Fluidized bed combustion
This patent describes improvement in a process for the fluidized bed regeneration of coke containing fluidized catalytic cracking (FCC) catalyst having an average particle size and an average settling velocity in an FCC regenerator operating in conjunction with an FCC reactor and conventional FCC catalyst and wherein oxygen or an oxygen containing gas is added to a single, dense phase fluidized bed of the FCC catalyst particles the dense bed comprising a lower one half and an upper one half, and wherein coke on the FCC catalyst is burned in the dense bed to produce regenerated catalyst, heat and a flue gas containing CO, CO{sub 2}, O{sub 2} and NO{sub x}. The improvement comprises: adding a CO combustion promoter in an amount sufficient to increase the combustion of CO to CO{sub 2} in the dense bed, the CO combustion promoter being disposed on particles, with most of the promote particles, by weight, having a particle size within the range of 20--50 microns and a density at least 10% greater than the density of the conventional FCC catalyst and a settling velocity which is smaller than the settling velocity of the average particles in the dense phase fluidized bed whereby the CO combustion promoter segregates in the dense phase fluidized bed so that at least 60% of the combustion promoter is present in the upper one half of the dense bed and maintaining a reducing atmosphere in the lower one half of the dense bed and converting therein at least a portion of the NO{sub x} produced during combustion to nitrogen in the reducing atmosphere.
- Assignee:
- Mobil Oil Corp., Fairfax, VA (USA)
- Patent Number(s):
- A; US 4997800
- Application Number:
- PPN: US 7-322753
- OSTI ID:
- 5383388
- Country of Publication:
- United States
- Language:
- English
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