A device and method for removing solid from oil slurry based on electrostatic separation method

Abstract

The application discloses a kind of based on electrostatic separation method oil slurry desolidification device and method, including electrostatic separator, oil slurry storage tank, purified oil slurry storage tank, backwashing liquid tank, oil slurry storage tank is used to store catalytic cracking oil slurry, oil slurry storage tank has heating function, oil slurry storage tank is connected with electrostatic separator by first pipe bundle, industrial peristaltic pump is provided on first pipe bundle, electrostatic separator is connected with purified oil slurry storage tank by second pipe bundle, electrostatic separator is connected with waste liquid tank by third pipe bundle, electrostatic separator is connected with backwashing liquid tank by fourth pipe bundle on the side away from oil slurry storage tank, and backwashing pump is provided on fourth pipe bundle.Based on electrostatic adsorption method, the method for electrostatic separation of two-phase impurities in oil is proposed, the charging characteristics of two-phase particle impurities in oil, the adsorption and separation method of impurities under the action of different external electric field intensity after polarization are obtained;The oil slurry electrostatic separation method proposed in the patent can be suitable for oil slurry containing different size particle impurities, and has good impurity separation effect and high purification efficiency.

Description

Technical Field

[0001] This invention relates to the field of oil slurry desolidification in petrochemical catalytic cracking, and in particular to an oil slurry desolidification device and method based on electrostatic separation. Background Technology

[0002] Catalytic cracking slurry oil (catalytic cracking) contains many potentially valuable saturated hydrocarbons and aromatics, which can be used to produce high-value-added products such as needle coke, carbon black, and carbon electrode materials. However, these industries have high requirements for the solid impurity content of catalytic cracking slurry oil. Removing solid impurities from catalytic cracking is a prerequisite for producing high-value-added refining products and achieving long-term safe operation of the slurry oil system. It is also an important guarantee for reducing the degree of environmental pollution during the use of slurry oil. Effectively removing solid particles from the slurry oil allows it to meet the raw material property requirements for producing high-value-added products, and has great development potential.

[0003] Currently, the main methods for removing solid particles from catalytic cracking slurry include sedimentation, filtration, and centrifugation. Each of these methods has its own advantages and disadvantages and cannot effectively solve the problem of solidification in slurry. Existing electrostatic separation methods are greatly affected by the properties of the slurry, and the number of effective adsorption sites on the packing material is limited. Furthermore, the "competitive adsorption" between asphaltenes and solid particles in the slurry leads to low efficiency and unstable operation of electrostatic separation devices, failing to meet the goal of deep solidification of the slurry. Summary of the Invention

[0004] In order to overcome the above-mentioned problems in the prior art, the present invention proposes an oil slurry desolidification device and method based on electrostatic separation.

[0005] The technical solution adopted by the present invention to solve its technical problem is: an oil slurry desolidification device based on electrostatic separation, comprising an electrostatic separator, an oil slurry storage tank, a purified oil slurry storage tank, and a backwash liquid tank. The oil slurry storage tank is used to store catalytic cracking oil slurry and has a heating function. The oil slurry storage tank is connected to the electrostatic separator through a first tube bundle, on which an industrial peristaltic pump is installed. The electrostatic separator is connected to the purified oil slurry storage tank through a second tube bundle. The electrostatic separator is connected to a waste liquid tank through a third tube bundle. The side of the electrostatic separator away from the oil slurry storage tank is connected to the backwash liquid tank through a fourth tube bundle, on which a backwash pump is installed.

[0006] The aforementioned oil slurry desolidification device based on electrostatic separation method has a first sampling port provided on the first tube bundle.

[0007] The aforementioned oil slurry desolidification device based on electrostatic separation method has a second sampling port provided on the second tube bundle.

[0008] The aforementioned electrostatic separation-based oil slurry desolidification device includes an electrostatic separator comprising a tank and a rotating cylinder. A heat transfer oil heating zone is provided between the tank and the rotating cylinder. A cavity composed of sieve plates is provided on the inner wall of the rotating cylinder. A catalytic cracking oil slurry inlet is provided on the rotating cylinder corresponding to the bottom of the cavity. An internal electrode is provided in the middle of the rotating cylinder and is connected to a high-voltage DC / AC power supply. Packing materials of different sizes are provided between the internal electrode and the inner wall of the rotating cylinder to allow the catalytic cracking oil slurry to flow fully in the electrostatic separator and separate solid impurities.

