A gas deep dehumidification membrane and preparation method thereof

Abstract

The present invention provides a gas deep dehumidification membrane and a preparation method thereof. The gas deep dehumidification membrane is mainly composed of a modified porous skeleton and a water-removing functional resin composite. The modified porous skeleton plays a supporting and reinforcing role in the entire membrane to ensure the high mechanical properties of the dehumidification membrane. The water-removing functional resin composite plays a role in deeply removing water molecules to ensure that water molecules move in a single direction in the membrane. The mass proportion of the modified porous skeleton in the dehumidification membrane is 5 to 90%. The present invention uses a coating technology to fill a functional resin composite that can selectively remove water molecules in and on the surface of the porous skeleton to prepare a deep dehumidification membrane with high water permeability and unique selectivity. The membrane has excellent temperature resistance, pollution resistance, and corrosion resistance, and can be applied to various conventional or harsh use environments. The dehumidification membrane material prepared by the present invention has good economic efficiency, a simple preparation method, and is easy to achieve large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of gas separation membranes and relates to a gas deep dehumidification membrane and a preparation method thereof. Background Art

[0002] In the production and use of precision instruments, medicines, foods and electronic equipment, there are strict requirements on the water vapor content in the air. Excessive air humidity will cause metals to rust, instruments to lose accuracy, and insulation parameters to decrease. Controlling humidity is of great significance to the development of production technology, ensuring production processes, and improving product quality.

[0003] Common dehumidification methods include cooling method, adsorbent method, rotary method, etc., but they have disadvantages such as low dehumidification efficiency, complex equipment, and secondary pollution. Membrane dehumidification is a potential technology, and the design and development of high-performance membrane materials is the key to this technology. Compared with traditional dehumidification processes, membrane dehumidification technology has the advantages of high selectivity, low energy consumption, simple process, no secondary pollution and small footprint. It is an economical, energy-saving, green and environmentally friendly process. Therefore, it is very necessary to develop this high-efficiency, energy-saving and environmentally friendly gas drying technology.

[0004] Dehumidification membrane materials are mainly polymer materials, such as polyimide, polyolefin, etc., but they have problems such as poor water absorption, low permeation rate and poor stability. Exploring a dehumidification membrane with high permeability and good selectivity is the key to this technology. Perfluorosulfonic acid resin (Nafion) has excellent proton conductivity and is widely used in fuel cells and other fields as a proton exchange membrane. The sulfonic acid groups contained in the resin give it strong water permeability, and its water absorption can reach 22% of its own weight. Unlike traditional dehumidification membranes that transfer water through a relatively slow diffusion process, Nafion removes water molecules through water absorption, which is a first-order kinetic reaction and reaches equilibrium quickly (milliseconds).

[0005] At present, there are commercially available Nafion drying tubes for deep dehumidification of gases. For example, the American Perma Pure Nafion gas drying tube is a dehumidification membrane with a small size and high dehumidification efficiency, which is suitable for continuous online monitoring of sample gas pretreatment and has been successfully applied to various gas analysis fields. However, the main constituent material of the drying tube is expensive perfluorosulfonic acid resin, the material price of the drying tube is relatively high, and the mechanical strength of the drying tube is relatively low, and it is easy to be damaged during installation and use. At the same time, the preparation process of this type of drying tube is mainly melt stretching technology, which requires relatively complex equipment and precise parameter control.

[0006] Therefore, how to use relatively economical and efficient materials and simple membrane-making technology to prepare membrane materials that can deeply dehumidify gases is a problem that needs to be broken through in this field. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a gas deep dehumidification membrane and a preparation method thereof. The dehumidification membrane of the present invention has high permeability, good selectivity, excellent pollution resistance and corrosion resistance, and can be applied to gas dehumidification in various fields.

[0008] To solve the above technical problems, the present invention is achieved as follows:

[0009] A gas deep dehumidification membrane comprises two parts: a modified porous skeleton and a water-removing functional resin composite. The modified porous skeleton plays a supporting role as the main body of the dehumidification membrane. The water-removing functional resin composite can selectively and directionally remove water molecules, and the two promote each other to complete the deep removal of water molecules in the gas.

