Core-shell structured composite material, and preparation method therefor and use thereof

Abstract

The present invention relates to the technical field of carbon dioxide capture. Disclosed are a core-shell structured composite material, and a preparation method therefor and a use thereof. The preparation method comprises: (1) in the presence of an initiator and a dispersant, subjecting a reaction system containing a monomer, a pore‑forming agent and water to a first reaction to obtain a spherical macroporous resin; (2) subjecting the spherical macroporous resin and a first organic amine to a second reaction to obtain a modified resin; and (3) subjecting the modified resin and a solution containing an alkali, a template agent, a silicon source and an aluminum source to a third reaction to obtain a core-shell structured composite material. The composite material provided in the present invention comprises a hydrophobic shell and a molecular sieve in the shell, and has the comprehensive effects of excellent hydrophobicity, strong CO2 adsorption capability, and high CO2 / N2 adsorption selectivity, thereby effectively solving the problem that solid CO2 adsorbents are difficult to achieve both strong hydrophobicity and excellent CO2 adsorption capability.

Description

Core-shell composite materials, their preparation methods and applications

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411566489.9, filed on November 5, 2024, entitled “Core-shell Composite Material and its Preparation Method and Application”, the contents of which are incorporated herein by reference. Background Technology

[0003] This invention relates to the field of carbon dioxide capture technology, specifically to a core-shell structured composite material, its preparation method, and its application. Technical Field

[0004] CO2 emissions are one of the main causes of global warming. Under the current energy structure, carbon capture, utilization and storage (CCUS) technology has become an indispensable part of carbon neutrality and technology. Among the many carbon capture technologies, organic amine solution absorption has high separation efficiency, wide applicability, and high CO2 product purity, but it has always suffered from problems such as short absorbent lifespan, severe equipment corrosion, high energy consumption, and high cost. In contrast, solid adsorption technology uses porous solid materials as carriers, without the participation of solvents, thus avoiding the additional energy consumption caused by solvent evaporation and preventing equipment corrosion. This technology has great potential for energy saving and consumption reduction and has good application prospects.

[0005] For solid adsorption technology, the adsorbent, as one of the core technologies, directly affects CO2 capture efficiency and cost. Numerous scholars both domestically and internationally have conducted research on adsorbents, but so far, no single technology has achieved a combination of superior properties such as high CO2 adsorption capacity, high selectivity, rapid kinetics, long lifespan, low cost, and favorable geometry. This prevents the full realization of the advantages of solid adsorption technology.

[0006] Molecular sieves are a type of adsorbent material with a regular and ordered internal structure, a large specific surface area, and a tunable structure, making them widely used in gas separation, catalysis, and other fields. However, for molecular sieves used to adsorb carbon dioxide, since flue gas after combustion often contains varying degrees of moisture, the molecular sieve preferentially adsorbs water molecules. During water absorption, water occupies the pores or CO2 adsorption sites of the molecular sieve, reducing the material's adsorption capacity and even directly causing the loss of CO2 adsorption capacity. Therefore, maintaining the original excellent carbon capture capacity of molecular sieves in the presence of water is a significant challenge.

[0007] The paper "Dynamic hydrophobic hindrance effect of zeolite@zeolitic imidazolate framework composites for CO2 capture in the presence of water" (J. Mater. Chem. A, 2015, 3, 8091) discloses a method combining pre-inoculation and two-step temperature-controlled crystallization to introduce ZIF-8 material onto the surface of 5A molecular sieves, preparing a series of 5A@ZIF-8 composite materials with enhanced surface hydrophobicity. These composite materials can achieve 80.7% of the original CO2 adsorption capacity of the 5A molecular sieve in the presence of water. The method requires first synthesizing the 5A molecular sieve, followed by two-step crystallization of ZIF-8 on its surface. Precise control of the ZIF-8 amount is crucial and challenging. More importantly, although the hydrophobicity of the composite materials prepared by this method is improved after hydrophobic modification, the original CO2 adsorption capacity of the molecular sieve is still not maintained, resulting in a decrease in adsorption efficiency.

[0008] CN115608326A discloses an adsorbent for high-humidity flue gas conditions, comprising an adsorption core and a core-shell hydrophobic material composed of an organic polymer coated on the adsorption core. The preparation method includes: (1) adding at least two molecular sieves of different configurations to a nitrate solution for ion exchange to obtain a mixed-type metal cation modified molecular sieve; (2) dissolving phenyltriethoxysilane in a dimethylformamide solution, then adding the mixed-type metal cation modified molecular sieve, and performing ultrasonic treatment to obtain a homogeneous mixture A; (3) adding styrene to a dimethylformamide solution, then adding divinylbenzene and stirring to obtain a homogeneous mixture B; (4) stirring and mixing the homogeneous mixture B with the homogeneous mixture A to obtain a mixture C; (5) adding azobisisobutyronitrile to mixture C and stirring to obtain the adsorbent. This scheme uses a post-modification method, which easily leads to uneven modification, resulting in an insignificant hydrophobic effect. Furthermore, the use of polymers easily causes blockage of the molecular sieve pores, reducing the adsorption capacity.

[0009] Furthermore, the adsorbent material prepared by the above method after hydrophobic modification is still in powder form and cannot be used directly. It needs to be shaped before use. Existing shaping methods, such as extrusion, tableting, pelletizing, and rolling, will further reduce the CO2 adsorption performance of the material due to the addition of binders with no CO2 adsorption effect and the increased diffusion resistance caused by the dense structure formed after shaping.

[0010] Therefore, there is an urgent need to develop a new method for hydrophobic modification of molecular sieve adsorbents, which can achieve hydrophobicity of molecular sieves while maintaining the material's CO2 adsorption performance and giving the molecular sieves a good geometric structure. This is of great significance for promoting the application of solid adsorption technology in the field of CO2 capture, especially for the efficient capture of CO2 under humid conditions. Summary of the Invention

[0011] This invention addresses the problem that existing solid CO2 adsorbents struggle to balance strong hydrophobicity and excellent CO2 adsorption performance by providing a core-shell structured composite material, its preparation method, and its applications.

[0012] To achieve the above objectives, a first aspect of the present invention provides a method for preparing a core-shell structured composite material, comprising:

[0013] (1) In the presence of an initiator and a dispersant, a reaction system containing monomers, porogens and water is subjected to a first reaction to obtain a spherical macroporous resin;

[0014] (2) The spherical macroporous resin is reacted with the first organic amine in a second reaction to obtain the modified resin;

[0015] (3) The modified resin is reacted with a solution containing alkali, template agent, silicon source and aluminum source in a third reaction to obtain a core-shell structured composite material;

[0016] The monomer is selected from at least one of acrylate monomers, alkenylbenzene and silane coupling agents containing unsaturated bonds;

[0017] The template agent is prepared by a fourth reaction of a raw material containing a second organic amine and a modifier; wherein the modifier is selected from at least one of chloroalkanes, epoxy-containing acrylates, epoxy-containing alkanes, epoxy-containing alcohols, epoxy-containing ketones, and epoxy-containing silane coupling agents.

[0018] The second aspect of the present invention provides a core-shell structured composite material prepared by the preparation method described in the first aspect above.

[0019] The third aspect of this invention provides the application of the core-shell structured composite material described in the second aspect above as a carbon dioxide adsorbent in the purification of carbon dioxide-containing flue gas.

