Gaseous passivation of metal contaminants on cracking catalyst

Claim 1

A process for passivating a metal on a crystalline zeolite fluidized cracking catalyst which has been contaminated with said metal due to the use of said catalyst in fluidized cracking system not involving the introduction of hydrogen and wherein said catalyst is cycled between a cracking zone, in which said catalyst is contacted at an elevated temperature with a hydrocarbon feedstock containing said metal contaminant which deposits on said catalyst, and a regeneration zone, in which carbon is oxidized and thereby removed from said catalyst, said metal being included in the group comprising nickel, vanadium or iron, which process comprises contacting said catalyst at reduction reaction conditions with reducing gas consisting essentially of hydrogen that has been saturated prior to its contact with said catalyst with water in a liquid phase at a temperature of about 70° F. to about 200° F. so as to effect a reduction reaction with said metal and thereby reduce the quantity of coke generated in the cracking zone.