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Vol. 51 N° 25 - Juin 2012 [texte imprimé] . - 2012 . - p. 8341-8708 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierAdsorption kinetic and thermodynamic studies of silk dyed with sodium copper chlorophyllin / Xiuliang Hou in Industrial & engineering chemistry research, Vol. 51 N° 25 (Juin 2012)
Titre : Adsorption kinetic and thermodynamic studies of silk dyed with sodium copper chlorophyllin Type de document : texte imprimé Auteurs : Xiuliang Hou, Auteur ; Ruiling Yang, Auteur ; Helan Xu, Auteur Année de publication : 2012 Article en page(s) : pp. 8341–8347 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Kinetic Thermodynamic Résumé : In this study, silk was dyed into a bright green shade with a natural dye derivative, sodium copper chlorophyllin (SCC). Kinetics and thermodynamics of SCC adsorption on silk in dye bath with and without sodium chloride at different temperatures were investigated. The pseudo second-order kinetic model fitted experimental data well. Addition of sodium chloride increased SCC adsorption at equilibrium qe, increased the diffusion coefficient D and decreased the half dyeing time t1/2. The Langmuir isotherm agreed well with a high correlation coefficient (R2 > 0.99) for dyeing temperatures of 70, 80, and 90 °C with SCC concentration varying from 0.1 to 2.9 g/L. The thermodynamic parameters of SCC adsorption with and without sodium chloride showed significant difference. The adsorption affinity (−Δμ°) and enthalpy change (ΔH°) of SCC dye on silk indicated that the adsorption is a spontaneous and exothermic process. SCC could be a good candidate as a natural green dye for protein fibers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300201j
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8341–8347[article] Adsorption kinetic and thermodynamic studies of silk dyed with sodium copper chlorophyllin [texte imprimé] / Xiuliang Hou, Auteur ; Ruiling Yang, Auteur ; Helan Xu, Auteur . - 2012 . - pp. 8341–8347.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8341–8347
Mots-clés : Adsorption Kinetic Thermodynamic Résumé : In this study, silk was dyed into a bright green shade with a natural dye derivative, sodium copper chlorophyllin (SCC). Kinetics and thermodynamics of SCC adsorption on silk in dye bath with and without sodium chloride at different temperatures were investigated. The pseudo second-order kinetic model fitted experimental data well. Addition of sodium chloride increased SCC adsorption at equilibrium qe, increased the diffusion coefficient D and decreased the half dyeing time t1/2. The Langmuir isotherm agreed well with a high correlation coefficient (R2 > 0.99) for dyeing temperatures of 70, 80, and 90 °C with SCC concentration varying from 0.1 to 2.9 g/L. The thermodynamic parameters of SCC adsorption with and without sodium chloride showed significant difference. The adsorption affinity (−Δμ°) and enthalpy change (ΔH°) of SCC dye on silk indicated that the adsorption is a spontaneous and exothermic process. SCC could be a good candidate as a natural green dye for protein fibers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300201j Exemplaires
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Titre : Synthesis of magnetic nanocrystals by thermal decomposition in glycol media : Effect of process variables and mechanistic study Type de document : texte imprimé Auteurs : Nuria Miguel-Sancho, Auteur ; Oscar Bomati-Miguel, Auteur ; Alejandro G. Roca, Auteur Année de publication : 2012 Article en page(s) : pp. 8348-8357 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermal decomposition Nanocrystal Résumé : The nucleation and growth of water dispersible iron-oxide nanoparticles synthesized by high temperature decomposition of iron(III) acetylacetonate in the presence of different solvents has been studied. A battery of techniques was used to characterize the products obtained under different conditions and to elucidate the synthesis mechanism. Results show that the synthesis of iron-oxide nanoparticles in triethylene glycol (TEG) proceeds through a multistep process whose first stage is likely to be the formation of an intermediate TEG-iron-complex that evolves into a low-crystallinity iron-oxide-organic precursor during aging at 180 °C. Raising the temperature above 240 °C caused the thermal decomposition of the precursor and the sudden nucleation of small iron-oxide nanocrystals. Keeping the reactant mixture at 280 °C led to the growth of iron-oxide nanocrystals, as did increasing the time at reflux temperature, the amount of initial iron precursor or the use high boiling point solvents. The particle size could be reproducibly controlled between 1.5 and 13 nm, with a relatively narrow size distribution. Larger particles could also be obtained using a solvothermal method in an autodave reactor. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066762
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8348-8357[article] Synthesis of magnetic nanocrystals by thermal decomposition in glycol media : Effect of process variables and mechanistic study [texte imprimé] / Nuria Miguel-Sancho, Auteur ; Oscar Bomati-Miguel, Auteur ; Alejandro G. Roca, Auteur . - 2012 . - pp. 8348-8357.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8348-8357
Mots-clés : Thermal decomposition Nanocrystal Résumé : The nucleation and growth of water dispersible iron-oxide nanoparticles synthesized by high temperature decomposition of iron(III) acetylacetonate in the presence of different solvents has been studied. A battery of techniques was used to characterize the products obtained under different conditions and to elucidate the synthesis mechanism. Results show that the synthesis of iron-oxide nanoparticles in triethylene glycol (TEG) proceeds through a multistep process whose first stage is likely to be the formation of an intermediate TEG-iron-complex that evolves into a low-crystallinity iron-oxide-organic precursor during aging at 180 °C. Raising the temperature above 240 °C caused the thermal decomposition of the precursor and the sudden nucleation of small iron-oxide nanocrystals. Keeping the reactant mixture at 280 °C led to the growth of iron-oxide nanocrystals, as did increasing the time at reflux temperature, the amount of initial iron precursor or the use high boiling point solvents. The particle size could be reproducibly controlled between 1.5 and 13 nm, with a relatively narrow size distribution. Larger particles could also be obtained using a solvothermal method in an autodave reactor. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066762 Exemplaires
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Titre : Synthesis and electrochemical properties of nano – micro spherical β - Ni(OH)2 with super high charge – discharge speed Type de document : texte imprimé Auteurs : Xihong Yue, Auteur ; Junqing Pan, Auteur ; Yanzhi Sun, Auteur Année de publication : 2012 Article en page(s) : pp. 8358-8365 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrochemical properties Résumé : A spherical β-Ni(OH)2 product with nano―micro structure was synthesized by a new controllable crystallization complexation precipitation method. The results show that the nano-micro spherical Ni(OH)2 possesses superior electrochemical properties due to its own nano―micro structure. Furthermore, the new samples of cobalt-doped, zinc-doped, and cobalt-zinc codoped Ni(OH)2 with nano-micro structure were also synthesized. The electrochemical properties of these four nano―micro spherical Ni(OH)2 samples were investigated by galvanostatic charge-discharge and cyclic voltammetric (CV) tests. The electrochemical experimental results indicate that the diffusivity of proton of the doped Ni(OH)2 samples is significantly improved as compared with the pure Ni(OH)2 sample. The Co—Zn codoped Ni(OH)2 sample offers a high discharge specific capacity of 257 mA h g―1 and a long life of more than 800 cycles at a super high charge—discharge speed of 50 C, and the charging time of the product is as short as to 1.2 min. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066763
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8358-8365[article] Synthesis and electrochemical properties of nano – micro spherical β - Ni(OH)2 with super high charge – discharge speed [texte imprimé] / Xihong Yue, Auteur ; Junqing Pan, Auteur ; Yanzhi Sun, Auteur . - 2012 . - pp. 8358-8365.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8358-8365
Mots-clés : Electrochemical properties Résumé : A spherical β-Ni(OH)2 product with nano―micro structure was synthesized by a new controllable crystallization complexation precipitation method. The results show that the nano-micro spherical Ni(OH)2 possesses superior electrochemical properties due to its own nano―micro structure. Furthermore, the new samples of cobalt-doped, zinc-doped, and cobalt-zinc codoped Ni(OH)2 with nano-micro structure were also synthesized. The electrochemical properties of these four nano―micro spherical Ni(OH)2 samples were investigated by galvanostatic charge-discharge and cyclic voltammetric (CV) tests. The electrochemical experimental results indicate that the diffusivity of proton of the doped Ni(OH)2 samples is significantly improved as compared with the pure Ni(OH)2 sample. The Co—Zn codoped Ni(OH)2 sample offers a high discharge specific capacity of 257 mA h g―1 and a long life of more than 800 cycles at a super high charge—discharge speed of 50 C, and the charging time of the product is as short as to 1.2 min. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066763 Exemplaires
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Titre : Leaching of spent pot - lining with aluminum anodizing wastewaters : Fluoride extraction and thermodynamic modeling of aqueous speciation Type de document : texte imprimé Auteurs : Diego F. Lisbona, Auteur ; Christopher Somerfield, Auteur ; Karen M. Steel, Auteur Année de publication : 2012 Article en page(s) : pp. 8366–8377 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermodynamic Aqueous speciation Résumé : The cotreatment of spent pot-lining (SPL), a high fluoride (20 wt %), and cyanide (up to 1 wt %) waste generated in aluminum smelting, and Al3+ wastewaters generated by the aluminum anodizing industry was identified in this work as a treatment alternative that holds the potential to virtually remove the need for purchasing chemical reagents while keeping carbon dioxide emissions to a minimum. The process proposed involves fluoride leaching with anodizing wastewaters and precipitation of AlF2OH by treatment with caustic waste from the aluminum anodizing industry. AlF2OH can be directly injected into fluidized beds that are used to convert Al(OH)3 to AlF3. Since AlF3 is used in primary aluminum smelting, aluminum and fluoride from aluminum industry wastes such as SPL and anodizing wastewaters are recovered in a form that can be readily used as a feedstock in the aluminum industry. In this paper, the results of SPL leaching studies using aluminum anodizing waste are presented together with a model of the solution equilibria, which has been used to interpret experimental observations. Mild leaching temperatures were used and no chemical reagents other than anodizing waste were necessary to extract the soluble fluoride. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006353
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8366–8377[article] Leaching of spent pot - lining with aluminum anodizing wastewaters : Fluoride extraction and thermodynamic modeling of aqueous speciation [texte imprimé] / Diego F. Lisbona, Auteur ; Christopher Somerfield, Auteur ; Karen M. Steel, Auteur . - 2012 . - pp. 8366–8377.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8366–8377
Mots-clés : Thermodynamic Aqueous speciation Résumé : The cotreatment of spent pot-lining (SPL), a high fluoride (20 wt %), and cyanide (up to 1 wt %) waste generated in aluminum smelting, and Al3+ wastewaters generated by the aluminum anodizing industry was identified in this work as a treatment alternative that holds the potential to virtually remove the need for purchasing chemical reagents while keeping carbon dioxide emissions to a minimum. The process proposed involves fluoride leaching with anodizing wastewaters and precipitation of AlF2OH by treatment with caustic waste from the aluminum anodizing industry. AlF2OH can be directly injected into fluidized beds that are used to convert Al(OH)3 to AlF3. Since AlF3 is used in primary aluminum smelting, aluminum and fluoride from aluminum industry wastes such as SPL and anodizing wastewaters are recovered in a form that can be readily used as a feedstock in the aluminum industry. In this paper, the results of SPL leaching studies using aluminum anodizing waste are presented together with a model of the solution equilibria, which has been used to interpret experimental observations. Mild leaching temperatures were used and no chemical reagents other than anodizing waste were necessary to extract the soluble fluoride. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006353 Exemplaires
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Titre : Debromination of tetrabromobisphenol a by nanoscale zerovalent Iron : Kinetics, influencing factors, and pathways Type de document : texte imprimé Auteurs : Kunde Lin, Auteur ; Jiafeng Ding, Auteur ; Xinwen Huang, Auteur Année de publication : 2012 Article en page(s) : pp. 8378-8385 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics Zerovalent metal Debromination Résumé : Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants and is ubiquitously present in the environment. In this study, we investigated the debromination of TBBPA by nanoscale zerovalent iron (nZVI) in methanol/water (50/50) solutions- Zerovalent iron nanoparticles demonstrated an excellent capacity to debrominate TBBPA to tribromobisphenol A, dibromobisphenol A, bromobisphenol A, and bisphenol A. More than 86% of TBBPA was debrominated within 16 h in a pH 7.5 reaction solution initially containing 3.0 g/L of nZVI. Debromination of TBBPA was apparently accompanied by the release of bromine ions and the elevation of solution pH. The debromination kinetics could be well-described by a three-parameter pseudo-first-order decay model. A higher loading of nZVI and acidic conditions facilitated the debromination process, while coexisting Ca2+ and Na+ species inhibited the reaction. On the basis of identified reaction intermediates and products, TBBPA debromination pathways by nZVI were proposed. This study suggests that nZVI may be potentially employed to debrominate TBBPA in soil and sediment. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066765
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8378-8385[article] Debromination of tetrabromobisphenol a by nanoscale zerovalent Iron : Kinetics, influencing factors, and pathways [texte imprimé] / Kunde Lin, Auteur ; Jiafeng Ding, Auteur ; Xinwen Huang, Auteur . - 2012 . - pp. 8378-8385.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8378-8385
