Method of removing nitrogen oxides in exhaust combustion gases

摘要

In a method of removing nitrogen oxides non-catalytically from an exhaust combustion gas by maintaining said combustion gas at a temperature of from 700 DEG to 1300 DEG C in the presence of oxygen and an ammonia source in a combustion apparatus which has heat exchange surfaces in a zone downstream of the position where the ammonia source is added, the improvement which comprises feeding said ammonia source to the exhaust combustion gas at a position where the heat exchange surface area in the space downstream of the position of ammonia source addition which has a combustion gas residence time of up to 1 second is less than 0.5 x 10-2 m2 per 1 Nm3/H of said combustion gas flow; and the temperature of said combustion gas at the outlet of said space is above 700 DEG C.