Nos Abonnements
Ressources Électroniques
|
[n° ou bulletin]
[n° ou bulletin]
Vol. 50 N° 11 - Juin 2011 [texte imprimé] . - 2011 . - p. 6517-7088 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
|
Exemplaires
| Code-barres | Cote | Support | Localisation | Section | Disponibilité |
|---|---|---|---|---|---|
| aucun exemplaire | |||||
|
Dépouillements
Ajouter le résultat dans votre panierProgress in study of non-isocyanate polyurethane / Jing Guan in Industrial & engineering chemistry research, Vol. 50 N° 11 (Juin 2011)
Titre : Progress in study of non-isocyanate polyurethane Type de document : texte imprimé Auteurs : Jing Guan, Auteur ; Yihu Song, Auteur ; Yu Lin, Auteur Année de publication : 2011 Article en page(s) : pp 6517–6527 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Polyurethane cyclo-carbonates Résumé : Non-isocyanate polyurethane (NIPU) is a novel kind of polyurethane prepared by reaction of cyclo-carbonates and amines without use of toxic isocyanates. NIPU has attracted increasing attention because of its improvements in porosity, water absorption, and thermal and chemical resistance over conventional polyurethanes. Their potential technological applications include chemical-resistant coating, sealants, foam, etc. In this paper, on the basis of a comprehensive survey of the currently available literature on NIPU, we summarize recent progress in NIPU, and mainly discuss the syntheses of cyclo-carbonates oligomers, the reaction mechanism, and the preparation and application of different kinds of NIPU. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101995j
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6517–6527[article] Progress in study of non-isocyanate polyurethane [texte imprimé] / Jing Guan, Auteur ; Yihu Song, Auteur ; Yu Lin, Auteur . - 2011 . - pp 6517–6527.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6517–6527
Mots-clés : Polyurethane cyclo-carbonates Résumé : Non-isocyanate polyurethane (NIPU) is a novel kind of polyurethane prepared by reaction of cyclo-carbonates and amines without use of toxic isocyanates. NIPU has attracted increasing attention because of its improvements in porosity, water absorption, and thermal and chemical resistance over conventional polyurethanes. Their potential technological applications include chemical-resistant coating, sealants, foam, etc. In this paper, on the basis of a comprehensive survey of the currently available literature on NIPU, we summarize recent progress in NIPU, and mainly discuss the syntheses of cyclo-carbonates oligomers, the reaction mechanism, and the preparation and application of different kinds of NIPU. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101995j Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Preparation, characterization and performance study of poly(isobutylene-alt-maleic anhydride) [PIAM] and polysulfone [PSf] composite membranes before and after alkali treatment Type de document : texte imprimé Auteurs : Mahesh Padaki, Auteur ; Arun M. Isloor, Auteur ; Ganesh Belavadi, Auteur Année de publication : 2011 Article en page(s) : pp 6528–6534 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Polysulfone Composite membranes Résumé : Recently, nanofiltration (NF) membranes have been drawing much attention in the field of filtration and the purification process of water/industrial effluents, because of their energy efficiency and low cost. Although reverse osmosis (RO) membranes are widely used in present desalination units, NF membranes are considered as “future membranes” for desalination, because of the low operating pressure. In the present paper, we hereby report the synthesis of a new composite NF membranes of poly(isobutylene-alt-maleic anhydride) (PIAM) with polysulfone, using a diffusion-induced phase separation (DIPS) method. The anhydride groups were converted to acid group by alkaline treatment. Newly prepared composite membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) studies. The membranes were tested for salt rejection and water swelling. The resulted NF membranes exhibited significantly enhanced water permeability while retaining high salt rejection. The flux and rejection rate of the NF membrane to Na2SO4 (500 ppm) reached to 11.73 L/(m2 h) and 49% rejection under 1 MPa and also 70:30 composition of the membrane showed 54% water swelling; contact angle measurement, ion exchange capacity, and water uptake of the membrane were recorded. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102387n
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6528–6534[article] Preparation, characterization and performance study of poly(isobutylene-alt-maleic anhydride) [PIAM] and polysulfone [PSf] composite membranes before and after alkali treatment [texte imprimé] / Mahesh Padaki, Auteur ; Arun M. Isloor, Auteur ; Ganesh Belavadi, Auteur . - 2011 . - pp 6528–6534.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6528–6534
Mots-clés : Polysulfone Composite membranes Résumé : Recently, nanofiltration (NF) membranes have been drawing much attention in the field of filtration and the purification process of water/industrial effluents, because of their energy efficiency and low cost. Although reverse osmosis (RO) membranes are widely used in present desalination units, NF membranes are considered as “future membranes” for desalination, because of the low operating pressure. In the present paper, we hereby report the synthesis of a new composite NF membranes of poly(isobutylene-alt-maleic anhydride) (PIAM) with polysulfone, using a diffusion-induced phase separation (DIPS) method. The anhydride groups were converted to acid group by alkaline treatment. Newly prepared composite membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) studies. The membranes were tested for salt rejection and water swelling. The resulted NF membranes exhibited significantly enhanced water permeability while retaining high salt rejection. The flux and rejection rate of the NF membrane to Na2SO4 (500 ppm) reached to 11.73 L/(m2 h) and 49% rejection under 1 MPa and also 70:30 composition of the membrane showed 54% water swelling; contact angle measurement, ion exchange capacity, and water uptake of the membrane were recorded. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102387n Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Intensification and selectivity modulation of ion-exchange resin catalyzed alkylation of phenol by microwave Type de document : texte imprimé Auteurs : Asraf A. Ali, Auteur ; Vilas G. Gaikar, Auteur Année de publication : 2011 Article en page(s) : pp 6556–6566 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microwave Kinetic model Alkylation phenol Résumé : Microwave irradiation has been used to intensify the alkylation reaction of phenol with tert-butyl alcohol using ion-exchange resin as the catalyst. About 86% conversion of phenol is obtained in 4 min under microwave irradiation. The major products are ortho-tert-butyl phenol (o-TBP), para-tert-butyl phenol (p-TBP) and 2,4-di-tert-butyl phenol (2,4-DTBP). o-TBP predominates in the product mixture as the kinetically favored product in shorter reaction times, but p-TBP is the major product for longer reaction times. The selectivity toward ortho- or para-substituted phenols can be manipulated by controlling the exposure time of the reaction mixture to the microwave irradiation. The Langmuir–Hinshelwood–Hougen–Watson (LHHW) surface reaction controlled model was used for the kinetic data analysis. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102051k
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6556–6566[article] Intensification and selectivity modulation of ion-exchange resin catalyzed alkylation of phenol by microwave [texte imprimé] / Asraf A. Ali, Auteur ; Vilas G. Gaikar, Auteur . - 2011 . - pp 6556–6566.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6556–6566
Mots-clés : Microwave Kinetic model Alkylation phenol Résumé : Microwave irradiation has been used to intensify the alkylation reaction of phenol with tert-butyl alcohol using ion-exchange resin as the catalyst. About 86% conversion of phenol is obtained in 4 min under microwave irradiation. The major products are ortho-tert-butyl phenol (o-TBP), para-tert-butyl phenol (p-TBP) and 2,4-di-tert-butyl phenol (2,4-DTBP). o-TBP predominates in the product mixture as the kinetically favored product in shorter reaction times, but p-TBP is the major product for longer reaction times. The selectivity toward ortho- or para-substituted phenols can be manipulated by controlling the exposure time of the reaction mixture to the microwave irradiation. The Langmuir–Hinshelwood–Hougen–Watson (LHHW) surface reaction controlled model was used for the kinetic data analysis. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102051k Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : A General and scalable formulation of pure CaAl-layered double hydroxide via an organic/water solution route Type de document : texte imprimé Auteurs : Sailong Xu, Auteur ; Bowen Zhang, Auteur ; Zhanrui Chen, Auteur Année de publication : 2011 Article en page(s) : pp 6567–6572 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydroxide Different organic Water solution Résumé : CaAl-layered double hydroxide (CaAl-LDH) has recently been proposed as potential concrete hardening accelerators, because of the similarity in the AFm phase (a family of hydrated calcium aluminate phases) that occurs in hydrated cement. The applications of the promising materials require synthesis routes to be capable of producing large-scale, byproduct-free, and easy-to-handle CaAl-LDH. Herein, we report a general and scalable synthesis of pure CaAl-LDH via an organic/water solution. The possibility of the formation of CaAl-LDH is addressed in terms of the prevention of ethanol from the generation of CaCO3 byproduct. The morphology and crystallinity of CaAl-LDH are tuned by varying different pH value, ethanol/water volumetric content, crystallization time, and temperature. A proper synthesis condition (for example, an ethanol/water volume ratio of 4:1, a pH value of 10.5–11.5, an aging time of 24 h, and a crystallization temperature of 70 °C) are optimized, and further readily scaled up, by a factor of up to 20, with respect to the initial starting materials. Our results of pure CaAl-LDH in different organic/water solutions may open up a means to produce promising concrete hardening accelerators in large amounts. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102135k
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6567–6572[article] A General and scalable formulation of pure CaAl-layered double hydroxide via an organic/water solution route [texte imprimé] / Sailong Xu, Auteur ; Bowen Zhang, Auteur ; Zhanrui Chen, Auteur . - 2011 . - pp 6567–6572.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6567–6572
Mots-clés : Hydroxide Different organic Water solution Résumé : CaAl-layered double hydroxide (CaAl-LDH) has recently been proposed as potential concrete hardening accelerators, because of the similarity in the AFm phase (a family of hydrated calcium aluminate phases) that occurs in hydrated cement. The applications of the promising materials require synthesis routes to be capable of producing large-scale, byproduct-free, and easy-to-handle CaAl-LDH. Herein, we report a general and scalable synthesis of pure CaAl-LDH via an organic/water solution. The possibility of the formation of CaAl-LDH is addressed in terms of the prevention of ethanol from the generation of CaCO3 byproduct. The morphology and crystallinity of CaAl-LDH are tuned by varying different pH value, ethanol/water volumetric content, crystallization time, and temperature. A proper synthesis condition (for example, an ethanol/water volume ratio of 4:1, a pH value of 10.5–11.5, an aging time of 24 h, and a crystallization temperature of 70 °C) are optimized, and further readily scaled up, by a factor of up to 20, with respect to the initial starting materials. Our results of pure CaAl-LDH in different organic/water solutions may open up a means to produce promising concrete hardening accelerators in large amounts. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102135k Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Enhancement of lignin production from olive tree pruning integrated in a green biorefinery Type de document : texte imprimé Auteurs : Ana Toledano, Auteur ; Luis Serrano, Auteur ; Jalel Labidi, Auteur Année de publication : 2011 Article en page(s) : pp 6573–6579 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Olive tree pruning Lignocellulosic Résumé : The green biorefinery concept relies on economically feasible processing to achieve a complete utilization of most lignocellulosic biomass components using green technologies. Among the main component of lignocellulosic biomass, lignin is one of the most interesting components since its aromatic nature makes lignin unique. The study presented here was focused on the enhancement of the organosolv lignin produced from olive wood from the point of view of not only operational conditions but also taking into account the purity and contamination of the obtained lignin. The results showed that the amount of lignin recovered in the liquor was strongly influenced by the process temperature. The ethanol concentration presented the opposite behavior with lignin, reaching high yields at low concentrations. Then, the obtained lignins under optimized conditions were analyzed in order to verify their purity. Almost all the obtained lignins presented hemicellulose contamination but there were differences between the polymerization degree of hemicelluloses and the abundance of hemicelluloses. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102142f
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6573–6579[article] Enhancement of lignin production from olive tree pruning integrated in a green biorefinery [texte imprimé] / Ana Toledano, Auteur ; Luis Serrano, Auteur ; Jalel Labidi, Auteur . - 2011 . - pp 6573–6579.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6573–6579
Mots-clés : Olive tree pruning Lignocellulosic Résumé : The green biorefinery concept relies on economically feasible processing to achieve a complete utilization of most lignocellulosic biomass components using green technologies. Among the main component of lignocellulosic biomass, lignin is one of the most interesting components since its aromatic nature makes lignin unique. The study presented here was focused on the enhancement of the organosolv lignin produced from olive wood from the point of view of not only operational conditions but also taking into account the purity and contamination of the obtained lignin. The results showed that the amount of lignin recovered in the liquor was strongly influenced by the process temperature. The ethanol concentration presented the opposite behavior with lignin, reaching high yields at low concentrations. Then, the obtained lignins under optimized conditions were analyzed in order to verify their purity. Almost all the obtained lignins presented hemicellulose contamination but there were differences between the polymerization degree of hemicelluloses and the abundance of hemicelluloses. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102142f Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Synthesis and physicochemical characterization of pure diammonium phosphate from industrial fertilizer Type de document : texte imprimé Auteurs : M. Gargouri, Auteur ; C. Chtara, Auteur ; P. Charrock, Auteur Année de publication : 2011 Article en page(s) : pp 6580–6584 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Diammonium phosphate Industrial fertilizer Résumé : Diammonium phosphate (DAP) is produced from industrial phosphoric acid that contains large amounts of anionic and cationic impurities (Co, Cu, Fe, Mn, Mo, Ni, Zn, F, As, Al, Hg, Pb and Cd). Consequently all those impurities will be found in DAP. However, the industrial DAP obtained can be used as fertilizers, but cannot be used for some industrial application like pharmaceutics and cosmetics. After purification, the price of DAP is three times more expensive than the same product before purification. The procedure for purification of industrial DAP is a recrystallization, by using several mixtures of solvents. The physicochemical characterization of this fertilizer upstream and downstream from the purification, through spectroscopic analyses and chemical analyses, shows that recrystallization eliminates impurities. Purified DAP was obtained, the physicochemical properties of which are comparable to those of the pure commercial DAP (Fisher). DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102237n
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6580–6584[article] Synthesis and physicochemical characterization of pure diammonium phosphate from industrial fertilizer [texte imprimé] / M. Gargouri, Auteur ; C. Chtara, Auteur ; P. Charrock, Auteur . - 2011 . - pp 6580–6584.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6580–6584
Mots-clés : Diammonium phosphate Industrial fertilizer Résumé : Diammonium phosphate (DAP) is produced from industrial phosphoric acid that contains large amounts of anionic and cationic impurities (Co, Cu, Fe, Mn, Mo, Ni, Zn, F, As, Al, Hg, Pb and Cd). Consequently all those impurities will be found in DAP. However, the industrial DAP obtained can be used as fertilizers, but cannot be used for some industrial application like pharmaceutics and cosmetics. After purification, the price of DAP is three times more expensive than the same product before purification. The procedure for purification of industrial DAP is a recrystallization, by using several mixtures of solvents. The physicochemical characterization of this fertilizer upstream and downstream from the purification, through spectroscopic analyses and chemical analyses, shows that recrystallization eliminates impurities. Purified DAP was obtained, the physicochemical properties of which are comparable to those of the pure commercial DAP (Fisher). DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102237n Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Covalent grafting of polydimethylsiloxane over surface-modified alumina nanoparticles Type de document : texte imprimé Auteurs : Satyajit Gupta, Auteur ; Praveen C. Ramamurthy, Auteur ; Giridhar Madras, Auteur Année de publication : 2011 Article en page(s) : pp 6585–6593 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Polymer nanocomposites Résumé : The synthesis of “smart structured” conducting polymers and the fabrication of devices using them are important areas of research. However, conducting polymeric materials that are used in devices are susceptible to degradation due to oxygen and moisture. Thus, protection of such devices to ensure long-term stability is always desirable. Polymer nanocomposites are promising materials for the encapsulation of such devices. Therefore, it is important to develop suitable polymer nanocomposites as encapsulation materials to protect such devices. This work presents a technique based on grafting between surface-decorated γ-alumina nanoparticles and polymer to make nanocomposites that can be used for the encapsulation of devices. Alumina was functionalized with allyltrimethoxysilane and used to conjugate polymer molecules (hydride-terminated polydimethylsiloxane) through a platinum-catalyzed hydrosilylation reaction. Fourier transform infrared spectroscopy, X-ray-photoelectron spectroscopy, and Raman spectroscopy were used to characterize the surface chemistry of the nanoparticles after surface modification. The grafting density of alkene groups on the surface of the modified nanoparticles was calculated using CHN and thermogravimetric analyses. The thermal stability of the composites was also evaluated using thermogravimetric analysis. The nanoindentation technique was used to analyze the mechanical characteristics of the composites. The densities of the composites were evaluated using a density gradient column, and the morphology of the composites was evaluated by scanning electron microscopy. All of our studies reveal that the composites have good thermal stability and mechanical flexibility and, thus, can potentially be used for the encapsulation of organic photovoltaic devices. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200283w
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6585–6593[article] Covalent grafting of polydimethylsiloxane over surface-modified alumina nanoparticles [texte imprimé] / Satyajit Gupta, Auteur ; Praveen C. Ramamurthy, Auteur ; Giridhar Madras, Auteur . - 2011 . - pp 6585–6593.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6585–6593
Mots-clés : Polymer nanocomposites Résumé : The synthesis of “smart structured” conducting polymers and the fabrication of devices using them are important areas of research. However, conducting polymeric materials that are used in devices are susceptible to degradation due to oxygen and moisture. Thus, protection of such devices to ensure long-term stability is always desirable. Polymer nanocomposites are promising materials for the encapsulation of such devices. Therefore, it is important to develop suitable polymer nanocomposites as encapsulation materials to protect such devices. This work presents a technique based on grafting between surface-decorated γ-alumina nanoparticles and polymer to make nanocomposites that can be used for the encapsulation of devices. Alumina was functionalized with allyltrimethoxysilane and used to conjugate polymer molecules (hydride-terminated polydimethylsiloxane) through a platinum-catalyzed hydrosilylation reaction. Fourier transform infrared spectroscopy, X-ray-photoelectron spectroscopy, and Raman spectroscopy were used to characterize the surface chemistry of the nanoparticles after surface modification. The grafting density of alkene groups on the surface of the modified nanoparticles was calculated using CHN and thermogravimetric analyses. The thermal stability of the composites was also evaluated using thermogravimetric analysis. The nanoindentation technique was used to analyze the mechanical characteristics of the composites. The densities of the composites were evaluated using a density gradient column, and the morphology of the composites was evaluated by scanning electron microscopy. All of our studies reveal that the composites have good thermal stability and mechanical flexibility and, thus, can potentially be used for the encapsulation of organic photovoltaic devices. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200283w Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Improvement of the benzene yield during pyrolysis of terephthalic acid using a CaO fixed-bed reactor Type de document : texte imprimé Auteurs : Shogo Kumagai, Auteur ; Guido Grause, Auteur ; Tomohito Kameda, Auteur Année de publication : 2011 Article en page(s) : pp 6594–6600 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pyrolysis Terephthalic acid Résumé : Effects of pyrolysis temperature and terephthalic acid (TPA) gas concentration on TPA degradation as a model substance for poly(ethylene terephthalate) (PET) degradation products were investigated with emphasis on benzene yield and decrease of carbonaceous residue. TPA was decarboxylated using a spiral tube reactor filled with CaO. The best results were achieved at 600 °C and TPA gas load of 28 mg L–1, yielding 84% benzene. Of the initial carbon, 29% remained in the reactor, consisting of carbonate and carbonaceous residue. Benzene purity was more than 97 wt % under all reaction conditions. Low TPA gas loads and high gas velocities resulted in good benzene yields and purities because TPA gas deeply penetrated the CaO fixed bed before adsorption. This resulted in lower TPA concentration at the CaO surface, reducing the interference between neighboring TPA molecules and limiting carbonaceous residue formation. DEWEY : 660 ISSN : 088-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102423m
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6594–6600[article] Improvement of the benzene yield during pyrolysis of terephthalic acid using a CaO fixed-bed reactor [texte imprimé] / Shogo Kumagai, Auteur ; Guido Grause, Auteur ; Tomohito Kameda, Auteur . - 2011 . - pp 6594–6600.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6594–6600
Mots-clés : Pyrolysis Terephthalic acid Résumé : Effects of pyrolysis temperature and terephthalic acid (TPA) gas concentration on TPA degradation as a model substance for poly(ethylene terephthalate) (PET) degradation products were investigated with emphasis on benzene yield and decrease of carbonaceous residue. TPA was decarboxylated using a spiral tube reactor filled with CaO. The best results were achieved at 600 °C and TPA gas load of 28 mg L–1, yielding 84% benzene. Of the initial carbon, 29% remained in the reactor, consisting of carbonate and carbonaceous residue. Benzene purity was more than 97 wt % under all reaction conditions. Low TPA gas loads and high gas velocities resulted in good benzene yields and purities because TPA gas deeply penetrated the CaO fixed bed before adsorption. This resulted in lower TPA concentration at the CaO surface, reducing the interference between neighboring TPA molecules and limiting carbonaceous residue formation. DEWEY : 660 ISSN : 088-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102423m Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Catalytic hydrogenation of corn stalk to ethylene glycol and 1,2-propylene glycol Type de document : texte imprimé Auteurs : Jifeng Pang, Auteur ; Mingyuan Zheng, Auteur ; Aiqin Wang, Auteur Année de publication : 2011 Article en page(s) : pp 6601–6608 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalytic Hydrogenation lignocellulosic biomass Résumé : The use of whole lignocellulosic biomass as the feedstock for cellulose conversion is of great significance for large-scale, low-cost biomass conversion to biofuel and other useful chemicals. We recently achieved the direct conversion of cellulose (pure microcrystalline cellulose) into ethylene glycol at high yields over tungsten carbide catalysts. Here, corn stalk, an agricultural residue available in large quantities, was used as a lignocellulosic feedstock for conversion over nickel-promoted tungsten carbide catalysts under hydrothermal conditions and a hydrogen atmosphere. Nine different pretreatment methods were employed to convert the raw corn stalk to cellulosic feedstock with different chemical components and structures before the catalytic reaction. We found that corn stalks pretreated with 1,4-butanediol, NaOH, H2O2, and ammonia produced much higher yields of ethylene glycol (EG) and 1,2-propylene glycol (1,2-PG) compared to raw corn stalks, whereas pretreatments with ethanol solution, hot water, hot limewater, and supercritical CO2 just slightly improved the EG and 1,2-PG yields and corn stalk conversion. The hemicellulose in the corn stalk can be effectively converted to EG and 1,2-PG without hindering the cellulose conversion. In contrast, the lignin was resistant to degradation in the reaction and also inhibited EG and 1,2-PG production. The crystallinity of cellulose did not appear to have notable influence on the EG and 1,2-PG production. In view of the environmental benignity and low cost, pretreatment with ammonia and/or diluted H2O2 solution might be a practical method for corn stalk conversion, after which the derived cellulosic feedstock is readily converted into EG and 1,2-PG at an overall yield of 48% in the reaction. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102505y
