A breakthrough has been achieved in my large-scale isothermal transformation device

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It boasts excellent operational metrics and good economic benefits. Source: China Chemical Industry News. On June 30, Hebei Yangmei Zhengyuan Chemical Group Co., Ltd. announced that the ZY-type isothermal shift technology, which was developed by the company and for which it holds full intellectual property rights, has been successfully applied in the “60-80” project at Cangzhou Zhengyuan Fertilizer Co., Ltd. – a project with an annual production capacity of 600,000 tons of synthetic ammonia and 800,000 tons of urea – for over two years now. This technology has also passed the evaluation of scientific and technological achievements conducted by the China Petroleum and Chemical Industry Federation. Experts unanimously agree that this technology exhibits excellent industrial performance indicators, is stable and reliable, and has reached international advanced levels, marking a significant breakthrough in large-scale isothermal transformation technology in our country. 　　After 72 hours of continuous operation testing of the isothermal shift unit for ammonia synthesis conducted by industry experts, the results showed that the localization rate of this unit was 100%. The ammonia synthesis output averaged 2,186.3 tons per day. Under a gas-to-vapor ratio of 0.52, the CO content at the outlet of the isothermal shift unit was 6.95%, and the pressure drop across the isothermal shift reactor was 0.018 MPa; all these parameters met or exceeded the design requirements. 　　It is understood that the gasification process in Zhengyuan Company’s “60-80” large-scale ammonia synthesis project utilizes a spacecraft furnace gasification technology. The CO content in the dry basis crude gas exceeds 65%, and the adiabatic shift reactor undergoes shift reactions under conditions of high CO content and high water-gas ratio, making it difficult to control the furnace temperature and prone to \"temperature spikes\". If the heat of reaction can be removed in some way simultaneously with the reaction, the problem of high bed temperature can be solved. Heat exchanger tubes in isothermal conversion furnaces can remove the heat of reaction in a timely manner, making them an appropriate solution to this issue. 　　It is reported that this technology is a large-scale isothermal shift technology developed independently, utilizing Zhenyuan Company’s own patented \"tube-type reactor\" technology along with experience gained from the use of fixed-bed atmospheric pressure gasification shift systems. To better regulate the temperature of the catalyst bed, a non-uniform tube arrangement is used in the bed heat transfer device, which brings the reaction temperature closer to the optimal curve. This helps to increase the reaction rate, improve conversion rates, reduce the amount of catalyst required, and maximize heat recovery. At the same time, the company has also developed a patented multi-vessel technology, with the reactor equipped with at least two layers of tube banks, each connected to its own vessel. The saturated temperature of the circulating water is controlled by producing steam at different pressures in the drum, thereby further reducing the final reaction temperature of the isothermal shift reactor to meet the requirements of deep conversion and shortening the conversion process. 　　Liu Jincheng, vice chairman of Yangmei Zhengyuan Company and the project’s overall supervisor, told reporters that this project is applied to the largest ammonia synthesis plant currently in operation in China, and it represents the first installation to use an isothermal shift process with a CO content of over 65%. The diameter of the isothermal shift reactor equipment is 4000 mm, with a design pressure of 4.2 MPa. Its continuous operation has basically met the expected objectives; it has resolved the problem of overheating in the adiabatic bed catalyst layer, resulting in a low CO content at the outlet as well as a low temperature of the shifted gas at the outlet. 　　The isothermal shift reactor and its catalyst frame adopt an axial-radial structure, while the gas distribution channels and gas collection channels use a “π”-shaped structure, ensuring uniform gas distribution ； The heat exchange tubes of the internal components feature a small-arc tube sheet structure, with all heat exchange tubes having the same length ； It features a center-extractable design for easy removal of the catalyst. 　　In addition, the internal components of the isothermal transformation furnace feature an arc-shaped heat exchange tube bundle structure, without large tube sheets or flanges, ensuring uniform catalyst distribution ； The heat exchange tubes have uniform lengths, which reduces the difficulty of processing, lowers the cost of the equipment, and facilitates scaling up and modularization ； A small flange hole is provided at the top of the outer cylinder to facilitate the assembly and maintenance of the internal components ； The bottom of the inner component features a flexible connection, facilitating the removal of the catalyst. 　　Compared with traditional adiabatic conversion processes, this technology features a simpler process flow and easier operation; it allows gas to be introduced at low pressure and low load, significantly reduces startup time, and the lower operating temperatures of the equipment and pipelines lead to reduced power consumption, thereby lowering production costs ； High-temperature equipment and pipelines have been significantly reduced, greatly improving the safety performance of ammonia synthesis plants. Calculations show that with this isothermal transformation process, the output of high-quality steam increases by approximately 16.4 t/h, and compression energy consumption is reduced by about 333.3 kW/h. This translates to an increase in ammonia production of around 4 kW per ton. The direct economic benefits resulting from annual operation amount to 10.26 million yuan, while the indirect economic benefits over a long operating period are 2.376 million yuan per year.