Documents disponibles écrits par cet auteur

Mitigating deactivation effects through rational design of hierarchically structured catalysts / Sanjeev M. Rao in Industrial & engineering chemistry research, Vol. 49 N° 21 (Novembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 11087-11097 Titre : Mitigating deactivation effects through rational design of hierarchically structured catalysts : Application to hydrodemetalation Type de document : texte imprimé Auteurs : Sanjeev M. Rao, Auteur ; Marc-Olivier Coppens, Auteur Année de publication : 2011 Article en page(s) : pp. 11087-11097 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst  Design  Deactivation Résumé : The broad pore network of a hierarchically structured hydrodemetalation catalyst, containing both nano- and macropores, is mathematically optimized to maximize the conversion of nickel metalloporphyrins in crude oil residue. A random spheres model (RSM) describing the nanoporous catalyst at the mesoscale is combined with a two-dimensional continuum approach to model the entire catalyst at the macroscale. Catalysts with a spatially uniform as well as a nonuniform macroporosity distribution are optimized. The macroporosity profiles of the optimal nonuniform catalysts fluctuate about the optimal uniform value, while the spatially and temporally integrated reaction rates from both types of optimized catalysts are almost the same. Moreover, the integrated reaction rate of the optimal hierarchically structured catalysts are almost 8 times higher than the yield obtained from a purely nanoporous catalyst. For a time on stream of 1 year, approximately 21% less catalytic material is required in the optimal hierarchically structured catalyst, compared to the purely nanoporous one. The mathematical optimization tools employed here can be extended to other industrially important reactions affected by deactivation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23448006 [article] Mitigating deactivation effects through rational design of hierarchically structured catalysts : Application to hydrodemetalation [texte imprimé] / Sanjeev M. Rao, Auteur ; Marc-Olivier Coppens, Auteur . - 2011 . - pp. 11087-11097. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 11087-11097 Mots-clés : Catalyst  Design  Deactivation Résumé : The broad pore network of a hierarchically structured hydrodemetalation catalyst, containing both nano- and macropores, is mathematically optimized to maximize the conversion of nickel metalloporphyrins in crude oil residue. A random spheres model (RSM) describing the nanoporous catalyst at the mesoscale is combined with a two-dimensional continuum approach to model the entire catalyst at the macroscale. Catalysts with a spatially uniform as well as a nonuniform macroporosity distribution are optimized. The macroporosity profiles of the optimal nonuniform catalysts fluctuate about the optimal uniform value, while the spatially and temporally integrated reaction rates from both types of optimized catalysts are almost the same. Moreover, the integrated reaction rate of the optimal hierarchically structured catalysts are almost 8 times higher than the yield obtained from a purely nanoporous catalyst. For a time on stream of 1 year, approximately 21% less catalytic material is required in the optimal hierarchically structured catalyst, compared to the purely nanoporous one. The mathematical optimization tools employed here can be extended to other industrially important reactions affected by deactivation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23448006