Dépouillements

Trimethylamine-modified lignophenol for the recovery of precious metals / Durga Parajuli in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10163–10168 Titre : Trimethylamine-modified lignophenol for the recovery of precious metals Type de document : texte imprimé Auteurs : Durga Parajuli, Auteur ; Koichi Hirota, Auteur ; Katsutoshi Inoue, Auteur Année de publication : 2010 Article en page(s) : pp. 10163–10168 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Trimethylamine-Modified--Lignophenol--Recovery--Precious--Metals Résumé : A quaternary amine-type sorbent has been prepared by the immobilization of trimethylamine group onto the cross-linked lignophenol matrix. The sorption behavior for a number of metal ions was studied in hydrochloric acid medium. From the batch test of individual metal ion as well as the mixture solution containing equal molar concentration of various metal ions, the sorbent was found to hold selectivity for Au(III), Pd(II), and Pt(IV) ions only with negligible sorption for other metal ions like Cu(II), Co(II), Fe(III), Ni(II), and Zn(II). The sorption kinetics was studied at 30, 50, and 65 °C and elucidated the order of sorption of Au(III), Pd(II), and Pt(IV) and from the values of rate constants at different temperatures, the energy of activation has been evaluated. The sorption isotherm study revealed the Langmuir type sorption and from the Langmuir charts the maximum loading capacity of Au(III), Pd(II), and Pt(IV) has been evaluated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801829w [article] Trimethylamine-modified lignophenol for the recovery of precious metals [texte imprimé] / Durga Parajuli, Auteur ; Koichi Hirota, Auteur ; Katsutoshi Inoue, Auteur . - 2010 . - pp. 10163–10168. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10163–10168 Mots-clés : Trimethylamine-Modified--Lignophenol--Recovery--Precious--Metals Résumé : A quaternary amine-type sorbent has been prepared by the immobilization of trimethylamine group onto the cross-linked lignophenol matrix. The sorption behavior for a number of metal ions was studied in hydrochloric acid medium. From the batch test of individual metal ion as well as the mixture solution containing equal molar concentration of various metal ions, the sorbent was found to hold selectivity for Au(III), Pd(II), and Pt(IV) ions only with negligible sorption for other metal ions like Cu(II), Co(II), Fe(III), Ni(II), and Zn(II). The sorption kinetics was studied at 30, 50, and 65 °C and elucidated the order of sorption of Au(III), Pd(II), and Pt(IV) and from the values of rate constants at different temperatures, the energy of activation has been evaluated. The sorption isotherm study revealed the Langmuir type sorption and from the Langmuir charts the maximum loading capacity of Au(III), Pd(II), and Pt(IV) has been evaluated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801829w

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Corrosion Behavior of Carbon Steel in the Monoethanolamine−H2O−CO2−O2−SO2 System: Products, Reaction Pathways, and Kinetics / Nattawan Kladkaew in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10169–10179 Titre : Corrosion Behavior of Carbon Steel in the Monoethanolamine−H2O−CO2−O2−SO2 System: Products, Reaction Pathways, and Kinetics Type de document : texte imprimé Auteurs : Nattawan Kladkaew, Auteur ; Raphael Idem, Auteur ; Paitoon Tontiwachwuthikul, Auteur Année de publication : 2010 Article en page(s) : pp. 10169–10179 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Corrosion Behavior--Carbon Steel--Monoethanolamine−  H2O−  CO2−  O2−  SO2--System--Products--Reaction--Pathways--Kinetics Résumé : This work investigates the effect of operating parameters on corrosion products, reaction pathways, and kinetics for the corrosion of carbon steel in the monoethanolamine−H2O−CO2−O2−SO2 system. Corrosion experiments were conducted using a 273A potentiostat unit under conditions in which monoethanolamine (MEA), O2, and SO2 concentrations and CO2 loading were in the range of 1−7 kmol/m3, 0−100%, 0−204 ppm, and 0−0.5 mol CO2/mol MEA, respectively, at corrosion temperatures of 303−353 K to mimic the absorption−regeneration sections. Analysis, performed for this system for the first time, shows that corrosion products generated from the effect of SO2 include FeSO4 and Fe2O3·H2O. Also, a higher concentration of SO2 in simulated flue gas stream induces a higher corrosion rate because of the increase in the hydrogen ion concentration generated by reactions of SO2 and H2O as well as SO2, O2, and H2O. A power-law model developed to correlate corrosion rate with the parameters in the MEA−H2O−CO2−O2−SO2 system shows that corrosion rate of carbon steel increases with an increase in O2 and SO2 concentrations in simulated flue gas stream, as well as MEA concentration, CO2 loading, and operating temperature. It was observed that CO2 loading had the highest impact on the corrosion rate, while SO2 and O2 show only slight effects on the corrosion rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900877p [article] Corrosion Behavior of Carbon Steel in the Monoethanolamine−H2O−CO2−O2−SO2 System: Products, Reaction Pathways, and Kinetics [texte imprimé] / Nattawan Kladkaew, Auteur ; Raphael Idem, Auteur ; Paitoon Tontiwachwuthikul, Auteur . - 2010 . - pp. 10169–10179. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10169–10179 Mots-clés : Corrosion Behavior--Carbon Steel--Monoethanolamine−  H2O−  CO2−  O2−  SO2--System--Products--Reaction--Pathways--Kinetics Résumé : This work investigates the effect of operating parameters on corrosion products, reaction pathways, and kinetics for the corrosion of carbon steel in the monoethanolamine−H2O−CO2−O2−SO2 system. Corrosion experiments were conducted using a 273A potentiostat unit under conditions in which monoethanolamine (MEA), O2, and SO2 concentrations and CO2 loading were in the range of 1−7 kmol/m3, 0−100%, 0−204 ppm, and 0−0.5 mol CO2/mol MEA, respectively, at corrosion temperatures of 303−353 K to mimic the absorption−regeneration sections. Analysis, performed for this system for the first time, shows that corrosion products generated from the effect of SO2 include FeSO4 and Fe2O3·H2O. Also, a higher concentration of SO2 in simulated flue gas stream induces a higher corrosion rate because of the increase in the hydrogen ion concentration generated by reactions of SO2 and H2O as well as SO2, O2, and H2O. A power-law model developed to correlate corrosion rate with the parameters in the MEA−H2O−CO2−O2−SO2 system shows that corrosion rate of carbon steel increases with an increase in O2 and SO2 concentrations in simulated flue gas stream, as well as MEA concentration, CO2 loading, and operating temperature. It was observed that CO2 loading had the highest impact on the corrosion rate, while SO2 and O2 show only slight effects on the corrosion rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900877p

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Rice polish / D. Ranjan in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10180–10185 Titre : Rice polish : an alternative to conventional adsorbents for treating arsenic bearing water by Up-flow column method Type de document : texte imprimé Auteurs : D. Ranjan, Auteur ; M. alat, Auteur ; S. H. Hasan, Auteur Année de publication : 2010 Article en page(s) : pp. 10180–10185 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Rice Polish--Alternative--Conventional--Adsorbents--Treating--Arsenic--Bearing--Up-Flow Column Method Résumé : “Rice polish”, an agrowaste from rice milling industries, was utilized as potential biosorbent for removal of arsenic from water in a continuous up-flow fixed bed column system. The experiments were conducted to study the effect of important design parameters such as bed height, flow rate, and initial metal ion concentration. At a bed height of 25 cm, flow rate 1.66 mL/min, and initial metal ion concentration 1000 μg/L, the metal uptake capacity of rice polish for As(III) and As(V) was found to be 66.95 and 78.95 μg/g, respectively. The bed depth service time (BDST) model was used to analyze the experimental data. The computed sorption capacity (No) was 28776 and 28248 μg/L for As(III) and As(V), respectively. The rate constant (Ka) was recorded as 0.117 × 10−3 and 0.26 × 10−4 (L/μg)/min for As(III) and As(V), respectively. The column regeneration studies were carried out using 10% NaOH as eluant for three sorption−desorption cycles. The high arsenic removal ability and regeneration efficiency of this biosorbent suggest its applicability in industrial processes and data generated would help in further upscaling of the adsorption process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900877p [article] Rice polish : an alternative to conventional adsorbents for treating arsenic bearing water by Up-flow column method [texte imprimé] / D. Ranjan, Auteur ; M. alat, Auteur ; S. H. Hasan, Auteur . - 2010 . - pp. 10180–10185. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10180–10185 Mots-clés : Rice Polish--Alternative--Conventional--Adsorbents--Treating--Arsenic--Bearing--Up-Flow Column Method Résumé : “Rice polish”, an agrowaste from rice milling industries, was utilized as potential biosorbent for removal of arsenic from water in a continuous up-flow fixed bed column system. The experiments were conducted to study the effect of important design parameters such as bed height, flow rate, and initial metal ion concentration. At a bed height of 25 cm, flow rate 1.66 mL/min, and initial metal ion concentration 1000 μg/L, the metal uptake capacity of rice polish for As(III) and As(V) was found to be 66.95 and 78.95 μg/g, respectively. The bed depth service time (BDST) model was used to analyze the experimental data. The computed sorption capacity (No) was 28776 and 28248 μg/L for As(III) and As(V), respectively. The rate constant (Ka) was recorded as 0.117 × 10−3 and 0.26 × 10−4 (L/μg)/min for As(III) and As(V), respectively. The column regeneration studies were carried out using 10% NaOH as eluant for three sorption−desorption cycles. The high arsenic removal ability and regeneration efficiency of this biosorbent suggest its applicability in industrial processes and data generated would help in further upscaling of the adsorption process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900877p

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Effect of dioxygen partial pressure on ligand degradation in chelated Iron dehydrosulfurization processes / Stephen A. Bedell in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10186–10189 Titre : Effect of dioxygen partial pressure on ligand degradation in chelated Iron dehydrosulfurization processes Type de document : texte imprimé Auteurs : Stephen A. Bedell, Auteur ; Clare M. Worley, Auteur Année de publication : 2010 Article en page(s) : pp. 10186–10189 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Effect--Dioxygen--Partial--Pressure--Ligand--Degradation--Chelated--Iron--Dehydrosulfurization--Processes Résumé : Chelated iron processes such as LO-CAT and SulFeroxSM utilize ferric chelate solutions for the oxidation of hydrogen sulfide to form aqueous suspensions of sulfur. During the ferrous chelate reoxidation, dioxygen reduction intermediates are believed to initiate oxidative degradation reactions of the aminocarboxylate ligands used in the process. This study shows that the same degree of Fe(II) oxidation (regeneration) can be achieved with reduced ligand degradation by decreasing the rate at which O2 is supplied to a reactor. This apparent mass transfer limited degradation is explained in terms of dioxygen reduction intermediate formation and reactions. A model for bubble column regeneration was used to predict local partial pressures of dioxygen for a number of reactor configurations. Such analysis predicts several changes in regenerator design which could substantially reduce the amount of chemical usage in such a process. Changes include reduction of the stoichiometric excess of air, use of multiple reactors, and recycling of spent air. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900904s [article] Effect of dioxygen partial pressure on ligand degradation in chelated Iron dehydrosulfurization processes [texte imprimé] / Stephen A. Bedell, Auteur ; Clare M. Worley, Auteur . - 2010 . - pp. 10186–10189. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10186–10189 Mots-clés : Effect--Dioxygen--Partial--Pressure--Ligand--Degradation--Chelated--Iron--Dehydrosulfurization--Processes Résumé : Chelated iron processes such as LO-CAT and SulFeroxSM utilize ferric chelate solutions for the oxidation of hydrogen sulfide to form aqueous suspensions of sulfur. During the ferrous chelate reoxidation, dioxygen reduction intermediates are believed to initiate oxidative degradation reactions of the aminocarboxylate ligands used in the process. This study shows that the same degree of Fe(II) oxidation (regeneration) can be achieved with reduced ligand degradation by decreasing the rate at which O2 is supplied to a reactor. This apparent mass transfer limited degradation is explained in terms of dioxygen reduction intermediate formation and reactions. A model for bubble column regeneration was used to predict local partial pressures of dioxygen for a number of reactor configurations. Such analysis predicts several changes in regenerator design which could substantially reduce the amount of chemical usage in such a process. Changes include reduction of the stoichiometric excess of air, use of multiple reactors, and recycling of spent air. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900904s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Influence of Soda−Air−AQ Pulping of Straw on Silica Precipitation, Paper Strength, and Performance of CPVA as a Dry Strength Additive / Pedram Fatehi in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10190–10195 Titre : Influence of Soda−Air−AQ Pulping of Straw on Silica Precipitation, Paper Strength, and Performance of CPVA as a Dry Strength Additive Type de document : texte imprimé Auteurs : Pedram Fatehi, Auteur ; Ahmet Tutus, Auteur ; Yonghao Ni, Auteur Année de publication : 2010 Article en page(s) : pp. 10190–10195 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Influence--Soda−  Air−  AQ--Pulping--Straw--Silica--Precipitation--Paper Strength--Performance--CPVA--Strength Additive Résumé : In this study, the impact of soda−air−anthraquinone (AQ) pulping conditions on delignification and silica precipitation onto pulp fibers and paper sheets was studied. The results showed that the yield and silica precipitation slightly increased upon application of AQ in soda−air pulping. Scanning electron microscopy (SEM) and elemental analysis confirmed the deposition of silica-related particles on fibers and on paper sheets for both soda−air and soda−air−AQ pulping. Furthermore, increasing the cooking temperature had a stronger impact on delignification and silica deposition than did increasing the cooking time for soda−air−AQ pulping. In another set of experiments, the influence of cationic poly(vinyl alcohol) (CPVA) with two different molecular weights on improving the strength properties of straw pulps produced under various soda−air−AQ pulping conditions was studied. The adsorption of CPVA onto straw pulp and its effect on silica retention for paper sheets were comprehensively investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901273m [article] Influence of Soda−Air−AQ Pulping of Straw on Silica Precipitation, Paper Strength, and Performance of CPVA as a Dry Strength Additive [texte imprimé] / Pedram Fatehi, Auteur ; Ahmet Tutus, Auteur ; Yonghao Ni, Auteur . - 2010 . - pp. 10190–10195. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10190–10195 Mots-clés : Influence--Soda−  Air−  AQ--Pulping--Straw--Silica--Precipitation--Paper Strength--Performance--CPVA--Strength Additive Résumé : In this study, the impact of soda−air−anthraquinone (AQ) pulping conditions on delignification and silica precipitation onto pulp fibers and paper sheets was studied. The results showed that the yield and silica precipitation slightly increased upon application of AQ in soda−air pulping. Scanning electron microscopy (SEM) and elemental analysis confirmed the deposition of silica-related particles on fibers and on paper sheets for both soda−air and soda−air−AQ pulping. Furthermore, increasing the cooking temperature had a stronger impact on delignification and silica deposition than did increasing the cooking time for soda−air−AQ pulping. In another set of experiments, the influence of cationic poly(vinyl alcohol) (CPVA) with two different molecular weights on improving the strength properties of straw pulps produced under various soda−air−AQ pulping conditions was studied. The adsorption of CPVA onto straw pulp and its effect on silica retention for paper sheets were comprehensively investigated. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901273m

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Recent Developments in the Use of Layered Double Hydroxides as Host Materials for the Storage and Triggered Release of Functional Anions / Aamir I. Khan in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10196–10205 Titre : Recent Developments in the Use of Layered Double Hydroxides as Host Materials for the Storage and Triggered Release of Functional Anions Type de document : texte imprimé Auteurs : Aamir I. Khan, Auteur ; Anusha Ragavan, Auteur ; Bonnie Fong, Auteur Année de publication : 2010 Article en page(s) : pp. 10196–10205 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Recent--Developments--Layered--Double--Hydroxides--Materials--Storage--Triggered--Release--Functional Anions Résumé : An extensive and systematic study of the intercalation of a number of commercially important anions into a range of layered double hydroxides (LDHs) has been undertaken. A pseudo-combinatorial approach was employed to determine rapidly the ideal reaction conditions for the intercalation of each guest. Over 50 LDH nanohybrids are reported, the vast majority of them having never previously been synthesized. Guest anions include key drugs, important agrochemicals, vitamins, fragrances, a dye, and a color fixant. The immense potential of LDH systems as reservoirs and to remove agrochemical pollutants from effluvium flows was demonstrated. The release of the guest anions was studied in representative conditions. Some of the thiosulfate intercalates show temperature programmable release characteristics which have not be observed previously. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012612 [article] Recent Developments in the Use of Layered Double Hydroxides as Host Materials for the Storage and Triggered Release of Functional Anions [texte imprimé] / Aamir I. Khan, Auteur ; Anusha Ragavan, Auteur ; Bonnie Fong, Auteur . - 2010 . - pp. 10196–10205. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10196–10205 Mots-clés : Recent--Developments--Layered--Double--Hydroxides--Materials--Storage--Triggered--Release--Functional Anions Résumé : An extensive and systematic study of the intercalation of a number of commercially important anions into a range of layered double hydroxides (LDHs) has been undertaken. A pseudo-combinatorial approach was employed to determine rapidly the ideal reaction conditions for the intercalation of each guest. Over 50 LDH nanohybrids are reported, the vast majority of them having never previously been synthesized. Guest anions include key drugs, important agrochemicals, vitamins, fragrances, a dye, and a color fixant. The immense potential of LDH systems as reservoirs and to remove agrochemical pollutants from effluvium flows was demonstrated. The release of the guest anions was studied in representative conditions. Some of the thiosulfate intercalates show temperature programmable release characteristics which have not be observed previously. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012612

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Voltammetric oxidation and determination of atenolol using a carbon paste electrode / Roopa H. Patil in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10206–10210 Titre : Voltammetric oxidation and determination of atenolol using a carbon paste electrode Type de document : texte imprimé Auteurs : Roopa H. Patil, Auteur ; Rajesh N. Hegde, Auteur ; S. T. Nandibewoor, Auteur Année de publication : 2010 Article en page(s) : pp. 10206–10210 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Voltammetric--Oxidation--Determination--Atenolol--Using--Carbon--Paste--Electrode Résumé : The electrochemical oxidation of atenolol, an antihypertensive drug, was studied in a phosphate medium at a carbon paste electrode. Cyclic voltammetric results showed one well-defined oxidation peak in the potential range from 0.2 to 1.2 V under different pH conditions, but the best results were obtained at pH 10.4. The oxidation was irreversible and exhibited diffusion-controlled behavior. The response was evaluated with respect to pH and scan rate. The number of electrons transferred in the oxidation process was calculated, and the probable oxidation mechanism was proposed. The proposed differential pulse voltammetric method was successfully applied to atenolol determination in pharmaceutical samples. The analytical performance of this method has been evaluated for detection of analyte in urine as a real sample. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901163k [article] Voltammetric oxidation and determination of atenolol using a carbon paste electrode [texte imprimé] / Roopa H. Patil, Auteur ; Rajesh N. Hegde, Auteur ; S. T. Nandibewoor, Auteur . - 2010 . - pp. 10206–10210. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10206–10210 Mots-clés : Voltammetric--Oxidation--Determination--Atenolol--Using--Carbon--Paste--Electrode Résumé : The electrochemical oxidation of atenolol, an antihypertensive drug, was studied in a phosphate medium at a carbon paste electrode. Cyclic voltammetric results showed one well-defined oxidation peak in the potential range from 0.2 to 1.2 V under different pH conditions, but the best results were obtained at pH 10.4. The oxidation was irreversible and exhibited diffusion-controlled behavior. The response was evaluated with respect to pH and scan rate. The number of electrons transferred in the oxidation process was calculated, and the probable oxidation mechanism was proposed. The proposed differential pulse voltammetric method was successfully applied to atenolol determination in pharmaceutical samples. The analytical performance of this method has been evaluated for detection of analyte in urine as a real sample. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901163k

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Photochemical degradation of 2,4,6-trichlorophenol in the brij 35 micellar solution / W. Chu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10211–10216 Titre : Photochemical degradation of 2,4,6-trichlorophenol in the brij 35 micellar solution : pH control on product distribution Type de document : texte imprimé Auteurs : W. Chu, Auteur ; Y. F. Rao, Auteur ; C. Y. Kwan, Auteur Année de publication : 2010 Article en page(s) : pp. 10211–10216 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Photochemical--Degradation--Trichlorophenol--Brij 35 Micellar--Solution--pH Control--Product Distribution Résumé : Surfactants have been used for separating organic pollutants from contaminated soils in soil-washing process. The extracted pollutants can be effectively degraded upon UV irradiation in the presence of surfactant micelles. The photodecay rate of 2,4,6-trichlorophenol (2,4,6-TCP) by UV light at 253.7 nm and photonic efficiency of 2,4,6-TCP degradation reaction were investigated at different pH levels with the addition of nonionic surfactant solutions above the critical micelle concentration (cmc). A continual examination on intermediates at all pHs was conducted and photochemical processes induced the dechlorination of TCP to form di- and monochlorinated intermediates and phenol. An additional reaction was observed when the initial pH level was above neutral, at which chlorinated hydroquinones were the resulting intermediates through photohydrolysis process. Two reaction mechanisms, one at acidic and the other at basic conditions, were proposed and verified by the evidence presented in this study. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9003943 [article] Photochemical degradation of 2,4,6-trichlorophenol in the brij 35 micellar solution : pH control on product distribution [texte imprimé] / W. Chu, Auteur ; Y. F. Rao, Auteur ; C. Y. Kwan, Auteur . - 2010 . - pp. 10211–10216. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10211–10216 Mots-clés : Photochemical--Degradation--Trichlorophenol--Brij 35 Micellar--Solution--pH Control--Product Distribution Résumé : Surfactants have been used for separating organic pollutants from contaminated soils in soil-washing process. The extracted pollutants can be effectively degraded upon UV irradiation in the presence of surfactant micelles. The photodecay rate of 2,4,6-trichlorophenol (2,4,6-TCP) by UV light at 253.7 nm and photonic efficiency of 2,4,6-TCP degradation reaction were investigated at different pH levels with the addition of nonionic surfactant solutions above the critical micelle concentration (cmc). A continual examination on intermediates at all pHs was conducted and photochemical processes induced the dechlorination of TCP to form di- and monochlorinated intermediates and phenol. An additional reaction was observed when the initial pH level was above neutral, at which chlorinated hydroquinones were the resulting intermediates through photohydrolysis process. Two reaction mechanisms, one at acidic and the other at basic conditions, were proposed and verified by the evidence presented in this study. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9003943

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Regiospecific epoxidation of carvone α,β-unsaturated ketone group with a basic resin / María A. Uguina in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10217–10221 Titre : Regiospecific epoxidation of carvone α,β-unsaturated ketone group with a basic resin Type de document : texte imprimé Auteurs : María A. Uguina, Auteur ; José A. Delgado, Auteur ; José Carretero, Auteur Année de publication : 2010 Article en page(s) : pp. 10217–10221 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Regiospecific--Epoxidation--Carvone α  ,β  -Unsaturated--Ketone Group--Basic Resin Résumé : A basic resin in OH− form (Amberlite IRA-900) has been used to catalyze the regiospecific epoxidation of carvone with H2O2 to obtain 5,6-epoxycarvone, showing high activity and selectivity (>99%). The effects of solvent, temperature, stirring rate, catalyst loading, oxidant/substrate ratio, and oxidant dosage have been analyzed. A second-order kinetic model has been proposed to describe the effect of substrate concentration, catalyst loading, and temperature on reaction rate, and the apparent activation energy of the reaction has been estimated. The catalyst has been tested in five consecutive runs and it has shown to be completely reusable after regeneration of its hydroxyl groups before each use. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010723 [article] Regiospecific epoxidation of carvone α,β-unsaturated ketone group with a basic resin [texte imprimé] / María A. Uguina, Auteur ; José A. Delgado, Auteur ; José Carretero, Auteur . - 2010 . - pp. 10217–10221. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10217–10221 Mots-clés : Regiospecific--Epoxidation--Carvone α  ,β  -Unsaturated--Ketone Group--Basic Resin Résumé : A basic resin in OH− form (Amberlite IRA-900) has been used to catalyze the regiospecific epoxidation of carvone with H2O2 to obtain 5,6-epoxycarvone, showing high activity and selectivity (>99%). The effects of solvent, temperature, stirring rate, catalyst loading, oxidant/substrate ratio, and oxidant dosage have been analyzed. A second-order kinetic model has been proposed to describe the effect of substrate concentration, catalyst loading, and temperature on reaction rate, and the apparent activation energy of the reaction has been estimated. The catalyst has been tested in five consecutive runs and it has shown to be completely reusable after regeneration of its hydroxyl groups before each use. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010723

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Influence of secondary reactions on the heat of pyrolysis of biomass / Claudia Gomez in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10222–10233 Titre : Influence of secondary reactions on the heat of pyrolysis of biomass Type de document : texte imprimé Auteurs : Claudia Gomez, Auteur ; Enric Velo, Auteur ; Federica Barontini, Auteur Année de publication : 2010 Article en page(s) : pp. 10222–10233 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Influence--Secondary--Reactions--Heat--Pyrolysis--Biomass Résumé : The thermal behaviors during the pyrolysis of two different biomass samples, beech wood from carpentry residuals and artichoke thistle from energy-dedicated crops, were investigated. Thermogravimetry/differential scanning calorimetry (TG-DSC) and thermogravimetry coupled to Fourier transform infrared (TG-FTIR) analysis of evolving products were used to investigate the thermal effects of the pyrolysis process. The role of pretreatments (hot-water washing, ethanol extraction, and their combination) was also analyzed. High alterations in the heat demand were observed as a function of the initial sample mass and pyrolysis conditions. The role of vapor−solid secondary interactions was evidenced by the evolution profiles of the main pyrolysis products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007985 [article] Influence of secondary reactions on the heat of pyrolysis of biomass [texte imprimé] / Claudia Gomez, Auteur ; Enric Velo, Auteur ; Federica Barontini, Auteur . - 2010 . - pp. 10222–10233. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10222–10233 Mots-clés : Influence--Secondary--Reactions--Heat--Pyrolysis--Biomass Résumé : The thermal behaviors during the pyrolysis of two different biomass samples, beech wood from carpentry residuals and artichoke thistle from energy-dedicated crops, were investigated. Thermogravimetry/differential scanning calorimetry (TG-DSC) and thermogravimetry coupled to Fourier transform infrared (TG-FTIR) analysis of evolving products were used to investigate the thermal effects of the pyrolysis process. The role of pretreatments (hot-water washing, ethanol extraction, and their combination) was also analyzed. High alterations in the heat demand were observed as a function of the initial sample mass and pyrolysis conditions. The role of vapor−solid secondary interactions was evidenced by the evolution profiles of the main pyrolysis products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007985