[0009] The aforementioned oil slurry desolidification device based on electrostatic separation method uses a polytetrafluoroethylene (PTFE) sieve plate, which is used for sufficient heat exchange and full filtration of large particulate impurities in catalytic cracking oil slurry.

[0010] In the aforementioned electrostatic separation-based oil slurry desolidification device, the rotating cylinder can rotate around the inner electrode.

[0011] The aforementioned oil slurry desolidification device based on electrostatic separation method includes a Soxhlet extraction device installed in the oil slurry storage tank and the purified oil slurry storage tank, and a constant temperature water bath installed in the oil slurry storage tank and the purified oil slurry storage tank to prevent the oil slurry from solidifying.

[0012] The aforementioned oil slurry desolidification device based on electrostatic separation method uses glass spheres and ceramic spheres of various diameters as fillers.

[0013] The aforementioned oil slurry desolidification device based on electrostatic separation method is equipped with temperature detection devices for the oil slurry storage tank, the purified oil slurry storage tank, and the electrostatic separator.

[0014] In the aforementioned electrostatic separation-based oil slurry desolidification device, the cavities are arranged opposite each other on the inner wall of the rotating cylinder, and the central angle of each cavity is greater than 90° and less than 180°.

[0015] The above-mentioned method of using an oil slurry desolidification device based on electrostatic separation includes the following steps:

[0016] Step 1: After the oil slurry is heated in the oil slurry storage tank, it is fed into the electrostatic separator through the first tube bundle and the industrial peristaltic pump.

[0017] Step 2: After the slurry enters the electrostatic separator, a sieve plate is set at the inlet of the catalytic cracking slurry to allow the slurry to exchange heat fully and filter large particulate impurities. The internal electrode is connected to a high-voltage DC / AC power supply and energized. Under the action of the high-voltage electric field, the slurry undergoes separation of solid impurities and purified slurry. The solid impurities are adsorbed onto the internal electrode and packing.

[0018] Step 3: To further improve purification efficiency, the rotating cylinder rotates around the inner electrode to ensure full contact between the oil slurry and the packing material.

[0019] Step 4: The purified slurry is transported to the purified slurry storage tank through the second tube bundle.

[0020] Step 5: The backwash liquid tank flushes the electrostatic separator through the fourth tube bundle, and the flushed waste liquid flows into the waste liquid tank through the third tube bundle.

[0021] The beneficial effects of this invention are that it proposes an electrostatic separation method for two-phase impurities in oil based on electrostatic adsorption, and obtains the charge characteristics of two-phase particulate impurities in oil, as well as the adsorption and separation method after impurity polarization under different applied electric field strengths; the electrostatic separation method for oil slurry proposed in this patent is applicable to oil slurry containing particulate impurities of different sizes, with good impurity separation effect and high purification efficiency. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a schematic diagram of the present invention;

[0024] Figure 2 This is an axial sectional view of the electrostatic separator of the present invention;

[0025] Figure 3 This is a top view of the rotating cylinder of the electrostatic separator of the present invention.

