A supergravity oil-solid separation device and a separation method

Abstract

This invention discloses a high-gravity oil-solid separation device and method. The device comprises two parts: high-gravity separation and membrane filtration separation. The high-gravity separation part includes a device body, an oil slurry inlet, a diluent inlet, a pipeline mixer, a rotating shaft, a liquid distributor, separation components, a slurry enrichment plate, a heavy phase outlet, a centrifugal pump, a light phase outlet, a motor, and a nitrogen inlet. The membrane filtration separation part includes pipelines and sliding baffles, with the pipelines divided into membrane filtration pipelines and diluent inlet pipelines. This invention first discharges most solid particles through high-gravity separation, and then uses membrane filtration separation to improve the solidification effect, overcoming the limitations of a single separation mode, enhancing the separation effect and long-term operational stability, while simplifying the process flow and saving floor space.

Description

Technical Field

[0001] This invention relates to the field of solid-liquid separation technology, and in particular to a supergravity oil-solid separation device and separation method. Background Technology

[0002] Catalytic cracking slurry oil, characterized by its high C-H ratio, high content of short-chain aromatics, and high density, is a high-quality feedstock for the production of advanced carbon materials. However, its extensive content of fine catalyst powder severely limits its further applications. With the development of electric vehicles, aerospace, and other fields in my country, and the increasingly thin profit margins of traditional refining industries, the deep processing and utilization of catalytic cracking slurry oil has become a new economic growth point for refineries. Therefore, there is an urgent need for efficient slurry oil desolidification technology for resource-based treatment.

[0003] Existing technologies for oil slurry desolidification have been documented. For example, patents CN 113181814A and CN 113816586A disclose a high-gravity oil-solid separation system. First, a special channel device is used to initially mix the oil sludge (oil slurry) with a cleaning agent (sedimenting agent). Then, a high-gravity device is used to enhance the mixing effect, followed by sedimentation separation. This method enhances the mass transfer between the chemical agents and the oil slurry, and strengthens the effect of chemical sedimentation, but still requires a storage tank for sedimentation separation. Patent CN111363584A discloses an oil slurry desolidification device based on a special membrane filtration system. By controlling the pipeline, the membrane filters can be connected in series and parallel to adjust the purification requirements of different oil slurries, while also achieving filter backwashing without retention. Patent CN 104726128A discloses a catalytic cracking slurry catalyst purification and separation device. This device first uses a high-temperature centrifuge at 120–180°C for centrifugal separation, then heats the mixture to 200–300°C for membrane filtration separation, and utilizes dry gas for online backwashing. Another example is patent CN 102553343A, which discloses a continuous separation method. First, a high-speed centrifuge is used for primary separation. The light liquid component enters a multi-layer sintered metal mesh filter for secondary separation. After separation, the ash content of the slurry is less than 65.80 μg / g. After running for 20–60 minutes, backflushing with backflushing air is required, and the filter residue is treated separately. Patent CN110747006A discloses a method for removing solid impurities from catalytic cracking slurry. This method includes a catalyst-oil mixing unit, a centrifugal deasphalting unit, a light slurry filtration unit, a light slurry desolventizing unit, and a heavy slurry desolventizing unit. Centrifugation is used to remove asphalt from the slurry, reducing the impact of asphalt on filtration and decreasing the frequency of filter cleaning and backwashing. Patent CN109207193A discloses a sedimentation-electrostatic separation-filtration combination for oil slurry purification. Through pretreatment with gravity and electrostatic fields, it can separate most solid particles and asphaltene, thereby reducing the filter's workload and extending its operating cycle. Another example is patent CN 113413646A, which discloses a supergravity device for solid-liquid separation. This device integrates a supergravity mixing section and a supergravity separation section within the same unit. This equipment combines the mixing of reagents with oil slurry and the separation of oil slurry from solid particles into a single unit, saving floor space. However, the improvement in solidification efficiency mainly depends on enhanced mixing. Patent CN206746152U discloses an ultrasonic centrifugal filtration device that combines ultrasonic technology, centrifugal separation technology, and filtration separation technology in the same device. Ultrasonic waves promote the fusion of oil slurry with solvents or chemical reagents, while the rotating shaft and screen accelerate solid-liquid separation. Essentially, it constitutes a filtration centrifuge, improving the separation efficiency by 10% compared to single centrifugal filtration, but it does not explain how the screen is regenerated.

