The gasification, methanol, and olefin plants of Zhongtian Hechuang are operating stably

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The gasification, methanol, and olefin production facilities of Zhongtian Hechuang are operating stably. Author/Source: Sinopec News Network; compiled and published by the Nitrogen Fertilizer and Methanol Technology Network. Date: May 28, 2019. Clicks: 12. From January to April, Zhongtian Hechuang produced more methanol and polyolefin products, with increases of 12.16% and 13.48% respectively compared to the previous year, resulting in a 31.72% increase in profits. The Zhongtian Hechuang gasification unit utilizes the coal-water slurry gasification technology developed by the American company GE, a technology that requires very high standards regarding the quality of the raw coal used. Due to the extremely high moisture and ash content of the raw coal used in conjunction with the gasification unit, sometimes the ash content can reach 22%–23%, which is far above the design specifications. This leads to fluctuations in the pressure difference at the burner of the gasification furnace, causing shutdowns, and makes it extremely difficult to ensure the stable, continuous, and efficient operation of the unit. To this end, Zhongtian Hechuang organized production in a scientific manner, ensuring the stable operation of 10 gasification units with 11 such units available, and at the same time established a task force dedicated to improving the gasification units. Through repeated experimentation and continuous improvements, a set of methods was developed to address low fluctuations in the pressure difference of the burners, thereby optimizing the control parameters for this pressure difference. To address the issue of high moisture content in the ash, the company focused on developing technologies for dehydrating both coarse and fine ash residues. Vibratory screens were installed at the outlets of 14 ash scoopers, which reduced the moisture content of the ash by 10% compared to before, **thereby lowering the costs associated with transporting the ash. After the optimization and modification of the methanol stripping system, the ammonia nitrogen content in the purified condensate was significantly reduced to below 50PPm. This not only effectively solved problems such as crystallization blockages in the purification pipelines and excessive ammonia nitrogen levels in the gasification graywater, thereby greatly reducing the burden on the wastewater treatment systems used in environmental protection facilities, but also yielded notable economic benefits. This research project won the first prize for QC achievements from Sinopec. Through technical improvements, the pretreatment unit for gasifying sewage is now capable of operating in single-series mode, which has reduced consumption; the rate of satisfactory sewage discharge has reached over 90%. The company’s technical staff also carried out technical upgrades on 14 coal grinding mills by installing magnets at their outlets and cleaning them on a weekly basis. In addition, filters were added to the outlet pipelines of the low-pressure coal slurry pumps, with regular drainage to ensure stable operation of the equipment. At the same time, Zhongtian Hechuang has also carried out in-depth activities to reduce costs and increase efficiency, strengthened the assessment of technical and economic indicators, and linked key economic metrics such as plant production volume, product quality, as well as material and energy consumption for the purpose of improving plant yield. The 8 production units in the Olefins Department of the Chemicals Branch strive to optimize operations and plant energy management, improve the use of recycled water and nitrogen, and strengthen on-site management to prevent leaks and losses, thereby achieving cost reduction and efficiency improvement. From January to April this year, the key economic indicators of 5 polyolefin plants, such as energy consumption and material usage, reached their best levels on record, reflecting an ongoing improvement in the level of operational management at these plants. Since January this year, the company’s No. 2 steam turbine generator set has shown insufficient load-carrying capacity under pure condensing conditions. The usual solution is to shut down the plant for major repairs, but the external power grid infrastructure in Inner Mongolia is weak, and the stable operation of Turbine No. 2 is crucial to the production process. In the absence of any existing reference experiences in the country, Zhongtian Hechuang innovatively developed an online cleaning solution for Turbine Generator Set No. 2. After implementation, the load-carrying capacity of Turbine Unit 2 under pure condensing operation increased significantly, from 114 megawatts to 143 megawatts. Based on a conservative estimate of an 20-megawatt increase in load, this results in an additional 14.4 million kWh of electricity generated per month, yielding approximately 2.88 million yuan in extra revenue each month.