Experimental Investigation of the Effect of Microstructure on Coalbed Methane Adsorption Characteristics Affected by Chemical Solvents

作者：Chunshan Zheng, Shuaili Liu, Feilin Han, Bingyou Jiang, Yang Zhao, Zhongwei Chen · 发表于：Langmuir · 年份：2025 · DOI：10.1021/acs.langmuir.4c04081 · 被引用次数：9 · 研究领域：Coal Properties and Utilization、Hydrocarbon exploration and reservoir analysis、Methane Hydrates and Related Phenomena

Coalbed methane (CBM) reservoir modification based on chemical solvent treatment could change the coal microstructure, which further affects the adsorption capacity and flow characteristics of this clean energy. Coal samples were extracted by tetrahydrofuran (THF), carbon disulfide (CS 2 ), and hydrochloric acid (HCl). Low-pressure nitrogen adsorption, carbon dioxide adsorption, Fourier transform infrared spectroscopy, and methane isothermal adsorption test were adopted. The variations of pore structure and chemical composition in coal were evaluated by density functional theory, Barrett–Joyner–Halenda model, and peak fitting method, and their impacts on methane adsorption characteristics were studied. Results show that (1) the micropores less than 2 nm show a bimodal distribution. After acidification, micropore specific surface areas of coal samples I and II increase by 16.79% and 11.72%, respectively, while that of coal sample III-HCl decreases by 4.29% closely related to carbonate and silicate minerals in coal. Microporous specific surface areas of sample II-CS 2 and III-CS 2 affected by solvent rise by 4.28% and 4.17%, respectively. (2) Among the three original coal samples, the highest level of OH–OH hydrogen bonds content is observed. Solvents have a tendency to interact with −CH 2 groups, which shorten the length of fat chains and increase the number of branched chains. THF tends to dissolve C–O–C groups and carbonyl C═O groups. Following CS 2 treatment, samples II and...