浑源煤焦CO_2气化反应的影响因素及动力学特性分析

Factors Influencing CO_2 Gasification of Hunyuan Coal Char and the Kinetic Characteristics

研究了热解温度、热解时间以及气化温度对浑源煤焦CO2气化反应的影响,并获得了气化反应的动力学模型.结果表明:浑源煤焦的气化活性随热解温度的提高而降低;每个热解温度都对应着一个最佳热解时间,且存在最佳热解时间随温度升高而缩短的趋势;提高气化温度能够显著提高煤焦的气化反应性能,气化温度对气化反应的影响大于热解温度的影响;低温度煤焦的气化活性随气化温度的提高而增加更为剧烈;900℃及以上的高温使活性点数增加,从而使煤焦间的活性差距分布均匀;浑源煤焦的气化反应适宜用体积模型来描述,所求取的动力学参数之间存在补偿效应,其等动力学温度约为1 199.6℃.

The effect of pyrolysis temperature,coke-forming time and gasification temperature on the CO2 gasification of Hunyuan coal char was studied,during which a dynamic model was obtained for the gasification reaction.Results show that the gasification reactivity of Hunyuan coal char decreases along with the increment of temperature.There may exist an optimal pyrolysis time at a specific temperature,which may decrease with the increment of gasification temperature.Improving the gasification temperature can remarkably increase the gasification reactivity,on which the gasification temperature has a stronger impact than the pyrolysis temperature.The gasification reactivity of coal char formed at lower pyrolysis temperatures increases obviously with rising gasification temperature.When the gasification temperature gets above 900 ℃,the gasification reactivity of coal char will have a slight change.It is recommended to use volumetric model to describe the gasification process of Hunyuan coal char,compensation effect exists among the kinetic parameters,in which the iso-kinetic temperature has been computed to be 1 199.6 ℃.