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U.S. Department of Energy
Office of Scientific and Technical Information

NOx control in fluidized bed combustion

Patent ·
OSTI ID:5951308
This patent describes a fluidized catalytic cracking (FCC) process wherein conventional FCC catalyst contacts conventional FCC feedstock in a conventional FCC reactor to produce cracked products and coked catalyst which is regenerated in a conventional FCC regenerator. It consists of a single dense bed to which air or an oxygen-containing gas is added to produce a regenerated catalyst and flue gas containing CO/sub 2/ and NO/sub x/ resulting from coke combustion, and wherein carbon monoxide (CO) combustion promotor is uniformly distributed in the catalyst bed to promote complete combustion of CO to CO/sub 2/. The improvement consists of maintaining a majority of the CO combustion promoter as a solid particle with a volume at least 10 times greater than the conventional FCC catalyst and having a low density, relative to the dense bed density, so that the promoter floats to the top of the regenerator dense bed of FCC catalyst in the FCC regenerator, and maintaining a reducing atmosphere in a lower one-half portion of the dense bed of FCC catalyst in the FCC regenerator and converting in the reducing atmosphere at least a portion of the NO/sub x/ formed during coke combustion to nitrogen.
Assignee:
Mobil Oil Corp., New York, NY
Patent Number(s):
US 4812431
OSTI ID:
5951308
Country of Publication:
United States
Language:
English