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Vol. 50 N° 12 - Juin 2011 [texte imprimé] . - 2011 . - p. 7089-7704 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierConversion of methane and carbon dioxide to higher value products / Vesna Havran in Industrial & engineering chemistry research, Vol. 50 N° 12 (Juin 2011)
Titre : Conversion of methane and carbon dioxide to higher value products Type de document : texte imprimé Auteurs : Vesna Havran, Auteur ; Milorad P. Dudukovic, Auteur ; Cynthia S. Lo, Auteur Année de publication : 2011 Article en page(s) : pp. 7089-7100 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon dioxide Résumé : In this manuscript we address the efforts reported in the literature on direct conversion of methane and carbon dioxide into higher value products. The abundance of these two greenhouse gases makes them potentially useful for chemical syntheses. However, strong intramolecular bonds render both molecules chemically inert and thermodynamically stable. Thus, significant energy inputs as well as properly designed catalytic systems are required for their reactions. In addition to traditional catalytic processes, new alternative routes-such as photocatalytic conversion and dielectric barrier discharges—have been suggested. Figures of merit for comparison of various approaches have not yet been reported and are overdue. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239022
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7089-7100[article] Conversion of methane and carbon dioxide to higher value products [texte imprimé] / Vesna Havran, Auteur ; Milorad P. Dudukovic, Auteur ; Cynthia S. Lo, Auteur . - 2011 . - pp. 7089-7100.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7089-7100
Mots-clés : Carbon dioxide Résumé : In this manuscript we address the efforts reported in the literature on direct conversion of methane and carbon dioxide into higher value products. The abundance of these two greenhouse gases makes them potentially useful for chemical syntheses. However, strong intramolecular bonds render both molecules chemically inert and thermodynamically stable. Thus, significant energy inputs as well as properly designed catalytic systems are required for their reactions. In addition to traditional catalytic processes, new alternative routes-such as photocatalytic conversion and dielectric barrier discharges—have been suggested. Figures of merit for comparison of various approaches have not yet been reported and are overdue. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239022 Exemplaires
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Titre : Catalytic activity of H3PW12O40/aliquat 336 in epoxidation of (Z,E,E)-1,5,9-cyclododecatriene to (E)-1,2-epoxy-(Z,E)-5,9-cyclododecadiene Type de document : texte imprimé Auteurs : Agnieszka Wolosiak, Auteur ; Grzegorz Lewandowski, Auteur ; Eugeniusz Milchert, Auteur Année de publication : 2011 Article en page(s) : pp 7101–7108 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalytic system Résumé : The influence of the technological parameters on the epoxidation of (Z,E,E)-1,5,9-cyclododecatriene (CDT) with 30% hydrogen peroxide to (E)-1,2-epoxy-(Z,E)-5,9-cyclododecadiene (ECDD) was studied under the conditions of phase transfer catalysis (PTC), in the presence of H3PW12O40/Aliquat 336 catalytic system. The parameters considered included stirring speed, the molar ratios of CDT:H2O2 and H2O2:H3PW12O40, temperature, and the nature and concentration of solvent. The variation ranges of these parameters ensuring a high CDT conversion and high selectivity of transformation to ECDD were established. The CDT conversion was 51.4–55.6% and the selectivity of transformation to ECDD was 79.8–95.1% DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1021738
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp 7101–7108[article] Catalytic activity of H3PW12O40/aliquat 336 in epoxidation of (Z,E,E)-1,5,9-cyclododecatriene to (E)-1,2-epoxy-(Z,E)-5,9-cyclododecadiene [texte imprimé] / Agnieszka Wolosiak, Auteur ; Grzegorz Lewandowski, Auteur ; Eugeniusz Milchert, Auteur . - 2011 . - pp 7101–7108.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp 7101–7108
Mots-clés : Catalytic system Résumé : The influence of the technological parameters on the epoxidation of (Z,E,E)-1,5,9-cyclododecatriene (CDT) with 30% hydrogen peroxide to (E)-1,2-epoxy-(Z,E)-5,9-cyclododecadiene (ECDD) was studied under the conditions of phase transfer catalysis (PTC), in the presence of H3PW12O40/Aliquat 336 catalytic system. The parameters considered included stirring speed, the molar ratios of CDT:H2O2 and H2O2:H3PW12O40, temperature, and the nature and concentration of solvent. The variation ranges of these parameters ensuring a high CDT conversion and high selectivity of transformation to ECDD were established. The CDT conversion was 51.4–55.6% and the selectivity of transformation to ECDD was 79.8–95.1% DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1021738 Exemplaires
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Titre : Photocatalytic degradation of acetone over sulfated MoOx/MgF2 composite : effect of molybdenum concentration and calcination temperature Type de document : texte imprimé Auteurs : Yiming He, Auteur ; Leihong Zhao, Auteur ; Yongjiao Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 7109-7119 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Calcining Composite material Photochemical degradation Résumé : This paper presents a novel visible-light-driven catalyst, a SO42―/MoOx/MgF2 composite, which was synthesized by a simple solution method. Multiple techniques, including Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS) were applied to investigate the physical and photophysical properties of the catalysts. The photocatalytic activities were evaluated in the degradation of acetone in gas phase. In the photodegradation of acetone, the highest conversion was obtained over a catalyst containing 5 mol % molybdenum. The XRD and Raman characterizations indicate that the molybdenum oxide was highly dispersed in the MgF2 matrix. These MoOx. species might be the active sites of the catalysts, which is the reason for the visible-light response of the composite catalyst. The MgF2 matrix acts to isolate the MoOx species and retard the electron-hole pair recombination. When the molybdenum concentration is >5 mol %, crystalline MoO3 phase was observed. The large MoO3 particle would decrease the separation efficiency. Thus, the photocatalytic activity was reduced. Besides the molybdenum concentration, the calcination temperature also shows a great effect on the activity. A sulfated 5 mol % MoOx/MgF2 catalyst that was calcined at 350 °C showed the highest photocatalytic activity. Based on the results of the characaterization, the origin of the high activity was discussed. The light absorption ability and the MoOx size effect are considered as the key factors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239024
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7109-7119[article] Photocatalytic degradation of acetone over sulfated MoOx/MgF2 composite : effect of molybdenum concentration and calcination temperature [texte imprimé] / Yiming He, Auteur ; Leihong Zhao, Auteur ; Yongjiao Wang, Auteur . - 2011 . - pp. 7109-7119.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7109-7119
Mots-clés : Calcining Composite material Photochemical degradation Résumé : This paper presents a novel visible-light-driven catalyst, a SO42―/MoOx/MgF2 composite, which was synthesized by a simple solution method. Multiple techniques, including Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS) were applied to investigate the physical and photophysical properties of the catalysts. The photocatalytic activities were evaluated in the degradation of acetone in gas phase. In the photodegradation of acetone, the highest conversion was obtained over a catalyst containing 5 mol % molybdenum. The XRD and Raman characterizations indicate that the molybdenum oxide was highly dispersed in the MgF2 matrix. These MoOx. species might be the active sites of the catalysts, which is the reason for the visible-light response of the composite catalyst. The MgF2 matrix acts to isolate the MoOx species and retard the electron-hole pair recombination. When the molybdenum concentration is >5 mol %, crystalline MoO3 phase was observed. The large MoO3 particle would decrease the separation efficiency. Thus, the photocatalytic activity was reduced. Besides the molybdenum concentration, the calcination temperature also shows a great effect on the activity. A sulfated 5 mol % MoOx/MgF2 catalyst that was calcined at 350 °C showed the highest photocatalytic activity. Based on the results of the characaterization, the origin of the high activity was discussed. The light absorption ability and the MoOx size effect are considered as the key factors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239024 Exemplaires
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Titre : Structure and catalytic property of Li–Al metal oxides from layered double hydroxide precursors prepared via a facile solution route Type de document : texte imprimé Auteurs : Jia Wang, Auteur ; Zhiyi Lei, Auteur ; Hua Qin, Auteur Année de publication : 2011 Article en page(s) : pp 7120–7128 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Precursor Catalytic reaction Résumé : This paper presents the synthesis of Li–Al mixed metal oxides from Li–Al layered double hydroxides (LiAl-LDHs) by using a novel separate nucleation and solvothermal aging steps method. The physicochemical properties of as-synthesized LiAl-LDHs and resulting calcined products at 600 °C were investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), simultaneous thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscope (SEM), and low-temperature nitrogen adsorption–desorption experiments. The results indicated that uniform LiAl-LDH particles with smaller sizes were obtained by using ethanol as solvent in the aging step, in contrast with those by using water and water/ethanol mixture. Especially, after calcination, the resulting mixed metal oxides showed variable surface basicities, which were strongly dependent on their crystallite sizes and surface areas. When used as solid base catalysts for the Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate, the mixed metal oxides with more strong basic sites exhibited a higher catalytic activity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239025
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp 7120–7128[article] Structure and catalytic property of Li–Al metal oxides from layered double hydroxide precursors prepared via a facile solution route [texte imprimé] / Jia Wang, Auteur ; Zhiyi Lei, Auteur ; Hua Qin, Auteur . - 2011 . - pp 7120–7128.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp 7120–7128
Mots-clés : Precursor Catalytic reaction Résumé : This paper presents the synthesis of Li–Al mixed metal oxides from Li–Al layered double hydroxides (LiAl-LDHs) by using a novel separate nucleation and solvothermal aging steps method. The physicochemical properties of as-synthesized LiAl-LDHs and resulting calcined products at 600 °C were investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), simultaneous thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscope (SEM), and low-temperature nitrogen adsorption–desorption experiments. The results indicated that uniform LiAl-LDH particles with smaller sizes were obtained by using ethanol as solvent in the aging step, in contrast with those by using water and water/ethanol mixture. Especially, after calcination, the resulting mixed metal oxides showed variable surface basicities, which were strongly dependent on their crystallite sizes and surface areas. When used as solid base catalysts for the Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate, the mixed metal oxides with more strong basic sites exhibited a higher catalytic activity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239025 Exemplaires
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Titre : Synthesis of selected vinylimidazolium ionic liquids and their effectiveness as corrosion inhibitors for carbon steel in aqueous sulfuric acid Type de document : texte imprimé Auteurs : Diego Guzman - Lucero, Auteur ; Octavio Olivares - Xometl, Auteur ; Rafael Martinez - Palou, Auteur Année de publication : 2011 Article en page(s) : pp. 7129-7140 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon steel Corrosion inhibitor Ionic liquid Résumé : ive imidazolium-type ionic liquids, containing both N 1 unsaturated and N3 long alkyl saturated chains as cations and bromide as anion (IL1―IL5), were obtained by conventional and microwave synthesis. Compounds were tested in aqueous 1 M H2SO4 as corrosion inhibitors for carbon steel. Weight loss and polarization curves indicated that inhibition efficiency increased with concentration, which turns out to be dependent on alkyl chain size linked to N3 (IL4 > IL3 > IL1 > IL2 > IL5). The relatively high inhibitory properties (88―95%) displayed by IL4 within 25―40 °C were ascribed to a chemisorption process that involved the following: the adsorption of protonated imidazolium molecules on both the anodic and cathodic sites, the latter in competition with hydrogen ions to mitigate hydrogen evolution; and also the formation of π bond with iron by the C=N group from imidazolium ring (this way inhibitor produced more than one center of adsorption action). Surface analysis indicated a considerable reduction of corrosion products after the addition of IL4. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239026
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7129-7140[article] Synthesis of selected vinylimidazolium ionic liquids and their effectiveness as corrosion inhibitors for carbon steel in aqueous sulfuric acid [texte imprimé] / Diego Guzman - Lucero, Auteur ; Octavio Olivares - Xometl, Auteur ; Rafael Martinez - Palou, Auteur . - 2011 . - pp. 7129-7140.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7129-7140
Mots-clés : Carbon steel Corrosion inhibitor Ionic liquid Résumé : ive imidazolium-type ionic liquids, containing both N 1 unsaturated and N3 long alkyl saturated chains as cations and bromide as anion (IL1―IL5), were obtained by conventional and microwave synthesis. Compounds were tested in aqueous 1 M H2SO4 as corrosion inhibitors for carbon steel. Weight loss and polarization curves indicated that inhibition efficiency increased with concentration, which turns out to be dependent on alkyl chain size linked to N3 (IL4 > IL3 > IL1 > IL2 > IL5). The relatively high inhibitory properties (88―95%) displayed by IL4 within 25―40 °C were ascribed to a chemisorption process that involved the following: the adsorption of protonated imidazolium molecules on both the anodic and cathodic sites, the latter in competition with hydrogen ions to mitigate hydrogen evolution; and also the formation of π bond with iron by the C=N group from imidazolium ring (this way inhibitor produced more than one center of adsorption action). Surface analysis indicated a considerable reduction of corrosion products after the addition of IL4. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239026 Exemplaires
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Titre : Preparation of strong cationic chitosan-graft-polyacrylamide flocculants and their flocculating properties Type de document : texte imprimé Auteurs : Yaobo Lu, Auteur ; Yabo Shang, Auteur ; Xin Huang, Auteur Année de publication : 2011 Article en page(s) : pp. 7141-7149 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flocculation reagent Preparation Résumé : Recently, more attentions have been paid to natural polymer-based flocculants in water treatment, since they are believed to be low-cost, nontoxic, and environmentally friendly materials. In this work, strong cationic chitosan-based graft copolymer flocculants (3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CTA) modified chitosan-graft-polyacrylamide, denoted as chitosan-CTA-g-PAM) have been prepared, and their flocculating properties were studied systematically, both at the laboratory scale and at the pilot scale. In laboratory scale, a kaolin suspension was employed as synthetic wastewater. The effects of dosage, temperature, and original turbidity of untreated wastewater were investigated, respectively. Moreover, in pilot scale, the raw water from the Zhenjiang part of the Yangtse River in China was used as wastewater. The influences of three external factors-dosage, sedimentation time, and mechanical mixing rate-on the flocculating performances have been studied by orthogonal testing, respectively. The experimental results in pilot scale were fairly consistent with those from the beaker experiment in laboratory scale. In comparison with polyferric sulfate, which is the flocculant currently used by the Zhenjiang Water Supply Company, chitosan-CTA-g-PAM showed better flocculating properties. Meanwhile, the effect of the degree of substitution of CTA on the flocculating properties has been also studied, both at the laboratory scale and at the pilot scale. It was indicated that chitosan-CTA-g-PAM with higher cationic degree had better flocculating performances, which was also confirmed by the flocculation kinetics analysis. Furthermore, the flocculation mechanisms of chitosan-CTA-g-PAM have been discussed in detail. Above all, the flocculating experiments in laboratory and pilot scales both indicated that chitosan-CTA-g-PAM showed good flocculating performances in water treatment. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239027
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7141-7149[article] Preparation of strong cationic chitosan-graft-polyacrylamide flocculants and their flocculating properties [texte imprimé] / Yaobo Lu, Auteur ; Yabo Shang, Auteur ; Xin Huang, Auteur . - 2011 . - pp. 7141-7149.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7141-7149
Mots-clés : Flocculation reagent Preparation Résumé : Recently, more attentions have been paid to natural polymer-based flocculants in water treatment, since they are believed to be low-cost, nontoxic, and environmentally friendly materials. In this work, strong cationic chitosan-based graft copolymer flocculants (3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CTA) modified chitosan-graft-polyacrylamide, denoted as chitosan-CTA-g-PAM) have been prepared, and their flocculating properties were studied systematically, both at the laboratory scale and at the pilot scale. In laboratory scale, a kaolin suspension was employed as synthetic wastewater. The effects of dosage, temperature, and original turbidity of untreated wastewater were investigated, respectively. Moreover, in pilot scale, the raw water from the Zhenjiang part of the Yangtse River in China was used as wastewater. The influences of three external factors-dosage, sedimentation time, and mechanical mixing rate-on the flocculating performances have been studied by orthogonal testing, respectively. The experimental results in pilot scale were fairly consistent with those from the beaker experiment in laboratory scale. In comparison with polyferric sulfate, which is the flocculant currently used by the Zhenjiang Water Supply Company, chitosan-CTA-g-PAM showed better flocculating properties. Meanwhile, the effect of the degree of substitution of CTA on the flocculating properties has been also studied, both at the laboratory scale and at the pilot scale. It was indicated that chitosan-CTA-g-PAM with higher cationic degree had better flocculating performances, which was also confirmed by the flocculation kinetics analysis. Furthermore, the flocculation mechanisms of chitosan-CTA-g-PAM have been discussed in detail. Above all, the flocculating experiments in laboratory and pilot scales both indicated that chitosan-CTA-g-PAM showed good flocculating performances in water treatment. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239027 Exemplaires
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Titre : Study of modified clay and Its industrial testing in aromatic refining Type de document : texte imprimé Auteurs : Jin-Ning Luan, Auteur ; Guo-liang Li, Auteur ; Li Shi, Auteur Année de publication : 2011 Article en page(s) : pp. 7150-7154 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Refining Résumé : A novel catalyst was synthesized and used to remove the trace olefins in aromatic hydrocarbons. Laboratory experiments and industrial siding tests indicated that the catalyst could improve the conversion of olefins and prolong the lifetime more than the commercial particulate clay. X-ray diffraction proved that the modification did not change the structure to active clay, N2 adsorption-desorption showed a decrease in surface area, and pyridine FTIR suggested that the intercalation of metal halides increased the amount of the total acid, especially the weak Lewis acid. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239028
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7150-7154[article] Study of modified clay and Its industrial testing in aromatic refining [texte imprimé] / Jin-Ning Luan, Auteur ; Guo-liang Li, Auteur ; Li Shi, Auteur . - 2011 . - pp. 7150-7154.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7150-7154
Mots-clés : Refining Résumé : A novel catalyst was synthesized and used to remove the trace olefins in aromatic hydrocarbons. Laboratory experiments and industrial siding tests indicated that the catalyst could improve the conversion of olefins and prolong the lifetime more than the commercial particulate clay. X-ray diffraction proved that the modification did not change the structure to active clay, N2 adsorption-desorption showed a decrease in surface area, and pyridine FTIR suggested that the intercalation of metal halides increased the amount of the total acid, especially the weak Lewis acid. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239028 Exemplaires
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Titre : Kinetics of esterification of acetic acid with methanol in the presence of ion exchange resin catalysts Type de document : texte imprimé Auteurs : P.E. Jagadeeshbabu, Auteur ; K. Sandesh, Auteur ; M.B. Saidutta, Auteur Année de publication : 2011 Article en page(s) : pp. 7155-7160 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst Ion exchange resin Esterification Kinetics Résumé : Esterification kinetics of acetic acid with methanol was studied with solid acid catalyst in an isothermal batch reactor at 333-353 K. Different types of ion exchange catalyst (Indion 130, Indion 190, and Amberlyst 15 wet) were used for the esterification of acetic acid. It was found that Indion 130 was an effective catalyst for acetic acid esterification. The effects of stirrer speed, reaction temperature, initial reactant concentration, and catalyst loading on reaction rate were investigated and optimized. Temperature dependence of the reaction rates and activation energies was determined by an Arrhenius plot. A complete kinetic equation for describing the reaction catalyzed by Indion 130 was developed. This equation can be used in the simulation and design of the catalytic distillation column for the synthesis of methyl acetate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239029
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7155-7160[article] Kinetics of esterification of acetic acid with methanol in the presence of ion exchange resin catalysts [texte imprimé] / P.E. Jagadeeshbabu, Auteur ; K. Sandesh, Auteur ; M.B. Saidutta, Auteur . - 2011 . - pp. 7155-7160.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7155-7160
Mots-clés : Catalyst Ion exchange resin Esterification Kinetics Résumé : Esterification kinetics of acetic acid with methanol was studied with solid acid catalyst in an isothermal batch reactor at 333-353 K. Different types of ion exchange catalyst (Indion 130, Indion 190, and Amberlyst 15 wet) were used for the esterification of acetic acid. It was found that Indion 130 was an effective catalyst for acetic acid esterification. The effects of stirrer speed, reaction temperature, initial reactant concentration, and catalyst loading on reaction rate were investigated and optimized. Temperature dependence of the reaction rates and activation energies was determined by an Arrhenius plot. A complete kinetic equation for describing the reaction catalyzed by Indion 130 was developed. This equation can be used in the simulation and design of the catalytic distillation column for the synthesis of methyl acetate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239029 Exemplaires
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Titre : Deactivation during 1-hexene isomerization over zeolite Y and ZSM5 catalysts under supercritical conditions Type de document : texte imprimé Auteurs : Faiza Hassan, Auteur ; Jiawei Wang, Auteur ; Peter I. Chigada, Auteur Année de publication : 2011 Article en page(s) : pp. 7161-7171. Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Zeolite catalysts Résumé : Catalytic deactivation caused by coking was studied in zeolite Y and ZSM5 during 1-hexene isomerization under subcritical and supercritical conditions. The effects of varying temperature and pressure, from 220 to 250 degrees C and from 10 to 70 bar, respectively, on conversion and coke deposition were studied in both zeolites. Thermogravimetric analysis (TGA) data, diffuse reflectance infrared Fourier transform spectra (DRIFTS), and nitrogen sorption isotherms for fresh and coked catalysts were compared. In zeolite Y an exponential decay in conversion was observed with the rate of deactivation being slower at supercritical conditions at 235 degrees C and 40 bar than subcritical conditions at 235 degrees C and 10 bar. It is thought that in zeolite Y the micropores with diameter 7.4 angstrom could accommodate coke molecules leading to the observed deactivation; however, in ZSM5 the micropores of 5.3-5.6 angstrom diameter were too small to accommodate coke molecules, and thus coke was deposited outside the zeolite crystals within the mesopores of the alumina binder. Although zeolite Y deactivated, while ZSM5 did not, the use of a supercritical fluid reaction environment enabled the conversion at 235 degrees C, 40 bar to be maintained at 42% over zeolite Y, which was higher than the conversion of 34% over ZSM5 catalyst under the same conditions. Operating with supercritical fluid led to the partial alleviation of the significant coking effects observed with zeolite Y and improved its viability for use in this reaction compared with the performance of ZSM5. DEWEY : 660 ISSN : 0888-5885 En ligne : http://opus.bath.ac.uk/24601/
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7161-7171.[article] Deactivation during 1-hexene isomerization over zeolite Y and ZSM5 catalysts under supercritical conditions [texte imprimé] / Faiza Hassan, Auteur ; Jiawei Wang, Auteur ; Peter I. Chigada, Auteur . - 2011 . - pp. 7161-7171.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7161-7171.
