Between destruction and creation in modern coal chemical industry

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How to achieve clean and efficient utilization of coal is an issue that cannot be ignored in the process of China’s energy revolution. Developing clean coal power and modern coal chemical industry are recognized as two viable paths. Against the backdrop of an already oversupplied coal power capacity, modern coal chemical industry is expected to play a more important role in the future development of coal. In the \"Action Plan for Innovation in Energy Technology Revolution (2016-2030)\) issued by the **National Development and Reform Commission** and the **Energy Administration**, strengthening innovation in technologies for the graded and high-quality conversion of coal, developing new technologies for the production of coal-based products, and enhancing the integration of coal chemical technology with other related energy technologies are listed as key tasks. The traditional coal chemical industry has a long history. In fact, modern chemical industry originated from coal chemical industry. Due to the characteristics of our country’s resource endowment, coal serves as the main source of energy and raw materials for the chemical industry in China, playing an undoubtedly important role in the development of the national economy and energy security. However, technological limitations have turned coal utilization into a major source of pollution for the environment and ecology. In the future, overcoming difficulties through technological progress and developing a new generation of coal chemical industries will be the only way forward. Modern coal chemical engineering is dedicated to the economic, efficient, and clean conversion and utilization of coal. By improving traditional coal chemical processes and enhancing their efficiency, developing new technologies and refining them, as well as integrating and coupling systems, coal chemistry can be combined with various related industries, thereby significantly increasing the efficiency of energy conversion. In conventional power systems, even with ultra-supercritical boilers, the energy conversion efficiency of coal is only 39%. If a conventional power system is combined with coal chemical engineering, using gasification-based cogeneration technology, the energy conversion efficiency is expected to reach 52%. The investment in modern coal chemical projects is enormous. For example, the investment budget for Shenhua Ningmei’s 4 million tons per year coal indirect liquefaction project amounted to 55 billion yuan, indicating inferior economic efficiency compared to petrochemical projects. Therefore, the slow industrialization of coal chemical industry has also, to some extent, restricted the pace of related technology research and development. Nevertheless, the coal chemical industry has still achieved some key technological breakthroughs in recent years. Coal gasification is key to modern coal chemical industry, as well as a challenge in it; its production capacity becomes the decisive factor limiting the overall capacity of the coal chemical industry. To enhance the gasification process, relevant enterprises in our country are actively exploring new technologies and processes in various demonstration projects. The daily processing capacity of gasification furnaces has now been increased to over 3,000 tons, with efforts underway to reach 4,000 tons. Thanks to technological advancements, the aforementioned Shenhua Ningmei 4 million tons per year coal indirect liquefaction project requires only 28 gasifiers. Another challenge in the coal gasification process is dealing with the complex and diverse range of coal resources. Most of the coal mined in our country is low-metamorphic coal, with a high proportion being high-alkali coal. Pre-treatment before gasification is a prerequisite for the proper operation of modern coal chemical processes. The reason why a domestic coal-to-gas project encountered problems in its early operation was a lack of understanding regarding the composition and properties of coal, as well as their impact on the gasification process. Alkaline substances such as potassium and sodium in high-alkalinity coal volatilize at high temperatures, eroding the inner wall of the reaction furnace. Large-scale development of the modern coal chemical industry requires in-depth characterization and analysis of coal, as well as the use of appropriate pretreatment methods, which are essential steps. Fortunately, for these problems that need to be solved, many research teams are currently working on them. The economic disadvantages require modern coal chemical industries to minimize the number of conversion steps as much as possible. Taking coal-to-olefins as an example, coal must first be gasified and purified to produce methanol from syngas, and then olefins are produced from methanol; the production process is quite lengthy. And with each additional step, there is some loss in efficiency. So, can olefins be produced directly from syngas? Recently, the prestigious British journal Nature confirmed that China has made significant breakthroughs in the research on direct olefin production from coal gasification. With the help of new composite catalysts, it is now possible to obtain low-carbon olefins through a single-step reaction, using the syngas produced by coal gasification, with high selectivity. This overturns the Fischer-Tropsch route that has been used in coal chemical industry for over 90 years. Admittedly, the relevant technologies are still some way away from industrial application, but they at least offer modern coal chemical enterprises a glimmer of hope for solving the problem. Overall, China’s modern coal chemical technology is already at the world’s leading level. However, the technical maturity of the entire industry chain still needs further improvement. Due to the downturn in economic development both domestically and internationally, resulting in weak demand for energy, as well as the fact that the validation and industrial demonstration of certain new coal chemical technologies require time, and that the cleanliness of the production processes needs to be improved, coupled with limitations related to the water resources necessary for the development of coal chemistry, China’s modern coal chemical industry is currently in a period of dormancy. After a period of technical exploration and accumulation, significant development is likely to occur. This significant development does not necessarily manifest in terms of scale and production capacity; it could be a major breakthrough at the technical level. And once breakthroughs are achieved in related technologies, issues such as cost-effectiveness and environmental pollution may be easily resolved. At present, China’s dependence on imported oil exceeds 60%, making energy security an issue that must be taken into consideration. For a country like ours that is rich in coal but poor in oil and gas, developing a modern coal chemical industry is of great strategic significance, as it allows coal to replace part of the oil used as fuel and raw material. For this very reason, **great emphasis has always been placed on the progress of coal chemical technology and its industrial development. In the **pilot projects under the key research and development program in 2016, research on technologies related to modern coal chemical engineering was listed as an important part of efforts to achieve clean and efficient utilization of coal as well as the development of new energy-saving technologies. However, relevant enterprises must remain rational in the process of industrial development, avoiding decisions that could disrupt its progress. Chinese enterprises tend to follow trends in a herd-like manner, which also poses a certain threat to the healthy development of the modern coal chemical industry. Some coal chemical products are already showing signs of overcapacity. Before making investment decisions, it is particularly important for companies to make a rational assessment of the market size, the progress of technological research and development, and their own competitiveness. Relevant policy makers also need to be rational. Especially when it comes to environmental protection, on the one hand, it is necessary to abandon the practice of neglecting environmental protection in pursuit of economic growth from previous years; on the other hand, extreme measures should also be avoided. In a society where people become nervous at the mere mention of coal, regulatory authorities need to find the right balance when formulating policies. It is undeniable that under current technological conditions, modern coal chemical industries generate certain levels of pollution, especially in terms of wastewater treatment; however, with strict management, pollutant emissions can be controlled. When formulating relevant environmental protection standards, seriousness must be maintained, so that companies can meet the requirements after making efforts in research and development, while those that fail to make such efforts are eliminated. Otherwise, the standards are too low to achieve the goal of driving technological progress in enterprises ； Excessively high standards force companies to either withdraw from the market or resort to fraud, just like Volkswagen did, which is not conducive to the development of the entire industry. The \"World and China Energy Outlook 2050\" published by the China Petroleum Economic and Technical Research Institute suggests that there will still be room for growth in the amount of coal used for coal chemical applications in the future, at around 150 million tons of oil equivalent. The Ministry of Environmental Protection has also resumed the approval process for environmental impact assessments related to modern coal chemical projects; coupled with the progress made in the Shenhua Ningxia coal project, this could bring some hope to the coal chemical industry. The modern coal chemical industry needs to seize opportunities, continuously overcome obstacles, and find breakthroughs in difficult situations in order to achieve sustainable development. (Xie Qiang is a professor and doctoral supervisor at China University of Mining and Technology (Beijing))