1. Study on biogenic methane generation mechanism and microstructure change characteristics under the recharge condition of aquiclude in the burning area of steep coal seam.
- Author
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Wang, Daxing, Tian, Jijun, Yang, Shuguang, Wei, Bo, Zou, Jiaqun, Li, Xin, Jia, Donglei, and Li, Liguo
- Subjects
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COAL , *COALBED methane , *CLUSTER sampling , *FUNCTIONAL groups , *METHANE , *ACETATES - Abstract
To enhance biogenic coalbed methane production, it is imperative to comprehend the processes by which methane is generated when microbes decompose coal in perched water zones situated in steeply inclined fire zones. Low-rank coal from Fukang mining was used to simulate biogenic gas production and investigate methane generation in perched water zones in steeply inclined coal fire zones. This study integrated characterization techniques, multifractal theory, and field data. Microbial activity increased oxygen-containing functional groups, reduced aromatic rings, and disrupted aliphatic clusters in samples. Aromatic nucleus interlayer spacing expanded; microcrystalline stacking, extensibility, and aromatic layers decreased. Coal structure degraded as microbes targeted aromatic then aliphatic carbon. Increased pore and fracture density enhanced pore connectivity (H) and reduced pore heterogeneity (△α), while pore types remained unchanged. Methane production via microbial degradation follows acetate and hydrogenotrophic pathways. Methane rates were affected by perched water zone distance, coal seam salinity, and pH. • Identified methane production mechanisms in steep coal seams under water recharge. • Microbial degradation improved pore connectivity and reduced heterogeneity in coal. • Biogenic methane generation via acetate and hydrogenotrophic pathways was confirmed. • Findings provide guidance for biogenic gas recovery in steeply dipping coal seams. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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