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Adsorption/desorption studies of 224-trimethylpentane in β-Zeolite and mesoporous materials using a tapered element oscillating microbalance (TEOM) / Kening Gong in Industrial & engineering chemistry research, Vol. 48 N° 21 (Novembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 21 (Novembre 2009) . - pp. 9490–9497 Titre : Adsorption/desorption studies of 224-trimethylpentane in β-Zeolite and mesoporous materials using a tapered element oscillating microbalance (TEOM) Type de document : texte imprimé Auteurs : Kening Gong, Auteur ; Tiepan Shi, Auteur ; Palghat A. Ramachandran, Auteur Année de publication : 2010 Article en page(s) : pp. 9490–9497 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : 224-Trimethylpentane  β-Zeolite  Mesoporous  materials Résumé : The facile desorption of C8 and heavier products from solid acid alkylation catalysts is essential to thwart catalyst deactivation by fouling. To better understand this phenomenon, a tapered element oscillating microbalance (TEOM) was employed to investigate the adsorption/desorption characteristics of 224-trimethylpentane (224-TMP), a proxy C8 alkylate product, on β-zeolite and mesoporous materials (T = 298−473 K, P224-TMP = 0−0.3 bar). It is found that the 224-TMP desorption rates from saturated β-zeolite (by helium purging) are characterized by a rapid initial “burst” of 224-TMP followed by a rather long desorption phase. Complementary experimental and modeling investigations using pelletized β-zeolites of known sizes indicate that the adsorption rate and initial desorption (during the burst phase) rate of 224-TMP are controlled by meso-/macropore diffusion resistance external to the β-zeolite crystals and that the long transient could be due to pore diffusion resistance within the β-zeolite crystals. In contrast, mesoporous silica materials provide facile pore accessibility for large alkylate molecules such as 224-TMP, as evidenced by complete desorption of 224-TMP even at mild temperatures. These insights provide guidance for rational engineering of stable solid acid alkylation catalysts. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900334g [article] Adsorption/desorption studies of 224-trimethylpentane in β-Zeolite and mesoporous materials using a tapered element oscillating microbalance (TEOM) [texte imprimé] / Kening Gong, Auteur ; Tiepan Shi, Auteur ; Palghat A. Ramachandran, Auteur . - 2010 . - pp. 9490–9497. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 21 (Novembre 2009) . - pp. 9490–9497 Mots-clés : 224-Trimethylpentane  β-Zeolite  Mesoporous  materials Résumé : The facile desorption of C8 and heavier products from solid acid alkylation catalysts is essential to thwart catalyst deactivation by fouling. To better understand this phenomenon, a tapered element oscillating microbalance (TEOM) was employed to investigate the adsorption/desorption characteristics of 224-trimethylpentane (224-TMP), a proxy C8 alkylate product, on β-zeolite and mesoporous materials (T = 298−473 K, P224-TMP = 0−0.3 bar). It is found that the 224-TMP desorption rates from saturated β-zeolite (by helium purging) are characterized by a rapid initial “burst” of 224-TMP followed by a rather long desorption phase. Complementary experimental and modeling investigations using pelletized β-zeolites of known sizes indicate that the adsorption rate and initial desorption (during the burst phase) rate of 224-TMP are controlled by meso-/macropore diffusion resistance external to the β-zeolite crystals and that the long transient could be due to pore diffusion resistance within the β-zeolite crystals. In contrast, mesoporous silica materials provide facile pore accessibility for large alkylate molecules such as 224-TMP, as evidenced by complete desorption of 224-TMP even at mild temperatures. These insights provide guidance for rational engineering of stable solid acid alkylation catalysts. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900334g