A hollow composite self-supporting membrane, a method for preparing and using the same, and a refrigerant separation device
By preparing a hollow composite self-supporting membrane, the problems of low permeability and complex preparation in traditional membrane separation technology were solved, achieving efficient separation of R32 and R410a, reducing costs and improving permeability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2023-04-07
- Publication Date
- 2026-06-19
AI Technical Summary
Existing technologies are difficult to separate R32 and R410a efficiently and at low cost. Traditional membrane separation technologies suffer from problems such as low permeability, easy contamination, and complex preparation.
A hollow composite self-supporting membrane, comprising a braided support tube and a surface separation layer, is used. The material is an ILs/MOFs/polymer composite material, prepared through steam treatment and solidification, and applied to a refrigerant separation device.
It improves the selectivity and penetration rate of R32/R125, enables continuous and rapid separation of R410a, and reduces preparation costs and process complexity.
Smart Images
Figure CN116407958B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of refrigerant separation technology, and in particular to a hollow composite self-supporting membrane, its preparation method and application, and a refrigerant separation device. Background Technology
[0002] Refrigerant R410a is a mixture of difluoromethane (R32) and pentafluoroethane (R125) and will be phased out in the future. R32 possesses good thermophysical properties and a high coefficient of performance (COP), making it a good additive for HFO (high-efficiency non-volatile organic compounds) and allowing for the production of mixed refrigerants such as R454b, R454c, R-455a, and R452b. Therefore, it is necessary to separate R32 from R410a for the preparation of new high-performance, low-GWP mixed refrigerants. Currently, the most common method for separating mixed refrigerant components is cryogenic distillation. However, R125 and R32 have similar boiling points, and the distillation process is expensive. Therefore, a new, low-cost, and highly efficient process for separating R32 and R410a is needed.
[0003] Membrane separation technology, as a novel gas separation process, offers advantages over traditional separation technologies, including low energy consumption, low pollution, no phase change process, high efficiency, and high economic benefits. Therefore, it has broad application prospects and significant economic value. Gas separation membranes can be classified into organic and inorganic membranes based on their material type. However, organic membranes suffer from drawbacks such as low permeability and susceptibility to fouling and deactivation. Inorganic membranes, on the other hand, generally exhibit high permeability, corrosion resistance, and ease of cleaning, but their preparation is complex, costly, brittle, and has poor processability, making it difficult to fabricate large-area, defect-free membranes. Therefore, providing a high-performance refrigerant gas separation membrane has become an urgent problem to solve. Summary of the Invention
[0004] The purpose of this invention is to provide a hollow composite self-supporting membrane, its preparation method and application, and a refrigerant separation device.
[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:
[0006] This invention provides a hollow composite self-supporting membrane, comprising a braided support tube 271 and a surface separation layer 272 covering the surface of the braided support tube;
[0007] The braided support tube 271 is made of polyester fiber or polyacrylonitrile fiber.
[0008] The surface separation layer 272 is made of an ILs / MOFs / polymer composite material;
[0009] The outer diameter of the hollow composite self-supporting membrane is 1.06~4.6mm.
[0010] Preferably, the inner diameter of the braided support tube 271 is 0.3~1.5mm, and the outer diameter of the braided support tube 271 is 1~2mm;
[0011] The thickness of the surface separation layer 272 is 0.03~1.3mm.
[0012] The present invention also provides a method for preparing the hollow composite self-supporting membrane, comprising the following steps:
[0013] After coating the surface of the braided support tube with the ILs / MOFs / polymer composite material, the hollow composite self-supporting membrane is obtained by sequentially steam treatment and solidification.
[0014] Preferably, the temperature of the steam treatment is 40~90℃, and the steam treatment time is 2~12s.
[0015] Preferably, the solidified solution is an N,N-dimethylformamide solution;
[0016] The concentration of the N,N-dimethylformamide solution is 10-30%;
[0017] The solidification temperature is 20~60℃, and the solidification time is 3~5s.
[0018] The present invention also provides the application of the hollow composite self-supporting membrane in a refrigerant separation device.
[0019] The present invention also provides a refrigerant separation device, comprising an R410a gas tank 1, a membrane separation tube 2, a CO2 absorption device 3, a water removal device 4, an R32 collection device 5, a shut-off valve 6, and a CO2 generator 7;
[0020] The membrane separation tube 2 includes a first inlet 21, a first outlet 22, a second inlet 23, a second outlet 24, a baffle 25, a hollow composite self-supporting membrane 27, an inter-membrane region 26, a tube shell 28, and sealant 29.
