The electrochemical oil removal technology for heavy and viscous oil wastewater, based on a low-pressure high-frequency pulsed magnetic field, independently developed by Changsha Huashi Jie Environmental Protection Technology

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Heavy crude oil wastewater is a major challenge plaguing the development of the refining industry. Changsha Huashi Jie Environmental Protection Technology Development Co., Ltd. has independently developed an electrochemical oil removal technology based on a low-pressure, high-frequency pulsed magnetic field for heavy and viscous oil-containing wastewater. This technology achieves rapid demulsification by altering the interfacial tension between oil and water, thereby \"forcing\" the separation of oil and water and enabling the \"one-click separation\" of such wastewater. To date, this technology has been in use in the facilities of CNOOC Huizhou Petrochemical Co., Ltd. for over a year, having processed more than 180,000 tons of heavy and viscous oil wastewater. 　　Our country has abundant heavy oil reserves, and a large amount of wastewater containing heavy oil is generated during its extraction, storage, transportation, and processing. These wastewater streams contain high levels of mineral oil, primarily in the form of floating oil and emulsified oil, giving them high value for recycling. Adding demulsifiers in the treatment of heavy oil wastewater is the easiest and most effective demulsification method when using existing sedimentation and filtration systems; however, demulsifiers tend to remain in the wastewater, having an adverse effect on subsequent processes, especially biochemical treatment. 　　Based on this, Dr. Jiang Xiaoyun’s team, the general manager of the company, developed an electrochemical oil removal technology for heavy and viscous oil wastewater based on low-voltage high-frequency pulsed magnetic fields. “This technology does not require the use of demulsifiers; instead, it employs a high-frequency pulsed electric field to break down the interfacial tension of oil-water micelles in the electric field, causing oil molecules to collide, aggregate, and grow larger until they can be separated from the water. ”Jiang Xiaoyun explained. At the same time, the research team also designed electrochemical equipment on their own, combining electric field effects with flow rates to control bubble growth and thereby produce a large number of microbubbles, which significantly improved the efficiency of oil-water separation. Currently, demulsification can be achieved within 50 seconds, and efficient oil-water separation is possible within 30 seconds. This technology has a wide range of applications and can be used for heavy and viscous oil wastewater such as electrodialysis black water with an oil content as high as 20%, crude oil tank sludge, and contaminated oil tank residues. 　　Furthermore, using this technology for the separation of heavy oil wastewater also prevents the uncontrolled release of gases; the quality of the treated oil is good, with the oil content in water being able to be reduced to less than 5 ppm. The equipment used features a wedge-shaped design, which results in low floor space requirements and a short installation period – installation can be completed in just half a month. This device also supports intelligent control, capable of automatically adjusting parameters based on the project conditions, enabling one-click start/stop operation and unattended operation. To date, 2 papers related to this technology have been published, and 2 patented inventions have been granted. 　　It is reported that the industrial demonstration unit for the electrochemical oil removal of heavy and viscous oil wastewater with a capacity of 60 cubic meters per hour, built using this technology, has delivered satisfactory results. The average levels of oil content and suspended solids were as low as 16.6 milligrams per liter and 25 milligrams per liter respectively, and the treatment cost was only 1.5 yuan per ton, which represents a reduction of over 60% compared to conventional technologies. 　　In the future, the research team will further apply this technology to the treatment of high-acid crude oil and aged oil wastewater in refining enterprises, and develop compact devices suitable for treating bottom sludge at various scales. At the same time, they will upgrade this technology to make it more intelligent, enabling real-time optimization of operational parameters.