[0004] In the existing technologies described above, if a single centrifugal separation method is used, the processed slurry often fails to meet the requirements for processing high-end carbon materials. While membrane filtration with smaller pore sizes can improve the desolidification effect, the accumulation of large amounts of ash leads to frequent membrane washing and regeneration, affecting membrane lifespan and process stability. Combined processes can mitigate these problems, but require connecting different functional devices in series, resulting in a large footprint. Furthermore, the waste liquid and residue generated by different separation devices need separate treatment, and the process conditions vary depending on the specific process. Due to hardware limitations, the temperature of centrifugal separation is typically below 100℃, and even with a high-temperature centrifuge, the operating temperature cannot exceed 180℃. Membrane filtration and electrostatic separation processes often require heating the slurry to above 200℃ to ensure sufficient flux, but this increases the complexity of the combined process. Summary of the Invention

[0005] This invention addresses the technical problems of poor desolidification efficiency and frequent cleaning in single separation devices, as well as the large footprint and complex processes of combined processes, by providing a high-gravity oil-solid separation device and method. This separation device integrates high-gravity separation and membrane filtration separation into a single unit, achieving efficient and continuous oil slurry desolidification.

[0006] In a first aspect, the present invention provides a supergravity oil-solid separation device, which is achieved by the following technical solution.

[0007] A supergravity oil-solid separation device includes a device body, with multiple pipelines above the device body, each pipeline containing a membrane filtration device. The pipelines are divided into two types: membrane filtration pipelines and diluent feed pipelines.

[0008] The device body forms an oil slurry feeding channel, with an oil slurry inlet at the upper end and a liquid distributor at the lower end. A pipe mixer is installed inside the oil slurry feeding channel, and a rotating shaft is located within the pipe mixer. A diluent inlet is opened on the upper side wall of the oil slurry feeding channel. Both the diluent inlet and the light phase outlet located at the top of the device body are connected to pipelines. Sliding baffles are installed at the diluent inlet and the light phase outlet, allowing the sliding baffles to switch between the diluent inlet and the light phase outlet being connected to the pipeline.

[0009] The device body is equipped with a separation component that communicates with the liquid distributor. A heavy phase outlet is formed at the bottom of the device body, and a movable slurry enrichment plate is provided above the heavy phase outlet. A centripetal pump is also provided in the device body near the light phase outlet.

[0010] Furthermore, there are a total of 2 to 10 pipelines, of which the ratio of the membrane filtration pipeline 13 and the diluent feed pipeline 14 can be adjusted according to the process requirements, with at least one of each type. Preferably, there are 4 to 8 pipelines.

[0011] Furthermore, the number of membrane filtration lines is 2 to 3 times that of the diluent feed lines.

[0012] Furthermore, the filter membrane in the membrane filtration device is selected from inorganic ceramic membranes or metal sintered membranes, and the pore size of the filter membrane is in the range of 0.2 to 20 μm, which can be adjusted according to process requirements.

[0013] Furthermore, the separation components can take the form of discs, baffles, or spirals.

[0014] Furthermore, the pipeline is equipped with a heating component; specifically, the heating component may be a resistance heater, an electromagnetic heater, a heat tracing coil or half-pipe, or steam heating, to improve the fluidity of the oil slurry.

[0015] Furthermore, the upper part of the device body is also provided with a nitrogen port for introducing nitrogen for protection.

[0016] Furthermore, the rotating shaft is directly or indirectly connected to the motor. Specifically, the motor is located above the device body and directly connected to the rotating shaft, or it is located on the side of the device body and driven by gears or belts.

[0017] Furthermore, the slurry enrichment plate is program-driven, adjusting the slag discharge cycle according to specific process conditions. During normal operation, the slurry enrichment plate is placed at an angle, blocking the heavy phase discharge outlet. During slag discharge, the slurry enrichment plate is in a vertical position, using oil slurry to carry the enriched slurry out from the heavy phase discharge outlet.

[0018] Secondly, the present invention provides a method for separating oil and solids under high gravity, which is achieved by the following technical solution.

[0019] A method for separating oil and solids under high gravity, using the aforementioned high gravity oil-solid separation device, comprises the following specific steps:

[0020] S1. The oil slurry entering from the oil slurry inlet and the diluent entering from the diluent inlet are mixed through the pipeline mixer and then diffused through the liquid distributor into the super gravity field generated by the rotating shaft driven by the motor. The separation component promotes solid-liquid separation. After the solid particles are enriched in the slurry enrichment plate, they are discharged from the heavy phase outlet at regular intervals.