Mots-clés : Zeolite catalysts Résumé : Catalytic deactivation caused by coking was studied in zeolite Y and ZSM5 during 1-hexene isomerization under subcritical and supercritical conditions. The effects of varying temperature and pressure, from 220 to 250 degrees C and from 10 to 70 bar, respectively, on conversion and coke deposition were studied in both zeolites. Thermogravimetric analysis (TGA) data, diffuse reflectance infrared Fourier transform spectra (DRIFTS), and nitrogen sorption isotherms for fresh and coked catalysts were compared. In zeolite Y an exponential decay in conversion was observed with the rate of deactivation being slower at supercritical conditions at 235 degrees C and 40 bar than subcritical conditions at 235 degrees C and 10 bar. It is thought that in zeolite Y the micropores with diameter 7.4 angstrom could accommodate coke molecules leading to the observed deactivation; however, in ZSM5 the micropores of 5.3-5.6 angstrom diameter were too small to accommodate coke molecules, and thus coke was deposited outside the zeolite crystals within the mesopores of the alumina binder. Although zeolite Y deactivated, while ZSM5 did not, the use of a supercritical fluid reaction environment enabled the conversion at 235 degrees C, 40 bar to be maintained at 42% over zeolite Y, which was higher than the conversion of 34% over ZSM5 catalyst under the same conditions. Operating with supercritical fluid led to the partial alleviation of the significant coking effects observed with zeolite Y and improved its viability for use in this reaction compared with the performance of ZSM5. DEWEY : 660 ISSN : 0888-5885 En ligne : http://opus.bath.ac.uk/24601/ Exemplaires
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Titre : Modeling of supercritical water gasification of xylose to hydrogen-rich gas in a hastelloy microchannel reactor Type de document : texte imprimé Auteurs : Aron K. Goodwin, Auteur ; Gregory L. Rorrer, Auteur Année de publication : 2011 Article en page(s) : pp. 7172-7182 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microreactor Gasification Supercritical state Modeling Résumé : Microchannel reactors offer high rates of heat transfer that intensify biomass gasification in supercritical water by sustaining the reaction temperature in the presence of endothermic reforming reactions and providing rapid fluid heating. Furthermore, the large ratio of surface area to volume in the micro channels enhances "unintentional" catalytic activity from the reactor wall for reactors comprised of nickel alloys such as Hastelloy. In this study, a parallel-channel Hastelloy C-276 microreactor was used to gasify xylose, a hemicellulose model compound, at 650 °C and 250 bar. The reactor consisted of 14 parallel microchannels, each measuring 127 μm × 1000 μm, integrated into a contiguous reactor block using scalable microfabrication techniques. The channels were configured in a serpentine design, which resulted in temperature gradients within the channels during fluid heating isolated from those in subsequent channel passes. Complete conversion of a 4.0 wt % aqueous xylose solution to hydrogen-rich gas was achieved with an average fluid residence time of 1.4 s. Computational fluid dynamics (CFD) modeling was used to simulate xylose gasification in the microchannel reactor and investigate temperature gradients produced by the heat of reaction for xylose gasification. Additional CFD simulations were used to show the effect of short residence times (less than 1.0 s) on the reacting fluid temperature while in the reactor. The results from this study suggest that parallel-channel Hastelloy microreactors potentially offer a unique way to improve biomass gasification by supercritical water. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239031
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7172-7182[article] Modeling of supercritical water gasification of xylose to hydrogen-rich gas in a hastelloy microchannel reactor [texte imprimé] / Aron K. Goodwin, Auteur ; Gregory L. Rorrer, Auteur . - 2011 . - pp. 7172-7182.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7172-7182
Mots-clés : Microreactor Gasification Supercritical state Modeling Résumé : Microchannel reactors offer high rates of heat transfer that intensify biomass gasification in supercritical water by sustaining the reaction temperature in the presence of endothermic reforming reactions and providing rapid fluid heating. Furthermore, the large ratio of surface area to volume in the micro channels enhances "unintentional" catalytic activity from the reactor wall for reactors comprised of nickel alloys such as Hastelloy. In this study, a parallel-channel Hastelloy C-276 microreactor was used to gasify xylose, a hemicellulose model compound, at 650 °C and 250 bar. The reactor consisted of 14 parallel microchannels, each measuring 127 μm × 1000 μm, integrated into a contiguous reactor block using scalable microfabrication techniques. The channels were configured in a serpentine design, which resulted in temperature gradients within the channels during fluid heating isolated from those in subsequent channel passes. Complete conversion of a 4.0 wt % aqueous xylose solution to hydrogen-rich gas was achieved with an average fluid residence time of 1.4 s. Computational fluid dynamics (CFD) modeling was used to simulate xylose gasification in the microchannel reactor and investigate temperature gradients produced by the heat of reaction for xylose gasification. Additional CFD simulations were used to show the effect of short residence times (less than 1.0 s) on the reacting fluid temperature while in the reactor. The results from this study suggest that parallel-channel Hastelloy microreactors potentially offer a unique way to improve biomass gasification by supercritical water. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239031 Exemplaires
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Titre : Synthesis of octyl dihydrocaffeate and Its transesterification with tricaprylin catalyzed by candida antarctica lipase Type de document : texte imprimé Auteurs : Vivian Feddern, Auteur ; Zhiyongh Yang, Auteur ; Xuebing Xu, Auteur Année de publication : 2011 Article en page(s) : pp. 7183-7190 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalytic reaction Transesterification Résumé : This work aimed at producing a phenolic ester from dihydrocaffeic acid (DHCA), besides carrying out transesterification reactions of this ester with tricaprylin. The esterification reaction was performed in two ratios (1:1 and 1:3 DHCA:octanol), and the transesterification was done in four ratios (1:1, 1:2, 1:5, and 1:10) between the produced ester and tricaprylin. In the last, a Central Composite Rotatable Design was employed, varying the amount of enzyme (1.6―18.4%), reaction time (9.9―35.1 h), and temperature (43.2―76.8 °C) on reagent consumption percentage. Novozym 435 was the catalyst in all reactions. The highest ester yield (50%) occurred in 8 days. In transesterification reactions, higher consumption of the produced ester was achieved at ratios 1:5 and 1:10, obtaining, respectively, 29.6% and 21.1% of octyl dihydrocaffeate residual, in 24 h. At higher temperatures and time above 26 h, there was less octyl dihydrocaffeate residual (18.7%). Three different phenolic compounds were identified. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239032
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7183-7190[article] Synthesis of octyl dihydrocaffeate and Its transesterification with tricaprylin catalyzed by candida antarctica lipase [texte imprimé] / Vivian Feddern, Auteur ; Zhiyongh Yang, Auteur ; Xuebing Xu, Auteur . - 2011 . - pp. 7183-7190.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7183-7190
Mots-clés : Catalytic reaction Transesterification Résumé : This work aimed at producing a phenolic ester from dihydrocaffeic acid (DHCA), besides carrying out transesterification reactions of this ester with tricaprylin. The esterification reaction was performed in two ratios (1:1 and 1:3 DHCA:octanol), and the transesterification was done in four ratios (1:1, 1:2, 1:5, and 1:10) between the produced ester and tricaprylin. In the last, a Central Composite Rotatable Design was employed, varying the amount of enzyme (1.6―18.4%), reaction time (9.9―35.1 h), and temperature (43.2―76.8 °C) on reagent consumption percentage. Novozym 435 was the catalyst in all reactions. The highest ester yield (50%) occurred in 8 days. In transesterification reactions, higher consumption of the produced ester was achieved at ratios 1:5 and 1:10, obtaining, respectively, 29.6% and 21.1% of octyl dihydrocaffeate residual, in 24 h. At higher temperatures and time above 26 h, there was less octyl dihydrocaffeate residual (18.7%). Three different phenolic compounds were identified. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239032 Exemplaires
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Titre : Carbon nanotube-supported metal catalysts for NOx reduction using hydrocarbon reductants : gas switching and adsorption studies Type de document : texte imprimé Auteurs : Eduardo Santillan - Jimenez, Auteur ; Mark Crocker, Auteur ; Agustin Bueno - Lopez, Auteur Année de publication : 2011 Article en page(s) : pp.7191-7200. Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon nanotube Catalysts Résumé : The selective catalytic reduction of NOx with hydrocarbons (HC-SCR) on functionalized multiwalled carbon nanotube (fMWCNT)-supported metal catalysts was investigated using a transient technique, together with kinetic and adsorption measurements. Results from the transient studies provide an explanation for the characteristic volcano shape of the NOx conversion curves: below Tmax, the temperature of maximum NOx conversion, the catalyst surface is covered by hydrocarbonaceous species, which results in the suppression of NOx reduction activity. Above Tmax, O2 adsorption becomes prevalent, favoring oxidation of both NO and the hydrocarbon. In an effort to understand the origin of the superior NOx reduction activity shown by 3:1 Pt–Rh/fMWCNTs as compared to Pt/fMWCNTs, Temperature Programmed Desorption (TPD) measurements were undertaken. Results indicate that hydrocarbon and/or hydrocarbon-derived species are more strongly adsorbed on the alloy than on Pt alone, while NO adsorption is weaker on the alloy than on Pt. This is suggested to give rise to a higher concentration of partially oxidized hydrocarbon intermediates on the surface of the Pt–Rh catalyst at the temperature of maximum deNOx activity, leading to higher NOx reduction activity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200054u
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp.7191-7200.[article] Carbon nanotube-supported metal catalysts for NOx reduction using hydrocarbon reductants : gas switching and adsorption studies [texte imprimé] / Eduardo Santillan - Jimenez, Auteur ; Mark Crocker, Auteur ; Agustin Bueno - Lopez, Auteur . - 2011 . - pp.7191-7200.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp.7191-7200.
Mots-clés : Carbon nanotube Catalysts Résumé : The selective catalytic reduction of NOx with hydrocarbons (HC-SCR) on functionalized multiwalled carbon nanotube (fMWCNT)-supported metal catalysts was investigated using a transient technique, together with kinetic and adsorption measurements. Results from the transient studies provide an explanation for the characteristic volcano shape of the NOx conversion curves: below Tmax, the temperature of maximum NOx conversion, the catalyst surface is covered by hydrocarbonaceous species, which results in the suppression of NOx reduction activity. Above Tmax, O2 adsorption becomes prevalent, favoring oxidation of both NO and the hydrocarbon. In an effort to understand the origin of the superior NOx reduction activity shown by 3:1 Pt–Rh/fMWCNTs as compared to Pt/fMWCNTs, Temperature Programmed Desorption (TPD) measurements were undertaken. Results indicate that hydrocarbon and/or hydrocarbon-derived species are more strongly adsorbed on the alloy than on Pt alone, while NO adsorption is weaker on the alloy than on Pt. This is suggested to give rise to a higher concentration of partially oxidized hydrocarbon intermediates on the surface of the Pt–Rh catalyst at the temperature of maximum deNOx activity, leading to higher NOx reduction activity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200054u Exemplaires
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Titre : Compound of nickel phosphate with Ni(OH)(PO4)2― layers and synergistic application with intumescent flame retardants in thermoplastic polyurethane elastomer Type de document : texte imprimé Auteurs : Xueying Shan, Auteur ; Ping Zhang, Auteur ; Lei Song, Auteur Année de publication : 2011 Article en page(s) : pp. 7201-7209 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flame retardant Synergism Résumé : In this paper, a new method was used to prepare flame retardant thermoplastic polyurethane elastomer (TPU). Nickel phosphate with Ni(OH)(PO4)2― layers, Na(H3O)2{Ni4(OH)4(HPO4)3(H2PO4)} (NaNiP), was prepared by a hydrothermal method, and it was added to the TPU and intumescent flame retardant (IFR) system. The synergistic effect between NaNiP and IFR was studied. With the addition of 1 wt % NaNiP, the limiting oxygen index (LOI) value of the TPU/ IFR system was increased from 27 to 32%. The UL-94 tests showed that TPU containing 20 wt % IFR had no rating, but TPU with 19 wt % IFR and 1 wt % NaNiP could reach the V-0 rating. The results of thermogravimetric analysis/infrared spectrometry (TGA―IR) showed that NaNiP could delay volatilized products in TPU/IFR system. Laser Raman spectroscopy (LRS) of residual char indicated that the ordered carbon was increased with the addition of 1 wt % NaNiP, and the content ratio of ordered carbon in outer char was larger than that in inner char. Scanning electron microscopy (SEM) indicated that NaNiP could help the TPU/IFR system form a dense and intumescent char layer. Therefore, a just-right formulation between IFR and NaNiP in TPU showed optimal synergistic effect. The synergistic mechanism was also proposed in this paper. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239034
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7201-7209[article] Compound of nickel phosphate with Ni(OH)(PO4)2― layers and synergistic application with intumescent flame retardants in thermoplastic polyurethane elastomer [texte imprimé] / Xueying Shan, Auteur ; Ping Zhang, Auteur ; Lei Song, Auteur . - 2011 . - pp. 7201-7209.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7201-7209
Mots-clés : Flame retardant Synergism Résumé : In this paper, a new method was used to prepare flame retardant thermoplastic polyurethane elastomer (TPU). Nickel phosphate with Ni(OH)(PO4)2― layers, Na(H3O)2{Ni4(OH)4(HPO4)3(H2PO4)} (NaNiP), was prepared by a hydrothermal method, and it was added to the TPU and intumescent flame retardant (IFR) system. The synergistic effect between NaNiP and IFR was studied. With the addition of 1 wt % NaNiP, the limiting oxygen index (LOI) value of the TPU/ IFR system was increased from 27 to 32%. The UL-94 tests showed that TPU containing 20 wt % IFR had no rating, but TPU with 19 wt % IFR and 1 wt % NaNiP could reach the V-0 rating. The results of thermogravimetric analysis/infrared spectrometry (TGA―IR) showed that NaNiP could delay volatilized products in TPU/IFR system. Laser Raman spectroscopy (LRS) of residual char indicated that the ordered carbon was increased with the addition of 1 wt % NaNiP, and the content ratio of ordered carbon in outer char was larger than that in inner char. Scanning electron microscopy (SEM) indicated that NaNiP could help the TPU/IFR system form a dense and intumescent char layer. Therefore, a just-right formulation between IFR and NaNiP in TPU showed optimal synergistic effect. The synergistic mechanism was also proposed in this paper. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239034 Exemplaires
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Titre : Magnetically separable ZnFe2O4―graphene catalyst and its high photocatalytic performance under visible light irradiation Type de document : texte imprimé Auteurs : Yongsheng Fu, Auteur ; Xin Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 7210-7218 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Visible radiation Photocatalysis Catalyst Résumé : A magnetically separable ZnFe2O4―graphene nanocomposite photocatalyst with different graphene content was prepared by a facile one-step hydrothermal method. The graphene sheets in this nanocomposite photocatalyst are exfoliated and decorated with ZnFe2O4 nanocrystals. It was found that in the presence of H2O2, the photodegradation rate of methylene blue (MB) was 88% after visible light irradiation for only 5 min and reached up to 99% after irradiation for 90 min. In comparison with pure ZnFe2O4 catalyst, ZnFe2O4―graphene serves a dual function as the catalyst for photoelectrochemical degradation of MB and the generator of a strong oxidant hydroxyl radical (·OH) via photoelectrochemical decomposition of H2O2 under visible light irradiation. ZnFe2O4 nanoparticles themselves have a magnetic property, which makes the ZnFe2O4―graphene composite magnetically separable in a suspension system, and therefore it does not require additional magnetic components as is the usual case. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239035
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7210-7218[article] Magnetically separable ZnFe2O4―graphene catalyst and its high photocatalytic performance under visible light irradiation [texte imprimé] / Yongsheng Fu, Auteur ; Xin Wang, Auteur . - 2011 . - pp. 7210-7218.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7210-7218
Mots-clés : Visible radiation Photocatalysis Catalyst Résumé : A magnetically separable ZnFe2O4―graphene nanocomposite photocatalyst with different graphene content was prepared by a facile one-step hydrothermal method. The graphene sheets in this nanocomposite photocatalyst are exfoliated and decorated with ZnFe2O4 nanocrystals. It was found that in the presence of H2O2, the photodegradation rate of methylene blue (MB) was 88% after visible light irradiation for only 5 min and reached up to 99% after irradiation for 90 min. In comparison with pure ZnFe2O4 catalyst, ZnFe2O4―graphene serves a dual function as the catalyst for photoelectrochemical degradation of MB and the generator of a strong oxidant hydroxyl radical (·OH) via photoelectrochemical decomposition of H2O2 under visible light irradiation. ZnFe2O4 nanoparticles themselves have a magnetic property, which makes the ZnFe2O4―graphene composite magnetically separable in a suspension system, and therefore it does not require additional magnetic components as is the usual case. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239035 Exemplaires
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Titre : Highly active S-modified ZnFe2O4 heterogeneous catalyst and Its photo-fenton behavior under UV–visible irradiation Type de document : texte imprimé Auteurs : Liangjun Liu, Auteur ; Guoliang Zhang, Auteur ; Ling Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 7219–7227. Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Heterogeneous Catalyst Résumé : Ultrafine Zn–Fe composite oxides have been synthesized by the sol–gel method and then modified by S═O. After preparation, these chalybeate compounds were characterized by BET surface area and porosity analyzer, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometry (FT-IR). The influence of introduced S═O on the performance of ZnFe2O4 catalysts was measured, and the reaction mechanism was investigated. To evaluate the activities of different catalysts, a series of photo-Fenton reactions have been conducted to decontaminate the Reactive Black KN-GR simulated wastewater. Results indicated that the prepared catalysts were porous-material with a high specific surface area of 38 m2 g–1. Significantly, the FT-IR spectrum suggested that sulfated ZnFe2O4 calcinated at 773 K (named S773 catalyst) exhibited a strong acid property and XPS analysis proved the presence of S6+(S═O), which led to the generation of acid sites. Under optimum conditions of 9.8 mM H2O2, 0.5 g L–1 catalyst, and pH = 6.0, up to 90% total organic carbon removal and 100% decolorization of a solution containing 100 mg L–1 Reactive Black KN-GR could be achieved after 150 min of treatment. The kinetics of acid catalysis were also discussed, and the stability of the catalyst was estimated on studying the iron leaching and S773 catalyst recycling. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2005516
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7219–7227.[article] Highly active S-modified ZnFe2O4 heterogeneous catalyst and Its photo-fenton behavior under UV–visible irradiation [texte imprimé] / Liangjun Liu, Auteur ; Guoliang Zhang, Auteur ; Ling Wang, Auteur . - 2011 . - pp. 7219–7227.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7219–7227.
