Zhu Mingyu, Jing Tieya, Yuan Haowei, Zhang Jian
National Key Laboratory of High-Efficiency Flexible Coal Power Generation and Carbon Capture Utilization and Storage, Huaneng Clean Energy Research Institute, Beijing 102209, China.
ACS Omega. 2024 Jul 29;9(32):34250-34258. doi: 10.1021/acsomega.3c08495. eCollection 2024 Aug 13.
Tectonic deformation significantly alters the physical structure of coals, holding great importance to the coal mining industry and coalbed methane. In this study, eight anthracite coal samples with varying degrees of deformation were collected to investigate the effects of tectonic deformation on the pore system and CH adsorption of anthracite coals. In addition, low-temperature gas adsorption (N and CO), Raman spectroscopy, and CH isothermal experiments were performed. The results revealed that coal samples with higher degrees of deformation exhibited larger ratios of D-band intensity to G-band intensity ( / ), indicating increased molecular defects induced by tectonic deformation. As the deformation degree of the coal samples increased, the mesopore volume increased from 0.00044 cm/g (primary coal) to 0.0019 cm/g (scaly coal). Conversely, the micropore volume tended to decrease with the increasing deformation degree of the coal samples. Moreover, the impact of deformation degree on the CH adsorption capacity of anthracite coals was complex. With the deformation degree increasing, the Langmuir volume initially decreased from 32.0 to 24.55 cm/g and then rose to 30.14 cm/g. This complexity arose from the differential effects of tectonic deformation on various pore types, where micropores and mesopores collectively determined the CH adsorption capacity of anthracite coals. This study analyzed the influence of tectonic deformation on the pore structure and CH adsorption capacity at the molecular level, providing valuable insights for evaluating the in situ CH content in anthracite coal seams.
构造变形显著改变了煤的物理结构，对煤炭开采行业和煤层气具有重要意义。本研究采集了八个不同变形程度的无烟煤样品，以研究构造变形对无烟煤孔隙系统和CH吸附的影响。此外，还进行了低温气体吸附（N和CO）、拉曼光谱和CH等温实验。结果表明，变形程度较高的煤样表现出更大的D带强度与G带强度之比（/），表明构造变形导致分子缺陷增加。随着煤样变形程度的增加，中孔体积从0.00044 cm/g（原生煤）增加到0.0019 cm/g（鳞片煤）。相反，微孔体积倾向于随着煤样变形程度的增加而减小。此外，变形程度对无烟煤CH吸附能力的影响较为复杂。随着变形程度的增加，朗缪尔体积最初从32.0降至24.55 cm/g，然后升至30.14 cm/g。这种复杂性源于构造变形对各种孔隙类型的不同影响，其中微孔和中孔共同决定了无烟煤的CH吸附能力。本研究在分子水平上分析了构造变形对孔隙结构和CH吸附能力的影响，为评估无烟煤煤层原位CH含量提供了有价值的见解。
