US Patent:
20030021737, Jan 30, 2003
Inventors:
Satish Tamhankar - Scotch Plains NJ, US
Kirk Limbach - Dresher PA, US
Subodh Ganguly - Plainsboro NJ, US
International Classification:
B01J008/00
B01J038/36
B01J008/26
US Classification:
422/144000, 502/042000, 422/194000, 422/195000, 422/223000, 422/178000
Abstract:
A process for regenerating a spent catalyst having coke deposits thereon in a catalyst regeneration vessel having a dense phase and a dilute phase, wherein the process comprises the steps of: (a) contacting the spent catalyst with a primary oxygen-containing gas in the dense phase, thereby combusting the coke, resulting in the formation of a combustion gas comprising nitrogen oxides and carbon monoxide which further reacts, thus reducing a majority of the nitrogen oxides to form elemental nitrogen; and (b) contacting the combustion gas with a secondary oxygen-containing gas, and typically a shield gas, in the dilute phase, thereby oxidizing the remaining CO to COwithout significant temperature rise in the dilute phase due to the after bum.