Mots-clés : Heterogeneous Catalyst Résumé : Ultrafine Zn–Fe composite oxides have been synthesized by the sol–gel method and then modified by S═O. After preparation, these chalybeate compounds were characterized by BET surface area and porosity analyzer, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometry (FT-IR). The influence of introduced S═O on the performance of ZnFe2O4 catalysts was measured, and the reaction mechanism was investigated. To evaluate the activities of different catalysts, a series of photo-Fenton reactions have been conducted to decontaminate the Reactive Black KN-GR simulated wastewater. Results indicated that the prepared catalysts were porous-material with a high specific surface area of 38 m2 g–1. Significantly, the FT-IR spectrum suggested that sulfated ZnFe2O4 calcinated at 773 K (named S773 catalyst) exhibited a strong acid property and XPS analysis proved the presence of S6+(S═O), which led to the generation of acid sites. Under optimum conditions of 9.8 mM H2O2, 0.5 g L–1 catalyst, and pH = 6.0, up to 90% total organic carbon removal and 100% decolorization of a solution containing 100 mg L–1 Reactive Black KN-GR could be achieved after 150 min of treatment. The kinetics of acid catalysis were also discussed, and the stability of the catalyst was estimated on studying the iron leaching and S773 catalyst recycling. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2005516 Exemplaires
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Titre : Synthesis, characterization, and adsorption properties of Fe/Cr-pillared bentonites Type de document : texte imprimé Auteurs : Fatma Tomul, Auteur Année de publication : 2011 Article en page(s) : pp. 7228-7240 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Adsorption Résumé : Bentonites pillared with iron, iron/chromium with different Fe/Cr molar ratios, and chromium were synthesized and tested as adsorbents of cadmium. The pillared bentonites were characterized by using scanning electron microscopy with energy dispersive system (SEM-EDS), powder X-ray diffraction (XRD), N2-adsorption/desorption, and Fourier-transformed infrared spectroscopy (FTIR). The thermal stability of the samples was studied with thermogravimetry (TG). Adsorption experiments were conducted by varying pH, contact time, and temperature. The content of the pillaring solution was the most important parameter that influenced the physicochemical, textural, and acidic properties of the pillared bentonites. The results revealed that the adsorption capacity of the materials increased with an increase in pH and contact time. The results also indicated that the equilibrium adsorption data of Cd2+ onto Cr-pillared bentonite best fit the Redlich―Peterson model, whereas adsorption onto Fe-pillared bentonite and Fe/Cr-pillared bentonite with Fe/Cr molar ratio of 5:5 correlated with the first-order model. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetic model. Thermodynamic studies suggested that the adsorption of Cd2+ onto Fe-pillared bentonite was an endothermic and spontaneous process. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239037
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7228-7240[article] Synthesis, characterization, and adsorption properties of Fe/Cr-pillared bentonites [texte imprimé] / Fatma Tomul, Auteur . - 2011 . - pp. 7228-7240.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7228-7240
Mots-clés : Adsorption Résumé : Bentonites pillared with iron, iron/chromium with different Fe/Cr molar ratios, and chromium were synthesized and tested as adsorbents of cadmium. The pillared bentonites were characterized by using scanning electron microscopy with energy dispersive system (SEM-EDS), powder X-ray diffraction (XRD), N2-adsorption/desorption, and Fourier-transformed infrared spectroscopy (FTIR). The thermal stability of the samples was studied with thermogravimetry (TG). Adsorption experiments were conducted by varying pH, contact time, and temperature. The content of the pillaring solution was the most important parameter that influenced the physicochemical, textural, and acidic properties of the pillared bentonites. The results revealed that the adsorption capacity of the materials increased with an increase in pH and contact time. The results also indicated that the equilibrium adsorption data of Cd2+ onto Cr-pillared bentonite best fit the Redlich―Peterson model, whereas adsorption onto Fe-pillared bentonite and Fe/Cr-pillared bentonite with Fe/Cr molar ratio of 5:5 correlated with the first-order model. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetic model. Thermodynamic studies suggested that the adsorption of Cd2+ onto Fe-pillared bentonite was an endothermic and spontaneous process. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239037 Exemplaires
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Titre : Bubbling reactor technology for rapid synthesis of uniform, small MFI-type zeolite crystals Type de document : texte imprimé Auteurs : Wei Liu, Auteur ; Yuxiang Rao, Auteur ; Haiying Wan, Auteur Année de publication : 2011 Article en page(s) : pp. 7241-7250 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Zeolite Reactor Bubbling Résumé : MFI-type zeolite is an important family of materials used in today's industries as catalysts and adsorbents. Preparation of this type of zeolite material as uniform and pure crystals with sizes from tens to hundreds of nanometers are not only desired for current catalytic and adsorption processes for enhanced reaction kinetics and/or selectivity, but also much needed for some new applications, such as CO2 capture adsorbents and composite materials. However, it has been a major challenge in the field of zeolite synthesis to prepare small crystals of MFI-type zeolite over a range of Si/Al ratios with very high throughput. In this work, a gas-bubbling flow reactor was used to conduct hydrothermal growth of the zeolite crystals with controllable Si/Al ratios and crystal sizes. Distinctive, uniform ZSM-5 crystals were successfully synthesized within 2 h ofreaction time, which is exceptionally short compared to the conventional synthesis process. The crystals were small enough to form a stable milk-like suspension in water. The Si/Al ratio was controlled by adjusting the growth solution composition and reaction conditions over a range from about 9 to infinity. Characterization by SEM/EDS, XRD, TEM, N2 adsorption/desorption, and NMR spectroscopy confirmed the ZSM-5 crystal structures and revealed the presence of mesoporosity in the resulting crystals. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239038
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7241-7250[article] Bubbling reactor technology for rapid synthesis of uniform, small MFI-type zeolite crystals [texte imprimé] / Wei Liu, Auteur ; Yuxiang Rao, Auteur ; Haiying Wan, Auteur . - 2011 . - pp. 7241-7250.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7241-7250
Mots-clés : Zeolite Reactor Bubbling Résumé : MFI-type zeolite is an important family of materials used in today's industries as catalysts and adsorbents. Preparation of this type of zeolite material as uniform and pure crystals with sizes from tens to hundreds of nanometers are not only desired for current catalytic and adsorption processes for enhanced reaction kinetics and/or selectivity, but also much needed for some new applications, such as CO2 capture adsorbents and composite materials. However, it has been a major challenge in the field of zeolite synthesis to prepare small crystals of MFI-type zeolite over a range of Si/Al ratios with very high throughput. In this work, a gas-bubbling flow reactor was used to conduct hydrothermal growth of the zeolite crystals with controllable Si/Al ratios and crystal sizes. Distinctive, uniform ZSM-5 crystals were successfully synthesized within 2 h ofreaction time, which is exceptionally short compared to the conventional synthesis process. The crystals were small enough to form a stable milk-like suspension in water. The Si/Al ratio was controlled by adjusting the growth solution composition and reaction conditions over a range from about 9 to infinity. Characterization by SEM/EDS, XRD, TEM, N2 adsorption/desorption, and NMR spectroscopy confirmed the ZSM-5 crystal structures and revealed the presence of mesoporosity in the resulting crystals. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239038 Exemplaires
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Titre : Limitations of current formulations when decreasing the coating layer thickness of papers for inkjet printing Type de document : texte imprimé Auteurs : Taina Lamminmaki, Auteur ; John Kettle, Auteur ; Hille Rautkoski, Auteur Année de publication : 2011 Article en page(s) : pp. 7251-7263 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Layer thickness Résumé : The porous network structure of a coating layer has a major effect on how quickly inkjet ink penetrates into the coated paper, and how large the pore volume is determines the capacity for ink volume uptake within the coating layer. If the penetration rate and/or pore volume are insufficient, the ink colors stay too long on the surface, resulting in undesirable mixing (intercolor bleeding) and trans-surface wicking (feathering). The aim of this work was to clarify whether it is possible to decrease the coating layer thickness of the specialty inkjet layer and still produce an inkjet printed surface using dye-based inks with low bleeding and, thereby, to define the reasons for limitations with respect to coat weight reduction. The online study of printed figures following printing nozzles on a high-speed inkjet printing press, by means of optical image capture, showed that the tendency for intercolor bleeding depends strongly on the coating layer thickness. As the printing speed increases, the pore network structure of the coating layer becomes increasingly important. The results show that, under the external pressure, aused by the surface tension and impact of the ink droplets themselves, the permeability of the coating layer dominates after at least 4 ms from the time of ink application. The coating pigment selection and the amount of poly( vinyl alcohol) binder did not influence this permeability onset time. Permeability allows the required ink volumes eventually to be absorbed, even if the total porosity of the coating is insufficient at low coat weight. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239039
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7251-7263[article] Limitations of current formulations when decreasing the coating layer thickness of papers for inkjet printing [texte imprimé] / Taina Lamminmaki, Auteur ; John Kettle, Auteur ; Hille Rautkoski, Auteur . - 2011 . - pp. 7251-7263.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7251-7263
Mots-clés : Layer thickness Résumé : The porous network structure of a coating layer has a major effect on how quickly inkjet ink penetrates into the coated paper, and how large the pore volume is determines the capacity for ink volume uptake within the coating layer. If the penetration rate and/or pore volume are insufficient, the ink colors stay too long on the surface, resulting in undesirable mixing (intercolor bleeding) and trans-surface wicking (feathering). The aim of this work was to clarify whether it is possible to decrease the coating layer thickness of the specialty inkjet layer and still produce an inkjet printed surface using dye-based inks with low bleeding and, thereby, to define the reasons for limitations with respect to coat weight reduction. The online study of printed figures following printing nozzles on a high-speed inkjet printing press, by means of optical image capture, showed that the tendency for intercolor bleeding depends strongly on the coating layer thickness. As the printing speed increases, the pore network structure of the coating layer becomes increasingly important. The results show that, under the external pressure, aused by the surface tension and impact of the ink droplets themselves, the permeability of the coating layer dominates after at least 4 ms from the time of ink application. The coating pigment selection and the amount of poly( vinyl alcohol) binder did not influence this permeability onset time. Permeability allows the required ink volumes eventually to be absorbed, even if the total porosity of the coating is insufficient at low coat weight. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239039 Exemplaires
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Titre : Synergized action of CuCI on recycled cigarette butts as corrosion inhibitor for N80 steel at 90 °C in 15% HCl Type de document : texte imprimé Auteurs : Juantao Zhang, Auteur ; Jun Zhao, Auteur ; Ningsheng Zhang, Auteur Année de publication : 2011 Article en page(s) : pp. 7264-7272 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Steel Corrosion inhibitor Résumé : One of effective ways to reduce pollution from cigarette butts is introduced by recycling the cigarette butts. Inhibitor from recycled cigarette butts shows good inhibition properties, but we do not know whether CuCl can help to improve the inhibition efficiency. So, in this study, the impact of CuCl on recycled cigarette butts as corrosion inhibitor for N80 steel at 90 °C in 15% HCl is studied by weight loss, electrochemical noise, polarization, impedance, and X-ray photoelectron spectroscopy. All the results show that the inhibition efficiency of water extracts from cigarette butts in the presence of CuCl is higher than in absence of CuCl, and it can reach 95.3% when 9% water extracts with copper added is used. The X-ray photoelectron spectroscopy results indicate that the N80 steel specimen surface is undamaged and covered with a protective coat formed by copper-added water extracts from cigarette butts. CuCl has synergizing action on recycled cigarette butts as a corrosion inhibitor for N80 steel at 90 °C in 15% HCl. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239040
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7264-7272[article] Synergized action of CuCI on recycled cigarette butts as corrosion inhibitor for N80 steel at 90 °C in 15% HCl [texte imprimé] / Juantao Zhang, Auteur ; Jun Zhao, Auteur ; Ningsheng Zhang, Auteur . - 2011 . - pp. 7264-7272.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7264-7272
Mots-clés : Steel Corrosion inhibitor Résumé : One of effective ways to reduce pollution from cigarette butts is introduced by recycling the cigarette butts. Inhibitor from recycled cigarette butts shows good inhibition properties, but we do not know whether CuCl can help to improve the inhibition efficiency. So, in this study, the impact of CuCl on recycled cigarette butts as corrosion inhibitor for N80 steel at 90 °C in 15% HCl is studied by weight loss, electrochemical noise, polarization, impedance, and X-ray photoelectron spectroscopy. All the results show that the inhibition efficiency of water extracts from cigarette butts in the presence of CuCl is higher than in absence of CuCl, and it can reach 95.3% when 9% water extracts with copper added is used. The X-ray photoelectron spectroscopy results indicate that the N80 steel specimen surface is undamaged and covered with a protective coat formed by copper-added water extracts from cigarette butts. CuCl has synergizing action on recycled cigarette butts as a corrosion inhibitor for N80 steel at 90 °C in 15% HCl. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239040 Exemplaires
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Titre : Corrosion and corrosion inhibition behavior of N80 and P110 carbon steels in CO2-saturated simulated formation water by rosin amide imidazoline Type de document : texte imprimé Auteurs : P.C. Okafor, Auteur ; C. B. Liu, Auteur ; Y. J. Zhu, Auteur Année de publication : 2011 Article en page(s) : pp. 7273-7281 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon dioxide steel Corrosion inhibition Résumé : The corrosion and corrosion inhibition of N80 and P110 carbon steels (CS) in CO2-saturated simulated formation water by rosin amide imidazoline (RAIM) was studied using electrochemical impedance spectroscopy and potentiodynamic polarization techniques. The results indicate that N80 CS performs better than P 110 CS with RAIM at lower temperature and P110 CS at higher temperatures. Inhibition efficiency increased with increase in RAIM concentration and temperature. The data suggest that RAIM functioned as inhibitor via a mixed-inhibitor mechanism and the inhibition process is attributed to the formation of a chemically adsorbed film of RAIM on the surface of the metal via its polycentric adsorption sites. Morphological studies of the carbon steel electrode surface were undertaken by scanning electron microscope (SEM) and atomic force microscopy (AFM). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239041
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7273-7281[article] Corrosion and corrosion inhibition behavior of N80 and P110 carbon steels in CO2-saturated simulated formation water by rosin amide imidazoline [texte imprimé] / P.C. Okafor, Auteur ; C. B. Liu, Auteur ; Y. J. Zhu, Auteur . - 2011 . - pp. 7273-7281.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7273-7281
Mots-clés : Carbon dioxide steel Corrosion inhibition Résumé : The corrosion and corrosion inhibition of N80 and P110 carbon steels (CS) in CO2-saturated simulated formation water by rosin amide imidazoline (RAIM) was studied using electrochemical impedance spectroscopy and potentiodynamic polarization techniques. The results indicate that N80 CS performs better than P 110 CS with RAIM at lower temperature and P110 CS at higher temperatures. Inhibition efficiency increased with increase in RAIM concentration and temperature. The data suggest that RAIM functioned as inhibitor via a mixed-inhibitor mechanism and the inhibition process is attributed to the formation of a chemically adsorbed film of RAIM on the surface of the metal via its polycentric adsorption sites. Morphological studies of the carbon steel electrode surface were undertaken by scanning electron microscope (SEM) and atomic force microscopy (AFM). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239041 Exemplaires
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Titre : Nanosilica addition dramatically improves the cell morphology and expansion ratio of polypropylene heterophasic copolymer foams blown in continuous extrusion Type de document : texte imprimé Auteurs : Wentao Zhai, Auteur ; Chul B. Park, Auteur ; Marianna Kontopoulou, Auteur Année de publication : 2011 Article en page(s) : pp. 7282-7289 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Extrusion Foam Expansion Morphology Résumé : Currently, the preparation of polypropylene (PP) foam with a well-defined cell structure and a high expansion ratio is receiving increased attention. However, the present technical problems such as poor cell nucleation ability and weak melt strength of polymer resin, hinder the broader use of linear PP in foam production. In this study, a PP heterophasic copolymer with a linear structure was selected together with nanosilica to challenge the fabrication of PP foam with uniform cell structure, high cell density, and a high expansion ratio using CO2 as a physical blowing agent. Scanning electron microscopy (SEM) observation indicated that silica particles tended to aggregate in the PP matrix, but the multisilica aggregates with sizes from 80 to 350 nm were well dispersed in PP because of the addition of a coupling agent (CA). PP foam exhibited poor cell morphology and low cell densities of ca. 104―5 cells/cm3at different die temperatures. An introduction of a small amount of nanosilica, 0.5 wt % and 1 wt %, dramatically improved the foaming behavior of PP, where the cell structure distribution of the resultant foams was uniform, and the cell density and foam expansion were high (i.e., 108―9 cells/cm3 and 16.9―19.5, respectively). Furthermore, the presence of nanosilica clearly broadened the foaming window of PP. By further increasing silica content, however, the foaming behavior of PP/silica nanocomposites became poor, especially at slightly higher die temperatures (i.e., above 140 °C), even though a high silica loading increased the number of heterogeneous nucleation sites. The effect of foaming on the dispersion of nanosilica in the PP matrix was also investigated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239042
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7282-7289[article] Nanosilica addition dramatically improves the cell morphology and expansion ratio of polypropylene heterophasic copolymer foams blown in continuous extrusion [texte imprimé] / Wentao Zhai, Auteur ; Chul B. Park, Auteur ; Marianna Kontopoulou, Auteur . - 2011 . - pp. 7282-7289.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7282-7289
Mots-clés : Extrusion Foam Expansion Morphology Résumé : Currently, the preparation of polypropylene (PP) foam with a well-defined cell structure and a high expansion ratio is receiving increased attention. However, the present technical problems such as poor cell nucleation ability and weak melt strength of polymer resin, hinder the broader use of linear PP in foam production. In this study, a PP heterophasic copolymer with a linear structure was selected together with nanosilica to challenge the fabrication of PP foam with uniform cell structure, high cell density, and a high expansion ratio using CO2 as a physical blowing agent. Scanning electron microscopy (SEM) observation indicated that silica particles tended to aggregate in the PP matrix, but the multisilica aggregates with sizes from 80 to 350 nm were well dispersed in PP because of the addition of a coupling agent (CA). PP foam exhibited poor cell morphology and low cell densities of ca. 104―5 cells/cm3at different die temperatures. An introduction of a small amount of nanosilica, 0.5 wt % and 1 wt %, dramatically improved the foaming behavior of PP, where the cell structure distribution of the resultant foams was uniform, and the cell density and foam expansion were high (i.e., 108―9 cells/cm3 and 16.9―19.5, respectively). Furthermore, the presence of nanosilica clearly broadened the foaming window of PP. By further increasing silica content, however, the foaming behavior of PP/silica nanocomposites became poor, especially at slightly higher die temperatures (i.e., above 140 °C), even though a high silica loading increased the number of heterogeneous nucleation sites. The effect of foaming on the dispersion of nanosilica in the PP matrix was also investigated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239042 Exemplaires
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Titre : Effectiveness of low-pressure metal-organic chemical vapor deposition coatings on metal surfaces for the mitigation of fouling from heated jet fuel Type de document : texte imprimé Auteurs : Arun Ram Mohan, Auteur ; Semih Eser, Auteur Année de publication : 2011 Article en page(s) : pp. 7290-7304 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fuel Fouling Pollution abatement Chemical vapor deposition Résumé : Thin films of alumina, zirconia, tantalum oxide, and platinum were deposited on AIS1304 by metal―organic chemical vapor deposition to investigate the effectiveness of these coatings in inhibiting carbon deposition and sulfide formation from thermal oxidative degradation of jet fuel. Coated AISI304 foils were heated in a laboratory scale flow reactor with a commercial jet fuel (Jet-A) flowing at 1 mL/min at a wall temperature of 350 °C and reactor pressure of 500 psig (3.4 MPa) for 5 h. Under these conditions, both liquid phase autoxidation and thermal decomposition of jet fuel contribute to carbon deposition. The surface composition of the metal oxide coatings was found by X-ray photoelectron spectroscopy. The morphology of the coating and the carbonaceous deposits formed during thermal stressing were examined by field emission scanning electron microscopy. The amount of solid carbonaceous deposits on the coated and uncoated surfaces was measured by temperature-programmed oxidation. The effectiveness of the coatings in mitigating carbon deposition was found to decrease in the following order: platinum > Ta2O5 > alumina from acetyl acetonate > ZrO2 > alumina from aluminum trisecondary butoxide > AISI304. The coatings cover the metal surface by forming a protective layer that inhibits the formation of metal sulfides from the reaction of sulfur compounds in jet fuel with iron and nickel on stainless steel and inconel surfaces, respectively. The variation in the activity of the coatings can be attributed to the interaction of oxygenated intermediates formed by autoxidation during thermal stressing with coating surfaces having different degrees of acidity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239043
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7290-7304[article] Effectiveness of low-pressure metal-organic chemical vapor deposition coatings on metal surfaces for the mitigation of fouling from heated jet fuel [texte imprimé] / Arun Ram Mohan, Auteur ; Semih Eser, Auteur . - 2011 . - pp. 7290-7304.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7290-7304
Mots-clés : Fuel Fouling Pollution abatement Chemical vapor deposition Résumé : Thin films of alumina, zirconia, tantalum oxide, and platinum were deposited on AIS1304 by metal―organic chemical vapor deposition to investigate the effectiveness of these coatings in inhibiting carbon deposition and sulfide formation from thermal oxidative degradation of jet fuel. Coated AISI304 foils were heated in a laboratory scale flow reactor with a commercial jet fuel (Jet-A) flowing at 1 mL/min at a wall temperature of 350 °C and reactor pressure of 500 psig (3.4 MPa) for 5 h. Under these conditions, both liquid phase autoxidation and thermal decomposition of jet fuel contribute to carbon deposition. The surface composition of the metal oxide coatings was found by X-ray photoelectron spectroscopy. The morphology of the coating and the carbonaceous deposits formed during thermal stressing were examined by field emission scanning electron microscopy. The amount of solid carbonaceous deposits on the coated and uncoated surfaces was measured by temperature-programmed oxidation. The effectiveness of the coatings in mitigating carbon deposition was found to decrease in the following order: platinum > Ta2O5 > alumina from acetyl acetonate > ZrO2 > alumina from aluminum trisecondary butoxide > AISI304. The coatings cover the metal surface by forming a protective layer that inhibits the formation of metal sulfides from the reaction of sulfur compounds in jet fuel with iron and nickel on stainless steel and inconel surfaces, respectively. The variation in the activity of the coatings can be attributed to the interaction of oxygenated intermediates formed by autoxidation during thermal stressing with coating surfaces having different degrees of acidity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239043 Exemplaires
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Titre : Fabrication of novel polyurethane elastomer composites containing hollow glass microspheres and their underwater applications Type de document : texte imprimé Auteurs : Hyungu Im, Auteur ; Sang Chul Roh, Auteur ; Chang Keun Kim, Auteur Année de publication : 2011 Article en page(s) : pp. 7305-7312 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microsphere Hollow glass Composite material Résumé : Thermoplastic polyurethane (TPU) elastomers are frequently used in underwater applications. Desirable polymeric materials have lower densities and lower swelling ratios for seawater and paraffin oil, along with better mechanical strength than TPU after impregnation. To fabricate desirable composites for underwater applications, hollow glass microspheres (HGMs), TPU prepared from poly(tetramethylene glycol) (PTMG), and methyl diphenyl diisocyanate (MDI) were used. TPU-grafted hollow glass microspheres (TPU-g-HGM) were prepared to fabricate a composite that has better interfacial adhesion between the TPU matrix and the HGMs. The tensile strength of the composite increased with increasing HGM content, whereas the swelling ratio and density of the composite decreased with increasing HGM content. At fixed HGM content in the composite, the TPU/TPU-g-HGM composite exhibited a lower swelling ratio and better tensile strength than the TPU/HGM composite. In addition, the TPU/TPU-g-HGM composite exhibited enhanced mechanical strength as compared to TPU after being impregnated with seawater and paraffin oil. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239044
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7305-7312[article] Fabrication of novel polyurethane elastomer composites containing hollow glass microspheres and their underwater applications [texte imprimé] / Hyungu Im, Auteur ; Sang Chul Roh, Auteur ; Chang Keun Kim, Auteur . - 2011 . - pp. 7305-7312.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7305-7312
