A carbon dioxide capture base membrane and its preparation method and carbon dioxide capture membrane used therein

Abstract

The present application relates to the field of gas separation membranes, and specifically discloses a carbon dioxide capture base membrane, a preparation method thereof, and an applied carbon dioxide capture membrane. The preparation method comprises the following steps: S1, modifying polysulfone with amino groups to obtain amino polysulfone; S2, mixing the prepared amino polysulfone, a fluorine-containing acrylamide modifier, and an organic solvent, then adding zeolite powder and a hyperdispersant, ultrasonically treating, and then adding a cross-linking agent containing genipin, calcining after reaction, cooling, and grinding to obtain modified polysulfone; S3, mixing the modified polysulfone with an organic solvent and polyethylene glycol to form a mixed solution, then coating the mixed solution on a non-woven fabric, and cooling to obtain a polysulfone base membrane; the present application also discloses a carbon dioxide capture base membrane prepared by the above method and an applied carbon dioxide capture membrane. The present application has the characteristics of improving the selective permeability and high-pressure operation stability of the carbon dioxide capture base membrane, and adapting to the carbon dioxide capture environment.

Description

Technical Field

[0001] The present application relates to the technical field of gas separation membranes, and more specifically, to a carbon dioxide capture base membrane, a preparation method thereof, and an applied carbon dioxide capture membrane. Background Art

[0002] Global warming has become one of the major environmental issues facing countries around the world. The main reason is the excessive emission of greenhouse gases, especially carbon dioxide. Carbon capture and storage refers to a technology that collects carbon dioxide produced by emission sources such as large power plants, steel mills, and chemical plants, and stores it in various ways to prevent it from being emitted into the atmosphere. This technology is considered to be the most economical and feasible way to reduce greenhouse gas emissions on a large scale and slow down global warming in the future.

[0003] Compared with traditional carbon capture technology, membrane separation technology has the advantages of simple operation, low cost, low energy consumption, and environmental friendliness. It is considered to be the second-generation carbon capture technology and has broad application prospects. Membrane separation is suitable for various processing scales, and can be used for large-scale carbon dioxide separation processes as well as small-scale dispersed carbon dioxide separation processes. It is particularly suitable for offshore platforms and other places with strict land requirements and oil and gas fields that lack supporting facilities.

[0004] Membrane separation relies on the selective dissolution and permeation between gas and membrane materials. Under the pressure difference on both sides of the membrane, one component dissolves quickly and passes through the membrane, thereby separating the mixed gas into two parts: residual gas flow and penetrating gas flow. The base membrane in the carbon dioxide capture membrane plays a supporting and conductive role. The structure and properties of the base membrane directly affect the membrane's separation effect and selectivity for gas.

[0005] In terms of performance requirements, the base membrane of the carbon dioxide capture membrane needs to meet the following requirements: good selectivity: the base membrane needs to have a high selectivity for carbon dioxide molecules, that is, it needs to be able to distinguish between carbon dioxide and other gas molecules, thereby achieving efficient separation of carbon dioxide; high permeability: the base membrane should have a sufficiently high permeability so that carbon dioxide molecules can pass through the membrane quickly, thereby improving the separation efficiency; the base membrane has the stability to operate stably under high-pressure operating conditions, and can withstand changes in various environmental conditions and operating conditions.

[0006] At present, the base membrane for carbon dioxide separation is mainly polysulfone. The pore size distribution on the surface of the polysulfone support layer is not uniform, which affects its selective permeability to carbon dioxide. Moreover, as an organic membrane, its strength is relatively low, which leads to the enhanced impact force of gas molecules on the membrane material under high-pressure operating conditions. The base membrane is not strong enough and deforms, resulting in changes in the gas permeation channel, thereby affecting the gas flux, resulting in a decrease in separation efficiency, affecting the separation stability of the base membrane under high-pressure conditions, and affecting the carbon dioxide capture effect. Therefore, it is of great significance to improve the polysulfone support base membrane to improve its selective permeability and high-pressure stability for carbon dioxide, which is of great significance for improving the carbon dioxide capture effect of carbon dioxide capture membranes. Summary of the invention

[0007] In order to improve the selective permeability and high-pressure stability of the carbon dioxide capture base membrane and adapt to the carbon dioxide capture environment, the present application provides a carbon dioxide capture base membrane and a preparation method and application thereof.

[0008] In a first aspect, the present application provides a method for preparing a carbon dioxide capture base membrane, using the following technical solution: A method for preparing a carbon dioxide capture base membrane, comprising the following steps:

[0009] S1, modifying polysulfone by amino to obtain amino polysulfone;

[0010] S2, mixing the prepared amino polysulfone, fluorine-containing acrylamide modifier and organic solvent, then adding zeolite powder and hyperdispersant, ultrasonic treatment, and then adding a cross-linking agent containing genipin, calcining at high temperature after the reaction, cooling, calcining at elevated temperature, cooling, and grinding to obtain modified polysulfone;

[0011] S3, mixing the modified polysulfone with an organic solvent and polyethylene glycol to form a mixed solution, then coating the mixed solution on a non-woven fabric, and cooling to obtain a polysulfone-based membrane.

