Catalytic cracking using a cracking catalyst in admixture with particles

Abstract

An improved fluid catalytic cracking process comprises a method for the regeneration of the fluidizable hydrocarbon conversion catalyst, particularly of the molecular sieve type, which has been deactivated with coke deposits while employed in a hydrocarbon catalytic cracking process, in which the coke-containing hydrocarbon conversion catalyst is contacted with an oxygen-containing gas to burn the coke from the catalyst under conditions providing substantially complete combustion of carbon monoxide and substantially complete combustion of the coke on the catalyst. In the regenerator, particles of the hydrocarbon conversion catalyst are in association with particles of a platinum group metal or rhenium oxidation catalyst which promotes the combustion of carbon monoxide to carbon dioxide. The catalyst composite contains a mixture of cracking catalyst particles and particles having the platinum group metal or rhenium oxidation catalyst supported on a substrate. Evolved heat is recovered by direct heat transfer to the catalyst, for example within a dilute or dense phase zone in the regenerator vessel. The gaseous effluent from the regenerator has a low content of carbon monoxide and may be discharged directly to the atmosphere with little discernible effect upon ambient air quality. The regenerated hydrocarbon conversion catalyst may have less than about 0.05 weight percent coke thereon.