–6886
Mots-clés : Adsorption Aqueous Solution Thermodynamic Kinetic Résumé : In this study, the adsorption potential of expanded perlite (EP) and manganese oxides-modified EP (Mn-MEP) for the removal of Sb(III) from aqueous solution were investigated. The influence of solution pH, adsorbent concentration, contact time and temperature on the Sb(III) adsorption were studied using the batch method. Modification of the surface of EP with 0.18 g of manganese oxide per gram EP showed an increase of 1.6-fold in its surface area. The raw EP and Mn-MEP samples with Sb(III) ions were characterized before and after the adsorption process using FT-IR and SEM analysis techniques. The monolayer adsorption capacity of EP and Mn-MEP for Sb(III) was found to be 54.4 and 76.5 mg g–1 at pH 4, respectively. The mean adsorption energy (6.3 kJ mol–1) calculated from the Dubinin–Radushkevich model indicated that the adsorption of Sb(III) onto Mn-MEP was physically carried out. After 10 times of adsorption/desorption cycles, the reusability of Mn-MEP decreased as slightly as 5% for adsorption and 7% for desorption. The calculated thermodynamic parameters (ΔGo, ΔHo, and ΔSo) showed that the adsorption was feasible, spontaneous, and exothermic. The kinetic parameters revealed that the adsorption of Sb(III) onto Mn-MEP followed well the pseudo-second-order kinetic model. In addition, from a practical viewpoint, Mn-MEP is a promising adsorbent for the removal of Sb(III) from aqueous solutions since it has large surface area, high adsorption capacity, easy availability, low-cost, and good reusability performance. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300243n Exemplaires
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Titre : Thermal, oxidative, and CO2 - induced degradation of supported polyethylenimine adsorbents Type de document : texte imprimé Auteurs : Aliakbar Heydari-Gorji, Auteur ; Abdelhamid Sayari, Auteur Année de publication : 2012 Article en page(s) : pp. 6887-6894 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon dioxide Oxidation Résumé : This work examines the stability of polyethylenimine(PEI)-impregnated mesoporous silica for CO2 removal over a wide range of conditions. The support used was a SBA-15 silica with platelet morphology and short pore channels (SBA-15PL). The effect of long-term exposure to different gaseous streams, including carbon-free air (CFair), simulated flue gas (SFG), and different CO2/O2/N2 mixtures on the carbon dioxide adsorption capacity was investigated. Extensive CO2 adsorption― desorption cycling using dry and humid streams at different adsorption and regeneration temperatures was also carried out Based on adsorption data, as well as diffuse reflectance infrared Fourier transform (DRIFT) and 13C CP MAS NMR measurements, it was found that PEI-modified adsorbents exhibit (i) high thermal stability at moderate temperatures, (ii) highly stable CO2 uptake in the presence of moisture, (iii) extensive degradation in the presence of dry CO2, particularly at high temperature, (iv) fast degradation upon exposure to CFair even at moderate temperatures, (v) excellent stability in the presence of humidified gases containing both CO2 and O2, ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900242
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6887-6894[article] Thermal, oxidative, and CO2 - induced degradation of supported polyethylenimine adsorbents [texte imprimé] / Aliakbar Heydari-Gorji, Auteur ; Abdelhamid Sayari, Auteur . - 2012 . - pp. 6887-6894.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6887-6894
Mots-clés : Carbon dioxide Oxidation Résumé : This work examines the stability of polyethylenimine(PEI)-impregnated mesoporous silica for CO2 removal over a wide range of conditions. The support used was a SBA-15 silica with platelet morphology and short pore channels (SBA-15PL). The effect of long-term exposure to different gaseous streams, including carbon-free air (CFair), simulated flue gas (SFG), and different CO2/O2/N2 mixtures on the carbon dioxide adsorption capacity was investigated. Extensive CO2 adsorption― desorption cycling using dry and humid streams at different adsorption and regeneration temperatures was also carried out Based on adsorption data, as well as diffuse reflectance infrared Fourier transform (DRIFT) and 13C CP MAS NMR measurements, it was found that PEI-modified adsorbents exhibit (i) high thermal stability at moderate temperatures, (ii) highly stable CO2 uptake in the presence of moisture, (iii) extensive degradation in the presence of dry CO2, particularly at high temperature, (iv) fast degradation upon exposure to CFair even at moderate temperatures, (v) excellent stability in the presence of humidified gases containing both CO2 and O2, ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900242 Exemplaires