[0020] The method for preparing core-shell composite materials provided by this invention first involves polymerizing a highly hydrophobic macroporous polymer resin using specific monomers under the action of a porogen. Then, a specific template agent is used to grow molecular sieves in situ within the macroporous polymer resin, which modulates the surface hydrophilicity and hydrophobicity of the molecular sieves and optimizes their pore structure. This results in a core-shell composite material. The synergistic effect of the hydrophobic outer shell and the internal molecular sieve endows this core-shell composite material with excellent hydrophobicity, strong CO2 adsorption performance, and high CO2 / N2 selectivity. The composite material exhibits a water absorption of ≤22% by weight at 40°C and 20% RH, a CO2 working adsorption capacity ≥0.7 mmol / g under flue gas adsorption conditions of 40°C and 10% CO2, and a CO2 / N2 adsorption selectivity ≥200 under regeneration conditions of 120°C and 100% CO2. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 is a scanning electron microscope image (internal morphology) of the core-shell composite material prepared in Example 1 of the present invention.

[0023] Figure 2 is a scanning electron microscope image (appearance morphology) of the core-shell structured composite material prepared in Example 1 of the present invention.

[0024] Figure 3 shows the XRD diffraction pattern of the core-shell composite material prepared in Example 1 of the present invention. Detailed Implementation

[0025] 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.

[0026] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0027] The first aspect of this invention provides a method for preparing a core-shell structured composite material, the method comprising:

[0028] (1) In the presence of an initiator and a dispersant, a reaction system containing monomers, porogens and water is subjected to a first reaction to obtain a spherical macroporous resin;

[0029] (2) The spherical macroporous resin is reacted with the first organic amine in a second reaction to obtain the modified resin;

[0030] (3) The modified resin is reacted with a solution containing alkali, template agent, silicon source and aluminum source in a third reaction to obtain a core-shell structured composite material;

[0031] The monomer is selected from at least one of acrylate monomers, alkenylbenzene and silane coupling agents containing unsaturated bonds;

[0032] The template agent is prepared by a fourth reaction of a raw material containing a second organic amine and a modifier; wherein the modifier is selected from at least one of chloroalkanes, epoxy-containing acrylates, epoxy-containing alkanes, epoxy-containing alcohols, epoxy-containing ketones, and epoxy-containing silane coupling agents.

[0033] According to the present invention, in the preparation method of the core-shell structure composite material, in step (1), in

[0034] Under the action of a porogen, a polymerization reaction is carried out using a specific type of monomer to obtain a spherical macroporous resin. The spherical macroporous resin has a large particle size, a macroporous structure, and strong hydrophobicity.

[0035] According to the present invention, preferably, the average particle size of the spherical macroporous resin is 500-1000 μm.

[0036] According to the present invention, the pore size distribution range of the spherical macroporous resin is 3-6 μm.

[0037] According to the present invention, in the preparation method of the core-shell structure composite material, in step (1), preferably, the monomer can be selected from acrylate monomers and / or silane coupling agents containing unsaturated bonds, which can make the polymerized spherical macroporous resin have better hydrophobic properties.

[0038] According to the present invention, preferably, the acrylate monomer may be selected from at least one of isodecyl methacrylate, phenyl methacrylate, glycidyl methacrylate, isopropyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, dodecafluoroheptanoate methacrylate, and pentafluorophenyl methacrylate.

[0039] More preferably, the acrylate monomer may be selected from at least one of ethyl methacrylate, phenyl methacrylate, glycidyl methacrylate, dodecafluoroheptanoate methacrylate, and pentafluorophenyl methacrylate.

[0040] According to the present invention, preferably, the alkenylbenzene may be selected from at least one of styrene, 3-chlorostyrene and α-methylstyrene.

[0041] More preferably, the alkenylbenzene is styrene.

[0042] According to the present invention, preferably, the silane coupling agent containing unsaturated bonds may be selected from at least one of γ-methacryloyloxypropyltrimethoxysilane, vinyltrimethoxysilane and γ-(methacryloyloxy)propyltriethoxysilane.

[0043] More preferably, the silane coupling agent containing unsaturated bonds is γ-methacryloyloxypropyltrimethoxysilane.

[0044] According to a preferred embodiment of the present invention, the monomer is glycidyl methacrylate, dodecafluoroheptanoate methacrylate, and γ-methacryloyloxypropyltrimethoxysilane. Preferably, the weight ratio of glycidyl methacrylate, dodecafluoroheptanoate methacrylate, and γ-methacryloyloxypropyltrimethoxysilane is 1:(0.9-1.2):(0.8-1.1).

[0045] According to the present invention, in the method for preparing the core-shell composite material, in step (1), the porogen can promote the construction of a macroporous structure in the material, providing space for the growth of molecular sieves inside the resin macropores in subsequent steps. Preferably, the porogen can be selected from at least one of toluene, xylene, and cyclohexane.

[0046] More preferably, the pore-forming agent is toluene.

[0047] According to the present invention, in the preparation method of the core-shell structure composite material, the initiator in step (1) is subject to a wide range of restrictions, such as azo initiators, peroxide initiators, etc.

[0048] In this invention, preferably, the azo initiator may be at least one of the following: dimethyl azobisisobutyrate (AIBME), azodicarbonamide (ADC), azobisisopropylimidazoline hydrochloride (AIB1), azobiscyclohexylformonitrile (ACCN), azobiscyanopentanoic acid (ACVA), azobisisopropylimidazoline (AIP), azobisisobutyronitrile (AIBN), azobisisovalerate (AMBN), and azobisisoheptanenitrile (ABVN), and more preferably azobisisobutyronitrile.

[0049] In this invention, preferably, the peroxide initiator may include, but is not limited to, at least one of hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate and benzoyl peroxide, and more preferably benzoyl peroxide.

[0050] According to the present invention, in the preparation method of the core-shell composite material, in step (1), the dispersant can reduce particle agglomeration and improve the stability of the reaction system. Preferably, the dispersant can be selected from at least one of polyvinyl alcohol, sodium carboxymethyl cellulose, and Tween.

[0051] More preferably, the dispersant is polyvinyl alcohol.

[0052] According to the present invention, in the preparation method of the core-shell structure composite material, in step (1), water can promote the formation of interconnected pores between macropores and increase the porosity of the polymerized resin.

[0053] According to the present invention, in the preparation method of the core-shell structure composite material, in step (1), preferably, the amounts of monomer, initiator, dispersant and water fed satisfy the following relationship:

[0054] The weight ratio of the monomer, initiator, dispersant and water is 1:(0.005-0.2):(0.5-1):(110-118).

[0055] According to the present invention, in the preparation method of the core-shell structure composite material, in step (1), preferably, the amount of porogen added satisfies the following: the weight ratio of the monomer to the porogen is 1:(0.8-2).

[0056] According to the present invention, in the preparation method of the core-shell structure composite material, in step (1), the reaction system further includes a crosslinking agent, a surfactant and an optional reducing agent.

[0057] The crosslinking agent acts as a bridging agent between monomer molecules, crosslinking the polymer through chemical bonds to form a three-dimensional network structure, thereby improving the material's heat resistance, water resistance, and mechanical strength. Preferably, the crosslinking agent can be selected from trimethylolpropane triacrylate and / or divinylbenzene. Preferably, the weight ratio of monomer to crosslinking agent is 1:(0.5-2).

[0058] The surfactant reduces surface tension and promotes the formation of a stable monomer emulsion reaction system. Preferably, the surfactant is selected from at least one of Span 80, polyethylene oxide-propylene oxide-ethylene oxide triblock copolymer, sodium dodecylbenzenesulfonate, and polyvinyl alcohol. Preferably, the weight ratio of monomer to surfactant is 1:(0.2-0.5).

