Formation of N2O in a Circulating Fluidized-Bed Combustor

Artikel i vetenskaplig tidskrift, 1993

Formation of N20 was studied in a circulating fluidized bed boiler by means of injection of CH3CN, NH3, or NO to various locations in the combustion chamber. The resulting changes in the emissions of NO and N20 were registered and the formation of N20 was estimated by means of the measured reduction (from similar experiments with injection of N20 to the combustion chamber). This was done while burning fuels with high as well as low volatile content: wood chips, bituminous coal and metallurgical coke. The results show that homogeneous gas-phase reactions are important for the formation of N20 despite the high particle loading in the combustion chamber. Cyanides show a higher tendency to form N20 than ammonia. The concentration of NO and char are also important factors contributing to the formation of N20.