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Vol. 51 N° 12 - Mars 2012 [texte imprimé] . - 2012 . - p. 4467-4768 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierEfficient polymerization inhibition systems for acrylic acid distillation / Renaud Nicolay in Industrial & engineering chemistry research, Vol. 51 N° 12 (Mars 2012)
Titre : Efficient polymerization inhibition systems for acrylic acid distillation : Vapor - phase inhibitors Type de document : texte imprimé Auteurs : Renaud Nicolay, Auteur ; Jaroslav Mosnacek, Auteur ; Kishore K. Kar, Auteur Année de publication : 2012 Article en page(s) : pp. 4467–4471 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Acrylic acid Polymerization Vapor phase Résumé : Nitroso compounds, such as 2-methyl-2-nitrosopropane, nitrosobenzene, and 4-nitrosophenol, were tested as volatile inhibitors for vapor-phase inhibition of acrylic acid polymerization during its reflux at 113 °C under reduced pressure. The experimental parameters were set to mimic the conditions employed for the industrial distillation of acrylic acid. Nitrosobenzene was found to be the most efficient vapor-phase inhibitor for the distillation of acrylic acid. The inhibition time was also found to be dependent on the pressure used for the experiments. Decreasing the pressure from 110 to 85 mbar resulted in an almost 2-fold increase in the inhibition time. The combination of nitrosobenzene with a liquid-phase inhibitor, namely, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, significantly improved the efficiency of vapor-phase inhibition by decreasing the consumption of nitrosobenzene in the liquid phase. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201709y
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4467–4471[article] Efficient polymerization inhibition systems for acrylic acid distillation : Vapor - phase inhibitors [texte imprimé] / Renaud Nicolay, Auteur ; Jaroslav Mosnacek, Auteur ; Kishore K. Kar, Auteur . - 2012 . - pp. 4467–4471.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4467–4471
Mots-clés : Acrylic acid Polymerization Vapor phase Résumé : Nitroso compounds, such as 2-methyl-2-nitrosopropane, nitrosobenzene, and 4-nitrosophenol, were tested as volatile inhibitors for vapor-phase inhibition of acrylic acid polymerization during its reflux at 113 °C under reduced pressure. The experimental parameters were set to mimic the conditions employed for the industrial distillation of acrylic acid. Nitrosobenzene was found to be the most efficient vapor-phase inhibitor for the distillation of acrylic acid. The inhibition time was also found to be dependent on the pressure used for the experiments. Decreasing the pressure from 110 to 85 mbar resulted in an almost 2-fold increase in the inhibition time. The combination of nitrosobenzene with a liquid-phase inhibitor, namely, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, significantly improved the efficiency of vapor-phase inhibition by decreasing the consumption of nitrosobenzene in the liquid phase. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201709y Exemplaires
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Titre : Removal of sulfur compounds from mineral insulating oils by extractive refining with N - methyl - 2 - pyrrolidone Type de document : texte imprimé Auteurs : Jelena M. Lukic, Auteur ; Draginja Nikolic, Auteur ; Valentina Mandic, Auteur Année de publication : 2012 Article en page(s) : pp. 4472–4477 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Mineral insulating oils Résumé : Copper sulfide deposits in the insulation systems of power transformers decrease the dielectric properties of the insulation and therefore constitute a significant risk for the operation of power transformers. Disulfides, oxidized sulfur compounds, thiols, and elemental sulfur, which could be present in insulating oil, have been recognized as the sources of reactive sulfur responsible for copper sulfide formation. Selective liquid–liquid extraction using N-methyl-2-pyrrolidone solvent was investigated for the purification of mineral insulating oils through the removal of compounds and precursors responsible for copper sulfide formation. The efficiency of the extraction process was evaluated using corrosive sulfur test IEC 62535, SEM/EDX measurements of paper before and after the IEC 62535 test, and measurements of the dibenzyl disulfide concentration in the oil using GC-ECD method. The oxidation stability of refined oils was evaluated using the IEC 61125 method. Precursors of copper sulfide deposits were completely removed from different mineral oils as a result of purification by extraction with N-methyl-2-pyrrolidone and 1.0 wt % water as a cosolvent. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300450e
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4472–4477[article] Removal of sulfur compounds from mineral insulating oils by extractive refining with N - methyl - 2 - pyrrolidone [texte imprimé] / Jelena M. Lukic, Auteur ; Draginja Nikolic, Auteur ; Valentina Mandic, Auteur . - 2012 . - pp. 4472–4477.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4472–4477
Mots-clés : Mineral insulating oils Résumé : Copper sulfide deposits in the insulation systems of power transformers decrease the dielectric properties of the insulation and therefore constitute a significant risk for the operation of power transformers. Disulfides, oxidized sulfur compounds, thiols, and elemental sulfur, which could be present in insulating oil, have been recognized as the sources of reactive sulfur responsible for copper sulfide formation. Selective liquid–liquid extraction using N-methyl-2-pyrrolidone solvent was investigated for the purification of mineral insulating oils through the removal of compounds and precursors responsible for copper sulfide formation. The efficiency of the extraction process was evaluated using corrosive sulfur test IEC 62535, SEM/EDX measurements of paper before and after the IEC 62535 test, and measurements of the dibenzyl disulfide concentration in the oil using GC-ECD method. The oxidation stability of refined oils was evaluated using the IEC 61125 method. Precursors of copper sulfide deposits were completely removed from different mineral oils as a result of purification by extraction with N-methyl-2-pyrrolidone and 1.0 wt % water as a cosolvent. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300450e Exemplaires
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Titre : Study on the relationship between absorbed S(IV) and pH in the seawater flue gas desulfurization process Type de document : texte imprimé Auteurs : Tian Lan, Auteur ; Xingwang Zhang, Auteur ; Qingni Yu, Auteur Année de publication : 2012 Article en page(s) : pp. 4478–4484 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Seawater Desulfurization Résumé : Seawater flue gas desulfurization (SFGD) is a promising process for coal-burning power plants located along the coast. The aim of this work was to study the seawater outflow characteristics, especially the relationship between absorbed S(IV) and pH in the SFGD process. The equilibrium concentration of SO2 in seawater was studied under different seawater usages and SO2 concentrations in the flue gas. The experimental results showed that approximately 25% of absorbed S(IV) was oxidized to S(VI) by surplus oxygen in the flue gas during the absorption process. An equilibrium model was established to describe the relationship between absorbed SO2 and pH. The integral desulfurization efficiency of the absorption system was analyzed, and the results showed that desulfurization efficiency can reach up to 90%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202770b
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4478–4484[article] Study on the relationship between absorbed S(IV) and pH in the seawater flue gas desulfurization process [texte imprimé] / Tian Lan, Auteur ; Xingwang Zhang, Auteur ; Qingni Yu, Auteur . - 2012 . - pp. 4478–4484.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4478–4484
Mots-clés : Seawater Desulfurization Résumé : Seawater flue gas desulfurization (SFGD) is a promising process for coal-burning power plants located along the coast. The aim of this work was to study the seawater outflow characteristics, especially the relationship between absorbed S(IV) and pH in the SFGD process. The equilibrium concentration of SO2 in seawater was studied under different seawater usages and SO2 concentrations in the flue gas. The experimental results showed that approximately 25% of absorbed S(IV) was oxidized to S(VI) by surplus oxygen in the flue gas during the absorption process. An equilibrium model was established to describe the relationship between absorbed SO2 and pH. The integral desulfurization efficiency of the absorption system was analyzed, and the results showed that desulfurization efficiency can reach up to 90%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202770b Exemplaires
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Titre : Preparation of 137Cs microspheres for their use in computer automated radioactive particle tracking studies Type de document : texte imprimé Auteurs : Sanjay Kumar Saxena, Auteur ; K. T. Pillai, Auteur ; Ramu Ram, Auteur Année de publication : 2012 Article en page(s) : pp. 4485–4492 Note générale : chimie industrielle Langues : Anglais (eng) Mots-clés : Microspheres Hydrothermal Radioactive Résumé : This paper describes a method for the preparation of 137Cs labeled mordenite-coated spheroidal alumina particles [ 0.7 mm ()] for their utility in the computer automated radioactive particle tracking technique for the calibration of detectors. Mordenite was coated successfully, in situ, on alumina microspheres under hydrothermal conditions and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analyses. A thorough optimization of experimental parameters such as pH of the adsorbing solution, reaction time, carrier concentration, reaction volume, and temperature, etc., were carried out to arrive at the conditions resulting in optimum impregnation of 137Cs activity into the microspheres. Under the optimized conditions, about 2.7–3.1 MBq (73–85 μCi) of 137Cs could be impregnated on individual microspheres in a reproducible manner. The radioactive microspheres were subsequently covered with a thin layer of polystyrene to prevent the dispersion of 137Cs activity during use. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300205p#aff1
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4485–4492[article] Preparation of 137Cs microspheres for their use in computer automated radioactive particle tracking studies [texte imprimé] / Sanjay Kumar Saxena, Auteur ; K. T. Pillai, Auteur ; Ramu Ram, Auteur . - 2012 . - pp. 4485–4492.
chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4485–4492
Mots-clés : Microspheres Hydrothermal Radioactive Résumé : This paper describes a method for the preparation of 137Cs labeled mordenite-coated spheroidal alumina particles [ 0.7 mm ()] for their utility in the computer automated radioactive particle tracking technique for the calibration of detectors. Mordenite was coated successfully, in situ, on alumina microspheres under hydrothermal conditions and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analyses. A thorough optimization of experimental parameters such as pH of the adsorbing solution, reaction time, carrier concentration, reaction volume, and temperature, etc., were carried out to arrive at the conditions resulting in optimum impregnation of 137Cs activity into the microspheres. Under the optimized conditions, about 2.7–3.1 MBq (73–85 μCi) of 137Cs could be impregnated on individual microspheres in a reproducible manner. The radioactive microspheres were subsequently covered with a thin layer of polystyrene to prevent the dispersion of 137Cs activity during use. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300205p#aff1 Exemplaires
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Titre : Compartment modeling and flow characterization in nonisothermal underground coal gasification cavities Type de document : texte imprimé Auteurs : Sateesh Daggupati, Auteur ; Ramesh N. Mandapati, Auteur ; Sanjay M. Mahajani, Auteur Année de publication : 2012 Article en page(s) : pp. 4493–4508 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gas flow Cavities Résumé : Characterization of reactant gas flow patterns in the underground coal gasification (UCG) cavity is important, because the flow is highly nonideal and likely to influence the quality of the product gas. In our earlier work [Daggupati et al., Energy2010, 35, 2374–2386], we have demonstrated a computational fluid dynamics (CFD)-based modeling approach to analyze the flow patterns in the cavity. A compartment model (network of ideal reactors) for the UCG cavity was developed based on the CFD simulation results. These studies were performed assuming that the UCG cavity is isothermal. In reality, large temperature gradients may prevail under certain conditions and, in turn, may influence the flow patterns. In this work, we consider different possible nonisothermal scenarios in the UCG cavity and propose a simplified compartment modeling strategy to reduce the computational burden. We also examine the effect of various operating and design parameters such as coal spalling, feed flow rate, feed temperature, and orientation of the inlet nozzle. All these effects are quantified by determining the corresponding compartment model parameters. The sensitivity of the compartment model parameters, with respect to the changes in various conditions, is studied. Furthermore, we validate the compartment modeling approach by comparing predicted conversions for a water-gas shift reaction with that of reaction-enabled CFD simulations under nonisothermal conditions. The results presented here provide adequate insight into the UCG process and can be conveniently used in the development of a computationally inexpensive phenomenological process model for the complex UCG process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200410u
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4493–4508[article] Compartment modeling and flow characterization in nonisothermal underground coal gasification cavities [texte imprimé] / Sateesh Daggupati, Auteur ; Ramesh N. Mandapati, Auteur ; Sanjay M. Mahajani, Auteur . - 2012 . - pp. 4493–4508.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4493–4508
Mots-clés : Gas flow Cavities Résumé : Characterization of reactant gas flow patterns in the underground coal gasification (UCG) cavity is important, because the flow is highly nonideal and likely to influence the quality of the product gas. In our earlier work [Daggupati et al., Energy2010, 35, 2374–2386], we have demonstrated a computational fluid dynamics (CFD)-based modeling approach to analyze the flow patterns in the cavity. A compartment model (network of ideal reactors) for the UCG cavity was developed based on the CFD simulation results. These studies were performed assuming that the UCG cavity is isothermal. In reality, large temperature gradients may prevail under certain conditions and, in turn, may influence the flow patterns. In this work, we consider different possible nonisothermal scenarios in the UCG cavity and propose a simplified compartment modeling strategy to reduce the computational burden. We also examine the effect of various operating and design parameters such as coal spalling, feed flow rate, feed temperature, and orientation of the inlet nozzle. All these effects are quantified by determining the corresponding compartment model parameters. The sensitivity of the compartment model parameters, with respect to the changes in various conditions, is studied. Furthermore, we validate the compartment modeling approach by comparing predicted conversions for a water-gas shift reaction with that of reaction-enabled CFD simulations under nonisothermal conditions. The results presented here provide adequate insight into the UCG process and can be conveniently used in the development of a computationally inexpensive phenomenological process model for the complex UCG process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200410u Exemplaires
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Titre : A kinetic analysis of wood degradation in supercritical alcohols Type de document : texte imprimé Auteurs : Jeeban Poudel, Auteur ; Sea Cheon Oh, Auteur Année de publication : 2012 Article en page(s) : pp. 4509–4514 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : kinetic analysis Wood degradation Résumé : The kinetic analysis method for degradation of wood in supercritical ethanol and methanol was proposed in this work. This method was applied to predict the degradation of wood in supercritical ethanol and supercritical methanol by a nonisothermal weight loss technique with heating rates of 3.1, 9.8, and 14.5 °C/min for ethanol and 5.2, 11.3, 16.3 °C/min for methanol. To verify the effectiveness of the kinetic analysis proposed in this work, the experimental values were compared with those of the numerical integration results using kinetic parameters obtained in this work. The kinetic analysis method proposed in this work gave reliable values of kinetic parameter for wood degradation in supercritical ethanol and supercritical methanol. To understand the effectiveness of the solvents as supercritical fluid, the calculation results of wood weight loss using the kinetic parameters obtained from this work were studied at a heating rate of 7 °C/min for both supercritical ethanol (SCE) and supercritical methanol (SCM). From this work, it can be seen that SCE is better solvent than SCM for wood degradation in supercritical alcohols. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200496b
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4509–4514[article] A kinetic analysis of wood degradation in supercritical alcohols [texte imprimé] / Jeeban Poudel, Auteur ; Sea Cheon Oh, Auteur . - 2012 . - pp. 4509–4514.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4509–4514
Mots-clés : kinetic analysis Wood degradation Résumé : The kinetic analysis method for degradation of wood in supercritical ethanol and methanol was proposed in this work. This method was applied to predict the degradation of wood in supercritical ethanol and supercritical methanol by a nonisothermal weight loss technique with heating rates of 3.1, 9.8, and 14.5 °C/min for ethanol and 5.2, 11.3, 16.3 °C/min for methanol. To verify the effectiveness of the kinetic analysis proposed in this work, the experimental values were compared with those of the numerical integration results using kinetic parameters obtained in this work. The kinetic analysis method proposed in this work gave reliable values of kinetic parameter for wood degradation in supercritical ethanol and supercritical methanol. To understand the effectiveness of the solvents as supercritical fluid, the calculation results of wood weight loss using the kinetic parameters obtained from this work were studied at a heating rate of 7 °C/min for both supercritical ethanol (SCE) and supercritical methanol (SCM). From this work, it can be seen that SCE is better solvent than SCM for wood degradation in supercritical alcohols. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200496b Exemplaires
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Titre : Synthetic doped amorphous ferrihydrite for the fischer – tropsch synthesis of alternative fuels Type de document : texte imprimé Auteurs : Bali, Sumit, Auteur ; Garima Bali, Auteur ; Frank E. Huggins, Auteur Année de publication : 2012 Article en page(s) : pp. 4515–4522 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ferrihydrites Oxyhydroxide minerals Résumé : Ferrihydrites (FHYDs) with the general formula of FeOOH·nH2O are naturally occurring oxyhydroxide minerals found in environments varying from river beds, lakes, and marshes to even living organisms. Here, we report the synthesis of a new kind of synthetic doped amorphous two-line FHYDs containing aluminum and copper, which are not usually known to be found in nature. Transmission electron microscopy carried out on synthetic FHYDs showed them to be amorphous in nature with some nanosized groupings in the form of nanoclusters of about 50–200 nm size without any hint of diffraction fringes associated with crystalline order. The synthetic doped FHYDs exhibit unique properties and have been characterized extensively by magnetic measurements, X-ray diffraction, and electron microscopy as well as by Mössbauer spectroscopic studies. After promotion with potassium, these FHYDs were found to have high activity as catalysts for the Fischer–Tropsch (F–T) conversion of syngas to liquid fuels over a period of 100 h in a fixed bed reactor at 265 °C and 100 psig pressures. The comparison of the preliminary 100 h data for the synthetic doped FHYD catalyst with those of a commercial fixed-bed catalyst pretreated under similar conditions suggests somewhat better catalytic activity of the synthetic doped FHYD than that of the commercial fixed-bed catalyst. The F–T oil and wax obtained as products were characterized extensively using gas chromatography, quantitative 13C NMR, and distortionless enhancement by polarization transfer NMR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200777v
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4515–4522[article] Synthetic doped amorphous ferrihydrite for the fischer – tropsch synthesis of alternative fuels [texte imprimé] / Bali, Sumit, Auteur ; Garima Bali, Auteur ; Frank E. Huggins, Auteur . - 2012 . - pp. 4515–4522.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4515–4522
Mots-clés : Ferrihydrites Oxyhydroxide minerals Résumé : Ferrihydrites (FHYDs) with the general formula of FeOOH·nH2O are naturally occurring oxyhydroxide minerals found in environments varying from river beds, lakes, and marshes to even living organisms. Here, we report the synthesis of a new kind of synthetic doped amorphous two-line FHYDs containing aluminum and copper, which are not usually known to be found in nature. Transmission electron microscopy carried out on synthetic FHYDs showed them to be amorphous in nature with some nanosized groupings in the form of nanoclusters of about 50–200 nm size without any hint of diffraction fringes associated with crystalline order. The synthetic doped FHYDs exhibit unique properties and have been characterized extensively by magnetic measurements, X-ray diffraction, and electron microscopy as well as by Mössbauer spectroscopic studies. After promotion with potassium, these FHYDs were found to have high activity as catalysts for the Fischer–Tropsch (F–T) conversion of syngas to liquid fuels over a period of 100 h in a fixed bed reactor at 265 °C and 100 psig pressures. The comparison of the preliminary 100 h data for the synthetic doped FHYD catalyst with those of a commercial fixed-bed catalyst pretreated under similar conditions suggests somewhat better catalytic activity of the synthetic doped FHYD than that of the commercial fixed-bed catalyst. The F–T oil and wax obtained as products were characterized extensively using gas chromatography, quantitative 13C NMR, and distortionless enhancement by polarization transfer NMR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200777v Exemplaires