Mots-clés : Kinetics Zerovalent metal Debromination Résumé : Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants and is ubiquitously present in the environment. In this study, we investigated the debromination of TBBPA by nanoscale zerovalent iron (nZVI) in methanol/water (50/50) solutions- Zerovalent iron nanoparticles demonstrated an excellent capacity to debrominate TBBPA to tribromobisphenol A, dibromobisphenol A, bromobisphenol A, and bisphenol A. More than 86% of TBBPA was debrominated within 16 h in a pH 7.5 reaction solution initially containing 3.0 g/L of nZVI. Debromination of TBBPA was apparently accompanied by the release of bromine ions and the elevation of solution pH. The debromination kinetics could be well-described by a three-parameter pseudo-first-order decay model. A higher loading of nZVI and acidic conditions facilitated the debromination process, while coexisting Ca2+ and Na+ species inhibited the reaction. On the basis of identified reaction intermediates and products, TBBPA debromination pathways by nZVI were proposed. This study suggests that nZVI may be potentially employed to debrominate TBBPA in soil and sediment. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066765 Exemplaires
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Titre : Design, polymerization, and properties of high - performance seed - oil - derived lubricants Type de document : texte imprimé Auteurs : Mark F. Sonnenschein, Auteur ; Martin R. Greaves, Auteur ; Bruce M. Bell, Auteur Année de publication : 2012 Article en page(s) : pp. 8386-8393 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Lubricant Polymerization Design Résumé : There is a significant amount of interest and research in seed-oil-derived lubricants because of elevated environmental consciousness among producers and consumers. While slowly making inroads into selected applications, performance deficits at low temperature and poor thermooxidative stability have consistently relegated seed oil derivatives to roles where biodegradability is paramount or where the performance requirements are relatively low. In this article, the structural attributes that result in seed-oil-derived lubricant properties are defined and quantified. Also, the seed oil triglyceride components are segregated, functionalized, and polymerized to provide a lubricant design that allows flexibility in defining the specified viscosity, while providing an improved low-temperature performance and removing the source of thermooxidative instability. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066766
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8386-8393[article] Design, polymerization, and properties of high - performance seed - oil - derived lubricants [texte imprimé] / Mark F. Sonnenschein, Auteur ; Martin R. Greaves, Auteur ; Bruce M. Bell, Auteur . - 2012 . - pp. 8386-8393.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8386-8393
Mots-clés : Lubricant Polymerization Design Résumé : There is a significant amount of interest and research in seed-oil-derived lubricants because of elevated environmental consciousness among producers and consumers. While slowly making inroads into selected applications, performance deficits at low temperature and poor thermooxidative stability have consistently relegated seed oil derivatives to roles where biodegradability is paramount or where the performance requirements are relatively low. In this article, the structural attributes that result in seed-oil-derived lubricant properties are defined and quantified. Also, the seed oil triglyceride components are segregated, functionalized, and polymerized to provide a lubricant design that allows flexibility in defining the specified viscosity, while providing an improved low-temperature performance and removing the source of thermooxidative instability. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066766 Exemplaires
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Titre : Thermal denitration of ammonium nitrate solution in a fluidized - bed reactor Type de document : texte imprimé Auteurs : Sandip Bhowmick, Auteur ; Hanmanth Rao, Auteur ; D. Sathiyamoorthy, Auteur Année de publication : 2012 Article en page(s) : pp. 8394–8403 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ammonium Nitrate Fluidized bed Résumé : Ammonium diuranate (ADU) filtrate, which contains mainly ammonium nitrate (80–100 g/L), is generated during hydrometallurgical processing of uranium. This filtrate stream poses a disposal problem because of its high nitrate content and residual radioactivity. Fluidized-bed thermal denitration is considered as a suitable chemical-free disposal option for the aqueous waste nitrate stream. Hence, investigations to explore the decomposition of ammonium nitrate in a fluidized bed have been carried out. To enable theoretical analysis and performance evaluation of the process, a mathematical model was developed. The model is based on two-phase theory of a bubbling fluidized bed. Model calculations were used to predict the axial concentration profile of ammonium nitrate in the emulsion and bubble phases and the axial temperature profiles of gas bubbles, emulsion gas, and emulsion particles. The mechanism of decomposition of ammonium nitrate in a fluidized bed was explored, and the conversion of ammonium nitrate was estimated. Model predictions were compared with experimental data available from a bench-scale plant. Good agreement was obtained between the model predictions and the experimental measurements. A steady-state parametric study indicated that conversion is enhanced with an increase in bed temperature and feed concentration. It was found that operation at higher feed concentration leads to local hot spots. The required reaction-zone length for complete conversion of ammonium nitrate vapor in the emulsion phase was found to decrease significantly with increased bed temperature. No marked effect of u/umf on conversion was observed. Optimum values of process parameters to maximize the conversion were derived. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202018t
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8394–8403[article] Thermal denitration of ammonium nitrate solution in a fluidized - bed reactor [texte imprimé] / Sandip Bhowmick, Auteur ; Hanmanth Rao, Auteur ; D. Sathiyamoorthy, Auteur . - 2012 . - pp. 8394–8403.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8394–8403
Mots-clés : Ammonium Nitrate Fluidized bed Résumé : Ammonium diuranate (ADU) filtrate, which contains mainly ammonium nitrate (80–100 g/L), is generated during hydrometallurgical processing of uranium. This filtrate stream poses a disposal problem because of its high nitrate content and residual radioactivity. Fluidized-bed thermal denitration is considered as a suitable chemical-free disposal option for the aqueous waste nitrate stream. Hence, investigations to explore the decomposition of ammonium nitrate in a fluidized bed have been carried out. To enable theoretical analysis and performance evaluation of the process, a mathematical model was developed. The model is based on two-phase theory of a bubbling fluidized bed. Model calculations were used to predict the axial concentration profile of ammonium nitrate in the emulsion and bubble phases and the axial temperature profiles of gas bubbles, emulsion gas, and emulsion particles. The mechanism of decomposition of ammonium nitrate in a fluidized bed was explored, and the conversion of ammonium nitrate was estimated. Model predictions were compared with experimental data available from a bench-scale plant. Good agreement was obtained between the model predictions and the experimental measurements. A steady-state parametric study indicated that conversion is enhanced with an increase in bed temperature and feed concentration. It was found that operation at higher feed concentration leads to local hot spots. The required reaction-zone length for complete conversion of ammonium nitrate vapor in the emulsion phase was found to decrease significantly with increased bed temperature. No marked effect of u/umf on conversion was observed. Optimum values of process parameters to maximize the conversion were derived. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202018t Exemplaires
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Titre : Optimization of biodiesel synthesis from waste frying soybean oil using fish scale - supported Ni catalyst Type de document : texte imprimé Auteurs : Rajat Chakraborty, Auteur ; Sujit K. Das, Auteur Année de publication : 2012 Article en page(s) : pp. 8404-8414 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Optimization Résumé : A novel Ni―Ca―hydroxyapatite solid acid catalyst was prepared through wet impregnation of Ni(NO3)2-6H2O on pretreated waste fish scale (PWFS) support, and the catalyst was characterized by TGA, XRD, FESEM, BET, BJH, and FTIR methods. The efficacy of the developed catalyst possessing a specific surface area of 90 m2/g, 0.1823 cm3/g pore volume, 54.83 nm modal pore diameter, and 7.52 mmol NaOH/g catalyst acidity was evaluated through esterification of free fatty acids (FFAs) of pretreated waste frying soybean oil (PWFSO) in a semibatch reactor. Optimal parametric values for esterification computed using response surface methodology (RSM) corresponding to maximum (i.e., 59.90%) conversion of FFAs to yield FAME (biodiesel) were 0.80 mL/min methanol flow rate, 30 wt % Ni(NO3)2-6H2O precursor dosage, and 300 °C calcination temperature. Subsequent batch transesterification of the unreacted triglycerides present in upstream product catalyzed by calcined fish scale (base catalyst) resulted in an ultimate 98.40% yield of biodiesel. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066768
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8404-8414[article] Optimization of biodiesel synthesis from waste frying soybean oil using fish scale - supported Ni catalyst [texte imprimé] / Rajat Chakraborty, Auteur ; Sujit K. Das, Auteur . - 2012 . - pp. 8404-8414.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8404-8414
Mots-clés : Catalyst Optimization Résumé : A novel Ni―Ca―hydroxyapatite solid acid catalyst was prepared through wet impregnation of Ni(NO3)2-6H2O on pretreated waste fish scale (PWFS) support, and the catalyst was characterized by TGA, XRD, FESEM, BET, BJH, and FTIR methods. The efficacy of the developed catalyst possessing a specific surface area of 90 m2/g, 0.1823 cm3/g pore volume, 54.83 nm modal pore diameter, and 7.52 mmol NaOH/g catalyst acidity was evaluated through esterification of free fatty acids (FFAs) of pretreated waste frying soybean oil (PWFSO) in a semibatch reactor. Optimal parametric values for esterification computed using response surface methodology (RSM) corresponding to maximum (i.e., 59.90%) conversion of FFAs to yield FAME (biodiesel) were 0.80 mL/min methanol flow rate, 30 wt % Ni(NO3)2-6H2O precursor dosage, and 300 °C calcination temperature. Subsequent batch transesterification of the unreacted triglycerides present in upstream product catalyzed by calcined fish scale (base catalyst) resulted in an ultimate 98.40% yield of biodiesel. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066768 Exemplaires
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Titre : Epoxy Resins Cross-Linked with Bisphenol A/Methylenedianiline Novolac Resin Type : Curing and Thermal Behavior Study Type de document : texte imprimé Auteurs : Fanica R. Mustata, Auteur ; Nita Tudorachi, Auteur ; Ioan Bicu, Auteur Année de publication : 2012 Article en page(s) : pp. 8415–8424 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermal behavior Résumé : A novolac type resin was synthesized from bisphenol A, 4,4′-methylenedianiline, and formaldehyde in the presence of HCl. The chemical structure was confirmed using elemental analysis, FT-IR spectroscopy, and 1H NMR spectroscopy. The curing kinetics of these epoxy resins at an epoxy ring/amine proton molar ratio of 1/1, were studied by nonisothermal differential scanning calorimetry (DSC) at different heating rates. The kinetic analysis of the curing reactions was evaluated using the variable peak exotherm method of Flynn–Wall–Ozawa and Kissinger. The thermal degradation mechanisms for novolac resin (FR) and cured resins were identified taking place between two and four steps, depending on the chemical structure of the sample. The most probable kinetic model and kinetic parameters of the degradation process were estimated using Netzsch Thermokinetics software. The cured resins have good thermal stability, with activation energies of thermal degradation reactions having values situated in the range 127–184 kJ·mol–1. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202909s
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8415–8424[article] Epoxy Resins Cross-Linked with Bisphenol A/Methylenedianiline Novolac Resin Type : Curing and Thermal Behavior Study [texte imprimé] / Fanica R. Mustata, Auteur ; Nita Tudorachi, Auteur ; Ioan Bicu, Auteur . - 2012 . - pp. 8415–8424.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8415–8424
Mots-clés : Thermal behavior Résumé : A novolac type resin was synthesized from bisphenol A, 4,4′-methylenedianiline, and formaldehyde in the presence of HCl. The chemical structure was confirmed using elemental analysis, FT-IR spectroscopy, and 1H NMR spectroscopy. The curing kinetics of these epoxy resins at an epoxy ring/amine proton molar ratio of 1/1, were studied by nonisothermal differential scanning calorimetry (DSC) at different heating rates. The kinetic analysis of the curing reactions was evaluated using the variable peak exotherm method of Flynn–Wall–Ozawa and Kissinger. The thermal degradation mechanisms for novolac resin (FR) and cured resins were identified taking place between two and four steps, depending on the chemical structure of the sample. The most probable kinetic model and kinetic parameters of the degradation process were estimated using Netzsch Thermokinetics software. The cured resins have good thermal stability, with activation energies of thermal degradation reactions having values situated in the range 127–184 kJ·mol–1. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202909s Exemplaires
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Titre : Dispersions of various titania nanoparticles in two different ionic liquids Type de document : texte imprimé Auteurs : Alexandra Wittmar, Auteur ; Mathias Ulbricht, Auteur Année de publication : 2012 Article en page(s) : pp. 8425-8433 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic liquid Nanoparticle Dispersion Résumé : The dispersibility of different lab-made and commercial TiO2 nanoparticles prepared by gas-phase processes in room temperature ionic liquids was for the first time studied by dynamic light scattering and advanced rheology. The characterization of the nanopowders has been done with transmission electron microscopy, X-ray diffraction analysis, nitrogen adsorption, and Brunauer―Emmett―Teller (BET) analysis and FT-IR spectroscopy. The colloidal stabilities of the resulting dispersions were strongly influenced by particle characteristics such as aggregation level, mean particle size, and surface functionality. The period of the ultrasound treatment, the powder concentration in the dispersion, and the hydrophilicity of the ionic liquid were also important influences. It was found that most types of powders disperse better in the hydrophilic ionic liquid because of the hydroxyl groups and adsorbed water present on the powders' surfaces. The best dispersions over a broader concentration range were obtained for a lab-made powder produced by chemical vapor synthesis (aerosol method) which had the smallest nonaggregated particles. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066770