Mots-clés : Microsphere Hollow glass Composite material Résumé : Thermoplastic polyurethane (TPU) elastomers are frequently used in underwater applications. Desirable polymeric materials have lower densities and lower swelling ratios for seawater and paraffin oil, along with better mechanical strength than TPU after impregnation. To fabricate desirable composites for underwater applications, hollow glass microspheres (HGMs), TPU prepared from poly(tetramethylene glycol) (PTMG), and methyl diphenyl diisocyanate (MDI) were used. TPU-grafted hollow glass microspheres (TPU-g-HGM) were prepared to fabricate a composite that has better interfacial adhesion between the TPU matrix and the HGMs. The tensile strength of the composite increased with increasing HGM content, whereas the swelling ratio and density of the composite decreased with increasing HGM content. At fixed HGM content in the composite, the TPU/TPU-g-HGM composite exhibited a lower swelling ratio and better tensile strength than the TPU/HGM composite. In addition, the TPU/TPU-g-HGM composite exhibited enhanced mechanical strength as compared to TPU after being impregnated with seawater and paraffin oil. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239044 Exemplaires
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Titre : Theoretical study of medium-sized azacycloalkane and dialkyl amine adsorption on the Fe(111) surface Type de document : texte imprimé Auteurs : Shinichi Satoh, Auteur ; Hiroshi Fujimoto, Auteur Année de publication : 2011 Article en page(s) : pp. 7313-7318 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Adsorption Résumé : To understand the difference in inhibition efficiency against corrosion of iron surfaces between medium-sized azacycloalkanes and dialkyl amines containing the same number of carbon atoms, the adsorption of azacycloundecane and of dipentyl amine onto a model Fe(111) surface has been studied using the molecular orbital and density functional theoretical methods. B3LYP calculations show that azacycloundecane gives a stronger interaction with the surface from an energy point of view. The difference between the two amines in the strength of interaction originates predominantly from the changes in structure of the carbon chains that take place during the adsorption process. The calculations suggest that a large C-N-C bond angle does not lead to efficient secondary-amine inhibitors that prevent the corrosion of iron surfaces. This conclusion is supported by a paired interaction orbital analysis. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239045
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7313-7318[article] Theoretical study of medium-sized azacycloalkane and dialkyl amine adsorption on the Fe(111) surface [texte imprimé] / Shinichi Satoh, Auteur ; Hiroshi Fujimoto, Auteur . - 2011 . - pp. 7313-7318.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7313-7318
Mots-clés : Adsorption Résumé : To understand the difference in inhibition efficiency against corrosion of iron surfaces between medium-sized azacycloalkanes and dialkyl amines containing the same number of carbon atoms, the adsorption of azacycloundecane and of dipentyl amine onto a model Fe(111) surface has been studied using the molecular orbital and density functional theoretical methods. B3LYP calculations show that azacycloundecane gives a stronger interaction with the surface from an energy point of view. The difference between the two amines in the strength of interaction originates predominantly from the changes in structure of the carbon chains that take place during the adsorption process. The calculations suggest that a large C-N-C bond angle does not lead to efficient secondary-amine inhibitors that prevent the corrosion of iron surfaces. This conclusion is supported by a paired interaction orbital analysis. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239045 Exemplaires
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Titre : Effect of fatty acid chain of tweens on the micellar behavior of dodecylbenzyldimethylammonium chloride Type de document : texte imprimé Auteurs : Reshu Sanan, Auteur ; Rakesh Kumar Mahajan, Auteur Année de publication : 2011 Article en page(s) : pp. 7319-7325 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fatty acid chain Résumé : The present work is aimed at studying the interactions between mixed micelles of nonionic surfactants, Tweens (Tween 20, Tween 40, Tween 60, and Tween 80) and cationic surfactant, dodecylbenzyldimethylammonium chloride (C 12BzCl), and to draw a comparison between the effect of different Tweens with respect to fatty acid chain present in them. Both from the industrial and research point of view, the present day need for newer materials has been diverted to surfactant-additive systems rather than single surfactant systems because of the great fundamental, technological, and biological importance associated with the mixed micelles. Moreover, Tweens being biocompatible, stable, and relatively nontoxic can be used to enhance the efficacy of benzalkonium (Bz)-based disinfection products. Conductivity and surface tension techniques have been employed to determine various micellar parameters like critical micellar concentration (cmc), degree of counterion binding (β), standard free energy of micellization (ΔGomic), excess free energy of mixing (ΔGoex), interaction parameter (βm) and activity coefficients for the Tweens (f1) and C12BzCl (f2) in the mixed micelles using Rubingh's, Motomura's, and Maeda's approach. The negative values of βm indicate synergism in the mixtures which is highly beneficial as it reduces the total amount of surfactant used in a particular application resulting in reduction of cost and environmental impact. The results have also been discussed in terms of short-range interactions between the two types of surfactants. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239046
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7319-7325[article] Effect of fatty acid chain of tweens on the micellar behavior of dodecylbenzyldimethylammonium chloride [texte imprimé] / Reshu Sanan, Auteur ; Rakesh Kumar Mahajan, Auteur . - 2011 . - pp. 7319-7325.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7319-7325
Mots-clés : Fatty acid chain Résumé : The present work is aimed at studying the interactions between mixed micelles of nonionic surfactants, Tweens (Tween 20, Tween 40, Tween 60, and Tween 80) and cationic surfactant, dodecylbenzyldimethylammonium chloride (C 12BzCl), and to draw a comparison between the effect of different Tweens with respect to fatty acid chain present in them. Both from the industrial and research point of view, the present day need for newer materials has been diverted to surfactant-additive systems rather than single surfactant systems because of the great fundamental, technological, and biological importance associated with the mixed micelles. Moreover, Tweens being biocompatible, stable, and relatively nontoxic can be used to enhance the efficacy of benzalkonium (Bz)-based disinfection products. Conductivity and surface tension techniques have been employed to determine various micellar parameters like critical micellar concentration (cmc), degree of counterion binding (β), standard free energy of micellization (ΔGomic), excess free energy of mixing (ΔGoex), interaction parameter (βm) and activity coefficients for the Tweens (f1) and C12BzCl (f2) in the mixed micelles using Rubingh's, Motomura's, and Maeda's approach. The negative values of βm indicate synergism in the mixtures which is highly beneficial as it reduces the total amount of surfactant used in a particular application resulting in reduction of cost and environmental impact. The results have also been discussed in terms of short-range interactions between the two types of surfactants. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239046 Exemplaires
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Titre : Preparation of acid-resisting ultramarine blue by novel two-step silica coating process Type de document : texte imprimé Auteurs : Sifang Li, Auteur ; Miao Liu, Auteur ; Lan Sun, Auteur Année de publication : 2011 Article en page(s) : pp. 7326-7331 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Coating process Preparation Résumé : Acid-resisting ultramarine blue pigment was prepared by a novel two-step silica coating process which is dense liquid coating followed by a sol―gel process. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and BET surface area analysis were used to characterize the composition of elements, surface structure, and morphology on the coating films. Uniform, smooth, and dense silica films on the irregular particles of ultramarine pigment were obtained via novel two-step coatings. Acid resistance of the silica-coated ultramarine blue was evaluated by immersing the pigment in 10 wt % hydrochloric acid. The silica-coated ultramarine blue prepared by the novel two-step process shows the 10th grade of acid resistance, which exhibits much higher acid resistance than that by dense liquid, sol―gel, and conventional two-step coatings. Furthermore, leaching experiments indicated that no sulfur was leached out for the sample prepared by novel two-step coatings, while hydrogen sulfide concentrations from 0.018 to 0.34 mg/L were detected in the leaching solutions for the samples prepared by the conventional two-step coating, dense liquid coating, and sol-gel process. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239047
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7326-7331[article] Preparation of acid-resisting ultramarine blue by novel two-step silica coating process [texte imprimé] / Sifang Li, Auteur ; Miao Liu, Auteur ; Lan Sun, Auteur . - 2011 . - pp. 7326-7331.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7326-7331
Mots-clés : Coating process Preparation Résumé : Acid-resisting ultramarine blue pigment was prepared by a novel two-step silica coating process which is dense liquid coating followed by a sol―gel process. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and BET surface area analysis were used to characterize the composition of elements, surface structure, and morphology on the coating films. Uniform, smooth, and dense silica films on the irregular particles of ultramarine pigment were obtained via novel two-step coatings. Acid resistance of the silica-coated ultramarine blue was evaluated by immersing the pigment in 10 wt % hydrochloric acid. The silica-coated ultramarine blue prepared by the novel two-step process shows the 10th grade of acid resistance, which exhibits much higher acid resistance than that by dense liquid, sol―gel, and conventional two-step coatings. Furthermore, leaching experiments indicated that no sulfur was leached out for the sample prepared by novel two-step coatings, while hydrogen sulfide concentrations from 0.018 to 0.34 mg/L were detected in the leaching solutions for the samples prepared by the conventional two-step coating, dense liquid coating, and sol-gel process. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239047 Exemplaires
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Titre : Modeling Pt2+ coordination process within poly(amidoamine) dendrimers for synthesis of dendrimer-encapsulated Pt nanoparticles Type de document : texte imprimé Auteurs : Daigo Yamamoto, Auteur ; Satoshi Watanabe, Auteur ; Minoru T. Miyahara, Auteur Année de publication : 2011 Article en page(s) : pp. 7332-7337 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanoparticle Modeling Résumé : Dendrimer-encapsulated Pt nanoparticles can be synthesized by Pt2+ coordination with dendrimers followed by reduction. In the present study, we have systematically investigated the coordination kinetics of PtCl42― with fourth-generation hydroxyl-terminated poly(amidoamine) (PAMAM G4-OH) dendrimers using UV-vis spectroscopy measurements. Our experimental investigation clarifies that Pt2+ coordination with dendrimers occurs after the H2O ligand exchange (aquation) of PtCl42― and that a resultant species PtCl2(H2O)2 predominantly coordinates with the dendrimers. From these results, we have proposed a simple dynamic model that describes the Pt2+ coordination as a consecutive reaction composed of the aquation reaction of PtCl42― and a subsequent coordination reaction of the resultant PtCl2(H2O)2 with the dendrimers. Our proposed model is in good agreement with the experimental results at a low concentration condition of PtCl42―, validating its performance. Furthermore, we suggest that the proposed scheme can be generalized and applied to metal species other than Pt2+. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239048
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7332-7337[article] Modeling Pt2+ coordination process within poly(amidoamine) dendrimers for synthesis of dendrimer-encapsulated Pt nanoparticles [texte imprimé] / Daigo Yamamoto, Auteur ; Satoshi Watanabe, Auteur ; Minoru T. Miyahara, Auteur . - 2011 . - pp. 7332-7337.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7332-7337
Mots-clés : Nanoparticle Modeling Résumé : Dendrimer-encapsulated Pt nanoparticles can be synthesized by Pt2+ coordination with dendrimers followed by reduction. In the present study, we have systematically investigated the coordination kinetics of PtCl42― with fourth-generation hydroxyl-terminated poly(amidoamine) (PAMAM G4-OH) dendrimers using UV-vis spectroscopy measurements. Our experimental investigation clarifies that Pt2+ coordination with dendrimers occurs after the H2O ligand exchange (aquation) of PtCl42― and that a resultant species PtCl2(H2O)2 predominantly coordinates with the dendrimers. From these results, we have proposed a simple dynamic model that describes the Pt2+ coordination as a consecutive reaction composed of the aquation reaction of PtCl42― and a subsequent coordination reaction of the resultant PtCl2(H2O)2 with the dendrimers. Our proposed model is in good agreement with the experimental results at a low concentration condition of PtCl42―, validating its performance. Furthermore, we suggest that the proposed scheme can be generalized and applied to metal species other than Pt2+. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239048 Exemplaires
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Titre : Reduction of nitro aromatic compounds over Ag/Al2O3 nanocatalyst prepared in water-in-oil microemulsion : effects of water-to-surfactant mole ratio and type of reducing agent Type de document : texte imprimé Auteurs : Jignasa N. Solanki, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur Année de publication : 2011 Article en page(s) : pp. 7338-7344 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Surfactant Microemulsion Résumé : Silver nanoparticles, with controlled sizes, are synthesized by chemical reduction of silver nitrate with sodium borohydride reducing agent by microemulsion method. To obtain small and monodisperse particles, as-synthesized Ag nanoparticles are readily tuned by varying the water-to-surfactant mole ratio, ω (most crucial operating parameter), and the type of reducing agent. Superior nanoparticles are obtained at intermediate ω (ω = 3). When hydrazine hydrate is used as reducing agent, further superior nanoparticles are obtained with a calculated surface area of 9.76 x 108 mm2/g and hence are chosen for further nanocatalyst synthesis by proper deposition of the same on alumina support. The catalyst is analyzed with UV―visible spectroscopy and X-ray diffraction techniques to confirm the presence of metallic silver. The synthesized catalyst can be conveniently recovered from the reaction system, leading to easy monitoring of the catalytic reaction by spectroscopic methods. Accordingly, reduction of model nitro aromatic compounds, viz., 4-nitrophenol and 4-nitroaniline, are studied. Gradual disappearance of the peak corresponding to nitro compounds reveals the degradation of nitro compounds with time. Furthermore, the appearance and increase of new peaks with time reveal the progressive formation of respective products. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239049
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7338-7344[article] Reduction of nitro aromatic compounds over Ag/Al2O3 nanocatalyst prepared in water-in-oil microemulsion : effects of water-to-surfactant mole ratio and type of reducing agent [texte imprimé] / Jignasa N. Solanki, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur . - 2011 . - pp. 7338-7344.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7338-7344
Mots-clés : Surfactant Microemulsion Résumé : Silver nanoparticles, with controlled sizes, are synthesized by chemical reduction of silver nitrate with sodium borohydride reducing agent by microemulsion method. To obtain small and monodisperse particles, as-synthesized Ag nanoparticles are readily tuned by varying the water-to-surfactant mole ratio, ω (most crucial operating parameter), and the type of reducing agent. Superior nanoparticles are obtained at intermediate ω (ω = 3). When hydrazine hydrate is used as reducing agent, further superior nanoparticles are obtained with a calculated surface area of 9.76 x 108 mm2/g and hence are chosen for further nanocatalyst synthesis by proper deposition of the same on alumina support. The catalyst is analyzed with UV―visible spectroscopy and X-ray diffraction techniques to confirm the presence of metallic silver. The synthesized catalyst can be conveniently recovered from the reaction system, leading to easy monitoring of the catalytic reaction by spectroscopic methods. Accordingly, reduction of model nitro aromatic compounds, viz., 4-nitrophenol and 4-nitroaniline, are studied. Gradual disappearance of the peak corresponding to nitro compounds reveals the degradation of nitro compounds with time. Furthermore, the appearance and increase of new peaks with time reveal the progressive formation of respective products. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239049 Exemplaires
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Titre : Optimal design of multistage membrane distillation systems for water purification Type de document : texte imprimé Auteurs : Yanyue Lu, Auteur ; Junghui Chen, Auteur Année de publication : 2011 Article en page(s) : pp. 7345-7354 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Membrane separation Purification distillation Optimal design Résumé : In this paper, a novel optimal design strategy is proposed to produce pure water in a multistage membrane distillation (MD) system. It is a systematic approach to modeling and analyzing multistage MD processes. The proposed method can generate the optimal system structure and operation conditions and avoid poor integration and suboptimal configuration of multistage MD systems. In this approach, an innovative module model is first established, and then the cost function relating the capital and the operation cost to the design variables and the structural variables of the designed system is introduced in the objective function. A superstructure flow sheet is presented to describe all the possible flow routes for the cold stream. Then optimal design problem can be formulated as a mixed-integer nonlinear programming (MINLP) problem to minimize the total annualized cost. Based on our simulation studies, the mode of the commonly used countercurrent operation is the optimal flow route for the MD system. The design results would also determine the configuration of the optimal separation stage, the optimal operating mode, and the corresponding operating conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239050
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7345-7354[article] Optimal design of multistage membrane distillation systems for water purification [texte imprimé] / Yanyue Lu, Auteur ; Junghui Chen, Auteur . - 2011 . - pp. 7345-7354.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7345-7354
Mots-clés : Membrane separation Purification distillation Optimal design Résumé : In this paper, a novel optimal design strategy is proposed to produce pure water in a multistage membrane distillation (MD) system. It is a systematic approach to modeling and analyzing multistage MD processes. The proposed method can generate the optimal system structure and operation conditions and avoid poor integration and suboptimal configuration of multistage MD systems. In this approach, an innovative module model is first established, and then the cost function relating the capital and the operation cost to the design variables and the structural variables of the designed system is introduced in the objective function. A superstructure flow sheet is presented to describe all the possible flow routes for the cold stream. Then optimal design problem can be formulated as a mixed-integer nonlinear programming (MINLP) problem to minimize the total annualized cost. Based on our simulation studies, the mode of the commonly used countercurrent operation is the optimal flow route for the MD system. The design results would also determine the configuration of the optimal separation stage, the optimal operating mode, and the corresponding operating conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239050 Exemplaires
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Titre : Developing a planning strategy with a focus on managing planning data Type de document : texte imprimé Auteurs : Jun-Hyung Ryu, Auteur Année de publication : 2011 Article en page(s) : pp. 7355-7362 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Planning Résumé : Considerable attention has been given to planning in academia. While most works are concerned with developing mathematical models and their computation algorithms, little attention has been given to managing the data in the planning. A new planning framework is thus presented by explicitly incorporating data management with planning decision-making processes. A numerical example of multiperiod batch process planning and a case study of a semiconductor manufacturing company are presented to illustrate the applicability of the presented framework. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239051
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7355-7362[article] Developing a planning strategy with a focus on managing planning data [texte imprimé] / Jun-Hyung Ryu, Auteur . - 2011 . - pp. 7355-7362.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7355-7362
Mots-clés : Planning Résumé : Considerable attention has been given to planning in academia. While most works are concerned with developing mathematical models and their computation algorithms, little attention has been given to managing the data in the planning. A new planning framework is thus presented by explicitly incorporating data management with planning decision-making processes. A numerical example of multiperiod batch process planning and a case study of a semiconductor manufacturing company are presented to illustrate the applicability of the presented framework. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239051 Exemplaires
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Titre : Freeze-drying cycle optimization using model predictive control techniques Type de document : texte imprimé Auteurs : Roberto Pisano, Auteur ; Davide Fissore, Auteur ; Antonello A. Barresi, Auteur Année de publication : 2011 Article en page(s) : pp. 7363-7379 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Predictive control Modeling Optimization Freeze drying Résumé : The problem of process control in the field of pharmaceutical freeze drying is discussed, and a model predictive control (MPC) system is proposed to control, and optimize, in-line the primary drying step, beside preserving product quality. The controller can provide the optimal recipe for a given product, taking into account process constraints and modeling errors. Two control algorithms are proposed: the former manipulates both the chamber pressure and the temperature of the technical fluid, while the latter manipulates only the temperature of the fluid. The optimal formulation of the algorithms and the tuning of controller parameters are discussed by means of mathematical simulations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239052
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7363-7379[article] Freeze-drying cycle optimization using model predictive control techniques [texte imprimé] / Roberto Pisano, Auteur ; Davide Fissore, Auteur ; Antonello A. Barresi, Auteur . - 2011 . - pp. 7363-7379.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7363-7379
Mots-clés : Predictive control Modeling Optimization Freeze drying Résumé : The problem of process control in the field of pharmaceutical freeze drying is discussed, and a model predictive control (MPC) system is proposed to control, and optimize, in-line the primary drying step, beside preserving product quality. The controller can provide the optimal recipe for a given product, taking into account process constraints and modeling errors. Two control algorithms are proposed: the former manipulates both the chamber pressure and the temperature of the technical fluid, while the latter manipulates only the temperature of the fluid. The optimal formulation of the algorithms and the tuning of controller parameters are discussed by means of mathematical simulations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239052 Exemplaires
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Titre : Partial decoupling control for multivariable processes Type de document : texte imprimé Auteurs : Yuling Shen, Auteur ; Shaoyuan Li, Auteur ; Ning Li, Auteur Année de publication : 2011 Article en page(s) : pp. 7380-7387 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Multivariable system Résumé : Based on the theory of equivalent transfer functions (ETFs), this work proposes a novel partial decoupling control technique for multivariable processes. By measuring the effect of each ETF element in decoupling control, a partial decoupling control structure selection criterion is proposed with the aims that the decoupler has the least complexity and that overall system performance is satisfied. The ETF parameters are then obtained under certain constraints. Consequently, a systematic design procedure is proposed in order to obtain a stable, proper, and causal partial decoupler matrix. Simulation results of several multivariable processes with different interaction characteristics are provided to demonstrate the simplicity and effectiveness of the design method. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239053
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7380-7387[article] Partial decoupling control for multivariable processes [texte imprimé] / Yuling Shen, Auteur ; Shaoyuan Li, Auteur ; Ning Li, Auteur . - 2011 . - pp. 7380-7387.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7380-7387
Mots-clés : Multivariable system Résumé : Based on the theory of equivalent transfer functions (ETFs), this work proposes a novel partial decoupling control technique for multivariable processes. By measuring the effect of each ETF element in decoupling control, a partial decoupling control structure selection criterion is proposed with the aims that the decoupler has the least complexity and that overall system performance is satisfied. The ETF parameters are then obtained under certain constraints. Consequently, a systematic design procedure is proposed in order to obtain a stable, proper, and causal partial decoupler matrix. Simulation results of several multivariable processes with different interaction characteristics are provided to demonstrate the simplicity and effectiveness of the design method. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239053 Exemplaires
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Titre : A Wiener neural network-based identification and adaptive generalized predictive control for nonlinear SISO systems Type de document : texte imprimé Auteurs : Jinzhu Peng, Auteur ; Rickey Dubay, Auteur ; Jose Mauricio Hernandez, Auteur Année de publication : 2011 Article en page(s) : pp. 7388-7397 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : SISO system Predictive control Neural network Résumé : In this study, a Wiener-type neural network (WNN) is derived for identification and control of single-input and single-output (SISO) nonlinear systems. The nonlinear system is identified by the WNN, which consists of a linear dynamic block in cascade with a nonlinear static gain. The Lipschitz criteria for model order determination and back propagation for the adjustment of weights in the network are presented. Using the parameters of the Wiener model, the analytical expressions used in the controller, generalized predictive control (GPC) is modified every time step, to handle the nonlinear dynamics of the controlled variable. Finally, the proposed WNN-based GPC algorithm is tested in simulation on several nonlinear plants with different degrees of nonlinearity. Simulation results show that WNN identification approach has better accuracy, in comparison to other neural network identifiers. The WNN-based GPC has better control performance, in comparison to standard GPC. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239054
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7388-7397[article] A Wiener neural network-based identification and adaptive generalized predictive control for nonlinear SISO systems [texte imprimé] / Jinzhu Peng, Auteur ; Rickey Dubay, Auteur ; Jose Mauricio Hernandez, Auteur . - 2011 . - pp. 7388-7397.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7388-7397