[0059] When the initiator is a peroxide initiator, the reaction system also includes a reducing agent, which can react with the oxidant (initiator) to generate free radicals, accelerating the polymerization process. Preferably, the reducing agent can be selected from at least one of N,N-dimethylaniline, N,N,N,N-tetramethylethylenediamine, and sodium sulfite. Preferably, the weight ratio of monomer to reducing agent is 1:(0.25-0.8).

[0060] According to the present invention, in the preparation method of the core-shell structure composite material, in step (1), the first reaction is a polymerization reaction, and the reaction conditions include: the reaction is carried out under stirring and a protective atmosphere; the reaction temperature is 50-90℃, preferably 60-80℃; the reaction time is 0.1-24h, preferably 0.25-24h; and the stirring rate is 150-350 rpm.

[0061] According to the present invention, the protective atmosphere can be a conventional choice in the field of organic synthesis, such as a nitrogen atmosphere, a helium atmosphere, a neon atmosphere, an argon atmosphere, etc.

[0062] According to the present invention, in the first reaction, by controlling the polymerization reaction at the above-mentioned stirring rate, the size of the polymerization product is controlled, thereby controlling the size of the final prepared composite material.

[0063] According to a preferred embodiment of the present invention, step (1) of preparing spherical macroporous resin can be carried out in the following manner:

[0064] According to the above feeding ratio, the monomer, crosslinking agent, surfactant, initiator, pore-forming agent and reducing agent are first mixed to obtain mixture I; then mixture I is second mixed with water to obtain mixture II; then, under continuous stirring and a protective atmosphere, mixture II is poured into the dispersant aqueous solution to carry out the first reaction; after the reaction is completed, the polymerization product particles are separated and then dried to obtain spherical macroporous resin.

[0065] In the preferred embodiment described above, to achieve better mixing of the oil and water phases, the second mixing is carried out under high-speed stirring conditions. Preferably, the stirring rate is 3000-8000 rpm, and the stirring time is 5-15 min.

[0066] In the preferred embodiment described above, the concentration of the dispersant in the aqueous solution is preferably 0.0007-0.02 g / mL, which is more conducive to the formation of spherical resin with uniform particle size distribution after the reaction. The total weight of the solute water in the aqueous solution and the water added in the second mixture is recorded as the amount of water added in step (1) above.

[0067] According to the present invention, in the preparation method of the core-shell structure composite material, in step (2), the first organic amine is used to perform amine functionalization modification on the spherical macroporous resin through the second reaction, so that the precursor solution of molecular sieve can more easily enter the interior of the resin in subsequent steps.

[0068] According to the present invention, the first organic amine may be selected from at least one of ethanolamine, triethanolamine, ethylenediamine, trimethylamine, isobutanolamine, polyethyleneimine, piperazine, N-(aminoethyl)piperazine, 2-aminomethylpiperidine, 1-(2-aminoethyl)piperidine and 2-amino-2-methyl-1-propanol.

[0069] According to the present invention, in the preparation method of the core-shell structure composite material, in step (2), preferably, the weight ratio of the spherical macroporous resin to the first organic amine is 1:(10-90).

[0070] According to the present invention, in the preparation method of the core-shell composite material, in step (2), the second reaction is carried out by impregnation. Preferably, the conditions for the second reaction include: a reaction temperature of 50-80°C and a reaction time of 0.5-3 h.

[0071] According to a preferred embodiment of the present invention, step (2) can be carried out to perform the second reaction in the following manner:

[0072] According to the above feeding ratio, the spherical macroporous resin is impregnated in the methanol solution of the first organic amine to carry out the second reaction, and then dried to obtain the modified resin.

[0073] Preferably, in the methanol solution of the first organic amine, the weight ratio of the first organic amine to methanol is 1:(1-5).

[0074] According to the present invention, in the preparation method of the core-shell structure composite material, in step (3), under the action of a specific template agent, the alkali, silicon source and aluminum source undergo a third reaction in the spherical macroporous resin, and in-situ crystallize and grow to form a molecular sieve. The template agent can modulate the hydrophilicity and hydrophobicity of the molecular sieve and the pore structure, so that the synthesized molecular sieve itself has good hydrophobicity and excellent adsorption performance.

[0075] The template agent used in this invention can be prepared by subjecting a raw material containing a second organic amine and a modifier to a fourth reaction. Preferably, in the fourth reaction, the amounts of the second organic amine and the modifier fed are such that the weight ratio of the second organic amine to the modifier is 1:(0.5-3).

[0076] According to the present invention, the second organic amine may be selected from at least one of ethanolamine, triethanolamine, ethylenediamine, trimethylamine, isobutanolamine, polyethyleneimine, piperazine, N-(aminoethyl)piperazine, 2-aminomethylpiperidine, 1-(2-aminoethyl)piperidine and 2-amino-2-methyl-1-propanol.

[0077] Preferably, the second organic amine is selected from at least one of ethanolamine, ethylenediamine, and polyethyleneimine, which is more conducive to regulating the molecular sieve structure and forming an enhanced hydrophobic effect.

[0078] According to the present invention, the modifier may be selected from at least one of ethylene glycol diglycidyl ether, epichlorohydrin, epichlorohydrin, 1,2-epoxycyclopentane, 2,3-epoxy-1-cyclohexanone, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane and γ-glycidyl etheroxypropyltrimethoxysilane.

[0079] According to the present invention, preferably, the conditions for the fourth reaction include: a reaction temperature of 10-60°C and a reaction time of 12-48 h.

[0080] According to a preferred embodiment of the present invention, step (3) can be carried out to perform the fourth reaction in the following manner:

[0081] According to the above-mentioned feeding ratio, the second organic amine, modifier, and solvent are thoroughly mixed to obtain mixture III. Then, mixture III is subjected to a fourth reaction. The reaction product is dried to remove the solvent, thus preparing the template agent. Preferably, the solvent is at least one of toluene, methanol, and N,N-dimethylformamide. Preferably, the weight ratio of solvent to (second organic amine + modifier + solvent) is (70-140):100.

[0082] According to the present invention, in the preparation method of the core-shell structure composite material, in step (3), the alkali can be selected from at least one of sodium hydroxide, potassium hydroxide and calcium hydroxide, preferably sodium hydroxide.

[0083] According to the present invention, in the preparation method of the core-shell composite material, step (3) has a relatively broad definition of the silicon source and aluminum source, and conventional silicon and aluminum sources used in the field of molecular sieve preparation can be adopted. Preferably, the silicon source can be selected from at least one of silica sol, water glass, sodium silicate, and sodium aluminum silicate. Preferably, the aluminum source can be selected from sodium aluminate and / or aluminum sulfate.

[0084] According to the present invention, in the preparation method of the core-shell structure composite material, in step (3), preferably, the amounts of the modified resin, alkali, template agent, silicon source and aluminum source fed in satisfy the following relationship:

[0085] The weight ratio of the modified resin: alkali: template agent: silicon source: aluminum source is 100:(195-1560):(390-1660):(1360-6162):(315-1560), preferably 100:(750-1560):(990-1660):(4660-6162):(810-1420).

[0086] According to the present invention, in the method for preparing the core-shell composite material, in step (3), the silicon source and aluminum source are fed in the form of an aqueous solution containing both silicon and aluminum sources. Preferably, in the aqueous solution containing silicon and aluminum sources, the total concentration of silicon and aluminum sources is 16-43% by weight.