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Liquid-phase hydrogenation of crotonaldehyde over platinum- and palladium-based catalysts / Betiana C. Campo in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10234–10239 Titre : Liquid-phase hydrogenation of crotonaldehyde over platinum- and palladium-based catalysts Type de document : texte imprimé Auteurs : Betiana C. Campo, Auteur ; María A. Volpe, Auteur ; Carlos E. Gigola, Auteur Année de publication : 2010 Article en page(s) : pp. 10234–10239 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Liquid-Phase--Hydrogenation--Crotonaldehyde--Platinum--Palladium-Based--Catalysts Résumé : The selective hydrogenation of crotonaldehyde in liquid phase, at a temperature of 353 K and a H2 pressure of 400 kPa, is studied over different palladium- and platinum-based catalysts (Pd−Pb/α-Al2O3, Pd−Zn/α-Al2O3, Pd/ZnO, and two Pt/ZnO samples, prepared from Pt(NH3)4(NO3)2 and H2PtCl6, respectively). The intrinsic selectivity of palladium cannot be modified by alloying or following a promotion with a second metal, and the selectivity to crotyl alcohol measured over palladium-based samples is nil or extremely low. The selectivity corresponding to the Pt/ZnO catalysts increases with the time-on-stream reaching high levels. The formation of a Pt−Zn alloy is the origin of the enhanced selectivity toward crotyl alcohol; this effect is more pronounced for the sample that has been prepared from H2PtCl6. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901217r [article] Liquid-phase hydrogenation of crotonaldehyde over platinum- and palladium-based catalysts [texte imprimé] / Betiana C. Campo, Auteur ; María A. Volpe, Auteur ; Carlos E. Gigola, Auteur . - 2010 . - pp. 10234–10239. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10234–10239 Mots-clés : Liquid-Phase--Hydrogenation--Crotonaldehyde--Platinum--Palladium-Based--Catalysts Résumé : The selective hydrogenation of crotonaldehyde in liquid phase, at a temperature of 353 K and a H2 pressure of 400 kPa, is studied over different palladium- and platinum-based catalysts (Pd−Pb/α-Al2O3, Pd−Zn/α-Al2O3, Pd/ZnO, and two Pt/ZnO samples, prepared from Pt(NH3)4(NO3)2 and H2PtCl6, respectively). The intrinsic selectivity of palladium cannot be modified by alloying or following a promotion with a second metal, and the selectivity to crotyl alcohol measured over palladium-based samples is nil or extremely low. The selectivity corresponding to the Pt/ZnO catalysts increases with the time-on-stream reaching high levels. The formation of a Pt−Zn alloy is the origin of the enhanced selectivity toward crotyl alcohol; this effect is more pronounced for the sample that has been prepared from H2PtCl6. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901217r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Reductive Precipitation of Elemental Selenium from Selenious Acidic Solutions Using Sodium Dithionite / Nicolas Geoffroy in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10240–10246 Titre : Reductive Precipitation of Elemental Selenium from Selenious Acidic Solutions Using Sodium Dithionite Type de document : texte imprimé Auteurs : Nicolas Geoffroy, Auteur ; George P. Demopoulos, Auteur Année de publication : 2010 Article en page(s) : pp. 10240–10246 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reductive--Precipitation--Elemental--Selenium--Selenious--Acidic--Solutions--Using Sodium--Dithionite Résumé : In this work, the batch-reactor reduction of selenious acid (H2SeO3) species with sodium dithionite (Na2S2O4) from weakly acidic sulfate solutions containing 300 mg/L of selenium at 23 οC was studied. The results showed that, at an initial pH value of 3, ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008502 [article] Reductive Precipitation of Elemental Selenium from Selenious Acidic Solutions Using Sodium Dithionite [texte imprimé] / Nicolas Geoffroy, Auteur ; George P. Demopoulos, Auteur . - 2010 . - pp. 10240–10246. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10240–10246 Mots-clés : Reductive--Precipitation--Elemental--Selenium--Selenious--Acidic--Solutions--Using Sodium--Dithionite Résumé : In this work, the batch-reactor reduction of selenious acid (H2SeO3) species with sodium dithionite (Na2S2O4) from weakly acidic sulfate solutions containing 300 mg/L of selenium at 23 οC was studied. The results showed that, at an initial pH value of 3, ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008502

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Influence of water quality on the efficiency of retention aids systems for the paper industry / Ruth Ordóñez in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10247–10252 Titre : Influence of water quality on the efficiency of retention aids systems for the paper industry Type de document : texte imprimé Auteurs : Ruth Ordóñez, Auteur ; Daphne Hermosilla, Auteur ; Elena de la Fuente, Auteur Année de publication : 2010 Article en page(s) : pp. 10247–10252 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Influence--Water--Quality--Efficiency--Retention--Systems--Paper--Industry Résumé : It has been reported that about 10−15% of the fresh water intake in a paper mill is used for feeding and diluting retention aids, so significant savings could be achieved by replacing fresh water with process water. Water from different sources and qualities—fresh water, the outflow from an internal ultrafiltration placed in the machine circuit of a paper mill, and water from a membrane bioreactor used to treat the final effluent of this paper mill—were used to prepare a dual retention system consisting of a cationic polyacrylamide and bentonite. While the behavior of bentonite was not significantly affected by the quality of the water used in its preparation, the efficiency of the cationic polyacrylamide was reduced to about 12% when it was prepared with water with high anionic trash content and conductivity as a result of a partial neutralization of the charged groups. The effect of nonionic chemical oxygen demand on the efficiency of the polymer was negligible. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010029 [article] Influence of water quality on the efficiency of retention aids systems for the paper industry [texte imprimé] / Ruth Ordóñez, Auteur ; Daphne Hermosilla, Auteur ; Elena de la Fuente, Auteur . - 2010 . - pp. 10247–10252. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10247–10252 Mots-clés : Influence--Water--Quality--Efficiency--Retention--Systems--Paper--Industry Résumé : It has been reported that about 10−15% of the fresh water intake in a paper mill is used for feeding and diluting retention aids, so significant savings could be achieved by replacing fresh water with process water. Water from different sources and qualities—fresh water, the outflow from an internal ultrafiltration placed in the machine circuit of a paper mill, and water from a membrane bioreactor used to treat the final effluent of this paper mill—were used to prepare a dual retention system consisting of a cationic polyacrylamide and bentonite. While the behavior of bentonite was not significantly affected by the quality of the water used in its preparation, the efficiency of the cationic polyacrylamide was reduced to about 12% when it was prepared with water with high anionic trash content and conductivity as a result of a partial neutralization of the charged groups. The effect of nonionic chemical oxygen demand on the efficiency of the polymer was negligible. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010029

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Industrial investigation on the origin of sulfur in fluid catalytic cracking gasoline / Dicho S. Stratiev in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10253–10261 Titre : Industrial investigation on the origin of sulfur in fluid catalytic cracking gasoline Type de document : texte imprimé Auteurs : Dicho S. Stratiev, Auteur ; Ivelina hishkova, Auteur ; Todor zingov, Auteur Année de publication : 2010 Article en page(s) : pp. 10253–10261 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Industrial--Investigation--Origin--Sulfur--Fluid--Catalytic--Cracking--Gasoline Résumé : Industrial experiments on the addition of H2S to the fluid catalytic cracking (FCC) feed (hydrotreated vacuum gas oil) were carried out in the commercial FCC unit at Lukoil Neftochim, Bulgaria. It was found that during cracking of pure hydrotreated vacuum gas oil to which was added about 550 ppm H2S that the FCC gasoline contained about 12 ppm more sulfur than the nonspiked feed. Both gasolines obtained from the pure feed and the H2S-spiked feed contained the same type of sulfur compounds: mercaptans, thiophenes, and benzothiophenes. In the case of the H2S-spiked feed, the additional FCC gasoline sulfur formed was about 1.2% of the sulfur in the H2S added to the feed. The FCC gasoline sulfur formed from the pure FCC feed, on the other hand, was about 2.5% of the sulfur in the feed. The higher percent of sulfur conversion of the pure FCC feed relative to the conversion of the H2S suggests that both reaction of H2S with olefins or diolefins (from the catalytic cracking of the hydrocarbons of the feed) and transformation of heavy sulfur compounds contained in the feed may be responsible for the entire FCC gasoline sulfur compounds formation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900985g [article] Industrial investigation on the origin of sulfur in fluid catalytic cracking gasoline [texte imprimé] / Dicho S. Stratiev, Auteur ; Ivelina hishkova, Auteur ; Todor zingov, Auteur . - 2010 . - pp. 10253–10261. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10253–10261 Mots-clés : Industrial--Investigation--Origin--Sulfur--Fluid--Catalytic--Cracking--Gasoline Résumé : Industrial experiments on the addition of H2S to the fluid catalytic cracking (FCC) feed (hydrotreated vacuum gas oil) were carried out in the commercial FCC unit at Lukoil Neftochim, Bulgaria. It was found that during cracking of pure hydrotreated vacuum gas oil to which was added about 550 ppm H2S that the FCC gasoline contained about 12 ppm more sulfur than the nonspiked feed. Both gasolines obtained from the pure feed and the H2S-spiked feed contained the same type of sulfur compounds: mercaptans, thiophenes, and benzothiophenes. In the case of the H2S-spiked feed, the additional FCC gasoline sulfur formed was about 1.2% of the sulfur in the H2S added to the feed. The FCC gasoline sulfur formed from the pure FCC feed, on the other hand, was about 2.5% of the sulfur in the feed. The higher percent of sulfur conversion of the pure FCC feed relative to the conversion of the H2S suggests that both reaction of H2S with olefins or diolefins (from the catalytic cracking of the hydrocarbons of the feed) and transformation of heavy sulfur compounds contained in the feed may be responsible for the entire FCC gasoline sulfur compounds formation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900985g

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Photocatalytic degradation of methylene blue dye using ultraviolet light emitting diodes / Rajesh J. Tayade in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10262–10267 Titre : Photocatalytic degradation of methylene blue dye using ultraviolet light emitting diodes Type de document : texte imprimé Auteurs : Rajesh J. Tayade, Auteur ; Thillai Sivakumar Natarajan, Auteur ; Hari C. Bajaj, Auteur Année de publication : 2010 Article en page(s) : pp. 10262–10267 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Photocatalytic--Degradation--Methylene--Blue Dye--Using--Ultraviolet--Emitting Diodes Résumé : This study was focused on the application of ultraviolet light emitting diodes (UV-LED) as an alternate source for the photocatalytic degradation of methylene blue (MB), which was used as a model compound. A simple reactor arrangement was made to carry out the photocatalytic degradation of methylene blue dye. The photocatalytic activity of P-25 Degussa TiO2 was evaluated using UV-LED reactor. The decomposition of MB dye in aqueous solution by TiO2 photocatalytic process with the UV-LED was found to be technically feasible. The effects of various parameters such as catalyst loading, initial dye concentration, pH, and addition of H2O2 on decolorization and degradation have been investigated to find the optimum conditions. The complete mineralization of MB dye (3.12 × 10−5 M) was confirmed by chemical oxygen demand analysis. Results demonstrated that the UV-LED/TiO2 process can effectively degrade methylene blue dye with optimum conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012437 [article] Photocatalytic degradation of methylene blue dye using ultraviolet light emitting diodes [texte imprimé] / Rajesh J. Tayade, Auteur ; Thillai Sivakumar Natarajan, Auteur ; Hari C. Bajaj, Auteur . - 2010 . - pp. 10262–10267. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10262–10267 Mots-clés : Photocatalytic--Degradation--Methylene--Blue Dye--Using--Ultraviolet--Emitting Diodes Résumé : This study was focused on the application of ultraviolet light emitting diodes (UV-LED) as an alternate source for the photocatalytic degradation of methylene blue (MB), which was used as a model compound. A simple reactor arrangement was made to carry out the photocatalytic degradation of methylene blue dye. The photocatalytic activity of P-25 Degussa TiO2 was evaluated using UV-LED reactor. The decomposition of MB dye in aqueous solution by TiO2 photocatalytic process with the UV-LED was found to be technically feasible. The effects of various parameters such as catalyst loading, initial dye concentration, pH, and addition of H2O2 on decolorization and degradation have been investigated to find the optimum conditions. The complete mineralization of MB dye (3.12 × 10−5 M) was confirmed by chemical oxygen demand analysis. Results demonstrated that the UV-LED/TiO2 process can effectively degrade methylene blue dye with optimum conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012437

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Investigation of physicochemical parameters that influence photocatalytic degradation of methyl orange over TiO2 nanotubes / York R. Smith in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10268–10276 Titre : Investigation of physicochemical parameters that influence photocatalytic degradation of methyl orange over TiO2 nanotubes Type de document : texte imprimé Auteurs : York R. Smith, Auteur ; Archana Kar, Auteur ; Vaidyanathan (Ravi) Subramanian, Auteur Année de publication : 2010 Article en page(s) : pp. 10268–10276 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Investigation--Physicochemical--Parameters--Influence--Photocatalytic--Degradation--Methyl--Orange--TiO2 Nanotubes Résumé : The photocatalytic degradation of a model textile dye, methyl orange (MO), using anodized titanium dioxide (TiO2) nanotubes has been investigated. The effects of light intensity, dye concentration, external bias, pH, and nanotube dimensions (length, diameter, and wall thickness) on MO photodegradation have been examined. The application of a minimal bias of +0.0 versus saturated calomel electrode (SCE) can enhance the dye degradation at least 10 times compared to unbiased conditions for dye concentrations between 20 and 100 μM. The overall initial dye degradation rate demonstrates three types of dependence on dye concentration over a range from 2.5−100 μM. For lower dye concentrations (2.5−40 μM) and natural pH (∼6.0) conditions, Langmuir−Hinshelwood (LH) kinetics was observed. The nanotubes diameter, calcination condition, and the anatase-to-rutile ratio in the crystalline TiO2 nanotubes together influence the photocatalytic and photoelectrochemical properties of the TiO2 nanotubes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801851p [article] Investigation of physicochemical parameters that influence photocatalytic degradation of methyl orange over TiO2 nanotubes [texte imprimé] / York R. Smith, Auteur ; Archana Kar, Auteur ; Vaidyanathan (Ravi) Subramanian, Auteur . - 2010 . - pp. 10268–10276. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10268–10276 Mots-clés : Investigation--Physicochemical--Parameters--Influence--Photocatalytic--Degradation--Methyl--Orange--TiO2 Nanotubes Résumé : The photocatalytic degradation of a model textile dye, methyl orange (MO), using anodized titanium dioxide (TiO2) nanotubes has been investigated. The effects of light intensity, dye concentration, external bias, pH, and nanotube dimensions (length, diameter, and wall thickness) on MO photodegradation have been examined. The application of a minimal bias of +0.0 versus saturated calomel electrode (SCE) can enhance the dye degradation at least 10 times compared to unbiased conditions for dye concentrations between 20 and 100 μM. The overall initial dye degradation rate demonstrates three types of dependence on dye concentration over a range from 2.5−100 μM. For lower dye concentrations (2.5−40 μM) and natural pH (∼6.0) conditions, Langmuir−Hinshelwood (LH) kinetics was observed. The nanotubes diameter, calcination condition, and the anatase-to-rutile ratio in the crystalline TiO2 nanotubes together influence the photocatalytic and photoelectrochemical properties of the TiO2 nanotubes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801851p

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Hybrid modeling of methane reformers. 3 / André L. Alberton in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10277–10283 Titre : Hybrid modeling of methane reformers. 3 : optimal geometries of perforated catalyst pellets Type de document : texte imprimé Auteurs : André L. Alberton, Auteur ; Marcio Schwaab, Auteur ; Roberto Carlos Bittencourt, Auteur Année de publication : 2010 Article en page(s) : pp. 10277–10283 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hybrid--Modeling--Methane--Reformers--Optimal--Geometries--Perforated--Catalyst Pellets Résumé : This paper studies the optimization of catalyst pellet geometries for the simultaneous maximization of the mechanical strength and catalyst activity of perforated catalyst pellets used for the reforming of methane. This multiobjective problem can be analyzed with the help of Pareto fronts. A previous work (Part 1: Alberton; et al. Ind. Eng. Chem. Res., in press) demonstrated that the effectiveness factor of catalysts with complex geometry used for the reforming of methane can be expressed as a linear function of the specific area of the pellet; consequently, catalyst activity can be expressed in terms of the geometric parameters of the pellet. It can also be assumed that the mechanical strength of perforated catalyst pellets is related to the minimum wall thickness of the solid piece. Therefore, two optimization problems can be proposed: (i) the simultaneous maximization of the specific area and of the minimum wall thickness of the pellet and (ii) the simultaneous maximization of the overall catalyst activity in the catalyst bed and of the minimum wall thickness of the pellet. These objective functions are evaluated here for several catalyst geometries and analyzed with a Pareto filter. The Pareto fronts obtained for the two analyzed cases are essentially the same, indicating that the maximization of the specific area constitutes a useful criterion for design of perforated catalysts in diffusion-controlled systems. Optimized catalyst geometries are presented for different catalyst designs and can be used as references for future manufacture of catalyst pellets. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9001662 [article] Hybrid modeling of methane reformers. 3 : optimal geometries of perforated catalyst pellets [texte imprimé] / André L. Alberton, Auteur ; Marcio Schwaab, Auteur ; Roberto Carlos Bittencourt, Auteur . - 2010 . - pp. 10277–10283. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10277–10283 Mots-clés : Hybrid--Modeling--Methane--Reformers--Optimal--Geometries--Perforated--Catalyst Pellets Résumé : This paper studies the optimization of catalyst pellet geometries for the simultaneous maximization of the mechanical strength and catalyst activity of perforated catalyst pellets used for the reforming of methane. This multiobjective problem can be analyzed with the help of Pareto fronts. A previous work (Part 1: Alberton; et al. Ind. Eng. Chem. Res., in press) demonstrated that the effectiveness factor of catalysts with complex geometry used for the reforming of methane can be expressed as a linear function of the specific area of the pellet; consequently, catalyst activity can be expressed in terms of the geometric parameters of the pellet. It can also be assumed that the mechanical strength of perforated catalyst pellets is related to the minimum wall thickness of the solid piece. Therefore, two optimization problems can be proposed: (i) the simultaneous maximization of the specific area and of the minimum wall thickness of the pellet and (ii) the simultaneous maximization of the overall catalyst activity in the catalyst bed and of the minimum wall thickness of the pellet. These objective functions are evaluated here for several catalyst geometries and analyzed with a Pareto filter. The Pareto fronts obtained for the two analyzed cases are essentially the same, indicating that the maximization of the specific area constitutes a useful criterion for design of perforated catalysts in diffusion-controlled systems. Optimized catalyst geometries are presented for different catalyst designs and can be used as references for future manufacture of catalyst pellets. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9001662

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Investigation of the Enhanced Water Gas Shift Reaction Using Natural and Synthetic Sorbents for the Capture of CO2 / Christoph R. Müller in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10284–10291 Titre : Investigation of the Enhanced Water Gas Shift Reaction Using Natural and Synthetic Sorbents for the Capture of CO2 Type de document : texte imprimé Auteurs : Christoph R. Müller, Auteur ; Roberta Pacciani, Auteur ; Christopher D. Bohn, Auteur Année de publication : 2010 Article en page(s) : pp. 10284–10291 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Investigation--Enhanced--Water Gas--Shift Reaction--Using Natural--Synthetic Sorbents--Capture--CO2 Résumé : The water gas shift (WGS) reaction was conducted in the presence of two natural and two synthetic CaO-based sorbents. It was shown that such sorbents can affect the WGS in two ways: (i) by catalysis of the reaction and (ii) by altering the equilibrium position by abstraction of CO2 from the gas phase. It was shown that CaO can significantly enhance the production of H2 during the WGS reaction; however, a trade-off between the production of H2 and contamination of the product gas with CO2 (the “CO2 slip”) has to be made. It was found that CaO catalyzes the WGS reaction. The carbonation reaction was very close to thermodynamic equilibrium, even at small contact times at 650 °C. However, the concentration of H2 was significantly below that predicted from equilibrium considerations. In our experiments, once the sorbent had been fully carbonated, it was regenerated by heating to release the CO2 so that it could be reused. In such a cyclic experiment, calcium magnesium acetate, a synthetic sorbent, was the best sorbent tested, albeit only over five cycles of reaction, with respect to the amount of H2 produced. The other sorbents, especially limestone, revealed a decrease in the production of hydrogen with the number of cycles. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900772q [article] Investigation of the Enhanced Water Gas Shift Reaction Using Natural and Synthetic Sorbents for the Capture of CO2 [texte imprimé] / Christoph R. Müller, Auteur ; Roberta Pacciani, Auteur ; Christopher D. Bohn, Auteur . - 2010 . - pp. 10284–10291. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10284–10291 Mots-clés : Investigation--Enhanced--Water Gas--Shift Reaction--Using Natural--Synthetic Sorbents--Capture--CO2 Résumé : The water gas shift (WGS) reaction was conducted in the presence of two natural and two synthetic CaO-based sorbents. It was shown that such sorbents can affect the WGS in two ways: (i) by catalysis of the reaction and (ii) by altering the equilibrium position by abstraction of CO2 from the gas phase. It was shown that CaO can significantly enhance the production of H2 during the WGS reaction; however, a trade-off between the production of H2 and contamination of the product gas with CO2 (the “CO2 slip”) has to be made. It was found that CaO catalyzes the WGS reaction. The carbonation reaction was very close to thermodynamic equilibrium, even at small contact times at 650 °C. However, the concentration of H2 was significantly below that predicted from equilibrium considerations. In our experiments, once the sorbent had been fully carbonated, it was regenerated by heating to release the CO2 so that it could be reused. In such a cyclic experiment, calcium magnesium acetate, a synthetic sorbent, was the best sorbent tested, albeit only over five cycles of reaction, with respect to the amount of H2 produced. The other sorbents, especially limestone, revealed a decrease in the production of hydrogen with the number of cycles. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900772q

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Characterization and vsible light photocatalytic activity of cerium- and Iron-doped titanium dioxide sol−gel materials / Meera Sidheswaran in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10292–10306 Titre : Characterization and vsible light photocatalytic activity of cerium- and Iron-doped titanium dioxide sol−gel materials Type de document : texte imprimé Auteurs : Meera Sidheswaran, Auteur ; Lawrence L. Tavlarides, Auteur Année de publication : 2010 Article en page(s) : pp. 10292–10306 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Characterization--Visible--Photocatalytic--Cerium--Iron-Doped--Titanium Dioxide--Sol−  Gel Materials Résumé : Cerium- and iron-based titanium dioxide catalysts are made at varying concentrations and cured at different temperatures to develop a new class of photocatalysts that displays catalytic activity for volatile organic compound destruction when irradiated with visible light. These catalysts are characterized using X-ray diffractometry, Raman spectroscopy, UV−vis diffuse reflectance spectroscopy and BET surface area analyses. The potential of these catalysts to destroy indoor air volatile organics is evaluated using a tubular reactor flow channel with visible light irradiated interior surfaces through which air contaminated with toluene, decane, ethanol, acetaldehyde, or linalool is reacted. It was found that both cerium- and iron-doped titania have lower band-gap energy than pure titania and can be activated with visible light. The anatase and rutile phase transitions of these doped titania is however similar to pure titania and is unaffected by dopants. The crystalinity is however altered and crystal sizes in the range of six to nine nanometers were obtained with the sol−gel type synthesis of the titania catalyst. Although both cerium- and iron-based titania show destruction of these volatile organics in visible light as compared to pure titania, cerium-based titania has better performance than iron-based titania. A photocatalytic oxidation reaction pathway for linalool is proposed on the basis of previous studies and compounds are identified in the exit stream of the reactor. Further, reaction rate constants for toluene, linalool, ethanol, and acetaldheyhde have been determined using a two-dimensional diffusion model (Sidheswaran and Tavlarides, 2008), and are compared with values from literature. It has been found that cerium-doped titania developed in this study performs comparably to the commercially available titania even when irradiated with visible light. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900773m [article] Characterization and vsible light photocatalytic activity of cerium- and Iron-doped titanium dioxide sol−gel materials [texte imprimé] / Meera Sidheswaran, Auteur ; Lawrence L. Tavlarides, Auteur . - 2010 . - pp. 10292–10306. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10292–10306 Mots-clés : Characterization--Visible--Photocatalytic--Cerium--Iron-Doped--Titanium Dioxide--Sol−  Gel Materials Résumé : Cerium- and iron-based titanium dioxide catalysts are made at varying concentrations and cured at different temperatures to develop a new class of photocatalysts that displays catalytic activity for volatile organic compound destruction when irradiated with visible light. These catalysts are characterized using X-ray diffractometry, Raman spectroscopy, UV−vis diffuse reflectance spectroscopy and BET surface area analyses. The potential of these catalysts to destroy indoor air volatile organics is evaluated using a tubular reactor flow channel with visible light irradiated interior surfaces through which air contaminated with toluene, decane, ethanol, acetaldehyde, or linalool is reacted. It was found that both cerium- and iron-doped titania have lower band-gap energy than pure titania and can be activated with visible light. The anatase and rutile phase transitions of these doped titania is however similar to pure titania and is unaffected by dopants. The crystalinity is however altered and crystal sizes in the range of six to nine nanometers were obtained with the sol−gel type synthesis of the titania catalyst. Although both cerium- and iron-based titania show destruction of these volatile organics in visible light as compared to pure titania, cerium-based titania has better performance than iron-based titania. A photocatalytic oxidation reaction pathway for linalool is proposed on the basis of previous studies and compounds are identified in the exit stream of the reactor. Further, reaction rate constants for toluene, linalool, ethanol, and acetaldheyhde have been determined using a two-dimensional diffusion model (Sidheswaran and Tavlarides, 2008), and are compared with values from literature. It has been found that cerium-doped titania developed in this study performs comparably to the commercially available titania even when irradiated with visible light. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900773m