Mots-clés : SISO system Predictive control Neural network Résumé : In this study, a Wiener-type neural network (WNN) is derived for identification and control of single-input and single-output (SISO) nonlinear systems. The nonlinear system is identified by the WNN, which consists of a linear dynamic block in cascade with a nonlinear static gain. The Lipschitz criteria for model order determination and back propagation for the adjustment of weights in the network are presented. Using the parameters of the Wiener model, the analytical expressions used in the controller, generalized predictive control (GPC) is modified every time step, to handle the nonlinear dynamics of the controlled variable. Finally, the proposed WNN-based GPC algorithm is tested in simulation on several nonlinear plants with different degrees of nonlinearity. Simulation results show that WNN identification approach has better accuracy, in comparison to other neural network identifiers. The WNN-based GPC has better control performance, in comparison to standard GPC. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239054 Exemplaires
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Titre : Photoassisted fusion behavior of decanethiol-passivated gold nanoparticles by vacuum ultraviolet light exposure Type de document : texte imprimé Auteurs : Motohiro Tagaya, Auteur ; Masaru Nakagawa, Auteur Année de publication : 2011 Article en page(s) : pp. 7398-7402 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanoparticle Résumé : The photoassisted fusion of a decanethiol-passivated Au-nanoparticle film on a glass substrate by exposure to vacuum-ultraviolet (vacuum-UV) light at 172 nm was investigated and compared to that by thermal fusion. On the basis of the thermal treatment at 200 °C, the X-ray diffraction patterns indicated that the Au-nanoparticle film with the particle diameter of 2.1 nm is completely converted to a crystalline Au film, and the film surface was coarsely granular, having a roughness of several tens of nanometers by field emission-scanning electron microscopy observation. After exposure to vacuum-UV light, the UV―vis absorption spectra revealed that the surface plasmon band at 535 nm showed a red shift with the increasing exposure time, and then the absorption band at 770 nm was clearly observed at 30 min. The diameter of the fused Au nanoparticles was larger than 20 nm on the basis of a transmission electron microscopy observation. These changes indicated that the Au nanoparticles were converted to the crystalline state due to photodecomposition of the decanethiol. Thus, the controllable mild fusion among neighboring Au nanoparticles at room temperature was achieved by vacuum-UV-light exposure due to photodecomposition of the decanethiol. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239055
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7398-7402[article] Photoassisted fusion behavior of decanethiol-passivated gold nanoparticles by vacuum ultraviolet light exposure [texte imprimé] / Motohiro Tagaya, Auteur ; Masaru Nakagawa, Auteur . - 2011 . - pp. 7398-7402.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7398-7402
Mots-clés : Nanoparticle Résumé : The photoassisted fusion of a decanethiol-passivated Au-nanoparticle film on a glass substrate by exposure to vacuum-ultraviolet (vacuum-UV) light at 172 nm was investigated and compared to that by thermal fusion. On the basis of the thermal treatment at 200 °C, the X-ray diffraction patterns indicated that the Au-nanoparticle film with the particle diameter of 2.1 nm is completely converted to a crystalline Au film, and the film surface was coarsely granular, having a roughness of several tens of nanometers by field emission-scanning electron microscopy observation. After exposure to vacuum-UV light, the UV―vis absorption spectra revealed that the surface plasmon band at 535 nm showed a red shift with the increasing exposure time, and then the absorption band at 770 nm was clearly observed at 30 min. The diameter of the fused Au nanoparticles was larger than 20 nm on the basis of a transmission electron microscopy observation. These changes indicated that the Au nanoparticles were converted to the crystalline state due to photodecomposition of the decanethiol. Thus, the controllable mild fusion among neighboring Au nanoparticles at room temperature was achieved by vacuum-UV-light exposure due to photodecomposition of the decanethiol. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239055 Exemplaires
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Titre : Effect of manipulated variables selection on the controllability of chemical processes Type de document : texte imprimé Auteurs : Zhihong Yuan, Auteur ; Bingzhen Chen, Auteur ; Jinsong Zhao, Auteur Année de publication : 2011 Article en page(s) : pp. 7403-7413 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Controllability Résumé : Chemical processes usually involve several alternative manipulated variables each having the potential to influence system operability. This work presents a methodology that illustrates how manipulated variables selection can relate to the open-loop stability and phase behavior of chemical processes over the entire feasible operating region. Within this framework, the first step explores the steady state maps, under different manipulated variable selections. The inherent characteristics, including open-loop stability and phase behavior, are then analyzed. After that, the effect of manipulated variable selection on the static controllability can be assessed. In the third step, based on the conventional model predictive controller, closed-loop dynamic simulations, with both reference tracking and disturbance rejection, are carried out. This allows the comparison of dynamic behaviors, under different operating policies, and a validation of outcomes from the open-loop theoretical analysis. Results from both the static and the dynamic analysis reveal the influence of the manipulated variable selection on the process controllability, over the feasible operating region. These conclusions can assist in process control structure selection and process operation. The proposed method is applied to a polymerization reaction process to demonstrate its efficiency. This example emphasizes how such a methodology can help clarify and handle the causes of the complex phenomena that arise in the design, operation, and control of chemical processes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239056
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7403-7413[article] Effect of manipulated variables selection on the controllability of chemical processes [texte imprimé] / Zhihong Yuan, Auteur ; Bingzhen Chen, Auteur ; Jinsong Zhao, Auteur . - 2011 . - pp. 7403-7413.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7403-7413
Mots-clés : Controllability Résumé : Chemical processes usually involve several alternative manipulated variables each having the potential to influence system operability. This work presents a methodology that illustrates how manipulated variables selection can relate to the open-loop stability and phase behavior of chemical processes over the entire feasible operating region. Within this framework, the first step explores the steady state maps, under different manipulated variable selections. The inherent characteristics, including open-loop stability and phase behavior, are then analyzed. After that, the effect of manipulated variable selection on the static controllability can be assessed. In the third step, based on the conventional model predictive controller, closed-loop dynamic simulations, with both reference tracking and disturbance rejection, are carried out. This allows the comparison of dynamic behaviors, under different operating policies, and a validation of outcomes from the open-loop theoretical analysis. Results from both the static and the dynamic analysis reveal the influence of the manipulated variable selection on the process controllability, over the feasible operating region. These conclusions can assist in process control structure selection and process operation. The proposed method is applied to a polymerization reaction process to demonstrate its efficiency. This example emphasizes how such a methodology can help clarify and handle the causes of the complex phenomena that arise in the design, operation, and control of chemical processes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239056 Exemplaires
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Titre : Preliminary synthesis of fuel gas networks to conserve energy and preserve the environment Type de document : texte imprimé Auteurs : M. M. Faruque Hasan, Auteur ; Iftekhar A. Karimi, Auteur ; Cory Matthew Avison, Auteur Année de publication : 2011 Article en page(s) : pp. 7414-7427 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fuel gas Résumé : Many chemical plants produce a variety of hydrocarbon gases with fuel value. A fuel gas network (FGN) integrates and uses these fuel gases appropriately to make best use of them. FGNs are critical components of many chemical plants including liquefied natural gas (LNG) plants and refineries. However, a systematic approach to design and operate realistic FGNs is not currently available in the literature. We address the optimal synthesis of an FGN with many practical features such as auxiliary equipment (valves, pipelines, compressors, heaters/ coolers, etc.), nonisobaric and nonisothermal operation, nonisothermal mixing, nonlinear fuel-quality specifications, fuel/utility costs, disposal and treatment costs, and emission standards. We develop a nonlinear program (NLP) based on a novel superstructure that embeds plausible alternatives for heating/cooling, moving, mixing, and splitting. We successfully apply our model to three real-life case studies from the LNG and refinery industries to demonstrate that an FGN can save 40―50% of the total energy costs of a plant and reduce the fuel-from-feed or fuel-from-product consumptions by similar amounts. This work represents an important contribution toward conserving energy, preserving the environment, and improving plant economics using advanced techniques of process systems optimization. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239057
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7414-7427[article] Preliminary synthesis of fuel gas networks to conserve energy and preserve the environment [texte imprimé] / M. M. Faruque Hasan, Auteur ; Iftekhar A. Karimi, Auteur ; Cory Matthew Avison, Auteur . - 2011 . - pp. 7414-7427.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7414-7427
Mots-clés : Fuel gas Résumé : Many chemical plants produce a variety of hydrocarbon gases with fuel value. A fuel gas network (FGN) integrates and uses these fuel gases appropriately to make best use of them. FGNs are critical components of many chemical plants including liquefied natural gas (LNG) plants and refineries. However, a systematic approach to design and operate realistic FGNs is not currently available in the literature. We address the optimal synthesis of an FGN with many practical features such as auxiliary equipment (valves, pipelines, compressors, heaters/ coolers, etc.), nonisobaric and nonisothermal operation, nonisothermal mixing, nonlinear fuel-quality specifications, fuel/utility costs, disposal and treatment costs, and emission standards. We develop a nonlinear program (NLP) based on a novel superstructure that embeds plausible alternatives for heating/cooling, moving, mixing, and splitting. We successfully apply our model to three real-life case studies from the LNG and refinery industries to demonstrate that an FGN can save 40―50% of the total energy costs of a plant and reduce the fuel-from-feed or fuel-from-product consumptions by similar amounts. This work represents an important contribution toward conserving energy, preserving the environment, and improving plant economics using advanced techniques of process systems optimization. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239057 Exemplaires
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Titre : Water reuse and wastewater minimization in chemical industries using differentiated regeneration of contaminants Type de document : texte imprimé Auteurs : Selene Maria de Arruda Guelli Ulson de Souza, Auteur ; Marcelo Fonseca Xavier, Auteur ; Adriano da Silva, Auteur Année de publication : 2011 Article en page(s) : pp. 7428-7436 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pollution Chemical industry Waste water Reuse Résumé : There is currently a great demand for tools that allow the analysis of water networks in a practical and objective way. In the modern scenarios chemical industries need to consume water in more rational forms to minimize the risk of water scarcity caused by pollution. Some of the alternatives for reducing water consumption involve the reuse and/or recycling of wastewater, such as the methodology based on the water source diagram (WSD), which is a flexible and dynamic alternative approach to generating viable scenarios for the management of water networks. In this study the implementation of the WSD to support the optimization software (GAMS) in a process of differentiated regeneration is studied, treating the operation of a chemical process of interest in an objective and systemic way. The method can be applied to resource networks with multiple impurities, even when the utility contains impurities. The possibilities for maximum reuse of water and differentiated effluent regeneration are studied, aiming to minimize the total flow of wastewater being treated inside the treatment units and the global cost of the network. The application of this methodology is illustrated through two case studies. The results show that this procedure allows the successful identification of different scenarios which present a condition of minimum water consumption together with a minimum network operation cost. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239058
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7428-7436[article] Water reuse and wastewater minimization in chemical industries using differentiated regeneration of contaminants [texte imprimé] / Selene Maria de Arruda Guelli Ulson de Souza, Auteur ; Marcelo Fonseca Xavier, Auteur ; Adriano da Silva, Auteur . - 2011 . - pp. 7428-7436.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7428-7436
Mots-clés : Pollution Chemical industry Waste water Reuse Résumé : There is currently a great demand for tools that allow the analysis of water networks in a practical and objective way. In the modern scenarios chemical industries need to consume water in more rational forms to minimize the risk of water scarcity caused by pollution. Some of the alternatives for reducing water consumption involve the reuse and/or recycling of wastewater, such as the methodology based on the water source diagram (WSD), which is a flexible and dynamic alternative approach to generating viable scenarios for the management of water networks. In this study the implementation of the WSD to support the optimization software (GAMS) in a process of differentiated regeneration is studied, treating the operation of a chemical process of interest in an objective and systemic way. The method can be applied to resource networks with multiple impurities, even when the utility contains impurities. The possibilities for maximum reuse of water and differentiated effluent regeneration are studied, aiming to minimize the total flow of wastewater being treated inside the treatment units and the global cost of the network. The application of this methodology is illustrated through two case studies. The results show that this procedure allows the successful identification of different scenarios which present a condition of minimum water consumption together with a minimum network operation cost. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239058 Exemplaires
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Titre : Normalized efficiency for stagewise operations Type de document : texte imprimé Auteurs : Branislav M. Jacimovic, Auteur ; Srbislav B. Genic, Auteur Année de publication : 2011 Article en page(s) : pp. 7437-7444 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Stagewise operations Résumé : Tray efficiency in gas-liquid operations is a widely discussed theme, and the shortcomings of Murphree's, Hausen's, Standart's, and Holland's efficiencies are well-known. The new parameter "normalized efficiency" is defined as the ratio of the real tray mass transfer rate and theoretically maximal mass transfer rate obtained for the counter-current plug-flow model for both phases in the case of infinite contact surface. Normalized efficiency has several advantages over the previously defined efficiencies: the range of normalized efficiency is 0―1; normalized efficiency values for gas and liquid phases are equal. Furthermore, normalized efficiency can be easily used for determining the required number of trays in mass-transfer operations or for estimating the overall column efficiency. The usage of normalized efficiency does not raise any dilemma about the interpretation of enperimentally obtained results for trays working in distillation and sorption columns. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239059
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7437-7444[article] Normalized efficiency for stagewise operations [texte imprimé] / Branislav M. Jacimovic, Auteur ; Srbislav B. Genic, Auteur . - 2011 . - pp. 7437-7444.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7437-7444
Mots-clés : Stagewise operations Résumé : Tray efficiency in gas-liquid operations is a widely discussed theme, and the shortcomings of Murphree's, Hausen's, Standart's, and Holland's efficiencies are well-known. The new parameter "normalized efficiency" is defined as the ratio of the real tray mass transfer rate and theoretically maximal mass transfer rate obtained for the counter-current plug-flow model for both phases in the case of infinite contact surface. Normalized efficiency has several advantages over the previously defined efficiencies: the range of normalized efficiency is 0―1; normalized efficiency values for gas and liquid phases are equal. Furthermore, normalized efficiency can be easily used for determining the required number of trays in mass-transfer operations or for estimating the overall column efficiency. The usage of normalized efficiency does not raise any dilemma about the interpretation of enperimentally obtained results for trays working in distillation and sorption columns. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239059 Exemplaires
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Titre : Normalized efficiency for stagewise operations Type de document : texte imprimé Auteurs : Branislav M. Jacimovic, Auteur ; Srbislav B. Genic, Auteur Année de publication : 2011 Article en page(s) : pp. 7437-7444 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Stagewise operations Résumé : Tray efficiency in gas-liquid operations is a widely discussed theme, and the shortcomings of Murphree's, Hausen's, Standart's, and Holland's efficiencies are well-known. The new parameter "normalized efficiency" is defined as the ratio of the real tray mass transfer rate and theoretically maximal mass transfer rate obtained for the counter-current plug-flow model for both phases in the case of infinite contact surface. Normalized efficiency has several advantages over the previously defined efficiencies: the range of normalized efficiency is 0―1; normalized efficiency values for gas and liquid phases are equal. Furthermore, normalized efficiency can be easily used for determining the required number of trays in mass-transfer operations or for estimating the overall column efficiency. The usage of normalized efficiency does not raise any dilemma about the interpretation of enperimentally obtained results for trays working in distillation and sorption columns. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239059
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7437-7444[article] Normalized efficiency for stagewise operations [texte imprimé] / Branislav M. Jacimovic, Auteur ; Srbislav B. Genic, Auteur . - 2011 . - pp. 7437-7444.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7437-7444
Mots-clés : Stagewise operations Résumé : Tray efficiency in gas-liquid operations is a widely discussed theme, and the shortcomings of Murphree's, Hausen's, Standart's, and Holland's efficiencies are well-known. The new parameter "normalized efficiency" is defined as the ratio of the real tray mass transfer rate and theoretically maximal mass transfer rate obtained for the counter-current plug-flow model for both phases in the case of infinite contact surface. Normalized efficiency has several advantages over the previously defined efficiencies: the range of normalized efficiency is 0―1; normalized efficiency values for gas and liquid phases are equal. Furthermore, normalized efficiency can be easily used for determining the required number of trays in mass-transfer operations or for estimating the overall column efficiency. The usage of normalized efficiency does not raise any dilemma about the interpretation of enperimentally obtained results for trays working in distillation and sorption columns. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239059 Exemplaires
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Titre : Tray efficiency versus stripping factor Type de document : texte imprimé Auteurs : Branislav M. Jacimovic, Auteur ; Srbislav B. Genic, Auteur Année de publication : 2011 Article en page(s) : pp. 7445-7451 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Stripping Plate column efficiency Résumé : Estimation of the tray (plate) efficiency is the basis of trayed column design. A newly introduced parameter "normalized efficiency" (η) is compared to the stripping factor (λ) in order to derive a correlation which can be useful in engineering practice. The proposed correlation is based on the numerous data gathered from various literature sources describing distillation, absorption, and stripping (desorption) columns and covering sieve, tunnel, bubble-cup, uniflux, and jet trays, in the range λ = 0.0391―2196. The final form of this correlation is with correlation ratio Θ = 0.883 and standard deviation Δav = 13.1%. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239060
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7445-7451[article] Tray efficiency versus stripping factor [texte imprimé] / Branislav M. Jacimovic, Auteur ; Srbislav B. Genic, Auteur . - 2011 . - pp. 7445-7451.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7445-7451
Mots-clés : Stripping Plate column efficiency Résumé : Estimation of the tray (plate) efficiency is the basis of trayed column design. A newly introduced parameter "normalized efficiency" (η) is compared to the stripping factor (λ) in order to derive a correlation which can be useful in engineering practice. The proposed correlation is based on the numerous data gathered from various literature sources describing distillation, absorption, and stripping (desorption) columns and covering sieve, tunnel, bubble-cup, uniflux, and jet trays, in the range λ = 0.0391―2196. The final form of this correlation is with correlation ratio Θ = 0.883 and standard deviation Δav = 13.1%. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239060 Exemplaires
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Titre : Purification and recovery of curcuminoids from curcuma ionga extract by reactive sorption using polymeric adsorbent carrying tertiary amine functional group Type de document : texte imprimé Auteurs : Anil R. Patil, Auteur ; Vilas G. Gaikar, Auteur Année de publication : 2011 Article en page(s) : pp. 7452–7461 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Sorption Extract Purification Résumé : A novel reactive sorption method has been devised for purification of curcuminoids from a complex multicomponent turmeric extract using a weakly basic polymer as a selective adsorbent. The experimental results are further supported by molecular simulation to quantify the specific interactions of curcumins with tertiary amine group of the adsorbent in the presence of organic solvents of different polarities. Both experimental data and theoretical calculations showed that methanol was the best solvent for adsorption, while acetone was useful for desorbing curcumins from the adsorbed state. Dynamic adsorption and particularly desorption operations showed a significant effect of intraparticle diffusivity limitations on the rate of adsorption and effective utilization of the adsorbent. However, increased temperature and exposure to ultrasound could increase desorption of curcumins from the column. Nearly 50% and 85% of curcuminoids are desorbed from the bed with acetone alone and with simultaneous exposure to ultrasound, respectively. After a single adsorption and desorption cycle, the purity of recovered curcuminoids increases to 98%. Individual components of the extract and the purified curcuminoid product were characterized by liquid chromatography―mass spectrometry. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239061
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7452–7461[article] Purification and recovery of curcuminoids from curcuma ionga extract by reactive sorption using polymeric adsorbent carrying tertiary amine functional group [texte imprimé] / Anil R. Patil, Auteur ; Vilas G. Gaikar, Auteur . - 2011 . - pp. 7452–7461.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7452–7461
Mots-clés : Sorption Extract Purification Résumé : A novel reactive sorption method has been devised for purification of curcuminoids from a complex multicomponent turmeric extract using a weakly basic polymer as a selective adsorbent. The experimental results are further supported by molecular simulation to quantify the specific interactions of curcumins with tertiary amine group of the adsorbent in the presence of organic solvents of different polarities. Both experimental data and theoretical calculations showed that methanol was the best solvent for adsorption, while acetone was useful for desorbing curcumins from the adsorbed state. Dynamic adsorption and particularly desorption operations showed a significant effect of intraparticle diffusivity limitations on the rate of adsorption and effective utilization of the adsorbent. However, increased temperature and exposure to ultrasound could increase desorption of curcumins from the column. Nearly 50% and 85% of curcuminoids are desorbed from the bed with acetone alone and with simultaneous exposure to ultrasound, respectively. After a single adsorption and desorption cycle, the purity of recovered curcuminoids increases to 98%. Individual components of the extract and the purified curcuminoid product were characterized by liquid chromatography―mass spectrometry. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239061 Exemplaires
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Titre : Approximate calculation of distillation boundaries for ternary azeotropic systems Type de document : texte imprimé Auteurs : Juan A. Reyes-Labarta, Auteur ; M. D. Serrano, Auteur ; R. Velasco, Auteur Année de publication : 2011 Article en page(s) : pp. 7462-7466 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Azeotropic mixture Distillation Résumé : As it is very well known, especially when dealing with the simulation and design of distillation processes and columns, it is essential to know the limitations defined by the vapor-liquid equilibrium (VLE) of the system under consideration. This paper uses a new straightforward algorithm to calculate and completely define the distillation boundaries in different ternary azeotropic systems. The method allows, using cubic splines, the calculation of different distillation trajectories and the selection of those corresponding to the searched distillation boundaries. The algorithm has been applied to eight ternary liquid―vapor systems to test its validity. To simplify the optimization process, an empirical but very accurate equation has been used to calculate the VLE. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239062
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7462-7466[article] Approximate calculation of distillation boundaries for ternary azeotropic systems [texte imprimé] / Juan A. Reyes-Labarta, Auteur ; M. D. Serrano, Auteur ; R. Velasco, Auteur . - 2011 . - pp. 7462-7466.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7462-7466
Mots-clés : Azeotropic mixture Distillation Résumé : As it is very well known, especially when dealing with the simulation and design of distillation processes and columns, it is essential to know the limitations defined by the vapor-liquid equilibrium (VLE) of the system under consideration. This paper uses a new straightforward algorithm to calculate and completely define the distillation boundaries in different ternary azeotropic systems. The method allows, using cubic splines, the calculation of different distillation trajectories and the selection of those corresponding to the searched distillation boundaries. The algorithm has been applied to eight ternary liquid―vapor systems to test its validity. To simplify the optimization process, an empirical but very accurate equation has been used to calculate the VLE. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239062 Exemplaires