[0012] By adopting the above technical scheme, in the present application, amino groups are first introduced by aminated modification of polysulfone, and then cross-linking is achieved between the polysulfone and the fluorinated acrylamide modifier through the action of a cross-linking agent, thereby introducing fluorinated groups on the polysulfone molecular chain. Since fluorine atoms have a small atomic radius and a high electronegativity, fluorinated polymers generally exhibit excellent hydrophobicity and low surface energy. The introduction of fluorinated groups into polysulfone can increase the free volume and porosity of polysulfone, provide more transmission channels and adsorption sites for carbon dioxide molecules, and enhance the interaction between the fluorinated groups and the carbon dioxide molecules, further enhance the selectivity of polysulfone for carbon dioxide, and further enhance the selective permeability of the base membrane for carbon dioxide. In the present application, a larger molecular chain is formed by the cross-linking and grafting method, which enhances the selective permeability of carbon dioxide while also enhancing the strength of the base membrane, so that the base membrane has better operating stability under high pressure conditions and better supports and conducts.

[0013] In addition, in the present application, zeolite powder is dispersed before cross-linking the amino polysulfone and the fluorinated acrylamide modifier. The addition of the super dispersant helps to disperse the zeolite powder in the polymer, so that the zeolite powder can be dispersed in the polymer network structure, which helps to improve its selective permeability to carbon dioxide and can also improve the supporting strength of the base membrane. The obtained capture membrane can be used in higher environments, expanding the environmental usage scenarios.

[0014] Finally, the base membrane in this application uses modified polysulfone as the support layer. The modified polysulfone support layer has better support strength and better selective permeability to carbon dioxide, which is helpful for the capture of carbon dioxide. The non-woven fabric is stacked on the outside of the modified polysulfone support layer to play a reinforcing and protective role. The non-woven fabric has good air permeability and filtration properties, which further improves the separation effect of the capture membrane for carbon dioxide. At the same time, the non-woven fabric can also prevent the capture membrane from being physically damaged and chemically corroded during use. This stacked structure allows the carbon dioxide capture membrane to maintain high-efficiency separation performance while also having good stability and durability, and can exert a better capture effect in practical applications.

[0015] Optionally, the zeolite powder in step S2 is prepared by amino modification, and the specific operation is as follows:

[0016] Dissolve polyethyleneimine and aminopropyltriethoxysilane in a methanol solution, then add zeolite powder, stir for 5-6 hours, then ultrasonically treat for 10-20 minutes, then reflux heat at 120-130°C for 10-12 hours, cool to 70-85°C and reflux heat for 20-24 hours, cool, filter and wash to obtain amino zeolite powder.

[0017] By adopting the above technical scheme, the present application adopts the method of impregnation-grafting combination to achieve the modification of zeolite powder. Polyethyleneimine and aminopropyltriethoxysilane are first impregnated and stirred with zeolite powder, and then ultrasonically treated, so that polyethyleneimine is first adsorbed on the zeolite powder by van der Waals force, and then at 120-130°C, aminopropyltriethoxysilane and the hydroxyl groups on the zeolite powder are covalently bonded to achieve amine fixation of the zeolite powder, and then the temperature is lowered to allow the desorbed polyethyleneimine to be re-bonded to the zeolite powder to achieve amino modification of the zeolite powder. In addition, aminosilane is used during the modification to achieve the introduction of silane groups and amino groups into the zeolite powder, thereby improving its dispersion in the organic polymer, and can form a macromolecular structure with amino polysulfone and fluorinated acrylamide modifier under the action of a cross-linking agent, further improving the selective permeability of carbon dioxide, and further improving the support strength of the base membrane. In addition, the introduction of silane groups forms a strong interaction with carbon dioxide molecules, which helps the base membrane to adsorb carbon dioxide molecules. Moreover, the silane groups can optimize the pore structure of the pore structure, which is more suitable for the diffusion and transmission of carbon dioxide molecules. By improving the dispersion of zeolite in the organic system, the dispersion is more uniform and the pore structure distribution of the base membrane is finally more uniform, thereby improving the carbon dioxide separation performance while increasing its supporting strength, improving the high-pressure stability of the base membrane, and achieving a better carbon dioxide capture effect.

[0018] Optionally, the mass ratio of polyethyleneimine to aminopropyltriethoxysilane is 1:(1.5-2), the amount of zeolite powder added is 2-3 times the mass of polyethyleneimine added, and the mass ratio of methanol solution added is 3-5 times the mass of polyethyleneimine added.

[0019] Optionally, the fluorine-containing acrylamide modifier in step S2 is prepared by the following method:

[0020] In an argon atmosphere, 3-phenyl-2-butenal and hexafluoroisopropanol are added to toluene, and then azacarbene catalyst, N-fluorobisbenzenesulfonimide and potassium carbonate are added, and the reaction is carried out at room temperature for 12-24 hours, and then triethylamine is added, and the reaction is carried out at 55-65°C for 18-20 hours. Dichloromethane is added to dilute, filter, wash, concentrate and chromatograph to obtain a fluorinated acrylamide modifier.

[0021] By adopting the above technical scheme, in the present application, 3-phenyl-2-butenal is used as a substrate to first prepare an active ester, and then triethylamine is added as a fatty amine nucleophile to prepare an amide through an amine ester exchange reaction. In addition, in this process, N-fluorobisbenzenesulfonyl imide is added as a fluorinating agent to achieve the introduction of fluorine groups in the final acrylamide.