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Effect of O2 on SO2 reduction with CO or H2 over SnO2−ZrO2 catalyst / Gi Bo Han in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10307–10313 Titre : Effect of O2 on SO2 reduction with CO or H2 over SnO2−ZrO2 catalyst Type de document : texte imprimé Auteurs : Gi Bo Han, Auteur ; No-Kuk Park, Auteur ; Tae Jin Lee, Auteur Année de publication : 2010 Article en page(s) : pp. 10307–10313 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : O2--SO2--Reduction--CO--H2--SnO2−  ZrO2--Catalyst Résumé : To investigate the effect of the O2 content on the direct sulfur recovery process (DSRP) combined with the hot gas desulfurization (HGD) process with the unreacted O2 emitted from the regeneration process, either CO or H2 was used as a reducing agent for the reduction of SO2 over SnO2−ZrO2 catalyst with a Sn/Zr molar ratio of 2/1. Then, the reaction conditions, including temperature, CO (or H2)/SO2 molar ratio, and space velocity, were optimized to maximize the sulfur yield in the presence and absence of 1 vol % O2. The temperature, CO (or H2)/SO2 molar ratio, and space velocity were varied in the ranges of 300−600 °C, 1.0−4.0, and 1000−30000 h−1, respectively. In SO2 reduction using CO with 1 vol % O2, the temperature, CO/SO2 molar ratio, and space velocity for the maximum sulfur yield were 600 °C, 3.5, and 10000 h−1, respectively, in which case the SO2 conversion and sulfur yield were about 85% and 77%, respectively. In SO2 reduction using H2 with 1 vol % O2, the temperature, H2/SO2 molar ratio, and space velocity optimized for the maximum sulfur yield were 600 °C, 3.0, and 10000 h−1, respectively, in which case the SO2 conversion and sulfur yield were about 89% and 57%, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900553s [article] Effect of O2 on SO2 reduction with CO or H2 over SnO2−ZrO2 catalyst [texte imprimé] / Gi Bo Han, Auteur ; No-Kuk Park, Auteur ; Tae Jin Lee, Auteur . - 2010 . - pp. 10307–10313. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10307–10313 Mots-clés : O2--SO2--Reduction--CO--H2--SnO2−  ZrO2--Catalyst Résumé : To investigate the effect of the O2 content on the direct sulfur recovery process (DSRP) combined with the hot gas desulfurization (HGD) process with the unreacted O2 emitted from the regeneration process, either CO or H2 was used as a reducing agent for the reduction of SO2 over SnO2−ZrO2 catalyst with a Sn/Zr molar ratio of 2/1. Then, the reaction conditions, including temperature, CO (or H2)/SO2 molar ratio, and space velocity, were optimized to maximize the sulfur yield in the presence and absence of 1 vol % O2. The temperature, CO (or H2)/SO2 molar ratio, and space velocity were varied in the ranges of 300−600 °C, 1.0−4.0, and 1000−30000 h−1, respectively. In SO2 reduction using CO with 1 vol % O2, the temperature, CO/SO2 molar ratio, and space velocity for the maximum sulfur yield were 600 °C, 3.5, and 10000 h−1, respectively, in which case the SO2 conversion and sulfur yield were about 85% and 77%, respectively. In SO2 reduction using H2 with 1 vol % O2, the temperature, H2/SO2 molar ratio, and space velocity optimized for the maximum sulfur yield were 600 °C, 3.0, and 10000 h−1, respectively, in which case the SO2 conversion and sulfur yield were about 89% and 57%, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900553s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Computational fluid dynamics study of pulverized coal combustion in blast furnace raceway / Y. S. Shen in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10314–10323 Titre : Computational fluid dynamics study of pulverized coal combustion in blast furnace raceway Type de document : texte imprimé Auteurs : Y. S. Shen, Auteur ; D. Maldonado, Auteur ; B.Y. Guo, Auteur Année de publication : 2010 Article en page(s) : pp. 10314–10323 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Computational--Fluid Dynamics--Pulverized--Coal--Combustion--Blast Furnace--Raceway Résumé : In this work, a numerical model is used to study the flow and coal combustion along the coal plume in a large-scale setting simulating the lance−blowpipe−tuyere−raceway region of a blast furnace. The model formulation is validated against the measurements in terms of burnout for both low and high volatile coals. The typical phenomena related to coal combustion along the coal plume are simulated and analyzed. The effects of some operational parameters on combustion behavior are also investigated. The results indicate that oxygen as a cooling gas gives a higher coal burnout than methane and air. The underlying mechanism of coal combustion is explored. It is shown that under the conditions examined, coal burnout strongly depends on the availability of oxygen and residence time. Moreover, the influences of two related issues, i.e. the treatment of volatile matter (VM) and geometric setting in modeling, are investigated. The results show that the predictions of final burnouts using three different VM treatments are just slightly different, but all comparable to the measurements. However, the influence of the geometric setting is not negligible when numerically examining the combustion of pulverized coal under blast furnace conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900853d [article] Computational fluid dynamics study of pulverized coal combustion in blast furnace raceway [texte imprimé] / Y. S. Shen, Auteur ; D. Maldonado, Auteur ; B.Y. Guo, Auteur . - 2010 . - pp. 10314–10323. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10314–10323 Mots-clés : Computational--Fluid Dynamics--Pulverized--Coal--Combustion--Blast Furnace--Raceway Résumé : In this work, a numerical model is used to study the flow and coal combustion along the coal plume in a large-scale setting simulating the lance−blowpipe−tuyere−raceway region of a blast furnace. The model formulation is validated against the measurements in terms of burnout for both low and high volatile coals. The typical phenomena related to coal combustion along the coal plume are simulated and analyzed. The effects of some operational parameters on combustion behavior are also investigated. The results indicate that oxygen as a cooling gas gives a higher coal burnout than methane and air. The underlying mechanism of coal combustion is explored. It is shown that under the conditions examined, coal burnout strongly depends on the availability of oxygen and residence time. Moreover, the influences of two related issues, i.e. the treatment of volatile matter (VM) and geometric setting in modeling, are investigated. The results show that the predictions of final burnouts using three different VM treatments are just slightly different, but all comparable to the measurements. However, the influence of the geometric setting is not negligible when numerically examining the combustion of pulverized coal under blast furnace conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900853d

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Hydrotreatment of fast pyrolysis oil using heterogeneous noble-metal catalysts / Jelle Wildschut in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10324–10334 Titre : Hydrotreatment of fast pyrolysis oil using heterogeneous noble-metal catalysts Type de document : texte imprimé Auteurs : Jelle Wildschut, Auteur ; Farchad H. Mahfud, Auteur ; Robbie H. Venderbosch, Auteur Année de publication : 2010 Article en page(s) : pp. 10324–10334 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrotreatment--Fast Pyrolysis--Oil Using--Heterogeneous--Noble-Metal--Catalysts Résumé : Fast pyrolysis oils from lignocellulosic biomass are promising second-generation biofuels. Unfortunately, the application range for such oils is limited because of the high acidity (pH∼2.5) and the presence of oxygen in a variety of chemical functionalities, and upgrading of the oils is required for most applications. Herein, we report an experimental study on the upgrading of fast pyrolysis oil by catalytic hydrotreatment. A variety of heterogeneous noble-metal catalysts were tested for this purpose (Ru/C, Ru/TiO2, Ru/Al2O3, Pt/C, and Pd/C), and the results were compared to those obtained with typical hydrotreatment catalysts (sulfided NiMo/Al2O3 and CoMo/Al2O3). The reactions were carried out at temperatures of 250 and 350 °C and pressures of 100 and 200 bar. The Ru/C catalyst was found to be superior to the classical hydrotreating catalysts with respect to oil yield (up to 60 wt %) and deoxygenation level (up to 90 wt %). The upgraded products were less acidic and contained less water than the original fast pyrolysis oil. The HHV was about 40 MJ/kg, which is about twice the value of pyrolysis oil. Analyses of the products by 1H NMR spectroscopy and 2D GC showed that the upgraded pyrolysis oil had lower contents of organic acids, aldehydes, ketones, and ethers than the feed, whereas the amounts of phenolics, aromatics, and alkanes were considerably higher. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9006003 [article] Hydrotreatment of fast pyrolysis oil using heterogeneous noble-metal catalysts [texte imprimé] / Jelle Wildschut, Auteur ; Farchad H. Mahfud, Auteur ; Robbie H. Venderbosch, Auteur . - 2010 . - pp. 10324–10334. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10324–10334 Mots-clés : Hydrotreatment--Fast Pyrolysis--Oil Using--Heterogeneous--Noble-Metal--Catalysts Résumé : Fast pyrolysis oils from lignocellulosic biomass are promising second-generation biofuels. Unfortunately, the application range for such oils is limited because of the high acidity (pH∼2.5) and the presence of oxygen in a variety of chemical functionalities, and upgrading of the oils is required for most applications. Herein, we report an experimental study on the upgrading of fast pyrolysis oil by catalytic hydrotreatment. A variety of heterogeneous noble-metal catalysts were tested for this purpose (Ru/C, Ru/TiO2, Ru/Al2O3, Pt/C, and Pd/C), and the results were compared to those obtained with typical hydrotreatment catalysts (sulfided NiMo/Al2O3 and CoMo/Al2O3). The reactions were carried out at temperatures of 250 and 350 °C and pressures of 100 and 200 bar. The Ru/C catalyst was found to be superior to the classical hydrotreating catalysts with respect to oil yield (up to 60 wt %) and deoxygenation level (up to 90 wt %). The upgraded products were less acidic and contained less water than the original fast pyrolysis oil. The HHV was about 40 MJ/kg, which is about twice the value of pyrolysis oil. Analyses of the products by 1H NMR spectroscopy and 2D GC showed that the upgraded pyrolysis oil had lower contents of organic acids, aldehydes, ketones, and ethers than the feed, whereas the amounts of phenolics, aromatics, and alkanes were considerably higher. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9006003

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Kinetics of cinnamaldehyde hydrogenation by supported ionic liquid catalysts (SILCA) / Pasi Virtanen in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10335–10342 Titre : Kinetics of cinnamaldehyde hydrogenation by supported ionic liquid catalysts (SILCA) Type de document : texte imprimé Auteurs : Pasi Virtanen, Auteur ; Tapio Salmi, Auteur ; Jyri-Pekka Mikkola, Auteur Année de publication : 2010 Article en page(s) : pp. 10335–10342 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics--Cinnamaldehyde--Hydrogenation--Supported--Ionic Liquid--Catalysts (SILCA) Résumé : The research of ionic liquids and their applications in catalysis are attracting increasing attention in chemistry and chemical engineering. A supported ionic liquid catalyst (SILCA) consists of immobilized catalytic species (e.g., transition-metal particles, metal complexes, or enzymes) residing in an ionic liquid layer immobilized on a porous solid support. The kinetics of cinnamaldehyde hydrogenation over SILCAs that contained palladium nanoparticles in ionic liquid, which, in turn, was immobilized on active carbon cloth (ACC), was studied and modeled in detail. A mechanistic kinetic model, which describes the differences of the activity and selectivity of the catalysts consisting of different ionic liquids, was developed. The model explained the experimental results well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901041z [article] Kinetics of cinnamaldehyde hydrogenation by supported ionic liquid catalysts (SILCA) [texte imprimé] / Pasi Virtanen, Auteur ; Tapio Salmi, Auteur ; Jyri-Pekka Mikkola, Auteur . - 2010 . - pp. 10335–10342. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10335–10342 Mots-clés : Kinetics--Cinnamaldehyde--Hydrogenation--Supported--Ionic Liquid--Catalysts (SILCA) Résumé : The research of ionic liquids and their applications in catalysis are attracting increasing attention in chemistry and chemical engineering. A supported ionic liquid catalyst (SILCA) consists of immobilized catalytic species (e.g., transition-metal particles, metal complexes, or enzymes) residing in an ionic liquid layer immobilized on a porous solid support. The kinetics of cinnamaldehyde hydrogenation over SILCAs that contained palladium nanoparticles in ionic liquid, which, in turn, was immobilized on active carbon cloth (ACC), was studied and modeled in detail. A mechanistic kinetic model, which describes the differences of the activity and selectivity of the catalysts consisting of different ionic liquids, was developed. The model explained the experimental results well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901041z

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Coke formation in the transfer line exchanger during steam cracking of hydrocarbons / Kevin M. Van Geem in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10343–10358 Titre : Coke formation in the transfer line exchanger during steam cracking of hydrocarbons Type de document : texte imprimé Auteurs : Kevin M. Van Geem, Auteur ; Inge Dhuyvetter, Auteur ; Serge Prokopiev, Auteur Année de publication : 2010 Article en page(s) : pp. 10343–10358 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Coke Formation--Transfer--Line Exchanger--during Steam--Cracking --Hydrocarbons Résumé : Coke formation under transfer line exchanger conditions, that is, at temperatures from 623 to 873 K and atmospheric pressure, is studied in an electrobalance setup. The coking rate is initially very high (catalytic coking) and drops after a few hours to a constant value. At the studied conditions the observed coking behavior on 15Mo3 alloy pigs can be explained via a catalytic mechanism only, and contributions of the free-radical mechanism and the condensation mechanism are insignificant. Experiments with ethane and naphtha steam cracking effluents and with well-defined reaction mixtures show that the coking rate is independent of the partial pressure of ethene (0−2.7 × 104 Pa), ortho-xylene (0−1.0 × 104 Pa), heavy aromatic hydrocarbons (0−3.0 × 102 Pa), and also 1,3-butadiene (0−2.7 × 104 Pa). The rate of coke deposition depends only on the temperature and the ratio of the partial pressures of water to dihydrogen. The activation energy for initial coke formation was estimated to be ∼90 kJ/mol, a value close to the experimentally determined diffusion energy of carbon in iron. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900124z [article] Coke formation in the transfer line exchanger during steam cracking of hydrocarbons [texte imprimé] / Kevin M. Van Geem, Auteur ; Inge Dhuyvetter, Auteur ; Serge Prokopiev, Auteur . - 2010 . - pp. 10343–10358. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10343–10358 Mots-clés : Coke Formation--Transfer--Line Exchanger--during Steam--Cracking --Hydrocarbons Résumé : Coke formation under transfer line exchanger conditions, that is, at temperatures from 623 to 873 K and atmospheric pressure, is studied in an electrobalance setup. The coking rate is initially very high (catalytic coking) and drops after a few hours to a constant value. At the studied conditions the observed coking behavior on 15Mo3 alloy pigs can be explained via a catalytic mechanism only, and contributions of the free-radical mechanism and the condensation mechanism are insignificant. Experiments with ethane and naphtha steam cracking effluents and with well-defined reaction mixtures show that the coking rate is independent of the partial pressure of ethene (0−2.7 × 104 Pa), ortho-xylene (0−1.0 × 104 Pa), heavy aromatic hydrocarbons (0−3.0 × 102 Pa), and also 1,3-butadiene (0−2.7 × 104 Pa). The rate of coke deposition depends only on the temperature and the ratio of the partial pressures of water to dihydrogen. The activation energy for initial coke formation was estimated to be ∼90 kJ/mol, a value close to the experimentally determined diffusion energy of carbon in iron. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900124z

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Study on several mesoporous materials catalysts applied to the removal of trace olefins from aromatics and commercial sidestream tests / Chang, Chih-Chen in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10359–10363 Titre : Study on several mesoporous materials catalysts applied to the removal of trace olefins from aromatics and commercial sidestream tests Type de document : texte imprimé Auteurs : Chang, Chih-Chen, Auteur ; Deh-Juan Wu, Auteur ; Xian-song Zeng, Auteur Année de publication : 2010 Article en page(s) : pp. 10359–10363 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Study--Several--Mesoporous--Materials--Catalysts--Applied--Removal Trace Olefins--Aromatics--Commercial--Sidestream Tests Résumé : Deep removal of trace olefins from aromatics using mesoporous materials and modified mesoporous materials was studied with regard to the removal of trace olefins from aromatic hydrocarbons. The mesoporous materials and the modified mesoporous molecular sieve materials were characterized by X-ray diffraction and Fourier transform infrared (FT-IR) spectroscopy. Under the commercial sidestream test, the effects of four types of mesoporous materials, with regard to the removal of olefins from the aromatics, were evaluated. The result showed that the mesoporous materials that had surface areas larger than 300 m2/g and modified with AlCl3 were best, with regard to the effect on the removal of olefins from aromatics. The FT-IR results showed that the modifier could increase the concentration of weak Lewis acid of mesoporous materials and obviously enhance the effect of removing olefins and prolonging the reaction time. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901062c [article] Study on several mesoporous materials catalysts applied to the removal of trace olefins from aromatics and commercial sidestream tests [texte imprimé] / Chang, Chih-Chen, Auteur ; Deh-Juan Wu, Auteur ; Xian-song Zeng, Auteur . - 2010 . - pp. 10359–10363. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10359–10363 Mots-clés : Study--Several--Mesoporous--Materials--Catalysts--Applied--Removal Trace Olefins--Aromatics--Commercial--Sidestream Tests Résumé : Deep removal of trace olefins from aromatics using mesoporous materials and modified mesoporous materials was studied with regard to the removal of trace olefins from aromatic hydrocarbons. The mesoporous materials and the modified mesoporous molecular sieve materials were characterized by X-ray diffraction and Fourier transform infrared (FT-IR) spectroscopy. Under the commercial sidestream test, the effects of four types of mesoporous materials, with regard to the removal of olefins from the aromatics, were evaluated. The result showed that the mesoporous materials that had surface areas larger than 300 m2/g and modified with AlCl3 were best, with regard to the effect on the removal of olefins from aromatics. The FT-IR results showed that the modifier could increase the concentration of weak Lewis acid of mesoporous materials and obviously enhance the effect of removing olefins and prolonging the reaction time. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901062c

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Effects of pretreatment of coal by CO2 on nitric Oxide emission and unburned carbon in various combustion environments / Benson B. Gathitu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10364–10374 Titre : Effects of pretreatment of coal by CO2 on nitric Oxide emission and unburned carbon in various combustion environments Type de document : texte imprimé Auteurs : Benson B. Gathitu, Auteur ; Wei-Yin Chen, Auteur Année de publication : 2010 Article en page(s) : pp. 10364–10374 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Effects--Pretreatment--CO2--Nitric Oxide--Emission--Unburned--Carbon--Various--Combustion--Environments Résumé : Polar solvents are known to swell coal, break hydrogen bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of the pretreatment of coal using supercritical CO2 on its physical structure and combustion properties have been studied at the bench-scale level. Emphasis has been placed on NO reburning, NO emissions during air-fired and oxy-fired combustion, and loss on ignition (LOI). Pretreatment was found to increase porosity and to significantly alter the fuel nitrogen reaction pathways. Consequently, NO reduction during reburning using bituminous coal increased, and NO emissions during oxidation of lignite decreased. These two benefits were achieved without negative impacts on LOI. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901069k [article] Effects of pretreatment of coal by CO2 on nitric Oxide emission and unburned carbon in various combustion environments [texte imprimé] / Benson B. Gathitu, Auteur ; Wei-Yin Chen, Auteur . - 2010 . - pp. 10364–10374. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10364–10374 Mots-clés : Effects--Pretreatment--CO2--Nitric Oxide--Emission--Unburned--Carbon--Various--Combustion--Environments Résumé : Polar solvents are known to swell coal, break hydrogen bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of the pretreatment of coal using supercritical CO2 on its physical structure and combustion properties have been studied at the bench-scale level. Emphasis has been placed on NO reburning, NO emissions during air-fired and oxy-fired combustion, and loss on ignition (LOI). Pretreatment was found to increase porosity and to significantly alter the fuel nitrogen reaction pathways. Consequently, NO reduction during reburning using bituminous coal increased, and NO emissions during oxidation of lignite decreased. These two benefits were achieved without negative impacts on LOI. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901069k

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Amine-functionalized ordered mesoporous silica transesterification catalysts / Victor Varela Guerrero in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10375–10380 Titre : Amine-functionalized ordered mesoporous silica transesterification catalysts Type de document : texte imprimé Auteurs : Victor Varela Guerrero, Auteur ; Daniel F. Shantz, Auteur Année de publication : 2010 Article en page(s) : pp. 10375–10380 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Amine-Functionalized--Ordered--Mesoporous--Silica--Transesterification--Catalysts Résumé : The synthesis, characterization, and catalytic behavior of several amine-functionalized ordered mesoporous silica (OMS) materials are reported. All samples show catalytic activity for the conversion of glyceryl tributyrate with methanol to methyl esters in high yield (>60%). The reactivity of the amines approximately correlates with the pK values of the free amines. The effect of the amine identity, loading, and substrate pore size is also reported. To determine if leached amine was responsible for the observed reactivity, the hot filtrate method was employed. Those experiments show that upon removal of the OMS material the reaction conversion does not increase, indicating surface-tethered amines are primarily responsible for the observed reactivity. The stability of the most promising catalyst, 3-(anilinopropyl)-MCM-41 was analyzed via recycle studies. Leaching of the amine is observed via a decrease in conversion with multiple recycles and a concomitant change in sample color. Capping the residual silanols groups with hexamethyldisilazane leads to an increase in the catalyst stability with a decrease in activity. The work indicates that these solids are interesting alternatives to conventional homogeneous catalysts for this class of chemistry. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9003915 [article] Amine-functionalized ordered mesoporous silica transesterification catalysts [texte imprimé] / Victor Varela Guerrero, Auteur ; Daniel F. Shantz, Auteur . - 2010 . - pp. 10375–10380. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10375–10380 Mots-clés : Amine-Functionalized--Ordered--Mesoporous--Silica--Transesterification--Catalysts Résumé : The synthesis, characterization, and catalytic behavior of several amine-functionalized ordered mesoporous silica (OMS) materials are reported. All samples show catalytic activity for the conversion of glyceryl tributyrate with methanol to methyl esters in high yield (>60%). The reactivity of the amines approximately correlates with the pK values of the free amines. The effect of the amine identity, loading, and substrate pore size is also reported. To determine if leached amine was responsible for the observed reactivity, the hot filtrate method was employed. Those experiments show that upon removal of the OMS material the reaction conversion does not increase, indicating surface-tethered amines are primarily responsible for the observed reactivity. The stability of the most promising catalyst, 3-(anilinopropyl)-MCM-41 was analyzed via recycle studies. Leaching of the amine is observed via a decrease in conversion with multiple recycles and a concomitant change in sample color. Capping the residual silanols groups with hexamethyldisilazane leads to an increase in the catalyst stability with a decrease in activity. The work indicates that these solids are interesting alternatives to conventional homogeneous catalysts for this class of chemistry. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9003915

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Osmium(VIII) catalyzed oxidative cleavage of pyrrolidine ring in l-proline by hexacyanoferrate(III) in alkaline media / K. Sharanabasamma in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10381–10386 Titre : Osmium(VIII) catalyzed oxidative cleavage of pyrrolidine ring in l-proline by hexacyanoferrate(III) in alkaline media Type de document : texte imprimé Auteurs : K. Sharanabasamma, Auteur ; Mahantesh A. Angadi, Auteur ; Manjalee S. Salunke, Auteur Année de publication : 2010 Article en page(s) : pp. 10381–10386 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Osmium(VIII)--Catalyzed--Oxidative Cleavage--Pyrrolidine--Proline--Hexacyanoferrate(III)--Alkaline Media Résumé : Kinetics of oxidation of l-proline by hexacyanoferrate(III) catalyzed by osmium(VIII) in alkaline medium was studied at 30 °C. A mechanism involving free radical path was proposed. Rate law of the reaction was derived as The rate constant k and equilibrium constants K1 and K2 were evaluated as 3.79 × 103 dm3 mol−1 s−1, 0.52 dm3 mol−1, and 3.78 × 103 dm3 mol−1, respectively. The main reactive species of the catalyst appears to be OsO5(OH)3−. The oxidative product of l-proline was identified as l-glutamic acid which is different from the earlier reports. The literature reveals that 4-amino butyric acid, 4-amino butaraldehyde and keto acids were the oxidative products. Activation parameters were evaluated as Ea = 33.5 ± 2 kJ mol−1, ΔH⧧ = 31.0 ± 0.2 kJ mol−1, ΔS⧧ = −24 ± 1.5 J K−1 mol−1, ΔG⧧ = 38.0 ± 2 kJ mol−1. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901049p [article] Osmium(VIII) catalyzed oxidative cleavage of pyrrolidine ring in l-proline by hexacyanoferrate(III) in alkaline media [texte imprimé] / K. Sharanabasamma, Auteur ; Mahantesh A. Angadi, Auteur ; Manjalee S. Salunke, Auteur . - 2010 . - pp. 10381–10386. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10381–10386 Mots-clés : Osmium(VIII)--Catalyzed--Oxidative Cleavage--Pyrrolidine--Proline--Hexacyanoferrate(III)--Alkaline Media Résumé : Kinetics of oxidation of l-proline by hexacyanoferrate(III) catalyzed by osmium(VIII) in alkaline medium was studied at 30 °C. A mechanism involving free radical path was proposed. Rate law of the reaction was derived as The rate constant k and equilibrium constants K1 and K2 were evaluated as 3.79 × 103 dm3 mol−1 s−1, 0.52 dm3 mol−1, and 3.78 × 103 dm3 mol−1, respectively. The main reactive species of the catalyst appears to be OsO5(OH)3−. The oxidative product of l-proline was identified as l-glutamic acid which is different from the earlier reports. The literature reveals that 4-amino butyric acid, 4-amino butaraldehyde and keto acids were the oxidative products. Activation parameters were evaluated as Ea = 33.5 ± 2 kJ mol−1, ΔH⧧ = 31.0 ± 0.2 kJ mol−1, ΔS⧧ = −24 ± 1.5 J K−1 mol−1, ΔG⧧ = 38.0 ± 2 kJ mol−1. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901049p