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6601–6608[article] Catalytic hydrogenation of corn stalk to ethylene glycol and 1,2-propylene glycol [texte imprimé] / Jifeng Pang, Auteur ; Mingyuan Zheng, Auteur ; Aiqin Wang, Auteur . - 2011 . - pp 6601–6608.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6601–6608
Mots-clés : Catalytic Hydrogenation lignocellulosic biomass Résumé : The use of whole lignocellulosic biomass as the feedstock for cellulose conversion is of great significance for large-scale, low-cost biomass conversion to biofuel and other useful chemicals. We recently achieved the direct conversion of cellulose (pure microcrystalline cellulose) into ethylene glycol at high yields over tungsten carbide catalysts. Here, corn stalk, an agricultural residue available in large quantities, was used as a lignocellulosic feedstock for conversion over nickel-promoted tungsten carbide catalysts under hydrothermal conditions and a hydrogen atmosphere. Nine different pretreatment methods were employed to convert the raw corn stalk to cellulosic feedstock with different chemical components and structures before the catalytic reaction. We found that corn stalks pretreated with 1,4-butanediol, NaOH, H2O2, and ammonia produced much higher yields of ethylene glycol (EG) and 1,2-propylene glycol (1,2-PG) compared to raw corn stalks, whereas pretreatments with ethanol solution, hot water, hot limewater, and supercritical CO2 just slightly improved the EG and 1,2-PG yields and corn stalk conversion. The hemicellulose in the corn stalk can be effectively converted to EG and 1,2-PG without hindering the cellulose conversion. In contrast, the lignin was resistant to degradation in the reaction and also inhibited EG and 1,2-PG production. The crystallinity of cellulose did not appear to have notable influence on the EG and 1,2-PG production. In view of the environmental benignity and low cost, pretreatment with ammonia and/or diluted H2O2 solution might be a practical method for corn stalk conversion, after which the derived cellulosic feedstock is readily converted into EG and 1,2-PG at an overall yield of 48% in the reaction. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102505y Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Synthesis of biosurfactants : enzymatic esterification of diglycerol and oleic acid. 1. kinetic modeling Type de document : texte imprimé Auteurs : Mercedes Martinez, Auteur ; Rubén Oliveros, Auteur ; José Aracil, Auteur Année de publication : 2011 Article en page(s) : pp 6609–6614 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Biosurfactants Enzyme Kinetic Résumé : The growing application of environmentally friendly products raised in the last few years has increased the interest in biodegradable nonionic surfactant products. As an example of these, polyglycerol fatty acid esters have a wide field of application in many industries as additives of cosmetics, food, photography, inks, etc. Also, the huge range of possible raw materials for these products increases cited interest. The esterification of diglycerol with oleic acid using an enzyme (NOVOZYM-435) as catalyst was studied in this work. Several experiments were carried out at different temperatures, catalyst concentrations, and acid/alcohol molar ratios. A pseudo-second-order kinetic model, including Langmuir adsorption factors for the acid, was developed. The results show that this proposed kinetic model reproduces the experimental data with a maximum 10% error. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102560b
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6609–6614[article] Synthesis of biosurfactants : enzymatic esterification of diglycerol and oleic acid. 1. kinetic modeling [texte imprimé] / Mercedes Martinez, Auteur ; Rubén Oliveros, Auteur ; José Aracil, Auteur . - 2011 . - pp 6609–6614.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6609–6614
Mots-clés : Biosurfactants Enzyme Kinetic Résumé : The growing application of environmentally friendly products raised in the last few years has increased the interest in biodegradable nonionic surfactant products. As an example of these, polyglycerol fatty acid esters have a wide field of application in many industries as additives of cosmetics, food, photography, inks, etc. Also, the huge range of possible raw materials for these products increases cited interest. The esterification of diglycerol with oleic acid using an enzyme (NOVOZYM-435) as catalyst was studied in this work. Several experiments were carried out at different temperatures, catalyst concentrations, and acid/alcohol molar ratios. A pseudo-second-order kinetic model, including Langmuir adsorption factors for the acid, was developed. The results show that this proposed kinetic model reproduces the experimental data with a maximum 10% error. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102560b Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : The [Bmim]4W10O23 catalyzed oxidation of 3,4-diaminofurazan to 3,4-dinitrofurazan in hydrogen peroxide Type de document : texte imprimé Auteurs : Hua-Ping Ren, Auteur ; Zhong-Wen Liu, Auteur ; Jian Lu, Auteur Année de publication : 2011 Article en page(s) : pp 6615–6619 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : catalyzed oxidation Hydrogen Peroxide. Résumé : -Methyl-3-butylimidazolium decatungstate ([C8H15N2]4W10O23, [Bmim]4W10O23) was prepared from 1-butyl-3-methylimidazolium bromide and sodium tungstate in hydrochloric acid solution. With the use of [Bmim]4W10O23 as the catalyst and 50% H2O2 as the oxidant, 3,4-dinitrofurazan (, DNF) was synthesized from 3,4-diaminofurazan (, DAF) in concentrated H2SO4. At a temperature of 35 °C, this process significantly increased the DNF yield from 39% to 58%, when compared with that with the conventional Na2WO4·2H2O catalyst under the same conditions. The effects of catalyst, reaction time, and temperature were investigated. A maximum DNF yield of 58% was obtained under optimal reaction conditions: 0.03 g of [Bmim]4W10O23, H2O2/H2SO4 molar ratio of 1.5:1, temperature and reaction time of 35 °C and 210 min, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200009g
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6615–6619[article] The [Bmim]4W10O23 catalyzed oxidation of 3,4-diaminofurazan to 3,4-dinitrofurazan in hydrogen peroxide [texte imprimé] / Hua-Ping Ren, Auteur ; Zhong-Wen Liu, Auteur ; Jian Lu, Auteur . - 2011 . - pp 6615–6619.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6615–6619
Mots-clés : catalyzed oxidation Hydrogen Peroxide. Résumé : -Methyl-3-butylimidazolium decatungstate ([C8H15N2]4W10O23, [Bmim]4W10O23) was prepared from 1-butyl-3-methylimidazolium bromide and sodium tungstate in hydrochloric acid solution. With the use of [Bmim]4W10O23 as the catalyst and 50% H2O2 as the oxidant, 3,4-dinitrofurazan (, DNF) was synthesized from 3,4-diaminofurazan (, DAF) in concentrated H2SO4. At a temperature of 35 °C, this process significantly increased the DNF yield from 39% to 58%, when compared with that with the conventional Na2WO4·2H2O catalyst under the same conditions. The effects of catalyst, reaction time, and temperature were investigated. A maximum DNF yield of 58% was obtained under optimal reaction conditions: 0.03 g of [Bmim]4W10O23, H2O2/H2SO4 molar ratio of 1.5:1, temperature and reaction time of 35 °C and 210 min, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200009g Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Biodiesel production by esterification of free fatty acids over 12-tungstophosphoric acid anchored to MCM-41 Type de document : texte imprimé Auteurs : Varsha Brahmkhatri, Auteur ; Anjali Patel, Auteur Année de publication : 2011 Article en page(s) : pp 6620–6628 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Biodiesel fatty acids Résumé : Heterogeneous acid catalyst comprising 12-tungstophosphoric acid (30%) and MCM-41 was synthesized and characterized by X-ray diffraction (XRD), surface area measurement (BET method), and solid state 29Si NMR. The use of synthesized catalyst was explored for biodiesel production by esterification of free fatty acid, palmitic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, and temperature were studied to optimize the conditions for maximum conversion. The catalyst shows high activity in terms of 100% conversion toward palmitic acid and a high turnover number, 1992. The kinetic studies as well as the Koros Nowak test were also carried out, and it was found that esterification of palmitic acid follows first order kinetics and the rates are not mass transfer limited. The excellent catalytic performance is attributed to the large surface area and pore diameter of the mesoporous support, MCM-41 as well as the Bronsted acid strength of TPA, as active sites. The catalyst shows the potential of being used as a recyclable catalytic material after simple regeneration without significant loss in conversion. As an application, preliminary studies were carried out for biodiesel production from waste cooking oil, as feedstock without any pretreatment, and with methanol over the present catalyst. Studies also reveal that the catalyst can be used for biodiesel production from waste cooking oil. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102066q
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6620–6628[article] Biodiesel production by esterification of free fatty acids over 12-tungstophosphoric acid anchored to MCM-41 [texte imprimé] / Varsha Brahmkhatri, Auteur ; Anjali Patel, Auteur . - 2011 . - pp 6620–6628.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6620–6628
Mots-clés : Biodiesel fatty acids Résumé : Heterogeneous acid catalyst comprising 12-tungstophosphoric acid (30%) and MCM-41 was synthesized and characterized by X-ray diffraction (XRD), surface area measurement (BET method), and solid state 29Si NMR. The use of synthesized catalyst was explored for biodiesel production by esterification of free fatty acid, palmitic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, and temperature were studied to optimize the conditions for maximum conversion. The catalyst shows high activity in terms of 100% conversion toward palmitic acid and a high turnover number, 1992. The kinetic studies as well as the Koros Nowak test were also carried out, and it was found that esterification of palmitic acid follows first order kinetics and the rates are not mass transfer limited. The excellent catalytic performance is attributed to the large surface area and pore diameter of the mesoporous support, MCM-41 as well as the Bronsted acid strength of TPA, as active sites. The catalyst shows the potential of being used as a recyclable catalytic material after simple regeneration without significant loss in conversion. As an application, preliminary studies were carried out for biodiesel production from waste cooking oil, as feedstock without any pretreatment, and with methanol over the present catalyst. Studies also reveal that the catalyst can be used for biodiesel production from waste cooking oil. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102066q Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Kinetic approach for investigating the “Microwave Effect” : decomposition of aqueous potassium persulfate Type de document : texte imprimé Auteurs : Basak Temur Ergan, Auteur ; Mahmut Bayramoglu, Auteur Année de publication : 2011 Article en page(s) : pp 6629–6637 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetic Potassium persulfate Résumé : In this work, the specific effect of microwave (MW) energy on chemical reactions was investigated by online monitoring of the decomposition kinetics of potassium persulfate (K2S2O8). Experiments conducted at constant temperature and constant MW power revealed that the rate constant was about 1.1–1.8 times higher than the rate constant of the thermally heated system at the same temperature, depending on the MW power. To model the dependence of the rate constant on the MW power as k = f(P) exp(−g(P)/T), various functional forms of MW power were envisaged for g(P) (activation energy Ea) and for f(P) (preexponential factor ko). Linear, quadratic, and cubic polynomial models were tried for both functions. Nonlinear regression analysis was performed and detailed statistical analysis was applied, and the best results were obtained with quadratic f(P) and cubic g(P) functions, with the highest R2adj (0.9975) and the lowest standard deviation (0.94 × 10–5). The mathematical model revealed that both the activation energy and preexponential factor were higher than their thermal counterparts (for P = 0.75 kW dm–3, ko,mw/ko,th = 120, Ea,mw/Ea,th = 1.12). DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200095y
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6629–6637[article] Kinetic approach for investigating the “Microwave Effect” : decomposition of aqueous potassium persulfate [texte imprimé] / Basak Temur Ergan, Auteur ; Mahmut Bayramoglu, Auteur . - 2011 . - pp 6629–6637.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6629–6637
Mots-clés : Kinetic Potassium persulfate Résumé : In this work, the specific effect of microwave (MW) energy on chemical reactions was investigated by online monitoring of the decomposition kinetics of potassium persulfate (K2S2O8). Experiments conducted at constant temperature and constant MW power revealed that the rate constant was about 1.1–1.8 times higher than the rate constant of the thermally heated system at the same temperature, depending on the MW power. To model the dependence of the rate constant on the MW power as k = f(P) exp(−g(P)/T), various functional forms of MW power were envisaged for g(P) (activation energy Ea) and for f(P) (preexponential factor ko). Linear, quadratic, and cubic polynomial models were tried for both functions. Nonlinear regression analysis was performed and detailed statistical analysis was applied, and the best results were obtained with quadratic f(P) and cubic g(P) functions, with the highest R2adj (0.9975) and the lowest standard deviation (0.94 × 10–5). The mathematical model revealed that both the activation energy and preexponential factor were higher than their thermal counterparts (for P = 0.75 kW dm–3, ko,mw/ko,th = 120, Ea,mw/Ea,th = 1.12). DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200095y Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Comparative Study of sonocatalytic enhancement for removal of bisphenol A and 17α-ethinyl estradiol Type de document : texte imprimé Auteurs : Namguk Her, Auteur ; Jong-Sung Park, Auteur ; Jaekyung Yoon, Auteur Année de publication : 2011 Article en page(s) : pp 6638–6645 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Sonocatalytic Bisphenol A stainless steel Résumé : A series of experiments were conducted to compare the effectiveness of various catalysts in the production of H2O2 and in the degradation of endocrine disrupting compounds (EDCs), including bisphenol A (BPA) and 17α-ethinyl estradiol (EE2), in water by sonocatalysis using ultrasonication at 28 kHz with a contact time of 60 min. The catalysts included a stainless steel wire mesh (SSWM), glass beads (GB), TiO2 powder, a Ti-wire mesh (Ti-WM), and an oxidized Ti-wire mesh (TiO2-WM). The most effective catalyst combination for the production of 215.7 μM of H2O2, was the use of SSWM with TiO2 as the cocatalyst. A significantly lower sonochemical reactivity was observed when there was no added catalyst (18.5 μM), SSWM (61.3 μM), and TiO2 alone (134.1 μM). For the given contact time and frequency, sonochemical reactivity was determined from the rate constants for H2O2 production. EDC sonodegradation occurred in the following order: SSWM + TiO2 (powder) > GB > TiO2 (powder) > SSWM + GB > TiO2-WM > Ti-WM > SSWM > no catalyst, although the catalyst type, surface area, and amount were varied. Our findings suggest that TiO2-WM can be continuously reused for the catalysis of H2O2 production and the degradation of EDC. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102419v
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6638–6645[article] Comparative Study of sonocatalytic enhancement for removal of bisphenol A and 17α-ethinyl estradiol [texte imprimé] / Namguk Her, Auteur ; Jong-Sung Park, Auteur ; Jaekyung Yoon, Auteur . - 2011 . - pp 6638–6645.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6638–6645
Mots-clés : Sonocatalytic Bisphenol A stainless steel Résumé : A series of experiments were conducted to compare the effectiveness of various catalysts in the production of H2O2 and in the degradation of endocrine disrupting compounds (EDCs), including bisphenol A (BPA) and 17α-ethinyl estradiol (EE2), in water by sonocatalysis using ultrasonication at 28 kHz with a contact time of 60 min. The catalysts included a stainless steel wire mesh (SSWM), glass beads (GB), TiO2 powder, a Ti-wire mesh (Ti-WM), and an oxidized Ti-wire mesh (TiO2-WM). The most effective catalyst combination for the production of 215.7 μM of H2O2, was the use of SSWM with TiO2 as the cocatalyst. A significantly lower sonochemical reactivity was observed when there was no added catalyst (18.5 μM), SSWM (61.3 μM), and TiO2 alone (134.1 μM). For the given contact time and frequency, sonochemical reactivity was determined from the rate constants for H2O2 production. EDC sonodegradation occurred in the following order: SSWM + TiO2 (powder) > GB > TiO2 (powder) > SSWM + GB > TiO2-WM > Ti-WM > SSWM > no catalyst, although the catalyst type, surface area, and amount were varied. Our findings suggest that TiO2-WM can be continuously reused for the catalysis of H2O2 production and the degradation of EDC. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102419v Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Removal of trace olefins from aromatics over metal-halides-modified clay and its industrial test Type de document : texte imprimé Auteurs : Guo-liang Li, Auteur ; Jin-Ning Luan, Auteur ; Xian-song Zeng, Auteur Année de publication : 2011 Article en page(s) : pp 6646–6649 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Olefins aromatics Metal Halides Résumé : Commercial clay modified with metal halides was prepared to remove olefins from aromatics in the laboratory, and its industrial test was conducted. Different amounts of metal-halides-modified clay were made and characterized by XRD and pyridine adsorption followed by FT-IR. The type and nature of active sites in the removal of olefins over the prepared catalysts have been examined. The study of acidic properties of the modified clay revealed that the L acid, especially the weak L acid plays an important role in the reaction. The experimental results revealed that commercial clay modified with metal halides had much better catalytic activity. During Sinopec Qilu company industrial test, modified clay had an effective running time six times as long as that of untreated commercial clay. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2001567
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6646–6649[article] Removal of trace olefins from aromatics over metal-halides-modified clay and its industrial test [texte imprimé] / Guo-liang Li, Auteur ; Jin-Ning Luan, Auteur ; Xian-song Zeng, Auteur . - 2011 . - pp 6646–6649.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6646–6649
Mots-clés : Olefins aromatics Metal Halides Résumé : Commercial clay modified with metal halides was prepared to remove olefins from aromatics in the laboratory, and its industrial test was conducted. Different amounts of metal-halides-modified clay were made and characterized by XRD and pyridine adsorption followed by FT-IR. The type and nature of active sites in the removal of olefins over the prepared catalysts have been examined. The study of acidic properties of the modified clay revealed that the L acid, especially the weak L acid plays an important role in the reaction. The experimental results revealed that commercial clay modified with metal halides had much better catalytic activity. During Sinopec Qilu company industrial test, modified clay had an effective running time six times as long as that of untreated commercial clay. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2001567 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Product yields and compositions in the continuous pyrolysis of high-density polyethylene in a conical spouted bed reactor Type de document : texte imprimé Auteurs : Gorka Elordi, Auteur ; Martin Olazar, Auteur ; Gartzen Lopez, Auteur Année de publication : 2011 Article en page(s) : pp 6650–6659 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pyrolysis High density Polyethylene Résumé : The pyrolysis of high-density polyethylene (HDPE) has been carried out in the range between 500 and 700 °C in continuous mode in a pilot-plant unit equipped with a conical spouted bed reactor. The products have been grouped into the lumps of gas (C4–), gasoline (C5–C11), diesel (C12–C20), and waxes (C21+). The product yields and compositions of these fractions were compared both to those previously obtained in the pyrolysis performed in discontinuous mode and to those obtained by other authors in fluidized bed reactors. The results confirm the optimal performance of the conical spouted bed reactor (CSBR) in obtaining high yields of waxes and fuels with low aromatic content, which is explained by the appropriate conditions of the CSBR needed to enhance heat and mass transfer between phases (capacity for coating the sand with plastic) and minimize secondary reactions (short residence time of the volatiles). DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200186m
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6650–6659[article] Product yields and compositions in the continuous pyrolysis of high-density polyethylene in a conical spouted bed reactor [texte imprimé] / Gorka Elordi, Auteur ; Martin Olazar, Auteur ; Gartzen Lopez, Auteur . - 2011 . - pp 6650–6659.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6650–6659
Mots-clés : Pyrolysis High density Polyethylene Résumé : The pyrolysis of high-density polyethylene (HDPE) has been carried out in the range between 500 and 700 °C in continuous mode in a pilot-plant unit equipped with a conical spouted bed reactor. The products have been grouped into the lumps of gas (C4–), gasoline (C5–C11), diesel (C12–C20), and waxes (C21+). The product yields and compositions of these fractions were compared both to those previously obtained in the pyrolysis performed in discontinuous mode and to those obtained by other authors in fluidized bed reactors. The results confirm the optimal performance of the conical spouted bed reactor (CSBR) in obtaining high yields of waxes and fuels with low aromatic content, which is explained by the appropriate conditions of the CSBR needed to enhance heat and mass transfer between phases (capacity for coating the sand with plastic) and minimize secondary reactions (short residence time of the volatiles). DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200186m Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : La1–xKxCoO3 and LaCo1–yFeyO3 perovskite oxides : preparation, characterization, and catalytic performance in the simultaneous removal of NOx and diesel soot Type de document : texte imprimé Auteurs : Feng Bin, Auteur ; Chonglin Song, Auteur ; Gang Lv, Auteur Année de publication : 2011 Article en page(s) : pp 6660–6667 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : catalysts Nitrogen sorption X-ray diffraction Résumé : Perovskite-type La1–xKxCoO3 and LaCo1–yFeyO3 catalysts were prepared and characterized by nitrogen sorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Catalytic activity for the simultaneous removal of NOx and soot was investigated using temperature-programmed reactions. For the La1–xKxCoO3 series, the introduction of K ions into the A-site caused the enhancement of Co valence state, which was beneficial to improving the catalytic activity. Excess K ions produced a Co3O4 phase adhering to the perovskite crystals, but the rhombohedral perovskite structure was well-maintained. In contrast, the B-site could be substituted by Fe ions with the doping ratio changing from null to 0.5, and no secondary phases were detected. With increasing K substitution, NOx conversion in the La1–xKxCoO3 series showed a declining trend after an initial ascent. The Co3O4 particles produced at high K content were responsible for this falling catalytic activity. For the LaCo1–yFeyO3 series, catalytic performances showed a monotonously decreasing trend as a function of Fe substitution. Among all of the perovskite oxides tested in this study, the La0.6K0.4CoO3 sample exhibited the highest catalytic activity for the simultaneous removal of NOx and soot. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200196r
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6660–6667[article] La1–xKxCoO3 and LaCo1–yFeyO3 perovskite oxides : preparation, characterization, and catalytic performance in the simultaneous removal of NOx and diesel soot [texte imprimé] / Feng Bin, Auteur ; Chonglin Song, Auteur ; Gang Lv, Auteur . - 2011 . - pp 6660–6667.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6660–6667
