Abstract: The commercial application of denitration additive TUD-DNS3 in FCC unit of SINOPEC-SK（Wuhan）Petrochemical Co. Ltd. was introduced. The results demonstrated that when the mass fraction of this additive accounted for 2.6% of total catalyst inventory，the ammonia nitrogen content in the effluent water of flue gas desulfurization unit reduced from 100 mg/L to less than 40 mg/L；the addition of additive lowered the furnace temperature of CO incinerator，and the emission of flue gas was qualified. No adverse effect on the operation of the plant, the product distribution and the qualities of gasoline and diesel products were found.

Key words: denitration additive, fluid catalytic cracking, ammonia nitrogen