[0021] The present invention has the following beneficial effects:
[0022] This invention provides a hollow composite self-supporting membrane 27, comprising a braided support tube 271 and a surface separation layer 272 covering the surface of the braided support tube; the braided support tube 271 is made of polyester fiber or polyacrylonitrile fiber; the surface separation layer 272 is made of an ILs / MOFs / polymer composite material with high R32 / R125 selectivity and R32 permeability. The above-mentioned hollow composite self-supporting membrane 27 combines a ternary composite membrane with a braided support tube, resulting in significantly enhanced tensile strength and refrigerant permeability compared to traditional mixed matrix membranes.
[0023] Meanwhile, the present invention applies the above-mentioned hollow composite self-supporting membrane to a refrigerant separation device, wherein several hollow composite self-supporting membranes 27 are arranged in a staggered manner inside the membrane separation tube 2. Compared with traditional flat sheet membranes, it has a larger refrigerant permeability and can achieve continuous and rapid separation of R410a.
[0024] This invention also provides a method for preparing a hollow composite self-supporting membrane, comprising the following steps: coating an ILs / MOFs / polymer composite material onto the surface of a braided support tube, followed by sequential steam treatment and condensation to obtain the hollow composite self-supporting membrane. The preparation method provided by this invention has low preparation cost, few steps, and is simple, enabling industrial-scale production. Attached Figure Description
[0025] Figure 1 This is a flowchart illustrating the preparation process of the ILs / MOFs / polymer composite material in Example 1;
[0026] Figure 2 This is a schematic diagram of the refrigerant separation device in Example 1;
[0027] Figure 3 This is a schematic diagram of the membrane separation tube in Example 1;
[0028] Figure 4 This is a schematic cross-sectional view of the membrane separation tube in Example 1;
[0029] Figure 5 This is a schematic diagram of the hollow composite self-supporting membrane in Example 1. Detailed Implementation
[0030] This invention provides a hollow composite self-supporting membrane, comprising a braided support tube 271 and a surface separation layer 272 covering the surface of the braided support tube;
[0031] The braided support tube 271 is made of polyester fiber or polyacrylonitrile fiber.
[0032] The surface separation layer 272 is made of an ILs / MOFs / polymer composite material;
[0033] The outer diameter of the hollow composite self-supporting membrane is 1.06~4.6mm.
[0034] In this invention, the outer diameter of the hollow composite self-supporting membrane is preferably 1.5~4.0 mm, more preferably 2.0~3.5 mm, and even more preferably 2.5~3.0 mm.
[0035] In this invention, the inner diameter of the braided support tube 271 is preferably 0.3~1.5mm, more preferably 0.5~1.2mm, and even more preferably 0.8~0.9mm; the outer diameter of the braided support tube 271 is preferably 1~2mm, more preferably 1.2~1.8mm, and even more preferably 1.4~1.6mm; the thickness of the surface separation layer 272 is preferably 0.03~1.3mm, more preferably 0.5~0.8mm, and even more preferably 0.6~0.7mm.
[0036] In this invention, the ILs / MOFs / polymer composite material comprises ZIF-8@[C2mim][BF4] composite particles and nylon particles.
[0037] This invention also provides a method for preparing ILs / MOFs / polymer composite materials, comprising the following steps:
[0038] (1) The composite particles are obtained by mixing the ionic liquid methanol solution with the nanoparticles;
[0039] (2) After mixing the composite particle solution and the resin particle solution, stir and sonicate in sequence to obtain the ILs / MOFs / polymer composite material.
[0040] In this invention, the ionic liquid is preferably [C2mim][BF4], and the nanoparticles are preferably ZIF-8.
[0041] In this invention, the ZIF-8 can be purchased or prepared.
[0042] This invention also provides a method for preparing ZIF-8 nanoparticles, comprising the following steps:
[0043] Zn(NO3) The ZIF-8 is obtained by mixing 6H2O with 2-methylimidazole and water, followed by washing, centrifugation and drying.
[0044] In this invention, the Zn(NO3) The preferred mass-to-volume ratio of 6H2O, 2-methylimidazole, and water is 0.65~0.85g:11.5~13.5g:100ml, more preferably 0.68~0.82g:11.8~13.2g:100ml, and even more preferably 0.70~0.80g:12~13g:100ml.
[0045] In this invention, the stirring speed for mixing is preferably 450~550 rpm, more preferably 460~540 rpm, and even more preferably 480~520 rpm; the mixing time is preferably 1~3 h, more preferably 1.5~2.5 h, and even more preferably 1.8~2.2 h; and the mixing temperature is preferably 20~30℃, more preferably 22~28℃, and even more preferably 24~26℃.