Mots-clés : catalysts Nitrogen sorption X-ray diffraction Résumé : Perovskite-type La1–xKxCoO3 and LaCo1–yFeyO3 catalysts were prepared and characterized by nitrogen sorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Catalytic activity for the simultaneous removal of NOx and soot was investigated using temperature-programmed reactions. For the La1–xKxCoO3 series, the introduction of K ions into the A-site caused the enhancement of Co valence state, which was beneficial to improving the catalytic activity. Excess K ions produced a Co3O4 phase adhering to the perovskite crystals, but the rhombohedral perovskite structure was well-maintained. In contrast, the B-site could be substituted by Fe ions with the doping ratio changing from null to 0.5, and no secondary phases were detected. With increasing K substitution, NOx conversion in the La1–xKxCoO3 series showed a declining trend after an initial ascent. The Co3O4 particles produced at high K content were responsible for this falling catalytic activity. For the LaCo1–yFeyO3 series, catalytic performances showed a monotonously decreasing trend as a function of Fe substitution. Among all of the perovskite oxides tested in this study, the La0.6K0.4CoO3 sample exhibited the highest catalytic activity for the simultaneous removal of NOx and soot. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200196r Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Low temperature NH3 selective catalytic reduction of NOx over substituted MnCr2O4 spinel-oxide catalysts Type de document : texte imprimé Auteurs : Miguel A. Zamudio, Auteur ; Nunzio Russo, Auteur ; Debora Fino, Auteur Année de publication : 2011 Article en page(s) : pp 6668–6672 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalysts X-ray diffraction Résumé : The present work describes the development of Mn1–xMxCr2O4 (M = Mg, Ca; x = 0–0.1) substituted spinel catalysts prepared via gel combustion synthesis for the low-temperature selective catalytic reduction (SCR) of NOx with NH3. The catalysts have been characterized by means of X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), field emission scanning electron microscopy (FESEM) and temperature programmed reduction (TPR) analyses, whereas their catalytic activity has been tested in a temperature programmed reaction (TPRe) apparatus over a temperature range of 100–200 °C (W/F = 0.072 g·s·cm–3) in the presence of oxygen. The catalytic activity of alkali earth-metal substituted Mn–Cr spinels is compared with that of the stoichiometric MnCr2O4 in order to assess the effect of the substitutions. All the spinel catalysts have shown both high NO conversion and high selectivity to N2. Mn0.95Ca0.05Cr2O4 has shown the best performance, reaching an NO conversion of 96% and a selectivity to N2 of 97% at 125 °C. All the catalysts were then deposited by means of a modified dip-coating procedure over cordierite honeycomb monoliths and tested in a lab-scale test rig. The monolith catalyzed with the Mn0.95Ca0.05Cr2O4 spinel showed the best performance, reaching an NO conversion of 87.4% at 200 °C, with a good selectivity to N2 (94.8%). When the catalyzed monoliths were also tested in the presence of 10 vol % of water vapor, an activity decrease was observed. The correlation between the reducibility of the B site, determined from TPR experiments, and the spinels' catalytic activity order is discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200227u
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6668–6672[article] Low temperature NH3 selective catalytic reduction of NOx over substituted MnCr2O4 spinel-oxide catalysts [texte imprimé] / Miguel A. Zamudio, Auteur ; Nunzio Russo, Auteur ; Debora Fino, Auteur . - 2011 . - pp 6668–6672.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6668–6672
Mots-clés : Catalysts X-ray diffraction Résumé : The present work describes the development of Mn1–xMxCr2O4 (M = Mg, Ca; x = 0–0.1) substituted spinel catalysts prepared via gel combustion synthesis for the low-temperature selective catalytic reduction (SCR) of NOx with NH3. The catalysts have been characterized by means of X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), field emission scanning electron microscopy (FESEM) and temperature programmed reduction (TPR) analyses, whereas their catalytic activity has been tested in a temperature programmed reaction (TPRe) apparatus over a temperature range of 100–200 °C (W/F = 0.072 g·s·cm–3) in the presence of oxygen. The catalytic activity of alkali earth-metal substituted Mn–Cr spinels is compared with that of the stoichiometric MnCr2O4 in order to assess the effect of the substitutions. All the spinel catalysts have shown both high NO conversion and high selectivity to N2. Mn0.95Ca0.05Cr2O4 has shown the best performance, reaching an NO conversion of 96% and a selectivity to N2 of 97% at 125 °C. All the catalysts were then deposited by means of a modified dip-coating procedure over cordierite honeycomb monoliths and tested in a lab-scale test rig. The monolith catalyzed with the Mn0.95Ca0.05Cr2O4 spinel showed the best performance, reaching an NO conversion of 87.4% at 200 °C, with a good selectivity to N2 (94.8%). When the catalyzed monoliths were also tested in the presence of 10 vol % of water vapor, an activity decrease was observed. The correlation between the reducibility of the B site, determined from TPR experiments, and the spinels' catalytic activity order is discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200227u Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Photo-fenton treatment of actual agro-industrial wastewaters Type de document : texte imprimé Auteurs : Bedoui Ahmed, Auteur ; Elalaoui Limem, Auteur ; Ahmed Abdel-Wahab, Auteur Année de publication : 2011 Article en page(s) : pp 6673–6680 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Agro-industrial wastewaters Photo-Fenton process Résumé : In this work, the treatment of actual agro-industrial wastewaters by photo-Fenton process was investigated. The actual agro-industrial wastewaters (AIW) were received from physicochemical treatment plants of wastewaters coming from the olive oil milling industry. These brown colored aqueous wastes have been characterized by high organic content with chemical oxygen demand (COD) in the range 2000–7000 mg O2 L–1, which makes difficult the degradation of these wastewaters by traditional biological methods. The photo-Fenton process was successfully used to totally decolorize these effluents and to satisfactory remove aromaticity and COD contained in these wastes. The influence of some experimental parameters such as H2O2 and Fe2+ doses, initial COD content, initial pH, and temperature on color, aromaticity, and COD removals has been studied to find out the optimum conditions leading to maximum efficiency of the photo-Fenton process. The best results of photo-Fenton process treatment of AIW (2000 mg O2 L–1) have been obtained using 3 g L–1 H2O2 and 30 mg L–1 Fe2+ at pH 3 and T = 26 °C and after 3 h UV irradiation. The comparison among photo-Fenton, Fenton, and UV/H2O2 processes has shown that the photo-Fenton process is more efficient and cost-effective than the two other processes. During the photo-Fenton process, photodecomposition and catalytic by Fe2+ ions decomposition of H2O2 leads to the production of higher amounts of hydroxyl radicals, proving that the efficiency of an advanced process is generally related to the amount of hydroxyl radicals produced during the treatment. The degradation of organics contained in the actual agro-industrial wastes during photo-Fenton treatment involves many successive oxidation/reduction reactions, including a rapid release of chromophores leading to the total decolorization, then an oxidative opening of benzene rings into aliphatic intermediates without carbon dioxide formation, and finally a slower oxidation of the aliphatic intermediates by hydroxyl radicals to achieve high COD removal. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200266d
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6673–6680[article] Photo-fenton treatment of actual agro-industrial wastewaters [texte imprimé] / Bedoui Ahmed, Auteur ; Elalaoui Limem, Auteur ; Ahmed Abdel-Wahab, Auteur . - 2011 . - pp 6673–6680.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6673–6680
Mots-clés : Agro-industrial wastewaters Photo-Fenton process Résumé : In this work, the treatment of actual agro-industrial wastewaters by photo-Fenton process was investigated. The actual agro-industrial wastewaters (AIW) were received from physicochemical treatment plants of wastewaters coming from the olive oil milling industry. These brown colored aqueous wastes have been characterized by high organic content with chemical oxygen demand (COD) in the range 2000–7000 mg O2 L–1, which makes difficult the degradation of these wastewaters by traditional biological methods. The photo-Fenton process was successfully used to totally decolorize these effluents and to satisfactory remove aromaticity and COD contained in these wastes. The influence of some experimental parameters such as H2O2 and Fe2+ doses, initial COD content, initial pH, and temperature on color, aromaticity, and COD removals has been studied to find out the optimum conditions leading to maximum efficiency of the photo-Fenton process. The best results of photo-Fenton process treatment of AIW (2000 mg O2 L–1) have been obtained using 3 g L–1 H2O2 and 30 mg L–1 Fe2+ at pH 3 and T = 26 °C and after 3 h UV irradiation. The comparison among photo-Fenton, Fenton, and UV/H2O2 processes has shown that the photo-Fenton process is more efficient and cost-effective than the two other processes. During the photo-Fenton process, photodecomposition and catalytic by Fe2+ ions decomposition of H2O2 leads to the production of higher amounts of hydroxyl radicals, proving that the efficiency of an advanced process is generally related to the amount of hydroxyl radicals produced during the treatment. The degradation of organics contained in the actual agro-industrial wastes during photo-Fenton treatment involves many successive oxidation/reduction reactions, including a rapid release of chromophores leading to the total decolorization, then an oxidative opening of benzene rings into aliphatic intermediates without carbon dioxide formation, and finally a slower oxidation of the aliphatic intermediates by hydroxyl radicals to achieve high COD removal. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200266d Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Template-free Synthesis and photocatalytic application of rutile TiO2 hierarchical nanostructures Type de document : texte imprimé Auteurs : M. Ge, Auteur ; J. W. Li, Auteur ; L. Liu, Auteur Année de publication : 2011 Article en page(s) : pp 6681–6687 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photocatalytic rutile Nanostructures Résumé : A simple template-free hydrothermal method was employed to synthesize flower-shaped single-crystal rutile TiO2 hierarchical nanostructures without calcination process. Scanning electron microscope and transmission electron microscope images show that rutile TiO2 nanostructures with diameters of 1–1.5 μm are composed of nanorods with a wimble shape. The band gap of the as-prepared rutile TiO2 is about 3.02 eV by ultraviolet–visible absorption spectrum. The photocatalytic performance of the as-obtained samples as catalysts for Rhodamine B (RhB) degradation under simulated solar light was greatly enhanced with the assistance of a small amount of H2O2. In the H2O2-containing system, the as-prepared rutile TiO2 photocatalyst was more efficient in the photodegradation of RhB than commercial P25. The stability and recycle of the rutile TiO2/H2O2 system were also investigated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1023113
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6681–6687[article] Template-free Synthesis and photocatalytic application of rutile TiO2 hierarchical nanostructures [texte imprimé] / M. Ge, Auteur ; J. W. Li, Auteur ; L. Liu, Auteur . - 2011 . - pp 6681–6687.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6681–6687
Mots-clés : Photocatalytic rutile Nanostructures Résumé : A simple template-free hydrothermal method was employed to synthesize flower-shaped single-crystal rutile TiO2 hierarchical nanostructures without calcination process. Scanning electron microscope and transmission electron microscope images show that rutile TiO2 nanostructures with diameters of 1–1.5 μm are composed of nanorods with a wimble shape. The band gap of the as-prepared rutile TiO2 is about 3.02 eV by ultraviolet–visible absorption spectrum. The photocatalytic performance of the as-obtained samples as catalysts for Rhodamine B (RhB) degradation under simulated solar light was greatly enhanced with the assistance of a small amount of H2O2. In the H2O2-containing system, the as-prepared rutile TiO2 photocatalyst was more efficient in the photodegradation of RhB than commercial P25. The stability and recycle of the rutile TiO2/H2O2 system were also investigated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1023113 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Simple solvothermal routes to synthesize 3D BiOBrxI1-x microspheres and their visible-light-induced photocatalytic properties Type de document : texte imprimé Auteurs : Zhifang Jia, Auteur ; Fumin Wang, Auteur ; Feng Xin, Auteur Année de publication : 2011 Article en page(s) : pp 6688–6694 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solvothermal routes Photocatalytic properties Résumé : The band structure-controlled solid solution of BiOBrxI1-x was successfully synthesized by a simple solvothermal route. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, UV–vis diffuse reflectance spectroscopy, and nitrogen sorption/desorption. The resulting BiOBrxI1-x samples were phase-pure and of three-dimensional (3D) microspheres composed of nanoplates. The samples with different x values exhibited composition-dependent absorption properties in the visible light region and the bandgaps were estimated to be between 1.89 and 2.53 eV. Rhodamine B (RhB) photocatalytic degradation experiments showed that these samples possessed excellent and composition-dependent performance. The highest catalytic performance of the 3D BiOBr0.2I0.8 microspheres may derive from a synergetic effect, including higher surface area, porous structure, and enhancement of light absorbance. Moreover, on the basis of the analysis of the valence band and conduction band, a possible mechanism of photocatalytic activity of BiOBrxI1-x samples was also proposed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102310a
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6688–6694[article] Simple solvothermal routes to synthesize 3D BiOBrxI1-x microspheres and their visible-light-induced photocatalytic properties [texte imprimé] / Zhifang Jia, Auteur ; Fumin Wang, Auteur ; Feng Xin, Auteur . - 2011 . - pp 6688–6694.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6688–6694
Mots-clés : Solvothermal routes Photocatalytic properties Résumé : The band structure-controlled solid solution of BiOBrxI1-x was successfully synthesized by a simple solvothermal route. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, UV–vis diffuse reflectance spectroscopy, and nitrogen sorption/desorption. The resulting BiOBrxI1-x samples were phase-pure and of three-dimensional (3D) microspheres composed of nanoplates. The samples with different x values exhibited composition-dependent absorption properties in the visible light region and the bandgaps were estimated to be between 1.89 and 2.53 eV. Rhodamine B (RhB) photocatalytic degradation experiments showed that these samples possessed excellent and composition-dependent performance. The highest catalytic performance of the 3D BiOBr0.2I0.8 microspheres may derive from a synergetic effect, including higher surface area, porous structure, and enhancement of light absorbance. Moreover, on the basis of the analysis of the valence band and conduction band, a possible mechanism of photocatalytic activity of BiOBrxI1-x samples was also proposed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102310a Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Synthesis, characterization, and catalytic behavior of Mg–Al–Zn–Fe mixed oxides from precursors layered double hydroxide Type de document : texte imprimé Auteurs : Anglica C. Heredia, Auteur ; Marcos I. Oliva, Auteur ; Carlos I. Zandalazini, Auteur Année de publication : 2011 Article en page(s) : pp 6695–6703 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalytic Layered double hydroxides Hydrothermal treatment Résumé : In the present work, Mg–Al–Zn–Fe layered double hydroxides (LDH) were prepared by coprecipitation reaction with hydrothermal treatment. Their corresponding calcinated products (mixed oxides) were used as catalyst for ethylbenzene dehydrogenation to styrene. The characterization of precursors and the mixed oxides was carried out by X-ray diffraction, XPS, TGA-DSC, UV–vis-DRS, specific surface area, and magnetic properties. The Fe3+ species were detected by XPS; they exist in two chemical states related to oxides and spinel environment. Zn is found in two possible contributions, such as ZnO or spinel. XRD data indicate that the hydrotalcite phase exists in all precursor samples, except for the sample without magnesium (HT100). In the mixed oxides the ZnO phase increases with the rise of the Zn content. Oxides show a decrease of surface areas with the increase of the Zn content. Ethylbenzene dehydrogenation was carried out with the mixed oxides synthesized. The HT25 sample with Zn/(Zn + Fe) = 0.25 molar ratio shows a 31.5% conversion and selectivity to styrene superior to 87%, which is directly related to the quantity of oxide, spinel phase and magnesium, as well as the high surface area and the magnetic response obtained. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102498s
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6695–6703[article] Synthesis, characterization, and catalytic behavior of Mg–Al–Zn–Fe mixed oxides from precursors layered double hydroxide [texte imprimé] / Anglica C. Heredia, Auteur ; Marcos I. Oliva, Auteur ; Carlos I. Zandalazini, Auteur . - 2011 . - pp 6695–6703.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6695–6703
Mots-clés : Catalytic Layered double hydroxides Hydrothermal treatment Résumé : In the present work, Mg–Al–Zn–Fe layered double hydroxides (LDH) were prepared by coprecipitation reaction with hydrothermal treatment. Their corresponding calcinated products (mixed oxides) were used as catalyst for ethylbenzene dehydrogenation to styrene. The characterization of precursors and the mixed oxides was carried out by X-ray diffraction, XPS, TGA-DSC, UV–vis-DRS, specific surface area, and magnetic properties. The Fe3+ species were detected by XPS; they exist in two chemical states related to oxides and spinel environment. Zn is found in two possible contributions, such as ZnO or spinel. XRD data indicate that the hydrotalcite phase exists in all precursor samples, except for the sample without magnesium (HT100). In the mixed oxides the ZnO phase increases with the rise of the Zn content. Oxides show a decrease of surface areas with the increase of the Zn content. Ethylbenzene dehydrogenation was carried out with the mixed oxides synthesized. The HT25 sample with Zn/(Zn + Fe) = 0.25 molar ratio shows a 31.5% conversion and selectivity to styrene superior to 87%, which is directly related to the quantity of oxide, spinel phase and magnesium, as well as the high surface area and the magnetic response obtained. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102498s Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Temperature-dependent mechanical properties and model of magnetorheological elastomers Type de document : texte imprimé Auteurs : Wei Zhang, Auteur ; Xinglong Gong, Auteur ; Shouhu Xuan, Auteur Année de publication : 2011 Article en page(s) : pp 6704–6712 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Magnetorheological elastomers Mechanical properties Résumé : Magnetorheological elastomers (MREs) are composed of magnetizable particles (iron particles) and a soft rubberlike matrix. Their mechanical properties, including modulus and damping capability, depend on both an external magnetic field and an environmental temperature. To systematically investigate thetemperature-dependent mechanical properties, six different kinds of MREs samples based on a mixed rubber matrices (cis-polybutadiene rubber and natural rubber) and their mass ratios of BR and NR were 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100, were fabricated in this study. The steady-state and dynamic mechanical properties of the samples were measured under different conditions by using a rheometer. The results revealed that storage modulus (G′) and loss modulus (G′′) of samples, which contained only cis-polybutadiene rubber (BR), decreased linearly with the temperature increment. However, the modulus of sample which contained much natural rubber (NR) showed different characteristic, and the relationships between stress and strain also exhibited different characteristics with different rubber matrix. An improved constitutive equation was developed to model these properties under different magnetic fields and temperatures. The comparison between modeling predicting results with experimental data demonstrated that the model can well-predict the modulus of MRE in different conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200386x
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6704–6712[article] Temperature-dependent mechanical properties and model of magnetorheological elastomers [texte imprimé] / Wei Zhang, Auteur ; Xinglong Gong, Auteur ; Shouhu Xuan, Auteur . - 2011 . - pp 6704–6712.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6704–6712
Mots-clés : Magnetorheological elastomers Mechanical properties Résumé : Magnetorheological elastomers (MREs) are composed of magnetizable particles (iron particles) and a soft rubberlike matrix. Their mechanical properties, including modulus and damping capability, depend on both an external magnetic field and an environmental temperature. To systematically investigate thetemperature-dependent mechanical properties, six different kinds of MREs samples based on a mixed rubber matrices (cis-polybutadiene rubber and natural rubber) and their mass ratios of BR and NR were 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100, were fabricated in this study. The steady-state and dynamic mechanical properties of the samples were measured under different conditions by using a rheometer. The results revealed that storage modulus (G′) and loss modulus (G′′) of samples, which contained only cis-polybutadiene rubber (BR), decreased linearly with the temperature increment. However, the modulus of sample which contained much natural rubber (NR) showed different characteristic, and the relationships between stress and strain also exhibited different characteristics with different rubber matrix. An improved constitutive equation was developed to model these properties under different magnetic fields and temperatures. The comparison between modeling predicting results with experimental data demonstrated that the model can well-predict the modulus of MRE in different conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200386x Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Systematic optimization of heat-integrated water allocation networks Type de document : texte imprimé Auteurs : Zuwei Liao, Auteur ; Gang Rong, Auteur ; Jingdai Wang, Auteur Année de publication : 2011 Article en page(s) : pp 6713–6727 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization heatintegrated water Résumé : This paper deals with the design of heat integrated water utilization networks. The nonisothermal mixing and freely splitting nature of hot and cold streams have made the problem far more complicated than the design of heat exchanger networks (HEN). By establishing an MILP model, promising heat exchange matches between hot and cold streams are obtained first without considering the detailed network design. Subsequently, a stage-wise HEN superstructure is introduced for the detailed network design. The proposed systematic approach can be applied for large scale problems. Examples from literature and a practical example in a PVC plant are used to illustrate the applicability of the approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1016392
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6713–6727[article] Systematic optimization of heat-integrated water allocation networks [texte imprimé] / Zuwei Liao, Auteur ; Gang Rong, Auteur ; Jingdai Wang, Auteur . - 2011 . - pp 6713–6727.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6713–6727