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Titre : Visible - solar - light - driven photocatalytic degradation of phenol with dye - sensitized TiO2 : Parametric and kinetic study Type de document : texte imprimé Auteurs : Pankaj Chowdhury, Auteur ; Jesus Moreira, Auteur ; Hassan Gomaa, Auteur Année de publication : 2012 Article en page(s) : pp. 4523–4532 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photocatalytic Phenol Kinetic Résumé : Phenol degradation with TiO2 photocatalyst under UV light is known to be an effective method. Under solar radiation, however, this approach does not receive adequate photons for catalyst activation, as the solar spectrum comprises mostly visible light (46%). In this study, we applied the dye-sensitization technique to prepare visible-light-active catalyst and used it under visible solar light generated from a solar simulator with a UV cutoff filter (λ > 420 nm) for phenol degradation. Eosin Y dye was used as a sensitizer for the TiO2 catalyst with a very low level of platinum as a cocatalyst. Triethanolamine was used as a sacrificial electron donor. Parametric studies were performed for the catalyst loading, initial triethnolamine concentration, initial phenol concentration, platinum content on TiO2, solution pH, and visible light intensity. About 93% degradation of 40 ppm phenol solution was achieved within 90 min using Eosin Y–TiO2/Pt photocatalyst under optimum conditions (pH 7.0, catalyst loading of 0.8 g/L, triethnolamine concentration of 0.2 M, 0.5% Pt loading on TiO2, visible solar light intensity of 100 mW/cm2). The kinetic rate constant and adsorption equilibrium constant were determined, and a Langmuir–Hinshelwood-type equation was proposed to describe phenol degradation on TiO2 at different visible light intensities. The model equation was found to predict the experimental results quite well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2025213
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4523–4532[article] Visible - solar - light - driven photocatalytic degradation of phenol with dye - sensitized TiO2 : Parametric and kinetic study [texte imprimé] / Pankaj Chowdhury, Auteur ; Jesus Moreira, Auteur ; Hassan Gomaa, Auteur . - 2012 . - pp. 4523–4532.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4523–4532
Mots-clés : Photocatalytic Phenol Kinetic Résumé : Phenol degradation with TiO2 photocatalyst under UV light is known to be an effective method. Under solar radiation, however, this approach does not receive adequate photons for catalyst activation, as the solar spectrum comprises mostly visible light (46%). In this study, we applied the dye-sensitization technique to prepare visible-light-active catalyst and used it under visible solar light generated from a solar simulator with a UV cutoff filter (λ > 420 nm) for phenol degradation. Eosin Y dye was used as a sensitizer for the TiO2 catalyst with a very low level of platinum as a cocatalyst. Triethanolamine was used as a sacrificial electron donor. Parametric studies were performed for the catalyst loading, initial triethnolamine concentration, initial phenol concentration, platinum content on TiO2, solution pH, and visible light intensity. About 93% degradation of 40 ppm phenol solution was achieved within 90 min using Eosin Y–TiO2/Pt photocatalyst under optimum conditions (pH 7.0, catalyst loading of 0.8 g/L, triethnolamine concentration of 0.2 M, 0.5% Pt loading on TiO2, visible solar light intensity of 100 mW/cm2). The kinetic rate constant and adsorption equilibrium constant were determined, and a Langmuir–Hinshelwood-type equation was proposed to describe phenol degradation on TiO2 at different visible light intensities. The model equation was found to predict the experimental results quite well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2025213 Exemplaires
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Titre : Kinetic studies on black light photocatalytic ozonation of diclofenac and sulfamethoxazole in water Type de document : texte imprimé Auteurs : Fernando J. Beltran, Auteur ; Almudena Aguinaco, Auteur ; Ana Rey, Auteur Année de publication : 2012 Article en page(s) : pp. 4533–4544 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetic Photocatalytic ozonation Résumé : Black light photocatalytic ozonation of two pharmaceutical compounds, sulfamethoxazole (SMX) and diclofenac (DCF), and the resulting total organic carbon (TOC) are studied. DCF and SMX removals from some mg·L–1 to 100 μg·L–1 are achieved in approximately 7 and 15 min ozonation, respectively, regardless of the ozone process, while the resulting TOC is eliminated via hydroxyl radical reactions. For initial concentrations lower than 50 μg·L–1, competition between direct ozonation and hydroxyl radical oxidation to eliminate SMX and DCF takes place. The initial reaction period for cases of high and low concentration is simulated through fast-moderate and slow gas–liquid second order reaction kinetics, respectively. For high starting concentrations the calculated results suggest the presence of ozone fast reacting intermediates. For low starting concentration, calculated results indicate the importance of hydroxyl radical oxidation and the synergic effect of ozone and photocatalytic oxidation. Kinetic data of TOC ozonation, photocatalytic oxidation, and photocatalytic ozonation are also presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202525f
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4533–4544[article] Kinetic studies on black light photocatalytic ozonation of diclofenac and sulfamethoxazole in water [texte imprimé] / Fernando J. Beltran, Auteur ; Almudena Aguinaco, Auteur ; Ana Rey, Auteur . - 2012 . - pp. 4533–4544.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4533–4544
Mots-clés : Kinetic Photocatalytic ozonation Résumé : Black light photocatalytic ozonation of two pharmaceutical compounds, sulfamethoxazole (SMX) and diclofenac (DCF), and the resulting total organic carbon (TOC) are studied. DCF and SMX removals from some mg·L–1 to 100 μg·L–1 are achieved in approximately 7 and 15 min ozonation, respectively, regardless of the ozone process, while the resulting TOC is eliminated via hydroxyl radical reactions. For initial concentrations lower than 50 μg·L–1, competition between direct ozonation and hydroxyl radical oxidation to eliminate SMX and DCF takes place. The initial reaction period for cases of high and low concentration is simulated through fast-moderate and slow gas–liquid second order reaction kinetics, respectively. For high starting concentrations the calculated results suggest the presence of ozone fast reacting intermediates. For low starting concentration, calculated results indicate the importance of hydroxyl radical oxidation and the synergic effect of ozone and photocatalytic oxidation. Kinetic data of TOC ozonation, photocatalytic oxidation, and photocatalytic ozonation are also presented. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202525f Exemplaires
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Titre : Preparation and characterization of alumina - based microreactors for application in methyl chloride synthesis Type de document : texte imprimé Auteurs : Sabrina A. Schmidt, Auteur ; Narendra Kumar, Auteur ; Biao Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 4545–4555 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microreactors Alumina catalyst Résumé : Microreactor platelets were coated with an alumina catalyst for use in methyl chloride synthesis. The coating was extensively characterized regarding its uniformity, thickness, and stability by using SEM, confocal microscopy, and EDX. The influence of the platelet pretreatment on the coating stability was investigated with different stability tests. A straightforward method to obtain a stable and uniform coating was developed, and the coated platelets were used for the synthesis of methyl chloride. The performance of the microreactor was compared with a tubular fixed bed reactor. The results obtained with both reactors were comparable, but the microreactor allows a rapid catalytic screening with a low consumption of chemicals. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202922x
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4545–4555[article] Preparation and characterization of alumina - based microreactors for application in methyl chloride synthesis [texte imprimé] / Sabrina A. Schmidt, Auteur ; Narendra Kumar, Auteur ; Biao Zhang, Auteur . - 2012 . - pp. 4545–4555.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4545–4555
Mots-clés : Microreactors Alumina catalyst Résumé : Microreactor platelets were coated with an alumina catalyst for use in methyl chloride synthesis. The coating was extensively characterized regarding its uniformity, thickness, and stability by using SEM, confocal microscopy, and EDX. The influence of the platelet pretreatment on the coating stability was investigated with different stability tests. A straightforward method to obtain a stable and uniform coating was developed, and the coated platelets were used for the synthesis of methyl chloride. The performance of the microreactor was compared with a tubular fixed bed reactor. The results obtained with both reactors were comparable, but the microreactor allows a rapid catalytic screening with a low consumption of chemicals. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202922x Exemplaires
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Titre : Estimating octanol – water partition coefficients for selected nanoscale building blocks using the COSMO - SAC segment contribution method Type de document : texte imprimé Auteurs : Patrick S. Redmill, Auteur Année de publication : 2012 Article en page(s) : pp. 4556–4566 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanoscale Estimation Octanolwater Résumé : The use of the conductor-like screening with segment activity coefficient (COSMO-SAC) model to predict octanol–water partition coefficients (log KO/W) for selected nanoscale building blocks (NBBs) has been evaluated. COSMO calculations have been performed using charge density information obtained from density functional theory calculations of the compounds that, in turn, provide input data that allow the calculation of the activity coefficient in the COSMO-SAC model. The NBBs of interest in this study are C60, the hydrogen functionalized polyhedral oligomeric silsesquioxane Si8O12H8 (H-POSS), and their functionalized variants C60(OH)32, Si8O12F8 (F-POSS), and Si8O12(OH)8 (OH-POSS). It is found that COSMO-SAC, while being unable to accurately predict the solubility of very hydrophobic compounds in water, can quickly and efficiently provide qualitative estimates of log KO/W for the selected solutes. The COSMO-SAC estimation of log KO/W for C60 is 6.79, which is consistent with the experimentally reported value and reflects the general consensus that C60 is strongly hydrophobic. No partitioning data are available for H-POSS or the functionalized NBBs studied. In this work, COSMO-SAC calculations on these particles indicate shifts toward water partitioning for C60(OH)32, F-POSS, and OH-POSS relative to their respective base particles (C60 and H-POSS). These shifts in water solubility are consistent with the calculation of the Gibbs free energy of hydration for each particle using molecular dynamics simulations and thermodynamic integration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202107t
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4556–4566[article] Estimating octanol – water partition coefficients for selected nanoscale building blocks using the COSMO - SAC segment contribution method [texte imprimé] / Patrick S. Redmill, Auteur . - 2012 . - pp. 4556–4566.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4556–4566
Mots-clés : Nanoscale Estimation Octanolwater Résumé : The use of the conductor-like screening with segment activity coefficient (COSMO-SAC) model to predict octanol–water partition coefficients (log KO/W) for selected nanoscale building blocks (NBBs) has been evaluated. COSMO calculations have been performed using charge density information obtained from density functional theory calculations of the compounds that, in turn, provide input data that allow the calculation of the activity coefficient in the COSMO-SAC model. The NBBs of interest in this study are C60, the hydrogen functionalized polyhedral oligomeric silsesquioxane Si8O12H8 (H-POSS), and their functionalized variants C60(OH)32, Si8O12F8 (F-POSS), and Si8O12(OH)8 (OH-POSS). It is found that COSMO-SAC, while being unable to accurately predict the solubility of very hydrophobic compounds in water, can quickly and efficiently provide qualitative estimates of log KO/W for the selected solutes. The COSMO-SAC estimation of log KO/W for C60 is 6.79, which is consistent with the experimentally reported value and reflects the general consensus that C60 is strongly hydrophobic. No partitioning data are available for H-POSS or the functionalized NBBs studied. In this work, COSMO-SAC calculations on these particles indicate shifts toward water partitioning for C60(OH)32, F-POSS, and OH-POSS relative to their respective base particles (C60 and H-POSS). These shifts in water solubility are consistent with the calculation of the Gibbs free energy of hydration for each particle using molecular dynamics simulations and thermodynamic integration. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202107t Exemplaires
