초록 ▼

Oxides of nitrogen (NO.sub.x) emissions from an FCC regenerator are reduced by operating the regenerator in partial CO burn mode and controlled turbulent/laminar flow processing of the flue gas. Partial CO burn FCC catalyst regeneration produces flue gas with CO and NO.sub.x precursors. Air is added

Oxides of nitrogen (NO.sub.x) emissions from an FCC regenerator are reduced by operating the regenerator in partial CO burn mode and controlled turbulent/laminar flow processing of the flue gas. Partial CO burn FCC catalyst regeneration produces flue gas with CO and NO.sub.x precursors. Air is added to a turbulent flow reactor such as a flue gas transfer line where most NO.sub.x precursors are homogeneously converted while leaving some CO unconverted. A downstream CO boiler thermally converts this unconverted CO. NO.sub.x emissions are less than would be experienced using a like amount of air injection to a conventional CO boiler.

대표청구항 ▼

[ I claim:] [1.] A catalytic cracking process for cracking a nitrogen-containing hydrocarbon feed comprising:a. cracking said feed in a cracking reactor with a source of regenerated cracking catalyst to produce catalytically cracked products which are removed as a product and spent catalyst containi

[ I claim:] [1.] A catalytic cracking process for cracking a nitrogen-containing hydrocarbon feed comprising:a. cracking said feed in a cracking reactor with a source of regenerated cracking catalyst to produce catalytically cracked products which are removed as a product and spent catalyst containing nitrogen-containing coke;b. regenerating said spent catalyst in a catalyst regenerator by contact with a controlled amount of air or oxygen-containing regeneration gas at regeneration conditions to produce regenerated catalyst which is recycled to said cracking reactor and regenerator flue gas;c. removing from the regenerator the regenerator flue gas stream comprising volatilized NO.sub.x precursors, at least 2.5 mole % carbon monoxide and more carbon monoxide than oxygen on a molar basis;d. adding air or oxygen containing gas to the regenerator flue gas flowing in a transfer line turbulent flow reactor operated between 1100.degree. F. and 1800.degree. F. and at a vapor velocity above 15 m/see to produce oxygen enriched flue gas in turbulent flow;e. homogeneously converting at least 25 mole % of volatilized NO.sub.x precursors, but less than 75 mole % of said CO, in said oxygen enriched flue gas in said turbulent flow reactor to produce homogeneously converted flue gas containing CO and a reduced content of volatilized NO.sub.x precursors; andf. burning said homogeneously converted flue gas in a CO boiler operating at CO combustion conditions including the injection of a stoichiometric excess of oxygen or oxygen containing gas and a vapor velocity lower than said vapor velocity in said turbulent flow reactor to produce product gas with less than 0.5 mole % CO, more oxygen than CO, and a reduced NO.sub.x content as compared to the NO.sub.x content of a like regenerator flue gas burned in a CO boiler to a like CO and oxygen content.