Mots-clés : Optimization heatintegrated water Résumé : This paper deals with the design of heat integrated water utilization networks. The nonisothermal mixing and freely splitting nature of hot and cold streams have made the problem far more complicated than the design of heat exchanger networks (HEN). By establishing an MILP model, promising heat exchange matches between hot and cold streams are obtained first without considering the detailed network design. Subsequently, a stage-wise HEN superstructure is introduced for the detailed network design. The proposed systematic approach can be applied for large scale problems. Examples from literature and a practical example in a PVC plant are used to illustrate the applicability of the approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1016392 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Development of a robust multiobjective simulated annealing algorithm for solving multiobjective optimization poblems Type de document : texte imprimé Auteurs : B. Sankararao, Auteur ; Chang Kyoo Yoo, Auteur Année de publication : 2011 Article en page(s) : pp 6728–6742 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Robust algorithm multiobjective Résumé : This paper describes the development of a robust algorithm for multiobjective optimization, known as robust multiobjective simulated annealing (rMOSA). rMOSA is a simulated annealing based multiobjective optimization algorithm, in which two new mechanisms are incorporated (1) to speed up the process of convergence to attain Pareto front (or a set of nondominating solutions) and (2) to get uniform nondominating solutions along the final Pareto front. A systematic procedure to call the process of choosing a random point in Archive for the perturbation step (in rMOSA) is chosen as the first mechanism to speed up the process of convergence to obtain/attain a final Pareto front, while the other is a systematic procedure to call the process of choosing a most uncrowded solution in Archive for the perturbation step to get a well-crowded uniform Pareto front. First, a Simple MOSA is developed by using the concepts of an archiving procedure, a simple probability function (which is used to set new-pt as current-pt), single parameter perturbation, and a simple annealing schedule. Then, the proposed two new mechanisms are implemented on top of Simple MOSA to develop a robust algorithm for multiobjective optimization (MOO), known as rMOSA. Seven steps involved in the development of rMOSA are thoroughly explained while presenting the algorithm. Four computationally intensive benchmark problems and one simulation-intensive two-objective problem for an industrial FCCU are solved using two newly developed algorithms (rMOSA and Simple MOSA) and two well-known currently existing MOO algorithms (NSGA-II-JG and NSGA-II). Performances of newly developed rMOSA and Simple MOSA (i.e., rMOSA without two new mechanisms) are compared with NSGA-II-JG and NSGA-II, using different metrics available in MOO literature. Newly developed rMOSA is proved to converge to Pareto sets in less number of simulations with well-crowded uniform nondominating solutions in them, for all the problems considered in this study. Hence, rMOSA can be considered as one of the best algorithm for solving computationally intensive and simulation-intensive MOO problems in chemical as well as other fields of engineering. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1016859
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6728–6742[article] Development of a robust multiobjective simulated annealing algorithm for solving multiobjective optimization poblems [texte imprimé] / B. Sankararao, Auteur ; Chang Kyoo Yoo, Auteur . - 2011 . - pp 6728–6742.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6728–6742
Mots-clés : Robust algorithm multiobjective Résumé : This paper describes the development of a robust algorithm for multiobjective optimization, known as robust multiobjective simulated annealing (rMOSA). rMOSA is a simulated annealing based multiobjective optimization algorithm, in which two new mechanisms are incorporated (1) to speed up the process of convergence to attain Pareto front (or a set of nondominating solutions) and (2) to get uniform nondominating solutions along the final Pareto front. A systematic procedure to call the process of choosing a random point in Archive for the perturbation step (in rMOSA) is chosen as the first mechanism to speed up the process of convergence to obtain/attain a final Pareto front, while the other is a systematic procedure to call the process of choosing a most uncrowded solution in Archive for the perturbation step to get a well-crowded uniform Pareto front. First, a Simple MOSA is developed by using the concepts of an archiving procedure, a simple probability function (which is used to set new-pt as current-pt), single parameter perturbation, and a simple annealing schedule. Then, the proposed two new mechanisms are implemented on top of Simple MOSA to develop a robust algorithm for multiobjective optimization (MOO), known as rMOSA. Seven steps involved in the development of rMOSA are thoroughly explained while presenting the algorithm. Four computationally intensive benchmark problems and one simulation-intensive two-objective problem for an industrial FCCU are solved using two newly developed algorithms (rMOSA and Simple MOSA) and two well-known currently existing MOO algorithms (NSGA-II-JG and NSGA-II). Performances of newly developed rMOSA and Simple MOSA (i.e., rMOSA without two new mechanisms) are compared with NSGA-II-JG and NSGA-II, using different metrics available in MOO literature. Newly developed rMOSA is proved to converge to Pareto sets in less number of simulations with well-crowded uniform nondominating solutions in them, for all the problems considered in this study. Hence, rMOSA can be considered as one of the best algorithm for solving computationally intensive and simulation-intensive MOO problems in chemical as well as other fields of engineering. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1016859 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Dynamic data-driven modeling of pharmaceutical processes Type de document : texte imprimé Auteurs : F. Boukouvala, Auteur ; F. J. Muzzio, Auteur ; Marianthi G. Lerapetritou, Auteur Année de publication : 2011 Article en page(s) : pp 6743–6754 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pharmaceutical process operations Dynamic neural network Résumé : n many pharmaceutical process operations, first-principle models describing the behavior of the processed powders are difficult to derive or computationally very expensive and thus can be considered as “black-box” processes. Kriging is an efficient data-driven methodology that has been shown previously to predict steady-state operation of black-box processes while providing error estimates for each prediction. In this work, the ability of Kriging to capture the dynamic behavior of processes is evaluated and compared to the performance of dynamic Neural Network (NN) models. Design of Experiment (DoE) concepts are employed to collect the necessary dynamic input–output information that forms the initial multivariate database of the model. The most important feature of the proposed dynamic Kriging methodology is the ability to improve its predictive efficiency as the database is augmented by additional useful information while the process operates. An error tolerance is used in the adaptive procedure, so that only predictions that satisfy a strict accuracy constraint are added to the database. The performance of the proposed method is compared to that of dynamic NN modeling, through their application to a roller compactor process. Results indicate that dynamic Kriging has a better ability to adapt to continuous transitions in the operating conditions, compared to NN modeling. This on-the-fly approach can have significant applications in real-time optimization and control of systems for which a closed-form model is not available. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102305a
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6743–6754[article] Dynamic data-driven modeling of pharmaceutical processes [texte imprimé] / F. Boukouvala, Auteur ; F. J. Muzzio, Auteur ; Marianthi G. Lerapetritou, Auteur . - 2011 . - pp 6743–6754.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6743–6754
Mots-clés : Pharmaceutical process operations Dynamic neural network Résumé : n many pharmaceutical process operations, first-principle models describing the behavior of the processed powders are difficult to derive or computationally very expensive and thus can be considered as “black-box” processes. Kriging is an efficient data-driven methodology that has been shown previously to predict steady-state operation of black-box processes while providing error estimates for each prediction. In this work, the ability of Kriging to capture the dynamic behavior of processes is evaluated and compared to the performance of dynamic Neural Network (NN) models. Design of Experiment (DoE) concepts are employed to collect the necessary dynamic input–output information that forms the initial multivariate database of the model. The most important feature of the proposed dynamic Kriging methodology is the ability to improve its predictive efficiency as the database is augmented by additional useful information while the process operates. An error tolerance is used in the adaptive procedure, so that only predictions that satisfy a strict accuracy constraint are added to the database. The performance of the proposed method is compared to that of dynamic NN modeling, through their application to a roller compactor process. Results indicate that dynamic Kriging has a better ability to adapt to continuous transitions in the operating conditions, compared to NN modeling. This on-the-fly approach can have significant applications in real-time optimization and control of systems for which a closed-form model is not available. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102305a Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Data-based, fault-tolerant model predictive control of a complex industrial dearomatization process Type de document : texte imprimé Auteurs : Markus Kettunen, Auteur ; Sirkka-Liisa Jamsa-Jounela, Auteur Année de publication : 2011 Article en page(s) : pp. 6755–6768 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Industrial dearomatization process Résumé : The main focus of this paper is on the development of an active data-based fault-tolerant model predictive controller (FTMPC) for an industrial dearomatization process. Three different fault-tolerant control (FTC) strategies are presented; these comprise data-based fault detection and diagnosis methods and fault accommodation- and controller reconfiguration-based FTC methods. These three strategies are tested with the simulated industrial dearomatization process. According to the validation and performance testing, the FTMPC performs efficiently and detects and prevents the effects of the most common faults in the analyzer, flow, and temperature measurements as well as the controller actuators. The reliability of the model predictive controller is increased and the profitability is enhanced owing to the lower off-spec production. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102312g
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6755–6768[article] Data-based, fault-tolerant model predictive control of a complex industrial dearomatization process [texte imprimé] / Markus Kettunen, Auteur ; Sirkka-Liisa Jamsa-Jounela, Auteur . - 2011 . - pp. 6755–6768.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6755–6768
Mots-clés : Industrial dearomatization process Résumé : The main focus of this paper is on the development of an active data-based fault-tolerant model predictive controller (FTMPC) for an industrial dearomatization process. Three different fault-tolerant control (FTC) strategies are presented; these comprise data-based fault detection and diagnosis methods and fault accommodation- and controller reconfiguration-based FTC methods. These three strategies are tested with the simulated industrial dearomatization process. According to the validation and performance testing, the FTMPC performs efficiently and detects and prevents the effects of the most common faults in the analyzer, flow, and temperature measurements as well as the controller actuators. The reliability of the model predictive controller is increased and the profitability is enhanced owing to the lower off-spec production. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102312g Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Design of reactor–separator–recycle systems based on the optimization of estimations of the domain of attraction Type de document : texte imprimé Auteurs : Luis G. Matallana, Auteur ; Anibal M. Blanco, Auteur ; J. Alberto Bandoni, Auteur Année de publication : 2011 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Reactor separator recycle Estimations attraction Résumé : In this paper, an optimization-based methodology is applied to the design of a reactor–separator–recycle system based on a measure of the extension of the domain of attraction of the operating equilibrium. The approach consists in maximizing the radius of a ball in the state space contained in the region of negative definiteness of the time derivative of a quadratic Lyapunov function. A two-level optimization strategy is proposed that solves a deterministic nonconvex global optimization problem at the inner level. To cope with the non-differentiability introduced by the inner problem, we applied a stochastic algorithm to manipulate the design variables at the outer level. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102326n
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011)[article] Design of reactor–separator–recycle systems based on the optimization of estimations of the domain of attraction [texte imprimé] / Luis G. Matallana, Auteur ; Anibal M. Blanco, Auteur ; J. Alberto Bandoni, Auteur . - 2011.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011)
Mots-clés : Reactor separator recycle Estimations attraction Résumé : In this paper, an optimization-based methodology is applied to the design of a reactor–separator–recycle system based on a measure of the extension of the domain of attraction of the operating equilibrium. The approach consists in maximizing the radius of a ball in the state space contained in the region of negative definiteness of the time derivative of a quadratic Lyapunov function. A two-level optimization strategy is proposed that solves a deterministic nonconvex global optimization problem at the inner level. To cope with the non-differentiability introduced by the inner problem, we applied a stochastic algorithm to manipulate the design variables at the outer level. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102326n Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Inferential Temperature control structures for different types of two-reactant reactive distillation systems Type de document : texte imprimé Auteurs : Devrim B. Kaymak, Auteur ; Denizhan Yilmaz, Auteur ; Ahmet Z. Gurer, Auteur Année de publication : 2011 Article en page(s) : pp. 6777-6793 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Distillation with reaction Temperature control Résumé : The control performance of three types of two-temperature inferential control structures for the economic optimum designs of two-reactant ideal reactive distillation systems is evaluated. Three commonly encountered reaction chemistries are studied, namely, a single-product ternary system without inert, a single-product ternary system with inert, and a two-product quaternary system. Closed loop results for the different reactive distillation systems demonstrate significant differences in terms of workable control structures and appropriate temperature control tray locations. A suitable two-temperature inferential control structure for the optimum designs of all the systems is found. The result for the ternary system with inert is in contrast to recent reports claiming the need for column internal composition control. The results also suggest that, with a properly designed two-temperature inferential control system, column overdesign for good controllability is not needed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199898
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6777-6793[article] Inferential Temperature control structures for different types of two-reactant reactive distillation systems [texte imprimé] / Devrim B. Kaymak, Auteur ; Denizhan Yilmaz, Auteur ; Ahmet Z. Gurer, Auteur . - 2011 . - pp. 6777-6793.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6777-6793
Mots-clés : Distillation with reaction Temperature control Résumé : The control performance of three types of two-temperature inferential control structures for the economic optimum designs of two-reactant ideal reactive distillation systems is evaluated. Three commonly encountered reaction chemistries are studied, namely, a single-product ternary system without inert, a single-product ternary system with inert, and a two-product quaternary system. Closed loop results for the different reactive distillation systems demonstrate significant differences in terms of workable control structures and appropriate temperature control tray locations. A suitable two-temperature inferential control structure for the optimum designs of all the systems is found. The result for the ternary system with inert is in contrast to recent reports claiming the need for column internal composition control. The results also suggest that, with a properly designed two-temperature inferential control system, column overdesign for good controllability is not needed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199898 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Economic and european union environmental sustainability criteria assesment of bio-oil-based biofuel systems : refinery integration cases Type de document : texte imprimé Auteurs : Jhuma Sadhukhan, Auteur ; Kok Siew Ng, Auteur Année de publication : 2011 Article en page(s) : pp. 6794–6808 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Bio-Oil-Based Biofuel Systems Résumé : The biofuel mix in transport in the U.K. must be increased from currently exploited 3.33% to the EU target mix of 10% by 2020. Under the face of this huge challenge, the most viable way forward is to process infrastructure-compatible intermediate, such as bio-oil from fast pyrolysis of lignocellulosic biomass, into biofuels. New facilities may integrate multiple distributed pyrolysis units producing bio-oil from locally available biomass and centralized biofuel production platforms, such as methanol or Fischer–Tropsch liquid synthesis utilizing syngas derived from gasification of bio-oil. An alternative to bio-oil gasification is hydrotreating and hydrocracking (upgrading) of bio-oil into stable oil with reduced oxygen content. The stable oil can then be coprocessed into targeted transportation fuel mix within refinery in exchange of refinery hydrogen to the upgrader. This Article focuses on the evaluation of economic and environmental sustainability of industrial scale biofuel production systems from bio-oils. An overview of bio-oil gasification-based system evaluation is presented, while comprehensive process reaction modeling (with 40 overall bio-oil hydrocracking and hydrotreating reaction steps), simulation, integration, and value analysis frameworks are illustrated for bio-oil upgrading and refinery coprocessing systems. The environmental analysis shows that the former technologies are able to meet the minimum greenhouse gas (GHG) emission reduction target of 60%, to be eligible for the European Union (EU) Directive’s 2020 target of 10% renewable energy in transport, while at least 20% renewable energy mix from an upgrader is required for meeting the EU GHG emission reduction target. Increases in the price of biodiesel and hydrogen make coprocessing of stable oils from bio-oil upgrader using refinery facilities economically more favorable than final biofuel blending from refineries and create win–win economic scenarios between the bio-oil upgrader and the refinery. The range of the cost of production (COP) of stable oil (328 MW or 0.424 t/t bio-oil), steam (49.5 MW or 0.926 t/t bio-oil), and off-gas or fuel gas (72.3 MW or 0.142 t/t bio-oil) from a bio-oil (LHV of 23.3 MJ/kg) upgrader process is evaluated on the basis of individual product energy values and global warming potential (GWP) impacts. The minimum and the maximum annualized capital charges predicted by the Discounted Cash Flow (DCF) analysis correspond to 25 operating years and 10% IRR, and 10 operating years and 20% IRR, respectively. On the basis of this DCF strategy and 1200 $/t of hydrogen and 540 $/t of biodiesel market prices, the selling prices of 259.32 $/t, 34.85 $/t, and 174.27 $/t of the stable oil, steam, and fuel gas, respectively, from the upgrader to the refinery were obtained to create win–win marginal incentive for the upgrader and refinery systems, individually. If stable oil from a bio-oil upgrader can be launched as a product potentially to be used in refinery hydrocracker (at a competitive price of 490 $/t), for the production of renewable diesel, upgrader can be operated independently, such as purchase hydrogen from vendors at competitive price, with comparative marginal incentives. The bio-oil upgraders, either stand-alone or integrated, were designed to meet desired product specifications, diesel with specific gravity 0.825 and cetane number 57 and stable oil with API 30.1 and cetane number 28.7, for coprocessing through the refinery hydrocracker, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102339r
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6794–6808[article] Economic and european union environmental sustainability criteria assesment of bio-oil-based biofuel systems : refinery integration cases [texte imprimé] / Jhuma Sadhukhan, Auteur ; Kok Siew Ng, Auteur . - 2011 . - pp. 6794–6808.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6794–6808
Mots-clés : Bio-Oil-Based Biofuel Systems Résumé : The biofuel mix in transport in the U.K. must be increased from currently exploited 3.33% to the EU target mix of 10% by 2020. Under the face of this huge challenge, the most viable way forward is to process infrastructure-compatible intermediate, such as bio-oil from fast pyrolysis of lignocellulosic biomass, into biofuels. New facilities may integrate multiple distributed pyrolysis units producing bio-oil from locally available biomass and centralized biofuel production platforms, such as methanol or Fischer–Tropsch liquid synthesis utilizing syngas derived from gasification of bio-oil. An alternative to bio-oil gasification is hydrotreating and hydrocracking (upgrading) of bio-oil into stable oil with reduced oxygen content. The stable oil can then be coprocessed into targeted transportation fuel mix within refinery in exchange of refinery hydrogen to the upgrader. This Article focuses on the evaluation of economic and environmental sustainability of industrial scale biofuel production systems from bio-oils. An overview of bio-oil gasification-based system evaluation is presented, while comprehensive process reaction modeling (with 40 overall bio-oil hydrocracking and hydrotreating reaction steps), simulation, integration, and value analysis frameworks are illustrated for bio-oil upgrading and refinery coprocessing systems. The environmental analysis shows that the former technologies are able to meet the minimum greenhouse gas (GHG) emission reduction target of 60%, to be eligible for the European Union (EU) Directive’s 2020 target of 10% renewable energy in transport, while at least 20% renewable energy mix from an upgrader is required for meeting the EU GHG emission reduction target. Increases in the price of biodiesel and hydrogen make coprocessing of stable oils from bio-oil upgrader using refinery facilities economically more favorable than final biofuel blending from refineries and create win–win economic scenarios between the bio-oil upgrader and the refinery. The range of the cost of production (COP) of stable oil (328 MW or 0.424 t/t bio-oil), steam (49.5 MW or 0.926 t/t bio-oil), and off-gas or fuel gas (72.3 MW or 0.142 t/t bio-oil) from a bio-oil (LHV of 23.3 MJ/kg) upgrader process is evaluated on the basis of individual product energy values and global warming potential (GWP) impacts. The minimum and the maximum annualized capital charges predicted by the Discounted Cash Flow (DCF) analysis correspond to 25 operating years and 10% IRR, and 10 operating years and 20% IRR, respectively. On the basis of this DCF strategy and 1200 $/t of hydrogen and 540 $/t of biodiesel market prices, the selling prices of 259.32 $/t, 34.85 $/t, and 174.27 $/t of the stable oil, steam, and fuel gas, respectively, from the upgrader to the refinery were obtained to create win–win marginal incentive for the upgrader and refinery systems, individually. If stable oil from a bio-oil upgrader can be launched as a product potentially to be used in refinery hydrocracker (at a competitive price of 490 $/t), for the production of renewable diesel, upgrader can be operated independently, such as purchase hydrogen from vendors at competitive price, with comparative marginal incentives. The bio-oil upgraders, either stand-alone or integrated, were designed to meet desired product specifications, diesel with specific gravity 0.825 and cetane number 57 and stable oil with API 30.1 and cetane number 28.7, for coprocessing through the refinery hydrocracker, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102339r Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Selection of prediction methods for thermophysical properties for process modeling and product design of biodiesel manufacturing Type de document : texte imprimé Auteurs : Yung-Chieh Su, Auteur ; Y. A. Liu, Auteur Année de publication : 2011 Article en page(s) : pp. 6809–6836 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermophysical Properties Biodiesel Manufacturing Résumé : To optimize biodiesel manufacturing, many reported studies have built simulation models to quantify the relationship between operating conditions and process performance. For mass and energy balance simulations, it is essential to know the four fundamental thermophysical properties of the feed oil: liquid density (ρL), vapor pressure (Pvap), liquid heat capacity (CPL), and heat of vaporization (ΔHvap). Additionally, to characterize the fuel qualities, it is critical to develop quantitative correlations to predict three biodiesel properties, namely, viscosity, cetane number, and flash point. Also, to ensure the operability of biodiesel in cold weather, one needs to quantitatively predict three low-temperature flow properties: cloud point (CP), pour point (PP), and cold filter plugging point (CFPP). This article presents the results from a comprehensive evaluation of the methods for predicting these four essential feed oil properties and six key biodiesel fuel properties. We compare the predictions to reported experimental data and recommend the appropriate prediction methods for each property based on accuracy, consistency, and generality. Of particular significance are (1) our presentation of simple and accurate methods for predicting the six key fuel properties based on the number of carbon atoms and the number of double bonds or the composition of total unsaturated fatty acid methyl esters (FAMEs) and (2) our posting of the Excel spreadsheets for implementing all of the evaluated accurate prediction methods on our group Web site (www.design.che.vt.edu) for the reader to download without charge. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102441u
