A CATALYTIC CRACKING PROCESS

摘要

In a catalytic cracking process for a heavy feed comprising non-distillable and distillable hydrocarbons, the feed is initially fractionated into a heavy fraction comprising at least 10 % by weight non-distillable hydrocarbons and at least one lighter fraction containing distillable hydrocarbons. The heavy fraction is then contacted with hot regenerated cracking catalyst in a first zone of a riser reactor at a catalyst:feed weight ratio of a least 5:1 and a temperature of at least 565 °C (1050 °F), such that the heavy fraction undergoes both thermal and catalytic reactions. The catalyst/feed mixture is then quenched in a quench zone of said riser reactor within 2 seconds of said contacting step with an amount of the lighter fraction at least equal to 100 wt.% of said non-distillable hydrocarbons added to said first zone. Catalytically cracked products and spent cracking catalyst are subsequently removed from the riser reactor, the spent cracking catalyst is regenerated in a catalyst regeneration zone to produce hot regenerated cracking catalyst which is recycled to contact said heavy fraction and cracked products are recovered.