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Vol. 49 N° 19 - Octobre 2010 [texte imprimé] . - 2010 . - p. 8877-9564 : ill. ; 28 cm. Chemical engineering Langues : Français (fre)
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Ajouter le résultat dans votre panierWater minimization techniques for batch processes / Jacques F. Gouws in Industrial & engineering chemistry research, Vol. 49 N° 19 (Octobre 2010)
Titre : Water minimization techniques for batch processes Type de document : texte imprimé Auteurs : Jacques F. Gouws, Auteur ; Thokozani Majozi, Auteur ; Dominic Chwan Yee Foo, Auteur Année de publication : 2010 Article en page(s) : pp. 8877–8893 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Water minimization Continuous processes Résumé : Water minimization in the process industry is becoming increasingly important as environmental legislation becomes increasingly stringent and the awareness of the impact of industrial activities on the environment increases. Much work has been done on water minimization in continuous processes as evidenced by the detailed reviews of Bagajewicz (2000) and Foo (2009). Although water minimization for batch processes (batch water network in short) has been ignored in the past, it is steadily gaining more attention in research. An overview of the developments and methodologies proposed for batch water network is presented. The methodologies for water minimization can roughly be divided into insight-based and mathematical techniques. The former always consists of a two-step approach (targeting and design) in synthesizing a batch water network that features the minimum freshwater and wastewater flows for a given production schedule. The mathematical techniques, on the other hand, may be categorized into two subsectors, that is, with and without scheduling consideration. In this review, various water minimization methodologies are discussed and comparisons are made among them. When necessary, they are illustrated through examples. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100130a
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8877–8893[article] Water minimization techniques for batch processes [texte imprimé] / Jacques F. Gouws, Auteur ; Thokozani Majozi, Auteur ; Dominic Chwan Yee Foo, Auteur . - 2010 . - pp. 8877–8893.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8877–8893
Mots-clés : Water minimization Continuous processes Résumé : Water minimization in the process industry is becoming increasingly important as environmental legislation becomes increasingly stringent and the awareness of the impact of industrial activities on the environment increases. Much work has been done on water minimization in continuous processes as evidenced by the detailed reviews of Bagajewicz (2000) and Foo (2009). Although water minimization for batch processes (batch water network in short) has been ignored in the past, it is steadily gaining more attention in research. An overview of the developments and methodologies proposed for batch water network is presented. The methodologies for water minimization can roughly be divided into insight-based and mathematical techniques. The former always consists of a two-step approach (targeting and design) in synthesizing a batch water network that features the minimum freshwater and wastewater flows for a given production schedule. The mathematical techniques, on the other hand, may be categorized into two subsectors, that is, with and without scheduling consideration. In this review, various water minimization methodologies are discussed and comparisons are made among them. When necessary, they are illustrated through examples. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100130a Exemplaires
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Titre : Adsorption isotherms and mordant dyeing properties of tea polyphenols on wool, silk, and nylon Type de document : texte imprimé Auteurs : Ren-Cheng Tang, Auteur ; Hui Tang, Auteur ; Cheng Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 8894–8901 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Adsorption polyphenols Isotherms Résumé : The adsorption behaviors of tea polyphenols (TP) on wool, silk, and nylon at pH 4.0 were investigated. The Langmuir−Nernst model had the best fitting to the adsorption isotherms. The analysis of adsorption mechanism suggested that the hydrogen bonding and electrostatic interactions operating between TP and fibers contribute to Langmuir adsorption, whereas other interactions (hydrophobic interaction and van der Waals forces) contribute to Nernst partition adsorption. Langmuir adsorption had greater contribution to total adsorption of TP on nylon, whereas partition adsorption imparted greater influence to TP adsorption on silk. In terms of the mordant dyeing of TP, silk and wool displayed much deeper color than nylon due to their higher content of the functional groups having the complex-forming ability, although they had lower adsorption capability for TP than nylon. The colors of the dyed fabrics mordanted with different metallic salts as well as their depth, were greatly dependent on the chemical nature of mordants and fibers, the metal ion−TP−fiber complex-forming ability, and the related complex structure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100052b
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8894–8901[article] Adsorption isotherms and mordant dyeing properties of tea polyphenols on wool, silk, and nylon [texte imprimé] / Ren-Cheng Tang, Auteur ; Hui Tang, Auteur ; Cheng Yang, Auteur . - 2010 . - pp. 8894–8901.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8894–8901
Mots-clés : Adsorption polyphenols Isotherms Résumé : The adsorption behaviors of tea polyphenols (TP) on wool, silk, and nylon at pH 4.0 were investigated. The Langmuir−Nernst model had the best fitting to the adsorption isotherms. The analysis of adsorption mechanism suggested that the hydrogen bonding and electrostatic interactions operating between TP and fibers contribute to Langmuir adsorption, whereas other interactions (hydrophobic interaction and van der Waals forces) contribute to Nernst partition adsorption. Langmuir adsorption had greater contribution to total adsorption of TP on nylon, whereas partition adsorption imparted greater influence to TP adsorption on silk. In terms of the mordant dyeing of TP, silk and wool displayed much deeper color than nylon due to their higher content of the functional groups having the complex-forming ability, although they had lower adsorption capability for TP than nylon. The colors of the dyed fabrics mordanted with different metallic salts as well as their depth, were greatly dependent on the chemical nature of mordants and fibers, the metal ion−TP−fiber complex-forming ability, and the related complex structure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100052b Exemplaires
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Titre : Synthesis of environmentally friendly overbased magnesium oleate detergent and high alkaline dispersant / magnesium oleate mixed substrate detergent Type de document : texte imprimé Auteurs : Yonglei Wang, Auteur ; Wumanjiang Eli, Auteur Année de publication : 2010 Article en page(s) : pp. 8902–8907 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Magnesium detergent Oleate Résumé : This article describes a method for synthesizing an environmentally friendly overbased magnesium oleate detergent using oleic acid and active-60 magnesium oxide as materials. Reaction conditions including solvent, molar ratio of active-60 magnesium oxide to oleic acid, molar ratio of methanol to active-60 magnesium oxide, molar ratio of ammonia to active-60 magnesium oxide, addition mode of ammonia, carbonation temperature, molar ratio of injected CO2 to active-60 magnesium oxide, and CO2 rate were optimized. Under the optimized conditions, the overbased magnesium oleate detergent with a total base number (TBN) of 402 mg of KOH/g could be obtained. To improve the dispersing capability and the stability of the magnesium oleate detergent, the different dispersant/magnesium oleate mixed substrate detergents were synthesized using Tuwen-80, poly-12-hydroxystearic acid-pentaerythritol (PTHSAP), and poly-12-hydroxystearic acid-polyethylene polyamine (PTHSAPP) as dispersants. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100377h
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8902–8907[article] Synthesis of environmentally friendly overbased magnesium oleate detergent and high alkaline dispersant / magnesium oleate mixed substrate detergent [texte imprimé] / Yonglei Wang, Auteur ; Wumanjiang Eli, Auteur . - 2010 . - pp. 8902–8907.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8902–8907
Mots-clés : Magnesium detergent Oleate Résumé : This article describes a method for synthesizing an environmentally friendly overbased magnesium oleate detergent using oleic acid and active-60 magnesium oxide as materials. Reaction conditions including solvent, molar ratio of active-60 magnesium oxide to oleic acid, molar ratio of methanol to active-60 magnesium oxide, molar ratio of ammonia to active-60 magnesium oxide, addition mode of ammonia, carbonation temperature, molar ratio of injected CO2 to active-60 magnesium oxide, and CO2 rate were optimized. Under the optimized conditions, the overbased magnesium oleate detergent with a total base number (TBN) of 402 mg of KOH/g could be obtained. To improve the dispersing capability and the stability of the magnesium oleate detergent, the different dispersant/magnesium oleate mixed substrate detergents were synthesized using Tuwen-80, poly-12-hydroxystearic acid-pentaerythritol (PTHSAP), and poly-12-hydroxystearic acid-polyethylene polyamine (PTHSAPP) as dispersants. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100377h Exemplaires
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Titre : TiO2 - coated cenospheres as catalysts for photocatalytic degradation of methylene blue, p - nitroaniline, n - decane, and n - tridecane under solar irradiation Type de document : texte imprimé Auteurs : Praveen K. Surolia, Auteur ; Rajesh J. Tayade, Auteur ; Raksh V. Jasra, Auteur Année de publication : 2010 Article en page(s) : pp. 8908–8919 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalysts Photocatalytic degradation Résumé : Fly ash cenosphere particles generated in coal-fired thermal power plants were coated with TiO2 using the sol−gel technique. Thus prepared photocatalysts were used for the degradation of methylene blue (MB), nitro-aromatic compound p-nitroaniline (PNA), and photocatalytic oxidation of n-decane and n-tridecane from aqueous solution under solar light irradiation. The morphology, composition, and crystallinity of both pristine and TiO2-coated cenospheres were studied. The UV−visible spectroscopic analysis was used to monitor the progress of the reaction for MB and PNA. The decrease in the amount of n-decane and n-tridecane was determined by gas chromatographic analysis. The decrease in the concentration for a 25 ppm initial concentration of MB and PNA was observed to be 99 and 26%, respectively, after 3 h of reaction time. This demonstrates that MB is more amenable toward degradation and mineralization as it acts as a sensitizer. Decreases up to 51 and 36% for n-decane and n-tridecane were observed with initial amounts of 3−12 mL, respectively, after 6 h. The coated cenosphere catalyst could be recovered by filtration and reused. The coating was found to be stable even after three uses of the catalyst in the photocatalytic degradation reaction of MB and PNA. The mineralization of dye and nitro-aromatic compound was confirmed by the chemical oxygen demand analysis. Cenospheres, because of their light weight, would make the catalyst particles float on the aqueous surface and hence could be directly activated by sunlight. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100388m
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8908–8919[article] TiO2 - coated cenospheres as catalysts for photocatalytic degradation of methylene blue, p - nitroaniline, n - decane, and n - tridecane under solar irradiation [texte imprimé] / Praveen K. Surolia, Auteur ; Rajesh J. Tayade, Auteur ; Raksh V. Jasra, Auteur . - 2010 . - pp. 8908–8919.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8908–8919
Mots-clés : Catalysts Photocatalytic degradation Résumé : Fly ash cenosphere particles generated in coal-fired thermal power plants were coated with TiO2 using the sol−gel technique. Thus prepared photocatalysts were used for the degradation of methylene blue (MB), nitro-aromatic compound p-nitroaniline (PNA), and photocatalytic oxidation of n-decane and n-tridecane from aqueous solution under solar light irradiation. The morphology, composition, and crystallinity of both pristine and TiO2-coated cenospheres were studied. The UV−visible spectroscopic analysis was used to monitor the progress of the reaction for MB and PNA. The decrease in the amount of n-decane and n-tridecane was determined by gas chromatographic analysis. The decrease in the concentration for a 25 ppm initial concentration of MB and PNA was observed to be 99 and 26%, respectively, after 3 h of reaction time. This demonstrates that MB is more amenable toward degradation and mineralization as it acts as a sensitizer. Decreases up to 51 and 36% for n-decane and n-tridecane were observed with initial amounts of 3−12 mL, respectively, after 6 h. The coated cenosphere catalyst could be recovered by filtration and reused. The coating was found to be stable even after three uses of the catalyst in the photocatalytic degradation reaction of MB and PNA. The mineralization of dye and nitro-aromatic compound was confirmed by the chemical oxygen demand analysis. Cenospheres, because of their light weight, would make the catalyst particles float on the aqueous surface and hence could be directly activated by sunlight. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100388m Exemplaires
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Titre : Double - hydrophilic block copolymers as precipitation inhibitors for calcium phosphate and iron(III) Type de document : texte imprimé Auteurs : Fu Change, Auteur ; Zhou Yuming, Auteur ; Xie Hongtao, Auteur Année de publication : 2010 Article en page(s) : pp. 8920–8926 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrophilic Copolymers Anhydride Résumé : Novel double-hydrophilic block copolymers, maleic anhydride (MA)−allylpolyethoxy carboxylate (APEC) and maleic anhydride (MA)−ammonium allylpolyethoxy sulfate (APES), were specially designed and synthesized from allyloxy polyethoxy ether (APEO) to inhibit the precipitation of calcium phosphate and iron (III). Structures of APEO, APEC, MA−APEC, APES, and MA−APES were characterized by FT-IR. The study shows that both MA−APEC and MA−APES have significant ability to inhibit the precipitation of calcium phosphate at the dosage of 6 mg/L, approximately showing 99 and 90% inhibition, respectively. The data of the light transmittance of ferrous solutions show that, compared to MA−APES, MA−APEC has superior ability to stabilize iron (III) in solutions. The light transmittance of ferrous solutions is about 23% in the presence of MA−APEC when the dosage is 6 mg/L, whereas in the presence of MA−APES, it is about 31% at a dosage of 12 mg/L. Scanning electron microscopy (SEM) shows that the copolymers influence the morphology of calcium phosphate crystallites. Transmission electron microscopy (TEM) indicates the excellent inhibition results from the formation of core−shell structure. Double-hydrophilic block copolymers of MA−APEC and MA−APES have also been proven to be effective inhibitors of calcium phosphate and iron (III) even at elevated solution temperature, pH, and Ca2+ and Fe2+ concentration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100395z#afn1
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8920–8926[article] Double - hydrophilic block copolymers as precipitation inhibitors for calcium phosphate and iron(III) [texte imprimé] / Fu Change, Auteur ; Zhou Yuming, Auteur ; Xie Hongtao, Auteur . - 2010 . - pp. 8920–8926.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8920–8926
Mots-clés : Hydrophilic Copolymers Anhydride Résumé : Novel double-hydrophilic block copolymers, maleic anhydride (MA)−allylpolyethoxy carboxylate (APEC) and maleic anhydride (MA)−ammonium allylpolyethoxy sulfate (APES), were specially designed and synthesized from allyloxy polyethoxy ether (APEO) to inhibit the precipitation of calcium phosphate and iron (III). Structures of APEO, APEC, MA−APEC, APES, and MA−APES were characterized by FT-IR. The study shows that both MA−APEC and MA−APES have significant ability to inhibit the precipitation of calcium phosphate at the dosage of 6 mg/L, approximately showing 99 and 90% inhibition, respectively. The data of the light transmittance of ferrous solutions show that, compared to MA−APES, MA−APEC has superior ability to stabilize iron (III) in solutions. The light transmittance of ferrous solutions is about 23% in the presence of MA−APEC when the dosage is 6 mg/L, whereas in the presence of MA−APES, it is about 31% at a dosage of 12 mg/L. Scanning electron microscopy (SEM) shows that the copolymers influence the morphology of calcium phosphate crystallites. Transmission electron microscopy (TEM) indicates the excellent inhibition results from the formation of core−shell structure. Double-hydrophilic block copolymers of MA−APEC and MA−APES have also been proven to be effective inhibitors of calcium phosphate and iron (III) even at elevated solution temperature, pH, and Ca2+ and Fe2+ concentration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100395z#afn1 Exemplaires
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Titre : Agro - industrial waste : A low - cost option for the biosorptive remediation of selenium anions Type de document : texte imprimé Auteurs : S. H. Hasan, Auteur ; D. Ranjan, Auteur Année de publication : 2010 Article en page(s) : pp. 8927–8934 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Biosorbent Agro industrial waste Résumé : For remediation purposes, initially, the screening and selection of potent biosorbent, among three agro-industrial wastes (i.e., wheat bran, maize bran, and rice bran) was done. Wheat bran was found to show maximum uptake in the case of both Se(IV) and Se(VI) ions. Effect of various parameters (pH, temperature, initial metal ion concentration, and biomass dose) was extensively investigated on the uptake of these metal ions by potent biosorbent using batch mode. Langmuir, Freundlich, and Dubinin−Radushkevich (D-R) isotherm models were applied and all three isotherms fitted well to sorption data. The maximum sorption capacity of wheat bran was 89.28 μg/g for Se(VI) and 80.65 μg/g for Se(VI) at 20 °C and pH 2.0. Values of mean sorption energy indicated sorption to be chemisorption. Thermodynamic study revealed that sorption was feasible, spontaneous and exothermic. The sorption reaction was determined to be pseudo-second-order. Fourier transform infrared (FTIR) analysis of raw and metal-loaded biosorbent was done to determine changes on the surface of the sorbent after sorption. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100622c
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8927–8934[article] Agro - industrial waste : A low - cost option for the biosorptive remediation of selenium anions [texte imprimé] / S. H. Hasan, Auteur ; D. Ranjan, Auteur . - 2010 . - pp. 8927–8934.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8927–8934
Mots-clés : Biosorbent Agro industrial waste Résumé : For remediation purposes, initially, the screening and selection of potent biosorbent, among three agro-industrial wastes (i.e., wheat bran, maize bran, and rice bran) was done. Wheat bran was found to show maximum uptake in the case of both Se(IV) and Se(VI) ions. Effect of various parameters (pH, temperature, initial metal ion concentration, and biomass dose) was extensively investigated on the uptake of these metal ions by potent biosorbent using batch mode. Langmuir, Freundlich, and Dubinin−Radushkevich (D-R) isotherm models were applied and all three isotherms fitted well to sorption data. The maximum sorption capacity of wheat bran was 89.28 μg/g for Se(VI) and 80.65 μg/g for Se(VI) at 20 °C and pH 2.0. Values of mean sorption energy indicated sorption to be chemisorption. Thermodynamic study revealed that sorption was feasible, spontaneous and exothermic. The sorption reaction was determined to be pseudo-second-order. Fourier transform infrared (FTIR) analysis of raw and metal-loaded biosorbent was done to determine changes on the surface of the sorbent after sorption. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100622c Exemplaires
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Titre : Volumetric method for free and total glycerin determination in biodiesel Type de document : texte imprimé Auteurs : M. L. Pisarello, Auteur ; B. O. Dalla Costa, Auteur ; N. S. Veizaga, Auteur Année de publication : 2010 Article en page(s) : pp. 8935–8941 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Biodiesel Volumetric method Résumé : In the past few years, biodiesel has gained considerable attention due to the increasing concern for the environmental problems associated with the use of fossil fuels. The quality control of this renewable fuel involves numerous analyses, several of them requiring the use of analytical instruments. According to ASTM and EN standards, the analyses of free and total glycerin which are of particular relevance to biodiesel quality must be carried out by GC analysis. This work presents an alternative volumetric method, which does not need expensive equipment, and is therefore particularly useful for quality control in small facilities. Another advantage of the proposed method is that it also overcomes the shortcomings of the GC procedure, such as detection limits and type of raw material used to produce biodiesel. While the GC analysis is restricted to biodiesel obtained from soybean, rapeseed or sunflower oil, the volumetric method has no limitations in this sense. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100725f
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8935–8941[article] Volumetric method for free and total glycerin determination in biodiesel [texte imprimé] / M. L. Pisarello, Auteur ; B. O. Dalla Costa, Auteur ; N. S. Veizaga, Auteur . - 2010 . - pp. 8935–8941.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8935–8941
Mots-clés : Biodiesel Volumetric method Résumé : In the past few years, biodiesel has gained considerable attention due to the increasing concern for the environmental problems associated with the use of fossil fuels. The quality control of this renewable fuel involves numerous analyses, several of them requiring the use of analytical instruments. According to ASTM and EN standards, the analyses of free and total glycerin which are of particular relevance to biodiesel quality must be carried out by GC analysis. This work presents an alternative volumetric method, which does not need expensive equipment, and is therefore particularly useful for quality control in small facilities. Another advantage of the proposed method is that it also overcomes the shortcomings of the GC procedure, such as detection limits and type of raw material used to produce biodiesel. While the GC analysis is restricted to biodiesel obtained from soybean, rapeseed or sunflower oil, the volumetric method has no limitations in this sense. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100725f Exemplaires
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Titre : Cu x H 3 - 2 x PW12O40 supported on MCM - 41 : Their activity to heck vinylation of aryl halides Type de document : texte imprimé Auteurs : Dharitri Rath, Auteur ; Surjyakanta Rana, Auteur ; K. M. Parida, Auteur Année de publication : 2010 Article en page(s) : pp. 8942-8948 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Heteropoly acid Catalysts Résumé : A series of Cu salts of heteropoly acid (CuxH3−2xPW12O40) supported MCM-41 catalysts (CuxH3−2xPW12O40/MCM-41) was synthesized by wet impregnation method and thoroughly characterized by using various analytical techniques, viz., X-ray diffraction, UV−vis diffused reflectance spectroscopy (UV−vis DRS), nitrogen adsorption desorption, temperature-programmed reduction (TPR), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). From XRD and FT-IR studies, we confirmed that the Keggin structure of heteropoly acid (HPA) is retained in Cu salt of HPA. Heck vinylation was performed to examine the catalytic properties of the catalysts. The 50 wt % CuxH3−2xPW12O40/MCM-41 showed remarkable catalytic performance of phenyl iodide (98% conversion) to cinnamic acid in aqueous medium compared with MCM-41 and other catalytic systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100895v
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8942-8948[article] Cu x H 3 - 2 x PW12O40 supported on MCM - 41 : Their activity to heck vinylation of aryl halides [texte imprimé] / Dharitri Rath, Auteur ; Surjyakanta Rana, Auteur ; K. M. Parida, Auteur . - 2010 . - pp. 8942-8948.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8942-8948
Mots-clés : Heteropoly acid Catalysts Résumé : A series of Cu salts of heteropoly acid (CuxH3−2xPW12O40) supported MCM-41 catalysts (CuxH3−2xPW12O40/MCM-41) was synthesized by wet impregnation method and thoroughly characterized by using various analytical techniques, viz., X-ray diffraction, UV−vis diffused reflectance spectroscopy (UV−vis DRS), nitrogen adsorption desorption, temperature-programmed reduction (TPR), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). From XRD and FT-IR studies, we confirmed that the Keggin structure of heteropoly acid (HPA) is retained in Cu salt of HPA. Heck vinylation was performed to examine the catalytic properties of the catalysts. The 50 wt % CuxH3−2xPW12O40/MCM-41 showed remarkable catalytic performance of phenyl iodide (98% conversion) to cinnamic acid in aqueous medium compared with MCM-41 and other catalytic systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100895v Exemplaires
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Titre : Chemical equilibrium modeling and experimental measurement of solubility for friedel’s salt in the Na − OH − Cl − N O3 − H 2O systems up to 200 °C Type de document : texte imprimé Auteurs : Jiayu Ma, Auteur ; Zhibao Li, Auteur Année de publication : 2010 Article en page(s) : pp.8949–8958 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solubility Friedel’s Salt Résumé : A chemical model for the solubility of Friedel’s salt (FS, 3CaO·Al2O3·CaCl2·10H2O) was developed. The model was built with the help of the OLI platform via regression of experimental solubility data for FS in the Na−OH−Cl−NO3−H2O systems. The solubility of FS in water was measured using a batch nickel autoclave over the temperature range of 20−200 °C, and the solubility product of FS (log10 Ksp) was obtained. It was found that the solubility of FS in water shows a maximum value as a function of temperature. The solubility of FS in 0−5 mol/L NaOH and 0−2.5 mol/L NaCl solutions was found to decrease with increasing NaOH and NaCl concentrations, because of the common ion effect; however, in 0−2.5 mol/L NaNO3 solutions, it was found to increase because of complexation. During the regression analysis, it was found that CaOH+ plays an important role in solubility modeling, and its dissociation constant was determined by an empirical equation. New Bromley−Zemaitis activity coefficient model parameters for the Ca2+−OH−, CaOH+−OH−, and CaCl+−OH− ion pairs were also regressed, using the experimental solubility data generated in the present study. The new model was shown to successfully predict the solubility of FS in mixed NaOH + NaNO3 solutions not used in model parametrization. With the aid of the newly developed model, the concentration and temperature effects on calcium species distribution were analyzed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101028c
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp.8949–8958[article] Chemical equilibrium modeling and experimental measurement of solubility for friedel’s salt in the Na − OH − Cl − N O3 − H 2O systems up to 200 °C [texte imprimé] / Jiayu Ma, Auteur ; Zhibao Li, Auteur . - 2010 . - pp.8949–8958.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp.8949–8958
Mots-clés : Solubility Friedel’s Salt Résumé : A chemical model for the solubility of Friedel’s salt (FS, 3CaO·Al2O3·CaCl2·10H2O) was developed. The model was built with the help of the OLI platform via regression of experimental solubility data for FS in the Na−OH−Cl−NO3−H2O systems. The solubility of FS in water was measured using a batch nickel autoclave over the temperature range of 20−200 °C, and the solubility product of FS (log10 Ksp) was obtained. It was found that the solubility of FS in water shows a maximum value as a function of temperature. The solubility of FS in 0−5 mol/L NaOH and 0−2.5 mol/L NaCl solutions was found to decrease with increasing NaOH and NaCl concentrations, because of the common ion effect; however, in 0−2.5 mol/L NaNO3 solutions, it was found to increase because of complexation. During the regression analysis, it was found that CaOH+ plays an important role in solubility modeling, and its dissociation constant was determined by an empirical equation. New Bromley−Zemaitis activity coefficient model parameters for the Ca2+−OH−, CaOH+−OH−, and CaCl+−OH− ion pairs were also regressed, using the experimental solubility data generated in the present study. The new model was shown to successfully predict the solubility of FS in mixed NaOH + NaNO3 solutions not used in model parametrization. With the aid of the newly developed model, the concentration and temperature effects on calcium species distribution were analyzed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101028c Exemplaires
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Titre : Calorimetric thermal hazards of tert - butyl hydroperoxide solutions Type de document : texte imprimé Auteurs : Yih-Wen Wang, Auteur ; Chi-Min Shu, Auteur Année de publication : 2010 Article en page(s) : pp. 8959–8968 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermal instability Hydroperoxide Résumé : Hazards evaluation was performed to investigate the thermal instability and incompatibility of tert-butyl hydroperoxide (TBHP) solution with various diluents. Two calorimeters, differential scanning calorimetry (DSC) and vent sizing package 2 (VSP2), are frequently used to characterize the inherent thermal hazards and adiabatic runaway features of organic peroxides. Through the thermal dynamic and isothermal scanning experiments, the enthalpy of energy-rich TBHP solutions to normalize various heats of decomposition was elucidated. The self-reactive rating of a runaway reaction can be characterized by the thermokinetic parameters, such as initial exothermic temperature (T0), self-heating rate (dT·dt−1), pressure rise rate (dP·dt−1), pressure−temperature profiles, noncondensable pressure, etc. We also suggested using the isothermal tests of DSC combined with the kinetic data to evaluate the exothermic enthalpy and reaction aging time of aqueous TBHP. The novel finding was that aqueous TBHP with DSC and VSP2 was observed to possess intrinsic qualities leading to thermal explosion, with a sharp self-reactive rate and pressure rise under adiabatic conditions. In summary, the thermal hazards of aqueous TBHP may cause a catastrophe or large loss in operation, storing, or transporting TBHP. This result also demonstrates that applying calorimetric methodology to classify the thermal hazards of organic peroxides is an alternative technology for research. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1010355