[0026] In the diagram, 1. Oil slurry storage tank, 2. Industrial peristaltic pump, 3. First sampling port, 4. Waste liquid tank, 5. Electrostatic separator, 6. Backwash pump, 7. Backwash liquid tank, 8. Purified oil slurry storage tank, 9. Second sampling port, 10. High voltage DC / AC power supply, 11. Rotating drum, 12. Tank body, 13. Heat transfer oil heating zone, 14. Catalytic cracking oil slurry inlet, 15. Sieve plate, 16. Cavity, 17. Packing, 18. Internal electrode, 19. Backwash inlet, 20. Catalytic cracking oil slurry outlet. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1As shown, this embodiment discloses an oil slurry desolidification device based on electrostatic separation, including an electrostatic separator 5, an oil slurry storage tank 1, a purified oil slurry storage tank 8, and a backwash liquid tank 7. The oil slurry storage tank 1 is used to store catalytic cracking oil slurry. The oil slurry storage tank 1 has a heating function and is equipped with a spiral heater and a high-temperature oil bath. The oil slurry storage tank 1 is connected to the electrostatic separator 5 through a first tube bundle, and an industrial peristaltic pump 2 is installed on the first tube bundle. The electrostatic separator 5 is connected to the purified oil slurry storage tank 8 through a second tube bundle. The electrostatic separator 5 is connected to the waste liquid tank 4 through a third tube bundle. The side of the electrostatic separator 5 away from the oil slurry storage tank 1 is connected to the backwash liquid tank 7 through a fourth tube bundle, and a backwash pump 6 is installed on the fourth tube bundle.

[0029] A first sampling port 3 is provided on the first tube bundle, and a second sampling port 9 is provided on the second tube bundle. Flow meters are provided at both the first sampling port 3 and the second sampling port 9.

[0030] like Figure 2 As shown, the electrostatic separator includes a tank 12 and a rotating cylinder 11. A heat transfer oil heating zone 13 is provided between the tank 12 and the rotating cylinder 11. A cavity 16 composed of sieve plates 15 is provided on the inner wall of the rotating cylinder 11. A catalytic cracking slurry inlet 14 is provided at the bottom of the cavity 16 corresponding to the rotating cylinder 11. An inner electrode 18 is provided in the middle of the rotating cylinder 11 and is connected to a high-voltage DC / AC power supply 10. Packing material 17 of different sizes is provided between the inner electrode 18 and the inner wall of the rotating cylinder 11 to allow the catalytic cracking slurry to flow fully in the electrostatic separator 5 and separate solid impurities. A backwash inlet 19 connected to a backwash liquid tank and a catalytic cracking slurry outlet 20 connected to a purified slurry storage tank are provided above the rotating cylinder 11.

[0031] The sieve plate 15 is a polytetrafluoroethylene sieve plate, which is used for sufficient heat exchange in catalytic cracking slurry and for thorough filtration of large particulate impurities. The rotating drum 11 can rotate around the inner electrode 18.

[0032] like Figure 3 As shown, the cavities are arranged opposite each other on the inner wall of the rotating cylinder. The central angle of each cavity is greater than 90° and less than 180°. In this embodiment, the central angle of each cavity is 120°. This arrangement is to facilitate the replacement and maintenance of the screen plate in later use and reduce the cost of use and maintenance.

[0033] Both the oil slurry storage tank 1 and the purified oil slurry storage tank 8 are equipped with Soxhlet extraction devices, and both are equipped with constant temperature water baths to prevent the oil slurry from solidifying. Temperature detection devices are also installed in the oil slurry storage tanks, the purified oil slurry storage tanks, and the electrostatic separator.

[0034] In this embodiment, the filler consists of glass spheres and ceramic spheres of various diameters.

[0035] The oil slurry storage tank and the purified oil slurry storage tank are equipped with a high-temperature oil bath function, which controls the maximum temperature of the oil slurry to be no less than 180℃.

[0036] The maximum flow rate of the slurry in the device is 24 L / min, and the slurry pressure is atmospheric pressure.

[0037] The high-voltage DC / AC power supply 10 can generate AC and DC electric fields. The AC electric field is frequency-adjustable and voltage-adjustable, and can output sine waves, triangle waves, pulse waves, etc. The output port can be connected to two power lines, with a maximum output voltage of 12kV and a power of not less than 3kVA. The DC electric field can achieve continuous voltage regulation from 0-20kV.

[0038] The above-mentioned device is used in the purification process of catalytic cracking slurry in petrochemical enterprises, and specifically includes the following steps.

[0039] Step 1: After the oil slurry is heated in the oil slurry storage tank, it is fed into the electrostatic separator through the first tube bundle and the industrial peristaltic pump.

