Regeneration of severely deactivated reforming catalysts

摘要

The invention is directed a process for regenerating deactivated reforming catalysts comprising at least one Group VIII metal on zeolite L, preferably wherein the catalysts are extruded using a binder material such as alumina or silica. The process includes: a) coke burn at severe conditions to improve the accessibility of the Group VIII catalytic metal particles by transporting them to the outside of the zeolite microchannels; b) catalytic metal redispersion by wet oxychlorination with elemental chlorine and oxygen; c) stripping with a gas stream comprising oxygen and water at low pressure to remove as much residual chlorine as possible; and d) reduction of catalytic metals with hydrogen at low pressure. The process is particularly effective for recovering activity of catalysts which have been severely deactivated.