Regarding the issue of electrical desalination
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Tahe crude oil is alkaline. During the refining process, the electric desalination system will produce emulsification, resulting in high salt content after desalination and high oil content in the sewage. Is there a good way to deal with it? The best thing is to adjust the process. At present, it is difficult to solve the problem with domestic demulsifiers. This post was last edited by chengkang on 2009-4-13 21:05 ]
Nowadays, some electric desalination uses bottom in and top out, with a drainage tank at the bottom, which should solve this problem.
After we changed the demulsifier from water-soluble to oil-soluble, the demulsification effect improved.
“Tower and crude oil are alkaline”? Is it "Tahe Crude Oil"? If the crude oil is alkaline, it does not mean that it cannot be desalted. You can consider increasing the electric desalination temperature appropriately. In addition, when injecting purified water, you should pay attention to the pH of the water not being too high, usually 7-8.
The mixing intensity of crude oil and demulsifier should be controlled moderately. If the intensity is too high, it will easily emulsify.
Control the mixing intensity well, keep the tank inlet temperature above 140°C, control the pressure of the desalting tank a little higher, and increase the water injection. :lol
The hydrogen sulfide content of Tahe crude oil is very high, exceeding the transportation standard, so alkali must be added to neutralize it, causing the crude oil to become alkaline.
The combination of demetalling agent and demulsifier can improve the oil-water separation effect after removing salt. Increase the reaction temperature and water injection volume appropriately. The pH value of water injection should also be paid attention to.
What you said above makes sense. The process parameters can be adjusted appropriately, such as mixing intensity, water injection volume, water injection method, oil-water interface control, etc., which all have a certain impact on the desalination and dehydration effect. Of course, the improvement of the demulsifier is more important!
1. Process adjustment: Optimize and adjust the mixing pressure difference, water injection amount, water injection source (nature), temperature, interface, etc., pay special attention to the amount of dirty oil added. Excessive amount of dirty oil added will have a great impact on desalination. 2. It is recommended to use imported oil-soluble demulsifiers as high-efficiency demulsifiers. The special reminder is that the adding points and methods of demulsifiers are particular. Please contact GE for consultation
It may be helpful to treat it with a decalcifier before breaking the emulsion. The decalcifier is an acidic component.
Reduce the mixing intensity of oil and water, increase the inlet temperature, increase the allowable range of the safety valve, and increase the inlet pressure.
The 11th floor is right. Strongly acidic decalcifying agent must be injected into the desalination water injection pipeline to lower the pH value of the water injection. The injection amount can be adjusted according to the pH value of the desalination water, which is generally controlled at around 7~8.
Raise the electrical desalting temperature, but it should not be too high. If the temperature is too high, water will vaporize, making it difficult to separate oil and water, causing a trip! In addition, when filling water, pay attention to the pH not being too high! In our unit, the demulsifier and metal agent are mixed in proportion and then put into the desalting tank!
In addition to paying attention to parameters such as temperature, pressure, and primary and secondary water injection, the key is the selection of demulsifier. Only after testing can a conclusion be drawn, because the operating conditions of each device are different.
Note a part of phosphoric acid or organic phosphonic acid, which can decalcify and adjust the pH. However, the crude oil in Tahe is relatively alkaline, so we need to find a solution from the source.
Electrical desalination is controlled at 135°C. Increase the electric desalination pressure appropriately and control the mixing pressure difference. I can give you a suggestion about process modification.: When fresh water is injected, it is directed to the second stage of electro-depollution, and the circulating water enters the first-stage electro-depollution. The salty sewage is cut into the electric decontamination oil tank from below the first decontamination. If there is a lot of emulsion, it can be cut into the electric decontamination oil tank, and pumped into the flash evaporation tower with a metering pump for operation. The disadvantage is that when the amount is unstable, it will cause fluctuations in the normal pressure! ! ! !
The emulsification phenomenon is generally referred to as "oil in water", which means that the dehydration effect there is not ideal. Appropriately increase the oil and water level, increase the settling time, and improve the oil and water separation effect. ； Change to a suitable demulsifier ； Increase the mixing valve pressure differential. You can make adjustments as a reference. I hope you can share your processing methods and ideas with everyone after you have accurate results based on the specific situation!
You can consider using oil-soluble demulsifiers and control the electric desalting temperature at 135-140
The first is to control the desalination temperature, and the second is that the amount of water injected in the first and second stages cannot be large. Easy emulsification is the key issue and the mixing intensity is reduced.