[0022] Optionally, the molar ratio of 3-phenyl-2-butenal and hexafluoroisopropanol is 1:(1-1.2), the amount of toluene added is 2-3 times the mass of the amount of 3-phenyl-2-butenal added, the amount of azacarbene catalyst added is 0.5-1wt% of 3-phenyl-2-butenal added, the amount of N-fluorobisbenzenesulfonimide added is 0.5-1wt% of 3-phenyl-2-butenal added, the amount of potassium carbonate added is 0.3-0.5wt% of 3-phenyl-2-butenal added, and the amount of triethylamine added is 8-15wt% of the amount of 3-phenyl-2-butenal added.

[0023] Optionally, in step S2, after adding the cross-linking agent, the calcination is carried out in two stages, and the specific operation is: first calcining at 130-150°C for 1-2h, then cooling to 90-100°C and treating at this temperature for 30-40min, then heating to 150-170°C and calcining for 3-4h.

[0024] By adopting the above technical solution and adding a cross-linking agent and then using a two-stage calcination treatment method, it is more helpful to establish the pore structure of the zeolite powder and the modified polysulfone, thereby improving the carbon dioxide capture performance.

[0025] Optionally, the specific operations of step S1 are:

[0026] The polysulfone powder is dissolved in dichloromethane, and then 1,4-dichloromethoxybutane and tin tetrachloride are added, and the reaction is carried out at 55-65°C for 3-4 hours, and then ethanol is added to precipitate, and washed to obtain chloromethylated polysulfone, and then the chloromethylated polysulfone is mixed with ethylenediamine, and reacted at 25-30°C for 20-30 minutes, washed, and dried to obtain amino polysulfone.

[0027] By adopting the above technical scheme, 1,4-dichloromethoxybutane is first used as a potassium chloride reagent to achieve chloromethylation modification of polysulfone under the action of a catalyst, tin tetrachloride, and then it is immersed in ethylenediamine, so that the aminolysis reagent ethylenediamine and the chloromethyl groups on the surface of the chloromethylated polysulfone undergo nucleophilic substitution to obtain amino polysulfone.

[0028] Optionally, in step S1, the mass ratio of polysulfone powder to dichloromethane is 1:8-10, the mass ratio of 1,4-dichloromethoxybutane to polysulfone powder is 1:(0.5-0.8), the mass ratio of tin tetrachloride is 1-3wt% of the polysulfone powder, and the mass ratio of ethylenediamine to chloromethylated polysulfone is 1:(0.6-0.8).

[0029] Optionally, in step S2, the mass ratio of the amino polysulfone to the fluorinated acrylamide modifier is 1:(0.1-0.3), and the amount of the organic solvent added is 3-5 times the mass of the amino polysulfone, the mass ratio of the zeolite powder to the amino polysulfone is 1:(8-10), the amount of the hyperdispersant added is 0.3-0.5wt% of the zeolite powder, and the amount of the cross-linking agent added is 0.3-0.5wt% of the amount of the amino polysulfone added;

[0030] In step S3, the added mass ratio of modified polysulfone to organic solvent and polyethylene glycol is 1:(2-3):(0.3-0.5); the cross-linking agent is selected from genipin and cerium salt in a mass ratio of 1:(0.4-0.6); the organic solvent is selected from one or two of N,N-dimethylformamide and N-methylpyrrolidone.

[0031] By adopting the above technical scheme, Jingipin can cross-link the amino-containing amino polysulfone and the fluorine-containing acrylamide modifier, and the zeolite after subsequent amination treatment can also form a chemical bond. The addition of cerium salt is more conducive to the chemical bonding of acrylamide compounds with polysulfone molecular chains, which is more conducive to the performance improvement of the final modified polysulfone-based membrane.

[0032] In a second aspect, the present application provides a carbon dioxide capture base membrane, which adopts the following technical solution:

[0033] A carbon dioxide capture base membrane prepared by the preparation method.

[0034] By adopting the above technical solution, the base membrane prepared in the present application has better carbon dioxide separation performance and higher support strength, thereby improving its stability under high-pressure operating conditions and achieving better carbon dioxide capture effect.

[0035] In a third aspect, the present application provides a carbon dioxide capture membrane, which adopts the following technical solution:

[0036] A carbon dioxide capture membrane comprises a separation layer, an intermediate layer and the base membrane which are arranged in sequence from top to bottom, wherein the intermediate layer is made by coating with polydimethylsiloxane, and the separation layer is made by coating with a separation coating liquid comprising polyvinylamine.

[0037] By adopting the above technical solution, the carbon dioxide capture membrane prepared in the present application has a better carbon dioxide capture effect, better supporting strength, and better stability under high-pressure operating conditions, thereby expanding its application scenarios for environmental requirements.