[0046] In this invention, the washing liquid is preferably methanol, the washing frequency is preferably 3-8 times, more preferably 4-7 times, and even more preferably 5-6 times; the centrifugation speed is preferably 2000-4000 rpm, more preferably 2500-3500 rpm, and even more preferably 2800-3200 rpm; the centrifugation time is preferably 10-30 min, more preferably 15-25 min, and even more preferably 18-22 min; the drying temperature is preferably 140-160℃, more preferably 145-155℃, and even more preferably 148-152℃; the drying time is preferably 12-24 h, more preferably 15-20 h, and even more preferably 17-18 h.
[0047] In this invention, the mass-to-volume ratio of the ionic liquid to methanol in the ionic liquid methanol solution is preferably 1g:20~40mL, more preferably 1g:25~35mL, and even more preferably 1g:29~31mL.
[0048] In this invention, an ionic liquid is added dropwise to methanol, followed by condensation and reflux.
[0049] In this invention, the rotation speed of the condensation reflux is preferably 450~550 rpm, more preferably 460~540 rpm, and even more preferably 480~520 rpm; the condensation reflux time is preferably 2~3 h, more preferably 2.2~2.8 h, and even more preferably 2.4~2.6 h; and the condensation reflux temperature is preferably 70~80℃, more preferably 72~78℃, and even more preferably 74~76℃.
[0050] In this invention, the mass ratio of the ionic liquid to the nanoparticles is preferably 0.8~1.2:0.8~1.2, more preferably 0.9~1.1:0.9~1.1, and even more preferably 0.95~1.05:0.95~1.05.
[0051] In this invention, the mixing method in step (1) is preferably to perform stirring and sonication sequentially.
[0052] In this invention, the stirring speed is preferably 450-550 rpm, more preferably 460-540 rpm, and even more preferably 480-520 rpm; the stirring time is preferably 1-4 h, more preferably 1.5-3.5 h, and even more preferably 2-3 h; the stirring temperature is preferably 100-120℃, more preferably 105-115℃, and even more preferably 108-112℃; the ultrasonic power is preferably 100-260 W, more preferably 150-210 W, and even more preferably 170-190 W; the ultrasonic time is preferably 2-6 h, more preferably 3-5 h, and even more preferably 3.5-4.5 h; and the ultrasonic temperature is preferably 10-40℃, more preferably 20-30℃, and even more preferably 23-27℃.
[0053] In this invention, the composite particles are obtained by mixing the ionic liquid methanol solution with the nanoparticles and then sequentially performing a first centrifugation, washing, a second centrifugation, and drying.
[0054] In this invention, the rotation speed of the first centrifugation is preferably 2000-4000 rpm, more preferably 2500-3500 rpm, and even more preferably 2800-3200 rpm; the centrifugation time of the first centrifugation is preferably 10-30 min, more preferably 15-25 min, and even more preferably 18-22 min; the washing liquid is preferably N,N-dimethylformamide solvent; the number of washings is preferably 2-8 times, more preferably 3-7 times, and even more preferably 4-6 times; the rotation speed of the second centrifugation is preferably... The speed of centrifugation is 2000~4000 rpm, more preferably 2500~3500 rpm, and even more preferably 2800~3200 rpm. The time for the second centrifugation is preferably 10~30 min, more preferably 15~25 min, and even more preferably 18~22 min. The drying temperature is preferably 100~120℃, more preferably 105~115℃, and even more preferably 108~112℃. The drying time is preferably 12~24 h, more preferably 15~20 h, and even more preferably 17~18 h.
[0055] In this invention, the resin particles described in step (2) are preferably of the Pebax type. ® 1657 particles.
[0056] In this invention, the solvent of the composite particle solution preferably comprises deionized water and anhydrous ethanol, and the mass ratio of water to ethanol is preferably 0.2~0.4:0.6~0.8, more preferably 0.25~0.35:0.65~0.75, and even more preferably 0.28~0.32:0.68~0.72.
[0057] In this invention, the mass-to-volume ratio of the composite particles to the solvent in step (2) is preferably 0.06g:1~10mL, more preferably 0.06g:2~8mL, and even more preferably 0.06g:4~6mL.
[0058] In this invention, the composite particles are added to a solvent and sonicated to obtain the composite particle solution.
[0059] In this invention, the frequency of the ultrasound is preferably 30-50 kHz, more preferably 35-45 kHz, and even more preferably 38-42 kHz. The duration of the ultrasound is preferably 15-30 min, more preferably 20-25 min, and even more preferably 22-24 min.
[0060] In this invention, the solvent of the resin particle solution preferably includes water and ethanol, and the mass ratio of water to ethanol is preferably 0.2~0.4:0.6~0.8, more preferably 0.25~0.35:0.65~0.75, and even more preferably 0.28~0.32:0.68~0.72.
[0061] In this invention, the mass-to-volume ratio of the resin particles to the solvent is preferably 10-20 g: 100 mL, more preferably 12-18 g: 100 mL, and even more preferably 14-16 g: 100 mL.