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8959–8968[article] Calorimetric thermal hazards of tert - butyl hydroperoxide solutions [texte imprimé] / Yih-Wen Wang, Auteur ; Chi-Min Shu, Auteur . - 2010 . - pp. 8959–8968.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8959–8968
Mots-clés : Thermal instability Hydroperoxide Résumé : Hazards evaluation was performed to investigate the thermal instability and incompatibility of tert-butyl hydroperoxide (TBHP) solution with various diluents. Two calorimeters, differential scanning calorimetry (DSC) and vent sizing package 2 (VSP2), are frequently used to characterize the inherent thermal hazards and adiabatic runaway features of organic peroxides. Through the thermal dynamic and isothermal scanning experiments, the enthalpy of energy-rich TBHP solutions to normalize various heats of decomposition was elucidated. The self-reactive rating of a runaway reaction can be characterized by the thermokinetic parameters, such as initial exothermic temperature (T0), self-heating rate (dT·dt−1), pressure rise rate (dP·dt−1), pressure−temperature profiles, noncondensable pressure, etc. We also suggested using the isothermal tests of DSC combined with the kinetic data to evaluate the exothermic enthalpy and reaction aging time of aqueous TBHP. The novel finding was that aqueous TBHP with DSC and VSP2 was observed to possess intrinsic qualities leading to thermal explosion, with a sharp self-reactive rate and pressure rise under adiabatic conditions. In summary, the thermal hazards of aqueous TBHP may cause a catastrophe or large loss in operation, storing, or transporting TBHP. This result also demonstrates that applying calorimetric methodology to classify the thermal hazards of organic peroxides is an alternative technology for research. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1010355 Exemplaires
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Titre : Use of hydrotalcites for the removal of toxic anions from aqueous solutions Type de document : texte imprimé Auteurs : Sara J. Palmer, Auteur ; Ray L. Frost, Auteur Année de publication : 2010 Article en page(s) : pp. 8969–8976 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrotalcites Aqueous solutions Résumé : The removal of toxic anions has been achieved using hydrotalcite via two methods: (1) coprecipitation and (2) thermal activation. Hydrotalcite formed via the coprecipitation method, using solutions containing arsenate and vanadate up to pH 10, are able to remove more than 95% of the toxic anions (0.2 M) from solution. The removal of toxic anions in solutions with a pH of >10 reduces the removal uptake percentage to 75%. Raman spectroscopy observed multiple A1 stretching modes of V−O and As−O at 930 and 810 cm−1, assigned to vanadate and arsenate, respectively. Analysis of the intensity and position of the A1 stretching modes helped to identify the vanadate and arsenate specie intercalated into the hydrotalcite structure. It has been determined that 3:1 hydrotalcite structure predominantly intercalate anions into the interlayer region, while the 2:1 and 4:1 hydrotalcite structures shows a large portion of anions being removed from solution by adsorption processes. Treatment of carbonate solutions (0.2 M) containing arsenate and vanadate (0.2 M) three times with thermally activated hydrotalcite has been shown to remove 76% and 81% of the toxic anions, respectively. Thermally activated hydrotalcite with a Mg:Al ratio of 2:1, 3:1, and 4:1 have all been shown to remove 95% of arsenate and vanadate (25 ppm). At increased concentrations of arsenate and vanadate, the removal uptake percentage decreased significantly, except for the 4:1 thermally activated hydrotalcite. Thermally activated Bayer hydrotalcite has also been shown to be highly effective in the removal of arsenate and vanadate. The thermal activation of the solid residue component (red mud) removes 30% of anions from solution (100 ppm of both anions), while seawater-neutralized red mud removes 70%. The formation of hydrotalcite during the seawater neutralization process removes anions via two mechanisms, rather than one observed for thermally activated red mud. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101104r
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8969–8976[article] Use of hydrotalcites for the removal of toxic anions from aqueous solutions [texte imprimé] / Sara J. Palmer, Auteur ; Ray L. Frost, Auteur . - 2010 . - pp. 8969–8976.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8969–8976
Mots-clés : Hydrotalcites Aqueous solutions Résumé : The removal of toxic anions has been achieved using hydrotalcite via two methods: (1) coprecipitation and (2) thermal activation. Hydrotalcite formed via the coprecipitation method, using solutions containing arsenate and vanadate up to pH 10, are able to remove more than 95% of the toxic anions (0.2 M) from solution. The removal of toxic anions in solutions with a pH of >10 reduces the removal uptake percentage to 75%. Raman spectroscopy observed multiple A1 stretching modes of V−O and As−O at 930 and 810 cm−1, assigned to vanadate and arsenate, respectively. Analysis of the intensity and position of the A1 stretching modes helped to identify the vanadate and arsenate specie intercalated into the hydrotalcite structure. It has been determined that 3:1 hydrotalcite structure predominantly intercalate anions into the interlayer region, while the 2:1 and 4:1 hydrotalcite structures shows a large portion of anions being removed from solution by adsorption processes. Treatment of carbonate solutions (0.2 M) containing arsenate and vanadate (0.2 M) three times with thermally activated hydrotalcite has been shown to remove 76% and 81% of the toxic anions, respectively. Thermally activated hydrotalcite with a Mg:Al ratio of 2:1, 3:1, and 4:1 have all been shown to remove 95% of arsenate and vanadate (25 ppm). At increased concentrations of arsenate and vanadate, the removal uptake percentage decreased significantly, except for the 4:1 thermally activated hydrotalcite. Thermally activated Bayer hydrotalcite has also been shown to be highly effective in the removal of arsenate and vanadate. The thermal activation of the solid residue component (red mud) removes 30% of anions from solution (100 ppm of both anions), while seawater-neutralized red mud removes 70%. The formation of hydrotalcite during the seawater neutralization process removes anions via two mechanisms, rather than one observed for thermally activated red mud. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101104r Exemplaires
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Titre : Catalytic cracking and coking of supercritical n - dodecane in microchannel coated with HZSM - 5 zeolites Type de document : texte imprimé Auteurs : Fanxu Meng, Auteur ; Guozhu Liu, Auteur ; Shudong Qu, Auteur Année de publication : 2010 Article en page(s) : pp. 8977–8983 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrocarbon fuels Thermal catalytic cracking Microchannel Résumé : To improve the cracking rate of supercritical hydrocarbon fuels, HZSM-5 coating was prepared over the inner surface of microchannels reactors by the washcoating method. Thermal or catalytic cracking of n-dodecane, a model compound of hydrocarbon fuels, was experimentally investigated in the stainless steel microchannel coated with HZSM-5 coatings under supercritical conditions (p > 4 MPa, T > 450 °C). It is found that cracking of n-dodecane was enhanced more than 100% by HZSM-5 coatings in 30 min reaction durations at 525 and 550 °C despite gradual deactivations of catalytic activities due to conversion coke from pyrolysis and acid-catalyzed reaction. Cokes deposited on the microchannels with and without HZSM-5 coating were characterized by scanning electron microscopy (SEM) and temperature-programmed oxidation (TPO), indicating that HZSM-5 coating effectively reduces formation of filamentous cokes and its damage on the micro channel surface by shielding surface metals when the temperature is higher than 600 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101158w
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8977–8983[article] Catalytic cracking and coking of supercritical n - dodecane in microchannel coated with HZSM - 5 zeolites [texte imprimé] / Fanxu Meng, Auteur ; Guozhu Liu, Auteur ; Shudong Qu, Auteur . - 2010 . - pp. 8977–8983.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8977–8983
Mots-clés : Hydrocarbon fuels Thermal catalytic cracking Microchannel Résumé : To improve the cracking rate of supercritical hydrocarbon fuels, HZSM-5 coating was prepared over the inner surface of microchannels reactors by the washcoating method. Thermal or catalytic cracking of n-dodecane, a model compound of hydrocarbon fuels, was experimentally investigated in the stainless steel microchannel coated with HZSM-5 coatings under supercritical conditions (p > 4 MPa, T > 450 °C). It is found that cracking of n-dodecane was enhanced more than 100% by HZSM-5 coatings in 30 min reaction durations at 525 and 550 °C despite gradual deactivations of catalytic activities due to conversion coke from pyrolysis and acid-catalyzed reaction. Cokes deposited on the microchannels with and without HZSM-5 coating were characterized by scanning electron microscopy (SEM) and temperature-programmed oxidation (TPO), indicating that HZSM-5 coating effectively reduces formation of filamentous cokes and its damage on the micro channel surface by shielding surface metals when the temperature is higher than 600 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101158w Exemplaires
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Titre : Investigation of the reaction network in ethanol steam reforming over supported cobalt catalysts Type de document : texte imprimé Auteurs : Hua, Song, Auteur ; Lingzhi Zhang, Auteur ; Umit S. Ozkan, Auteur Année de publication : 2010 Article en page(s) : pp. 8984–8989 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ethanol steam Isotopic labeling Catalysts Résumé : In this study, a network of reactions involved in the ethanol steam reforming (ESR) over supported Co catalysts has been investigated using temperature-programmed reaction (TPRxn) and isotopic labeling techniques. The products and intermediates in the gas phase have been monitored by mass spectrometry (MS) as a function of temperature. Ethanol conversion and product distribution obtained in steady-state reaction experiments have also been presented. The results point to a complex network of reactions that directly impact the selectivity and H2 yield that can be obtained in ethanol steam reforming. The reaction network is governed by the temperature range as well as the type of catalyst used, with catalysts exhibiting higher oxygen mobility favoring complete oxidation of ethanol to CO2 and leading to increased hydrogen yield as well as improved stability. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100006z
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8984–8989[article] Investigation of the reaction network in ethanol steam reforming over supported cobalt catalysts [texte imprimé] / Hua, Song, Auteur ; Lingzhi Zhang, Auteur ; Umit S. Ozkan, Auteur . - 2010 . - pp. 8984–8989.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8984–8989
Mots-clés : Ethanol steam Isotopic labeling Catalysts Résumé : In this study, a network of reactions involved in the ethanol steam reforming (ESR) over supported Co catalysts has been investigated using temperature-programmed reaction (TPRxn) and isotopic labeling techniques. The products and intermediates in the gas phase have been monitored by mass spectrometry (MS) as a function of temperature. Ethanol conversion and product distribution obtained in steady-state reaction experiments have also been presented. The results point to a complex network of reactions that directly impact the selectivity and H2 yield that can be obtained in ethanol steam reforming. The reaction network is governed by the temperature range as well as the type of catalyst used, with catalysts exhibiting higher oxygen mobility favoring complete oxidation of ethanol to CO2 and leading to increased hydrogen yield as well as improved stability. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100006z Exemplaires
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Titre : Vacuum pyrolysis of waste tires by continuously feeding into a conical spouted bed reactor Type de document : texte imprimé Auteurs : Gartzen Lopez, Auteur ; Martin Olazar, Auteur ; Roberto Aguado, Auteur Année de publication : 2010 Article en page(s) : pp. 8990–8997 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pyrolysis Waste tires Résumé : The continuous pyrolysis of waste tires under vacuum conditions (25 and 50 kPa) has been studied in a pilot plant equipped with a conical spouted bed reactor and operating with continuous feed at 425 and 500 °C. The effects of vacuum on product distribution and properties have been studied. The main effect of vacuum is an increase in the diesel fraction yield of the liquid product. A remarkable yield of isoprene has been obtained operating under vacuum, reaching yields of higher than 7 wt %. Moreover, a positive effect on the quality of the residual carbon black has been observed, given that a decrease in pore blockage gives way to higher surface areas of the carbon blacks obtained. The results show that vacuum operation does not limit the good perspectives for waste tire valorization by pyrolysis in a conical spouted bed, and energy requirements for heating the inert gas and the condensation section are significantly reduced. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000604
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8990–8997[article] Vacuum pyrolysis of waste tires by continuously feeding into a conical spouted bed reactor [texte imprimé] / Gartzen Lopez, Auteur ; Martin Olazar, Auteur ; Roberto Aguado, Auteur . - 2010 . - pp. 8990–8997.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8990–8997
Mots-clés : Pyrolysis Waste tires Résumé : The continuous pyrolysis of waste tires under vacuum conditions (25 and 50 kPa) has been studied in a pilot plant equipped with a conical spouted bed reactor and operating with continuous feed at 425 and 500 °C. The effects of vacuum on product distribution and properties have been studied. The main effect of vacuum is an increase in the diesel fraction yield of the liquid product. A remarkable yield of isoprene has been obtained operating under vacuum, reaching yields of higher than 7 wt %. Moreover, a positive effect on the quality of the residual carbon black has been observed, given that a decrease in pore blockage gives way to higher surface areas of the carbon blacks obtained. The results show that vacuum operation does not limit the good perspectives for waste tire valorization by pyrolysis in a conical spouted bed, and energy requirements for heating the inert gas and the condensation section are significantly reduced. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000604 Exemplaires
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Titre : Heteropolyanion - based ionic liquid for deep desulfurization of fuels in ionic liquids Type de document : texte imprimé Auteurs : Wangli Huang, Auteur ; Wenshuai Zhu, Auteur ; Huaming Li, Auteur Année de publication : 2010 Article en page(s) : pp. 8998–9003 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Heteropolyanion Ionic liquid Catalyst Desulfurization Résumé : A heteropolyanion-based ionic liquid, [(3-sulfonic acid) propylpyridine]3PW12O40·2H2O, [PSPy]3PW12O40·2H2O, abbreviated [PSPy]3PW, was synthesized and approved as an effective catalyst for desulfurization of fuels in [omim]PF6 by using aqueous H2O2 as oxidant. The catalysis was fulfilled with advantages of high activity, simplified workup, and flexible recyclability. The catalytic oxidation reactivity of sulfur-containing compounds was in the order dibenzothiophene (DBT) > 4,6-dimethyldibenzothiophene (4,6-DMDBT) > benzothiophene (BT). The effects of the amount of [PSPy]3PW, H2O2, and reaction time and temperature were investigated in detail. Under the optimal conditions, the removal of DBT achieved 99.4%. Especially, we found that the removal of 4,6-DMDBT could be up to 98.8%, and the system could be recycled at least 9 times without significant decrease in activity. The sulfur level of FCC gasoline could be reduced from 360 to 70 ppm in the extraction and catalytic oxidation system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100234d
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8998–9003[article] Heteropolyanion - based ionic liquid for deep desulfurization of fuels in ionic liquids [texte imprimé] / Wangli Huang, Auteur ; Wenshuai Zhu, Auteur ; Huaming Li, Auteur . - 2010 . - pp. 8998–9003.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 8998–9003
Mots-clés : Heteropolyanion Ionic liquid Catalyst Desulfurization Résumé : A heteropolyanion-based ionic liquid, [(3-sulfonic acid) propylpyridine]3PW12O40·2H2O, [PSPy]3PW12O40·2H2O, abbreviated [PSPy]3PW, was synthesized and approved as an effective catalyst for desulfurization of fuels in [omim]PF6 by using aqueous H2O2 as oxidant. The catalysis was fulfilled with advantages of high activity, simplified workup, and flexible recyclability. The catalytic oxidation reactivity of sulfur-containing compounds was in the order dibenzothiophene (DBT) > 4,6-dimethyldibenzothiophene (4,6-DMDBT) > benzothiophene (BT). The effects of the amount of [PSPy]3PW, H2O2, and reaction time and temperature were investigated in detail. Under the optimal conditions, the removal of DBT achieved 99.4%. Especially, we found that the removal of 4,6-DMDBT could be up to 98.8%, and the system could be recycled at least 9 times without significant decrease in activity. The sulfur level of FCC gasoline could be reduced from 360 to 70 ppm in the extraction and catalytic oxidation system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100234d Exemplaires
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Titre : Co / pillared clay bifunctional catalyst for controlling the product distribution of fischer − tropsch synthesis Type de document : texte imprimé Auteurs : Qing-Qing Hao, Auteur ; Guang-Wei Wang, Auteur ; Zhao-Tie Liu, Auteur Année de publication : 2010 Article en page(s) : pp. 9004–9011 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pillared clays Catalyst Résumé : Pillared interlayer clays (PILCs) were synthesized by pillaring montmorillonite with SiO2, Al2O3, and ZrO2, and Co-supported PILCs were prepared by the impregnation method. For comparison, Co/SiO2 and Co-supported montmorillonite treated with dilute HNO3 (acid-clay) were also prepared. The materials were characterized by XRD, H2-TPR, NH3-TPD, O2 titration, and N2 adsorption−desorption. The Co-supported catalysts were comparatively investigated for Fischer−Tropsch (FT) synthesis in a fixed-bed reactor under the conditions of 1 MPa, 508 K, H2/CO = 2, and W/F = 5.02 g·h·mol−1. The results indicate that the activities of the catalysts (i.e., CO conversions) increase in the order of Co/Na-Clay Co/Si-PILC ≈ Co/acid-clay ≈ Co/Al-PILC ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101163w
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9004–9011[article] Co / pillared clay bifunctional catalyst for controlling the product distribution of fischer − tropsch synthesis [texte imprimé] / Qing-Qing Hao, Auteur ; Guang-Wei Wang, Auteur ; Zhao-Tie Liu, Auteur . - 2010 . - pp. 9004–9011.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9004–9011
Mots-clés : Pillared clays Catalyst Résumé : Pillared interlayer clays (PILCs) were synthesized by pillaring montmorillonite with SiO2, Al2O3, and ZrO2, and Co-supported PILCs were prepared by the impregnation method. For comparison, Co/SiO2 and Co-supported montmorillonite treated with dilute HNO3 (acid-clay) were also prepared. The materials were characterized by XRD, H2-TPR, NH3-TPD, O2 titration, and N2 adsorption−desorption. The Co-supported catalysts were comparatively investigated for Fischer−Tropsch (FT) synthesis in a fixed-bed reactor under the conditions of 1 MPa, 508 K, H2/CO = 2, and W/F = 5.02 g·h·mol−1. The results indicate that the activities of the catalysts (i.e., CO conversions) increase in the order of Co/Na-Clay Co/Si-PILC ≈ Co/acid-clay ≈ Co/Al-PILC ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101163w Exemplaires
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Titre : CFD method to couple three - dimensional transport and reaction inside catalyst particles to the fixed bed flow field Type de document : texte imprimé Auteurs : Anthony G. Dixon, Auteur ; M. Ertan Taskin, Auteur ; Michiel Nijemeisland, Auteur Année de publication : 2010 Article en page(s) : pp. 9012–9025 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Computational fluid dynamics Catalyst particles Flow field Résumé : A new method is presented to couple the fluid flow in a fixed bed to the transport and reaction inside a catalyst particle, using computational fluid dynamics (CFD). The particle is modeled as solid, allowing no-slip surface flow boundary conditions to be used. Species transport inside the particle is represented by user-defined scalars, and the catalytic reactions are represented by user-defined functions. The new method is validated using standard cases for which exact results are known. Previous work has used a porous representation of the catalyst particle, which results in inaccurate temperature and species profiles due to an artifact of convective flux across the particle−fluid interface. This also gives incorrect values of the particle-to-fluid heat transfer coefficient, compared to standard correlations. Simulation results are presented for methane steam reforming using spherical particles in a wall segment, under tube inlet and midtube conditions, to illustrate the solid particle method. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100298q
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9012–9025[article] CFD method to couple three - dimensional transport and reaction inside catalyst particles to the fixed bed flow field [texte imprimé] / Anthony G. Dixon, Auteur ; M. Ertan Taskin, Auteur ; Michiel Nijemeisland, Auteur . - 2010 . - pp. 9012–9025.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9012–9025
Mots-clés : Computational fluid dynamics Catalyst particles Flow field Résumé : A new method is presented to couple the fluid flow in a fixed bed to the transport and reaction inside a catalyst particle, using computational fluid dynamics (CFD). The particle is modeled as solid, allowing no-slip surface flow boundary conditions to be used. Species transport inside the particle is represented by user-defined scalars, and the catalytic reactions are represented by user-defined functions. The new method is validated using standard cases for which exact results are known. Previous work has used a porous representation of the catalyst particle, which results in inaccurate temperature and species profiles due to an artifact of convective flux across the particle−fluid interface. This also gives incorrect values of the particle-to-fluid heat transfer coefficient, compared to standard correlations. Simulation results are presented for methane steam reforming using spherical particles in a wall segment, under tube inlet and midtube conditions, to illustrate the solid particle method. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100298q Exemplaires
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Titre : Flow, transport, and reaction interactions for cylindrical particles with strongly endothermic reactions Type de document : texte imprimé Auteurs : M. Ertan Taskin, Auteur ; Alexandre Troupel, Auteur ; Anthony G. Dixon, Auteur Année de publication : 2010 Article en page(s) : pp. 9026–9037 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst particles Methane steam reforming Dehydrogenation Résumé : Interactions between reaction rates, conduction, and diffusion inside catalyst particles can be complex, especially when influenced by nonuniform surface conditions produced by the flow field external to the particle, or by the highly directional temperature field near a heated tube wall. In this work, a three-dimensional, realistic flow field was coupled to species and energy balances in cylindrical catalyst particles using computational fluid dynamics (CFD). Two strongly endothermic reactions were studied: methane steam reforming and propane dehydrogenation. Detailed pellet surface and intraparticle temperature, species, and reaction rate distributions were obtained for a near-wall particle. Nonuniform and nonsymmetric surface and intraparticle variations were observed. These effects are primarily attributed to the steep temperature gradients at the tube wall, as well as depletion of the reactants in regions of low or stagnant flow where particles approach each other closely. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003619
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9026–9037[article] Flow, transport, and reaction interactions for cylindrical particles with strongly endothermic reactions [texte imprimé] / M. Ertan Taskin, Auteur ; Alexandre Troupel, Auteur ; Anthony G. Dixon, Auteur . - 2010 . - pp. 9026–9037.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9026–9037
Mots-clés : Catalyst particles Methane steam reforming Dehydrogenation Résumé : Interactions between reaction rates, conduction, and diffusion inside catalyst particles can be complex, especially when influenced by nonuniform surface conditions produced by the flow field external to the particle, or by the highly directional temperature field near a heated tube wall. In this work, a three-dimensional, realistic flow field was coupled to species and energy balances in cylindrical catalyst particles using computational fluid dynamics (CFD). Two strongly endothermic reactions were studied: methane steam reforming and propane dehydrogenation. Detailed pellet surface and intraparticle temperature, species, and reaction rate distributions were obtained for a near-wall particle. Nonuniform and nonsymmetric surface and intraparticle variations were observed. These effects are primarily attributed to the steep temperature gradients at the tube wall, as well as depletion of the reactants in regions of low or stagnant flow where particles approach each other closely. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003619 Exemplaires
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Titre : Effect of oxygen addition on the thermokinetic properties of CO2 chemisorption on Li2ZrO3 Type de document : texte imprimé Auteurs : Lorena Martinez-dlCruz, Auteur ; Heriberto Pfeiffer, Auteur Année de publication : 2010 Article en page(s) : pp. 9038-9042 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Chemisorption Carbon dioxide Résumé : Lithium zirconate doped with potassium (K-Li2ZrO3) was synthesized by solid-state reaction and then its CO2 chemisorption capacity was evaluated using different CO2-O2 gas mixtures. These experiments were performed in order to evaluate the effect produced by the O2 on the kinetic parameters and on the CO2 absorption reaction mechanism. Although the CO2 capture dynamic experiments did not show significant variations as a function of the O2 content, isothermal experiments and their fitting to the Eyring's model did. Different enthalpy activation (ΔH‡) values were estimated for the CO2 chemisorption process, as CO2 capture is produced by two processes: Initially, the CO2 chemisorption occurs directly over the K-Li2ZrO3 surface. Then, once a Li2CO3-ZrO2 external shell is produced, CO2 chemisorption is kinetically controlled by diffusion processes, which must imply the lithium and oxygen diffusion. The ΔH‡ values, of the CO2 direct chemisorption, increased as a function of the O2 content. It was explained in terms of a CO2-O2 competition to occupy the Li2ZrO3 surface. On the other hand, the ΔH‡ values, of the CO2 chemisorption kinetically controlled by diffusion processes, decreased as a function of the O2 content. This result confirmed the oxygen diffusion dependency of the CO2 chemisorption on lithium zirconate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289634
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9038-9042[article] Effect of oxygen addition on the thermokinetic properties of CO2 chemisorption on Li2ZrO3 [texte imprimé] / Lorena Martinez-dlCruz, Auteur ; Heriberto Pfeiffer, Auteur . - 2010 . - pp. 9038-9042.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9038-9042
Mots-clés : Chemisorption Carbon dioxide Résumé : Lithium zirconate doped with potassium (K-Li2ZrO3) was synthesized by solid-state reaction and then its CO2 chemisorption capacity was evaluated using different CO2-O2 gas mixtures. These experiments were performed in order to evaluate the effect produced by the O2 on the kinetic parameters and on the CO2 absorption reaction mechanism. Although the CO2 capture dynamic experiments did not show significant variations as a function of the O2 content, isothermal experiments and their fitting to the Eyring's model did. Different enthalpy activation (ΔH‡) values were estimated for the CO2 chemisorption process, as CO2 capture is produced by two processes: Initially, the CO2 chemisorption occurs directly over the K-Li2ZrO3 surface. Then, once a Li2CO3-ZrO2 external shell is produced, CO2 chemisorption is kinetically controlled by diffusion processes, which must imply the lithium and oxygen diffusion. The ΔH‡ values, of the CO2 direct chemisorption, increased as a function of the O2 content. It was explained in terms of a CO2-O2 competition to occupy the Li2ZrO3 surface. On the other hand, the ΔH‡ values, of the CO2 chemisorption kinetically controlled by diffusion processes, decreased as a function of the O2 content. This result confirmed the oxygen diffusion dependency of the CO2 chemisorption on lithium zirconate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289634 Exemplaires