[0087] According to the present invention, in the preparation method of the core-shell composite material, in step (3), the third reaction is carried out by impregnation. Preferably, the conditions for the third reaction include: a reaction temperature of 60-120°C and a reaction time of 6-24 h.

[0088] According to a preferred embodiment of the present invention, step (3) can be carried out to perform the third reaction in the following manner:

[0089] According to the above feeding ratio, the alkali, template agent and aqueous solution containing silicon source and aluminum source are mixed to obtain mixture IV. The modified resin is impregnated in mixture IV to carry out the third reaction. After the reaction is completed, the obtained particulate product is dried to obtain spherical core-shell structure composite material.

[0090] In this invention, molecular sieve synthesis is performed by impregnating the modified resin in a solution containing both silicon and aluminum sources. This allows the resulting core-shell composite material to possess excellent CO2 adsorption performance, hydrophobic properties, and high CO2 content. 2 / N2 adsorption selectivity. However, the composite material prepared by using a stepwise impregnation method (i.e., the modified resin is first impregnated in a solution containing a single silicon source, and then impregnated in a solution containing a single aluminum source; or the modified resin is first impregnated in a solution containing a single aluminum source, and then impregnated in a solution containing a single silicon source) has lower CO2 adsorption performance, hydrophobic properties, and CO2 / N2 adsorption selectivity than the core-shell structure composite material prepared by the method of the present invention.

[0091] Existing methods for preparing core-shell structured adsorbent materials typically involve first synthesizing molecular sieves and then coating their surfaces with hydrophobic materials. However, these methods do not modulate the molecular sieve structure, making it difficult to maintain the original good CO2 adsorption performance after hydrophobic modification, resulting in reduced adsorption efficiency. Furthermore, the adsorbent material obtained after hydrophobic modification is still in powder form and requires molding before use, which further reduces the material's CO2 adsorption performance. In contrast to existing technologies, this invention provides a novel method for the directional synthesis of hydrophobic molecular sieves. This method utilizes the polymerization of specific monomers to form a strongly hydrophobic spherical macroporous resin. A specific template agent is introduced into the spherical macroporous resin to synthesize molecular sieves, thereby modulating the surface hydrophilicity / hydrophobicity of the molecular sieve and optimizing its pore structure. Through in-situ structural molding, a core-shell structured composite material is prepared. This composite material has an average particle size of 500-1000 μm and can be directly used for adsorption without secondary molding. The core-shell composite material prepared by this method has a strong hydrophobic barrier effect, with a water absorption of ≤22% by weight at 40℃ and 20% RH. The material has strong CO2 adsorption performance and high CO2 / N2 adsorption selectivity. Specifically, the working CO2 adsorption capacity is ≥0.7 mmol / g under flue gas adsorption conditions of 40℃ and 10% CO2 and regeneration conditions of 120℃ and 100% CO2, and the CO2 / N2 adsorption selectivity is ≥200 under conditions of 40℃ and 10% CO2 and 70% N2.

[0092] The second aspect of the present invention provides a core-shell structured composite material prepared by the preparation method described in the first aspect above.

[0093] According to the present invention, the core-shell composite material comprises: a resin shell and a molecular sieve core encapsulated within the resin shell. Preferably, the weight ratio of the resin shell to the molecular sieve core is 100:(300-800).

[0094] According to the present invention, the molecular sieve in the molecular sieve core is at least one of type X, type Y and type A.

[0095] According to the present invention, the core-shell composite material has a strong hydrophobic barrier effect. Preferably, the water absorption of the core-shell composite material at 25°C and 20% RH is ≤17% by weight.

[0096] According to the present invention, the core-shell composite material exhibits strong CO2 adsorption performance. Preferably, the material has a working CO2 adsorption capacity ≥ 0.7 mmol / g under flue gas adsorption conditions of 40°C and 10 vol% CO2, and under regeneration conditions of 120°C and 100 vol% CO2.

[0097] According to the present invention, the core-shell composite material exhibits high CO2 / N2 adsorption selectivity during adsorption. Preferably, the material has a CO2 / N2 adsorption selectivity ≥200 under conditions of 40°C and 10 vol% CO2 and 70 vol% N2.

[0098] According to the present invention, the core-shell structured composite material has an average particle size of 500-1000 μm, and can be directly used for CO2 adsorption without the need for secondary molding of traditional powder-type molecular sieve materials.

[0099] The third aspect of this invention provides the application of the core-shell structured composite material described in the second aspect above as a carbon dioxide adsorbent in the purification of carbon dioxide-containing flue gas.

[0100] The core-shell composite material provided by this invention, as a solid adsorbent, can be well used to purify carbon dioxide-containing flue gas, especially showing significant advantages in the efficient capture of CO2 under humid conditions. It has the comprehensive effects of good hydrophobicity, strong CO2 adsorption capacity, and high CO2 / N2 adsorption selectivity.

[0101] In this invention, for CO2 capture under humid conditions, the target gas for purification can include, but is not limited to, conventional air, kiln flue gas, coal-fired flue gas, natural gas purification, refining tail gas, and other gases containing water vapor and carbon dioxide. Preferably, the water content in the carbon dioxide-containing flue gas is 10-50% by volume.

[0102] The present invention will be described in detail below through examples. Unless otherwise specified, the following examples and comparative examples are all conventional methods; the reagents and materials used are commercially available unless otherwise specified.

[0103] Example 1

[0104] (1) The monomers (dodecyl fluoroheptanoate methacrylate, γ-methacryloyloxypropyltrimethoxysilane and glycidyl methacrylate, in a weight ratio of 1:1:1), trimethylolpropane triacrylate (crosslinking agent), Span 80 (surfactant), benzoyl peroxide (initiator), toluene (porogen) and N,N-dimethylaniline (reducing agent) were mixed to obtain mixture I; then mixture I was mixed with water (stirred at 6000 rpm for 10 min) to obtain mixture II; then, under continuous stirring (250 rpm) and nitrogen protection, mixture II was slowly poured into a polyvinyl alcohol aqueous solution (polyvinyl alcohol concentration of 0.01 g / mL) for polymerization reaction at 70 °C for 0.5 h; after the reaction was completed, the polymerization product particles were separated and dried at 80 °C for 6 h to obtain spherical macroporous resin (denoted as B1, where the pore size distribution range is 3-4 μm);

[0105] The weight ratio of monomer:initiator:dispersant:water (including water in polyvinyl alcohol aqueous solution) is 1:0.015:1:110; the weight ratio of monomer:porogen is 1:1.45; the weight ratio of monomer:crosslinking agent is 1:1; the weight ratio of monomer:surfactant is 1:0.3; and the weight ratio of monomer:reducing agent is 1:0.25.

[0106] (2) The spherical macroporous resin B1 was impregnated in a methanol solution of polyethyleneimine (the weight ratio of polyethyleneimine to methanol was 1:2.3), reacted at 60°C for 1 h, and then dried at 80°C for 6 h to obtain the modified resin.

[0107] The weight ratio of spherical macroporous resin B1 to polyethyleneimine is 1:30.

[0108] (3) Template preparation: Polyethyleneimine, γ-glycidyl etheroxypropyltrimethoxysilane (modifier) ​​and toluene are thoroughly mixed to obtain mixture-III. Mixture-III is reacted at 60°C for 24 h, and the reaction product is dried in a vacuum drying oven at 60°C for 24 h to obtain liquid template.

[0109] The weight ratio of polyethyleneimine to γ-glycidoxypropyltrimethoxysilane is 1:1.6; the weight ratio of methanol to (polyethyleneimine + γ-glycidoxypropyltrimethoxysilane + methanol) is 70:100.