[0062] In this invention, the resin particles are added to a solvent and stirred to obtain the resin particle solution.
[0063] In this invention, the resin particles need to be dried; the drying temperature is preferably 90~120℃, more preferably 100~110℃, more preferably 103~107℃, and the drying time is preferably 6~18h, more preferably 10~14h, and even more preferably 11~13h.
[0064] In this invention, the stirring temperature is preferably 70~90℃, more preferably 75~85℃, and even more preferably 78~82℃, and the stirring time is preferably 1~3h, more preferably 1.5~2.5h, and even more preferably 1.8~2.2h.
[0065] In this invention, the mass ratio of the composite particles to the resin particles in step (2) is preferably 0.05~0.07:0.5~0.7, more preferably 0.055~0.065:0.55~0.65, and even more preferably 0.058~0.062:0.58~0.62.
[0066] In this invention, the mixing in step (2) is preferably done by first mixing the first part of the resin particle solution with the composite particle solution, then adding the remaining resin particle solution, and then stirring and sonicating in sequence to obtain the ILs / MOFs / polymer composite material.
[0067] In this invention, the mass of the first portion of resin particle solution is preferably 10-20% of the mass of the resin particle solution, more preferably 12-18%, and even more preferably 14-16%.
[0068] In this invention, the mixing temperature of the first portion of resin particle solution and composite particle solution is preferably 70~90℃, more preferably 75~85℃, and even more preferably 78~82℃; the mixing time is preferably 2~5h, more preferably 2.5~4.5h, and even more preferably 3.0~4.0h; the stirring speed after adding the remaining resin particle solution is preferably 450~550rpm, more preferably 460~540rpm, and even more preferably 480~520rpm; the stirring time is preferably 5~15min, and even more preferably 7~ The ultrasound duration is preferably 13 minutes, more preferably 9-11 minutes; the frequency of the ultrasound is preferably 30-50 kHz, further preferably 35-45 kHz, more preferably 38-42 kHz; the temperature of the ultrasound is preferably 10-40°C, further preferably 20-30°C, more preferably 23-27°C; the duration of the ultrasound is preferably 20-40 minutes, further preferably 25-35 minutes, more preferably 28-32 minutes; the number of ultrasound sessions is preferably 4-8 times, further preferably 5-7 times, more preferably 6 times.
[0069] In this invention, adding the resin particle solution in two stages can better disperse it, and adding the resin particle solution in the first stage can better activate the filler.
[0070] In this invention, the stirring speed in step (2) is preferably 450~550 rpm, more preferably 460~540 rpm, and even more preferably 480~520 rpm; the stirring time is preferably 12~24 h, more preferably 15~20 h, and even more preferably 17~18 h; the stirring temperature is preferably 70~90℃, more preferably 75~85℃, and even more preferably 78~82℃; the ultrasonic frequency is preferably 30~50 kHz, more preferably 35~45 kHz, and even more preferably 38~42 kHz; the ultrasonic time is preferably 20~40 min, more preferably 25~35 min, and even more preferably 28~32 min; and the ultrasonic temperature is preferably 10~40℃, more preferably 20~30℃, and even more preferably 23~27℃.
[0071] In this invention, the purpose of ultrasound in step (2) is to perform defoaming.
[0072] The present invention also provides a method for preparing the hollow composite self-supporting membrane, comprising the following steps:
[0073] After coating the surface of the braided support tube with the ILs / MOFs / polymer composite material, the hollow composite self-supporting membrane is obtained by sequentially steam treatment and solidification.
[0074] In this invention, the braided support tube is traction-guided to the concentric hollow coating head, where it is combined with the ILs / MOFs / polymer composite material to form a nascent hollow composite self-supporting membrane, which is then subjected to steam treatment.
[0075] In this invention, the temperature of the steam treatment is preferably 40~90℃, more preferably 50~80℃, and even more preferably 60~70℃; the time of the steam treatment is preferably 2~12s, more preferably 4~10s, and even more preferably 6~8s; the distance between the air sections of the steam treatment is preferably 1~100cm, more preferably 20~80cm, and even more preferably 40~60cm.
[0076] In this invention, the coagulated solution is preferably an N,N-dimethylformamide solution; the concentration of the N,N-dimethylformamide solution is preferably 10-30%, more preferably 15-25%, and even more preferably 18-22%; the coagulation temperature is preferably 20-60°C, more preferably 30-50°C, and even more preferably 35-45°C; and the coagulation time is preferably 3-5 seconds, more preferably 3.5-4.5 seconds, and even more preferably 3.8-4.2 seconds.
[0077] In this invention, the hollow composite self-supporting membrane is obtained by washing after solidification.