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Titre : Fenton’s depuration of weathered olive mill wastewaters over a Fe − Ce − O solid catalyst Type de document : texte imprimé Auteurs : Rui C. Martins, Auteur ; Teresa Gomes, Auteur ; Rosa M. Quinta-Ferreira, Auteur Année de publication : 2010 Article en page(s) : pp. 9043–9051 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Treatment wastewaters Catalyst Résumé : The treatment of actual olive mill wastewaters, coming from an evaporation pond subjected to climatic conditions, was studied by the heterogeneous Fenton process with the laboratory catalyst Fe−Ce−O 70/30. Investigating the impact of the solid load, hydrogen peroxide concentration, and pH over the methodology efficiency a full factorial experimental design was followed by results stating that the amount of Fe−Ce−O 70/30 and pH had a high influence on final depuration, while [H2O2] was not statistically relevant. Reduced models based on those data showed some ability to predict chemical oxygen demand (COD) removal, final effluent biodegradability, and iron leached concentration. Also respirometric and luminescence techniques were used to evaluate toxicity. The recommend operational conditions gathered up when each one of the response factors was optimized were diverse. From those, it seemed appropriate to run with high Fe−Ce−O loads (1.5 g/L) allied with pH = 4 and [H2O2] = 115 mM since, even if COD degradation (24%) was not the highest one, the final effluent was very biodegradable (BOD5/COD = 0.54) allowing the application of an activated sludge post-treatment. Furthermore, for these conditions, catalyst stability was safeguarded since Fe elution was low (0.12 mg/L). Finally, the catalytic system involving Fenton’s peroxidation Fe−Ce−O 70/30 was revealed to be promising for real olive mill wastewaters biodegradability improvement and toxicity removal enabling a proper postbioremediation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101203p
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9043–9051[article] Fenton’s depuration of weathered olive mill wastewaters over a Fe − Ce − O solid catalyst [texte imprimé] / Rui C. Martins, Auteur ; Teresa Gomes, Auteur ; Rosa M. Quinta-Ferreira, Auteur . - 2010 . - pp. 9043–9051.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9043–9051
Mots-clés : Treatment wastewaters Catalyst Résumé : The treatment of actual olive mill wastewaters, coming from an evaporation pond subjected to climatic conditions, was studied by the heterogeneous Fenton process with the laboratory catalyst Fe−Ce−O 70/30. Investigating the impact of the solid load, hydrogen peroxide concentration, and pH over the methodology efficiency a full factorial experimental design was followed by results stating that the amount of Fe−Ce−O 70/30 and pH had a high influence on final depuration, while [H2O2] was not statistically relevant. Reduced models based on those data showed some ability to predict chemical oxygen demand (COD) removal, final effluent biodegradability, and iron leached concentration. Also respirometric and luminescence techniques were used to evaluate toxicity. The recommend operational conditions gathered up when each one of the response factors was optimized were diverse. From those, it seemed appropriate to run with high Fe−Ce−O loads (1.5 g/L) allied with pH = 4 and [H2O2] = 115 mM since, even if COD degradation (24%) was not the highest one, the final effluent was very biodegradable (BOD5/COD = 0.54) allowing the application of an activated sludge post-treatment. Furthermore, for these conditions, catalyst stability was safeguarded since Fe elution was low (0.12 mg/L). Finally, the catalytic system involving Fenton’s peroxidation Fe−Ce−O 70/30 was revealed to be promising for real olive mill wastewaters biodegradability improvement and toxicity removal enabling a proper postbioremediation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101203p Exemplaires
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Titre : Effect of SO2 on the reaction of calcium hydroxide with CO2 at low temperatures Type de document : texte imprimé Auteurs : Liu, Chiung-Fang, Auteur ; Shin-Min Shih, Auteur ; Tsai-Bang Huang, Auteur Année de publication : 2010 Article en page(s) : pp. 9052–9057 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydroxide Low temperature CO2 Résumé : The flue gas generated from a coal-fired power plant contains CO2 and SO2. The effect of SO2 concentration (≤1000 ppm) on the reaction of CO2 with Ca(OH)2 was studied using a differential fixed-bed reactor under the low-temperature and humid conditions similar to those in the bag filters of a dry or semidry flue gas desulfurization (FGD) system. When both CO2 and SO2 were present, they reacted with Ca(OH)2 simultaneously to form calcium carbonate and sulfite, but part of the carbonate formed reacted further with SO2 to form sulfite. Ca(OH)2 ceased to react due to the formation of an impervious product layer. The fraction of carbonate increased significantly with decreasing SO2 concentration in the range below 500 ppm SO2, but the fraction of sulfite decreased little except in the range below 100 ppm SO2 or at a relative humidity (RH) above 70%. Both fractions of carbonate and sulfite increased markedly with increasing relative humidity and slightly with increasing temperature, but they were little affected by the CO2 concentration and the presence of O2. At SO2 concentrations ≤100 ppm, conversions of Ca(OH)2 to carbonate in the range comparable to or higher than the typical conversions of Ca(OH)2 for SO2 removal in a dry or semidry FGD process could be achieved. The results of this work are useful for evaluating the feasibility of using solid wastes containing CaO and/or Ca(OH)2 to capture CO2 from flue gas at low temperatures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100924z
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9052–9057[article] Effect of SO2 on the reaction of calcium hydroxide with CO2 at low temperatures [texte imprimé] / Liu, Chiung-Fang, Auteur ; Shin-Min Shih, Auteur ; Tsai-Bang Huang, Auteur . - 2010 . - pp. 9052–9057.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9052–9057
Mots-clés : Hydroxide Low temperature CO2 Résumé : The flue gas generated from a coal-fired power plant contains CO2 and SO2. The effect of SO2 concentration (≤1000 ppm) on the reaction of CO2 with Ca(OH)2 was studied using a differential fixed-bed reactor under the low-temperature and humid conditions similar to those in the bag filters of a dry or semidry flue gas desulfurization (FGD) system. When both CO2 and SO2 were present, they reacted with Ca(OH)2 simultaneously to form calcium carbonate and sulfite, but part of the carbonate formed reacted further with SO2 to form sulfite. Ca(OH)2 ceased to react due to the formation of an impervious product layer. The fraction of carbonate increased significantly with decreasing SO2 concentration in the range below 500 ppm SO2, but the fraction of sulfite decreased little except in the range below 100 ppm SO2 or at a relative humidity (RH) above 70%. Both fractions of carbonate and sulfite increased markedly with increasing relative humidity and slightly with increasing temperature, but they were little affected by the CO2 concentration and the presence of O2. At SO2 concentrations ≤100 ppm, conversions of Ca(OH)2 to carbonate in the range comparable to or higher than the typical conversions of Ca(OH)2 for SO2 removal in a dry or semidry FGD process could be achieved. The results of this work are useful for evaluating the feasibility of using solid wastes containing CaO and/or Ca(OH)2 to capture CO2 from flue gas at low temperatures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100924z Exemplaires
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Titre : Entrainer - based reactive distillation for esterification of glycerol with acetic acid Type de document : texte imprimé Auteurs : Amit Hasabnis, Auteur ; Sanjay Mahajani, Auteur Année de publication : 2010 Article en page(s) : pp. 9058–9067 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Reactive distillation Esterification Glycerol Résumé : The applicability of reactive distillation for esterification of glycerol with acetic acid in the presence of Amberlyst-15 as catalyst and ethylene dichloride as an entrainer is evaluated through experiments and simulation. The reaction is studied in both semibatch and continuous reactive distillation systems. The effect of different parameters such as entrainer amount, catalyst loading, and reboiler duty is studied. The results indicate that entrainer-based semibatch reactive distillation can enhance the selectivity toward triacetin to about 100%, which is much greater than that offered by any conventional reactor with stoichiometric mole ratio of reactants. Simulations for both semibatch and continuous reactive distillation are performed, and results agree reasonably well with those obtained by experiments. The best possible design and operating parameters are obtained through detailed simulation using an experimentally validated model. A column configuration is recommended for a continuous process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100937p
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9058–9067[article] Entrainer - based reactive distillation for esterification of glycerol with acetic acid [texte imprimé] / Amit Hasabnis, Auteur ; Sanjay Mahajani, Auteur . - 2010 . - pp. 9058–9067.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9058–9067
Mots-clés : Reactive distillation Esterification Glycerol Résumé : The applicability of reactive distillation for esterification of glycerol with acetic acid in the presence of Amberlyst-15 as catalyst and ethylene dichloride as an entrainer is evaluated through experiments and simulation. The reaction is studied in both semibatch and continuous reactive distillation systems. The effect of different parameters such as entrainer amount, catalyst loading, and reboiler duty is studied. The results indicate that entrainer-based semibatch reactive distillation can enhance the selectivity toward triacetin to about 100%, which is much greater than that offered by any conventional reactor with stoichiometric mole ratio of reactants. Simulations for both semibatch and continuous reactive distillation are performed, and results agree reasonably well with those obtained by experiments. The best possible design and operating parameters are obtained through detailed simulation using an experimentally validated model. A column configuration is recommended for a continuous process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100937p Exemplaires
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Titre : New heterogeneous catalytic transesterification of vegetable and used frying oil Type de document : texte imprimé Auteurs : Maria del Remedio Hernandez, Auteur ; Juan A. Reyes-Labarta, Auteur ; Francisco J. Valdés, Auteur Année de publication : 2010 Article en page(s) : pp. 9068-9076 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Edible species Transesterification Catalytic reaction Résumé : In the present work, a new heterogeneous catalyst for oil transesterification with methanol has been developed. The catalyst is based on the introduction of sodium in calcined hydrotalcite. Two different raw materials have been used to determine the usefulness of this new catalyst: sunflower oil and used frying oil from a university restaurant. In this way, the efficiency of the new heterogeneous catalyst by using an urban residue was tested. Different parameters that can modify the extension of the transesterification reaction have been evaluated. Results obtained at 60 °C show that hydrotalcite modified with sodium presents adequate characteristics for this kind of reactions with both raw materials evaluated. An important factor observed in the present study is that no soap was formed in any of the reactions carried out, even in the case of used oil with high acid index. The iodine index of biodiesel generated with waste cooking oil presents values within the limits established by general biodiesel specifications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289638
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9068-9076[article] New heterogeneous catalytic transesterification of vegetable and used frying oil [texte imprimé] / Maria del Remedio Hernandez, Auteur ; Juan A. Reyes-Labarta, Auteur ; Francisco J. Valdés, Auteur . - 2010 . - pp. 9068-9076.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9068-9076
Mots-clés : Edible species Transesterification Catalytic reaction Résumé : In the present work, a new heterogeneous catalyst for oil transesterification with methanol has been developed. The catalyst is based on the introduction of sodium in calcined hydrotalcite. Two different raw materials have been used to determine the usefulness of this new catalyst: sunflower oil and used frying oil from a university restaurant. In this way, the efficiency of the new heterogeneous catalyst by using an urban residue was tested. Different parameters that can modify the extension of the transesterification reaction have been evaluated. Results obtained at 60 °C show that hydrotalcite modified with sodium presents adequate characteristics for this kind of reactions with both raw materials evaluated. An important factor observed in the present study is that no soap was formed in any of the reactions carried out, even in the case of used oil with high acid index. The iodine index of biodiesel generated with waste cooking oil presents values within the limits established by general biodiesel specifications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289638 Exemplaires
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Titre : A kinetic and mechanistic study on the oxidation of 3 - carboxy - 3 - hydroxy pentanedioic acid in buffered medium Type de document : texte imprimé Auteurs : V. Sumithra, Auteur ; Crystal Y. Wilson, Auteur ; D. Easwaramoorthy, Auteur Année de publication : 2010 Article en page(s) : pp. 9077-9081 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oxidation Kinetics Résumé : The oxidation of 3-carboxy-3-hydroxy pentanedioic acid (citric acid) by N-bromosuccinimide (NBS) in an acetic acid/sodium acetate buffered medium (pH 3.6-5.2) was carried out at 308 K with a constant ionic strength. The rate was first order with respect to both 3-carboxy-3-hydroxy pentanedioic acid and NBS. The rate was inverse first order in succinimide, the reduction product of N-bromosuccinimide. The rate decreased with an increase in pH. A mechanism consistent with the experimental results was proposed and supported by kinetic orders, spectrophotometric evidence, negative entropy of activation, and observed zero ionic strength of the medium. The reaction was carried out at four different temperatures, and the activation parameters were determined. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289639
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9077-9081[article] A kinetic and mechanistic study on the oxidation of 3 - carboxy - 3 - hydroxy pentanedioic acid in buffered medium [texte imprimé] / V. Sumithra, Auteur ; Crystal Y. Wilson, Auteur ; D. Easwaramoorthy, Auteur . - 2010 . - pp. 9077-9081.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9077-9081
Mots-clés : Oxidation Kinetics Résumé : The oxidation of 3-carboxy-3-hydroxy pentanedioic acid (citric acid) by N-bromosuccinimide (NBS) in an acetic acid/sodium acetate buffered medium (pH 3.6-5.2) was carried out at 308 K with a constant ionic strength. The rate was first order with respect to both 3-carboxy-3-hydroxy pentanedioic acid and NBS. The rate was inverse first order in succinimide, the reduction product of N-bromosuccinimide. The rate decreased with an increase in pH. A mechanism consistent with the experimental results was proposed and supported by kinetic orders, spectrophotometric evidence, negative entropy of activation, and observed zero ionic strength of the medium. The reaction was carried out at four different temperatures, and the activation parameters were determined. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289639 Exemplaires
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Titre : NaY zeolites catalyze dehydration of lactic acid to acrylic acid : Studies on the effects of anions in potassium salts Type de document : texte imprimé Auteurs : Peng Sun, Auteur ; Dinghua Yu, Auteur ; Zhenchen Tang, Auteur Année de publication : 2010 Article en page(s) : pp. 9082–9087 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Zeolite Catalyst Dehydration acid Potassium salts Résumé : NaY zeolite catalysts with and without potassium salt modifications were studied with respect to dehydration of lactic acid to acrylic acid. The selectivity for acrylic acid could be dramatically enhanced by modification of the NaY catalysts with potassium salts. The KI-modified NaY catalyst exhibited the best catalytic performance for lactic acid dehydration, over which 97.6% conversion and 67.9% acrylic acid selectivity could be gained at 598 K. Characterizations with TGA, XRD, N2 adsorption, 27Al MAS NMR, XPS, NH3-TPD, CO2-TPD, and mechanism analysis revealed that the counteranions in potassium salts exerted a significant influence on the catalytic behaviors via an electronic effect. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101093x
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9082–9087[article] NaY zeolites catalyze dehydration of lactic acid to acrylic acid : Studies on the effects of anions in potassium salts [texte imprimé] / Peng Sun, Auteur ; Dinghua Yu, Auteur ; Zhenchen Tang, Auteur . - 2010 . - pp. 9082–9087.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9082–9087
Mots-clés : Zeolite Catalyst Dehydration acid Potassium salts Résumé : NaY zeolite catalysts with and without potassium salt modifications were studied with respect to dehydration of lactic acid to acrylic acid. The selectivity for acrylic acid could be dramatically enhanced by modification of the NaY catalysts with potassium salts. The KI-modified NaY catalyst exhibited the best catalytic performance for lactic acid dehydration, over which 97.6% conversion and 67.9% acrylic acid selectivity could be gained at 598 K. Characterizations with TGA, XRD, N2 adsorption, 27Al MAS NMR, XPS, NH3-TPD, CO2-TPD, and mechanism analysis revealed that the counteranions in potassium salts exerted a significant influence on the catalytic behaviors via an electronic effect. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101093x Exemplaires
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Titre : Reburning in oxy - fuel combustion : A parametric study of the combustion chemistry Type de document : texte imprimé Auteurs : Fredrik Normann, Auteur ; Klas Andersson, Auteur ; Filip Johnsson, Auteur Année de publication : 2010 Article en page(s) : pp. 9088–9094 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nitrogen oxides Oxy fuel combustion Résumé : The present work investigates reburning reduction of nitrogen oxides in oxy-fuel combustion by means of a detailed reaction mechanism applied to a plug-flow reactor. Reburning reactions, which are known to convert NOx into N2, are of special interest in oxy-fuel combustion because of extensive recirculation of flue gases, including NOx, to the flame. Furthermore, the high concentration of carbon dioxide in oxy-fuel combustion is known to influence the radical pool (H/O/OH), which is critical to the combustion chemistry. In the present work, it is shown how the changes in the radical pool alter the nitrogen chemistry both directly and indirectly by influencing the formation and oxidation of hydrocarbon radicals. It is shown that reburning is more sensitive to the combustion temperature but is less affected by the combustion stoichiometry under oxy-fuel compared to air conditions. The main reasons are the impact of increased CO2 concentration on hydrocarbon oxidation and the increased importance of CH3 as a reactant in oxy-fuel combustion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101192a
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9088–9094[article] Reburning in oxy - fuel combustion : A parametric study of the combustion chemistry [texte imprimé] / Fredrik Normann, Auteur ; Klas Andersson, Auteur ; Filip Johnsson, Auteur . - 2010 . - pp. 9088–9094.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9088–9094
Mots-clés : Nitrogen oxides Oxy fuel combustion Résumé : The present work investigates reburning reduction of nitrogen oxides in oxy-fuel combustion by means of a detailed reaction mechanism applied to a plug-flow reactor. Reburning reactions, which are known to convert NOx into N2, are of special interest in oxy-fuel combustion because of extensive recirculation of flue gases, including NOx, to the flame. Furthermore, the high concentration of carbon dioxide in oxy-fuel combustion is known to influence the radical pool (H/O/OH), which is critical to the combustion chemistry. In the present work, it is shown how the changes in the radical pool alter the nitrogen chemistry both directly and indirectly by influencing the formation and oxidation of hydrocarbon radicals. It is shown that reburning is more sensitive to the combustion temperature but is less affected by the combustion stoichiometry under oxy-fuel compared to air conditions. The main reasons are the impact of increased CO2 concentration on hydrocarbon oxidation and the increased importance of CH3 as a reactant in oxy-fuel combustion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101192a Exemplaires
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Titre : Kinetic model for the reversible hydration of carbon dioxide catalyzed by human carbonic anhydrase II Type de document : texte imprimé Auteurs : F. Larachi, Auteur Année de publication : 2010 Article en page(s) : pp. 9095–9104 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetic Hydration carbon dioxide Résumé : Four variants of the two-step Ping Pong mechanism for the reversible hydration of carbon dioxide to bicarbonate catalyzed by free human carbonic anhydrase II (HCA II) in solutions were derived and their goodness-of-fit to match measured initial hydration rates tested. The pseudo (i.e., no central complex) random Quad Quad Iso Ping Pong mechanism with one transitory complex was retained which implied a possible competitive intermolecular proton transfer step by the CO2/HCO3− pair with respect to external buffer. The model suggests this role could be emphasized in product inhibition conditions at high bicarbonate/buffer concentration ratios. A 4-parameter kinetic model was derived to complement the existing single- (intra- or intermolecular) limiting-step models for HCA II catalyzed hydration of CO2 in which were accounted for altogether the enzyme isomerization and CO2/HCO3− proton transfer via a [CO2]·[HCO3−] coupling, the CO2/HCO3− proton transfer via [HCO3−]2 and [CO2]·[HCO3−]2 couplings, and an enzyme−substrate transitory complex via [CO2]·[HCO3−]·[Buffer] coupling. This model may prove helpful for analysis of CO2 capture reactor models subject to mixed (intra- or intermolecular) proton-transfer control, intermolecular proton transfer competition by the CO2/HCO3− pair, and large CO2 conversions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101338r
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9095–9104[article] Kinetic model for the reversible hydration of carbon dioxide catalyzed by human carbonic anhydrase II [texte imprimé] / F. Larachi, Auteur . - 2010 . - pp. 9095–9104.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9095–9104
Mots-clés : Kinetic Hydration carbon dioxide Résumé : Four variants of the two-step Ping Pong mechanism for the reversible hydration of carbon dioxide to bicarbonate catalyzed by free human carbonic anhydrase II (HCA II) in solutions were derived and their goodness-of-fit to match measured initial hydration rates tested. The pseudo (i.e., no central complex) random Quad Quad Iso Ping Pong mechanism with one transitory complex was retained which implied a possible competitive intermolecular proton transfer step by the CO2/HCO3− pair with respect to external buffer. The model suggests this role could be emphasized in product inhibition conditions at high bicarbonate/buffer concentration ratios. A 4-parameter kinetic model was derived to complement the existing single- (intra- or intermolecular) limiting-step models for HCA II catalyzed hydration of CO2 in which were accounted for altogether the enzyme isomerization and CO2/HCO3− proton transfer via a [CO2]·[HCO3−] coupling, the CO2/HCO3− proton transfer via [HCO3−]2 and [CO2]·[HCO3−]2 couplings, and an enzyme−substrate transitory complex via [CO2]·[HCO3−]·[Buffer] coupling. This model may prove helpful for analysis of CO2 capture reactor models subject to mixed (intra- or intermolecular) proton-transfer control, intermolecular proton transfer competition by the CO2/HCO3− pair, and large CO2 conversions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101338r Exemplaires
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Titre : Carbonation of CaO - based sorbents enhanced by steam addition Type de document : texte imprimé Auteurs : Vasilije Manovic, Auteur ; Edward J. Anthony, Auteur Année de publication : 2010 Article en page(s) : pp. 9105–9110 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbonation Combustion Thermogravimetric analyzer Résumé : The carbonation reaction has recently been intensively investigated as a means of CO2 capture from gas mixtures such as flue gas produced during fossil fuel combustion. Unfortunately, this gas−solid reaction is limited due to formation of the solid product (CaCO3) at the reacting surface and sintering, all of which reduce the carrying capacity of the sorbent. In this work the enhancement of carbonation conversion by means of steam addition to the carbonating gas was studied. Seven limestones of different origin and composition as well as one synthetic sorbent (calcium aluminate pellets) were tested. A thermogravimetric analyzer (TGA) was employed for the carbonation tests at different temperatures (350−800 °C) in a gas mixture containing typically 20% CO2 and 10 or 20% H2O(g). The samples tested were calcined under an N2 (800 °C) or CO2 (950 °C) atmosphere to explore the influence of different levels of sample sintering, and the results obtained were compared with those seen for carbonation in dry (no steam) gas mixtures. The morphology of samples after carbonation under different conditions was examined by a scanning electron microscope (SEM). It was found that carbonation is enhanced by steam, but this is more pronounced at lower temperatures and for more sintered samples. With increasing temperature and carbonation time, the enhancement of carbonation becomes negligible because the conversion reaches a “maximum” value (75−80% for samples calcined in N2) even without steam. Carbonation of samples calcined in CO2 is enhanced at different levels depending on the sorbent tested. The shape of carbonation profiles and morphology of carbonated samples show that steam enhances solid state diffusion and, consequently, conversion during carbonation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101352s
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9105–9110[article] Carbonation of CaO - based sorbents enhanced by steam addition [texte imprimé] / Vasilije Manovic, Auteur ; Edward J. Anthony, Auteur . - 2010 . - pp. 9105–9110.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9105–9110
Mots-clés : Carbonation Combustion Thermogravimetric analyzer Résumé : The carbonation reaction has recently been intensively investigated as a means of CO2 capture from gas mixtures such as flue gas produced during fossil fuel combustion. Unfortunately, this gas−solid reaction is limited due to formation of the solid product (CaCO3) at the reacting surface and sintering, all of which reduce the carrying capacity of the sorbent. In this work the enhancement of carbonation conversion by means of steam addition to the carbonating gas was studied. Seven limestones of different origin and composition as well as one synthetic sorbent (calcium aluminate pellets) were tested. A thermogravimetric analyzer (TGA) was employed for the carbonation tests at different temperatures (350−800 °C) in a gas mixture containing typically 20% CO2 and 10 or 20% H2O(g). The samples tested were calcined under an N2 (800 °C) or CO2 (950 °C) atmosphere to explore the influence of different levels of sample sintering, and the results obtained were compared with those seen for carbonation in dry (no steam) gas mixtures. The morphology of samples after carbonation under different conditions was examined by a scanning electron microscope (SEM). It was found that carbonation is enhanced by steam, but this is more pronounced at lower temperatures and for more sintered samples. With increasing temperature and carbonation time, the enhancement of carbonation becomes negligible because the conversion reaches a “maximum” value (75−80% for samples calcined in N2) even without steam. Carbonation of samples calcined in CO2 is enhanced at different levels depending on the sorbent tested. The shape of carbonation profiles and morphology of carbonated samples show that steam enhances solid state diffusion and, consequently, conversion during carbonation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101352s Exemplaires
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Titre : Highly efficient dye - sensitized solar cells by using a mesostructured anatase TiO2 electrode with high dye loading capacity Type de document : texte imprimé Auteurs : Wei Shao, Auteur ; Feng Gu, Auteur ; Chunzhong Li, Auteur Année de publication : 2010 Article en page(s) : pp. 9111–9116 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Mesostructured anatase Electrode Résumé : The growth and assembly of TiO2 nanostructures with enhanced charge transfer and light harvesting have attracted much attention for fabricating highly efficient dye-sensitized solar cells. In this study, we report an environmentally friendly and easy synthetic route for fabrication of mesostructured anatase TiO2 by controlling the hydrolyzing of n-butyl titanate in boric acid solution. The well-defined mesoporous TiO2 aggregates are obtained by the tensorial reaction-limited aggregation probability. The photovoltaic measurements indicate that the mesoporous TiO2 layer enhances the dye loading capacity, the electron transfer efficiency, and the photocurrent of the cell, contributing to the significant improvement of the energy conversion efficiency of the dye-sensitized solar cells. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901692z
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9111–9116[article] Highly efficient dye - sensitized solar cells by using a mesostructured anatase TiO2 electrode with high dye loading capacity [texte imprimé] / Wei Shao, Auteur ; Feng Gu, Auteur ; Chunzhong Li, Auteur . - 2010 . - pp. 9111–9116.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9111–9116
