Online self-cleaning system of filter in alpha-olefin production device

Abstract

The utility model discloses an online self-cleaning system of a filter in an alpha-olefin production device, and belongs to the field of alpha-olefin production devices. Comprising a first filter; the second filter and the first filter are arranged in parallel; the first solvent tank is respectively communicated with the first filter and the second filter, and heating equipment is arranged in the first solvent tank; the solvent separation tank is respectively communicated with the first filter and the second filter; and back-flushing the first filter and the second filter by using the high-temperature solvent. And online cleaning of the first filter and the second filter is realized. The problem that in an existing technological process, production needs to be suspended, and a first filter and a second filter need to be detached for cleaning is solved. Potential safety hazards caused by organic gas leakage due to disassembly of the first filter and the second filter are avoided, and environmental pollution is reduced.

Description

Technical Field

[0001] This application relates to the field of α-olefin production devices, and more particularly, to an on-line self-cleaning system for a filter in an α-olefin production device. Background Art

[0002] α-olefins are an important class of organic chemical raw materials and intermediates, with wide applications in the polymer industry and the fine chemicals industry. They can be used as comonomers for the production of high-performance linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), and polyolefin elastomer (POE), and can also be used to produce high-end lubricants, plasticizers, surfactants and other fine chemicals.

[0003] For example, in CN107746365A, a bag filter is arranged on the upstream pipeline of the heat exchanger. After the reaction liquid is taken out, it passes through the filter to remove polymers, and then after recovering the reaction heat through the heat exchanger, it enters the separation unit. In CN116422059A, after the reaction liquid removes most of the products by flash evaporation, the liquid enters a settling filter, and under the action of gravity, a large amount of polymers are deposited at the bottom. The bottom discharges slowly to the filter to filter polymers more efficiently. There are also some production processes that use on-line filtration. After the reactants are taken out, they directly enter the separation section. For example, in CN114762837A, it is described that a circulating pump circulates the reaction liquid in the reactor to the filter, and after filtering out PE impurities, the reaction liquid returns to the reaction kettle. The reaction products are taken out from the side line of the reactor. However, the above processes will all cause the filter to become blocked. The usual solution is to prepare two sets of filter units and switch between them. While one set of filters is in use, the other set of filters is cleaned. For example, in CN112370856A, a filtration separation and recovery system for fine powder in a solution in the production of ethylene oligomerization is described. An anti-blowing pipeline is added to the filter structure to blow off the filter cake deposited on the filter element of the filter, so as to clean the filter and recover the polymers. However, in actual production operations, the polymers generated by the reaction have high viscosity and will stick to the surface and filter element of the filter. In order to facilitate the subsequent use of the filter, the filter needs to be cleaned.

[0004] However, in this α-olefin production device, the filter cannot be cleaned online and needs to be removed for cleaning. This reduces the production efficiency of the device. When the filter is removed, a certain amount of reactants and solvents will be released. These substances not only have a bad smell and are harmful to the human body, but are also flammable and explosive gases, posing certain safety hazards. At the same time, the cleaning of the filter consumes a lot of labor costs.

[0005] Now, an on-line self-cleaning system for a filter in an α-olefin production device is provided. Summary of the Invention

[0006] The content part of this application is used to briefly introduce concepts, which will be described in detail in the specific implementation part later. The content part of this application is not intended to identify the key features or essential features of the claimed technical solution, nor is it intended to limit the scope of the claimed technical solution.

[0007] To solve the technical problems mentioned in the above background art section, some embodiments of this application provide an on-line self-cleaning system for a filter in an α-olefin production device, including: a first filter; a second filter arranged in parallel with the first filter; a first solvent tank communicated with the first filter and the second filter respectively, and a heating device is arranged in the first solvent tank; a solvent separation tank communicated with the first filter and the second filter respectively; a recovered solvent tank communicated with the solvent separation tank; a high-pressure nitrogen system communicated with the recovered solvent tank and the first solvent tank respectively, and a first drain valve is arranged between the high-pressure nitrogen system and the recovered solvent tank; a first valve group arranged at the left end of the first filter; a second valve group arranged at the left end of the second filter; a third valve group arranged at the right end of the second filter; a fourth valve group arranged at the right end of the first filter; a fifth valve group arranged between the first solvent tank and the high-pressure nitrogen system, and at the same time the fifth valve group is arranged between the recovered solvent tank and the first solvent tank; wherein, the α-olefin production device is communicated with the first filter and the second filter respectively, and both the first filter and the second filter are used to filter the reaction liquid discharged from the α-olefin production device.