[0078] In this invention, the washing solution is preferably water, the washing temperature is preferably 20~60℃, more preferably 30~50℃, and even more preferably 35~45℃, and the washing time is preferably 5~30h, more preferably 15~20h, and even more preferably 17~18h.
[0079] The present invention also provides the application of the hollow composite self-supporting membrane in a refrigerant separation device.
[0080] The present invention also provides a refrigerant separation device, comprising an R410a gas tank 1, a membrane separation tube 2, a CO2 absorption device 3, a water removal device 4, an R32 collection device 5, a shut-off valve 6, and a CO2 generator 7.
[0081] In this invention, the membrane separation tube 2 includes a first inlet 21, a first outlet 22, a second inlet 23, a second outlet 24, a baffle 25, a hollow composite self-supporting membrane 27, an inter-membrane region 26, a tube shell 28, and a sealant 29.
[0082] In this invention, the first inlet 21 is located on the left side of the membrane separation tube 2 and is connected to the R410a gas tank 1; the first outlet 22 is located on the right side of the membrane separation tube 2 and is connected to the outside; the second inlet 23 is located on the lower right side of the membrane separation tube and is connected to the CO2 generator 7; the second outlet 24 is located on the upper left side of the membrane separation tube and is connected to the CO2 absorption device 3.
[0083] In this invention, the spoiler 25 is preferably a semi-circular aluminum alloy plate, and the number of spoilers is preferably ≥2, more preferably ≥3, and even more preferably ≥4; at least one spoiler is located on the lower side of the second inlet 23; at least one spoiler is located on the upper side of the second outlet 24.
[0084] In this invention, the spoiler forms an S-shaped passage.
[0085] In this invention, the hollow composite self-supporting membrane 27 is arranged in a staggered manner within the membrane separation tube 2, and its length is shorter than that of the membrane separation tube. The membrane inter-membrane areas at both ends of the hollow composite self-supporting membrane are strictly sealed with sealant.
[0086] In this invention, the 410a air intake 10 flows inside the braided support tube 271.
[0087] In this invention, the CO2 absorption device 3 is connected to the water removal device 4 directly above; it is connected to the CO2 generator 7 on the right side via a shut-off valve 6; the water removal device 4 is connected to the R32 collection device 5 directly above; and the water removal device 4 is a filter valve.
[0088] In this invention, the CO2 absorption device 3 contains a solution of composite amine and activator, which can effectively and quickly absorb CO2, react to generate carbamate, and discharge it into the CO2 generator 7 after reaching a certain amount.
[0089] In this invention, the carbamate solution is heated in the CO2 generating device 7, and the released CO2 is used as a purge gas to reach the membrane separation tube 2. The remaining complex amine solution is returned to the CO2 absorption device 3 for reuse.
[0090] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0091] Example 1
[0092] 0.65g Zn(NO3) ZIF-8 was obtained by stirring 6H2O with 11.5g of 2-methylimidazole and 100ml of water at 25℃ for 2h at 500rpm, washing three times with methanol, centrifuging the material at 3000rpm for 20min, and drying at 150℃ for 15h.
[0093] Dissolve 1g of [C2mim][BF4] in 20ml of methanol solution, and reflux at 80℃ with stirring speed of 500rpm for 2h to obtain [C2mim][BF4] methanol solution.
[0094] Take 1g of ZIF-8 particles and the ionic liquid methanol solution prepared above, stir at 500rpm for 2h at 110℃, then sonicate at 180W for 4h at 50℃, and then centrifuge at 3000rpm for 20min. Wash the solid obtained from the first centrifugation with N,N-dimethylformamide solvent 4 times, and then centrifuge at 3000rpm for 20min at 110℃. Dry the obtained solid at 110℃ for 15h to obtain ZIF-8@[C2mim][BF4] composite particles.
[0095] Dissolve 0.06g of ZIF-8@[C2mim][BF4] composite particles in 10ml of ethanol solution (water / ethanol mass ratio is 3 / 7), and sonicate at 40KHz for 20min to obtain ZIF-8@[C2mim][BF4] composite particle solution.
[0096] Add 0.5g of Pebax ® Pebax was obtained by drying 1657 granules at 105℃ for 12 hours, dissolving them in 5 mL of ethanol solution (water / ethanol mass ratio of 3 / 7), and stirring at 70℃ for 2 hours. ® 1657 particle solution.
[0097] The ZIF-8@[C2mim][BF4] composite particle solution prepared above was mixed with the first part of Pebax. ® 1657 Particle Solution (Part 1 Pebax) ® 1657 particle solution accounts for Pebax ® Mix 15% (by mass of 1657 granules solution) at 80°C for 3 hours, then add the remaining Pebax. ® The 1657 particle solution was stirred at 500 rpm for 10 min and then sonicated at 40 kHz for 30 min. After sonication 4 times, a mixed system was obtained.
