煤燃烧过程生成氮氧化物前驱体的研究

The formation of Nox precursors (HCN and NH3) during the coal combustion at 400 ℃～900 ℃ was investigated in a fluidized bed reactor made of quartz tube, in which the concentration of HCN and NH3 was measured by an ion chromatogram system and the coal combustion characteristic under the air atmosphere was analyzed by a TG-DTA (Thermogravimetry-Differential Thermal Analysis) system. The results show that the nitrogen in the coal can produce high proportion of HCN and NH3 during combustion. In the temperature range 400 ℃～500 ℃, about 50%～70% of coal-N was transformed to HCN and NH3. It can be clearly seen that not only the volatile-N of coal but also the char-N can produce NOx precursors. It is very different from the pyrolysis experiments at same temperature. The combustion of coal sample at temperature higher than 700 ℃ will yield less NOx precursors due to the increase of HCN and NH3 transformed to NOx.