| abstract |
Oxides of nitrogen (NOx) emissions from an FCC regenerator are reduced by operating the regenerator in partial CO burn mode to produce flue gas with more CO than O2 and with NOx precursors. This flue gas is then enriched with controlled amounts of oxygen and charged over catalyst, preferably Group VIII noble metal on a support, to convert most NOx precursors to nitrogen. Flue gas may then be charged to a CO boiler. Eliminating more than 90% of NOx emissions is possible by operating the FCC regenerator in partial CO burn mode, then adding air and catalytically converting NOx precursors at substoichiometric conditions. Conversion of NOx, if formed in the regenerator, may be achieved as well. |