Mots-clés : Mesostructured anatase Electrode Résumé : The growth and assembly of TiO2 nanostructures with enhanced charge transfer and light harvesting have attracted much attention for fabricating highly efficient dye-sensitized solar cells. In this study, we report an environmentally friendly and easy synthetic route for fabrication of mesostructured anatase TiO2 by controlling the hydrolyzing of n-butyl titanate in boric acid solution. The well-defined mesoporous TiO2 aggregates are obtained by the tensorial reaction-limited aggregation probability. The photovoltaic measurements indicate that the mesoporous TiO2 layer enhances the dye loading capacity, the electron transfer efficiency, and the photocurrent of the cell, contributing to the significant improvement of the energy conversion efficiency of the dye-sensitized solar cells. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901692z Exemplaires
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Titre : Bridging gravimetric and electrochemical approaches to determine the corrosion rate of metals and metal alloys in cooling systems : Bench scale evaluation method Type de document : texte imprimé Auteurs : Ming-Kai Hsieh, Auteur ; David A. Dzombak, Auteur ; Radisav D. Vidic, Auteur Année de publication : 2010 Article en page(s) : pp. 9117–9123 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gravimetric Electrochemical Metal alloys Evaluation method Résumé : The gravimetric weight loss method and the electrochemical polarization resistance methods were combined to evaluate instantaneous corrosion rates for metals and metal alloys in industrial cooling-water systems. Metal and metal−alloy samples were exposed to synthetic cooling water in a bench-scale recirculating system constructed to study corrosion under flow conditions similar to those of a cooling-water system. The measurements yielded by both methods were related through a coefficient, B′, to convert polarization resistance measurements to instantaneous corrosion rates. The metals and metal alloys tested in this study included mild steel, aluminum, copper, and cupronickel. B′ was observed to change with time initially but approach a constant value for long-term exposure (>3 days) for most metal materials. B′ values varied with metal or metal alloy studied. It was concluded that combining both methods to determine the B′ value for a metal or a metal alloy under particular exposure conditions provides a means of obtaining an accurate instantaneous corrosion rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100217k
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9117–9123[article] Bridging gravimetric and electrochemical approaches to determine the corrosion rate of metals and metal alloys in cooling systems : Bench scale evaluation method [texte imprimé] / Ming-Kai Hsieh, Auteur ; David A. Dzombak, Auteur ; Radisav D. Vidic, Auteur . - 2010 . - pp. 9117–9123.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9117–9123
Mots-clés : Gravimetric Electrochemical Metal alloys Evaluation method Résumé : The gravimetric weight loss method and the electrochemical polarization resistance methods were combined to evaluate instantaneous corrosion rates for metals and metal alloys in industrial cooling-water systems. Metal and metal−alloy samples were exposed to synthetic cooling water in a bench-scale recirculating system constructed to study corrosion under flow conditions similar to those of a cooling-water system. The measurements yielded by both methods were related through a coefficient, B′, to convert polarization resistance measurements to instantaneous corrosion rates. The metals and metal alloys tested in this study included mild steel, aluminum, copper, and cupronickel. B′ was observed to change with time initially but approach a constant value for long-term exposure (>3 days) for most metal materials. B′ values varied with metal or metal alloy studied. It was concluded that combining both methods to determine the B′ value for a metal or a metal alloy under particular exposure conditions provides a means of obtaining an accurate instantaneous corrosion rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100217k Exemplaires
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Titre : One - pot preparation of titania - nanoparticles through hairy and crew - cut type micelle templates Type de document : texte imprimé Auteurs : Jinkee Hong, Auteur ; Sang Wook Kang, Auteur Année de publication : 2010 Article en page(s) : pp. 9124–9127 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanoparticles Titanium oxide Résumé : A facile approach successfully produced block copolymer micelle templated titanium oxide nanoparticles via electrostatic interaction based adsorption between cationic polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) and negatively charged titania precursor, titanium(IV) bis(ammonium lactate)dihydroxide (TALH) complexes in aqueous solution. Both hairy and crew-cut types of block copolymer micelles were examined as a particle scaffold. The diameter of the titiania nanoparticles prepared were from 10 to 70 nm depending on the molecular weight or type of block copolymer micelle template. Also, mass production of titania nanoparticles on the Si-wafer was shown by a one-pot process. The size morphologies and distributions shown were confirmed by field emission scanning electron microscopy (FESEM). The results suggest that the versatile and environmentally friendly technique to manufacture titania nanoparticles, which could be easily widened to prepare electrostatic interaction based organic/inorganic complexes with further applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1010838
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9124–9127[article] One - pot preparation of titania - nanoparticles through hairy and crew - cut type micelle templates [texte imprimé] / Jinkee Hong, Auteur ; Sang Wook Kang, Auteur . - 2010 . - pp. 9124–9127.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9124–9127
Mots-clés : Nanoparticles Titanium oxide Résumé : A facile approach successfully produced block copolymer micelle templated titanium oxide nanoparticles via electrostatic interaction based adsorption between cationic polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) and negatively charged titania precursor, titanium(IV) bis(ammonium lactate)dihydroxide (TALH) complexes in aqueous solution. Both hairy and crew-cut types of block copolymer micelles were examined as a particle scaffold. The diameter of the titiania nanoparticles prepared were from 10 to 70 nm depending on the molecular weight or type of block copolymer micelle template. Also, mass production of titania nanoparticles on the Si-wafer was shown by a one-pot process. The size morphologies and distributions shown were confirmed by field emission scanning electron microscopy (FESEM). The results suggest that the versatile and environmentally friendly technique to manufacture titania nanoparticles, which could be easily widened to prepare electrostatic interaction based organic/inorganic complexes with further applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1010838 Exemplaires
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Titre : Selective synthesis of potassium titanate whiskers starting from metatitanic acid and potassium carbonate Type de document : texte imprimé Auteurs : Jiancui Cao, Auteur ; Aili Wang, Auteur ; Hengbo Yin, Auteur Année de publication : 2010 Article en page(s) : pp. 9128–9134 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Potassium titanate whiskers Résumé : Selective synthesis of potassium titanate whiskers starting from metatitanic acid and potassium carbonate was successfully carried out by a facile calcination method. The mole ratio of potassium carbonate to metatitanic acid and the calcination temperature and time were crucial to the formation of different-structured potassium titanate whiskers. Well-crystallized potassium tetratitanate whiskers were prepared at a calcination temperature of 1000 °C when the mole ratio of potassium carbonate to metatitanic acid was 1:2.5. Potassium hexatitanate whiskers were dominantly formed at 1150 °C when the mole ratios of potassium carbonate to metatitanic acid were in a range of 1:3.5−1:4.5. Well-crystallized potassium octatitanate whiskers were prepared when potassium tetratitanate whiskers were boiled in water and then dried at a high temperature of 400 °C. The growth directions of all the potassium titanate whiskers are along their [010] crystal directions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101154q
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9128–9134[article] Selective synthesis of potassium titanate whiskers starting from metatitanic acid and potassium carbonate [texte imprimé] / Jiancui Cao, Auteur ; Aili Wang, Auteur ; Hengbo Yin, Auteur . - 2010 . - pp. 9128–9134.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9128–9134
Mots-clés : Potassium titanate whiskers Résumé : Selective synthesis of potassium titanate whiskers starting from metatitanic acid and potassium carbonate was successfully carried out by a facile calcination method. The mole ratio of potassium carbonate to metatitanic acid and the calcination temperature and time were crucial to the formation of different-structured potassium titanate whiskers. Well-crystallized potassium tetratitanate whiskers were prepared at a calcination temperature of 1000 °C when the mole ratio of potassium carbonate to metatitanic acid was 1:2.5. Potassium hexatitanate whiskers were dominantly formed at 1150 °C when the mole ratios of potassium carbonate to metatitanic acid were in a range of 1:3.5−1:4.5. Well-crystallized potassium octatitanate whiskers were prepared when potassium tetratitanate whiskers were boiled in water and then dried at a high temperature of 400 °C. The growth directions of all the potassium titanate whiskers are along their [010] crystal directions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101154q Exemplaires
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Titre : Durable hydrophobic cellulose fabric prepared with polycarboxylic acid catalyzed silica sol Type de document : texte imprimé Auteurs : Wenqi Huang, Auteur ; Yang Song, Auteur ; Yanjun Xing, Auteur Année de publication : 2010 Article en page(s) : pp. 9135–9142 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrophobic cellulose Polycarboxylic acid Résumé : Nine polycarboxylic acids (PAs) were employed in silica sol to offer an alternative approach in improving washing durability of the hydrophobic cellulose fabric by the sol−gel method. Polycarboxylic acids played a twofold role since they work not only as catalysts in hydrolyzing silica precursor but more importantly as cross-linkers to bind silica coating to cellulose substrate. Washing durability of hydrophobic cellulose fabric finished by the sol−gel method was obviously enhanced. The polycarboxylic acid with the proper number of carboxylic acid groups and distance between the terminal carboxylic acid groups could enhance the washing durability of the hydrophobicity of the cotton fabric by the sol−gel method. 1,2,3,4-Butanetetracarboxylic acid (BTCA) led to the best durability of hydrophobic cellulose fabric with a water contact angle of 138.6° (recovery percentage 96.5%) after washing 30 times. The effect of BTCA on durability was also characterized by scanning electron microscopy (SEM). This study suggested that the organic−inorganic sol−gel hybrid using PA as a catalyst is appropriate for achieving a durable hydrophobic cellulose fabric. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1012695
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9135–9142[article] Durable hydrophobic cellulose fabric prepared with polycarboxylic acid catalyzed silica sol [texte imprimé] / Wenqi Huang, Auteur ; Yang Song, Auteur ; Yanjun Xing, Auteur . - 2010 . - pp. 9135–9142.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9135–9142
Mots-clés : Hydrophobic cellulose Polycarboxylic acid Résumé : Nine polycarboxylic acids (PAs) were employed in silica sol to offer an alternative approach in improving washing durability of the hydrophobic cellulose fabric by the sol−gel method. Polycarboxylic acids played a twofold role since they work not only as catalysts in hydrolyzing silica precursor but more importantly as cross-linkers to bind silica coating to cellulose substrate. Washing durability of hydrophobic cellulose fabric finished by the sol−gel method was obviously enhanced. The polycarboxylic acid with the proper number of carboxylic acid groups and distance between the terminal carboxylic acid groups could enhance the washing durability of the hydrophobicity of the cotton fabric by the sol−gel method. 1,2,3,4-Butanetetracarboxylic acid (BTCA) led to the best durability of hydrophobic cellulose fabric with a water contact angle of 138.6° (recovery percentage 96.5%) after washing 30 times. The effect of BTCA on durability was also characterized by scanning electron microscopy (SEM). This study suggested that the organic−inorganic sol−gel hybrid using PA as a catalyst is appropriate for achieving a durable hydrophobic cellulose fabric. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1012695 Exemplaires
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Titre : On synthesis and optimization of steam system networks. 1. : Sustained boiler eficiency Type de document : texte imprimé Auteurs : Thokozani Majozi, Auteur ; Tim Price, Auteur Année de publication : 2010 Article en page(s) : pp. 9143–9153 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization Steam system Résumé : The traditional steam system comprises a steam boiler and the associated heat exchanger network (HEN). Most research published in literature tends to address both the elements of the steam system as separate entities instead of analyzing, synthesizing, and optimizing the overall system in a holistic manner. True optimality of the steam system can only be achieved if the analysis is conducted within an integrated framework. Process integration has proven to be a powerful tool in similar situations. This paper presents a process integration technique for network synthesis using conceptual and mathematical analysis without compromising boiler efficiency. It was found that the steam flow rate to the HEN could be reduced while maintaining boiler efficiency by utilizing sensible heat from the high pressure steam leaving the boiler. In the event of too little sensible energy being available, a compromise in either minimum steam flow rate or boiler efficiency must be made. A dedicated preheater can also be added to the HEN so as to guarantee the boiler efficiency is maintained; however, this will compromise the minimum steam flow rate. It was found that the flow rate could be reduced by 29.6% while still maintaining the boiler efficiency for an example problem. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1007008
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9143–9153[article] On synthesis and optimization of steam system networks. 1. : Sustained boiler eficiency [texte imprimé] / Thokozani Majozi, Auteur ; Tim Price, Auteur . - 2010 . - pp. 9143–9153.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9143–9153
Mots-clés : Optimization Steam system Résumé : The traditional steam system comprises a steam boiler and the associated heat exchanger network (HEN). Most research published in literature tends to address both the elements of the steam system as separate entities instead of analyzing, synthesizing, and optimizing the overall system in a holistic manner. True optimality of the steam system can only be achieved if the analysis is conducted within an integrated framework. Process integration has proven to be a powerful tool in similar situations. This paper presents a process integration technique for network synthesis using conceptual and mathematical analysis without compromising boiler efficiency. It was found that the steam flow rate to the HEN could be reduced while maintaining boiler efficiency by utilizing sensible heat from the high pressure steam leaving the boiler. In the event of too little sensible energy being available, a compromise in either minimum steam flow rate or boiler efficiency must be made. A dedicated preheater can also be added to the HEN so as to guarantee the boiler efficiency is maintained; however, this will compromise the minimum steam flow rate. It was found that the flow rate could be reduced by 29.6% while still maintaining the boiler efficiency for an example problem. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1007008 Exemplaires
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Titre : Synthesis and optimization of steam system networks. 2. : Multiple steam levels Type de document : texte imprimé Auteurs : Tim Price, Auteur ; Thokozani Majozi, Auteur Année de publication : 2010 Article en page(s) : pp. 9154–9164 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimisation steam system multiple Résumé : The use of steam in heat exchanger networks (HENs) can be reduced by the application of heat integration with the intention of debottlenecking the steam boiler and indirectly reducing the water requirement [Coetzee and Majozi. Ind. Eng. Chem. Res. 2008, 47, 4405−4413]. By reducing the steam flow rate, the return condensate temperature to the boiler is compromised which adversely affects the boiler operation. A means of maintaining efficient boiler operation is to reheat the return flow to the boiler. Steam systems typically employ turbines of which the exhaust is frequently used as a heating utility in the background process. Since turbines operate at various steam levels, a means for incorporating these steam levels into the HEN optimization framework is necessary. Consequently this paper concerns the restructuring of all steam system heat exchangers using conceptual and mathematical analysis to create a series HEN with the aim of reducing the overall steam flow rate, while maintaining the boiler efficiency. In an example problem, it was found that the steam flow rate could be reduced by up to 26.3% while still maintaining the boiler efficiency. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008579
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9154–9164[article] Synthesis and optimization of steam system networks. 2. : Multiple steam levels [texte imprimé] / Tim Price, Auteur ; Thokozani Majozi, Auteur . - 2010 . - pp. 9154–9164.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9154–9164
Mots-clés : Optimisation steam system multiple Résumé : The use of steam in heat exchanger networks (HENs) can be reduced by the application of heat integration with the intention of debottlenecking the steam boiler and indirectly reducing the water requirement [Coetzee and Majozi. Ind. Eng. Chem. Res. 2008, 47, 4405−4413]. By reducing the steam flow rate, the return condensate temperature to the boiler is compromised which adversely affects the boiler operation. A means of maintaining efficient boiler operation is to reheat the return flow to the boiler. Steam systems typically employ turbines of which the exhaust is frequently used as a heating utility in the background process. Since turbines operate at various steam levels, a means for incorporating these steam levels into the HEN optimization framework is necessary. Consequently this paper concerns the restructuring of all steam system heat exchangers using conceptual and mathematical analysis to create a series HEN with the aim of reducing the overall steam flow rate, while maintaining the boiler efficiency. In an example problem, it was found that the steam flow rate could be reduced by up to 26.3% while still maintaining the boiler efficiency. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008579 Exemplaires
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Titre : On synthesis and optimization of steam system networks. 3. : Pressure drop consideration Type de document : texte imprimé Auteurs : Tim Price, Auteur ; Thokozani Majozi, Auteur Année de publication : 2010 Article en page(s) : pp. 9165–9174 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization steam system Résumé : Heat exchanger networks in steam systems are traditionally designed to operate in parallel. Coetzee and Majozi (Ind. Eng. Chem. Res. 2008, 47, 4405−4413) found that by reusing steam condensate within the network the steam flow rate could be reduced. This was achieved by restructuring the networks into a series design, with the consequence of greatly increasing the pressure drop of the system. The boiler return condensate temperature was also reduced, which was found to decrease the boiler efficiency. Maintaining the boiler efficiency has been considered in the first two papers in this series, and pressure drop is introduced in this paper. The formulations from the previous two papers are used to find the minimum steam flow rate for a HEN while maintaining the boiler efficiency. The network exhibiting the minimum pressure drop for this flow rate is then designed using the critical path algorithm. The boiler efficiency is maintained using the constraints explored in papers I (Ind. Eng. Chem. Res. DOI: 10.1021/ie1007008) and II (Ind. Eng. Chem. Res. DOI: 10.1021/ie1008579) of this series. The minimum pressure drop for the network exhibiting the minimum flow rate found in paper I was 344.4 kPa; however, the flow rate was reduced by 29.6% as shown in paper I. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008585
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9165–9174[article] On synthesis and optimization of steam system networks. 3. : Pressure drop consideration [texte imprimé] / Tim Price, Auteur ; Thokozani Majozi, Auteur . - 2010 . - pp. 9165–9174.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9165–9174
Mots-clés : Optimization steam system Résumé : Heat exchanger networks in steam systems are traditionally designed to operate in parallel. Coetzee and Majozi (Ind. Eng. Chem. Res. 2008, 47, 4405−4413) found that by reusing steam condensate within the network the steam flow rate could be reduced. This was achieved by restructuring the networks into a series design, with the consequence of greatly increasing the pressure drop of the system. The boiler return condensate temperature was also reduced, which was found to decrease the boiler efficiency. Maintaining the boiler efficiency has been considered in the first two papers in this series, and pressure drop is introduced in this paper. The formulations from the previous two papers are used to find the minimum steam flow rate for a HEN while maintaining the boiler efficiency. The network exhibiting the minimum pressure drop for this flow rate is then designed using the critical path algorithm. The boiler efficiency is maintained using the constraints explored in papers I (Ind. Eng. Chem. Res. DOI: 10.1021/ie1007008) and II (Ind. Eng. Chem. Res. DOI: 10.1021/ie1008579) of this series. The minimum pressure drop for the network exhibiting the minimum flow rate found in paper I was 344.4 kPa; however, the flow rate was reduced by 29.6% as shown in paper I. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008585 Exemplaires
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Titre : Output relevant fault reconstruction and fault subspace extraction in total projection to latent structures models Type de document : texte imprimé Auteurs : Gang Li, Auteur ; S. Joe Qin, Auteur ; Donghua Zhou, Auteur Année de publication : 2010 Article en page(s) : pp. 9175–9183 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Operations industrial processes Résumé : Statistical data-driven process monitoring is critical for efficient operations of industrial processes. However, deviations from normal regions in the process data may or may not lead to poor quality of products. This paper proposes a new combined index for detecting output-relevant faults, which affect the output data, and studies the output-relevant fault detectability based on total projection to latent structures (T-PLS). Given actual fault direction, fault-free data can be reconstructed and output-relevant part of fault magnitude can be estimated. Two new methods are derived to extract output-relevant fault subspace from faulty data. A simulation example and a case study on the Tennessee Eastman process are used to show the effectiveness of the proposed methods. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901939n
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9175–9183[article] Output relevant fault reconstruction and fault subspace extraction in total projection to latent structures models [texte imprimé] / Gang Li, Auteur ; S. Joe Qin, Auteur ; Donghua Zhou, Auteur . - 2010 . - pp. 9175–9183.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9175–9183
Mots-clés : Operations industrial processes Résumé : Statistical data-driven process monitoring is critical for efficient operations of industrial processes. However, deviations from normal regions in the process data may or may not lead to poor quality of products. This paper proposes a new combined index for detecting output-relevant faults, which affect the output data, and studies the output-relevant fault detectability based on total projection to latent structures (T-PLS). Given actual fault direction, fault-free data can be reconstructed and output-relevant part of fault magnitude can be estimated. Two new methods are derived to extract output-relevant fault subspace from faulty data. A simulation example and a case study on the Tennessee Eastman process are used to show the effectiveness of the proposed methods. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901939n Exemplaires
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Titre : Unsupervised process fault detection with random forests Type de document : texte imprimé Auteurs : Lidia Auret, Auteur ; Chris Aldrich, Auteur Année de publication : 2010 Article en page(s) : pp.9184–9194 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Process Detection Résumé : Process monitoring technology plays a vital role in the automation of mineral processing plants, where there is an increased emphasis on safe, cost-effective, and environmentally responsible operation. Members of an important class of advanced diagnostic systems are data-driven and deal with potentially large numbers of variables at any given time by generating diagnostic sequences in lower-dimensional spaces. Despite rapid development in this field, nonlinear process systems remain challenging, and in this investigation, a novel approach to the monitoring of complex systems based on the use of random forest models is proposed. Random forest models consist of ensembles of classification and regression trees in which the model response is determined by voting committees of independent binary decision trees. In this study, a framework for diagnosing steady- and unsteady-state faults with random forests is proposed and demonstrated with simulated and real-world case studies. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901975c
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp.9184–9194[article] Unsupervised process fault detection with random forests [texte imprimé] / Lidia Auret, Auteur ; Chris Aldrich, Auteur . - 2010 . - pp.9184–9194.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp.9184–9194
Mots-clés : Process Detection Résumé : Process monitoring technology plays a vital role in the automation of mineral processing plants, where there is an increased emphasis on safe, cost-effective, and environmentally responsible operation. Members of an important class of advanced diagnostic systems are data-driven and deal with potentially large numbers of variables at any given time by generating diagnostic sequences in lower-dimensional spaces. Despite rapid development in this field, nonlinear process systems remain challenging, and in this investigation, a novel approach to the monitoring of complex systems based on the use of random forest models is proposed. Random forest models consist of ensembles of classification and regression trees in which the model response is determined by voting committees of independent binary decision trees. In this study, a framework for diagnosing steady- and unsteady-state faults with random forests is proposed and demonstrated with simulated and real-world case studies. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901975c Exemplaires
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Titre : Time - optimal control of dividing - wall distillation columns Type de document : texte imprimé Auteurs : Alexandru Woinaroschy, Auteur ; Raluca Isopescu, Auteur Année de publication : 2010 Article en page(s) : pp. 9195–9208 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimal control Distillation Résumé : Time-optimal control of startup traditional distillation columns by iterative programming proposed by Woinaroschy for ideal [Ind. Eng. Chem. Res. 2008, 47, 4158] and nonideal mixtures [Ind. Eng. Chem. Res. 2009, 48, 3873] is extended to the case of dividing-wall distillation columns. The minimization of distillation startup time is performed by iterative dynamic programming employing randomly chosen candidates for admissible control. The control variables are the reflux ratio, the reboiler heat duty, and the side-draw flow rate. The dynamic distillation model proposed by the author in the previous papers is applied. Two illustrative case studies for the separation in a dividing-wall column with sieve trays and lateral downcomers are presented as follows: the separation of an ideal benzene−toluene−ethylbenzene ternary mixture and the separation of a nonideal methanol−ethanol−1-propanol mixture. In another case study, a conventional two-column system is presented in comparison to the dividing-wall column. As in the cases of traditional distillation columns, the startup time decrease and the corresponding reboiler energy savings are significant for each of the control variables. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100090p
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9195–9208[article] Time - optimal control of dividing - wall distillation columns [texte imprimé] / Alexandru Woinaroschy, Auteur ; Raluca Isopescu, Auteur . - 2010 . - pp. 9195–9208.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9195–9208
Mots-clés : Optimal control Distillation Résumé : Time-optimal control of startup traditional distillation columns by iterative programming proposed by Woinaroschy for ideal [Ind. Eng. Chem. Res. 2008, 47, 4158] and nonideal mixtures [Ind. Eng. Chem. Res. 2009, 48, 3873] is extended to the case of dividing-wall distillation columns. The minimization of distillation startup time is performed by iterative dynamic programming employing randomly chosen candidates for admissible control. The control variables are the reflux ratio, the reboiler heat duty, and the side-draw flow rate. The dynamic distillation model proposed by the author in the previous papers is applied. Two illustrative case studies for the separation in a dividing-wall column with sieve trays and lateral downcomers are presented as follows: the separation of an ideal benzene−toluene−ethylbenzene ternary mixture and the separation of a nonideal methanol−ethanol−1-propanol mixture. In another case study, a conventional two-column system is presented in comparison to the dividing-wall column. As in the cases of traditional distillation columns, the startup time decrease and the corresponding reboiler energy savings are significant for each of the control variables. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100090p Exemplaires