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Titre : Highly active CaO - based sorbents for CO2 Capture using the precipitation method : Preparation and characterization of the sorbent powder Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 4567–4572 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Sorbents Calcium oxide Résumé : Calcium oxide is a known adsorbent for the capture of carbon dioxide. In this study, CaO-based sorbents were prepared using the precipitation of solutions containing different anion precursors, including nitrate NO3– and chloride Cl–, by different alkaline precipitants. The sorbents prepared from the precipitation of salt solutions by alkaline solutions under specific precipitation conditions resulted in the excellent uptake capacity for CO2. These sorbents formed as a fine powder with a BET surface area (16.5 m2/g) and pore volume (0.35 cm3/g) showed almost 100% carbonation, at temperatures between 650 and 750 °C. Moreover, the carbonation proceeded predominantly during an initial short period. Under numerous carbonation/calcination cycles, these sorbents demonstrated a good reversibility. During a 17-cycle operation, the sorbents maintained a fairly high conversion of 70% at 700 °C. As the carbonation/calcination cycles progress, sorbent particles conglomerate to a loosely integrated lump resulting in a greater mass transfer resistance for CO2 molecules to reach the unreacted core of calcium oxide. It is observed that grinding of the formed chunk to fine particles could recover the activity of sorbent completely. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024257
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4567–4572[article] Highly active CaO - based sorbents for CO2 Capture using the precipitation method : Preparation and characterization of the sorbent powder [texte imprimé] . - 2012 . - pp. 4567–4572.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4567–4572
Mots-clés : Sorbents Calcium oxide Résumé : Calcium oxide is a known adsorbent for the capture of carbon dioxide. In this study, CaO-based sorbents were prepared using the precipitation of solutions containing different anion precursors, including nitrate NO3– and chloride Cl–, by different alkaline precipitants. The sorbents prepared from the precipitation of salt solutions by alkaline solutions under specific precipitation conditions resulted in the excellent uptake capacity for CO2. These sorbents formed as a fine powder with a BET surface area (16.5 m2/g) and pore volume (0.35 cm3/g) showed almost 100% carbonation, at temperatures between 650 and 750 °C. Moreover, the carbonation proceeded predominantly during an initial short period. Under numerous carbonation/calcination cycles, these sorbents demonstrated a good reversibility. During a 17-cycle operation, the sorbents maintained a fairly high conversion of 70% at 700 °C. As the carbonation/calcination cycles progress, sorbent particles conglomerate to a loosely integrated lump resulting in a greater mass transfer resistance for CO2 molecules to reach the unreacted core of calcium oxide. It is observed that grinding of the formed chunk to fine particles could recover the activity of sorbent completely. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024257 Exemplaires
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Titre : One - step reduction and functionalization of graphene oxide with phosphorus - based compound to produce flame - retardant epoxy nanocomposite Type de document : texte imprimé Auteurs : Shu-Hang Liao, Auteur ; Po-Lan Liu, Auteur ; Min-Chien Hsiao, Auteur Année de publication : 2012 Article en page(s) : pp. 4573–4581 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanocomposite Graphene oxide Résumé : 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) has been grafted onto the surface of graphene oxide (GO) by reacting epoxy ring groups together with the reduced graphene structure (DOPO-rGO). X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and UV–vis spectroscopy confirm that DOPO not only covalently bonded to the GO, as a functionalization moiety, but also partly restored the conjugate structure of GO, as a reducing agent. A pelletlike structure of DOPO on rGO sheets was observed by means of transmission electron microscopy (TEM), contributing to good dispersion of rGO in nonpolar toluene. Furthermore, the flame retardancy and thermal stability of DOPO-rGO/epoxy nanocomposites containing various weight fractions of DOPO-rGO were investigated by the limiting oxygen index (LOI) test and thermogravimetric analysis (TGA) in nitrogen. Significant increases in the char yield and LOI were achieved with the addition of 10 wt % DOPO-rGO in epoxy, giving improvements of 81% and 30%, respectively. DOPO-rGO/epoxy nanocomposites with phosphorus and graphene layer structures were found to contribute to excellent flame retardancy compared to that of neat epoxy. Therefore, the synergestic effect of DOPO-rGO is quite useful, and this material can be utilized as a potential flame retardant. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2026647
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4573–4581[article] One - step reduction and functionalization of graphene oxide with phosphorus - based compound to produce flame - retardant epoxy nanocomposite [texte imprimé] / Shu-Hang Liao, Auteur ; Po-Lan Liu, Auteur ; Min-Chien Hsiao, Auteur . - 2012 . - pp. 4573–4581.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4573–4581
Mots-clés : Nanocomposite Graphene oxide Résumé : 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) has been grafted onto the surface of graphene oxide (GO) by reacting epoxy ring groups together with the reduced graphene structure (DOPO-rGO). X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and UV–vis spectroscopy confirm that DOPO not only covalently bonded to the GO, as a functionalization moiety, but also partly restored the conjugate structure of GO, as a reducing agent. A pelletlike structure of DOPO on rGO sheets was observed by means of transmission electron microscopy (TEM), contributing to good dispersion of rGO in nonpolar toluene. Furthermore, the flame retardancy and thermal stability of DOPO-rGO/epoxy nanocomposites containing various weight fractions of DOPO-rGO were investigated by the limiting oxygen index (LOI) test and thermogravimetric analysis (TGA) in nitrogen. Significant increases in the char yield and LOI were achieved with the addition of 10 wt % DOPO-rGO in epoxy, giving improvements of 81% and 30%, respectively. DOPO-rGO/epoxy nanocomposites with phosphorus and graphene layer structures were found to contribute to excellent flame retardancy compared to that of neat epoxy. Therefore, the synergestic effect of DOPO-rGO is quite useful, and this material can be utilized as a potential flame retardant. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2026647 Exemplaires
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Titre : Improving the stability of immobilized penicillin G acylase via the modification of supports with ionic liquids Type de document : texte imprimé Auteurs : Huacong Zhou, Auteur ; Liangrong Yang, Auteur ; Wei Li, Auteur Année de publication : 2012 Article en page(s) : pp. 4582–4590 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ionic liquids Nanoparticles Résumé : With the aim of improving the stability of penicillin G acylase (PGA), functional ionic liquids (ILs) were used to modify the surface chemistry of the supports on which they were physically adsorbed. Four kinds of ILs—specifically, 1-methyl-3-(triethoxysilylpropyl)-imidazolium salts, with Cl–, BF4–, PF6–, and Tf2N– as the anions (IL-Cl–, BF4–, PF6–, and Tf2N–, respectively)—were used to tune the hydrophilic or hydrophobic properties of the ILs. The synthesized ILs were first immobilized on magnetic silica nanoparticles (Fe3O4/SiO2), and the composite material (Fe3O4/SiO2–IL) was then applied to immobilize PGA via physical adsorption. The amount of protein loading, the specific activity, the immobilization yield, and the stability of immobilized PGA were investigated to evaluate the effects of the ILs on the PGA immobilization. The results showed that PGA immobilized on Fe3O4/SiO2–ILs was more stable than that immobilized on Fe3O4/SiO2 with no IL modification. Among the four kinds of ILs tested, the hydrophilic ILs (IL-Cl–, and IL-BF4–) were superior to the hydrophobic ones (IL-PF6–, and IL-Tf2N–) for PGA immobilization. The reusability of the immobilized PGA on Fe3O4/SiO2–IL (BF4–) was evaluated; a high residual activity (70% of the initial activity) was observed after 9 consecutive operation cycles under the experimental conditions. This activity was 1.8 times higher than that of immobilized PGA on naked Fe3O4/SiO2 (40%). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202745c
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4582–4590[article] Improving the stability of immobilized penicillin G acylase via the modification of supports with ionic liquids [texte imprimé] / Huacong Zhou, Auteur ; Liangrong Yang, Auteur ; Wei Li, Auteur . - 2012 . - pp. 4582–4590.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4582–4590
Mots-clés : Ionic liquids Nanoparticles Résumé : With the aim of improving the stability of penicillin G acylase (PGA), functional ionic liquids (ILs) were used to modify the surface chemistry of the supports on which they were physically adsorbed. Four kinds of ILs—specifically, 1-methyl-3-(triethoxysilylpropyl)-imidazolium salts, with Cl–, BF4–, PF6–, and Tf2N– as the anions (IL-Cl–, BF4–, PF6–, and Tf2N–, respectively)—were used to tune the hydrophilic or hydrophobic properties of the ILs. The synthesized ILs were first immobilized on magnetic silica nanoparticles (Fe3O4/SiO2), and the composite material (Fe3O4/SiO2–IL) was then applied to immobilize PGA via physical adsorption. The amount of protein loading, the specific activity, the immobilization yield, and the stability of immobilized PGA were investigated to evaluate the effects of the ILs on the PGA immobilization. The results showed that PGA immobilized on Fe3O4/SiO2–ILs was more stable than that immobilized on Fe3O4/SiO2 with no IL modification. Among the four kinds of ILs tested, the hydrophilic ILs (IL-Cl–, and IL-BF4–) were superior to the hydrophobic ones (IL-PF6–, and IL-Tf2N–) for PGA immobilization. The reusability of the immobilized PGA on Fe3O4/SiO2–IL (BF4–) was evaluated; a high residual activity (70% of the initial activity) was observed after 9 consecutive operation cycles under the experimental conditions. This activity was 1.8 times higher than that of immobilized PGA on naked Fe3O4/SiO2 (40%). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202745c Exemplaires
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Titre : planning and sequencing product distribution in a real - world pipeline network : An MILP decomposition approach Type de document : texte imprimé Auteurs : Suelen Neves Boschetto Magatao, Auteur ; Leandro Magatao, Auteur ; Helton Luis Polli, Auteur Année de publication : 2012 Article en page(s) : pp. 4591–4609 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oil industry planning scheduling Résumé : In the oil industry, any improvement in the planning and execution of the associated operations (e.g., production, storage, distribution) can generate considerable profits. To achieve this, the related activities need to be optimized. Within these activities, planning and scheduling occur at the different levels of the oil supply chain, from the strategic to the operational levels looking from global networks to sets of individual resources. This work looks into the planning, namely the assignment/sequencing of activities that occur in a multiproduct, multipipeline system. The aim is to contribute to the definition of generic models that can help the decision-making process characterized by a high level of complexity. An approach formed by two mixed integer linear programming (MILP) formulations that act in sequence is proposed. The first generic MILP planning model calculates volumes for attending the necessary requirements on inventory management of the producer and consumer areas. As a result, this model defines the products and the total volumes to be transported in order to attain storage goals, while respecting operational constraints, demands of consumers, and pipeline capacity. Then, the planning model results are used by an MILP assignment and sequencing model, which splits the total volume into operational batches and determines the sequence of pumping for the batches during the available horizon. The developed approach is applied to a real-world pipeline network that includes 30 bidirectional multiproduct pipelines associated with 14 node areas: four refineries, two harbors, six depots/parks of pumps and valves, and two final clients. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2010252
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4591–4609[article] planning and sequencing product distribution in a real - world pipeline network : An MILP decomposition approach [texte imprimé] / Suelen Neves Boschetto Magatao, Auteur ; Leandro Magatao, Auteur ; Helton Luis Polli, Auteur . - 2012 . - pp. 4591–4609.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4591–4609
