Hollow fiber carbon dioxide separation membrane, method for preparing the same, and use thereof

Abstract

The application relates to the technical field of membrane separation materials, and discloses a hollow fiber carbon dioxide separation membrane and a preparation method and application thereof. The separation membrane comprises a base film and a functional layer formed on the inner surface and / or the outer surface of the base film through an interfacial polymerization method; the separation membrane comprises a hollow part and a solid part, wherein the solid part of the base film comprises a polymer microporous membrane prepared through non-solvent induced phase separation, melt stretching or thermal induced phase separation; the functional layer is formed through interfacial polymerization of an oil phase solution and / or an aqueous phase solution on the base film. The hollow fiber carbon dioxide separation membrane has high carbon dioxide flux and high CO2 / N2 separation coefficient.

Description

Technical Field

[0001] This invention relates to the field of membrane separation materials technology, specifically to a hollow fiber carbon dioxide separation membrane, its preparation method, and its application. Background Technology

[0002] Carbon capture and storage (CCS) is considered an effective way to reduce CO2 emissions in the short term. Compared with other CO2 capture processes, membrane separation technology has advantages such as high energy efficiency, overcoming thermodynamic solubility limitations, no harmful byproducts generated during the separation process, compact membrane module systems, small footprint, simple operation, and easy scale-up, making it a CO2 capture process with great potential for large-scale application. Membrane materials are one of the key factors limiting the large-scale industrial application of membrane separation technology. Ideal CO2 separation membrane materials need to have good film-forming properties and mechanical stability, excellent CO2 permeability and selectivity, reasonable preparation cost, and preparation stability.

[0003] Interfacial polymerization technology utilizes the relative diffusion of two highly reactive monomers or prepolymers at the interface of two immiscible solvents, resulting in a rapid polymerization reaction that forms a thin and dense composite layer on the surface of the support layer. The composite membrane prepared by this technology allows for separate optimization of the support and separation layers. Furthermore, because the effective separation layer is extremely thin, the required material is relatively small compared to the support layer, making it easier to introduce materials with good gas selectivity but higher costs (reference: https: / / doi.org / 10.1016 / j.jece.2021.105624). This technology is simple, fast, and effective, and is currently a feasible method for preparing carbon dioxide separation membranes. However, it mostly only produces flat sheet membranes, and the method of separately wetting two phase solutions makes it difficult to prepare hollow fiber membranes with uniform functional layers. Controlling the thickness of the functional layer and its bonding effect with the base membrane is also more challenging.

[0004] CN101002999A discloses a method for preparing a carbon dioxide separation membrane, which is a flat sheet membrane prepared by interfacial polymerization of acyl chloride and amine monomers. However, its permeability coefficient and selectivity are low, and the packing area of ​​the flat sheet membrane is small, its pressure resistance is poor, and it is not easy to scale up the process.

[0005] CN101480583A discloses a method for preparing a hollow fiber carbon dioxide separation membrane, which adopts a dry-wet phase conversion one-time molding process. The polyetherimide material used has good selectivity for carbon dioxide, but its molding is relatively difficult. Moreover, due to the large thickness of the separation layer, its permeation rate is relatively low, and the cost is relatively high.

[0006] CN110869107A discloses a method for preparing a hollow fiber carbon dioxide separation membrane, which uses an dip-coating method to prepare a multilayer hollow fiber composite membrane. This method can also be used to prepare flat sheet membranes. The problem is that the preparation process of this method is complex, the functional layers of the membrane are not easy to control, and the interfacial bonding strength is poor, resulting in low strength of the membrane fibers, poor solvent resistance of the membrane fiber surface, and low anti-plasticization effect.

[0007] CN110975646A discloses a hollow fiber carbon dioxide membrane and its preparation method, which includes local crosslinking between a support layer and a functional layer to achieve a more tightly bonded and fused relationship between the two layers. While this method improves the process and produces hollow fiber carbon dioxide separation membranes with higher mechanical strength and operational stability, the crosslinking process reduces the overall permeability of the membrane.

[0008] Therefore, it is of great significance to research and develop a hollow fiber carbon dioxide separation membrane with higher mechanical strength and better separation effect. Summary of the Invention

[0009] The purpose of this invention is to overcome the problems of low mechanical strength and poor separation effect of hollow fiber carbon dioxide membranes in the prior art, and to provide a hollow fiber carbon dioxide separation membrane, its preparation method and application. The hollow fiber carbon dioxide separator has a high carbon dioxide flux and a high CO2 / N2 separation coefficient.