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Titre : Modeling liquid–liquid and liquid–vapor equilibria of binary systems containing water with an alkane, an aromatic hydrocarbon, an alcohol or a gas (Methane, Ethane, CO2 or H2S), using group contribution polar perturbed-chain statistical associating fluid theory Type de document : texte imprimé Auteurs : Dong Nguyen-Huynh, Auteur ; Jean-Charles de Hemptinne, Auteur ; Rafael Lugo, Auteur Année de publication : 2011 Article en page(s) : pp. 7467-7483 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Multiphase equilibrium Hydrogen sulfides Carbon dioxide Binary system Liquid liquid vapor Modeling Résumé : The present paper proposes to use the group contribution (GC) polar perturbed-chain-statistical associating fluid theory (GC-PPC-SAFT) equation of state (EoS), that has already been used with success on various organic mixtures, and extend it to model simultaneously the liquid―liquid equilibrium (LLE) and vapor-liquid equilibrium (VLE) of hydrocarbons + water systems, in wide ranges of pressure and temperature. Mixtures of water with aliphatics, aromatics, alcohols, carbon dioxide, and hydrogen sulfide have been investigated. Pure water is assumed associative (according to the 4C association scheme) and dipolar; the aromatic compounds are quadrupolar. Alcohols are autoassociative with a 3B association scheme. A cross-association between water and alcohols or H2S is taken into account. Cross association between water and other polar molecules (CO2 or aromatic molecules) was also taken into account explicitly. Only one set of cross association parameters εcross/k and κcross values were used for all the water + aromatic mixtures considered here. εcross/k was adjusted on experimental data, whereas κcross is set to the value found for pure water. For each system, the same binary interaction parameter kij was used for simultaneous modeling LLE and VLE. This parameter was correlated to pseudo-ionization energy parameters for pure compounds through London's dispersion force theory, and reused from previous works [Nguyen-Huynh, D.; Passarello, J.P.; Tobaly, P.; de Hemptinne, J.C. Ind. Eng. Chem. Res., 2008, 47, 8847―8858]. For pure water, the average deviation on vapor pressure is 3.36% and that on volume 4.74%. The water solubility in the organic phase is very well reproduced (AAD = 7.5% for water + n-hexane), but most importantly the hydrocarbon solubility in water shows an overall AAD of 30% which is very small considering the very low solubility values. Trends are similar for all families as tabulated in the manuscript and detailed in the Supporting Information. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239063
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7467-7483[article] Modeling liquid–liquid and liquid–vapor equilibria of binary systems containing water with an alkane, an aromatic hydrocarbon, an alcohol or a gas (Methane, Ethane, CO2 or H2S), using group contribution polar perturbed-chain statistical associating fluid theory [texte imprimé] / Dong Nguyen-Huynh, Auteur ; Jean-Charles de Hemptinne, Auteur ; Rafael Lugo, Auteur . - 2011 . - pp. 7467-7483.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7467-7483
Mots-clés : Multiphase equilibrium Hydrogen sulfides Carbon dioxide Binary system Liquid liquid vapor Modeling Résumé : The present paper proposes to use the group contribution (GC) polar perturbed-chain-statistical associating fluid theory (GC-PPC-SAFT) equation of state (EoS), that has already been used with success on various organic mixtures, and extend it to model simultaneously the liquid―liquid equilibrium (LLE) and vapor-liquid equilibrium (VLE) of hydrocarbons + water systems, in wide ranges of pressure and temperature. Mixtures of water with aliphatics, aromatics, alcohols, carbon dioxide, and hydrogen sulfide have been investigated. Pure water is assumed associative (according to the 4C association scheme) and dipolar; the aromatic compounds are quadrupolar. Alcohols are autoassociative with a 3B association scheme. A cross-association between water and alcohols or H2S is taken into account. Cross association between water and other polar molecules (CO2 or aromatic molecules) was also taken into account explicitly. Only one set of cross association parameters εcross/k and κcross values were used for all the water + aromatic mixtures considered here. εcross/k was adjusted on experimental data, whereas κcross is set to the value found for pure water. For each system, the same binary interaction parameter kij was used for simultaneous modeling LLE and VLE. This parameter was correlated to pseudo-ionization energy parameters for pure compounds through London's dispersion force theory, and reused from previous works [Nguyen-Huynh, D.; Passarello, J.P.; Tobaly, P.; de Hemptinne, J.C. Ind. Eng. Chem. Res., 2008, 47, 8847―8858]. For pure water, the average deviation on vapor pressure is 3.36% and that on volume 4.74%. The water solubility in the organic phase is very well reproduced (AAD = 7.5% for water + n-hexane), but most importantly the hydrocarbon solubility in water shows an overall AAD of 30% which is very small considering the very low solubility values. Trends are similar for all families as tabulated in the manuscript and detailed in the Supporting Information. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239063 Exemplaires
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Titre : Impacts of cocontaminants on the performances of perchlorate and nitrate specialty ion-exchange resins Type de document : texte imprimé Auteurs : Behrang Pakzadeh, Auteur ; Jacimaria R. Batista, Auteur Année de publication : 2011 Article en page(s) : pp. 7484-7493 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ion exchange resin Résumé : The influence ofanionic inorganic cocontaminants including nitrate, Cr(VI), Se(VI), and As(V) on the application of nitrate and perchlorate specialty resins in water treatment was investigated. It was found that nitrate can be removed from waters using perchlorate specialty resins, but the resin is poorly regenerated. Perchlorate was not easily removed from either nitrate or perchlorate specialty resins. Simultaneous removal of nitrate and Cr(VI) was optimal when using nitrate specialty resin. Perchlorate/ nitrate specialty resins were inefficient in removing As(V), but can exchange Cr(VI) or Se(VI). A major concern is the presence of high levels of Cr(VI), As(V), or Se(VI) in the waste brine, which affects waste brine disposal and cost. Perchlorate specialty resins showed very low run length for Cr(VI), As(V), or Se(VI). Nitrate specialty resins were very efficient in removing Cr(VI), and they can be easily regenerated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239064
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7484-7493[article] Impacts of cocontaminants on the performances of perchlorate and nitrate specialty ion-exchange resins [texte imprimé] / Behrang Pakzadeh, Auteur ; Jacimaria R. Batista, Auteur . - 2011 . - pp. 7484-7493.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7484-7493
Mots-clés : Ion exchange resin Résumé : The influence ofanionic inorganic cocontaminants including nitrate, Cr(VI), Se(VI), and As(V) on the application of nitrate and perchlorate specialty resins in water treatment was investigated. It was found that nitrate can be removed from waters using perchlorate specialty resins, but the resin is poorly regenerated. Perchlorate was not easily removed from either nitrate or perchlorate specialty resins. Simultaneous removal of nitrate and Cr(VI) was optimal when using nitrate specialty resin. Perchlorate/ nitrate specialty resins were inefficient in removing As(V), but can exchange Cr(VI) or Se(VI). A major concern is the presence of high levels of Cr(VI), As(V), or Se(VI) in the waste brine, which affects waste brine disposal and cost. Perchlorate specialty resins showed very low run length for Cr(VI), As(V), or Se(VI). Nitrate specialty resins were very efficient in removing Cr(VI), and they can be easily regenerated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239064 Exemplaires
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Titre : Ion-exchange membrane electrodialysis for saline water desalination and its application to seawater concentration Type de document : texte imprimé Auteurs : Yoshinobu Tanaka, Auteur Année de publication : 2011 Article en page(s) : pp. 7494-7503 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Membrane separation Seawater Desalination Electrodialysis Ion exchange membrane Résumé : Membrane pair characteristics of commercially available ion-exchange membranes are measured by changing current density and seawater temperature supplied to the electrodialyzer. The hydraulic permeabilities (leading parameter) for three types of commercially available membranes are almost the same, and their averages are expressed by the empirical function of temperature. Hydraulic osmosis is predominant at lower current density and electro-osmosis is predominant at larger current density. The influence of temperature and salt concentration on the physical properties of saline water, such as solution density, specific conductance, and NaCl activity coefficient, is expressed by empirical equations. Ionic constituents in a concentrated solution are expressed by empirical equations. Electric current screening ratio of a spacer is defined and calculated. Direct current electric resistance of a membrane pair is calculated, and it is predominant over that of a desalting cell and a concentrating cell. It is necessary to decrease electric resistance of an ion-exchange membrane for reducing energy consumption in a salt manufacturing process. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239065
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7494-7503[article] Ion-exchange membrane electrodialysis for saline water desalination and its application to seawater concentration [texte imprimé] / Yoshinobu Tanaka, Auteur . - 2011 . - pp. 7494-7503.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7494-7503
Mots-clés : Membrane separation Seawater Desalination Electrodialysis Ion exchange membrane Résumé : Membrane pair characteristics of commercially available ion-exchange membranes are measured by changing current density and seawater temperature supplied to the electrodialyzer. The hydraulic permeabilities (leading parameter) for three types of commercially available membranes are almost the same, and their averages are expressed by the empirical function of temperature. Hydraulic osmosis is predominant at lower current density and electro-osmosis is predominant at larger current density. The influence of temperature and salt concentration on the physical properties of saline water, such as solution density, specific conductance, and NaCl activity coefficient, is expressed by empirical equations. Ionic constituents in a concentrated solution are expressed by empirical equations. Electric current screening ratio of a spacer is defined and calculated. Direct current electric resistance of a membrane pair is calculated, and it is predominant over that of a desalting cell and a concentrating cell. It is necessary to decrease electric resistance of an ion-exchange membrane for reducing energy consumption in a salt manufacturing process. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239065 Exemplaires
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Titre : Model development and experimental verification of liquid desiccant drying of gelcast α-alumina ceramic objects Type de document : texte imprimé Auteurs : Aboulfazl Barati, Auteur ; Hamid Reza Norouzi, Auteur ; Sedighe Khaleghi Rostamkolaei, Auteur Année de publication : 2011 Article en page(s) : pp. 7504-7512 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ceramic materials Drying Modeling Résumé : In this work, the effect of molecular weight of poly(ethylene glycol) (PEG) on the drying rate of gelcast α-alumina objects was investigated. Moreover, the effect of the sample shape (cylindrical, spherical, and slab-like shapes) and various effective thicknesses of these shapes were studied. Thermogravimetric analysis and differential scanning calorimetry were used in order to study the diffusion of PEG in the porous network structure. A general model was proposed for drying of green objects in liquid desiccant solutions. The results show that using higher average molecular weight of PEG increases the drying rate. PEG chains diffuse into the network during the drying process and the amount of diffused PEG decreases as the molecular weight of polymer increases and the concentration of solution decreases. The proposed model successfully predicts the drying rate and the dynamic volume change of ceramic objects in various desiccant solutions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239066
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7504-7512[article] Model development and experimental verification of liquid desiccant drying of gelcast α-alumina ceramic objects [texte imprimé] / Aboulfazl Barati, Auteur ; Hamid Reza Norouzi, Auteur ; Sedighe Khaleghi Rostamkolaei, Auteur . - 2011 . - pp. 7504-7512.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7504-7512
Mots-clés : Ceramic materials Drying Modeling Résumé : In this work, the effect of molecular weight of poly(ethylene glycol) (PEG) on the drying rate of gelcast α-alumina objects was investigated. Moreover, the effect of the sample shape (cylindrical, spherical, and slab-like shapes) and various effective thicknesses of these shapes were studied. Thermogravimetric analysis and differential scanning calorimetry were used in order to study the diffusion of PEG in the porous network structure. A general model was proposed for drying of green objects in liquid desiccant solutions. The results show that using higher average molecular weight of PEG increases the drying rate. PEG chains diffuse into the network during the drying process and the amount of diffused PEG decreases as the molecular weight of polymer increases and the concentration of solution decreases. The proposed model successfully predicts the drying rate and the dynamic volume change of ceramic objects in various desiccant solutions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239066 Exemplaires
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Titre : Selective separation of wood components based on hansen’s theory of solubility Type de document : texte imprimé Auteurs : Huaming Yu, Auteur ; Jia Hu, Auteur ; Jie Chang, Auteur Année de publication : 2011 Article en page(s) : pp. 7513-7519 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solubility Wood Résumé : A new method for selective separation of wood components is presented. Based on Hansen's theory of solubility, ionic liquid (IL) 1-butyl-3-methylimidazolium bromine ([Bmin]Br) was mixed with aqueous ethanol HBr the acid catalyst in the degradation of wood components, was found to form in situ by ion exchange between IL and organic acid. The hydrogen bonding capacity of the mixture was enhanced as the presence of IL, which led to the promotion of the solubilization of lignin and other products from carbohydrates hydrolysis. The data showed that, variations of the IL concentration caused cellulose to be separated from pine wood with a purity of more than 94%, or to be hydrolyzed and converted into saccharides together with hemicellulose. Because of the complete hydrolysis of hemicellulose, the cross-linked matrix oflignin and hemicellulose was destroyed, which led to the isolation of lignin with a high purity of about 93%. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239067
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7513-7519[article] Selective separation of wood components based on hansen’s theory of solubility [texte imprimé] / Huaming Yu, Auteur ; Jia Hu, Auteur ; Jie Chang, Auteur . - 2011 . - pp. 7513-7519.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7513-7519
Mots-clés : Solubility Wood Résumé : A new method for selective separation of wood components is presented. Based on Hansen's theory of solubility, ionic liquid (IL) 1-butyl-3-methylimidazolium bromine ([Bmin]Br) was mixed with aqueous ethanol HBr the acid catalyst in the degradation of wood components, was found to form in situ by ion exchange between IL and organic acid. The hydrogen bonding capacity of the mixture was enhanced as the presence of IL, which led to the promotion of the solubilization of lignin and other products from carbohydrates hydrolysis. The data showed that, variations of the IL concentration caused cellulose to be separated from pine wood with a purity of more than 94%, or to be hydrolyzed and converted into saccharides together with hemicellulose. Because of the complete hydrolysis of hemicellulose, the cross-linked matrix oflignin and hemicellulose was destroyed, which led to the isolation of lignin with a high purity of about 93%. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239067 Exemplaires
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Titre : Influence of triglycerides on fouling of glycerol–water with ultrafiltration membranes Type de document : texte imprimé Auteurs : M. A. Indok Nurul Hasyimah, Auteur ; A.W. Mohammad, Auteur ; M. Markom, Auteur Année de publication : 2011 Article en page(s) : pp. 7520-7526 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Membrane separation Ultrafiltration Fouling Résumé : In the present study, the ability of two ultrafiltration (UF) polymeric membranes to clarify synthetic glycerin-rich solutions containing triglycerides (TGs) was evaluated. The membranes were made of poly(ether sulfone) (PES) and poly-(vinylidene fluoride) (PVDF) and had molecular-weight cutoff (MWCO) values of 25000 and 30000 Da, respectively. A commercial TG (RBD Palm Olein) was employed, and the effects of membrane surface chemistry and solution pH on the permeation flux and TG retention rate were studied. In glycerol-water mixtures containing TG, the contribution of the solute to fouling was more severe than that of fatty acid (FA), with lower permeation rates being shown. Furthermore, the present study revealed that the nature of the membrane and the pH of the solution have significant effects on the fouling potential and can be used to quantitatively determine the TG rejection rate. Moreover, PVDF membranes were found to provide higher fluxes and lower TG rejection rates (81%) than PES membranes (91%). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239068
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7520-7526[article] Influence of triglycerides on fouling of glycerol–water with ultrafiltration membranes [texte imprimé] / M. A. Indok Nurul Hasyimah, Auteur ; A.W. Mohammad, Auteur ; M. Markom, Auteur . - 2011 . - pp. 7520-7526.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7520-7526
Mots-clés : Membrane separation Ultrafiltration Fouling Résumé : In the present study, the ability of two ultrafiltration (UF) polymeric membranes to clarify synthetic glycerin-rich solutions containing triglycerides (TGs) was evaluated. The membranes were made of poly(ether sulfone) (PES) and poly-(vinylidene fluoride) (PVDF) and had molecular-weight cutoff (MWCO) values of 25000 and 30000 Da, respectively. A commercial TG (RBD Palm Olein) was employed, and the effects of membrane surface chemistry and solution pH on the permeation flux and TG retention rate were studied. In glycerol-water mixtures containing TG, the contribution of the solute to fouling was more severe than that of fatty acid (FA), with lower permeation rates being shown. Furthermore, the present study revealed that the nature of the membrane and the pH of the solution have significant effects on the fouling potential and can be used to quantitatively determine the TG rejection rate. Moreover, PVDF membranes were found to provide higher fluxes and lower TG rejection rates (81%) than PES membranes (91%). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239068 Exemplaires
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Titre : Desulfurization of model gasoline on modified bentonite Type de document : texte imprimé Auteurs : Xiao-lin Tang, Auteur ; Xuan Meng, Auteur ; Li Shi, Auteur Année de publication : 2011 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling Desulfurization Résumé : This work mainly involved the investigation of the adsorption of propylmercaptan (PM) on modified bentonite adsorbents. The adsorbents were prepared by loading it separately with Cu2+, Cu+, Fe3+, and MnO4―. In general, these bentonite adsorbents tested for sulfur adsorption capacity at breakthrough followed the order: KMnO4―bentonite > Cu(I)―bentonite > Cu(II)―bentonite > Fe(III)―bentonite. Several factors that influence the desulfurization capability, including loading and baking temperature, were investigated. The results of X-ray diffraction (XRD), nitrogen sorption (BET), thermal analysis (TGA), and Fourier transform infrared (FT-IR) spectroscopy showed that the ability of modified bentonite to adsorb PM depends strongly on its surface chemistry, particularly on the presence of basic oxygen-containing groups and acid content. The high sulfur capacities of KMnO4―bentonite and Fe(III)―bentonite were because of the powerful oxidization of MnO4― and Fe3+. The high sulfur capacities of Cu(I)―bentonite and Cu(II)―bentonite were due to π-complexation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239069
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011)[article] Desulfurization of model gasoline on modified bentonite [texte imprimé] / Xiao-lin Tang, Auteur ; Xuan Meng, Auteur ; Li Shi, Auteur . - 2011.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011)
Mots-clés : Modeling Desulfurization Résumé : This work mainly involved the investigation of the adsorption of propylmercaptan (PM) on modified bentonite adsorbents. The adsorbents were prepared by loading it separately with Cu2+, Cu+, Fe3+, and MnO4―. In general, these bentonite adsorbents tested for sulfur adsorption capacity at breakthrough followed the order: KMnO4―bentonite > Cu(I)―bentonite > Cu(II)―bentonite > Fe(III)―bentonite. Several factors that influence the desulfurization capability, including loading and baking temperature, were investigated. The results of X-ray diffraction (XRD), nitrogen sorption (BET), thermal analysis (TGA), and Fourier transform infrared (FT-IR) spectroscopy showed that the ability of modified bentonite to adsorb PM depends strongly on its surface chemistry, particularly on the presence of basic oxygen-containing groups and acid content. The high sulfur capacities of KMnO4―bentonite and Fe(III)―bentonite were because of the powerful oxidization of MnO4― and Fe3+. The high sulfur capacities of Cu(I)―bentonite and Cu(II)―bentonite were due to π-complexation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239069 Exemplaires
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Titre : Application of bifunctional ionic liquid extractants [A336][CA-12] and [A336][CA-100] to the lanthanum extraction and separation from rare earths in the chloride medium Type de document : texte imprimé Auteurs : Wei Wang, Auteur ; Hualing Yang, Auteur ; Hongmin Cui, Auteur Année de publication : 2011 Article en page(s) : pp. 7534-7541 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ionic liquid Résumé : In this Article, bifunctional ionic liquid extractants (Bif-ILEs) tricaprylmethylammonium sec-octylphenoxy acetic acid ([A366][CA-12]) and tricaprylmethylammonium sec-nonylphenoxy acetic acid ([A336][CA-100]) used for the rare earths (REs) extraction from the chloride medium have been investigated. The effects of extractants concentration, equilibrium pH of aqueous phase, salt concentration, temperature, etc., were discussed. The results show that the extraction ability of [A336][CA-12] and [A336] [CA-100] is higher than that of the conventional extractants sec-octylphenoxy acetic acid (CA-12), sec-nonylphenoxy acetic acid (CA-100), tri-n-butyl phosphate (TBP), and di-(1-metylheptyl)methyl phosphate (P350) under the same conditions. Furthermore, in the [A336][CA-12] system, the separation factors (β) between La(III) and other REs(III) are higher than 6.0, which indicates that [A336][CA-12] would be suitable for the La(III) extraction and separation. The extraction mechanism is also proposed, and there is a similar extraction tendency in both the [A336][CA-12] and the [A336][CA-100] systems. The loaded organic phase is easy to strip; more than 95% La(III) could be stripped from the loaded organic phase when the stripping acidity is higher than 0.03 M. The recycling experiments also indicate that the two extraction systems could be recycled without loss of the extraction efficiency. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239070
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7534-7541[article] Application of bifunctional ionic liquid extractants [A336][CA-12] and [A336][CA-100] to the lanthanum extraction and separation from rare earths in the chloride medium [texte imprimé] / Wei Wang, Auteur ; Hualing Yang, Auteur ; Hongmin Cui, Auteur . - 2011 . - pp. 7534-7541.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7534-7541
Mots-clés : Ionic liquid Résumé : In this Article, bifunctional ionic liquid extractants (Bif-ILEs) tricaprylmethylammonium sec-octylphenoxy acetic acid ([A366][CA-12]) and tricaprylmethylammonium sec-nonylphenoxy acetic acid ([A336][CA-100]) used for the rare earths (REs) extraction from the chloride medium have been investigated. The effects of extractants concentration, equilibrium pH of aqueous phase, salt concentration, temperature, etc., were discussed. The results show that the extraction ability of [A336][CA-12] and [A336] [CA-100] is higher than that of the conventional extractants sec-octylphenoxy acetic acid (CA-12), sec-nonylphenoxy acetic acid (CA-100), tri-n-butyl phosphate (TBP), and di-(1-metylheptyl)methyl phosphate (P350) under the same conditions. Furthermore, in the [A336][CA-12] system, the separation factors (β) between La(III) and other REs(III) are higher than 6.0, which indicates that [A336][CA-12] would be suitable for the La(III) extraction and separation. The extraction mechanism is also proposed, and there is a similar extraction tendency in both the [A336][CA-12] and the [A336][CA-100] systems. The loaded organic phase is easy to strip; more than 95% La(III) could be stripped from the loaded organic phase when the stripping acidity is higher than 0.03 M. The recycling experiments also indicate that the two extraction systems could be recycled without loss of the extraction efficiency. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239070 Exemplaires
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Titre : Comparison of two separation technologies applied in the manufacture of botanical injections : second ethanol precipitation and solvent extraction Type de document : texte imprimé Auteurs : Xingchu Gong, Auteur ; Shanshan Wang, Auteur ; Haibin Qu, Auteur Année de publication : 2011 Article en page(s) : pp. 7542-7548 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solvent extraction Résumé : A botanical injection is a special drug preparation with extremely high safety requirements. Therefore, many separation technologies, such as ethanol precipitation and liquid―liquid extraction, are applied in the manufacturing process of botanical injections to purify efficacy compounds and remove impurities. In this work, second ethanol precipitation and 1-butanol extraction were compared in the purification of the concentrated supernatant of danshen (the dried root of Salvia miltiorrhiza). These two separation technologies showed satisfactory recovery of phenolic compounds and similar removal of total protein. Liquid-liquid extraction removed more saccharides than second ethanol precipitation. Accordingly, the purity of phenolic compounds increased remarkably after liquid—liquid extraction. According to the characteristics of the two separation technologies, the combination technology of "ethanol precipitation + liquid―liquid extraction" showed more advantages in drug safety and product quality control than the combination technology of "ethanol precipitation + second ethanol precipitation". DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239071
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7542-7548[article] Comparison of two separation technologies applied in the manufacture of botanical injections : second ethanol precipitation and solvent extraction [texte imprimé] / Xingchu Gong, Auteur ; Shanshan Wang, Auteur ; Haibin Qu, Auteur . - 2011 . - pp. 7542-7548.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7542-7548
Mots-clés : Solvent extraction Résumé : A botanical injection is a special drug preparation with extremely high safety requirements. Therefore, many separation technologies, such as ethanol precipitation and liquid―liquid extraction, are applied in the manufacturing process of botanical injections to purify efficacy compounds and remove impurities. In this work, second ethanol precipitation and 1-butanol extraction were compared in the purification of the concentrated supernatant of danshen (the dried root of Salvia miltiorrhiza). These two separation technologies showed satisfactory recovery of phenolic compounds and similar removal of total protein. Liquid-liquid extraction removed more saccharides than second ethanol precipitation. Accordingly, the purity of phenolic compounds increased remarkably after liquid—liquid extraction. According to the characteristics of the two separation technologies, the combination technology of "ethanol precipitation + liquid―liquid extraction" showed more advantages in drug safety and product quality control than the combination technology of "ethanol precipitation + second ethanol precipitation". DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239071 Exemplaires
