Coal methane control and its emission reduction potential in China

Methane is the most important non-CO₂ greenhouse gas, which has attracted more and more attention. Coal methane is the most important methane emission source in China, and China is also the country with the largest amount of coal methane emissions in the world. Therefore, the effective emission control and the efficient development and utilization of coal methane have triple benefits, such as greenhouse gas emission reduction, energy gas development and utilization, and hazardous gas control. Based on the accumulation of systematic investigation and research, the background of coal methane emission control was summarized and conclusion was made for the coal methane emission and its control all over the world and in the representative countries. Besides, the process of coal methane development, utilization and its emission control, as well as the development trend in China was explained. Then, the path and potential of coal methane emission reduction in China were discussed and looked forward. The current researches have shown that the coal methane emission in China mainly comes from the underground coal mining in the form of ventilation air methane, which will also be the main source of coal methane in China for a long time. With the increase of closed mines in China, the coal methane emissions from closed mines will increase, which is a key coal methane source that cannot be ignored in China. With the proposal of "carbon neutrality" goal by China, the policy guidance of greenhouse gas emission reduction has gradually become the focus of the coal methane emission control in China, and the direction of coal methane emission reduction was also clarified. Through the coal methane emission control, the key technology path has been formed in China, which is characterized by the full concentration utilization of coal methane, including the exploration, exploitation and utilization of coalbed methane, the drainage and utilization of coalbed methane in closed or abandoned coal mine, and the utilization of ventilation air gas in the full life cycle before, during and after coal mining. In China, coal methane emission control still faces great pressure and severe challenges with many problems of policy, system and technology to be solved urgently. Thus, the major development directions of the coal methane control in China include the efficient exploration and development technology system of coalbed methane breaking through the adaptability to complex geological conditions, the accurate, digital and intelligent low-carbon efficient drainage technology system of coal mine gas, the emission reduction control and utilization technology system of coal methane in the closed/abandoned coal mine, and the comprehensive utilization technology system of full-concentration coal methane.