Formation of N2O in Circulating Fluidized Bed Boilers

The N20 formation in circulating fluidized bed boilers is assumed to be influenced by two formation routes, either by char or by hydrogen cyanide originating from the fuel volatiles. A test program was carried out with the purpose of better understanding the formation routes. The test program consisted of step response tests in a 12-MW circulating fluidized bed boiler. Concentration profiles of 02, CO2, CO, NO, HCN, NH3, and C1 to C3 hydrocarbons in the combustion chamber of the boiler were also measured in order to support the conclusions of the step response tests. The importance of the two routes is discussed, but no definite conclusions can be drawn about their magnitude