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Accelerating the planning and construction of a new energy system and building a new pattern of energy system development is crucial for ensuring national energy security and achieving green and low-carbon transformation in China. On the basis of reviewing the development course of China’s energy system over the past ten years and grasping the current situation of the international energy field and the new goals of China’s energy development, this study clarifies the implications of a new energy system that is “safe and efficient,” “clean and low-carbon,” “multi-dimensional and collaborative,” and “intelligent and inclusive.” It explores the new energy system from the aspects of total energy consumption and structural evolution, security guarantee of coal, increase in reserves and production of oil and gas, and cost reduction and efficiency improvement of non-fossil energy sources. Moreover, a development strategy of adhering to systematic thinking, innovation, and reforms is proposed, as well as the construction goals of the new energy system by 2035 and 2050. Furthermore, key measures for the construction of the new energy system are recommended, including (1) promoting the green and low-carbon transformation of the energy sector, (2) promoting the coordinated development of urban and rural energy systems, (3) building a multi-drive energy-supply system, (4) strengthening research on key core technologies, and (5) establishing a new energy-evaluation system. The study is expected to provide theoretical guidance and practical support for the construction of the new energy system.

Energy is the lifeblood of the national economy. At present, China’s energy development situation is severe, and its external dependence on crude oil and natural gas is relatively high. Considering the national conditions of coal, strengthening the clean and efficient utilization of coal is strategically significant; specifically, the clean and efficient coal transformation is an important approach. This study summarized the status quo of clean and efficient coal transformation, and analyzed the high-end, diversified, low-carbon, and intelligent development trend of the industry as well as the technology development trends that include coal transformation to clean fuels, coal transformation to bulk and special chemicals, and pollutant control in coal transformation. Moreover, the study analyzed the development challenges regarding water resources, carbon emissions, product competitiveness, and supporting policies, and proposed a development idea that is led by planning, demonstration, and innovation. The research suggests that the strategic position of clean and efficient coal transformation in the energy system should be clarified, the national coal-to-oil-and-gas strategic reserve mechanism should be established, financial credit and energy statistics policy support should be strengthened, and the scientific and technological innovation ability should be improved by building research and development platforms.

The period before 2035 is critical for China to realize socialist modernization. The high-quality development of its energy industry must consider basic national conditions and development stages. Moreover, promoting the green and low-carbon transformation of the energy industry while guaranteeing a stable energy supply is the prerequisite for ensuring the sustainable economic and social development. This study summarized the current status of China’s energy development from six aspects: energy capacity, energy structure, comprehensive energy efficiency, energy science and technology, system and mechanism, and energy security. The key issues of energy development were analyzed, focusing on the role of coal for guaranteeing energy security, replacement of traditional energies with renewable energies for incremental energy consumption, sustainable supply of oil and gas, independent development of nuclear power, and large-scale development of the hydrogen energy industry. Four stages were proposed for the energy revolution and carbon reduction in China by 2035. Furthermore, we suggest that energy conservation should be prioritized in all aspects, clean and efficient use of coal should be promoted, renewable energies should be the major source of future energy increment, and low-carbon transformation should be accelerated to create an energy system that features multi-energy complementation.

The coordinated development of energy, economic society, and ecological environment has always been one of the major issues facing China. Although achievements have been made in some regions in China regarding the coordinated development, varied contradictions and problems still exist. Therefore, China should consider these significant differences in regional development while promoting energy revolution. This study elaborates the significance of regional energy revolution and analyzes the current status of economic society, energy, and ecological environment in the Beijing–Tianjin–Hebei region, Yangtze River Delta, Pearl River Delta, old industrial bases, the central region, energy-rich areas, and the Southwest in China. To promote the regional energy revolution, China should strengthen the top-level design for energy revolution and clarify the strategic objectives and key tasks for medium- and long-term development. A mode of well-planned and coordinated development should be established by clarifying the functions of regional energy revolution. The pilots of regional energy revolution should be promoted, thus to explore an efficient mechanism for the energy revolution. Moreover, the responsibilities of the regional governments should be clarified and an assessment and supervision mechanism should be established, so as to ensure that the regional energy revolution achieves expected effects.

Understanding the ignition mechanism of spontaneous combustion is critical for preventing it. In this work, the effects of different test conditions including oxygen concentration, heating rate, oxidation carrier gas flow rate, and sample amount on the ignition temperature were studied with a thermal gravimetric analyzer. Further, the effects of coal properties on the ignition temperature were also investigated using 15 different low-rank coals. A heterogenous ignition model was proposed that small amount of active species is the key material leading to ignition. The heterogenous ignition mechanism well explained the complex effects of test conditions and coal properties on the ignition temperature of low-rank coal. Finally, an empirical formula for predicting the ignition temperature was derived for the rapid assessment of the spontaneous combustion potential.

Low-rank coal contains abundant hydroxyl, carboxyl and alkyl side chains, and reactions related to these groups are the main reason for the spontaneous combustion of low-rank coal. Here, two different low-rank coals (BRXL, YJL52) are selected. Firstly, the ignition temperatures of the coals are determined by thermogravimetric method. Secondly, the coals are heated at 100°C temperature intervals before the ignition temperature in the thermogravimetry, and infrared measurement is performed to explore the changes of these groups. Combining previous studies in the literatures with infrared analysis, it is found that reactions related are as follows: phenolic hydroxyl converting into alcoholic hydroxyl, alcoholic hydroxyl further oxidizing to carboxyl, and carboxyl decarboxylating into alkyl side chains. After that, the changes of phenolic hydroxyl and carboxyl on the surface of the coal at 100°C temperature intervals are determined by titration, which further reveal the main reactions occurred in every temperature interval. Additionally, the actual heat release in different temperature ranges is discussed with the reaction enthalpies of the above-mentioned main reactions. As a result, the key temperature stage that causes spontaneous combustion is found. The screening study in this paper on the reaction of low-rank coal before spontaneous combustion provides a theoretical basis for the control of spontaneous combustion of low-rank coal.