[0010] Furthermore, the modified porous skeleton and the water removal functional resin composite are compounded into an integral structure by filling or coating; the mass proportion of the modified porous skeleton in the gas deep dehumidification membrane is 5 to 90%.

[0011] Furthermore, the modified porous skeleton is formed by modifying the porous skeleton by surface plasma or chemical grafting; the porous skeleton is a polytetrafluoroethylene membrane, a polyvinylidene fluoride membrane, a polyacrylonitrile membrane, a polyethylene membrane, a polypropylene membrane, a porous ceramic membrane or a metal membrane.

[0012] Furthermore, the water-removing functional resin complex includes a functional resin and a water-absorbing material; the functional resin includes one or a combination of two or more materials selected from perfluorosulfonic acid resin, sulfonated polystyrene, sulfonated polyetheretherketone, sulfonated polybenzimidazole, sulfonated polyvinylidene fluoride, etc.; the water-absorbing material includes one or a combination of two or more materials selected from calcium chloride, lithium chloride, and magnesium chloride.

[0013] Furthermore, the structure of the porous skeleton is a tubular structure or a sheet structure; the inner diameter of the tubular structure is 0.5 to 100 mm, and the wall thickness is 0.1 to 5 mm; the thickness of the sheet structure is 0.05 to 2 mm.

[0014] Furthermore, during the deep removal process, a sweep gas is introduced into the permeation side of the gas deep dehumidification membrane; the sweep gas comes from part of the dry gas after the membrane is dehumidified or dry gas introduced from the outside.

[0015] The preparation method of the gas deep dehumidification membrane comprises the following steps:

[0016] (1) Porous skeleton modification: The porous skeleton is modified by surface plasma or chemical grafting to ensure that the resin complex can smoothly fill the internal pores of the skeleton during the coating process.

[0017] (2) preparing a water-removing functional resin complex dispersion, dissolving the functional resin and the water-absorbing material in a corresponding solvent to obtain a resin complex solution, and then stirring and degassing to obtain a water-removing functional resin complex dispersion;

[0018] (3) Preparing a gas deep dehumidification membrane, in a clean space, immersing the modified porous skeleton obtained in step (1) into the dehydration functional resin complex dispersion obtained in step (2), and filling or covering the surface of the modified porous skeleton with the dehydration functional resin complex under certain coating conditions, and completing the preparation of the gas deep dehumidification membrane after drying.

[0019] Furthermore, in the step (1), the porous skeleton is modified by surface plasma or chemical grafting to give the modified porous skeleton interior and surface more oxygen-containing groups having affinity with the water-removing functional resin complex dispersion.

[0020] Furthermore, in the step (2), the solid content of the dewatered functional resin composite dispersion is 5 to 50%, and the functional resin accounts for 50 to 100% of the solid content.

[0021] Furthermore, the coating conditions in step (3) are: under vacuum conditions, the vacuum degree ranges from 0.01 to 0.1 MPa; under high temperature conditions, the temperature ranges from 60 to 200°C.

[0022] Compared with the prior art, the present invention has the following significant advantages:

[0023] 1. The deep dehumidification membrane of the present invention can deeply remove water molecules from various types of gases. It has high water permeability and is a uniquely selective deep dehumidification membrane. It has excellent temperature resistance, pollution resistance, and corrosion resistance and can be used in conventional or harsh environments.

[0024] 2. The dehumidification membrane prepared by the present invention has good flexibility, can be bent at will, has high mechanical strength, and has water vapor permeability comparable to that of commercially available Nafion drying tubes. However, due to the low content of perfluorosulfonic acid resin, the cost is lower than that of commercially available dehumidification membranes, which can promote the application of such dehumidification membranes in more fields.

[0025] 3. The preparation process of the dehumidification membrane of the present invention is simple to operate, does not require complicated equipment, is environmentally friendly, pollution-free, and is easy to achieve batch preparation.

