Formation of N2O in Circulating Fluidized Bed Boilers

The N2O 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 has been carried out with the purpose to better understand the formation routes. The test program consists of step response tests in a 12 MW circulating fluidized bed boiler. Concentration profiles of O2, 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 from the step response tests. The importance of the two routes is discussed but no conclusions can be made about their magnitude