Mots-clés : Oil industry planning scheduling Résumé : In the oil industry, any improvement in the planning and execution of the associated operations (e.g., production, storage, distribution) can generate considerable profits. To achieve this, the related activities need to be optimized. Within these activities, planning and scheduling occur at the different levels of the oil supply chain, from the strategic to the operational levels looking from global networks to sets of individual resources. This work looks into the planning, namely the assignment/sequencing of activities that occur in a multiproduct, multipipeline system. The aim is to contribute to the definition of generic models that can help the decision-making process characterized by a high level of complexity. An approach formed by two mixed integer linear programming (MILP) formulations that act in sequence is proposed. The first generic MILP planning model calculates volumes for attending the necessary requirements on inventory management of the producer and consumer areas. As a result, this model defines the products and the total volumes to be transported in order to attain storage goals, while respecting operational constraints, demands of consumers, and pipeline capacity. Then, the planning model results are used by an MILP assignment and sequencing model, which splits the total volume into operational batches and determines the sequence of pumping for the batches during the available horizon. The developed approach is applied to a real-world pipeline network that includes 30 bidirectional multiproduct pipelines associated with 14 node areas: four refineries, two harbors, six depots/parks of pumps and valves, and two final clients. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2010252 Exemplaires
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Titre : Control of a Plate Heat Exchanger Using the Terminal Sliding Mode Technique Type de document : texte imprimé Auteurs : Naif B. Almutairi, Auteur ; Mohamed Zribi, Auteur Année de publication : 2012 Article en page(s) : pp. 4610–4623 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Heat exchanger Résumé : Heat exchangers are devices used to transfer heat from one fluid to another. In this paper we investigate the application of three different terminal sliding mode (TSM) controllers to a plate heat exchanger. The main objective of the designed controllers is to adjust the outlet cold water temperature to a desired set point temperature. First, a fast TSM controller is designed. To reduce chattering in the control signal, a second-order fast TSM controller is designed. In addition, a dynamic fast TSM controller is designed to further reduce the chattering. The performances of the closed loop system are simulated using MATLAB. The simulation results clearly show that the proposed three control schemes work very well. Moreover, the proposed control schemes are implemented using an experimental setup. The implementation results indicate that the proposed controllers work very well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201545z
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4610–4623[article] Control of a Plate Heat Exchanger Using the Terminal Sliding Mode Technique [texte imprimé] / Naif B. Almutairi, Auteur ; Mohamed Zribi, Auteur . - 2012 . - pp. 4610–4623.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4610–4623
Mots-clés : Heat exchanger Résumé : Heat exchangers are devices used to transfer heat from one fluid to another. In this paper we investigate the application of three different terminal sliding mode (TSM) controllers to a plate heat exchanger. The main objective of the designed controllers is to adjust the outlet cold water temperature to a desired set point temperature. First, a fast TSM controller is designed. To reduce chattering in the control signal, a second-order fast TSM controller is designed. In addition, a dynamic fast TSM controller is designed to further reduce the chattering. The performances of the closed loop system are simulated using MATLAB. The simulation results clearly show that the proposed three control schemes work very well. Moreover, the proposed control schemes are implemented using an experimental setup. The implementation results indicate that the proposed controllers work very well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201545z Exemplaires
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Titre : Dual composition control in continuous, middle - vessel distillation columns, with a draw stream in the middle vessel Type de document : texte imprimé Auteurs : Rosendo Monroy-Loperena, Auteur ; José Alvarez-Ramírez, Auteur Année de publication : 2012 Article en page(s) : pp. 4624–4631 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Distillation Continuous middle Résumé : The dual composition control problem for a class of continuous middle-vessel distillation, which accepts a draw stream in the middle vessel, is studied in this work. This distillation configuration is advantageous when the separation goal is to recover high-purity light and heavy components from a multicomponent mixture with sufficiently large separation between relative volatilities. By using an estimator of the input–output modeling error, a first-order output-feedback compensator is designed which is shown to be equivalent to a multi-input multi-output proportional–integral (MIMO PI) controller. Tuning issues in terms of two time constants are given, and the ability of the controller to regulate the distillate and bottom product compositions in the face of sampled/delayed measurements is shown via numerical simulations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203018k
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4624–4631[article] Dual composition control in continuous, middle - vessel distillation columns, with a draw stream in the middle vessel [texte imprimé] / Rosendo Monroy-Loperena, Auteur ; José Alvarez-Ramírez, Auteur . - 2012 . - pp. 4624–4631.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4624–4631
Mots-clés : Distillation Continuous middle Résumé : The dual composition control problem for a class of continuous middle-vessel distillation, which accepts a draw stream in the middle vessel, is studied in this work. This distillation configuration is advantageous when the separation goal is to recover high-purity light and heavy components from a multicomponent mixture with sufficiently large separation between relative volatilities. By using an estimator of the input–output modeling error, a first-order output-feedback compensator is designed which is shown to be equivalent to a multi-input multi-output proportional–integral (MIMO PI) controller. Tuning issues in terms of two time constants are given, and the ability of the controller to regulate the distillate and bottom product compositions in the face of sampled/delayed measurements is shown via numerical simulations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203018k Exemplaires
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Titre : Optimal design of the accelerator disk in a two - stage piston pusher centrifuge using numerical simulation Type de document : texte imprimé Auteurs : Wei Tan, Auteur ; Lin Qiao, Auteur ; Endian Sha, Auteur Année de publication : 2012 Article en page(s) : pp. 4632–4642 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimal design Centrifuge Numerical simulation Résumé : This Article presented a numerical investigation for the optimal design of the accelerator disk of a two-stage piston pusher centrifuge, including the disk structure and the blade geometry. With six blades added, a novel accelerator disk was designed, and the effects of these blades on the centrifuge performance were analyzed. The calculated results showed that such new disk design could improve the mass flow rate and the transient velocity of the particles. Therefore, it indicated that the flow field was mostly dominated by blades. Besides, the new disk was tested by an industrial experiment. However, unfortunately, due to that the edges of blades were fractured during the industrial experiment, the geometric outline of the blades was further investigated. The force analysis results showed that the height and length of the blades had a major effect on the blades stresses. Thus, three ways including reducing height, shortening length, and cutting 45° angle were adopted to decrease the blades stress. Finally, according to the calculated results, an optimized geometric outline of the blades was obtained, and a disk with new design of blades was experimentally tested, which validated the design and optimization process by its good performance. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201331x
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4632–4642[article] Optimal design of the accelerator disk in a two - stage piston pusher centrifuge using numerical simulation [texte imprimé] / Wei Tan, Auteur ; Lin Qiao, Auteur ; Endian Sha, Auteur . - 2012 . - pp. 4632–4642.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4632–4642
Mots-clés : Optimal design Centrifuge Numerical simulation Résumé : This Article presented a numerical investigation for the optimal design of the accelerator disk of a two-stage piston pusher centrifuge, including the disk structure and the blade geometry. With six blades added, a novel accelerator disk was designed, and the effects of these blades on the centrifuge performance were analyzed. The calculated results showed that such new disk design could improve the mass flow rate and the transient velocity of the particles. Therefore, it indicated that the flow field was mostly dominated by blades. Besides, the new disk was tested by an industrial experiment. However, unfortunately, due to that the edges of blades were fractured during the industrial experiment, the geometric outline of the blades was further investigated. The force analysis results showed that the height and length of the blades had a major effect on the blades stresses. Thus, three ways including reducing height, shortening length, and cutting 45° angle were adopted to decrease the blades stress. Finally, according to the calculated results, an optimized geometric outline of the blades was obtained, and a disk with new design of blades was experimentally tested, which validated the design and optimization process by its good performance. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201331x Exemplaires
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Titre : Thermodynamic insights on the feasibility of homogeneous batch extractive distillation. 3. azeotropic hixtures with light entrainer. Type de document : texte imprimé Auteurs : Ivonne Rodriguez-Donis, Auteur Année de publication : 2012 Article en page(s) : pp. 4643–4660 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamic Feasibility Distillation Résumé : This article shows how knowledge of the location of univolatility lines and residue curve analysis helps in assessing the feasibility of extractive distillation of minimum-boiling (minT) or maximum-boiling (maxT) azeotropic mixtures or low-relative-volatility (low-α) mixtures (A–B) by using a light-boiling entrainer (E), in accordance with the general feasibility criterion of Rodriguez-Donis et al. [ Ind. Eng. Chem. Res. 2009, 48 (7), 3544−3559]. Considering all possible locations of the univolatility line αAB, three minT azeotropic mixtures with a light entrainer (1.0–2 class), namely, ethanol–water with methanol, ethanol–toluene with acetone, and methyl ethyl ketone–benzene with acetone; three maxT azeotropic mixtures with a light entrainer (1.0–1a class), namely, water–ethylenediamine with methanol, acetone–chloroform with dichlomethane, and propanoic acid–dimethyl formamide with methyl isobutyl ketone; and one low-α mixture with a light entrainer (0.0–1 class), namely, ethyl acetate–benzene with acetone, were studied in a stripping extractive column. For the 1.0–2 class, both A and B can be recovered as the bottom product, depending on the location of αAB = 1, which sets limiting values for the entrainer feed flow rate FE/LT for one of the product. In addition, the feasible region of the extractive distillation process is larger than for the azeotropic distillation process. For the 1.0–1a class, the product is either A or B, depending on the location of αAB = 1, which sets a minimum value of (FE/LT)min for one of the product. For the 0.0–1 class, feasibility depends on the existence αAB = 1. When it does not exist, B is the unique possible product. When it does, both A and B are products, with B below a maximum value of (FE/LT)max,B and A above a minimum value (FE/LT)min,A. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201942b
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4643–4660[article] Thermodynamic insights on the feasibility of homogeneous batch extractive distillation. 3. azeotropic hixtures with light entrainer. [texte imprimé] / Ivonne Rodriguez-Donis, Auteur . - 2012 . - pp. 4643–4660.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4643–4660
Mots-clés : Thermodynamic Feasibility Distillation Résumé : This article shows how knowledge of the location of univolatility lines and residue curve analysis helps in assessing the feasibility of extractive distillation of minimum-boiling (minT) or maximum-boiling (maxT) azeotropic mixtures or low-relative-volatility (low-α) mixtures (A–B) by using a light-boiling entrainer (E), in accordance with the general feasibility criterion of Rodriguez-Donis et al. [ Ind. Eng. Chem. Res. 2009, 48 (7), 3544−3559]. Considering all possible locations of the univolatility line αAB, three minT azeotropic mixtures with a light entrainer (1.0–2 class), namely, ethanol–water with methanol, ethanol–toluene with acetone, and methyl ethyl ketone–benzene with acetone; three maxT azeotropic mixtures with a light entrainer (1.0–1a class), namely, water–ethylenediamine with methanol, acetone–chloroform with dichlomethane, and propanoic acid–dimethyl formamide with methyl isobutyl ketone; and one low-α mixture with a light entrainer (0.0–1 class), namely, ethyl acetate–benzene with acetone, were studied in a stripping extractive column. For the 1.0–2 class, both A and B can be recovered as the bottom product, depending on the location of αAB = 1, which sets limiting values for the entrainer feed flow rate FE/LT for one of the product. In addition, the feasible region of the extractive distillation process is larger than for the azeotropic distillation process. For the 1.0–1a class, the product is either A or B, depending on the location of αAB = 1, which sets a minimum value of (FE/LT)min for one of the product. For the 0.0–1 class, feasibility depends on the existence αAB = 1. When it does not exist, B is the unique possible product. When it does, both A and B are products, with B below a maximum value of (FE/LT)max,B and A above a minimum value (FE/LT)min,A. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201942b Exemplaires