[0098] The mixture was stirred at 80°C and 500 rpm for 15 h, and then sonicated at 25°C and 40 kHz for 30 min to obtain the ILs / MOFs / polymer composite material.
[0099] The preparation process of the ILs / MOFs / polymer composite material in this embodiment is as follows: Figure 1 As shown.
[0100] The ILs / MOFs / polymer composite material prepared above was coated onto the surface of a braided support tube with an inner diameter of 1.2 mm and an outer diameter of 2 mm, with a coating thickness of 1 mm. After coating, it was steam-treated at 70°C for 8 s, with an air section distance of 100 cm during the steam treatment. Subsequently, it was coagulated at 30°C with a 15% N,N-dimethylformamide solution for 4 s, and then washed with deionized water at 30°C for 18 h to obtain the hollow composite self-supporting membrane.
[0101] The refrigerant separation device in this embodiment includes an R410a gas tank 1, a membrane separation tube 2, a CO2 absorption device 3, a water removal device 4, an R32 collection device 5, a shut-off valve 6, and a CO2 generator 7.
[0102] The membrane separation tube 2 includes a first inlet 21, a first outlet 22, a second inlet 23, a second outlet 24, a baffle 25, a hollow composite self-supporting membrane 27, an inter-membrane region 26, a tube shell 28, and a sealant 29.
[0103] The first inlet 21 is located on the left side of the membrane separation tube 2 and is connected to the R410a gas tank 1; the first outlet 22 is located on the right side of the membrane separation tube 2 and is connected to the outside; the second inlet 23 is located on the lower right side of the membrane separation tube and is connected to the CO2 generator 7; the second outlet 24 is located on the upper left side of the membrane separation tube and is connected to the CO2 absorption device 3.
[0104] The spoiler 25 is a semi-circular aluminum alloy plate, and there are two of them. The first spoiler is located on the lower side of the second inlet 23; the second spoiler is located on the upper side of the second outlet 24, forming an S-shaped passage.
[0105] The hollow composite self-supporting membrane 27 is arranged in a staggered manner in the membrane separation tube 2, and its length is shorter than that of the membrane separation tube. The membrane area at both ends of the hollow composite self-supporting membrane is strictly sealed with sealant. The surface of the hollow composite self-supporting membrane is a surface separation layer 272. R410a air inlet 10 flows inside the braided support tube 271.
[0106] The CO2 absorption device 3 is connected to the water removal device 4 directly above; it is connected to the CO2 generator 7 via the shut-off valve 6 on the right; the water removal device 4 is connected to the R32 collection device 5 directly above; the water removal device 4 is a filter valve.
[0107] A schematic diagram of the refrigerant separation device in this embodiment is shown below. Figure 2 As shown.
[0108] The schematic diagram of the membrane separation tube structure in this embodiment is shown below. Figure 3 As shown.
[0109] A schematic diagram of the cross-section of the membrane separation tube in this embodiment is shown below. Figure 4 As shown.
[0110] The structural schematic of the hollow composite self-supporting membrane in this embodiment is shown below. Figure 5 As shown.
[0111] Open the R410a gas tank 1 and introduce the mixed gas into the membrane separation tube 2 through the left inlet for gas separation. The R125-rich gas is discharged to the outside through the right outlet, and the R32-rich gas is blown out from the upper left outlet as CO2 purge gas. After passing through the CO2 absorption device 3 to remove CO2 and the water removal device 4 to remove water, it is collected and stored in the R32 collection device 5.
[0112] The CO2 absorption device 3 contains a solution of composite alcohol amine and activator, which reacts with CO2 to generate carbamate. Once a certain amount is reached, the carbamate is discharged into the CO2 generator 7.
[0113] The carbamate solution is heated in the CO2 generator 7 to a temperature of 80°C. The released CO2 is used as a purge gas and enters the membrane separation tube 2. The remaining complex amine solution is returned to the CO2 absorption unit 3 for reuse.
[0114] Example 2
[0115] The preparation process of the ILs / MOFs / polymer composite material is the same as in Example 1.
[0116] The ILs / MOFs / polymer composite material prepared above was coated onto the surface of a braided support tube with an inner diameter of 1 mm and an outer diameter of 1.5 mm, with a coating thickness of 0.5 mm. After coating, it was steam-treated at 70°C for 6 s, with the steam treatment distance being 100 cm. Subsequently, it was coagulated at 30°C with a 15% N,N-dimethylformamide solution for 4 s, and then washed with deionized water at 30°C for 18 h to obtain the hollow composite self-supporting membrane.
[0117] A refrigerant separation device includes an R410a gas tank 1, a membrane separation tube 2, a CO2 absorption device 3, a water removal device 4, an R32 collection device 5, a shut-off valve 6, and a CO2 generator 7.