[0110] Sodium hydroxide, the above template agent, and an aqueous solution containing sodium silicate (without water of crystallization) and sodium aluminate (total concentration of sodium silicate and sodium aluminate is 36% by weight) were mixed to obtain mixture IV; the above modified resin was impregnated in mixture IV and reacted at 90°C for 6 hours. After the reaction was completed, spherical particulate products were separated and dried at 120°C for 12 hours to obtain spherical core-shell structured composite material (denoted as P1, with an average particle size of 900 μm and a weight ratio of resin shell to molecular sieve core (NaX molecular sieve) of 100:700 in P1);

[0111] The weight ratio of modified resin, sodium hydroxide, template agent, sodium silicate, and sodium aluminate is 100:780:1560:6120:830.

[0112] Scanning electron microscopy (SEM) was performed on P1, and its internal morphology is shown in Figure 1. Molecular sieves are visible growing inside the resin shell of P1. The external morphology is shown in Figure 2, and the synthesized composite material is a regular, near-millimeter-sized sphere.

[0113] XRD tests were performed on P1, and the results are shown in Figure 3. The original molecular sieve (NaX molecular sieve) corresponds one-to-one with the crystal planes of the composite material

[0111] ,

[0331] and

[0642] , showing the characteristic peaks of the FAU topology, indicating that the molecular sieve was successfully synthesized in situ inside the resin.

[0114] Example 2

[0115] (1) Glycidyl methacrylate, dodecafluoroheptanoate methacrylate and phenyl methacrylate (weight ratio 1:1:1), trimethylolpropane triacrylate (crosslinking agent), Span 80 (surfactant), azobisisobutyronitrile (initiator) and toluene (porogen) were mixed to obtain mixture I; then mixture I was mixed with water (stirred at 6000 rpm for 10 min) to obtain mixture II; then, under continuous stirring (300 rpm) and nitrogen protection, mixture II was slowly poured into a polyvinyl alcohol aqueous solution (polyvinyl alcohol concentration of 0.01 g / mL) for polymerization reaction at 70 °C for 24 h; after the reaction was completed, the polymerization product particles were separated and dried at 80 °C for 6 h to obtain spherical macroporous resin (denoted as B2, where the pore size distribution range is 3-5 μm);

[0116] The weight ratio of monomer:initiator:dispersant:water (including water in polyvinyl alcohol aqueous solution) is 1:0.07:1:110; the weight ratio of monomer:porogen is 1:0.8; the weight ratio of monomer:crosslinking agent is 1:0.5; and the weight ratio of monomer:surfactant is 1:0.2.

[0117] (2) The spherical macroporous resin B2 was impregnated in a methanol solution of ethanolamine (the weight ratio of ethanolamine to methanol was 1:1.5), reacted at 70°C for 0.5 h, and then dried at 80°C for 6 h to obtain the modified resin.

[0118] The weight ratio of spherical macroporous resin B2 to ethanolamine is 1:50.

[0119] (3) Template preparation: Ethanolamine, epichlorohydrin (modifier) ​​and methanol were thoroughly mixed to obtain mixture-III. Mixture-III was reacted at 25°C for 12 h, and the reaction product was dried in a vacuum drying oven at 60°C for 24 h to obtain liquid template.

[0120] The weight ratio of ethanolamine to epichlorohydrin is 1:0.7; the weight ratio of methanol to (ethanolamine + epichlorohydrin + methanol) is 80:100.

[0121] Sodium hydroxide, the above template agent, and an aqueous solution containing sodium silicate nonahydrate and sodium aluminate (the total concentration of sodium silicate nonahydrate and sodium aluminate aluminum is 32% by weight) were mixed to obtain mixture IV; the above modified resin was impregnated in mixture IV and reacted at 100°C for 6 hours. After the reaction was completed, spherical particulate products were separated and dried at 120°C for 24 hours to obtain spherical core-shell structured composite material (denoted as P2, the average particle size of P2 is 800 μm, and the weight ratio of resin shell to molecular sieve core (NaX molecular sieve) in P2 is 100:620).

[0122] The weight ratio of modified resin, sodium hydroxide, template agent, sodium silicate nonahydrate, and sodium aluminate is 100:1170:1560:4740:1420.

[0123] Example 3

[0124] (1) The monomers (ethyl methacrylate, glycidyl methacrylate and pentafluorophenyl methacrylate, weight ratio 1:1:1), trimethylolpropane triacrylate (crosslinking agent), Span 80 (surfactant), benzoyl peroxide (initiator), toluene (porogen) and N,N-dimethylaniline (reducing agent) were mixed to obtain mixture I; then mixture I was mixed with water (stirred at 6000 rpm for 10 min) to obtain mixture II; then, under continuous stirring (300 rpm) and nitrogen protection, mixture II was slowly poured into polyvinyl alcohol aqueous solution (polyvinyl alcohol concentration of 0.01 g / mL) for polymerization reaction, and polymerized at 60 °C for 4 h; after the reaction was completed, the polymer product particles were separated and dried at 80 °C for 6 h to obtain spherical macroporous resin (denoted as B3, where the pore size distribution range is 4-5 μm);

[0125] The weight ratio of monomer:initiator:dispersant:water (including water in polyvinyl alcohol aqueous solution) is 1:0.08:1:110; the weight ratio of monomer:porogen is 1:1.2; the weight ratio of monomer:crosslinking agent is 1:0.7; the weight ratio of monomer:surfactant is 1:0.35; and the weight ratio of monomer:reducing agent is 1:0.25.

[0126] (2) The spherical macroporous resin B3 was impregnated in a methanol solution of ethylenediamine (the weight ratio of ethylenediamine to methanol was 1:4), reacted at 60°C for 3 h, and then dried at 80°C for 6 h to obtain the modified resin.

[0127] The weight ratio of spherical macroporous resin B3 to ethylenediamine is 1:40.

[0128] (3) Template preparation: Ethylenediamine, ethylene glycol diglycidyl ether (modifier) ​​and methanol were thoroughly mixed to obtain mixture-III. Mixture-III was reacted at 10°C for 48 h, and the reaction product was dried at 60°C for 24 h in a vacuum drying oven to obtain liquid template.

[0129] The weight ratio of ethylenediamine to ethylene glycol diglycidyl ether is 1:0.5; the weight ratio of methanol to (ethylenediamine + ethylene glycol diglycidyl ether + methanol) is 110:100.

[0130] Sodium hydroxide, the above template agent, and an aqueous solution containing sodium silicate pentahydrate and sodium aluminate (the total concentration of sodium silicate pentahydrate and sodium aluminate is 26% by weight) were mixed to obtain mixture IV; the above modified resin was impregnated in mixture IV and reacted at 90°C for 6 hours. After the reaction was completed, spherical particulate products were separated and dried at 120°C for 24 hours to obtain spherical core-shell structured composite material (denoted as P3, the average particle size of P3 is 700 μm, and the weight ratio of resin shell to molecular sieve core (NaX molecular sieve) in P3 is 100:607).

[0131] The weight ratio of modified resin, sodium hydroxide, template agent, sodium silicate pentahydrate, and sodium aluminate is 100:780:1170:4740:830.

