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Commissioning of the air separation unit in Datang Fuxin coal-to-natural gas project / Author/Source: Huahua Network – Coal Chemical Industry / Date: 2019-08-27 / Views: 26 On August 23, good news came from the site of the Datang International Fuxin coal-to-natural gas project in Liaoning: Unit 2 of the air separation unit was successfully commissioned, and oxygen and nitrogen products were produced, marking a positive start for the successful operation of the first phase of the project. The first-phase project of Fuxin Company includes the construction of two KDON-48000/22500 type air separation units. Each unit has a production capacity of 48,000 Nm3/h of oxygen and 22,500 Nm3/h of nitrogen. It employs an air circulation system, a hydrogen-free argon production method, and a dual-pump internal compression process. The unit consists of a compression system, a pre-cooling system, a molecular sieve system, an expansion refrigeration system, a distillation system, a liquid storage and vaporization system, as well as an instrumentation and control system. Six years after the last time it was driven, the air separation unit is facing unprecedented difficulties and challenges. Prolonged idling of the unit leads to severe rusting of equipment and pipelines, as well as malfunctioning valves. Stone is used for sharpening, turning dullness into sharpness. The personnel in charge of air separation units took proactive actions and assumed responsibility; since the project resumed construction in 2018, they worked tirelessly to carry out various preparatory tasks prior to commissioning, such as the inspection and maintenance of air separation equipment, static testing of large-scale units, and cleaning of instruments and pipelines. By March 2019, the units were ready for commissioning. At 7:20 p.m. on August 16, the air separation unit began to be purged using high and medium pressure steam. On August 17, the single-turbine unit was tested and commissioned. At 8:30 a.m. on August 21, testing of Unit 2 of the air separation unit commenced; by 12:00 p.m., the compression unit had reached its rated speed. At 3:00 a.m. on August 22, the expander was started up, and the process of cooling, liquid accumulation, and purification began. By 3:00 a.m. on August 23, Unit 2 of the air separation unit was successfully capable of producing oxygen and nitrogen products. The Liaoning Datang International Fuxin Coal-to-Natural Gas Project was officially approved by the **National Development and Reform Commission on March 5, 2010. It is China’s third coal-to-natural gas project to receive approval from this commission. It represents the first project in Fuxin’s coal chemical industry cluster, as well as the largest investment project in Liaoning Province in recent years. It also serves as a landmark project for Fuxin, which is considered a pilot city for economic transformation in resource-depleted areas. The project covers an area of 354.35 hectares, with a construction scale of 4 billion cubic meters per year of coal-to-natural gas production (12 million cubic meters per day). It will be developed in three phases on a rolling basis, with each phase having a production capacity of 1.3 billion cubic meters per year. A series of construction projects officially commenced in July 2011; after going through initial construction phases and periods of delayed work, the project resumed on a full scale on April 12, 2018, entering a phase of rapid development. Datang Fuxin aims to ensure that the first-phase project is completed to high standards, undergoes testing of high quality, and begin gas production by the end of 2019. The coal used for project planning comes from the lignite produced by Datang Xilinhot Dongshengli No. 2 Coal Mine. The coal is processed using the pressurized gasification technology; through units such as low-temperature methanol washing, sulfur recovery, and methanation, high-quality natural gas is generated, while by-products such as tar, mixed benzene, crude phenol, sulfur, ammonium sulfate, and liquid ammonia are also produced simultaneously. The project also includes the construction of a natural gas pipeline with a total length of 344 kilometers. Once in operation, it will supply gas to Shenyang via the Fuxin–Shenyang main pipeline, and branch lines will be established from this main pipeline to supply gas to cities in central Liaoning such as Tieling, Fushun, and Benxi.