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6809–6836[article] Selection of prediction methods for thermophysical properties for process modeling and product design of biodiesel manufacturing [texte imprimé] / Yung-Chieh Su, Auteur ; Y. A. Liu, Auteur . - 2011 . - pp. 6809–6836.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6809–6836
Mots-clés : Thermophysical Properties Biodiesel Manufacturing Résumé : To optimize biodiesel manufacturing, many reported studies have built simulation models to quantify the relationship between operating conditions and process performance. For mass and energy balance simulations, it is essential to know the four fundamental thermophysical properties of the feed oil: liquid density (ρL), vapor pressure (Pvap), liquid heat capacity (CPL), and heat of vaporization (ΔHvap). Additionally, to characterize the fuel qualities, it is critical to develop quantitative correlations to predict three biodiesel properties, namely, viscosity, cetane number, and flash point. Also, to ensure the operability of biodiesel in cold weather, one needs to quantitatively predict three low-temperature flow properties: cloud point (CP), pour point (PP), and cold filter plugging point (CFPP). This article presents the results from a comprehensive evaluation of the methods for predicting these four essential feed oil properties and six key biodiesel fuel properties. We compare the predictions to reported experimental data and recommend the appropriate prediction methods for each property based on accuracy, consistency, and generality. Of particular significance are (1) our presentation of simple and accurate methods for predicting the six key fuel properties based on the number of carbon atoms and the number of double bonds or the composition of total unsaturated fatty acid methyl esters (FAMEs) and (2) our posting of the Excel spreadsheets for implementing all of the evaluated accurate prediction methods on our group Web site (www.design.che.vt.edu) for the reader to download without charge. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102441u Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Global local structure analysis model and its application for fault detection and identification Type de document : texte imprimé Auteurs : Muguang Zhang, Auteur ; Zhiqiang Ge, Auteur ; Zhihuan Song, Auteur Année de publication : 2011 Article en page(s) : pp. 6837-6848 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Failure detection Modeling Résumé : In this paper, a new fault detection and identification scheme that is based on the global―Iocal structure analysis (GLSA) model is proposed. By exploiting the underlying geometrical manifold and simultaneously keeping the global data information, the GLSA model constructs a dual-objective optimization function for dimension reduction of the process dataset. It combines the advantages of both locality preserving projections (LPP) and principal component analysis (PCA), under a unified framework Meanwhile, GLSA can successfully avoid the singularity problem that may occur in LPP and shares the orthogonal property of the PCA method. In order to balance the two subobjectives (corresponding to global and local structure preservings), a tuning parameter is introduced, and an energy-function-based strategy is proposed to determine the value of the introduced tuning parameter. For the purpose of fault detection, two statistics are constructed, based on the GLSA model Furthermore, the Bayesian inference algorithm is introduced upon the two monitoring statistics for fault identification. Two case studies are provided to demonstrate the efficiencies of the GLSA model. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199901
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6837-6848[article] Global local structure analysis model and its application for fault detection and identification [texte imprimé] / Muguang Zhang, Auteur ; Zhiqiang Ge, Auteur ; Zhihuan Song, Auteur . - 2011 . - pp. 6837-6848.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6837-6848
Mots-clés : Failure detection Modeling Résumé : In this paper, a new fault detection and identification scheme that is based on the global―Iocal structure analysis (GLSA) model is proposed. By exploiting the underlying geometrical manifold and simultaneously keeping the global data information, the GLSA model constructs a dual-objective optimization function for dimension reduction of the process dataset. It combines the advantages of both locality preserving projections (LPP) and principal component analysis (PCA), under a unified framework Meanwhile, GLSA can successfully avoid the singularity problem that may occur in LPP and shares the orthogonal property of the PCA method. In order to balance the two subobjectives (corresponding to global and local structure preservings), a tuning parameter is introduced, and an energy-function-based strategy is proposed to determine the value of the introduced tuning parameter. For the purpose of fault detection, two statistics are constructed, based on the GLSA model Furthermore, the Bayesian inference algorithm is introduced upon the two monitoring statistics for fault identification. Two case studies are provided to demonstrate the efficiencies of the GLSA model. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199901 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Synthesis of a mass integrated biodiesel process Type de document : texte imprimé Auteurs : Carlos D. Fischer, Auteur ; Oscar A. Iribarren, Auteur Année de publication : 2011 Article en page(s) : pp. 6849-6859 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Mass integrated Biodiesel process Résumé : A hierarchical decision procedure is proposed for the synthesis of processes that are mass integrated to an existing industrial environment. The procedure takes the information about already installed processes as input. Decisions required to complete the design of the new process are then made considering this environment. The procedure decides among alternative technologies for producing the new product and on the use of output streams from the environment as inputs to the new process and vice versa. It also decides whether this use should be done through new processing facilities to condition these streams. The hierarchical decision procedure described by Douglas was adapted to include these mass integration decisions and to resort to mass exchange network synthesis and source-sink allocation procedures at the appropriate level of the hierarchy. The procedure is illustrated by designing a new biodiesel process, integrated to the agro-industrial complex already existing in the city of Reconquista, Argentina. The alternative technologies considered for producing biodiesel are acid, basic, and enzymatic catalyzed transesterification processes. The considered raw materials are a pretreated stream from an edible oils refinery and residual fatty streams from other factories, with high free fatty acid content. The acid raw materials could be converted to biodiesel either directly through an acid process or after an esterification treatment through the same basic process that is utilized for good quality edible oils raw material The produced biodiesel could be sold to oil companies or to the local agro-machinery business. The raw glycerin byproduct could be sold as glycerin after purification, fermented to ethanol in a cereals bioethanol factory, used as fuel in properly designed boilers, or used in the formulation of cattle food in local feed lots. This paper discusses (i) the trade-off between implementing mass exchangers or separation processes in the case of methanol added in excess and alkali added as a catalyst in the reaction step, (ii) the adaptation ofthe standard source sink allocation approach adding constraints of the diet problem, and (iii) the order of decisions in the hierarchy, which strongly affects the programming effort to solve this synthesis and design problem. Results analysis shows that both the economic and environmental performance of the biodiesel process is significantly improved when taking into account the local industrial environment of the new plant. Furthermore, as the integrated plant is able to process multiple raw materials and offer alternative product specifications to end consumers, its operation is adjustable to changing market conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199902
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6849-6859[article] Synthesis of a mass integrated biodiesel process [texte imprimé] / Carlos D. Fischer, Auteur ; Oscar A. Iribarren, Auteur . - 2011 . - pp. 6849-6859.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6849-6859
Mots-clés : Mass integrated Biodiesel process Résumé : A hierarchical decision procedure is proposed for the synthesis of processes that are mass integrated to an existing industrial environment. The procedure takes the information about already installed processes as input. Decisions required to complete the design of the new process are then made considering this environment. The procedure decides among alternative technologies for producing the new product and on the use of output streams from the environment as inputs to the new process and vice versa. It also decides whether this use should be done through new processing facilities to condition these streams. The hierarchical decision procedure described by Douglas was adapted to include these mass integration decisions and to resort to mass exchange network synthesis and source-sink allocation procedures at the appropriate level of the hierarchy. The procedure is illustrated by designing a new biodiesel process, integrated to the agro-industrial complex already existing in the city of Reconquista, Argentina. The alternative technologies considered for producing biodiesel are acid, basic, and enzymatic catalyzed transesterification processes. The considered raw materials are a pretreated stream from an edible oils refinery and residual fatty streams from other factories, with high free fatty acid content. The acid raw materials could be converted to biodiesel either directly through an acid process or after an esterification treatment through the same basic process that is utilized for good quality edible oils raw material The produced biodiesel could be sold to oil companies or to the local agro-machinery business. The raw glycerin byproduct could be sold as glycerin after purification, fermented to ethanol in a cereals bioethanol factory, used as fuel in properly designed boilers, or used in the formulation of cattle food in local feed lots. This paper discusses (i) the trade-off between implementing mass exchangers or separation processes in the case of methanol added in excess and alkali added as a catalyst in the reaction step, (ii) the adaptation ofthe standard source sink allocation approach adding constraints of the diet problem, and (iii) the order of decisions in the hierarchy, which strongly affects the programming effort to solve this synthesis and design problem. Results analysis shows that both the economic and environmental performance of the biodiesel process is significantly improved when taking into account the local industrial environment of the new plant. Furthermore, as the integrated plant is able to process multiple raw materials and offer alternative product specifications to end consumers, its operation is adjustable to changing market conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199902 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Integration of nonlinear crude distillation unit models in refinery planning optimization Type de document : texte imprimé Auteurs : Abdulrahman M. Alattas, Auteur ; Ignacio E. Grossmann, Auteur ; Ignasi Palou-Rivera, Auteur Année de publication : 2011 Article en page(s) : pp. 6860-6870 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization Planning Refinery Modeling Distillation Résumé : Production planning modeling is an essential tool in the operation and management of modern refineries. It has traditionally relied on linear programming (LP) principles and methods for simple and robust planning models, such as the fixed-yield planning models and swing cuts planning models. However, these models fail to reflect the true nonlinear nature of the processing units. In this work, the fractionation index model (FI) is developed to add nonlinearity to the linear refinery planning models. The FI model is developed as a more accurate nonlinear model for the complex crude distillation unit (CDU) than the fixed yield or the swing cuts models. The resulting simple model optimizes the crude cuts quantities and temperature. It has the benefits of being crude independent, characteristics of the CDU, and readily calculated. An example of the FI CDU model is presented. The FI-based refinery planning model is then developed and tested with a refinery planning example. The results are compared to the common fixed yield and swing cuts models. The FI refinery planning model predicted higher profit based on different crude purchase decision. Despite an order of magnitude increase in the problem size, the FI planning model did not require significantly longer solution times. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199903
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6860-6870[article] Integration of nonlinear crude distillation unit models in refinery planning optimization [texte imprimé] / Abdulrahman M. Alattas, Auteur ; Ignacio E. Grossmann, Auteur ; Ignasi Palou-Rivera, Auteur . - 2011 . - pp. 6860-6870.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6860-6870
Mots-clés : Optimization Planning Refinery Modeling Distillation Résumé : Production planning modeling is an essential tool in the operation and management of modern refineries. It has traditionally relied on linear programming (LP) principles and methods for simple and robust planning models, such as the fixed-yield planning models and swing cuts planning models. However, these models fail to reflect the true nonlinear nature of the processing units. In this work, the fractionation index model (FI) is developed to add nonlinearity to the linear refinery planning models. The FI model is developed as a more accurate nonlinear model for the complex crude distillation unit (CDU) than the fixed yield or the swing cuts models. The resulting simple model optimizes the crude cuts quantities and temperature. It has the benefits of being crude independent, characteristics of the CDU, and readily calculated. An example of the FI CDU model is presented. The FI-based refinery planning model is then developed and tested with a refinery planning example. The results are compared to the common fixed yield and swing cuts models. The FI refinery planning model predicted higher profit based on different crude purchase decision. Despite an order of magnitude increase in the problem size, the FI planning model did not require significantly longer solution times. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199903 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Evaluation of Acid Activation under the Adsorption capacity of double layered hydroxides of Mg―AI―CO3 type for fluoride removal from aqueous medium Type de document : texte imprimé Auteurs : Luciane Batistella, Auteur ; Luciana D. Venquiaruto, Auteur ; Marco Di Luccio, Auteur Année de publication : 2011 Article en page(s) : pp. 6871-6876 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous medium Adsorption capacity Activation Résumé : The main objective of this work was to investigate the effect of acid activation on the adsorption ability of synthesized double layered hydroxides (DLH) for fluoride ions present in aqueous solution. Samples of DLH synthesized presented an enhancement of adsorption capacity for fluorides related to their precursors, a consequence of substitution of CO32― anions (after acid degradation) present on the DLH structure by monovalent anions (chloride and formate) that are more easily interchangeable compared to fluoride ions. Both variables evaluated in the activation step (acid concentration and contact time) presented a positive effect on the adsorption capacity for fluoride ions. Results demonstrated the necessity of a rigorous control of these variables to avoid complete degradation of the DLH structure. The adsorption assays permitted the conclusion that an enhancement on adsorption capacity was verified at pH 3.5 (compared to pH 5.0) and temperature of 50 °C (compared to 10 °C), indicating the endothermic nature of the process (ΔS = +28.35 J·K―1·mol―1). The high adsorption capacity of fluoride ions observed in this work (303.54 mg·g―1) demonstrates the potential of these adsorbents toward treatment of water contaminated with this element. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199904
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6871-6876[article] Evaluation of Acid Activation under the Adsorption capacity of double layered hydroxides of Mg―AI―CO3 type for fluoride removal from aqueous medium [texte imprimé] / Luciane Batistella, Auteur ; Luciana D. Venquiaruto, Auteur ; Marco Di Luccio, Auteur . - 2011 . - pp. 6871-6876.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6871-6876
Mots-clés : Aqueous medium Adsorption capacity Activation Résumé : The main objective of this work was to investigate the effect of acid activation on the adsorption ability of synthesized double layered hydroxides (DLH) for fluoride ions present in aqueous solution. Samples of DLH synthesized presented an enhancement of adsorption capacity for fluorides related to their precursors, a consequence of substitution of CO32― anions (after acid degradation) present on the DLH structure by monovalent anions (chloride and formate) that are more easily interchangeable compared to fluoride ions. Both variables evaluated in the activation step (acid concentration and contact time) presented a positive effect on the adsorption capacity for fluoride ions. Results demonstrated the necessity of a rigorous control of these variables to avoid complete degradation of the DLH structure. The adsorption assays permitted the conclusion that an enhancement on adsorption capacity was verified at pH 3.5 (compared to pH 5.0) and temperature of 50 °C (compared to 10 °C), indicating the endothermic nature of the process (ΔS = +28.35 J·K―1·mol―1). The high adsorption capacity of fluoride ions observed in this work (303.54 mg·g―1) demonstrates the potential of these adsorbents toward treatment of water contaminated with this element. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199904 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Fractional characterization of hemicellulosic polymers isolated from caragana korshinskii kom Type de document : texte imprimé Auteurs : Hai-Yan Yang, Auteur ; Xian-Liang Song, Auteur ; Tong - Qi Yuan, Auteur Année de publication : 2011 Article en page(s) : pp.6877-6885 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hemicellulosic Polymers Résumé : Hemicellulosic polymers were fractionated into eight fractions by successive extractions with water, ethanol, and alkali with different concentrations from Caragana korshinskii Kom, which together accounted for 70.7% of the original hemicelluloses. The physicochemical properties of each fraction were investigated by sugar analysis, gel permeation chromatography, Fourier transform IR, 1H and 13C NMR, heteronuclear single quantum coherence, thermogravimetric analysis, and differential thermal analysis. The results showed that 4-O-methyl-α-d-glucurono-d-xylans were the dominant component in the hemicelluloses of C. korshinskii Kom. Molecular weights of the fractions ranged from 9830 to 217000 g/mol. In a comparison of all fractions, it was found that the hot water released smaller sized and more branched polysaccharides, while adding alkali as the solvent enhanced dissolution of larger-molecule-sized polysaccharides. Moreover, thermal stability analysis suggested that the hemicellulosic fraction with a low substitution degree and a large molecular weight has a slightly higher thermal stability. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1016738
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp.6877-6885[article] Fractional characterization of hemicellulosic polymers isolated from caragana korshinskii kom [texte imprimé] / Hai-Yan Yang, Auteur ; Xian-Liang Song, Auteur ; Tong - Qi Yuan, Auteur . - 2011 . - pp.6877-6885.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp.6877-6885
Mots-clés : Hemicellulosic Polymers Résumé : Hemicellulosic polymers were fractionated into eight fractions by successive extractions with water, ethanol, and alkali with different concentrations from Caragana korshinskii Kom, which together accounted for 70.7% of the original hemicelluloses. The physicochemical properties of each fraction were investigated by sugar analysis, gel permeation chromatography, Fourier transform IR, 1H and 13C NMR, heteronuclear single quantum coherence, thermogravimetric analysis, and differential thermal analysis. The results showed that 4-O-methyl-α-d-glucurono-d-xylans were the dominant component in the hemicelluloses of C. korshinskii Kom. Molecular weights of the fractions ranged from 9830 to 217000 g/mol. In a comparison of all fractions, it was found that the hot water released smaller sized and more branched polysaccharides, while adding alkali as the solvent enhanced dissolution of larger-molecule-sized polysaccharides. Moreover, thermal stability analysis suggested that the hemicellulosic fraction with a low substitution degree and a large molecular weight has a slightly higher thermal stability. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1016738 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : A New model for the calculation of height equivalent to theoretical plate in high pressure columns equipped with structured packing for iC4/nC4 separation Type de document : texte imprimé Auteurs : Mohmmad Reza Rahimpour, Auteur ; Momeni Hossein, Auteur ; Khadijeh Paymooni, Auteur Année de publication : 2011 Article en page(s) : pp. 6886-6897 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ordered packing Modeling Résumé : A semi-empirical model is proposed to investigate the performance of packed columns equipped with structured packing at high pressures. The mass transfer efficiency is determined in terms of height equivalent to theoretcial plate (HETP) for empirical data of an iC4/nC4 mixture at elevated pressures. Some unexpected phenomena cause predictive models of mass transfer to be inaccurate at high pressures. The effects of the gas phase backmixing and the liquid maldistribution on the gas phase mass transfer coefficient and the effective interfacial area have been investigated in this study. The modified model is developed on the basis of the Delft model to predict the mass transfer behavior of structured packing at high pressures. The proposed model is validated by the empirical data and good agreement is observed between the empirical data and the results of the modified model. The error of HETP calculation by the modified model is less than the other models especially at moderate and high pressures. At low pressures, predicted values of different models are almost the same and they show minor errors. The difference between predicted HETP by various models increases by pressure rising. Moreover, the effect of liquid load on mass transfer in packed columns is investigated. The proposed model can predict the effect of liquid load on mass transfer performance. Proper efficiency has been obtained by the modified model for iC4/nC4 separation process in structured packed column at high pressures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199906
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6886-6897[article] A New model for the calculation of height equivalent to theoretical plate in high pressure columns equipped with structured packing for iC4/nC4 separation [texte imprimé] / Mohmmad Reza Rahimpour, Auteur ; Momeni Hossein, Auteur ; Khadijeh Paymooni, Auteur . - 2011 . - pp. 6886-6897.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6886-6897
Mots-clés : Ordered packing Modeling Résumé : A semi-empirical model is proposed to investigate the performance of packed columns equipped with structured packing at high pressures. The mass transfer efficiency is determined in terms of height equivalent to theoretcial plate (HETP) for empirical data of an iC4/nC4 mixture at elevated pressures. Some unexpected phenomena cause predictive models of mass transfer to be inaccurate at high pressures. The effects of the gas phase backmixing and the liquid maldistribution on the gas phase mass transfer coefficient and the effective interfacial area have been investigated in this study. The modified model is developed on the basis of the Delft model to predict the mass transfer behavior of structured packing at high pressures. The proposed model is validated by the empirical data and good agreement is observed between the empirical data and the results of the modified model. The error of HETP calculation by the modified model is less than the other models especially at moderate and high pressures. At low pressures, predicted values of different models are almost the same and they show minor errors. The difference between predicted HETP by various models increases by pressure rising. Moreover, the effect of liquid load on mass transfer in packed columns is investigated. The proposed model can predict the effect of liquid load on mass transfer performance. Proper efficiency has been obtained by the modified model for iC4/nC4 separation process in structured packed column at high pressures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199906 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Preparation of a macroporous silica-based pyridine impregnated material and its adsorption for palladium Type de document : texte imprimé Auteurs : Anyun Zhang, Auteur ; Yaping Zhu, Auteur ; Yunhai Liu, Auteur Année de publication : 2011 Article en page(s) : pp. 6898-6905 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Adsorption Macroporosity Preparation Résumé : A macroporous silica-based 2,6-bis(5,6-di(iso-heayl)-1,2,4-triazine-3-yl)pyridine (BDIHTP) multinitrogen molecular recognition material, BDIHTP/SiO2-P, was prepared. It was performed through impregnation and immobilization of BDIHTP into the pores of the macroporous SiO2-P particle support with a mean diameter of 50 μm. The adsorption of some typical alkali metal and alkaline earths Cs(I), Na(I), K(I), Rb(I), Sr(II), and Ba(II), as well as Pd(II), a representative of precious metals, contained in highly active liquid waste (HLW), onto the BDIHTP/SiO2-P material was investigated at 298 K. It was carried out by examining the effects of contact time and the HNO3 concentration in the range 0.3―5.0 M BDIHTP/SiO2-P showed excellent adsorption ability and high selectivity for Pd(II) over all the tested metals, which had weak or almost no adsorption. It was attributed to the strong chemical complexation of Pd(II), a soft Lewis acid and an electron-pair acceptor, with nitrogen inside BDIHTP, a soft Lewis base and an electron-pair donor. On the basis of the related results, the chromatographic separation of Pd(II) from 1.0 M HNO3 solution containing the tested metals was performed by BDIHTP/SiO2-P packed column. Pd(II) was effectively eluted with 0.2 M thiourea and separated from the others. The results are very beneficial to building an effective partitioning of minor actinides and Pd(II) together from HLW by the BDIHTP/SiO2-P materials. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199907
