Patent ID: 6206685
Filing Date: 2001-03-27
Classification: B01D,F23G,F23J

Abstract:
A method for decreasing the concentration of nitrogen oxides in a combustion flue gas, comprising the steps of:(a) providing a combustion zone adapted to react a combustible fuel and an oxidizing agent;(b) adding a combustible fuel and an oxidizing agent to the combustion zone to produce a combustion flue gas including nitrogen oxides;(c) introducing a first amount of a metal-containing additive into the combustion zone;(d) allowing the first amount of the metal-containing additive to react within the combustion flue gas to decrease the concentration of nitrogen oxides therein;(e) adding a reburning fuel to the combustion flue gas downstream from the combustion zone to form a reburning zone;(f) introducing a second amount of a metal-containing additive into the reburning zone; and(g) allowing the second amount of the metal-containing additive to react within the combustion flue gas in the reburning zone to further decrease the concentration of nitrogen oxides therein.