Core-shell structured composite material, method for preparing the same, and use thereof

Abstract

The present application relates to the technical field of carbon dioxide capture, and discloses a core-shell structure composite material and a preparation method and application thereof. The preparation method comprises the following steps: (1) performing a first reaction on a reaction system containing monomers, a pore-forming agent and water in the presence of an initiator and a dispersant to obtain spherical macroporous resin; (2) performing a second reaction on the spherical macroporous resin and a first organic amine to obtain modified resin; and (3) performing a third reaction on the modified resin and a solution containing alkali, a template agent, a silicon source and an aluminum source to obtain a core-shell structure composite material. The composite material provided by the present application comprises a hydrophobic shell and a molecular sieve in the shell, and has the comprehensive effects of excellent hydrophobicity, strong CO2 adsorption performance and high CO2 / N2 adsorption selectivity, thereby effectively solving the problem that a solid CO2 adsorbent is difficult to have both strong hydrophobicity and excellent CO2 adsorption performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon dioxide capture, in particular to a core-shell structure composite material and a preparation method and application thereof. BACKGROUND

[0002] CO2 emission is one of the main reasons for climate warming. Under the condition of existing energy structure, carbon capture, utilization and storage (CCUS) technology has become an indispensable part of carbon neutralization technology. Among many carbon capture technologies, organic amine solution absorption method has high separation efficiency, wide adaptability and high CO2 product gas purity, but there are problems of short service life of absorbent, serious equipment corrosion, high energy consumption and high cost. Compared with the former, solid adsorption technology uses porous solid materials as carriers and does not involve solvents, which can avoid additional energy consumption caused by solvent evaporation and does not cause equipment corrosion. This technology has great potential for energy saving and consumption reduction and has good application prospect.

[0003] For solid adsorption technology, the adsorbent as one of the technical cores directly affects the CO2 capture efficiency and cost. Many scholars at home and abroad have carried out research on adsorbents, but at present, none of them has realized the excellent performance of high CO2 adsorption capacity, high selectivity, fast kinetics, long service life, low cost and good geometric structure, which leads to the fact that the advantages of solid adsorption technology cannot be fully played.

[0004] Molecular sieve is one of many adsorption materials, which has regular and ordered internal structure of channels and large specific surface area, and the structure is adjustable, and is widely used in the fields of gas separation, catalysis and the like. For molecular sieves for adsorbing carbon dioxide, due to the fact that flue gas after combustion often contains water in varying degrees, the molecular sieve will preferentially adsorb water molecules, and in the water adsorption process, water will occupy the channels or CO2 adsorption sites of the molecular sieve, resulting in reduction of the adsorption capacity of the material, and even directly leading to loss of CO2 adsorption capacity. Therefore, it is a great challenge to maintain the original excellent carbon capture capacity of the molecular sieve in the presence of water.

[0005] 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 of introducing ZIF-8 material on the surface of 5A molecular sieve by pre-seeding and two-step temperature-controlled crystallization, and a series of 5A@ZIF-8 composite materials with enhanced surface hydrophobicity are prepared. The composite material can reach 80.7% of the CO2 adsorption capacity of the original 5A molecular sieve in the presence of water. In the method, 5A molecular sieve needs to be synthesized first, and then ZIF-8 two-step crystallization is carried out on the surface of the molecular sieve. The amount of ZIF-8 needs to be accurately controlled, which is difficult to achieve. More importantly, although the hydrophobicity of the composite material prepared by the method is improved, the CO2 adsorption capacity of the original molecular sieve cannot be maintained, resulting in a decrease in adsorption effect.

