System and method of decreasing no x emissions from a fluidized bed reactor

摘要

NOx emissions are decreased in a combustion system which consists of an enclosure (28) for receiving particulate materials including a nitrogen-containing particulate fuel. The fuel is burned in the enclosure. A duct (34) is connected to the upper portion of the enclosure. An oxygen-containing, fluidizing gas is introduced into the lower end of the enclosure to support combustion of the particulate fuel and to fluidise the particulate materials. Flue gases entraining particulate materials are evolved and pass upwardly and through the duct. The duct is disposed so that the gases tend to pass through a first portion of it adjacent to a first side wall and the particulate materials pass through a second portion adjacent a second wall of the duct. A reactant is selectively introduced into the first portion of the duct for decreasing the NOx levels in the flue gases passing through the duct.