[0021] S2. After the solids are removed, the light phase is pressurized by a centripetal pump, discharged into the pipeline through the light phase outlet, and heated by the heating element before being filtered and separated in the pipeline.

[0022] S3. After running for a specified period, move the sliding baffle to close the light phase outlet, connect the pipeline to the diluent inlet, and use the diluent to backwash the filter membrane. The diluted solution after backwashing is then incorporated into the oil slurry and enters the main body of the device.

[0023] Furthermore, the diluent includes component oils, liquid alkanes, and liquid aromatics; the component oils include naphtha, gasoline, diesel, heavy cycle oil, and solvent oil.

[0024] This application has the following beneficial effects.

[0025] This invention integrates gravity separation and membrane filtration into a single device. First, gravity separation removes most solid particles, reducing the burden on the membrane separation section and extending the operating cycle. After gravity separation, some asphaltenes and gum are discharged with the solid particles, reducing the slurry viscosity. Furthermore, the addition of diluent and the heating effect of the heating components in the membrane filtration line ensure sufficient slurry throughput, making it possible for gravity separation and membrane filtration to coexist on the same device. On the other hand, the same pipeline simultaneously serves as both diluent feed and membrane backwashing, overcoming the limitations of traditional membrane filtration processes in terms of backwashing volume and time. The separated solid particles are intermittently flushed out using slurry according to a set program, facilitating long-distance pumping and achieving continuous process operation. This invention integrates two separation schemes into one device, overcoming the limitations of a single separation mode, enhancing separation efficiency and long-term operational stability, while saving floor space and simplifying the process flow. This invention can also be used for desoldering other heavy and inferior oil products such as sludge. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the supergravity oil-solid separation device of the present invention.

[0027] The components include: 1. Oil slurry inlet; 2. Diluent inlet; 3. Pipeline mixer; 4. Rotating shaft; 5. Liquid distributor; 6. Separation component; 7. Slurry enrichment plate; 8. Heavy phase outlet; 9. Centripetal pump; 10. Light phase outlet; 11. Motor; 12. Heating assembly; 13. Membrane filter line; 14. Diluent inlet line; 15. Sliding baffle; 16. Nitrogen port; 17. Unit body; and 18. Oil slurry feed channel. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] like Figure 1 As shown, a supergravity oil-solid separation device includes two parts: supergravity separation and membrane filtration separation.

[0030] The hypergravity separation section includes a device body 17, an oil slurry feed channel 18, an oil slurry inlet 1, a diluent inlet 2, a pipe mixer 3, a rotating shaft 4, a liquid distributor 5, a separation component 6, a slurry enrichment plate 7, a heavy phase outlet 8, a centripetal pump 9, a light phase outlet 10, a motor 11, and a nitrogen inlet 16. The oil slurry inlet 1 and the diluent inlet 2 are located above the pipe mixer 3, and the liquid distributor 5 is located below it. The liquid distributor 5 communicates with the separation component 6 and is located inside the device body 17. Below the separation component 6, the slurry enrichment plate 7 and the heavy phase outlet 8 are arranged downwards. The pipe mixer 3 contains a rotating shaft 4 that generates a hypergravity field, and the rotating shaft 4 is connected to the motor 11. The device body 17 also has a centripetal pump 9 axially arranged to discharge the light phase, and the device body 17 has a light phase outlet 10 at its upper part.

[0031] The membrane filtration separation section includes a heating element 12, pipelines, and a sliding baffle 15. The pipelines are of two types: a membrane filtration pipeline 13 and a diluent feed pipeline 14. The membrane filtration pipeline 13 is connected to the light phase outlet 10, and the diluent feed pipeline 14 is connected to the diluent inlet 2. The pipeline can be switched between membrane filtration pipeline 13 and diluent feed pipeline 14 via the sliding baffle 15 to achieve membrane backwashing.

[0032] The following describes this application in more detail, taking the device body 17 connected to two pipelines, one being a membrane filtration pipeline 13 and the other being a diluent feed pipeline 14.