[0010] To achieve the above objectives, a first aspect of the present invention provides a hollow fiber carbon dioxide separation membrane, the separation membrane comprising a hollow portion and a solid portion, wherein the solid portion of the separation membrane comprises a base membrane and a functional layer formed on the inner and / or outer surfaces of the base membrane by an interfacial polymerization method; wherein the base membrane is a polymer microporous membrane prepared by non-solvent-induced phase separation, melt stretching, and thermally induced phase separation; the functional layer comprises an oil phase solution and / or an aqueous phase solution formed on the base membrane by an interfacial polymerization reaction.

[0011] A second aspect of the present invention provides a method for preparing a hollow fiber carbon dioxide separation membrane, wherein the method comprises: (1) A hollow fiber carbon dioxide separation membrane preparation device is used, and an oil phase solution or an aqueous phase solution is introduced into the hollow inner core of the polymer microporous membrane as the core liquid by a core liquid pump; (2) An oil-phase solution or an aqueous-phase solution is introduced into the spinneret as a coating liquid, and the coating liquid is scraped onto the base film using a doctor blade; the core liquid and the coating liquid diffuse towards each other on the inner and / or outer sides of the polymer microporous membrane, and form a functional layer on the polymer microporous membrane through interfacial polymerization reaction; wherein, the core liquid and the coating liquid are different; (3) The polymer microporous membrane is pulled through the spinneret to prepare a hollow fiber carbon dioxide separation membrane.

[0012] A third aspect of the present invention provides a hollow fiber carbon dioxide separation membrane prepared by the preparation method described above.

[0013] The fourth aspect of the present invention provides an application of the aforementioned hollow fiber carbon dioxide separation membrane in the separation and purification of CO2 / N2.

[0014] Through the above technical solution, the present invention has the following beneficial effects: (1) The functional layer of the hollow fiber carbon dioxide separation membrane prepared by the present invention is tightly bonded to the base membrane; (2) The formation position of the functional layer of the hollow fiber carbon dioxide separation membrane prepared by the present invention can be adjusted by the difference between the oil phase and the water phase, as well as the difference between the operating pressure and the contact time; (3) During the film formation process, the core liquid and the coating liquid diffuse towards each other on both sides of the base film, and the thickness and position of the functional layer after film formation can be controlled; (4) The process of the present invention is simple, the cost is low, and it is easy to scale up; (5) The present invention uses a polymer microporous membrane as the base membrane, which improves the mechanical properties of the membrane fibers and fully meets the application requirements when the airflow fluctuation is large and the transmembrane pressure difference is high. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the apparatus used in this invention for preparing hollow fiber carbon dioxide separation membranes; Figure 2 This is a schematic diagram of the process for preparing the hollow fiber carbon dioxide separation membrane according to the present invention; Figure 3 Here is a SEM image of the hollow fiber carbon dioxide separation membrane prepared in Example 1 of this aspect; Figure 4 This is a photograph of the hollow fiber carbon dioxide separation membrane prepared in Example 1 of the present invention. Detailed Implementation

[0016] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0017] As previously described, the first aspect of the present invention provides a hollow fiber carbon dioxide separation membrane, the separation membrane comprising a hollow portion and a solid portion, wherein the solid portion of the separation membrane comprises a base membrane and a functional layer formed on the inner and / or outer surfaces of the base membrane by an interfacial polymerization method; wherein the base membrane comprises a polymer microporous membrane prepared by non-solvent-induced phase separation, melt stretching, and thermally induced phase separation; the functional layer comprises an oil phase solution and / or an aqueous phase solution formed on the base membrane by an interfacial polymerization reaction.

[0018] The inventors of this invention discovered that during the preparation of hollow fiber carbon dioxide separation membranes, the core liquid and coating liquid diffuse towards each other simultaneously on both sides of the base membrane, resulting in a tighter bond between the base membrane and the functional layer. Furthermore, by adjusting the pressure, contact time, and temperature of the oil and aqueous solutions, as well as the relative displacement velocity between the base membrane and the spinneret, the thickness of the functional layer after membrane formation can be controlled. Additionally, using a polymer microporous membrane as the base membrane improves the mechanical properties of the membrane fibers, fully meeting the requirements for applications with large airflow fluctuations and high transmembrane pressure differences.

[0019] According to the present invention, the oil phase monomer in the oil phase solution is selected from one or more of pyromellitic methyl chloride, terephthaloyl chloride, isophthaloyl chloride and benzyl p-dichloroisocyanurate, preferably pyromellitic methyl chloride.

[0020] According to the present invention, the solvent in the oil phase solution is selected from one or more of n-hexane, n-heptane, isoparaffin solvents Isopar G, Isopar E, Isopar H, Isopar L, and Isopar M, preferably one or more of n-hexane, Isopar G, and Isopar E. It should be noted that the Isopar series refers to commercially available industrial organic solvent brands, whose main components are high-purity isoparaffins.

[0021] According to the present invention, the aqueous monomer in the aqueous solution is selected from one or more of piperazine, m-phenylenediamine, ethylenediamine, triethylenetetramine, polyethylenepolyamine, polyethyleneimine, and polyetheramine, preferably one or more of m-phenylenediamine, triethylenetetramine, polyethyleneimine, and polyetheramine.

[0022] According to the present invention, the polymer microporous membrane is selected from one or more of polypropylene, polyethylene, polytetrafluoroethylene, polyvinylidene fluoride and polysulfone; wherein the polyethylene is high-density polyethylene and / or ultra-high molecular weight polyethylene, the density of the high-density polyethylene is 0.94-0.96 g / cm³, and the weight-average molecular weight of the ultra-high molecular weight polyethylene is 1 million to 5 million.

[0023] According to the present invention, the average diameter of the hollow portion of the separation membrane is 100-2000 μm, preferably 300-1200 μm, and more preferably 300-1000 μm.

[0024] According to the present invention, the average thickness of the functional layer is 10-2000 nm, preferably 20-400 nm, and more preferably 50-300 nm.

[0025] A second aspect of the present invention provides a method for preparing a hollow fiber carbon dioxide separation membrane, wherein the method comprises: (1) A hollow fiber carbon dioxide separation membrane preparation device is used, and an oil phase solution or an aqueous phase solution is introduced into the hollow inner core of the polymer microporous membrane as the core liquid by a core liquid pump; (2) An oil-phase solution or an aqueous-phase solution is introduced into the spinneret as a coating liquid, and the coating liquid is scraped onto the base film using a doctor blade; the core liquid and the coating liquid diffuse towards each other on the inner and / or outer sides of the polymer microporous membrane, and form a functional layer on the polymer microporous membrane through interfacial polymerization reaction; wherein, the core liquid and the coating liquid are different; (3) The polymer microporous membrane is pulled through the spinneret to prepare a hollow fiber carbon dioxide separation membrane.

[0026] According to the present invention, the polymer microporous membrane, the oil phase solution and the aqueous phase solution are as described above, and will not be repeated here.

[0027] According to the present invention, the concentration of the oil phase solution is 0.01-0.5 wt%, preferably 0.1-0.4 wt%.

[0028] According to the present invention, the concentration of the aqueous solution is 0.02-5 wt%, preferably 0.2-2 wt%.

[0029] According to the present invention, in step (1), the pressure of the oil phase solution introduced into the hollow inner core is 0-1 MPa, the flow velocity is 0-1 m / s, and the temperature is 0-100 °C; preferably, the pressure of the oil phase solution introduced into the hollow inner core is 0.01-0.5 MPa, the flow velocity is 0.01-1 m / s, and the temperature is 20-50 °C.

[0030] According to the present invention, in step (2), the coating film thickness of the coating liquid is 50-1000 μm.

[0031] According to the present invention, the distance between the coating liquid and the base film inside the spinneret is 1-100 cm.

[0032] According to the present invention, in step (3), the relative displacement speed between the base film and the spinneret is 5-50 cm / min, preferably 10-30 cm / min.

[0033] In this invention, Figure 1 This is a schematic diagram of the apparatus used in this invention for preparing hollow fiber carbon dioxide separation membranes; from Figure 1 It can be seen that the device for preparing hollow fiber carbon dioxide separation membrane includes a base membrane, a base membrane holder, an annular scraper, a base membrane positioner, and a core tube; wherein, the base membrane positioner forms a cavity around the base membrane; the cavity is used to store coating liquid, and the cavity is provided with a coating liquid injection port and a coating liquid outlet; one end of the cavity is connected to the base membrane positioner to form a closed end, and the other end of the cavity is provided with the annular scraper, the diameter of which is smaller than the width of the base membrane positioner; the core tube is built into the interior of the base membrane.

