The present invention provides a catalytic cracking process. The process includes
introducing at least one species of a natural or synthetic residuum containing
feedstock and a catalyst into a catalytic cracker reaction zone, and thereafter
cracking the feedstock into a lower molecular weight gaseous product and spent
cracking catalyst with hydrocarbonaceous product deposited thereon. Among others,
the lower molecular weight gaseous product includes ethylene or propylene. The
spent cracking catalyst obtained from the catalytic cracker reaction zone may then
be regenerated using a first and a second regeneration zone. The first regeneration
zone may be operated in an oxidizing mode resulting in a remaining coke of reduced
hydrogen content which lowers the moisture content of flue gas in subsequent regeneration
zones. The second regeneration zone, may be operated in a partial oxidizing mode
and with a controlled carbon dioxide content in the second combustion atmosphere
as a reactant with carbon for forming additional carbon monoxide in the flue gas
of the second regeneration zone.
