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Nickel catalyst stability toward carboxylic acids / Andrew D. Pienaar in Industrial & engineering chemistry research, Vol. 47 n°14 (Juillet 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°14 (Juillet 2008) . - p. 4962–4965 Titre : Nickel catalyst stability toward carboxylic acids Type de document : texte imprimé Auteurs : Andrew D. Pienaar, Auteur ; Arno de Klerk, Auteur Année de publication : 2008 Article en page(s) : p. 4962–4965 Note générale : Bibliogr. p. 4965 Langues : Anglais (eng) Mots-clés : Nickel  catalysts;  Carboxylic  acids Résumé : Reduced (unsulfided) nickel catalysts can be used for hydroprocessing sulfur-free Fischer−Tropsch derived feed materials, but catalyst deactivation by metal leaching can be a problem in the presence of carboxylic acids. Leaching of reduced nickel catalysts by carboxylic acids takes place by the formation of nickel carboxylates. Carboxylic acid leaching of nickel can be prevented by operating above the carboxylate decomposition temperature, which was found to be in the range 280−305 °C for the C2−C5 nickel carboxylates. Unfortunately this is not industrially practical, because of the hydrogenolysis propensity of reduced nickel catalysts at these conditions. It was also found that nickel leaching did not monotonically increase with temperature, but was inhibited at >200 °C, probably due to polymerization of the nickel carboxylates. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071628m [article] Nickel catalyst stability toward carboxylic acids [texte imprimé] / Andrew D. Pienaar, Auteur ; Arno de Klerk, Auteur . - 2008 . - p. 4962–4965. Bibliogr. p. 4965 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°14 (Juillet 2008) . - p. 4962–4965 Mots-clés : Nickel  catalysts;  Carboxylic  acids Résumé : Reduced (unsulfided) nickel catalysts can be used for hydroprocessing sulfur-free Fischer−Tropsch derived feed materials, but catalyst deactivation by metal leaching can be a problem in the presence of carboxylic acids. Leaching of reduced nickel catalysts by carboxylic acids takes place by the formation of nickel carboxylates. Carboxylic acid leaching of nickel can be prevented by operating above the carboxylate decomposition temperature, which was found to be in the range 280−305 °C for the C2−C5 nickel carboxylates. Unfortunately this is not industrially practical, because of the hydrogenolysis propensity of reduced nickel catalysts at these conditions. It was also found that nickel leaching did not monotonically increase with temperature, but was inhibited at >200 °C, probably due to polymerization of the nickel carboxylates. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071628m