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Titre : Amine - functionalized MIL - 53 metal – organic framework in polyimide mixed matrix membranes for CO2 / CH4 separation Type de document : texte imprimé Auteurs : Xiao Yuan Chen, Auteur ; Hoang Vinh-Thang, Auteur ; Denis Rodrigue, Auteur Année de publication : 2012 Article en page(s) : pp. 6895-6906 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon dioxide Résumé : Flexible crystalline metal-organic framework (MOF) of nanosize particles (Al-MIL-53) and 6FDA-ODA polyimides were used to produce mixed matrix membranes (MMM). These MMM display excellent CO2/CH4 separation properties even without any compatibilization (amine grafting). The ideal selectivity and separation factor were found to increase with increasing MOF loading. Furthermore, these materials have an improved CO2/CH4 separation factor with increasing pressure, in contrast to traditional polymer membranes. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900243
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6895-6906[article] Amine - functionalized MIL - 53 metal – organic framework in polyimide mixed matrix membranes for CO2 / CH4 separation [texte imprimé] / Xiao Yuan Chen, Auteur ; Hoang Vinh-Thang, Auteur ; Denis Rodrigue, Auteur . - 2012 . - pp. 6895-6906.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6895-6906
Mots-clés : Carbon dioxide Résumé : Flexible crystalline metal-organic framework (MOF) of nanosize particles (Al-MIL-53) and 6FDA-ODA polyimides were used to produce mixed matrix membranes (MMM). These MMM display excellent CO2/CH4 separation properties even without any compatibilization (amine grafting). The ideal selectivity and separation factor were found to increase with increasing MOF loading. Furthermore, these materials have an improved CO2/CH4 separation factor with increasing pressure, in contrast to traditional polymer membranes. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900243 Exemplaires
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Titre : Evaluation of a primary amine - functionalized ion - exchange resin for CO2 capture Type de document : texte imprimé Auteurs : W. Richard Alesi, Auteur ; John R. Kitchin, Auteur Année de publication : 2012 Article en page(s) : pp. 6907-6915 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon dioxide Ion exchange resin Résumé : A primary amine-functionalized polymeric ion-exchange resin (Lewatit VP OC 1065, Lanxess) was evaluated for use in CO2 capture applications. The polymeric resin was characterized by SEM, DRIFTS-IR, N2 adsorption isotherms, and packed bed sorption measurements to determine some of the characteristic properties of the resin. Capture capacities ranging from 1.85 to 1.15 mol CO2/kg sorbent were obtained in a packed bed reactor exposed to 10 vol % CO2 in N2 at adsorption temperatures ranging from 30 to 70 °C. The capture capacity of the resin was stable over 18 adsorption/regeneration cycles. The resin was evaluated through thermogravimetric analysis to have a low moisture adsorption (1.5 mol H2O/kg sorbent). It is possible to completely regenerate the resin under 1 atm of CO2 at 200 °C. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900244
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6907-6915[article] Evaluation of a primary amine - functionalized ion - exchange resin for CO2 capture [texte imprimé] / W. Richard Alesi, Auteur ; John R. Kitchin, Auteur . - 2012 . - pp. 6907-6915.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6907-6915
Mots-clés : Carbon dioxide Ion exchange resin Résumé : A primary amine-functionalized polymeric ion-exchange resin (Lewatit VP OC 1065, Lanxess) was evaluated for use in CO2 capture applications. The polymeric resin was characterized by SEM, DRIFTS-IR, N2 adsorption isotherms, and packed bed sorption measurements to determine some of the characteristic properties of the resin. Capture capacities ranging from 1.85 to 1.15 mol CO2/kg sorbent were obtained in a packed bed reactor exposed to 10 vol % CO2 in N2 at adsorption temperatures ranging from 30 to 70 °C. The capture capacity of the resin was stable over 18 adsorption/regeneration cycles. The resin was evaluated through thermogravimetric analysis to have a low moisture adsorption (1.5 mol H2O/kg sorbent). It is possible to completely regenerate the resin under 1 atm of CO2 at 200 °C. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900244 Exemplaires