[0038] In summary, this application has the following beneficial effects:

[0039] 1. In the present application, an amino group is first introduced by aminated modification of polysulfone, and then the fluorinated acrylamide modifier is cross-linked with the fluorinated acrylamide modifier through the action of a cross-linking agent, thereby introducing a fluorinated group on the polysulfone molecular chain to improve the selective permeability of the base membrane to carbon dioxide. In addition, in the present application, a larger molecular chain is formed by a cross-linking grafting method, which not only enhances the selective permeability to carbon dioxide, but also improves the strength of the base membrane, has better stability under high-pressure operating conditions, and better plays a supporting and conductive role;

[0040] 2. In the present application, zeolite powder is dispersed before the amino polysulfone and the fluorinated acrylamide modifier are cross-linked. The addition of the superdispersant helps to disperse the zeolite powder in the polymer, so that the zeolite powder can be dispersed in the polymer network structure, which helps to improve its selective permeability to carbon dioxide and can also improve the support strength of the base membrane. The obtained capture membrane can be used in a higher environment, broadening the environmental use scenarios;

[0041] 3. In the present application, the polyethyleneimine impregnation-aminopropyltriethoxysilane grafting combination method is used to achieve the modification of the zeolite powder, and the silane group and the amino group are introduced into the zeolite powder, thereby improving its dispersion in the organic polymer, and it can form a macromolecular structure with the amino polysulfone and the fluorinated acrylamide modifier under the action of the cross-linking agent, further improving the selective permeability of carbon dioxide, and further improving the supporting strength of the base membrane, thereby improving its operating stability under high pressure conditions. DETAILED DESCRIPTION

[0042] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0043] The hyperdispersant used in the following examples is a hyperdispersant of model RD-9774 produced by Tianjin Ruike Chemical Trading Co., Ltd.

[0044] Preparation Examples 1-4 are preparation examples of fluorinated acrylamide modifiers

[0045] Preparation Example 1

[0046] A method for preparing a fluorine-containing acrylamide modifier comprises the following steps:

[0047] Taking 3-phenyl-2-butenal addition as 1 kg, 3-phenyl-2-butenal and hexafluoroisopropanol were mixed at a molar ratio of 1:1.1 in an argon atmosphere, and then added to toluene, wherein the amount of toluene added was 3 times the mass of the amount of 3-phenyl-2-butenal added;

[0048] Then add 2,6-diisopropylphenyl nitrogen heterocyclic carbene catalyst, N-fluorobisbenzenesulfonyl imide and potassium carbonate, the addition amount of 2,6-diisopropylphenyl nitrogen heterocyclic carbene catalyst is 0.8wt% of 3-phenyl-2-butenal, the addition amount of N-fluorobisbenzenesulfonyl imide is 0.8wt% of 3-phenyl-2-butenal, and the addition amount of potassium carbonate is 0.4wt% of 3-phenyl-2-butenal. React at room temperature for 18h, then add triethylamine, the addition amount of triethylamine is 12wt% of the addition amount of 3-phenyl-2-butenal, react at 60°C for 20h, add dichloromethane to dilute, filter, wash the obtained filter cake with dichloromethane, concentrate, and then chromatograph to obtain a fluorinated acrylamide modifier, and the eluent during chromatography is petroleum ether and ethyl acetate with a mass ratio of 3:1.

[0049] Preparation Example 2

[0050] A method for preparing a fluorine-containing acrylamide modifier comprises the following steps:

[0051] Taking 3-phenyl-2-butenal addition as 1 kg, 3-phenyl-2-butenal and hexafluoroisopropanol were mixed at a molar ratio of 1:1 in an argon atmosphere, and then added to toluene, wherein the amount of toluene added was 2 times the mass of the amount of 3-phenyl-2-butenal added;

[0052] Then add 2,6-diisopropylphenyl nitrogen heterocyclic carbene catalyst, N-fluorobisbenzenesulfonyl imide and potassium carbonate, the addition amount of 2,6-diisopropylphenyl nitrogen heterocyclic carbene catalyst is 0.5wt% of 3-phenyl-2-butenal, the addition amount of N-fluorobisbenzenesulfonyl imide is 0.5wt% of 3-phenyl-2-butenal, and the addition amount of potassium carbonate is 0.3wt% of 3-phenyl-2-butenal. React at room temperature for 12 hours, then add triethylamine, the addition amount of triethylamine is 8wt% of the addition amount of 3-phenyl-2-butenal, react at 55°C for 20 hours, add dichloromethane to dilute, filter, wash the obtained filter cake with dichloromethane, concentrate, and then chromatograph to obtain a fluorinated acrylamide modifier, and the eluent during chromatography is petroleum ether and ethyl acetate with a mass ratio of 3:1.

[0053] Preparation Example 3

[0054] A method for preparing a fluorine-containing acrylamide modifier comprises the following steps:

[0055] Taking 3-phenyl-2-butenal addition as 1 kg, 3-phenyl-2-butenal and hexafluoroisopropanol were mixed at a molar ratio of 1:1.2 in an argon atmosphere, and then added to toluene, wherein the amount of toluene added was 3 times the mass of the amount of 3-phenyl-2-butenal added;

[0056] Then add 2,6-diisopropylphenyl nitrogen heterocyclic carbene catalyst, N-fluorobisbenzenesulfonyl imide and potassium carbonate, the amount of 2,6-diisopropylphenyl nitrogen heterocyclic carbene catalyst added is 1wt% of 3-phenyl-2-butenal, the amount of N-fluorobisbenzenesulfonyl imide added is 1wt% of 3-phenyl-2-butenal, the amount of potassium carbonate added is 0.5wt% of 3-phenyl-2-butenal, react at room temperature for 24 hours, then add triethylamine, the amount of triethylamine added is 15wt% of the amount of 3-phenyl-2-butenal added, react at 65°C for 18 hours, add dichloromethane to dilute, filter, wash the obtained filter cake with dichloromethane, concentrate, and then chromatograph to obtain a fluorinated acrylamide modifier, and the eluent during chromatography is petroleum ether and ethyl acetate with a mass ratio of 3:1.