[0026] In summary, the dehumidification membrane designed by the present invention uses less perfluorosulfonic acid resin, has significant material cost advantages, and this type of dehumidification membrane has excellent temperature resistance, pollution resistance, and corrosion resistance, and can be applied to various conventional or harsh use environments. The membrane making technology of the present invention is a simple coating process, the preparation method is simple, and it is easy to achieve large-scale production. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below by means of specific implementation methods. Unless otherwise specified, all percentages involved are by mass.

[0028] Example 1

[0029] The gas deep dehumidification membrane comprises two parts: a modified porous skeleton and a water-removing functional resin complex; the modified porous skeleton plays a supporting role as the main body of the dehumidification membrane; the water-removing functional resin complex can selectively and directionally remove water molecules, and the two promote each other to complete the deep removal of water molecules in the gas.

[0030] The modified porous skeleton and the water removal functional resin composite are compounded into an integral structure by filling or coating; the mass proportion of the modified porous skeleton in the gas deep dehumidification membrane is 5 to 90%.

[0031] The modified porous skeleton is formed by modifying the porous skeleton by surface plasma or chemical grafting; the porous skeleton is a polytetrafluoroethylene membrane, a polyvinylidene fluoride membrane, a polyacrylonitrile membrane, a polyethylene membrane, a polypropylene membrane, a porous ceramic membrane or a metal membrane.

[0032] The water-removing functional resin complex comprises a functional resin and a water-absorbing material; the functional resin comprises one or a combination of two or more materials selected from perfluorosulfonic acid resin, sulfonated polystyrene, sulfonated polyetheretherketone, sulfonated polybenzimidazole, sulfonated polyvinylidene fluoride and the like; the water-absorbing material comprises one or a combination of two or more materials selected from calcium chloride, lithium chloride and magnesium chloride.

[0033] The porous skeleton has a tubular structure or a sheet structure; the inner diameter of the tubular structure is 0.5 to 100 mm, and the wall thickness is 0.1 to 5 mm; the thickness of the sheet structure is 0.05 to 2 mm.

[0034] The preparation method of the gas deep dehumidification membrane comprises the following steps:

[0035] 1. Porous skeleton modification: Place a polytetrafluoroethylene porous hollow membrane tube with an inner diameter of 5 mm, a wall thickness of 0.2 mm, and an average pore size of 0.2 μm in a 50% sulfuric acid solution and treat it at 45°C for 0.5 hours. Take it out and rinse it with excess deionized water, then place it in 15% hydrogen peroxide and keep it at 40°C for 2.5 hours. Finally, take out the membrane tube, rinse it in excess deionized water, dry it, and set it aside.

[0036] 2. Prepare a water-removing functional resin complex dispersion: Mix 5.0 g of a perfluorosulfonic acid resin with an ion exchange capacity of 1.2 mmol / g, 0.5 g of lithium chloride and a certain amount of dimethylformamide solvent, stir vigorously for 12 hours, and degas under vacuum conditions for 6 hours to obtain a water-removing functional resin complex dispersion with a solid content of 11%, which is then sealed and set aside.

[0037] 3. Preparation of dehumidification membrane: Place the modified porous skeleton in a 100°C drying oven for 0.5 hours, then quickly immerse it in the above-mentioned dehydration functional resin complex dispersion, take it out after keeping it for 30 seconds, and then place it in a 140°C drying oven for 6 hours to obtain the gas deep dehumidification membrane designed by the present invention. After calculation, the mass proportion of the functional resin in the gas dehumidification membrane is 35%.

[0038] Example 2

[0039] The gas deep dehumidification membrane comprises two parts: a modified porous skeleton and a water-removing functional resin complex; the modified porous skeleton plays a supporting role as the main body of the dehumidification membrane; the water-removing functional resin complex can selectively and directionally remove water molecules, and the two promote each other to complete the deep removal of water molecules in the gas.

[0040] The modified porous skeleton and the water removal functional resin composite are compounded into an integral structure by filling or coating; the mass proportion of the modified porous skeleton in the gas deep dehumidification membrane is 5 to 90%.

[0041] The modified porous skeleton is formed by modifying the porous skeleton by surface plasma or chemical grafting; the porous skeleton is a polytetrafluoroethylene membrane, a polyvinylidene fluoride membrane, a polyacrylonitrile membrane, a polyethylene membrane, a polypropylene membrane, a porous ceramic membrane or a metal membrane.

