Documents disponibles écrits par cet auteur

Activation of waste tire char upon cyclic oxygen chemisorption-desorption / Francisco Heras in Industrial & engineering chemistry research, Vol. 48 N° 10 (Mai 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 10 (Mai 2009) . - pp. 4664–4670 Titre : Activation of waste tire char upon cyclic oxygen chemisorption-desorption Type de document : texte imprimé Auteurs : Francisco Heras, Auteur ; Noelia Alasino, Auteur ; Miguel A. Gilarranz, Auteur Année de publication : 2009 Article en page(s) : pp. 4664–4670 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Waste  tire  char  Chemisorption−desorption  BET  surface Résumé : Activation of waste tire char upon cyclic oxygen chemisorption−desorption permits a controlled development of porosity versus burnoff using air as feed gas for the activation process. A slow but monotonical increase of BET surface area is obtained from cycle to cycle. Initially the process led to the development of mesoporosity without generating micropores and then the micropore volume is increased whereas a decrease of narrow mesopore (20−80 nm) volume is observed, probably as a consequence of mesopore widening. Although the SBET reaches relatively low values (below 250 m2/g) even after 15 cycles, this surface development is associated with low burnoff values (around 22% for indicated BET surface area) and corresponds in an important percentage (up to about 50%) to external (nonmicropore) area. Temperatures around 210 and 550 °C for chemisorption and desorption, respectively, have been found as optimum for the purpose of preparing granular mesoporous carbons which can be interesting candidates as catalytic supports for liquid phase applications. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801764x [article] Activation of waste tire char upon cyclic oxygen chemisorption-desorption [texte imprimé] / Francisco Heras, Auteur ; Noelia Alasino, Auteur ; Miguel A. Gilarranz, Auteur . - 2009 . - pp. 4664–4670. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 10 (Mai 2009) . - pp. 4664–4670 Mots-clés : Waste  tire  char  Chemisorption−desorption  BET  surface Résumé : Activation of waste tire char upon cyclic oxygen chemisorption−desorption permits a controlled development of porosity versus burnoff using air as feed gas for the activation process. A slow but monotonical increase of BET surface area is obtained from cycle to cycle. Initially the process led to the development of mesoporosity without generating micropores and then the micropore volume is increased whereas a decrease of narrow mesopore (20−80 nm) volume is observed, probably as a consequence of mesopore widening. Although the SBET reaches relatively low values (below 250 m2/g) even after 15 cycles, this surface development is associated with low burnoff values (around 22% for indicated BET surface area) and corresponds in an important percentage (up to about 50%) to external (nonmicropore) area. Temperatures around 210 and 550 °C for chemisorption and desorption, respectively, have been found as optimum for the purpose of preparing granular mesoporous carbons which can be interesting candidates as catalytic supports for liquid phase applications. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801764x