【Ten Years of Rapid Development in Chemical Equipment】The first large-scale domestically produced environmental protection facility in China was successfully put into operation at the Zhenhai site between 2015 and 2021
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The chemical processing industry has seen significant development over the past decade; let’s praise the prosperity and strength of modern China. Wishing everyone a happy New Year, and may their families be safe and healthy. By contributing our ideas, we can create a more lively atmosphere for discussion. With you all, Haichuan becomes even better – we encourage everyone to participate more actively in forum discussions. On December 15, 2021, the facility for the “Development and Industrial Testing of Wet Oxidation Technology for Tons of Sulfur-Containing Waste Alkaline Liquids” as part of Sinopec’s “Ten Dragon” technology development project was successfully put into operation, marking a new breakthrough in wastewater treatment technology in China. This system is the first of its kind in China to utilize domestically developed and independent technology for a waste alkali wet oxidation unit integrated with a large-scale ethylene plant. It was developed under the leadership of Zhenhai Refining & Chemical Co., in collaboration with institutions such as the Dalian Petrochemical Research Institute, Sinopec Engineering Construction Co., Ltd., and East China University of Science and Technology. In December 2020, it was selected as one of Sinopec’s “Ten Dragon” scientific and technological projects. This device has three main features: first, it has greater capacity, as it represents the first large-scale application of domestically developed technology for treating waste alkali. Secondly, it is more efficient, with the treatment efficiency of waste alkaline solution sulfides improving by more than 5 times. Third, investment is more cost-effective; the investment costs for the same scale are reduced by over 50% compared to imported technologies. At present, domestic refining and chemical enterprises generate large amounts of waste alkali solution from ethylene production; this solution has high concentrations of sulfides and COD, and poor biodegradability, making it the last hurdle that needs to be overcome for the complete domestic production of ethylene on a million-ton scale. The successful deployment of this device has effectively broken Siemens’ long-standing monopoly in this field in China, truly achieving the goal of \"using Chinese technology to manage China’s wastewater.\" Thus, Sinopec now possesses a large-scale, domestically developed complete set of technologies for the wet oxidation treatment of waste alkali.
As of April 12, 2022, Zhenhai Refining & Chemical Company’s No. 2 waste alkali wet oxidation unit had been operating steadily for three months, marking a success in Sinopec’s efforts to develop the first domestically produced waste alkali oxidation unit over a long period of time, and achieving the goals set for the first phase of this project. This unit is the first in China to be equipped as a supporting system for an ethylene plant with a capacity of 1.2 million tons per year, utilizing domestic technology. The reactor’s processing capacity is 19.2 tons per hour; compared to the company’s imported No. 1 waste alkali wet oxidation unit, it offers higher processing capacity, better efficiency, and lower investment costs.
After the plant began operations at the beginning of 2022, the Zhenhai Refining & Chemicals technical team set itself the goals of minimizing investment, reducing energy consumption, and extending the operational cycle. By continuously summarizing the experience gained during trial operations, optimizing control parameters, and adjusting control strategies, they managed to surpass the leading foreign process technologies in two areas: eliminating the need for reflux in the liquid separation tank discharge process, and enabling online switching of high-pressure feed pumps. This approach helped to achieve better results in using Chinese technology to treat wastewater in China. In addition, the technical team worked together with the company’s design institute, Zhejiang Zhongkong, and other relevant units to develop an improved online switching scheme for high-pressure feed pumps. By enabling short-term online switching of the production water valve and feed valve, it was possible to reduce the time it takes for production water to enter the system, thereby significantly lowering the risk of scaling.
Sulfur-containing waste alkaline solutions, sulfur paste, petroleum coke, rubber exhaust gases, alkaline slag, salt sludge, and gasification CO are all hazardous wastes in petrochemical plants that are produced in large quantities and difficult to handle. It is necessary to address each of these issues one by one, aiming to reduce their volume and promote a circular economy in order to generate economic benefits.