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8425-8433[article] Dispersions of various titania nanoparticles in two different ionic liquids [texte imprimé] / Alexandra Wittmar, Auteur ; Mathias Ulbricht, Auteur . - 2012 . - pp. 8425-8433.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8425-8433
Mots-clés : Ionic liquid Nanoparticle Dispersion Résumé : The dispersibility of different lab-made and commercial TiO2 nanoparticles prepared by gas-phase processes in room temperature ionic liquids was for the first time studied by dynamic light scattering and advanced rheology. The characterization of the nanopowders has been done with transmission electron microscopy, X-ray diffraction analysis, nitrogen adsorption, and Brunauer―Emmett―Teller (BET) analysis and FT-IR spectroscopy. The colloidal stabilities of the resulting dispersions were strongly influenced by particle characteristics such as aggregation level, mean particle size, and surface functionality. The period of the ultrasound treatment, the powder concentration in the dispersion, and the hydrophilicity of the ionic liquid were also important influences. It was found that most types of powders disperse better in the hydrophilic ionic liquid because of the hydroxyl groups and adsorbed water present on the powders' surfaces. The best dispersions over a broader concentration range were obtained for a lab-made powder produced by chemical vapor synthesis (aerosol method) which had the smallest nonaggregated particles. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066770 Exemplaires
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Titre : Synthesis and properties of UV - curable polyester - based waterborne polyurethane / functionalized silica composites and morphology of their nanostructured films Type de document : texte imprimé Auteurs : Lihui Zhang, Auteur ; Hong Zhang, Auteur ; Jinshan Guo, Auteur Année de publication : 2012 Article en page(s) : pp. 8434-8441 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Morphology Composite material Ultraviolet radiation Résumé : In this study, environmentally friendly UV-curable polyester-based waterbome polyurethane (WPU)/ functionalized silica nanocomposites were successfully prepared. The functionalized silica was combined with WPU by chemical bonds and existed as effective cross-link points to form composites. Because of the existence of organic molecule chains from the functionalized silica, the compatibility of WPU with silica was improved obviously. This makes the composite latex possesses certain stability when the silica content rose up to 17.5 wt %. The composite latex particles kept the structure where the functionalized silica was covered by WPU during the film formation process, which could greatly decrease the aggregation of silica. What's more, the existence of functionalized silica improved thermo-stability, hardness, and water resistance of composite films effectively and the composite films possessed good transparency. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066771
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8434-8441[article] Synthesis and properties of UV - curable polyester - based waterborne polyurethane / functionalized silica composites and morphology of their nanostructured films [texte imprimé] / Lihui Zhang, Auteur ; Hong Zhang, Auteur ; Jinshan Guo, Auteur . - 2012 . - pp. 8434-8441.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8434-8441
Mots-clés : Morphology Composite material Ultraviolet radiation Résumé : In this study, environmentally friendly UV-curable polyester-based waterbome polyurethane (WPU)/ functionalized silica nanocomposites were successfully prepared. The functionalized silica was combined with WPU by chemical bonds and existed as effective cross-link points to form composites. Because of the existence of organic molecule chains from the functionalized silica, the compatibility of WPU with silica was improved obviously. This makes the composite latex possesses certain stability when the silica content rose up to 17.5 wt %. The composite latex particles kept the structure where the functionalized silica was covered by WPU during the film formation process, which could greatly decrease the aggregation of silica. What's more, the existence of functionalized silica improved thermo-stability, hardness, and water resistance of composite films effectively and the composite films possessed good transparency. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066771 Exemplaires
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Titre : Deproteinized natural rubber latex / hydroxypropylmethyl cellulose blending polymers for nicotine matrix films Type de document : texte imprimé Auteurs : Wiwat Pichayakorn, Auteur ; Jirapornchai Suksaeree, Auteur ; Prapaporn Boonme, Auteur Année de publication : 2012 Article en page(s) : pp. 8442-8452 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Polymers Nicotine Résumé : Nicotine matrix films were prepared using DNRL/HPMC blends for transdermal delivery. Several plasticizers were also mixed. The mechanical and physicochemical properties, moisture uptake, and swelling ratio of films depended on HPMC and plasticizers. The compatibility of each ingredient in the blended films was confirmed by FT-IR, XRD, and DSC. The in vitro release of nicotine showed a monophasic slow release pattern. The polymer and plasticizer blends produced a faster release rate. The kinetics of nicotine release from the films fitted the diffusion type. Surprisingly, the permeation of the nicotine into the skin occurred by zero-order kinetics. It was concluded that nicotine matrix films could be produced that could provide a controlled release of the drug and suitable permeation patterns. Moreover, they were safe to apply to the skin as they did not cause irritation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300608j
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8442-8452[article] Deproteinized natural rubber latex / hydroxypropylmethyl cellulose blending polymers for nicotine matrix films [texte imprimé] / Wiwat Pichayakorn, Auteur ; Jirapornchai Suksaeree, Auteur ; Prapaporn Boonme, Auteur . - 2012 . - pp. 8442-8452.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8442-8452
Mots-clés : Polymers Nicotine Résumé : Nicotine matrix films were prepared using DNRL/HPMC blends for transdermal delivery. Several plasticizers were also mixed. The mechanical and physicochemical properties, moisture uptake, and swelling ratio of films depended on HPMC and plasticizers. The compatibility of each ingredient in the blended films was confirmed by FT-IR, XRD, and DSC. The in vitro release of nicotine showed a monophasic slow release pattern. The polymer and plasticizer blends produced a faster release rate. The kinetics of nicotine release from the films fitted the diffusion type. Surprisingly, the permeation of the nicotine into the skin occurred by zero-order kinetics. It was concluded that nicotine matrix films could be produced that could provide a controlled release of the drug and suitable permeation patterns. Moreover, they were safe to apply to the skin as they did not cause irritation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300608j Exemplaires
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Titre : Simultaneous optimization of crude oil blending and purchase planning with delivery uncertainty consideration Type de document : texte imprimé Auteurs : Jian Zhang, Auteur ; Yanqin Wen, Auteur ; Qiang Xu, Auteur Année de publication : 2012 Article en page(s) : pp. 8453-8464 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Uncertainty Planning Crude oil Optimization Résumé : Crude-oil blending is a common practice to obtain qualified mixing oils for refinery processing at low costs. The blending component crudes are subject to inventory constraints, which in turn are dynamically affected by the refinery purchase plan including the crude-oil types, amounts, and delivery over a planned period of time. As the crude-oil price and availability constantly changes in a volatile market, the crude-oil blending and purchase planning should be coordinated and simultaneously optimized to maximize the potential profitability of a refinery plant This becomes even more important when the uncertainty of crude-oil delivery time is also taken into account. In this paper, a general MINLP (mixed-integer nonlinear programming) model is developed to address the profit optimization of crude-oil blending and purchase planning in refinery plants. Inventory-related flexibility indexes are developed to characterize the ability of a refinery for handling the uncertainty of crude-oil delivery delays. In-depth relations between the production flexibility and the plant profit are also disclosed The efficacy of the developed methodology is demonstrated by industrial case studies. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066773
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8453-8464[article] Simultaneous optimization of crude oil blending and purchase planning with delivery uncertainty consideration [texte imprimé] / Jian Zhang, Auteur ; Yanqin Wen, Auteur ; Qiang Xu, Auteur . - 2012 . - pp. 8453-8464.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8453-8464
Mots-clés : Uncertainty Planning Crude oil Optimization Résumé : Crude-oil blending is a common practice to obtain qualified mixing oils for refinery processing at low costs. The blending component crudes are subject to inventory constraints, which in turn are dynamically affected by the refinery purchase plan including the crude-oil types, amounts, and delivery over a planned period of time. As the crude-oil price and availability constantly changes in a volatile market, the crude-oil blending and purchase planning should be coordinated and simultaneously optimized to maximize the potential profitability of a refinery plant This becomes even more important when the uncertainty of crude-oil delivery time is also taken into account. In this paper, a general MINLP (mixed-integer nonlinear programming) model is developed to address the profit optimization of crude-oil blending and purchase planning in refinery plants. Inventory-related flexibility indexes are developed to characterize the ability of a refinery for handling the uncertainty of crude-oil delivery delays. In-depth relations between the production flexibility and the plant profit are also disclosed The efficacy of the developed methodology is demonstrated by industrial case studies. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066773 Exemplaires
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Titre : Novel model - free approach for stiction compensation in control valves Type de document : texte imprimé Auteurs : Marco Antônio de Souza L. Cuadros, Auteur ; Celso J. Munaro, Auteur ; Saul Munareto, Auteur Année de publication : 2012 Article en page(s) : pp. 8465–8476 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Control valves Résumé : Stiction in control valves is a frequent cause of loop performance deterioration. The solution is maintenance, but since plant shutdown to perform this task can take a long time, loop performance improvement through stiction compensation affords increased efficiency and profitability by reducing the necessity for unscheduled plant shutdowns. Non-model-based methods add compensating pulses to the control signal, thereby reducing process variability. However, the current practice of this strategy transfers variability to the control valve stem, degrading this actuator prematurely. In this paper, such methods are analyzed and a new method for reducing both process variability and valve stem actuation is proposed. The essence of this new method is to add the pulses only when they are required for reduction of process error. The compensation algorithm presented can handle set point changes and perturbations as is illustrated via simulation and through application to a pilot plant flow loop. The proposed method’s performance is measured using integral absolute error and valve reversal indexes. It produces better results than similar methods found in the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2015262
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8465–8476[article] Novel model - free approach for stiction compensation in control valves [texte imprimé] / Marco Antônio de Souza L. Cuadros, Auteur ; Celso J. Munaro, Auteur ; Saul Munareto, Auteur . - 2012 . - pp. 8465–8476.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8465–8476
Mots-clés : Control valves Résumé : Stiction in control valves is a frequent cause of loop performance deterioration. The solution is maintenance, but since plant shutdown to perform this task can take a long time, loop performance improvement through stiction compensation affords increased efficiency and profitability by reducing the necessity for unscheduled plant shutdowns. Non-model-based methods add compensating pulses to the control signal, thereby reducing process variability. However, the current practice of this strategy transfers variability to the control valve stem, degrading this actuator prematurely. In this paper, such methods are analyzed and a new method for reducing both process variability and valve stem actuation is proposed. The essence of this new method is to add the pulses only when they are required for reduction of process error. The compensation algorithm presented can handle set point changes and perturbations as is illustrated via simulation and through application to a pilot plant flow loop. The proposed method’s performance is measured using integral absolute error and valve reversal indexes. It produces better results than similar methods found in the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2015262 Exemplaires
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Titre : Observer – PID stabilization strategy for unstable first - order linear systems with large time delay Type de document : texte imprimé Auteurs : J. F. Márquez-Rubio, Auteur ; B. del-Muro-Cuéllar, Auteur ; M. Velasco-Villa, Auteur Année de publication : 2012 Article en page(s) : pp. 8477-8487 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Linear system First order Stabilization Observer Résumé : This work considers the stabilization and control of a class of unstable first-order linear systems subject to a relatively large input-output time delay. As a first step, a particular observer scheme is proposed in order to predict a specific internal signal in the process. Conditions to ensure the adequate prediction convergence of the signals are formally stated. In a second step, the internal predicted signal is used to implement classical P, PI, and PID controllers providing stability conditions for the resulting closed-loop system. The proposed control strategy allows one to address time delays as large as four times the unstable time constant of the open-loop system, in contrast with the reported related literature where the maximal bound has been stated until now as two times the unstable time constant of the open-loop system. The proposed observer-based control structure considers also the tracking of step reference signals and the rejection of input step disturbances. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066775
