Methods for estimating carbon emissions from coals in underground mines: A case study of the western Fukang mining area

Carbon emissions have come into sharp focus of human society. The carbon emissions from coals rank as the most predominant part of China’s total carbon emissions. Presently, there is no available study on the accurate calculation of carbon emissions from coals in typical underground mines in Xinjiang, with the CH₄ emission even overlooked. This study centers on the carbon emissions from coals in underground mines in the western Fukang mining area. As per the occurrence laws of CH₄ and CO₂ in coal seams, as well as coal mining plans, this study classified the sources of carbon emissions from coals (excluding the emissions from fossil combustion, power generation, and thermal supply) into four parts: carbon emissions from coals mined, planned coals to be mined, unrecovered coals, and underground coal pillars. Based on this, the total carbon emissions from coals were calculated. The findings include: (1) based on the average mining years of underground mines, the carbon emissions from coals mined, planned coals to be mined, unrecovered coals, and underground coal pillars were calculated at 21700 t/a, 53500 t/a, 4000 t/a, and 7400 t/a, respectively, totaling 86600 t/a. (2) Given that the four types of carbon emission sources are in the order of planned coals to be mined > coals mined > underground coal pillars > unmined coals, this study suggested conducting gas extraction before coal mining, strengthening filling to inhibit emissions from unmined resources and coal pillars, performing comprehensive recycling and utilization of gas of different concentrations to reduce carbon emissions in the process of coal mining. (3) The carbon emissions from coals in the underground mines are primarily influenced by the total coal production (sum of coals mined and planned coals to be mined), the CH₄ and CO₂ content in coal seams, desorption rate, and the metamorphic degree of coals. These carbon emissions increase with the values of these four factors. The results of this study will provide suggestions for controlling carbon emissions from coals and determining measures for carbon emission reduction in the western Fukang mining area.