煤焦油二次热解过程中HCN及NH3释放特性研究

The HCN and NH3 formation during tar secondary pyrolysis for four Chinese coals was investigated with a two stage fixed-bed quartz reactor at 600 ℃～1 000 ℃. The influences of coal rank，ash content and temperature were examined. With the increase of coal rank，the nitrogen in coal tar decreases and the conversion of nitrogen to HCN and NH3 decreases. The conversion of nitrogen to HCN and NH3increases with temperature, and HCN reaches the highest yield in the range of temperature from 800 ℃ to 900 ℃. The presence of ash in coal can reduce the content of nitrogen in tar, which gives rise to the decrease of the yield of HCN and NH3 during the secondary pyrolysis of tar.