[0118] The membrane separation tube 2 includes a first inlet 21, a first outlet 22, a second inlet 23, a second outlet 24, a baffle 25, a hollow composite self-supporting membrane 27, an inter-membrane region 26, a tube shell 28, and a sealant 29.
[0119] The first inlet 21 is located on the left side of the membrane separation tube 2 and is connected to the R410a gas tank 1; the first outlet 22 is located on the right side of the membrane separation tube 2 and is connected to the outside; the second inlet 23 is located on the lower right side of the membrane separation tube and is connected to the CO2 generator 7; the second outlet 24 is located on the upper left side of the membrane separation tube and is connected to the CO2 absorption device 3.
[0120] The spoiler 25 is a semi-circular aluminum alloy plate, and there are two of them. The first spoiler is located on the lower side of the second inlet 23; the second spoiler is located on the upper side of the second outlet 24, forming an S-shaped passage.
[0121] The hollow composite self-supporting membrane 27 is arranged in a staggered manner inside the membrane separation tube 2, and its length is shorter than that of the membrane separation tube. The membrane area at both ends of the hollow composite self-supporting membrane is strictly sealed with sealant, and the R410a air intake 10 flows inside the braided support tube 271.
[0122] The CO2 absorption device 3 is connected to the water removal device 4 directly above; it is connected to the CO2 generator 7 via the shut-off valve 6 on the right; the water removal device 4 is connected to the R32 collection device 5 directly above; the water removal device 4 is a filter valve.
[0123] Open the R410a gas tank 1 and introduce the mixed gas into the membrane separation tube 2 through the left inlet for gas separation. The R125-rich gas is discharged to the outside through the right outlet, and the R32-rich gas is blown out from the upper left outlet as CO2 purge gas. After passing through the CO2 absorption device 3 to remove CO2 and the water removal device 4 to remove water, it is collected and stored in the R32 collection device 5.
[0124] The CO2 absorption device 3 contains a solution of composite alcohol amine and activator, which reacts with CO2 to generate carbamate. Once a certain amount is reached, the carbamate is discharged into the CO2 generator 7.
[0125] The carbamate solution is heated in the CO2 generator 7 to a temperature of 80°C. The released CO2 is used as a purge gas and enters the membrane separation tube 2. The remaining complex amine solution is returned to the CO2 absorption unit 3 for reuse.
[0126] Example 3
[0127] The preparation process of the ILs / MOFs / polymer composite material is the same as in Example 1.
[0128] The ILs / MOFs / polymer composite material prepared above was coated onto the surface of a braided support tube with an inner diameter of 1.2 mm and an outer diameter of 1.3 mm, with a coating thickness of 0.6 mm. After coating, it was steam-treated at 70°C for 7 s, with the steam treatment distance being 100 cm. Subsequently, it was coagulated at 30°C with a 15% N,N-dimethylformamide solution for 4 s, and then washed with deionized water at 30°C for 18 h to obtain the hollow composite self-supporting membrane.
[0129] A refrigerant separation device includes an R410a gas tank 1, a membrane separation tube 2, a CO2 absorption device 3, a water removal device 4, an R32 collection device 5, a shut-off valve 6, and a CO2 generator 7.
[0130] The membrane separation tube 2 includes a first inlet 21, a first outlet 22, a second inlet 23, a second outlet 24, a baffle 25, a hollow composite self-supporting membrane 27, an inter-membrane region 26, a tube shell 28, and a sealant 29.
[0131] The first inlet 21 is located on the left side of the membrane separation tube 2 and is connected to the R410a gas tank 1; the first outlet 22 is located on the right side of the membrane separation tube 2 and is connected to the outside; the second inlet 23 is located on the lower right side of the membrane separation tube and is connected to the CO2 generator 7; the second outlet 24 is located on the upper left side of the membrane separation tube and is connected to the CO2 absorption device 3.
[0132] The spoiler 25 is a semi-circular aluminum alloy plate, and there are two of them. The first spoiler is located on the lower side of the second inlet 23; the second spoiler is located on the upper side of the second outlet 24, forming an S-shaped passage.
[0133] The hollow composite self-supporting membrane 27 is arranged in a staggered manner inside the membrane separation tube 2, and its length is shorter than that of the membrane separation tube. The membrane area at both ends of the hollow composite self-supporting membrane is strictly sealed with sealant, and the R410a air intake 10 flows inside the braided support tube 271.
[0134] The CO2 absorption device 3 is connected to the water removal device 4 directly above; it is connected to the CO2 generator 7 via the shut-off valve 6 on the right; the water removal device 4 is connected to the R32 collection device 5 directly above; the water removal device 4 is a filter valve.