[0006] CN115608326A discloses an adsorbent for flue gas under high humidity conditions, comprising an adsorption core and a core-shell coated hydrophobic material composed of an organic polymer coated on the adsorption core, and a preparation method thereof comprising: (1) adding at least two different configuration molecular sieves into 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 ultrasonic treatment to obtain a homogeneous mixture A; (3) adding styrene into a dimethylformamide solution, then adding divinylbenzene and stirring to obtain a homogeneous mixture B; (4) stirring and mixing the homogeneous mixture B and the homogeneous mixture A to obtain a mixture C; (5) adding azobisisobutyronitrile to the mixture C and stirring to obtain the adsorbent. The scheme uses a post-modification method, which is prone to cause uneven modification and poor hydrophobic effect. Moreover, the use of high molecular polymers is prone to cause blockage of the molecular sieve channels, resulting in a decrease in adsorption capacity.

[0007] In addition, the adsorbent material prepared by the above-mentioned hydrophobic modification method is still in a powder state and cannot be directly used. Before use, it needs to be formed first. The existing forming methods, such as extrusion, tabletting, drop pill, and rolling ball, add binders without CO2 adsorption effect, and the dense structure formed after forming increases the diffusion resistance, which further reduces the CO2 adsorption performance of the material.

[0008] 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

[0009] 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.

[0010] To achieve the above objectives, a first aspect of the present invention provides a method for preparing a core-shell structured composite material, comprising:

[0011] (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;

[0012] (2) The spherical macroporous resin is reacted with the first organic amine in a second reaction to obtain the modified resin;

[0013] (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;

[0014] The monomer is selected from at least one of acrylate monomers, alkenylbenzene and silane coupling agents containing unsaturated bonds;

[0015] 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.

[0016] 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.

[0017] 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.

[0018] The preparation method of the core-shell structure composite material provided by the application first obtains a strong hydrophobic macroporous resin by polymerization of specific monomers under the action of a porogen, and then in-situ grows a molecular sieve inside the macroporous resin by using a specific template agent, and the template agent plays a role in adjusting the surface hydrophilicity and hydrophobicity of the molecular sieve itself and optimizing the pore structure of the molecular sieve, so that the core-shell structure composite material is prepared. Under the synergistic action of the hydrophobic shell and the molecular sieve in the shell, the core-shell type composite material has the comprehensive effects of excellent hydrophobicity, strong CO2 adsorption performance, and high CO2 / N2 selectivity. The water absorption of the composite material is ≤22 wt% under the condition of 40°C and 20% RH, the CO2 working adsorption capacity of the composite material is ≥0.7 mmol / g under the conditions of 40°C and 10 vol% CO2 flue gas adsorption and 120°C and 100 vol% CO2 regeneration, and the CO2 / N2 adsorption selectivity of the composite material is ≥200 under the conditions of 40°C and 10 vol% CO2 and 70 vol% N2. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of the application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the application, and together with the description serve to explain the principles of the application. In the drawings:

[0020] Figure 1 A scanning electron microscope image (internal morphology) of the core-shell structure composite material prepared for Example 1 of the application.

[0021] Figure 2 A scanning electron microscope image (external appearance morphology) of the core-shell structure composite material prepared for Example 1 of the application.

[0022] Figure 3 An XRD diffraction spectrum of the core-shell structure composite material prepared for Example 1 of the application. DETAILED DESCRIPTION

[0023] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are provided as approximate descriptions of the ranges and are understood to be open-ended. Each range endpoint is thus provided as a separate point value, and each point value is provided as a separate range endpoint. The disclosure is therefore understood to encompass all values and ranges between the low and high ends of the ranges and values disclosed herein.

[0024] The first aspect of the application provides a preparation method of a core-shell structure composite material, and the preparation method comprises:

[0025] (1) performing a first reaction on a reaction system containing monomers, a porogen, and water in the presence of an initiator and a dispersant to obtain a spherical macroporous resin;

[0026] (2) the spherical macroporous resin is subjected to a second reaction with a first organic amine to obtain a modified resin;

[0027] (3) the modified resin is subjected to a third reaction with a solution containing alkali, a template agent, a silicon source and an aluminum source to obtain a core-shell structure composite material;

[0028] The monomer is selected from at least one of an acrylate monomer, an alkenyl benzene and an unsaturated bond-containing silane coupling agent.