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8477-8487[article] Observer – PID stabilization strategy for unstable first - order linear systems with large time delay [texte imprimé] / J. F. Márquez-Rubio, Auteur ; B. del-Muro-Cuéllar, Auteur ; M. Velasco-Villa, Auteur . - 2012 . - pp. 8477-8487.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8477-8487
Mots-clés : Linear system First order Stabilization Observer Résumé : This work considers the stabilization and control of a class of unstable first-order linear systems subject to a relatively large input-output time delay. As a first step, a particular observer scheme is proposed in order to predict a specific internal signal in the process. Conditions to ensure the adequate prediction convergence of the signals are formally stated. In a second step, the internal predicted signal is used to implement classical P, PI, and PID controllers providing stability conditions for the resulting closed-loop system. The proposed control strategy allows one to address time delays as large as four times the unstable time constant of the open-loop system, in contrast with the reported related literature where the maximal bound has been stated until now as two times the unstable time constant of the open-loop system. The proposed observer-based control structure considers also the tracking of step reference signals and the rejection of input step disturbances. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066775 Exemplaires
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Titre : An iterated eigenvalue algorithm for vapor – liquid split in flash calculations Type de document : texte imprimé Auteurs : Rosendo Monroy-Loperena, Auteur Année de publication : 2012 Article en page(s) : pp. 8488-8494 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Algorithm Résumé : Flash calculations are used extensively in computer-aided process simulation programs. Inherent to flash calculations is the determination of the vapor―liquid split. Currently, to calculate the vapor―liquid split, the Rachford―Rice calculations is the detemvnation of the vapor―liquid split. Currently, to calculate the vapor―liquid split, the Itachford―Rice equation is the most accepted method. In this work, it is shown that the Rachford―Rice equation can be posed as a generalized eigenvalue problem, where each eigenvalue of the resulting system is exactly a root of the Rachford-Rice equation. In this way, an ad hoc strategy based on linear algebra is proposed for finding the vapor―liquid split. The main advantage of the proposed strategy is that the resulting linear system has an almost-diagonal structure and generates a discrepancy function with a more linear shape than that of the Rachford―Rice equation. In this way, the solution of the system is simple and computationally inexpensive. Numerical experiments show the reliability of the proposed solution strategy for calculating the vapor―liquid split. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066776
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8488-8494[article] An iterated eigenvalue algorithm for vapor – liquid split in flash calculations [texte imprimé] / Rosendo Monroy-Loperena, Auteur . - 2012 . - pp. 8488-8494.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8488-8494
Mots-clés : Algorithm Résumé : Flash calculations are used extensively in computer-aided process simulation programs. Inherent to flash calculations is the determination of the vapor―liquid split. Currently, to calculate the vapor―liquid split, the Rachford―Rice calculations is the detemvnation of the vapor―liquid split. Currently, to calculate the vapor―liquid split, the Itachford―Rice equation is the most accepted method. In this work, it is shown that the Rachford―Rice equation can be posed as a generalized eigenvalue problem, where each eigenvalue of the resulting system is exactly a root of the Rachford-Rice equation. In this way, an ad hoc strategy based on linear algebra is proposed for finding the vapor―liquid split. The main advantage of the proposed strategy is that the resulting linear system has an almost-diagonal structure and generates a discrepancy function with a more linear shape than that of the Rachford―Rice equation. In this way, the solution of the system is simple and computationally inexpensive. Numerical experiments show the reliability of the proposed solution strategy for calculating the vapor―liquid split. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066776 Exemplaires
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Titre : Statistical modeling and online monitoring based on between - set regression analysis Type de document : texte imprimé Auteurs : Chunhui Zhao, Auteur ; Furong Gao, Auteur ; Youxian Sun, Auteur Année de publication : 2012 Article en page(s) : pp. 8495-8509 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Regression analysis Surveillance Modeling Résumé : In the present work, a monitoring strategy based on between-set regression analysis is developed for the online monitoring of processes with multiple "modes". The definition of modes here differs from the conventional ones in that, the modes here may be different sets of variables collected for the same set of objects (called variable mode) or they may be process measurements collected at different times (called time mode). The subject of analysis includes two predictor data sets, corresponding to two neighboring process modes, and one matrix containing data on quality with which both predictor data sets are associated. The basic assumption is that a certain part of the underlying quality-concemed process variability stays constant despite the changeover of process modes. On the basis of between-set regression analysis, the quality-relevant systematic information in each mode space is decomposed into two parts: the between-mode common subspace and the between-mode specific subspace. The former reveals the between-mode quality-relevant similarity and the latter the dissimilarity. The two parts are then used in the development of an online monitoring system. The feasibility and performance of the proposed method are illustrated with a simple numerical case and a typical multiphase batch process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066777
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8495-8509[article] Statistical modeling and online monitoring based on between - set regression analysis [texte imprimé] / Chunhui Zhao, Auteur ; Furong Gao, Auteur ; Youxian Sun, Auteur . - 2012 . - pp. 8495-8509.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8495-8509
Mots-clés : Regression analysis Surveillance Modeling Résumé : In the present work, a monitoring strategy based on between-set regression analysis is developed for the online monitoring of processes with multiple "modes". The definition of modes here differs from the conventional ones in that, the modes here may be different sets of variables collected for the same set of objects (called variable mode) or they may be process measurements collected at different times (called time mode). The subject of analysis includes two predictor data sets, corresponding to two neighboring process modes, and one matrix containing data on quality with which both predictor data sets are associated. The basic assumption is that a certain part of the underlying quality-concemed process variability stays constant despite the changeover of process modes. On the basis of between-set regression analysis, the quality-relevant systematic information in each mode space is decomposed into two parts: the between-mode common subspace and the between-mode specific subspace. The former reveals the between-mode quality-relevant similarity and the latter the dissimilarity. The two parts are then used in the development of an online monitoring system. The feasibility and performance of the proposed method are illustrated with a simple numerical case and a typical multiphase batch process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066777 Exemplaires
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Titre : Inferential model for industrial polypropylene melt index prediction with embedded priori knowledge and delay estimation Type de document : texte imprimé Auteurs : Haichuan Lou, Auteur ; Hongye Su, Auteur ; Lei Xie, Auteur Année de publication : 2012 Article en page(s) : pp. 8510-8525 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Prediction Modeling Résumé : Melt index inferential model plays an important role in the control and optimization of polypropylene production. This study proposed a novel multiple-priori-knowledge based neural network (MPKNN) inferential model for melt index prediction. The prior knowledge from the industrial propylene polymerization process is fully exploited and embedded into the construction of multilayer perceptron neural network in the form of nonlinear constraints. Meanwhile, an adaptive PSO-SQP (particle swarm optimization-sequential quadratics programming) is proposed to optimize the network weights. The proposed MPKNN model has good fitting and prediction ability. Meanwhile, it can avoid unwanted zero value and wrong signal of the model gains. By embedding priori knowledge, the model ensures the safety in the quality control of melt index. In addition, a hybrid model combining the MPKNN model with a simplified mechanism model is proposed to enhance the extrapolation capability. A normalized mutual information method is employed to estimate the delay between independent variables and dependent variables. The proposed hybrid inferential model is validated on recorded data from an industrial double-loop propylene-polymerization reaction process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066778
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8510-8525[article] Inferential model for industrial polypropylene melt index prediction with embedded priori knowledge and delay estimation [texte imprimé] / Haichuan Lou, Auteur ; Hongye Su, Auteur ; Lei Xie, Auteur . - 2012 . - pp. 8510-8525.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8510-8525
Mots-clés : Prediction Modeling Résumé : Melt index inferential model plays an important role in the control and optimization of polypropylene production. This study proposed a novel multiple-priori-knowledge based neural network (MPKNN) inferential model for melt index prediction. The prior knowledge from the industrial propylene polymerization process is fully exploited and embedded into the construction of multilayer perceptron neural network in the form of nonlinear constraints. Meanwhile, an adaptive PSO-SQP (particle swarm optimization-sequential quadratics programming) is proposed to optimize the network weights. The proposed MPKNN model has good fitting and prediction ability. Meanwhile, it can avoid unwanted zero value and wrong signal of the model gains. By embedding priori knowledge, the model ensures the safety in the quality control of melt index. In addition, a hybrid model combining the MPKNN model with a simplified mechanism model is proposed to enhance the extrapolation capability. A normalized mutual information method is employed to estimate the delay between independent variables and dependent variables. The proposed hybrid inferential model is validated on recorded data from an industrial double-loop propylene-polymerization reaction process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066778 Exemplaires
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Titre : Energy efficiency estimation based on data fusion strategy : Case study of ethylene product industry Type de document : texte imprimé Auteurs : Zhiqiang Geng, Auteur ; Yongming Han, Auteur ; Xiangbai Gu, Auteur Année de publication : 2012 Article en page(s) : pp. 8526-8534 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Energetic efficiency Résumé : Data fusion is an emerging technology to fuse data from multiple data or information of the environment through measurement and detection to make a more accurate and reliable estimation or decision. In this Article, energy consumption data are collected from ethylene plants with the high temperature steam cracking process technology. An integrated framework of the energy efficiency estimation is proposed on the basis of data fusion strategy. A Hierarchical Variable Variance Fusion (HWF) algorithm and a Fuzzy Analytic Hierarchy Process (FAHP) method are proposed to estimate energy efficiencies of ethylene equipments. For different equipment scales with the same process technology, the HVVF algorithm is used to estimate energy efficiency ranks among different equipments. For different technologies based on HVVF results, the FAHP method based on the approximate fuzzy eigenvector is used to get energy efficiency indices (EEI) of total ethylene industries. The comparisons are used to assess energy utilization states of different equipments and technologies. It is helpful to decision-makers to identify quantitative energy consumptions and major influence factors to improve energy-saving chances. Furthermore, the proposed strategy can be used to evaluate energy efficiencies in other process units too. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066779
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8526-8534[article] Energy efficiency estimation based on data fusion strategy : Case study of ethylene product industry [texte imprimé] / Zhiqiang Geng, Auteur ; Yongming Han, Auteur ; Xiangbai Gu, Auteur . - 2012 . - pp. 8526-8534.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8526-8534
Mots-clés : Energetic efficiency Résumé : Data fusion is an emerging technology to fuse data from multiple data or information of the environment through measurement and detection to make a more accurate and reliable estimation or decision. In this Article, energy consumption data are collected from ethylene plants with the high temperature steam cracking process technology. An integrated framework of the energy efficiency estimation is proposed on the basis of data fusion strategy. A Hierarchical Variable Variance Fusion (HWF) algorithm and a Fuzzy Analytic Hierarchy Process (FAHP) method are proposed to estimate energy efficiencies of ethylene equipments. For different equipment scales with the same process technology, the HVVF algorithm is used to estimate energy efficiency ranks among different equipments. For different technologies based on HVVF results, the FAHP method based on the approximate fuzzy eigenvector is used to get energy efficiency indices (EEI) of total ethylene industries. The comparisons are used to assess energy utilization states of different equipments and technologies. It is helpful to decision-makers to identify quantitative energy consumptions and major influence factors to improve energy-saving chances. Furthermore, the proposed strategy can be used to evaluate energy efficiencies in other process units too. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066779 Exemplaires