[0042] The water-removing functional resin complex comprises a functional resin and a water-absorbing material; the functional resin comprises one or a combination of two or more materials selected from perfluorosulfonic acid resin, sulfonated polystyrene, sulfonated polyetheretherketone, sulfonated polybenzimidazole, sulfonated polyvinylidene fluoride and the like; the water-absorbing material comprises one or a combination of two or more materials selected from calcium chloride, lithium chloride and magnesium chloride.

[0043] The porous skeleton has a tubular structure or a sheet structure; the inner diameter of the tubular structure is 0.5 to 100 mm, and the wall thickness is 0.1 to 5 mm; the thickness of the sheet structure is 0.05 to 2 mm.

[0044] The preparation method of the gas deep dehumidification membrane comprises the following steps:

[0045] 1. Porous skeleton modification: Place a porous alumina ceramic membrane (5 cm × 5 cm) with a thickness of 1.5 mm and an average pore size of 0.1 μm in 25% hydrogen peroxide and keep it at 60°C for 2.5 hours. Finally, take out the membrane tube, rinse it in excess deionized water, dry it, and set it aside.

[0046] 2. Prepare a water-removing functional resin complex dispersion: Mix 3.5 grams of perfluorosulfonic acid resin with an ion exchange capacity of 0.8 mmol / g, 0.3 grams of magnesium chloride and a certain amount of dimethylformamide, stir vigorously for 12 hours, degas under vacuum conditions for 6 hours, and obtain a water-removing functional resin complex dispersion with a solid content of 7.6%. Seal it and set it aside.

[0047] 3. Preparation of dehumidification membrane: Place the modified porous skeleton in a 200°C drying oven for 0.5 hour, then quickly immerse it in the above-mentioned dehydration functional resin composite dispersion, take it out after keeping it for 60 seconds, and then place it in a 160°C drying oven for 4 hours to obtain the gas deep dehumidification membrane designed by the present invention. After calculation, the mass proportion of the functional resin in the gas dehumidification membrane is 15%.

[0048] Example 3

[0049] The gas deep dehumidification membrane comprises two parts: a modified porous skeleton and a water-removing functional resin complex; the modified porous skeleton plays a supporting role as the main body of the dehumidification membrane; the water-removing functional resin complex can selectively and directionally remove water molecules, and the two promote each other to complete the deep removal of water molecules in the gas.

[0050] The modified porous skeleton and the water removal functional resin composite are compounded into an integral structure by filling or coating; the mass proportion of the modified porous skeleton in the gas deep dehumidification membrane is 5 to 90%.

[0051] The modified porous skeleton is formed by modifying the porous skeleton by surface plasma or chemical grafting; the porous skeleton is a polytetrafluoroethylene membrane, a polyvinylidene fluoride membrane, a polyacrylonitrile membrane, a polyethylene membrane, a polypropylene membrane, a porous ceramic membrane or a metal membrane.

[0052] The water-removing functional resin complex comprises a functional resin and a water-absorbing material; the functional resin comprises one or a combination of two or more materials selected from perfluorosulfonic acid resin, sulfonated polystyrene, sulfonated polyetheretherketone, sulfonated polybenzimidazole, sulfonated polyvinylidene fluoride and the like; the water-absorbing material comprises one or a combination of two or more materials selected from calcium chloride, lithium chloride and magnesium chloride.

[0053] The porous skeleton has a tubular structure or a sheet structure; the inner diameter of the tubular structure is 0.5 to 100 mm, and the wall thickness is 0.1 to 5 mm; the thickness of the sheet structure is 0.05 to 2 mm.

[0054] The preparation method of the gas deep dehumidification membrane comprises the following steps:

[0055] 1. Porous skeleton modification: Place a polyacrylonitrile porous hollow membrane tube with an inner diameter of 3 mm, a wall thickness of 0.5 mm, and an average pore size of 0.1 μm in a 60% sulfuric acid solution and treat it at 60°C for 0.5 hours. Take it out and rinse it with excess deionized water, then place it in 20% hydrogen peroxide and keep it at 30°C for 1.5 hours. Finally, take out the membrane tube, rinse it in excess deionized water, dry it, and set it aside.

