Patent ID: 7425258
Filing Date: 2008-09-16
Classification: C10G

Abstract:
1. A process for increasing the yield of propylene from heavy hydrocarbonaceous feeds selected from the group consisting of heavy hydrocarbon oils comprising materials boiling above 565° C., heavy and reduced petroleum crude oil, petroleum atmospheric distillation bottoms, petroleum vacuum distillation, pitch, asphalt, bitumen, other heavy hydrocarbon residues, tar sand oils, shale oil and liquid products derived from coal liquefaction processes, in a Fluid Catalytic Cracking (FCC) Unit comprising at least a reaction zone, a stripping zone, a regeneration zone, and a fractionation zone, which process comprises: (a) contacting, in said reaction zone under fluidized catalytic cracking conditions, a heavy hydrocarbonaceous feed with a catalytic cracking catalyst comprising at least a mixture of at least one large-pore molecular sieve and at least one medium-pore molecular sieve, wherein the average pore diameter of said large-pore molecular sieve is greater than about 0.7 nm, and the average pore diameter of said medium pore molecular sieve is less than about 0.7 nm, thereby resulting in spent catalyst particles containing carbon deposited thereon and a lower boiling product stream; (b) contacting at least a portion of said spent catalyst particles with a stripping gas in the stripping zone under conditions effective at removing at least a portion of any volatiles therefrom thereby resulting in at least stripped spent catalyst particles; (c) regenerating at least a portion of said stripped spent catalysts in a regeneration zone in the presence of an oxygen-containing gas under conditions effective at burning off at least a portion of said carbon deposited thereon thereby producing at least regenerated catalyst particles; (d) recycling at least a portion of said regenerated catalyst particles to said reaction zone; (e) fractionating said product stream of step (a) to produce at least a fraction rich in propylene, a C (f) collecting at least a portion of the fraction rich in propylene and naphtha fraction; and (g) recycling at least a portion of said C