[0135] Open the R410a gas tank 1 and introduce the mixed gas into the membrane separation tube 2 through the left inlet for gas separation. The R125-rich gas is discharged to the outside through the right outlet, and the R32-rich gas is blown out from the upper left outlet as CO2 purge gas. After passing through the CO2 absorption device 3 to remove CO2 and the water removal device 4 to remove water, it is collected and stored in the R32 collection device 5.
[0136] The CO2 absorption device 3 contains a solution of composite alcohol amine and activator, which reacts with CO2 to generate carbamate. Once a certain amount is reached, the carbamate is discharged into the CO2 generator 7.
[0137] The carbamate solution is heated in the CO2 generator 7 to a temperature of 80°C. The released CO2 is used as a purge gas and enters the membrane separation tube 2. The remaining complex amine solution is returned to the CO2 absorption unit 3 for reuse.
[0138] The refrigerant separation device provided in this application embodiment was used to perform separation tests on R410a at room temperature and 0.2 MPa, and the separation ratio of R32 / R125 was 13, and the permeability of R32 was 0.3 GPU.
[0139] As can be seen from the above embodiments, the present invention provides a hollow composite self-supporting membrane, comprising a braided support tube 271 and a surface separation layer 272 covering the surface of the braided support tube; the braided support tube 271 is made of polyester fiber or polyacrylonitrile fiber; the surface separation layer 272 is made of ILs / MOFs / polymer composite material. The present invention utilizes the high R32 / R125 selectivity and R32 permeability of the ILs / MOFs / polymer composite membrane to achieve continuous and rapid separation of R410a. Combining the ternary composite membrane with the braided support tube significantly increases the tensile strength and refrigerant permeability compared to traditional mixed matrix membranes. Furthermore, when the above-mentioned hollow composite self-supporting membrane is applied to a refrigerant separation device, several hollow composite self-supporting membranes 27 are arranged at staggered intervals within the membrane separation tube 2, exhibiting a larger refrigerant permeability compared to traditional flat sheet membranes, enabling continuous and rapid separation of R410a. As can be seen from the embodiments, the separation device provided by the present invention achieves a separation ratio of R32 / R125 of 13 and a permeability of R32 of 0.3 GPU under the condition of room temperature and 0.2 MPa, which has excellent separation and permeation effects.
[0140] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A hollow composite self-supporting membrane, characterized in that, It includes a braided support tube (271) and a surface separation layer (272) covering the surface of the braided support tube. The braided support tube (271) is made of polyester fiber or polyacrylonitrile fiber. The surface separation layer (272) is made of ILs / MOFs / polymer composite material; The outer diameter of the hollow composite self-supporting membrane is 1.06~4.6mm; The preparation method of the ILs / MOFs / polymer composite material includes the following steps: (1) The composite particles are obtained by mixing the ionic liquid methanol solution with the nanoparticles; (2) The composite particle solution and the resin particle solution are mixed and stirred and sonicated in sequence to obtain the ILs / MOFs / polymer composite material; The ionic liquid is [C2mim][BF4], and the nanoparticles are ZIF-8; The resin particles in step (2) are of the type Pebax ® 1657 particles.
2. The hollow composite self-supporting membrane as described in claim 1, characterized in that, The inner diameter of the braided support tube (271) is 0.3~1.5mm, and the outer diameter of the braided support tube (271) is 1~2mm; The thickness of the surface separation layer (272) is 0.03~1.3mm.
3. The method of producing a hollow composite self-supporting film according to claim 1 or 2, characterized in that, Includes the following steps: After coating the surface of the braided support tube with the ILs / MOFs / polymer composite material, the hollow composite self-supporting membrane is obtained by sequentially steam treatment and solidification.
4. The production method according to claim 3, wherein The steam treatment temperature is 40~90℃, and the steam treatment time is 2~12s.
5. The production method according to claim 4, wherein The solidified solution is an N,N-dimethylformamide solution; The concentration of the N,N-dimethylformamide solution is 10-30%; The solidification temperature is 20~60℃, and the solidification time is 3~5s.
6. The application of the hollow composite self-supporting membrane according to claim 1 or 2 in a refrigerant separation device.
7. A refrigerant separation device characterized by comprising: It includes an R410a gas tank (1), a membrane separator (2), a CO2 absorption device (3), a water removal device (4), an R32 collection device (5), a shut-off valve (6), and a CO2 generator (7). The membrane separation tube (2) includes a first inlet (21), a first outlet (22), a second inlet (23), a second outlet (24), a baffle (25), a hollow composite self-supporting membrane (27), an inter-membrane region (26), a tube shell (28), and a sealant (29). The hollow composite self-supporting membrane (27) is the hollow composite self-supporting membrane according to claim 1.