Oil-water separation agent for oil-containing wastewater treatment and application thereof in electric desalination and drainage treatment of crude oil

Abstract

The invention provides an oil-water separation agent for oil-containing wastewater treatment. The oil-water separation agent is prepared from, by mass, 100 parts of ethylene glycol di-tert-butyl ether, 30-80 parts of polyisobutylene with the average molecular weight of 800-1300, 20-60 parts of propylene glycol diacetate and 5-20 parts of alpha-pyrrolidone. The agent is suitable for treating oil-in-water type wastewater containing mineral oil and biolipid, especially suitable for treating oil-containing wastewater discharged by an electric desalination device under the condition of adding moredemulsifiers into crude oil such as high-acid and low-quality crude oil and heavy inferior crude oil, after separation, the oil content in a water phase can be controlled below 150 mg / L, and the watercontent of an oil phase can be less than 0.3 m%. The oil-water separation agent can be pumped into the crude oil obtained after electric desalination and then enters a crude oil unit for normal processing.

Description

technical field [0001] The invention belongs to the field of wastewater treatment, and in particular relates to an oil-water separation agent for treating oily wastewater and its application in crude oil electric desalination wastewater treatment. Background technique [0002] Deep electric desalting is the basic method to deal with the salt contained in crude oil. Under the condition of high-voltage electric field and heating, supplemented by means of demulsifier, ultrasonic wave, etc., the salt contained in crude oil is removed by injecting 2-5% water once or more times. Partial washing into water, followed by oil-water separation, while controlling the water content of the treated crude oil and the oil content of the drain. Through the deep electric desalting process, crude oil can generally be treated to a salt content of less than 3mg / L and a water content of less than 0.2%, and the oil content of the discharged wastewater can be controlled to within 150mg / L. When the ...

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Problems solved by technology

[0003] However, due to the fluctuation and complexity of crude oil conditions, and the limitation and lag of electric desalination control and adjustment methods, many electric desalination devices in many oil refineries often discharge a large amount of wastewater with an oil content far exceeding 150mg / L, and sometimes the oil content in the drainage water can even reach 10 %, the effect of mixing this high oily wastewater into the electric desalination injection water and returning to the electric desalination treatment is usually limited, or it may cause the problem that the salt content and water content of the crude oil do not meet the standard after electric desalination

This kind of electric desalination wastewater with high oil content will cause a great impact on the oil separation-flotation-biochemical process or be difficult to handle when it is sent to the sewage plant for treatment, often causing wastewater to block the reservoir

On the other hand, the waste oil recovered from the treatment of the electric desalination wastewater with high oil content in the sewage plant is usually inconvenient to be directly used as a raw material for atmospheric and vacuum, catalytic cracking or coking due to the enrichment of other complex components in the wastewater. Some are difficult to transport

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