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Titre : Performance improvement of polysulfone ultrafiltration membrane using well - dispersed polyaniline – poly (vinylpyrrolidone) nanocomposite as the additive Type de document : texte imprimé Auteurs : Song Zhao, Auteur ; Zhi Wang, Auteur ; Xin Wei, Auteur Année de publication : 2012 Article en page(s) : pp. 4661–4672 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ultrafiltration membrane Nanocomposite Résumé : Well-dispersed polyaniline–poly(vinylpyrrolidone) (PANI–PVP) nanocomposite was synthesized through dispersion polymerization and then used as a novel additive to prepare a polysulfone (PSf)/PANI–PVP nanocomposite membrane via immersion precipitation process. During membrane formation, a portion of PVP acted as a pore-forming agent while another PANI–PVP nanocomposite, combined by hydrogen bonds between carbonyl groups of PVP and N-hydrogen groups of PANI, acted as a hydrophilic modification agent. The addition of PANI–PVP nanocomposite increased membrane surface pore size, porosity, and hydrophilicity. Pure water fluxes of PSf/PANI–PVP nanocomposite membranes were 1.8–3.5 times that of PSf membrane with a slight change of bovine serum albumin (BSA) rejection. The membrane antifouling property was examined by the cross-flow ultafiltration using BSA solution as the model system. The results of flux decline behavior and flux recovery ratio showed that PSf/PANI–PVP nanocomposite membranes had an excellent antifouling property. Compared with PSf/PVP membranes prepared using PVP as the additive, PSf/PANI–PVP nanocomposite membranes processed higher pure water flux and better hydrophilicity, antifouling property, and stability. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202503p
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4661–4672[article] Performance improvement of polysulfone ultrafiltration membrane using well - dispersed polyaniline – poly (vinylpyrrolidone) nanocomposite as the additive [texte imprimé] / Song Zhao, Auteur ; Zhi Wang, Auteur ; Xin Wei, Auteur . - 2012 . - pp. 4661–4672.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4661–4672
Mots-clés : Ultrafiltration membrane Nanocomposite Résumé : Well-dispersed polyaniline–poly(vinylpyrrolidone) (PANI–PVP) nanocomposite was synthesized through dispersion polymerization and then used as a novel additive to prepare a polysulfone (PSf)/PANI–PVP nanocomposite membrane via immersion precipitation process. During membrane formation, a portion of PVP acted as a pore-forming agent while another PANI–PVP nanocomposite, combined by hydrogen bonds between carbonyl groups of PVP and N-hydrogen groups of PANI, acted as a hydrophilic modification agent. The addition of PANI–PVP nanocomposite increased membrane surface pore size, porosity, and hydrophilicity. Pure water fluxes of PSf/PANI–PVP nanocomposite membranes were 1.8–3.5 times that of PSf membrane with a slight change of bovine serum albumin (BSA) rejection. The membrane antifouling property was examined by the cross-flow ultafiltration using BSA solution as the model system. The results of flux decline behavior and flux recovery ratio showed that PSf/PANI–PVP nanocomposite membranes had an excellent antifouling property. Compared with PSf/PVP membranes prepared using PVP as the additive, PSf/PANI–PVP nanocomposite membranes processed higher pure water flux and better hydrophilicity, antifouling property, and stability. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202503p Exemplaires
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Titre : Membrane-Mediated Delivery of Carbon Dioxide for Consumption by Photoautotrophs : Eliminating Thermal Regeneration in Carbon Capture Type de document : texte imprimé Auteurs : James D. Noel, Auteur ; William J. Koros, Auteur ; Benjamin A. McCool, Auteur Année de publication : 2012 Article en page(s) : pp. 4673–4681 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photoautotrophs Thermal regeneration Carbon Résumé : Photoautotrophs, such as microalgae and cyanobacteria, use sunlight to convert inorganic carbon, especially dissolved CO2 and bicarbonates, to organic materials, commonly biofuels or biofuel precursors. For large-scale biofuel production, the CO2 abundance in ambient air is not sufficient and CO2 must be delivered in a concentrated form, ideally captured from anthropogenic sources such as flue gas streams from power plants. Carbon dioxide capture and delivery to the photoautotrophic culture can add significantly to the cost of biofuels. Much of that cost can be attributed to the regeneration of the CO2 sorbent, a generally energy intensive process. Herein, a liquid-based CO2 delivery methodology is described and demonstrated. The system involves a conventional CO2 sorption system (exemplified by an amine-functionalized sorbent), and a carbonate stripping solution that produces a bicarbonate-rich solution after contacting the absorber. The latter solution serves as the feed stream for a CO2 selective membrane with the permeate side of the membrane being swept by a seawater solution, designed as a model for a photoautotrophic culture medium. Changes in pH and carbon content of the solutions, as well as the lack of any ionic transport across the membrane, are consistent with molecular transport of CO2. The CO2 flux is shown to be consistent with the chemical potential differential provided by the carbon-rich stripping solution and the carbon-depleted seawater solution. In application to biofuel production, the driving force would be sustained by carbon consumption in the photosynthetic process. Thus, photosynthesis provides much of the energy for the CO2 sorbent regeneration in the form of the regenerated carbonate stripping solution. The overall liquid-based CO2 delivery process described here provides the potential for a more cost-effective biofuel production process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2027124
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4673–4681[article] Membrane-Mediated Delivery of Carbon Dioxide for Consumption by Photoautotrophs : Eliminating Thermal Regeneration in Carbon Capture [texte imprimé] / James D. Noel, Auteur ; William J. Koros, Auteur ; Benjamin A. McCool, Auteur . - 2012 . - pp. 4673–4681.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4673–4681
Mots-clés : Photoautotrophs Thermal regeneration Carbon Résumé : Photoautotrophs, such as microalgae and cyanobacteria, use sunlight to convert inorganic carbon, especially dissolved CO2 and bicarbonates, to organic materials, commonly biofuels or biofuel precursors. For large-scale biofuel production, the CO2 abundance in ambient air is not sufficient and CO2 must be delivered in a concentrated form, ideally captured from anthropogenic sources such as flue gas streams from power plants. Carbon dioxide capture and delivery to the photoautotrophic culture can add significantly to the cost of biofuels. Much of that cost can be attributed to the regeneration of the CO2 sorbent, a generally energy intensive process. Herein, a liquid-based CO2 delivery methodology is described and demonstrated. The system involves a conventional CO2 sorption system (exemplified by an amine-functionalized sorbent), and a carbonate stripping solution that produces a bicarbonate-rich solution after contacting the absorber. The latter solution serves as the feed stream for a CO2 selective membrane with the permeate side of the membrane being swept by a seawater solution, designed as a model for a photoautotrophic culture medium. Changes in pH and carbon content of the solutions, as well as the lack of any ionic transport across the membrane, are consistent with molecular transport of CO2. The CO2 flux is shown to be consistent with the chemical potential differential provided by the carbon-rich stripping solution and the carbon-depleted seawater solution. In application to biofuel production, the driving force would be sustained by carbon consumption in the photosynthetic process. Thus, photosynthesis provides much of the energy for the CO2 sorbent regeneration in the form of the regenerated carbonate stripping solution. The overall liquid-based CO2 delivery process described here provides the potential for a more cost-effective biofuel production process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2027124 Exemplaires
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Titre : Removal mechanism of thiophenic compounds in model oil by inorganic lewis acids Type de document : texte imprimé Auteurs : Jia-jun Gao, Auteur ; Hong-qiang Li, Auteur ; Hong - Xing Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 4682–4691 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Adsorption Inorganic lewis Résumé : The adsorptive desulfurization ability of four inorganic Lewis acids (AlCl3, FeCl3, ZnCl2, and CuCl) for three thiophenic S-compounds, viz., 3-methylthiophene (3-MT), benzothiophene (BT), and dibenzothiophene (DBT), from their model oils were studied here experimentally at 290 K. The results were explained in terms of the theory of hard and soft acids and bases (HSAB) reasonably. The results show that AlCl3 has excellent removal ability for 3-MT with its adsorbance being 141.4 without toluene and 123.0 mgS/g with 25 wt % toluene. It is noteworthy that 3-MT is removed solely through complexing adsorption; in contrast, BT is adsorbed, accompanied with the formation of oil soluble BT oligomers under catalysis of AlCl3 which can promote the complexation greatly. Further, the addition of benzene and toluene can accelerate the desulfurization rate of 3-MT and BT due to the concentration of aromatics on the adsorbent and the oligomerization between BT and the aromatics. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202831p
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4682–4691[article] Removal mechanism of thiophenic compounds in model oil by inorganic lewis acids [texte imprimé] / Jia-jun Gao, Auteur ; Hong-qiang Li, Auteur ; Hong - Xing Zhang, Auteur . - 2012 . - pp. 4682–4691.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4682–4691
Mots-clés : Adsorption Inorganic lewis Résumé : The adsorptive desulfurization ability of four inorganic Lewis acids (AlCl3, FeCl3, ZnCl2, and CuCl) for three thiophenic S-compounds, viz., 3-methylthiophene (3-MT), benzothiophene (BT), and dibenzothiophene (DBT), from their model oils were studied here experimentally at 290 K. The results were explained in terms of the theory of hard and soft acids and bases (HSAB) reasonably. The results show that AlCl3 has excellent removal ability for 3-MT with its adsorbance being 141.4 without toluene and 123.0 mgS/g with 25 wt % toluene. It is noteworthy that 3-MT is removed solely through complexing adsorption; in contrast, BT is adsorbed, accompanied with the formation of oil soluble BT oligomers under catalysis of AlCl3 which can promote the complexation greatly. Further, the addition of benzene and toluene can accelerate the desulfurization rate of 3-MT and BT due to the concentration of aromatics on the adsorbent and the oligomerization between BT and the aromatics. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202831p Exemplaires
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Titre : Separation of C6 paraffins using zeolitic imidazolate frameworks : Comparison with zeolite 5A Type de document : texte imprimé Auteurs : David Peralta, Auteur ; Gérald Chaplais, Auteur ; Angélique Simon-Masseron, Auteur Année de publication : 2012 Article en page(s) : pp. 4692–4702 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Paraffin isomers Zeolite Résumé : The separation of paraffin isomers is a very important topic in the petrochemical industry. Zeolite 5A is industrially used to sieve alkane isomers, but its pore size does not allow the separation of monobranched and dibranched alkanes by a kinetic mechanism. In this publication, we compare three ZIF materials in the separation of C6-paraffin isomers: ZIF-8, ZIF-76, and a new material called IM-22. The performance of the materials is evaluated by a breakthrough curve of binary mixtures of n-hexane, 3-methylpentane, and 2,2-dimethylbutane. We show that ZIF-8 is a very attractive alternative to zeolite 5A because it exhibits a high (kinetic) selectivity for the adsorption of linear alkanes and at the same time a high adsorption capacity. The new material IM-22, a ZIF with CHA topology, seems to be particularly suited for the separation of mono- and dibranched paraffin isomers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202995g
