METHOD OF FIRING BLACK LIQUOR IN RECOVERY BOILERS AND A RECOVERY BOILER FOR FIRING BLACK LIQUOR

摘要

Disclosed is a method for firing black liquor in arecovery boiler for obtaining fumes having a low content ofnitrogen oxides, the method comprising the step ofintroducing a portion of combustion air into the boiler ata distance above a black liquor inlet so as to provide areducing atmosphere with a residence time of at least aboutthree seconds between the black liquor inlet and theintroduction of the portion of combustion air, wherein thereducing atmosphere is generated without extra addition ofreduction gases.