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Heterogeneously-catalyzed glycerolysis of fatty acid methyl esters / Cristián A. Ferretti in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10387–10394 Titre : Heterogeneously-catalyzed glycerolysis of fatty acid methyl esters : reaction parameter optimization Type de document : texte imprimé Auteurs : Cristián A. Ferretti, Auteur ; Roberto N. Olcese, Auteur ; Carlos R. Apesteguía, Auteur Année de publication : 2010 Article en page(s) : pp. 10387–10394 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heterogeneously-Catalyzed--Glycerolysis--Fatty Acid--Methyl--Esters--Reaction Parameter--Optimization Résumé : The synthesis of monoglycerides by glycerolysis of methyl oleate, an unsaturated fatty acid methyl ester, was studied on strongly basic high surface area MgO as an alternative to the current commercial technology that uses liquid base catalysts. Initially, the reaction conditions such as catalyst particle size and stirring rate required for operating the four-phase reactor under a kinetically controlled regime were determined. Then, the optimization of the reaction parameters for achieving high monoglyceride yields was performed. Results showed that glycerolysis of methyl oleate on MgO compares favorably with the corresponding homogeneously catalyzed process. In fact, when using high reaction temperatures (493−523 K), glycerol/methyl oleate molar ratios between 2 and 6, and catalyst/reactant ratios of about 30 g/mol, glycerolysis of methyl oleate on MgO yields up to 77% monoglycerides in 2 h, a much higher value than those usually obtained via the liquid-base-catalyzed homogeneous process (40−60%). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9004783 [article] Heterogeneously-catalyzed glycerolysis of fatty acid methyl esters : reaction parameter optimization [texte imprimé] / Cristián A. Ferretti, Auteur ; Roberto N. Olcese, Auteur ; Carlos R. Apesteguía, Auteur . - 2010 . - pp. 10387–10394. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10387–10394 Mots-clés : Heterogeneously-Catalyzed--Glycerolysis--Fatty Acid--Methyl--Esters--Reaction Parameter--Optimization Résumé : The synthesis of monoglycerides by glycerolysis of methyl oleate, an unsaturated fatty acid methyl ester, was studied on strongly basic high surface area MgO as an alternative to the current commercial technology that uses liquid base catalysts. Initially, the reaction conditions such as catalyst particle size and stirring rate required for operating the four-phase reactor under a kinetically controlled regime were determined. Then, the optimization of the reaction parameters for achieving high monoglyceride yields was performed. Results showed that glycerolysis of methyl oleate on MgO compares favorably with the corresponding homogeneously catalyzed process. In fact, when using high reaction temperatures (493−523 K), glycerol/methyl oleate molar ratios between 2 and 6, and catalyst/reactant ratios of about 30 g/mol, glycerolysis of methyl oleate on MgO yields up to 77% monoglycerides in 2 h, a much higher value than those usually obtained via the liquid-base-catalyzed homogeneous process (40−60%). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9004783

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Morphological characterization of ceramic sponges for applications in chemical engineeringc / Julia Grosse in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10395–10401 Titre : Morphological characterization of ceramic sponges for applications in chemical engineeringc Type de document : texte imprimé Auteurs : Julia Grosse, Auteur ; Benjamin Dietrich, Auteur ; Gerardo Incera Garrido, Auteur Année de publication : 2010 Article en page(s) : pp. 10395–10401 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Morphological--Characterization--Ceramic Sponges--Applications--Chemical Engineering Résumé : An extensive study on morphological parameters of ceramic sponge structures of different material, porosity, and pores per linear inch (ppi) number was performed. Volume image analyses of magnetic resonance imaging (MRI) and X-ray tomography (CT) measurements were carried out to determine experimentally the geometric specific surface area of the structures. Furthermore, face and strut diameters, porosities, and densities were assessed through conventional methods including optical microscopy, mercury porosimetry, and helium pycnometry. The resulting data were used to evaluate morphological models representing the irregular strut network by packings of regular polyhedra. On the basis of an adapted Weaire−Phelan model, a novel correlation was developed that enables the calculation of the specific surface area of sponges with high accuracy. The input parameters for this correlation are easily accessible by standard microscopy and porosimetry measurements. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900651c [article] Morphological characterization of ceramic sponges for applications in chemical engineeringc [texte imprimé] / Julia Grosse, Auteur ; Benjamin Dietrich, Auteur ; Gerardo Incera Garrido, Auteur . - 2010 . - pp. 10395–10401. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10395–10401 Mots-clés : Morphological--Characterization--Ceramic Sponges--Applications--Chemical Engineering Résumé : An extensive study on morphological parameters of ceramic sponge structures of different material, porosity, and pores per linear inch (ppi) number was performed. Volume image analyses of magnetic resonance imaging (MRI) and X-ray tomography (CT) measurements were carried out to determine experimentally the geometric specific surface area of the structures. Furthermore, face and strut diameters, porosities, and densities were assessed through conventional methods including optical microscopy, mercury porosimetry, and helium pycnometry. The resulting data were used to evaluate morphological models representing the irregular strut network by packings of regular polyhedra. On the basis of an adapted Weaire−Phelan model, a novel correlation was developed that enables the calculation of the specific surface area of sponges with high accuracy. The input parameters for this correlation are easily accessible by standard microscopy and porosimetry measurements. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900651c

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Au/FeOx−TiO2 catalysts for the preferential oxidation of CO in a H2 stream / Yi-Fen Yang in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10402–10407 Titre : Au/FeOx−TiO2 catalysts for the preferential oxidation of CO in a H2 stream Type de document : texte imprimé Auteurs : Yi-Fen Yang, Auteur ; Palanivelu Sangeetha, Auteur ; Chen, Yu-Wen, Auteur Année de publication : 2010 Article en page(s) : pp. 10402–10407 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Au/FeOx−  TiO2--Catalysts--Preferential--Oxidation--CO--H2--Stream Résumé : A series of gold catalysts supported on Fe2O3−TiO2 with various iron contents were prepared. A FeOx−TiO2 support was prepared via incipient-wetness impregnation with aqueous solution of Fe(NO3)3 on TiO2. A gold catalyst with a nominal loading of 1 wt % was prepared by deposition−precipitation at pH 7 and 65 °C. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalytic performance of these catalysts were investigated by preferential oxidation of carbon monoxide in hydrogen stream (PROX). The reaction was conducted in a fixed-bed microreactor with a feed of CO:O2:H2:He = 1:1:49:49 (volume ratios). A limited amount of oxygen was used. Gold catalysts have been reported to be efficient catalysts for the PROX reaction to reduce CO concentration to ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900806r [article] Au/FeOx−TiO2 catalysts for the preferential oxidation of CO in a H2 stream [texte imprimé] / Yi-Fen Yang, Auteur ; Palanivelu Sangeetha, Auteur ; Chen, Yu-Wen, Auteur . - 2010 . - pp. 10402–10407. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10402–10407 Mots-clés : Au/FeOx−  TiO2--Catalysts--Preferential--Oxidation--CO--H2--Stream Résumé : A series of gold catalysts supported on Fe2O3−TiO2 with various iron contents were prepared. A FeOx−TiO2 support was prepared via incipient-wetness impregnation with aqueous solution of Fe(NO3)3 on TiO2. A gold catalyst with a nominal loading of 1 wt % was prepared by deposition−precipitation at pH 7 and 65 °C. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalytic performance of these catalysts were investigated by preferential oxidation of carbon monoxide in hydrogen stream (PROX). The reaction was conducted in a fixed-bed microreactor with a feed of CO:O2:H2:He = 1:1:49:49 (volume ratios). A limited amount of oxygen was used. Gold catalysts have been reported to be efficient catalysts for the PROX reaction to reduce CO concentration to ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900806r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Dependence of sulfadiazine oxidative degradation on physicochemical properties of manganese dioxides / Chengshuai Liu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10408–10413 Titre : Dependence of sulfadiazine oxidative degradation on physicochemical properties of manganese dioxides Type de document : texte imprimé Auteurs : Chengshuai Liu, Auteur ; Lijia Zhang, Auteur ; Fangbai Li, Auteur Année de publication : 2010 Article en page(s) : pp. 10408–10413 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dependence--Sulfadiazine--Oxidative--Degradation--Physicochemical--Properties--Manganese--Dioxides Résumé : Manganese dioxides as active oxidants are the common minerals in environment, and different types of manganese dioxides may exhibit varied oxidative activity. In this study, eight manganese dioxides were used to conduct sulfadiazine (SD) oxidative degradation. SD can be oxidatively degraded and even mineralized by these manganese dioxides, and the toxicity of the SD sample can also be reduced significantly. The experiments in this study demonstrated that the kinetic reaction rate constant k values of SD degradation strongly depended on the physicochemical properties of different manganese dioxides, including average oxidation state (AOS), reductive potential (Eh), pH at the point of zero charge (pHPZC), and apparent activation energy (Ea). The k values were positively correlated with the AOS and Eh, while negatively correlated with pHPZC and Ea. The values of these physicochemical properties can be used to quantitatively estimate the oxidative activity of a manganese dioxide to some extent for better understanding of the degradation of organic pollutants with manganese dioxides. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900812j [article] Dependence of sulfadiazine oxidative degradation on physicochemical properties of manganese dioxides [texte imprimé] / Chengshuai Liu, Auteur ; Lijia Zhang, Auteur ; Fangbai Li, Auteur . - 2010 . - pp. 10408–10413. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10408–10413 Mots-clés : Dependence--Sulfadiazine--Oxidative--Degradation--Physicochemical--Properties--Manganese--Dioxides Résumé : Manganese dioxides as active oxidants are the common minerals in environment, and different types of manganese dioxides may exhibit varied oxidative activity. In this study, eight manganese dioxides were used to conduct sulfadiazine (SD) oxidative degradation. SD can be oxidatively degraded and even mineralized by these manganese dioxides, and the toxicity of the SD sample can also be reduced significantly. The experiments in this study demonstrated that the kinetic reaction rate constant k values of SD degradation strongly depended on the physicochemical properties of different manganese dioxides, including average oxidation state (AOS), reductive potential (Eh), pH at the point of zero charge (pHPZC), and apparent activation energy (Ea). The k values were positively correlated with the AOS and Eh, while negatively correlated with pHPZC and Ea. The values of these physicochemical properties can be used to quantitatively estimate the oxidative activity of a manganese dioxide to some extent for better understanding of the degradation of organic pollutants with manganese dioxides. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900812j

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Effect of Citric Acid Addition on Co−Mo/B2O3/Al2O3 Catalysts Prepared by a Post-Treatment Method / Nino Rinaldi in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10414–10424 Titre : Effect of Citric Acid Addition on Co−Mo/B2O3/Al2O3 Catalysts Prepared by a Post-Treatment Method Type de document : texte imprimé Auteurs : Nino Rinaldi, Auteur ; Tekeshi Kubota, Auteur ; Yasuaki Okamoto, Auteur Année de publication : 2010 Article en page(s) : pp. 10414–10424 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Effect--Citric--Acid Addition--Co−  Mo/B2O3/Al2O3--Catalysts--Prepared--Post-Treatment--Method Résumé : Co−Mo/B2O3/Al2O3 catalysts were prepared by a post-treatment of the calcined states with citric acid (CA) and were tested for the hydrodesulfurization (HDS) reaction of thiophene. The catalysts were characterized by LRS, UV−visible spectroscopy, Mo K-edge EXAFS, TEM, NO adsorption capacity, and surface area measurements. Catalysts obtained by simultaneous impregnation with citric acid were also prepared for comparison. Sulfided catalysts were characterized by a chemical vapor deposition (CVD) technique using Co(CO)3NO. The addition of citric acid in a post-treatment more effectively increased the catalytic activity and NO adsorption capacity than did addition by a simultaneous-impregnation method. Co-CA and Mo-CA surface complexes formed at the expense of CoMoO4 and polymolybdates. The maximum potential activity of Co−Mo/B2O3/Al2O3 was obtained by a simple post-treatment of the calcined catalyst with citric acid. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008343 [article] Effect of Citric Acid Addition on Co−Mo/B2O3/Al2O3 Catalysts Prepared by a Post-Treatment Method [texte imprimé] / Nino Rinaldi, Auteur ; Tekeshi Kubota, Auteur ; Yasuaki Okamoto, Auteur . - 2010 . - pp. 10414–10424. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10414–10424 Mots-clés : Effect--Citric--Acid Addition--Co−  Mo/B2O3/Al2O3--Catalysts--Prepared--Post-Treatment--Method Résumé : Co−Mo/B2O3/Al2O3 catalysts were prepared by a post-treatment of the calcined states with citric acid (CA) and were tested for the hydrodesulfurization (HDS) reaction of thiophene. The catalysts were characterized by LRS, UV−visible spectroscopy, Mo K-edge EXAFS, TEM, NO adsorption capacity, and surface area measurements. Catalysts obtained by simultaneous impregnation with citric acid were also prepared for comparison. Sulfided catalysts were characterized by a chemical vapor deposition (CVD) technique using Co(CO)3NO. The addition of citric acid in a post-treatment more effectively increased the catalytic activity and NO adsorption capacity than did addition by a simultaneous-impregnation method. Co-CA and Mo-CA surface complexes formed at the expense of CoMoO4 and polymolybdates. The maximum potential activity of Co−Mo/B2O3/Al2O3 was obtained by a simple post-treatment of the calcined catalyst with citric acid. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008343

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Kinetics of oxidative decarboxylation of 3,4-methylenedioxymandelic acid to piperonal with dilute nitric acid / Hongjuan Xi in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10425–10430 Titre : Kinetics of oxidative decarboxylation of 3,4-methylenedioxymandelic acid to piperonal with dilute nitric acid Type de document : texte imprimé Auteurs : Hongjuan Xi, Auteur ; Zhixian Gao, Auteur ; Jianguo Wang, Auteur Année de publication : 2010 Article en page(s) : pp. 10425–10430 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics--Oxidative--Decarboxylation--3,4-Methylenedioxymandelic--Acid--Piperonal--Dilute Nitric Résumé : The oxidative decarboxylation of 3,4-methylenedioxymandelic acid (DMA) to piperonal with dilute nitric acid was investigated. This reaction was initiated by NaNO2 and catalyzed by H2SO4, but the autocatalytic behavior, which was noted in most nitric acid oxidation reactions, was not observed. Detailed kinetic study showed that the respective reaction orders of NaNO2, H2SO4, HNO3, and DMA were 0.5, 0.5, 1.2, and 1.8, and the activation energy was 59.65 kJ/mol. The gained reaction rate equation provided a good model for the reaction under other temperatures and even the condition of a slightly higher concentration of nitric acid. Additional experimental data suggested that HNO2 was the reactive species. On the basis of the results, a possible reaction mechanism was proposed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900961r [article] Kinetics of oxidative decarboxylation of 3,4-methylenedioxymandelic acid to piperonal with dilute nitric acid [texte imprimé] / Hongjuan Xi, Auteur ; Zhixian Gao, Auteur ; Jianguo Wang, Auteur . - 2010 . - pp. 10425–10430. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10425–10430 Mots-clés : Kinetics--Oxidative--Decarboxylation--3,4-Methylenedioxymandelic--Acid--Piperonal--Dilute Nitric Résumé : The oxidative decarboxylation of 3,4-methylenedioxymandelic acid (DMA) to piperonal with dilute nitric acid was investigated. This reaction was initiated by NaNO2 and catalyzed by H2SO4, but the autocatalytic behavior, which was noted in most nitric acid oxidation reactions, was not observed. Detailed kinetic study showed that the respective reaction orders of NaNO2, H2SO4, HNO3, and DMA were 0.5, 0.5, 1.2, and 1.8, and the activation energy was 59.65 kJ/mol. The gained reaction rate equation provided a good model for the reaction under other temperatures and even the condition of a slightly higher concentration of nitric acid. Additional experimental data suggested that HNO2 was the reactive species. On the basis of the results, a possible reaction mechanism was proposed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900961r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Evolution of char structure during the steam gasification of biochars produced from the pyrolysis of various mallee biomass components / Hongwei Wu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10431–10438 Titre : Evolution of char structure during the steam gasification of biochars produced from the pyrolysis of various mallee biomass components Type de document : texte imprimé Auteurs : Hongwei Wu, Auteur ; Kongvui Yip, Auteur ; Fujun Tian, Auteur Année de publication : 2010 Article en page(s) : pp. 10431–10438 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Evolution--Structure--during--Steam--Gasification--Biochars--Produced--Pyrolysis--Various--Mallee--Biomass--Components Résumé : This study reports the evolution of char structure during the steam gasification of biochars under chemical-reaction-controlled conditions. Partially gasified samples were collected at various conversion levels during the steam gasification of both the raw biochars and the acid-treated biochars that had been prepared via acid-washing of the raw biochars. Results from FT-Raman spectroscopy show that the biochars have highly heterogeneous and disordered structures, which are selectively consumed with progress of steam gasification, leading to enrichment of larger aromatic ring systems, hence the so-called “selective gasification”. Selective gasification of biochar can be significantly influenced by the inherent alkali and alkaline earth metallic (AAEM) species in the biochars. The abundant catalysts present in the raw biochars can alter the gasification reaction pathway, but such an alteration appears to have little effect on the evolution of pore surface area, which increases significantly with conversion. While the wood biochar has too low a content of AAEM species to have an apparent effect on selective gasification, for the raw leaf and bark biochars with high contents of AAEM species, selective gasification is considerably less significant in comparison with the respective acid-treated biochars. For acid-treated biochars, gasification seems to take place slowly throughout the biochar on carbon active sites to consume the smaller rings selectively; the reactivity is controlled by the biochar carbon structure. However, for the raw leaf and bark biochars, gasification would be more focused or localized on the catalytic sites so that the activity of carbon active sites becomes less important. The catalytic effect of the inherent AAEM species seems to in turn depend on the carbon structure that probably affects the catalyst dispersion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901025d [article] Evolution of char structure during the steam gasification of biochars produced from the pyrolysis of various mallee biomass components [texte imprimé] / Hongwei Wu, Auteur ; Kongvui Yip, Auteur ; Fujun Tian, Auteur . - 2010 . - pp. 10431–10438. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10431–10438 Mots-clés : Evolution--Structure--during--Steam--Gasification--Biochars--Produced--Pyrolysis--Various--Mallee--Biomass--Components Résumé : This study reports the evolution of char structure during the steam gasification of biochars under chemical-reaction-controlled conditions. Partially gasified samples were collected at various conversion levels during the steam gasification of both the raw biochars and the acid-treated biochars that had been prepared via acid-washing of the raw biochars. Results from FT-Raman spectroscopy show that the biochars have highly heterogeneous and disordered structures, which are selectively consumed with progress of steam gasification, leading to enrichment of larger aromatic ring systems, hence the so-called “selective gasification”. Selective gasification of biochar can be significantly influenced by the inherent alkali and alkaline earth metallic (AAEM) species in the biochars. The abundant catalysts present in the raw biochars can alter the gasification reaction pathway, but such an alteration appears to have little effect on the evolution of pore surface area, which increases significantly with conversion. While the wood biochar has too low a content of AAEM species to have an apparent effect on selective gasification, for the raw leaf and bark biochars with high contents of AAEM species, selective gasification is considerably less significant in comparison with the respective acid-treated biochars. For acid-treated biochars, gasification seems to take place slowly throughout the biochar on carbon active sites to consume the smaller rings selectively; the reactivity is controlled by the biochar carbon structure. However, for the raw leaf and bark biochars, gasification would be more focused or localized on the catalytic sites so that the activity of carbon active sites becomes less important. The catalytic effect of the inherent AAEM species seems to in turn depend on the carbon structure that probably affects the catalyst dispersion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901025d

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

The development of a macro kinetic model for a commercial Co/Pt/Al2O3 fischer−tropsch catalyst / F. Gideon Botes in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10439–10447 Titre : The development of a macro kinetic model for a commercial Co/Pt/Al2O3 fischer−tropsch catalyst Type de document : texte imprimé Auteurs : F. Gideon Botes, Auteur ; Braam van Dyk, Auteur ; Craig McGregor, Auteur Année de publication : 2010 Article en page(s) : pp. 10439–10447 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Development--Macro--Kinetic--Model--Commercial--Co/Pt/Al2O3--Fischer−  Tropsch--Catalyst Résumé : An experimental study was performed with an aged Co/Pt/Al2O3 catalyst in a laboratory slurry reactor to develop a macrokinetic expression for the Fischer−Tropsch (FT) synthesis. A semiempirical model was found to be the preferred two-parameter rate equation of the reaction. However, it was shown that this model is virtually indistinguishable from a mechanistically derived three-parameter rate model that assumes the following kinetically relevant steps in the cobalt-FT synthesis: CO dissociation occurs without hydrogen interaction and is not a rate-limiting step; the first hydrogen addition to surface carbon and the second hydrogen addition to surface oxygen are the rate-determining steps. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900119z [article] The development of a macro kinetic model for a commercial Co/Pt/Al2O3 fischer−tropsch catalyst [texte imprimé] / F. Gideon Botes, Auteur ; Braam van Dyk, Auteur ; Craig McGregor, Auteur . - 2010 . - pp. 10439–10447. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10439–10447 Mots-clés : Development--Macro--Kinetic--Model--Commercial--Co/Pt/Al2O3--Fischer−  Tropsch--Catalyst Résumé : An experimental study was performed with an aged Co/Pt/Al2O3 catalyst in a laboratory slurry reactor to develop a macrokinetic expression for the Fischer−Tropsch (FT) synthesis. A semiempirical model was found to be the preferred two-parameter rate equation of the reaction. However, it was shown that this model is virtually indistinguishable from a mechanistically derived three-parameter rate model that assumes the following kinetically relevant steps in the cobalt-FT synthesis: CO dissociation occurs without hydrogen interaction and is not a rate-limiting step; the first hydrogen addition to surface carbon and the second hydrogen addition to surface oxygen are the rate-determining steps. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900119z

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Modeling of the kinetics for methanol synthesis using Cu/ZnO/Al2O3/ZrO2 catalyst / Hye-Won Lim in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10448–10455 Titre : Modeling of the kinetics for methanol synthesis using Cu/ZnO/Al2O3/ZrO2 catalyst : influence of carbon dioxide during hydrogenation Type de document : texte imprimé Auteurs : Hye-Won Lim, Auteur ; Myung-June Park, Auteur ; Suk-Hwan Kang, Auteur Année de publication : 2010 Article en page(s) : pp. 10448–10455 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Modeling--Kinetics--Methanol--Synthesis--using--Cu/ZnO/Al2O3/ZrO2--Catalyst--Influence--Carbon Dioxide--during Hydrogenation Résumé : A kinetic model for methanol (MeOH) synthesis over Cu/ZnO/Al2O3/ZrO2 catalyst has been developed and selected to evaluate the effect of carbon dioxide on the reaction rates due to its high activity and stability. Detailed kinetic mechanism, on the basis of different sites on Cu for the adsorption of carbon monoxide and carbon dioxide, is applied, and the water−gas shift (WGS) reaction is included in order to provide the relationship between the hydrogenations of carbon monoxide and carbon dioxide. Parameter estimation results show that, among 48 reaction rates from different combinations of rate determining steps (RDSs) in each reaction, the surface reaction of a methoxy species, the hydrogenation of a formate intermediate HCO2, and the formation of a formate intermediate are the RDS for CO and CO2 hydrogenations and the WGS reaction, respectively. It is shown that the CO2 hydrogenation rate is much lower than the CO hydrogenation rate, and this affects the methanol production rate. However, carbon dioxide decreases the WGS reaction rate, which prevents methanol from converting to dimethyl ether, a byproduct. In such a way, a small fraction of carbon dioxide accelerates the production of methanol indirectly within a limited range, showing a threshold value of the CO2 fraction for the maximum methanol synthesis. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901081f [article] Modeling of the kinetics for methanol synthesis using Cu/ZnO/Al2O3/ZrO2 catalyst : influence of carbon dioxide during hydrogenation [texte imprimé] / Hye-Won Lim, Auteur ; Myung-June Park, Auteur ; Suk-Hwan Kang, Auteur . - 2010 . - pp. 10448–10455. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10448–10455 Mots-clés : Modeling--Kinetics--Methanol--Synthesis--using--Cu/ZnO/Al2O3/ZrO2--Catalyst--Influence--Carbon Dioxide--during Hydrogenation Résumé : A kinetic model for methanol (MeOH) synthesis over Cu/ZnO/Al2O3/ZrO2 catalyst has been developed and selected to evaluate the effect of carbon dioxide on the reaction rates due to its high activity and stability. Detailed kinetic mechanism, on the basis of different sites on Cu for the adsorption of carbon monoxide and carbon dioxide, is applied, and the water−gas shift (WGS) reaction is included in order to provide the relationship between the hydrogenations of carbon monoxide and carbon dioxide. Parameter estimation results show that, among 48 reaction rates from different combinations of rate determining steps (RDSs) in each reaction, the surface reaction of a methoxy species, the hydrogenation of a formate intermediate HCO2, and the formation of a formate intermediate are the RDS for CO and CO2 hydrogenations and the WGS reaction, respectively. It is shown that the CO2 hydrogenation rate is much lower than the CO hydrogenation rate, and this affects the methanol production rate. However, carbon dioxide decreases the WGS reaction rate, which prevents methanol from converting to dimethyl ether, a byproduct. In such a way, a small fraction of carbon dioxide accelerates the production of methanol indirectly within a limited range, showing a threshold value of the CO2 fraction for the maximum methanol synthesis. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901081f