[0029] The template agent is obtained by subjecting raw materials containing a second organic amine and a modifier to a fourth reaction; the modifier is selected from at least one of a chloroalkane, an epoxy group-containing acrylate, an epoxy group-containing alkane, an epoxy group-containing alcohol, an epoxy group-containing ketone and an epoxy group-containing silane coupling agent.

[0030] According to the application, in the preparation method of the core-shell structure composite material, in step (1), a specific type of monomer is used for polymerization under the action of a porogen to obtain a spherical macroporous resin. The spherical macroporous resin has a large particle size, a macroporous structure and strong hydrophobicity.

[0031] According to the application, preferably, the average particle size of the spherical macroporous resin is 500-1000 μm.

[0032] According to the application, the pore size distribution range of the spherical macroporous resin is 3-6 μm.

[0033] According to the application, in the preparation method of the core-shell structure composite material, in step (1), preferably, the monomer can be selected from an acrylate monomer and / or an unsaturated bond-containing silane coupling agent, so that the obtained spherical macroporous resin has better hydrophobicity.

[0034] According to the application, preferably, the acrylate monomer can be selected from at least one of isodecyl methacrylate, phenyl methacrylate, glycidyl methacrylate, isopropyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, dodecafluoroheptyl methacrylate and pentafluorophenyl methacrylate.

[0035] Further preferably, the acrylate monomer can be further selected from at least one of ethyl methacrylate, phenyl methacrylate, glycidyl methacrylate, dodecafluoroheptyl methacrylate and pentafluorophenyl methacrylate.

[0036] According to the application, preferably, the alkenyl benzene can be selected from at least one of styrene, 3-chlorostyrene and α-methylstyrene.

[0037] Further preferably, the alkenyl benzene is styrene.

[0038] According to the present application, preferably, the silane coupling agent containing unsaturated bond can be selected from at least one of γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane and γ-(methacryloxy)propyltriethoxysilane.

[0039] Further preferably, the silane coupling agent containing unsaturated bond is γ-methacryloxypropyltrimethoxysilane.

[0040] According to a most preferred embodiment of the present application, the monomers are glycidyl methacrylate, dodecafluoroheptyl methacrylate and γ-methacryloxypropyltrimethoxysilane. Preferably, the weight ratio of glycidyl methacrylate, dodecafluoroheptyl methacrylate and γ-methacryloxypropyltrimethoxysilane is 1:(0.9-1.2):(0.8-1.1).

[0041] According to the present application, in the preparation method of the core-shell structure composite material, in step (1), the pore-forming agent can promote the macroporous structure of the building material, and provide space for the growth of the molecular sieve inside the macropore of the resin in the subsequent steps. Preferably, the pore-forming agent can be selected from at least one of toluene, xylene and cyclohexane.

[0042] Further preferably, the pore-forming agent is toluene.

[0043] According to the present application, in the preparation method of the core-shell structure composite material, in step (1), the initiator is limited widely, for example, azo initiator, peroxide initiator, etc. can be used.

[0044] In the present application, preferably, the azo initiator can include but is not limited to at least one of dimethyl 2,2'-azobis(2-methylpropionate) (AIBME), azobisformamide (ADC), azobisimidoform hydrochloride (AIB1), azobiscyclohexanenitrile (ACCN), azobis(cyanvaleric acid) (ACVA), azobisimidoform (AIP), azobis(isobutyronitrile) (AIBN), azobis(isopentanenitrile) (AMBN) and azobis(isoheptanenitrile) (ABVN), and further preferably azobis(isobutyronitrile).

[0045] In the present application, preferably, the peroxide initiator can include but is not limited to at least one of hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate and benzoyl peroxide, and further preferably benzoyl peroxide.

