Progressive flow cracking of contaminated hydrocarbon feedstocks

Claim 1

A METHOD FOR PRODUCING GASOLINE IN AN ELONGATED UPFLOW CATALYTIC CRACKING REACTION PATH WHICH COMPRISES FEEDING TO THE RACTION PATH, HELD AT A TEMPERATURE OF ABOUT 750 TO 1200*F. AND AT A PRESSURE OF ABOUT ATMOSPHERIC TO 100 P.S.I.G., A MIXTURE OF FINELY DIVIDED CATALYST CONSISTING ESSENTIALLY OF ABOUT 10 TO 65% TOTAL ALUMINA AND BEING PREPARED BY THE ADDITION OF ABOUT 3 TO 100 PARTS BY WEIGHT OF A SYNTHETIC ALUMINA HYDRATE GEL TO 100 PARTS OF A SILICA-ALUMINA SUBSTRATE, MIXED WITH PETROLEUM HYDROCARBONS BOILING IN THE GAS OIL RANGE CONTAINING LESS THAN ABOUT 1 P.P.M. METAL CONTAMINANTS AND COMPRISING ABOUT 50 TO 99% OF THE TOTAL FEED, AT A LATER POINT IN THE REACTION PATH INTRODUCING A HEAVIER GAS OIL CONTAINING MORE THAN ABOUT ONE P.P.M. NICKEL AND TWO P.P.M. VANADIUM, SEPARATING CATALYST FROM THE HYDROCARBON EFFLUENT OF THE REACTION PATH AND RECOVERING HYDROCARBON PRODUCTS, THE CONVERSION OF THE FEEDSTOCK INTO PRODUCTS BOILING IN THE GASOLINE RANGE BEING ABOUT 40 TO 60%, PASSING CATALYST TO A REGENERATION ZONE WHERE CARBON IS BURNED FROM THE CATALYST TO A CATALYST CARBON CONTENT OF LESS THAN ABOUT 1.2%, BLEEDING A PORTION OF CATALYST CONTAINING NIO AND V2O5 FROM THE CRACKING-REGENERATION SYSTEM, REMOVING VANADIUM FROM THE CATALYST AND RETURNING DEMETALIZED CATALYST TO THE CRACKING-REGENERATION SYSTEM.