[0034] In this invention, Figure 2 This is a schematic diagram of the process for preparing the hollow fiber carbon dioxide separation membrane according to the present invention; from Figure 2 It can be seen that: First, a base membrane is selected and fixed using a base membrane holder; an oil-phase solution or an aqueous-phase solution is introduced into the hollow core of the polymer microporous membrane using a core liquid pump; a coating liquid is injected through the coating liquid inlet; a ring-shaped doctor blade is used for coating, and excess coating liquid flows out through the coating liquid outlet, while some coating liquid permeates into the base membrane; the core liquid and the coating liquid diffuse towards each other on the inner and / or outer sides of the polymer microporous membrane, and form a functional layer on the polymer microporous membrane through an interfacial polymerization reaction; the polymer microporous membrane is then pulled through the spinneret to prepare a hollow fiber carbon dioxide separation membrane.

[0035] According to the present invention, in a preferred embodiment, the polymer microporous membrane may be further modified; in a more preferred embodiment, the interior of the polymer microporous membrane is a fiber braided tube support.

[0036] In this invention, a method for preparing a hollow fiber carbon dioxide separation membrane includes: (a) After thoroughly grinding and mixing polyethylene, hydrophilic additives and pore-forming agents using a ball mill, add diluent and stir thoroughly to obtain a mixed liquid. (b) The mixture is processed by a twin-screw extruder to form a uniform spinning solution at a certain spinning temperature. Based on the thermally induced phase separation method, concentric circle composite spinning technology is used. The spinning solution is contacted with the braided tube through the spinneret and coated on the outer layer of the braided tube. After being solidified by air bath and coagulation bath, it is then wound, extracted by extractant and washed with water to obtain a hydrophilic modified high-strength hollow fiber carbon dioxide separation membrane.

[0037] According to the present invention, based on the total weight of the mixture, the content of polyethylene is 4-20 wt%, the content of hydrophilic additive is 5-20 wt%, the content of pore-forming agent is 5-20 wt%, the content of diluent is 40-86 wt%, and the sum of all components is 100 wt%.

[0038] According to the present invention, the hydrophilic additive comprises a hydrophilic polymer additive and a hydrophilic inorganic additive in a mass ratio of 5:(1-5), wherein the hydrophilic polymer additive comprises at least one of ethylene-vinyl acetate copolymer, polyethylene-polyethylene glycol copolymer, polyvinyl butyral, ethylene-vinyl alcohol copolymer and ethylene-acrylic acid copolymer; and the hydrophilic inorganic additive comprises at least one of hydrophilic silica, hydrophilic titanium dioxide and zinc oxide.

[0039] According to the present invention, the hydrophilic additive is thoroughly ball-milled and mixed with polyethylene before use.

[0040] According to the present invention, the pore-forming agent includes at least one selected from polyethylene glycol, polyethylene oxide, calcium chloride and sodium chloride, preferably polyethylene glycol.

[0041] According to the present invention, the diluent is a solvent that can dissolve polyethylene at high temperatures. Preferably, the diluent includes one or a mixture of two or more of white oil, decahydronaphthalene, tetrahydronaphthalene, diphenyl ether, phthalate, soybean oil and liquid paraffin. More preferably, it is white oil with low volatility and low toxicity.

[0042] According to the present invention, the spinning temperature is 150-230℃, the contact distance between the spinning solution and the spinneret is 3-10cm, the air bath height is 5-25cm, and the coagulation bath temperature is 10-50℃.

[0043] According to the present invention, the braided tube is a polyester fiber braided tube or a polyethylene fiber braided tube with an outer diameter of 1.4-2 mm, and the conveying speed is determined by the winding speed as 10-40 m / min.

[0044] A third aspect of the present invention provides a hollow fiber carbon dioxide separation membrane prepared by the aforementioned preparation method.

[0045] The fourth aspect of the present invention provides an application of the aforementioned hollow fiber carbon dioxide separation membrane in the separation and purification of CO2 / N2.

[0046] The present invention will be described in detail below through embodiments.

[0047] In the following examples and comparative examples: Permeation flux parameters were measured using the differential pressure method; Isopar G, Isopar E, Isopar H, Isopar L, and Isopar M are commercially available products from ExxonMobil.

[0048] Example 1 This embodiment is intended to illustrate the hollow fiber carbon dioxide separation membrane prepared according to the present invention.