[0046] According to the present application, in the preparation method of the core-shell structure composite material, in step (1), the dispersant can reduce the agglomeration between particles 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.

[0047] Further preferably, the dispersant is polyvinyl alcohol.

[0048] According to the present application, in the preparation method of the core-shell structure composite material, in step (1), water can promote the formation of connecting holes between large holes, and improve the porosity of the resin formed by polymerization.

[0049] According to the present application, in the preparation method of the core-shell structure composite material, in step (1), preferably, the feeding amount of the monomer, initiator, dispersant and water satisfies the following relationship:

[0050] The weight ratio of the monomer: initiator: dispersant: water is 1: (0.005-0.2): (0.5-1): (110-118).

[0051] According to the present application, in the preparation method of the core-shell structure composite material, in step (1), preferably, the feeding amount of the porogen satisfies: the weight ratio of the monomer to porogen is 1: (0.8-2).

[0052] According to the present application, in the preparation method of the core-shell structure composite material, in step (1), further, the reaction system further includes a crosslinking agent, a surfactant and an optional reducing agent.

[0053] The crosslinking agent can bridge between monomer molecules, crosslink the polymer by forming chemical bonds, form a three-dimensional network structure, and thus improve the heat resistance, water resistance and mechanical strength of the material. Preferably, the crosslinking agent can be selected from trimethylolpropane triacrylate and / or divinylbenzene. Preferably, the weight ratio of the monomer: crosslinking agent is 1: (0.5-2).

[0054] The surfactant can reduce the surface tension and promote the formation of a stable monomer emulsion reaction system. Preferably, the surfactant can be selected from at least one of Span 80, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, sodium dodecylbenzenesulfonate and polyvinyl alcohol. Preferably, the weight ratio of the monomer: surfactant is 1: (0.2-0.5).

[0055] For the case where the initiator is a peroxide initiator, the reaction system further includes a reducing agent, which can react with the oxidizing agent (initiator) to produce free radicals and accelerate 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 the monomer: reducing agent is 1: (0.25-0.8).

[0056] According to the present application, 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°C, preferably 60-80°C; the reaction time is 0.1-24h, preferably 0.25-24h; and the stirring rate is 150-350rpm.

[0057] According to the present application, the protective atmosphere can be selected according to the conventional selection in the field of organic synthesis, such as a nitrogen atmosphere, a helium atmosphere, a neon atmosphere, an argon atmosphere, etc.

[0058] According to the present application, in the first reaction, by controlling the polymerization reaction under the above stirring rate, the size of the polymerization product is controlled, and thus the size of the finally prepared composite material is controlled.

[0059] According to a preferred embodiment of the present application, the step (1) can be implemented in the following manner to prepare the spherical macroporous resin:

[0060] According to the above feeding ratio, the monomers, the crosslinking agent, the surfactant, the initiator, the porogen and the reducing agent are first mixed to obtain a mixed solution-I; then the mixed solution-I is second mixed with water to obtain a mixed solution-II; then the mixed solution-II is poured into the aqueous dispersant solution under continuous stirring and a protective atmosphere to carry out the first reaction; after the reaction is completed, the polymerization product particles are separated out, and then dried to obtain the spherical macroporous resin.

[0061] In the above preferred embodiment, in order to obtain a better oil-water two-phase mixing effect, the second mixing is carried out under high-speed stirring. Preferably, the stirring rate is 3000-8000rpm, and the stirring time is 5-15min.

[0062] In the above preferred embodiment, in the aqueous dispersant solution, preferably, the concentration of the dispersant is 0.0007-0.02g / mL, which is more conducive to forming the spherical resin with uniform particle size distribution after the reaction. The total weight of the solute water in the aqueous dispersant solution and the water fed in the second mixing is referred to as the feeding amount of water in the above step (1).

