Removal of vanadium and nickel from silica based cracking catalyst

Claim 1

A METHOD FOR TREATING A SYNTHETIC GEL, SILICA-BASED CRACKING CATALYST WHICH HAS BEEN POISONED BY CONTAIMINATION WITH A METAL SELECTED FROM THE GROUP CONSISTING OF NICKEL AND VANADIUM DUE TO USE OF SAID CATALYST IN A CRACKING SYSTEM WHEREIN CATALYST IS CYCLED BETWEEN A CRACKING ZONE, IN WHICH THE CATALYST IS CONTRACTED AT AN ELEVATED TEMPERATURE WITH A HYDROCARBON FEEDSTOCK CONTAINING SAID METAL CONTAMINANT WHICH DEPOSITS ON THE CATALYST, AND A REGENERATION ZONE, IN WHICH CARBON IS OXIDIZED AND THEREBY REMOVED FROM THE CATALYST, WHICH COMPRISES BLEEDING A PORTION OF METAL CONTAIMINATED CATALYST FROM THE CRACKING SYSTEM, CONTACTING BLED CATALYST WITH A SULFIDING GAS AT A TEMPERATURE OF ABOUT 500 TO 1500*F. TO ENHANCE SUBSEQUENT METAL REMOVAL, CHLORINATING POISONING METAL COMPONENT ON THE CATALYST BY CONTACT AT A TEMPERATURE OF UP TO ABOUT 100*F WITH AN ESSENTIALLY ANHYDROUS CHLORINATING MIXTURE COMPRISING A CHLORINATING GAS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN CHLORIDE AND MOLECULAR CHLORINE IN AMOUNTS UP TO ABOUT 100 PERCENT BASED ON THE WEIGHT OF THE CATALYST, A CO-VALENT COMPOUND OF CHLORINE WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF CARBON AND SULFUR IN AMOUNTS OF ABOUT 0.5-50 PERCENT BASED ON THE WEIGHT OF THE CATALYST, WASHING THE CHLORINATED CATALYST WITH A LIQUID AQUEOUS MEDIUM TO REMOVE METAL CHLORIDE AND RETURNING RESULTING DEMETALLIZED CATALYST TO A HYDROCARBON CRACKING SYSTEM.

Claim 2

A METHOD FOR TREATING A SYNTHETIC GEL, SILICA-BASED CRACKING CATALYST WHICH HAS BEEN POISONED BY CONTAIMINATION WITH A METAL SELECTED FROM THE GROUP CONSISTING OF NICKEL AND VANADIUM DUE TO USE OF SAID CATALYST IN A CRACKING SYSTEM WHEREIN CATALYST IS CYCLED BETWEEN A CRACKING ZONE, IN WHICH THE CATALYST IS CONTRACTED AT AN ELEVATED TEMPERATURE WITH A HYDROCARBON FEEDSTOCK CONTAINING SAID METAL CONTAMINANT WHICH DEPOSITS ON THE CATALYST, AND A REGENERATION ZONE, IN WHICH CARBON IS OXIDIZED AND THEREBY REMOVED FROM THE CATALYST, WHICH COMPRISES BLEEDING A PORTION OF METAL CONTAIMINATED CATALYST FROM THE CRACKING SYSTEM, CONTACTING BLED CATALYST WITH A SULFIDING GAS AT A TEMPERATURE OF ABOUT 500 TO 1500*F. TO ENHANCE SUBSEQUENT METAL REMOVAL, CHLORINATING POISONING METAL COMPONENT ON THE CATALYST BY CONTACT AT A TEMPERATURE OF UP TO ABOUT 100*F WITH AN ESSENTIALLY ANHYDROUS CHLORINATING MIXTURE COMPRISING A CHLORINATING GAS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN CHLORIDE AND MOLECULAR CHLORINE IN AMOUNTS UP TO ABOUT 100 PERCENT BASED ON THE WEIGHT OF THE CATALYST, A CO-VALENT COMPOUND OF CHLORINE WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF CARBON AND SULFUR IN AMOUNTS OF ABOUT 0.5-50 PERCENT BASED ON THE WEIGHT OF THE CATALYST, WASHING THE CHLORINATED CATALYST WITH A LIQUID AQUEOUS MEDIUM TO REMOVE METAL CHLORIDE AND RETURNING RESULTING DEMETALLIZED CATALYST TO A HYDROCARBON CRACKING SYSTEM.