【Analysis】There is a solution to the water resource constraints in coal chemical industry

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The inverse distribution of coal and water has always been a prominent feature of China’s resource endowment and a major constraint on the development of the coal chemical industry. However, in recent years, provinces and regions in the west such as Inner Mongolia, Ningxia, Gansu, Shaanxi, and Xinjiang have adopted the coal chemical industry as a driver for economic growth, establishing numerous coal chemical industry bases. According to available data, the four provinces of Shanxi, Shaanxi, Inner Mongolia, and Ningxia in the middle and upper reaches of the Yellow River account for 67% of the country’s coal resources, yet they only possess 3.85% of the nation’s total water resources. A large number of coal chemical enterprises are located in this region. Water is a major problem for the coal chemical industry. On April 16, 2015, the State Council officially issued the Action Plan for Water Pollution Prevention and Control, commonly referred to as the \"Ten Measures on Water Affairs\". The coal chemical industry has high water consumption, making wastewater treatment extremely important; the introduction of the \"Ten Measures on Water Management\" poses unprecedented challenges to this industry. The treatment of high-concentration wastewater from coal chemical industries will become more stringent. The high-concentration wastewater discharged from such industries contains extremely complex pollutant components, with many substances that are difficult to degrade; in addition, this wastewater includes various highly toxic substances such as monophenols, polyphenols, and sulfides. Due to differences in coal quality and processing methods, the levels and types of pollutants also vary. For example, the wastewater generated from fixed-bed gasification contains high levels of phenols; unlike wastewater from other types of gasification, it requires special treatment methods. At present, in terms of wastewater treatment, coal chemical enterprises still face numerous issues such as inadequate separation and collection, unreasonable treatment processes, and insufficient funding. “The \"Ten Measures on Water Management\" require that industrial wastewater from industrial zones must be pre-treated to meet the requirements for centralized treatment before it can be sent to centralized wastewater treatment facilities. When establishing or upgrading industrial clusters, pollution control facilities such as centralized wastewater and waste treatment systems should be planned and constructed simultaneously. If completion is not achieved by the deadline, the approval and authorization for construction projects that aim to increase wastewater pollutant emissions will be suspended, and their status as part of the industrial park will be revoked in accordance with relevant regulations. This imposes extremely high requirements on the rationality of the overall preliminary planning for the coal chemical industry. Wastewater treatment has become a key issue that must be considered in the planning of all coal chemical projects. Total water volume control will exacerbate the water resource challenges faced by coal chemical projects. In China, coal resources and water resources are distributed in opposite patterns: the five provinces (autonomous regions) of Shanxi, Shaanxi, Ningxia, Inner Mongolia, and Xinjiang have abundant coal resources, accounting for about 76% of the country’s total coal reserves, yet their total water resources account for only 6.14% of the national total. “The \"Ten Measures on Water\" also call for promoting the transformation and upgrading of the economic structure, as well as making efforts to conserve and protect water resources. Determine production based on water availability and control the total amount of water used. Compared to petrochemical processes, coal chemical processes consume significantly more water; the extremely high water usage per unit of product poses a serious constraint on the industry’s layout and development. According to statistics from relevant agencies, a coal-to-natural gas plant with an output of 4 billion cubic meters per year requires 26.9 million tons of water per year. A 600,000-ton/year coal-to-olefins plant consumes 27 million tons of fresh water per year. A coal-to-oil project with an annual production capacity of 1 million tons will consume around 6.6 million tons of water per year. This is equivalent to the water resources available per hundred thousand people, or the water resources available in an area of over 100 square kilometers. In water-scarce areas, the coal chemical industry’s extreme dependence on water resources has begun to encroach on water used for agriculture, domestic purposes, and other applications, making the situation increasingly difficult. So, what water-saving and water-management measures do coal chemical enterprises have at present? One is water-saving demonstration projects. Harbin Institute of Technology is researching some practical technologies aimed at achieving \"zero emissions\" in coal chemical projects. These technologies are already being used in the large-scale fertilizer production project at China Coal Ordos Tuk, where it is said that all water can be recycled, resulting in zero emissions. In April 2015, Xinjiang officially launched a technology and demonstration project for the treatment and resource utilization of coal chemical wastewater in arid regions. The project focuses on conducting systematic research on wastewater resource utilization and recycling technologies to address issues such as the large volume of wastewater generated in coal chemical industries, severe pollution, high energy consumption and difficulties associated with phenol and ammonia treatment, high treatment costs, as well as the challenges in ensuring that wastewater meets discharge standards and can be reused. Upon implementation, this project will play a positive role in promoting the development of coal chemical industry and the exploitation of resources in arid regions. Second, it is regulated through economic measures such as water rights. Water rights conversion has also become an important means to achieve efficient use of water resources. In simple terms, water rights conversion involves industrial enterprises that have a need for water and meet the relevant criteria investing in agricultural water-saving renovation projects, thereby obtaining the water rights associated with the water saved. Inner Mongolia has been listed as one of the national pilot provinces and regions for water rights. In recent years, Inner Mongolia has been exploring this innovative model, which has helped more than 30 chemical enterprises on the verge of closure due to water-related issues to revive, with coal-based chemical enterprises accounting for a large proportion of them. It is understood that the current cost of water rights conversion is 10–20 yuan per cubic meter for the transfer of Yellow River water resources across different regions. The Yellow River Water Resources Commission’s plans estimate that 8.65 yuan needs to be invested in water-saving projects for each cubic meter of water involved in such conversions. Based on the market prices of water rights and water itself, the price at which water can be transferred to users is 11.65 yuan per cubic meter. Coal chemical projects face significant environmental pressures; improper wastewater treatment can easily lead to water pollution, which in turn can result in a \"water-quality-related water shortage.\" In addition, coal chemical projects also face the problem of high water consumption. In the future, water-saving technologies will be widely applied in coal chemical industry, such as the use of water-saving processes and equipment; the replacement of water cooling with air cooling; the reuse of recycled water; and the recovery of condensate. The water consumption per unit of product reflects the water usage level of coal chemical plants; it is only by reducing this figure that real progress can be achieved. Using systematic water-saving optimization analysis methods to guide water conservation is worth promoting. In the northwestern region, water is the factor that restricts the development of coal chemical industry; this represents a dilemma of conflict and unity between economic interests and environmental considerations. Managing the relationship between these two is the path to healthy development in the coal chemical industry. (China Coal Resources Network)