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6898-6905[article] Preparation of a macroporous silica-based pyridine impregnated material and its adsorption for palladium [texte imprimé] / Anyun Zhang, Auteur ; Yaping Zhu, Auteur ; Yunhai Liu, Auteur . - 2011 . - pp. 6898-6905.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6898-6905
Mots-clés : Adsorption Macroporosity Preparation Résumé : A macroporous silica-based 2,6-bis(5,6-di(iso-heayl)-1,2,4-triazine-3-yl)pyridine (BDIHTP) multinitrogen molecular recognition material, BDIHTP/SiO2-P, was prepared. It was performed through impregnation and immobilization of BDIHTP into the pores of the macroporous SiO2-P particle support with a mean diameter of 50 μm. The adsorption of some typical alkali metal and alkaline earths Cs(I), Na(I), K(I), Rb(I), Sr(II), and Ba(II), as well as Pd(II), a representative of precious metals, contained in highly active liquid waste (HLW), onto the BDIHTP/SiO2-P material was investigated at 298 K. It was carried out by examining the effects of contact time and the HNO3 concentration in the range 0.3―5.0 M BDIHTP/SiO2-P showed excellent adsorption ability and high selectivity for Pd(II) over all the tested metals, which had weak or almost no adsorption. It was attributed to the strong chemical complexation of Pd(II), a soft Lewis acid and an electron-pair acceptor, with nitrogen inside BDIHTP, a soft Lewis base and an electron-pair donor. On the basis of the related results, the chromatographic separation of Pd(II) from 1.0 M HNO3 solution containing the tested metals was performed by BDIHTP/SiO2-P packed column. Pd(II) was effectively eluted with 0.2 M thiourea and separated from the others. The results are very beneficial to building an effective partitioning of minor actinides and Pd(II) together from HLW by the BDIHTP/SiO2-P materials. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199907 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Influence of flow regime on mass transfer in different types of microchannels Type de document : texte imprimé Auteurs : Madhvanand N. Kashid, Auteur ; Albert Renken, Auteur ; Lioubov Kiwi-Minsker, Auteur Année de publication : 2011 Article en page(s) : pp. 6906-6914 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Mass transfer Flow regime Résumé : The performance of microstructured reactors (or microchannels) for mass-transfer-controlled liquid―liquid reactions depends on flow regimes that define the specific interfacial area for the mass transfer. In the present work, experiments were carried out to investigate the two phase-flow regimes and the mass transfer at relatively high throughput for a single microchannel (of 1―18 mL/min) in five generic microchannel designs (with and without structured internal surfaces), using a nonreacting water-acetone-toluene system. When the flow results were analyzed collectively in all microchannels, six different flow regimes such as slug, slug-drop, deformed interface, parallel/ annular, slug-dispersed, and dispersed flow were observed. The mass-transfer comparison shows that the microchannel with structured internal surfaces shows better performance, because it creates a very fine dispersion, providing high interfacial area, compared to other microchannels. Finally, the mass-transfer data were correlated, which can be used for a priori predictions of mass-transfer rates in microchannels, DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199908
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6906-6914[article] Influence of flow regime on mass transfer in different types of microchannels [texte imprimé] / Madhvanand N. Kashid, Auteur ; Albert Renken, Auteur ; Lioubov Kiwi-Minsker, Auteur . - 2011 . - pp. 6906-6914.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6906-6914
Mots-clés : Mass transfer Flow regime Résumé : The performance of microstructured reactors (or microchannels) for mass-transfer-controlled liquid―liquid reactions depends on flow regimes that define the specific interfacial area for the mass transfer. In the present work, experiments were carried out to investigate the two phase-flow regimes and the mass transfer at relatively high throughput for a single microchannel (of 1―18 mL/min) in five generic microchannel designs (with and without structured internal surfaces), using a nonreacting water-acetone-toluene system. When the flow results were analyzed collectively in all microchannels, six different flow regimes such as slug, slug-drop, deformed interface, parallel/ annular, slug-dispersed, and dispersed flow were observed. The mass-transfer comparison shows that the microchannel with structured internal surfaces shows better performance, because it creates a very fine dispersion, providing high interfacial area, compared to other microchannels. Finally, the mass-transfer data were correlated, which can be used for a priori predictions of mass-transfer rates in microchannels, DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199908 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Microfluidic extraction of docosahexaenoic acid ethyl ester : comparison between slug flow and emulsion Type de document : texte imprimé Auteurs : Eiji Kamio, Auteur ; Yu Seike, Auteur ; Hidekazu Yoshizawa, Auteur Année de publication : 2011 Article en page(s) : pp. 6915-6924 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fluid mechanics Emulsion Slug flow Microfluidics Résumé : Microfluidic liquid―liquid extraction of the ethyl ester of docosahexaenoic acid (DHA-Et) with silver ions was investigated using slug flow and a water-in-oil (W/O) emulsion as specific flow patterns possessing large interfacial areas. To compare the extraction rates of both systems, slug flow and a W/O emulsion with similar specific interfacial areas were prepared. Extraction rates for the systems were the same at 298 K. However, at 268 K, slug flow had a faster extraction rate than the W/O emulsion. Theoretical calculation follows the results for both systems at 298 K and for the slug flow system at 268 K, suggesting that the emulsion stabilizer inhibits complex formation between DHA-Et and silver ions at the O/W interface. A reduction in extraction rate was observed in the slug flow system at 268 K when the emulsion stabilizer was used. Slug flow can be prepared without stabilizer, offering advantages over emulsions in microfluidic extraction. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199909
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6915-6924[article] Microfluidic extraction of docosahexaenoic acid ethyl ester : comparison between slug flow and emulsion [texte imprimé] / Eiji Kamio, Auteur ; Yu Seike, Auteur ; Hidekazu Yoshizawa, Auteur . - 2011 . - pp. 6915-6924.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6915-6924
Mots-clés : Fluid mechanics Emulsion Slug flow Microfluidics Résumé : Microfluidic liquid―liquid extraction of the ethyl ester of docosahexaenoic acid (DHA-Et) with silver ions was investigated using slug flow and a water-in-oil (W/O) emulsion as specific flow patterns possessing large interfacial areas. To compare the extraction rates of both systems, slug flow and a W/O emulsion with similar specific interfacial areas were prepared. Extraction rates for the systems were the same at 298 K. However, at 268 K, slug flow had a faster extraction rate than the W/O emulsion. Theoretical calculation follows the results for both systems at 298 K and for the slug flow system at 268 K, suggesting that the emulsion stabilizer inhibits complex formation between DHA-Et and silver ions at the O/W interface. A reduction in extraction rate was observed in the slug flow system at 268 K when the emulsion stabilizer was used. Slug flow can be prepared without stabilizer, offering advantages over emulsions in microfluidic extraction. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199909 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Alternative influence of binary surfactant mixtures on the rate of mass transfer in a liquid - liquid extraction process Type de document : texte imprimé Auteurs : Javad Saien, Auteur ; Somayeh Rezabeigy, Auteur Année de publication : 2011 Article en page(s) : pp. 6925-6932 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Liquid liquid extraction Mass transfer Surfactant Résumé : The effect of binary mixtures of cationic and nonionic surfactants dodecyltrimethylammonium chloride (DTMAC) and Triton X―100 on hydrodynamic and mass transfer of the liquid-liquid extraction process was investigated. Mass transfer coefficients of acetone from toluene drops to the continuous aqueous phase and inverse direction were obtained. For the acetone analysis, gas chromatography was used. The rate of mass transfer closely relates to the adsorption behavior of surfactant mixtures at the interface, and the overall mass transfer coefficient, Kod, exhibits the similar variation of surfactants molecular interaction at the interface. The minimum mass transfer rate appears at Triton bulk mole fractions (surfactants based only) of about 0.01 and 0.2 and the maximum at about 0.6. The latter introduces the best composition to achieve the highest separation rate. Meanwhile, the mass transfer coefficient decreases rapidly with a tiny amount of total surfactants under a constant bulk mole fraction, and the solute transfer is always more for dispersed to continuous phase direction. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199910
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6925-6932[article] Alternative influence of binary surfactant mixtures on the rate of mass transfer in a liquid - liquid extraction process [texte imprimé] / Javad Saien, Auteur ; Somayeh Rezabeigy, Auteur . - 2011 . - pp. 6925-6932.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6925-6932
Mots-clés : Liquid liquid extraction Mass transfer Surfactant Résumé : The effect of binary mixtures of cationic and nonionic surfactants dodecyltrimethylammonium chloride (DTMAC) and Triton X―100 on hydrodynamic and mass transfer of the liquid-liquid extraction process was investigated. Mass transfer coefficients of acetone from toluene drops to the continuous aqueous phase and inverse direction were obtained. For the acetone analysis, gas chromatography was used. The rate of mass transfer closely relates to the adsorption behavior of surfactant mixtures at the interface, and the overall mass transfer coefficient, Kod, exhibits the similar variation of surfactants molecular interaction at the interface. The minimum mass transfer rate appears at Triton bulk mole fractions (surfactants based only) of about 0.01 and 0.2 and the maximum at about 0.6. The latter introduces the best composition to achieve the highest separation rate. Meanwhile, the mass transfer coefficient decreases rapidly with a tiny amount of total surfactants under a constant bulk mole fraction, and the solute transfer is always more for dispersed to continuous phase direction. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199910 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Improving the stability of a CaO-based sorbent for CO2 by thermal pretreatment Type de document : texte imprimé Auteurs : Dursun Can Ozcan, Auteur ; Brent H. Shanks, Auteur ; Thomas D. Wheelock, Auteur Année de publication : 2011 Article en page(s) : pp. 6933-6942 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pretreatment Carbon dioxide Stability Résumé : Although the reversible absorption of CO2 by CaO at high temperature has been proposed as a promising method for capturing and removing CO2 from hot gas streams produced by the combustion of fossil fuels and other industrial processes, the activity of the sorbent has invariably declined when applied over many cycles of CO2 absorption and desorption. The objective of the present investigation was to extend the life cycle performance of the absorbent through improved thermal pretreatment as the absorbent was prepared from limestone, dolomite, calcium acetate, or plaster of Paris. The first three materials were converted to CaO by calcination, while the third being an impure form of CaSO4 required a combination of reduction and oxidation. The life cycle performance of an absorbent derived by calcination was found to depend on the calcination conditions including particle size, temperature, atmosphere, and length of treatment. Sorbent stability was favored by calcining fine-size particles (10 μm) at high temperature (1000 °C) in an atmosphere containing 50% CO2 or more. The sorbent derived from plaster of Paris by a cyclic process of reduction and oxidation at 1070 °C proved to be a very unusual material when applied because its activity increased rapidly and was still increasing after 200 cycles of absorption and regeneration. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199911
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6933-6942[article] Improving the stability of a CaO-based sorbent for CO2 by thermal pretreatment [texte imprimé] / Dursun Can Ozcan, Auteur ; Brent H. Shanks, Auteur ; Thomas D. Wheelock, Auteur . - 2011 . - pp. 6933-6942.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6933-6942
Mots-clés : Pretreatment Carbon dioxide Stability Résumé : Although the reversible absorption of CO2 by CaO at high temperature has been proposed as a promising method for capturing and removing CO2 from hot gas streams produced by the combustion of fossil fuels and other industrial processes, the activity of the sorbent has invariably declined when applied over many cycles of CO2 absorption and desorption. The objective of the present investigation was to extend the life cycle performance of the absorbent through improved thermal pretreatment as the absorbent was prepared from limestone, dolomite, calcium acetate, or plaster of Paris. The first three materials were converted to CaO by calcination, while the third being an impure form of CaSO4 required a combination of reduction and oxidation. The life cycle performance of an absorbent derived by calcination was found to depend on the calcination conditions including particle size, temperature, atmosphere, and length of treatment. Sorbent stability was favored by calcining fine-size particles (10 μm) at high temperature (1000 °C) in an atmosphere containing 50% CO2 or more. The sorbent derived from plaster of Paris by a cyclic process of reduction and oxidation at 1070 °C proved to be a very unusual material when applied because its activity increased rapidly and was still increasing after 200 cycles of absorption and regeneration. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199911 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : High sorptive removal of borate from aqueous solution using calcined ZnAI layered double hydroxides Type de document : texte imprimé Auteurs : Paulmanickam Koilraj, Auteur ; Kannan Srinivasan, Auteur Année de publication : 2011 Article en page(s) : pp. 6943-6951 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Calcining Aqueous solution Résumé : Borate uptake studies were carried out over both as-synthesized and calcined ZnAl layered double hydroxides (LDHs) containing carbonate or chloride as interlayer anions, with different Zn/Al atomic ratios (2,3, and 4). Chloride-containing materials in both as-synthesized and calcined forms showed higher borate uptake than carbonate-containing forms. A maximum borate uptake of 31 mgB/g was achieved for the 400 °C heat-treated Zn2Al―Cl LDH material (referred here as Zn2Al―Cl―CLDH). The mechanism of borate uptake for heat-treated materials involves reconstruction as elucidated from PXRD, FT-IR, and SEM measurements. Interestingly, solid state transformation of tetraborate to monoborate anion occurred in the interlayer on drying for longer time. At a ratio of 4 g Zn2Al―Cl―CLDH per liter of 100 mgB/L solution, the uptake of borate reached 97% further, and at 5 mgB/L solution the borate concentration reduced below the value of 0.5 mgB/L recommended by the World Health Organization (WHO), using 1 g/L ratio of sorbent. The borate uptake adsorption isotherm fitted well to a monolayer Langmuir adsorption model. The influence of various parameters such as the mass of adsorbent, reaction time, borate concentration, temperature, and pH of the medium was studied. Constant borate uptake was observed over the pH range 3―7 owing to the buffering nature of LDH. The influence of the copresence of other anions on borate uptake by Zn2Al―Cl―CLDH depended on the charge to radius ratio of the anion. Cyclic adsorption-desorption studies revealed that the material was recyclable. High uptake capacity along with recyclability of this material suggests the promise as a sorbent for wastewater remediation of borate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199912
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6943-6951[article] High sorptive removal of borate from aqueous solution using calcined ZnAI layered double hydroxides [texte imprimé] / Paulmanickam Koilraj, Auteur ; Kannan Srinivasan, Auteur . - 2011 . - pp. 6943-6951.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6943-6951
Mots-clés : Calcining Aqueous solution Résumé : Borate uptake studies were carried out over both as-synthesized and calcined ZnAl layered double hydroxides (LDHs) containing carbonate or chloride as interlayer anions, with different Zn/Al atomic ratios (2,3, and 4). Chloride-containing materials in both as-synthesized and calcined forms showed higher borate uptake than carbonate-containing forms. A maximum borate uptake of 31 mgB/g was achieved for the 400 °C heat-treated Zn2Al―Cl LDH material (referred here as Zn2Al―Cl―CLDH). The mechanism of borate uptake for heat-treated materials involves reconstruction as elucidated from PXRD, FT-IR, and SEM measurements. Interestingly, solid state transformation of tetraborate to monoborate anion occurred in the interlayer on drying for longer time. At a ratio of 4 g Zn2Al―Cl―CLDH per liter of 100 mgB/L solution, the uptake of borate reached 97% further, and at 5 mgB/L solution the borate concentration reduced below the value of 0.5 mgB/L recommended by the World Health Organization (WHO), using 1 g/L ratio of sorbent. The borate uptake adsorption isotherm fitted well to a monolayer Langmuir adsorption model. The influence of various parameters such as the mass of adsorbent, reaction time, borate concentration, temperature, and pH of the medium was studied. Constant borate uptake was observed over the pH range 3―7 owing to the buffering nature of LDH. The influence of the copresence of other anions on borate uptake by Zn2Al―Cl―CLDH depended on the charge to radius ratio of the anion. Cyclic adsorption-desorption studies revealed that the material was recyclable. High uptake capacity along with recyclability of this material suggests the promise as a sorbent for wastewater remediation of borate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199912 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Solubility of glucose in ionic liquid + antisolvent mixtures Type de document : texte imprimé Auteurs : Weina Liu, Auteur ; Yucui Hou, Auteur ; Weize Wu, Auteur Année de publication : 2011 Article en page(s) : pp. 6952-6956 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ionic liquid Solubility Résumé : An extended study on the solubility of glucose in ionic liquid (IL) + antisolvent mixtures has been performed to find a way to separate glucose from ILs. These Ils, commonly used in cellulose conversion processes, are based on combination of cations of I-methyl-3-alkylimidazolium and anions of chloride, bromide, acetate, and hydrogen sulfate. Effects of temperatures, antisolvents, ILs, mass ratios of antisolvent to IL, and water contents on the solubility of glucose have been investigated in this work. The results demonstrate that the solubility of glucose increases with decreasing mass ratio of antisolvent to IL and elevating temperatures. The solubility of glucose in IL + ethanol mixtures increases in the following order: [emim][Br], [bmim][Cl], [bmim][HSO4], [bmim][CH3COO], and [emim] [CH3COO]. The addition of water can increase the solubility of glucose in IL + antisolvent mixtures. Ethanol can be selected as a better antisolvent to separate glucose from IL than methanol, acetone, and acetonitrile. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199913
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6952-6956[article] Solubility of glucose in ionic liquid + antisolvent mixtures [texte imprimé] / Weina Liu, Auteur ; Yucui Hou, Auteur ; Weize Wu, Auteur . - 2011 . - pp. 6952-6956.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6952-6956
Mots-clés : Ionic liquid Solubility Résumé : An extended study on the solubility of glucose in ionic liquid (IL) + antisolvent mixtures has been performed to find a way to separate glucose from ILs. These Ils, commonly used in cellulose conversion processes, are based on combination of cations of I-methyl-3-alkylimidazolium and anions of chloride, bromide, acetate, and hydrogen sulfate. Effects of temperatures, antisolvents, ILs, mass ratios of antisolvent to IL, and water contents on the solubility of glucose have been investigated in this work. The results demonstrate that the solubility of glucose increases with decreasing mass ratio of antisolvent to IL and elevating temperatures. The solubility of glucose in IL + ethanol mixtures increases in the following order: [emim][Br], [bmim][Cl], [bmim][HSO4], [bmim][CH3COO], and [emim] [CH3COO]. The addition of water can increase the solubility of glucose in IL + antisolvent mixtures. Ethanol can be selected as a better antisolvent to separate glucose from IL than methanol, acetone, and acetonitrile. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199913 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Absorption of carbon dioxide with ionic liquid in a rotating packed bed contactor : mass transfer study Type de document : texte imprimé Auteurs : Liang - Liang Zhang, Auteur ; Jie-Xin Wang, Auteur ; Yang Xiang, Auteur Année de publication : 2011 Article en page(s) : pp. 6957-6964 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Mass transfer Packed bed Ionic liquid Carbon dioxide Résumé : Using ionic liquids for CO2 capture is of great interest due to their unique characteristics. However, low gas―liquid mass transfer rates in conventional gas-liquid contactors due to the high viscosities of ionic liquids lead to the significant limitation for large-scale applications of CO2 capture using ionic liquids. Therefore, there is an urgent demand to develop a novel gas―liquid contactor for the intensification of the mass transfer efficiency in such a system. In this article, CO2 absorption with an ionic liquid in a rotating packed bed (RPB) gas-liquid contactor is first reported. It was found that the RPB markedly enhanced the physical absorption of CO2 in the ionic liquid in a very short contact time, within seconds. Only one cycle gas-liquid contact in the RPB could make the saturation ratio of CO2 in the ionic liquid reach 60%. The effects of various operation conditions on the liquid side volumetric mass transfer coefficient (kLα) were elucidated. Increasing the rotating speed from 1100 to 3100 rpm doubled the kLα. The increase of the liquid flow rate also benefited the enhancement of the kLα. The experimentally measured kLα in the RPB is at least 1 order of magnitude higher than that in a conventional packed tower. A model based on penetration theory was proposed to describe the mechanism of gas―liquid mass transfer in the RPB. The predicted kLα was in good agreement with the experimental data with a deviation of less than 15%. The RPB shows great potential for the industrial application of CO2 capture using ionic liquids. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199914
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6957-6964[article] Absorption of carbon dioxide with ionic liquid in a rotating packed bed contactor : mass transfer study [texte imprimé] / Liang - Liang Zhang, Auteur ; Jie-Xin Wang, Auteur ; Yang Xiang, Auteur . - 2011 . - pp. 6957-6964.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6957-6964