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Photocatalytic reactor employing titanium dioxide / Roberto L. Romero in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10456–10466 Titre : Photocatalytic reactor employing titanium dioxide : from a theoretical model to realistic experimental results Type de document : texte imprimé Auteurs : Roberto L. Romero, Auteur ; Orlando M. Alfano, Auteur ; Alberto E. Cassano, Auteur Année de publication : 2010 Article en page(s) : pp. 10456–10466 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Photocatalytic--Reactor--Employing--Titanium Dioxide--Theoretical--Model--Realistic Experimental--Results Résumé : The performance of a reacting system for degradation of trichloroethylene (TCE) in a pilot-size annular photocatalytic reactor having a tubular lamp located at its centerline was studied. The reactor operation was carried out with commercial catalytic particles of titanium dioxide (Aldrich) in a water suspension. The description of the reactor performance was made by employing a kinetic model developed in a laboratory reactor of different size and configuration, irradiated with similar lamps of lower output power. The annular reactor was operated in the continuous mode but inside the loop of a recirculation system.The performance of the annular reactor was modeled by assuming three different behaviors: (i) a well-stirred tank reactor, (ii) a pseudo-steady-state laminar flow reactor in a batch recycle, and (iii) a transient-state laminar flow reactor in a recycle. Case iii produced the best representation of the experimental data. Along with the experimental validation of the developed theoretical models, three practical features were unveiled that had to be taken into account in any subsequent design: (a) an important change in the pH, from 6.5 to 3.5, along the reaction time; (b) a significant titanium dioxide deposition on the reactor walls; and (c) an appreciable catalyst agglomeration produced by the recirculation system and magnified by the change in pH. Only after the first 120 min of reaction time, the reactor conditions became almost stabilized; thus, the observed transformations had to be incorporated into the modeling. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900354y [article] Photocatalytic reactor employing titanium dioxide : from a theoretical model to realistic experimental results [texte imprimé] / Roberto L. Romero, Auteur ; Orlando M. Alfano, Auteur ; Alberto E. Cassano, Auteur . - 2010 . - pp. 10456–10466. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10456–10466 Mots-clés : Photocatalytic--Reactor--Employing--Titanium Dioxide--Theoretical--Model--Realistic Experimental--Results Résumé : The performance of a reacting system for degradation of trichloroethylene (TCE) in a pilot-size annular photocatalytic reactor having a tubular lamp located at its centerline was studied. The reactor operation was carried out with commercial catalytic particles of titanium dioxide (Aldrich) in a water suspension. The description of the reactor performance was made by employing a kinetic model developed in a laboratory reactor of different size and configuration, irradiated with similar lamps of lower output power. The annular reactor was operated in the continuous mode but inside the loop of a recirculation system.The performance of the annular reactor was modeled by assuming three different behaviors: (i) a well-stirred tank reactor, (ii) a pseudo-steady-state laminar flow reactor in a batch recycle, and (iii) a transient-state laminar flow reactor in a recycle. Case iii produced the best representation of the experimental data. Along with the experimental validation of the developed theoretical models, three practical features were unveiled that had to be taken into account in any subsequent design: (a) an important change in the pH, from 6.5 to 3.5, along the reaction time; (b) a significant titanium dioxide deposition on the reactor walls; and (c) an appreciable catalyst agglomeration produced by the recirculation system and magnified by the change in pH. Only after the first 120 min of reaction time, the reactor conditions became almost stabilized; thus, the observed transformations had to be incorporated into the modeling. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900354y

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Hydrothermal Decarboxylation of Pentafluorobenzoic Acid and Quinolinic Acid / Jie Fu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10467–10471 Titre : Hydrothermal Decarboxylation of Pentafluorobenzoic Acid and Quinolinic Acid Type de document : texte imprimé Auteurs : Jie Fu, Auteur ; Phillip E. Savage, Auteur ; Xiuyang Lu, Auteur Année de publication : 2010 Article en page(s) : pp. 10467–10471 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrothermal--Decarboxylation--Pentafluorobenzoic--Acid--Quinolinic--Acid Résumé : We report herein the first kinetics studies of hydrothermal decarboxylation of a fully halogenated benzoic acid and a heterocyclic aromatic diacid. Decarboxylation was the only reaction path observed, and there was no evidence of dehalogenation. Experiments at different initial reactant concentrations and different batch holding times revealed that both compounds exhibited first-order kinetics. Experiments at different temperatures showed that the first-order rate constants displayed Arrhenius behavior with activation energies of 157 kJ mol−1 for pentafluorobenzoic acid decarboxylation and 141 kJ mol−1 for quinolinic acid decarboxylation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901182y [article] Hydrothermal Decarboxylation of Pentafluorobenzoic Acid and Quinolinic Acid [texte imprimé] / Jie Fu, Auteur ; Phillip E. Savage, Auteur ; Xiuyang Lu, Auteur . - 2010 . - pp. 10467–10471. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10467–10471 Mots-clés : Hydrothermal--Decarboxylation--Pentafluorobenzoic--Acid--Quinolinic--Acid Résumé : We report herein the first kinetics studies of hydrothermal decarboxylation of a fully halogenated benzoic acid and a heterocyclic aromatic diacid. Decarboxylation was the only reaction path observed, and there was no evidence of dehalogenation. Experiments at different initial reactant concentrations and different batch holding times revealed that both compounds exhibited first-order kinetics. Experiments at different temperatures showed that the first-order rate constants displayed Arrhenius behavior with activation energies of 157 kJ mol−1 for pentafluorobenzoic acid decarboxylation and 141 kJ mol−1 for quinolinic acid decarboxylation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901182y

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

New insights into coating uniformity and base sheet structures / Christina Dahlstrom in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10472–10478 Titre : New insights into coating uniformity and base sheet structures Type de document : texte imprimé Auteurs : Christina Dahlstrom, Auteur ; Tetsu Uesaka, Auteur Année de publication : 2010 Article en page(s) : pp. 10472–10478 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : New Insights--Coating--Uniformity--Base Sheet--Structures Résumé : Base sheet structures, such as surface roughness and mass density distribution (formation), have been known to affect coating uniformity. However, the literature is not necessarily consistent in determining which structure controls coating uniformity. This study employed scanning electron microscopy (SEM) and image analysis, combined with autocorrelation and frequency analyses, to investigate the fundamental mechanisms of coating and to resolve some of the controversies in the literature regarding the base sheet effects. The results showed that coating thickness variation resembles a process of random deposition with leveling. At small length scales (in the size of fiber width), leveling causes a very strong dependence of coating thickness variations on the surface profile of the base sheet, whereas at larger length scales, coating thickness variation diminishes in its intensity by the same leveling effect, but still retains a significant correlation with base sheet structure, particularly formation. Frequency analyses clearly showed that the discrepancies in the results for the base sheet effects in the literature are due to the length scales used in the experiments, that is, the sampling area and the resolution of the measurements. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900819c [article] New insights into coating uniformity and base sheet structures [texte imprimé] / Christina Dahlstrom, Auteur ; Tetsu Uesaka, Auteur . - 2010 . - pp. 10472–10478. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10472–10478 Mots-clés : New Insights--Coating--Uniformity--Base Sheet--Structures Résumé : Base sheet structures, such as surface roughness and mass density distribution (formation), have been known to affect coating uniformity. However, the literature is not necessarily consistent in determining which structure controls coating uniformity. This study employed scanning electron microscopy (SEM) and image analysis, combined with autocorrelation and frequency analyses, to investigate the fundamental mechanisms of coating and to resolve some of the controversies in the literature regarding the base sheet effects. The results showed that coating thickness variation resembles a process of random deposition with leveling. At small length scales (in the size of fiber width), leveling causes a very strong dependence of coating thickness variations on the surface profile of the base sheet, whereas at larger length scales, coating thickness variation diminishes in its intensity by the same leveling effect, but still retains a significant correlation with base sheet structure, particularly formation. Frequency analyses clearly showed that the discrepancies in the results for the base sheet effects in the literature are due to the length scales used in the experiments, that is, the sampling area and the resolution of the measurements. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900819c

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Computational study on the influences of framework charges on CO2 uptake in metal−organic frameworks / Chengcheng Zheng in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10479–10484 Titre : Computational study on the influences of framework charges on CO2 uptake in metal−organic frameworks Type de document : texte imprimé Auteurs : Chengcheng Zheng, Auteur ; Dahuan Liu, Auteur ; Qingyuan Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 10479–10484 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Computational--Influences--Framework--Charges--CO2 Uptake--Metal-−  Organic--Frameworks Résumé : This work involved a computational study to investigate the influences of framework charges on CO2 uptake in metal−organic frameworks (MOFs), in which a total of 20 MOFs with different topologies, pore sizes, and chemical characteristics were examined. The results showed that, at atmospheric pressure, the contribution of the framework charges is generally large, and a linear relationship with pore size was found, showing that, when the pore size is larger than 3.3 nm, the contribution becomes smaller than 10%. On the other hand, the framework charge contribution was found to decrease rapidly with increasing pressure and to become less than 10% at pressures higher than 2.0 MPa. This work shows that the framework charge contribution in MOFs cannot be ignored in computational screening of MOF materials for CO2 capture under low-pressure conditions, whereas at moderate operating pressures, the contribution can be ignored in large-scale prescreening such as in the natural gas upgrading process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901000x [article] Computational study on the influences of framework charges on CO2 uptake in metal−organic frameworks [texte imprimé] / Chengcheng Zheng, Auteur ; Dahuan Liu, Auteur ; Qingyuan Yang, Auteur . - 2010 . - pp. 10479–10484. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10479–10484 Mots-clés : Computational--Influences--Framework--Charges--CO2 Uptake--Metal-−  Organic--Frameworks Résumé : This work involved a computational study to investigate the influences of framework charges on CO2 uptake in metal−organic frameworks (MOFs), in which a total of 20 MOFs with different topologies, pore sizes, and chemical characteristics were examined. The results showed that, at atmospheric pressure, the contribution of the framework charges is generally large, and a linear relationship with pore size was found, showing that, when the pore size is larger than 3.3 nm, the contribution becomes smaller than 10%. On the other hand, the framework charge contribution was found to decrease rapidly with increasing pressure and to become less than 10% at pressures higher than 2.0 MPa. This work shows that the framework charge contribution in MOFs cannot be ignored in computational screening of MOF materials for CO2 capture under low-pressure conditions, whereas at moderate operating pressures, the contribution can be ignored in large-scale prescreening such as in the natural gas upgrading process. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901000x

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Treatment of fractionated fibers with various cationic-modified poly(vinyl alcohols) and Its iImpact on paper properties / Pedram Fatehi in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10485–10490 Titre : Treatment of fractionated fibers with various cationic-modified poly(vinyl alcohols) and Its iImpact on paper properties Type de document : texte imprimé Auteurs : Pedram Fatehi, Auteur ; Jeffery E. Ward, Auteur ; Huining Xiao, Auteur Année de publication : 2010 Article en page(s) : pp. 10485–10490 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Treatment--Fractionated Fibers--Various--Cationic-Modified--Poly(vinyl alcohols--Impact--Paper Properties Résumé : In this work, the effects of various high molecular weight cationic poly(vinyl alcohols), CPVAs, on the fiber morphology and the properties of papers made from fractionated refined fibers were investigated. At first, bleached sulfite fibers were refined under various revolutions and then refined fibers were fractionated under various time intervals to obtain refined fibers with a similar fiber length and fines content. Then, 20 mg/g CPVAs with various charge densities was adsorbed on the fractionated refined fibers prior to making hand sheets. The results showed that the lower the charge density of CPVA, the higher the effectiveness of CPVA in improving the paper strength at any refining revolution. The reasons for such a phenomenon were perhaps the different configurations of CPVAs on the surface of the fibers and the different adhesion/repulsion forces developed between CPVA-modified fibers in hand sheets. Also, by reducing the freeness of the fractionated fibers (increasing the refining revolutions), the effect of CPVA in improving the paper strength was reduced. In this case, the CPVAs tended to cover the fibrils on the fiber surface, which was demonstrated by SEM observations, thus reducing the contact area of the fractionated refined fibers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900999n [article] Treatment of fractionated fibers with various cationic-modified poly(vinyl alcohols) and Its iImpact on paper properties [texte imprimé] / Pedram Fatehi, Auteur ; Jeffery E. Ward, Auteur ; Huining Xiao, Auteur . - 2010 . - pp. 10485–10490. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10485–10490 Mots-clés : Treatment--Fractionated Fibers--Various--Cationic-Modified--Poly(vinyl alcohols--Impact--Paper Properties Résumé : In this work, the effects of various high molecular weight cationic poly(vinyl alcohols), CPVAs, on the fiber morphology and the properties of papers made from fractionated refined fibers were investigated. At first, bleached sulfite fibers were refined under various revolutions and then refined fibers were fractionated under various time intervals to obtain refined fibers with a similar fiber length and fines content. Then, 20 mg/g CPVAs with various charge densities was adsorbed on the fractionated refined fibers prior to making hand sheets. The results showed that the lower the charge density of CPVA, the higher the effectiveness of CPVA in improving the paper strength at any refining revolution. The reasons for such a phenomenon were perhaps the different configurations of CPVAs on the surface of the fibers and the different adhesion/repulsion forces developed between CPVA-modified fibers in hand sheets. Also, by reducing the freeness of the fractionated fibers (increasing the refining revolutions), the effect of CPVA in improving the paper strength was reduced. In this case, the CPVAs tended to cover the fibrils on the fiber surface, which was demonstrated by SEM observations, thus reducing the contact area of the fractionated refined fibers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900999n

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Mechanical and morphological properties of chemically treated coir-filled polypropylene composites / Md. Nazrul Islam in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10491–10497 Titre : Mechanical and morphological properties of chemically treated coir-filled polypropylene composites Type de document : texte imprimé Auteurs : Md. Nazrul Islam, Auteur ; Md. Mominul Haque, Auteur ; Md. Monimul Huque, Auteur Année de publication : 2010 Article en page(s) : pp. 10491–10497 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mechanical--Morphological--Chemically Treated--Coir-Filled--Polypropylene Composites Résumé : In the present work, coir was chemically treated first with sodium perchlorate and then with 2,4-dinitrophenyl hydrazine (DNPH) to improve the mechanical properties of the coir−PP composites. Untreated, oxidized, and DNPH-treated coir samples at different mixing ratios were utilized to prepare the composites. Mechanical properties of the composites prepared from both perchlorate and DNPH-treated coir were found to be better than those of untreated ones. The tensile strengths of both untreated and treated coir−PP composites decreased with an increase in fiber content. However, the values were found to be higher than those of corresponding values of untreated ones. Treated coir−PP composites were found to absorb a lower amount of water than the untreated ones. To understand why the mechanical properties of composites prepared under different conditions of coir were different, surface morphologies of the tensile fractured surfaces of the specimens were recorded using scanning electron microscopy (SEM). The SEM images clearly revealed that there were fewer fiber agglomerations, microvoids, and fiber pull out traces in both perchorate and DNPH-treated coir−PP composite than in the untreated one, indicating that better distribution of the fiber into the matrix as well as stronger fiber matrix interfacial adhesion occurred upon treatment of coir. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900824c [article] Mechanical and morphological properties of chemically treated coir-filled polypropylene composites [texte imprimé] / Md. Nazrul Islam, Auteur ; Md. Mominul Haque, Auteur ; Md. Monimul Huque, Auteur . - 2010 . - pp. 10491–10497. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10491–10497 Mots-clés : Mechanical--Morphological--Chemically Treated--Coir-Filled--Polypropylene Composites Résumé : In the present work, coir was chemically treated first with sodium perchlorate and then with 2,4-dinitrophenyl hydrazine (DNPH) to improve the mechanical properties of the coir−PP composites. Untreated, oxidized, and DNPH-treated coir samples at different mixing ratios were utilized to prepare the composites. Mechanical properties of the composites prepared from both perchlorate and DNPH-treated coir were found to be better than those of untreated ones. The tensile strengths of both untreated and treated coir−PP composites decreased with an increase in fiber content. However, the values were found to be higher than those of corresponding values of untreated ones. Treated coir−PP composites were found to absorb a lower amount of water than the untreated ones. To understand why the mechanical properties of composites prepared under different conditions of coir were different, surface morphologies of the tensile fractured surfaces of the specimens were recorded using scanning electron microscopy (SEM). The SEM images clearly revealed that there were fewer fiber agglomerations, microvoids, and fiber pull out traces in both perchorate and DNPH-treated coir−PP composite than in the untreated one, indicating that better distribution of the fiber into the matrix as well as stronger fiber matrix interfacial adhesion occurred upon treatment of coir. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900824c

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Glass-based processing of mixed-oxide desulfurization sorbents / Michael D. Dolan in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10498–10503 Titre : Glass-based processing of mixed-oxide desulfurization sorbents Type de document : texte imprimé Auteurs : Michael D. Dolan, Auteur ; Alex Y. Ilyushechkin, Auteur ; Keith G. McLennan, Auteur Année de publication : 2010 Article en page(s) : pp. 10498–10503 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Glass-Based--Processing--Mixed-Oxide--Desulfurization--Sorbents Résumé : The favorable thermodynamics of the reaction between H2S and oxides of iron, nickel, and zinc make these materials suitable for the sorption of sulfur from coal-derived synthesis gas. As an alternative to traditional solid-state processing, the suitability for coal gas desulfurization of glass-ceramics based on transition metal oxides has been evaluated. Glass-ceramics based on NiAl2O4 and ZnFe2O4 have similar sorption properties and a high resistance to agglomeration, but the inexpensive raw materials and moderate processing temperature of the ZnFe2O4-based glass makes it more suitable for a commercial application. The overall performance is highly dependent on the particle size of the sorbent, but these materials can be formed with relatively high surface areas by using fiber-based processing. This material is a potential alternative to mixed oxide sorbents prepared by solid-state processing, as it offers comparable performance combined with the ability to process the glass by existing glass-processing techniques. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901170f [article] Glass-based processing of mixed-oxide desulfurization sorbents [texte imprimé] / Michael D. Dolan, Auteur ; Alex Y. Ilyushechkin, Auteur ; Keith G. McLennan, Auteur . - 2010 . - pp. 10498–10503. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10498–10503 Mots-clés : Glass-Based--Processing--Mixed-Oxide--Desulfurization--Sorbents Résumé : The favorable thermodynamics of the reaction between H2S and oxides of iron, nickel, and zinc make these materials suitable for the sorption of sulfur from coal-derived synthesis gas. As an alternative to traditional solid-state processing, the suitability for coal gas desulfurization of glass-ceramics based on transition metal oxides has been evaluated. Glass-ceramics based on NiAl2O4 and ZnFe2O4 have similar sorption properties and a high resistance to agglomeration, but the inexpensive raw materials and moderate processing temperature of the ZnFe2O4-based glass makes it more suitable for a commercial application. The overall performance is highly dependent on the particle size of the sorbent, but these materials can be formed with relatively high surface areas by using fiber-based processing. This material is a potential alternative to mixed oxide sorbents prepared by solid-state processing, as it offers comparable performance combined with the ability to process the glass by existing glass-processing techniques. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901170f

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Near-optimization of operating conditions and residence times in multizone dryers for polymer coatings / Raj K. Arya in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10504–10514 Titre : Near-optimization of operating conditions and residence times in multizone dryers for polymer coatings Type de document : texte imprimé Auteurs : Raj K. Arya, Auteur ; Madhu Vinjamur, Auteur Année de publication : 2010 Article en page(s) : pp. 10504–10514 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Near-Optimization--Operating Conditions--Residence--Multizone--Dryers--Polymer Coatings Résumé : Several polymeric coatings are dried by blowing jets of hot air on them from the top and bottom sides in multizone dryers. The goal of quickly removing solvent from a coating by manipulating air flow and temperature, together called operating conditions in this work, conflicts with the goal of producing blister-free coatings. Optimum operating conditions ensure both minimum residual solvent and no defects. Determining optimum conditions for multizone dryers is a difficult task with severe convergence problems. In this work, an easy method is developed to determine near-optimum operating conditions and residence times. The results indicate that the air flow on the top side should always be lower than or equal to that on the bottom side; the minimum residence time in first zone should be such that, toward the end, the solvent concentration starts to fall at the bottom. As long as the residence times are reasonably long, several different combinations of residence times in the second and subsequent zones nearly minimize residual solvent. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900604f [article] Near-optimization of operating conditions and residence times in multizone dryers for polymer coatings [texte imprimé] / Raj K. Arya, Auteur ; Madhu Vinjamur, Auteur . - 2010 . - pp. 10504–10514. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10504–10514 Mots-clés : Near-Optimization--Operating Conditions--Residence--Multizone--Dryers--Polymer Coatings Résumé : Several polymeric coatings are dried by blowing jets of hot air on them from the top and bottom sides in multizone dryers. The goal of quickly removing solvent from a coating by manipulating air flow and temperature, together called operating conditions in this work, conflicts with the goal of producing blister-free coatings. Optimum operating conditions ensure both minimum residual solvent and no defects. Determining optimum conditions for multizone dryers is a difficult task with severe convergence problems. In this work, an easy method is developed to determine near-optimum operating conditions and residence times. The results indicate that the air flow on the top side should always be lower than or equal to that on the bottom side; the minimum residence time in first zone should be such that, toward the end, the solvent concentration starts to fall at the bottom. As long as the residence times are reasonably long, several different combinations of residence times in the second and subsequent zones nearly minimize residual solvent. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900604f

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Predictive ratio control for interacting processes / Tan, Kok Kiong in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10515–10521 Titre : Predictive ratio control for interacting processes Type de document : texte imprimé Auteurs : Tan, Kok Kiong, Auteur ; Tay, Arthur, Auteur ; Zhao Shao, Auteur Année de publication : 2010 Article en page(s) : pp. 10515–10521 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Predictive--Ratio--Control--Interacting--Processes Résumé : In this paper, a predictive-PID ratio control scheme is developed for multivariable processes. The Generalized predictive control based PID configuration is incorporated into various conventional ratio control schemes. Conventional parallel and series ratio control cannot satisfy the stringent requirements. The proposed method is applied to the wafer temperature uniformity control in the lithography. Both simulation and experimental results show the effectiveness of the proposed predictive ratio control method. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900219u [article] Predictive ratio control for interacting processes [texte imprimé] / Tan, Kok Kiong, Auteur ; Tay, Arthur, Auteur ; Zhao Shao, Auteur . - 2010 . - pp. 10515–10521. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10515–10521 Mots-clés : Predictive--Ratio--Control--Interacting--Processes Résumé : In this paper, a predictive-PID ratio control scheme is developed for multivariable processes. The Generalized predictive control based PID configuration is incorporated into various conventional ratio control schemes. Conventional parallel and series ratio control cannot satisfy the stringent requirements. The proposed method is applied to the wafer temperature uniformity control in the lithography. Both simulation and experimental results show the effectiveness of the proposed predictive ratio control method. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900219u

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Crystallization of hydrated ferric arsenate. process design using METSIM / Pía C. Hernández in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10522–10531 Titre : Crystallization of hydrated ferric arsenate. process design using METSIM Type de document : texte imprimé Auteurs : Pía C. Hernández, Auteur ; María E. Taboada, Auteur ; Teófilo A. Graber, Auteur Année de publication : 2010 Article en page(s) : pp. 10522–10531 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystallization--Hydrated--Ferric--Arsenate--Process Design--Using METSIM Résumé : An industrial process for extracting arsenic from solutions through scorodite crystallization at 70 °C was designed and simulated using METSIM software. Using equilibrium information from the phase diagram of the system As(V)/Fe(III)/H2O at 50 and 70 °C, experimental tests were carried out of crystallization of scorodite at 50, 70, and 95 °C, as well as crystallization at 170 °C in an autoclave. This information provides the preliminary operational conditions for the process. The tests show that temperature influences the quality of crystals and the velocity of scorodite crystallization (residence time between 3 h and 3 days). The simulated process allows for the analysis of different evaporation ratios (42.5, 71.97, and 86.7%), determining the material and energy balances and the quality of the products and residues, thus providing important information for potential industrial applications. The energy requirements for each evaporation ratio are 21 568, 33 747, and 39 836 Mcal/h, and the sums of the total flows are 11 588.60, 8876.28, and 7520.11 tons/day, respectively. This last variable is related to the size of the equipment used in the process. Molar Fe/As ratios of 1, 0.9, and 0.8 result in yields of 93, 88, and 78%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900639e [article] Crystallization of hydrated ferric arsenate. process design using METSIM [texte imprimé] / Pía C. Hernández, Auteur ; María E. Taboada, Auteur ; Teófilo A. Graber, Auteur . - 2010 . - pp. 10522–10531. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10522–10531 Mots-clés : Crystallization--Hydrated--Ferric--Arsenate--Process Design--Using METSIM Résumé : An industrial process for extracting arsenic from solutions through scorodite crystallization at 70 °C was designed and simulated using METSIM software. Using equilibrium information from the phase diagram of the system As(V)/Fe(III)/H2O at 50 and 70 °C, experimental tests were carried out of crystallization of scorodite at 50, 70, and 95 °C, as well as crystallization at 170 °C in an autoclave. This information provides the preliminary operational conditions for the process. The tests show that temperature influences the quality of crystals and the velocity of scorodite crystallization (residence time between 3 h and 3 days). The simulated process allows for the analysis of different evaporation ratios (42.5, 71.97, and 86.7%), determining the material and energy balances and the quality of the products and residues, thus providing important information for potential industrial applications. The energy requirements for each evaporation ratio are 21 568, 33 747, and 39 836 Mcal/h, and the sums of the total flows are 11 588.60, 8876.28, and 7520.11 tons/day, respectively. This last variable is related to the size of the equipment used in the process. Molar Fe/As ratios of 1, 0.9, and 0.8 result in yields of 93, 88, and 78%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900639e

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Two-stripper/decanter flowsheet for methanol recovery in the TAME reactive-distillation process / Yi Chang Wu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10532–10540 Titre : Two-stripper/decanter flowsheet for methanol recovery in the TAME reactive-distillation process Type de document : texte imprimé Auteurs : Yi Chang Wu, Auteur ; Chien, I-Lung, Auteur Année de publication : 2010 Article en page(s) : pp. 10532–10540 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Two-Stripper/Decanter--Flowsheet--Methanol--Recovery--TAME--Reactive-Distillation--Process Résumé : The process to produce TAME via reactive distillation requires a methanol-recovery section because the presence of C5/methanol azeotropes means that a significant amount of methanol is present in the distillate from the reactive column. The use of pressure-swing azeotropic distillation and extractive distillation were studied in a previous paper in which both the steady-state design and the plantwide control of the entire process were developed. This paper considers a third alternative flowsheet for the separation of the C5/methanol azeotropes that takes advantage of the heterogeneity of the azeotrope. Two stripping columns and a decanter are used. The total annual cost of this flowsheet is a factor of 4 less than that of the pressure-swing system. The system is demonstrated to be easy to control by controlling a tray temperature in each stripping column. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900670f [article] Two-stripper/decanter flowsheet for methanol recovery in the TAME reactive-distillation process [texte imprimé] / Yi Chang Wu, Auteur ; Chien, I-Lung, Auteur . - 2010 . - pp. 10532–10540. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10532–10540 Mots-clés : Two-Stripper/Decanter--Flowsheet--Methanol--Recovery--TAME--Reactive-Distillation--Process Résumé : The process to produce TAME via reactive distillation requires a methanol-recovery section because the presence of C5/methanol azeotropes means that a significant amount of methanol is present in the distillate from the reactive column. The use of pressure-swing azeotropic distillation and extractive distillation were studied in a previous paper in which both the steady-state design and the plantwide control of the entire process were developed. This paper considers a third alternative flowsheet for the separation of the C5/methanol azeotropes that takes advantage of the heterogeneity of the azeotrope. Two stripping columns and a decanter are used. The total annual cost of this flowsheet is a factor of 4 less than that of the pressure-swing system. The system is demonstrated to be easy to control by controlling a tray temperature in each stripping column. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900670f

