Regeneration of cracking catalyst in a vessel with a partition forming an upper and lower zone

Claim 1

A process for the regeneration of a fluidizable cracking catalyst which has been deactivated with coke deposits while employed in a catalytic hydrocarbon cracking process, comprising the steps of passing coked catalyst particles to a lower portion of a regeneration vessel, said regeneration vessel having a partition dividing said vessel into a lower zone and an upper zone and said partition being at a position which is about 25 to 80 percent of the internal height of the vessel; contacting the coked catalyst particles in the lower zone of the regeneration vessel with an oxygen-containing regeneration gas stream at fluidizing velocities, said gas stream providing at least sufficient oxygen for burning coke from the catalyst particles and for essentially complete combustion of the resulting carbon monoxide formed during the burning of the coke; burning the coke from the catalyst particles within the lower zone which contains a dense catalyst phase, and essentially completely combusting resulting carbon monoxide while the carbon monoxide and oxygen-containing regeneration gas are within the lower zone, wherein said partition, in conjunction with the burning, facilitates the maintenance of temperatures sufficient for essentially complete combustion of carbon monoxide within the lower zone while in contact with said catalyst particles in an amount sufficient to absorb a major amount of heat resulting from the carbon monoxide combustion and avoid temperatures which may be damaging to catalyst particles; passing the resulting combustion gases and entrained catalyst particles through catalyst separation means whereby most of the catalyst particles are returned to the lower zone and the combustion gases with remaining entrained catalyst particles are sent to the upper zone wherein said combustion gases, with the remaining entrained catalyst particles, reach a temperature which is lower than in said separation means; passing the combustion gases with remaining entrained catalyst particles through catalyst separation means in the upper zone, whereby particles separated from the combustion gases are returned to the lower zone, and the combustion gases having a low carbon monoxide content are exhausted; and withdrawing regenerated catalyst particles having a low content of residual coke, from the lower zone of the regeneration vessel.