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Titre : Experiments and modeling of volumetric properties and phase behavior for condensate gas under ultra - high - pressure conditions Type de document : texte imprimé Auteurs : Chang-Yu Sun, Auteur ; Huang Liu, Auteur ; Ke-Le Yan, Auteur Année de publication : 2012 Article en page(s) : pp. 6916-6925 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Modeling Résumé : Four reservoir samples under ultra-high-pressure and high-temperature conditions were collected from condensate gas fields in China. Constant-composition expansion tests were performed to determine the phase behavior and volumetric properties of reservoir fluid using an ultra-high-pressure fluid PVT test system. The compressibility factor and dew-point pressure were obtained at four temperatures for four samples. The range of pressure was from 22.03 to 118.89 MPa. For the samples studied, the experimental results showed that the dew-point pressure decreased with increasing temperature and the compressibility factors increased with increasing pressure but decreased with increasing temperature at a given high reduced pressure. A thermodynamic model based on an equation of state was developed to describe the volumetric properties and phase behavior of the condensate gas under ultra-high-pressure conditions. The calculated results are in good accordance with the experimental data, which is important for the development of condensate gas reservoirs in ultra-high-pressure environments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900245
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6916-6925[article] Experiments and modeling of volumetric properties and phase behavior for condensate gas under ultra - high - pressure conditions [texte imprimé] / Chang-Yu Sun, Auteur ; Huang Liu, Auteur ; Ke-Le Yan, Auteur . - 2012 . - pp. 6916-6925.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6916-6925
Mots-clés : Modeling Résumé : Four reservoir samples under ultra-high-pressure and high-temperature conditions were collected from condensate gas fields in China. Constant-composition expansion tests were performed to determine the phase behavior and volumetric properties of reservoir fluid using an ultra-high-pressure fluid PVT test system. The compressibility factor and dew-point pressure were obtained at four temperatures for four samples. The range of pressure was from 22.03 to 118.89 MPa. For the samples studied, the experimental results showed that the dew-point pressure decreased with increasing temperature and the compressibility factors increased with increasing pressure but decreased with increasing temperature at a given high reduced pressure. A thermodynamic model based on an equation of state was developed to describe the volumetric properties and phase behavior of the condensate gas under ultra-high-pressure conditions. The calculated results are in good accordance with the experimental data, which is important for the development of condensate gas reservoirs in ultra-high-pressure environments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900245 Exemplaires
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Titre : Development of a hybrid model for industrial ethylene oxide reactor Type de document : texte imprimé Auteurs : Na Luo, Auteur ; Wenli Du, Auteur ; Zhencheng Ye, Auteur Année de publication : 2012 Article en page(s) : pp. 6926-6932 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reactor Modeling Résumé : A hybrid modeling approach for an ethylene oxidation reactor with silver catalyst is proposed. Under the form of mechanistic model, support vector regression is used to construct the catalyst deactivation model with the operating data coming from real plant. Prior knowledge is extracted to enhance the generalization of the deactivation model. With the hybrid model, the prediction error is less than 5% for the prediction of industrial reactor. The approach is shown to predict the production more accurately and have more reliable extrapolation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900246
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6926-6932[article] Development of a hybrid model for industrial ethylene oxide reactor [texte imprimé] / Na Luo, Auteur ; Wenli Du, Auteur ; Zhencheng Ye, Auteur . - 2012 . - pp. 6926-6932.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6926-6932
Mots-clés : Reactor Modeling Résumé : A hybrid modeling approach for an ethylene oxidation reactor with silver catalyst is proposed. Under the form of mechanistic model, support vector regression is used to construct the catalyst deactivation model with the operating data coming from real plant. Prior knowledge is extracted to enhance the generalization of the deactivation model. With the hybrid model, the prediction error is less than 5% for the prediction of industrial reactor. The approach is shown to predict the production more accurately and have more reliable extrapolation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900246 Exemplaires