[0063] According to the present application, in the preparation method of the core-shell structure composite material, in step (2), by the second reaction, the spherical macroporous resin is modified by amine group functionalization using the first organic amine, so that the precursor solution of the molecular sieve is more easily introduced into the resin in the subsequent step.

[0064] According to the application, the first organic amine can be 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.

[0065] According to the application, in the preparation method of the core-shell structure composite material, in step (2), preferably, the weight ratio of the spherical macroporous resin: the first organic amine is 1:(10-90).

[0066] According to the application, in the preparation method of the core-shell structure composite material, in step (2), the second reaction is carried out by impregnation. Preferably, the conditions of the second reaction include: the reaction temperature is 50-80℃, and the reaction time is 0.5-3h.

[0067] According to a preferred embodiment of the application, the second reaction in step (2) can be carried out in the following way:

[0068] 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.

[0069] Preferably, in the methanol solution of the first organic amine, the weight ratio of the first organic amine:methanol is 1:(1-5).

[0070] According to the application, in the preparation method of the core-shell structure composite material, in step (3), under the action of a specific template agent, the base, the silicon source and the aluminum source in the spherical macroporous resin carry out a third reaction, in-situ crystallization and growth to form a molecular sieve, and the template agent can adjust 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.

[0071] The template agent used in the application can be prepared by carrying out a fourth reaction on raw materials containing a second organic amine and a modifier. Preferably, in the fourth reaction, the feeding amount of the second organic amine and the modifier satisfies: the weight ratio of the second organic amine to the modifier is 1:(0.5-3).

[0072] According to the application, the second organic amine can be 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.

[0073] Preferably, the second organic amine is at least one of ethanolamine, ethylenediamine and polyethyleneimine, which is more conducive to adjusting the structure of the molecular sieve and forming enhanced hydrophobic effect.

[0074] According to the present application, the modifier can be selected from at least one of ethylene glycol diglycidyl ether, epichlorohydrin, epoxypropanol, 1,2-epoxycyclopentane, 2,3-epoxy-1-cyclohexanone, 3-[(2,3)-glycidoxypropoxy]propylmethyldimethoxysilane and γ-glycidoxypropyltrimethoxysilane.

[0075] According to the present application, preferably, the conditions of the fourth reaction include: the reaction temperature is 10-60℃, and the reaction time is 12-48h.

[0076] According to a preferred embodiment of the present application, the fourth reaction in step (3) can be carried out in the following manner:

[0077] According to the above feeding ratio, the second organic amine, the modifier and the solvent are mixed to obtain a mixed solution-III, and then the mixed solution-III is subjected to the fourth reaction, and the reaction product is dried to remove the solvent to prepare the template agent. Preferably, the solvent is at least one of toluene, methanol and N,N-dimethylformamide. Preferably, the weight ratio of the solvent to (the second organic amine + the modifier + the solvent) is (70-140):100.

[0078] According to the present application, in the preparation method of the core-shell structure composite material, in step (3), the base can be selected from at least one of sodium hydroxide, potassium hydroxide and calcium hydroxide, and is preferably sodium hydroxide.

[0079] According to the present application, in the preparation method of the core-shell structure composite material, in step (3), the silicon source and the aluminum source are limited to a wide range, and the conventional silicon source and aluminum source selection in the molecular sieve preparation field can be used. 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 metaaluminate and / or aluminum sulfate.

[0080] According to the present application, in the preparation method of the core-shell structure composite material, in step (3), preferably, the feeding amount of the modified resin, the base, the template agent, the silicon source and the aluminum source satisfies the following relationship:

[0081] The weight ratio of the modified resin: base: template agent: silicon source: aluminum source is 100:(195-1560):(390-1660):(1360-6162):(315-1560), and is preferably 100:(750-1560):(990-1660):(4660-6162):(810-1420).

