Abstract This invention relates to a process for combined catalytic cracking and catalytic hydrocracking comprising a hydrocracker, a low severity catalytic cracker operating at a reactor temperature of at least about 900* F., and a high severity catalytic cracker operating at a severity essentially greater than said low severity catalytic cracker. A heavy virgin petroleum feedstock boiling from at least about 700* F. to at least about 1,000* F. is cracked in the low severity cracking zone and a light virgin petroleum feedstock boiling from at least about 400* F. to at least about 700* F. is cracked in the high severity catalytic cracking zone. The combined catalytic gas oils produced from the two catalytic crackers are processed in the hydrocracking zone and the heavy product from the hydrocracker is recycled to the high severity catalytic cracking zone.
A PROCESS FOR TREATING PETROLEUM WHICH COMPRISES A. CATALYTICALLY CRACKING, IN A FIRST CRACKING ZONE, A HEAVY VINGIN FEEDSTOCK AT A TEMPERATURE OF AT LEAST ABOUT 900* F., B. CATALYTICALLY CRACKING, IN A SECOND CRACKING ZONE, A LIGHT VIRGIN FEEDSTOCK AT A SEVERITY ESSENTIALLY HIGHER THAN THAT IN STEP A, C. SEPARATING IN A DISTILLATION ZONE AN AROMATIC CYCLE OIL FROM THE CRACKED PRODUCTS OF STEPS A AND B, D. CATALYTICALLY HYDROCRACKING THE AROMATIC CYCLE OIL PRODUCED IN STEP C IN A HYDROCRACKING ZONE, E. SEPARATING THE BOTTOM FRACTION BOILING ABOVE AT LEAST ABOUT 400*F. FROM THE EFFLUENT OF STEP D IN A DISTILLATION ZONE, SAID BOTTOM FRACTION, BEING OF SUFFICIENT PARAFFIN CONTENT, THAT IS AT LEAST ABOUT 70 PERCENT DUE TO THE CATALYTIC HYDROCRACKING OF STEP D TO COMPRISE AN ACCEPTABLE CATALYTIC CRACKER FEEDSTOCK WITHOUT FURTHER PROCESSING AND F. RECYCLING SAID BOTTOM FRACTION PRODUCED IN STEP E TO THE CATALYTIC CRACKING ZONE OF STEP B.
Claim 2
Dependent Claim
156 words
A PROCESS FOR TREATING PETROLEUM WHICH COMPRISES A. CATALYTICALLY CRACKING, IN A FIRST CRACKING ZONE, A HEAVY VINGIN FEEDSTOCK AT A TEMPERATURE OF AT LEAST ABOUT 900* F., B. CATALYTICALLY CRACKING, IN A SECOND CRACKING ZONE, A LIGHT VIRGIN FEEDSTOCK AT A SEVERITY ESSENTIALLY HIGHER THAN THAT IN STEP A, C. SEPARATING IN A DISTILLATION ZONE AN AROMATIC CYCLE OIL FROM THE CRACKED PRODUCTS OF STEPS A AND B, D. CATALYTICALLY HYDROCRACKING THE AROMATIC CYCLE OIL PRODUCED IN STEP C IN A HYDROCRACKING ZONE, E. SEPARATING THE BOTTOM FRACTION BOILING ABOVE AT LEAST ABOUT 400*F. FROM THE EFFLUENT OF STEP D IN A DISTILLATION ZONE, SAID BOTTOM FRACTION, BEING OF SUFFICIENT PARAFFIN CONTENT, THAT IS AT LEAST ABOUT 70 PERCENT DUE TO THE CATALYTIC HYDROCRACKING OF STEP D TO COMPRISE AN ACCEPTABLE CATALYTIC CRACKER FEEDSTOCK WITHOUT FURTHER PROCESSING AND F. RECYCLING SAID BOTTOM FRACTION PRODUCED IN STEP E TO THE CATALYTIC CRACKING ZONE OF STEP B.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein the bottom fraction from the distillation zone of step e is recycled to the catalytic cracking zone of step a.