Patent ID: 7585803
Filing Date: 2009-09-08
Classification: B01J

Abstract:
1. A method of operating a continuous system for a catalyst regeneration process wherein a regeneration section includes at least a combustion zone, at least one oxygen boost zone, and a halogenation zone which method comprises: a) continuously circulating an oxygen-containing recycle gas from a flue gas outlet to a recycle gas inlet in a recycle gas loop, venting a vent gas comprising combustion products from the recycle gas loop and adding gas to the recycle gas loop; b) passing catalyst particles containing a platinum group metal and having coke deposited thereon to the combustion zone and contacting the catalyst particles with a portion of the oxygen-containing recycle gas and added nitrogen gas to combust coke from the catalyst particles, wherein the oxygen-containing recycle gas and the added nitrogen gas together comprises from about 0.5 to about 1.5 volume percent oxygen; c) passing the catalyst particles from the combustion zone to the oxygen boost zone and contacting the catalyst particles with a portion of the oxygen-containing recycle gas enhanced with additional oxygen containing gas to further combust coke from the catalyst particles, wherein the recycle gas enhanced with additional oxygen containing gas comprises from about 1.5 to about 4 volume percent oxygen and the recycle gas enhanced with additional oxygen containing gas in the oxygen boost zone has an elevated level of oxygen as compared to the oxygen-containing recycle gas and the added nitrogen gas together in the combustion zone; d) passing the catalyst particles from the oxygen boost zone to the halogenation zone and contacting the catalyst particles with a halogen-containing gas and redispersing the platinum group metal on the catalyst particles; and e) recovering a regenerated catalyst from the regeneration section.