Method for reducing emissions when burning nitrogen containing fuels

Abstract From the Canadian patent

The amount of N2O in flue gases discharged from a first fluidized bed combustion system is minimized by adding an N2O decomposing catalyst in a reactor stage downstream of the combustor. The catalyst preferably is a calcium based sorbent, such as CaO or limestone although NiO and other catalysts also may be utilized. Typically, the N2O decomposition takes place without increasing the temperature of the flue gases above the 700-1000°C level that exists in the combustor. However, under some circumstances if a, second fluidized bed is provided as the reactor stage, additional fuel and oxygen can be added to increase the temperature of the flue gases to insure that it is over 800°C After N2O …