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Titre : Correlation of solubilities of hydrophilic pharmaceuticals versus dielectric constants of binary solvents Type de document : texte imprimé Auteurs : Xinwei Zhang, Auteur ; Qiuxiang Yin, Auteur ; Penglei Cui, Auteur Année de publication : 2012 Article en page(s) : pp. 6933-693 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solubility Correlation analysis Résumé : In this paper, the polarity of binary solvents was studied by the sum law of cube roots of the dielectric constant During the antisolvent crystallization process, the composition of the binary solvents and their dielectric constants changed simultaneously. These results demonstrated that variation of the solubility is dependent on the polarity of the binary solvents. On the basis of experiments, a new model was put forward to quantitatively describe the relationship between the solubility of hydrophilic pharmaceuticals and the dielectric constants of the binary solvents. Furthermore, this model was tested and verified by solubility data of other pharmaceuticals published in the literature with high accuracy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900247
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6933-693[article] Correlation of solubilities of hydrophilic pharmaceuticals versus dielectric constants of binary solvents [texte imprimé] / Xinwei Zhang, Auteur ; Qiuxiang Yin, Auteur ; Penglei Cui, Auteur . - 2012 . - pp. 6933-693.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6933-693
Mots-clés : Solubility Correlation analysis Résumé : In this paper, the polarity of binary solvents was studied by the sum law of cube roots of the dielectric constant During the antisolvent crystallization process, the composition of the binary solvents and their dielectric constants changed simultaneously. These results demonstrated that variation of the solubility is dependent on the polarity of the binary solvents. On the basis of experiments, a new model was put forward to quantitatively describe the relationship between the solubility of hydrophilic pharmaceuticals and the dielectric constants of the binary solvents. Furthermore, this model was tested and verified by solubility data of other pharmaceuticals published in the literature with high accuracy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900247 Exemplaires
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Titre : Analysis on Laminar chaotic mixing based on configuration of streak lobes in an impeller - agitated vessel Type de document : texte imprimé Auteurs : Shunsuke Hashimoto, Auteur ; Ryota Osaka, Auteur ; Makiko Kawamata, Auteur Année de publication : 2012 Article en page(s) : pp 6939–6947 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : laminar chaotic Résumé : In the case of laminar chaotic mixing in a stirred tank, our previous study theoretically revealed that the streakline originating from the tip of the impeller provides the formation of a mixing pattern and its outline comes close to the configuration of the streakline with respect to time. In the present study, the laminar chaotic mixing in a 3-D stirred tank was investigated experimentally by use of a new index, “streak lobes”, which were equivalent to the region surrounded by the streakline. The streak lobes were created by the minute perturbation wave (traveling wave) that is generated by the rotation of the impeller blade in a stirred tank. The amplitude and frequency of their traveling waves were dominant for the size (width and area) and/or number of streak lobes. The experimental results demonstrated that the large area of streak lobes in the 3-D velocity field resulted in good chaotic mixing, even if the number of streak lobes is small. In addition, the fluid exchange between top and bottom regions in the stirred tank occurred rapidly in the case where the streak lobes could come and go between two regions. It was suggested that the streak lobes can play an important role as an index whether or not good chaotic mixing occurs in the stirred tank. The present study proposed that the control of the size and/or number of streak lobes adjusting the amplitude and frequency of the traveling wave caused by impeller rotation resulted in a shortcut to enhance laminar chaotic mixing. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203036n