[0040] Step 2: After the slurry enters the electrostatic separator, a sieve plate is set at the inlet of the catalytic cracking slurry to allow the slurry to exchange heat fully and filter large particulate impurities. The internal electrode is connected to a high-voltage DC / AC power supply and energized. Under the action of the high-voltage electric field, the slurry undergoes separation of solid impurities and purified slurry. The solid impurities are adsorbed onto the internal electrode and packing.

[0041] Step 3: To further improve purification efficiency, the rotating cylinder rotates around the inner electrode to ensure full contact between the oil slurry and the packing material.

[0042] Step 4: The purified slurry is transported to the purified slurry storage tank through the second tube bundle.

[0043] Step 5: The backwash liquid tank flushes the electrostatic separator through the fourth tube bundle, and the flushed waste liquid flows into the waste liquid tank through the third tube bundle.

[0044]

Example 1

[0045] Single electrostatic separation of oil slurry desolidification

[0046] Step 1: The residue catalytic cracking slurry produced in a certain oil refinery is stored in a slurry storage tank and heated to 240°C in a high-temperature oil bath.

[0047] Step 2: The heated catalytic cracking slurry enters the electrostatic separator via the tube bundle and the industrial peristaltic pump. The industrial peristaltic pump is connected to the electrostatic separator via the tube bundle, which is equipped with a sampling port 1 and a flow meter for detecting the slurry.

[0048] Step 3: After the oil slurry enters the electrostatic separator, a polytetrafluoroethylene screen plate with flow micropores is set at the inlet of the catalytic cracking oil slurry to ensure sufficient heat exchange of the oil slurry and to fully filter large particulate impurities. The outermost layer of the electrostatic separator is equipped with a heat transfer oil heating zone to maintain the oil slurry in the electrostatic separator at a suitable purification temperature.

[0049] Step 4: The electrostatic separator contains columnar high-voltage electrodes, each made of different materials and with different diameters. These electrodes are connected to a high-voltage power supply as the anode, and the outer wall is grounded as the cathode. It can generate high-voltage DC and AC power. The AC electric field is frequency and voltage adjustable, and can output sine waves, triangular waves, pulse waves, etc. The output port can connect to two power lines, with a maximum output voltage of 12kV and a power of no less than 3kVA. The DC electric field can achieve continuous voltage regulation from 0-20kV. High-voltage DC electrostatic separation is preferred. A 10kV continuous voltage regulation setting is selected and maintained for a period of time. Under the action of the high-voltage electric field, solid impurities and purified oil slurry are separated. Solid impurities are adsorbed onto the high-voltage electrodes and packing balls, thus purifying the catalytic cracking oil slurry.

[0050] Step 5: To further improve purification efficiency, the inside of the electrostatic separator can rotate axially along the high-voltage electrode rod to ensure full contact between the oil slurry and the packing.

[0051] Step 6: Different sized packing materials are placed between the electrostatic separator and the high-voltage electrode to allow the catalytic cracking slurry to flow fully in the electrostatic separator, separating solid impurities for adsorbing solid particles in FCC.

[0052] Step 7: The purified slurry is transported to the purified slurry storage tank through the tube bundle. The connecting tube bundle between the electrostatic separator and the purified slurry storage tank is equipped with sampling port 2 and flow meter for detecting the purified slurry.

[0053] Step 8: The composition of the oil slurry at sampling port 2 is tested to ensure it meets the requirements of subsequent processes. The purified oil slurry is then heated in a high-temperature oil bath to prepare it for further use.

[0054] Step 9: The electrostatic separator is connected to the backwash liquid tank via tube bundle, flow meter, backwash pump, and backwash liquid tank for cleaning and rinsing the electrostatic separator. The backwash liquid tank is used to hold the backwash liquid.

[0055] Step 10: The lower part of the electrostatic separator is connected to a waste liquid tank to store the waste liquid after separation, adsorption and rinsing.

[0056] The simulated oil slurry flow rate was selected as 50 ml / min, the solid impurity concentration was 8 mg / g, the packing material was glass spheres with a particle size between 3 mm and 3.5 mm, the central electrode voltage was 10 kV, the total simulated oil slurry volume was 25 kg, and the electrostatic separation efficiency was 96% after 1 hour of separation.