[0049] (1) Take 0.66 g of pyromellitic chloride, dissolve it in 1000 mL of n-hexane to prepare an oil phase solution with a mass concentration of 0.1%; take 20 g of m-phenylenediamine, dissolve it in 980 mL of deionized water to prepare an aqueous phase solution with a mass concentration of 2%; (2) A polysulfone hollow fiber base membrane was used, and the spinneret core liquid tube was fixed. An aqueous solution was introduced into the hollow core of the base membrane by a core liquid pump at a pressure of 0.2 MPa, a temperature of 25 °C, a flow rate of 5 mL / min, and a stable flow time of 3 min. (3) The oil phase solution is introduced into the spinneret as a coating liquid at a flow rate of 5 mL / min, and the coating liquid is scraped onto the base film using a doctor blade; the base film is lifted at a rate of 20 cm / min so that the hollow fiber base film passes through the spinneret. (4) Let the fully reacted hollow fiber composite membrane stand in the air for 5 minutes, wash it thoroughly with deionized water, and then let it air dry.

[0050] The hollow fiber carbon dioxide separation membrane prepared as a whole had an average diameter of 500 μm and an average thickness of 300 nm for the hollow portion. The hollow fiber carbon dioxide separation membrane has a tensile strength of 33 MPa, a water contact angle of 99°, a carbon dioxide flux of 280 GPU at a test pressure of 0.1 MPa, and a CO2 / N2 separation coefficient of 204.

[0051] Figure 3 This is a SEM image of the hollow fiber carbon dioxide separation membrane prepared in Example 1 of this aspect; from Figure 3 It can be seen that the outer surface is dense.

[0052] Figure 4 These are photographs of the hollow fiber carbon dioxide separation membrane prepared in Example 1 of this invention; from Figure 4 It can be seen that the outer surface of the hollow fiber carbon dioxide separation membrane is uniform, dense, and free of defects.

[0053] Example 2 This embodiment is intended to illustrate the hollow fiber carbon dioxide separation membrane prepared according to the present invention.

[0054] (1) Take 0.66 g of pyromellitic chloride, dissolve it in 1000 mL of Isopar E, and prepare an oil phase solution with a mass concentration of 0.1%; take 20 g of triethylenetetramine, dissolve it in 980 mL of deionized water, and prepare an aqueous phase solution with a mass concentration of 2%; (2) A polysulfone hollow fiber base membrane was used, and the spinneret core liquid tube was fixed. An aqueous solution was introduced into the hollow core of the base membrane by a core liquid pump at a pressure of 0.2 MPa, a temperature of 35 °C, a flow rate of 5 mL / min, and a stable flow time of 3 min. (3) The oil phase solution is introduced into the spinneret as a coating liquid at a flow rate of 5 mL / min. The coating liquid is then applied to the base film using a doctor blade. The base film is then pulled up at a rate of 5 cm / min to allow the hollow fiber base film to pass through the spinneret. (4) Let the fully reacted hollow fiber composite membrane stand in the air for 5 minutes, wash it thoroughly with deionized water, and then let it air dry.

[0055] The hollow fiber carbon dioxide separation membrane prepared as a whole had an average diameter of 800 μm and an average thickness of 200 nm for the hollow portion. The hollow fiber carbon dioxide separation membrane has a tensile strength of 20 MPa, a water contact angle of 67°, a carbon dioxide flux of 787 GPU at a test pressure of 0.1 MPa, and a CO2 / N2 separation coefficient of 85.

[0056] Example 3 This embodiment is intended to illustrate the hollow fiber carbon dioxide separation membrane prepared according to the present invention.

[0057] (1) Take 0.66 g of pyromellitic chloride, dissolve it in 1000 mL of Isopar G, and prepare an oil phase solution with a mass concentration of 0.1%; take 20 g of polyetheramine, dissolve it in 980 mL of deionized water, and prepare an aqueous phase solution with a mass concentration of 2%; (2) A tetrafluoroethylene hollow fiber base membrane was used, and the spinneret core liquid tube was fixed. An aqueous solution was introduced into the hollow core of the base membrane by a core liquid pump at a pressure of 0.3 MPa, a temperature of 40 °C, a flow rate of 5 mL / min, and a stable flow time of 3 min. (3) The oil phase solution is introduced into the spinneret as a coating liquid at a flow rate of 5 mL / min. The coating liquid is then applied to the base film using a doctor blade. The base film is then pulled up at a rate of 20 cm / min to allow the hollow fiber base film to pass through the spinneret. (4) After the fully reacted hollow fiber composite membrane is heat-treated in an 80°C ventilated oven for 10 minutes, it is taken out, thoroughly cleaned with deionized water, and then naturally dried.

