Catalytic cracking of a poisoned feedstock

Claim 1

A METHOD FOR PRODUCING GASOLINE IN A HYDROCARBON CRACKING SYSTEM CONSISTING ESSENTIALLY OF A CATALYTIC CRACKING ZONE AND A CATALYST REGENERATION ZONE BETWEEN WHICH CATALYST IS CYCLED, WHICH CONSISTS ESSENTIALLY OF PROVIDING SAID CRACKING ZONE WITH A CALCINED CATALYST CONSISTING ESSENTIALLY OF ABOUT 10 TO 65% ALUMINA, THE BALANCE SUBSTANTIALLY SILICA, MADE BY COATING 100 PARTS OF A SOLID SILICA-ALUMINA SUBSTRATE WITH ABOUT 3 TO 100 PARTS, ON A DRY BASIS, OF A SYNTHETIC HYDROUS ALUMINA, CONTACTING SAID CATALYST IN SAID CRACKING ZONE WITH A HYDROCARBON FEEDSTOCK HEAVIER THAN GASOLINE AND CONTAINING MORE THAN ABOUT 5 P.P.M. NICKEL, WHICH NICKEL DEPOSITS ON THE CATALYST, COLLECTING CRACKED HYDROCARBON PRODUCTS INCLUDING GASOLINE, CONTACTING CATALYSTS IN SAID REGENERATION ZONE WITH A COMBUSTION SUPPORTING GAS WHEREBY CARBON IS OXIDIZED AND THEREBY REMOVED FROM THE CATALYST, BLEEDING FROM THE CRACKING SYSTEM A PORTION OF CATALYST CONTAINING AT LEAST ABOUT 800 P.P.M. NICKEL, SULFIDING BLED CATALYST BY CONTACT WITH A SULFIDING VAPOR AT ABOUT 700-1300*F., CHLORINATING SULFIDED CATALYST BY CONTACT WITH CHLORINE VAPOR AT ABOUT ROOM TEMPERATURE TO 900*F., SAID SULFIDING AND CHLORINATING SERVING TO ENHANCE SUBSEQUENT NICKEL REMOVAL, WASHING THE CATALYST WITH AN AQUEOUS MEDIUM SELECTED FROM THE GROUP CONSISTING OF (1) A SOLUTION HAVING A PH BELOW ABOUT 5 AND CONTAINING A REDUCING AGENT HAVING A SINGLE ELECTRODE POTENTIAL LESS THAN ABOUT 0.8 VOLT, (2) A SOLUTION CONTAINING A CHELATING AGENT FOR THE CONTAMINANT, AND (3) WHEN THE CATALYST HAS BEEN CONTACTED BETWEEN CHLORINATION AND WASHING WITH A VAPOROUS REDUCING AGENT HAVING THE PROPERTIES DESCRIBED, WATER, AND RETURNING RESULTING DENICKELIZED CATALYST TO A HYDROCARBON CRACKING SYSTEM.

Claim 2

A METHOD FOR PRODUCING GASOLINE IN A HYDROCARBON CRACKING SYSTEM CONSISTING ESSENTIALLY OF A CATALYTIC CRACKING ZONE AND A CATALYST REGENERATION ZONE BETWEEN WHICH CATALYST IS CYCLED, WHICH CONSISTS ESSENTIALLY OF PROVIDING SAID CRACKING ZONE WITH A CALCINED CATALYST CONSISTING ESSENTIALLY OF ABOUT 10 TO 65% ALUMINA, THE BALANCE SUBSTANTIALLY SILICA, MADE BY COATING 100 PARTS OF A SOLID SILICA-ALUMINA SUBSTRATE WITH ABOUT 3 TO 100 PARTS, ON A DRY BASIS, OF A SYNTHETIC HYDROUS ALUMINA, CONTACTING SAID CATALYST IN SAID CRACKING ZONE WITH A HYDROCARBON FEEDSTOCK HEAVIER THAN GASOLINE AND CONTAINING MORE THAN ABOUT 5 P.P.M. NICKEL, WHICH NICKEL DEPOSITS ON THE CATALYST, COLLECTING CRACKED HYDROCARBON PRODUCTS INCLUDING GASOLINE, CONTACTING CATALYSTS IN SAID REGENERATION ZONE WITH A COMBUSTION SUPPORTING GAS WHEREBY CARBON IS OXIDIZED AND THEREBY REMOVED FROM THE CATALYST, BLEEDING FROM THE CRACKING SYSTEM A PORTION OF CATALYST CONTAINING AT LEAST ABOUT 800 P.P.M. NICKEL, SULFIDING BLED CATALYST BY CONTACT WITH A SULFIDING VAPOR AT ABOUT 700-1300*F., CHLORINATING SULFIDED CATALYST BY CONTACT WITH CHLORINE VAPOR AT ABOUT ROOM TEMPERATURE TO 900*F., SAID SULFIDING AND CHLORINATING SERVING TO ENHANCE SUBSEQUENT NICKEL REMOVAL, WASHING THE CATALYST WITH AN AQUEOUS MEDIUM SELECTED FROM THE GROUP CONSISTING OF (1) A SOLUTION HAVING A PH BELOW ABOUT 5 AND CONTAINING A REDUCING AGENT HAVING A SINGLE ELECTRODE POTENTIAL LESS THAN ABOUT 0.8 VOLT, (2) A SOLUTION CONTAINING A CHELATING AGENT FOR THE CONTAMINANT, AND (3) WHEN THE CATALYST HAS BEEN CONTACTED BETWEEN CHLORINATION AND WASHING WITH A VAPOROUS REDUCING AGENT HAVING THE PROPERTIES DESCRIBED, WATER, AND RETURNING RESULTING DENICKELIZED CATALYST TO A HYDROCARBON CRACKING SYSTEM.