Fang Shuhao, Zhu Hongqing, Gao Min, He Xin, Liao Qi, Hu Lintao
School of Emergency Management and Safety Engineering, China University of Mining and Technology-Beijing, Beijing, China.
Sci Rep. 2022 Feb 24;12(1):3117. doi: 10.1038/s41598-022-07118-2.
To ascertain the evolution of pore characteristics and methane adsorption characteristics of the unit cell of Nanshan 1/3 coking coal under different stresses, proximate analysis, ultimate analysis, solid-state C nuclear magnetic resonance spectroscopy (C-NMR) and X-ray photoelectron spectroscopy (XPS) experiments were performed on the coal samples, and a molecular unit cell model of 1/3 coking coal was established. As the increase of stress, pore diameter, proportion of larger pores, number of pores, surface area, and pore volume all decrease, the rate of decrease gradually decreases, and the smaller pores are less affected. Under 8 kinds of stress, the methane adsorption capacity and the overall system energies all conform to the Langmuir adsorption curve; as the stress increases, the methane adsorption capacity and the overall system energies both decrease, the rate of decrease gradually decreases, and the order of the adsorbed methane increases. Stress changes the methane adsorption capacity by changing the pore characteristics of the unit cell, and the stress has a more obvious effect on larger pores. As the stress increases, the speed of the stress's influence on the pores weakens. This has certain guiding significance for studying the saturated adsorption capacity of methane under different original in-situ stresses.
为确定南山1/3焦煤晶胞在不同应力下孔隙特征及甲烷吸附特征的演化规律，对煤样进行了工业分析、元素分析、固态碳核磁共振光谱（C-NMR）和X射线光电子能谱（XPS）实验，并建立了1/3焦煤分子晶胞模型。随着应力增加，孔径、大孔比例、孔隙数量、比表面积和孔容均减小，减小速率逐渐降低，小孔受影响较小。在8种应力作用下，甲烷吸附量和体系总能量均符合Langmuir吸附曲线；随着应力增加，甲烷吸附量和体系总能量均减小，减小速率逐渐降低，吸附甲烷排序增加。应力通过改变晶胞孔隙特征来改变甲烷吸附量，且应力对大孔的影响更明显。随着应力增加，应力对孔隙的影响速度减弱。这对研究不同原始地应力下甲烷饱和吸附量具有一定指导意义。