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Titre : Rule - based scheduling of single - stage multiproduct batch plants with parallel units Type de document : texte imprimé Auteurs : Bin Shi, Auteur ; Lie-Xiang Yan, Auteur ; Wei, Wu, Auteur Année de publication : 2012 Article en page(s) : pp. 8535-8549 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Batchwise Scheduling Résumé : A new rule-based model for single-stage multiproduct scheduling problem (SMSP) in batch plants with parallel units is proposed. The scheduling problem is decomposed into two subproblems of order assignment and order sequencing. A group of order assignment rules are introduced to select suitable units for customer orders. While flexible constraint handling strategies are proposed to eliminate the constraints of forbidden units and unit release times and convert the hard constraint of forbidden sequences to a soft one, leading to any arbitrary order sequence can be synthesized into a legal schedule. The line-up competition algorithm (LUCA) is presented to obtain optimal order sequence and order assignment rule, which can minimize makespan, total tardiness, or total cost. Through comparative study, the proposed approach has demonstrated its effectiveness for solving a large size SMSP. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066780
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8535-8549[article] Rule - based scheduling of single - stage multiproduct batch plants with parallel units [texte imprimé] / Bin Shi, Auteur ; Lie-Xiang Yan, Auteur ; Wei, Wu, Auteur . - 2012 . - pp. 8535-8549.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8535-8549
Mots-clés : Batchwise Scheduling Résumé : A new rule-based model for single-stage multiproduct scheduling problem (SMSP) in batch plants with parallel units is proposed. The scheduling problem is decomposed into two subproblems of order assignment and order sequencing. A group of order assignment rules are introduced to select suitable units for customer orders. While flexible constraint handling strategies are proposed to eliminate the constraints of forbidden units and unit release times and convert the hard constraint of forbidden sequences to a soft one, leading to any arbitrary order sequence can be synthesized into a legal schedule. The line-up competition algorithm (LUCA) is presented to obtain optimal order sequence and order assignment rule, which can minimize makespan, total tardiness, or total cost. Through comparative study, the proposed approach has demonstrated its effectiveness for solving a large size SMSP. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066780 Exemplaires
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Titre : Integration of scheduling and control with closed loop implementation Type de document : texte imprimé Auteurs : Jinjun Zhuge, Auteur ; Marianthi G. Ierapetritou, Auteur Année de publication : 2012 Article en page(s) : pp. 8550-8565 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Closed loop Scheduling Résumé : We propose a closed loop strategy to implement simultaneous scheduling and control for chemical processes subject to disturbances. Evidences from published work in the literature suggest that the integration of scheduling and control for multiproduct processes results in optimal production taking into consideration transition stages. On the basis of that, we build a dosed loop implementation for simultaneous scheduling and control, which mitigates the effects of disturbances by generating new solutions once the state deviation due to disturbances is detected. To test the performance of the proposed methodology, we use two case studies, and compare their performance with that of open loop implementation. The results of the case studies verify the effectiveness of closed loop strategy in dealing with process disturbances. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066781
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8550-8565[article] Integration of scheduling and control with closed loop implementation [texte imprimé] / Jinjun Zhuge, Auteur ; Marianthi G. Ierapetritou, Auteur . - 2012 . - pp. 8550-8565.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8550-8565
Mots-clés : Closed loop Scheduling Résumé : We propose a closed loop strategy to implement simultaneous scheduling and control for chemical processes subject to disturbances. Evidences from published work in the literature suggest that the integration of scheduling and control for multiproduct processes results in optimal production taking into consideration transition stages. On the basis of that, we build a dosed loop implementation for simultaneous scheduling and control, which mitigates the effects of disturbances by generating new solutions once the state deviation due to disturbances is detected. To test the performance of the proposed methodology, we use two case studies, and compare their performance with that of open loop implementation. The results of the case studies verify the effectiveness of closed loop strategy in dealing with process disturbances. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066781 Exemplaires
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Titre : New control structure for feed - effluent heat exchanger / reactor systems Type de document : texte imprimé Auteurs : William L. Luyben, Auteur Année de publication : 2012 Article en page(s) : pp. 8566-8574 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reactor Heat exchanger Résumé : Feed-effluent heat exchangers (FEHEs) are widely used in high-temperature exothermic adiabatic tubular reactor systems to conserve energy. The hot reactor effluent is recycled back to a feed preheater to provide all or a portion of the energy required to preheat the reactor feed to the optimum reactor inlet temperature. Several alternative flowsheets have been presented in the literature for this type of configuration. Some use bypassing of cold material around the FEHE, some use a furnace after the FEHE and before the reactor, and some use a cooler (steam generator) after the reactor. A number of control structures have been proposed to control the reactor inlet temperature, which is critical for the steady-state performance (achieving the desired conversion and staying below some maximum temperature). It is also critical for dynamic performance since these systems can be openloop unstable as a result of the positive feedback of energy from the reactor back to the preheat system. The control structure must prevent quenching to low temperatures ("blowout") and temperature runaways ("blowup"). The most commonly suggested control structure recommends controlling the temperature of the mixed stream after the FEHE by manipulating the bypass flow and controlling the reactor inlet temperature by manipulating fuel to the furnace. This paper presents an alternative process and control configuration that reduces furnace energy consumption while maintaining good dynamic control in the face of very large disturbances. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066782
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8566-8574[article] New control structure for feed - effluent heat exchanger / reactor systems [texte imprimé] / William L. Luyben, Auteur . - 2012 . - pp. 8566-8574.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8566-8574
Mots-clés : Reactor Heat exchanger Résumé : Feed-effluent heat exchangers (FEHEs) are widely used in high-temperature exothermic adiabatic tubular reactor systems to conserve energy. The hot reactor effluent is recycled back to a feed preheater to provide all or a portion of the energy required to preheat the reactor feed to the optimum reactor inlet temperature. Several alternative flowsheets have been presented in the literature for this type of configuration. Some use bypassing of cold material around the FEHE, some use a furnace after the FEHE and before the reactor, and some use a cooler (steam generator) after the reactor. A number of control structures have been proposed to control the reactor inlet temperature, which is critical for the steady-state performance (achieving the desired conversion and staying below some maximum temperature). It is also critical for dynamic performance since these systems can be openloop unstable as a result of the positive feedback of energy from the reactor back to the preheat system. The control structure must prevent quenching to low temperatures ("blowout") and temperature runaways ("blowup"). The most commonly suggested control structure recommends controlling the temperature of the mixed stream after the FEHE by manipulating the bypass flow and controlling the reactor inlet temperature by manipulating fuel to the furnace. This paper presents an alternative process and control configuration that reduces furnace energy consumption while maintaining good dynamic control in the face of very large disturbances. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066782 Exemplaires
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Titre : Production of 125I from neutron irradiation of natural Xe gas and a wet distillation process for radiopharmaceutical applications Type de document : texte imprimé Auteurs : P. V. Joshi, Auteur ; K. C. Jagadeesan, Auteur ; R. B. Manolkar, Auteur Année de publication : 2012 Article en page(s) : pp. 8575-8582 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Distillation Production Résumé : In this article, we describe a simple and facile approach for the production of 125I from the neutron-irradiated natural Xe using wet chemical distillation. First, we outline the design of the irradiation container, its fabrication, cryogenic loading of the gaseous Xe target into the irradiation container, and hermetic sealing of the irradiation container. Quality-assurance tests of the irradiation containers were performed to ensure their safety during neutron irradiation. In light of the implicit need to obtain 125I activity with minimum126I radionuclidic contamination, the irradiation time, neutron flux, and target cooling time were judiciously optimized. A thorough optimization of esperimental parameters of distillation was carried out to obtain the optimal yield of 125I having the desired purity. In each batch, typically 4 g of natural xenon gas was irradiated in the BARC Dhruva reactor for 15 days with a thermal neutron flux of approximately 5 × 1013 cm―2 s―1. After irradiation, the targets were left to decay for typically ∼50 days to reduce the 126I contamination. Several batches of 125I were successfully produced using the developed procedure at a level of ∼18.5 GBq (500 mCi) 125I per batch. The 125I quality in terms of radionuclidic purity, radiochemical purity, and radioactive concentration was evaluated and found to be acceptable for radiolabeling studies. This reported method currently has been adapted for the routine production of 125I to meet local needs. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066783
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8575-8582[article] Production of 125I from neutron irradiation of natural Xe gas and a wet distillation process for radiopharmaceutical applications [texte imprimé] / P. V. Joshi, Auteur ; K. C. Jagadeesan, Auteur ; R. B. Manolkar, Auteur . - 2012 . - pp. 8575-8582.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8575-8582
Mots-clés : Distillation Production Résumé : In this article, we describe a simple and facile approach for the production of 125I from the neutron-irradiated natural Xe using wet chemical distillation. First, we outline the design of the irradiation container, its fabrication, cryogenic loading of the gaseous Xe target into the irradiation container, and hermetic sealing of the irradiation container. Quality-assurance tests of the irradiation containers were performed to ensure their safety during neutron irradiation. In light of the implicit need to obtain 125I activity with minimum126I radionuclidic contamination, the irradiation time, neutron flux, and target cooling time were judiciously optimized. A thorough optimization of esperimental parameters of distillation was carried out to obtain the optimal yield of 125I having the desired purity. In each batch, typically 4 g of natural xenon gas was irradiated in the BARC Dhruva reactor for 15 days with a thermal neutron flux of approximately 5 × 1013 cm―2 s―1. After irradiation, the targets were left to decay for typically ∼50 days to reduce the 126I contamination. Several batches of 125I were successfully produced using the developed procedure at a level of ∼18.5 GBq (500 mCi) 125I per batch. The 125I quality in terms of radionuclidic purity, radiochemical purity, and radioactive concentration was evaluated and found to be acceptable for radiolabeling studies. This reported method currently has been adapted for the routine production of 125I to meet local needs. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066783 Exemplaires
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Titre : Control configuration selection for multivariable nonlinear systems Type de document : texte imprimé Auteurs : Hamid Reza Shaker, Auteur ; Mohammad Komareji, Auteur Année de publication : 2012 Article en page(s) : pp. 8583-8587 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Non linear system Multivariable Résumé : Control configuration selection is the procedure of choosing the appropriate input and output pairs for the design of SISO (or block) controllers. This step is an important prerequisite for a successful industrial control strategy. In industrial practices, it is often the case that systems, which are needed to be controlled, are nonlinear, and linear models are insufficient to describe the behavior of the processes. The focus of this work is on the problem of control configuration selection for such systems. A gramian-based interaction measure for control configuration selection of MIMO nonlinear processes is described. In general, most of the results on the control configuration selection, which have been proposed so far, can only support linear systems. The proposed gramian-based interaction measure not only supports nonlinear processes but also can be used to propose a richer sparse or block diagonal controller structure. The interaction measure is used for control configuration selection of the nonlinear quadruple-tank process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066784
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8583-8587[article] Control configuration selection for multivariable nonlinear systems [texte imprimé] / Hamid Reza Shaker, Auteur ; Mohammad Komareji, Auteur . - 2012 . - pp. 8583-8587.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8583-8587
Mots-clés : Non linear system Multivariable Résumé : Control configuration selection is the procedure of choosing the appropriate input and output pairs for the design of SISO (or block) controllers. This step is an important prerequisite for a successful industrial control strategy. In industrial practices, it is often the case that systems, which are needed to be controlled, are nonlinear, and linear models are insufficient to describe the behavior of the processes. The focus of this work is on the problem of control configuration selection for such systems. A gramian-based interaction measure for control configuration selection of MIMO nonlinear processes is described. In general, most of the results on the control configuration selection, which have been proposed so far, can only support linear systems. The proposed gramian-based interaction measure not only supports nonlinear processes but also can be used to propose a richer sparse or block diagonal controller structure. The interaction measure is used for control configuration selection of the nonlinear quadruple-tank process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066784 Exemplaires