[0132] Example 4

[0133] (1) The monomers (glycidyl methacrylate, cyclohexyl methacrylate and γ-(methacryloyloxy)propyltriethoxysilane, in a weight ratio of 1:0.8:1.2), trimethylolpropane triacrylate (crosslinking agent), Span 80 (surfactant), benzoyl peroxide (initiator), toluene (porogen) and N,N-dimethylaniline (reducing agent) were mixed to obtain mixture I; then mixture I was mixed with water (stirred at 6000 rpm for 10 min) to obtain mixture II; then, under continuous stirring (250 rpm) and nitrogen protection, mixture II was slowly poured into a polyvinyl alcohol aqueous solution (polyvinyl alcohol concentration of 0.01 g / mL) for polymerization reaction, and polymerized at 60 °C for 3 h; after the reaction was completed, the polymer product particles were separated and dried at 80 °C for 6 h to obtain spherical macroporous resin (denoted as B4, where the pore size distribution range is 3-5 μm);

[0134] The weight ratio of monomer:initiator:dispersant:water (including water in polyvinyl alcohol aqueous solution) is 1:0.08:1:112; the weight ratio of monomer:porogen is 1:1.5; the weight ratio of monomer:crosslinking agent is 1:0.8; the weight ratio of monomer:surfactant is 1:0.4; and the weight ratio of monomer:reducing agent is 1:0.25.

[0135] (2) The spherical macroporous resin B4 was impregnated in a methanol solution of 2-amino-2-methyl-1-propanol (the weight ratio of 2-amino-2-methyl-1-propanol to methanol was 1:4), reacted at 60°C for 3 h, and then dried at 80°C for 6 h to obtain the modified resin.

[0136] The weight ratio of spherical macroporous resin B4 to 2-amino-2-methyl-1-propanol is 1:45.

[0137] (3) Template preparation: 2-amino-2-methyl-1-propanol, 1,2-epoxycyclopentane (modifier) ​​and methanol were thoroughly mixed to obtain mixture-III. Mixture-III was reacted at 30°C for 36 h, and the reaction product was dried in a vacuum drying oven at 60°C for 24 h to obtain liquid template.

[0138] The weight ratio of 2-amino-2-methyl-1-propanol to 1,2-epoxycyclopentane is 1:0.7; the weight ratio of methanol to (2-amino-2-methyl-1-propanol + 1,2-epoxycyclopentane + methanol) is 115:100.

[0139] Sodium hydroxide, the above template agent, and an aqueous solution containing silica sol and sodium aluminate (total concentration of silica sol and sodium aluminate is 22% by weight) were mixed to obtain mixture IV; the above modified resin was impregnated in mixture IV and reacted at 80°C for 12 h. After the reaction was completed, spherical particulate products were separated and dried at 120°C for 24 h to obtain spherical core-shell structured composite material (denoted as P4, with an average particle size of 700 μm and a weight ratio of resin shell to molecular sieve core (NaX molecular sieve) of 100:566).

[0140] The weight ratio of modified resin, sodium hydroxide, template agent, silica sol, and sodium aluminate is 100:740:740:4120:780.

[0141] Example 5

[0142] (1) Monomers (isodecyl methacrylate, vinyltrimethoxysilane and styrene, weight ratio 1:0.9:1.1), divinylbenzene (crosslinking agent), Span 80 (surfactant), azobisisobutyronitrile (initiator), and toluene (porogen) were mixed to obtain mixture I; then mixture I was mixed with water (stirred at 6000 rpm for 10 min) to obtain mixture II; then, under continuous stirring (200 rpm) and nitrogen protection, mixture II was slowly poured into a polyvinyl alcohol aqueous solution (polyvinyl alcohol concentration of 0.01 g / mL) for polymerization reaction, and polymerized at 70 °C for 24 h; after the reaction was completed, the polymer product particles were separated and dried at 80 °C for 6 h to obtain spherical macroporous resin (denoted as B5, where the pore size distribution range is 3-5 μm);

[0143] The weight ratio of monomer:initiator:dispersant:water (including water in polyvinyl alcohol aqueous solution) is 1:0.13:1:110; the weight ratio of monomer:porogen is 1:1.4; the weight ratio of monomer:crosslinking agent is 1:0.7; and the weight ratio of monomer:surfactant is 1:0.5.

[0144] (2) The spherical macroporous resin B5 was impregnated in a methanol solution of N-(aminoethyl)piperazine (the weight ratio of N-(aminoethyl)piperazine to methanol was 1:4.5), reacted at 55°C for 2.5 h, and then dried at 80°C for 6 h to obtain the modified resin.

[0145] The weight ratio of spherical macroporous resin B5 to N-(aminoethyl)piperazine is 1:60.

[0146] (3) Template preparation: N-(aminoethyl)piperazine, 2,3-epoxy-1-cyclohexanone (modifier) ​​and methanol were thoroughly mixed to obtain mixture-III. Mixture-III was reacted at 25°C for 36 h, and the reaction product was dried in a vacuum drying oven at 60°C for 24 h to obtain liquid template.

[0147] The weight ratio of N-(aminoethyl)piperazine to 2,3-epoxy-1-cyclohexanone is 1:1.5; the weight ratio of methanol to (N-(aminoethyl)piperazine + 2,3-epoxy-1-cyclohexanone + methanol) is 123:100.

[0148] Sodium hydroxide, the above template agent, and an aqueous solution containing water glass and sodium aluminate (total concentration of water glass and sodium aluminate is 19% by weight) were mixed to obtain mixture IV; the above modified resin was impregnated in mixture IV and reacted at 90°C for 6 hours. After the reaction was completed, spherical particulate products were separated and dried at 120°C for 24 hours to obtain spherical core-shell structured composite material (denoted as P5, with an average particle size of 800 μm and a weight ratio of resin shell to molecular sieve core (NaX molecular sieve) of 100:496).

[0149] The weight ratio of modified resin, sodium hydroxide, template agent, water glass, and sodium aluminate is 100:719:725:3890:736.

[0150] Example 6

[0151] (1) Monomers (isopropyl methacrylate, vinyltrimethoxysilane and α-methylstyrene, weight ratio 1:0.7:1.3), divinylbenzene (crosslinking agent), Span 80 (surfactant), azobisisobutyronitrile (initiator), and toluene (porogen) were mixed to obtain mixture I; then mixture I was mixed with water (stirred at 6000 rpm for 10 min) to obtain mixture II; then, under continuous stirring (250 rpm) and nitrogen protection, mixture II was slowly poured into a polyvinyl alcohol aqueous solution (polyvinyl alcohol concentration of 0.01 g / mL) for polymerization reaction, and polymerized at 70 °C for 24 h; after the reaction was completed, the polymer product particles were separated and dried at 80 °C for 6 h to obtain spherical macroporous resin (denoted as B6, where the pore size distribution range is 4-6 μm);

[0152] The weight ratio of monomer:initiator:dispersant:water (including water in polyvinyl alcohol aqueous solution) is 1:0.12:1:110; the weight ratio of monomer:porogen is 1:1.3; the weight ratio of monomer:crosslinking agent is 1:0.7; and the weight ratio of monomer:surfactant is 1:0.6.

[0153] (2) The spherical macroporous resin B6 was impregnated in a methanol solution of isobutanolamine (the weight ratio of isobutanolamine to methanol was 1:5), reacted at 50°C for 3 h, and then dried at 80°C for 6 h to obtain the modified resin.

[0154] The weight ratio of spherical macroporous resin B6 to isobutanolamine is 1:70.

[0155] (3) Template preparation: Isobutanolamine, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane (modifier) ​​and methanol were thoroughly mixed to obtain mixture-III. Mixture-III was reacted at 30°C for 36 h, and the reaction product was dried in a vacuum drying oven at 60°C for 24 h to obtain liquid template.