[0057] Preparation Example 4

[0058] A method for preparing a fluorine-containing acrylamide modifier is carried out according to the method in Preparation Example 1, except that an equal amount of 3-phenyl-2-butenal in the raw material is replaced by benzaldehyde.

[0059] Example 1

[0060] A method for preparing a carbon dioxide capture base membrane comprises the following steps:

[0061] S1. Based on the addition amount of polysulfone powder of 1 kg, the polysulfone powder is dissolved in dichloromethane, the mass ratio of polysulfone powder to dichloromethane is 1:9, and then 1,4-dichloromethoxybutane and tin tetrachloride are added, and the mixture is reacted at 60°C for 3.5 hours, and then ethanol is added to precipitate and washed to obtain chloromethylated polysulfone, and then the chloromethylated polysulfone is mixed with ethylenediamine, and the mixture is reacted at 30°C for 20 minutes, washed, and dried to obtain amino polysulfone;

[0062] The mass ratio of 1,4-dichloromethoxybutane to polysulfone powder is 1:0.6, the mass ratio of tin tetrachloride to polysulfone powder is 2wt%, and the mass ratio of ethylenediamine to chloromethylated polysulfone is 1:0.7.

[0063] S2, the amino polysulfone prepared in step S1, the fluorine-containing acrylamide modifier prepared in preparation example 1 and an organic solvent are mixed, and then zeolite powder and a hyperdispersant are added, and ultrasonic treatment is performed for 25 minutes, and then a cross-linking agent is added, wherein the cross-linking agent is selected from genipin and cerium salt in a mass ratio of 1:0.5, and the reaction is carried out for 3 hours, followed by calcination, cooling, and grinding to obtain modified polysulfone;

[0064] The mass ratio of the amino polysulfone to the fluorinated acrylamide modifier is 1:0.2, and the amount of the organic solvent added is 4 times the mass of the amino polysulfone, the mass ratio of the zeolite powder to the amino polysulfone is 1:9, the amount of the superdispersant added is 0.4wt% of the zeolite powder, and the amount of the crosslinker added is 0.4wt% of the amount of the amino polysulfone added;

[0065] The calcination after the cross-linking agent reaction is a two-stage calcination, and the specific operation is: first calcination at 140°C for 1.5 hours, then cooling to 95°C and treating at this temperature for 35 minutes, then heating to 160°C and calcining for 3.5 hours;

[0066] S3, mixing the modified polysulfone with an organic solvent and polyethylene glycol in a mass ratio of 1:2.5:0.4 to form a mixed solution, then coating the mixed solution on a non-woven fabric, and cooling to obtain a polysulfone-based membrane consisting of a non-woven fabric layer and a polysulfone support layer.

[0067] The organic solvent in steps S2 and S3 is N,N-dimethylformamide.

[0068] Example 2

[0069] A method for preparing a carbon dioxide capture base membrane comprises the following steps:

[0070] S1. Based on the addition amount of polysulfone powder of 1 kg, the polysulfone powder is dissolved in dichloromethane, the mass ratio of polysulfone powder to dichloromethane is 1:8, and then 1,4-dichloromethoxybutane and tin tetrachloride are added, and the mixture is reacted at 55°C for 4 hours, and then ethanol is added to precipitate and washed to obtain chloromethylated polysulfone, and then the chloromethylated polysulfone is mixed with ethylenediamine, and the mixture is reacted at 25°C for 30 minutes, washed, and dried to obtain amino polysulfone;

[0071] The mass ratio of 1,4-dichloromethoxybutane to polysulfone powder is 1:0.5, the mass ratio of tin tetrachloride to polysulfone powder is 1wt%, and the mass ratio of ethylenediamine to chloromethylated polysulfone is 1:0.6.

[0072] S2, the amino polysulfone prepared in step S1, the fluorine-containing acrylamide modifier prepared in preparation example 2 and an organic solvent are mixed, and then zeolite powder and a hyperdispersant are added, and ultrasonic treatment is performed for 20 minutes, and then a cross-linking agent is added, wherein the cross-linking agent is selected from genipin and cerium salt in a mass ratio of 1:0.4, and the reaction is carried out for 2 hours, and then calcined, cooled, and ground to obtain modified polysulfone;

[0073] The addition mass ratio of the amino polysulfone to the fluorinated acrylamide modifier is 1:0.1, and the addition amount of the organic solvent is 3 times the mass of the amino polysulfone, the addition mass ratio of the zeolite powder to the amino polysulfone is 1:8, the addition amount of the superdispersant is 0.3wt% of the zeolite powder, and the addition amount of the crosslinker is 0.3wt% of the addition amount of the amino polysulfone;

[0074] The calcination after the cross-linking agent reaction is a two-stage calcination, and the specific operation is: first calcination at 130°C for 2 hours, then cooling to 90°C and treating at this temperature for 40 minutes, and then heating to 150°C and calcining for 4 hours;

[0075] S3. The modified polysulfone is mixed with an organic solvent and polyethylene glycol in a mass ratio of 1:2:0.3 to form a mixed solution, and then the mixed solution is coated on a non-woven fabric, and cooled to obtain a polysulfone-based membrane consisting of a non-woven fabric layer and a polysulfone support layer.

[0076] The organic solvent in steps S2 and S3 is N,N-dimethylformamide.

