Catalyst regeneration apparatus

Abstract

Apparatus for effecting multiple treatment steps needed to regenerate spent hydrocarbon conversion catalyst. Catalyst is contacted with a hot oxygen-containing gas stream in order to remove coke which accumulates on the catalyst while it is in a hydrocarbon conversion zone. After the coke is burned off in a combustion zone, catalyst is passed into a halogenation zone wherein a halogen is deposited on the catalyst. Catalyst leaving the halogenation zone is passed into a drying zone for removal of water formed in the combustion zone which has remained on the catalyst instead of being carried off with combustion gases. Water removal is accomplished by passing a hot dry air stream through the catalyst in the drying zone. A portion of the air stream which has passed through the drying zone is passed through the halogenation zone in admixture with a halogen, while the balance of the air stream leaving the drying zone is removed from the regeneration apparatus by venting it to the atmosphere or another disposal location. That portion of the air stream which is utilized in the halogenation zone is then passed into the combustion zone where it provides the oxygen required to accomplish burning of the carbon. The flow of air into the drying zone is controlled at a rate established to accomplish the degree of desired drying. The oxygen content of the gas flowing to the combustion zone is monitored and the amount of gas vented from the drying zone is adjusted in order to maintain the desired concentration of oxygen. In this manner, the amount of air supplied to the combustion zone is adjusted independently of the air supplied to the drying zone.