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Titre : Selective extraction of 1 - hexene against n - hexane in ionic liquids with or without silver salt Type de document : texte imprimé Auteurs : Rulong Li, Auteur ; Huabin Xing, Auteur ; Qiwei Yang, Auteur Année de publication : 2012 Article en page(s) : pp. 8588-8597 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic liquid Selective extraction Résumé : This paper presents an extensive study on the feasibility of ionic liquids (ILs) for the extractive separation of a 1-hexene/n-hexane mixture. Seventeen ILs were tested at 313 K. The extraction selectivities of 1-hexene to n-hexane were in the range 1.5-3.0. The chemical structures of anion and cation in ILs greatly affected the extraction, and the functional groups, such as carbon―carbon double bond, nitrile, ester, and amide, in the ILs led to higher selectivities. The increase of alkyl chain length in cation led to the increase of extraction capacity of I-hexene. To increase the distribution of 1-hexene in IL phase, silver salt was added to the ILs. It was found that ILs containing silver salt had a high distribution of 1-hexene, as well as high selectivity of 1-hexene against n-hexane. The extraction efficiency increased with the concentration of silver salt in ILs. When the initial feed concentration of 1-hexene was smaller, the selectivity of 1-hexene to n-hexane was higher. A simple mathematical model has been developed to describe the total 1-hexene content in the reaction media under study, on the basis of the formation of complexes between silver and 1-hexene with different stoichiometry. This work proves that the ILs can act as effective extractants in 1-hexene/n-hexane separation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066785
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8588-8597[article] Selective extraction of 1 - hexene against n - hexane in ionic liquids with or without silver salt [texte imprimé] / Rulong Li, Auteur ; Huabin Xing, Auteur ; Qiwei Yang, Auteur . - 2012 . - pp. 8588-8597.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8588-8597
Mots-clés : Ionic liquid Selective extraction Résumé : This paper presents an extensive study on the feasibility of ionic liquids (ILs) for the extractive separation of a 1-hexene/n-hexane mixture. Seventeen ILs were tested at 313 K. The extraction selectivities of 1-hexene to n-hexane were in the range 1.5-3.0. The chemical structures of anion and cation in ILs greatly affected the extraction, and the functional groups, such as carbon―carbon double bond, nitrile, ester, and amide, in the ILs led to higher selectivities. The increase of alkyl chain length in cation led to the increase of extraction capacity of I-hexene. To increase the distribution of 1-hexene in IL phase, silver salt was added to the ILs. It was found that ILs containing silver salt had a high distribution of 1-hexene, as well as high selectivity of 1-hexene against n-hexane. The extraction efficiency increased with the concentration of silver salt in ILs. When the initial feed concentration of 1-hexene was smaller, the selectivity of 1-hexene to n-hexane was higher. A simple mathematical model has been developed to describe the total 1-hexene content in the reaction media under study, on the basis of the formation of complexes between silver and 1-hexene with different stoichiometry. This work proves that the ILs can act as effective extractants in 1-hexene/n-hexane separation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066785 Exemplaires
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Titre : Chelating resins silica gel supported aminophosphonic acids prepared by a heterogeneous synthesis method and a homogeneous synthesis method and the removal properties for Hg(II) from aqueous solutions Type de document : texte imprimé Auteurs : Zengdi Wang, Auteur ; Ping Yin, Auteur ; Zhi Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 8598-8607 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aqueous solution Silica gel Résumé : Two kinds of composites silica gel supported by aminophosphonic acids SG-T-P-1 and SG-T-P-2 were prepared successfully by functionalization of silica gel via a heterogeneous synthesis method and a homogeneous synthesis method, respectively, and they were characterized by infrared spectra (IR), scanning electron microscope (SEM), and energy dispersive X-ray analysis system spectrum (EDXAS). Moreover, the static adsorption capabilities of these two chelating resins toward transition-metal ions were studied. Our objective was to choose the adsorbent with high adsorption capacities via different synthesis methods, and the results showed that SG-T-P prepared via a homogeneous synthesis method had excellent adsorption capacities and high adsorption selectivity for Hg(II) ions. The Langmuir model was better than the Freundlich model to fit the adsorption isotherms of SG-T-P for Hg(II), and the maximum adsorption capacity was 303.03 mg/g at 15 °C. Thus, the novel chelating resin silica gel supported by aminophosphonic acids SG-T-P prepared by a homogeneous synthesis method is favorable and useful for the removal of Hg(II) ions from aqueous solutions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066786
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8598-8607[article] Chelating resins silica gel supported aminophosphonic acids prepared by a heterogeneous synthesis method and a homogeneous synthesis method and the removal properties for Hg(II) from aqueous solutions [texte imprimé] / Zengdi Wang, Auteur ; Ping Yin, Auteur ; Zhi Wang, Auteur . - 2012 . - pp. 8598-8607.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8598-8607
Mots-clés : Aqueous solution Silica gel Résumé : Two kinds of composites silica gel supported by aminophosphonic acids SG-T-P-1 and SG-T-P-2 were prepared successfully by functionalization of silica gel via a heterogeneous synthesis method and a homogeneous synthesis method, respectively, and they were characterized by infrared spectra (IR), scanning electron microscope (SEM), and energy dispersive X-ray analysis system spectrum (EDXAS). Moreover, the static adsorption capabilities of these two chelating resins toward transition-metal ions were studied. Our objective was to choose the adsorbent with high adsorption capacities via different synthesis methods, and the results showed that SG-T-P prepared via a homogeneous synthesis method had excellent adsorption capacities and high adsorption selectivity for Hg(II) ions. The Langmuir model was better than the Freundlich model to fit the adsorption isotherms of SG-T-P for Hg(II), and the maximum adsorption capacity was 303.03 mg/g at 15 °C. Thus, the novel chelating resin silica gel supported by aminophosphonic acids SG-T-P prepared by a homogeneous synthesis method is favorable and useful for the removal of Hg(II) ions from aqueous solutions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066786 Exemplaires
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Titre : 13C NMR spectroscopy of a novel amine species in the DEAB–CO2–H2O system : VLE model Type de document : texte imprimé Auteurs : Huancong Shi, Auteur ; Teerawat Sema, Auteur ; Abdulaziz Naami, Auteur Année de publication : 2012 Article en page(s) : pp. 8608–8615 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Spectroscopy Résumé : In the present work, ion speciation studies in solutions of the novel amine 4-(diethylamine)-2-butanol (DEAB), at various CO2 loadings (0–0.8 mol of CO2/mol of amine) and amine concentrations (0.52–1.97 M), were determined by 13C nuclear magnetic resonance (NMR) spectroscopy. In addition, the dissociation constant K of DEABH+ was determined at 24.5, 35, and 45 °C using a pH meter. The ion speciation plot, which contains various sets of concentrations of DEAB, protonated DEAB, bicarbonate, and carbonate, was successfully generated. Because DEAB is a novel solvent, this is the first time that the ion speciation plots of the DEAB–CO2–H2O system have been developed. It is also the first time that the 13C NMR calibration technique was applied to develop the vapor–liquid equilibrium (VLE) model for an amine–CO2–H2O system. The results obtained from the present work can be a great help for the further analysis of the DEAB VLE model, as well as CO2 absorption and kinetics studies. Furthermore, it was found that the novel 13C NMR calibration technique developed in this work provides higher accuracy than the conventional technique. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300358c
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8608–8615[article] 13C NMR spectroscopy of a novel amine species in the DEAB–CO2–H2O system : VLE model [texte imprimé] / Huancong Shi, Auteur ; Teerawat Sema, Auteur ; Abdulaziz Naami, Auteur . - 2012 . - pp. 8608–8615.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8608–8615
Mots-clés : Spectroscopy Résumé : In the present work, ion speciation studies in solutions of the novel amine 4-(diethylamine)-2-butanol (DEAB), at various CO2 loadings (0–0.8 mol of CO2/mol of amine) and amine concentrations (0.52–1.97 M), were determined by 13C nuclear magnetic resonance (NMR) spectroscopy. In addition, the dissociation constant K of DEABH+ was determined at 24.5, 35, and 45 °C using a pH meter. The ion speciation plot, which contains various sets of concentrations of DEAB, protonated DEAB, bicarbonate, and carbonate, was successfully generated. Because DEAB is a novel solvent, this is the first time that the ion speciation plots of the DEAB–CO2–H2O system have been developed. It is also the first time that the 13C NMR calibration technique was applied to develop the vapor–liquid equilibrium (VLE) model for an amine–CO2–H2O system. The results obtained from the present work can be a great help for the further analysis of the DEAB VLE model, as well as CO2 absorption and kinetics studies. Furthermore, it was found that the novel 13C NMR calibration technique developed in this work provides higher accuracy than the conventional technique. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300358c Exemplaires
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Titre : Continuous supercritical emulsions extraction : Packed tower characterization and application to poly (lactic-co-glycolic Acid) + insulin microspheres production Type de document : texte imprimé Auteurs : Nunzia Falco, Auteur ; Ernesto Reverchon, Auteur ; Giovanna Della Porta, Auteur Année de publication : 2012 Article en page(s) : pp. 8616-8623 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Production Microsphere Packed column Emulsion Supercritical state Résumé : The continuous supercritical emulsions extraction (SEE-C) process uses a countercurrent packed tower for the continuous extraction of the organic solvents from emulsions. The continuous operation allows the formation of microspheres that are recovered at the bottom of the tower in the form of a water suspension, avoiding coalescence problems and batch-to-batch repeatability, typical of traditional processes. In this work, the packed tower used for SEE-C was characterized from a fluidodynamic point of view: flooding conditions and the allowable density difference were calculated from the experimental data. Then, an active principle (insulin) was tested for its encapsulation in poly(lactic-co-glycolic acid) (PLGA) microspheres, starting from a double emulsion: particle size, morphology, and encapsulation efficiency of the produced microdevices were evaluated. Spherical, not collapsed microspheres with a mean diameter between 1.8 μm (SD ± 0.9) and 4.8 μm (SD ± 2.8) and encapsulation efficiencies up to 70% were obtained. The very fast solvent extraction rate did not influence the particle morphology but had a significant effect on the size distribution of the precipitates which were always smaller than the starting droplets. A solvent residue (ethyl acetate) lower than about 600 ppm was obtained in all the experiments performed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066788
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8616-8623[article] Continuous supercritical emulsions extraction : Packed tower characterization and application to poly (lactic-co-glycolic Acid) + insulin microspheres production [texte imprimé] / Nunzia Falco, Auteur ; Ernesto Reverchon, Auteur ; Giovanna Della Porta, Auteur . - 2012 . - pp. 8616-8623.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8616-8623
Mots-clés : Production Microsphere Packed column Emulsion Supercritical state Résumé : The continuous supercritical emulsions extraction (SEE-C) process uses a countercurrent packed tower for the continuous extraction of the organic solvents from emulsions. The continuous operation allows the formation of microspheres that are recovered at the bottom of the tower in the form of a water suspension, avoiding coalescence problems and batch-to-batch repeatability, typical of traditional processes. In this work, the packed tower used for SEE-C was characterized from a fluidodynamic point of view: flooding conditions and the allowable density difference were calculated from the experimental data. Then, an active principle (insulin) was tested for its encapsulation in poly(lactic-co-glycolic acid) (PLGA) microspheres, starting from a double emulsion: particle size, morphology, and encapsulation efficiency of the produced microdevices were evaluated. Spherical, not collapsed microspheres with a mean diameter between 1.8 μm (SD ± 0.9) and 4.8 μm (SD ± 2.8) and encapsulation efficiencies up to 70% were obtained. The very fast solvent extraction rate did not influence the particle morphology but had a significant effect on the size distribution of the precipitates which were always smaller than the starting droplets. A solvent residue (ethyl acetate) lower than about 600 ppm was obtained in all the experiments performed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066788 Exemplaires
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Titre : Regeneration of spent activated charcoals used for lignin removal from prehydrolysis - kraft prehydrolyzates Type de document : texte imprimé Auteurs : Jenny Sabrina Gutsch, Auteur ; Herbert Sixta, Auteur Année de publication : 2012 Article en page(s) : pp. 8624-8630 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Activated charcoals Résumé : Lignin in prehydrolysis-kraft prehydrolyzates leads to incrustations and impedes the utilization of the hemicellulosic fraction as a product. The adsorption of the lignin on activated charcoal directly after prehydrolysis at prehydrolysis temperatures prevents the formation of these incrustations efficiently. However, reutilization of the charcoal is necessary to ensure an economic process. To develop adequate recycling strategies for the spent activated charcoal, solvent extraction and thermal regeneration were investigated with respect to the recycling performance of the regenerated charcoals. Solvent extraction of the spent charcoals showed only limited efficiency, while the adsorption capacity of the activated charcoal was quantitatively restored by a thermal treatment at 950 °C. This was demonstrated by a pore size distribution and a lignin adsorption behavior of the recycled activated charcoal comparable to that of a fresh one which allows the reutilization of the charcoal in the adsorption process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006116?mi=snxuk8&af=R&pageSize=20&searchT [...]
