What is the impact of the water injection temperature in crude oil electrodialysis on the electrodialysis efficiency?

The water injection temperature has a certain impact on desalination; generally, 60–80 degrees is suitable. Too low a temperature will result in a lower desalination temperature, which hinders the separation of oil and water, while high-temperature water should also be avoided for injection. Since the electrodialysis temperature is generally around 130, too high a temperature also results in higher energy consumption.

The water injection temperature should not exceed 90 degrees, and it should be no lower than 60 degrees; the water volume is generally between 5–15%. . This is based on accelerating the dissolution rate of salts in the oil without significantly lowering the desalination temperature. . . The desalination temperature is generally between 110 and 145. . . High temperature for heavy oil recovery, low temperature for light oil recovery. . . Furthermore, and most importantly, it is necessary to choose the right demulsifier. . . :lol

I agree with what was said above, but is it possible to achieve more than 5%???

In reply to the person above: with cyclic water injection, as long as the secondary water injection level reaches over 5%, the primary level will also reach that value; both of our systems are capable of achieving this.

What kind of crude oil is the original poster referring to? The question you asked is closely related to the types of crude oil. For crude oil with high viscosity, the electrodesalination temperature must be higher, but energy consumption is also greater ； Crude oils with low viscosity (light oils, paraffin-based oils) can be desalted at lower temperatures. Generally speaking, it is advisable for the secondary water injection temperature to be close to the electrodialysis temperature. However, it depends on the temperature after heat exchange between the injected water and the water from the first stage of dehydration; a heat exchanger with good performance allows for a higher value. It is generally probably 20–30 degrees lower than the temperature in the electrodesalination tank

It is usually around 80 degrees; too high or too low a temperature can affect the temperature of the crude oil, thereby impacting the desalination process. At lower temperatures, the viscosity of the crude oil increases, which hinders the sedimentation of salts in the crude oil. At higher temperatures, energy consumption rises

Excuse me, on the 4th floor: could you explain in detail how to choose a good demulsifier?

There are two common laboratory methods for screening demulsifiers: First, thermal demulsification, which involves adding crude oil, water, and the demulsifier into a screening flask and then slowly carrying out demulsification in a water bath at 90 degrees. The advantage of this method is its simplicity of equipment and ease of operation, as well as the clear differences in the demulsifying effect of various demulsifiers on crude oil. However, its drawback is that the experimental time is long, and it differs from actual field conditions; since no electric field is used, it can only be used for qualitative screening. II. Electrical demulsification: This method uses an electrical demulsification evaluator; crude oil, water, and a demulsifier are mixed together, and appropriate experimental conditions are set. The advantage is that the evaluation results are relatively accurate, but the downside is that the conditions must be chosen carefully – otherwise, the demulsification effect may either be very good or very poor, making it difficult to determine what is good and what is not. However, due to the poor reproducibility of demulsifier evaluation experiments, multiple trials are required to reach a conclusion, so we generally use the above methods simultaneously.

Our original water injection rate was 5%, resulting in average desalination performance; now that the rate has been increased to around 10%, there has been no significant improvement in performance. What is the optimal water injection ratio for electrodialysis in order to achieve the best desalination results, as well as the most efficient energy consumption ratio? Could you elaborate on what those 5-15% you mentioned refer to?

The water used for injection must be free of salts; it is best not to use recycled water with a high salt content. . . On one hand, it **reduces the desalination efficiency**. It is recommended to use desalinated and softened water. . . :) Demulsifiers are also crucial; the amount of water you inject is sufficient. Please be sure to choose the right manufacturers for water injection and demulsifier supply. . . (I recommend the demulsifiers produced by Binzhou Lier Aditives Company; those we use work very well.) It is suitable for both heavy oil and ordinary crude oil. Contact number: 13305430280)

For electrodesalination water injection, we choose 0–4% for the first time； Secondary 2–5%. For water injection, purified water from the sulfur treatment unit is used, with a water temperature of 60–90 degrees. The temperature of the crude oil entering the tank ranges from 110–150 degrees. The water injection temperature is determined based on the properties of the crude oil; too low a temperature results in a small density difference, which hinders dehydration and sedimentation, while too high a temperature can lead to emulsification, increasing energy consumption. It may also cause oil to be carried along with the water.

Consider the energy consumption issue. . Too low a level is not conducive to the effectiveness of electrodesalination

The temperature of the water we feed into the device is 45°C; after heat exchange with the wastewater from electrodialysis, it can reach 110°C, while the temperature of the wastewater from electrodialysis is around 130°C. After heat exchange with wastewater and injection water, it undergoes further heat exchange with crude oil (once), and the final discharge temperature is 32°C. So I think the temperature of the water injected has nothing to do with energy consumption. As for the control of the water injection temperature, it is sufficient as long as the temperature of the mixture of water and crude oil is not lower than the temperature required for desalination.