Patent ID: 7906448

Claim:
A method for continuously regenerating particles of a coke-containing catalyst that does not contain a CO oxidation promoter, the method comprising the steps of: a) charging particles of the coke-containing catalyst to at least one coked catalyst inlet conduit in communication with an upper end of a combustion zone of a moving bed regeneration apparatus, wherein the apparatus comprises a vertically elongated regeneration vessel comprising (i) concentric inner and outer screens in an upper region of the vessel, forming the combustion zone between the screens, a combustion gas distribution zone between the outer screen and an inner wall of the vessel, and a flue gas collection zone in an interior space of the inner screen; (ii) a catalyst disengagement zone in a lower region of the vessel and in communication with a lower end of the combustion zone; (iii) at least one primary combustion gas inlet conduit in communication with the combustion gas distribution zone; (iv) a regenerated catalyst outlet conduit in a bottom region of the catalyst disengagement zone; (v) a CO oxidation zone containing a catalytically effective amount of a CO oxidation catalyst in an upper region of the flue gas collection zone and having an inlet in communication with the flue gas collection zone; and (vi) a flue gas outlet conduit in the upper region of the vessel and in communication with the CO oxidation zone, wherein the particles of the coke-containing catalyst are charged at a rate that corresponds to a residence time in the combustion zone sufficient to burn off 50 to 100% of the coke deposits; b) passing a combustion gas stream containing about 0.5 to 2.0 vol-% oxygen in admixture with inert gases into the primary combustion gas inlet conduit at a rate sufficient to provide sufficient oxygen to burn coke off the catalyst; c) distributing the combustion gas stream in the combustion gas distribution zone and passing the combustion gas into the combustion zone so that it flows radially across the moving bed of catalyst at coke combustion conditions including a temperature of about 350° to 650° C. (662° to 1202° F.) or higher sufficient to sustain coke combustion; d) withdrawing a flue gas containing undesired amounts of CO from the combustion zone into the flue gas collection zone and passing substantially all of the resulting CO-containing flue gas into the inlet of the CO oxidation zone and therein contacting the CO-containing flue gas with the CO oxidation catalyst at CO oxidation conditions effective to convert at least 95 mol-% of the entering CO to CO 2 and to form an effluent flue gas stream containing only innocuous amounts of CO and withdrawing the effluent flue gas stream via the flue gas outlet conduit; and e) withdrawing regenerated catalyst particles from the combustion zone and passing them into the catalyst disengagement zone wherein they are disengaged from contact with the radially flowing combustion gas and recovering regenerated catalyst particles from the regenerated catalyst outlet conduit.