Demulsifier selector

1、 Purpose:

In the process of electric desalination in refineries, demulsifiers play an important role, and their demulsification effect directly affects the desalination (dehydration) effect. Moreover, the same demulsifier is used for crude oils with different properties. The demulsification effect is also different. In addition, the properties of crude oil supplied to refineries also frequently change. In order to ensure the stability of desalination (dehydration) effect, it is necessary to constantly adjust the dosage of demulsifiers, and even change the variety of demulsifiers. Therefore, the selection of demulsifiers is an indispensable means in the process center of refinery electric desalination technology.

At present, various refineries in China use thermochemical selection method to screen demulsifiers, which has a slow speed and a large gap with the actual production process of electric desalination, and the selection results cannot meet the production needs.

This instrument mainly uses electrochemical methods. Thermochemical methods are used as a supplement. First, heat an appropriate amount of crude oil and then select the demulsifier under the action of an electric field. It is similar to the actual working conditions of electric desalination. The selection results are more accurate and reliable than thermochemical methods, and can simultaneously select 6 types of demulsifiers, or select 6 different dosages of the same demulsifier. The selection speed is fast (about three times that of thermochemical methods), the power consumption is low, and the energy consumption is one tenth of thermochemical methods.

This instrument has adjustable voltage, free temperature setting, easy and fast operation, compact structure, and small volume, making it suitable for laboratory use and on-site service. It is an ideal instrument for selecting demulsifiers.

2、 As long as the technical indicators are met

1. Input voltage: AC220V~10% 50Hz

2. Output voltage: 0-6000V continuously adjustable

3. Output AC current: 0-100mA high voltage output (0-500mA low voltage output)

4. Heater power: 800W

5. Whole machine power: not exceeding 1000W

6. Automatic control range of heater temperature: can be set freely between room temperature and 140 ℃

Low temperature glass electrode: Room temperature~95 ℃

7. Temperature control accuracy ± 1 ℃

8. Preheating time: When the temperature is preset at 75 ℃, the preheating time is about 15 minutes (the preheating time may vary slightly depending on the room temperature)

9. Electric field strength regulation: stepless adjustment of output AC voltage

10. Instrument operating environment temperature: -10 ℃ to+40 ℃

11. Relative humidity: not exceeding 85%

12. Dimensions: 600 (length) x 484 (width) x 466 (height)

13. Weight: Approximately 65Kg

3、 Instrument working principle

Crude oil contains a certain amount of water. During extraction and transportation, oil and water form emulsions due to collision, stirring, and friction. At the same time, in the process of crude oil desalination, water washing is mainly used to remove salts from the oil. Therefore, a certain amount of water must be injected first and the oil and water must be thoroughly mixed to form an emulsion. This emulsion exists in the form of oil in water or water in oil aggregates. Due to the natural emulsifiers such as gum and asphaltene in crude oil, they are less attracted by oil molecules and can be arranged at the oil-water interface to form a barrier. Therefore, emulsions are relatively stable and appropriate measures must be taken to break down, dehydrate, and desalinate. The process of electric desalination is essentially a dehydration process

In order to improve dehydration efficiency, a small amount of demulsifier is often added during the dehydration process, for different types of demulsifiers and crude oils with different properties. It is necessary to select a more suitable demulsifier and appropriate dosage in order to achieve the goal of improving the demulsification water.

The principle of selecting demulsifiers with this instrument is to first take a certain amount of crude oil, add a certain amount of water in proportion, and vigorously stir to fully emulsify the oil and water. Then, take 100mL of each and pour it into six centrifuge bottles. Then, add a certain amount of demulsifier in sequence and heat it appropriately to reduce the viscosity of the crude oil. In addition, apply AC high voltage to generate a strong magnetic field, which causes charge exchange between small oil droplets and water droplets, achieving the purpose of electrical neutralization. Thus, the collision between droplets is strengthened and gradually coalesces and settles, achieving the purpose of dehydration. Then, the quality of the demulsifier is evaluated based on the amount of water poured or the measured chloride ion content in the water.

4、 Structure Overview:

The instrument is mainly divided into four parts: high-voltage rectification circuit, central controller, microcomputer touch system, and electric field demulsification system. The instrument is divided into two parts: the controller and the high-pressure heating element, which work together through corresponding connecting wires. The electric field demulsification part mainly relies on coaxial electrodes and centrifugal bottles filled with crude oil.