Mercury oxidation over the V2O5(WO3)/tiO2 commercial scr catalyst / Hiroyuki Kamata in Industrial & engineering chemistry research, Vol. 47 n°21 (Novembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 n°21 (Novembre 2008) . - p 8136–8141 Titre : Mercury oxidation over the V2O5(WO3)/tiO2 commercial scr catalyst Type de document : texte imprimé Auteurs : Hiroyuki Kamata, Auteur ; Shun-ichiro Ueno, Auteur ; Toshiyuki Naito, Auteur Année de publication : 2008 Article en page(s) : p 8136–8141 Note générale : chemical engineering Langues : Anglais (eng) Mots-clés : Mercury oxidationHydrochloric acid Résumé : Mercury oxidation by hydrochloric acid over the V2O5(WO3)/TiO2 commercial SCR catalyst was investigated. Both fresh and aged catalysts with honeycomb structure, which were exposed to a coal combustion flue gas in a coal-fired boiler for over 71 000 h, were examined. The aged catalysts were characterized by X-ray and SEM-EDX analysis to examine the presence of ash deposition on the surface. The mercury oxidation rate was enhanced by increasing HCl concentrations and inhibited strongly by the presence of NH3. This behavior could be explained by a kinetic model assuming that HCl competes for the catalyst active sites against NH3. As the catalyst operation time increased, the mercury oxidation rate was observed to decrease considerably in the presence of NH3 while NO reduction rate was apparently nearly unchanged. By examining aged catalysts, deposits stemming from fly ash and SO2/SO3 were observed to accumulate continuously on the catalyst surface. The ash deposited on the surface may partially block the active catalyst sites and decrease their number. The decrease of the number of active sites on the catalyst surface caused NH3 to remain unreacted in the honeycomb catalyst. The decrease of the Hg0 oxidation rate was caused by the inhibition effect of NH3 remaining in the catalyst. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800363g [article] Mercury oxidation over the V2O5(WO3)/tiO2 commercial scr catalyst [texte imprimé] / Hiroyuki Kamata, Auteur ; Shun-ichiro Ueno, Auteur ; Toshiyuki Naito, Auteur . - 2008 . - p 8136–8141. chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°21 (Novembre 2008) . - p 8136–8141 Mots-clés : Mercury oxidationHydrochloric acid Résumé : Mercury oxidation by hydrochloric acid over the V2O5(WO3)/TiO2 commercial SCR catalyst was investigated. Both fresh and aged catalysts with honeycomb structure, which were exposed to a coal combustion flue gas in a coal-fired boiler for over 71 000 h, were examined. The aged catalysts were characterized by X-ray and SEM-EDX analysis to examine the presence of ash deposition on the surface. The mercury oxidation rate was enhanced by increasing HCl concentrations and inhibited strongly by the presence of NH3. This behavior could be explained by a kinetic model assuming that HCl competes for the catalyst active sites against NH3. As the catalyst operation time increased, the mercury oxidation rate was observed to decrease considerably in the presence of NH3 while NO reduction rate was apparently nearly unchanged. By examining aged catalysts, deposits stemming from fly ash and SO2/SO3 were observed to accumulate continuously on the catalyst surface. The ash deposited on the surface may partially block the active catalyst sites and decrease their number. The decrease of the number of active sites on the catalyst surface caused NH3 to remain unreacted in the honeycomb catalyst. The decrease of the Hg0 oxidation rate was caused by the inhibition effect of NH3 remaining in the catalyst. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800363g

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire