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.
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