[Ten years of major development in chemical equipment] 847-2016 Localization of air-cooled reactors for methanol plants in Nanjing Guochang Chemical Technology

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Datang Duolun Coal Chemical Company's original single-series 1.68 million tons/year methanol plant introduced technology from Germany's Lurgi Company and adopted a low-pressure series methanol synthesis process route. Because the air-cooled methanol reactor in the unit needs to be replaced, Datang Nenghua Company and Duolun Coal Chemical Company, after multiple inspections and meetings, selected Guochang Company as the preferred partner for the localization of the synthesis reactor of the large-scale methanol unit, and jointly implemented localized technological transformation of the air-cooled methanol reactor in the methanol unit. The entire equipment of the project lasted more than 6 months from design to manufacturing. It overcame technical difficulties such as tube plate processing, tube and shell pressure testing, gas distribution box welding and other technical difficulties in the internal equipment manufacturing process. The manufacturing task was completed in September 2014, and it was officially put into operation in June 2015. At present, the air-cooled methanol reactor performs well and the synthesis system operates smoothly. The operating process parameters and production capacity of domestically produced equipment meet or exceed the design level of imported equipment. After nearly a year of stable operation, the 1.68 million tons/year methanol plant gas-cooled reactor localization technology project jointly completed by Nanjing Guochang Chemical Technology Co., Ltd., Datang Energy and Chemical Co., Ltd., and Datang Inner Mongolia Duolun Coal Chemical Co., Ltd. has reached and surpassed foreign technical levels in terms of total system resistance, internal temperature distribution, gas flow and other technical indicators. On May 13, 2016, the project passed the scientific and technological achievements appraisal organized by the China Petroleum and Chemical Industry Federation in Beijing. After a 72-hour on-site assessment by an expert group organized by the China Petroleum and Chemical Industry Federation, the key data of the device met the contract requirements. The net alcohol value of the air-cooled methanol reactor is 5.7%, reaching the design value ； The shell side (catalyst bed) resistance of the air-cooled methanol reactor is 0.18MPa, and the tube side resistance is 0.08MPa, which is better than the design specifications. ； The axial flow gas secondary distribution technology and the new involute gas box structure make the average temperature difference in the same axial plane at different latitudes less than 5℃, which is better than the assessment index. 　　The appraisal committee believes that the key equipment of this system is the first domestically produced large-scale air-cooled methanol reactor in China, which has successfully replaced foreign imported equipment. It has independent intellectual property rights, advanced and reasonable structural design, and has reached the international advanced level. The main innovation point of this domestically produced large-scale complete set of methanol technology is to adopt a modular design concept and develop an air-cooled methanol reactor module (including synthetic methanol reaction kinetics and thermodynamics, heat exchange unit calculation, fluid dynamics calculation, resistance calculation, etc.), and successfully applied it to the process and structural design of the air-cooled methanol reactor. ； It adopts a split structure of pressure-bearing shell and internal parts. The internal parts are suspended from the upper part of the shell. Parts with different temperatures can expand freely, ensuring high safety and reliability. ； Using secondary distribution technology and a new involute gas box structure, hot and cold gases are evenly distributed and the catalyst bed reaction effect is good. ； Adopting a new involute groove structure, the catalyst on the shell side is evenly filled and easy to load and unload. The first successful application of the new air-cooled methanol reactor in a 1.68 million tons/year methanol plant has achieved the goal of domestically producing large-scale core methanol reactors of this type and broke the monopoly of foreign technology on large-scale methanol synthesis units.