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Titre : Measurements of dispersion coefficients for FCC particles in a free board Type de document : texte imprimé Auteurs : Mayank Kashyap, Auteur ; Dimitri Gidaspow, Auteur Année de publication : 2011 Article en page(s) : pp. 7549-7565 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Dispersion Résumé : Particle image velocimetry (PIV) experiments were performed noninvasively in the Illinois Institute of Technology (IIT) two-dimensional circulating fluidized bed (2-D CFB) of fluid catalytic cracking (FCC) particles to measure laminar and turbulent properties, near the front wall in the z-direction; at the center and near the right and left walls in the x-direction; and in the free board region in the y-direction. The PIV measurements were obtained simultaneously in the y- and x-axes, using a charge-coupled device (CCD) camera, with the aid of a colored rotating transparency. The instantaneous and hydrodynamic velocities were used to obtain laminar properties for particles and turbulent properties for clusters, respectively. Laminar and turbulent properties for solids conveyed anisotropy. The y-axis solids velocities, power spectral densities of hydrodynamic velocities, and granular temperatures were highest at the center in the x-direction. The mixing was on the level of particles. The y- and x-axes solids dispersion coefficients were several orders of magnitude lower than the literature values, because of the low particle velocities in the free board. However, total granular temperatures were reasonably close to the literature values. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239072
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7549-7565[article] Measurements of dispersion coefficients for FCC particles in a free board [texte imprimé] / Mayank Kashyap, Auteur ; Dimitri Gidaspow, Auteur . - 2011 . - pp. 7549-7565.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7549-7565
Mots-clés : Dispersion Résumé : Particle image velocimetry (PIV) experiments were performed noninvasively in the Illinois Institute of Technology (IIT) two-dimensional circulating fluidized bed (2-D CFB) of fluid catalytic cracking (FCC) particles to measure laminar and turbulent properties, near the front wall in the z-direction; at the center and near the right and left walls in the x-direction; and in the free board region in the y-direction. The PIV measurements were obtained simultaneously in the y- and x-axes, using a charge-coupled device (CCD) camera, with the aid of a colored rotating transparency. The instantaneous and hydrodynamic velocities were used to obtain laminar properties for particles and turbulent properties for clusters, respectively. Laminar and turbulent properties for solids conveyed anisotropy. The y-axis solids velocities, power spectral densities of hydrodynamic velocities, and granular temperatures were highest at the center in the x-direction. The mixing was on the level of particles. The y- and x-axes solids dispersion coefficients were several orders of magnitude lower than the literature values, because of the low particle velocities in the free board. However, total granular temperatures were reasonably close to the literature values. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239072 Exemplaires
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Titre : Aggregation of hydrophobic substituents of poly(acrylate)s and their competitive complexation by β- and γ-cyclodextrins and their linked dimers in aqueous solution Type de document : texte imprimé Auteurs : Jie Wang, Auteur ; Li, L., Auteur ; Xuhong Guo, Auteur Année de publication : 2011 Article en page(s) : pp. 7566–7571 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrophobic substituents Aqueous solution Résumé : Competition between the aggregation of the octadecyl substituents of 3% randomly substituted poly(acrylate), PAAC18, and of the dodecyl substituents of the PAAC12 analogue, and their complexation by β-cyclodextrin, βCD, the linked dimers, N,N′-bis(6A-deoxy-6A-β-cyclodextrin)urea, 66βCD2ur, and N,N′-bis(6A-deoxy-6A-β-cyclodextrin)succinamide, 66βCD2su, and γ-cyclodextrin, γCD, and the analogous dimers 66γCD2ur and 66γCD2su have been studied in aqueous solution. The zero-shear viscosities of 3.3 wt % aqueous solutions of PAAC18, decreases in the presence of βCD, 66βCD2ur, 66βCD2su and γCD, is little changed in the presence of 66γCD2ur, and increases in the presence of 66γCD2su. In contrast, the zero-shear viscosities of aqueous solutions of PAAC12 increase in the presence of βCD, γCD, and their dimers but they are much less than those of the corresponding PAAC18 solutions. These macroscopic variations are due to host–guest complexation of the octadecyl and dodecyl substituents by βCD, γCD, and their dimers (as shown by 2D 1H NOESY NMR spectroscopy) competing with aggregation of the octadecyl and dodecyl substituents where differences in substituent length and cyclodextrin annular size are dominant factors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101705e
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7566–7571[article] Aggregation of hydrophobic substituents of poly(acrylate)s and their competitive complexation by β- and γ-cyclodextrins and their linked dimers in aqueous solution [texte imprimé] / Jie Wang, Auteur ; Li, L., Auteur ; Xuhong Guo, Auteur . - 2011 . - pp. 7566–7571.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7566–7571
Mots-clés : Hydrophobic substituents Aqueous solution Résumé : Competition between the aggregation of the octadecyl substituents of 3% randomly substituted poly(acrylate), PAAC18, and of the dodecyl substituents of the PAAC12 analogue, and their complexation by β-cyclodextrin, βCD, the linked dimers, N,N′-bis(6A-deoxy-6A-β-cyclodextrin)urea, 66βCD2ur, and N,N′-bis(6A-deoxy-6A-β-cyclodextrin)succinamide, 66βCD2su, and γ-cyclodextrin, γCD, and the analogous dimers 66γCD2ur and 66γCD2su have been studied in aqueous solution. The zero-shear viscosities of 3.3 wt % aqueous solutions of PAAC18, decreases in the presence of βCD, 66βCD2ur, 66βCD2su and γCD, is little changed in the presence of 66γCD2ur, and increases in the presence of 66γCD2su. In contrast, the zero-shear viscosities of aqueous solutions of PAAC12 increase in the presence of βCD, γCD, and their dimers but they are much less than those of the corresponding PAAC18 solutions. These macroscopic variations are due to host–guest complexation of the octadecyl and dodecyl substituents by βCD, γCD, and their dimers (as shown by 2D 1H NOESY NMR spectroscopy) competing with aggregation of the octadecyl and dodecyl substituents where differences in substituent length and cyclodextrin annular size are dominant factors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101705e Exemplaires
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Titre : Natural-fiber-reinforced composite treated with polyamines used as a support for the biodegradation and adsorption of toluene Type de document : texte imprimé Auteurs : Olga B. Gutiérrez Acosta, Auteur ; Vladimir A. Escobar Barrios, Auteur Année de publication : 2011 Article en page(s) : pp. 7572-7578 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Adsorption Biodegradation Composite material Résumé : The effect of the addition of two different polyamines into a foamed polymeric matrix with embedded natural fiber, to synthesize biocomposites, was studied during the degradation of toluene in batch experiments. The synthesized biocomposites were able to adsorb and facilitate the degradation of toluene by micro-organisms attached in the biocomposite matrix, at a high extent (80%), in a very short period of time (1 day). The adsorption and biodegradation processes were simultaneous. The molecular weight of polyamine had a slight effect on toluene adsorption, with the lower-molecular-weight polyamine being more favorable for the adsorption process. However, the biocomposites, with polyamines, were not able to carry out the complete biodegradation of toluene during the term of experiment (26 days). The absence of polyamine in the biocomposite had a dramatic effect on adsorption and biodegradation of toluene, improving both processes and showing a CO2 production that is 730% higher than biocomposites synthesized with polyamine, because of a toxic and/or barrier effect of polyamine. This biocomposite, synthesized without polyamine, was able to carry out the complete biodegradation during the first 5 days, and it had adequate cyclic performance. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239074
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7572-7578[article] Natural-fiber-reinforced composite treated with polyamines used as a support for the biodegradation and adsorption of toluene [texte imprimé] / Olga B. Gutiérrez Acosta, Auteur ; Vladimir A. Escobar Barrios, Auteur . - 2011 . - pp. 7572-7578.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7572-7578
Mots-clés : Adsorption Biodegradation Composite material Résumé : The effect of the addition of two different polyamines into a foamed polymeric matrix with embedded natural fiber, to synthesize biocomposites, was studied during the degradation of toluene in batch experiments. The synthesized biocomposites were able to adsorb and facilitate the degradation of toluene by micro-organisms attached in the biocomposite matrix, at a high extent (80%), in a very short period of time (1 day). The adsorption and biodegradation processes were simultaneous. The molecular weight of polyamine had a slight effect on toluene adsorption, with the lower-molecular-weight polyamine being more favorable for the adsorption process. However, the biocomposites, with polyamines, were not able to carry out the complete biodegradation of toluene during the term of experiment (26 days). The absence of polyamine in the biocomposite had a dramatic effect on adsorption and biodegradation of toluene, improving both processes and showing a CO2 production that is 730% higher than biocomposites synthesized with polyamine, because of a toxic and/or barrier effect of polyamine. This biocomposite, synthesized without polyamine, was able to carry out the complete biodegradation during the first 5 days, and it had adequate cyclic performance. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239074 Exemplaires
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Titre : Wet industrial flue gas desulfurization unit : model development and validation on industrial data Type de document : texte imprimé Auteurs : Thibaut Neveux, Auteur ; Yann Le Moullec, Auteur Année de publication : 2011 Article en page(s) : pp. 7579-7592 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling Desulfurization Flue gas purification Résumé : A dynamic model representing an industrial flue gas desulfurization (FGD) unit has been developed. The purpose of this model is to anticipate new SO2 emission legislation and to study some industrial issues such as the influence of a NH3 slip (from the selective catalytic reduction (SCR) unit) or fly ashes (from the electrostatic precipitator). Interaction between gas, liquid, and solid phases have been taken into account as well as a detailed liquid chemistry with the main acid-base equilibria and nonideal thermodynamic behavior. All major rate-controlling steps are modeled: limestone dissolution, sulfites oxidation, and precipitation of gypsum. The absorber hydrodynamic is modeled using an Euler―Euler approach to represent countercurrent flow between flue gas and droplets; the oxidation reactor is modeled as a bubble reactor. Fly ash collection and solid handling were also implemented in order to predict the gypsum quality. The model results were successfully compared with industrial data acquired in the Cordemais (France) coal-fired power plant. The average deviation between model results and industrial data is 5%. Most of the differences between model and experiment are probably due to the lack of a precise and actualized liquid composition to initialize the model. The transient response of the model represents correctly the behavior encounter in the Cordemais power plant. Some detailed transient response experiments are needed in order to definitely validate the transient response of the model. The main hypotheses and parameters of the model were discussed and tested in order to quantify their respective influence. It appears that the aerodynamic hypothesis in the gas inlet zone and the droplet size estimation were affecting very significantly the model results. None of the rate-based submodel can be neglected: liquid and gas transfer, absorption enhancement factor, sulfite oxidation, and limestone dissolution. The expression of SO2 absorption enhancement factor is crucial for the good representation of SO2 absorption; our simplified enhancement factor gives good results in terms of being representative of the holding tank pH. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239075
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7579-7592[article] Wet industrial flue gas desulfurization unit : model development and validation on industrial data [texte imprimé] / Thibaut Neveux, Auteur ; Yann Le Moullec, Auteur . - 2011 . - pp. 7579-7592.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7579-7592
Mots-clés : Modeling Desulfurization Flue gas purification Résumé : A dynamic model representing an industrial flue gas desulfurization (FGD) unit has been developed. The purpose of this model is to anticipate new SO2 emission legislation and to study some industrial issues such as the influence of a NH3 slip (from the selective catalytic reduction (SCR) unit) or fly ashes (from the electrostatic precipitator). Interaction between gas, liquid, and solid phases have been taken into account as well as a detailed liquid chemistry with the main acid-base equilibria and nonideal thermodynamic behavior. All major rate-controlling steps are modeled: limestone dissolution, sulfites oxidation, and precipitation of gypsum. The absorber hydrodynamic is modeled using an Euler―Euler approach to represent countercurrent flow between flue gas and droplets; the oxidation reactor is modeled as a bubble reactor. Fly ash collection and solid handling were also implemented in order to predict the gypsum quality. The model results were successfully compared with industrial data acquired in the Cordemais (France) coal-fired power plant. The average deviation between model results and industrial data is 5%. Most of the differences between model and experiment are probably due to the lack of a precise and actualized liquid composition to initialize the model. The transient response of the model represents correctly the behavior encounter in the Cordemais power plant. Some detailed transient response experiments are needed in order to definitely validate the transient response of the model. The main hypotheses and parameters of the model were discussed and tested in order to quantify their respective influence. It appears that the aerodynamic hypothesis in the gas inlet zone and the droplet size estimation were affecting very significantly the model results. None of the rate-based submodel can be neglected: liquid and gas transfer, absorption enhancement factor, sulfite oxidation, and limestone dissolution. The expression of SO2 absorption enhancement factor is crucial for the good representation of SO2 absorption; our simplified enhancement factor gives good results in terms of being representative of the holding tank pH. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239075 Exemplaires
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Titre : Study on the drag of a cylinder-shaped particle in steady upward gas flow Type de document : texte imprimé Auteurs : Bing Ren, Auteur ; Wenqi Zhong, Auteur ; Baosheng Jin, Auteur Année de publication : 2011 Article en page(s) : pp. 7593-7600 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gas flow Drag Résumé : Studies on the drag of 28 kinds of cylinder-shaped particles with different sizes and materials were experimentally carried out in steady upward gas flow. The drags were determined by high-resolution digital image processing. Two charge-coupled devices with different frame rates were employed to record the particle movements during experimental investigations. The effects of particle properties (length, diameter, density, and sphericity) and operating conditions (gas velocity and particle Reynolds number) on drag coefficients of single falling cylinder have been systematically tested. The results showed that the drag coefficient first declines sharply and then gradually with increasing particle Reynolds number; finally, it can reach a constant level if the Reynolds number is large enough to exceed a certain value. It was found that the drag coefficient is significantly dependent on particle shape and size for a fixed particle Reynolds number. It increases with increasing particle length and density but decreases with increasing particle diameter and sphericity. In addition, the usability of correlations in publications for predicting the drag coefficient was evaluated by comparing our experimental data. A new correlation considering the effect of particle size, shape, orientation, and density was proposed for predicting the drag coefficient for cylinders, which was in satisfactory agreement with the present experiments and some published experimental results. The correlation is helpful for predicting the drag coefficient for cylinders in ranges of the particle Reynolds number Rep = 500―10 500, flatness ratio da/dv = 0.95―1.28, and sphericity ϕ = 0.70―0.87. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239076
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7593-7600[article] Study on the drag of a cylinder-shaped particle in steady upward gas flow [texte imprimé] / Bing Ren, Auteur ; Wenqi Zhong, Auteur ; Baosheng Jin, Auteur . - 2011 . - pp. 7593-7600.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7593-7600
Mots-clés : Gas flow Drag Résumé : Studies on the drag of 28 kinds of cylinder-shaped particles with different sizes and materials were experimentally carried out in steady upward gas flow. The drags were determined by high-resolution digital image processing. Two charge-coupled devices with different frame rates were employed to record the particle movements during experimental investigations. The effects of particle properties (length, diameter, density, and sphericity) and operating conditions (gas velocity and particle Reynolds number) on drag coefficients of single falling cylinder have been systematically tested. The results showed that the drag coefficient first declines sharply and then gradually with increasing particle Reynolds number; finally, it can reach a constant level if the Reynolds number is large enough to exceed a certain value. It was found that the drag coefficient is significantly dependent on particle shape and size for a fixed particle Reynolds number. It increases with increasing particle length and density but decreases with increasing particle diameter and sphericity. In addition, the usability of correlations in publications for predicting the drag coefficient was evaluated by comparing our experimental data. A new correlation considering the effect of particle size, shape, orientation, and density was proposed for predicting the drag coefficient for cylinders, which was in satisfactory agreement with the present experiments and some published experimental results. The correlation is helpful for predicting the drag coefficient for cylinders in ranges of the particle Reynolds number Rep = 500―10 500, flatness ratio da/dv = 0.95―1.28, and sphericity ϕ = 0.70―0.87. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239076 Exemplaires
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Titre : State of the art of friendly “Green” scale control inhibitors : a review article Type de document : texte imprimé Auteurs : David Hasson, Auteur ; Hilla Shemer, Auteur ; Alexander Sher, Auteur Année de publication : 2011 Article en page(s) : pp. 7601-7607 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : State of the art Résumé : Scale deposition is a difficulty encountered with water containing ions of sparingly soluble salts. A widely used technique for controlling scale deposition is by dosage of an antiscalant. Large quantities of polymeric scale inhibitors are used for scale control in cooling water systems, water desalination processes, and oil field operations. Like most conventional polymers, scale inhibitors are built for long existence and persist for many years after their disposal. Increasing environmental concern and discharge limitations have caused scale-inhibitor chemistry to move toward "green antiscalants" that readily biodegrade, have low mobility for minimum environmental impact, and are cost-effective. This review summarizes efforts to develop cost-effective ecologically benign scale inhibitors. Currently, the most promising green scale inhibitors are based on poly(aspartic acid). However, field operation data are very limited, and widespread use of poly(aspartic acid) scale inhibitors awaits field operation experience. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239077
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7601-7607[article] State of the art of friendly “Green” scale control inhibitors : a review article [texte imprimé] / David Hasson, Auteur ; Hilla Shemer, Auteur ; Alexander Sher, Auteur . - 2011 . - pp. 7601-7607.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7601-7607
Mots-clés : State of the art Résumé : Scale deposition is a difficulty encountered with water containing ions of sparingly soluble salts. A widely used technique for controlling scale deposition is by dosage of an antiscalant. Large quantities of polymeric scale inhibitors are used for scale control in cooling water systems, water desalination processes, and oil field operations. Like most conventional polymers, scale inhibitors are built for long existence and persist for many years after their disposal. Increasing environmental concern and discharge limitations have caused scale-inhibitor chemistry to move toward "green antiscalants" that readily biodegrade, have low mobility for minimum environmental impact, and are cost-effective. This review summarizes efforts to develop cost-effective ecologically benign scale inhibitors. Currently, the most promising green scale inhibitors are based on poly(aspartic acid). However, field operation data are very limited, and widespread use of poly(aspartic acid) scale inhibitors awaits field operation experience. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239077 Exemplaires
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Titre : A Complete heatline analysis on visualization of heat flow and thermal mixing during mixed convection in a square cavity with various wall heating Type de document : texte imprimé Auteurs : Tanmay Basak, Auteur ; P. V. Krishna Pradeep, Auteur ; S. Roy, Auteur Année de publication : 2011 Article en page(s) : pp. 7608-7630 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Heat transfer Heating Convection Mixing flow Résumé : A wide range of applications involving mixed-convection studies can be found in various engineering processes such as thermal discharge of water bodies, float glass production, heat exchangers, nuclear reactors, and crystallization process. The present study focuses on understanding the thermal mixing scenarios for mixed-convection lid-driven flow in a square cavity using heatlines. Thermal mixing is analyzed for four different thermal boundary conditions, and heat flow patterns in mixed convection are analyzed using Bejan's heatlines concept for wide ranges of parameters (Pr = 0.015―7.2, Re = 1―100, and Gr = 103―105, where Pr, Re, and Gr denote the Prandtl, Reynolds, and Grashof numbers, respectively). The results indicate that, at low Prvalues (Pr = 0.015), the transport is conduction-dominant irrespective of the values of Gr and Re. The trends of heatlines and streamlines are identical near the core for high-Re cases. A single circulation cell was observed in the streamlines for any Pr ≥ 0.7 at high Re and low Gr values for uniform heating of the bottom surface with cold side walls. It was observed that thermal mixing increased significantly with subsequent rises in Gr for high-Pr fluids. Patterns of heatlines and multiple circulation cells of heatlines were found to lead to enhanced thermal mixing, with the thermal boundary layer much compressed toward the walls for linearly heated side walls. The heat-transfer rates along the walls are illustrated by the local Nusselt number distribution based on gradients of heatfunctions for the first time in this work. Nusselt numbers with infinitely large magnitudes were observed at hot―old junctions, illustrating high heat-transfer rates. An oscillatory distribution in the local heatfunction rate was observed as a result of sinusoidal heating of the bottom surface for high-Pr fluids. Negative heat-transfer rates or local Nusselt numbers were observed along the side walls when side wall(s) was/were linearly heated, as explained based on negative heatfunction gradients. Also, the effect of Gr on the local and average Nusselt numbers in different cases can be adequately explained based on heatlines. Dense heatlines signifying higher overall heat-transfer rates along the bottom surface and side walls were observed for uniform bottom surface heating, whereas lower heat-transfer rates were observed for sinusoidal heating. Nonmonotonic distributions in overall heat-transfer rates along the bottom surface and left wall were observed when both walls were linearly heated, whereas a smooth and exponential increase was observed when the right wall was isothermally cooled. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239078
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7608-7630[article] A Complete heatline analysis on visualization of heat flow and thermal mixing during mixed convection in a square cavity with various wall heating [texte imprimé] / Tanmay Basak, Auteur ; P. V. Krishna Pradeep, Auteur ; S. Roy, Auteur . - 2011 . - pp. 7608-7630.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7608-7630
Mots-clés : Heat transfer Heating Convection Mixing flow Résumé : A wide range of applications involving mixed-convection studies can be found in various engineering processes such as thermal discharge of water bodies, float glass production, heat exchangers, nuclear reactors, and crystallization process. The present study focuses on understanding the thermal mixing scenarios for mixed-convection lid-driven flow in a square cavity using heatlines. Thermal mixing is analyzed for four different thermal boundary conditions, and heat flow patterns in mixed convection are analyzed using Bejan's heatlines concept for wide ranges of parameters (Pr = 0.015―7.2, Re = 1―100, and Gr = 103―105, where Pr, Re, and Gr denote the Prandtl, Reynolds, and Grashof numbers, respectively). The results indicate that, at low Prvalues (Pr = 0.015), the transport is conduction-dominant irrespective of the values of Gr and Re. The trends of heatlines and streamlines are identical near the core for high-Re cases. A single circulation cell was observed in the streamlines for any Pr ≥ 0.7 at high Re and low Gr values for uniform heating of the bottom surface with cold side walls. It was observed that thermal mixing increased significantly with subsequent rises in Gr for high-Pr fluids. Patterns of heatlines and multiple circulation cells of heatlines were found to lead to enhanced thermal mixing, with the thermal boundary layer much compressed toward the walls for linearly heated side walls. The heat-transfer rates along the walls are illustrated by the local Nusselt number distribution based on gradients of heatfunctions for the first time in this work. Nusselt numbers with infinitely large magnitudes were observed at hot―old junctions, illustrating high heat-transfer rates. An oscillatory distribution in the local heatfunction rate was observed as a result of sinusoidal heating of the bottom surface for high-Pr fluids. Negative heat-transfer rates or local Nusselt numbers were observed along the side walls when side wall(s) was/were linearly heated, as explained based on negative heatfunction gradients. Also, the effect of Gr on the local and average Nusselt numbers in different cases can be adequately explained based on heatlines. Dense heatlines signifying higher overall heat-transfer rates along the bottom surface and side walls were observed for uniform bottom surface heating, whereas lower heat-transfer rates were observed for sinusoidal heating. Nonmonotonic distributions in overall heat-transfer rates along the bottom surface and left wall were observed when both walls were linearly heated, whereas a smooth and exponential increase was observed when the right wall was isothermally cooled. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239078 Exemplaires
