EO/EG units, precious metal catalysts

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On July 13, 2023, a visit was made to the Chemical New Materials Industrial Park in Chapu Port; the EO/EG plant consists of three units: the oxidation unit and the EO and EG production units. The EO/EG plant uses high-purity oxygen and ethylene as raw materials to produce EO (ethylene oxide). Very high cleanliness standards are required for the reactors, as even a small amount of rust remaining in them can cause EO to polymerize, leading to dangerous situations. The catalyst used is a precious metal catalyst based on honeycomb ceramic. The oxidation section is the part where the feed materials are reacted; it is located at the front of the entire installation and constitutes its core. Tasks such as catalyst loading in the reactor, ensuring airtightness of the circulating gas, and managing the circulation of heat removal agents are all of utmost importance. Work such as sandblasting, endoscopy, installing sponge columns, thermal inspection, and catalyst loading. The installation quality of 5,513 reactor tubes meets the requirements. The EO unit is located in the middle of the entire plant; it serves as a link between upstream and downstream sections. Its main function is to absorb some of the by-products generated during the reaction, produce pure EO, and supply this EO to the next unit as a raw material for producing EG. The control of various parameters in the EO section, as well as pipeline cleanliness, is crucial. According to the startup procedure for the EG unit, it is necessary first to inject finished ethylene glycol into the EG unit in the rear section in order to start the circulation there; after that, oxygen is introduced into the front section, using a reverse startup method. The reverse driving scheme requires higher airtightness for the vacuum system. Immediately after the positive pressure airtightness test of the vacuum system is completed, the boiling tower stage begins. The installation team adopted a method of replacing the contents while the tower was in operation, thereby removing impurities such as grease from the tray surfaces and ensuring their cleanliness. After about a month, the reverse operation process of the EO/EG unit was finalized, allowing the production of qualified products; samples of the ethylene glycol products were taken for testing, and they met the standards for premium quality. Sanjiang Chemical Co., Ltd. (stock code: HK2198) is a wholly foreign-owned enterprise established in December 2003, mainly dealing in products such as ethylene oxide, surfactants, and polypropylene. The company currently possesses production facilities for ethylene oxide, surfactants, and polypropylene. It is a leader in the domestic private sector in ethylene oxide production, and it is also the largest manufacturer and supplier of AEO surfactants in China.