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp 6939–6947[article] Analysis on Laminar chaotic mixing based on configuration of streak lobes in an impeller - agitated vessel [texte imprimé] / Shunsuke Hashimoto, Auteur ; Ryota Osaka, Auteur ; Makiko Kawamata, Auteur . - 2012 . - pp 6939–6947.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp 6939–6947
Mots-clés : laminar chaotic Résumé : In the case of laminar chaotic mixing in a stirred tank, our previous study theoretically revealed that the streakline originating from the tip of the impeller provides the formation of a mixing pattern and its outline comes close to the configuration of the streakline with respect to time. In the present study, the laminar chaotic mixing in a 3-D stirred tank was investigated experimentally by use of a new index, “streak lobes”, which were equivalent to the region surrounded by the streakline. The streak lobes were created by the minute perturbation wave (traveling wave) that is generated by the rotation of the impeller blade in a stirred tank. The amplitude and frequency of their traveling waves were dominant for the size (width and area) and/or number of streak lobes. The experimental results demonstrated that the large area of streak lobes in the 3-D velocity field resulted in good chaotic mixing, even if the number of streak lobes is small. In addition, the fluid exchange between top and bottom regions in the stirred tank occurred rapidly in the case where the streak lobes could come and go between two regions. It was suggested that the streak lobes can play an important role as an index whether or not good chaotic mixing occurs in the stirred tank. The present study proposed that the control of the size and/or number of streak lobes adjusting the amplitude and frequency of the traveling wave caused by impeller rotation resulted in a shortcut to enhance laminar chaotic mixing. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203036n Exemplaires
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Titre : Direct simulations of mixing of liquids with density and viscosity differences Type de document : texte imprimé Auteurs : J. J. Derksen, Auteur Année de publication : 2012 Article en page(s) : pp. 6948-6957 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Viscosity Density Mixing Résumé : Simulations of flow and scalar transport in stirred tanks operated in transitional and mildly turbulent regimes (Re = 3000―12000) are presented. The moderate Reynolds numbers allow the flow to be simulated directly, without the use of turbulence closure or subgrid-scale models. The Newtonian liquids that are blended have different densities and/or viscosities, and the emphasis is on how these differences affect mixing times. The density difference is characterized by a Richardson number (Ri) that varies in the range of 0―0.5. The kinematic viscosity ratio is between 1 and 4. The results show that mixing times increase steeply with increasing Ri and that changing the tank layout can partly mitigate this effect. The viscosity ratio has a much weaker influence on the mixing time. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900249
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6948-6957[article] Direct simulations of mixing of liquids with density and viscosity differences [texte imprimé] / J. J. Derksen, Auteur . - 2012 . - pp. 6948-6957.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6948-6957
Mots-clés : Viscosity Density Mixing Résumé : Simulations of flow and scalar transport in stirred tanks operated in transitional and mildly turbulent regimes (Re = 3000―12000) are presented. The moderate Reynolds numbers allow the flow to be simulated directly, without the use of turbulence closure or subgrid-scale models. The Newtonian liquids that are blended have different densities and/or viscosities, and the emphasis is on how these differences affect mixing times. The density difference is characterized by a Richardson number (Ri) that varies in the range of 0―0.5. The kinematic viscosity ratio is between 1 and 4. The results show that mixing times increase steeply with increasing Ri and that changing the tank layout can partly mitigate this effect. The viscosity ratio has a much weaker influence on the mixing time. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900249 Exemplaires