[0008] In one embodiment, the first valve group includes a first valve, a second valve, and a third valve, and the first valve and the second valve are arranged between the α-olefin production device and the first filter, and the second valve and the third valve are arranged between the first filter and the solvent separation tank.

[0009] In one embodiment, the second valve group includes a fourth valve, a fifth valve, and a sixth valve, and the fourth valve and the sixth valve are arranged between the α-olefin production device and the second filter, and the fifth valve and the sixth valve are arranged between the second filter and the solvent separation tank.

[0010] In one embodiment, the third valve group includes a seventh valve, an eighth valve, and a ninth valve, and the seventh valve and the eighth valve are arranged between the second filter and the first solvent tank.

[0011] In one embodiment, the fourth valve group includes a thirteenth valve, a fourteenth valve, and a fifteenth valve, and the fifteenth valve and the thirteenth valve are arranged between the first filter and the first solvent tank.

[0012] In one embodiment, the fifth valve group includes a tenth valve, an eleventh valve, and a twelfth valve. The tenth valve and the twelfth valve are arranged between the recycled solvent tank and the first solvent tank, and the eleventh valve and the twelfth valve are arranged between the high-pressure nitrogen system and the first solvent tank.

[0013] In one embodiment, a back-pressure valve is provided on the solvent separation tank.

[0014] In one embodiment, a second evacuation valve is provided on the first solvent tank.

[0015] In one embodiment, the heating device has an internal coil or jacket structure.

[0016] The beneficial effects of this application are as follows:

[0017] The first filter and the second filter are backflushed with high-temperature solvent. The online cleaning of the first filter and the second filter is realized. It solves the problem in the existing process flow that production needs to be suspended and the first filter and the second filter need to be disassembled for cleaning. It avoids the safety hazards caused by the leakage of organic gases due to the disassembly of the first filter and the second filter, and reduces environmental pollution. At the same time, the labor cost is reduced. In this method, the high polymer and the flushing solvent are also recovered, further improving the economic benefits of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings forming a part of this application are used to provide a further understanding of this application, making other features, objects, and advantages of this application more obvious. The schematic embodiments and their descriptions of this application are used to explain this application and do not constitute an improper limitation to this application.

[0019] In addition, throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the elements and elements are not necessarily drawn to scale.

[0020] In the drawings:

[0021] Figure 1 is a schematic diagram of the structure of the filtration unit.

[0022] In the figure: 1. Solvent separation tank; 2. High-pressure nitrogen system; 3. First valve; 4. Second valve; 5. Third valve; 6. First filter; 7. Second filter; 8. Fourth valve; 9. First solvent tank; 10. Second drain valve; 11. First drain valve; 12. Recycled solvent tank; 13. Back pressure valve; 14. Fifth valve; 15. Sixth valve; 16. Seventh valve; 17. Eighth valve; 18. Ninth valve; 19. Tenth valve; 20. Eleventh valve; 21. Twelfth valve; 22. Thirteenth valve; 23. Fourteenth valve; 24. Fifteenth valve; 25. First valve group; 26. Second valve group; 27. Third valve group; 28. Fourth valve group; 29. Fifth valve group; 30. α-olefin production unit. Detailed implementation manners

[0023] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present disclosure. It should be understood that the accompanying drawings and embodiments of the present disclosure are only for illustrative purposes and are not used to limit the protection scope of the present disclosure.

[0024] In addition, it should be noted that for the sake of convenience of description, only parts related to the relevant invention are shown in the drawings. Without conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other.

[0025] It should be noted that the concepts such as "first" and "second" mentioned in the present disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order of the functions executed by these devices, modules or units or the interdependent relationship therebetween.