[0082] According to the present application, in the preparation method of the core-shell structure composite material, in step (3), the silicon source and the aluminum source are fed in the form of an aqueous solution containing both the silicon source and the aluminum source. Preferably, in the aqueous solution containing the silicon source and the aluminum source, the total concentration of the silicon source and the aluminum source is 16-43% by weight.

[0083] According to the present application, in the preparation method of the core-shell structure composite material, in step (3), the third reaction is carried out by impregnation. Preferably, the conditions of the third reaction include: the reaction temperature is 60-120℃, and the reaction time is 6-24h.

[0084] According to a preferred embodiment of the present application, step (3) for carrying out the third reaction can be implemented in the following manner:

[0085] According to the above feeding ratio, the base, the template agent and the aqueous solution containing the silicon source and the aluminum source are mixed to obtain a mixed solution-IV, the modified resin is impregnated in the mixed solution-IV to carry out the third reaction, after the reaction is completed, the obtained granular product is dried to obtain a spherical core-shell structure composite material.

[0086] In the present application, the modified resin is impregnated in the solution containing both the silicon source and the aluminum source to synthesize the molecular sieve, so that the prepared core-shell structure composite material has excellent CO2 adsorption performance, hydrophobic performance and high CO2 / N2 adsorption selectivity. However, if the modified resin is impregnated in the solution containing only the silicon source first and then in the solution containing only the aluminum source, or the modified resin is impregnated in the solution containing only the aluminum source first and then in the solution containing only the silicon source, the CO2 adsorption performance, the hydrophobic performance and the CO2 / N2 adsorption selectivity of the prepared composite material are not as good as those of the core-shell structure composite material prepared by the method of the present application.

[0087] The preparation method of the existing core-shell structure adsorbent material is generally to synthesize a molecular sieve first, and then coat a hydrophobic material on the surface of the molecular sieve, without regulating the structure of the molecular sieve, so that the CO2 adsorption performance of the molecular sieve is difficult to maintain after hydrophobic modification, the adsorption effect is reduced, and the adsorbent material prepared after hydrophobic modification is still in powder form and needs to be formed before use, and the forming process will further cause the loss of CO2 adsorption performance of the material. Compared with the prior art, the present application provides a new method for directional synthesis of hydrophobic molecular sieve, which uses specific monomers to polymerize to form a spherical macroporous resin with strong hydrophobicity, introduces a specific template to synthesize a molecular sieve in the spherical macroporous resin, adjusts the surface hydrophilicity and hydrophobicity of the molecular sieve itself and optimizes the pore structure of the molecular sieve, and through in-situ structure forming, a composite material with a core-shell structure is prepared. The average particle size of the composite material is 500-1000 μm, which can be directly used for adsorption operation without secondary forming. The core-shell structure composite material prepared by the method has strong hydrophobic barrier effect, and the water absorption amount of the material is ≤22 wt% under the condition of 40℃ and 20% RH. The CO2 adsorption performance of the material is strong, and the CO2 / N2 adsorption selectivity is high. Specifically, the CO2 working adsorption capacity of the material is ≥0.7 mmol / g under the conditions of 40℃ and 10% CO2 flue gas adsorption and 120℃ and 100% CO2 regeneration, and the CO2 / N2 adsorption selectivity of the material is ≥200 under the conditions of 40℃ and 10% CO2 and 70% N2.

[0088] The second aspect of the present application provides a core-shell structure composite material prepared by the preparation method of the first aspect.

[0089] According to the present application, the core-shell structure composite material comprises a resin shell and a molecular sieve core wrapped in the resin shell. Preferably, the weight ratio of the resin shell to the molecular sieve core is 100:(300-800).

[0090] According to the present application, the core-shell structure composite material has strong hydrophobic barrier effect. Preferably, the water absorption amount of the core-shell structure composite material is ≤17 wt% under the condition of 25℃ and 20% RH.