[0033] The diluent inlet 2 is connected to the diluent feed line 14, and the light phase outlet 10 is connected to the membrane filtration line 13. Figure 1 In this state, the pipeline located on the left side of the device body 17 is the diluent feed pipeline 14, and the pipeline located on the right side of the device body 17 is the membrane filtration pipeline 13. At this time, the sliding baffle 15 blocks the light phase outlet 10 on the left and the diluent inlet 2 on the right, and opens the diluent inlet 2 on the left and the light phase outlet 10 on the right.

[0034] The rotating shaft 4, driven by motor 11, generates a supergravity field. Nitrogen gas is first introduced through nitrogen port 16 to replace the air in the device before feeding. The oil slurry entering from oil slurry inlet 1 and the diluent entering from diluent inlet 2 are mixed by pipeline mixer 3 and reach the bottom of the equipment. They are then diffused into the supergravity field by liquid distributor 5. The separation component 6 promotes solid-liquid separation. The light phase after solid removal is pressurized by centripetal pump 9 and discharged through light phase outlet 10. After being heated by heating component 12, it is filtered and separated in membrane filter pipeline 13 to further improve the solid removal effect.

[0035] According to a pre-programmed sequence, the slurry enrichment plate 7 in the supergravity separation section periodically changes from an inclined position to a vertical position, exposing the heavy phase discharge outlet 8. The enriched slurry is then carried out of the heavy phase discharge outlet 8 by the oil slurry. Subsequently, the slurry enrichment plate 7 returns to its original position and continues to collect solid particles.

[0036] When the filtration pressure drop is too large or the expected replacement cycle is reached, slide the sliding baffle 15 to block the light phase outlet 10 on the right and the diluent inlet 2 on the left, and open the diluent inlet 2 on the right and the light phase outlet 10 on the left. At this time, the pipeline on the left side of the device body 17 changes from the diluent inlet pipeline 14 to the membrane filtration pipeline 13, and the pipeline on the right side of the device body 17 changes from the membrane filtration pipeline 13 to the diluent inlet pipeline 14. Switch the external pipeline valve so that the diluent enters the diluent inlet 2 through the new diluent inlet pipeline 14 (right side pipeline), and backwash the filter membrane until the next replacement cycle.

[0037] The following uses the ultragravity oil-solid separation device of this application to desolidify the oil slurry, and the ash content of the oil slurry is measured according to the method specified in the national standard GB / T 508-85 Petroleum Products Ash Content Determination Method to evaluate the desolidification effect of the oil slurry.

[0038] Example 1

[0039] The rotational speed of shaft 4 was set to 7000 rpm, the feed rate of the slurry (ash content 0.523%) was 700 kg / h, and the diluent was selected as diesel oil with a feed rate of 300 kg / h. The slurry entered through a diluent feed line 14 and exited through a membrane filtration line 13. A disc-type separation component was used, with a slag discharge cycle set to 60 minutes. The temperature of the membrane filtration line 13 was maintained at 150℃ by adjusting the heating component 12. After 7 days of continuous operation, the ash content of the slurry was 0.003%, the deashing rate was 99.43%, and the filtration pressure drop increased by 0.45%.

[0040] Example 2

[0041] The rotational speed of shaft 4 was set to 3000 rpm, the feed rate of slurry (ash content 0.523%) was 900 kg / h, and diesel oil was selected as the diluent with a feed rate of 100 kg / h. The slurry entered through one diluent feed line 14 and exited through nine membrane filtration lines 13. A baffle-type separation component was used, with a slag discharge cycle set to 10 minutes. The temperature of membrane filtration lines 13 was maintained at 110℃ by adjusting the heating component 12. After 7 days of continuous operation, the ash content of the slurry was 0.010%, the deashing rate was 98.09%, and the filtration pressure drop increased by 2.33%.

[0042] Example 3

[0043] The rotational speed of shaft 4 was set to 5000 rpm, the feed rate of slurry (ash content 0.523%) was 800 kg / h, and diesel oil was selected as the diluent with a feed rate of 200 kg / h. The slurry entered through two diluent feed lines 14 and exited through four membrane filtration lines 13. A spiral separation component was used, with a slag discharge cycle set to 60 minutes. The temperature of membrane filtration lines 13 was maintained at 130℃ by adjusting the heating component 12. After 7 days of continuous operation, the ash content of the slurry was 0.007%, the deashing rate was 98.66%, and the filtration pressure drop increased by 1.62%.

[0044] Comparative Example 1

[0045] Using the supergravity separation technology alone, with different separation components, different rotation speeds, different diesel fuel addition amounts, and different slag discharge cycles, the ash content and deashing rate of the oil slurry after 7 days of continuous operation are shown in Table 1.