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Titre : Criteria for performance assessment of plantwide control systems Type de document : texte imprimé Auteurs : Suraj Vasudevan, Auteur ; G.P. Rangaiah, Auteur Année de publication : 2010 Article en page(s) : pp. 9209–9221 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Plantwide control systems Résumé : Performance analysis of plantwide control (PWC) systems, which is one of the important areas of PWC of industrial processes, has not received much attention in the past. In this paper, many measures based on plant dynamics are described and discussed for evaluating the performance of different control structures in the presence of disturbances. These include overall process settling time, dynamic disturbance sensitivity, the total variation in the plant manipulated variables, net variation from the nominal profit, deviation from the production rate target, and the integral absolute error in product purity. These measures are developed and then applied to four alternative control structures of an important industrial process, namely, styrene monomer plant, in order to test their applicability. The results indicate that some of the presented measures are indeed effective in evaluating and comparing different PWC structures. The most important contribution of this paper is the presentation of some clear and easily computable criteria for the performance assessment of PWC systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001795
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9209–9221[article] Criteria for performance assessment of plantwide control systems [texte imprimé] / Suraj Vasudevan, Auteur ; G.P. Rangaiah, Auteur . - 2010 . - pp. 9209–9221.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9209–9221
Mots-clés : Plantwide control systems Résumé : Performance analysis of plantwide control (PWC) systems, which is one of the important areas of PWC of industrial processes, has not received much attention in the past. In this paper, many measures based on plant dynamics are described and discussed for evaluating the performance of different control structures in the presence of disturbances. These include overall process settling time, dynamic disturbance sensitivity, the total variation in the plant manipulated variables, net variation from the nominal profit, deviation from the production rate target, and the integral absolute error in product purity. These measures are developed and then applied to four alternative control structures of an important industrial process, namely, styrene monomer plant, in order to test their applicability. The results indicate that some of the presented measures are indeed effective in evaluating and comparing different PWC structures. The most important contribution of this paper is the presentation of some clear and easily computable criteria for the performance assessment of PWC systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001795 Exemplaires
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Titre : Optimizing treatment performance of microbial fuel cells by reactor staging Type de document : texte imprimé Auteurs : Roberto P. Pinto, Auteur ; Boris Tartakovsky, Auteur ; Michel Perrier, Auteur Année de publication : 2010 Article en page(s) : pp. 9222–9229 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microbial fuel cells Optimizing Résumé : Microbial fuel cells (MFCs) are capable of producing electricity while cleaning wastewater. The goal of this work is to optimize an MFC-based wastewater treatment process to maximize the amount of wastewater that is cleaned. An MFC mathematical model is used to compare different operating modes and reactor configurations. The following observations are made based on the model analysis: (i) the ratio between the anodophilic and methanogenic populations can be controlled by the electrical load; (ii) coexistence of the two populations decreases reactor performance; (iii) MFCs that are connected in series always improve treatment efficiency; and (iv) influent and effluent concentrations can be used to define the best series configuration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1004898
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9222–9229[article] Optimizing treatment performance of microbial fuel cells by reactor staging [texte imprimé] / Roberto P. Pinto, Auteur ; Boris Tartakovsky, Auteur ; Michel Perrier, Auteur . - 2010 . - pp. 9222–9229.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9222–9229
Mots-clés : Microbial fuel cells Optimizing Résumé : Microbial fuel cells (MFCs) are capable of producing electricity while cleaning wastewater. The goal of this work is to optimize an MFC-based wastewater treatment process to maximize the amount of wastewater that is cleaned. An MFC mathematical model is used to compare different operating modes and reactor configurations. The following observations are made based on the model analysis: (i) the ratio between the anodophilic and methanogenic populations can be controlled by the electrical load; (ii) coexistence of the two populations decreases reactor performance; (iii) MFCs that are connected in series always improve treatment efficiency; and (iv) influent and effluent concentrations can be used to define the best series configuration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1004898 Exemplaires
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Titre : Theoretical evaluation of feedstock gasification using H2/C ratio and ROC as main input variables Type de document : texte imprimé Auteurs : Michael Stemmler, Auteur ; Michael Müller, Auteur Année de publication : 2010 Article en page(s) : pp. 9230–9237 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gasification Thermochemical process Résumé : Chemical equilibrium models for simulation of thermochemical processes such as feedstock gasification developed so far either focus on the determination of several producer gas compositions or include a parametric study of feedstock depending parameters such as relative fuel/air ratio (Frg) and moisture content of biomass (h). This article presents a thermochemical process model based on the H2/C ratio and relative oxygen content (ROC). Therefore, all oxygen-, hydrogen-, and carbon-containing components inside a gasifier are considered, and the model enables the prediction of feedstock behavior as well as an optimization of the feedstock gasification. Furthermore, producer gas compositions are determinable in a unique way as well as the achievable producer gas compositions deriving from several feedstocks combined with several gasifying agents (O2 and H2O). The calculated results show that the area of achievable producer gas compositions (AAPGC) derived from hard coal clearly exceeds the AAPGC derived from biomass. Whereas the AAPGC derived from lignite only exceeds the AAPGC derived from biomass for low H2/C ratios. The LHV of the producer gases decreases with increasing the H2/C ratio and ROC values. However, the resulting gas flow for the steam gasification is clearly higher compared to that of the oxygen gasification. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100726b
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9230–9237[article] Theoretical evaluation of feedstock gasification using H2/C ratio and ROC as main input variables [texte imprimé] / Michael Stemmler, Auteur ; Michael Müller, Auteur . - 2010 . - pp. 9230–9237.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9230–9237
Mots-clés : Gasification Thermochemical process Résumé : Chemical equilibrium models for simulation of thermochemical processes such as feedstock gasification developed so far either focus on the determination of several producer gas compositions or include a parametric study of feedstock depending parameters such as relative fuel/air ratio (Frg) and moisture content of biomass (h). This article presents a thermochemical process model based on the H2/C ratio and relative oxygen content (ROC). Therefore, all oxygen-, hydrogen-, and carbon-containing components inside a gasifier are considered, and the model enables the prediction of feedstock behavior as well as an optimization of the feedstock gasification. Furthermore, producer gas compositions are determinable in a unique way as well as the achievable producer gas compositions deriving from several feedstocks combined with several gasifying agents (O2 and H2O). The calculated results show that the area of achievable producer gas compositions (AAPGC) derived from hard coal clearly exceeds the AAPGC derived from biomass. Whereas the AAPGC derived from lignite only exceeds the AAPGC derived from biomass for low H2/C ratios. The LHV of the producer gases decreases with increasing the H2/C ratio and ROC values. However, the resulting gas flow for the steam gasification is clearly higher compared to that of the oxygen gasification. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100726b Exemplaires
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Titre : Adsorption of Phenolic Compounds from Aqueous Solutions onto Chitosan-Coated Perlite Beads as Biosorbent Type de document : texte imprimé Auteurs : N. S. Kumar, Auteur ; M. Suguna, Auteur ; M. V. Subbaiah, Auteur Année de publication : 2010 Article en page(s) : pp. 9238-9247 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous solution Adsorption Résumé : Chitosan-coated perlite (CCP) beads were prepared by dropwise addition of a liquid slurry containing chitosan and perlite to an alkaline bath. The resulting beads were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and surface area analysis. The chitosan content of the beads is 23% as determined by a pyrolysis method. Adsorption of phenolic compounds (phenol, 2-chlorophenol, and 4- chlorophenol) from aqueous solutions on chitosan-coated perlite beads was studied under batch equilibrium and column flow conditions. The binding capacity of the biosorbent was investigated as a function of initial pH, contact time, initial concentration of adsorbate, and dosage of adsorbent. Adsorption kinetic and isotherm studies, respectively, showed that the adsorption process followed a pseudo-first-order kinetic model and the Langmuir isotherm. The maximum monolayer adsorption capacity of phenol, 2-CP, and 4-CP on to the chitosan-coated perlite beads was found to be 192, 263, and 322 mg g-1, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289658
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9238-9247[article] Adsorption of Phenolic Compounds from Aqueous Solutions onto Chitosan-Coated Perlite Beads as Biosorbent [texte imprimé] / N. S. Kumar, Auteur ; M. Suguna, Auteur ; M. V. Subbaiah, Auteur . - 2010 . - pp. 9238-9247.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9238-9247
Mots-clés : Aqueous solution Adsorption Résumé : Chitosan-coated perlite (CCP) beads were prepared by dropwise addition of a liquid slurry containing chitosan and perlite to an alkaline bath. The resulting beads were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and surface area analysis. The chitosan content of the beads is 23% as determined by a pyrolysis method. Adsorption of phenolic compounds (phenol, 2-chlorophenol, and 4- chlorophenol) from aqueous solutions on chitosan-coated perlite beads was studied under batch equilibrium and column flow conditions. The binding capacity of the biosorbent was investigated as a function of initial pH, contact time, initial concentration of adsorbate, and dosage of adsorbent. Adsorption kinetic and isotherm studies, respectively, showed that the adsorption process followed a pseudo-first-order kinetic model and the Langmuir isotherm. The maximum monolayer adsorption capacity of phenol, 2-CP, and 4-CP on to the chitosan-coated perlite beads was found to be 192, 263, and 322 mg g-1, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289658 Exemplaires
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Titre : Evaluation of Ion-Exchange and Adsorbent Resins for the Detoxification of Beet Distillery Effluents Type de document : texte imprimé Auteurs : Claire Fargues, Auteur ; Richard Lewandowski, Auteur ; Marie-Laure Lameloise, Auteur Année de publication : 2010 Article en page(s) : pp. 9248–9257 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ion exchange Adsorbent Résumé : Batch isotherm experiments were carried out to select the best chromatographic supports for the purification of beet distillery condensates with the aim of recovering fermentable water. Adsorption parameters of four inhibitory solutes of the condensates chosen as targets were obtained, leading to the selection of a weak anion-exchanger and a polystyrenic resin. These results were further used for the chromatographic scaleup. Dynamic adsorption experiments run on both resins with a synthetic mixture of the four target solutes showed the presence of competition for the adsorption. The extended Langmuir model was then found to be applicable for a first estimation of the solute breakthrough. The treatment efficiencies of the two supports were confirmed with an industrial condensate, indicating components in the effluent that were not considered did not significantly affect the adsorption of the main compounds. Eventually, a combination of the two complementary resins was proposed for complete effluent detoxification. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100330y
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9248–9257[article] Evaluation of Ion-Exchange and Adsorbent Resins for the Detoxification of Beet Distillery Effluents [texte imprimé] / Claire Fargues, Auteur ; Richard Lewandowski, Auteur ; Marie-Laure Lameloise, Auteur . - 2010 . - pp. 9248–9257.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9248–9257
Mots-clés : Ion exchange Adsorbent Résumé : Batch isotherm experiments were carried out to select the best chromatographic supports for the purification of beet distillery condensates with the aim of recovering fermentable water. Adsorption parameters of four inhibitory solutes of the condensates chosen as targets were obtained, leading to the selection of a weak anion-exchanger and a polystyrenic resin. These results were further used for the chromatographic scaleup. Dynamic adsorption experiments run on both resins with a synthetic mixture of the four target solutes showed the presence of competition for the adsorption. The extended Langmuir model was then found to be applicable for a first estimation of the solute breakthrough. The treatment efficiencies of the two supports were confirmed with an industrial condensate, indicating components in the effluent that were not considered did not significantly affect the adsorption of the main compounds. Eventually, a combination of the two complementary resins was proposed for complete effluent detoxification. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100330y Exemplaires
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Titre : Enhanced separation performance of a five - zone simulated moving bed process by using partial collection strategy based on alternate opening and closing of a product port Type de document : texte imprimé Auteurs : Sungyong Mun, Auteur Année de publication : 2010 Article en page(s) : pp. 9258-9270 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Simulated moving bed Résumé : A five-zone simulated moving bed (SMB) process for ternary separation has been developed previously and applied to the purification of biochemicals in the literature. Although this process was effective to some degree in many of previous research studies, its separation performance was always limited by the presence of overlap between the highest-affinity and the intermediate-affinity solutes. Since a proper control of the overlap was almost impossible under the current configuration and operation method, the application scope of a conventional five-zone SMB was restricted within the separation tasks that permitted either relatively medium purities or low throughput. To overcome such a limitation, an efficient operation strategy for improving the five-zone SMB performance was proposed in this study. The core of the proposed strategy is to partially collect the product stream by alternate opening and closing of the extract-2 port, which is in charge of recovering the intermediate-affinity solute molecules. Simultaneously, the zone II flow rate during the port-opening state is adjusted properly for complete desorption of the intermediate-affinity solute in zone II. The application of such a strategy was found to improve the five-zone SMB performance dramatically. One of the noteworthy improvements was that all three products could be recovered with extremely high purities at the same time. Furthermore, a marked increase in the throughput could also be obtained under the given purity requirements. Therefore, the strategy proposed in this study is expected to substantially upgrade the five-zone SMB performance, allowing its application to the separation tasks that demand either high purities or high throughput. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289660
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9258-9270[article] Enhanced separation performance of a five - zone simulated moving bed process by using partial collection strategy based on alternate opening and closing of a product port [texte imprimé] / Sungyong Mun, Auteur . - 2010 . - pp. 9258-9270.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9258-9270
Mots-clés : Simulated moving bed Résumé : A five-zone simulated moving bed (SMB) process for ternary separation has been developed previously and applied to the purification of biochemicals in the literature. Although this process was effective to some degree in many of previous research studies, its separation performance was always limited by the presence of overlap between the highest-affinity and the intermediate-affinity solutes. Since a proper control of the overlap was almost impossible under the current configuration and operation method, the application scope of a conventional five-zone SMB was restricted within the separation tasks that permitted either relatively medium purities or low throughput. To overcome such a limitation, an efficient operation strategy for improving the five-zone SMB performance was proposed in this study. The core of the proposed strategy is to partially collect the product stream by alternate opening and closing of the extract-2 port, which is in charge of recovering the intermediate-affinity solute molecules. Simultaneously, the zone II flow rate during the port-opening state is adjusted properly for complete desorption of the intermediate-affinity solute in zone II. The application of such a strategy was found to improve the five-zone SMB performance dramatically. One of the noteworthy improvements was that all three products could be recovered with extremely high purities at the same time. Furthermore, a marked increase in the throughput could also be obtained under the given purity requirements. Therefore, the strategy proposed in this study is expected to substantially upgrade the five-zone SMB performance, allowing its application to the separation tasks that demand either high purities or high throughput. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289660 Exemplaires
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Titre : Microwave - assisted extraction of forskolin from coleus roots and its purification by adsorptive separation using functionalized polymer designed by molecular simulation Type de document : texte imprimé Auteurs : Leena P. Devendra, Auteur ; Vilas G. Gaikar, Auteur Année de publication : 2010 Article en page(s) : pp. 9271–9278 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microwave Adsorptive separation Molecular simulation Résumé : The extraction of forskolin from Coleus forskohlii roots using organic solvents was facilitated by irradiation of the raw material by microwave and studied for effect of time of irradiation, power level and water soaking of the raw material prior to irradiation on the rate of extraction. Methanol gave 92% extraction of forskolin after 2 min of the irradiation at 160 W under optimized conditions, with simultaneous increase in the rate of extraction. Molecular modeling approach was taken to design a specific adsorbent for selective adsorption of forskolin analogues from the complex extract. The forskolin analogues showed greater affinity toward a diethanolamine-loaded polymer as compared to forskolin. The purification of forskolin by adsorption on diethanolamine substituted polystyrene validated the predictions from molecular simulation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100495u
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9271–9278[article] Microwave - assisted extraction of forskolin from coleus roots and its purification by adsorptive separation using functionalized polymer designed by molecular simulation [texte imprimé] / Leena P. Devendra, Auteur ; Vilas G. Gaikar, Auteur . - 2010 . - pp. 9271–9278.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9271–9278
Mots-clés : Microwave Adsorptive separation Molecular simulation Résumé : The extraction of forskolin from Coleus forskohlii roots using organic solvents was facilitated by irradiation of the raw material by microwave and studied for effect of time of irradiation, power level and water soaking of the raw material prior to irradiation on the rate of extraction. Methanol gave 92% extraction of forskolin after 2 min of the irradiation at 160 W under optimized conditions, with simultaneous increase in the rate of extraction. Molecular modeling approach was taken to design a specific adsorbent for selective adsorption of forskolin analogues from the complex extract. The forskolin analogues showed greater affinity toward a diethanolamine-loaded polymer as compared to forskolin. The purification of forskolin by adsorption on diethanolamine substituted polystyrene validated the predictions from molecular simulation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100495u Exemplaires
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Titre : De - emulsification of kerosene / water emulsions with plate - type microchannels Type de document : texte imprimé Auteurs : Xiao Chen, Auteur ; Houfang Lu, Auteur ; Wei Jiang, Auteur Année de publication : 2010 Article en page(s) : pp. 9279–9288 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microchannels Emulsions Résumé : Kerosene-in-water emulsions were de-emulsified by narrow plate-type microchannels. The emulsions with different Sauter diameters of 5 or 10 μm were formed by high-shear homogenization method and passed through microchannels with clearances of 100 to 200 μm. The de-emulsification efficiency was from 10% to 30% in a single pass through the channel. By repeatedly passing through the microchannels, up to 90% de-emulsification efficiency can be achieved. The results showed that the de-emulsification efficiency was influenced by the flow rate, Sauter diameter, microchannel size, and wall materials. Hydrophobic surface of the microchannel improved the de-emulsification efficiency. A coupled two-step mechanism was proposed to illustrate the de-emulsification process. Specially, polytetrafluoroethylene−stainless steel (PTFE-SS) plate combination of the microchannel induced different velocities of the continuous phase close to the wall surface and helped the droplets of the emulsion move toward the PTFE wall and be captured. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1005228
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9279–9288[article] De - emulsification of kerosene / water emulsions with plate - type microchannels [texte imprimé] / Xiao Chen, Auteur ; Houfang Lu, Auteur ; Wei Jiang, Auteur . - 2010 . - pp. 9279–9288.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9279–9288
Mots-clés : Microchannels Emulsions Résumé : Kerosene-in-water emulsions were de-emulsified by narrow plate-type microchannels. The emulsions with different Sauter diameters of 5 or 10 μm were formed by high-shear homogenization method and passed through microchannels with clearances of 100 to 200 μm. The de-emulsification efficiency was from 10% to 30% in a single pass through the channel. By repeatedly passing through the microchannels, up to 90% de-emulsification efficiency can be achieved. The results showed that the de-emulsification efficiency was influenced by the flow rate, Sauter diameter, microchannel size, and wall materials. Hydrophobic surface of the microchannel improved the de-emulsification efficiency. A coupled two-step mechanism was proposed to illustrate the de-emulsification process. Specially, polytetrafluoroethylene−stainless steel (PTFE-SS) plate combination of the microchannel induced different velocities of the continuous phase close to the wall surface and helped the droplets of the emulsion move toward the PTFE wall and be captured. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1005228 Exemplaires
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Titre : Comparative study of cocurrent and countercurrent modes of operation for a thermal hydrolyzer in an industrial urea wastewater treatment loop Type de document : texte imprimé Auteurs : M. R. Rahimpour, Auteur ; H. R. Mottaghi, Auteur Année de publication : 2010 Article en page(s) : pp. 9289–9299 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Waste water purification Countercurrent flow Cocurrent Comparative study Résumé : In this work, a comparison of cocurrent and countercurrent modes of operation for an industrial wastewater treatment loop of an industrial urea plant has been carried out. In both modes of operation, a loop with a thermal hydrolyzer is used for urea decomposition, and two desorbers are used for the removal of ammonia and carbon dioxide. In the proposed model, the extended electrolytic UNIQUAC equation is used to describe the nonideality of the liquid phase of the NH3-CO2-H2O-urea system, and the perturbed-hard-sphere (PHS) equation of state is applied to predict the vapor fugacity coefficients. Also, the urea hydrolysis reactors are divided into several continuously stirred tank reactors (CSTRs) and the equilibrium-stage model is applied for modeling of both kinds of reactors and of the desorbers. The simulation results show that countercurrent mode of operation is necessary to achieve new environmental standards and complete treatment. The data predicted using the model were consistent with available plant data, indicating the validity of the model. The impact of different parameters on the performance of the urea wastewater treatment loops has been examined. Overall, this study results in beneficial information about the use of the cocurrent and countercurrent hydrolysis reactors in the urea wastewater treatment process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289663
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9289–9299[article] Comparative study of cocurrent and countercurrent modes of operation for a thermal hydrolyzer in an industrial urea wastewater treatment loop [texte imprimé] / M. R. Rahimpour, Auteur ; H. R. Mottaghi, Auteur . - 2010 . - pp. 9289–9299.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9289–9299
Mots-clés : Waste water purification Countercurrent flow Cocurrent Comparative study Résumé : In this work, a comparison of cocurrent and countercurrent modes of operation for an industrial wastewater treatment loop of an industrial urea plant has been carried out. In both modes of operation, a loop with a thermal hydrolyzer is used for urea decomposition, and two desorbers are used for the removal of ammonia and carbon dioxide. In the proposed model, the extended electrolytic UNIQUAC equation is used to describe the nonideality of the liquid phase of the NH3-CO2-H2O-urea system, and the perturbed-hard-sphere (PHS) equation of state is applied to predict the vapor fugacity coefficients. Also, the urea hydrolysis reactors are divided into several continuously stirred tank reactors (CSTRs) and the equilibrium-stage model is applied for modeling of both kinds of reactors and of the desorbers. The simulation results show that countercurrent mode of operation is necessary to achieve new environmental standards and complete treatment. The data predicted using the model were consistent with available plant data, indicating the validity of the model. The impact of different parameters on the performance of the urea wastewater treatment loops has been examined. Overall, this study results in beneficial information about the use of the cocurrent and countercurrent hydrolysis reactors in the urea wastewater treatment process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289663 Exemplaires
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Titre : Numerical and experimental fluid - dynamic analysis to improve the mass transfer performances of Pd − Ag membrane modules for hydrogen purification Type de document : texte imprimé Auteurs : Mirella Coroneo, Auteur ; Giuseppina Montante, Auteur ; Alessandro Paglianti, Auteur Année de publication : 2010 Article en page(s) : pp. 9300-9309 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Purification Mass transfer Hydrodynamics Résumé : This work is aimed at investigating the impact of the fluid flow features on the behavior of gas separation membrane modules. The investigation is carried out by particle image velocimetry (PIV) experiments and computational fluid dynamics (CFD) simulations. The experimental velocity data collected in a laboratory scale membrane module confirm the reliability of the gas velocity field calculated numerically solving the Navier-Stokes equations by a general-purpose finite volume CFD code, and the effect of the observed nonideal flow distribution on the module separation performances is discussed. Afterward, the case of a pilot scale module equipped with three Pd-Ag membranes, which are well-suited for the separation of H2 from methane steam reforming gas mixtures, is considered. The appropriateness of the selected CFD method for the design and the geometric optimization of membrane modules of pilot size is demonstrated. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289664
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9300-9309[article] Numerical and experimental fluid - dynamic analysis to improve the mass transfer performances of Pd − Ag membrane modules for hydrogen purification [texte imprimé] / Mirella Coroneo, Auteur ; Giuseppina Montante, Auteur ; Alessandro Paglianti, Auteur . - 2010 . - pp. 9300-9309.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9300-9309