[0026] It should be noted that the modifications of "one" and "multiple" mentioned in the present disclosure are illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0027] The present disclosure will be described in detail below with reference to the drawings and in combination with embodiments.

[0028] Refer to Figure 1, An on-line self-cleaning system for a filter in an α-olefin production device, comprising: a first filter 6, a second filter 7, a first solvent tank 9, a solvent separation tank 1, a recovered solvent tank 12, a first valve group 25, a second valve group 26, a third valve group 27, a fourth valve group 28, and a fifth valve group 29. The second filter 7 is arranged in parallel with the first filter 6. The first solvent tank 9 is respectively communicated with the first filter 6 and the second filter 7, and a heating device is arranged in the first solvent tank 9. The solvent separation tank 1 is respectively communicated with the first filter 6 and the second filter 7. The recovered solvent tank 12 is communicated with the solvent separation tank 1. A high-pressure nitrogen system 2 is respectively communicated with the recovered solvent tank 12 and the first solvent tank 9, and a first exhaust valve 11 is arranged between the high-pressure nitrogen system 2 and the recovered solvent tank 12. The first valve group 25 is arranged at the left end of the first filter 6. The second valve group 26 is arranged at the left end of the second filter 7. The third valve group 27 is arranged at the right end of the second filter 7. The fourth valve group 28 is arranged at the right end of the first filter 6. The fifth valve group 29 is arranged between the first solvent tank 9 and the high-pressure nitrogen system 2, and at the same time, the fifth valve group 29 is arranged between the recovered solvent tank 12 and the first solvent tank 9. Among them, the α-olefin production device 30 is respectively communicated with the first filter 6 and the second filter 7, and both the first filter 6 and the second filter 7 are used for filtering the reaction liquid discharged from the α-olefin production device 30.

[0029] The first valve group 25 includes a first valve 3, a second valve 4, and a third valve 5, and the first valve 3 and the second valve 4 are arranged between the α-olefin production device 30 and the first filter 6, and the second valve 4 and the third valve 5 are arranged between the first filter 6 and the solvent separation tank 1. The second valve group 26 includes a fourth valve 8, a fifth valve 14, and a sixth valve 15, and the fourth valve 8 and the sixth valve 15 are arranged between the α-olefin production device 30 and the second filter 7, and the fifth valve 14 and the sixth valve 15 are arranged between the second filter 7 and the solvent separation tank 1. The third valve group 27 includes a seventh valve 16, an eighth valve 17, and a ninth valve 18, and the seventh valve 16 and the eighth valve 17 are arranged between the second filter 7 and the first solvent tank 9. The fourth valve group 28 includes a thirteenth valve 22, a fourteenth valve 23, and a fifteenth valve 24, and the fifteenth valve 24 and the thirteenth valve 22 are arranged between the first filter 6 and the first solvent tank 9. The fifth valve group 29 includes a tenth valve 19, an eleventh valve 20, and a twelfth valve 21, and the tenth valve 19 and the twelfth valve 21 are arranged between the recovered solvent tank 12 and the first solvent tank 9, and the eleventh valve 20 and the twelfth valve 21 are arranged between the high-pressure nitrogen system 2 and the first solvent tank 9.

[0030] The solvent separation tank 1 is provided with a back pressure valve 13. A second drain valve 10 is arranged on the first solvent tank 9. The heating device is of an internal coil or jacket structure. The heating device being of an internal coil or jacket structure is a prior art, and the solvent temperature is raised by hot oil circulation, electric heating or steam heating.

[0031] In this method, a new self-cleaning unit structure is added to the first filter 6 and the second filter 7, and the first filter 6 and the second filter 7 are backwashed with high-temperature solvent. Online cleaning of the first filter 6 and the second filter 7 is achieved. It solves the process of suspending production and disassembling the first filter 6 and the second filter 7 for cleaning in the existing process flow. It avoids the safety hazards caused by organic gas leakage due to the disassembly of the first filter 6 and the second filter 7, and reduces environmental pollution. At the same time, the labor cost is reduced. In this method, the polymer and the rinsing solvent are also recovered, further improving the economic benefits of the device.

[0032] The rinsing solvent is selected from any one or a mixture of several of alkanes or aromatics with C5 - C18, and liquid paraffin. The alkanes or aromatics with C5 - C18 are selected from any one or a mixture of several of pentane, isopentane, n-hexane, benzene, heptane, 2-methylhexane, toluene, 2,6-dimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, 2-ethylhexane, decane, 2,2-dimethyloctane, methylpropylbenzene, naphthalene, p-methylethylbenzene, laurane, 3-butyldecane, n-tetradecane, n-hexadecane, n-octadecane.

[0033] The solvent separation tank 1 is provided with a back pressure valve 13 for maintaining the pressure in the solvent separation tank 1 ≤ 0.1 MPa, and multiple layers of filter meshes are arranged in the solvent separation tank 1 to accelerate solid-liquid separation. The high-pressure nitrogen system 2 includes a pressure regulating valve and a gas buffer tank, which is a prior art and is used to stabilize the nitrogen output pressure.

[0034] The ethylene oligomerization reaction process of the present utility model is as follows: 1. Under specific temperature / pressure conditions, the catalyst, cocatalyst, ethylene and solvent (selectively added) enter the main reactor for reaction respectively. 2. The reaction liquid passes through the first filter 6 and the second filter 7 to remove the polymer, and then circulates in the reaction system through a circulation pump and a heat exchanger. 3. The product flows out of the main reactor, passes through a catalyst inactivation tank, an ethylene recovery tower (the recovered ethylene is sent back to the reactor for continuous reaction), and a product rectification tower (the corresponding number of rectification towers is selected according to the product properties).

[0035] The system self-cleaning process is as follows:

[0036] S1. Open the tenth valve 19, the twelfth valve 21, the first drain valve 11, and the second drain valve 10. Use high-pressure nitrogen to add the solvent in the recovered solvent tank 12 to the first solvent tank 9. After completion, close the tenth valve 19, the eleventh valve 20, the twelfth valve 21, the first drain valve 11, and the second drain valve 10.

[0037] S2. Start the hot oil machine circulation and heat the solvent in the first solvent tank 9 to 180 °C.

[0038] S3. Close the first valve 3, the second valve 4, the third valve 5, the thirteenth valve 22, the fourteenth valve 23, the fifteenth valve 24, and close the pipeline of the first filter 6.

[0039] S4. Open the fourth valve 8, the sixth valve 15, the seventh valve 16, and the ninth valve 18. Switch the reaction liquid to the pipeline of the second filter 7 and continue the reaction system circulation.

[0040] S5. Open the second valve 4 and the third valve 5. The first filter 6 is depressurized, and the remaining liquid in the first filter 6 is drained into the solvent separation tank 1 until the internal pressure drops to 0.1 MPa. Then close the first valve 3, the second valve 4, and the third valve 5.

[0041] Set the back pressure valve 13 on the solvent separation tank 1 to 0.1 mpa to maintain the system pressure ≤ 0.1 mpa so that the atmosphere in the system will not be polluted by air.

[0042] S6. Open the eleventh valve 20 and the twelfth valve 21 to pre-pressurize the pressure in the first solvent tank 9 to 3 mpa.

[0043] S7. Open the second valve 4, the third valve 5, the fifteenth valve 24, and the thirteenth valve 22 in sequence. Under the action of high-pressure nitrogen, the hot solvent quickly flushes into the first filter 6 and is drained into the solvent separation tank 1 after passing through the first filter 6.

[0044] S8. After all the hot solvent is drained, close the tenth valve 19, the eleventh valve 20, and the twelfth valve 21 until the pressure in the first filter 6 drops to 0.1 MPa. Then close the fifteenth valve 24, the fourteenth valve 23, the thirteenth valve 22, the first valve 3, the second valve 4, and the third valve 5 in sequence.

[0045] Repeat the process of steps S1 - S8 for 1 - 5 times. The first filter 6 completes on-line self-cleaning and resumes normal function. The flushing liquid of the first filter 6 is drained into the solvent separation tank 1, where it is allowed to stand and settle to separate the polymer filter residue and the solvent. The filtered polymer filter residue is dried and recycled. The solvent is drained into the recovered solvent tank 12 and reused as the flushing solvent.

[0046] The above description is only some preferred embodiments of the present disclosure and an explanation of the technical principles applied. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above inventive concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) disclosed in the embodiments of the present disclosure that have similar functions.

Claims

1. An on-line self-cleaning system for a filter in an α-olefin production device, comprising: A first filter (6); A second filter (7), arranged in parallel with the first filter (6); A first solvent tank (9), communicating with the first filter (6) and the second filter (7) respectively, and a heating device is arranged in the first solvent tank (9); A solvent separation tank (1), communicating with the first filter (6) and the second filter (7) respectively; A recovered solvent tank (12), communicating with the solvent separation tank (1); A high-pressure nitrogen system (2), communicating with the recovered solvent tank (12) and the first solvent tank (9) respectively, and a first drain valve (11) is arranged between the high-pressure nitrogen system (2) and the recovered solvent tank (12); A first valve group (25), arranged at the left end of the first filter (6); A second valve group (26), arranged at the left end of the second filter (7); A third valve group (27), arranged at the right end of the second filter (7); A fourth valve group (28), arranged at the right end of the first filter (6); A fifth valve group (29), arranged between the first solvent tank (9) and the high-pressure nitrogen system (2), and at the same time the fifth valve group (29) is arranged between the recovered solvent tank (12) and the first solvent tank (9); Wherein, the α-olefin production device (30) communicates with the first filter (6) and the second filter (7) respectively, and both the first filter (6) and the second filter (7) are used for filtering the reaction liquid discharged from the α-olefin production device (30).

2. The on-line self-cleaning system for a filter in an α-olefin production device according to claim 1, characterized in that: The first valve group (25) includes a first valve (3), a second valve (4), and a third valve (5), and the first valve (3) and the second valve (4) are arranged between the α-olefin production device (30) and the first filter (6), and the second valve (4) and the third valve (5) are arranged between the first filter (6) and the solvent separation tank (1).

3. The on-line self-cleaning system for a filter in an α-olefin production device according to claim 1, characterized in that: The second valve group (26) includes a fourth valve (8), a fifth valve (14), and a sixth valve (15), and the fourth valve (8) and the sixth valve (15) are arranged between the α-olefin production device (30) and the second filter (7), and the fifth valve (14) and the sixth valve (15) are arranged between the second filter (7) and the solvent separation tank (1).

4. The on-line self-cleaning system for a filter in an α-olefin production device according to claim 1, characterized in that: The third valve group (27) includes a seventh valve (16), an eighth valve (17), and a ninth valve (18), and the seventh valve (16) and the eighth valve (17) are arranged between the second filter (7) and the first solvent tank (9).

5. The on-line self-cleaning system for a filter in an α-olefin production device according to claim 1, characterized in that: The fourth valve group (28) includes a thirteenth valve (22), a fourteenth valve (23), and a fifteenth valve (24). The fifteenth valve (24) and the thirteenth valve (22) are arranged between the first filter (6) and the first solvent tank (9).

6. The on-line self-cleaning system for a filter in an α-olefin production device according to claim 1, characterized in that: The fifth valve group (29) includes a tenth valve (19), an eleventh valve (20), and a twelfth valve (21). The tenth valve (19) and the twelfth valve (21) are arranged between the recovered solvent tank (12) and the first solvent tank (9), and the eleventh valve (20) and the twelfth valve (21) are arranged between the high-pressure nitrogen system (2) and the first solvent tank (9).

7. The on-line self-cleaning system for a filter in an α-olefin production device according to claim 1, characterized in that: The solvent separation tank (1) is provided with a back pressure valve (13).

8. The on-line self-cleaning system for a filter in an α-olefin production device according to claim 1, characterized in that: A second drain valve (10) is arranged on the first solvent tank (9).

9. The on-line self-cleaning system for a filter in an α-olefin production device according to claim 1, characterized in that: The heating device is of an internal coil or jacket structure.

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