A Refined Assessment Model of Methane Emission from Underground Coal Mining Based on Mining Methods and Measured Gas Contents

To address the limitations in the accuracy of existing methods for calculating greenhouse gas emission intensity from underground coal mining, this study develops a more precise model for estimating methane emissions. The model is grounded in the methane release mechanism of coal, and incorporates field-measured original gas content, residual gas content after extraction, and retained gas content following ventilation. The model defines the computational scope based on different mining methods (with and without coal pillars) and incorporates potential direct emission reduction measures applicable at various stages of the mining process. Case studies of both a high-gas mine and a low-gas mine reveal that, while the pillarless mining method increases total methane emissions, emission intensity is reduced. Furthermore, the study demonstrates that preventing the direct release of low-concentration methane from ventilation systems is critical for further emission reductions. Compared to existing methods, the proposed framework adopts a computational approach that reduces operational complexity while maintaining accuracy through the use of readily available field-measured data. These findings offer a scientific basis for formulating tailored emission reduction strategies in the coal mining sector.