Mots-clés : Purification Mass transfer Hydrodynamics Résumé : This work is aimed at investigating the impact of the fluid flow features on the behavior of gas separation membrane modules. The investigation is carried out by particle image velocimetry (PIV) experiments and computational fluid dynamics (CFD) simulations. The experimental velocity data collected in a laboratory scale membrane module confirm the reliability of the gas velocity field calculated numerically solving the Navier-Stokes equations by a general-purpose finite volume CFD code, and the effect of the observed nonideal flow distribution on the module separation performances is discussed. Afterward, the case of a pilot scale module equipped with three Pd-Ag membranes, which are well-suited for the separation of H2 from methane steam reforming gas mixtures, is considered. The appropriateness of the selected CFD method for the design and the geometric optimization of membrane modules of pilot size is demonstrated. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289664 Exemplaires
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Titre : Gas - transport - property performance of hybrid carbon molecular sieve − polymer materials Type de document : texte imprimé Auteurs : Mita Das, Auteur ; John D. Perry, Auteur ; William J. Koros, Auteur Année de publication : 2010 Article en page(s) : pp. 9310–9321 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gas Hybrid Polymer Résumé : High-performance hybrid materials using carbon molecular sieve materials and 6FDA−6FpDA were produced. A detailed analysis of the effects of casting processes and the annealing temperature is reported. Two existing major obstacles, sieve agglomeration and residual stress, were addressed in this work, and subsequently a new membrane formation technique was developed to produce high-performing membranes. The successfully improved interfacial region of the hybrid membranes allows the sieves to increase the selectivity of the membranes above the neat polymer properties. Furthermore, an additional performance enhancement was seen with increased sieve loading in the hybrid membranes, leading to an actual performance above the upper bound for pure polymer membranes. The membranes were also tested under a mixed-gas environment, which further demonstrated promising results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100843r
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9310–9321[article] Gas - transport - property performance of hybrid carbon molecular sieve − polymer materials [texte imprimé] / Mita Das, Auteur ; John D. Perry, Auteur ; William J. Koros, Auteur . - 2010 . - pp. 9310–9321.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9310–9321
Mots-clés : Gas Hybrid Polymer Résumé : High-performance hybrid materials using carbon molecular sieve materials and 6FDA−6FpDA were produced. A detailed analysis of the effects of casting processes and the annealing temperature is reported. Two existing major obstacles, sieve agglomeration and residual stress, were addressed in this work, and subsequently a new membrane formation technique was developed to produce high-performing membranes. The successfully improved interfacial region of the hybrid membranes allows the sieves to increase the selectivity of the membranes above the neat polymer properties. Furthermore, an additional performance enhancement was seen with increased sieve loading in the hybrid membranes, leading to an actual performance above the upper bound for pure polymer membranes. The membranes were also tested under a mixed-gas environment, which further demonstrated promising results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100843r Exemplaires
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Titre : Enhancement of the flotation deinking selectivity by natural polymeric dispersants Type de document : texte imprimé Auteurs : Elisa Zeno, Auteur ; Patrick Huber, Auteur ; Xavier Rousset, Auteur Année de publication : 2010 Article en page(s) : pp. 9322-9329 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Dispersant Deinking Flotation Résumé : The impact of natural polymeric dispersants, that is, carboxymethyl cellulose and guar gum, on the flotation selectivity was investigated on a flotation deinking pilot plant. Their effect on pulp flocculation, air bubble size, and gas hold-up was determined by implementing a fiber flocculation sensor, an automated bubble measurement device, and a gas hold-up sensor on the pilot cell. Dispersants reduced pulp flocculation and induced an increase in gas hold-up and a slight decrease in the air bubble size. Their addition promoted ink removal and, at the same time, depressed fiber entrainment and mineral fillers flotation, thus increasing exceptionally the flotation selectivity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289666
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9322-9329[article] Enhancement of the flotation deinking selectivity by natural polymeric dispersants [texte imprimé] / Elisa Zeno, Auteur ; Patrick Huber, Auteur ; Xavier Rousset, Auteur . - 2010 . - pp. 9322-9329.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9322-9329
Mots-clés : Dispersant Deinking Flotation Résumé : The impact of natural polymeric dispersants, that is, carboxymethyl cellulose and guar gum, on the flotation selectivity was investigated on a flotation deinking pilot plant. Their effect on pulp flocculation, air bubble size, and gas hold-up was determined by implementing a fiber flocculation sensor, an automated bubble measurement device, and a gas hold-up sensor on the pilot cell. Dispersants reduced pulp flocculation and induced an increase in gas hold-up and a slight decrease in the air bubble size. Their addition promoted ink removal and, at the same time, depressed fiber entrainment and mineral fillers flotation, thus increasing exceptionally the flotation selectivity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289666 Exemplaires
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Titre : Performance of solvent - pretreated polyimide nanofiltration membranes for separation of dissolved dyes from toluene Type de document : texte imprimé Auteurs : Siavash Darvishmanesh, Auteur ; Jan Degreve, Auteur ; Bart Van der Bruggen, Auteur Année de publication : 2010 Article en page(s) : pp. 9330–9338 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solvent Nanofiltration Toluene Résumé : The major problem reported for commercially available membranes is their limited chemical stability in organic solvents. This article reports the influence of organic solvents with different polarity (methanol, acetone, acetic acid, toluene, and n-hexane) on the filtration performance of STARMEM membranes. These membranes are specified to be compatible with the solvents used. The pure toluene flux of these membranes and the rejection of azo dyes (Sudan Black and Rhodanile Blue) were measured before and after a week of exposure to one of the above-mentioned solvents. The results show that the structure of the membrane changed after pretreatment with polar solvents (methanol, acetone, acetic acid) and that the membrane performance shifts toward lower rejections with higher solvent flux. Nonpolar solvents do not change the polyimide membrane performances significantly. Contact angle measurements on new and solvent-treated membranes show that organic solvents change the hydrophobicity of polymeric membrane surfaces, leading to different toluene permeabilities before and after solvent treatment. Swelling measurements confirm the theory that a reorganization of the membrane material takes place, which leads to differences in porosity and changes in rejection. The study also shows that pretreatment of polyimide membranes with polar solvents increases the recovery of the membrane system when the solute size is large enough. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101050k
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9330–9338[article] Performance of solvent - pretreated polyimide nanofiltration membranes for separation of dissolved dyes from toluene [texte imprimé] / Siavash Darvishmanesh, Auteur ; Jan Degreve, Auteur ; Bart Van der Bruggen, Auteur . - 2010 . - pp. 9330–9338.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9330–9338
Mots-clés : Solvent Nanofiltration Toluene Résumé : The major problem reported for commercially available membranes is their limited chemical stability in organic solvents. This article reports the influence of organic solvents with different polarity (methanol, acetone, acetic acid, toluene, and n-hexane) on the filtration performance of STARMEM membranes. These membranes are specified to be compatible with the solvents used. The pure toluene flux of these membranes and the rejection of azo dyes (Sudan Black and Rhodanile Blue) were measured before and after a week of exposure to one of the above-mentioned solvents. The results show that the structure of the membrane changed after pretreatment with polar solvents (methanol, acetone, acetic acid) and that the membrane performance shifts toward lower rejections with higher solvent flux. Nonpolar solvents do not change the polyimide membrane performances significantly. Contact angle measurements on new and solvent-treated membranes show that organic solvents change the hydrophobicity of polymeric membrane surfaces, leading to different toluene permeabilities before and after solvent treatment. Swelling measurements confirm the theory that a reorganization of the membrane material takes place, which leads to differences in porosity and changes in rejection. The study also shows that pretreatment of polyimide membranes with polar solvents increases the recovery of the membrane system when the solute size is large enough. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101050k Exemplaires
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Titre : Novel type of four - impinging - jets reactor for oxidative desulfurization of light fuel oils Type de document : texte imprimé Auteurs : Mohammad Amin Sobati, Auteur ; Asghar Molaei Dehkordi, Auteur ; Mohammad Shahrokhi, Auteur Année de publication : 2010 Article en page(s) : pp. 9339–9348 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oxidative Desulfurization Résumé : A novel type of four-impinging-jets reactor (FIJR) has been proposed and tested successfully for the oxidative desulfurization of kerosene as a typical light fuel oil. The FIJR is characterized by a high-intensity mixing chamber located at the bottom of the reactor and equipped with four impinging jets. The influences of various operating and design parameters such as feed flow rate, internozzle distance, jet diameter, and jet Reynolds number on the performance of the FIJR have been carefully investigated. As a result of both the impinging process and shear forces exerted on the phases, the rate of desulfurization in FIJR increased significantly compared to that obtained by a conventional reactor system such as stirred-tank reactor (STR). This can be attributed to a decrease in the mass-transfer resistance, complex flow pattern within the reaction chamber, energy released as the result of impinging-jets collision, and high intensity mixing at the impingement zone of FIJR. Moreover, about 92% sulfur removal of kerosene has been obtained in FIJR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101065q
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9339–9348[article] Novel type of four - impinging - jets reactor for oxidative desulfurization of light fuel oils [texte imprimé] / Mohammad Amin Sobati, Auteur ; Asghar Molaei Dehkordi, Auteur ; Mohammad Shahrokhi, Auteur . - 2010 . - pp. 9339–9348.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9339–9348
Mots-clés : Oxidative Desulfurization Résumé : A novel type of four-impinging-jets reactor (FIJR) has been proposed and tested successfully for the oxidative desulfurization of kerosene as a typical light fuel oil. The FIJR is characterized by a high-intensity mixing chamber located at the bottom of the reactor and equipped with four impinging jets. The influences of various operating and design parameters such as feed flow rate, internozzle distance, jet diameter, and jet Reynolds number on the performance of the FIJR have been carefully investigated. As a result of both the impinging process and shear forces exerted on the phases, the rate of desulfurization in FIJR increased significantly compared to that obtained by a conventional reactor system such as stirred-tank reactor (STR). This can be attributed to a decrease in the mass-transfer resistance, complex flow pattern within the reaction chamber, energy released as the result of impinging-jets collision, and high intensity mixing at the impingement zone of FIJR. Moreover, about 92% sulfur removal of kerosene has been obtained in FIJR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101065q Exemplaires
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Titre : Environmentally benign chiral resolution of trans - 1,2 - cyclohexanediol by two - step supercritical fluid extraction Type de document : texte imprimé Auteurs : Edit Szekely, Auteur ; Gyorgy Bansaghi, Auteur ; Paul Thorey, Auteur Année de publication : 2010 Article en page(s) : pp. 9349–9354 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Cyclohexanediol Supercritical fluid extraction Résumé : A racemic mixture of trans-1,2-cyclohexanediol (CHD) is reacted with S,S- or R,R-tartaric acid in ethanol with a 0.5 or higher molar ratio of resolving agent to racemic CHD. The tartaric acid (TA) forms a diastereomeric cocrystal with only one of the enantiomers; the other enantiomer remains unreacted at any molar ratio. The unreacted mixture of enantiomers is recovered from the sample by supercritical fluid extraction at 20 MPa and 33 °C. A subsequent extraction is then performed at 20 MPa and at least 73 °C. During this second extraction step, the diastereomeric cocrystal is decomposed in situ. Both enantiomers are recovered in nearly 50−50% yield with enantiomeric excess values of 65−90%. The mixtures of enantiomerss rich in S,S-CHD and R,R-CHD are then reacted with S,S-TA and R,R-TA, respectively, and the procedure is repeated. In two resolution steps, both enantiomers of CHD were produced in quantitative yields in a purity of ee > 99%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101107u
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9349–9354[article] Environmentally benign chiral resolution of trans - 1,2 - cyclohexanediol by two - step supercritical fluid extraction [texte imprimé] / Edit Szekely, Auteur ; Gyorgy Bansaghi, Auteur ; Paul Thorey, Auteur . - 2010 . - pp. 9349–9354.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9349–9354
Mots-clés : Cyclohexanediol Supercritical fluid extraction Résumé : A racemic mixture of trans-1,2-cyclohexanediol (CHD) is reacted with S,S- or R,R-tartaric acid in ethanol with a 0.5 or higher molar ratio of resolving agent to racemic CHD. The tartaric acid (TA) forms a diastereomeric cocrystal with only one of the enantiomers; the other enantiomer remains unreacted at any molar ratio. The unreacted mixture of enantiomers is recovered from the sample by supercritical fluid extraction at 20 MPa and 33 °C. A subsequent extraction is then performed at 20 MPa and at least 73 °C. During this second extraction step, the diastereomeric cocrystal is decomposed in situ. Both enantiomers are recovered in nearly 50−50% yield with enantiomeric excess values of 65−90%. The mixtures of enantiomerss rich in S,S-CHD and R,R-CHD are then reacted with S,S-TA and R,R-TA, respectively, and the procedure is repeated. In two resolution steps, both enantiomers of CHD were produced in quantitative yields in a purity of ee > 99%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101107u Exemplaires
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Titre : Energy - efficient noble metal recovery by the use of acid - stable nanomagnets Type de document : texte imprimé Auteurs : Michael Rossier, Auteur ; Fabian M. Koehler, Auteur ; Evagelos K. Athanassiou, Auteur Année de publication : 2010 Article en page(s) : pp. 9355–9362 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Metal Nanomagnets Résumé : The present work investigates the potential use of metal-based carbon-coated magnetic nanoparticles for the efficient extraction of gold and platinum at high dilution (milligram to gram per ton ≡ ppb to ppm) at a mini-pilot level (0.1 m3). Acid-stable nanomagnets were first prepared by reducing flame synthesis and consisted of graphene-like carbon-coated cobalt metal nanoparticles (20−40 nm diameter) with an onion-like core/shell structure. The use of a metal core affords high saturation magnetization, while carbon shells are highly resistant to most chemical conditions. The nanomagnet surface was further coated with a standard noble metal extraction resin-like polymer (thiourea groups on a poly(ethylene imine)). Extraction runs were tested both at laboratory scale (0.1−10 L; Au and Pt removal > 95%; down to the milligram per ton level) and in a tank model (vertical tank section, 4 m height, 0.1 m3 volume, Pt removal > 80% at 50 mg/ton of acid water). Delivery of freshly dispersed nanomagnet dispersions onto the top layer of the tank model’s water zone (top 0.1 m) resulted in agglomeration and subsequent sedimentation through the tank model’s water column while simultaneously adsorbing platinum with an efficiency of 90%. At the bottom of the tank model, the nanomagnets could be efficiently collected through sweeping the tank model’s bottom surface with an array of permanent magnets. This process circumvents moving a tank’s liquid volume (energy costs for pumping) through conventionally used and time-consuming fixed-bed assemblies. In contrast, the presented process only moves a very small mass ( ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101117c
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9355–9362[article] Energy - efficient noble metal recovery by the use of acid - stable nanomagnets [texte imprimé] / Michael Rossier, Auteur ; Fabian M. Koehler, Auteur ; Evagelos K. Athanassiou, Auteur . - 2010 . - pp. 9355–9362.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9355–9362
Mots-clés : Metal Nanomagnets Résumé : The present work investigates the potential use of metal-based carbon-coated magnetic nanoparticles for the efficient extraction of gold and platinum at high dilution (milligram to gram per ton ≡ ppb to ppm) at a mini-pilot level (0.1 m3). Acid-stable nanomagnets were first prepared by reducing flame synthesis and consisted of graphene-like carbon-coated cobalt metal nanoparticles (20−40 nm diameter) with an onion-like core/shell structure. The use of a metal core affords high saturation magnetization, while carbon shells are highly resistant to most chemical conditions. The nanomagnet surface was further coated with a standard noble metal extraction resin-like polymer (thiourea groups on a poly(ethylene imine)). Extraction runs were tested both at laboratory scale (0.1−10 L; Au and Pt removal > 95%; down to the milligram per ton level) and in a tank model (vertical tank section, 4 m height, 0.1 m3 volume, Pt removal > 80% at 50 mg/ton of acid water). Delivery of freshly dispersed nanomagnet dispersions onto the top layer of the tank model’s water zone (top 0.1 m) resulted in agglomeration and subsequent sedimentation through the tank model’s water column while simultaneously adsorbing platinum with an efficiency of 90%. At the bottom of the tank model, the nanomagnets could be efficiently collected through sweeping the tank model’s bottom surface with an array of permanent magnets. This process circumvents moving a tank’s liquid volume (energy costs for pumping) through conventionally used and time-consuming fixed-bed assemblies. In contrast, the presented process only moves a very small mass ( ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101117c Exemplaires
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Titre : Aminosilane cross - linked PEG/PEPEG/PPEPG membranes for CO2/N2 and CO2/H2 separation Type de document : texte imprimé Auteurs : Hailin Cong, Auteur ; Bing Yu, Auteur Année de publication : 2010 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aminosilane Nanocomposite membranes Résumé : Aminosilane-modified poly(ethylene glycol) (PEG), PEG-block-poly(propylene glycol) (PPG)-block-PEG (PEPEG), and PPG-block-PEG-block-PPG (PPEPG) diacrylate prepolymers are synthesized as new membrane materials for gas separation. By combining the in situ sol−gel process and cross-linking process together, the silane-modified prepolymers form flexible nanocomposite membranes with a maximum CO2 permeability of 274 barrer and CO2/N2 selectivity of about 30. The CO2 permeabilities of silane cross-linked PEPEG and PPEPG membranes are higher than those of silane cross-linked PEG membranes, whereas the CO2/N2 and CO2/H2 selectivities increase as the PEG content increases in the membrane. A proper aminosilane/prepolymer reaction ratio benefits the gas separation performance of the membrane due to the formation of different cross-linking structures and composites. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1012568
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010)[article] Aminosilane cross - linked PEG/PEPEG/PPEPG membranes for CO2/N2 and CO2/H2 separation [texte imprimé] / Hailin Cong, Auteur ; Bing Yu, Auteur . - 2010.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010)
Mots-clés : Aminosilane Nanocomposite membranes Résumé : Aminosilane-modified poly(ethylene glycol) (PEG), PEG-block-poly(propylene glycol) (PPG)-block-PEG (PEPEG), and PPG-block-PEG-block-PPG (PPEPG) diacrylate prepolymers are synthesized as new membrane materials for gas separation. By combining the in situ sol−gel process and cross-linking process together, the silane-modified prepolymers form flexible nanocomposite membranes with a maximum CO2 permeability of 274 barrer and CO2/N2 selectivity of about 30. The CO2 permeabilities of silane cross-linked PEPEG and PPEPG membranes are higher than those of silane cross-linked PEG membranes, whereas the CO2/N2 and CO2/H2 selectivities increase as the PEG content increases in the membrane. A proper aminosilane/prepolymer reaction ratio benefits the gas separation performance of the membrane due to the formation of different cross-linking structures and composites. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1012568 Exemplaires
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Titre : Diffusivity of carbon dioxide in room - temperature ionic liquids Type de document : texte imprimé Auteurs : Surya S. Moganty, Auteur ; Ruth E. Baltus, Auteur Année de publication : 2010 Article en page(s) : pp. 9370–9376 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Dioxide Ionic liquids Résumé : A transient thin liquid film gas uptake technique was used to measure the diffusion coefficients of carbon dioxide under infinite dilution conditions in eight commercially available room-temperature ionic liquids at 10, 25, and 40 °C. The measured CO2 diffusion coefficients were 1 × 10−6 cm2/s, an order of magnitude smaller than coefficients for CO2 diffusion in traditional organic solvents. Combining these results with diffusivity values reported in the literature for CO2 diffusivity in nonionic fluids shows a generally universal relationship between diffusivity and solvent viscosity, with diffusivity inversely proportional to the square root of viscosity. Activation energies for CO2 diffusion in ionic liquids were found to be considerably smaller than activation energies for self-diffusion of ionic liquids (determined from NMR measurements) and activation energies for ionic liquid viscosity. These relative values are different than for CO2 diffusion, self-diffusion and viscosity in traditional nonionic solvents, where activation energy values for the three different processes are generally comparable. Results were used to develop correlations relating CO2 diffusion to ionic liquid properties and system temperature. Different expressions were needed to describe diffusion in ionic liquids with bis(trifluoromethylsulfonyl)imide anion than for ionic liquids with a different anion. Diffusivity values predicted using these correlations agree within 25% with experimentally measured values. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101260j
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9370–9376[article] Diffusivity of carbon dioxide in room - temperature ionic liquids [texte imprimé] / Surya S. Moganty, Auteur ; Ruth E. Baltus, Auteur . - 2010 . - pp. 9370–9376.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9370–9376
Mots-clés : Dioxide Ionic liquids Résumé : A transient thin liquid film gas uptake technique was used to measure the diffusion coefficients of carbon dioxide under infinite dilution conditions in eight commercially available room-temperature ionic liquids at 10, 25, and 40 °C. The measured CO2 diffusion coefficients were 1 × 10−6 cm2/s, an order of magnitude smaller than coefficients for CO2 diffusion in traditional organic solvents. Combining these results with diffusivity values reported in the literature for CO2 diffusivity in nonionic fluids shows a generally universal relationship between diffusivity and solvent viscosity, with diffusivity inversely proportional to the square root of viscosity. Activation energies for CO2 diffusion in ionic liquids were found to be considerably smaller than activation energies for self-diffusion of ionic liquids (determined from NMR measurements) and activation energies for ionic liquid viscosity. These relative values are different than for CO2 diffusion, self-diffusion and viscosity in traditional nonionic solvents, where activation energy values for the three different processes are generally comparable. Results were used to develop correlations relating CO2 diffusion to ionic liquid properties and system temperature. Different expressions were needed to describe diffusion in ionic liquids with bis(trifluoromethylsulfonyl)imide anion than for ionic liquids with a different anion. Diffusivity values predicted using these correlations agree within 25% with experimentally measured values. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101260j Exemplaires
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Titre : High - purity oxygen production from air using perovskite hollow fiber membranes Type de document : texte imprimé Auteurs : Fangyi Liang, Auteur ; Heqing Jiang, Auteur ; Thomas Schiestel, Auteur Année de publication : 2010 Article en page(s) : pp. 9377–9384 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production pure oxygen Résumé : The production of O2-enriched air and of high-purity oxygen was studied in a flow-through and in a dead-end permeator with BaCoxFeyZr1−x−yO3−δ (BCFZ) hollow fiber membranes at high temperatures using (i) pressurized air/O2-enriched air as feed, (ii) reduced pressure on the permeate side, and (iii) a combination of both. For the effective production of oxygen with a high space-time yield, a two-step process is proposed. In a first step, O2-enriched air with an oxygen concentration of 30−50 vol % is produced in a flow-through permeator from 1 bar of air as feed applying a vacuum pump to keep the pressure on the O2-enriched air side at about 0.12 bar. In a second step, pure oxygen is produced in a dead-end permeator using the O2-enriched air from step 1 as pressurized feed and using again a vacuum pump to establish a reduced oxygen pressure of about 0.05 bar on the permeate side. The oxygen permeation fluxes increase with increasing temperature, pressure on the feed side, and oxygen concentration in the fed O2-enriched air. An oxygen permeation flux of 10.2 cm3 (STP) cm−2 min−1 was reached using O2-enriched air with 50 vol % O2 at 5 bar as feed and reduced pressure of 0.05 bar on the permeate side at 900 °C. A high oxygen purity up to 99.9 vol % and high permeation rates of almost 10 cm3 (STP) cm−2 min−1 were obtained at 900 °C in a 150 h operation under the conditions of 0.05 bar on the oxygen side and oxygen-enriched air at 4 bar on the feed side. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101311g
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9377–9384[article] High - purity oxygen production from air using perovskite hollow fiber membranes [texte imprimé] / Fangyi Liang, Auteur ; Heqing Jiang, Auteur ; Thomas Schiestel, Auteur . - 2010 . - pp. 9377–9384.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9377–9384
Mots-clés : Production pure oxygen Résumé : The production of O2-enriched air and of high-purity oxygen was studied in a flow-through and in a dead-end permeator with BaCoxFeyZr1−x−yO3−δ (BCFZ) hollow fiber membranes at high temperatures using (i) pressurized air/O2-enriched air as feed, (ii) reduced pressure on the permeate side, and (iii) a combination of both. For the effective production of oxygen with a high space-time yield, a two-step process is proposed. In a first step, O2-enriched air with an oxygen concentration of 30−50 vol % is produced in a flow-through permeator from 1 bar of air as feed applying a vacuum pump to keep the pressure on the O2-enriched air side at about 0.12 bar. In a second step, pure oxygen is produced in a dead-end permeator using the O2-enriched air from step 1 as pressurized feed and using again a vacuum pump to establish a reduced oxygen pressure of about 0.05 bar on the permeate side. The oxygen permeation fluxes increase with increasing temperature, pressure on the feed side, and oxygen concentration in the fed O2-enriched air. An oxygen permeation flux of 10.2 cm3 (STP) cm−2 min−1 was reached using O2-enriched air with 50 vol % O2 at 5 bar as feed and reduced pressure of 0.05 bar on the permeate side at 900 °C. A high oxygen purity up to 99.9 vol % and high permeation rates of almost 10 cm3 (STP) cm−2 min−1 were obtained at 900 °C in a 150 h operation under the conditions of 0.05 bar on the oxygen side and oxygen-enriched air at 4 bar on the feed side. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101311g Exemplaires
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Titre : Solubility, solubility modeling, and precipitation of naproxen from subcritical water solutions Type de document : texte imprimé Auteurs : Adam G. Carr, Auteur ; Raffaella Mammucari, Auteur ; Neil R. Foster, Auteur Année de publication : 2010 Article en page(s) : pp. 9385–9393 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solubility naproxen Résumé : In this paper, the solubility of naproxen in subcritical water (SBCW) between 130 and 170 °C is measured. The solubility of naproxen in SBCW was correlated to temperature using a Modified Universal Functional Activity Coefficient (M-UNIFAC) model. Errors in the model were minimized by optimizing the water−carboxylic acid interaction parameter, as other side groups were already optimized. The micronization of naproxen via processes that used the tunable solvent power of SBCW was conducted. Two precipitation techniques were developed. In the first technique, the temperature of a SBCW solution containing naproxen was rapidly quenched by injection into cold water solutions. The quenching media were either pure water or 1% w/v solution of lactose in water. Variations in SBCW−naproxen solution injection temperature and supersaturation ratios in pure water were examined. Product morphology was robust toward changes in operating conditions and consisted of flaky crystals with a particle size distribution ranging from 0.5 to 100 μm. Under specific experimental conditions, naproxen crystals formed spherical agglomerates. Particles produced from lactose/water solutions were slightly smaller than those produced from pure water. In the second technique, precipitation was induced by vaporization of SBCW−naproxen solutions. The SBCW solutions were injected into a vessel that was connected to a vacuum pump. The process generated large naproxen microcrystals with broad particle size distributions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019825