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8624-8630[article] Regeneration of spent activated charcoals used for lignin removal from prehydrolysis - kraft prehydrolyzates [texte imprimé] / Jenny Sabrina Gutsch, Auteur ; Herbert Sixta, Auteur . - 2012 . - pp. 8624-8630.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8624-8630
Mots-clés : Activated charcoals Résumé : Lignin in prehydrolysis-kraft prehydrolyzates leads to incrustations and impedes the utilization of the hemicellulosic fraction as a product. The adsorption of the lignin on activated charcoal directly after prehydrolysis at prehydrolysis temperatures prevents the formation of these incrustations efficiently. However, reutilization of the charcoal is necessary to ensure an economic process. To develop adequate recycling strategies for the spent activated charcoal, solvent extraction and thermal regeneration were investigated with respect to the recycling performance of the regenerated charcoals. Solvent extraction of the spent charcoals showed only limited efficiency, while the adsorption capacity of the activated charcoal was quantitatively restored by a thermal treatment at 950 °C. This was demonstrated by a pore size distribution and a lignin adsorption behavior of the recycled activated charcoal comparable to that of a fresh one which allows the reutilization of the charcoal in the adsorption process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006116?mi=snxuk8&af=R&pageSize=20&searchT [...] Exemplaires
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Titre : Analysis of equilibrium - based TSA processes for direct capture of CO2 from air Type de document : texte imprimé Auteurs : Ambarish R. Kulkarni, Auteur ; David S. Sholl, Auteur Année de publication : 2012 Article en page(s) : pp. 8631–8645 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption processes Capture CO2 Résumé : Direct capture of CO2 from air is a concept that, if successfully implemented, could lead to capture of CO2 from disperse sources. We have developed process models to consider the viability of adsorption-based air capture technologies. Our models focus on using an amino-modified silica adsorbent, TRI-PE-MCM-41, and a structured monolithic contactor unit. We have studied several different temperature swing adsorption processes using the purity of CO2 and annual product throughput as metrics for comparing process performance. This analysis identifies some of the operational parameters, adsorbent characteristics, and other factors that have a significant effect on the performance of the process. Using the total energy requirement of the process and available sources of energy, such as low pressure steam and electricity, we carry out an economic analysis to obtain a net operating cost for air capture of CO2. We identify a process with a daily throughput of 1.1 t CO2 at 88.5% purity using standard shipping container sized air capture units. The total energy required (6745 MJ/t CO2) is dominated by the parasitic losses—sensible heat requirements of the contactor (40%) and the adsorbent (28%) and not by the mechanical energy associated with air flow (5%). On the basis of our analysis of factors such as source of electricity, availability of low pressure steam, and geographic location, the net operating cost of capture is estimated to be $100/t CO2. These cost estimates do not include capital expenses necessary to construct or maintain the air capture units. Potential strategies for further reducing the energy and monetary cost of these processes are identified. Our analysis supports continued work to establish the technological and economic feasibility of adsorption-based air capture. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300691c
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8631–8645[article] Analysis of equilibrium - based TSA processes for direct capture of CO2 from air [texte imprimé] / Ambarish R. Kulkarni, Auteur ; David S. Sholl, Auteur . - 2012 . - pp. 8631–8645.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8631–8645
Mots-clés : Adsorption processes Capture CO2 Résumé : Direct capture of CO2 from air is a concept that, if successfully implemented, could lead to capture of CO2 from disperse sources. We have developed process models to consider the viability of adsorption-based air capture technologies. Our models focus on using an amino-modified silica adsorbent, TRI-PE-MCM-41, and a structured monolithic contactor unit. We have studied several different temperature swing adsorption processes using the purity of CO2 and annual product throughput as metrics for comparing process performance. This analysis identifies some of the operational parameters, adsorbent characteristics, and other factors that have a significant effect on the performance of the process. Using the total energy requirement of the process and available sources of energy, such as low pressure steam and electricity, we carry out an economic analysis to obtain a net operating cost for air capture of CO2. We identify a process with a daily throughput of 1.1 t CO2 at 88.5% purity using standard shipping container sized air capture units. The total energy required (6745 MJ/t CO2) is dominated by the parasitic losses—sensible heat requirements of the contactor (40%) and the adsorbent (28%) and not by the mechanical energy associated with air flow (5%). On the basis of our analysis of factors such as source of electricity, availability of low pressure steam, and geographic location, the net operating cost of capture is estimated to be $100/t CO2. These cost estimates do not include capital expenses necessary to construct or maintain the air capture units. Potential strategies for further reducing the energy and monetary cost of these processes are identified. Our analysis supports continued work to establish the technological and economic feasibility of adsorption-based air capture. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300691c Exemplaires
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Titre : Effectiveness of aluminum chlorohydrate (ACH) for decolorization of silk dyebath effluents Type de document : texte imprimé Auteurs : Akshaya K. Verma, Auteur ; Puspendu Bhunia, Auteur ; Rajesh R. Dash, Auteur Année de publication : 2012 Article en page(s) : pp. 8646–8651 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Decolorization silk dyebath effluents Résumé : The present study focuses on the decolorization of real silk dyebath effluents using analytical-grade magnesium chloride (MCl) with and without guar gum (GG) as a coagulant aid and industrial-grade polyaluminium chloride (PACl) and aluminum chlorohydrate (ACH) as coagulants. A higher decolorization efficiency of 97% at a very high dosage of 1800 mg L–1 was observed for MCl. However, considering the purity, dosage, decolorization efficiency, and quantity and quality of sludge production, ACH was found to be the best coagulant, giving 91% decolorization efficiency at a dose of just 100 mg L–1. To achieve this high degree of decolorization efficiency, the dosage for PACl was found to be approximately 50% higher than that of ACH. Effective decolorization (>90%) at a very low dosage (100 mg L–1) and minimal quantity of sludge production by ACH demonstrate that ACH is an effective coagulant for decolorization of silk dyebath effluents. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301201r
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8646–8651[article] Effectiveness of aluminum chlorohydrate (ACH) for decolorization of silk dyebath effluents [texte imprimé] / Akshaya K. Verma, Auteur ; Puspendu Bhunia, Auteur ; Rajesh R. Dash, Auteur . - 2012 . - pp. 8646–8651.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8646–8651
Mots-clés : Decolorization silk dyebath effluents Résumé : The present study focuses on the decolorization of real silk dyebath effluents using analytical-grade magnesium chloride (MCl) with and without guar gum (GG) as a coagulant aid and industrial-grade polyaluminium chloride (PACl) and aluminum chlorohydrate (ACH) as coagulants. A higher decolorization efficiency of 97% at a very high dosage of 1800 mg L–1 was observed for MCl. However, considering the purity, dosage, decolorization efficiency, and quantity and quality of sludge production, ACH was found to be the best coagulant, giving 91% decolorization efficiency at a dose of just 100 mg L–1. To achieve this high degree of decolorization efficiency, the dosage for PACl was found to be approximately 50% higher than that of ACH. Effective decolorization (>90%) at a very low dosage (100 mg L–1) and minimal quantity of sludge production by ACH demonstrate that ACH is an effective coagulant for decolorization of silk dyebath effluents. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301201r Exemplaires
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Titre : Circulating - fluidized - bed - based calcium - looping gasifier : Experimental studies on the calcination – carbonation cycle Type de document : texte imprimé Auteurs : Bishnu Acharya, Auteur ; Animesh Dutta, Auteur ; Prabir Basu, Auteur Année de publication : 2012 Article en page(s) : pp. 8652–8660 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biomass Gasification Résumé : The interest in hydrogen energy is rising. Biomass could be its potential resource. Steam gasification of biomass in the presence of the sorbent calcium oxide (CaO) can produce a gas rich in hydrogen along with in situ capture of the carbon dioxide (CO2) produced. Calcium-looping gasification (CLG) produces a gas rich in hydrogen and at the same time captures CO2 during the process while also regenerating sorbent producing pure CO2. However, deposition of char and tar, sintering because of high-temperature operation, and cyclic heating and cooling in the looping system can drastically reduce the ability of sorbent to capture CO2 and at the same time for its regeneration. Therefore, this paper presents the study conducted to examine the performance of the sorbent as it goes through a number of alternating calcination–carbonation cycles. This research is carried out using two rigs. With the first one, kinetic rates are developed for calcination in the presence of three media: nitrogen (N2), CO2, and steam (H2O). With the second one, the effects of the particle size, medium, and temperature on the calcination and carbonation reactions are studied. An empirical relationship, in order to predict the loss during carbonation as the sorbent goes through successive calcination–carbonation cycles, is developed and presented here. With the calcium-looping system at the laboratory scale, (a) assessment of the fluid dynamics of the process, distribution of the pressure, and particles lost by attrition and (b) a study of the calcination–carbonation cycle are made and presented in this paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300629a
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8652–8660[article] Circulating - fluidized - bed - based calcium - looping gasifier : Experimental studies on the calcination – carbonation cycle [texte imprimé] / Bishnu Acharya, Auteur ; Animesh Dutta, Auteur ; Prabir Basu, Auteur . - 2012 . - pp. 8652–8660.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8652–8660
Mots-clés : Biomass Gasification Résumé : The interest in hydrogen energy is rising. Biomass could be its potential resource. Steam gasification of biomass in the presence of the sorbent calcium oxide (CaO) can produce a gas rich in hydrogen along with in situ capture of the carbon dioxide (CO2) produced. Calcium-looping gasification (CLG) produces a gas rich in hydrogen and at the same time captures CO2 during the process while also regenerating sorbent producing pure CO2. However, deposition of char and tar, sintering because of high-temperature operation, and cyclic heating and cooling in the looping system can drastically reduce the ability of sorbent to capture CO2 and at the same time for its regeneration. Therefore, this paper presents the study conducted to examine the performance of the sorbent as it goes through a number of alternating calcination–carbonation cycles. This research is carried out using two rigs. With the first one, kinetic rates are developed for calcination in the presence of three media: nitrogen (N2), CO2, and steam (H2O). With the second one, the effects of the particle size, medium, and temperature on the calcination and carbonation reactions are studied. An empirical relationship, in order to predict the loss during carbonation as the sorbent goes through successive calcination–carbonation cycles, is developed and presented here. With the calcium-looping system at the laboratory scale, (a) assessment of the fluid dynamics of the process, distribution of the pressure, and particles lost by attrition and (b) a study of the calcination–carbonation cycle are made and presented in this paper. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300629a Exemplaires
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Titre : Hydrodynamics of electrostatic charge in polypropylene fluidized beds Type de document : texte imprimé Auteurs : Piyawan Tiyapiboonchaiya a, Auteur ; Dimitri Gidaspow, Auteur ; Somsak Damronglerd, Auteur Année de publication : 2012 Article en page(s) : pp. 8661-8668 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fluidized bed Fluidization Electrostatic charge Hydrodynamics Résumé : Experiments were performed in a double jacket gas―solid fluidized bed to investigate the process and degree of electrification in polypropylene fluidized beds. Five copper rings attached to the inner column wall were connected to a picoammeter for measuring the electrical current at the different vertical levels. It was found that both positive and negative electrical currents were traced in the whole bed. The magnitude of positive current value was observed at the bottom of the bed while at the top part of the bed the magnitude of negative current value was found The influence of initial bed height, fluidization velocity, and gas temperature on the degree of electrification was investigated. The effect of gas temperature played a significant role in the charge dissipation. Also, the degree of electrification increased with initial bed height and gas velocity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066793
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8661-8668[article] Hydrodynamics of electrostatic charge in polypropylene fluidized beds [texte imprimé] / Piyawan Tiyapiboonchaiya a, Auteur ; Dimitri Gidaspow, Auteur ; Somsak Damronglerd, Auteur . - 2012 . - pp. 8661-8668.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8661-8668
Mots-clés : Fluidized bed Fluidization Electrostatic charge Hydrodynamics Résumé : Experiments were performed in a double jacket gas―solid fluidized bed to investigate the process and degree of electrification in polypropylene fluidized beds. Five copper rings attached to the inner column wall were connected to a picoammeter for measuring the electrical current at the different vertical levels. It was found that both positive and negative electrical currents were traced in the whole bed. The magnitude of positive current value was observed at the bottom of the bed while at the top part of the bed the magnitude of negative current value was found The influence of initial bed height, fluidization velocity, and gas temperature on the degree of electrification was investigated. The effect of gas temperature played a significant role in the charge dissipation. Also, the degree of electrification increased with initial bed height and gas velocity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066793 Exemplaires
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Titre : Influence of pressure gradient on column efficiency in GC separations Type de document : texte imprimé Auteurs : Weiqiang Hao, Auteur ; Bin Di, Auteur ; Qiang Chen, Auteur Année de publication : 2012 Article en page(s) : pp. 8669-8674 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pressure gradient Résumé : Pressure gradient along the column in gas chromatography leads to the decompression of the carrier gas and thus varied flow velocity that can be accounted for by the Darcy's law. By solving mathematical models such as the equilibrium dispersive (ED) and the transport models, which account for axial dispersion and mass transfer processes between mobile and stationary phases, respectively, the expressions for retention time and plate height under such nonuniform condition were obtained. As a first approximation, it is assumed that pressure gradient has little affect on the mass transfer coefficients such as axial dispersion coefficient (D) and lumped mass transfer coeffident (kf). It is found that, by using average flow velocity (u) that includes the parameter of inlet—outlet pressure ratio (γ), the expressions obtained from the transport model can be reduced to the mathematical forms of the expressions deduced by assuming uniform flow velocity. By contrast, the expressions obtained from the ED model show some differences. These results indicate the coupling effect between pressure gradient and axial dispersion. In most practical cases, retention time expressions obtained from these models are consistent due to large value of average Peclet number. The plate height accounting for axial dispersion effects will vary from 2D /u to 2.7D /u when γ changes from 1 to infinity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066794
