Viewing the fixed-bed batch gasifier objectively

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An Objective View of Fixed-Bed Batch Gasifiers Author/Source: Sinochem News Network Date: 2021-03-17 Clicks: 38 Since 1958, through many challenges and successes, China’s fertilizer industry has developed from nothing to something, from small scale to large scale, from weak to strong, transforming the country from a fertilizer importer into a major producer and consumer of fertilizers. 　　For over 60 years, China’s fertilizer industry has ensured food security and laid a solid foundation for the development of agriculture, rural areas, and farmers, as well as for rural revitalization. Among them, coal chemical products such as ammonium bicarbonate, urea, and synthetic ammonia are indeed contributions made by the Chinese nation to the world. In this development process, the batch fixed-bed gasifier has played a crucial role. With the progress of the fertilizer industry, China’s batch fixed-bed gasifiers have also been continuously improved. Fertilizer companies have also made considerable efforts and gone through great difficulties in transforming their raw material supply chains as well as in implementing measures for safety and environmental protection. For example, the intermittent fixed-bed gas generator in Anhui Province has always been the key unit in the province’s coal chemical industry. The former Feixi Fertilizer Factory and Guoyang Fertilizer Factory, as well as today’s Jinhe Chemical Company, Huartai Chemical Company, Debang Company, Quansheng Chemical Company, Guotai Chemical Company, and others, have all achieved excellent results in reducing energy consumption. In particular, Jinhe Chemical Company has an ammonia production energy consumption of 1,050–1,100 kilograms of standard coal per ton. It can be said that significant progress has been made in current intermittent fixed-bed gas generation furnace technology, achieving mature processes, compliance with environmental standards, and safe and controllable operation. 　　In 2019, the **National Development and Reform Commission issued the \"Guidance Catalogue for Industrial Structure Adjustment,\" placing fixed-bed atmospheric gasification units in the list of technologies to be phased out. Policy documents issued by the People’s Government of Anhui Province, such as the \"Implementation Plan for the Three-Year Action Plan to Win the Battle to Protect the Blue Sky,\" also set requirements for fixed-bed gasification furnaces, which has had a significant impact on fertilizer production enterprises in Anhui Province and across the country. In response, the Anhui Chemical Industry Association adopted a pragmatic approach, engaging in learning and practice as well as conducting on-the-ground investigations, and specifically held symposiums for enterprises using the fixed-bed batch gasification process. Research has found that fertilizer enterprises in Anhui Province have carried out a great deal of effective work on intermittent fixed-bed gas furnaces, such as adopting DCS automatic control systems and automatic coal feeding systems; conducting secondary incineration of waste residues, and treating wastewater through physical and biochemical methods before discharging it in compliance with standards; using devices for desulfurization, denitrification, and ultra-low emissions for the three types of waste; installing wet electrostatic dust removal devices on furnaces that burn these wastes together; sealing the hot water tanks used in the gas production process to capture any escaping hot air for secondary combustion in the furnaces; reusing all process wastewater, as well as the concentrated wastewater resulting from water treatment processes, and adding additional devices for removing dust from this concentrated wastewater. 　　At present, some key coal chemical enterprises in Anhui Province use intermittent fixed-bed units in conjunction with new gas furnaces, in compliance with the relevant regulations set by ** and the province. However, since the beginning of this year, the shutdown of the intermittent fixed-bed units has led to reduced production capacity, rising fertilizer prices, shortages of fertilizers for spring plowing, and increased burdens on farmers. 　　In this regard, the author puts forward two suggestions. 　　First, ** and the relevant functional departments might consider reevaluating fixed-bed batch gasifiers and synthetic ammonia production technologies with a capacity of 300,000 tons per year or less. Regarding production processes, as long as they meet safety, environmental protection, and energy consumption standards, they should not be forcibly phased out in a one-size-fits-all manner. We can learn from and draw on the experience of Hebei Dongguang Chemical Company in implementing upgrades to fixed-bed batch gasification technology, and encourage the upgrading of existing fixed-bed batch gasifiers. 　　Second, it is recommended to organize specialized pilot projects for intermittent fixed-bed gasifiers. Funding can be raised in collaboration with the enterprise; advanced technologies can be examined and analyzed. After thorough discussion, evaluation, and summarization, reforms should be implemented promptly, with focused efforts directed at making improvements and using these successes as a model for broader application. 　　We must not forget our original intention of putting food production at the core and our mission to revitalize rural areas. On the one hand, we should appreciate the hard work of those who have been working in the fertilizer industry over the past 60 years; on the other hand, we must adhere to the principle of seeking truth from facts and keeping pace with the times, so as to jointly contribute to the high-quality development of this industry.