"After the realization of intelligent N00 mine, the ventilation of the mine will be canceled, and coalbed gas can be extracted simultaneously while mining coal, achieving gas co-extraction. This has important strategic significance for ensuring national energy security, promoting energy conservation and emission reduction, and achieving the "30∙60" dual carbon goals as soon as possible," said He Manchao, a member of the National Committee of the Chinese People's Political Consultative Conference, Academician of the Chinese Academy of Sciences, and Professor at China University of Mining and Technology (Beijing) in an interview with reporters.

Coalbed gas is a high-quality clean energy that exists in coal seams and their surrounding rocks, coexisting with coal. China has rich reserves of associated coalbed gas, with resources of 36.8 trillion cubic meters of coalbed gas within 2000 meters deep, ranking third in the world. He Manchao stated: "Currently, the coalbed gas and coal mining systems in China are separated, with coalbed gas extraction mainly relying on drilling and depressurization; coal mining mainly uses the European and American 121 method (mining one working face, driving two tunnels, leaving one coal pillar). During the coal mining process, coalbed gas is directly discharged through the ventilation system, which not only leads to a significant loss of coalbed gas resources but also causes the random discharge of coalbed gas to produce carbon dioxide, exacerbating the greenhouse effect."

National Committee member of the Chinese People's Political Consultative Conference, Academician of the Chinese Academy of Sciences, Professor He Manchao from China University of Mining and Technology (Beijing)

Coal and coalbed methane are originally associated and symbiotic resources. According to He Manchao, the current gas separation mining method has the following prominent problems in terms of resources, environment, safety, etc.: firstly, the separation and mining of symbiotic resources results in high repeated investment costs. At present, both coal and coalbed methane mining require a large number of tunnel excavation or drilling projects to be carried out in advance. According to statistics, for every 10000 tons of coal mined in China, an average of 34 meters of roadway length needs to be excavated. Based on the coal production of 3.84 billion tons in 2020, the annual amount of roadway excavation is about 13000 kilometers, and the annual investment cost for roadway excavation is as high as 100 billion yuan. However, the exploitation of coalbed methane did not fully utilize the coal mining channels and instead carried out complex processes such as drilling, completion, and fracturing, with an investment of over 100 billion yuan, large repeat investment, long preparation time, and high exploitation costs. The second issue is the low extraction rate of coalbed methane and the serious waste of resources. According to the national average gas content of about 10 cubic meters per ton in coal seams, China's domestic coal production reached 3.84 billion tons in 2020, and the coalbed methane reserves can reach 38.4 billion cubic meters. According to statistics, in 2020, China's coalbed methane production was only 10.08 billion cubic meters, with a recovery rate of only 26%. Most coalbed methane is often not utilized but directly discharged, resulting in waste of coalbed methane resources. The third is the direct discharge of coalbed methane, which damages the ecological environment. Behind the direct emissions of coalbed methane is a large amount of greenhouse gases entering the atmosphere, which produces a greenhouse effect 20 times that of carbon dioxide and has a destructive power on the ozone layer 7 times that of carbon dioxide. This will pose a threat to the environment and hinder the achievement of the 2030 carbon peak and 2060 carbon neutrality goals. The fourth is that gas resources turn into disasters, causing gas explosion accidents.
He Manchao suggested that China's independently developed intelligent N00 mine complete set of technology and equipment can automatically form all underground tunnels while mining, making the intelligentization of the entire mine possible. For this reason, he suggested that firstly, the intelligent coal gas co mining N00 method should be listed as a major scientific and technological plan, and special efforts should be made to promote the innovation and research of the basic theory and key technologies of the intelligent coal gas co mining N00 method. The second is to establish a new model of intelligent mine development layout for coal gas co mining, form a comprehensive system for coal mining and gas extraction, preliminarily establish industry standards for intelligent coal gas co mining, improve coal and coalbed methane extraction rates while reducing carbon emissions in the coal industry, and strive to achieve the "30-60" dual carbon goal of the coal industry. Thirdly, relevant departments should support tax policies for coal and coalbed methane resources, encourage Chinese coal enterprises to use the intelligent coal gas co mining N00 method while ensuring safety, conduct pilot engineering experiments, and link the coal and coalbed methane extraction rates with tax policies. According to the current extraction rates, relevant tax preferential policies should be provided to support the extraction of more coal and coalbed methane resources.
Website Editor: Gong Li