[0156] The weight ratio of isobutanolamine to 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane is 1:1.9; the weight ratio of methanol to (isobutanolamine + 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane + methanol) is 132:100.

[0157] Sodium hydroxide, the above template agent, and an aqueous solution containing silica sol and sodium aluminate (the total concentration of silica sol and sodium aluminate is 17% by weight) were mixed to obtain mixture IV; the above modified resin was impregnated in mixture IV and reacted at 80°C for 6 hours. After the reaction was completed, spherical particulate products were separated and dried at 120°C for 24 hours to obtain spherical core-shell structured composite material (denoted as P6, the average particle size of P6 is 850 μm, and the weight ratio of resin shell to molecular sieve core (NaX molecular sieve) in P6 is 100:451).

[0158] The weight ratio of modified resin, sodium hydroxide, template agent, silica sol, and sodium aluminate is 100:699:708:3788:619.

[0159] Example 7

[0160] (1) Following the same steps as in Example 6 (1), a spherical macroporous resin (denoted as B6) was prepared.

[0161] (2) The spherical macroporous resin B6 was impregnated in a methanol solution of 1-(2-aminoethyl)piperidine (the weight ratio of 1-(2-aminoethyl)piperidine to methanol was 1:5), reacted at 50°C for 3 h, and then dried at 80°C for 6 h to obtain the modified resin.

[0162] The weight ratio of spherical macroporous resin B6 to 1-(2-aminoethyl)piperidine is 1:70.

[0163] (3) Template preparation: 1-(2-aminoethyl)piperidine, glycidol (modifier) ​​and methanol were thoroughly mixed to obtain mixture-III. The mixture was reacted at 30°C for 36 h. The reaction product was dried in a vacuum drying oven at 60°C for 24 h to obtain liquid template.

[0164] The weight ratio of 1-(2-aminoethyl)piperidine to glycidol is 1:1.9; the weight ratio of methanol to (1-(2-aminoethyl)piperidine + glycidol + methanol) is 132:100.

[0165] Sodium hydroxide, the above template agent, and an aqueous solution containing silica sol and sodium aluminate (the total concentration of silica sol and sodium aluminate is 17% by weight) were mixed to obtain mixture IV; the above modified resin was impregnated in mixture IV and reacted at 80°C for 6 hours. After the reaction was completed, spherical particulate products were separated and dried at 120°C for 24 hours to obtain spherical core-shell structured composite material (denoted as P7, the average particle size of P7 is 840 μm, and the weight ratio of resin shell to molecular sieve core (NaX molecular sieve) in P7 is 100:446).

[0166] The weight ratio of modified resin, sodium hydroxide, template agent, silica sol, and sodium aluminate is 100:699:708:3788:619.

[0167] Example 8

[0168] (1) Following the same steps as in Example 6 (1), a spherical macroporous resin (denoted as B6) was prepared.

[0169] (2) The spherical macroporous resin B6 was impregnated in a methanol solution of 1-(2-aminoethyl)piperidine (the weight ratio of 1-(2-aminoethyl)piperidine to methanol was 1:5), reacted at 50°C for 3 h, and then dried at 80°C for 6 h to obtain the modified resin.

[0170] The weight ratio of spherical macroporous resin B6 to 1-(2-aminoethyl)piperidine is 1:70.

[0171] (3) Template preparation: Piperazine, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane (modifier) ​​and methanol were thoroughly mixed to obtain Mixed Liquid-III. The mixture was reacted at 30°C for 36 h, and the reaction product was dried in a vacuum drying oven at 60°C for 24 h to obtain liquid template.

[0172] The weight ratio of piperazine to 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane is 1:1.9; the weight ratio of methanol to (piperazine + 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane + methanol) is 132:100.

[0173] Sodium hydroxide, the above template agent, and an aqueous solution containing silica sol and sodium aluminate (the total concentration of silica sol and sodium aluminate is 17% by weight) were mixed to obtain mixture IV; the above modified resin was impregnated in mixture IV and reacted at 80°C for 6 hours. After the reaction was completed, spherical particulate products were separated and dried at 120°C for 24 hours to obtain spherical core-shell structured composite material (denoted as P8, the average particle size of P8 is 845 μm, and the weight ratio of resin shell to molecular sieve core (NaX molecular sieve) in P8 is 100:439).

[0174] The weight ratio of modified resin, sodium hydroxide, template agent, silica sol, and sodium aluminate is 100:699:708:3788:619.

[0175] Comparative Example 1

[0176] The core-shell composite material (denoted as DP1) was prepared according to steps (2) and (3) disclosed in Example 1 of CN117160429A.

[0177] Comparative Example 2

[0178] The method of Example 8 is followed, except that in step (3), an equal weight of tetrapropylammonium bromide is used as a template agent, and the other steps and conditions are the same as in Example 8, to obtain a spherical core-shell structure composite material (denoted as DP2, the average particle size of DP2 is 910 μm, and the weight ratio of resin shell to molecular sieve core in DP2 is 100:370).

[0179] Comparative Example 3

[0180] The method of Example 8 differs in that, in step (3), sodium hydroxide, the above template agent and an aqueous solution containing silica sol (the concentration of silica sol is 9% by weight) are mixed to obtain a mixture; the modified resin is immersed in the above mixture and reacted at 80°C for 3 hours. After the reaction, the spherical particle product is separated and dried at 120°C for 6 hours; then the dried spherical particle product is immersed in an aqueous solution containing sodium aluminate (the concentration of sodium aluminate is 8% by weight) and reacted at 80°C for 3 hours. After the reaction, the spherical particle product is separated and dried at 120°C for 24 hours to obtain a spherical core-shell structure composite material (denoted as DP3, the average particle size of DP3 is 890 μm, and the weight ratio of resin shell to molecular sieve core in DP3 is 100:388); wherein, the weight ratio of modified resin: sodium hydroxide: template agent: silica sol: sodium aluminate is 100:699:708:3788:619. The other steps and conditions are the same as in Example 8.

[0181] Test case

[0182] 1. Hydrophobicity test

[0183] The water absorption of the composite materials P1-P8 prepared in Examples 1-8 was tested, and the test procedure is as follows:

[0184] Weigh a certain mass of sample and vacuum dry it at 150℃ for 12 hours. Place the dried sample on a vapor adsorption apparatus for water absorption testing (40℃, relative humidity 20%RH). Calculate the water absorption using the following formula:

[0185] The results are shown in Table 1.

[0186] Table 1 Note: The NaX molecular sieve in Table 1 has the same chemical composition as the molecular sieve core in P1.

[0187] As shown in Table 1, the core-shell composite materials P1-P8 prepared by the method of the present invention have a water absorption of no more than 22% by weight under conditions of 40℃ and 20% RH relative humidity, exhibiting excellent hydrophobic properties. Compared with NaX molecular sieves, the water absorption of composite material P1 is significantly reduced, indicating that the resin shell of P1 has a strong hydrophobic barrier effect.

[0188] 2. CO2 adsorption performance test

[0189] The CO2 adsorption performance of the composite materials P1-P8 and DP1-DP3 prepared in Examples 1-8 and Comparative Examples 1-3 was tested, and the procedure is as follows:

[0190] A certain mass of sample was placed in a vacuum at 120℃ for 3 hours. The dried sample was then placed in a gravimetric adsorption analyzer. The CO2 adsorption capacity of the sample was tested by passing a mixed gas of 10% volume CO2 and 20% volume water vapor (the remaining components were balanced with nitrogen) through the gas at 40℃. Then, the sample was desorbed in a CO2 atmosphere at 120℃. The amount of CO2 desorbed was the working CO2 adsorption capacity of the sample. The results are shown in Table 2.