[0077] Example 3

[0078] A method for preparing a carbon dioxide capture base membrane comprises the following steps:

[0079] S1. Based on the addition amount of polysulfone powder of 1 kg, the polysulfone powder is dissolved in dichloromethane, the mass ratio of polysulfone powder to dichloromethane is 1:10, and then 1,4-dichloromethoxybutane and tin tetrachloride are added, and the mixture is reacted at 65°C for 3 hours, and then ethanol is added to precipitate and wash to obtain chloromethylated polysulfone, and then the chloromethylated polysulfone is mixed with ethylenediamine, and the mixture is reacted at 30°C for 20 minutes, and then washed and dried to obtain amino polysulfone;

[0080] The mass ratio of 1,4-dichloromethoxybutane to polysulfone powder is 1:0.5, the mass ratio of tin tetrachloride to polysulfone powder is 3wt%, and the mass ratio of ethylenediamine to chloromethylated polysulfone is 1:0.8.

[0081] S2, the amino polysulfone prepared in step S1, the fluorine-containing acrylamide modifier prepared in Preparation Example 3 and an organic solvent are mixed, and then zeolite powder and a hyperdispersant are added, and ultrasonic treatment is performed for 30 minutes, and then a cross-linking agent mixed with genipin and cerium salt in a mass ratio of 1:0.6 is added, and the mixture is reacted for 4 hours, and then calcined, cooled, and ground to obtain modified polysulfone;

[0082] The mass ratio of the amino polysulfone to the fluorinated acrylamide modifier is 1:0.3, and the amount of the organic solvent added is 5 times the mass of the amino polysulfone, the mass ratio of the zeolite powder to the amino polysulfone is 1:10, the amount of the superdispersant added is 0.5wt% of the zeolite powder, and the amount of the crosslinker added is 0.5wt% of the amount of the amino polysulfone added;

[0083] The calcination after the cross-linking agent reaction is a two-stage calcination, and the specific operation is: first calcination at 150°C for 1 hour, then cooling to 90°C and treating at this temperature for 40 minutes, and then heating to 170°C and calcining for 3 hours;

[0084] S3. The modified polysulfone is mixed with an organic solvent and polyethylene glycol in a mass ratio of 1:3:0.5 to form a mixed solution, and then the mixed solution is coated on a non-woven fabric, and cooled to obtain a polysulfone-based membrane consisting of a non-woven fabric layer and a polysulfone supporting layer.

[0085] The organic solvent in steps S2 and S3 is N,N-dimethylformamide.

[0086] Example 4

[0087] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 1, except that the fluorine-containing acrylamide modifier in step S2 is the fluorine-containing acrylamide modifier prepared in Preparation Example 4.

[0088] Example 5

[0089] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 1, except that the zeolite powder in step S2 is added after being modified to obtain amino zeolite powder, and the modification method is specifically as follows:

[0090] Polyethyleneimine and aminopropyltriethoxysilane are mixed in a mass ratio of 1:1.8, and then dissolved in a methanol solution with a mass concentration of 35%, the added mass ratio of the methanol solution is 4 times the mass of the added amount of polyethyleneimine, to obtain a mixed solution, and then zeolite powder is added, the added amount of zeolite powder is 3 times the mass of the added amount of polyethyleneimine, stirred for 5.5 hours, then ultrasonically treated for 15 minutes, and then refluxed at 125°C for 11 hours, cooled to 80°C and refluxed for 22 hours, cooled, filtered, and washed to obtain amino zeolite powder.

[0091] Example 6

[0092] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 1, except that the zeolite powder in step S2 is added after being modified to obtain amino zeolite powder, and the modification method is specifically as follows:

[0093] Polyethyleneimine and aminopropyltriethoxysilane are mixed in a mass ratio of 1:1.5, and then dissolved in a methanol solution with a mass concentration of 35%, the added mass ratio of the methanol solution is 3 times the mass of the added amount of polyethyleneimine, to obtain a mixed solution, and then zeolite powder is added, the added amount of zeolite powder is 2 times the mass of the added amount of polyethyleneimine, stirred for 5 hours, then ultrasonically treated for 10 minutes, and then refluxed at 120°C for 12 hours, cooled to 70°C and refluxed for 24 hours, cooled, filtered, and washed to obtain amino zeolite powder.

[0094] Example 7

[0095] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 1, except that the zeolite powder in step S2 is added after being modified to obtain amino zeolite powder, and the modification method is specifically as follows:

[0096] Polyethyleneimine and aminopropyltriethoxysilane are mixed in a mass ratio of 1:2, and then dissolved in a methanol solution with a mass concentration of 35%, the added mass ratio of the methanol solution is 5 times the mass of the added amount of polyethyleneimine, to obtain a mixed solution, and then zeolite powder is added, the added amount of zeolite powder is 3 times the mass of the added amount of polyethyleneimine, stirred for 6 hours, and then ultrasonically treated for 20 minutes, and then reflux heated at 130°C for 10 hours, cooled to 85°C and reflux heated for 20 hours, cooled, filtered, and washed to obtain amino zeolite powder.

[0097] Example 8

[0098] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 5, except that during the modification of the zeolite powder, an equal amount of polyethyleneimine is replaced by aminopropyltriethoxysilane.

[0099] Example 9

[0100] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 5, except that during the modification of the zeolite powder, an equal amount of aminopropyltriethoxysilane is replaced by polyethyleneimine.

[0101] Comparative Example 1

[0102] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 1, except that the polysulfone is not subjected to the modification operation of steps S1 and S2, and the modified polysulfone in step S3 is directly replaced by polysulfone in an equal amount.

