【Ten Years of Rapid Development in Chemical Equipment】The coal-based nitrogen fertilizer co-production with LNG and liquid nitrogen washing process 2263-2025 has passed evaluation

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Let’s give praise and encouragement to the achievements made in China’s chemical engineering technology and equipment; your participation in discussions is the greatest encouragement. **********************【Ten Years of Progress in Chemical Engineering Equipment】Continuous updates and summaries are available; feel free to join the discussions: https://bbs.hcbbs.com/thread-3576046-1-1.html ***************** The coal-based nitrogen fertilizer production process combined with LNG and liquid nitrogen washing is at the leading level in China. On March 25th, this process, developed and put into industrial use by Hubei Jinkong Gas Co., Ltd. (abbreviated as Jinkong Gas Company) and Hangzhou Zhongtai Cryogenic Technology Co., Ltd., passed the technical achievement evaluation organized by the China Nitrogen Fertilizer Industry Association in Dangyang, Hubei. After conducting the evaluation, the expert panel headed by Gu Zongqin, president of the China Nitrogen Fertilizer Industry Association, unanimously concluded that this technology is at the leading level in China and recommended its widespread adoption in the nitrogen fertilizer industry. It is reported that the main technological innovations of this process are as follows: first, the methane distillation tower and the nitrogen washing tower are integrated within a cold box, enabling gas purification and refinement as well as the production of LNG products; this approach results in fewer processing units and a more compact layout. Secondly, the MRC refrigeration + lithium bromide pre-cooling process is used to provide cooling capacity for liquid nitrogen washing, resulting in significant energy savings. Third, this process unit offers great operational flexibility, a short startup time, and low startup costs. According to Luo Junjie, general manager of JinKong Gas Company, in the coal-based nitrogen fertilizer production process that utilizes fixed-bed coal gasification technology, the characteristics of this gasification method result in a crude gas containing 8%–12% methane. As methane is a high-value product, it is crucial to choose an appropriate process to separate methane from the crude gas during its purification process so that it can be extracted as a product. In current industrial processes, methane is typically extracted in the liquid nitrogen washing stage, where it is cryogenically liquefied into LNG. After comprehensive evaluation, the JinKong Gas liquid nitrogen washing process involves adding a methane distillation tower to the cryogenic tank, thereby enabling the purification of gases and the liquefaction of methane within that cryogenic tank. The resulting LNG is stored in product tanks for sale, with a methane content of up to 99.5% in the LNG product. This process enables the direct extraction of LNG products while ensuring the purification of the feed gas, thereby significantly reducing the capital costs for plant construction as well as the ongoing operational and maintenance expenses. Luo Junjie explained that in the liquid nitrogen washing process, the system needs to continuously supply cooling capacity to maintain a balance of cooling power, making the selection of the refrigeration method particularly important. Different refrigeration processes are suitable for various applications and have different energy consumption levels, which exert varying impacts on a company’s production and operations. The project of JinKong Gas Company adopts a mixed refrigerant cooling system; the cycle using mixed refrigerants can significantly reduce energy consumption, offering a significant advantage. Compared with the traditional liquid nitrogen washing process, by first producing CNG and then generating LNG through compression refrigeration, the overall energy consumption per unit of LNG produced is reduced by nearly 30%. The methane in the feed gas is separated through a cryogenic distillation process using liquid nitrogen, resulting in methane of higher quality; it meets the standards for lean liquids in LNG **standards, with a methane content of over 99%. Luo Junjie said that since its operation began in 2024, Jincheng Gas Company has processed over 1.5 billion cubic meters of raw gas in total, producing 500,000 tons of synthetic ammonia and 100,000 tons of LNG products, while reducing carbon dioxide emissions by 1.2 million tons. This process innovatively combines liquid nitrogen washing with methane liquefaction, using the MRC refrigeration technique to supply additional cooling, thereby enabling gas purification and LNG production to be carried out simultaneously. Compared to traditional processes, the number of devices is reduced by 30%, the production layout is more compact, there is greater operational flexibility, and the startup cost is lowered by 40%. The expert group noted that the project is well-documented and relies on reliable data. For the production of synthetic ammonia along with LNG using coal dust, coke oven gas, and other raw materials, this process technology offers advantages such as advanced technology and low costs, making it worthy of widespread adoption. Industrial applications have already been realized, and similar technological innovations are driving the transformation of traditional coal chemical industries toward greener and lower-carbon models.