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8669-8674[article] Influence of pressure gradient on column efficiency in GC separations [texte imprimé] / Weiqiang Hao, Auteur ; Bin Di, Auteur ; Qiang Chen, Auteur . - 2012 . - pp. 8669-8674.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8669-8674
Mots-clés : Pressure gradient Résumé : Pressure gradient along the column in gas chromatography leads to the decompression of the carrier gas and thus varied flow velocity that can be accounted for by the Darcy's law. By solving mathematical models such as the equilibrium dispersive (ED) and the transport models, which account for axial dispersion and mass transfer processes between mobile and stationary phases, respectively, the expressions for retention time and plate height under such nonuniform condition were obtained. As a first approximation, it is assumed that pressure gradient has little affect on the mass transfer coefficients such as axial dispersion coefficient (D) and lumped mass transfer coeffident (kf). It is found that, by using average flow velocity (u) that includes the parameter of inlet—outlet pressure ratio (γ), the expressions obtained from the transport model can be reduced to the mathematical forms of the expressions deduced by assuming uniform flow velocity. By contrast, the expressions obtained from the ED model show some differences. These results indicate the coupling effect between pressure gradient and axial dispersion. In most practical cases, retention time expressions obtained from these models are consistent due to large value of average Peclet number. The plate height accounting for axial dispersion effects will vary from 2D /u to 2.7D /u when γ changes from 1 to infinity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066794 Exemplaires
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Titre : Analysis of melt flow mixing in czochralski crystal growth process Type de document : texte imprimé Auteurs : Mojtaba Izadi, Auteur ; Stevan Dubljevic, Auteur Année de publication : 2012 Article en page(s) : pp. 8675–8683 Note générale : Industrial chemistry Langues : Anglais (eng) Résumé : The prime example of a relevant industrial process in which fluid flow dynamics impacts desired process specifications is given by the Czochralski (CZ) crystal growth process. Melt flow in the crucible induces a variety of transport phenomena with profound effects on the mass, momentum, and heat transfer during the process. To provide novel insight into the transport phenomena associated with the CZ process melt flow, the approach of discerning the mixing templates by identifying Lagrangian coherent structures (LCS) is explored. In particular, the LCS have been extracted to identify transport features in the melt during the crystal growth. The finite-element method has been employed to simulate realistic axisymmetric melt flow accounting for physically relevant geometries (including the melt–crystal and melt–ambient interfaces) for identification of the LCS. These structures are known to represent dynamically driven material surfaces, and they provide insight into mixing properties of the melt flow that influence the characteristics of the grown crystal. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2029656
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8675–8683[article] Analysis of melt flow mixing in czochralski crystal growth process [texte imprimé] / Mojtaba Izadi, Auteur ; Stevan Dubljevic, Auteur . - 2012 . - pp. 8675–8683.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8675–8683
Résumé : The prime example of a relevant industrial process in which fluid flow dynamics impacts desired process specifications is given by the Czochralski (CZ) crystal growth process. Melt flow in the crucible induces a variety of transport phenomena with profound effects on the mass, momentum, and heat transfer during the process. To provide novel insight into the transport phenomena associated with the CZ process melt flow, the approach of discerning the mixing templates by identifying Lagrangian coherent structures (LCS) is explored. In particular, the LCS have been extracted to identify transport features in the melt during the crystal growth. The finite-element method has been employed to simulate realistic axisymmetric melt flow accounting for physically relevant geometries (including the melt–crystal and melt–ambient interfaces) for identification of the LCS. These structures are known to represent dynamically driven material surfaces, and they provide insight into mixing properties of the melt flow that influence the characteristics of the grown crystal. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2029656 Exemplaires
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Titre : Elemental distribution and mineralogical composition of ash deposits in a large - scale wastewater incineration plant : A case study Type de document : texte imprimé Auteurs : Lin Mu, Auteur ; Liang Zhao, Auteur ; Liang Liu, Auteur Année de publication : 2012 Article en page(s) : pp. 8684-8694 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Incineration plant Waste water Ash Mineralogy Mineralogical composition Résumé : Release and transformation of incombustible inorganic substances during petrochemical industrial wastewater incineration form a large number of ash-forming species, which deposit and accumulate on the surfaces of heat transfer tubes, and can pose some severe operational problems, such as fouling, slagging, and even low heat transfer efficiency. Ash deposits characterization has been performed to investigate ash transformation and deposition behavior in a large-scale petrochemical industrial wastewater incineration plant using analytical techniques, including XRF, SEM―EDS, and XRD for elemental composition, morphology, and mineralogy. The results show that this volatile element has a dominated contribution to form varied ash deposits in a wide temperature range from 1000 to about 260 °C. Nickel and iron mainly in the oxide forms are transported by ash particles, have strong deposition propensity at high temperatures, and can be captured by the sticky initial deposition layer. Meanwhile, sulfur is enriched at low temperatures due to condensation, nucleation of alkali metal sulfates, and sorption of SO2/SO3. In the temperature range of 550―900 °C, eutectic mixtures which are temperature-dependent are formed in the molten phase and an "evolving" branched structure detected from SEM indicates the formation of a sintered deposition layer. Acidic salt sodium sesquisulfate is generated at low temperatures and should be responsible for the initiation of low temperature corrosion. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066796
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8684-8694[article] Elemental distribution and mineralogical composition of ash deposits in a large - scale wastewater incineration plant : A case study [texte imprimé] / Lin Mu, Auteur ; Liang Zhao, Auteur ; Liang Liu, Auteur . - 2012 . - pp. 8684-8694.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8684-8694
Mots-clés : Incineration plant Waste water Ash Mineralogy Mineralogical composition Résumé : Release and transformation of incombustible inorganic substances during petrochemical industrial wastewater incineration form a large number of ash-forming species, which deposit and accumulate on the surfaces of heat transfer tubes, and can pose some severe operational problems, such as fouling, slagging, and even low heat transfer efficiency. Ash deposits characterization has been performed to investigate ash transformation and deposition behavior in a large-scale petrochemical industrial wastewater incineration plant using analytical techniques, including XRF, SEM―EDS, and XRD for elemental composition, morphology, and mineralogy. The results show that this volatile element has a dominated contribution to form varied ash deposits in a wide temperature range from 1000 to about 260 °C. Nickel and iron mainly in the oxide forms are transported by ash particles, have strong deposition propensity at high temperatures, and can be captured by the sticky initial deposition layer. Meanwhile, sulfur is enriched at low temperatures due to condensation, nucleation of alkali metal sulfates, and sorption of SO2/SO3. In the temperature range of 550―900 °C, eutectic mixtures which are temperature-dependent are formed in the molten phase and an "evolving" branched structure detected from SEM indicates the formation of a sintered deposition layer. Acidic salt sodium sesquisulfate is generated at low temperatures and should be responsible for the initiation of low temperature corrosion. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066796 Exemplaires
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Titre : Dual pressure swing adsorption units for gas separation and purification Type de document : texte imprimé Auteurs : Carlos A. Grande, Auteur ; Richard Blom, Auteur Année de publication : 2012 Article en page(s) : pp. 8695-8699 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Purification Pressure swing adsorption Résumé : This work presents a new application of pressure swing adsorption (PSA) technology. Using the dual PSA concept it is possible to separate a gaseous stream and obtain two high purity products. The dual PSA concept resembles distillation in its spatial distribution with two well-defined subsections: stripping and rectifying. After the gas mixture passes through the stripping section, the most-adsorbed gas is produced with high purity and the less-adsorbed gas is produced as top product from the rectifying section. Stripping and rectifying sections can operate under different operating conditions, have different adsorbents, and, most importantly, have different cycle scheduling. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066797
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8695-8699[article] Dual pressure swing adsorption units for gas separation and purification [texte imprimé] / Carlos A. Grande, Auteur ; Richard Blom, Auteur . - 2012 . - pp. 8695-8699.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8695-8699
Mots-clés : Purification Pressure swing adsorption Résumé : This work presents a new application of pressure swing adsorption (PSA) technology. Using the dual PSA concept it is possible to separate a gaseous stream and obtain two high purity products. The dual PSA concept resembles distillation in its spatial distribution with two well-defined subsections: stripping and rectifying. After the gas mixture passes through the stripping section, the most-adsorbed gas is produced with high purity and the less-adsorbed gas is produced as top product from the rectifying section. Stripping and rectifying sections can operate under different operating conditions, have different adsorbents, and, most importantly, have different cycle scheduling. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066797 Exemplaires
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Titre : Control of product distribution of fischer – tropsch synthesis with a novel rotating packed - bed reactor : From diesel to light olefin Type de document : texte imprimé Auteurs : Jian-feng Chen, Auteur ; Yi Liu, Auteur ; Yi Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 8700-8703 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fixed bed reactor Fischer Tropsch synthesis Résumé : A rotating packed-bed (RPB) reactor has been first applied to the Fischer―Tropsch synthesis (FTS) reaction. The main products of the FTS can be selectively formed by choosing the optimum high gravity level of the RPB reactor, which has opened a door to tailor the product distribution of FTS. The high selectivity of light olefins in RPB reactor provides a novel pathway to directly and effectively form light olefins from syngas, syngas to olefin (STO), which would avoid low-efficiency methanol synthesis and methanol-to-olefin (MTO) process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066798
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8700-8703[article] Control of product distribution of fischer – tropsch synthesis with a novel rotating packed - bed reactor : From diesel to light olefin [texte imprimé] / Jian-feng Chen, Auteur ; Yi Liu, Auteur ; Yi Zhang, Auteur . - 2012 . - pp. 8700-8703.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8700-8703
Mots-clés : Fixed bed reactor Fischer Tropsch synthesis Résumé : A rotating packed-bed (RPB) reactor has been first applied to the Fischer―Tropsch synthesis (FTS) reaction. The main products of the FTS can be selectively formed by choosing the optimum high gravity level of the RPB reactor, which has opened a door to tailor the product distribution of FTS. The high selectivity of light olefins in RPB reactor provides a novel pathway to directly and effectively form light olefins from syngas, syngas to olefin (STO), which would avoid low-efficiency methanol synthesis and methanol-to-olefin (MTO) process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066798 Exemplaires
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Titre : Spongy Hydrogels of Cyanobacterial Polyanions Mediate Energy-Saving Electrolytic Metal-Refinement Type de document : texte imprimé Auteurs : Maiko K. Okajima, Auteur ; Masatoshi Nakamura, Auteur ; Tetsuya Ogawa, Auteur Année de publication : 2012 Article en page(s) : pp. 8704-8707 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Energy conservation Résumé : The freeze-drying of anionic megamolecules extracted from gelatinous cyanobacteria, Aphanothece sacrum, formed spongy materials capable of metal adsorption to form hydrogels. Cryogenic-transmission electron microscopy demonstrated that thicker nanofibers were formed in sacran/In3+ complexes than in sacran/Sn4+. The preferential sorption of In3+ into the hydrogels occurred in the mixed solution of In3+ and Sn4+ with concentrations below 40 mM. Since In3+ was condensed in the sponges, electrolytic refinement of indium was made using the ion-complex hydrogels at room temperature to obtain indium metal foil at a pure grade over 99.9%. Furthermore, the sponges were recovered and used again, to successfully obtain highly pure indium metal, in even the second and third trials. Thus epochal energy-saving methods for indium refinement were established using spongy hydrogels of cyanobacterial polyanions.
Revue / Journal TitleISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066799
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8704-8707[article] Spongy Hydrogels of Cyanobacterial Polyanions Mediate Energy-Saving Electrolytic Metal-Refinement [texte imprimé] / Maiko K. Okajima, Auteur ; Masatoshi Nakamura, Auteur ; Tetsuya Ogawa, Auteur . - 2012 . - pp. 8704-8707.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8704-8707
Mots-clés : Energy conservation Résumé : The freeze-drying of anionic megamolecules extracted from gelatinous cyanobacteria, Aphanothece sacrum, formed spongy materials capable of metal adsorption to form hydrogels. Cryogenic-transmission electron microscopy demonstrated that thicker nanofibers were formed in sacran/In3+ complexes than in sacran/Sn4+. The preferential sorption of In3+ into the hydrogels occurred in the mixed solution of In3+ and Sn4+ with concentrations below 40 mM. Since In3+ was condensed in the sponges, electrolytic refinement of indium was made using the ion-complex hydrogels at room temperature to obtain indium metal foil at a pure grade over 99.9%. Furthermore, the sponges were recovered and used again, to successfully obtain highly pure indium metal, in even the second and third trials. Thus epochal energy-saving methods for indium refinement were established using spongy hydrogels of cyanobacterial polyanions.
Revue / Journal TitleISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066799 Exemplaires
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