CATALYTIC CRACKING PROCESS AND APPARATUS THEREFOR

摘要

A catalytic cracking process and apparatus therefor are de- scribed, wherein hot, active cracking catalyst particles are circulat- ed from a regenerator (12) to a reactor (11) wherein they are brought into contact with a hydrocarbon feed to convert the latter to cracked products. The cracked products and resultingly spent catalyst particles are separately recovered and the spent particles are passed to a stripping zone (22) for contact with a stripping gas to remove therefrom strippable hydrocarbon materials, which also are recovered. The stripped catalyst particles are circulated to the regenerator (12) for contact with an oxygen-containing gas to reactivate and heat them before recirculation to the reactor (11). At least some of the hot regenerated catalyst particles are passed through an indirect heat exchanger in indirect heat exchange with at least some of the stripped catalyst particles whereby the former are cooled and the latter are heated. The regenerated catalyst which contacts the feed is thus cooler than it would otherwise be, and there is a reduction in thermal cracking. The stripped catalyst entering the regenerator is hotter than it would otherwise be there- by improving the efficacy of the regeneration step.