[0057]

Example 2

[0058] Multiple electrostatic separation of oil slurry for desolidification

[0059] Step 1: The residue catalytic cracking slurry produced in a certain oil refinery is stored in a slurry storage tank and heated to 240°C in a high-temperature oil bath.

[0060] Step 2: The heated catalytic cracking slurry enters the electrostatic separator via the tube bundle and the industrial peristaltic pump. The industrial peristaltic pump is connected to the electrostatic separator via the tube bundle, which is equipped with a sampling port 1 and a flow meter for detecting the slurry.

[0061] Step 3: After the oil slurry enters the electrostatic separator, a polytetrafluoroethylene screen plate with flow micropores is set at the inlet of the catalytic cracking oil slurry to ensure sufficient heat exchange of the oil slurry and to fully filter large particulate impurities. The outermost layer of the electrostatic separator is equipped with a heat transfer oil heating zone to maintain the oil slurry in the electrostatic separator at a suitable purification temperature.

[0062] Step 4: The electrostatic separator is equipped with columnar high-voltage electrodes, each made of different materials and diameters. These electrodes are connected to a high-voltage power supply as the anode, and the outer wall is grounded as the cathode. It can generate high-voltage DC and AC power. The AC electric field is frequency and voltage adjustable, and can output sine waves, triangular waves, pulse waves, etc. The output port can connect to two power lines, with a maximum output voltage of 12kV and a power of no less than 3kVA. The DC electric field can achieve continuous voltage regulation from 0-20kV. High-voltage DC electrostatic separation is preferred. Continuous voltage regulation settings of 5, 10, 15, and 20kV are maintained for 1-10 minutes. Under the action of the high-voltage electric field, solid impurities and purified oil slurry are separated. Solid impurities are adsorbed onto the high-voltage electrodes and packing balls, thus purifying the catalytic cracking oil slurry.

[0063] Step 5: To further improve purification efficiency, the inside of the electrostatic separator can rotate axially along the high-voltage electrode rod to ensure full contact between the oil slurry and the packing.

[0064] Step 6: Different sized packing materials are placed between the electrostatic separator and the high-voltage electrode to allow the catalytic cracking slurry to flow fully in the electrostatic separator, separating solid impurities for adsorbing solid particles in FCC.

[0065] Step 7: The purified slurry is transported to the purified slurry storage tank through the tube bundle. The connecting tube bundle between the electrostatic separator and the purified slurry storage tank is equipped with sampling port 2 and flow meter for detecting the purified slurry.

[0066] Step 8: If the composition of the oil slurry detected at sampling port 2 does not meet the requirements of subsequent processes, the purified oil slurry will be heated in a high-temperature oil bath to prepare for further use.

[0067] Step 9: The electrostatic separator is connected to the backwash liquid tank via tube bundle, flow meter, backwash pump, and backwash liquid tank for cleaning and rinsing the electrostatic separator. The backwash liquid tank is used to hold the backwash liquid.

[0068] Step 10: The lower part of the electrostatic separator is connected to a waste liquid tank to store the waste liquid after separation, adsorption and rinsing.

[0069] Step 11: The oil slurry storage tank is connected to the purified oil slurry storage tank by a tube bundle for secondary separation and purification of the purified oil slurry. Oil slurry that does not meet the requirements of subsequent processes is transported to the oil slurry storage tank for secondary electrostatic separation and purification. During the secondary separation and purification, an AC electric field electrostatic separation can be selected until the oil slurry composition detected at sampling port 2 meets the requirements of subsequent processes.

[0070] The simulated oil slurry flow rate was selected as 200 ml / min, the solid impurity concentration was 8 mg / g, the packing material was glass spheres with a particle size between 3 mm and 3.5 mm, the central electrode voltage was 10 kV, the total simulated oil slurry volume was 25 kg, the electrostatic separation efficiency was 77% after 1 hour of separation, 74% after 4 hours of separation, and 82% after 8 hours of separation.

