Some experiments were carried out on a small fluidized bed at 500~800 ℃ to explore the effect of Zhungeer coal ash on nitrogen transformation during pyrolysis of Zhungeer coal and Xiaolongtan coal. The results showed that

adding the coal ash reduced the yield of tar-N and promoted the generation of NH3 and HCN. After adding 300% ash

during pyrolysis of Zhungeer coal at 700 ℃

the yield of tar-N decreased by 16.7% while the yield of NH3-N increased from 4.0% to 5.6% and the yield of HCN-N increased from 1.5% to 5.5%. Coal ash significantly reduced the yield of char-N during pyrolysis of Xiaolongtan coal. The mechanism of coal ash in this study is that the ash heat carrier catalyzes the secondary decomposition of the tar when fully contacted with tar in the fluidized bed dilute phase. Coal ash can also catalyze the formation of NH3 by activating the char-N of Xiaolongtan coal.