METHOD FOR OXIDATIVE RECOVERY OF FINELY DIVIDED CRACKING CATALYST Russian patent published in 1996 - IPC

FIELD: cracking process. SUBSTANCE: novelty is that all the flow of partially recovered catalyst from the 1st recovery zone is directed into fluidized layer of the 2nd zone along the perimeter of circle coaxial with fluidized layer and having diameter amounting to value from 1/6 to 3/4 of fluidized layer diameter. The flow enters perpendicularly to direction of recovery gas flow in the 2nd zone with velocity 2.5-6.0 m/s at the distance from 1/6 to 1/3 of fluidized layer height from its surface. Method makes it possible to increase recovery degree of catalyst and reduce its irreversible inactivation in settling zone of recovery plant owing to uniformly distributing partially recovered catalyst from the 1st zone in cross-section of upper part of fluidized layer in the 2nd zone. The latter favors more effective contact of partially recovered catalyst with oxygen-containing gas in the 2nd zone and reduces taking off partially recovered catalyst from the 1st zone into underlayer space thereby reducing average temperature inside catalyst particles when coke burns on them in the settling zone of recovery plant. Due to reducing residual coke on recovered catalyst and increased catalyst activity index in the system, yield of target products of cracking process is increased by 2.3%, gasoline yield by 1.6%. EFFECT: increased efficiency and yield of products.