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4692–4702[article] Separation of C6 paraffins using zeolitic imidazolate frameworks : Comparison with zeolite 5A [texte imprimé] / David Peralta, Auteur ; Gérald Chaplais, Auteur ; Angélique Simon-Masseron, Auteur . - 2012 . - pp. 4692–4702.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4692–4702
Mots-clés : Paraffin isomers Zeolite Résumé : The separation of paraffin isomers is a very important topic in the petrochemical industry. Zeolite 5A is industrially used to sieve alkane isomers, but its pore size does not allow the separation of monobranched and dibranched alkanes by a kinetic mechanism. In this publication, we compare three ZIF materials in the separation of C6-paraffin isomers: ZIF-8, ZIF-76, and a new material called IM-22. The performance of the materials is evaluated by a breakthrough curve of binary mixtures of n-hexane, 3-methylpentane, and 2,2-dimethylbutane. We show that ZIF-8 is a very attractive alternative to zeolite 5A because it exhibits a high (kinetic) selectivity for the adsorption of linear alkanes and at the same time a high adsorption capacity. The new material IM-22, a ZIF with CHA topology, seems to be particularly suited for the separation of mono- and dibranched paraffin isomers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202995g Exemplaires
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Titre : Dual phase composite oxide of Ce0.9Gd0.1O2-δ-Ba0.5Sr0.5Co0.8Fe0.2O3-δ with excellent oxygen permeation Type de document : texte imprimé Auteurs : Jian Xue, Auteur ; Qin Zheng, Auteur ; Yanying Wei, Auteur Année de publication : 2012 Article en page(s) : pp. 4703–4709 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Phase membrane Oxygen permeation Résumé : A dual phase membrane of 60 wt % Ce0.9Gd0.1O2-δ-40 wt % Ba0.5Sr0.5Co0.8Fe0.2O3-δ (60CGO-40BSCF), which exhibits high oxygen permeation, has been prepared. X-ray diffraction (XRD) results reveal that the two oxides are compatible. An oxygen permeation flux of 2.1 mL/(min·cm2) is obtained with a 0.5 mm thick membrane under the gradient of air/He at 975 °C, which keeps steady during 180 h of operation. The oxygen permeation process is mainly controlled by the bulk diffusion of oxygen ions in 60CGO-40BSCF membrane when the membrane thickness is higher than 0.8 mm and controlled by both the surface reaction and the bulk diffusion at reduced thickness of 0.5 mm as the temperature increased from 800 to 975 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300083r
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4703–4709[article] Dual phase composite oxide of Ce0.9Gd0.1O2-δ-Ba0.5Sr0.5Co0.8Fe0.2O3-δ with excellent oxygen permeation [texte imprimé] / Jian Xue, Auteur ; Qin Zheng, Auteur ; Yanying Wei, Auteur . - 2012 . - pp. 4703–4709.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4703–4709
Mots-clés : Phase membrane Oxygen permeation Résumé : A dual phase membrane of 60 wt % Ce0.9Gd0.1O2-δ-40 wt % Ba0.5Sr0.5Co0.8Fe0.2O3-δ (60CGO-40BSCF), which exhibits high oxygen permeation, has been prepared. X-ray diffraction (XRD) results reveal that the two oxides are compatible. An oxygen permeation flux of 2.1 mL/(min·cm2) is obtained with a 0.5 mm thick membrane under the gradient of air/He at 975 °C, which keeps steady during 180 h of operation. The oxygen permeation process is mainly controlled by the bulk diffusion of oxygen ions in 60CGO-40BSCF membrane when the membrane thickness is higher than 0.8 mm and controlled by both the surface reaction and the bulk diffusion at reduced thickness of 0.5 mm as the temperature increased from 800 to 975 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300083r Exemplaires
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Titre : Study on the performance of lambda cyhalothrin microemulsion with biodiesel as an alternative solvent Type de document : texte imprimé Auteurs : Chih-Ping Chin, Auteur ; Chi-Wei Lan, Auteur ; Ho-Shing Wu, Auteur Année de publication : 2012 Article en page(s) : pp. 4710–4718 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microemulsion Biodiesel Solvent Résumé : This study investigates a lambda cyhalothrin 2.5% (w/w) microemulsion formulation, with biodiesel as an alternative solvent, as a potential pesticide delivery system for oil-soluble pesticide active ingredients (AIs). This study presents a pseudoternary phase diagram of the investigated system, at room temperature by titration, and the surfactant/cosurfactant mass ratios (S/C), the oil-to-surfactant/cosurfactant mass ratios (O/SC) and the optimum formulation. This study also investigates the continuous structural inversion from water-in-oil to oil-in-water microemulsions after dilution with the water phase. The electrical conductivities of the selected system at constant S/C (5:1) and O/SC (1:1.2) ratios with biodiesel were also studied, and the percolation phenomenon was observed. The study examines the performance and stability of a formulation with biodiesel in comparison to commercial formulations. Residue and phytotoxicity tests were carried out on cabbage plants in a greenhouse. Experimental results indicate that biodiesel has good handling characteristics when it forms a microemulsion. The microemulsion formulation, with biodiesel as a solvent, had an acceptable transparent appearance, broader transparency temperature range, and better performance and stability than the commercial formulation. Using biodiesel in a pesticide formulation had no adverse effects on the AI activity and is comparatively safe for crops and plants. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201151p
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4710–4718[article] Study on the performance of lambda cyhalothrin microemulsion with biodiesel as an alternative solvent [texte imprimé] / Chih-Ping Chin, Auteur ; Chi-Wei Lan, Auteur ; Ho-Shing Wu, Auteur . - 2012 . - pp. 4710–4718.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4710–4718
Mots-clés : Microemulsion Biodiesel Solvent Résumé : This study investigates a lambda cyhalothrin 2.5% (w/w) microemulsion formulation, with biodiesel as an alternative solvent, as a potential pesticide delivery system for oil-soluble pesticide active ingredients (AIs). This study presents a pseudoternary phase diagram of the investigated system, at room temperature by titration, and the surfactant/cosurfactant mass ratios (S/C), the oil-to-surfactant/cosurfactant mass ratios (O/SC) and the optimum formulation. This study also investigates the continuous structural inversion from water-in-oil to oil-in-water microemulsions after dilution with the water phase. The electrical conductivities of the selected system at constant S/C (5:1) and O/SC (1:1.2) ratios with biodiesel were also studied, and the percolation phenomenon was observed. The study examines the performance and stability of a formulation with biodiesel in comparison to commercial formulations. Residue and phytotoxicity tests were carried out on cabbage plants in a greenhouse. Experimental results indicate that biodiesel has good handling characteristics when it forms a microemulsion. The microemulsion formulation, with biodiesel as a solvent, had an acceptable transparent appearance, broader transparency temperature range, and better performance and stability than the commercial formulation. Using biodiesel in a pesticide formulation had no adverse effects on the AI activity and is comparatively safe for crops and plants. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201151p Exemplaires
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Titre : Systematic multiscale method for studying the structure – performance relationship of drug - delivery systems Type de document : texte imprimé Auteurs : Xin Dong Guo, Auteur ; Li Juan Zhang, Auteur ; Yu Qian, Auteur Année de publication : 2012 Article en page(s) : pp. 4719–4730 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Atomic simulation methods Mesoscale Résumé : A systematic multiscale method is presented for studying the structure–performance relationship of drug-delivery systems (DDSs). The objective is to provide direction and guidelines toward the design and development of novel DDSs. Atomic simulation methods are used to evaluate the interactions between each pair of components in a DDS, from which the compatibility between drug and carriers can be well-predicted. Mesoscale simulation is applied to investigate the mesostructures of DDSs, from which the performances of products can be predicted. Finally, the drug-loaded nanoparticles can be prepared and evaluated through experiments involving loading efficiency, drug-release behaviors, and so on. The hydrophobic drugs doxorubicin and paclitaxel were considered as examples. The multiscale approach was used to investigate the structure–performance relationship of DDSs for these two drugs. All of the experimental results agreed well with the simulation results, indicating that the systematic multiscale method can provide a powerful tool for designing and developing DDSs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2014668
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4719–4730[article] Systematic multiscale method for studying the structure – performance relationship of drug - delivery systems [texte imprimé] / Xin Dong Guo, Auteur ; Li Juan Zhang, Auteur ; Yu Qian, Auteur . - 2012 . - pp. 4719–4730.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4719–4730
Mots-clés : Atomic simulation methods Mesoscale Résumé : A systematic multiscale method is presented for studying the structure–performance relationship of drug-delivery systems (DDSs). The objective is to provide direction and guidelines toward the design and development of novel DDSs. Atomic simulation methods are used to evaluate the interactions between each pair of components in a DDS, from which the compatibility between drug and carriers can be well-predicted. Mesoscale simulation is applied to investigate the mesostructures of DDSs, from which the performances of products can be predicted. Finally, the drug-loaded nanoparticles can be prepared and evaluated through experiments involving loading efficiency, drug-release behaviors, and so on. The hydrophobic drugs doxorubicin and paclitaxel were considered as examples. The multiscale approach was used to investigate the structure–performance relationship of DDSs for these two drugs. All of the experimental results agreed well with the simulation results, indicating that the systematic multiscale method can provide a powerful tool for designing and developing DDSs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2014668 Exemplaires
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Titre : Determination of the crystal growth rate of paracetamol as a function of solvent composition Type de document : texte imprimé Auteurs : C. T. O' Ciardha, Auteur ; N. A. Mitchell, Auteur ; K. W. Hutton, Auteur Année de publication : 2012 Article en page(s) : pp. 4731–4740 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : kinetics Solvent Crystallization Résumé : Growth kinetics, growth mechanisms, and the effect of solvent composition for the antisolvent crystallization of paracetamol in methanol–water mixtures have been determined by means of isothermal seeded batch experiments at constant solvent composition. A numerical model incorporating the population balance equation based on antisolvent free solubility was fitted to the desupersaturation data, and growth rate parameters are evaluated. An attenuated total reflectance–Fourier transform infrared (ATR-FTIR) probe was employed to measure online solute concentration and focused beam reflectance measurement (FBRM) was utilized to ensure negligible nucleation occurred. The model is validated by the final particle size distributions (PSDs) and online solute concentration measurements. Crystal growth rate was found to decrease with increasing water mass fractions up to a mass fraction of 0.68 where an increase is observed. A method has been introduced linking the effect of solvent composition with the growth mechanism and the growth rates. Utilizing the growth mechanism it has been postulated that a combination of the solubility gradient, viscosity, selective adsorption, and surface roughening are responsible for the reduction in growth rates with solvent composition. Furthermore, the effects of seed mass, size and initial supersaturation on the crystal growth rates were investigated to demonstrate the efficacy of the model at predicting these various phenomena. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2020262
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4731–4740[article] Determination of the crystal growth rate of paracetamol as a function of solvent composition [texte imprimé] / C. T. O' Ciardha, Auteur ; N. A. Mitchell, Auteur ; K. W. Hutton, Auteur . - 2012 . - pp. 4731–4740.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4731–4740
