Claims
- 1. A catalytic cracking process wherein a heavy feed comprising non-distillable and distillable hydrocarbons is catalytically cracked in a riser reaction zone by contact with a source of hot, regenerated cracking catalyst to produce catalytically cracked products and spent cracking catalyst, cracked products are withdrawn as products, and spent cracking catalyst is regenerated in a catalyst regeneration means to produce hot regenerated cracking catalyst which is recycled to contact said heavy feed, characterized by:
- fractionating said heavy feed into at least a heavy fraction containing at least 10 wt % non-distillable hydrocarbons and at least one lighter fraction containing distillable hydrocarbons;
- blasting in a blast zone in the base of the riser said heavy fraction by contacting same with hot regenerated cracking catalyst at a cat:feed weight ratio of a least 5:1 and wherein the amount and temperature of the hot regenerated catalyst are sufficient to produce a catalyst/heavy fraction mixture having a temperature of at least 1050 F., and thereby inducing both thermal and catalytic reactions in said heavy fraction; and
- quenching said mixture in a quench zone within said riser reactor within 2 seconds with said at least one lighter fraction containing distillable hydrocarbons which undergoes endothermic reactions at the conditions present within said quench zone, said reactive quench added in an amount at least equal to 100 wt % of said non-distillable hydrocarbons added to said blasting zone.
- 2. The process of claim 1 wherein the quench is selected from the group of hydrocarbon feeds boiling in the gas oil and vacuum gas oil range, naphtha boiling range hydrocarbons, and normally gaseous hydrocarbons.
- 3. The process of claim 1 wherein said reactive quench is added in an amount equal to 100 to 1000 wt % of said non-distillable hydrocarbons added to said blasting zone.
- 4. The process of claim 1 wherein said reactive quench is added in an amount equal to 200 to 750 wt % of said non-distillable hydrocarbons added to said blasting zone.
- 5. The process of claim 1 wherein said heavy fraction comprises at least 50 wt % material boiling above 500 C.
- 6. The process of claim 1 wherein the quenching zone reduces temperatures at least 100 F. within 0.5 seconds.
- 7. The process of claim 1 wherein the quenching zone reduces temperatures at least 150 F. within 0.5 seconds.
- 8. The process of claim 1 wherein the quenching zone reduces temperatures at least 200 F. within 0.5 seconds.
- 9. The process of claim 1 wherein a non-reactive quench fluid is added to said quench zone in addition to said reactive quench, and said non-reactive quench fluid is present in an amount equal to 10 to 100 wt % of said non-distillable feed added to said blast zone.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation-In-Part of our prior co-pending application Ser. No. 165,869, filed on Mar. 3, 1988, and now abandoned, which is relied upon and incorporated herein by reference.
US Referenced Citations (7)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
165869 |
Mar 1988 |
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