[0103] Comparative Example 2

[0104] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 1, except that no zeolite powder and super dispersant are added in step S2. The specific operation is: the amino polysulfone prepared in step S1 and the fluorine-containing acrylamide modifier prepared in Preparation Example 1 are mixed with an organic solvent, and then a cross-linking agent is added. The cross-linking agent is selected from genipin and cerium salt in a mass ratio of 1:0.5. After reacting for 3 hours, the mixture is calcined, cooled, and ground to obtain modified polysulfone.

[0105] Comparative Example 3

[0106] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 1, except that the fluorine-containing acrylamide modifier in step S2 is replaced by acrylamide in an equal amount.

[0107] Comparative Example 4

[0108] A method for preparing a carbon dioxide capture base membrane is carried out according to the method in Example 1, except that the amino polysulfone prepared in step S1 is not treated in step S2, and the modified polysulfone in step S3 is replaced by the amino polysulfone in step S1 in equal amounts.

[0109] Application Examples

[0110] The carbon dioxide capture base membrane prepared in the present application is used to prepare a carbon dioxide capture membrane. Specifically, polydimethylsiloxane (PDMS) is coated on the side of the polysulfone support layer away from the non-woven fabric layer to form an intermediate layer, and then a separation coating liquid is coated on the intermediate layer to form a separation layer. The separation coating liquid includes a mixture of polyvinylamine, sodium polyacrylate, sodium dodecyl sulfate and polyvinyl alcohol in a mass ratio of 1:0.1:0.1:0.2, and then polydimethylsiloxane (PDMS) is coated on the separation layer to form a protective layer. Finally, a protective layer, a separation layer, an intermediate layer and a base membrane are arranged in sequence from top to bottom, and the base membrane includes a multilayer structure of a polysulfone support layer and a non-woven fabric layer connected to the intermediate layer.

[0111] Performance Testing

[0112] First, the operation stability of the carbon dioxide capture base membrane prepared in the examples and comparative examples of the present application was tested. The prepared base membrane was run through water at 225psi, and the decay rate of the water flux in half an hour was calculated (specifically, the initial flux value of the base membrane was recorded at a pressure of 225psi, and then the pressure was maintained at 225psi for half an hour, and the flux value of the base membrane was measured again, decay rate = (initial flux value - half an hour flux value) / initial flux value × 100%). The test results are shown in Table 1 below. The flux stability of the base membrane under high pressure conditions is measured by testing the half-hour flux decay rate of the base membrane.

[0113] In addition, the carbon dioxide capture base membrane prepared in the examples and comparative examples of the present application was used to prepare a carbon dioxide capture membrane according to the method of the above-mentioned application example, and the carbon dioxide separation performance of the capture membrane was tested. When testing the separation performance, the test pressure was 0.5 MPa and the test temperature was 40°C. The test results are shown in Table 2 below.

[0114] Table 1:

[0115]

[0116] Table 2:

[0117]

[0118]

[0119] The above permeation rate is CO 2 Gas permeation rate, unit is GPU, 1GPU = 10 -6 cm 3 (STP)cm -2 s -1 cmHg -1 ; Separation factor is CO 2 The ratio of gas permeation rate to the permeation rates of N2 and CH4 gases.

[0120] When the strength of the base membrane pores is low, the base membrane pores collapse, the base membrane half-hour flux decreases, and the half-hour flux decay rate is large. Referring to the test results of Example 1 and Example 4, when preparing the fluorinated acrylamide modifier, when the substrate is selected from benzaldehyde, compared with the selection of aldehydes containing benzene rings and double-bond functional groups, the strength of the final base membrane is reduced, the stability is reduced under high-pressure operating conditions, and the separation performance of carbon dioxide is also reduced. Referring to the test results of Example 1 and Examples 5-7, it can be seen that the zeolite is added after amino modification, which is conducive to the formation of a macromolecular network structure, and its strength and separation performance for carbon dioxide are further improved, and the stability is improved under high-pressure operating conditions; combined with the test results of Example 5 and Examples 8 and 9, it can be seen that in the process of zeolite powder modification, when a single aminopropyltriethoxysilane or polyethyleneimine is used, its high-pressure stability and carbon dioxide separation performance are reduced, especially when only polyethyleneimine is selected, the carbon dioxide separation effect is reduced.

[0121] Referring to the test results of Example 1 and Comparative Example 1, when the base membrane directly uses unmodified polysulfone, its high-pressure stability and carbon dioxide separation performance are significantly reduced compared to the modified polysulfone in Example 1. Combined with the test results of Comparative Example 2, when zeolite powder and superdispersant are not added when modifying the polysulfone, its high-pressure stability is significantly reduced, and the carbon dioxide separation performance is also reduced. Referring to the test results of Comparative Example 3, when the fluorinated acrylamide modifier is replaced with acrylamide, the carbon dioxide separation performance of the obtained base membrane is significantly reduced. Combined with Comparative Example 4, in which the polysulfone is only amino-modified without being treated with the fluorinated acrylamide modifier in step S2, the carbon dioxide separation performance is improved compared to Comparative Example 1, but it is still weaker than the test results of Example 1, and the high-pressure stability is also significantly reduced.