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9385–9393[article] Solubility, solubility modeling, and precipitation of naproxen from subcritical water solutions [texte imprimé] / Adam G. Carr, Auteur ; Raffaella Mammucari, Auteur ; Neil R. Foster, Auteur . - 2010 . - pp. 9385–9393.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9385–9393
Mots-clés : Solubility naproxen Résumé : In this paper, the solubility of naproxen in subcritical water (SBCW) between 130 and 170 °C is measured. The solubility of naproxen in SBCW was correlated to temperature using a Modified Universal Functional Activity Coefficient (M-UNIFAC) model. Errors in the model were minimized by optimizing the water−carboxylic acid interaction parameter, as other side groups were already optimized. The micronization of naproxen via processes that used the tunable solvent power of SBCW was conducted. Two precipitation techniques were developed. In the first technique, the temperature of a SBCW solution containing naproxen was rapidly quenched by injection into cold water solutions. The quenching media were either pure water or 1% w/v solution of lactose in water. Variations in SBCW−naproxen solution injection temperature and supersaturation ratios in pure water were examined. Product morphology was robust toward changes in operating conditions and consisted of flaky crystals with a particle size distribution ranging from 0.5 to 100 μm. Under specific experimental conditions, naproxen crystals formed spherical agglomerates. Particles produced from lactose/water solutions were slightly smaller than those produced from pure water. In the second technique, precipitation was induced by vaporization of SBCW−naproxen solutions. The SBCW solutions were injected into a vessel that was connected to a vacuum pump. The process generated large naproxen microcrystals with broad particle size distributions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019825 Exemplaires
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Titre : Group - contribution method for the molecular parameters of the PC - SAFT equation of state taking into account the proximity effect. application to nonassociated compounds Type de document : texte imprimé Auteurs : Javier Vijande, Auteur ; Manuel M. Pineiro, Auteur ; Jose L. Legido, Auteur Année de publication : 2010 Article en page(s) : pp. 9394–9406 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Molecular parameters Résumé : A new group-contribution method to obtain the PC-SAFT molecular parameters of nonassociated compounds (linear alkanes, branched alkanes, linear monoethers, and esters) is developed on the basis of their regular trends against molecular mass. The method takes into account the proximity effect among all functional groups of a molecule in order to describe the deviations of shorter chain molecular parameters from the regular trend observed for the larger chain ones. The group-contribution scheme considers the molecular parameters as a linear combination of reference functional-group parameters and their mutual perturbations, which are responsible for the deviations from the reference ones. Both types of parameters (the reference functional-group parameters and the mutual perturbations) are optimized to the available molecular parameters published in the literature and obtained by direct fitting from experimental data of saturation pressures and saturated liquid densities. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1002813
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9394–9406[article] Group - contribution method for the molecular parameters of the PC - SAFT equation of state taking into account the proximity effect. application to nonassociated compounds [texte imprimé] / Javier Vijande, Auteur ; Manuel M. Pineiro, Auteur ; Jose L. Legido, Auteur . - 2010 . - pp. 9394–9406.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9394–9406
Mots-clés : Molecular parameters Résumé : A new group-contribution method to obtain the PC-SAFT molecular parameters of nonassociated compounds (linear alkanes, branched alkanes, linear monoethers, and esters) is developed on the basis of their regular trends against molecular mass. The method takes into account the proximity effect among all functional groups of a molecule in order to describe the deviations of shorter chain molecular parameters from the regular trend observed for the larger chain ones. The group-contribution scheme considers the molecular parameters as a linear combination of reference functional-group parameters and their mutual perturbations, which are responsible for the deviations from the reference ones. Both types of parameters (the reference functional-group parameters and the mutual perturbations) are optimized to the available molecular parameters published in the literature and obtained by direct fitting from experimental data of saturation pressures and saturated liquid densities. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1002813 Exemplaires
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Titre : Adsorption behaviors of optical brightening agents and precipitated calcium carbonate onto pulp fibers Type de document : texte imprimé Auteurs : Hongjie Zhang, Auteur ; Lanfeng Hui, Auteur ; Yonghao Ni, Auteur Année de publication : 2010 Article en page(s) : pp. 9407–9412 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optical brightening agents Adsorption Résumé : High-yield pulps (HYPs) can be used in the production of high-quality fine paper grades. In such applications, optical brightening agents (OBA) and inorganic fillers, such as precipitated calcium carbonate (PCC) may be used to improve the paper properties, including optical properties, such as brightness, whiteness, opacity. In this study, some fundamental parameters regarding OBA and PCC adsorption onto pulp fibers were investigated. Results showed that OBA was preferably adsorbed onto bleached kraft pulp (BKP) fibers than onto HYP fibers when present in a mixed furnish. The OBA adsorption at a low adsorbed amount followed the Langmuir adsorption isotherm for both BKP and HYP; the adsorbed OBA in a monolayer was more for the BKP than for the HYP. The PCC adsorption behaviors on the same two pulp systems, however, are different from those of OBA: the HYP had more PCC adsorption than the BKP. The results on the adsorption of PCC onto the HYP and kraft pulp fibers showed that they also followed the Langmuir kinetics very well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003976
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9407–9412[article] Adsorption behaviors of optical brightening agents and precipitated calcium carbonate onto pulp fibers [texte imprimé] / Hongjie Zhang, Auteur ; Lanfeng Hui, Auteur ; Yonghao Ni, Auteur . - 2010 . - pp. 9407–9412.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9407–9412
Mots-clés : Optical brightening agents Adsorption Résumé : High-yield pulps (HYPs) can be used in the production of high-quality fine paper grades. In such applications, optical brightening agents (OBA) and inorganic fillers, such as precipitated calcium carbonate (PCC) may be used to improve the paper properties, including optical properties, such as brightness, whiteness, opacity. In this study, some fundamental parameters regarding OBA and PCC adsorption onto pulp fibers were investigated. Results showed that OBA was preferably adsorbed onto bleached kraft pulp (BKP) fibers than onto HYP fibers when present in a mixed furnish. The OBA adsorption at a low adsorbed amount followed the Langmuir adsorption isotherm for both BKP and HYP; the adsorbed OBA in a monolayer was more for the BKP than for the HYP. The PCC adsorption behaviors on the same two pulp systems, however, are different from those of OBA: the HYP had more PCC adsorption than the BKP. The results on the adsorption of PCC onto the HYP and kraft pulp fibers showed that they also followed the Langmuir kinetics very well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1003976 Exemplaires
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Titre : Simple channel geometry for enhancement of chemical reactions in microchannels Type de document : texte imprimé Auteurs : B. R. Fu, Auteur ; Chin Pan, Auteur Année de publication : 2010 Article en page(s) : pp. 9413–9422 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Chemical reactions Microchannel Microfluidic Résumé : The mixing of different fluids or chemical species flowing through a microchannel is of great concern in many microfluidic applications, especially microchannel reactors. Flows in a microchannel are generally laminar, and mixing occurs due to molecular diffusion, which is a slow process. Mixing of solutions as a phenomenon is driven by the diffusion itself, but change of the channel shape results in the change of the mixing properties of particular microfluidic structure. This paper presents an experimental and theoretical investigation into the effect of channel axial cross-section shape on mixing and chemical reaction in microchannels. Three microchannels with uniform, converging, and diverging axial cross-sections were used to perform a liquid−liquid acid−base reaction that produces CO2 gas. Flow visualization demonstrated that the most intense chemical reactions (enhanced bubble formation) occurred in the diverging microchannel. Results of both qualitative mixing experiments using two reactive solutions and theoretical analysis indicated that the flow deceleration effect in the diverging microchannel significantly enhanced diffusive mixing in the lateral direction and, consequently, chemical reactions. From these results, it is concluded that a microchannel with a simple diverging cross-section can be used to develop microfluidic devices such as microchannel reactors. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100589c
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9413–9422[article] Simple channel geometry for enhancement of chemical reactions in microchannels [texte imprimé] / B. R. Fu, Auteur ; Chin Pan, Auteur . - 2010 . - pp. 9413–9422.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9413–9422
Mots-clés : Chemical reactions Microchannel Microfluidic Résumé : The mixing of different fluids or chemical species flowing through a microchannel is of great concern in many microfluidic applications, especially microchannel reactors. Flows in a microchannel are generally laminar, and mixing occurs due to molecular diffusion, which is a slow process. Mixing of solutions as a phenomenon is driven by the diffusion itself, but change of the channel shape results in the change of the mixing properties of particular microfluidic structure. This paper presents an experimental and theoretical investigation into the effect of channel axial cross-section shape on mixing and chemical reaction in microchannels. Three microchannels with uniform, converging, and diverging axial cross-sections were used to perform a liquid−liquid acid−base reaction that produces CO2 gas. Flow visualization demonstrated that the most intense chemical reactions (enhanced bubble formation) occurred in the diverging microchannel. Results of both qualitative mixing experiments using two reactive solutions and theoretical analysis indicated that the flow deceleration effect in the diverging microchannel significantly enhanced diffusive mixing in the lateral direction and, consequently, chemical reactions. From these results, it is concluded that a microchannel with a simple diverging cross-section can be used to develop microfluidic devices such as microchannel reactors. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100589c Exemplaires
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Titre : Prediction of pressure drop using artificial neural network for gas non - newtonian liquid flow through piping components Type de document : texte imprimé Auteurs : Nirjhar Bar, Auteur ; Manindra Nath Biswas, Auteur ; Sudip Kumar Das, Auteur Année de publication : 2010 Article en page(s) : pp. 9423–9429 Langues : Anglais (eng) Mots-clés : Gas Non Newtonian liquid flow Résumé : The ANN approach proved its worth when rigorous fluid mechanics treatment based on the solution of first principle equations is not tractable. Evaluation and prediction of the frictional pressure drop across different piping components such as orifices, gate and globe valves, elbows, and horizontal pipe in 0.0127 m diameter for gas non-Newtonian liquid flow is manifested in this paper. In this paper, we have used the power-law-model (Oswald−de Waele model) liquids only. The experimental data used for the prediction is taken from our earlier work, Bandyopadhyay (Bandyopadhyay, T. K. Studies on non-Newtonian and gas-non-Newtonian liquid flow through horizontal tube and piping components. Ph.D Thesis, University of Calcutta, Kolkata, India, 2002) and the subsequent publications (Banerjee T. K.; Das, S. K. Gas-non-Newtonian liquid flow through globe and gate valves. Chem. Eng. Commun. 1998, 167, 133−146. Samanta A. K.; Banerjee, T. K.; Das, S. K. Pressure loses in orifices for the flow of gas-non-Newtonian liquids. Can. J. Chem. Eng. 1999, 77, 579−583. Bandyopadhyay, T. K.; Banerjee, T. K.; Das, S. K. Gas-non-Newtonian liquid flow through elbows. Chem. Eng. Commun. 2000, 82, 21−33). The proposed approach toward the prediction is done using a multilayer perceptron (MLP with one hidden layer and four different transfer functions), which is trained with backpropagation algorithm. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1007739
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9423–9429[article] Prediction of pressure drop using artificial neural network for gas non - newtonian liquid flow through piping components [texte imprimé] / Nirjhar Bar, Auteur ; Manindra Nath Biswas, Auteur ; Sudip Kumar Das, Auteur . - 2010 . - pp. 9423–9429.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9423–9429
Mots-clés : Gas Non Newtonian liquid flow Résumé : The ANN approach proved its worth when rigorous fluid mechanics treatment based on the solution of first principle equations is not tractable. Evaluation and prediction of the frictional pressure drop across different piping components such as orifices, gate and globe valves, elbows, and horizontal pipe in 0.0127 m diameter for gas non-Newtonian liquid flow is manifested in this paper. In this paper, we have used the power-law-model (Oswald−de Waele model) liquids only. The experimental data used for the prediction is taken from our earlier work, Bandyopadhyay (Bandyopadhyay, T. K. Studies on non-Newtonian and gas-non-Newtonian liquid flow through horizontal tube and piping components. Ph.D Thesis, University of Calcutta, Kolkata, India, 2002) and the subsequent publications (Banerjee T. K.; Das, S. K. Gas-non-Newtonian liquid flow through globe and gate valves. Chem. Eng. Commun. 1998, 167, 133−146. Samanta A. K.; Banerjee, T. K.; Das, S. K. Pressure loses in orifices for the flow of gas-non-Newtonian liquids. Can. J. Chem. Eng. 1999, 77, 579−583. Bandyopadhyay, T. K.; Banerjee, T. K.; Das, S. K. Gas-non-Newtonian liquid flow through elbows. Chem. Eng. Commun. 2000, 82, 21−33). The proposed approach toward the prediction is done using a multilayer perceptron (MLP with one hidden layer and four different transfer functions), which is trained with backpropagation algorithm. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1007739 Exemplaires
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Titre : Individual ionic activity coefficients of sodium halides in glucose − water solutions at 298.15 K Type de document : texte imprimé Auteurs : Weiyan Dong, Auteur ; Yang Zhao, Auteur ; Kelei Zhuo, Auteur Année de publication : 2010 Article en page(s) : pp. 9430-9435 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamic properties Activity coefficient Ionic activity Résumé : The individual ionic activity coefficients of sodium halides (NaX) in the NaX−glucose−water solutions were experimentally determined at 298.15 K by using ion selective electrodes. The individual ionic activity coefficients evaluated by the use of the extended Debye—Hückel equation are in agreement with those by the Pitzer equation. In addition, dependences of the individual ionic activity coefficients upon molalities, properties of cations and anions are discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289679
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9430-9435[article] Individual ionic activity coefficients of sodium halides in glucose − water solutions at 298.15 K [texte imprimé] / Weiyan Dong, Auteur ; Yang Zhao, Auteur ; Kelei Zhuo, Auteur . - 2010 . - pp. 9430-9435.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9430-9435
Mots-clés : Thermodynamic properties Activity coefficient Ionic activity Résumé : The individual ionic activity coefficients of sodium halides (NaX) in the NaX−glucose−water solutions were experimentally determined at 298.15 K by using ion selective electrodes. The individual ionic activity coefficients evaluated by the use of the extended Debye—Hückel equation are in agreement with those by the Pitzer equation. In addition, dependences of the individual ionic activity coefficients upon molalities, properties of cations and anions are discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289679 Exemplaires
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Titre : Renormalization - group corrections to the perturbed - chain statistical associating fluid theory for binary mixtures Type de document : texte imprimé Auteurs : Xiaohua Tang, Auteur ; Joachim Gross, Auteur Année de publication : 2010 Article en page(s) : pp. 9436–9444 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Statistical associating fluid theory Résumé : Classical fluid theories do not describe the long-range fluctuations that occur in the vicinity of a pure component or mixture’s critical point. The perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state is extended with a renormalization group theory for mixtures. The theory accounts for the long-range density fluctuations and the results reduce to the results of the classical PC-SAFT equation of state away from the critical point. Two approximation methods, the isomorphic approximation and phase-space cell approximation, are used for the renormalization group corrections of mixtures. The two variants are evaluated by comparison to experimental vapor−liquid data for systems of alkanes, carbon dioxide and hydrogen sulfide. Overall, the considered implementation of the phase-space cell approximation is slightly superior to the isomorphic approximation for the mixtures investigated here. The phase-space cell approximation tends to overestimate the renormalization corrections for some cases but generally leads to good agreement with experimental data for binary mixtures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100890d
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9436–9444[article] Renormalization - group corrections to the perturbed - chain statistical associating fluid theory for binary mixtures [texte imprimé] / Xiaohua Tang, Auteur ; Joachim Gross, Auteur . - 2010 . - pp. 9436–9444.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9436–9444
Mots-clés : Statistical associating fluid theory Résumé : Classical fluid theories do not describe the long-range fluctuations that occur in the vicinity of a pure component or mixture’s critical point. The perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state is extended with a renormalization group theory for mixtures. The theory accounts for the long-range density fluctuations and the results reduce to the results of the classical PC-SAFT equation of state away from the critical point. Two approximation methods, the isomorphic approximation and phase-space cell approximation, are used for the renormalization group corrections of mixtures. The two variants are evaluated by comparison to experimental vapor−liquid data for systems of alkanes, carbon dioxide and hydrogen sulfide. Overall, the considered implementation of the phase-space cell approximation is slightly superior to the isomorphic approximation for the mixtures investigated here. The phase-space cell approximation tends to overestimate the renormalization corrections for some cases but generally leads to good agreement with experimental data for binary mixtures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100890d Exemplaires
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Titre : Measurement of liquid distributions in particle packings using wire - mesh sensor versus transmission tomographic imaging Type de document : texte imprimé Auteurs : Andre Bieberle, Auteur ; Markus Schubert, Auteur ; Marco Jose da Silva, Auteur Année de publication : 2010 Article en page(s) : pp. 9445–9453 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Imaging techniques Hydrodynamics Résumé : The paper compares two different imaging techniques for the investigation of the hydrodynamics in a laboratory packed bed reactor operating at different stationary states and with two different particle packings. The wire-mesh sensor offers cross-sectional liquid holdup distribution imaging at an ultra high speed of 10000 frames/s and good spatial resolution of 6 mm. It is therefore a very useful imaging tool for transient and periodic flow conditions. Up to now its influence on the flow in a packed bed was never analyzed. γ-ray computed tomography uses 662 keV γ photons to obtain cross-sectional phase distribution images. It offers as well a good spatial resolution of 2 mm and does not influence the flow but needs rather long scanning times. As a noninvasive technique γ-ray tomography has been used as a reference modality to evaluate the wire-mesh sensor measurements. Data from both imaging modalities are compared utilizing different analyzing models and showed good agreement. For the wire-mesh sensor only marginal intrusive effects for the specific situation were found. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100900g
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9445–9453[article] Measurement of liquid distributions in particle packings using wire - mesh sensor versus transmission tomographic imaging [texte imprimé] / Andre Bieberle, Auteur ; Markus Schubert, Auteur ; Marco Jose da Silva, Auteur . - 2010 . - pp. 9445–9453.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9445–9453
Mots-clés : Imaging techniques Hydrodynamics Résumé : The paper compares two different imaging techniques for the investigation of the hydrodynamics in a laboratory packed bed reactor operating at different stationary states and with two different particle packings. The wire-mesh sensor offers cross-sectional liquid holdup distribution imaging at an ultra high speed of 10000 frames/s and good spatial resolution of 6 mm. It is therefore a very useful imaging tool for transient and periodic flow conditions. Up to now its influence on the flow in a packed bed was never analyzed. γ-ray computed tomography uses 662 keV γ photons to obtain cross-sectional phase distribution images. It offers as well a good spatial resolution of 2 mm and does not influence the flow but needs rather long scanning times. As a noninvasive technique γ-ray tomography has been used as a reference modality to evaluate the wire-mesh sensor measurements. Data from both imaging modalities are compared utilizing different analyzing models and showed good agreement. For the wire-mesh sensor only marginal intrusive effects for the specific situation were found. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100900g Exemplaires
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Titre : Analysis of dissolved - gas atomization : Supercritical CO2 dissolved in water Type de document : texte imprimé Auteurs : Giuseppe Caputo, Auteur ; Renata Adami, Auteur ; Ernesto Reverchon, Auteur Année de publication : 2010 Article en page(s) : pp. 9454–9461 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gas Atomization Dissolved Résumé : Supercritical dissolved-gas atomization is an atomization process in which carbon dioxide at temperature and pressure above its critical point is used as the atomizing gas. The spray characteristics in terms of droplets size and distribution have been experimentally studied using a laser diffraction method based on a Malvern apparatus. The main parameter that influences the droplets size is the gas-to-liquid mass ratio (GLR); the injection pressure in the range of 7.4−13 MPa has a minor effect. Upon variation of the GLR from 0.5 to 3, the droplet mean diameter changes from about 8.0 to 2.0 μm; very narrow droplet size distributions are also produced. From the point of view of the atomization mechanism, the mean droplet diameter is mainly influenced by the sudden release of the gas dissolved in the liquid. The overall analysis of the experimental data confirms that dissolved-gas atomization allows for the formation of micrometric droplets that can produce precipitates with controlled sizes and distributions that are useful in several fine-particles production processes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100925w
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9454–9461[article] Analysis of dissolved - gas atomization : Supercritical CO2 dissolved in water [texte imprimé] / Giuseppe Caputo, Auteur ; Renata Adami, Auteur ; Ernesto Reverchon, Auteur . - 2010 . - pp. 9454–9461.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9454–9461
Mots-clés : Gas Atomization Dissolved Résumé : Supercritical dissolved-gas atomization is an atomization process in which carbon dioxide at temperature and pressure above its critical point is used as the atomizing gas. The spray characteristics in terms of droplets size and distribution have been experimentally studied using a laser diffraction method based on a Malvern apparatus. The main parameter that influences the droplets size is the gas-to-liquid mass ratio (GLR); the injection pressure in the range of 7.4−13 MPa has a minor effect. Upon variation of the GLR from 0.5 to 3, the droplet mean diameter changes from about 8.0 to 2.0 μm; very narrow droplet size distributions are also produced. From the point of view of the atomization mechanism, the mean droplet diameter is mainly influenced by the sudden release of the gas dissolved in the liquid. The overall analysis of the experimental data confirms that dissolved-gas atomization allows for the formation of micrometric droplets that can produce precipitates with controlled sizes and distributions that are useful in several fine-particles production processes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100925w Exemplaires
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Titre : Liquid − liquid equilibrium data in ionic liquid + 4 - methyldibenzothiophene + n - dodecane systems Type de document : texte imprimé Auteurs : Leonardo Hadlich de Oliveira, Auteur ; Martin Aznar, Auteur Année de publication : 2010 Article en page(s) : pp. 9462–9468 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Liquid equilibrium Résumé : In this work, liquid−liquid equilibrium data for 1-ethyl-3-methylimidazolium diethylphosphate ([emim][DEtPO4]) or 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]) + 4-methyl-dibenzothiophene (4-MDBT) + n-dodecane systems at 25 and 40 °C and atmospheric pressure (≈95 kPa) were determined by refractometry. 4-MDBT is a DBT derivative and it is one of the most difficult diesel sulfur pollutants to remove by the conventional process of hydrodesulfurization. The liquid−liquid equilibrium data were used to study the 4-MDBT extraction from n-dodecane as model diesel oil. 4-MDBT distribution coefficients, solvent selectivities, and extraction data also indicate that [emim][DEtPO4] is a better solvent for extractive desulfurization of n-dodecane than [emim][EtSO4]. For a solvent/n-dodecane mass ratio of 0.6, the sulfur content in n-dodecane decreases 17−24% and 5−15% for [emim][DEtPO4] and [emim][EtSO4], respectively. The quality of the data was ascertained by the Hand and Othmer−Tobias correlations, which presented R2 > 0.97 for all systems. The NRTL model was used to correlate the data and showed root-mean-square deviations of ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1009876
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9462–9468[article] Liquid − liquid equilibrium data in ionic liquid + 4 - methyldibenzothiophene + n - dodecane systems [texte imprimé] / Leonardo Hadlich de Oliveira, Auteur ; Martin Aznar, Auteur . - 2010 . - pp. 9462–9468.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9462–9468
Mots-clés : Liquid equilibrium Résumé : In this work, liquid−liquid equilibrium data for 1-ethyl-3-methylimidazolium diethylphosphate ([emim][DEtPO4]) or 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]) + 4-methyl-dibenzothiophene (4-MDBT) + n-dodecane systems at 25 and 40 °C and atmospheric pressure (≈95 kPa) were determined by refractometry. 4-MDBT is a DBT derivative and it is one of the most difficult diesel sulfur pollutants to remove by the conventional process of hydrodesulfurization. The liquid−liquid equilibrium data were used to study the 4-MDBT extraction from n-dodecane as model diesel oil. 4-MDBT distribution coefficients, solvent selectivities, and extraction data also indicate that [emim][DEtPO4] is a better solvent for extractive desulfurization of n-dodecane than [emim][EtSO4]. For a solvent/n-dodecane mass ratio of 0.6, the sulfur content in n-dodecane decreases 17−24% and 5−15% for [emim][DEtPO4] and [emim][EtSO4], respectively. The quality of the data was ascertained by the Hand and Othmer−Tobias correlations, which presented R2 > 0.97 for all systems. The NRTL model was used to correlate the data and showed root-mean-square deviations of ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1009876 Exemplaires
