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The wastewater treatment plant for Zhongan United Coal Chemical Co., Ltd.’s project for producing 1.7 million tons per year of methanol and converted olefins has been fully built and put into operation. Author/Source: Coal Chemical Industry Information Network. Date: December 3, 2019. Clicks: 57. On November 28, 2019, good news came from Zhongan United Coal Chemical: the wastewater treatment plant for this project, which is one of Sinopec’s “Ten Dragon” technology development projects, has been fully completed and is now in use. 1. Assist resource-depleted cities in their transformation and development. As a key construction project of Sinopec and a major project in Anhui Province, the Zhongan Coal Chemical Integration Project has a total investment of 26.7 billion yuan. Once the coal-based methanol production facility with an annual capacity of 1.7 million tons, along with the related olefin conversion facilities, operated by Zhongan United Coal Chemical Co., Ltd., come online, they will play a significant role in promoting the economic transformation of Anhui Province and helping to build it into a strong industrial province. The chemical products produced by this project will help fill the demand for chemical raw materials such as polyethylene and polypropylene in the surrounding markets. The operation of this project not only extends the industrial chain but also contributes to the local economic development. It offers good economic, social, and environmental benefits. It has positive practical significance. 2 Enhance the internal quality of enterprises and achieve green development. It is understood that Anhui Province currently does not have any large-scale polyolefin manufacturing enterprises; Zhong’an United will fundamentally address this weakness in the region’s economic development, thereby helping to adjust, optimize, and upgrade the local industrial structure. Zhongan United Coal Chemical Co., Ltd. operates a methanol-to-olefins (MTO) plant with an annual production capacity of 1.7 million tons. The core technology of this MTO plant is the \"High-Efficiency Methanol-to-Olefins Full Process (S-MTO)\」patent technology owned by Sinopec, which utilizes methanol as raw material to produce low-carbon olefins such as ethylene and propylene, which in turn serve as feedstocks for downstream polypropylene and polyethylene production facilities. The C4 and C5 olefins, which have low added value, are converted into high-value ethylene and propylene products using OCC units. The treatment of saline wastewater at the end of the coal chemical process is particularly important. In this project, the high-salinity water unit, evaporation unit, and crystallization unit are used to treat the reverse osmosis concentrate from the clean wastewater stream. After further pretreatment, membrane concentration, evaporation, and crystallization to separate salts, most of the wastewater is recovered, yielding sodium chloride and sodium sulfate; a small amount of mother liquor is dried and transported away. The water produced by the high-salinity water treatment process is mixed with the water from the clean wastewater stream, and this mixture is reused as feedwater for the chemical water plant or as water for recirculation. The scale of the high-salinity water treatment system is 360 m3/h; the pretreatment section has a treatment capacity of 500 m3/h for the incoming water, while the membrane concentration section has a capacity of 3603 m3/h for the incoming water. The annual operating time is 8000 hours. The high-salinity water treatment project represents further purification of the wastewater generated by Zhong’an United Coal Chemical Plant. As a result, Zhong’an United has become the first to meet the **environmental assessment requirements set by the Ministry of Ecology and Environment for “zero emissions.” This ensures that no pollutants enter the Huai River under any circumstances, achieving true “pollution-free” and “zero-emission” discharge of coal chemical wastewater. It also contributes to China Petrochemical’s implementation of the green development concept that **“lucid waters and lush mountains are invaluable assets.”** 3 Optimize structural adjustment and improve quality, efficiency, and upgrading. The project commenced on September 1, 2018. On July 20, 2019, the waste alkali incineration unit for Zhongan United Coal Chemical Co., Ltd.’s project for producing 1.7 million tons per year of methanol and converted olefins was completed. On October 3, the evaporation and crystallization plant in the high-salinity water treatment area of the same project was successfully finished ； On October 21, important components of the high-salinity water treatment area, such as the chemical dosing system and water treatment system, the high-density sedimentation system, and the fluidized sand filtration system, were all handed over simultaneously. On November 28, with the completion and operation of the wastewater treatment facility for Zhong’an United Coal Chemical Co., Ltd.’s project for producing 1.7 million tons per year of methanol and converted olefins, the project was officially completed and entered its production and operation phase. The commissioning of this project not only fills the gap in terms of large-scale polyolefin manufacturing enterprises in Anhui Province, but it also contributes to ensuring energy strategic security, promoting local economic transformation and development. Additionally, it helps China’s petrochemical industry optimize its raw material structure, improve efficiency, and advance the clean and efficient use of coal, thereby helping China to take a leading role in this field worldwide.