Mots-clés : Mass transfer Packed bed Ionic liquid Carbon dioxide Résumé : Using ionic liquids for CO2 capture is of great interest due to their unique characteristics. However, low gas―liquid mass transfer rates in conventional gas-liquid contactors due to the high viscosities of ionic liquids lead to the significant limitation for large-scale applications of CO2 capture using ionic liquids. Therefore, there is an urgent demand to develop a novel gas―liquid contactor for the intensification of the mass transfer efficiency in such a system. In this article, CO2 absorption with an ionic liquid in a rotating packed bed (RPB) gas-liquid contactor is first reported. It was found that the RPB markedly enhanced the physical absorption of CO2 in the ionic liquid in a very short contact time, within seconds. Only one cycle gas-liquid contact in the RPB could make the saturation ratio of CO2 in the ionic liquid reach 60%. The effects of various operation conditions on the liquid side volumetric mass transfer coefficient (kLα) were elucidated. Increasing the rotating speed from 1100 to 3100 rpm doubled the kLα. The increase of the liquid flow rate also benefited the enhancement of the kLα. The experimentally measured kLα in the RPB is at least 1 order of magnitude higher than that in a conventional packed tower. A model based on penetration theory was proposed to describe the mechanism of gas―liquid mass transfer in the RPB. The predicted kLα was in good agreement with the experimental data with a deviation of less than 15%. The RPB shows great potential for the industrial application of CO2 capture using ionic liquids. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199914 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : On Quantification of residual Ink content and deinking efficiency in recycling of mixed office waste paper Type de document : texte imprimé Auteurs : Bo Li, Auteur ; Gaosheng Wang, Auteur ; Kefu Chen, Auteur Année de publication : 2011 Article en page(s) : pp. 6965-6971 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Waste paper Recycling Deinking Ink Résumé : Although (flotation) deinking has been a common industry practice for several decades, true residual ink content and deinking efficiency have never been quantified. Paper brightness and ERIC (Effective Residual Ink Concentration), based on measurements of the absorption coefficient of deinked pulp, have been used to determine performance of flotation deinking processes and the quality of deinked pulps. This study demonstrated a new method for quantifying true residual ink content of mixed office waste paper by determining the trace iron content in pulp samples. Two sets of laboratory studies were conducted, one using mixed pulp samples of different ink contents and the other using samples from flotation deinking experiments with different surfactant dosages.All pulp samples including flotation feeds and accepts were characterized byERIC, brightness, and iron-content-derived ink content The results suggest that ERIC and brightness are less suitable than iron content for evaluating the residual ink in very clean papers. In flotation studies, both ERIC and brightness predict lower deinking efficiencies than are obtained from iron-content measurements. However, brightness is suitable for evaluating the final quality of very clean deinked pulp because of its high accuracy at high brightness levels. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199915
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6965-6971[article] On Quantification of residual Ink content and deinking efficiency in recycling of mixed office waste paper [texte imprimé] / Bo Li, Auteur ; Gaosheng Wang, Auteur ; Kefu Chen, Auteur . - 2011 . - pp. 6965-6971.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6965-6971
Mots-clés : Waste paper Recycling Deinking Ink Résumé : Although (flotation) deinking has been a common industry practice for several decades, true residual ink content and deinking efficiency have never been quantified. Paper brightness and ERIC (Effective Residual Ink Concentration), based on measurements of the absorption coefficient of deinked pulp, have been used to determine performance of flotation deinking processes and the quality of deinked pulps. This study demonstrated a new method for quantifying true residual ink content of mixed office waste paper by determining the trace iron content in pulp samples. Two sets of laboratory studies were conducted, one using mixed pulp samples of different ink contents and the other using samples from flotation deinking experiments with different surfactant dosages.All pulp samples including flotation feeds and accepts were characterized byERIC, brightness, and iron-content-derived ink content The results suggest that ERIC and brightness are less suitable than iron content for evaluating the residual ink in very clean papers. In flotation studies, both ERIC and brightness predict lower deinking efficiencies than are obtained from iron-content measurements. However, brightness is suitable for evaluating the final quality of very clean deinked pulp because of its high accuracy at high brightness levels. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199915 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Biomass combustion with in situ CO2 capture with CaO. I. process description and economics Type de document : texte imprimé Auteurs : Juan Carlos Abanades, Auteur ; Monica Alonso, Auteur ; Nuria Rodriguez, Auteur Année de publication : 2011 Article en page(s) : pp. 6972-6981 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon dioxide In situ Combustion Biomass Résumé : A novel concept is proposed to capture CO2 from biomass, burned in a circulating fluidized bed at a sufficiently low temperature (below 700 °C) to allow capture "in situ" by CaO. This step is followed by the calcination of CaCO3 in an interconnected oxy-fuel combustor that delivers a concentrated stream of CO2 suitable for permanent geological storage. A conceptual design and cost estimation exercise is presented and compared with other similar power plant schemes based on biomass and fossil fuels. A sensitivity analysis of the main cost variables reveals that the concept proposed is competitive against other low-carbon systems for lower values of Green Certificates and higher values of a carbon tax. The process could have long-term applications for large-scale biomass-fired systems and medium-term applications in helping large-scale power plants with CO2 capture and storage to meet the target of zero emissions by taking advantage of the negative emissions achieved from CO2 captured from biomass. A second part of this work (see the next article in this issue) demonstrates the concept in a 30 kW circulating fluidizedbed test facility. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199916
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6972-6981[article] Biomass combustion with in situ CO2 capture with CaO. I. process description and economics [texte imprimé] / Juan Carlos Abanades, Auteur ; Monica Alonso, Auteur ; Nuria Rodriguez, Auteur . - 2011 . - pp. 6972-6981.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6972-6981
Mots-clés : Carbon dioxide In situ Combustion Biomass Résumé : A novel concept is proposed to capture CO2 from biomass, burned in a circulating fluidized bed at a sufficiently low temperature (below 700 °C) to allow capture "in situ" by CaO. This step is followed by the calcination of CaCO3 in an interconnected oxy-fuel combustor that delivers a concentrated stream of CO2 suitable for permanent geological storage. A conceptual design and cost estimation exercise is presented and compared with other similar power plant schemes based on biomass and fossil fuels. A sensitivity analysis of the main cost variables reveals that the concept proposed is competitive against other low-carbon systems for lower values of Green Certificates and higher values of a carbon tax. The process could have long-term applications for large-scale biomass-fired systems and medium-term applications in helping large-scale power plants with CO2 capture and storage to meet the target of zero emissions by taking advantage of the negative emissions achieved from CO2 captured from biomass. A second part of this work (see the next article in this issue) demonstrates the concept in a 30 kW circulating fluidizedbed test facility. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199916 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Biomass combustion with in situ CO2 capture by CaO. II. experimental results Type de document : texte imprimé Auteurs : Mónica Alonson, Auteur ; Nuria Rodriguez, Auteur ; Belén Gonzalez, Auteur Année de publication : 2011 Article en page(s) : pp. 6982-6989 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon dioxide In situ Combustion Biomass Résumé : Experiments to test the concept of biomass combustion with in situ CO2 capture by CaO have been conducted in a 30 kW interconnected fluidized-bed test facility. The CO2 capture efficiency in a combustor―carbonator reactor was measured over a range of operating conditions, using three biomass feeds (olive pits, saw dust, and pellets). Overall CO2 capture efficiencies higher than 80% were achieved with sufficiently high solids circulation rates of CaO and solids inventories in the combustor―carbonator. Emissions of CO and CH4 were detected during the experiments, possibly because of pulse feeding and/or an inappropriate air/fuel mixture. The application of a simple reactor model for combining biomass combustion and CO2 capture allows an effectiveness factor of 0.74 to be derived for all of the experiments. This could be valuable for scaling-up purposes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199917
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6982-6989[article] Biomass combustion with in situ CO2 capture by CaO. II. experimental results [texte imprimé] / Mónica Alonson, Auteur ; Nuria Rodriguez, Auteur ; Belén Gonzalez, Auteur . - 2011 . - pp. 6982-6989.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6982-6989
Mots-clés : Carbon dioxide In situ Combustion Biomass Résumé : Experiments to test the concept of biomass combustion with in situ CO2 capture by CaO have been conducted in a 30 kW interconnected fluidized-bed test facility. The CO2 capture efficiency in a combustor―carbonator reactor was measured over a range of operating conditions, using three biomass feeds (olive pits, saw dust, and pellets). Overall CO2 capture efficiencies higher than 80% were achieved with sufficiently high solids circulation rates of CaO and solids inventories in the combustor―carbonator. Emissions of CO and CH4 were detected during the experiments, possibly because of pulse feeding and/or an inappropriate air/fuel mixture. The application of a simple reactor model for combining biomass combustion and CO2 capture allows an effectiveness factor of 0.74 to be derived for all of the experiments. This could be valuable for scaling-up purposes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199917 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Using an online image analysis technique to characterize sucrose crystal morphology during a crystallization run Type de document : texte imprimé Auteurs : A. Ferreira, Auteur ; N. Faria, Auteur ; F. Rocha, Auteur Année de publication : 2011 Article en page(s) : pp. 6990-7002 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Crystallization Crystal morphology Image analysis Résumé : The morphological forms and habits of crystals and agglomeration are important properties on crystallization processes. Online techniques for realtime measurement of these properties are mandatory for a better comprehension of crystal growth phenomenon. The present paper presents and describes a new online method to determine the complexity level of a crystal or a population of crystals during a crystallization process. An image analysis technique is combined with discriminant factorial analysis leading to results that allow the computation of the complexity of crystals through the parameter agglomeration degree of crystals. With this methodology, it has been possible to distinguish online and automatically among three different classes of crystals according to their complexity. It further describes the application of such methodology on the study of CaCl2, D-fructose, and D-glucose influence on the crystallization of sucrose, namely, on crystal size, morphology, and complexity. The effect of supersaturation, growth rate, and impurity concentration on the type, amount, and complexity level of the agglomerates was determined at different temperatures. The combination of image analysis and kinetic results allowed to understand better the crystallization phenomena in the presence and absence of impurities. The image analysis results suggest the possible application of this tool for process control, optimizing, by this way, laboratory and industrial crystallizers. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199918
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6990-7002[article] Using an online image analysis technique to characterize sucrose crystal morphology during a crystallization run [texte imprimé] / A. Ferreira, Auteur ; N. Faria, Auteur ; F. Rocha, Auteur . - 2011 . - pp. 6990-7002.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6990-7002
Mots-clés : Crystallization Crystal morphology Image analysis Résumé : The morphological forms and habits of crystals and agglomeration are important properties on crystallization processes. Online techniques for realtime measurement of these properties are mandatory for a better comprehension of crystal growth phenomenon. The present paper presents and describes a new online method to determine the complexity level of a crystal or a population of crystals during a crystallization process. An image analysis technique is combined with discriminant factorial analysis leading to results that allow the computation of the complexity of crystals through the parameter agglomeration degree of crystals. With this methodology, it has been possible to distinguish online and automatically among three different classes of crystals according to their complexity. It further describes the application of such methodology on the study of CaCl2, D-fructose, and D-glucose influence on the crystallization of sucrose, namely, on crystal size, morphology, and complexity. The effect of supersaturation, growth rate, and impurity concentration on the type, amount, and complexity level of the agglomerates was determined at different temperatures. The combination of image analysis and kinetic results allowed to understand better the crystallization phenomena in the presence and absence of impurities. The image analysis results suggest the possible application of this tool for process control, optimizing, by this way, laboratory and industrial crystallizers. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199918 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Modified bounded homotopies in the solving of phase stability problems for liquid-liquid phase-splitting calculations Type de document : texte imprimé Auteurs : Jani Kangas, Auteur ; Ilkka Malinen, Auteur ; Juha Tanskanen, Auteur Année de publication : 2011 Article en page(s) : pp. 7003-7018 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Liquid phase Phase stability Homotopy Résumé : In this study, the modified bounded homotopies presented by Malinen and Tanskanen (Malinen, L; Tanskanen, J. Modified bounded homotopies to enable a narrow bounding zone. Chem. Eng. Sci. 2008, 63, 3419) are investigated in order to solve phase stability analysis problems in liquid―liquid equilibrium cases for phase-splitting calculations. The tangent-plane distance criterion is used to analyze the phase stability. The emphasis is on approaching the first root on the homotopy path. According to the observations, the bounding of the homotopy path with respect to the problem variables aids in the solving of a phase stability analysis problem. The main shortcomings of the modified bounded Newton, affine, and fixed-point homotopies are the starting point isolas, the existence of unfeasible solutions, and the convergence to only certain roots, respectively. The attraction domain of the global minimum was observed to be the largest with the fixed-point homotopy. Sequential usage of the fixed-point homotopy and starting points near pure components results in a robust algorithm for phase stability analysis and gives feasible initial estimates for the solving of phase splitting. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199919
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7003-7018[article] Modified bounded homotopies in the solving of phase stability problems for liquid-liquid phase-splitting calculations [texte imprimé] / Jani Kangas, Auteur ; Ilkka Malinen, Auteur ; Juha Tanskanen, Auteur . - 2011 . - pp. 7003-7018.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7003-7018
Mots-clés : Liquid phase Phase stability Homotopy Résumé : In this study, the modified bounded homotopies presented by Malinen and Tanskanen (Malinen, L; Tanskanen, J. Modified bounded homotopies to enable a narrow bounding zone. Chem. Eng. Sci. 2008, 63, 3419) are investigated in order to solve phase stability analysis problems in liquid―liquid equilibrium cases for phase-splitting calculations. The tangent-plane distance criterion is used to analyze the phase stability. The emphasis is on approaching the first root on the homotopy path. According to the observations, the bounding of the homotopy path with respect to the problem variables aids in the solving of a phase stability analysis problem. The main shortcomings of the modified bounded Newton, affine, and fixed-point homotopies are the starting point isolas, the existence of unfeasible solutions, and the convergence to only certain roots, respectively. The attraction domain of the global minimum was observed to be the largest with the fixed-point homotopy. Sequential usage of the fixed-point homotopy and starting points near pure components results in a robust algorithm for phase stability analysis and gives feasible initial estimates for the solving of phase splitting. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199919 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Experimental studies and thermodynamic modeling of the solubilities of potassium nitrate, potassium chloride, potassium bromide, and sodium chloride in dimethyl sulfoxide Type de document : texte imprimé Auteurs : Bingwen Long, Auteur Année de publication : 2011 Article en page(s) : pp. 7019-7026 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solubility Modeling Résumé : Using appropriate nonaqueous solvents to replace water as reaction medium in chemical industries has gained more and more attention recently. Many of them have the special ability to dissolve some compounds and thus may make the reaction more stable in comparison with a water-containing environment Dimethyl sulfoxide (DMSO) is probably the most frequently mentioned aprotic nonaqueous solvent with extensive applications because of its high stability and powerful solubility. In this study, the solubilities of four inorganic salts, namely potassium nitrate (KNO3), potassium chloride (KCl), potassium bromide (KBr) and sodium chloride (NaCl), in DMSO are measured in the temperature range of 302 through 354 K using a dynamic method. The solubility order of the salts in DMSO is experimentally determined as KNO3 > KBr > NaCl > KCl. The molality solubilities show linear dependencies on temperature and the temperature effect on the solubility for the salts follows the same order as the solubility result. The solubility products of the salts in DMSO at different temperatures are obtained by estimating the solubility products in water and the Gibbs energy of transfer from water to DMSO. Then electrolyte models of the Wilson, NRTL, and UNIQUAC equations are used to model the solubility of the inorganic salts in DMSO. It is found that the three-parameter E-Wilson equation gives the best correlation results followed by the Pitzer, E-NRTL, and E-UNIQUAC equations, while the two-parameter E-Wilson equation presents the worst results in terms of the overall standard deviation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199920
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7019-7026[article] Experimental studies and thermodynamic modeling of the solubilities of potassium nitrate, potassium chloride, potassium bromide, and sodium chloride in dimethyl sulfoxide [texte imprimé] / Bingwen Long, Auteur . - 2011 . - pp. 7019-7026.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7019-7026
Mots-clés : Solubility Modeling Résumé : Using appropriate nonaqueous solvents to replace water as reaction medium in chemical industries has gained more and more attention recently. Many of them have the special ability to dissolve some compounds and thus may make the reaction more stable in comparison with a water-containing environment Dimethyl sulfoxide (DMSO) is probably the most frequently mentioned aprotic nonaqueous solvent with extensive applications because of its high stability and powerful solubility. In this study, the solubilities of four inorganic salts, namely potassium nitrate (KNO3), potassium chloride (KCl), potassium bromide (KBr) and sodium chloride (NaCl), in DMSO are measured in the temperature range of 302 through 354 K using a dynamic method. The solubility order of the salts in DMSO is experimentally determined as KNO3 > KBr > NaCl > KCl. The molality solubilities show linear dependencies on temperature and the temperature effect on the solubility for the salts follows the same order as the solubility result. The solubility products of the salts in DMSO at different temperatures are obtained by estimating the solubility products in water and the Gibbs energy of transfer from water to DMSO. Then electrolyte models of the Wilson, NRTL, and UNIQUAC equations are used to model the solubility of the inorganic salts in DMSO. It is found that the three-parameter E-Wilson equation gives the best correlation results followed by the Pitzer, E-NRTL, and E-UNIQUAC equations, while the two-parameter E-Wilson equation presents the worst results in terms of the overall standard deviation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199920 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Modeling of the thermodynamic properties of aqueous ionic liquid solutions with an equation of state for square-well chain fluid with variable range Type de document : texte imprimé Auteurs : Jinglong Li, Auteur ; Changchun He, Auteur ; Changjun Peng, Auteur Année de publication : 2011 Article en page(s) : pp. 7027-7040 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Equations of state Ionic liquid Thermodynamic properties Modeling Résumé : A new thermodynamic model based on an equation of state for square-well chain fluid with variable range (SWCF-VR) is proposed to describe the thermodynamic properties of aqueous solutions of ionic liquids. In this approach the electrostatic interactions are characterized via the mean spherical approximation and the ionic associations between the cations and anions of the ionic liquid are considered through the shield-sticky approach. The liquid densities, osmotic coefficients, and vapor pressures of aqueous solutions ofnine ionic liquids (ILs) containing [Cxmim] [Br] (x=2,...,6), [C4mim] [BF4] and [Cxmim] [MSO4] (x= 1, 3, 4) have been modeled with the new model. Two ionic parameters for each anion and three for each cation of the ionic liquids were adjusted to experimental liquid densities and osmotic coefficients, and the corresponding average deviations are only 0.87% and 2.49%, respectively. Using the same ionic parameters, the vapor pressures of ionic liquid solutions are accurately predicted. The predicted equilibrium constants of the ionic association between the cations and anions of ILs in water were consistent with experimental observations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199921
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7027-7040[article] Modeling of the thermodynamic properties of aqueous ionic liquid solutions with an equation of state for square-well chain fluid with variable range [texte imprimé] / Jinglong Li, Auteur ; Changchun He, Auteur ; Changjun Peng, Auteur . - 2011 . - pp. 7027-7040.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7027-7040
Mots-clés : Equations of state Ionic liquid Thermodynamic properties Modeling Résumé : A new thermodynamic model based on an equation of state for square-well chain fluid with variable range (SWCF-VR) is proposed to describe the thermodynamic properties of aqueous solutions of ionic liquids. In this approach the electrostatic interactions are characterized via the mean spherical approximation and the ionic associations between the cations and anions of the ionic liquid are considered through the shield-sticky approach. The liquid densities, osmotic coefficients, and vapor pressures of aqueous solutions ofnine ionic liquids (ILs) containing [Cxmim] [Br] (x=2,...,6), [C4mim] [BF4] and [Cxmim] [MSO4] (x= 1, 3, 4) have been modeled with the new model. Two ionic parameters for each anion and three for each cation of the ionic liquids were adjusted to experimental liquid densities and osmotic coefficients, and the corresponding average deviations are only 0.87% and 2.49%, respectively. Using the same ionic parameters, the vapor pressures of ionic liquid solutions are accurately predicted. The predicted equilibrium constants of the ionic association between the cations and anions of ILs in water were consistent with experimental observations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199921 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Improved method for determining the atmospheric distillation curve of biodiesel fuels from reduced pressure Type de document : texte imprimé Auteurs : Magin Lapuerta, Auteur ; Laureano Canoira, Auteur ; Jesus Raez, Auteur Année de publication : 2011 Article en page(s) : pp. 7041-7048 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fuel Distillation Résumé : Vacuum distillation is widely accepted as a useful technique for obtaining the distillation curves of fuels that boil beyond their decomposition temperatures at atmospheric pressure. After their measurement, the obtained curves must be converted to atmospheric-equivalent-temperature curves following the standard method proposed in ASTM D1160. However, this method was originally developed for petroleum-derived hydrocarbons, but not for oxygenated fuels. A specific method to convert reduced-pressure distillation curves of biodiesel fuels to their atmospheric distillation curves is proposed, based on their projection toward a focal point specifically selected for the methyl esters usually composing biodiesel fuels. This projection was made using a generalized Antoine-type equation with Antoine coefficients estimated from a two-parameter correlation as a function of the number of carbon atoms of the original fatty acid and the number of double bonds. The method (named here the Calingaert-like method) is based on the observation that saturation Antonie-type curved lines for pure hydrocarbons converge to a focal point when plotted in the form of log p versus 1/T and was found to be more accurate than ASTM D1160 method. Another tested method (named here the Cox-like method), based on the convergence of straight lines to a different focal point, was shown to provide intermediate results. Therefore, the Calingaert-like method is proposed as an improved alternative to the ASTM D1160 method for the distillation of biodiesel fuels at reduced pressure. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199922