[0191] Table 2 Note: The NaX molecular sieve in Table 2 has the same chemical composition as the molecular sieve core in P1.

[0192] As shown in Table 2, the core-shell composite materials P1-P8 prepared by the method of the present invention exhibit a working CO2 adsorption capacity of no less than 0.7 mmol / g under flue gas adsorption conditions of 40℃ and 10 vol% CO2, and under regeneration conditions of 120℃ and 100 vol% CO2, which is significantly higher than that of DP1-DP3. A comparison of the working CO2 adsorption capacity of composite material P1 with that of NaX molecular sieves shows that the hydrophobic modification of the adsorbent by the method of the present invention does not reduce its CO2 adsorption performance; it still exhibits excellent working CO2 adsorption capacity, and its working CO2 adsorption capacity is superior to that of the corresponding NaX molecular sieves.

[0193] 3. CO2 / N2 adsorption selectivity test

[0194] The CO2 / N2 adsorption selectivity of the composite materials P1-P8 and DP1-DP3 prepared in Examples 1-8 and Comparative Examples 1-3 was tested as follows:

[0195] A certain mass of sample was placed in a vacuum at 120℃ for 3 hours. The dried sample was then placed in a static volumetric adsorption analyzer, and gases containing CO2 and N (containing 10 vol% CO2 and 70 vol% N2) were introduced at 40℃. The CO2 / N2 adsorption selectivity of the sample was calculated according to the ideal solution adsorption theory (IAST), and the results are shown in Table 3.

[0196] Table 3 Note: The NaX molecular sieve in Table 3 has the same chemical composition as the molecular sieve core in P1.

[0197] As can be seen from the data in Table 3, the core-shell composite materials P1-P8 prepared by the method of the present invention have a CO2 / N2 adsorption selectivity of not less than 200 under the conditions of 40℃ and 10 vol% CO2 and 70 vol% N2. The CO2 adsorption selectivity is significantly higher than that of DP1-DP3 and NaX molecular sieve, showing excellent CO2 / N2 selectivity.

[0198] 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 preparing a core-shell structured composite material, characterized in that, The preparation method includes: (1) In the presence of an initiator and a dispersant, a reaction system containing monomers, porogens and water is subjected to a first reaction to obtain a spherical macroporous resin; (2) The spherical macroporous resin is reacted with the first organic amine in a second reaction to obtain the modified resin; (3) The modified resin is reacted with a solution containing alkali, template agent, silicon source and aluminum source in a third reaction to obtain a core-shell structured composite material; The monomer is selected from at least one of acrylate monomers, alkenylbenzene and silane coupling agents containing unsaturated bonds; The template agent is prepared by a fourth reaction of a raw material containing a second organic amine and a modifier; wherein the modifier is selected from at least one of chloroalkanes, epoxy-containing acrylates, epoxy-containing alkanes, epoxy-containing alcohols, epoxy-containing ketones, and epoxy-containing silane coupling agents.

2. The preparation method according to claim 1, wherein, In step (1), the monomer is selected from acrylate monomers and / or silane coupling agents containing unsaturated bonds.

3. The preparation method according to claim 1 or 2, wherein, The acrylate monomers are selected from at least one of isodecyl methacrylate, phenyl methacrylate, glycidyl methacrylate, isopropyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, dodecyl fluoroheptaacrylate, and pentafluorophenyl methacrylate. And / or, the alkenylbenzene is selected from at least one of styrene, 3-chlorostyrene, and α-methylstyrene; And / or, the silane coupling agent containing unsaturated bonds is selected from at least one of γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane and γ-(methacryloxy)propyltriethoxysilane; And / or, the pore-forming agent is selected from at least one of toluene, xylene, and cyclohexane.

4. The preparation method according to claim 1 or 2, wherein, In step (1), the weight ratio of monomer: initiator: dispersant: water is 1:(0.005-0.2):(0.5-1):(110-118); And / or, the weight ratio of the monomer to the porogen is 1:(0.8-2).

5. The preparation method according to claim 1 or 2, wherein, In step (1), the reaction system also includes a crosslinking agent, a surfactant, and an optional reducing agent.

6. The preparation method according to claim 5, wherein, The weight ratio of the monomer to the crosslinking agent is 1:(0.5-2); And / or, the weight ratio of the monomer to the surfactant is 1:(0.2-0.5); And / or, the weight ratio of the monomer to the reducing agent is 1:(0.25-0.8).

7. The preparation method according to claim 1 or 2, wherein, In step (1), the conditions for the first reaction include: the reaction is carried out under stirring and a protective atmosphere, the reaction temperature is 50-90℃, the reaction time is 0.1-24h, and the stirring rate is 150-350 rpm.

8. The preparation method according to claim 1 or 2, wherein, In step (2), the first organic amine is selected from at least one of ethanolamine, triethanolamine, ethylenediamine, trimethylamine, isobutanolamine, polyethyleneimine, piperazine, N-(aminoethyl)piperazine, 2-aminomethylpiperidine, 1-(2-aminoethyl)piperidine and 2-amino-2-methyl-1-propanol; And / or, the weight ratio of the spherical macroporous resin to the first organic amine is 1:(10-90); And / or, the conditions for the second reaction include: a reaction temperature of 50-80°C and a reaction time of 0.5-3 h.

9. The preparation method according to claim 1 or 2, wherein, In step (3), the silicon source is selected from at least one of silica sol, water glass, sodium silicate, and sodium aluminum silicate; And / or, the aluminum source is sodium aluminate and / or aluminum sulfate.

10. The preparation method according to claim 1 or 2, wherein, In step (3), the weight ratio of modified resin: alkali: template agent: silicon source: aluminum source is 100:(195-1560):(390-1660):(1360-6162):(315-1560); And / or, the conditions for the third reaction include: a reaction temperature of 60-120°C and a reaction time of 6-24 h.

11. The preparation method according to claim 1 or 2, wherein, The second organic amine is selected from At least one of ethanolamine, triethanolamine, ethylenediamine, trimethylamine, isobutanolamine, polyethyleneimine, piperazine, N-(aminoethyl)piperazine, 2-aminomethylpiperidine, 1-(2-aminoethyl)piperidine and 2-amino-2-methyl-1-propanol; And / or, the modifier is selected from at least one of ethylene glycol diglycidyl ether, epichlorohydrin, epichlorohydrin, 1,2-epoxycyclopentane, 2,3-epoxy-1-cyclohexanone, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane and γ-glycidyl etheroxypropyltrimethoxysilane; And / or, the weight ratio of the second organic amine to the modifier is 1:(0.5-3).

12. The preparation method according to claim 11, wherein, The conditions for the fourth reaction include: a reaction temperature of 10-60℃ and a reaction time of 12-48h.

13. A core-shell composite material prepared by any one of claims 1-12.

14. The core-shell composite material according to claim 13, wherein, The core-shell composite material comprises: a resin shell and a molecular sieve core enclosed within the resin shell; wherein the weight ratio of the resin shell to the molecular sieve core is 100:(300-800). And / or, the average particle size of the core-shell composite material is 500-1000 μm.

15. The application of the core-shell composite material of claim 13 or 14 as a carbon dioxide adsorbent in the purification of carbon dioxide-containing flue gas.

16. The application according to claim 15, wherein, The water content in the carbon dioxide-containing flue gas is 10-50% by volume.

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