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Titre : Measurements and correlation of physical solubility of carbon dioxide in (Monoethanolamine + Water) by a modified technique Type de document : texte imprimé Auteurs : Ying Jiru, Auteur ; Dag A. Eimer, Auteur ; Yi Wenjuan, Auteur Année de publication : 2012 Article en page(s) : pp. 6958–6966 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Physical solubility Carbon Dioxide Résumé : A modified experimental technique for measuring the physical solubility of CO2 in monoethanolamine (MEA) aqueous solutions using the “N2O analogy” method is proposed in this work. The modified technique employs a scaled spiral glass tube with a small drop of mercury as a eudiometer as an alternative to a three-branch U-tube setup to keep the system pressure constant and measure the volume of a drop of absorbed gas at constant temperature. The results were in good agreement with literature values, suggesting that the technique is feasible and reliable. Compared with the three-branch U-tube setup, the new technique is easy to operate and more sensitive and accurate. The physical solubility of CO2 in aqueous MEA solutions over the full range of concentrations was measured using this modified technique over the temperature range from 298.15 to 323.15 K under a constant ambient pressure. Wang et al.’s model ( Chem. Eng. J. 1992, 48, 31−40) was used to correlate the data, and the results showed that the model is good for predicting the behavior of the (monoethanolamine + water) system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3002588
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6958–6966[article] Measurements and correlation of physical solubility of carbon dioxide in (Monoethanolamine + Water) by a modified technique [texte imprimé] / Ying Jiru, Auteur ; Dag A. Eimer, Auteur ; Yi Wenjuan, Auteur . - 2012 . - pp. 6958–6966.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6958–6966
Mots-clés : Physical solubility Carbon Dioxide Résumé : A modified experimental technique for measuring the physical solubility of CO2 in monoethanolamine (MEA) aqueous solutions using the “N2O analogy” method is proposed in this work. The modified technique employs a scaled spiral glass tube with a small drop of mercury as a eudiometer as an alternative to a three-branch U-tube setup to keep the system pressure constant and measure the volume of a drop of absorbed gas at constant temperature. The results were in good agreement with literature values, suggesting that the technique is feasible and reliable. Compared with the three-branch U-tube setup, the new technique is easy to operate and more sensitive and accurate. The physical solubility of CO2 in aqueous MEA solutions over the full range of concentrations was measured using this modified technique over the temperature range from 298.15 to 323.15 K under a constant ambient pressure. Wang et al.’s model ( Chem. Eng. J. 1992, 48, 31−40) was used to correlate the data, and the results showed that the model is good for predicting the behavior of the (monoethanolamine + water) system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3002588 Exemplaires
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Titre : Use of single - screw extruder for continuous silane cross - linked polyethylene recycling process using supercritical alcohol Type de document : texte imprimé Auteurs : Toshiharu Goto, Auteur ; Shingo Ashihara, Auteur ; Manabu Kato, Auteur Année de publication : 2012 Article en page(s) : pp. 6967–6971 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Twin-screw extruder Supercritical fluids Résumé : The development of a continuous process for supercritical fluids is desirable for high-pressure technology. In a previous study, it was revealed that a twin-screw extruder was applicable as the reactor and feeder for industrial supercritical fluid processes (Goto, T.; et al. Ind. Eng. Chem. Res. 2011, 50, 5661–5666). The advantages of twin-screw extruders include their conveying ability and flexibility of design, which make them ideal for research on the applications of extruder. However, twin-screw extruders are expensive because of their complicated gearbox, cylinder shape, screw, etc. Here we report that a single-screw extruder, which is less expensive and simpler than a twin-screw extruder, is also applicable as the reactor and feeder for commercial supercritical fluid processes. Moreover, the equipment for a single-screw extruder is more compact than that of a twin-screw extruder. The results of this study will promote the application of extruders in supercritical fluid engineering research and contribute to the industrialization of a wide range of supercritical fluid techniques. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202303y
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6967–6971[article] Use of single - screw extruder for continuous silane cross - linked polyethylene recycling process using supercritical alcohol [texte imprimé] / Toshiharu Goto, Auteur ; Shingo Ashihara, Auteur ; Manabu Kato, Auteur . - 2012 . - pp. 6967–6971.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6967–6971