[0058] The hollow fiber carbon dioxide separation membrane prepared as a whole had an average diameter of 600 μm and an average thickness of 200 nm for the hollow portion. The hollow fiber carbon dioxide separation membrane has a tensile strength of 150 MPa, a water contact angle of 120° on its outer surface, a carbon dioxide flux of 950 GPU at a test pressure of 0.1 MPa, and a CO2 / N2 separation coefficient of 96.

[0059] Example 4 This embodiment is intended to illustrate the hollow fiber carbon dioxide separation membrane prepared according to the present invention.

[0060] (1) Take 2.67 g of pyromellitic chloride, dissolve it in 1000 mL of n-hexane to prepare an oil phase solution with a mass concentration of 0.4%; take 2 g of m-phenylenediamine, dissolve it in 998 mL of deionized water to prepare an aqueous phase solution with a mass concentration of 0.2%; (2) A polypropylene hollow fiber base membrane was used, and the spinneret core liquid tube was fixed. An oil phase solution was introduced into the hollow core of the base membrane by a core liquid pump. The pressure was 0.1 MPa, the temperature was 25℃, the flow rate was 5 mL / min, and the flow was stable for 3 min. (3) The aqueous solution is introduced into the spinneret as a coating liquid at a flow rate of 5 mL / min. The coating liquid is then applied to the base membrane using a doctor blade. The base membrane is then pulled up at a rate of 20 cm / min to allow the hollow fiber base membrane to pass through the spinneret. (4) After the fully reacted hollow fiber composite membrane is heat-treated in a ventilated oven at 60°C for 5 minutes, it is taken out, thoroughly cleaned with deionized water, and then naturally dried.

[0061] The hollow fiber carbon dioxide separation membrane prepared as a result had an average diameter of 1000 μm for the hollow portion and an average thickness of 50 nm for the functional layer. The hollow fiber carbon dioxide separation membrane has a tensile strength of 150 MPa, a water contact angle of 74°, a carbon dioxide flux of 1082 GPU at a test pressure of 0.1 MPa, and a CO2 / N2 separation coefficient of 74.

[0062] Example 5 This embodiment is intended to illustrate the hollow fiber carbon dioxide separation membrane prepared according to the present invention.

[0063] (1) Take 3g of pyromellitic chloride, dissolve it in 1000mL of Isopar G, and prepare an oil phase solution with a mass concentration of 0.4%; take 2g of polyethyleneimine, dissolve it in 998mL of deionized water, and prepare an aqueous phase solution with a mass concentration of 0.2%; (2) A polypropylene hollow fiber base membrane was used, and the spinneret core liquid tube was fixed. An oil phase solution was introduced into the hollow core of the base membrane by a core liquid pump. The pressure was 0.15 MPa, the temperature was 40℃, the flow rate was 5 mL / min, and the flow was stable for 3 min. (3) The aqueous solution is introduced into the spinneret as a coating liquid at a flow rate of 5 mL / min. The coating liquid is then applied to the base membrane using a doctor blade. The base membrane is then pulled up at a rate of 20 cm / min to allow the hollow fiber base membrane to pass through the spinneret. (4) After the fully reacted hollow fiber composite membrane is heat-treated in a ventilated oven at 60°C for 5 minutes, it is taken out, thoroughly cleaned with deionized water, and then naturally dried.

[0064] The hollow fiber carbon dioxide separation membrane prepared as a result had an average diameter of 900 μm for the hollow portion and an average thickness of 60 nm for the functional layer. The hollow fiber carbon dioxide separation membrane has a water contact angle of 45°, a carbon dioxide flux of 1295 GPU at a test pressure of 0.1 MPa, and a CO2 / N2 separation coefficient of 96.8.

[0065] Example 6 This embodiment is intended to illustrate the hollow fiber carbon dioxide separation membrane prepared according to the present invention.

