利用发射光谱研究等离子体辅助下煤的气化机理

Study of coal gasification in arc plasma by the emission spectra

以水蒸气为气化介质,以空气为输送介质,研究等离子体辅助条件下煤的气化行为.考察了磁场线圈电流、空气流量、电弧的输入功率等工艺条件对煤气组成的影响,同时采用可见发射光谱技术对等离子体中的活性粒子进行诊断,探讨等离子体辅助下煤的气化机理.可见发射光谱研究表明H2,CO,CO2,O2的产量及C原子、CO+离子、CH自由基、H原子的相对峰强度随着磁场电流的增加出现一个最大值;随着空气流量的增加,CO,CO2,O2的产量逐渐增加;H2的产量随着C原子或H原子相对峰强度的增加而增加;随着电弧输入功率的增加,H2,CO的产量逐渐增加.

Coal gasification mechanism in stedium was investigated by optical emission spectroscopy(OES)and gas chromatography(GS).The emission intensities of active species were corrected with the gas yields quantitatively. It has been found that the yields of H2, CO, CO2 and O2 as well as the peak intensities of C atom, CO+ion, CH radical and H atom have a maximum with increasing the coil current. The yields of CO, CO2 and O2 increase while the yield of H2 and the peak intensities of OH radical C atom, H atom and CH radical decrease with the increase of the flow rate of carrier gas(air). Lastly, a possible mechanism of coal gasification is proposed on the basis of emission spectra measurements and products analysis under arc plasma conditions.