【Major Industrial Equipment in the Chemical Industry】030 – China’s first large-scale oxidation-dehydrogenation facility for producing butadiene: screw-type compressor for generating butadiene gas

Jiangsu Sierbang Petrochemical Co., Ltd.’s 100,000 tons per year styrene plant was successfully commissioned for the first time, producing polymer-grade styrene products. This marks the success of the first domestic large-scale screw-type butadiene generation gas compression unit developed and produced by 711 for this project. Butadiene has reactive chemical properties and polymerizes very easily at high temperatures. The gas generation compressor is a key equipment in the butadiene plant; any failure of it will result in the shutdown of the entire butadiene production facility, causing losses of millions of yuan per day. Previously, the imported units used by domestic petrochemical enterprises were expensive, had long delivery times, and their supply of key technologies and major components, as well as operational services, were dependent on foreign countries, which had an adverse impact on the development of China’s butadiene industry. In 2009, commissioned by the Sinopec Office for the Localization of Major Equipment, Institute 711 took on the project to develop domestically produced DMF-extracted butadiene gas compressors, marking the beginning of the localization of butadiene production units. After its successful development, the project was put into use at Sinopec Maoming Branch, setting multiple industry firsts. In 2014, Unit 711 took on the project for compressing the gas produced by Sierbang Petrochemical’s butadiene plant. This was the first set of screw-type compressors of its kind in China for use in large-scale oxidation-dehydrogenation processes to produce butadiene; the annual production capacity of each production line increased to 100,000 tons per year. This was the first time such technology was used in China, and the project involved a large number of equipment, complex processes, high temperatures, and significant technical challenges. The inlet gas flow rate of this generated gas compressor reaches 824 m3/min, which is the highest processing capacity among screw-type process gas compressors available in China at present. At the same time, butadiene has very strict requirements regarding temperature control, which poses new challenges for the design of the gas generation compressors. The Screw Machinery Division of 711 Institute dedicated specific efforts to research and development, successfully mastering the key technologies for the design and manufacture of large-scale screw compressors. It also made breakthroughs in areas such as temperature control technology, main unit structure design, shaft seal design, bearing design, and shaft system dynamics analysis. The successful development of this project not only fills a gap in the domestic market but also plays an important role in helping manufacturing enterprises shorten project timelines and save costs.

The 【Haichuan Equipment Guessing】 series is being updated continuously in 2022; all Haichuan community members are welcome to participate actively! https://bbs.hcbbs.com/thread-2079686-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum) Summary post on the series 【Major Equipment in the Chemical Equipment Industry】 https://bbs.hcbbs.com/thread-3312079-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum) Summary post discussing the components of cracking furnace equipment for 【Ethylene Cracking】 https://bbs.hcbbs.com/thread-3308724-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum)

Butadiene, as the most important petrochemical raw material in the C4 fraction, is widely used in the production of chemical products such as rubber, resins, coatings, and nylon. Industrially, the production methods of butadiene include: the C4 fraction separation method, the synthetic method, and the dehydrogenation methods (including butane dehydrogenation, butene dehydrogenation, and butene oxidative dehydrogenation, etc.). The gas compression unit is one of the key equipment in the process of producing butadiene via the oxidation dehydrogenation of butylene. In the butylene oxidation unit, the gas compressor used for gas generation is located between the cooling tower and the aldehyde washing tower. Its main function is to compress the mixed gas, making it easier for the solvent oil to absorb the pressurized mixed gas and thereby separating out the C4 components. The butadiene mixture transported by the gas compressor includes mainly butadiene, butylene, butane, nitrogen, a small amount of oxygen and oxygen-containing compounds. Since butadiene contains 2 unsaturated double bonds, it is highly prone to self-polymerization at high temperatures, even posing a risk of explosion; therefore, the selection of the appropriate equipment is crucial. As one of the few compressors capable of temperature control via liquid injection, the screw compressor has become the best choice for gas generation compressors. In the early days, the single-line capacity of oxidation-dehydrogenation units for producing butadiene built in China was only 25,000 t/year, and the gas generators were primarily equipped with small domestic oil-free screw compressors. With the trend toward larger-scale chemical plants, large-scale process gas compressors have become a technical bottleneck for such plants. At the end of 2012, following thorough expert evaluation, domestic development of this equipment was undertaken for a 100,000 t/a oxidation-dehydrogenation butadiene production plant in China, in order to address the critical supply constraints.