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Effects of H2O and particles on the simultaneous removal of SO2 and fly ash using a fluidized-bed sorbent/catalyst reactor / Jui-Yeh Rau in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10541–10550 Titre : Effects of H2O and particles on the simultaneous removal of SO2 and fly ash using a fluidized-bed sorbent/catalyst reactor Type de document : texte imprimé Auteurs : Jui-Yeh Rau, Auteur ; Jyh-Cherng Chen, Auteur ; Ming-Yen Wey, Auteur Année de publication : 2010 Article en page(s) : pp. 10541–10550 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Effects--H2O--Particles--Simultaneous--Removal--SO2--Using--Fluidized-Bed--Sorbent/Catalyst Reactor Résumé : This study investigated the potential of a fluidized-bed sorbent/catalyst reactor for the simultaneous removals of SO2 and fly ash from a simulated flue gas containing different H2O and particles. Experimental results showed that the removal efficiency of particles and SO2 was 85%−96% and 5.75−2.97 mg SO2/g, respectively, as the H2O content was 1.5−5.3%. The activities of sorbent/catalysts for simultaneous removals of SO2 and particles were inhibited by H2O and particles, and the inhibition effects increased with the content of H2O. As the H2O content increased, the particle size distribution (PSD) of fine particles shifted to the coarse particles. The results of BET analysis show that the obstruction phenomenon of the sorbent/catalyst caused by the particles was diminished with the increased content of H2O. The results showed this aggregation phenomenon of fine particles shifted to the coarse particles may cause increased water vapor content in fluidized-bed sorbent/catalyst reactor. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900843f [article] Effects of H2O and particles on the simultaneous removal of SO2 and fly ash using a fluidized-bed sorbent/catalyst reactor [texte imprimé] / Jui-Yeh Rau, Auteur ; Jyh-Cherng Chen, Auteur ; Ming-Yen Wey, Auteur . - 2010 . - pp. 10541–10550. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10541–10550 Mots-clés : Effects--H2O--Particles--Simultaneous--Removal--SO2--Using--Fluidized-Bed--Sorbent/Catalyst Reactor Résumé : This study investigated the potential of a fluidized-bed sorbent/catalyst reactor for the simultaneous removals of SO2 and fly ash from a simulated flue gas containing different H2O and particles. Experimental results showed that the removal efficiency of particles and SO2 was 85%−96% and 5.75−2.97 mg SO2/g, respectively, as the H2O content was 1.5−5.3%. The activities of sorbent/catalysts for simultaneous removals of SO2 and particles were inhibited by H2O and particles, and the inhibition effects increased with the content of H2O. As the H2O content increased, the particle size distribution (PSD) of fine particles shifted to the coarse particles. The results of BET analysis show that the obstruction phenomenon of the sorbent/catalyst caused by the particles was diminished with the increased content of H2O. The results showed this aggregation phenomenon of fine particles shifted to the coarse particles may cause increased water vapor content in fluidized-bed sorbent/catalyst reactor. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900843f

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Design and control of the monoisopropylamine process / William L. Luyben in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10551–10563 Titre : Design and control of the monoisopropylamine process Type de document : texte imprimé Auteurs : William L. Luyben, Auteur Année de publication : 2010 Article en page(s) : pp. 10551–10563 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Design--Control--Monoisopropylamine--Process Résumé : The monoisopropylamine (MIPA) process provides an interesting example of plantwide economic design optimization and plantwide control. The process consists of a tubular reactor and three distillation columns. There are both gas and liquid recycles. Fresh feed streams of isopropyl alcohol and ammonia are introduced into the process. The desired products are MIPA and water. An undesirable byproduct of di-isopropylamine (DIPA) is also produced and is recycled to extinction since its formation reaction is reversible. An excess of ammonia in the reactor inhibits the DIPA reaction, so ammonia is also recycled. The purpose of this paper is to present the details of the process for use by other workers as a test case for use in plantwide design and control studies. A heuristic economic optimum design and a control structure are developed. The process illustrates the classical design trade-off between reactor costs versus separation costs. In addition, the process has two recycles, which are both distillate products from different distillation columns, and this leads to another trade-off. Using more ammonia recycle produces less DIPA recycle. So the optimum design must balance the separation costs of the two recycles. Two of the distillation columns can be effectively controlled using a single temperature and a reflux-to-feed ratio control structure. The third column requires a dual control structure ratio (one temperature and one composition). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900965s [article] Design and control of the monoisopropylamine process [texte imprimé] / William L. Luyben, Auteur . - 2010 . - pp. 10551–10563. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10551–10563 Mots-clés : Design--Control--Monoisopropylamine--Process Résumé : The monoisopropylamine (MIPA) process provides an interesting example of plantwide economic design optimization and plantwide control. The process consists of a tubular reactor and three distillation columns. There are both gas and liquid recycles. Fresh feed streams of isopropyl alcohol and ammonia are introduced into the process. The desired products are MIPA and water. An undesirable byproduct of di-isopropylamine (DIPA) is also produced and is recycled to extinction since its formation reaction is reversible. An excess of ammonia in the reactor inhibits the DIPA reaction, so ammonia is also recycled. The purpose of this paper is to present the details of the process for use by other workers as a test case for use in plantwide design and control studies. A heuristic economic optimum design and a control structure are developed. The process illustrates the classical design trade-off between reactor costs versus separation costs. In addition, the process has two recycles, which are both distillate products from different distillation columns, and this leads to another trade-off. Using more ammonia recycle produces less DIPA recycle. So the optimum design must balance the separation costs of the two recycles. Two of the distillation columns can be effectively controlled using a single temperature and a reflux-to-feed ratio control structure. The third column requires a dual control structure ratio (one temperature and one composition). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900965s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Design and control of heterogeneous azeotropic column system for the separation of pyridine and water / Yi Chang Wu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10564–10576 Titre : Design and control of heterogeneous azeotropic column system for the separation of pyridine and water Type de document : texte imprimé Auteurs : Yi Chang Wu, Auteur ; Chien, I-Lung, Auteur Année de publication : 2010 Article en page(s) : pp. 10564–10576 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Design--Control--Heterogeneous--Azeotropic--Column-- Separation--Pyridine Résumé : The design and control of two types of separation systems using heterogeneous azeotropic distillation have been studied in the literature. One type (e.g., isopropyl alcohol dehydration) is to add a light entrainer (cyclohexane) into the system so that a minimum-boiling ternary azeotrope is formed which can split into two liquid phases in a decanter. This type of system also introduces two additional azeotropes (isopropyl alcohol−cyclohexane and water−cyclohexane), thus dividing the ternary system into three distillation regions. Another type (e.g., acetic acid dehydration) does not contain azeotrope in the original system. However, due to a tangent pinch near the pure water end an entrainer (isobutyl acetate) is added into the system to aid the separation. This type of system has only one binary heterogeneous azeotrope (water−isobutyl acetate); thus there is only one distillation region. In this paper, design and control of a different residue curve map (RCM) type of separation system utilizing heterogeneous azeotropic distillation will be studied. An example of this RCM type is pyridine and water separation using toluene as entrainer. Adding toluene into this system introduces two additional azeotropes, one is minimum-boiling binary heterogeneous azeotrope (water−toluene) and the other one is a binary homogeneous azeotrope (pyridine−toluene). There is no ternary azeotrope for this system. Two alternative design flow sheets are compared in this paper to find the one which is most economical and also meet stringent product purity specifications. A simple overall control strategy of this process has also been developed which requires only one temperature control loop in each column. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901231s [article] Design and control of heterogeneous azeotropic column system for the separation of pyridine and water [texte imprimé] / Yi Chang Wu, Auteur ; Chien, I-Lung, Auteur . - 2010 . - pp. 10564–10576. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10564–10576 Mots-clés : Design--Control--Heterogeneous--Azeotropic--Column-- Separation--Pyridine Résumé : The design and control of two types of separation systems using heterogeneous azeotropic distillation have been studied in the literature. One type (e.g., isopropyl alcohol dehydration) is to add a light entrainer (cyclohexane) into the system so that a minimum-boiling ternary azeotrope is formed which can split into two liquid phases in a decanter. This type of system also introduces two additional azeotropes (isopropyl alcohol−cyclohexane and water−cyclohexane), thus dividing the ternary system into three distillation regions. Another type (e.g., acetic acid dehydration) does not contain azeotrope in the original system. However, due to a tangent pinch near the pure water end an entrainer (isobutyl acetate) is added into the system to aid the separation. This type of system has only one binary heterogeneous azeotrope (water−isobutyl acetate); thus there is only one distillation region. In this paper, design and control of a different residue curve map (RCM) type of separation system utilizing heterogeneous azeotropic distillation will be studied. An example of this RCM type is pyridine and water separation using toluene as entrainer. Adding toluene into this system introduces two additional azeotropes, one is minimum-boiling binary heterogeneous azeotrope (water−toluene) and the other one is a binary homogeneous azeotrope (pyridine−toluene). There is no ternary azeotrope for this system. Two alternative design flow sheets are compared in this paper to find the one which is most economical and also meet stringent product purity specifications. A simple overall control strategy of this process has also been developed which requires only one temperature control loop in each column. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901231s

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Asymmetric hollow fiber membranes for separation of CO2 from hydrocarbons and fluorocarbons at high-pressure conditions relevant to C2F4 polymerization / Madhava R. Kosuri in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10577–10583 Titre : Asymmetric hollow fiber membranes for separation of CO2 from hydrocarbons and fluorocarbons at high-pressure conditions relevant to C2F4 polymerization Type de document : texte imprimé Auteurs : Madhava R. Kosuri, Auteur ; William J. Koros, Auteur Année de publication : 2010 Article en page(s) : pp. 10577–10583 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Asymmetric--Hollow Fiber--Membranes--Separation--CO2--Hydrocarbons --Fluorocarbons--High-Pressure--Conditions--Relevant--C2F4--Polymerization Résumé : Separation of high-pressure carbon dioxide from fluorocarbons is important for the production of fluoropolymers such as poly(tetrafluoroethylene). Typical polymeric membranes plasticize under high CO2 partial pressure conditions and fail to provide adequate selective separations. Torlon, a polyamide−imide polymer, with the ability to form interchain hydrogen bonding, is shown to provide stability against aggressive CO2 plasticization. Torlon membranes in the form of asymmetric hollow fibers (the most productive form of membranes) are considered for an intended separation of CO2/C2F4. To avoid safety issues with tetrafluoroethylene (C2F4), which could detonate under testing conditions, safer surrogate mixtures (C2H2F2 and C2H4) are considered in this paper. Permeation measurements (at 35 °C) indicate that the Torlon membranes are not plasticized even up to 1250 psi of CO2. The membranes provide mixed gas CO2/C2H2F2 and CO2/C2H4 selectivities of 100 and 30, respectively, at 1250 psi partial pressures of CO2. On the basis of the measured separation performances of CO2/C2H2F2 and CO2/C2H4 mixtures, the selectivity of the CO2/C2F4 mixture is expected to be greater than 100. Long-term stability studies indicate that the membranes provide stable separations over a period of 5 days at 1250 psi partial pressures of CO2, thereby making the membrane approach attractive. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900803z [article] Asymmetric hollow fiber membranes for separation of CO2 from hydrocarbons and fluorocarbons at high-pressure conditions relevant to C2F4 polymerization [texte imprimé] / Madhava R. Kosuri, Auteur ; William J. Koros, Auteur . - 2010 . - pp. 10577–10583. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10577–10583 Mots-clés : Asymmetric--Hollow Fiber--Membranes--Separation--CO2--Hydrocarbons --Fluorocarbons--High-Pressure--Conditions--Relevant--C2F4--Polymerization Résumé : Separation of high-pressure carbon dioxide from fluorocarbons is important for the production of fluoropolymers such as poly(tetrafluoroethylene). Typical polymeric membranes plasticize under high CO2 partial pressure conditions and fail to provide adequate selective separations. Torlon, a polyamide−imide polymer, with the ability to form interchain hydrogen bonding, is shown to provide stability against aggressive CO2 plasticization. Torlon membranes in the form of asymmetric hollow fibers (the most productive form of membranes) are considered for an intended separation of CO2/C2F4. To avoid safety issues with tetrafluoroethylene (C2F4), which could detonate under testing conditions, safer surrogate mixtures (C2H2F2 and C2H4) are considered in this paper. Permeation measurements (at 35 °C) indicate that the Torlon membranes are not plasticized even up to 1250 psi of CO2. The membranes provide mixed gas CO2/C2H2F2 and CO2/C2H4 selectivities of 100 and 30, respectively, at 1250 psi partial pressures of CO2. On the basis of the measured separation performances of CO2/C2H2F2 and CO2/C2H4 mixtures, the selectivity of the CO2/C2F4 mixture is expected to be greater than 100. Long-term stability studies indicate that the membranes provide stable separations over a period of 5 days at 1250 psi partial pressures of CO2, thereby making the membrane approach attractive. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900803z

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Heavy Metal Ions Removal in the Presence of 1-Hydroxyethane-1,1-diphosphonic Acid From Aqueous Solutions on Polystyrene Anion Exchangers / Dorota Kołodyńska in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10584–10593 Titre : Heavy Metal Ions Removal in the Presence of 1-Hydroxyethane-1,1-diphosphonic Acid From Aqueous Solutions on Polystyrene Anion Exchangers Type de document : texte imprimé Auteurs : Dorota Kołodyńska, Auteur ; Zbigniew Hubicki, Auteur ; Alicja Skiba, Auteur Année de publication : 2010 Article en page(s) : pp. 10584–10593 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heavy Metal--Removal--Presence--1-Hydroxyethane-1--1-diphosphonic--Acid--Aqueous--Solutions--Polystyrene--Anion Exchangers Résumé : In the presented paper, the ability of commercially available gel and macroporous polystyrene anion exchangers for the removal of copper(II), zinc(II), nickel(II), and cadmium(II) complexes with 1-hydroxyethane-1,1-diphosphonic acid (HEDP) from aqueous solutions was investigated under various experimental conditions. In the experiments, the strongly basic anion exchangers Lewatit MonoPlus M 600, Lewatit MonoPlus MP 500, and Amberlite IRA 402 with the quaternary ammonium functional groups as well as the medium basic anion exchanger Lewatit MonoPlus MP 64 with the quaternary ammonium/tertiary amine functional groups were used. Special attention was paid to the concentration of heavy metal ions, M(II)−HEDP molar ratio, pH of solutions, temperature, and the physicochemical properties of the anion exchangers used. The effect of the interfered ions such as Ca(II), Mg(II), Cl−, NO3−, and SO42− on the efficiency of heavy metal complexes with HEDP sorption was also investigated. It was found that polystyrene anion exchangers rapidly sorbed the test metal complexes with HEDP, and the process became saturated in 20 min. The sorption kinetic data showed pseudo-second-order reaction kinetics rather than the pseudo-first-order kinetics. The adsorption behavior of Cu(II), Zn(II), Ni(II), and Cd(II) complexes with HEDP was studied in single as well as in multicomponent competitive systems. The obtained data were fitted well by the Langmuir adsorption isotherm model. Maximum sorption capacities for Cu(II), Zn(II), Ni(II), and Cd(II) complexes with HEDP occurred for strongly basic anion exchanger Lewatit MonoPlus M 600 at the optimal pH 11.5 and were found to be 96.15, 80.64, 70.42, and 142.85 mg/g, respectively. For binary and quaternary metal complexes solutions, these values were smaller than those from single metal solutions. The presence of Cu(II) and Zn(II) complexes more strongly inhibited Ni(II) and Cd(II) once sorption occured which indicates their greater affinity than that of the remaining complexes for the anion exchangers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901195j [article] Heavy Metal Ions Removal in the Presence of 1-Hydroxyethane-1,1-diphosphonic Acid From Aqueous Solutions on Polystyrene Anion Exchangers [texte imprimé] / Dorota Kołodyńska, Auteur ; Zbigniew Hubicki, Auteur ; Alicja Skiba, Auteur . - 2010 . - pp. 10584–10593. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10584–10593 Mots-clés : Heavy Metal--Removal--Presence--1-Hydroxyethane-1--1-diphosphonic--Acid--Aqueous--Solutions--Polystyrene--Anion Exchangers Résumé : In the presented paper, the ability of commercially available gel and macroporous polystyrene anion exchangers for the removal of copper(II), zinc(II), nickel(II), and cadmium(II) complexes with 1-hydroxyethane-1,1-diphosphonic acid (HEDP) from aqueous solutions was investigated under various experimental conditions. In the experiments, the strongly basic anion exchangers Lewatit MonoPlus M 600, Lewatit MonoPlus MP 500, and Amberlite IRA 402 with the quaternary ammonium functional groups as well as the medium basic anion exchanger Lewatit MonoPlus MP 64 with the quaternary ammonium/tertiary amine functional groups were used. Special attention was paid to the concentration of heavy metal ions, M(II)−HEDP molar ratio, pH of solutions, temperature, and the physicochemical properties of the anion exchangers used. The effect of the interfered ions such as Ca(II), Mg(II), Cl−, NO3−, and SO42− on the efficiency of heavy metal complexes with HEDP sorption was also investigated. It was found that polystyrene anion exchangers rapidly sorbed the test metal complexes with HEDP, and the process became saturated in 20 min. The sorption kinetic data showed pseudo-second-order reaction kinetics rather than the pseudo-first-order kinetics. The adsorption behavior of Cu(II), Zn(II), Ni(II), and Cd(II) complexes with HEDP was studied in single as well as in multicomponent competitive systems. The obtained data were fitted well by the Langmuir adsorption isotherm model. Maximum sorption capacities for Cu(II), Zn(II), Ni(II), and Cd(II) complexes with HEDP occurred for strongly basic anion exchanger Lewatit MonoPlus M 600 at the optimal pH 11.5 and were found to be 96.15, 80.64, 70.42, and 142.85 mg/g, respectively. For binary and quaternary metal complexes solutions, these values were smaller than those from single metal solutions. The presence of Cu(II) and Zn(II) complexes more strongly inhibited Ni(II) and Cd(II) once sorption occured which indicates their greater affinity than that of the remaining complexes for the anion exchangers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901195j

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Method for evaluating single-end control of distillation columns / William L. Luyben in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10594–10603 Titre : Method for evaluating single-end control of distillation columns Type de document : texte imprimé Auteurs : William L. Luyben, Auteur Année de publication : 2010 Article en page(s) : pp. 10594–10603 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Method--Evaluating--Single--Control--Distillation--Columns Résumé : Distillation columns are, in an ideal situation, controlled using a dual-composition structure in which the light-key impurity in the bottoms and heavy-key impurity in the distillate are both maintained at the specified values. This structure minimizes energy consumption. However, it is often almost as efficient to use one-end control of either a composition or a temperature. This single-end distillation control structure is widely used in industry because of its simplicity and because it avoids dynamic interaction between the two competing loops. Because distillation columns have two control degrees of freedom, another variable besides the single temperature or composition must be selected among several alternatives. Usually these choices involve a ratio so that feed rate changes can be effectively handled. However, different ratio schemes handle feed composition changes with different degrees of effectiveness. The two most commonly used are either a reflux-to-feed ratio (R/F) or a reflux ratio (RR). The purpose of this Article is to present a methodology for deciding if single-end control can be effective and, if so, which ratio should be used. A steady-state simulation is used in which the two product purities (or impurities) are held constant as feed composition is varied around the design value. Plots are made of the two ratios (R/F and RR). If one of these curves shows little sensitivity to feed composition, it should be used in a single-end control structure. If both ratios show significant change, a dual control structure (two compositions, two temperatures, or one of each) is required to handle feed composition disturbances. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900778r [article] Method for evaluating single-end control of distillation columns [texte imprimé] / William L. Luyben, Auteur . - 2010 . - pp. 10594–10603. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10594–10603 Mots-clés : Method--Evaluating--Single--Control--Distillation--Columns Résumé : Distillation columns are, in an ideal situation, controlled using a dual-composition structure in which the light-key impurity in the bottoms and heavy-key impurity in the distillate are both maintained at the specified values. This structure minimizes energy consumption. However, it is often almost as efficient to use one-end control of either a composition or a temperature. This single-end distillation control structure is widely used in industry because of its simplicity and because it avoids dynamic interaction between the two competing loops. Because distillation columns have two control degrees of freedom, another variable besides the single temperature or composition must be selected among several alternatives. Usually these choices involve a ratio so that feed rate changes can be effectively handled. However, different ratio schemes handle feed composition changes with different degrees of effectiveness. The two most commonly used are either a reflux-to-feed ratio (R/F) or a reflux ratio (RR). The purpose of this Article is to present a methodology for deciding if single-end control can be effective and, if so, which ratio should be used. A steady-state simulation is used in which the two product purities (or impurities) are held constant as feed composition is varied around the design value. Plots are made of the two ratios (R/F and RR). If one of these curves shows little sensitivity to feed composition, it should be used in a single-end control structure. If both ratios show significant change, a dual control structure (two compositions, two temperatures, or one of each) is required to handle feed composition disturbances. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900778r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Magnesia-stabilized calcium oxide absorbents with improved durability for high temperature CO2 capture / Liyu Li in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10604–10613 Titre : Magnesia-stabilized calcium oxide absorbents with improved durability for high temperature CO2 capture Type de document : texte imprimé Auteurs : Liyu Li, Auteur ; David L. King, Auteur ; Zimin Nie, Auteur Année de publication : 2010 Article en page(s) : pp. 10604–10613 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Magnesia-Stabilized--Calcium--Oxide--Absorbents--Improved--Durability--Temperature--CO2 Capture Résumé : Calcium oxide based materials are attractive regenerable absorbents for separating CO2 from hot gas streams because of their high reactivity, high CO2 capacity, and low material cost. Their high carbonation temperature makes it possible to recover and use high quality heat released during CO2 capture, which increases overall process efficiency. However, the performance of all reported CaO-based absorbents deteriorates as the number of carbonation−decarbonation cycles increases. This is caused by absorbent sintering during the highly exothermic carbonation process. We have found that sintering can be effectively mitigated by properly mixing with a modest amount of MgO. A class of CaO-based absorbents with improved durability and CO2 reactivity were prepared by physical mixing of Ca(CH3COO)2 with small MgO particles followed by high temperature calcination. With 26 wt % MgO content, a CaO−MgO mixture prepared by this method gives as high as 53 wt % CO2 capacity after 50 carbonation−decarbonation cycles at 758 °C. Without MgO addition, the CO2 capacity of pure CaO obtained from the same source decreases from 66 wt % for the first cycle to 26 wt % for the 50th cycle under the same test conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901166b [article] Magnesia-stabilized calcium oxide absorbents with improved durability for high temperature CO2 capture [texte imprimé] / Liyu Li, Auteur ; David L. King, Auteur ; Zimin Nie, Auteur . - 2010 . - pp. 10604–10613. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10604–10613 Mots-clés : Magnesia-Stabilized--Calcium--Oxide--Absorbents--Improved--Durability--Temperature--CO2 Capture Résumé : Calcium oxide based materials are attractive regenerable absorbents for separating CO2 from hot gas streams because of their high reactivity, high CO2 capacity, and low material cost. Their high carbonation temperature makes it possible to recover and use high quality heat released during CO2 capture, which increases overall process efficiency. However, the performance of all reported CaO-based absorbents deteriorates as the number of carbonation−decarbonation cycles increases. This is caused by absorbent sintering during the highly exothermic carbonation process. We have found that sintering can be effectively mitigated by properly mixing with a modest amount of MgO. A class of CaO-based absorbents with improved durability and CO2 reactivity were prepared by physical mixing of Ca(CH3COO)2 with small MgO particles followed by high temperature calcination. With 26 wt % MgO content, a CaO−MgO mixture prepared by this method gives as high as 53 wt % CO2 capacity after 50 carbonation−decarbonation cycles at 758 °C. Without MgO addition, the CO2 capacity of pure CaO obtained from the same source decreases from 66 wt % for the first cycle to 26 wt % for the 50th cycle under the same test conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901166b

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Turnip (brassica rapa) peroxidase / Sepideh Motamed in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10614–10618 Titre : Turnip (brassica rapa) peroxidase : purification and characterization Type de document : texte imprimé Auteurs : Sepideh Motamed, Auteur ; Farnoosh Ghaemmaghami, Auteur ; Alemzadeh, Iran, Auteur Année de publication : 2010 Article en page(s) : pp. 10614–10618 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Turnip--(Brassica rapa)--Peroxidase--Purification--Characterization Résumé : Partial purification of plant peroxidase from turnip (Brassica rapa) was optimized. Aqueous two phase system and precipitation by ammonium sulfate (as two parallel purification methods) were used. Polyethylene glycol/ammonium sulfate/NaCl (25:7:3%, w/v) system followed by gel-filtration chromatography gave a purification factor of about 36 fold. On the other hand, ammonium sulfate precipitation (60−80% deg) followed by gel filtration gave only about 13 purification fold. Hence, the aqueous two-phase system was more efficient and useful method as a primary purification step since it was less laborious, less time-consuming, and led to more purification factor. The partially purified turnip enzyme was stable at a pH range 2.6−6.0 and had an optimum pH at 4.0. The enzyme was stable up to 55 °C with an optimum activity at 35 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801997e [article] Turnip (brassica rapa) peroxidase : purification and characterization [texte imprimé] / Sepideh Motamed, Auteur ; Farnoosh Ghaemmaghami, Auteur ; Alemzadeh, Iran, Auteur . - 2010 . - pp. 10614–10618. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10614–10618 Mots-clés : Turnip--(Brassica rapa)--Peroxidase--Purification--Characterization Résumé : Partial purification of plant peroxidase from turnip (Brassica rapa) was optimized. Aqueous two phase system and precipitation by ammonium sulfate (as two parallel purification methods) were used. Polyethylene glycol/ammonium sulfate/NaCl (25:7:3%, w/v) system followed by gel-filtration chromatography gave a purification factor of about 36 fold. On the other hand, ammonium sulfate precipitation (60−80% deg) followed by gel filtration gave only about 13 purification fold. Hence, the aqueous two-phase system was more efficient and useful method as a primary purification step since it was less laborious, less time-consuming, and led to more purification factor. The partially purified turnip enzyme was stable at a pH range 2.6−6.0 and had an optimum pH at 4.0. The enzyme was stable up to 55 °C with an optimum activity at 35 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801997e

