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Influence of hydrogen in catalytic deoxygenation of fatty acids and their derivatives over Pd/C / Bartosz Rozmyslowicz in Industrial & engineering chemistry research, Vol. 51 N° 26 (Juillet 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp. 8922–8927 Titre : Influence of hydrogen in catalytic deoxygenation of fatty acids and their derivatives over Pd/C Type de document : texte imprimé Auteurs : Bartosz Rozmyslowicz, Auteur ; Paivi Maki-Arvela, Auteur ; Anton Tokarev, Auteur Année de publication : 2012 Article en page(s) : pp. 8922–8927 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogen  Catalytic  Deoxygenation Résumé : The influence of hydrogen on the catalytic deoxygenation of fatty acids was investigated in the semibatch reactor over a mesoporous 5 wt % Pd/C (Sibunit) catalyst. Transformations of a model fatty acid (lauric acid) and reaction intermediates (lauric aldehyde and lauryl alcohol) were performed under inert and hydrogen rich atmosphere. Analysis of the liquid and gas phases of the reaction mixture revealed that different reactions occurred depending on hydrogen content in the reaction atmosphere. A higher yield of hydrocarbons (59 mol %) was obtained in the fatty acid deoxygenation under hydrogen pressure compared to an experiment under argon where the yield of hydrocarbons reached 39 mol % after 300 min of the reaction. Different product distributions, intermediates and reaction pathways depending on hydrogen content in the reaction atmosphere, are discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202421x [article] Influence of hydrogen in catalytic deoxygenation of fatty acids and their derivatives over Pd/C [texte imprimé] / Bartosz Rozmyslowicz, Auteur ; Paivi Maki-Arvela, Auteur ; Anton Tokarev, Auteur . - 2012 . - pp. 8922–8927. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp. 8922–8927 Mots-clés : Hydrogen  Catalytic  Deoxygenation Résumé : The influence of hydrogen on the catalytic deoxygenation of fatty acids was investigated in the semibatch reactor over a mesoporous 5 wt % Pd/C (Sibunit) catalyst. Transformations of a model fatty acid (lauric acid) and reaction intermediates (lauric aldehyde and lauryl alcohol) were performed under inert and hydrogen rich atmosphere. Analysis of the liquid and gas phases of the reaction mixture revealed that different reactions occurred depending on hydrogen content in the reaction atmosphere. A higher yield of hydrocarbons (59 mol %) was obtained in the fatty acid deoxygenation under hydrogen pressure compared to an experiment under argon where the yield of hydrocarbons reached 39 mol % after 300 min of the reaction. Different product distributions, intermediates and reaction pathways depending on hydrogen content in the reaction atmosphere, are discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202421x

Kinetic modeling of propene hydroformylation with Rh/TPP and Rh/CHDPP catalysts / Andreas Bernas in Industrial & engineering chemistry research, Vol. 47 N° 13 (Juillet 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N° 13 (Juillet 2008) . - p. 4317–4324 Titre : Kinetic modeling of propene hydroformylation with Rh/TPP and Rh/CHDPP catalysts Type de document : texte imprimé Auteurs : Andreas Bernas, Auteur ; Paivi Maki-Arvela, Auteur ; Juha Lehtonen, Auteur ; Tapio Salmi, Auteur Année de publication : 2008 Article en page(s) : p. 4317–4324 Note générale : Bibliogr. p. 4324 Langues : Anglais (eng) Mots-clés : Propene  hydroformylation;  Solubility;  Rhodium/triphenylphosphine  catalysts Résumé : Hydroformylation of propene to isobutyraldehyde and n-butyraldehyde was studied in the kinetic regime in a semibatch stainless steel reactor at 70−115 °C and 1−15 bar overpressure in 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate solvent with rhodium/cyclohexyl diphenylphosphine (Rh/CHDPP) and rhodium/triphenylphosphine (Rh/TPP) catalysts. The influence of process parameters such as Rh concentration (50−250 ppm), ligand mass fraction (0−10 wt %), H2-to-CO ratio, and stirring power was investigated and the influence of solvent concentration was studied by using mixtures of valeraldehyde and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate as solvent. The solubility of propene, H2, and CO in 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate was measured in the same reactor. Rh/CHDPP showed lower normal/isometric aldehyde ratio (n/i) than Rh/TPP. The rate was temperature and pressure dependent, while the Rh concentration or syngas composition did not have any significant impact. The n/i ratio was always independent of the conversion, but dependent on the ligand concentration: higher ligand concentration promoted isobutyraldehyde formation. Based on experimentally recorded kinetic data, a stoichiometric scheme was proposed and parameters of power-law rate models were determined by using nonlinear regression analysis. The experimental system was described as a perfectly mixed gas−liquid reactor. As showed by sensitivity analysis, the kinetic parameters were well identified and physically reasonable and they were in accordance with qualitative observations. The kinetic models with a degree of explanation of more than 0.9 described the formation of the products with satisfying accuracy. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071401r [article] Kinetic modeling of propene hydroformylation with Rh/TPP and Rh/CHDPP catalysts [texte imprimé] / Andreas Bernas, Auteur ; Paivi Maki-Arvela, Auteur ; Juha Lehtonen, Auteur ; Tapio Salmi, Auteur . - 2008 . - p. 4317–4324. Bibliogr. p. 4324 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 13 (Juillet 2008) . - p. 4317–4324 Mots-clés : Propene  hydroformylation;  Solubility;  Rhodium/triphenylphosphine  catalysts Résumé : Hydroformylation of propene to isobutyraldehyde and n-butyraldehyde was studied in the kinetic regime in a semibatch stainless steel reactor at 70−115 °C and 1−15 bar overpressure in 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate solvent with rhodium/cyclohexyl diphenylphosphine (Rh/CHDPP) and rhodium/triphenylphosphine (Rh/TPP) catalysts. The influence of process parameters such as Rh concentration (50−250 ppm), ligand mass fraction (0−10 wt %), H2-to-CO ratio, and stirring power was investigated and the influence of solvent concentration was studied by using mixtures of valeraldehyde and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate as solvent. The solubility of propene, H2, and CO in 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate was measured in the same reactor. Rh/CHDPP showed lower normal/isometric aldehyde ratio (n/i) than Rh/TPP. The rate was temperature and pressure dependent, while the Rh concentration or syngas composition did not have any significant impact. The n/i ratio was always independent of the conversion, but dependent on the ligand concentration: higher ligand concentration promoted isobutyraldehyde formation. Based on experimentally recorded kinetic data, a stoichiometric scheme was proposed and parameters of power-law rate models were determined by using nonlinear regression analysis. The experimental system was described as a perfectly mixed gas−liquid reactor. As showed by sensitivity analysis, the kinetic parameters were well identified and physically reasonable and they were in accordance with qualitative observations. The kinetic models with a degree of explanation of more than 0.9 described the formation of the products with satisfying accuracy. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071401r

Modeling of a three - phase continuously operating isothermal packed - bed reactor / Teuvo Kilpio in Industrial & engineering chemistry research, Vol. 51 N° 26 (Juillet 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp. 8858-8866 Titre : Modeling of a three - phase continuously operating isothermal packed - bed reactor : Kinetics, mass - transfer, and dispersion effects in the hydrogenation of citral Type de document : texte imprimé Auteurs : Teuvo Kilpio, Auteur ; Paivi Maki-Arvela, Auteur ; Mats Ronnholm, Auteur Année de publication : 2012 Article en page(s) : pp. 8858-8866 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogenation  Dispersion  Mass  transfer  Kinetics  Fixed  bed  reactor  Modeling Résumé : A continuously operating isothermal dynamic packed-bed reactor was modeled. The model included chemical reaction, gas―liquid mass transfer, convection, axial dispersion, pore diffusion, and catalyst deactivation. The model was solved by using the method of lines. The model was applied on experimental data from citral hydrogenation over a supported nickel catalyst. The experiments had been carried out at 25―65 °C and at 6.1 bar in a laboratory-scale trickle-bed reactor (d = 1 cm; L = 5 cm). The parameters in the model were the rate constants, pore diffusivity, coking rate constant, Pedet number, and gas―liquid mass-transfer coefficient. A sensitivity study was performed to reveal how much a change in each of these changed the product concentration trend. The simulations revealed that the gas―liquid mass-transfer coefficient and effective diffusivity should have been well below expected values to significantly reduce the productivity. The gas-liquid mass transfer and pore diffusion were not rate-limiting; because hydrogen was used in excess, particles were small and the system was dilute. The citral concentration-dependent deactivation model based on site competition was able to describe the observed activity decline. Parameter estimation for the reaction rate and coking rate was carried out. A reasonable agreement with the experimental trends was obtained. An estimate of the Peclet number was obtained from step-response measurements with an inert tracer, which revealed that the reactor did not operate completely as a plug-flow unit. The model described here can be extended to be applicable for other hydrogenation and oxygenation reactions of other fine chemicals. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26107440 [article] Modeling of a three - phase continuously operating isothermal packed - bed reactor : Kinetics, mass - transfer, and dispersion effects in the hydrogenation of citral [texte imprimé] / Teuvo Kilpio, Auteur ; Paivi Maki-Arvela, Auteur ; Mats Ronnholm, Auteur . - 2012 . - pp. 8858-8866. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp. 8858-8866 Mots-clés : Hydrogenation  Dispersion  Mass  transfer  Kinetics  Fixed  bed  reactor  Modeling Résumé : A continuously operating isothermal dynamic packed-bed reactor was modeled. The model included chemical reaction, gas―liquid mass transfer, convection, axial dispersion, pore diffusion, and catalyst deactivation. The model was solved by using the method of lines. The model was applied on experimental data from citral hydrogenation over a supported nickel catalyst. The experiments had been carried out at 25―65 °C and at 6.1 bar in a laboratory-scale trickle-bed reactor (d = 1 cm; L = 5 cm). The parameters in the model were the rate constants, pore diffusivity, coking rate constant, Pedet number, and gas―liquid mass-transfer coefficient. A sensitivity study was performed to reveal how much a change in each of these changed the product concentration trend. The simulations revealed that the gas―liquid mass-transfer coefficient and effective diffusivity should have been well below expected values to significantly reduce the productivity. The gas-liquid mass transfer and pore diffusion were not rate-limiting; because hydrogen was used in excess, particles were small and the system was dilute. The citral concentration-dependent deactivation model based on site competition was able to describe the observed activity decline. Parameter estimation for the reaction rate and coking rate was carried out. A reasonable agreement with the experimental trends was obtained. An estimate of the Peclet number was obtained from step-response measurements with an inert tracer, which revealed that the reactor did not operate completely as a plug-flow unit. The model described here can be extended to be applicable for other hydrogenation and oxygenation reactions of other fine chemicals. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26107440

Synthesis of dimethyl carbonate from methanol and carbon dioxide / Valerie Eta in Industrial & engineering chemistry research, Vol. 49 N° 20 (Octobre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 20 (Octobre 2010) . - pp. 9609–9617 Titre : Synthesis of dimethyl carbonate from methanol and carbon dioxide : Circumventing thermodynamic limitations Type de document : texte imprimé Auteurs : Valerie Eta, Auteur ; Paivi Maki-Arvela, Auteur ; Anne-Riikka Leino, Auteur Année de publication : 2011 Article en page(s) : pp. 9609–9617 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon  dioxide Résumé : The synthesis of dimethyl carbonate from methanol and CO2 catalyzed by ZrO2 doped with KCl was investigated using chemical traps for water to circumvent thermodynamic limitations. The reaction, promoted by magnesium, occurred via the formation of carbonated magnesium methoxide (CMM) which adsorbed on the surface of ZrO2. The surface migration of the oxygen atom of ZrO2 to the surface methoxy groups of CMM resulted in the formation of dimethyl carbonate. The resulting MgO then reacted with methanol forming water and regenerating magnesium methoxide. The water formed reacted with the dehydrating agent, thus shifting the equilibrium toward a higher yield of DMC. The yield of 7.2 mol % DMC and 13.6 mol % conversion of methanol was obtained when methanol reacted with CO2 at 150 °C and 9.5 MPa for 8 h. The plausible reaction pathway is described. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23325778 [article] Synthesis of dimethyl carbonate from methanol and carbon dioxide : Circumventing thermodynamic limitations [texte imprimé] / Valerie Eta, Auteur ; Paivi Maki-Arvela, Auteur ; Anne-Riikka Leino, Auteur . - 2011 . - pp. 9609–9617. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 20 (Octobre 2010) . - pp. 9609–9617 Mots-clés : Carbon  dioxide Résumé : The synthesis of dimethyl carbonate from methanol and CO2 catalyzed by ZrO2 doped with KCl was investigated using chemical traps for water to circumvent thermodynamic limitations. The reaction, promoted by magnesium, occurred via the formation of carbonated magnesium methoxide (CMM) which adsorbed on the surface of ZrO2. The surface migration of the oxygen atom of ZrO2 to the surface methoxy groups of CMM resulted in the formation of dimethyl carbonate. The resulting MgO then reacted with methanol forming water and regenerating magnesium methoxide. The water formed reacted with the dehydrating agent, thus shifting the equilibrium toward a higher yield of DMC. The yield of 7.2 mol % DMC and 13.6 mol % conversion of methanol was obtained when methanol reacted with CO2 at 150 °C and 9.5 MPa for 8 h. The plausible reaction pathway is described. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23325778