Mots-clés : Twin-screw extruder Supercritical fluids Résumé : The development of a continuous process for supercritical fluids is desirable for high-pressure technology. In a previous study, it was revealed that a twin-screw extruder was applicable as the reactor and feeder for industrial supercritical fluid processes (Goto, T.; et al. Ind. Eng. Chem. Res. 2011, 50, 5661–5666). The advantages of twin-screw extruders include their conveying ability and flexibility of design, which make them ideal for research on the applications of extruder. However, twin-screw extruders are expensive because of their complicated gearbox, cylinder shape, screw, etc. Here we report that a single-screw extruder, which is less expensive and simpler than a twin-screw extruder, is also applicable as the reactor and feeder for commercial supercritical fluid processes. Moreover, the equipment for a single-screw extruder is more compact than that of a twin-screw extruder. The results of this study will promote the application of extruders in supercritical fluid engineering research and contribute to the industrialization of a wide range of supercritical fluid techniques. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202303y Exemplaires
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Titre : A note on the analytical solution of cubic equations of state in process simulation Type de document : texte imprimé Auteurs : Rosendo Monroy-Loperena, Auteur Année de publication : 2012 Article en page(s) : pp. 6972-6976 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermodynamic properties Equations of state Résumé : This work address the problem of round-off errors in the analytical solution (Cardano's Method) of cubic equations of state inside the simulation of chemical processes in the low-temperature region, as it is the case of cryogenic processes involving hydrates calculations. It is proposed as a strategy that can be taken as an iterative refinement of the solution obtained by the analytical method and allows one to take advantage of the calculations fulfilled in the application of the analytical solution (Cardano's Method). Numerical experimentations are presented in order to show the application of the proposed strategy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900252
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6972-6976[article] A note on the analytical solution of cubic equations of state in process simulation [texte imprimé] / Rosendo Monroy-Loperena, Auteur . - 2012 . - pp. 6972-6976.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6972-6976
Mots-clés : Thermodynamic properties Equations of state Résumé : This work address the problem of round-off errors in the analytical solution (Cardano's Method) of cubic equations of state inside the simulation of chemical processes in the low-temperature region, as it is the case of cryogenic processes involving hydrates calculations. It is proposed as a strategy that can be taken as an iterative refinement of the solution obtained by the analytical method and allows one to take advantage of the calculations fulfilled in the application of the analytical solution (Cardano's Method). Numerical experimentations are presented in order to show the application of the proposed strategy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900252 Exemplaires
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Titre : Membrane retrofit option for paraffin / olefin separation — a technoeconomic evaluation Type de document : texte imprimé Auteurs : Anatolie Motelica, Auteur ; Odolphus S. L. Bruinsma, Auteur ; Robert Kreiter, Auteur Année de publication : 2012 Article en page(s) : pp. 6977–6986 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Paraffin Olefin Résumé : The technical and economic feasibility of a hybrid separation process in which gas separation membranes are combined with conventional distillation are assessed for the separation of ethylene from ethane and of butadiene from a C4-mixture. The potentials for increased energy efficiency and debottlenecking were determined in relation to the required membrane performances. The energy saving potential for the separation of ethylene from ethane is rather low owing to the required very high membrane selectivity. Energy savings can be expected when the membrane selectivity for ethylene is >60. However, the possibility to increase the column capacity in an existing plant by using a membrane is very high. This can become economically attractive if the membrane has a selectivity for ethylene of ≥10. In the case of butadiene separation, the energy savings can be as high as 30% depending on membrane selectivity and process configuration. This high value can be reached when the membrane selectivity for butadiene relative to saturated hydrocarbons equals 15. Again, an increase in the production capacity of butadiene can be achieved in an economic viable fashion. DEWEY : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300587u
