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Porosity development in activated carbons prepared from walnut shells by carbon dioxide or steam activation / Juan F. González in Industrial & engineering chemistry research, Vol. 48 N° 16 (Août 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 16 (Août 2009) . - pp. 7474–7481 Titre : Porosity development in activated carbons prepared from walnut shells by carbon dioxide or steam activation Type de document : texte imprimé Auteurs : Juan F. González, Auteur ; Silvia Román, Auteur ; Carmen M. González-García, Auteur Année de publication : 2009 Article en page(s) : pp. 7474–7481 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Activated  carbons  Porosity  development  Walnut  shells Résumé : The influence of carbon dioxide and steam as activating agents on the porosity development of activated carbons produced from walnut shells was investigated. The study was made covering a wide range of burnoff (12−76%) and employing different temperatures and times: in carbon dioxide activation, 850 °C varying the activation time in the range 60−480 min, and in steam activation, 700, 850, and 900 °C (for 30−120 min). It was found that the gasifying agent has a profound influence on the activated carbon porosity development. First, steam is more reactive and produces, in general, activated carbons with greater N2 adsorption capacity. Second, the increase in the fraction of mesopores with activation time is more pronounced for steam. While steam generates micro-, meso-, and macropores from the early stages of the process, carbon dioxide produces highly microporous carbons, with broadening of the microporosity only for long activation times. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801848x [article] Porosity development in activated carbons prepared from walnut shells by carbon dioxide or steam activation [texte imprimé] / Juan F. González, Auteur ; Silvia Román, Auteur ; Carmen M. González-García, Auteur . - 2009 . - pp. 7474–7481. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 16 (Août 2009) . - pp. 7474–7481 Mots-clés : Activated  carbons  Porosity  development  Walnut  shells Résumé : The influence of carbon dioxide and steam as activating agents on the porosity development of activated carbons produced from walnut shells was investigated. The study was made covering a wide range of burnoff (12−76%) and employing different temperatures and times: in carbon dioxide activation, 850 °C varying the activation time in the range 60−480 min, and in steam activation, 700, 850, and 900 °C (for 30−120 min). It was found that the gasifying agent has a profound influence on the activated carbon porosity development. First, steam is more reactive and produces, in general, activated carbons with greater N2 adsorption capacity. Second, the increase in the fraction of mesopores with activation time is more pronounced for steam. While steam generates micro-, meso-, and macropores from the early stages of the process, carbon dioxide produces highly microporous carbons, with broadening of the microporosity only for long activation times. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801848x