[0056] 2. Prepare a water-removing functional resin complex dispersion: Mix 30.0 g of a perfluorosulfonic acid resin with an ion exchange capacity of 1.0 mmol / g, 15.2 g of calcium chloride and a certain amount of dimethylformamide solvent, stir vigorously for 12 hours, and degas under vacuum conditions for 6 hours to obtain a water-removing functional resin complex dispersion with a solid content of 45%, which is then sealed and set aside.

[0057] 3. Preparation of dehumidification membrane: Place the modified porous skeleton in the above-mentioned dehumidification functional resin complex dispersion, keep it at a vacuum degree of 0.065 MPa for 60 seconds, then take it out, and then place it in a drying oven at 120°C for 8 hours to obtain the gas deep dehumidification membrane designed by the present invention. After calculation, the mass proportion of the functional resin in the gas dehumidification membrane is 75%.

[0058] Example 4

[0059] The gas deep dehumidification membrane comprises two parts: a modified porous skeleton and a water-removing functional resin complex; the modified porous skeleton plays a supporting role as the main body of the dehumidification membrane; the water-removing functional resin complex can selectively and directionally remove water molecules, and the two promote each other to complete the deep removal of water molecules in the gas.

[0060] The modified porous skeleton and the water removal functional resin composite are compounded into an integral structure by filling or coating; the mass proportion of the modified porous skeleton in the gas deep dehumidification membrane is 5 to 90%.

[0061] The modified porous skeleton is formed by modifying the porous skeleton by surface plasma or chemical grafting; the porous skeleton is a polytetrafluoroethylene membrane, a polyvinylidene fluoride membrane, a polyacrylonitrile membrane, a polyethylene membrane, a polypropylene membrane, a porous ceramic membrane or a metal membrane.

[0062] The water-removing functional resin complex comprises a functional resin and a water-absorbing material; the functional resin comprises one or a combination of two or more materials selected from perfluorosulfonic acid resin, sulfonated polystyrene, sulfonated polyetheretherketone, sulfonated polybenzimidazole, sulfonated polyvinylidene fluoride and the like; the water-absorbing material comprises one or a combination of two or more materials selected from calcium chloride, lithium chloride and magnesium chloride.

[0063] The porous skeleton has a tubular structure or a sheet structure; the inner diameter of the tubular structure is 0.5 to 100 mm, and the wall thickness is 0.1 to 5 mm; the thickness of the sheet structure is 0.05 to 2 mm.

[0064] The preparation method of the gas deep dehumidification membrane comprises the following steps:

[0065] 1. Porous skeleton modification: Place a porous stainless steel membrane (10 cm × 6 cm) with a thickness of 1.0 mm and an average pore size of 0.5 μm in 20% hydrogen peroxide and keep it at 35°C for 1.5 hours. Finally, take out the membrane tube, rinse it in excess deionized water, dry it, and set it aside.

[0066] 2. Prepare a water-removing functional resin complex dispersion: Mix 5.5 grams of perfluorosulfonic acid resin with an ion exchange capacity of 1.4 mmol / g, 1.2 grams of lithium chloride and a certain amount of dimethylformamide, stir vigorously for 12 hours, degas under vacuum conditions for 6 hours, and obtain a water-removing functional resin complex dispersion with a solid content of 24%, which is sealed and set aside.

[0067] 3. Preparation of dehumidification membrane: Place the modified porous skeleton in a 120°C drying oven for 0.5 hour, then quickly immerse it in the above-mentioned dehumidification functional resin complex dispersion, keep it at a vacuum degree of 0.05 MPa for 120 seconds, then take it out, and then place it in a 100°C drying oven for 24 hours to obtain the gas deep dehumidification membrane designed by the present invention. After calculation, the mass proportion of the functional resin in the gas dehumidification membrane is 42%.

