Liang Yuehui, Shi Biming, Yue Jiwei, Zhang Chengcheng, Shen Xiaojing, Hu Tao, Han Qijun
School of Safety Science and Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001, China.
Technology Research and Development Platform for Disaster Prevention and Control Technology of Deep Coal Mining, Anhui University of Science and Technology, Huainan 232001, China.
ACS Omega. 2024 Mar 25;9(14):16176-16186. doi: 10.1021/acsomega.3c10156. eCollection 2024 Apr 9.
The gas desorption characteristics of coal are closely related to the gas content of the coal seam. The gas in heavy hydrocarbon-rich coal seams contains CH and CH heavy hydrocarbons. However, most current research on the gas desorption characteristics of coal seams focuses on CH analysis, ignoring the influence of the CH heavy hydrocarbon gas. To accurately determine the gas content of a heavy hydrocarbon-rich coal seam, methods based on CH analysis are inadequate and the desorption characteristics of CH-CH mixed gas must be clarified. This work experimentally and theoretically studies the desorption characteristics of single-component gas and CH-CH mixed gas from coal samples. The results show that increasing the adsorption-equilibrium pressure was found to increase the desorption quantity and desorption speed of single-component gas and increase the desorption quantity, desorption ratio, and diffusion coefficient of mixed gas. Under the same adsorption-equilibrium pressure, the desorption quantity and rate of single-component CH gas exceeded those of CH. The quantity and speed of mixed gas desorption increased with rising CH concentration and decreased with rising CH concentration. The change in the mixed gas concentration during desorption reflects the distribution characteristics of light hydrocarbon components on the outer surface and heavy hydrocarbon components on the inner surface of coal. From the desorption characteristics of mixed gas, desorption models of mixed gas were obtained at different concentrations, laying a theoretical foundation for accurate determinations of gas contents in heavy hydrocarbon-rich coal seams.
煤的瓦斯解吸特性与煤层瓦斯含量密切相关。富含重烃的煤层瓦斯中含有CH和CH重烃。然而，目前大多数关于煤层瓦斯解吸特性的研究都集中在CH分析上，忽略了CH重烃气体的影响。为准确测定富含重烃煤层的瓦斯含量，基于CH分析的方法并不充分，必须阐明CH-CH混合气体的解吸特性。这项工作从实验和理论上研究了煤样中单组分气体和CH-CH混合气体的解吸特性。结果表明，发现增加吸附平衡压力会增加单组分气体的解吸量和解吸速度，并增加混合气体的解吸量、解吸率和扩散系数。在相同的吸附平衡压力下，单组分CH气体的解吸量和解吸速率超过CH。混合气体解吸的量和速度随CH浓度升高而增加，随CH浓度升高而降低。解吸过程中混合气体浓度的变化反映了煤外表面轻烃组分和内表面重烃组分的分布特征。从混合气体的解吸特性出发，得到了不同浓度下混合气体的解吸模型，为准确测定富含重烃煤层的瓦斯含量奠定了理论基础。