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Catalytic wet peroxide oxidation of phenol in a new two-impinging-jets reactor / Asghar Molaei Dehkordi in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10619–10626 Titre : Catalytic wet peroxide oxidation of phenol in a new two-impinging-jets reactor Type de document : texte imprimé Auteurs : Asghar Molaei Dehkordi, Auteur ; Amir Ali Ebrahimi, Auteur Année de publication : 2010 Article en page(s) : pp. 10619–10626 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalytic--Peroxide--Oxidation--Phenol--Impinging-Jets--Reactor Résumé : The catalytic wet peroxide oxidation (CWPO) of phenol with activated carbon (AC) as the catalyst has been successfully tested in a novel type of two-impinging-jets reactor (TIJR). The TIJR is characterized by a high-intensity reaction chamber, which is separated by a perforated plate from other parts of the reactor. The perforated plate was used as a filter to keep the catalyst particles within the reaction chamber. The influences of various operating and design parameters such as jet Reynolds number, feed flow rate, internozzle distance, and the jet diameter on the performance capability of the TIJR were investigated. As a result of the impinging process, turbulence, complex trajectory of AC particles, relatively high local concentration of hydrogen peroxide, and the relatively high local catalyst loading within the reaction chamber, the fractional disappearance of phenol and the total organic carbon (TOC) removal, obtained in the TIJR, increased compared to those obtained by conventional reaction systems such as packed-bed reactors and batch stirred-tank reactors. This may be attributed to the elimination of the external mass-transfer resistance around the solid particles, complex flow pattern within the reaction chamber, energy released as the result of impinging-jets collision, efficient use of hydrogen peroxide caused by the contact pattern provided by the TIJR, and the high-intensity mixing especially at the impingement zone of the TIJR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9004496 [article] Catalytic wet peroxide oxidation of phenol in a new two-impinging-jets reactor [texte imprimé] / Asghar Molaei Dehkordi, Auteur ; Amir Ali Ebrahimi, Auteur . - 2010 . - pp. 10619–10626. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10619–10626 Mots-clés : Catalytic--Peroxide--Oxidation--Phenol--Impinging-Jets--Reactor Résumé : The catalytic wet peroxide oxidation (CWPO) of phenol with activated carbon (AC) as the catalyst has been successfully tested in a novel type of two-impinging-jets reactor (TIJR). The TIJR is characterized by a high-intensity reaction chamber, which is separated by a perforated plate from other parts of the reactor. The perforated plate was used as a filter to keep the catalyst particles within the reaction chamber. The influences of various operating and design parameters such as jet Reynolds number, feed flow rate, internozzle distance, and the jet diameter on the performance capability of the TIJR were investigated. As a result of the impinging process, turbulence, complex trajectory of AC particles, relatively high local concentration of hydrogen peroxide, and the relatively high local catalyst loading within the reaction chamber, the fractional disappearance of phenol and the total organic carbon (TOC) removal, obtained in the TIJR, increased compared to those obtained by conventional reaction systems such as packed-bed reactors and batch stirred-tank reactors. This may be attributed to the elimination of the external mass-transfer resistance around the solid particles, complex flow pattern within the reaction chamber, energy released as the result of impinging-jets collision, efficient use of hydrogen peroxide caused by the contact pattern provided by the TIJR, and the high-intensity mixing especially at the impingement zone of the TIJR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9004496

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Adsorption of divalent lead on a montmorillonite−illite type of clay / John U. Kennedy Oubagaranadin in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10627–10636 Titre : Adsorption of divalent lead on a montmorillonite−illite type of clay Type de document : texte imprimé Auteurs : John U. Kennedy Oubagaranadin, Auteur ; Z. V. P. Murthy, Auteur Année de publication : 2010 Article en page(s) : pp. 10627–10636 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption--Divalent Lead--Montmorillonite−  Illite--Clay Résumé : Lead(II) was removed from aqueous solution by adsorption on a montmorillonite−illite type of clay (MIC) collected from the Gulbarga district of Karnataka, India. The objectives of the current work were (i) to characterize the clay (adsorbent) and (ii) to perform equilibrium, kinetic, mass-transfer, and thermodynamic studies for the adsorption of Pb(II) on the clay. Batch adsorption equilibrium data were determined with different initial Pb(II) concentrations (100, 150, and 200 ppm) at pH 4 and 37 °C, and the data were tested with isotherm models. The three-parameter Freundlich−Langmuir model gave the best fit to the equilibrium data (R2 = 0.9979). However, as the initial Pb(II) concentration was increased (150 and 200 ppm), multilayer adsorption was observed. The maximum monolayer adsorption capacity of the clay was determined to be ∼52 mg/g. Kinetic studies indicated that the rate of adsorption of Pb(II) on the clay followed a second-order rate mechanism, with decreasing rate constant values of 0.1097, 0.0571, and 0.0022 g/(mg min) as the initial Pb(II) concentration was increased in the order of 100, 150, and 200 ppm, respectively. The value of the Freundlich constant (n) in the range of 2.5−4.6 indicated that MIC was a good adsorbent of divalent lead. At a higher initial Pb(II) concentration (200 ppm), the adsorption process was determined to be film-diffusion-controlled, with a rate of 0.051 min−1. The mean values of the thermodynamic parameters—the change in the free energy (ΔH°), the change in the entropy (ΔS°), and the change in the Gibbs free energy (ΔG°) showed that the adsorption process was endothermic, thermodynamically favorable, and spontaneous. A two-stage adsorber system that has been proposed reduced the clay dose by 8.5%, compared to that of a single-stage adsorption system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005047 [article] Adsorption of divalent lead on a montmorillonite−illite type of clay [texte imprimé] / John U. Kennedy Oubagaranadin, Auteur ; Z. V. P. Murthy, Auteur . - 2010 . - pp. 10627–10636. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10627–10636 Mots-clés : Adsorption--Divalent Lead--Montmorillonite−  Illite--Clay Résumé : Lead(II) was removed from aqueous solution by adsorption on a montmorillonite−illite type of clay (MIC) collected from the Gulbarga district of Karnataka, India. The objectives of the current work were (i) to characterize the clay (adsorbent) and (ii) to perform equilibrium, kinetic, mass-transfer, and thermodynamic studies for the adsorption of Pb(II) on the clay. Batch adsorption equilibrium data were determined with different initial Pb(II) concentrations (100, 150, and 200 ppm) at pH 4 and 37 °C, and the data were tested with isotherm models. The three-parameter Freundlich−Langmuir model gave the best fit to the equilibrium data (R2 = 0.9979). However, as the initial Pb(II) concentration was increased (150 and 200 ppm), multilayer adsorption was observed. The maximum monolayer adsorption capacity of the clay was determined to be ∼52 mg/g. Kinetic studies indicated that the rate of adsorption of Pb(II) on the clay followed a second-order rate mechanism, with decreasing rate constant values of 0.1097, 0.0571, and 0.0022 g/(mg min) as the initial Pb(II) concentration was increased in the order of 100, 150, and 200 ppm, respectively. The value of the Freundlich constant (n) in the range of 2.5−4.6 indicated that MIC was a good adsorbent of divalent lead. At a higher initial Pb(II) concentration (200 ppm), the adsorption process was determined to be film-diffusion-controlled, with a rate of 0.051 min−1. The mean values of the thermodynamic parameters—the change in the free energy (ΔH°), the change in the entropy (ΔS°), and the change in the Gibbs free energy (ΔG°) showed that the adsorption process was endothermic, thermodynamically favorable, and spontaneous. A two-stage adsorber system that has been proposed reduced the clay dose by 8.5%, compared to that of a single-stage adsorption system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005047

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Modeling of cross-flow filtration processes in an airlift ceramic membrane reactor / Feng Zhang in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10637–10642 Titre : Modeling of cross-flow filtration processes in an airlift ceramic membrane reactor Type de document : texte imprimé Auteurs : Feng Zhang, Auteur ; Wenheng Jing, Auteur ; Weihong Xing, Auteur Année de publication : 2010 Article en page(s) : pp. 10637–10642 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Modeling--Cross-Flow--Filtration--Processes--Airlift--Ceramic--Membrane--Reactor Résumé : Air sparging is recognized as an effective way to overcome concentration polarization in membrane filtration processes. The mechanism of flux enhancement in the case of slug flow in tubular ceramic membrane is discussed in this Article. The region near the gas slug is divided into three different zones: gas slug zone, wake zone, and remaining liquid slug zone. Air sparging significantly increases shear stress and flow instabilities, and consequently lowers concentration polarization for the gas slug zone and the wake zone. A novel model based on hydrodynamics of air−liquid two-phase flow is developed to predicting permeate flux in such processes. The dimensionless groups of filtrate resistance number and shear stress number are used to analyze the cake resistance induced by the concentration polarization, and, from these, the average permeate flux for air sparged ultrafiltration can be calculated. The model was tested by the ultrafiltration of T2000 dextran at different gas flow rates with an external-loop airlift ceramic membrane reactor. The model is validated with experimental data with an error of 10%. Experimental results show that air sparging can enhance the permeate flux significantly. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900512g [article] Modeling of cross-flow filtration processes in an airlift ceramic membrane reactor [texte imprimé] / Feng Zhang, Auteur ; Wenheng Jing, Auteur ; Weihong Xing, Auteur . - 2010 . - pp. 10637–10642. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10637–10642 Mots-clés : Modeling--Cross-Flow--Filtration--Processes--Airlift--Ceramic--Membrane--Reactor Résumé : Air sparging is recognized as an effective way to overcome concentration polarization in membrane filtration processes. The mechanism of flux enhancement in the case of slug flow in tubular ceramic membrane is discussed in this Article. The region near the gas slug is divided into three different zones: gas slug zone, wake zone, and remaining liquid slug zone. Air sparging significantly increases shear stress and flow instabilities, and consequently lowers concentration polarization for the gas slug zone and the wake zone. A novel model based on hydrodynamics of air−liquid two-phase flow is developed to predicting permeate flux in such processes. The dimensionless groups of filtrate resistance number and shear stress number are used to analyze the cake resistance induced by the concentration polarization, and, from these, the average permeate flux for air sparged ultrafiltration can be calculated. The model was tested by the ultrafiltration of T2000 dextran at different gas flow rates with an external-loop airlift ceramic membrane reactor. The model is validated with experimental data with an error of 10%. Experimental results show that air sparging can enhance the permeate flux significantly. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900512g

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Studies on performance of crossflow concentric-ring rotating bed / Guang Q. Wang in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10643–10649 Titre : Studies on performance of crossflow concentric-ring rotating bed Type de document : texte imprimé Auteurs : Guang Q. Wang, Auteur ; Yun Q. Jiao, Auteur ; Zhi C. Xu, Auteur Année de publication : 2010 Article en page(s) : pp. 10643–10649 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Studies--Performance--Crossflow--Concentric-Ring--Rotating Bed Résumé : A new kind of high-gravity device—crossflow concentric-ring rotating bed was developed, of which the rotor contains a series of perforated concentric rings. In operation, the gas could repeatedly crosscurrently make contact with the dispersed liquid flow between the concentric rings. The rotor structures and flow arrangements determine the device’s potential features, such as lower pressure drop and power consumption, which, together with the multiple-contact mechanism, are favorable to gas−liquid stripping processes. In a pilot crossflow concentric-ring rotating bed, the performance of the rotor was investigated under different operation conditions. The experimental results show that the pressure drop Δp, the power consumption P, and the mass transfer coefficient kLa fall within the range of 0.03−1.02 kPa, 0.65−1.08 kW, and 0.027−0.071 s−1, respectively. Empirical correlations based upon the experimental data were proposed to describe the dependence of pressure drop and power consumption on operation parameters. Compared with packed columns and spray contactor, the crossflow concentric-ring rotating bed has great advantages in mass transfer, equipment size, and gas/liquid loading despite the additional energy consumption. Moreover, the crossflow concentric-ring rotating bed shows lower pressure drop, power consumption, and mass transfer coefficient than that of counterflow or crossflow rotating packed beds. However, considering that stripping makes no high demand on mass transfer, crossflow concentric-ring rotating bed can be a promising option in performing stripping processes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900956r [article] Studies on performance of crossflow concentric-ring rotating bed [texte imprimé] / Guang Q. Wang, Auteur ; Yun Q. Jiao, Auteur ; Zhi C. Xu, Auteur . - 2010 . - pp. 10643–10649. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10643–10649 Mots-clés : Studies--Performance--Crossflow--Concentric-Ring--Rotating Bed Résumé : A new kind of high-gravity device—crossflow concentric-ring rotating bed was developed, of which the rotor contains a series of perforated concentric rings. In operation, the gas could repeatedly crosscurrently make contact with the dispersed liquid flow between the concentric rings. The rotor structures and flow arrangements determine the device’s potential features, such as lower pressure drop and power consumption, which, together with the multiple-contact mechanism, are favorable to gas−liquid stripping processes. In a pilot crossflow concentric-ring rotating bed, the performance of the rotor was investigated under different operation conditions. The experimental results show that the pressure drop Δp, the power consumption P, and the mass transfer coefficient kLa fall within the range of 0.03−1.02 kPa, 0.65−1.08 kW, and 0.027−0.071 s−1, respectively. Empirical correlations based upon the experimental data were proposed to describe the dependence of pressure drop and power consumption on operation parameters. Compared with packed columns and spray contactor, the crossflow concentric-ring rotating bed has great advantages in mass transfer, equipment size, and gas/liquid loading despite the additional energy consumption. Moreover, the crossflow concentric-ring rotating bed shows lower pressure drop, power consumption, and mass transfer coefficient than that of counterflow or crossflow rotating packed beds. However, considering that stripping makes no high demand on mass transfer, crossflow concentric-ring rotating bed can be a promising option in performing stripping processes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900956r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Potential of silver-based room-temperature ionic liquids for ethylene/ethane separation / Lara M. Galán Sánchez in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10650–10656 Titre : Potential of silver-based room-temperature ionic liquids for ethylene/ethane separation Type de document : texte imprimé Auteurs : Lara M. Galán Sánchez, Auteur ; G. Wytze Meindersma, Auteur ; André B. Haan, Auteur Année de publication : 2010 Article en page(s) : pp. 10650–10656 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Potential--Silver-Based--Room-Temperature--Ionic Liquids--Ethylene/Ethane--Separation Résumé : The potential of room-temperature ionic liquids (RTILs) in separating ethylene from ethane is investigated. The absorption of olefins is enhanced by chemical absorption via π-complex formation with a transition-metal cation added to a standard RTIL. The effects of the ionic liquid structure of silver-based RTILs that contain Ag(I) salts (AgNO3, Ag[TfO], and Ag[Tf2N]) on gas absorption and solvent stability are investigated. The absorption isotherms of C2H4 and C2H6 into standard RTILs and designed silver-based RTILs were measured with a gravimetric balance between 303 and 333 K and up to 10 bar. C2H4 absorption was chemically enhanced in the silver-based RTILs and was considerably higher than that in the standard RTILs. Absorption of C2H6 in the silver-based RTILs is based on physical interactions only. The olefin/paraffin selectivity at a pressure of 1 bar was ∼30−50 higher in the silver-based RTILs than in standard ionic liquids. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010244 [article] Potential of silver-based room-temperature ionic liquids for ethylene/ethane separation [texte imprimé] / Lara M. Galán Sánchez, Auteur ; G. Wytze Meindersma, Auteur ; André B. Haan, Auteur . - 2010 . - pp. 10650–10656. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10650–10656 Mots-clés : Potential--Silver-Based--Room-Temperature--Ionic Liquids--Ethylene/Ethane--Separation Résumé : The potential of room-temperature ionic liquids (RTILs) in separating ethylene from ethane is investigated. The absorption of olefins is enhanced by chemical absorption via π-complex formation with a transition-metal cation added to a standard RTIL. The effects of the ionic liquid structure of silver-based RTILs that contain Ag(I) salts (AgNO3, Ag[TfO], and Ag[Tf2N]) on gas absorption and solvent stability are investigated. The absorption isotherms of C2H4 and C2H6 into standard RTILs and designed silver-based RTILs were measured with a gravimetric balance between 303 and 333 K and up to 10 bar. C2H4 absorption was chemically enhanced in the silver-based RTILs and was considerably higher than that in the standard RTILs. Absorption of C2H6 in the silver-based RTILs is based on physical interactions only. The olefin/paraffin selectivity at a pressure of 1 bar was ∼30−50 higher in the silver-based RTILs than in standard ionic liquids. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010244

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Adsorption of aniline on cross-linked starch sulfate from aqueous solution / Lei Guo in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10657–10663 Titre : Adsorption of aniline on cross-linked starch sulfate from aqueous solution Type de document : texte imprimé Auteurs : Lei Guo, Auteur ; Guiying Li, Auteur ; Junshen Liu, Auteur Année de publication : 2010 Article en page(s) : pp. 10657–10663 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption--Aniline--Cross-Linked--Starch--Sulfate--Aqueous--Solution Résumé : A new environment friendly adsorbent, cross-linked starch sulfate (CSS), was prepared and used to adsorb aniline from aqueous solution. Different adsorption parameters like initial pH, adsorption time, equilibrium aniline concentration, and temperature were thoroughly studied, and the kinetic, equilibrium, and thermodynamics of the adsorption process were further investigated. It showed that CSS can effectively remove aniline from the solution. The adsorption capacity is highly dependent on the amount of sulfate groups on adsorbents and the initial pH. The pseudo-first-order and pseudo-second-order kinetic models were applied to test the experimental data, and the pseudo-second-order kinetic model provided a better correlation of the experimental data in comparison with the pseudo-first-order model. The maximum removal efficiency of aniline is 75.29% using 1 g L−1 of CSS3 dose. Langmuir, Freundlich, Dubinin−Radushkevich, and Sips models have been applied to study the adsorption equilibrium, and the equilibrium adsorption data were well described by the Sips isotherms. The Scatchard plot analysis was used to evaluate the binding sites of CSS. The adsorption of aniline on CSS is exothermic in nature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010782 [article] Adsorption of aniline on cross-linked starch sulfate from aqueous solution [texte imprimé] / Lei Guo, Auteur ; Guiying Li, Auteur ; Junshen Liu, Auteur . - 2010 . - pp. 10657–10663. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10657–10663 Mots-clés : Adsorption--Aniline--Cross-Linked--Starch--Sulfate--Aqueous--Solution Résumé : A new environment friendly adsorbent, cross-linked starch sulfate (CSS), was prepared and used to adsorb aniline from aqueous solution. Different adsorption parameters like initial pH, adsorption time, equilibrium aniline concentration, and temperature were thoroughly studied, and the kinetic, equilibrium, and thermodynamics of the adsorption process were further investigated. It showed that CSS can effectively remove aniline from the solution. The adsorption capacity is highly dependent on the amount of sulfate groups on adsorbents and the initial pH. The pseudo-first-order and pseudo-second-order kinetic models were applied to test the experimental data, and the pseudo-second-order kinetic model provided a better correlation of the experimental data in comparison with the pseudo-first-order model. The maximum removal efficiency of aniline is 75.29% using 1 g L−1 of CSS3 dose. Langmuir, Freundlich, Dubinin−Radushkevich, and Sips models have been applied to study the adsorption equilibrium, and the equilibrium adsorption data were well described by the Sips isotherms. The Scatchard plot analysis was used to evaluate the binding sites of CSS. The adsorption of aniline on CSS is exothermic in nature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9010782

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

The Modified Sanchez−Lacombe Equation of State Applied to Polydisperse Polyethylene Solutions / Ryan A. Krenz in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10664–10681 Titre : The Modified Sanchez−Lacombe Equation of State Applied to Polydisperse Polyethylene Solutions Type de document : texte imprimé Auteurs : Ryan A. Krenz, Auteur ; Torben Laursen, Auteur ; Robert A. Heidemann, Auteur Année de publication : 2010 Article en page(s) : pp. 10664–10681 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Modified--Sanchez−  Lacombe--Equation--Applied--Polydisperse--Polyethylene--Solutions Résumé : The modified Sanchez−Lacombe equation of state (MSL-EOS) is Neau’s version of the Sanchez−Lacombe equation of state modified to include a Péneloux-type volume translation. The purpose of this work is to report parameters for modeling the phase behavior of polyethylene solutions. The MSL equation is an empirical equation that contains four parameters to define each pure compound whether a solvent or a polydisperse polymer. The MSL equation uses conventional linear and quadratic mixing rules. A parametrization can be used to obtain the pure compound parameters from the molar mass, critical temperature, critical pressure, and acentric factor. These properties cannot be defined for polydisperse polymers, and parameters were determined from a combination of liquid density (PVT) data and polymer + solvent cloud point (xPT) data. Binary interaction parameters have been obtained for over 50 mixtures by correlating the fluid phase boundaries. Binary mixtures including ethylene, hexane, and/or cyclohexane are of particular interest to polyethylene production. A single binary interaction parameter is usually sufficient to represent vapor−liquid equilibrium, but temperature dependence is required to accurately represent liquid−liquid equilibrium. The MSL equation of state can be used to correlate the cloud points of polyethylene solutions at high pressures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801451a [article] The Modified Sanchez−Lacombe Equation of State Applied to Polydisperse Polyethylene Solutions [texte imprimé] / Ryan A. Krenz, Auteur ; Torben Laursen, Auteur ; Robert A. Heidemann, Auteur . - 2010 . - pp. 10664–10681. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10664–10681 Mots-clés : Modified--Sanchez−  Lacombe--Equation--Applied--Polydisperse--Polyethylene--Solutions Résumé : The modified Sanchez−Lacombe equation of state (MSL-EOS) is Neau’s version of the Sanchez−Lacombe equation of state modified to include a Péneloux-type volume translation. The purpose of this work is to report parameters for modeling the phase behavior of polyethylene solutions. The MSL equation is an empirical equation that contains four parameters to define each pure compound whether a solvent or a polydisperse polymer. The MSL equation uses conventional linear and quadratic mixing rules. A parametrization can be used to obtain the pure compound parameters from the molar mass, critical temperature, critical pressure, and acentric factor. These properties cannot be defined for polydisperse polymers, and parameters were determined from a combination of liquid density (PVT) data and polymer + solvent cloud point (xPT) data. Binary interaction parameters have been obtained for over 50 mixtures by correlating the fluid phase boundaries. Binary mixtures including ethylene, hexane, and/or cyclohexane are of particular interest to polyethylene production. A single binary interaction parameter is usually sufficient to represent vapor−liquid equilibrium, but temperature dependence is required to accurately represent liquid−liquid equilibrium. The MSL equation of state can be used to correlate the cloud points of polyethylene solutions at high pressures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801451a

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Characteristics and precipitation of glucose oligomers in the fresh liquid products obtained from the hydrolysis of cellulose in hot-compressed water / Yun Yu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10682–10690 Titre : Characteristics and precipitation of glucose oligomers in the fresh liquid products obtained from the hydrolysis of cellulose in hot-compressed water Type de document : texte imprimé Auteurs : Yun Yu, Auteur ; Hongwei Wu, Auteur Année de publication : 2010 Article en page(s) : pp. 10682–10690 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Characteristics--Precipitation--Glucose--Oligomers--Fresh Liquid--Products--Obtained--Hydrolysis--Cellulose--Hot-Compressed--Water Résumé : Using a high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), this study shows the presence of a wide range of glucose oligomers with the degrees of polymerization (DPs) up to 30 and their derivatives in the fresh liquid products produced from cellulose hydrolysis in hot-compressed water (HCW) using a semicontinuous reactor system at 280 °C and 20 MPa. None of those oligomers can be detected by a high-performance liquid chromatography with evaporative light scattering detector (HPLC-ELSD) that however can detect glucose oligomers with DPs up to 6 after the liquid solutions are concentrated by 25 times via vacuum evaporation at 40 °C, during which a large amount of precipitate is formed. While quantitative analysis of the glucose oligomers with DPs > 5 cannot be done due to the lack of standards, that of the glucose oligomers from glucose (DP = 1) to cellopentaose (DP = 5) using both HPAEC-PAD and HPLC-ELSD are in good agreement, suggesting that these low-DP glucose oligomers do not contribute to the precipitate formation. Results from a set of purposely designed precipitation experiments indicate that the precipitation starts as the fresh liquid sample is collected and is fast during the initial 8 h, levels off as the precipitation time increases further, and completes after 120 h (5 days). On the basis of a new approach developed for the quantification of glucose oligomer retention during the precipitation process, it is found that the contribution of glucose oligomers to precipitate formation increases with DP. The higher the DP is, the lower the solubility of the glucose oligomer is. The glucose oligomers from glucose to cellopentaose and their derivatives (DPs = 1−5) contribute little to the precipitate formation, which explains why HPLC-ELSD can correctly analyze these glucose oligomers in the concentrated solutions prepared by vacuum evaporation. The glucose oligomers and their derivatives with DP > 5, which are soluble in HCW but become supersaturated in the solutions under ambient conditions, are responsible for precipitate formation. Most (but not all) of the glucose oligomers and their derivatives with DPs > 16 contribute to the precipitate formation as tiny peaks of these glucose oligomers are still shown in the chromatograms, suggesting that these glucose oligomers have very low (but nonzero) solubilities in ambient water. The retentions of glucose oligomers and their derivatives increase substantially with the DP decreasing from 16 to 6, indicating that less of these lower-DP oligomers contribute to the precipitate formation. To avoid the effect of precipitation on oligomer analysis, the fresh liquid products must be analyzed immediately after sample collection. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900768m [article] Characteristics and precipitation of glucose oligomers in the fresh liquid products obtained from the hydrolysis of cellulose in hot-compressed water [texte imprimé] / Yun Yu, Auteur ; Hongwei Wu, Auteur . - 2010 . - pp. 10682–10690. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10682–10690 Mots-clés : Characteristics--Precipitation--Glucose--Oligomers--Fresh Liquid--Products--Obtained--Hydrolysis--Cellulose--Hot-Compressed--Water Résumé : Using a high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), this study shows the presence of a wide range of glucose oligomers with the degrees of polymerization (DPs) up to 30 and their derivatives in the fresh liquid products produced from cellulose hydrolysis in hot-compressed water (HCW) using a semicontinuous reactor system at 280 °C and 20 MPa. None of those oligomers can be detected by a high-performance liquid chromatography with evaporative light scattering detector (HPLC-ELSD) that however can detect glucose oligomers with DPs up to 6 after the liquid solutions are concentrated by 25 times via vacuum evaporation at 40 °C, during which a large amount of precipitate is formed. While quantitative analysis of the glucose oligomers with DPs > 5 cannot be done due to the lack of standards, that of the glucose oligomers from glucose (DP = 1) to cellopentaose (DP = 5) using both HPAEC-PAD and HPLC-ELSD are in good agreement, suggesting that these low-DP glucose oligomers do not contribute to the precipitate formation. Results from a set of purposely designed precipitation experiments indicate that the precipitation starts as the fresh liquid sample is collected and is fast during the initial 8 h, levels off as the precipitation time increases further, and completes after 120 h (5 days). On the basis of a new approach developed for the quantification of glucose oligomer retention during the precipitation process, it is found that the contribution of glucose oligomers to precipitate formation increases with DP. The higher the DP is, the lower the solubility of the glucose oligomer is. The glucose oligomers from glucose to cellopentaose and their derivatives (DPs = 1−5) contribute little to the precipitate formation, which explains why HPLC-ELSD can correctly analyze these glucose oligomers in the concentrated solutions prepared by vacuum evaporation. The glucose oligomers and their derivatives with DP > 5, which are soluble in HCW but become supersaturated in the solutions under ambient conditions, are responsible for precipitate formation. Most (but not all) of the glucose oligomers and their derivatives with DPs > 16 contribute to the precipitate formation as tiny peaks of these glucose oligomers are still shown in the chromatograms, suggesting that these glucose oligomers have very low (but nonzero) solubilities in ambient water. The retentions of glucose oligomers and their derivatives increase substantially with the DP decreasing from 16 to 6, indicating that less of these lower-DP oligomers contribute to the precipitate formation. To avoid the effect of precipitation on oligomer analysis, the fresh liquid products must be analyzed immediately after sample collection. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900768m