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6977–6986[article] Membrane retrofit option for paraffin / olefin separation — a technoeconomic evaluation [texte imprimé] / Anatolie Motelica, Auteur ; Odolphus S. L. Bruinsma, Auteur ; Robert Kreiter, Auteur . - 2012 . - pp. 6977–6986.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6977–6986
Mots-clés : Paraffin Olefin Résumé : The technical and economic feasibility of a hybrid separation process in which gas separation membranes are combined with conventional distillation are assessed for the separation of ethylene from ethane and of butadiene from a C4-mixture. The potentials for increased energy efficiency and debottlenecking were determined in relation to the required membrane performances. The energy saving potential for the separation of ethylene from ethane is rather low owing to the required very high membrane selectivity. Energy savings can be expected when the membrane selectivity for ethylene is >60. However, the possibility to increase the column capacity in an existing plant by using a membrane is very high. This can become economically attractive if the membrane has a selectivity for ethylene of ≥10. In the case of butadiene separation, the energy savings can be as high as 30% depending on membrane selectivity and process configuration. This high value can be reached when the membrane selectivity for butadiene relative to saturated hydrocarbons equals 15. Again, an increase in the production capacity of butadiene can be achieved in an economic viable fashion. DEWEY : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300587u Exemplaires
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Titre : Reaction of tricalcium aluminate with hydrogen chloride under simulated bag filter conditions Type de document : texte imprimé Auteurs : Kouki Kasuya, Auteur ; Naomi Onodera, Auteur ; Atsushi Iizuka, Auteur Année de publication : 2012 Article en page(s) : pp. 6987-6990 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Bag filter Résumé : The influence of metals present in fly ash on the dechlorination reaction that occurs at bag filters installed in municipal waste incinerators and melting furnaces has not been investigated previously. Tricalcium aluminate (3CaO·Al2O3, C3A) is considered to be a precursor of complex oxychlorides, and its reaction with HCl was investigated in a gas flow reactor under simulated bag filter conditions (473 K, 1000 ppm HCl, 30 vol% H2O, 5 vol% O2). The molar chlorination ratio of C3A leveled off at about 1 after 24 h. The chlorination reaction rate of C3A was similar to that of calcium hydroxide (Ca(OH)2). C3A chlorination products had a mainly amorphous structure. Elemental mapping images of the surface of chlorinated C3A indicated the likely generation of complex oxychlorides of calcium and aluminum. It is possible that complex oxychlorides are produced at bag filters from complex oxides generated in high-temperature incinerators. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900254
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6987-6990[article] Reaction of tricalcium aluminate with hydrogen chloride under simulated bag filter conditions [texte imprimé] / Kouki Kasuya, Auteur ; Naomi Onodera, Auteur ; Atsushi Iizuka, Auteur . - 2012 . - pp. 6987-6990.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6987-6990
Mots-clés : Bag filter Résumé : The influence of metals present in fly ash on the dechlorination reaction that occurs at bag filters installed in municipal waste incinerators and melting furnaces has not been investigated previously. Tricalcium aluminate (3CaO·Al2O3, C3A) is considered to be a precursor of complex oxychlorides, and its reaction with HCl was investigated in a gas flow reactor under simulated bag filter conditions (473 K, 1000 ppm HCl, 30 vol% H2O, 5 vol% O2). The molar chlorination ratio of C3A leveled off at about 1 after 24 h. The chlorination reaction rate of C3A was similar to that of calcium hydroxide (Ca(OH)2). C3A chlorination products had a mainly amorphous structure. Elemental mapping images of the surface of chlorinated C3A indicated the likely generation of complex oxychlorides of calcium and aluminum. It is possible that complex oxychlorides are produced at bag filters from complex oxides generated in high-temperature incinerators. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900254 Exemplaires
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