Mots-clés : kinetics Solvent Crystallization Résumé : Growth kinetics, growth mechanisms, and the effect of solvent composition for the antisolvent crystallization of paracetamol in methanol–water mixtures have been determined by means of isothermal seeded batch experiments at constant solvent composition. A numerical model incorporating the population balance equation based on antisolvent free solubility was fitted to the desupersaturation data, and growth rate parameters are evaluated. An attenuated total reflectance–Fourier transform infrared (ATR-FTIR) probe was employed to measure online solute concentration and focused beam reflectance measurement (FBRM) was utilized to ensure negligible nucleation occurred. The model is validated by the final particle size distributions (PSDs) and online solute concentration measurements. Crystal growth rate was found to decrease with increasing water mass fractions up to a mass fraction of 0.68 where an increase is observed. A method has been introduced linking the effect of solvent composition with the growth mechanism and the growth rates. Utilizing the growth mechanism it has been postulated that a combination of the solubility gradient, viscosity, selective adsorption, and surface roughening are responsible for the reduction in growth rates with solvent composition. Furthermore, the effects of seed mass, size and initial supersaturation on the crystal growth rates were investigated to demonstrate the efficacy of the model at predicting these various phenomena. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2020262 Exemplaires
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Titre : Working pair selection of compression and absorption hybrid cycles through predicting the activity coefficients of hydrofluorocarbon + ionic liquid Systems by the UNIFAC model Type de document : texte imprimé Auteurs : Li Dong, Auteur ; Danxing Zheng, Auteur ; Xianghong Wu, Auteur Année de publication : 2012 Article en page(s) : pp. 4741–4747 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Absorption hybrid Ionic liquid Résumé : Hydrofluorocarbon (HFC) + ionic liquid (IL) systems can be adopted as working pairs for compression/absorption hybrid cycles. A method of selecting novel working pairs has been proposed in this paper, that the infinite dilution activity coefficients (γ1∞) of working pair system need to be obtained, and the UNIFAC model is implemented to predict the activity coefficients of the working pair system. With the help of published experimental vapor–liquid equilibrium (VLE) data of 18 HFC + IL systems, 16 new group interaction parameters for four anion ILs and nine HFCs have been fitted to extend the evaluating and predicting range of HFC + IL systems for developing alternative working pairs. To validate the reliability of the method, the model parameters have been used to calculate the VLE data with the average relative deviations (ARDs) of pressures less than 8.5%. The prediction of the γ1∞ shows that the solubility and affinity between HFCs and ILs increase with the decrease of the γ1∞, which is in agreement with the experimental results. It is found by the prediction that the combinations of R32/R134 and [Tf2N]-based ILs may be two kinds of potential working pairs to improve the performances of compression/absorption hybrid cycles. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202029d
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4741–4747[article] Working pair selection of compression and absorption hybrid cycles through predicting the activity coefficients of hydrofluorocarbon + ionic liquid Systems by the UNIFAC model [texte imprimé] / Li Dong, Auteur ; Danxing Zheng, Auteur ; Xianghong Wu, Auteur . - 2012 . - pp. 4741–4747.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4741–4747
Mots-clés : Absorption hybrid Ionic liquid Résumé : Hydrofluorocarbon (HFC) + ionic liquid (IL) systems can be adopted as working pairs for compression/absorption hybrid cycles. A method of selecting novel working pairs has been proposed in this paper, that the infinite dilution activity coefficients (γ1∞) of working pair system need to be obtained, and the UNIFAC model is implemented to predict the activity coefficients of the working pair system. With the help of published experimental vapor–liquid equilibrium (VLE) data of 18 HFC + IL systems, 16 new group interaction parameters for four anion ILs and nine HFCs have been fitted to extend the evaluating and predicting range of HFC + IL systems for developing alternative working pairs. To validate the reliability of the method, the model parameters have been used to calculate the VLE data with the average relative deviations (ARDs) of pressures less than 8.5%. The prediction of the γ1∞ shows that the solubility and affinity between HFCs and ILs increase with the decrease of the γ1∞, which is in agreement with the experimental results. It is found by the prediction that the combinations of R32/R134 and [Tf2N]-based ILs may be two kinds of potential working pairs to improve the performances of compression/absorption hybrid cycles. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202029d Exemplaires
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Titre : Bubble characterization in a fluidized bed with vertical tubes Type de document : texte imprimé Auteurs : Martin Rüdisüli, Auteur ; Tilman J. Schildhauer, Auteur ; Serge M. A. Biollaz, Auteur Année de publication : 2012 Article en page(s) : pp. 4748–4758 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fluidized beds Heat exchanger Résumé : Vertical tubes are commonly used in industrial fluidized beds as heat exchanger tubes. In this study, the influence of vertical tube banks on the axial bubble growth in a 145-mm inner diameter (ID) fluidized bed with Geldart B particles is experimentally investigated by means of pressure fluctuation measurement (PFM) and optical probing (OP). The employed tube bank configurations differ in their tube-to-tube spacing, tube diameter, and tube arrangement (square versus triangular). PFM and OP show that immersed vertical tube banks, irrespective of their configuration, significantly reduce the axial bubble growth. The bubble size reduction is even more significant for higher gas velocities (u0/umf > 4.6, where u0 is the superficial gas velocity and umf is the minimum fluidization velocity) as well as if the tube-to-tube spacing is narrow and the tube diameter is small. The tube arrangement (square versus triangular), in turn, does not show any significant differences. Depending on the gas velocity, the ratio of the bubble diameter to the tube diameter and the tube-to-tube spacing is changed. This change invokes a different bubble flow pattern between the vertical tubes and different bubble growth mechanism, which defines the effectiveness of vertical tubes to delay slugging and makes the fluidization smoother. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2022306
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4748–4758[article] Bubble characterization in a fluidized bed with vertical tubes [texte imprimé] / Martin Rüdisüli, Auteur ; Tilman J. Schildhauer, Auteur ; Serge M. A. Biollaz, Auteur . - 2012 . - pp. 4748–4758.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4748–4758
Mots-clés : Fluidized beds Heat exchanger Résumé : Vertical tubes are commonly used in industrial fluidized beds as heat exchanger tubes. In this study, the influence of vertical tube banks on the axial bubble growth in a 145-mm inner diameter (ID) fluidized bed with Geldart B particles is experimentally investigated by means of pressure fluctuation measurement (PFM) and optical probing (OP). The employed tube bank configurations differ in their tube-to-tube spacing, tube diameter, and tube arrangement (square versus triangular). PFM and OP show that immersed vertical tube banks, irrespective of their configuration, significantly reduce the axial bubble growth. The bubble size reduction is even more significant for higher gas velocities (u0/umf > 4.6, where u0 is the superficial gas velocity and umf is the minimum fluidization velocity) as well as if the tube-to-tube spacing is narrow and the tube diameter is small. The tube arrangement (square versus triangular), in turn, does not show any significant differences. Depending on the gas velocity, the ratio of the bubble diameter to the tube diameter and the tube-to-tube spacing is changed. This change invokes a different bubble flow pattern between the vertical tubes and different bubble growth mechanism, which defines the effectiveness of vertical tubes to delay slugging and makes the fluidization smoother. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2022306 Exemplaires
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Titre : An acidic two - step hydrothermal process to enhance acetic acid production from carbohydrate biomass Type de document : texte imprimé Auteurs : Yan Fang, Auteur ; Xu Zeng, Auteur ; Peng Yan, Auteur Année de publication : 2012 Article en page(s) : pp. 4759–4763 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrothermal process Carbohydrate Biomass Résumé : An acidic two-step hydrothermal process to improve acetic acid production was investigated. In the first-step reaction, levulinic acid is formed in the presence of an acid catalyst. In the second-step reaction, the levulinic acid is converted into acetic acid via oxidation with newly supplied oxygen. The acetic acid yield from this two-step process was much higher than that without the acid catalysts in the first step. The acetic acid yield reached 23% with a purity of 47% from glucose and 26% with a purity of 52% from fructose. These yields were achieved at a reaction temperature of 523 K, a reaction time of 300 s, and pH 0.5 with HCl as an acid catalyst for the first step and at a reaction temperature of 523 K, a reaction time of 60 s, and an oxygen supply of 100% for the second step. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202506c
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4759–4763[article] An acidic two - step hydrothermal process to enhance acetic acid production from carbohydrate biomass [texte imprimé] / Yan Fang, Auteur ; Xu Zeng, Auteur ; Peng Yan, Auteur . - 2012 . - pp. 4759–4763.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4759–4763
Mots-clés : Hydrothermal process Carbohydrate Biomass Résumé : An acidic two-step hydrothermal process to improve acetic acid production was investigated. In the first-step reaction, levulinic acid is formed in the presence of an acid catalyst. In the second-step reaction, the levulinic acid is converted into acetic acid via oxidation with newly supplied oxygen. The acetic acid yield from this two-step process was much higher than that without the acid catalysts in the first step. The acetic acid yield reached 23% with a purity of 47% from glucose and 26% with a purity of 52% from fructose. These yields were achieved at a reaction temperature of 523 K, a reaction time of 300 s, and pH 0.5 with HCl as an acid catalyst for the first step and at a reaction temperature of 523 K, a reaction time of 60 s, and an oxygen supply of 100% for the second step. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202506c Exemplaires
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Titre : QSPR molecular approach for estimating henry’s law constants of pure compounds in water at ambient conditions Type de document : texte imprimé Auteurs : Farhad Gharagheizi, Auteur ; Poorandokht Ilani-Kashkouli, Auteur ; Seyyed Alireza Mirkhani, Auteur Année de publication : 2012 Article en page(s) : pp. 4764–4767 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Quantitative structure property relationship Résumé : In this article, we present a comprehensive quantitative structure–property relationship (QSPR) to estimate the Henry’s law constant (H) of pure compounds in water at ambient conditions. This relationship is a multilinear equation containing eight chemical-structure-based parameters. The parameters were selected by the genetic algorithm multivariate linear regression (GA-MLR) method using more than 3000 molecular descriptors. The squared correlation coefficient of the model (R2) over 1954 pure compounds is equal to 0.983 (logarithmic-based data). Therefore, the model is comprehensive and accurate enough to be used to predict the Henry’s law constants of various compounds in water. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202646u
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4764–4767[article] QSPR molecular approach for estimating henry’s law constants of pure compounds in water at ambient conditions [texte imprimé] / Farhad Gharagheizi, Auteur ; Poorandokht Ilani-Kashkouli, Auteur ; Seyyed Alireza Mirkhani, Auteur . - 2012 . - pp. 4764–4767.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4764–4767
Mots-clés : Quantitative structure property relationship Résumé : In this article, we present a comprehensive quantitative structure–property relationship (QSPR) to estimate the Henry’s law constant (H) of pure compounds in water at ambient conditions. This relationship is a multilinear equation containing eight chemical-structure-based parameters. The parameters were selected by the genetic algorithm multivariate linear regression (GA-MLR) method using more than 3000 molecular descriptors. The squared correlation coefficient of the model (R2) over 1954 pure compounds is equal to 0.983 (logarithmic-based data). Therefore, the model is comprehensive and accurate enough to be used to predict the Henry’s law constants of various compounds in water. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202646u Exemplaires
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