Method and system for effecting catalytic cracking of high boiling hydrocarbons with fluid conversion catalysts
AssigneeMobil Oil Corporation
InventorJohn C. Zahner
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Abstract
A method and system for cracking hydrocarbons with distinct fluid catalyst particles differing in activity, selectivity and physical characteristics is described wherein a common catalyst regeneration system is employed which will measurably contribute to the heat requirements of the operation as well as the activity/selectivity characteristics of the catalyst employed. Except for size, the catalysts upon make-up may have different or identical catalytic characteristics. However, upon contact with a particular hydrocarbon stream, such as vacuum resid, the selectivity and coke producing characteristics of the catalysts may be altered.
Claims16
In a process for converting hydrocarbons with fluid particles of catalyst and regenerating the catalyst particles by burning carbonaceous deposits on the catalyst in an adjacent catalyst regeneration thereby heating the catalyst particles to an elevated temperature before recycle to said hydrocarbon conversion operation, the improvement which comprises
- providing at least two separate catalyst conversion zones for processing hydrocarbon fractions of different boiling range and coke producing characteristics,
- converting a low coke producing first hydrocarbon fraction in the presence of a first mass of active crystalline zeolite fluid particles of catalyst of selected activity and physical characteristics under elevated temperature conversion conditions,
- converting a second hydrocarbon fraction of higher coke producing characteristics in the presence of a second mass of active crystalline zeolite fluid particles of physical characteristics different from said first catalyst mass,
- recovering catalyst particles from each of said conversion operations comprising different amounts of carbonaceous deposits of said conversion, recovering hydrocarbon conversion products of each of said hydrocarbon conversion operations,
- passing said recovered catalyst comprising catalyst of said first and second mass of catalyst particles in admixture with one another into a catalyst regeneration under conditions selected to heat said mixture of particles of catalyst to an elevated temperature above 1200.degree. F. by burning said carbonaceous deposits, separating by elutriation in said regeneration zone said first mass of fluid particles from said second mass of fluid particles,
- recovering one of said catalyst masses from an upper portion of the regeneration zone and the other from a lower portion of the regeneration zone,
- recycling the separately recovered regenerated first and second mass of catalysts to the conversion zone from which obtained and recycling a portion of one of said first and second mass of catalyst particles recovered from said regeneration zone to said catalyst regeneration operation for admixtures with particles of catalyst containing carbonaceous deposits being regenerated in said catalyst regeneration operation.
Dependencies are inferred from the claim text.