Another achievement for \"Made in China\" in methanol production: domestic production of large-scale methanol gas-cooled reactors

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Another success for \"Made in China\" in methanol production: domestic production of large-scale methanol gas-cooled reactors Author/Source: China Chemical Industry News Date: May 19, 2016 Clicks: 8 After nearly a year of stable operation, the project to develop domestic technology for gas-cooled reactors in methanol production facilities with an annual capacity of 1.68 million tons, carried out jointly by Nanjing Guochang Chemical Technology Co., Ltd., Datang Energy Chemical Co., Ltd., and Datang Inner Mongolia Dolun Coal Chemical Co., Ltd., has achieved technical parameters such as overall system resistance, internal temperature distribution, and gas flow rate that are on par with or even exceed those of foreign technologies. On May 13, the project passed the evaluation of its scientific and technological achievements in Beijing, organized by the China Petroleum and Chemical Industry Federation. The appraisal committee believes that the key equipment of this system is China’s first domestically produced large-scale air-cooled methanol reactor; it has successfully replaced imported foreign equipment, possesses independent intellectual property rights, features an advanced and rational structural design, and reaches international advanced standards. Lü Zhongming, chairman of Nanjing Guochang Company, told a reporter from China Chemical Industry News that it took over 6 months to develop and manufacture all the equipment for this project; various technical challenges were overcome, including those related to the processing of tube sheets during the manufacturing of internal components, pressure testing of the tube and shell circuits, and welding of gas distribution boxes. The manufacturing process was completed in September 2014, and the equipment was put into operation in June 2015. Currently, the air-cooled methanol reactor is performing well, and the synthesis system is operating smoothly. The operational parameters and production capacity of domestically produced equipment meet or exceed those designed for imported equipment. Following 72 hours of on-site assessment by an expert panel organized by the China Petroleum and Chemical Industry Federation, the key parameters of the plant met the requirements specified in the contract. The alcohol purity in the air-cooled methanol reactor is 5.7%, meeting the design value ； The pressure drop in the shell side (catalyst bed) of the air-cooled methanol reactor is 0.18 MPa, and that in the tube side is 0.08 MPa, which is better than the design specifications ； The axial flow gas secondary distribution technology and the new involute-type gas box structure ensure that the average temperature difference within the same axial plane at different latitudes is less than 5°C, which exceeds the specified requirements. It is reported that Datang Duolun Coal Chemical Company originally had a single-series methanol production facility with an annual capacity of 1.68 million tons; this facility utilized technology provided by the German company Lurgi and adopted a low-pressure series combination process for methanol production. Due to the need to replace the air-cooled methanol reactor in the facility, Datang Energy Chemical Company and Dolun Coal Chemical Company, after conducting various investigations and holding discussions, selected Guochang Company as the preferred partner for the localization of this large-scale methanol plant’s synthesis reactors, with the aim of jointly carrying out technical upgrades to make these reactors domestically produced. It is reported that the main innovation of this domestically developed large-scale methanol technology lies in its modular design approach; modular gas-cooled methanol reactor units were developed (covering aspects such as the reaction kinetics and thermodynamics of methanol synthesis, heat exchange unit calculations, fluid dynamics calculations, and resistance calculations), and these were successfully applied to the process and structural design of gas-cooled methanol reactors ； It features a split structure with a pressure-resistant housing and internal components; the internal components are suspended above the housing, allowing components with different temperatures to expand freely, thereby ensuring high safety and reliability ； By utilizing quadratic distribution technology and a new type of involute-shaped gas box structure, the hot and cold gases are distributed evenly, resulting in excellent reaction performance in the catalyst bed ； With a new type of involute groove structure, the catalyst in the shell side is evenly distributed and easy to install and remove. Lü Zhongming said that the successful first application of the new air-cooled methanol reactor in a 1.68 million tons/year methanol plant achieved the goal of scaling up the production of such core methanol reactors domestically, breaking the foreign technology monopoly over large-scale methanol synthesis plants. 　 News link: The development of domestic methanol production. The world’s advanced methanol synthesis industry relies on large-scale plants, with each plant typically having a production capacity of several million tons per year; the largest plants currently have an annual production capacity of 2.25 million tons. China’s methanol industry began in the 1950s, and high-pressure methanol synthesis plants were built in Lanzhou, Taiyuan, and Jilin using zinc-chromium catalysts based on former Soviet technology. During the 1960s and 1970s, the Wujing Chemical Plant in Shanghai built methanol synthesis units using coke and naphtha as raw materials. The Research Institute of Nanjing Chemical Industry Company developed medium-pressure copper-based catalysts for the simultaneous production of ammonia and methanol, which promoted the industrial development of ammonia synthesis coupled with methanol production. In the 1970s, the Sichuan Vinylon Factory introduced China’s first low-pressure methanol synthesis unit, which used acetylene off-gases as raw material and employed the ICI low-pressure cold-quenching synthesis process. In the mid-1980s, Qilu No. 2 Chemical Plant introduced a Lurgi low-pressure methanol synthesis unit that used residue oil as raw material. After the 1990s, with the rapid growth in demand for methanol, hundreds of methanol and dimethyl ether production facilities were built using both imported and domestic technologies, leading to unprecedented progress in methanol production in China. In 2010, China’s annual methanol production capacity was 37.5 million tons, accounting for about 50% of the world’s total capacity. Its production volume accounted for around 32% of the global total, while its apparent consumption accounted for approximately 45% of the world’s total consumption, making it the largest producer and consumer of methanol in the world. According to incomplete statistics, China’s annual methanol production capacity reached 76.7 million tons in 2015, and it is expected to reach 98.68 million tons by 2020. China’s synthetic methanol industry has grown from nothing to something substantial, expanding rapidly over more than 20 years. Today, the latest technologies used in China’s small and medium-sized synthetic methanol plants (with a capacity of 300,000 tons per year) are generally at the world’s advanced level. However, large-scale methanol production facilities in China with a capacity of millions of tons have not yet been fully localized; significant efforts are still needed in areas such as large-scale methanol production processes and large reactors in order to break foreign monopolies in this market. In 2011, China’s first domestically produced gas-cooled methanol synthesis reactor successfully passed hydraulic and pneumatic tests at CNNC’s Xinhe Company; the strength and sealing performance of the equipment met the requirements specified in the drawings and relevant standards. This air-cooled synthesis reactor was developed on the basis of adapting the British David process. With the same volume per individual unit, it requires less material in total, its weight is reduced by nearly 30%, production energy consumption is significantly lowered, while output is greatly increased.