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Yanbian University and YanNeng explore new ways for the efficient utilization of low-grade cohesive coal through university-industry cooperation. Author/Source: Shaanxi Petrochemical News Network. Date: May 19, 2020. Clicks: 6. A new path has been found for the efficient use of low-grade cohesive coal in China. On May 17, the scientific and technological achievement of “Development of Technologies for the Resource Utilization of Low-grade Cohesive Medium Coal through Pyrolysis and Industrial Demonstration” underwent an evaluation organized by the Shaanxi Petroleum and Chemical Industry Federation in Xi’an. Experts believe that this technology introduces for the first time a conceptual approach for the resource utilization of low-grade coking coal through pyrolysis, opening up a new path for the efficient and selective clean utilization of such coal resources in China; it reaches an internationally leading level, and they recommend accelerating its industrialization. This technology was developed by the Yanneng-Yanda Comprehensive Energy Industry Technology Research Institute (Yan’an Cohen Energy Technology Co., Ltd.), established jointly by Yan’an University and Yan’an Energy and Chemical Industry (Group) Co., Ltd., with the industrial pilot production carried out by Zichang Chemical Co., Ltd., a subsidiary of Yan’an Energy and Chemical Industry (Group) Co., Ltd. “Taking into account the characteristics of low-rank coking medium coal, we utilize the synergistic advantages of low-rank coking coal and non-coking coal during medium- and low-temperature pyrolysis. By leveraging the differences in their caking properties, these two types of coal are combined in a suitable manner to complement each other’s strengths and maximize their synergistic effects during pyrolysis. ”Fu Feng, the director of the research institute and a professor at Yan’an University, explained that through joint efforts in recent years, they have developed a new type of five-stage moving-bed vertical pyrolysis furnace using gas as the heat carrier. This furnace features a structure comprising a drying stage, an upper pyrolysis stage, a middle pyrolysis stage, a lower pyrolysis stage, and a cooling stage. Using Yan’an Zichang cohesive medium coal and Yulin weakly cohesive or non-cohesive coal with particle sizes ranging from 0 to 50 mm as raw materials, the semi-coke (lancang) produced has high strength, high calorific value, and low sulfur content, making it suitable as a fuel for domestic use or as a raw material for gasification. The evaluation committee, headed by Li Wenhong, a professor at the School of Chemical Engineering at Northwest University, concluded that this technology introduces for the first time an approach to the resource utilization of low-grade cohesive medium coal through pyrolysis. The five-stage pyrolysis furnace employs a unique large-volume circulation process and multi-channel gas distribution method, which enables precise temperature control in different zones of the reactor and solves the problem of stabilizing the material flow pattern within the furnace. Through the operation and evaluation of industrial demonstration units, a complete technological innovation system for the resource utilization of cohesive medium-bituminous coal has been developed, enabling the clean and efficient utilization of this type of coal. It is understood that the Yan’an region in Shaanxi Province is rich in coal resources. The coal processed in Zichang City possesses high cohesion (with a G index of 45). Existing coal pyrolysis technologies in China all use coal with low or no cohesion as raw material, and thus are not applicable to coal with high cohesion. After the washing and processing of raw coal in Zichang, the refined coal is mainly used as feedstock for coking. The annual output of medium-grade coal from the intermediate products is over 2 million tons; at the same time, large amounts of coal gangue and coal slurry are generated as by-products. The volatiles content in Chinese coal ranges from 25% to 30%, while its oil content and ash content are as high as 9% and 20% respectively. It has strong cohesion, making it difficult to convert and utilize effectively; it can only be burned directly for power generation, which results in poor economic benefits and leads to waste of resources as well as environmental pollution. In September 2019, the Yanneng-Yanda Comprehensive Energy Industry Technology Research Institute and Yanneng Group’s Zichang Chemical Company built China’s first industrial-scale test facility for low-grade cohesive medium coal pyrolysis technology with a capacity of 15,000 tons per year in the Zichang Industrial Park. Subsequently, testing was carried out, including experiments on the proportion of medium coal – with this proportion reaching up to 70% – as well as tests on semi-coke gasification and coal gangue pyrolysis. During this period, a complete set of experimental data on the pyrolysis process as well as the key process parameters for industrial scale-up were obtained, leading to several key technological breakthroughs and innovations in process technology, key equipment, and technical theory. The performance evaluation results of the test unit show that the lignite carbon yield is 64.29%, the coal tar yield exceeds 6.19% (the low tar yield is due to the fact that the unit does not use electrostatic collectors for tar collection), the gas production rate is 1400 Nm3/h, with a calorific value of approximately 1500 kcal/m3, and the energy conversion efficiency reaches 88.09%. Since the cost of medium coal is much lower than that of traditional pyrolysis feedstocks such as weak-caking coal or non-caking coal, it offers high economic and social benefits. It is reported that Yan’an Energy and Chemical Group will leverage this technology sowie the region’s unique advantages in terms of binding medium coal resources, with plans to build a new industrial facility in Zichang for the comprehensive utilization of low-grade binding medium coal through pyrolysis, with an annual production capacity of 5 million tons.