温度作用下考虑过剩吸附的煤岩吸附模型

Research on a modified model for adsorption of methane on coal under temperature effect considering excess adsorption

为研究深部开采下煤岩吸附特性,利用等温吸附试验仪器开展不同温度下等温吸附试验,基于吸附热理论建立温度作用下考虑过剩吸附的煤岩吸附模型(改进的L—F模型),通过试验结果与模型预测结果对比验证其有效性。试验结果显示:煤岩吸附瓦斯属于物理吸附,且为放热反应,随瓦斯吸附量增加,煤岩等量吸附热逐渐下降;随瓦斯压力升高,在较低压力段中煤岩瓦斯过剩吸附量呈先快速增加后逐渐平缓的趋势,在较高压力段中过剩吸附量呈先增加后逐渐减小的趋势,随温度升高煤岩瓦斯吸附量逐渐减小。结果表明:相比常规模型(L、双L模型),改进的L—F模型对试验数据拟合效果较好,且能更好地预测不同温度下煤岩瓦斯吸附量。

In order to study the adsorption characteristics of coal in deep mining,isothermal adsorption of methane on coal experiments were carried out at different temperatures by using an isothermal adsorption device. Based on the theory of adsorption heat, an adsorption model considering the correction of temperature and excess adsorption( the modified L-F model) was built,and its effectiveness was verified by comparing the experimental results with the predicted by the model. The results show that the adsorptionof methane on coal is a physical adsorption process,an exothermic reaction,that the adsorption heat decreases with the increase of adsorption volume,that the methane excess adsorption on coal is a nonelinear function of methane pressure, that the methane adsorption volume gradually decreases with increasing temperature,and that compared with the conventional adsorption models( L and dual-site L model),the modified L-F model fits the experimental data and can better predict the methane adsorption volume on coal at different temperatures.