A Method for Carbon Emission Accounting in Underground Coal Mines and Emission Reduction Pathways through CCUS

Objective Coal production and utilization constitute a substantial source of global carbon emissions. While the carbon footprint of underground coal mines has attracted growing attention, research regarding systematic emission reduction pathways remains nascent.

Method This study employs Y Coal Mine as a case study. Employing life cycle assessment (LCA), emission factor methodologies, and monitoring-based approaches, we established the carbon accounting boundaries, identified emission sources, quantified total emissions, and delineated the mine's carbon emission profile. Drawing upon the principles and key technical elements of Carbon Capture, Utilization, and Storage (CCUS), and integrating the mine’s specific emission characteristics and geological conditions, a CCUS-based mitigation framework was constructed.

Results and Conclusions (1) The accounting boundary encompasses the entire lifecycle, spanning underground mining, washing, processing, and product transportation. Emission sources were classified into direct and indirect categories. Direct emissions primarily comprise greenhouse gases, specifically methane (CH₄) and carbon dioxide (CO₂), emitted during mining and post-mining operations, alongside emissions from fossil fuel combustion. Indirect emissions mainly originate from purchased electricity and water consumption. (2) Results indicate that the total annual carbon emissions of Y Coal Mine are 7.43×10⁵ t CO₂e. Notably, fugitive gas emissions represent the dominant source, accounting for approximately 6.74×10⁵ t CO₂e (90.8% of the total). In contrast, emissions from fuel combustion are negligible, totaling 728.56 t CO₂e (0.2%). Indirect emissions constitute approximately 9% of the total, driven primarily by electricity consumption (6.65×10⁴ t CO₂e) and water resource consumption (1.24×10³ t CO₂e). (3) The carbon emission profile of Y Coal Mine is characterized by a “methane-dominated” structure. Consequently, mitigation strategies should prioritize methane drainage, utilization, and fugitive emission control. This study presents a quantitative methodology for developing carbon emission accounting systems in underground coal mines. Coupled with the proposed CCUS-based mitigation pathway, this research offers theoretical support and practical references for the green, low-carbon transition of the coal mining industry.