[0122] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing a carbon dioxide capture base membrane, characterized in that: The following steps are involved: S1, modifying polysulfone by amino to obtain amino polysulfone; S2, mixing the prepared amino polysulfone, fluorine-containing acrylamide modifier and organic solvent, then adding zeolite powder and hyperdispersant, ultrasonic treatment, and then adding a cross-linking agent containing genipin, calcining after reaction, cooling, and grinding to obtain modified polysulfone; S3, mixing the modified polysulfone with an organic solvent and polyethylene glycol to form a mixed solution, then coating the mixed solution on a non-woven fabric, and cooling to obtain a polysulfone-based membrane.

2. The method for preparing a carbon dioxide capture base membrane according to claim 1, characterized in that: The zeolite powder in step S2 is obtained by amino modification, and the specific operation is as follows: Dissolve polyethyleneimine and aminopropyltriethoxysilane in a methanol solution to obtain a mixed solution, then add zeolite powder, stir for 5-6 hours, then ultrasonically treat for 10-20 minutes, then reflux heat at 120-130°C for 10-12 hours, cool to 70-85°C and reflux heat for 20-24 hours, cool, filter, and wash to obtain amino zeolite powder.

3. The method for preparing a carbon dioxide capture base membrane according to claim 2, characterized in that: The added mass ratio of polyethyleneimine and aminopropyltriethoxysilane is 1:(1.5-2), the added amount of zeolite powder is 2-3 times the added amount of polyethyleneimine, and the added mass ratio of methanol solution is 3-5 times the added amount of polyethyleneimine.

4. The method for preparing a carbon dioxide capture base membrane according to claim 1, characterized in that: The fluorine-containing acrylamide modifier in step S2 is prepared by the following method: In an argon atmosphere, 3-phenyl-2-butenal and hexafluoroisopropanol are added to toluene, and then an azacarbene catalyst, N-fluorobisbenzenesulfonimide and potassium carbonate are added, and the mixture is reacted at room temperature for 12-24 hours, and then triethylamine is added, and the mixture is reacted at 55-65° C. for 18-20 hours, and dichloromethane is added for dilution, filtration, washing, concentration and chromatography are performed to obtain a fluorinated acrylamide modifier; Among them, the molar ratio of 3-phenyl-2-butenal and hexafluoroisopropanol is 1: (1-1.2), the amount of toluene added is 2-3 times the mass of the amount of 3-phenyl-2-butenal added, the amount of azacarbene catalyst added is 0.5-1wt% of 3-phenyl-2-butenal added, the amount of N-fluorobisbenzenesulfonimide added is 0.5-1wt% of 3-phenyl-2-butenal added, the amount of potassium carbonate added is 0.3-0.5wt% of 3-phenyl-2-butenal added, and the amount of triethylamine added is 8-15wt% of the amount of 3-phenyl-2-butenal added.

5. The method for preparing a carbon dioxide capture base membrane according to claim 1, characterized in that: In step S2, after adding the crosslinking agent, the calcination is carried out in two stages, and the specific operation is: firstly calcining at 130-150°C for 1-2h, then cooling to 90-100°C and treating at this temperature for 30-40min, then heating to 150-170°C and calcining for 3-4h.

6. The method for preparing a carbon dioxide capture base membrane according to claim 1, characterized in that: The specific operations of step S1 are: The polysulfone powder is dissolved in dichloromethane, and then 1,4-dichloromethoxybutane and tin tetrachloride are added, and the reaction is carried out at 55-65°C for 3-4 hours, and then ethanol is added to precipitate, and washed to obtain chloromethylated polysulfone, and then the chloromethylated polysulfone is mixed with ethylenediamine, and reacted at 25-30°C for 20-30 minutes, washed, and dried to obtain amino polysulfone.

7. The method for preparing a carbon dioxide capture base membrane according to claim 6, characterized in that: In step S1, the mass ratio of polysulfone powder to dichloromethane is 1:8-10, the mass ratio of 1,4-dichloromethoxybutane to polysulfone powder is 1:(0.5-0.8), the mass ratio of tin tetrachloride is 1-3wt% of the polysulfone powder, and the mass ratio of ethylenediamine to chloromethylated polysulfone is 1:(0.6-0.8).

8. The method for preparing a carbon dioxide capture base membrane according to claim 1, characterized in that: In step S2, the mass ratio of the amino polysulfone to the fluorinated acrylamide modifier is 1:(0.1-0.3), and the amount of the organic solvent added is 3-5 times the mass of the amino polysulfone, the mass ratio of the zeolite powder to the amino polysulfone is 1:(8-10), the amount of the superdispersant added is 0.3-0.5wt% of the zeolite powder, and the amount of the cross-linking agent added is 0.3-0.5wt% of the amount of the amino polysulfone added; In step S3, the added mass ratio of modified polysulfone to organic solvent and polyethylene glycol is 1:(2-3):(0.3-0.5); The cross-linking agent is selected from genipin and cerium salt in a mass ratio of 1: (0.4-0.6); the organic solvent is selected from one or two of N,N-dimethylformamide and N-methylpyrrolidone.

9. A carbon dioxide capture base membrane prepared by the preparation method according to any one of claims 1 to 8.

10. A carbon dioxide capture membrane, characterized in that: The invention comprises a separation layer, an intermediate layer and the base film as claimed in claim 9 which are arranged in sequence from top to bottom, wherein the intermediate layer is made by coating with polydimethylsiloxane, and the separation layer is made by coating with a separation coating liquid comprising polyvinylamine.

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