Experimental and modeling analysis of NO reduction by CO for a FCC regeneration process

The catalyzed NO-CO-O-2 reaction system was studied, where the catalyst was either a FCC catalyst or a Pt-based catalyst. With the Re/USY FCC catalyst, NO was both reduced directly to N-2 and converted first to NO2 and then reduced to N-2 by CO. O-2 was an inhibiter of the reduction of NO by CO, and the CO-NO reaction did not occur until the O-2 concentration was less than 0.1%. The reduction of NO by CO was enhanced by the Pt/SAPO-34 catalyst, even at lower temperatures, because O-2 was consumed by CO in the presence of this catalyst. The reaction mechanism and effect of O-2 were discussed. The modeling of the NO-CO-O-2 reaction system with a reduced mechanism was in good agreement with the experimental results in a wide range of temperatures. NO conversion was affected by the molar ratio of O-2/CO. Inhibition of NO reduction by CO due to O-2 addition was attributed to the decrease of CO(s) and increase of O(s). Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.