[0071] [Comparative Example]

[0072] The concentration of solid impurities was 8 mg / g, and the total amount of simulated oil slurry was 25 kg. The impurities were separated by sedimentation centrifugation. After 1 hour of separation, the electrostatic separation efficiency was 40%, after 4 hours of separation, the electrostatic separation efficiency was 54%, and after 8 hours of separation, the electrostatic separation efficiency was 69%, which was lower than the separation efficiency of the electrostatic separation method.

[0073] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. An oil slurry desolidification device based on electrostatic separation, characterized in that: The system includes an electrostatic separator, an oil slurry storage tank, a purified oil slurry storage tank, and a backwash liquid tank. The oil slurry storage tank is used to store catalytic cracking oil slurry and has a heating function. The oil slurry storage tank is connected to the electrostatic separator through a first tube bundle, on which an industrial peristaltic pump is installed. The electrostatic separator is connected to the purified oil slurry storage tank through a second tube bundle. The electrostatic separator is connected to a waste liquid tank through a third tube bundle. The side of the electrostatic separator away from the oil slurry storage tank is connected to the backwash liquid tank through a fourth tube bundle, on which a backwash pump is installed. The electrostatic separator includes a tank and a rotating cylinder. A heat transfer oil heating zone is provided between the tank and the rotating cylinder. A cavity composed of sieve plates is provided on the inner wall of the rotating cylinder. A catalytic cracking slurry inlet is provided on the rotating cylinder corresponding to the bottom of the cavity. An inner electrode is provided in the middle of the rotating cylinder. The inner electrode is connected to a high-voltage DC / AC power supply. Packing materials of different sizes are provided between the inner electrode and the inner wall of the rotating cylinder to allow the catalytic cracking slurry to flow fully in the electrostatic separator and separate solid impurities. The sieve plate is used for sufficient heat exchange in catalytic cracking slurry and for thorough filtration of large particulate impurities. The rotating cylinder can rotate around the inner electrode.

2. The oil slurry desolidification device based on electrostatic separation method according to claim 1, characterized in that, The first tube bundle is provided with a first sampling port.

3. The oil slurry desolidification device based on electrostatic separation according to claim 1, characterized in that, The second tube bundle is provided with a second sampling port.

4. The oil slurry desolidification device based on electrostatic separation method according to claim 1, characterized in that, The sieve plate is a polytetrafluoroethylene sieve plate.

5. The oil slurry desolidification device based on electrostatic separation according to claim 1, characterized in that, The oil slurry storage tank and the purified oil slurry storage tank are equipped with Soxhlet extraction devices, and the oil slurry storage tank and the purified oil slurry storage tank are equipped with constant temperature water baths to prevent the oil slurry from solidifying.

6. The oil slurry desolidification device based on electrostatic separation according to claim 1, characterized in that, The filler consists of glass spheres and ceramic spheres of various diameters.

7. The oil slurry desolidification device based on electrostatic separation according to claim 1, characterized in that, The oil slurry storage tank, the purified oil slurry storage tank, and the electrostatic separator are all equipped with temperature detection devices.

8. The oil slurry desolidification device based on electrostatic separation according to claim 1, characterized in that, The cavities are arranged opposite each other on the inner wall of the rotating cylinder, and the central angle opposite each cavity is greater than 90° and less than 180°.

9. A method of using an oil slurry desolidification device based on electrostatic separation as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: After the oil slurry is heated in the oil slurry storage tank, it is fed into the electrostatic separator through the first tube bundle and the industrial peristaltic pump. Step 2: After the slurry enters the electrostatic separator, a sieve plate is set at the inlet of the catalytic cracking slurry to allow the slurry to exchange heat fully and filter large particulate impurities. The internal electrode is connected to a high-voltage DC / AC power supply and energized. Under the action of the high-voltage electric field, the slurry undergoes separation of solid impurities and purified slurry. The solid impurities are adsorbed onto the internal electrode and packing. Step 3: To further improve purification efficiency, the rotating cylinder rotates around the inner electrode to ensure full contact between the oil slurry and the packing material. Step 4: The purified oil slurry is transported to the purified oil slurry storage tank through the second tube bundle; Step 5: The backwash liquid tank flushes the electrostatic separator through the fourth tube bundle, and the flushed waste liquid flows into the waste liquid tank through the third tube bundle.

Images