Successful commissioning of the air separation turbine for coal-based olefins production at Zhongtian Hechuang

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Recently, the turbine of the air separation unit in the Zhongtian Hechuang project was successfully started up for the first time, marking another achievement of a key milestone in the project. This development creates favorable conditions for the first air separation unit to produce qualified oxygen and nitrogen by June 8th. At 8:16 p.m. that day, the order was given to start the turbine in Unit 116 of the air separation unit at the Zhongtian Hechuang project. The start button was pressed on site; as the control valves were slowly opened, the turbine gradually increased its speed to the warm-up speed of 1350 r/min. Once this speed was achieved, it was raised to the rated speed of 4504 r/min, until finally the overspeed test was conducted. Throughout the testing process, the machine operated normally and smoothly, with performance parameters such as temperature, vibration, and pressure meeting the technical requirements. The 6 sets of air separation units with a capacity of 82,000 standard cubic meters each at Zhongtian Hechuang were EPC-general contracted by Sinopec Ningbo Engineering Company. The civil construction work for these air separation units began on July 23, 2013, and full completion was achieved on September 30, 2015, with a total construction period of 800 days. The air separation plant consists of 6 air separation units and 1 backup system. Each air separation unit includes an air compression system, an air pre-cooling system, an air purification system, an expansion refrigeration system, a cryogenic tank and distillation system, as well as a product oxygen delivery system. It employs the process technology of the French company Air Liquide, and is equipped with imported air compressors, boosters, and steam turbines. Once completed, this facility will supply high-pressure oxygen required for the normal operation of the gasification unit, as well as high-pressure and low-pressure nitrogen needed for the proper functioning of the entire coal chemical and coal processing facilities. The Zhongtian Hechuang project is currently the world’s largest coal-to-olefins project. It is expected to be fully operational by 2016, and upon completion, the capacity for producing olefins from methanol will reach 3.6 million tons per year. The project utilizes the S-MTO technology developed through a collaboration between Sinopec Refining & Chemical Engineering and PetroChina Corporation. In 2013, the **National Development and Reform Commission approved the preliminary work for Zhongtian Hechuang’s 1.4 million-ton coal-to-olefins project. The total investment in the project is nearly 90 billion yuan. (Source: Huahua Net Coal Chemicals)