[0046] Table 1 Results of oil slurry treatment using centrifugal separation technology alone

[0047]

[0048] Comparative Example 2

[0049] Table 2 shows the increase in ash content, deashing rate, and filtration pressure drop of the oil slurry after 7 days of continuous operation at different diesel fuel addition amounts and temperatures using membrane filtration technology alone.

[0050] Table 2 Results of oil slurry treatment using membrane filtration separation technology alone

[0051]

[0052] Note: "×" indicates that the filter membrane was clogged and the operating time was less than 7 days.

[0053] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A supergravity oil-solid separation device, comprising a device body (17), characterized in that: The device body (17) is provided with multiple pipelines above it, and membrane filtration devices are provided in the pipelines. The pipelines are divided into two types: membrane filtration pipeline (13) and diluent feed pipeline (14). The device body (17) forms an oil slurry feeding channel (18), the upper end of the oil slurry feeding channel (18) forms an oil slurry inlet (1), the lower end of the oil slurry feeding channel (18) is provided with a liquid distributor (5), the oil slurry feeding channel (18) is provided with a pipeline mixer (3), and the pipeline mixer (3) is provided with a rotating shaft (4); the upper side wall of the oil slurry feeding channel (18) is provided with a diluent inlet (2), the diluent inlet (2) and the light phase outlet (10) set at the top of the device body (17) are both connected to the pipeline; the diluent inlet (2) and the light phase outlet (10) are provided with sliding baffles (15), the sliding baffles (15) switch the diluent inlet (2) or the light phase outlet (10) to be connected to the pipeline; The device body (17) is provided with a separation component (6) that communicates with the liquid distributor (5). A heavy phase outlet (8) is formed at the bottom of the device body (17). A movable slurry enrichment plate (7) is provided above the heavy phase outlet (8). A centripetal pump (9) is also provided in the device body (17) near the light phase outlet (10).

2. The ultragravity oil-solid separation device according to claim 1, characterized in that: There are a total of 2 to 10 pipelines, of which at least one membrane filtration pipeline (13) and one diluent feed pipeline (14) are included.

3. The ultragravity oil-solid separation device according to claim 2, characterized in that: The number of membrane filtration lines (13) is 2 to 3 times that of diluent feed lines (14).

4. The ultragravity oil-solid separation device according to claim 1, characterized in that: The filter membrane in the membrane filtration device is selected from inorganic ceramic membranes or metal sintered membranes, and the pore size range of the filter membrane is 0.2~20μm.

5. The ultragravity oil-solid separation device according to claim 1, characterized in that: The separation component (6) can be in the form of a disc, a baffle, or a spiral.

6. The ultragravity oil-solid separation device according to claim 1, characterized in that: The pipeline is equipped with a heating component (12).

7. The ultragravity oil-solid separation device according to claim 1, characterized in that: The upper part of the device body (17) is also provided with a nitrogen port (16).

8. The ultragravity oil-solid separation device according to claim 1, characterized in that: The rotating shaft (4) is directly or indirectly connected to the motor (11).

9. A method for separating oil and solids under high gravity, characterized in that: The specific steps of using the supergravity oil-solid separation device according to any one of claims 1-8 are as follows: S1. The oil slurry entering from the oil slurry inlet (1) and the diluent entering from the diluent inlet (2) are mixed by the pipeline mixer (3), and then diffused by the liquid distributor (5) into the supergravity field generated by the rotating shaft (4) driven by the motor (11). The solid-liquid separation is promoted by the separation component (6). After the solid particles are enriched in the slurry enrichment plate (7), they are discharged from the heavy phase outlet (8) at regular intervals. S2. After the solids are removed, the light phase is pressurized by the centripetal pump (9), discharged through the light phase outlet (10), enters the pipeline, and is heated by the heating component (12) before being filtered and separated in the pipeline. S3. After running to the specified cycle, move the sliding baffle (15) to close the light phase outlet (10) so that the pipeline is connected to the diluent inlet (2) and the diluent is used to backwash the filter membrane. The diluted liquid after backwashing is incorporated into the oil slurry and enters the device body (17).

10. The method for separating oil and solids under high gravity according to claim 9, characterized in that: The diluent includes component oil, liquid alkanes, and liquid aromatics; the component oil includes naphtha, gasoline, diesel, or heavy cycle oil.

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