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Titre : Sorption and swelling measurements of CO2 and N2 on polyol for their use as blowing agents in a new PU foaming process device Type de document : texte imprimé Auteurs : Tobias Fieback, Auteur ; Walter Michaeli, Auteur ; Simon Latz, Auteur Année de publication : 2011 Article en page(s) : pp. 7631-7636 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Foaming Swelling Sorption Résumé : From an industrial point of view, polymeric foams are of great importance because of their good mechanical and thermal properties and their low weight. Among them, polyurethane foams are the most versatile and, thus, the most consumed. Traditional methods for polyurethane foaming have the disadvantages of negative spin-offs due to chemical foaming reactions or use offlammable gases. A new foaming process device has been developed to overcome these drawbacks by performing physical foaming with safe blowing gases. In relation to this setup, the sorption of a polyol provided by Bayer MaterialScience, in the presence of pure N2 and pure CO2, was examined at three isotherms at 293, 303, and 313 K and at pressures up to 6 MPa. Swelling measurements for CO2 were also performed at 293 K at pressures up to 5.6 MPa. Both sorption and swelling measuring methods were based on the magnetic suspension balance. Sorption data were obtained by means of a very accurate gravimetric method, whereas swelling data were acquired visually by using an optical pressurized cell. Results for N2 sorption on polyol showed that no appreciable sorption occurred for this gas. However, CO2 sorption was observed to be significant, and thus, the swelling of the polyol sample was measured to correct the CO2 sorption values. Corrected sorption results for CO2 on the polyol yielded a maximum uptake of 617 mg/g at 293 K and 5.4 MPa with an increase in the sample volume of about 47%. Measuring data showed that CO2 sorption increased with pressure and decreased with temperature. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239079
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7631-7636[article] Sorption and swelling measurements of CO2 and N2 on polyol for their use as blowing agents in a new PU foaming process device [texte imprimé] / Tobias Fieback, Auteur ; Walter Michaeli, Auteur ; Simon Latz, Auteur . - 2011 . - pp. 7631-7636.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7631-7636
Mots-clés : Foaming Swelling Sorption Résumé : From an industrial point of view, polymeric foams are of great importance because of their good mechanical and thermal properties and their low weight. Among them, polyurethane foams are the most versatile and, thus, the most consumed. Traditional methods for polyurethane foaming have the disadvantages of negative spin-offs due to chemical foaming reactions or use offlammable gases. A new foaming process device has been developed to overcome these drawbacks by performing physical foaming with safe blowing gases. In relation to this setup, the sorption of a polyol provided by Bayer MaterialScience, in the presence of pure N2 and pure CO2, was examined at three isotherms at 293, 303, and 313 K and at pressures up to 6 MPa. Swelling measurements for CO2 were also performed at 293 K at pressures up to 5.6 MPa. Both sorption and swelling measuring methods were based on the magnetic suspension balance. Sorption data were obtained by means of a very accurate gravimetric method, whereas swelling data were acquired visually by using an optical pressurized cell. Results for N2 sorption on polyol showed that no appreciable sorption occurred for this gas. However, CO2 sorption was observed to be significant, and thus, the swelling of the polyol sample was measured to correct the CO2 sorption values. Corrected sorption results for CO2 on the polyol yielded a maximum uptake of 617 mg/g at 293 K and 5.4 MPa with an increase in the sample volume of about 47%. Measuring data showed that CO2 sorption increased with pressure and decreased with temperature. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239079 Exemplaires
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Titre : New approach to pesticide delivery using nanosuspensions : research and applications Type de document : texte imprimé Auteurs : Chih-Ping Chin, Auteur ; Ho-Shing Wu, Auteur ; Shaw S. Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 7637-7643 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pesticides Résumé : In pharmacology, development of a formulated nanosuspension, a potential drug delivery system for poorly soluble drugs, has been investigated to overcome the bioavailability problems caused by weak solubility, limited chemical stability following administration (i.e., a short half-life), poor bioavailability, and potentially strong side effects requiring drug enrichment at the site of action. For first time use in a pesticide delivery system, a two-step milling process for preparing a nanosuspension in a system of active compound/surfactant/water is described in this paper. First, all the components were mixed at a certain composition to prepare a microsuspension by the general milling process. Then, the microsuspension was taken into a nanomilling process with zirconium oxide beads, having a diameter range of 0.1―0.2 mm, as the milling media to generate the nanosuspension. Therefore, a nanosuspension concentrate was formed. To demonstrate the potential applications of this novel system, it was used to make a formulation with a poorly soluble crystalline insecticide, carbofuran. In a comparative study, two kinds of carbofuran formulations, a microsuspension (commercial) and a nanosuspension, were administered to a diamondback moth (DBM) to test their efficacy and stability as a pesticide. The results indicate that carbofuran has the same efficacy at a lower dose for the nanosuspension compared to the microsuspension. The nanosuspension system was also physically and chemically stable over a period of 2 years, as indicated by the unchanged particle size and specification tests. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239080
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7637-7643[article] New approach to pesticide delivery using nanosuspensions : research and applications [texte imprimé] / Chih-Ping Chin, Auteur ; Ho-Shing Wu, Auteur ; Shaw S. Wang, Auteur . - 2011 . - pp. 7637-7643.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7637-7643
Mots-clés : Pesticides Résumé : In pharmacology, development of a formulated nanosuspension, a potential drug delivery system for poorly soluble drugs, has been investigated to overcome the bioavailability problems caused by weak solubility, limited chemical stability following administration (i.e., a short half-life), poor bioavailability, and potentially strong side effects requiring drug enrichment at the site of action. For first time use in a pesticide delivery system, a two-step milling process for preparing a nanosuspension in a system of active compound/surfactant/water is described in this paper. First, all the components were mixed at a certain composition to prepare a microsuspension by the general milling process. Then, the microsuspension was taken into a nanomilling process with zirconium oxide beads, having a diameter range of 0.1―0.2 mm, as the milling media to generate the nanosuspension. Therefore, a nanosuspension concentrate was formed. To demonstrate the potential applications of this novel system, it was used to make a formulation with a poorly soluble crystalline insecticide, carbofuran. In a comparative study, two kinds of carbofuran formulations, a microsuspension (commercial) and a nanosuspension, were administered to a diamondback moth (DBM) to test their efficacy and stability as a pesticide. The results indicate that carbofuran has the same efficacy at a lower dose for the nanosuspension compared to the microsuspension. The nanosuspension system was also physically and chemically stable over a period of 2 years, as indicated by the unchanged particle size and specification tests. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239080 Exemplaires
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Titre : Study on flame characteristics in aerosols by industrial heat transfer fluids Type de document : texte imprimé Auteurs : Peng Lian, Auteur ; Dedy Ng, Auteur ; Andres F. Mejia, Auteur Année de publication : 2011 Article en page(s) : pp. 7644-7652 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aerosols Flame Résumé : Due to the complexity of aerosol formation and the combustion process, fire and explosion hazards of flammable aerosols formed in the process industry are not fully understood. In this study, the flame propagation process of aerosolized industrial heat transfer fluids was investigated to understand the combustion phenomena in aerosol systems. Experimental observation shows different characteristics of flames propagation in aerosol systems, which are determined by the evaporated fuel vapor in aerosol system prior to encountering the flame and the amount of fuel vapor from droplets evaporating inside flames. Numerical modeling revealed that these factors were mainly determined by aerosol droplet size and velocity. The observed characteristics of the aerosol flames and the nature of continuous fuel evaporation that causes the reduction of droplet sizes suggest that ignition of flammable aerosols in the process plant might create more severe consequences than ignition of vapor mixtures. Results also imply that the aerosol dispersion conditions, as well as its formation conditions in scenarios of industrial fluid release, which determine the droplet size and movement velocity, need to be considered in assessment of fire hazard from the flammable aerosols. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239081
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7644-7652[article] Study on flame characteristics in aerosols by industrial heat transfer fluids [texte imprimé] / Peng Lian, Auteur ; Dedy Ng, Auteur ; Andres F. Mejia, Auteur . - 2011 . - pp. 7644-7652.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7644-7652
Mots-clés : Aerosols Flame Résumé : Due to the complexity of aerosol formation and the combustion process, fire and explosion hazards of flammable aerosols formed in the process industry are not fully understood. In this study, the flame propagation process of aerosolized industrial heat transfer fluids was investigated to understand the combustion phenomena in aerosol systems. Experimental observation shows different characteristics of flames propagation in aerosol systems, which are determined by the evaporated fuel vapor in aerosol system prior to encountering the flame and the amount of fuel vapor from droplets evaporating inside flames. Numerical modeling revealed that these factors were mainly determined by aerosol droplet size and velocity. The observed characteristics of the aerosol flames and the nature of continuous fuel evaporation that causes the reduction of droplet sizes suggest that ignition of flammable aerosols in the process plant might create more severe consequences than ignition of vapor mixtures. Results also imply that the aerosol dispersion conditions, as well as its formation conditions in scenarios of industrial fluid release, which determine the droplet size and movement velocity, need to be considered in assessment of fire hazard from the flammable aerosols. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239081 Exemplaires
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Titre : Numerical and experimental investigation of bubbling gas–solid fluidized beds with dense immersed tube bundles Type de document : texte imprimé Auteurs : Matthias Schreibe, Auteur ; Teklay W. Asegehegn, Auteur ; Hans J. Krautz, Auteur Année de publication : 2011 Article en page(s) : pp. 7653-7666 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Tube bundle Fluidized bed Fluidization Gas solid Bubbling Résumé : Numerical simulations of gas-solid bubbling fluidized beds with and without dense immersed horizontal tubes were performed using the Eulerian-Eulerian Two Fluid Model (TFM) and applying the Kinetic Theory of Granular Flow (KTGF). The results were compared with experimental data obtained from a pseudo-2D fluidized bed test rig using a developed digital image analysis technique (DIAT). The influences of dense immersed horizontal tubes on bed properties (bed pressure drop and expansion ratio) and bubble hydrodynamics (bubble size, rise velocity, aspect ratio, and shape factor) were investigated numerically as well as experimentally. In the first part grid sensitivity with different mesh sizes was checked and effects using 2D and 3D domains were examined. Simulations with 3D domains gave better agreement with experimental data but were seen to be computationally expensive. For conducting intensive parametric studies of fluidized bed behavior the use of 2D domains remains indispensable. In the second part it could be shown that dense tube arrangements in the fluidized bed lead to repeated bubble break-up and coalescence in the tube bank region and therefore to fluctuating values of bubble size, rise velocity, aspect ratio, and shape factor. For different superficial velocities similar results were found which shows the high influence of dense immersed tubes on fluidized bed behavior. In addition no significant differences between staggered and in-line tube arrangement were observed. In general the simulations based on the Two Fluid Model showed good agreement with the experimental results. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239082
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7653-7666[article] Numerical and experimental investigation of bubbling gas–solid fluidized beds with dense immersed tube bundles [texte imprimé] / Matthias Schreibe, Auteur ; Teklay W. Asegehegn, Auteur ; Hans J. Krautz, Auteur . - 2011 . - pp. 7653-7666.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7653-7666
Mots-clés : Tube bundle Fluidized bed Fluidization Gas solid Bubbling Résumé : Numerical simulations of gas-solid bubbling fluidized beds with and without dense immersed horizontal tubes were performed using the Eulerian-Eulerian Two Fluid Model (TFM) and applying the Kinetic Theory of Granular Flow (KTGF). The results were compared with experimental data obtained from a pseudo-2D fluidized bed test rig using a developed digital image analysis technique (DIAT). The influences of dense immersed horizontal tubes on bed properties (bed pressure drop and expansion ratio) and bubble hydrodynamics (bubble size, rise velocity, aspect ratio, and shape factor) were investigated numerically as well as experimentally. In the first part grid sensitivity with different mesh sizes was checked and effects using 2D and 3D domains were examined. Simulations with 3D domains gave better agreement with experimental data but were seen to be computationally expensive. For conducting intensive parametric studies of fluidized bed behavior the use of 2D domains remains indispensable. In the second part it could be shown that dense tube arrangements in the fluidized bed lead to repeated bubble break-up and coalescence in the tube bank region and therefore to fluctuating values of bubble size, rise velocity, aspect ratio, and shape factor. For different superficial velocities similar results were found which shows the high influence of dense immersed tubes on fluidized bed behavior. In addition no significant differences between staggered and in-line tube arrangement were observed. In general the simulations based on the Two Fluid Model showed good agreement with the experimental results. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239082 Exemplaires
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Titre : Fractal impeller for stirred tank reactors Type de document : texte imprimé Auteurs : Amol A. Kulkarni, Auteur ; Neha Jha, Auteur ; Abhishek Singh, Auteur Année de publication : 2011 Article en page(s) : pp. 7667-7676 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Stirred tank reactor Agitator Fractal Résumé : Stirred tank reactors are used for variety of applications at different scales of operation. The conventional impellers tend to develop regions having nonuniform energy dissipation rates in the stirred reactor. In this work, we propose a novel fractal impeller, which helps in reducing such nonuniformities and help develop a uniform randomness throughout the reactor. The impeller geometry is discussed in detail. Experimental measurements of the power consumption, mixing time, suspension quality, and the ability for gas dispersion were carried out, and the performance is compared with the conventional impellers. The impeller is seen to have a low power number, and it can generate a uniform suspension of particles even at relatively lower impeller speeds and can efficiently disperse gas into liquid to yield relatively higher gas hold-up values. The Fourier analysis of the power consumption time series data indicates that no specific prominent frequency events exist in the reactor, and the spectrum showed several frequency events to exist in the reactor with almost identical prominence. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239083
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7667-7676[article] Fractal impeller for stirred tank reactors [texte imprimé] / Amol A. Kulkarni, Auteur ; Neha Jha, Auteur ; Abhishek Singh, Auteur . - 2011 . - pp. 7667-7676.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7667-7676
Mots-clés : Stirred tank reactor Agitator Fractal Résumé : Stirred tank reactors are used for variety of applications at different scales of operation. The conventional impellers tend to develop regions having nonuniform energy dissipation rates in the stirred reactor. In this work, we propose a novel fractal impeller, which helps in reducing such nonuniformities and help develop a uniform randomness throughout the reactor. The impeller geometry is discussed in detail. Experimental measurements of the power consumption, mixing time, suspension quality, and the ability for gas dispersion were carried out, and the performance is compared with the conventional impellers. The impeller is seen to have a low power number, and it can generate a uniform suspension of particles even at relatively lower impeller speeds and can efficiently disperse gas into liquid to yield relatively higher gas hold-up values. The Fourier analysis of the power consumption time series data indicates that no specific prominent frequency events exist in the reactor, and the spectrum showed several frequency events to exist in the reactor with almost identical prominence. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239083 Exemplaires
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Titre : Online near-Infrared spectroscopy combined with alternating trilinear decomposition for process analysis of industrial production and quality assurance Type de document : texte imprimé Auteurs : Jingjing Liu, Auteur ; Xiang Ma, Auteur ; Yadong Wen, Auteur Année de publication : 2011 Article en page(s) : pp 7677–7681 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Spectroscopy Process Analysis Résumé : Process analysis is a great challenge in industry due to the complexity of industrial production. In the present work, an approach was developed based on online near-infrared spectroscopy and alternating trilinear decomposition (ATLD) method for industrial process analysis. The basic idea of the approach is to extract the common information that represents the common property of the batches using ATLD. Using common information, the production process can be monitored by investigating the variation of the common property, and quality assurance can be achieved by discrimination analysis. Taking the tobacco production as an example, the results show that the method is able to capture the intrinsic information of the products and performs well in process analysis and quality assurance. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200543v
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp 7677–7681[article] Online near-Infrared spectroscopy combined with alternating trilinear decomposition for process analysis of industrial production and quality assurance [texte imprimé] / Jingjing Liu, Auteur ; Xiang Ma, Auteur ; Yadong Wen, Auteur . - 2011 . - pp 7677–7681.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp 7677–7681
Mots-clés : Spectroscopy Process Analysis Résumé : Process analysis is a great challenge in industry due to the complexity of industrial production. In the present work, an approach was developed based on online near-infrared spectroscopy and alternating trilinear decomposition (ATLD) method for industrial process analysis. The basic idea of the approach is to extract the common information that represents the common property of the batches using ATLD. Using common information, the production process can be monitored by investigating the variation of the common property, and quality assurance can be achieved by discrimination analysis. Taking the tobacco production as an example, the results show that the method is able to capture the intrinsic information of the products and performs well in process analysis and quality assurance. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200543v Exemplaires
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Titre : Determination of sulfur content of various gases using chrastil-type equations Type de document : texte imprimé Auteurs : Ali Eslamimanesh, Auteur ; Amir H. Mohammadi, Auteur ; Dominique Richon, Auteur Année de publication : 2011 Article en page(s) : pp. 7682-7687 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Natural gases Chrastil-type equations Résumé : Accurate knowledge of the sulfur content of gases is a significant factor for prediction of the sulfur precipitation conditions in production of sour natural gases. However, because the concentration of sulfur in the gas phase is very low, the measurement difficulties consequently result in scarce experimental solubility values available in the literature. In this work, application of four commonly used Chrastil-type equations including the original Chrastil, Adachi and Lu, del Valle and Aguilera, and Mèndez-Santiago and Teja, which consider the effects of temperature, density of gas (solvent), and pressures on the sulfur solubility, are investigated to calculate the sulfur content of different gases at various temperature, pressure, and sulfur content ranges. In this study, sulfur is treated as single molecule S8. The Valderrama-Patel-Teja equation of state with non-density dependent mixing rules is used to calculate the densities ofgases. It is found out that the absolute average deviations (AAD %) of the evaluated sulfur contents by the aforementioned equations for 260 investigated experimental values are 21%, 12%, 19%, and 20%, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239085
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7682-7687[article] Determination of sulfur content of various gases using chrastil-type equations [texte imprimé] / Ali Eslamimanesh, Auteur ; Amir H. Mohammadi, Auteur ; Dominique Richon, Auteur . - 2011 . - pp. 7682-7687.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7682-7687
Mots-clés : Natural gases Chrastil-type equations Résumé : Accurate knowledge of the sulfur content of gases is a significant factor for prediction of the sulfur precipitation conditions in production of sour natural gases. However, because the concentration of sulfur in the gas phase is very low, the measurement difficulties consequently result in scarce experimental solubility values available in the literature. In this work, application of four commonly used Chrastil-type equations including the original Chrastil, Adachi and Lu, del Valle and Aguilera, and Mèndez-Santiago and Teja, which consider the effects of temperature, density of gas (solvent), and pressures on the sulfur solubility, are investigated to calculate the sulfur content of different gases at various temperature, pressure, and sulfur content ranges. In this study, sulfur is treated as single molecule S8. The Valderrama-Patel-Teja equation of state with non-density dependent mixing rules is used to calculate the densities ofgases. It is found out that the absolute average deviations (AAD %) of the evaluated sulfur contents by the aforementioned equations for 260 investigated experimental values are 21%, 12%, 19%, and 20%, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239085 Exemplaires
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Titre : Influence of the eluent in the MIL-53(Al) selectivity for xylene isomers separation Type de document : texte imprimé Auteurs : Mariana A. Moreira, Auteur ; Joao Carlos Santos, Auteur ; Alexandre F. P. Ferreira, Auteur Année de publication : 2011 Article en page(s) : pp. 7688-7695 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Isomer Résumé : Metal―organic framework MIL-53(Al) pellets were tested for selective adsorption and separation of xylene isomers with the aim of studying the influence of the solvent used at bulk concentrations. In this way, a set of single and multicomponent pulse experiments to measure selectivities was conducted, with iso-octane, n-hexane, and n-heptane as eluents, at 313 K. In order to complete this study, multicomponent breakthrough experiments were also performed, under the same conditions, in the presence of these three eluents, and the obtained selectivities were compared. MLL-53(Al) presented a preference for o-xylene over m-xylene and p-xylene in all experiments. The selectivity was higher when n-heptane was the eluent. For the breakthrough experiments that used n-heptane as the eluent, selectivities of 2.1 were obtained for o-xylene over m-xylene and overp-xylene. It was possible to conclude that the choice of eluent influences the adsorption selectivity and capacity of the adsorbent. This could result, among other factors, from the adsorbent-adsorbate interactions. These interactions may also occur with the eluent molecules (as an adsorbate), which influences the adsorption capacity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239086
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7688-7695[article] Influence of the eluent in the MIL-53(Al) selectivity for xylene isomers separation [texte imprimé] / Mariana A. Moreira, Auteur ; Joao Carlos Santos, Auteur ; Alexandre F. P. Ferreira, Auteur . - 2011 . - pp. 7688-7695.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7688-7695
Mots-clés : Isomer Résumé : Metal―organic framework MIL-53(Al) pellets were tested for selective adsorption and separation of xylene isomers with the aim of studying the influence of the solvent used at bulk concentrations. In this way, a set of single and multicomponent pulse experiments to measure selectivities was conducted, with iso-octane, n-hexane, and n-heptane as eluents, at 313 K. In order to complete this study, multicomponent breakthrough experiments were also performed, under the same conditions, in the presence of these three eluents, and the obtained selectivities were compared. MLL-53(Al) presented a preference for o-xylene over m-xylene and p-xylene in all experiments. The selectivity was higher when n-heptane was the eluent. For the breakthrough experiments that used n-heptane as the eluent, selectivities of 2.1 were obtained for o-xylene over m-xylene and overp-xylene. It was possible to conclude that the choice of eluent influences the adsorption selectivity and capacity of the adsorbent. This could result, among other factors, from the adsorbent-adsorbate interactions. These interactions may also occur with the eluent molecules (as an adsorbate), which influences the adsorption capacity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239086 Exemplaires
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Titre : Property estimation using analogous series Type de document : texte imprimé Auteurs : Brian K. Peterson, Auteur Année de publication : 2011 Article en page(s) : pp. 7696-7704 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Property estimatiion Analogous Series Résumé : A previously introduced method for predicting the properties of physical substances is described in detail and is given a mathematical justification. The method, here called the method of Analogous Series, requires only that the molecular structure of the target species be known and that the physical property of interest be known for several other species of known structure. It is shown to be very general and is successfully applied to the accurate prediction ofpure-component properties (critical temperatures, liquid heat capacities), mixture properties (solution Henry constants, adsorption in zeolites, gas solubility in liquids, GC retention times), and to complex properties such as flash points. The relationship of the method to other predictive methods is discussed. The reference substance method is shown to be a special case of the Analogous Series method. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239087
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7696-7704[article] Property estimation using analogous series [texte imprimé] / Brian K. Peterson, Auteur . - 2011 . - pp. 7696-7704.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7696-7704
Mots-clés : Property estimatiion Analogous Series Résumé : A previously introduced method for predicting the properties of physical substances is described in detail and is given a mathematical justification. The method, here called the method of Analogous Series, requires only that the molecular structure of the target species be known and that the physical property of interest be known for several other species of known structure. It is shown to be very general and is successfully applied to the accurate prediction ofpure-component properties (critical temperatures, liquid heat capacities), mixture properties (solution Henry constants, adsorption in zeolites, gas solubility in liquids, GC retention times), and to complex properties such as flash points. The relationship of the method to other predictive methods is discussed. The reference substance method is shown to be a special case of the Analogous Series method. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239087 Exemplaires
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