He Jun, Wang Bohao, Zhang Gang
College of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo 454003, China.
ACS Omega. 2024 Nov 1;9(45):45117-45126. doi: 10.1021/acsomega.4c05701. eCollection 2024 Nov 12.
CO injection into coal seams not only enhances coalbed methane (CBM) extraction but also allows for CO sequestration. Microwave irradiation is considered to be an effective technology to enhance CBM extraction. In this paper, the effects of microwave irradiation and supercritical CO immersion on the pore structure of low-rank coals were investigated by scanning electron microscopy (SEM), mercury-in-pressure (MIP), low-temperature nitrogen adsorption (LTNGA), and carbon dioxide isothermal adsorption/desorption (COIA/D) of coal samples. The results showed that the macropores and micropores of the coal samples were more developed after microwave irradiation. After carbon dioxide immersion, the coal samples showed huge fissures, and the meso- and micropores were reduced. In contrast, microwave-assisted carbon dioxide not only reduced the specific surface area in the meso- and microporous stages and decreased the adsorption sites of methane but also enhanced the pore connectivity in the macroporous stage instead of the appearance of huge fissures. This study illustrates the potential of microwave-assisted supercritical carbon dioxide for enhanced coalbed methane extraction and carbon dioxide sequestration.
向煤层注入二氧化碳不仅能提高煤层气（CBM）的开采效率，还能实现二氧化碳封存。微波辐射被认为是提高煤层气开采效率的有效技术。本文通过扫描电子显微镜（SEM）、压汞法（MIP）、低温氮吸附（LTNGA）以及煤样的二氧化碳等温吸附/脱附（COIA/D），研究了微波辐射和超临界二氧化碳浸泡对低阶煤孔隙结构的影响。结果表明，微波辐射后煤样的大孔和微孔更加发育。二氧化碳浸泡后，煤样出现巨大裂缝，中孔和微孔减少。相比之下，微波辅助二氧化碳不仅降低了中孔和微孔阶段的比表面积，减少了甲烷的吸附位点，还增强了大孔阶段的孔隙连通性，而没有出现巨大裂缝。本研究揭示了微波辅助超临界二氧化碳在提高煤层气开采和二氧化碳封存方面的潜力。
