| abstract |
The fluidized catalytic cracking process described herein is undertaken in a first and a second riser reaction zone in which a variety of hydrocarbon conversion reactions take place, at least one stripping zone in which entrained hydrocarbon material is removed from catalyst and at least one hydrothermal catalyst regeneration zone in which spent cracking catalyst is regenerated. The process comprises: (a) converting a hydrogen-deficient first heavy hydrocarbon feed in the first riser reaction zone in the presence of at least the first catalyst component of a mixed catalyst composition comprising as said first catalyst component, an amorphous cracking catalyst and/or a large pore crystalline cracking catalyst to provide gasoline boiling range material and one or more light hydrocarbons; (b) converting a hydrogen-rich hydrocarbon feed in a lower region of the second riser reaction zone in the presence of a second catalyst composition to provide gasiform material contributing mobile hydrogen species and/or carbon-hydrogen fragments for combination with a thermally treated, relatively hydrogen-deficient second heavy hydrogen feed introduced to an upper region of the second riser reaction zone; and (c) converting the gasiform material and thermally treated, relatively hydrogen-deficient second heavy hydrocarbon feed in an upper region of the second riser reaction zone in the presence of the mixed catalyst composition to provide a gasoline product of increased octane number. |