O formation was studied at different temperatures on a bench scale fluidized bed reactor for three different kinds of coals.Special attention was paid to N 2O formation during coal devolatilization and char combustion.Test results indicate that the transformation rate of N 2O depends much on coal rank in different stages of coal combustion.There is a high transformation rate of N 2O during combustion of volatile matter.The higher the volatile content
the lower the transformation rate of N 2O.The most inportant factor influcing N 2O emission is the temperature in furnace.