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Titre : Modeling Temperature-Dependent Properties of Oxygen, Argon, and Nitrogen via Response Modeling Methodology (RMM) and Comparison with Acceptable Models Type de document : texte imprimé Auteurs : Haim Shore, Auteur ; Diamanta Benson-Karhi, Auteur Année de publication : 2010 Article en page(s) : pp. 9469-9485 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling Résumé : In a recent paper, temperature-dependent properties of water were modeled via response modeling methodology (RMM), and the resultant models were compared to models obtained by TableCurve2D (a dedicated software for relational modeling), and to "Acceptable models", recommended by DIPPR (a widely used database for constant and temperature-dependent physical properties). In this paper, we extend the comparison to oxygen, argon and nitrogen. Model comparison has been conducted for 10 temperature-dependent physical and thermodynamic properties. Detailed results are reported in this paper. Summary tables, which rank the various models in terms of goodness-of-fit and stability over all properties, are provided. The three variations of the RMM model (two-, three-, and four-parameter models) compare favorably with other models, often with more parameters, in terms of both goodness-of-fit and stability. The unique desirable properties of RMM models are discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289684
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9469-9485[article] Modeling Temperature-Dependent Properties of Oxygen, Argon, and Nitrogen via Response Modeling Methodology (RMM) and Comparison with Acceptable Models [texte imprimé] / Haim Shore, Auteur ; Diamanta Benson-Karhi, Auteur . - 2010 . - pp. 9469-9485.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9469-9485
Mots-clés : Modeling Résumé : In a recent paper, temperature-dependent properties of water were modeled via response modeling methodology (RMM), and the resultant models were compared to models obtained by TableCurve2D (a dedicated software for relational modeling), and to "Acceptable models", recommended by DIPPR (a widely used database for constant and temperature-dependent physical properties). In this paper, we extend the comparison to oxygen, argon and nitrogen. Model comparison has been conducted for 10 temperature-dependent physical and thermodynamic properties. Detailed results are reported in this paper. Summary tables, which rank the various models in terms of goodness-of-fit and stability over all properties, are provided. The three variations of the RMM model (two-, three-, and four-parameter models) compare favorably with other models, often with more parameters, in terms of both goodness-of-fit and stability. The unique desirable properties of RMM models are discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289684 Exemplaires
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Titre : Wall effects on flow and drag phenomena of spheroid particles at moderate reynolds numbers Type de document : texte imprimé Auteurs : Nanda Kishore, Auteur ; Sai Gu, Auteur Année de publication : 2010 Article en page(s) : pp. 9486–9495 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Spheroid particles Résumé : Two dimensional steady Newtonian flow past oblate and prolate spheroid particles confined in cylindrical tubes of different diameters has been numerically investigated. The flow and drag phenomena of confined spheroid particles are governed by the equations of continuity and conservation of momentum. These equations along with appropriate boundary conditions have been solved using commercial software based on computational fluid dynamics. Extensive new results were obtained on individual and total drag coefficients of spheroid particles, along with streamline contours, distributions of pressure coefficients, and vorticity magnitudes on the surface of spheroid particles as functions of the Reynolds number (Re), the aspect ratio (e), and the wall factor (λ) over the following range of conditions: 1 ≤ Re ≤ 200, 0.25 ≤ e ≤ 2.5, and 2 ≤ λ ≤ 30. For all values of the aspect ratio, as values of the Reynolds numbers and/or the wall factor increase, the length of recirculation wake increases. For fixed values of the aspect ratio and the Reynolds number, the increase in the value of the wall factor decrease both individual and the total drag coefficients. On the whole, regardless of the value of the aspect ratio, the wall effect was found to gradually diminish with the increasing Reynolds number and/or the wall factor. Finally, on the basis of the present numerical results a simple correlation has been proposed for the total drag coefficient of confined spheroid particles which can be used in new applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1011189
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9486–9495[article] Wall effects on flow and drag phenomena of spheroid particles at moderate reynolds numbers [texte imprimé] / Nanda Kishore, Auteur ; Sai Gu, Auteur . - 2010 . - pp. 9486–9495.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9486–9495
Mots-clés : Spheroid particles Résumé : Two dimensional steady Newtonian flow past oblate and prolate spheroid particles confined in cylindrical tubes of different diameters has been numerically investigated. The flow and drag phenomena of confined spheroid particles are governed by the equations of continuity and conservation of momentum. These equations along with appropriate boundary conditions have been solved using commercial software based on computational fluid dynamics. Extensive new results were obtained on individual and total drag coefficients of spheroid particles, along with streamline contours, distributions of pressure coefficients, and vorticity magnitudes on the surface of spheroid particles as functions of the Reynolds number (Re), the aspect ratio (e), and the wall factor (λ) over the following range of conditions: 1 ≤ Re ≤ 200, 0.25 ≤ e ≤ 2.5, and 2 ≤ λ ≤ 30. For all values of the aspect ratio, as values of the Reynolds numbers and/or the wall factor increase, the length of recirculation wake increases. For fixed values of the aspect ratio and the Reynolds number, the increase in the value of the wall factor decrease both individual and the total drag coefficients. On the whole, regardless of the value of the aspect ratio, the wall effect was found to gradually diminish with the increasing Reynolds number and/or the wall factor. Finally, on the basis of the present numerical results a simple correlation has been proposed for the total drag coefficient of confined spheroid particles which can be used in new applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1011189 Exemplaires
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Titre : Water solubility in ionic liquids and application to absorption cycles Type de document : texte imprimé Auteurs : A. Yokozeki, Auteur ; Mark B. Shiflett, Auteur Année de publication : 2010 Article en page(s) : pp. 9496–9503 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Absorption Solubility water Résumé : The absorption cooling cycle has been in use for more than 100 years. Although the vapor compression cycle is now used for most air-conditioning and refrigeration applications, the well-known refrigerant−absorbent systems (water−LiBr and ammonia−water) are still being used for space cooling and industrial refrigeration. Recently, absorption cooling cycles using water + room-temperature ionic liquids (RTILs) have been proposed as a replacement for the water + LiBr system. There have been a few reports in the literature since about the year 2000 on the solubility of water in RTILs, and some of the hydrophilic RTILs show extremely high mutual solubility with water, indicating formation of chemical complexes. Almost all solubility data have been correlated with the use of activity (or solution) models. In the present report, we apply an equation of state (EOS) model in order to understand the solubility characteristics, as well as the chemical complex formation, consistently with the same thermodynamic model. Also, such a model is convenient for estimating the performance of the absorption cooling cycle, as we have demonstrated in the past for the absorption cycle performance of various hydrofluorocarbons (HFCs) + solvents and ammonia + RTILs. The present purpose is to examine the feasibility of using water and RTILs in an absorption cooling cycle and to show some promising results for this application. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1011432
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9496–9503[article] Water solubility in ionic liquids and application to absorption cycles [texte imprimé] / A. Yokozeki, Auteur ; Mark B. Shiflett, Auteur . - 2010 . - pp. 9496–9503.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9496–9503
Mots-clés : Absorption Solubility water Résumé : The absorption cooling cycle has been in use for more than 100 years. Although the vapor compression cycle is now used for most air-conditioning and refrigeration applications, the well-known refrigerant−absorbent systems (water−LiBr and ammonia−water) are still being used for space cooling and industrial refrigeration. Recently, absorption cooling cycles using water + room-temperature ionic liquids (RTILs) have been proposed as a replacement for the water + LiBr system. There have been a few reports in the literature since about the year 2000 on the solubility of water in RTILs, and some of the hydrophilic RTILs show extremely high mutual solubility with water, indicating formation of chemical complexes. Almost all solubility data have been correlated with the use of activity (or solution) models. In the present report, we apply an equation of state (EOS) model in order to understand the solubility characteristics, as well as the chemical complex formation, consistently with the same thermodynamic model. Also, such a model is convenient for estimating the performance of the absorption cooling cycle, as we have demonstrated in the past for the absorption cycle performance of various hydrofluorocarbons (HFCs) + solvents and ammonia + RTILs. The present purpose is to examine the feasibility of using water and RTILs in an absorption cooling cycle and to show some promising results for this application. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1011432 Exemplaires
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Titre : Calculation for mineral phases in the calcination of desulfurization residue to produce sulfoaluminate cement Type de document : texte imprimé Auteurs : Wenlong Wang, Auteur ; Peng Wang, Auteur ; Chunyuan Ma, Auteur Année de publication : 2010 Article en page(s) : pp. 9504–9510 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flue gas desulfurization Résumé : The utilization of dry flue gas desulfurization (FGD) residue has become an environmental issue in China. A new method is introduced here to produce sulfoaluminate cement using the dry FGD residue and fly ash without modification of the cement plant equipments. The bench- and pilot-scale experimental studies indicated that the obtained sulfoaluminate cement product had excellent performance. FACTSAGE was improved by a new database and then used for raw material proportion optimization. The mineral phases of a CaO−SiO2−Al2O3−CaSO4 system after calcination were calculated. The theoretical and experimental results are accordant. This technology has good potential to decrease the raw material costs and energy consumption at cement plants. It is also beneficial in CO2 emission reduction and circular economy development. The calculation results may be generally referred in the studies on the chemical processes such as sulfur fixation at high temperature, mineral optimization, and cement production, etc. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101228h
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9504–9510[article] Calculation for mineral phases in the calcination of desulfurization residue to produce sulfoaluminate cement [texte imprimé] / Wenlong Wang, Auteur ; Peng Wang, Auteur ; Chunyuan Ma, Auteur . - 2010 . - pp. 9504–9510.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9504–9510
Mots-clés : Flue gas desulfurization Résumé : The utilization of dry flue gas desulfurization (FGD) residue has become an environmental issue in China. A new method is introduced here to produce sulfoaluminate cement using the dry FGD residue and fly ash without modification of the cement plant equipments. The bench- and pilot-scale experimental studies indicated that the obtained sulfoaluminate cement product had excellent performance. FACTSAGE was improved by a new database and then used for raw material proportion optimization. The mineral phases of a CaO−SiO2−Al2O3−CaSO4 system after calcination were calculated. The theoretical and experimental results are accordant. This technology has good potential to decrease the raw material costs and energy consumption at cement plants. It is also beneficial in CO2 emission reduction and circular economy development. The calculation results may be generally referred in the studies on the chemical processes such as sulfur fixation at high temperature, mineral optimization, and cement production, etc. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101228h Exemplaires
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Titre : Thermodynamics of mixtures containing oxaalkanes. 4. : Random mixing and orientational effects in ether + alkane systems Type de document : texte imprimé Auteurs : Juan Antonio Gonzalez, Auteur Année de publication : 2010 Article en page(s) : pp. 9511–9524 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamics Ether Alkane systems Résumé : Molar excess enthalpies, HmE, and volumes, VmE, of linear or cyclic ether + n-alkane systems have been discussed in terms of the effective dipole moment, μ̅, of the ether, differences of standard enthalpies of vaporization of the ether and of the isomeric alkane, the number and relative positions of the oxygen atoms, the shape of the ether, and the relative size of the mixture compounds. The mentioned solutions have also been studied using the Flory model and the Kirkwood−Buff formalism. Both theories provide consistent results. At 298.15 K, the random mixing hypothesis is a good approximation for mixtures including linear or cyclic monoethers or linear diethers. Orientational effects become stronger in solutions with 2,5,8-trioxanonane, 2,5,8,11-tetraoxadodecane, or 2,5,8,11,14-pentaoxapentadecane. In the case of 1,3-dioxolane mixtures, this type of effect is more relevant than in systems with 1,4-dioxane. This is supported by W-shaped Cp,mE curves, large variations of the Flory interaction parameter, X12, with x1, the oxaalkane concentration, and local mole fractions of the ether−ether type that are higher than the bulk ones, particularly at lower x1 values. The latter means that orientational effects are more important at this condition, and this is confirmed by large X12 variations with x1 in the region of low x1 values. At equimolar composition, X12 values of solutions containing 2,5,8,11-tetraoxadodecane or cyclic ethers remain nearly constant with the number of C atoms of the alkane, which reveals that systems with such oxaalkanes are similar from an interactional point of view. From values of the internal excess energies at constant volume, UVmE, it is shown that interactions between like molecules are usually overestimated. Nevertheless, the general trends observed are independent of the HmE or UVmE data considered. Structural effects are present in mixtures with components that differ largely in size (e.g., dipropyl ether + hexadecane or 2,5,8,11,14-pentaoxapentadecane + hexane). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101264p
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9511–9524[article] Thermodynamics of mixtures containing oxaalkanes. 4. : Random mixing and orientational effects in ether + alkane systems [texte imprimé] / Juan Antonio Gonzalez, Auteur . - 2010 . - pp. 9511–9524.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9511–9524
Mots-clés : Thermodynamics Ether Alkane systems Résumé : Molar excess enthalpies, HmE, and volumes, VmE, of linear or cyclic ether + n-alkane systems have been discussed in terms of the effective dipole moment, μ̅, of the ether, differences of standard enthalpies of vaporization of the ether and of the isomeric alkane, the number and relative positions of the oxygen atoms, the shape of the ether, and the relative size of the mixture compounds. The mentioned solutions have also been studied using the Flory model and the Kirkwood−Buff formalism. Both theories provide consistent results. At 298.15 K, the random mixing hypothesis is a good approximation for mixtures including linear or cyclic monoethers or linear diethers. Orientational effects become stronger in solutions with 2,5,8-trioxanonane, 2,5,8,11-tetraoxadodecane, or 2,5,8,11,14-pentaoxapentadecane. In the case of 1,3-dioxolane mixtures, this type of effect is more relevant than in systems with 1,4-dioxane. This is supported by W-shaped Cp,mE curves, large variations of the Flory interaction parameter, X12, with x1, the oxaalkane concentration, and local mole fractions of the ether−ether type that are higher than the bulk ones, particularly at lower x1 values. The latter means that orientational effects are more important at this condition, and this is confirmed by large X12 variations with x1 in the region of low x1 values. At equimolar composition, X12 values of solutions containing 2,5,8,11-tetraoxadodecane or cyclic ethers remain nearly constant with the number of C atoms of the alkane, which reveals that systems with such oxaalkanes are similar from an interactional point of view. From values of the internal excess energies at constant volume, UVmE, it is shown that interactions between like molecules are usually overestimated. Nevertheless, the general trends observed are independent of the HmE or UVmE data considered. Structural effects are present in mixtures with components that differ largely in size (e.g., dipropyl ether + hexadecane or 2,5,8,11,14-pentaoxapentadecane + hexane). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101264p Exemplaires
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Titre : Effect of bed configuration on dispersion in a packed - bed reactor Type de document : texte imprimé Auteurs : Renu Gupta, Auteur ; Ajay Bansal, Auteur Année de publication : 2010 Article en page(s) : pp. 9525–9528 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Dispersion Reactor Résumé : The axial dispersion coefficient is one of the important parameters in the design of the reactors. It has a strong influence on the conversion and selectivity. The present study has been conducted on a packed-bed reactor that had a diameter of 10 cm with particles of various configurations, using the pulse tracer technique. The dynamic response was well-explained by a single-parameter dispersion model. Dispersion, in terms of the Peclet number (Pe) and the Bodenstein number (Bo) has been observed for different bed configurations. Pe increased as the liquid flow rates increased. For spherical particles, Pe was determined to increase as the particle size increased. However, the Pe value for nonspherical particles was greater than that for spherical particles. Based on the experimental results, a correlation has been developed to estimate the dispersion in terms of Bo for packed beds involving different bed configurations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901376s
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9525–9528[article] Effect of bed configuration on dispersion in a packed - bed reactor [texte imprimé] / Renu Gupta, Auteur ; Ajay Bansal, Auteur . - 2010 . - pp. 9525–9528.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9525–9528
Mots-clés : Dispersion Reactor Résumé : The axial dispersion coefficient is one of the important parameters in the design of the reactors. It has a strong influence on the conversion and selectivity. The present study has been conducted on a packed-bed reactor that had a diameter of 10 cm with particles of various configurations, using the pulse tracer technique. The dynamic response was well-explained by a single-parameter dispersion model. Dispersion, in terms of the Peclet number (Pe) and the Bodenstein number (Bo) has been observed for different bed configurations. Pe increased as the liquid flow rates increased. For spherical particles, Pe was determined to increase as the particle size increased. However, the Pe value for nonspherical particles was greater than that for spherical particles. Based on the experimental results, a correlation has been developed to estimate the dispersion in terms of Bo for packed beds involving different bed configurations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901376s Exemplaires
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Titre : Effect of annealing on the stress corrosion cracking of α - brass in aqueous electrolytes containing aggressive ions Type de document : texte imprimé Auteurs : Nageh K. Allam, Auteur ; Ahmed Abdel Nazeer, Auteur ; Elsayed A. Ashour, Auteur Année de publication : 2010 Article en page(s) : pp. 9529–9533 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous electrolytes Résumé : A continuing challenge in materials design is the achievement of greater operational efficiency through improvements in performance criterion, particularly, high strength and service lifetime characteristics. In this study, we report on the effect of heat treatment (annealing) on the stress corrosion cracking (SCC) behavior of α-brass (71Cu−28Zn) in aqueous electrolytes containing some aggressive anions (Cl−, ClO3−, NO2−, and SO42−). The annealed specimens suffered from SCC in all tested electrolytes under the anodic polarization conditions while they were susceptible to SCC only in NaNO2 and Na2SO4 solutions under the open circuit condition. The susceptibility toward SCC was found to decrease considerably in NaCl, KClO3, and Na2SO4 solutions and very slightly in NaNO2 solutions upon annealing the specimens. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101603w
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9529–9533[article] Effect of annealing on the stress corrosion cracking of α - brass in aqueous electrolytes containing aggressive ions [texte imprimé] / Nageh K. Allam, Auteur ; Ahmed Abdel Nazeer, Auteur ; Elsayed A. Ashour, Auteur . - 2010 . - pp. 9529–9533.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9529–9533
Mots-clés : Aqueous electrolytes Résumé : A continuing challenge in materials design is the achievement of greater operational efficiency through improvements in performance criterion, particularly, high strength and service lifetime characteristics. In this study, we report on the effect of heat treatment (annealing) on the stress corrosion cracking (SCC) behavior of α-brass (71Cu−28Zn) in aqueous electrolytes containing some aggressive anions (Cl−, ClO3−, NO2−, and SO42−). The annealed specimens suffered from SCC in all tested electrolytes under the anodic polarization conditions while they were susceptible to SCC only in NaNO2 and Na2SO4 solutions under the open circuit condition. The susceptibility toward SCC was found to decrease considerably in NaCl, KClO3, and Na2SO4 solutions and very slightly in NaNO2 solutions upon annealing the specimens. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101603w Exemplaires
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Titre : A New Intensified Heat Integration in Distillation Column Type de document : texte imprimé Auteurs : Ajay Mane, Auteur ; Amiya K. Jana, Auteur Année de publication : 2010 Article en page(s) : pp. 9534–9541 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Heat distillation Résumé : In this contribution, a new intensified energy integration technique is introduced for the distillation column. The influence of the proposed intensified heat-integrated distillation column (int-HIDiC) scheme on the energetic and economic aspects is evaluated through intensive comparison against the heat-integrated distillation column (HIDiC) and the conventional stand-alone column. The HIDiC and the conventional distillation column (CDiC) are conceptually designed by the minimization of total annual cost (TAC). Here, two int-HIDiC structures are developed by introducing further thermal coupling between the overhead vapor of rectifying section and the bottom liquid of stripping section of the HIDiC scheme. This intensified energy integration approach reduces the steam consumption in the reboiler and avoids the use of a trim-condenser. For a binary distillation, it is observed that the proposed int-HIDiCs provide positive energy savings and better economic figures than the HIDiC and the conventional column. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100942p
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9534–9541[article] A New Intensified Heat Integration in Distillation Column [texte imprimé] / Ajay Mane, Auteur ; Amiya K. Jana, Auteur . - 2010 . - pp. 9534–9541.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9534–9541
Mots-clés : Heat distillation Résumé : In this contribution, a new intensified energy integration technique is introduced for the distillation column. The influence of the proposed intensified heat-integrated distillation column (int-HIDiC) scheme on the energetic and economic aspects is evaluated through intensive comparison against the heat-integrated distillation column (HIDiC) and the conventional stand-alone column. The HIDiC and the conventional distillation column (CDiC) are conceptually designed by the minimization of total annual cost (TAC). Here, two int-HIDiC structures are developed by introducing further thermal coupling between the overhead vapor of rectifying section and the bottom liquid of stripping section of the HIDiC scheme. This intensified energy integration approach reduces the steam consumption in the reboiler and avoids the use of a trim-condenser. For a binary distillation, it is observed that the proposed int-HIDiCs provide positive energy savings and better economic figures than the HIDiC and the conventional column. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100942p Exemplaires
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Titre : Correlation of infinite - dilution diffusion coefficients in supercritical fluids Type de document : texte imprimé Auteurs : Yingzi Shi, Auteur ; Jiangang Lu, Auteur Année de publication : 2010 Article en page(s) : pp. 9542-9547 Langues : Anglais (eng) Mots-clés : Supercritical state Diffusion coefficient Infinite dilution Correlation analysis ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289692
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9542-9547[article] Correlation of infinite - dilution diffusion coefficients in supercritical fluids [texte imprimé] / Yingzi Shi, Auteur ; Jiangang Lu, Auteur . - 2010 . - pp. 9542-9547.
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9542-9547
Mots-clés : Supercritical state Diffusion coefficient Infinite dilution Correlation analysis ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289692 Exemplaires
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Titre : Advances in the Correlation of Thermodynamic properties of binary systems applied to methanol mixtures with butyl esters Type de document : texte imprimé Auteurs : Fernando Espiau, Auteur ; Juan Ortega, Auteur ; Eduvigis Penco, Auteur Année de publication : 2010 Article en page(s) : pp. 9548-9558 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Binary system Thermodynamic properties Correlation analysis Résumé : This work analyzes the utility of a new model to correlate thermodynamic properties of solutions, the foundations of which have been published in a previous study. The model is applied to a set of experimental data for several properties of binary systems of methanol with four butyl alkanoates (vapor-liquid equilibria at p = 141.32 kPa and excess enthalpies and volumes at 298.15 and 318.15 K). Vapor-liquid equilibrium data (VLE) indicate that the four binary systems deviate positively from Raoult's law and do not present azeotrope. Excess enthalpies (hE) are positive for the entire range of compositions and decrease regularly with increasing length of the ester chain, with (∂hE/∂T)p,x > 0. The excess volumes (υE) decrease regularly with the length of the acid chain; they are positive for the binary systems of methanol with butyl (methanoate, ethanoate, and propanoate) and become negative for the system with butyl butanoate, with (∂vE/∂T)p,x > 0. The new model can be used to obtain a satisfactory correlation for Gibbs function gE = gE(p, T, xi), and for its derivatives. Correlation procedures for the data are described for the stages (x, hE) → [x, gE(T)] for the isobaric data reported here and (x, vE) → [x, gE(p)] for isothermal data reported in the literature. The new method allows a better correlation than the one obtained with the classical models of Wilson, NRTL, and UNIQUAC. We also present a unique correlation of all the properties of the methanol + butyl ethanoate system in the form of an analytical expression ξ(p, T, x, y) = 0 and conclude that, on the whole, its implementation can be considered an advance in the data treatment of the properties of liquid solutions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289693
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9548-9558[article] Advances in the Correlation of Thermodynamic properties of binary systems applied to methanol mixtures with butyl esters [texte imprimé] / Fernando Espiau, Auteur ; Juan Ortega, Auteur ; Eduvigis Penco, Auteur . - 2010 . - pp. 9548-9558.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9548-9558
Mots-clés : Binary system Thermodynamic properties Correlation analysis Résumé : This work analyzes the utility of a new model to correlate thermodynamic properties of solutions, the foundations of which have been published in a previous study. The model is applied to a set of experimental data for several properties of binary systems of methanol with four butyl alkanoates (vapor-liquid equilibria at p = 141.32 kPa and excess enthalpies and volumes at 298.15 and 318.15 K). Vapor-liquid equilibrium data (VLE) indicate that the four binary systems deviate positively from Raoult's law and do not present azeotrope. Excess enthalpies (hE) are positive for the entire range of compositions and decrease regularly with increasing length of the ester chain, with (∂hE/∂T)p,x > 0. The excess volumes (υE) decrease regularly with the length of the acid chain; they are positive for the binary systems of methanol with butyl (methanoate, ethanoate, and propanoate) and become negative for the system with butyl butanoate, with (∂vE/∂T)p,x > 0. The new model can be used to obtain a satisfactory correlation for Gibbs function gE = gE(p, T, xi), and for its derivatives. Correlation procedures for the data are described for the stages (x, hE) → [x, gE(T)] for the isobaric data reported here and (x, vE) → [x, gE(p)] for isothermal data reported in the literature. The new method allows a better correlation than the one obtained with the classical models of Wilson, NRTL, and UNIQUAC. We also present a unique correlation of all the properties of the methanol + butyl ethanoate system in the form of an analytical expression ξ(p, T, x, y) = 0 and conclude that, on the whole, its implementation can be considered an advance in the data treatment of the properties of liquid solutions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23289693 Exemplaires
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