[0066] (1) Take 3g of pyromellitic chloride, dissolve it in 1000mL of Isopar G, and prepare an oil phase solution with a mass concentration of 0.4%; take 1g of triethylenetetramine and 1g of m-phenylenediamine, dissolve them in 996mL of deionized water, and prepare an aqueous phase solution with a mass concentration of 0.2%; (2) A polypropylene hollow fiber base membrane was used, and the spinneret core liquid tube was fixed. An oil phase solution was introduced into the hollow core of the base membrane by a core liquid pump. The pressure was 0.1 MPa, the temperature was 30℃, the flow rate was 5 mL / min, and the flow was stable for 3 min. (3) The aqueous solution is introduced into the spinneret as a coating liquid at a flow rate of 5 mL / min. The coating liquid is then applied to the base membrane using a doctor blade. The base membrane is then pulled up at a rate of 20 cm / min to allow the hollow fiber base membrane to pass through the spinneret. (4) After the fully reacted hollow fiber composite membrane is heat-treated in a ventilated oven at 60°C for 5 minutes, it is taken out, thoroughly cleaned with deionized water, and then naturally dried.

[0067] The hollow fiber carbon dioxide separation membrane prepared as a whole had an average diameter of 300 μm and an average thickness of 100 nm for the hollow portion. The hollow fiber carbon dioxide separation membrane has a water contact angle of 60°, a carbon dioxide flux of 410 GPU at a test pressure of 0.1 MPa, and a CO2 / N2 separation coefficient of 70.

[0068] Comparative Example 1 Using the oil phase solution and aqueous phase solution composition of Example 3, a polysulfone hollow fiber base membrane was used. The polysulfone hollow fiber base membrane was immersed in the aqueous phase solution for 3 minutes, then removed and air-dried for 5 minutes to remove residual moisture on the surface. It was then immersed in the oil phase solution for 3 minutes, removed, and placed in a ventilated oven at 60°C for 5 minutes for heat treatment. It was then cleaned with deionized water and air-dried.

[0069] The result showed that the average diameter of the hollow portion of the prepared hollow fiber carbon dioxide separation membrane remained unchanged; the average thickness of the functional layer was 200 nm. The hollow fiber carbon dioxide separation membrane has a tensile strength of 150 MPa, a water contact angle of 64°, a carbon dioxide flux of 35 GPU at a test pressure of 0.1 MPa, and a CO2 / N2 separation coefficient of 18.

[0070] Comparative Example 2 Using the oil phase solution and aqueous phase solution composition of Example 6, a polyvinylidene fluoride hollow fiber base membrane was used. The polyvinylidene fluoride hollow fiber base membrane was immersed in the oil phase solution for 3 minutes and then removed, then immersed in the aqueous phase solution for 3 minutes and removed. It was then placed in a 60°C ventilated oven for 5 minutes for heat treatment, cleaned with deionized water and air-dried.

[0071] The result showed that the average diameter of the hollow portion of the prepared hollow fiber carbon dioxide separation membrane remained unchanged; the average thickness of the functional layer was 100 nm. The hollow fiber carbon dioxide separation membrane has a tensile strength of 13 MPa, a water contact angle of 60°, a carbon dioxide flux of 40 GPU at a test pressure of 0.1 MPa, and a CO2 / N2 separation coefficient of 34.

[0072] Comparative Example 3 Hollow fiber carbon dioxide separation membranes were prepared using the same method as in Example 1, except that the phrase "the oil phase solution was introduced into the spinneret as a coating liquid at a flow rate of 5 mL / min, and the coating liquid was scraped onto the base membrane using a doctor blade; the base membrane was pulled up at a rate of 20 cm / min to allow the hollow fiber base membrane to pass through the spinneret" in Example 1 was replaced with "the oil phase solution was used as a coating liquid to immerse the base membrane; and then the base membrane was transferred to an aqueous phase solution and soaked for 60 s".

[0073] The hollow fiber carbon dioxide separation membrane prepared as a result has an unchanged average diameter of the hollow portion; an average thickness of 100 nm for the functional layer; and a unchanged tensile strength. Under a test pressure of 0.1 MPa, the carbon dioxide flux is 1290 GPU and the CO2 / N2 separation coefficient is 6.9.

[0074] Comparative Example 4 The hollow fiber carbon dioxide separation membrane was prepared using the same method as in Example 1, except that the phrase "pulling the base membrane at a rate of 20 cm / min to allow the hollow fiber base membrane to pass through the spinneret" in Example 1 was replaced with "pulling the base membrane at a rate of 1 cm / min to allow the hollow fiber base membrane to pass through the spinneret".

