Method for removing vanadium and nickel from a silica based catalyst

Claim 1

A METHOD FOR REMOVING VANADIUM FROM A SYNTHETIC GEL, SILICA-BASED CATALYST WHICH HAS BEEN POISONED BY CONTAMINATION WITH VANADIUM DUE TO USE OF SAID CATALYST IN CRACKING AT ELEVATED TEMPERATURE A HYDROCARBON FEEDSTOCK CONTAINING VANADIUM, SAID CRAKCING INCLUDING A CATALYTIC CRACKING ZONE AND A CATALYST REGENERATION ZONE BETWEEN WHICH THE CATALYST IS CYCLED AND IN WHICH CRACKING ZONE THE CATALYST BECOMES CONTAIMINATED WITH VANADIUM OF SAID HYDROCARBON FEEDSTOCK AND IN WHICH REGENERATION ZONE CARBON IS OXIDIZED AT AN ELEVATED TEMPERATURE AND THEREBY REMOVED FROM THE CATALYST, WHICH COMPRISES BLEEDING A PORTION OF THE VANADIUM-CONTAMINATED CATALYST FROM THE CRACKING SYSTEM, CONTACTING BLED, SUBSTANTIALLY CARBONFREE CATALYST FOR AT LEAST ABOUT 15 MINUTES WITH A GASCONTAINING MOLECULAR OXYGEN AT A TEMPERATURE OF AT LEAST ABOUT 1150*F., BUT BELOW A TEMPERATURE DELETERIOUS TO THE CATALYST TO INCREASE SUBSEQUENT VANADIUM REMOVAL FROM SAID CATALYST, DISCONTINUING CONTACT WITH SAID GAS CONTAINING MOLECULAR OXYGEN, SUBSEQUENTLY REMOVING VANADIUM FROM THE OXYGEN-TREATED CATALYST AT A TEMPERATURE OF UP TO ABOUT 100*F. WITHOUT UNDUE DELETERIOUS CHANGE IN THE PHYSICAL AND CHEMICAL CHARACTERISTICS OF THE CATALYST, AND RETURNING RESULTING DEVANDIZED CATALYST TO A HYDROCARBON CRACKING SYSTEM.

Claim 2

A METHOD FOR REMOVING VANADIUM FROM A SYNTHETIC GEL, SILICA-BASED CATALYST WHICH HAS BEEN POISONED BY CONTAMINATION WITH VANADIUM DUE TO USE OF SAID CATALYST IN CRACKING AT ELEVATED TEMPERATURE A HYDROCARBON FEEDSTOCK CONTAINING VANADIUM, SAID CRAKCING INCLUDING A CATALYTIC CRACKING ZONE AND A CATALYST REGENERATION ZONE BETWEEN WHICH THE CATALYST IS CYCLED AND IN WHICH CRACKING ZONE THE CATALYST BECOMES CONTAIMINATED WITH VANADIUM OF SAID HYDROCARBON FEEDSTOCK AND IN WHICH REGENERATION ZONE CARBON IS OXIDIZED AT AN ELEVATED TEMPERATURE AND THEREBY REMOVED FROM THE CATALYST, WHICH COMPRISES BLEEDING A PORTION OF THE VANADIUM-CONTAMINATED CATALYST FROM THE CRACKING SYSTEM, CONTACTING BLED, SUBSTANTIALLY CARBONFREE CATALYST FOR AT LEAST ABOUT 15 MINUTES WITH A GASCONTAINING MOLECULAR OXYGEN AT A TEMPERATURE OF AT LEAST ABOUT 1150*F., BUT BELOW A TEMPERATURE DELETERIOUS TO THE CATALYST TO INCREASE SUBSEQUENT VANADIUM REMOVAL FROM SAID CATALYST, DISCONTINUING CONTACT WITH SAID GAS CONTAINING MOLECULAR OXYGEN, SUBSEQUENTLY REMOVING VANADIUM FROM THE OXYGEN-TREATED CATALYST AT A TEMPERATURE OF UP TO ABOUT 100*F. WITHOUT UNDUE DELETERIOUS CHANGE IN THE PHYSICAL AND CHEMICAL CHARACTERISTICS OF THE CATALYST, AND RETURNING RESULTING DEVANDIZED CATALYST TO A HYDROCARBON CRACKING SYSTEM.