大尺度褐煤煤焦气化特性研究

Gasification characteristics of large size lignite-char

煤层气化是将地下煤层进行有控制的燃烧来获取清洁燃气的技术。本文针对煤层气化过程的特点,利用自行设计的气化实验平台,研究气化剂流量、温度、原煤粒径对大尺度煤焦-水蒸气气化反应碳转化率和反应速率的影响。结果表明:在一定范围内,随水蒸气流量的增加,同一反应时间内煤焦碳转化率增加,气化反应速率也增大。原煤粒径对其气化反应性的影响显著,但无明显变化规律。随着气化温度的升高,煤焦固定碳达到相同碳转化率所需时间逐渐缩短。反应速率常数k随温度升高逐渐变大,反应级数随温度升高降低。实验结果为煤层气化现场实验工艺条件的优化提供了理论参考。

Underground coal gasification （UCG） technology can achieve clean gas through controlling the combustion of coal seam underground. Based on the characteristics of coal seam gasification, char-steam reactions at elevated temperature are investigated kinetically using self-designed UCG-simulated gasifier. The effects of temperature, flow rate of steam and particle size of coal on gasification reaction are researched with relevant kinetic parameters. The results show that, in a certain range,with the increase of steam flow rate, the carbon conversion rate and gasification rate increase. The particle size of coal has a significant effect on gasification process, while no obvious change law is observed. The higher the gasification temperature, the shorter the time needed to reach the same carbon conversion rate. The constant of reaction rate k gradually increases with the rise of temperature, but reaction order shows the contrary trend. The results supply a theoretical reference to the optimization of process conditions in UCG.