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Kinetics of 4-chlorophenol hydrodechlorination with alumina and activated carbon-supported Pd and Rh catalysts / Elena Díaz in Industrial & engineering chemistry research, Vol. 48 N° 7 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3351–3358 Titre : Kinetics of 4-chlorophenol hydrodechlorination with alumina and activated carbon-supported Pd and Rh catalysts Type de document : texte imprimé Auteurs : Elena Díaz, Auteur ; José A. Casas, Auteur ; Ángel F. Mohedano, Auteur Année de publication : 2009 Article en page(s) : pp. 3351–3358 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : 4-chlorophenol  Hydrodechlorination  Y-alumina  Stirred  basket  reactor Résumé : The hydrodechlorination of 4-chlorophenol promoted by different commercial catalysts based on Pd and Rh on γ-alumina and activated carbon has been investigated in a continuous stirred basket reactor (20−40 °C and 1 bar) in order to analyze the kinetics of the reaction. External and internal mass transfer effects were found to be negligible from the values of the Carberry and Weisz−Prater numbers. The reaction rate showed a first-order dependence with respect to 4-chlorophenol. All catalysts were effective in the removal of 4-chlorophenol, with phenol, cyclohexanone, and cyclohexanol identified as reaction products, although the last one was only detected with the Rh/AC catalyst. The highest apparent kinetic constant values correspond to the hydrogenation of 4-chlorophenol to phenol. These values were in the range 146−478 L/kgcat·h for Pd/Al2O3, 179−713 L/kgcat·h for Pd/AC, and 44−172 L/kgcat·h for Rh/AC. The values of the apparent activation energy for 4-chlorophenol disappearance ranged within 47−58 kJ/mol. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801462b [article] Kinetics of 4-chlorophenol hydrodechlorination with alumina and activated carbon-supported Pd and Rh catalysts [texte imprimé] / Elena Díaz, Auteur ; José A. Casas, Auteur ; Ángel F. Mohedano, Auteur . - 2009 . - pp. 3351–3358. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3351–3358 Mots-clés : 4-chlorophenol  Hydrodechlorination  Y-alumina  Stirred  basket  reactor Résumé : The hydrodechlorination of 4-chlorophenol promoted by different commercial catalysts based on Pd and Rh on γ-alumina and activated carbon has been investigated in a continuous stirred basket reactor (20−40 °C and 1 bar) in order to analyze the kinetics of the reaction. External and internal mass transfer effects were found to be negligible from the values of the Carberry and Weisz−Prater numbers. The reaction rate showed a first-order dependence with respect to 4-chlorophenol. All catalysts were effective in the removal of 4-chlorophenol, with phenol, cyclohexanone, and cyclohexanol identified as reaction products, although the last one was only detected with the Rh/AC catalyst. The highest apparent kinetic constant values correspond to the hydrogenation of 4-chlorophenol to phenol. These values were in the range 146−478 L/kgcat·h for Pd/Al2O3, 179−713 L/kgcat·h for Pd/AC, and 44−172 L/kgcat·h for Rh/AC. The values of the apparent activation energy for 4-chlorophenol disappearance ranged within 47−58 kJ/mol. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801462b

Kinetics of the hydrodechlorination of 4-chlorophenol in water using Pd, Pt, and Rh/Al2O3 catalysts / Elena Díaz in Industrial & engineering chemistry research, Vol. 47 n°11 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3840–3846 Titre : Kinetics of the hydrodechlorination of 4-chlorophenol in water using Pd, Pt, and Rh/Al2O3 catalysts Type de document : texte imprimé Auteurs : Elena Díaz, Auteur ; José A. Casas, Auteur ; Ángel F. Mohedano, Auteur ; Luisa Calvo, Auteur Année de publication : 2008 Article en page(s) : p. 3840–3846 Note générale : Bibliogr. p. 3845-3846 Langues : Anglais (eng) Mots-clés : 4-chlorophenol;  Hydrodechlorination;  Tank  reactor;  Catalytic  activity Résumé : The hydrodechlorination of 4-chlorophenol in an aqueous phase was studied in a semicontinuous basket stirred tank reactor using Pd, Pt, and Rh on γ-alumina commercial catalysts (0.5% w/w) under mild reaction conditions. The catalytic activity was studied in the temperature range of 20−40 °C. Pd and Rh showed a higher catalytic activity than Pt. From consumption of 4-chlorophenol and evolution of the reaction products, phenol, cyclohexanone, and cyclohexanol, a reaction scheme based on a parallel-series pathway and a kinetic model based on pseudo-first-order dependence on 4-chlorophenol have been proposed. Hydrodechlorination of 4-chlorophenol to phenol exhibits the largest apparent kinetic constant for Pd (k1 = 0.42–0.73 h−1) and Pt (k1 = 0.20–0.42 h−1) catalysts, while in the case of Rh, the three reactions, hydrodechlorination of 4-chlorophenol to phenol (k1 = 0.43–0.64 h−1) and hydrogenation of phenol to cyclohexanone (k3 = 0.42–0.78 h−1) and to cyclohexanol (k4 = 0.38–0.65 h−1), have comparable values of the kinetic constant. The apparent activation energy for 4-chlorophenol disappearance was determined, and values of 21.0, 26.2, and 15.3 kJ/mol were obtained for Pd, Pt, and Rh, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071517n [article] Kinetics of the hydrodechlorination of 4-chlorophenol in water using Pd, Pt, and Rh/Al2O3 catalysts [texte imprimé] / Elena Díaz, Auteur ; José A. Casas, Auteur ; Ángel F. Mohedano, Auteur ; Luisa Calvo, Auteur . - 2008 . - p. 3840–3846. Bibliogr. p. 3845-3846 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3840–3846 Mots-clés : 4-chlorophenol;  Hydrodechlorination;  Tank  reactor;  Catalytic  activity Résumé : The hydrodechlorination of 4-chlorophenol in an aqueous phase was studied in a semicontinuous basket stirred tank reactor using Pd, Pt, and Rh on γ-alumina commercial catalysts (0.5% w/w) under mild reaction conditions. The catalytic activity was studied in the temperature range of 20−40 °C. Pd and Rh showed a higher catalytic activity than Pt. From consumption of 4-chlorophenol and evolution of the reaction products, phenol, cyclohexanone, and cyclohexanol, a reaction scheme based on a parallel-series pathway and a kinetic model based on pseudo-first-order dependence on 4-chlorophenol have been proposed. Hydrodechlorination of 4-chlorophenol to phenol exhibits the largest apparent kinetic constant for Pd (k1 = 0.42–0.73 h−1) and Pt (k1 = 0.20–0.42 h−1) catalysts, while in the case of Rh, the three reactions, hydrodechlorination of 4-chlorophenol to phenol (k1 = 0.43–0.64 h−1) and hydrogenation of phenol to cyclohexanone (k3 = 0.42–0.78 h−1) and to cyclohexanol (k4 = 0.38–0.65 h−1), have comparable values of the kinetic constant. The apparent activation energy for 4-chlorophenol disappearance was determined, and values of 21.0, 26.2, and 15.3 kJ/mol were obtained for Pd, Pt, and Rh, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071517n