Appeal No. 1999-1252 Application No. 08/648,520 The subject matter on appeal relates to a process which includes the step of contacting a regenerated catalyst with a reducing gas under conditions suitable for countering effects of contaminating metals thereon. This appealed subject matter is adequately illustrated by independent claim 1 and independent claim 35 which read as follows: 1. In a process for the catalytic cracking of a hydrocarbon feed wherein said feed is contacted with a crystalline zeolite aluminosilicate cracking catalyst containing at least one contaminating metal selected from the group consisting of nickel, vanadium, and iron under cracking conditions and at least a portion of said cracking catalyst is periodically regenerated by contact with a combustion supporting gas under regeneration conditions and at least a portion of the regenerated catalyst is employed in the catalytic cracking of hydrocarbon feed, the improvement consisting essentially of contacting at least a portion of said regenerated catalyst with a reducing gas under conditions suitable for countering effects of contaminating metals thereon to produce a passivated catalyst and employing at least a portion of said [reduced] passivated catalyst in cracking said hydrocarbon feed. 35. A process for the cracking of a hydrocarbon feedstock comprising contacting said feedstock under cracking conditions in a cracking zone with a cracking catalyst prepared by (1) starting with a contaminated cracking catalyst comprising crystalline zeolite alumino-silicate wherein said contaminants comprise carbon and at least one metal contaminant selected from the group consisting of nickel, vanadium, and iron, (2) exposing said contaminated cracking catalyst in an oxidation step to a combustion-supporting gas under conditions sufficient to result in combustion of carbon contaminant, and (3) then exposing the resulting catalyst in a reduction step to a reducing gas under conditions suitable for countering adverse effects of said contaminating metals. 2Page: Previous 1 2 3 4 5 6 7 NextLast modified: November 3, 2007