[0068] Dehumidification membrane performance test, the method refers to GB / T1037-1988 and GB / T1038-2000. The conditions are: 25℃, the humidity difference on both sides of the water vapor dehumidification membrane sample is 90%, the partial pressure difference on both sides of the nitrogen permeation test membrane is 0.1MPa, and the flow rate is 5L / min. The permeation test uses argon purge, the flow rate is 10L / min, and the test system is self-made. The test results are shown in the following table.

[0069]

[0070] As can be seen from the above table, the present invention successfully prepared a new membrane material that can dehumidify gas deeply and efficiently. After a simple economic calculation, the cost of the membrane material of the present invention is only 20-40% of the commercially available dehumidification membrane.

[0071] The applicant declares that the present invention illustrates the gas deep dehumidification membrane and the preparation method thereof through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a gas deep dehumidification membrane, characterized in that: The steps include: (1) Porous skeleton modification: A polytetrafluoroethylene porous hollow membrane tube with an inner diameter of 5 mm, a wall thickness of 0.2 mm, and an average pore size of 0.2 μm was placed in a 50% sulfuric acid solution and treated at 45°C for 0.5 h. The membrane tube was taken out and rinsed with excess deionized water and then placed in 15% hydrogen peroxide at 40°C for 2.5 h. Finally, the membrane tube was taken out and rinsed in excess deionized water, dried, and set aside. (2) preparing a water-removing functional resin composite dispersion: 5.0 g of a perfluorosulfonic acid resin having an ion exchange capacity of 1.2 mmol / g, 0.5 g of lithium chloride and a certain amount of dimethylformamide solvent were mixed, stirred vigorously for 12 hours, and degassed under vacuum conditions for 6 hours to obtain a water-removing functional resin composite dispersion having a solid content of 11%, which was then sealed and set aside; (3) Preparation of dehumidification membrane: The modified porous skeleton was placed in a drying oven at 100°C for 0.5 hours, and then quickly immersed in the above-mentioned dehumidification functional resin composite dispersion, and taken out after being kept for 30 seconds, and then placed in a drying oven at 140°C for 6 hours, and finally the gas deep dehumidification membrane designed by the present invention was obtained. After calculation, the mass proportion of the functional resin in the gas dehumidification membrane was 35%; The above-mentioned gas deep dehumidification membrane comprises two parts: a modified porous skeleton and a water-removing functional resin composite; the modified porous skeleton plays a supporting role as the main body of the dehumidification membrane; the water-removing functional resin composite can selectively and directionally remove water molecules, and the two promote each other to complete the deep removal of water molecules in the gas; The modified porous skeleton and the water-removing functional resin composite are compounded into an integral structure in a filling manner; the mass proportion of the modified porous skeleton in the gas deep dehumidification membrane is 65%.

2. A method for preparing a gas deep dehumidification membrane, characterized in that: The steps include: (1) Porous skeleton modification: A 5 cm × 5 cm porous alumina ceramic membrane with a thickness of 1.5 mm and an average pore size of 0.1 μm was placed in 25% hydrogen peroxide and kept at 60 °C for 2.5 hours; finally, the membrane was taken out and rinsed in excess deionized water, dried, and set aside; (2) Preparation of water-removing functional resin composite dispersion: 3.5 g of perfluorosulfonic acid resin with an ion exchange capacity of 0.8 mmol / g, 0.3 g of magnesium chloride and a certain amount of dimethylformamide were mixed, stirred vigorously for 12 hours, and degassed under vacuum conditions for 6 hours to obtain a water-removing functional resin composite dispersion with a solid content of 7.6%, which was sealed and set aside; (3) Preparation of dehumidification membrane: The modified porous skeleton was placed in a drying oven at 200°C for 0.5 hours, and then quickly immersed in the above-mentioned dehumidification functional resin composite dispersion, and taken out after being kept for 60 seconds, and then placed in a drying oven at 160°C for 4 hours to obtain the gas deep dehumidification membrane designed by the present invention. After calculation, the mass proportion of the functional resin in the gas dehumidification membrane was 15%; The above-mentioned gas deep dehumidification membrane comprises two parts: a modified porous skeleton and a water-removing functional resin composite; the modified porous skeleton plays a supporting role as the main body of the dehumidification membrane; the water-removing functional resin composite can selectively and directionally remove water molecules, and the two promote each other to complete the deep removal of water molecules in the gas; The modified porous skeleton and the water-removing functional resin composite are compounded into an integral structure in a filling manner; the mass proportion of the modified porous skeleton in the gas deep dehumidification membrane is 85%.

