Process for minimizing afterburn in a FCC regenerator
AssigneeExxonMobil Research and Engineering Company
InventorsNicholas C. Nahas, Richard E. Walter, Dean C. Draemel, Bruce J. Artuso
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Abstract
The invention relates to a process and apparatus for controlling afterburning in the regenerator of a FCC unit. The process and apparatus inject steam into the dilute phase within a regenerator to promote combustion of carbon monoxide before it enters the regenerator cyclones, plenum, or flue gas transfer lines.
Claims24
A process for controlling afterburn in a catalyst regenerator of a fluidized catalytic cracking unit, said regenerator comprising a catalyst bed and a dilute phase, said dilute phase positioned above said catalyst bed and below an inlet to a solid-gas separator, said dilute phase comprising (a) a first zone comprising oxygen, wherein combustion in said first zone is fuel-limited;
- (b) a second zone comprising carbon monoxide, wherein combustion in said second zone is oxygen-limited, said process comprising the step of injecting an effective amount of steam into said dilute phase to substantially mix said gases from said first zone and said second zone so that a substantial portion of the carbon monoxide combusts before passing through the inlet to the solid-gas separator.
A process for regenerating spent catalyst from the reaction zone of a fluidized catalytic cracking reactor comprising the steps of:
- (a) passing spent catalyst from the reaction zone of a fluid catalytic cracking reactor to a regenerator, said regenerator having therein a fluidized catalyst bed and a dilute phase zone above said catalyst bed, said dilute phase zone comprising the gases carbon monoxide and oxygen;
- (b) contacting the spent catalyst with a gas comprising oxygen to produce a regenerated catalyst;
- (c) passing said regenerated catalyst to the reaction zone;
- and,
- (d) injecting an effective amount of steam to mix the gases present in the dilute phase zone so that a substantial portion of the carbon monoxide present in the dilute phase zone combusts.
A process for controlling afterburn in a catalyst regenerator of a fluidized catalytic cracking unit, said regenerator adapted to operate under partial burn conditions, said regenerator comprising a catalyst bed and a dilute phase, said dilute phase positioned above said catalyst bed and below an inlet to a solid-gas separator, said dilute phase comprising (a) a first zone comprising oxygen, wherein combustion in said first zone is fuel-limited;
- (b) a second zone comprising carbon monoxide, wherein combustion in said second zone is oxygen-limited, said process comprising the step of using steam to substantially mix said gases from said first zone and said second zone so that a substantial portion of the oxygen present in said dilute phase reacts with carbon monoxide before passing through the inlet to the solid-gas separator.
Dependencies are inferred from the claim text.