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7041-7048[article] Improved method for determining the atmospheric distillation curve of biodiesel fuels from reduced pressure [texte imprimé] / Magin Lapuerta, Auteur ; Laureano Canoira, Auteur ; Jesus Raez, Auteur . - 2011 . - pp. 7041-7048.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7041-7048
Mots-clés : Fuel Distillation Résumé : Vacuum distillation is widely accepted as a useful technique for obtaining the distillation curves of fuels that boil beyond their decomposition temperatures at atmospheric pressure. After their measurement, the obtained curves must be converted to atmospheric-equivalent-temperature curves following the standard method proposed in ASTM D1160. However, this method was originally developed for petroleum-derived hydrocarbons, but not for oxygenated fuels. A specific method to convert reduced-pressure distillation curves of biodiesel fuels to their atmospheric distillation curves is proposed, based on their projection toward a focal point specifically selected for the methyl esters usually composing biodiesel fuels. This projection was made using a generalized Antoine-type equation with Antoine coefficients estimated from a two-parameter correlation as a function of the number of carbon atoms of the original fatty acid and the number of double bonds. The method (named here the Calingaert-like method) is based on the observation that saturation Antonie-type curved lines for pure hydrocarbons converge to a focal point when plotted in the form of log p versus 1/T and was found to be more accurate than ASTM D1160 method. Another tested method (named here the Cox-like method), based on the convergence of straight lines to a different focal point, was shown to provide intermediate results. Therefore, the Calingaert-like method is proposed as an improved alternative to the ASTM D1160 method for the distillation of biodiesel fuels at reduced pressure. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199922 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : New approach for simultaneous measurement of gas absorption and swelling Type de document : texte imprimé Auteurs : Tobias M. Fieback, Auteur ; Frieder Dreisbach, Auteur Année de publication : 2011 Article en page(s) : pp. 7049-7055 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Swelling Gas absorption Simultaneous measurement Résumé : For sorption measurements many different methods are applicable, but nearly all of them require a correction of the raw experimental data by a factor including the sample's volume. This can be determined by a separate volume measurement for samples with constant volumes. If the sample volume is not constant because of swelling effects, the actual volume is usually calculated by suitable equations of state (EOS) for the sample-gas-system (if available) or estimated by optical or spectroscopic sample observation and assumptions about orientation of swelling. The advantage of the new approach presented here is that one measurement leads to both unknown quantities: sample volume and absorption. Not only is the volume measurement for constant sample volumes is obsolete, also the actual volume of swollen samples can be determined with minimal effort. The method can be applied to liquid and solid state samples without optical or spectroscopic sample observation or any assumption about orientation of swelling. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199923
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7049-7055[article] New approach for simultaneous measurement of gas absorption and swelling [texte imprimé] / Tobias M. Fieback, Auteur ; Frieder Dreisbach, Auteur . - 2011 . - pp. 7049-7055.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7049-7055
Mots-clés : Swelling Gas absorption Simultaneous measurement Résumé : For sorption measurements many different methods are applicable, but nearly all of them require a correction of the raw experimental data by a factor including the sample's volume. This can be determined by a separate volume measurement for samples with constant volumes. If the sample volume is not constant because of swelling effects, the actual volume is usually calculated by suitable equations of state (EOS) for the sample-gas-system (if available) or estimated by optical or spectroscopic sample observation and assumptions about orientation of swelling. The advantage of the new approach presented here is that one measurement leads to both unknown quantities: sample volume and absorption. Not only is the volume measurement for constant sample volumes is obsolete, also the actual volume of swollen samples can be determined with minimal effort. The method can be applied to liquid and solid state samples without optical or spectroscopic sample observation or any assumption about orientation of swelling. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199923 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Facile synthesis of processable semiaromatic polyamides containing thioether units Type de document : texte imprimé Auteurs : Gang Zhang, Auteur ; Guang - Shun Huang, Auteur ; Dong - Sheng Li, Auteur Année de publication : 2011 Article en page(s) : pp. 7056-7064 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Semiaromatic polyamides Résumé : Semiaromatic polyamides containing thioether units were synthesized through the reaction of 4,4'-thiodibenzoyl chloride (TDC) and diamine by the method of interfacial polycondensation. The inherent viscosities of the resultant polyamides prepared with optimum synthesis conditions were 1.08―1.26 dL/g. These polyamides had excellent thermal properties with glass transition temperatures (Tg) of 119.8-190.1 °C, melting temperatures (Tm) of 281.4―355.5 °C, and initial degradation temperatures (Td) of 433.5―466 °C. They had wider processing windows than traditional semiaromatic polyamides. At the same time, they had better tensile strengths of 62.1―86.5 MPa, better low-temperature mechanical properties, lower water absorption, lower dielectric constants of 3.16―3.81 at 100 kHz, and better melt flowability properties. The results suggest that these semiaromatic polyamides containing thioether units [poly(hexanelene 4,4'-thiodibenzoamide) (PA-6), poly(octanelene 4,4'-thiodibenzoamide) (PA-8), and poly(decanelene 4,4'-thiodibenzoamide) (PA-10)] represent a promising type of heat-resistant and processable engineering plastic. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199924
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7056-7064[article] Facile synthesis of processable semiaromatic polyamides containing thioether units [texte imprimé] / Gang Zhang, Auteur ; Guang - Shun Huang, Auteur ; Dong - Sheng Li, Auteur . - 2011 . - pp. 7056-7064.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7056-7064
Mots-clés : Semiaromatic polyamides Résumé : Semiaromatic polyamides containing thioether units were synthesized through the reaction of 4,4'-thiodibenzoyl chloride (TDC) and diamine by the method of interfacial polycondensation. The inherent viscosities of the resultant polyamides prepared with optimum synthesis conditions were 1.08―1.26 dL/g. These polyamides had excellent thermal properties with glass transition temperatures (Tg) of 119.8-190.1 °C, melting temperatures (Tm) of 281.4―355.5 °C, and initial degradation temperatures (Td) of 433.5―466 °C. They had wider processing windows than traditional semiaromatic polyamides. At the same time, they had better tensile strengths of 62.1―86.5 MPa, better low-temperature mechanical properties, lower water absorption, lower dielectric constants of 3.16―3.81 at 100 kHz, and better melt flowability properties. The results suggest that these semiaromatic polyamides containing thioether units [poly(hexanelene 4,4'-thiodibenzoamide) (PA-6), poly(octanelene 4,4'-thiodibenzoamide) (PA-8), and poly(decanelene 4,4'-thiodibenzoamide) (PA-10)] represent a promising type of heat-resistant and processable engineering plastic. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199924 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Analyse de l'incertitude pour la planification de la production des raffineries Type de document : texte imprimé Auteurs : Abdallah Al -Shammari, Auteur ; Mohammed S. Ba - Shammakh, Auteur Année de publication : 2011 Article en page(s) : pp 7065-7072 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production planning Refinery Uncertainty Résumé : Aujourd'hui, les raffineries de pétrole sont confrontés à une tâche difficile à optimiser leurs niveaux de production et augmenter leurs revenus. The objective of refinery optimization is to determine the best production levels that can maximize profit and minimize operating costs with respect to operational and environmental constraints. L'objectif de l'optimisation de la raffinerie est de déterminer les meilleurs niveaux de production qui peuvent maximiser les profits et minimiser les coûts d'exploitation par rapport aux contraintes opérationnelles et environnementales. The existence of uncertainty or variations in some parameters such as the prices of raw materials and products can seriously affect the optimization results and lead to inefficient operation. L'existence d'une incertitude ou des variations de certains paramètres tels que les prix des matières premières et de produits peuvent sérieusement affecter les résultats d'optimisation et de conduire à un fonctionnement inefficace. Many techniques of stochastic programming were proposed to handle the effect of variations in process parameters in order to determine a robust operation conditions; however, applications of postoptimality analysis have received less attention, especially in the refinery industry. De nombreuses techniques de programmation stochastique ont été proposées pour gérer les effets des variations des paramètres du processus afin de déterminer les conditions de fonctionnement robuste une, cependant, les applications d'analyse postoptimality ont reçu moins d'attention, en particulier dans l'industrie du raffinage. In this work, postoptimality analysis is used to study the effect of such variations on the optimal solution of refinery process that is simplified and formulated as a LP model. Dans ce travail, l'analyse postoptimality est utilisée pour étudier l'effet de ces variations sur la solution optimale du processus de raffinage qui est simplifiée et formulé comme un modèle LP. We used a modified method of postoptimality analysis that jointly use sensitivity relations and stability region calculations to provide the decision maker in the refinery with valuable and easy-to-use information that helps in handling the effect of variation in process parameters. Nous avons utilisé une méthode modifiée de l'analyse postoptimality qui utilisent conjointement les relations de sensibilité et des calculs région de stabilité pour fournir au décideur dans la raffinerie de précieuses informations et facile à utiliser qui aide à la manipulation de l'effet de la variation des paramètres du procédé. The results of this study can help the decision maker to identify sensitive parameters that need accurate estimate or intensive monitoring; and compute their stability limits, allowable variation ranges, within which the operation remains optimum. Les résultats de cette étude peut aider le décideur à identifier les paramètres sensibles qui ont besoin d'estimer avec précision ou de surveillance intensive, et calculer leur limite de stabilité, plages de variation permise, dans lequel l'opération reste optimale. Independent and simultaneous variations in the products prices or in the capacities of process units are considered in this study; and it is shown how the refinery profit can be increased up to 4.2% by utilizing sensitivity and stability results. Variations indépendantes et simultanées des prix des produits ou dans les capacités des unités de traitement sont considérés dans cette étude, et il est montré comment le profit raffinerie peut être augmenté jusqu'à 4,2% en utilisant les résultats de sensibilité et de stabilité. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199925
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 7065-7072[article] Analyse de l'incertitude pour la planification de la production des raffineries [texte imprimé] / Abdallah Al -Shammari, Auteur ; Mohammed S. Ba - Shammakh, Auteur . - 2011 . - pp 7065-7072.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 7065-7072
Mots-clés : Production planning Refinery Uncertainty Résumé : Aujourd'hui, les raffineries de pétrole sont confrontés à une tâche difficile à optimiser leurs niveaux de production et augmenter leurs revenus. The objective of refinery optimization is to determine the best production levels that can maximize profit and minimize operating costs with respect to operational and environmental constraints. L'objectif de l'optimisation de la raffinerie est de déterminer les meilleurs niveaux de production qui peuvent maximiser les profits et minimiser les coûts d'exploitation par rapport aux contraintes opérationnelles et environnementales. The existence of uncertainty or variations in some parameters such as the prices of raw materials and products can seriously affect the optimization results and lead to inefficient operation. L'existence d'une incertitude ou des variations de certains paramètres tels que les prix des matières premières et de produits peuvent sérieusement affecter les résultats d'optimisation et de conduire à un fonctionnement inefficace. Many techniques of stochastic programming were proposed to handle the effect of variations in process parameters in order to determine a robust operation conditions; however, applications of postoptimality analysis have received less attention, especially in the refinery industry. De nombreuses techniques de programmation stochastique ont été proposées pour gérer les effets des variations des paramètres du processus afin de déterminer les conditions de fonctionnement robuste une, cependant, les applications d'analyse postoptimality ont reçu moins d'attention, en particulier dans l'industrie du raffinage. In this work, postoptimality analysis is used to study the effect of such variations on the optimal solution of refinery process that is simplified and formulated as a LP model. Dans ce travail, l'analyse postoptimality est utilisée pour étudier l'effet de ces variations sur la solution optimale du processus de raffinage qui est simplifiée et formulé comme un modèle LP. We used a modified method of postoptimality analysis that jointly use sensitivity relations and stability region calculations to provide the decision maker in the refinery with valuable and easy-to-use information that helps in handling the effect of variation in process parameters. Nous avons utilisé une méthode modifiée de l'analyse postoptimality qui utilisent conjointement les relations de sensibilité et des calculs région de stabilité pour fournir au décideur dans la raffinerie de précieuses informations et facile à utiliser qui aide à la manipulation de l'effet de la variation des paramètres du procédé. The results of this study can help the decision maker to identify sensitive parameters that need accurate estimate or intensive monitoring; and compute their stability limits, allowable variation ranges, within which the operation remains optimum. Les résultats de cette étude peut aider le décideur à identifier les paramètres sensibles qui ont besoin d'estimer avec précision ou de surveillance intensive, et calculer leur limite de stabilité, plages de variation permise, dans lequel l'opération reste optimale. Independent and simultaneous variations in the products prices or in the capacities of process units are considered in this study; and it is shown how the refinery profit can be increased up to 4.2% by utilizing sensitivity and stability results. Variations indépendantes et simultanées des prix des produits ou dans les capacités des unités de traitement sont considérés dans cette étude, et il est montré comment le profit raffinerie peut être augmenté jusqu'à 4,2% en utilisant les résultats de sensibilité et de stabilité. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199925 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Improvements in the electrochemical production of ferrates with conductive diamond anodes using goethite as raw material and ultrasound Type de document : texte imprimé Auteurs : Ana Sanchez-Carretero, Auteur ; Cristina Saez, Auteur ; Pablo Canizares, Auteur Année de publication : 2011 Article en page(s) : pp. 7073-7076 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ultrasound Raw materials Production Résumé : The improvement in the electrochemical production of ferrates with conductive diamond anodes using goethite as raw material and ultrasounds has been studied. The conductive-diamond electrolysis of suspensions of goethite leads to a higher ferrate concentration than that of Fe(OH)3 suspensions and of iron-powder bed. With this raw material, the ferrate concentration increases continuously with a constant production rate, after a first more efficient stage in which results are similar to the other two raw materials. In addition, the ferrate production rate is significantly improved in the sonoelectrochemical system, suggesting that the amount of soluble iron ready to be oxidized to ferrates increases with the ultrasound effect The initial iron concentration only seems to have an influence on the first stage of the process. On the other hand, the concentration of ferrate strongly depends on the hydroxide anion concentration: the higher is the hydroxide concentration, the higher the ferrate concentration is. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199926
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7073-7076[article] Improvements in the electrochemical production of ferrates with conductive diamond anodes using goethite as raw material and ultrasound [texte imprimé] / Ana Sanchez-Carretero, Auteur ; Cristina Saez, Auteur ; Pablo Canizares, Auteur . - 2011 . - pp. 7073-7076.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7073-7076
Mots-clés : Ultrasound Raw materials Production Résumé : The improvement in the electrochemical production of ferrates with conductive diamond anodes using goethite as raw material and ultrasounds has been studied. The conductive-diamond electrolysis of suspensions of goethite leads to a higher ferrate concentration than that of Fe(OH)3 suspensions and of iron-powder bed. With this raw material, the ferrate concentration increases continuously with a constant production rate, after a first more efficient stage in which results are similar to the other two raw materials. In addition, the ferrate production rate is significantly improved in the sonoelectrochemical system, suggesting that the amount of soluble iron ready to be oxidized to ferrates increases with the ultrasound effect The initial iron concentration only seems to have an influence on the first stage of the process. On the other hand, the concentration of ferrate strongly depends on the hydroxide anion concentration: the higher is the hydroxide concentration, the higher the ferrate concentration is. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199926 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Electrocatalysis of sandwich-structured Pd/polypyrrole/Pd composites toward formic acid oxidation Type de document : texte imprimé Auteurs : Keqiang Ding, Auteur ; Haitao Jia, Auteur ; Suying Wei, Auteur Année de publication : 2011 Article en page(s) : pp. 7077-7082 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oxidation Composite material Electrocatalysis Résumé : Palladium (Pd) nanoparticle catalysts were electrodeposited onto a graphite electrode by cyclic voltammetry (CV) technique from a 0.5 M HCl solution containing 0.2 M PdCl2, and then a film of polypyrrole (PPy) was immobilized onto the as-prepared Pd-coated graphite electrode, leading to a PPy/Pd-coated electrode. Pd particles were repeatedly electrodeposited on the PPy/Pd-coated electrode to generate a Pd/PPy/Pd sandwich structured composite coated electrode. This developed composite electrode showed a satisfactory electrocatalysis toward the formic acid oxidation (FAO). The catalysis mechanism of the sandwich structured Pd/PPy/Pd composite catalyst toward FAO was also discussed on the basis of the obtained cyclic voltammograms and FT-IR spectra. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199927
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7077-7082[article] Electrocatalysis of sandwich-structured Pd/polypyrrole/Pd composites toward formic acid oxidation [texte imprimé] / Keqiang Ding, Auteur ; Haitao Jia, Auteur ; Suying Wei, Auteur . - 2011 . - pp. 7077-7082.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7077-7082
Mots-clés : Oxidation Composite material Electrocatalysis Résumé : Palladium (Pd) nanoparticle catalysts were electrodeposited onto a graphite electrode by cyclic voltammetry (CV) technique from a 0.5 M HCl solution containing 0.2 M PdCl2, and then a film of polypyrrole (PPy) was immobilized onto the as-prepared Pd-coated graphite electrode, leading to a PPy/Pd-coated electrode. Pd particles were repeatedly electrodeposited on the PPy/Pd-coated electrode to generate a Pd/PPy/Pd sandwich structured composite coated electrode. This developed composite electrode showed a satisfactory electrocatalysis toward the formic acid oxidation (FAO). The catalysis mechanism of the sandwich structured Pd/PPy/Pd composite catalyst toward FAO was also discussed on the basis of the obtained cyclic voltammograms and FT-IR spectra. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199927 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Investigating the validity of the knudsen prescription for diffusivities in a mesoporous covalent organic framework Type de document : texte imprimé Auteurs : Rajamani Krishna, Auteur ; Jasper M. Van Baten, Auteur Année de publication : 2011 Article en page(s) : pp. 7083-7087 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Diffusion coefficient Résumé : Molecular dynamics (MD) simolations were performed to determine the self-diffusivity (Di,self) and the Mazwell―Stefan diffusivity (Di) of hydrogen, argon, carbon dioxide, methane, ethane, propane, n-butane, n-pentane, and n-hexane in BTP-COF, which is a covalent organic framework (COF) that has one-dimensional 3.4-nm-sized channels. The MD simulations show that the zero-loading diffusivity (Đi(0)) is consistently lower, by up to a factor of 10, than the Knudsen diffusivity (D¡,Kn) values. The ratio Đi(0)/Di,Kn is found to correlate with the isosteric heat of adsorption, which, in turn, is a reflection of the binding energy for adsorption on the pore walls: the stronger the binding energy, the lower the ratio Ði(0)/Di,Kn. The diffusion selectivity, which is defined by the ratio D1,self/ D2,self for binary mixtures, was determined to be significantly different from the Knudsen selectivity (M2/M1) 1/2, where M¡ is the molar mass of species i. For mixtures in which component 2 is more strongly adsorbed than component 1, the expression (D1,self/D2,self)/ (M2/M1)1/2 has values in the range of 1―10; the departures from the Knudsen selectivity increased with increasing differences in adsorption strengths of the constituent species. The results of this study have implications in the modeling of diffusion within mesoporous structures, such as MCM-41 and SBA-15. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199928
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7083-7087[article] Investigating the validity of the knudsen prescription for diffusivities in a mesoporous covalent organic framework [texte imprimé] / Rajamani Krishna, Auteur ; Jasper M. Van Baten, Auteur . - 2011 . - pp. 7083-7087.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 7083-7087
Mots-clés : Diffusion coefficient Résumé : Molecular dynamics (MD) simolations were performed to determine the self-diffusivity (Di,self) and the Mazwell―Stefan diffusivity (Di) of hydrogen, argon, carbon dioxide, methane, ethane, propane, n-butane, n-pentane, and n-hexane in BTP-COF, which is a covalent organic framework (COF) that has one-dimensional 3.4-nm-sized channels. The MD simulations show that the zero-loading diffusivity (Đi(0)) is consistently lower, by up to a factor of 10, than the Knudsen diffusivity (D¡,Kn) values. The ratio Đi(0)/Di,Kn is found to correlate with the isosteric heat of adsorption, which, in turn, is a reflection of the binding energy for adsorption on the pore walls: the stronger the binding energy, the lower the ratio Ði(0)/Di,Kn. The diffusion selectivity, which is defined by the ratio D1,self/ D2,self for binary mixtures, was determined to be significantly different from the Knudsen selectivity (M2/M1) 1/2, where M¡ is the molar mass of species i. For mixtures in which component 2 is more strongly adsorbed than component 1, the expression (D1,self/D2,self)/ (M2/M1)1/2 has values in the range of 1―10; the departures from the Knudsen selectivity increased with increasing differences in adsorption strengths of the constituent species. The results of this study have implications in the modeling of diffusion within mesoporous structures, such as MCM-41 and SBA-15. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199928 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