[0075] The result showed that the average diameter of the hollow portion of the prepared hollow fiber carbon dioxide separation membrane remained unchanged; the average thickness of the functional layer was 500 nm. The hollow fiber carbon dioxide separation membrane maintains its tensile strength, and under a test pressure of 0.1 MPa, the carbon dioxide flux is 36 GPU, and the CO2 / N2 separation coefficient is 55.

[0076] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for producing a hollow fiber carbon dioxide separation membrane, characterized by, The method includes: (1) A hollow fiber carbon dioxide separation membrane preparation device is used, wherein an oil phase solution or an aqueous phase solution is introduced into the hollow inner core of the polymer microporous membrane as the core liquid by a core liquid pump; wherein the hollow fiber carbon dioxide separation membrane preparation device includes a base membrane, a base membrane holder, an annular scraper, a base membrane positioner and a core tube; the base membrane positioner forms a cavity around the base membrane, the cavity is used to store the coating liquid, the annular scraper is provided at the other end of the cavity, and the core tube is built into the interior of the base membrane; (2) An oil-phase solution or an aqueous-phase solution is introduced into the spinneret as a coating liquid, and the coating liquid is scraped onto the base film using a doctor blade; the core liquid and the coating liquid diffuse towards each other on the inner or outer side of the polymer microporous membrane, and form a functional layer on the polymer microporous membrane through interfacial polymerization reaction; wherein, the core liquid and the coating liquid are different; (3) The polymer microporous membrane is pulled through the spinneret to prepare a hollow fiber carbon dioxide separation membrane.

2. The method of claim 1, wherein, The polymer microporous membrane is selected from one or more of polypropylene, polyethylene, polytetrafluoroethylene, polyvinylidene fluoride, and polysulfone. And / or, the oil phase monomer in the oil phase solution is selected from one or more of pyromellitic terephthaloyl chloride, terephthaloyl chloride, isophthaloyl chloride, and p-dichlorobenzyl; the solvent in the oil phase solution is selected from one or more of n-hexane, n-heptane, isoparaffin solvents Isopar G, Isopar E, Isopar H, Isopar L, and Isopar M; And / or, the aqueous monomer in the aqueous solution is selected from one or more of piperazine, m-phenylenediamine, ethylenediamine, polyethylenepolyamine, polyethyleneimine, and polyetheramine.

3. The method of claim 1 or 2, wherein, The concentration of the oil phase solution is 0.01-0.5 wt%; And / or, the concentration of the aqueous solution is 0.02-5 wt%.

4. The method of claim 1, wherein, In step (1), the pressure of the oil phase solution introduced into the hollow inner core is 0-1 MPa, the flow rate is 0-1 m / s, and the temperature is 0-100℃.

5. The method of claim 4, wherein, The pressure of the oil phase solution introduced into the hollow inner core is 0.01-0.5 MPa, the flow velocity is 0.01-1 m / s, and the temperature is 20-50℃.

6. The method of claim 1, wherein, In step (2), the coating film thickness of the coating liquid is 50-1000 μm; And / or, in step (3), the relative displacement velocity between the base film and the spinneret is 5-50 cm / min.

7. The method of claim 1, wherein, The cavity is provided with a coating liquid injection port and a coating liquid outlet; and one end of the cavity is connected to the base film positioner to form a closed end, and the diameter of the annular scraper is smaller than the width of the base film positioner.

8. A hollow fiber carbon dioxide separation membrane prepared by the preparation method according to any one of claims 1-7.

9. The hollow fiber carbon dioxide separation membrane according to claim 8, comprising a hollow portion and a solid portion, wherein, The solid portion of the separation membrane includes a base membrane and a functional layer formed on the inner and / or outer surfaces of the base membrane by interfacial polymerization. The base membrane is prepared by non-solvent-induced phase separation, melt stretching, and thermal phase separation of a polymer microporous membrane. The functional layer is formed on the base membrane by interfacial polymerization of an oil phase solution and an aqueous phase solution.

10. The separation membrane according to claim 8 or 9, wherein, The average diameter of the hollow portion of the separation membrane is 100-2000 μm; And / or, the average thickness of the functional layer is 10-2000 nm.

11. The separation membrane according to claim 8 or 9, wherein, The average thickness of the functional layer is 20-400 nm.

12. The use of a hollow fiber carbon dioxide separation membrane according to any one of claims 8-11 in the separation and purification of CO2 / N2.

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