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Pilot-scale gasification of corn stover, switchgrass, wheat straw, and wood / Whitney Jablonski in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10691–10701 Titre : Pilot-scale gasification of corn stover, switchgrass, wheat straw, and wood : 2. identification of global chemistry using multivariate curve resolution techniques Type de document : texte imprimé Auteurs : Whitney Jablonski, Auteur ; Katherine R. Gaston, Auteur ; Mark R. Nimlos, Auteur Année de publication : 2010 Article en page(s) : pp. 10691–10701 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pilot-Scale--Gasification--Corn Stover--Switchgrass--Wheat Straw--Wood--Identification--Global Chemistry--Using Multivariate--Curve Resolution--Techniques Résumé : A pilot-scale study was conducted to examine the effect of the steam-to-biomass ratio, the gasification temperature, and the thermal cracker temperature for Vermont wood, wheat straw, switchgrass, and corn stover on the formation and speciation of tars. This study is divided into two parts; the first paper detailed the processing conditions and gives quantitative information on low-molecular-weight species. This paper, which is the second part of this study, uses multivariate curve resolution techniques to correlate process variables with the mass spectra gathered during the study to (1) identify the global chemistry of the system and (2) to identify differences or similarities of the product gas streams for each feedstock. Three main groups of products were identified statistically: (1) primary and secondary pyrolysis products (e.g., guaiacol, furfural), (2) cracking products (e.g., phenol, cresol), and (3) polynuclear aromatic hydrocarbons (PAHs). Our findings support known global reaction mechanisms that delineate the formation of the more-refractory PAHs, whereby oxygenated pyrolysis products are cracked into smaller fragments that contain less oxygen. These crack further into small hydrocarbons and radicals that undergo molecular weight growth to produce PAHs. The results from this statistical analysis indicate that, at high temperatures, where PAHs dominate, there is little variation observed between the feedstocks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900596v [article] Pilot-scale gasification of corn stover, switchgrass, wheat straw, and wood : 2. identification of global chemistry using multivariate curve resolution techniques [texte imprimé] / Whitney Jablonski, Auteur ; Katherine R. Gaston, Auteur ; Mark R. Nimlos, Auteur . - 2010 . - pp. 10691–10701. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10691–10701 Mots-clés : Pilot-Scale--Gasification--Corn Stover--Switchgrass--Wheat Straw--Wood--Identification--Global Chemistry--Using Multivariate--Curve Resolution--Techniques Résumé : A pilot-scale study was conducted to examine the effect of the steam-to-biomass ratio, the gasification temperature, and the thermal cracker temperature for Vermont wood, wheat straw, switchgrass, and corn stover on the formation and speciation of tars. This study is divided into two parts; the first paper detailed the processing conditions and gives quantitative information on low-molecular-weight species. This paper, which is the second part of this study, uses multivariate curve resolution techniques to correlate process variables with the mass spectra gathered during the study to (1) identify the global chemistry of the system and (2) to identify differences or similarities of the product gas streams for each feedstock. Three main groups of products were identified statistically: (1) primary and secondary pyrolysis products (e.g., guaiacol, furfural), (2) cracking products (e.g., phenol, cresol), and (3) polynuclear aromatic hydrocarbons (PAHs). Our findings support known global reaction mechanisms that delineate the formation of the more-refractory PAHs, whereby oxygenated pyrolysis products are cracked into smaller fragments that contain less oxygen. These crack further into small hydrocarbons and radicals that undergo molecular weight growth to produce PAHs. The results from this statistical analysis indicate that, at high temperatures, where PAHs dominate, there is little variation observed between the feedstocks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900596v

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Comparison of mercury retention by fly ashes using different experimental devices / M. Antonia López-Antón in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10702–10707 Titre : Comparison of mercury retention by fly ashes using different experimental devices Type de document : texte imprimé Auteurs : M. Antonia López-Antón, Auteur ; Patricia Abad-Valle, Auteur ; Mercedes Díaz-Somoano, Auteur Année de publication : 2010 Article en page(s) : pp. 10702–10707 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Comparison--Mercury Retention--Fly Ashes--Using--Different--Experimental--Devices Résumé : To study mercury (Hg) retention in solid sorbents, researchers generally employ similar laboratory-scale devices. However, despite their similarities, these devices are generally used under different experimental conditions. The Hg concentration in the gas phase, gas flow, and sorbent-bed characteristics are variables that influence the contact time, mass transfer, and kinetics and may greatly modify the quantities of Hg retained when the same sorbents are compared. These differences in the experimental conditions do not impede an evaluation of the sorbents as long as the results obtained points toward the same qualitative conclusions. However, the extent of variation needs to be defined to avoid misinterpretation. To illustrate the range of interpretations, the results of a preliminary approach using four experimental devices in two laboratories have been compared in this work. All the experiments were carried out under a nitrogen atmosphere and Hg0 in the gas phase. The same sorbents were employed in all the devices. These were fly ashes obtained from the combustion of coals of different rank and with different unburned carbon contents. From the results obtained it can be inferred that it is necessary to strictly control the influence of the experimental variables to infer a correct interpretation of the results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900766y [article] Comparison of mercury retention by fly ashes using different experimental devices [texte imprimé] / M. Antonia López-Antón, Auteur ; Patricia Abad-Valle, Auteur ; Mercedes Díaz-Somoano, Auteur . - 2010 . - pp. 10702–10707. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10702–10707 Mots-clés : Comparison--Mercury Retention--Fly Ashes--Using--Different--Experimental--Devices Résumé : To study mercury (Hg) retention in solid sorbents, researchers generally employ similar laboratory-scale devices. However, despite their similarities, these devices are generally used under different experimental conditions. The Hg concentration in the gas phase, gas flow, and sorbent-bed characteristics are variables that influence the contact time, mass transfer, and kinetics and may greatly modify the quantities of Hg retained when the same sorbents are compared. These differences in the experimental conditions do not impede an evaluation of the sorbents as long as the results obtained points toward the same qualitative conclusions. However, the extent of variation needs to be defined to avoid misinterpretation. To illustrate the range of interpretations, the results of a preliminary approach using four experimental devices in two laboratories have been compared in this work. All the experiments were carried out under a nitrogen atmosphere and Hg0 in the gas phase. The same sorbents were employed in all the devices. These were fly ashes obtained from the combustion of coals of different rank and with different unburned carbon contents. From the results obtained it can be inferred that it is necessary to strictly control the influence of the experimental variables to infer a correct interpretation of the results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900766y

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Generalized cubic equation of state adjusted to the virial coefficients of real gases and its prediction of auxiliary thermodynamic properties / Ilya Polishuk in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10708–10717 Titre : Generalized cubic equation of state adjusted to the virial coefficients of real gases and its prediction of auxiliary thermodynamic properties Type de document : texte imprimé Auteurs : Ilya Polishuk, Auteur Année de publication : 2010 Article en page(s) : pp. 10708–10717 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Generalized--Cubic Equation--Adjusted--Virial Coefficients--Real Gases--Prediction--Auxiliary--Thermodynamic--Properties Résumé : This study demonstrates that the overall reliability of a simplest cubic equation of state (EOS) might be improved by developing its accuracy in estimating the virial coefficients. In particular, it has been demonstrated that the progress can be achieved in predicting the sound velocities and, probably, the Joule−Thomson inversion curves. At the same time, the limitations of the simplest model are evident. In particular, it fails in predicting of the virial coefficients in the low temperature range. As a result, its predictions of the liquid phase properties are still imperfect. Further directions of development of the proposed EOS are discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900905p [article] Generalized cubic equation of state adjusted to the virial coefficients of real gases and its prediction of auxiliary thermodynamic properties [texte imprimé] / Ilya Polishuk, Auteur . - 2010 . - pp. 10708–10717. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10708–10717 Mots-clés : Generalized--Cubic Equation--Adjusted--Virial Coefficients--Real Gases--Prediction--Auxiliary--Thermodynamic--Properties Résumé : This study demonstrates that the overall reliability of a simplest cubic equation of state (EOS) might be improved by developing its accuracy in estimating the virial coefficients. In particular, it has been demonstrated that the progress can be achieved in predicting the sound velocities and, probably, the Joule−Thomson inversion curves. At the same time, the limitations of the simplest model are evident. In particular, it fails in predicting of the virial coefficients in the low temperature range. As a result, its predictions of the liquid phase properties are still imperfect. Further directions of development of the proposed EOS are discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900905p

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Multistage fluidized bed reactor performance characterization for adsorption of carbon dioxide / Sudeshna Roy in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10718–10727 Titre : Multistage fluidized bed reactor performance characterization for adsorption of carbon dioxide Type de document : texte imprimé Auteurs : Sudeshna Roy, Auteur ; C. R. Mohanty, Auteur ; B. C. Meikap, Auteur Année de publication : 2010 Article en page(s) : pp. 10718–10727 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Multistage--Fluidized--Reactor Performance--Characterization--Adsorption--Carbon Dioxide Résumé : Carbon dioxide and its different compounds are generated as primary greenhouse gases from the flue gases of coal-fired thermal power plants, boilers, and other stationary combustion processes. This greenhouse gas causes global warming after being emitted to the environment. To deal with this problem, a new dry scrubbing process was tested in this study. A three-stage countercurrent fluidized bed adsorber was developed, designed, and fabricated. It was used as a removal apparatus and operated in a continuous regime for the two-phase system. The height of each stage was 0.30 m, and the inner diameter was 0.10 m. The paper presents the removal of CO2 from gas mixtures by chemical sorption on porous granular calcium oxide particles in the reactor at ambient temperature. The advantages of a multistage fluidized bed reactor for high mass transfer and high gas−solid contact can enhance the removal of the gas when using a dry method. The effects of the operating parameters such as sorbent, superficial gas velocity, and the Weir height on CO2 removal efficiency in the multistage fluidized bed were investigated. The results indicate that the removal efficiency of the carbon dioxide was around 71% at a high solid flow rate corresponding to lower gas velocity at room temperature. In comparison with wet scrubbers, this dry process appears to have lower cost, less complicated configuration, and simpler disposal of used sorbent. The results in this study assume importance from the perspective of use of a multistage fluidized bed adsorber for control of gaseous pollutants at high temperature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901133r [article] Multistage fluidized bed reactor performance characterization for adsorption of carbon dioxide [texte imprimé] / Sudeshna Roy, Auteur ; C. R. Mohanty, Auteur ; B. C. Meikap, Auteur . - 2010 . - pp. 10718–10727. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10718–10727 Mots-clés : Multistage--Fluidized--Reactor Performance--Characterization--Adsorption--Carbon Dioxide Résumé : Carbon dioxide and its different compounds are generated as primary greenhouse gases from the flue gases of coal-fired thermal power plants, boilers, and other stationary combustion processes. This greenhouse gas causes global warming after being emitted to the environment. To deal with this problem, a new dry scrubbing process was tested in this study. A three-stage countercurrent fluidized bed adsorber was developed, designed, and fabricated. It was used as a removal apparatus and operated in a continuous regime for the two-phase system. The height of each stage was 0.30 m, and the inner diameter was 0.10 m. The paper presents the removal of CO2 from gas mixtures by chemical sorption on porous granular calcium oxide particles in the reactor at ambient temperature. The advantages of a multistage fluidized bed reactor for high mass transfer and high gas−solid contact can enhance the removal of the gas when using a dry method. The effects of the operating parameters such as sorbent, superficial gas velocity, and the Weir height on CO2 removal efficiency in the multistage fluidized bed were investigated. The results indicate that the removal efficiency of the carbon dioxide was around 71% at a high solid flow rate corresponding to lower gas velocity at room temperature. In comparison with wet scrubbers, this dry process appears to have lower cost, less complicated configuration, and simpler disposal of used sorbent. The results in this study assume importance from the perspective of use of a multistage fluidized bed adsorber for control of gaseous pollutants at high temperature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901133r

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Thermodynamic analysis on the mineralization of trace organic contaminants with oxidants in advanced oxidation processes / Yuanhui Ji in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10728–10733 Titre : Thermodynamic analysis on the mineralization of trace organic contaminants with oxidants in advanced oxidation processes Type de document : texte imprimé Auteurs : Yuanhui Ji, Auteur ; Zhuhong Yang, Auteur ; Xiaoyan Ji, Auteur Année de publication : 2010 Article en page(s) : pp. 10728–10733 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermodynamic--Analysis--Mineralization--Trace Organic--Contaminants--Oxidants--Advanced--Oxidation--Processes Résumé : There is a growing demand for the efficient treatment of organic polluted wastewaters by advanced oxidation processes (AOPs) which calls for the determination of the mineralization order of ease for the organic contaminants with oxidants. The mineralization abilities of organic contaminants in AOPs are investigated in this work. Photocatalytic experiments for three representative organic contaminants are carried out, and their corresponding reaction rates are determined experimentally. Meanwhile, molar Gibbs free energy changes ΔrGm° for the reactions of 31 organic contaminants (10 chlorinated hydrocarbons, four brominated hydrocarbons, 11 aromatic hydrocarbons and their derivatives, three chloroacetic acid, and three chloroacetyl chloride) with oxidants of •OH, H2O2, •O−, O3, and O2 are calculated, and the mineralization order of ease is determined theoretically on the basis of ΔrGm°. The agreement of the theoretical and experimental mineralization abilities for most of the organic contaminants investigated implies the reliability of the determination of the mineralization ability from the magnitude of ΔrGm° for the mineralization of trace organic contaminants. Results also show that for most of the organic contaminants studied, the mineralization abilities are •OH > H2O2 > •O− > O3 > O2, and the mineralization ability of the organic contaminants depends on not only the oxidants but also the structure and properties of the organic contaminants themselves, and the degradation reaction products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900620n [article] Thermodynamic analysis on the mineralization of trace organic contaminants with oxidants in advanced oxidation processes [texte imprimé] / Yuanhui Ji, Auteur ; Zhuhong Yang, Auteur ; Xiaoyan Ji, Auteur . - 2010 . - pp. 10728–10733. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10728–10733 Mots-clés : Thermodynamic--Analysis--Mineralization--Trace Organic--Contaminants--Oxidants--Advanced--Oxidation--Processes Résumé : There is a growing demand for the efficient treatment of organic polluted wastewaters by advanced oxidation processes (AOPs) which calls for the determination of the mineralization order of ease for the organic contaminants with oxidants. The mineralization abilities of organic contaminants in AOPs are investigated in this work. Photocatalytic experiments for three representative organic contaminants are carried out, and their corresponding reaction rates are determined experimentally. Meanwhile, molar Gibbs free energy changes ΔrGm° for the reactions of 31 organic contaminants (10 chlorinated hydrocarbons, four brominated hydrocarbons, 11 aromatic hydrocarbons and their derivatives, three chloroacetic acid, and three chloroacetyl chloride) with oxidants of •OH, H2O2, •O−, O3, and O2 are calculated, and the mineralization order of ease is determined theoretically on the basis of ΔrGm°. The agreement of the theoretical and experimental mineralization abilities for most of the organic contaminants investigated implies the reliability of the determination of the mineralization ability from the magnitude of ΔrGm° for the mineralization of trace organic contaminants. Results also show that for most of the organic contaminants studied, the mineralization abilities are •OH > H2O2 > •O− > O3 > O2, and the mineralization ability of the organic contaminants depends on not only the oxidants but also the structure and properties of the organic contaminants themselves, and the degradation reaction products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900620n

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Investigation of bulk and interfacial properties for nitrogen and light hydrocarbon binary mixtures by perturbed-chain statistical associating fluid theory combined with density-gradient theory / SongTao Liu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10734–10739 Titre : Investigation of bulk and interfacial properties for nitrogen and light hydrocarbon binary mixtures by perturbed-chain statistical associating fluid theory combined with density-gradient theory Type de document : texte imprimé Auteurs : SongTao Liu, Auteur ; Dong Fu, Auteur ; JianYi Lu, Auteur Année de publication : 2010 Article en page(s) : pp. 10734–10739 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Investigation--Bulk--Interfacial--Properties--Nitrogen-- Hydrocarbon--Binary--Mixtures--Perturbed-Chain--Statistical--Associating--Fluid Theory--Combined--Density-Gradient Résumé : The perturbed-chain statistical associating fluid theory (PC-SAFT) and density-gradient theory (DGT) are used to construct an equation of state (EOS) for the phase behavior of the binary mixtures of nitrogen and light hydrocarbons. With the molecular parameters and influence parameters respectively regressed from bulk properties and surface tensions of pure fluids as input, both the bulk and the interfacial properties for binary mixtures are investigated. The calculated surface tensions of nitrogen−pentane, nitrogen−hexane, nitrogen−heptane, nitrogen−octane, nitrogen−decane, and nitrogen−toluene binary mixtures are satisfactory as compared to the experimental data. Our results show that PC-SAFT combined with DGT is able to describe the interfacial properties of the binary mixtures of nitrogen−light hydrocarbons in wide pressure range and illustrate the influences of temperature, pressure, and bulk properties on the interfacial properties. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007437 [article] Investigation of bulk and interfacial properties for nitrogen and light hydrocarbon binary mixtures by perturbed-chain statistical associating fluid theory combined with density-gradient theory [texte imprimé] / SongTao Liu, Auteur ; Dong Fu, Auteur ; JianYi Lu, Auteur . - 2010 . - pp. 10734–10739. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10734–10739 Mots-clés : Investigation--Bulk--Interfacial--Properties--Nitrogen-- Hydrocarbon--Binary--Mixtures--Perturbed-Chain--Statistical--Associating--Fluid Theory--Combined--Density-Gradient Résumé : The perturbed-chain statistical associating fluid theory (PC-SAFT) and density-gradient theory (DGT) are used to construct an equation of state (EOS) for the phase behavior of the binary mixtures of nitrogen and light hydrocarbons. With the molecular parameters and influence parameters respectively regressed from bulk properties and surface tensions of pure fluids as input, both the bulk and the interfacial properties for binary mixtures are investigated. The calculated surface tensions of nitrogen−pentane, nitrogen−hexane, nitrogen−heptane, nitrogen−octane, nitrogen−decane, and nitrogen−toluene binary mixtures are satisfactory as compared to the experimental data. Our results show that PC-SAFT combined with DGT is able to describe the interfacial properties of the binary mixtures of nitrogen−light hydrocarbons in wide pressure range and illustrate the influences of temperature, pressure, and bulk properties on the interfacial properties. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007437

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Estimating crystal growth rates using in situ ATR-FTIR and raman spectroscopy in a calibration-free manner / Jeroen Cornel in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10740–10745 Titre : Estimating crystal growth rates using in situ ATR-FTIR and raman spectroscopy in a calibration-free manner Type de document : texte imprimé Auteurs : Jeroen Cornel, Auteur ; Mazzotti, Marco, Auteur Année de publication : 2010 Article en page(s) : pp. 10740–10745 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Estimating--Crystal--Growth--Rates--Using--situ ATR-FTIR--Raman--Spectroscopy-- Calibration-Free Manner Résumé : Seeded batch desupersaturation experiments of paracetamol in water were monitored using in situ ATR-FTIR and in situ Raman spectroscopy. On the basis of the linear relationship between the measured signal and the concentrations of the involved components, in situ ATR-FTIR and Raman spectroscopy could be used quantitatively in a calibration-free manner to estimate the crystal growth rate of paracetamol. Using a population balance model and a nonlinear least-squares optimization routine, it was shown that by fitting the measured time-resolved ATR-FTIR spectra directly and by fitting the desupersaturation profiles obtained from these spectra combined with a previously developed calibration model, essentially the same growth rate parameters can be estimated. Very similar growth rate parameters could be obtained by fitting the measured time-resolved Raman spectra using the same population balance model. These results show that crystal growth rates can be estimated in a calibration-free manner using both in situ spectroscopic techniques, thereby avoiding lengthy calibration procedures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008138 [article] Estimating crystal growth rates using in situ ATR-FTIR and raman spectroscopy in a calibration-free manner [texte imprimé] / Jeroen Cornel, Auteur ; Mazzotti, Marco, Auteur . - 2010 . - pp. 10740–10745. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10740–10745 Mots-clés : Estimating--Crystal--Growth--Rates--Using--situ ATR-FTIR--Raman--Spectroscopy-- Calibration-Free Manner Résumé : Seeded batch desupersaturation experiments of paracetamol in water were monitored using in situ ATR-FTIR and in situ Raman spectroscopy. On the basis of the linear relationship between the measured signal and the concentrations of the involved components, in situ ATR-FTIR and Raman spectroscopy could be used quantitatively in a calibration-free manner to estimate the crystal growth rate of paracetamol. Using a population balance model and a nonlinear least-squares optimization routine, it was shown that by fitting the measured time-resolved ATR-FTIR spectra directly and by fitting the desupersaturation profiles obtained from these spectra combined with a previously developed calibration model, essentially the same growth rate parameters can be estimated. Very similar growth rate parameters could be obtained by fitting the measured time-resolved Raman spectra using the same population balance model. These results show that crystal growth rates can be estimated in a calibration-free manner using both in situ spectroscopic techniques, thereby avoiding lengthy calibration procedures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008138

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Determination of effective diffusion coefficients through the walls of coated diesel particulate filters / Oliver Krocher in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10746–10750 Titre : Determination of effective diffusion coefficients through the walls of coated diesel particulate filters Type de document : texte imprimé Auteurs : Oliver Krocher, Auteur ; Martin Elsener, Auteur ; Martin Votsmeier, Auteur Année de publication : 2010 Article en page(s) : pp. 10746–10750 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Determination--Effective--Diffusion--Coefficients--through--Walls--Coated Diesel--Particulate Filters Résumé : We demonstrate in this paper that the effective diffusion coefficient in the wall of a particulate filter can be determined by measuring the diffusion of NO between two adjacent channels of a filter segment in a simple apparatus based on a modified experimental method of Beeckman. The effective diffusion coefficient in the walls of an uncoated SiC particulate filter is determined as 2.8 × 10−6 m2/s at room temperature. Coating the filter with 30 or 65 g/L of wall-integrated washcoat leads to an insignificant increase in the diffusion coefficient, whereas coating the same filter with a high washcoat loading of 140 g/L leads to a decrease of the diffusion coefficient to 2.0 × 10−6 m2/s. All of the determined diffusion coefficients increase with temperature proportional to T1.5. This indicates that the diffusion in the wall is mainly molecular diffusion and that Knudsen diffusion plays a minor role. Fitting the parallel pore model to the experimental diffusion coefficient of the uncoated filter results in a tortuosity factor of 3.5. The random pore model overpredicts the effective diffusion coefficient by almost 50%. Neither of the two models reproduces the threshold-type dependency of the effective diffusion coefficient on washcoat loading. However, all experimental results are predicted by both pore models with an accuracy of better than 50%, so that an estimation of the effective diffusion coefficient might be a feasible solution for many practical simulation tasks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901269v [article] Determination of effective diffusion coefficients through the walls of coated diesel particulate filters [texte imprimé] / Oliver Krocher, Auteur ; Martin Elsener, Auteur ; Martin Votsmeier, Auteur . - 2010 . - pp. 10746–10750. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10746–10750 Mots-clés : Determination--Effective--Diffusion--Coefficients--through--Walls--Coated Diesel--Particulate Filters Résumé : We demonstrate in this paper that the effective diffusion coefficient in the wall of a particulate filter can be determined by measuring the diffusion of NO between two adjacent channels of a filter segment in a simple apparatus based on a modified experimental method of Beeckman. The effective diffusion coefficient in the walls of an uncoated SiC particulate filter is determined as 2.8 × 10−6 m2/s at room temperature. Coating the filter with 30 or 65 g/L of wall-integrated washcoat leads to an insignificant increase in the diffusion coefficient, whereas coating the same filter with a high washcoat loading of 140 g/L leads to a decrease of the diffusion coefficient to 2.0 × 10−6 m2/s. All of the determined diffusion coefficients increase with temperature proportional to T1.5. This indicates that the diffusion in the wall is mainly molecular diffusion and that Knudsen diffusion plays a minor role. Fitting the parallel pore model to the experimental diffusion coefficient of the uncoated filter results in a tortuosity factor of 3.5. The random pore model overpredicts the effective diffusion coefficient by almost 50%. Neither of the two models reproduces the threshold-type dependency of the effective diffusion coefficient on washcoat loading. However, all experimental results are predicted by both pore models with an accuracy of better than 50%, so that an estimation of the effective diffusion coefficient might be a feasible solution for many practical simulation tasks. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901269v

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire