Low-concentration gas enrichment and membrane repair self-circulation device

Abstract

The invention discloses a low-concentration gas enrichment and membrane repair self-circulation device which comprises a kettle body, a guide channel and a turnover mechanism. The interior of the kettle body is divided into an enrichment area and a restoration area; a membrane adsorption separation module is arranged in the enrichment area and comprises an adsorption membrane; a film self-repairing module is arranged in the repairing area and comprises a cleaning material; the guide channel is used for guiding decomposition products of the cleaning material to enter the adsorption film of the enrichment area; a valve for controlling opening and closing is mounted on a pipeline of the guide channel; a solar driving module is embedded in the outer wall of the bottom of the kettle body and used for providing heat energy for the cleaning materials. And the overturning mechanism can drive the kettle body to overturn and stand upside down. The cleaning material is driven by heat energy to automatically clean impurities on the surface of the membrane, so that efficient treatment of low-concentration gas and the self-repairing function of the membrane are realized, the service life of the membrane is prolonged, the manual maintenance cost is reduced, the service life of the membrane is prolonged, and the membrane is environment-friendly and safe.

Description

Technical Field

[0001] The present invention relates to the technical field of low-concentration gas enrichment and separation, and in particular to a low-concentration gas enrichment and membrane repair self-circulation device. Background Art

[0002] With the continued advancement of industrialization, the treatment of low-concentration gas has gradually attracted widespread attention. Especially in the fields of coal mining, natural gas, and oil extraction, the emission of low-concentration gas not only wastes resources but also poses a potential threat to the environment and human health. Therefore, how to efficiently and sustainably recover and utilize this low-concentration gas has become a pressing technical challenge.

[0003] Traditional low-concentration gas treatment technologies mainly include adsorption, membrane separation and catalytic methods. Among them, membrane separation technology has been widely used due to its advantages such as low energy consumption, simple operation and no secondary pollution. However, existing membrane separation devices usually face the problem that the membrane material will be deposited and contaminated by impurities during long-term use, resulting in membrane performance degradation and reduced treatment efficiency. Especially when treating low-concentration gas, due to its complex composition, the membrane surface is easily clogged by harmful substances and pollutants, which in turn affects the service life of the membrane. In order to overcome this problem, researchers have proposed a variety of membrane repair technologies, hoping to extend the service life of the membrane through external cleaning, chemical repair and other methods. However, these methods often require additional energy and manual intervention, and cannot effectively solve the problem of incomplete repair caused by the accumulation of pollutants during the use of the membrane.

[0004] Therefore, there is an urgent need for a new type of membrane separation device to solve the shortcomings of the above-mentioned existing technologies, such as the membrane materials are easily contaminated, resulting in reduced performance and treatment efficiency, and the existing membrane repair technology requires additional energy and manual intervention, and the repair is incomplete. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a low-concentration gas enrichment and membrane repair self-circulation device; by combining the design of adsorption membrane and self-cleaning repair membrane, thermal energy is used to drive the repair material to automatically clean impurities on the membrane surface, thereby achieving efficient treatment of low-concentration gas and the self-repair function of the membrane, extending the service life of the membrane and reducing manual maintenance costs.

[0006] In order to achieve the above-mentioned object, the present invention provides a low-concentration gas enrichment and membrane repair self-circulation device, comprising a kettle body, a guide channel and a turning mechanism;

[0007] The kettle body is provided with a mouth at the top, and the interior of the kettle body is divided into an upper enrichment zone and a lower repair zone; a membrane adsorption separation module is provided in the enrichment zone, and the membrane adsorption separation module includes an adsorption membrane for adsorbing low-concentration gas; a membrane self-repair module is provided in the repair zone, and the membrane self-repair module includes a cleaning material;

[0008] The guide channel is located outside the kettle body, with one end of the pipeline connected to the repair area and the other end connected to the enrichment area, and is used to guide the decomposition products of the cleaning material into the adsorption membrane in the enrichment area; a valve for controlling opening and closing is installed on the pipeline of the guide channel; the valve of the guide channel is a gravity-driven one-way valve;

[0009] The outer wall of the bottom of the kettle body is inlaid with a solar drive module, which is used to provide heat energy for the cleaning material;

[0010] The turning mechanism includes a bracket and a turning motor arranged on the bracket. The output shaft of the turning motor is connected to the side wall of the kettle body and can drive the kettle body to turn over and stand upside down.

[0011] Furthermore, the adsorption membrane uses polyethersulfone as a polymer matrix, and modified activated carbon and NU-1000 are added into the matrix as fillers.

[0012] Furthermore, the preparation method of the adsorption film includes:

[0013] S1: adding polyvinyl pyrrolidone and polyether sulfone to dimethyl sulfoxide in a mass ratio of 1:10-1:20; stirring at 40-100°C for 5-10 hours to completely dissolve the two, to obtain a PES solution;

[0014] S2: adding the modified activated carbon to dimethyl sulfoxide at a ratio of 1-10 wt%, and ultrasonically treating for 30-180 minutes to uniformly disperse the modified activated carbon particles to obtain an activated carbon solution; adding NU-1000 to dimethyl sulfoxide at a ratio of 10-30 wt%, and ultrasonically treating for 30-180 minutes to uniformly disperse the NU-1000 particles to obtain a NU-1000 solution;

[0015] S3: Add the activated carbon and NU-1000 solution dispersed in step S2 to the PES solution obtained in step S1, stir at 50-100°C for 1-3 hours, and then place in an ultrasonic bath for 30-180 minutes to prevent filler agglomeration and ensure uniform distribution of the activated carbon and NU-1000 in the solution;

[0016] S4: Finally, the mixed solution obtained in step S3 is poured into the membrane mold and dried at 60-80°C for 8-12 hours to form an adsorption membrane, which is then cut and installed in the enrichment area.

[0017] Furthermore, the cleaning material adopts a composite particle product of ZIF-8 material, polylactic acid and polyvinyl alcohol. The composite particle product can be decomposed to produce ZnO under the action of thermal energy to clean impurities on the surface of the adsorption film.

[0018] Furthermore, the preparation method of the cleaning material includes:

[0019] S1: adding polyvinyl alcohol and polylactic acid in a mass ratio of 1:1-4:1 to a mixed solution of ethanol and water, wherein the ratio of ethanol to water is 7:3-9:1; stirring at 60-100° C. to dissolve the two;

[0020] S2: Add ZIF-8 material to the solution obtained in step S1, wherein the amount of ZIF-8 material added is 10%-50% of the total mass of polyvinyl alcohol and polylactic acid, and stir for 10-20 minutes to uniformly distribute the ZIF-8;

[0021] S1: After evaporating the solvent obtained in step S2, the mixture is dried and ground to form particles with a size of 100-500 μm.

[0022] Furthermore, the solar drive module is arranged on the bottom outer shell of the kettle body. When the membrane adsorption separation module needs to be cleaned, the kettle body is flipped 160-180 degrees, and the solar drive module is used to accumulate heat energy to promote the decomposition of the cleaning material in the repair area. The decomposition products enter the area where the adsorption membrane is located through the guide channel to achieve self-repair of the membrane.

[0023] Furthermore, it also includes a methane outlet, which is connected to the enrichment zone and is used to discharge the methane separated and enriched by the adsorption membrane. A membrane flux detector is installed at the methane outlet.

[0024] Beneficial effects of the present invention:

[0025] 1. The membrane adsorption separation module of the present invention utilizes a mixed matrix design consisting of a polyethersulfone matrix, modified activated carbon, and a NU-1000 metal-organic framework. The high specific surface area of ​​the modified activated carbon increases gas adsorption sites, while the regular pore structure of NU-1000 enhances methane selectivity. These two synergistically improve the separation efficiency of low-concentration gas, effectively enriching methane from low-concentration gas and reducing resource waste. This provides practical technical support for gas recovery in coal mining, oil and gas extraction, and other fields.

[0026] 2. The ZIF-8 / PLA / PVA composite particles in the repair area of ​​the present invention decompose under the action of the thermal energy provided by the solar drive module to produce ZnO active ingredients, which enter the membrane layer through the guide channel and oxidize and decompose pollutants such as oil and dust; the membrane flux detector at the methane outlet monitors the membrane performance in real time. When the flux drops to the set range, the flip mechanism is automatically started and the gravity-driven one-way valve is opened synchronously, without the need for manual judgment or operation, thus solving the problem of traditional membrane repair requiring additional energy and manual maintenance.

[0027] 3. The device of the present invention realizes the autonomous cycle of gas treatment and membrane maintenance through the closed-loop logic of "enrichment-pollution-repair-re-enrichment": when the membrane is polluted, repair is automatically started, and it automatically resets to the enrichment state after the repair is completed, without the need for frequent shutdown to replace membrane materials; the solar drive module uses clean energy as its main energy source, and the gravity-driven one-way valve has a non-powered design to further reduce energy consumption and operating costs, making it suitable for long-term outdoor operation scenarios.

[0028] 4. The present invention integrates core components such as the enrichment area, repair area, and guide channel into the kettle body, which is compact and highly sealed and can adapt to complex industrial environments. The coordinated design of mechanical components such as the flip mechanism and gravity valve and the membrane system and solar module not only ensures the gas separation efficiency during enrichment, but also ensures the precise delivery of cleaning materials during repair. The overall structure has high stability and low failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention.

[0030] Figure 2 It is a schematic structural diagram of the interior of the kettle body according to an embodiment of the present invention.

[0031] In the figure: 1. Pot body; 11. Pot mouth; 12. Enrichment area; 13. Repair area; 14. Membrane adsorption separation module; 15. Membrane self-repair module; 16. Guide channel; 17. Methane outlet; 2. Solar drive module; 3. Flipping mechanism; 31. Bracket; 32. Flipping motor. DETAILED DESCRIPTION

[0032] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0033] The invention discloses a low-concentration gas enrichment and membrane repair self-circulation device.

[0034] Reference Figure 1 and Figure 2A low-concentration gas enrichment and membrane repair self-circulation device is designed based on the "backflow pot" principle, mainly used for low-concentration gas enrichment and membrane pollution self-repair, including a pot body 1, a solar drive module 2, a guide channel 16 and a flip mechanism 3;

[0035] A mouth 11 is provided on the top of the kettle body 1 for the entry of low-concentration gas, and the interior is divided into an upper enrichment area 12 and a lower repair area 13;

[0036] The enrichment zone 12 is equipped with a membrane adsorption separation module 14, the core of which is a highly selective adsorption membrane used to adsorb methane in low-concentration gas and separate impurities such as nitrogen and carbon dioxide. A methane outlet 17 is provided on the side of the enrichment zone 12, which is connected to the outside world and is used to discharge the enriched methane. A membrane flux detector is installed at the methane outlet 17.

[0037] The repair area 13 is located in the lower layer of the kettle body 1 and has built-in cleaning materials for self-repair after membrane pollution;

[0038] The solar drive module 2 is embedded in the bottom shell of the kettle body 1, which can absorb solar energy and convert it into heat energy, providing the energy required for the decomposition of the cleaning materials in the repair area 13;

[0039] The guide channel 16 is located outside the kettle body 1. One end of its pipeline is connected to the repair area 13, and the other end is connected to the membrane adsorption separation module 14 of the enrichment area 12. A valve that controls opening and closing is installed on the pipeline of the guide channel 16. The guide channel 16 is used to guide the decomposition products of the cleaning material into the adsorption membrane area. The valve of the guide channel 16 can be a manual valve or a gravity-driven one-way valve, preferably a gravity-driven one-way valve. When the device is in the enrichment upright state, the valve core contacts the sealing surface under the action of its own gravity, closing the channel and ensuring that the gas in the enrichment area 12 is separated only by the membrane system and does not connect with the repair area 13. During the inverted repair stage, the valve core is affected by the reverse force of gravity, detaches from the sealing surface, and the channel is opened. The decomposition products of the cleaning material can enter the membrane layer driven by gravity and airflow to complete the cleaning. No additional power is required, and the enrichment and repair self-circulation is achieved.

[0040] The flipping mechanism 3 includes a bracket 31 and a flipping motor 32 mounted on the bracket 31 . The output end of the flipping motor 32 is connected to the side wall of the kettle body 1 , thereby driving the kettle body 1 to tilt and flip.

[0041] When the membrane flux detector detects that the membrane flux has dropped to a set value, the flip mechanism 3 tilts the kettle body 1 and activates the membrane repair function. The solar drive module 2 flips upward and absorbs solar energy, converting it into heat energy to decompose the cleaning material. The valve in the guide channel 16 automatically opens, allowing the decomposition products to enter the adsorption membrane in the enrichment zone 12 for membrane repair. After the membrane flux returns to the set value, the flip mechanism 3 flips the kettle body 1 to an upright enrichment state. The interaction of these structures realizes a self-circulating process of gas enrichment, membrane fouling, self-repair, and re-enrichment without the need for continuous human intervention.

[0042] The core of the membrane adsorption separation module 14 is the adsorption membrane. The adsorption membrane uses polyethersulfone (PES) as a matrix, with modified activated carbon and NU-1000 (metal organic framework, MOF) added as fillers. The specific preparation steps are as follows:

[0043] S1: Weigh polyvinylpyrrolidone (PVP) and polyethersulfone (PES) in a mass ratio of 1:10-1:20 and add sufficient dimethyl sulfoxide (DMF, solvent); place the mixed solution in a constant temperature environment of 40-100°C and stir continuously with a magnetic stirrer for 5-10 hours until the PVP and PES are completely dissolved to form a uniform and transparent PES solution; let it stand for 1-2 hours to remove bubbles and set aside.

[0044] S2: Dispersion of modified activated carbon: Weigh 1-10 wt% of modified activated carbon (relative to the mass of DMF) and add it to DMF; ultrasonicate for 30-180 minutes to fully disperse the activated carbon particles without obvious agglomeration, to obtain an activated carbon dispersion;

[0045] NU-1000 dispersion: NU-1000 was weighed at a ratio of 10-30 wt% (relative to the mass of DMF) and added to DMF; the mixture was also ultrasonicated for 30-180 minutes to ensure uniform dispersion of NU-1000 particles to obtain a NU-1000 dispersion.

[0046] S3: The activated carbon dispersion and NU-1000 dispersion are sequentially added to the PES matrix solution, and stirred at 50-100°C for 1-3 hours at a stirring rate of 300-500 r / min to achieve preliminary mixing of the filler and the matrix; the mixed solution is then placed in an ultrasonic bath and ultrasonicated for 30-180 minutes to completely break up the filler agglomerates and ensure that the activated carbon and NU-1000 are evenly distributed in the solution; finally, the mixed solution is poured into a membrane mold and dried at 60-80°C for 8-12 hours to form an adsorption membrane, which is then cut and installed in the membrane adsorption separation module 14 of the enrichment zone 12.

[0047] The PES matrix in the adsorption membrane provides the mechanical strength of the membrane, the high specific surface area of ​​the modified activated carbon can increase the gas adsorption sites, and the regular pore structure of NU-1000 can enhance the selective adsorption of methane. The three together can improve the enrichment efficiency of low-concentration gas.

[0048] The cleaning material is a composite granular product of ZIF-8 material, polylactic acid (PLA) and polyvinyl alcohol (PVA). Under the action of thermal energy, it can decompose to produce ZnO for cleaning impurities on the membrane surface. The specific preparation steps are as follows:

[0049] S1: Weigh PLA and PVA in a mass ratio of 1:1-4:1 and add them to a mixed solvent of ethanol and water with a volume ratio of ethanol to water of 7:3-9:1; place the mixed solution in a water bath at 60-100°C and stir at a stirring rate of 200-300 r / min for 30-60 minutes until the PLA and PVA are completely dissolved to form a uniform polymer solution.

[0050] S2: Weigh ZIF-8 material (metal organic framework, which can decompose to produce ZnO) according to 10%-50% of the total mass of PLA and PVA, and add it to the above polymer solution; continue stirring for 10-20 minutes to evenly disperse ZIF-8 in the solution to form a mixed slurry.

[0051] S3: Place the mixed slurry in a rotary evaporator and evaporate the solvent under reduced pressure at 60-100°C to obtain a solid block product; place the block product in a vacuum drying oven (60-80°C) and dry it for 4-6 hours to remove the residual solvent; then grind it with a grinder and screen it through a 100-500 mesh sieve to obtain composite particles with a size of 100-500 μm, which are then loaded into the repair area 13 for use.

[0052] PLA and PVA in the cleaning material provide structural support for the particles. ZnO produced by the decomposition of ZIF-8 under the action of thermal energy has strong oxidizing properties and can oxidize and decompose impurities such as oil, dust, etc. on the surface of the membrane, thereby achieving self-cleaning of the membrane.

[0053] Example 1:

[0054] Preparation of adsorption membrane: Weigh 50g PES and 5g PVP, add them to 500mL DMF, stir at 50°C for 6 hours until completely dissolved, and let it stand for degassing; weigh 5g activated carbon (1wt% relative to DMF) and add it to 500mL DMF, and sonicate for 60 minutes; weigh 5g NU-1000 (10wt% relative to DMF) and add it to 50mL DMF, and sonicate for 60 minutes; add the activated carbon and NU-1000 solution to the PES solution, stir at 50°C for 2 hours, and then sonicate for 60 minutes; pour the mixed solution into a membrane mold, dry it to form a membrane, and then install it in the enrichment zone 12.

[0055] Preparation of cleaning material: Weigh 9g of PLA and 3g of PVA, add them to a mixed solvent of ethanol:water = 7:3, and stir and dissolve at 60°C; add 2.4g of ZIF-8 (accounting for 20% of the total mass of PLA and PVA), stir and dissolve at 60°C for 20 minutes, evaporate the solvent, dry, grind into 300μm particles, and load into repair area 13.

[0056] Test results: When a mixed gas of 10% methane and 90% nitrogen was introduced, the device's selectivity for CH4 / N2 reached 5.0 at room temperature and 1 bar. Simulating membrane fouling, i.e., soaking the adsorption membrane in oil, the inverted device started repairing it. After 6 hours, the amount of residual oil on the membrane surface dropped to 30%, and the membrane flux recovered to 80% of the initial value.

[0057] Example 2:

[0058] Preparation of adsorption membrane: Weigh 50g PES and 5g PVP, add them to 500mL DMF, and stir at 80°C for 8 hours until completely dissolved; weigh 10g activated carbon (2wt% relative to DMF) and add it to 500mL DMF, and sonicate for 80 minutes; weigh 8g NU-1000 (16wt% relative to DMF) and add it to 50mL DMF, and sonicate for 120 minutes; after mixing, stir at 80°C for 1 hour and sonicate for 120 minutes; after drying to form a membrane, install it in the enrichment area 12.

[0059] Preparation of cleaning material: Weigh 12g of PLA and 3g of PVA (mass ratio 4:1), add them to a mixed solvent of ethanol:water = 9:1, and stir to dissolve at 80°C; add 4.5g of ZIF-8 (accounting for 30% of the total mass of PLA and PVA), stir for 20 minutes, evaporate the solvent, dry, grind to 200μm particles, and load into repair area 13.

[0060] Test results: When a mixed gas of 10% methane and 90% nitrogen was introduced, the device achieved a CH4 / N2 selectivity of 8.01 at room temperature and 1 bar. After simulating membrane fouling, the membrane flux recovered to 92% of the initial value within 6 hours of repair, demonstrating a significant cleaning effect.

[0061] The working principle of the low-concentration gas enrichment and membrane repair self-circulation device of the present invention is as follows: low-concentration gas, such as containing 10%-30% methane and the rest nitrogen, carbon dioxide, etc., enters the enrichment area 12 through the pot mouth 11. In the membrane adsorption separation module 14, the adsorption membrane selectively adsorbs methane molecules, and impurities such as nitrogen and carbon dioxide are intercepted and discharged with the tail gas; the adsorbed methane is discharged from the methane outlet 17 driven by the pressure difference, completing the enrichment.

[0062] After the device has been running for a period of time, when the membrane flux detector detects that the membrane flux has dropped to a set value, such as when the membrane flux has dropped to 70% of the initial value, it is determined that the membrane is contaminated, and a signal is transmitted to the flip mechanism 3. The flip mechanism 3 tilts the kettle body 1 160-180 degrees, so that the repair area 13 is located above the enrichment area 12, and the gravity-driven one-way valve of the guide channel 16 is automatically opened; the solar drive module 2 absorbs solar energy and converts it into heat energy or supplements it through an external auxiliary heat source, so that the temperature of the repair area 13 rises to 80-150°C, and the cleaning material decomposes due to heat: the PLA and PVA matrices are broken, and the ZIF-8 decomposes to produce ZnO active particles; the ZnO particles enter the enrichment area 12 through the guide channel 16, and undergo oxidation reactions with pollutants on the membrane surface, such as oil stains and carbon particles, decomposing them into harmless small molecules such as CO2 and H2O, which are discharged with the air flow.

[0063] When the membrane flux detector detects that the membrane flux has returned to the set value, such as when the membrane flux is above 85%, the flipping mechanism 3 resets the kettle body 1, the valve of the guide channel 16 is automatically closed, and the device re-enters the gas enrichment process; the above-mentioned "enrichment-pollution-repair-re-enrichment" process can be automatically triggered or manually controlled according to the change in membrane flux, forming a self-circulation, which significantly reduces the frequency of manual maintenance.

[0064] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A low-concentration gas enrichment and membrane repair self-circulation device, characterized by: It comprises a kettle body (1), a guide channel (16) and a turning mechanism (3); The kettle body (1) is provided with a kettle mouth (11) at the top, and the interior of the kettle body (1) is divided into an upper enrichment zone (12) and a lower repair zone (13); a membrane adsorption separation module (14) is provided in the enrichment zone (12), and the membrane adsorption separation module (14) includes an adsorption membrane for adsorbing low-concentration gas; a membrane self-repairing module (15) is provided in the repair zone (13), and the membrane self-repairing module (15) includes a cleaning material; The guide channel (16) is located outside the kettle body (1), with one end of the pipeline connected to the repair area (13) and the other end connected to the enrichment area (12), and is used to guide the decomposition products of the cleaning material into the adsorption membrane of the enrichment area (12); a valve for controlling opening and closing is installed on the pipeline of the guide channel (16); the valve of the guide channel (16) is a gravity-driven one-way valve; The outer wall of the bottom of the kettle body (1) is inlaid with a solar drive module (2), and the solar drive module (2) is used to provide heat energy for the cleaning material; The turning mechanism (3) comprises a bracket (31) and a turning motor (32) arranged on the bracket (31); the output shaft of the turning motor (32) is connected to the side wall of the kettle body (1) and can drive the kettle body (1) to turn over and stand upside down.

2. The low-concentration gas enrichment and membrane repair self-circulation device according to claim 1, characterized in that: The adsorption membrane uses polyethersulfone as a polymer matrix, and modified activated carbon and NU-1000 are added into the matrix as fillers.

3. The low-concentration gas enrichment and membrane repair self-circulation device according to claim 2, characterized in that: The preparation method of the adsorption film comprises: S1: adding polyvinyl pyrrolidone and polyether sulfone to dimethyl sulfoxide in a mass ratio of 1:10-1:20; stirring at 40-100°C for 5-10 hours to completely dissolve the two, to obtain a PES solution; S2: adding the modified activated carbon to dimethyl sulfoxide at a ratio of 1-10 wt%, and ultrasonically treating for 30-180 minutes to uniformly disperse the modified activated carbon particles to obtain an activated carbon solution; adding NU-1000 to dimethyl sulfoxide at a ratio of 10-30 wt%, and ultrasonically treating for 30-180 minutes to uniformly disperse the NU-1000 particles to obtain a NU-1000 solution; S3: Add the activated carbon and NU-1000 solution dispersed in step S2 to the PES solution obtained in step S1, stir at 50-100°C for 1-3 hours, and then place in an ultrasonic bath for 30-180 minutes to prevent filler agglomeration and ensure uniform distribution of the activated carbon and NU-1000 in the solution; S4: Finally, the mixed solution obtained in step S3 is poured into the membrane mold and dried at 60-80°C for 8-12 hours to form an adsorption membrane, which is then cut and installed in the enrichment area (12).

4. A low-concentration gas enrichment and membrane repair self-circulation device according to any one of claims 1 to 3, characterized in that: The cleaning material adopts a composite particle product of ZIF-8 material, polylactic acid and polyvinyl alcohol. The composite particle product can be decomposed to produce ZnO under the action of thermal energy to clean impurities on the surface of the adsorption film.

5. The low-concentration gas enrichment and membrane repair self-circulation device according to claim 4, characterized in that: The preparation method of the cleaning material comprises: S1: adding polyvinyl alcohol and polylactic acid in a mass ratio of 1:1-4:1 to a mixed solution of ethanol and water, wherein the ratio of ethanol to water is 7:3-9:1; stirring at 60-100° C. to dissolve the two; S2: Add ZIF-8 material to the solution obtained in step S1, wherein the amount of ZIF-8 material added is 10%-50% of the total mass of polyvinyl alcohol and polylactic acid, and stir for 10-20 minutes to uniformly distribute the ZIF-8; S1: After evaporating the solvent obtained in step S2, the mixture is dried and ground to form particles with a size of 100-500 μm.

6. The low-concentration gas enrichment and membrane repair self-circulation device according to claim 5, characterized in that: The solar drive module (2) is arranged on the bottom shell of the kettle body (1). When the membrane adsorption separation module (14) needs to be cleaned, the kettle body (1) is turned 160-180 degrees. The solar drive module (2) accumulates heat energy to promote the decomposition of the cleaning material in the repair area (13). The decomposition products enter the area where the adsorption membrane is located through the guide channel (16) to achieve self-repair of the membrane.

7. The low-concentration gas enrichment and membrane repair self-circulation device according to claim 1, characterized in that: The methane outlet (17) is also included. The methane outlet (17) is communicated with the enrichment zone (12) and is used to discharge the methane separated and enriched by the adsorption membrane. A membrane flux detector is installed at the methane outlet (17).

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