3. A method for preparing a gas deep dehumidification membrane, characterized in that: The steps include: (1) Porous skeleton modification: A polyacrylonitrile porous hollow membrane tube with an inner diameter of 3 mm, a wall thickness of 0.5 mm, and an average pore size of 0.1 μm was placed in a 60% sulfuric acid solution and treated at 60°C for 0.5 h. The membrane tube was taken out and rinsed with excess deionized water and then placed in 20% hydrogen peroxide at 30°C for 1.5 h. Finally, the membrane tube was taken out and rinsed in excess deionized water, dried, and set aside. (2) Preparation of water-removing functional resin composite dispersion: 30.0 g of perfluorosulfonic acid resin with an ion exchange capacity of 1.0 mmol / g, 15.2 g of calcium chloride and a certain amount of dimethylformamide solvent were mixed, stirred vigorously for 12 hours, and degassed under vacuum conditions for 6 hours to obtain a water-removing functional resin composite dispersion with a solid content of 45%, which was sealed and set aside; (3) Preparation of dehumidification membrane: The modified porous skeleton is placed in the above-mentioned dehumidification functional resin composite dispersion, kept at a vacuum degree of 0.065 MPa for 60 seconds, then taken out, and then placed in a drying oven at 120°C for 8 hours, and finally the gas deep dehumidification membrane designed by the present invention is obtained. After calculation, the mass proportion of the functional resin in the gas dehumidification membrane is 75%; The above-mentioned gas deep dehumidification membrane comprises two parts: a modified porous skeleton and a water-removing functional resin composite; the modified porous skeleton plays a supporting role as the main body of the dehumidification membrane; the water-removing functional resin composite can selectively and directionally remove water molecules, and the two promote each other to complete the deep removal of water molecules in the gas; The modified porous skeleton and the water-removing functional resin composite are compounded into an integral structure in a filling manner; the mass proportion of the modified porous skeleton in the gas deep dehumidification membrane is 25%.

4. A method for preparing a gas deep dehumidification membrane, characterized in that: The steps include: (1) Porous skeleton modification: A 10 cm × 6 cm porous stainless steel membrane with a thickness of 1.0 mm and an average pore size of 0.5 μm was placed in 20% hydrogen peroxide and kept at 35 °C for 1.5 hours; finally, the membrane was taken out and rinsed in excess deionized water, dried, and set aside; (2) Preparation of a water-removing functional resin composite dispersion: 5.5 g of a perfluorosulfonic acid resin having an ion exchange capacity of 1.4 mmol / g, 1.2 g of lithium chloride and a certain amount of dimethylformamide were mixed, stirred vigorously for 12 hours, and degassed under vacuum conditions for 6 hours to obtain a water-removing functional resin composite dispersion having a solid content of 24%, which was sealed and set aside; (3) Preparation of dehumidification membrane: The modified porous skeleton was placed in a drying oven at 120°C for 0.5 hours, and then quickly immersed in the above-mentioned dehumidification functional resin composite dispersion, and was taken out after being kept at a vacuum degree of 0.05 MPa for 120 seconds, and then placed in a drying oven at 100°C for 24 hours. Finally, the gas deep dehumidification membrane designed by the present invention was obtained. After calculation, the mass proportion of the functional resin in the gas dehumidification membrane was 42%; The above-mentioned gas deep dehumidification membrane comprises two parts: a modified porous skeleton and a water-removing functional resin composite; the modified porous skeleton plays a supporting role as the main body of the dehumidification membrane; the water-removing functional resin composite can selectively and directionally remove water molecules, and the two promote each other to complete the deep removal of water molecules in the gas; The modified porous skeleton and the water-removing functional resin composite are compounded into an integral structure in a filling manner; the modified porous skeleton accounts for 58% of the mass of the gas deep dehumidification membrane.

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