Patent ID: 6579820
Filing Date: 2003-06-17
Classification: B01D,C10G,C10M,Y02A,Y02C,Y02P

Abstract:
A process for substantially reducing the emission of nitrogen oxides from a regeneration reactor during the regeneration of spent catalyst having coke deposits thereon, which comprises the steps of:(a) contacting said spent catalyst with a primary oxygen-containing gas in a dense phase of said reactor, thereby combusting said coke and forming a combustion gas comprising nitrogen oxide and carbon monoxide which further react in said dense phase, thus reducing a majority of the nitrogen oxides to form elemental nitrogen, thereby forming a nitrogen-enriched combustion gas; and (b) passing said nitrogen-enriched combustion gas through the interface between said dense phase and a dilute phase; contacting said nitrogen-enriched combustion gas with secondary oxygen-containing gas at a location just above said interface, and contacting said nitrogen-enriched combustion gas with secondary oxygen-containing gas in said dilute phase, wherein said carbon monoxide is oxidized into carbon dioxide; wherein the amount of said primary oxygen-containing gas in step (a) is adjusted so that said nitrogen-enriched combustion gas prior to step (b) comprises up to 1% carbon monoxide.