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Studies on the regeneration mechanism of Mg-Al-Ce-Fe mixed spinel De-SOx additives / Wen-Hui Yang in Industrial & engineering chemistry research, Vol. 51 N° 40 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13085-13091 Titre : Studies on the regeneration mechanism of Mg-Al-Ce-Fe mixed spinel De-SOx additives Type de document : texte imprimé Auteurs : Wen-Hui Yang, Auteur ; Qiang Zhang, Auteur ; Chun-Yi Li, Auteur Année de publication : 2012 Article en page(s) : pp. 13085-13091 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Additive Résumé : The regeneration mechanism of sulfur species formed on the Mg-Al-Ce-Fe mixed-spinel sulfur-transfer additives is clarified in this paper. Sulfate is the main sulfur species on the sulfur-transfer catalysts after the oxidative adsorption of SO2, and the S―O bond within sulfates shows lower stability in spinel phase than in the MgO phase. The reduction of these sulfate species leads to the emission of SO2 as well as H2S, and the formation of the two reductive products are both correlated with the change in Mg/Al ratio; however, SO2 is much more sensitive. When the regeneration was conducted at 550 °C, only H2S was observed as a reductive product; yet, at 700 °C, the small amount of H2S was preceded by a large amount of SO2. The mechanism for the sulfate reductive decomposition has been proposed that sulfite is the intermediate, which can be pyrolyzed into SO2 or undergo redox reaction to form H2S. The pyrolysis reaction is closely related to the relative magnitudes of the energy provided and required to break the S―O bond in sulfates, while the probability of the redox reaction is more likely to be dependent on the H2 concentration. Sulfur-transfer additives with more surface-active sites should be developed to enhance the reductive ability, since more time is needed for the bulk-like sulfate to be reduced. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26451457 [article] Studies on the regeneration mechanism of Mg-Al-Ce-Fe mixed spinel De-SOx additives [texte imprimé] / Wen-Hui Yang, Auteur ; Qiang Zhang, Auteur ; Chun-Yi Li, Auteur . - 2012 . - pp. 13085-13091. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13085-13091 Mots-clés : Additive Résumé : The regeneration mechanism of sulfur species formed on the Mg-Al-Ce-Fe mixed-spinel sulfur-transfer additives is clarified in this paper. Sulfate is the main sulfur species on the sulfur-transfer catalysts after the oxidative adsorption of SO2, and the S―O bond within sulfates shows lower stability in spinel phase than in the MgO phase. The reduction of these sulfate species leads to the emission of SO2 as well as H2S, and the formation of the two reductive products are both correlated with the change in Mg/Al ratio; however, SO2 is much more sensitive. When the regeneration was conducted at 550 °C, only H2S was observed as a reductive product; yet, at 700 °C, the small amount of H2S was preceded by a large amount of SO2. The mechanism for the sulfate reductive decomposition has been proposed that sulfite is the intermediate, which can be pyrolyzed into SO2 or undergo redox reaction to form H2S. The pyrolysis reaction is closely related to the relative magnitudes of the energy provided and required to break the S―O bond in sulfates, while the probability of the redox reaction is more likely to be dependent on the H2 concentration. Sulfur-transfer additives with more surface-active sites should be developed to enhance the reductive ability, since more time is needed for the bulk-like sulfate to be reduced. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26451457