[0091] According to the present application, the core-shell structure composite material has strong CO2 adsorption performance. Preferably, the CO2 working adsorption capacity of the material is ≥0.7 mmol / g under the conditions of 40℃ and 10% CO2 flue gas adsorption and 120℃ and 100% CO2 regeneration.

[0092] According to the present application, the core-shell structure composite material has high CO2 / N2 adsorption selectivity during the adsorption process. Preferably, the CO2 / N2 adsorption selectivity of the material is ≥200 under the conditions of 40℃ and 10% CO2 and 70% N2.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] Example 1

[0099] (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);

[0100] The weight ratio of monomer: initiator: dispersant: water (including water in the 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.

[0101] (2) The spherical macroporous resin B1 is immersed in a methanol solution of polyethyleneimine (the weight ratio of polyethyleneimine: methanol is 1:2.3) and reacted at 60°C for 1 h, and then dried at 80°C for 6 h to obtain a modified resin;

[0102] The weight ratio of the spherical macroporous resin B1: polyethyleneimine is 1:30.

[0103] (3) Template preparation: polyethyleneimine, γ-glycidoxypropyltrimethoxysilane (modifier) and toluene are mixed to obtain a mixed solution-III, the mixed solution-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 a liquid template;

[0104] The weight ratio of polyethyleneimine: γ-glycidoxypropyltrimethoxysilane is 1:1.6; and the weight ratio of methanol: (polyethyleneimine + γ-glycidoxypropyltrimethoxysilane + methanol) is 70:100.

[0105] Sodium hydroxide, the above-mentioned template and an aqueous solution containing sodium silicate (without crystal water) and sodium metaaluminate (the total concentration of sodium silicate and sodium metaaluminate is 36% by weight) are mixed to obtain a mixed solution-IV; the above-mentioned modified resin is immersed in the mixed solution-IV and reacted at 90°C for 6 h, after the reaction is completed, the spherical particle product is separated out and dried at 120°C for 12 h to obtain a spherical core-shell structure composite material (denoted as P1, the average particle size of P1 is 900 μm, and the weight ratio of the resin shell: molecular sieve core (NaX molecular sieve) in P1 is 100:700);

[0106] The weight ratio of the modified resin: sodium hydroxide: template: sodium silicate: sodium metaaluminate is 100:780:1560:6120:830.

[0107] The P1 is subjected to scanning electron microscope test, the internal morphology is as shown in Figure 1 , it can be seen that the molecular sieve grows in the resin shell of P1; the apparent morphology is as shown in Figure 2 , it can be seen that the synthesized composite material is regular near-millimeter spherical shape.

[0108] The P1 is subjected to XRD test, the result is as shown in Figure 3As shown, the original molecular sieve (NaX molecular sieve) corresponds to the crystal faces of

[111] ,

[331] and

[642] of the composite material one by one, shows the characteristic peaks of the FAU topology, indicating that the molecular sieve is successfully synthesized in situ inside the resin.

[0109] Example 2

[0110] (1) The monomers glycidyl methacrylate, dodecafluoroheptyl methacrylate and phenyl methacrylate (weight ratio 1:1:1), trimethylolpropane triacrylate (crosslinking agent), Span 80 (surfactant), azobisisobutyronitrile (initiator), toluene (porogen) were mixed to obtain a mixed solution-I; then the mixed solution-I was mixed with water (stirring and mixing for 10 min at 6000 rpm) to obtain a mixed solution-II; then the mixed solution-II was slowly poured into an aqueous polyvinyl alcohol solution (polyvinyl alcohol concentration 0.01 g / mL) under continuous stirring (300 rpm) and nitrogen protection for polymerization, and polymerization was carried out 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 a spherical macroporous resin (denoted as B2, wherein the pore size distribution range is 3-5 μm);

[0111] wherein the weight ratio of monomer: initiator: dispersant: water (including water in the aqueous polyvinyl alcohol 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; the weight ratio of monomer: surfactant is 1:0.2;

[0112] (2) The spherical macroporous resin B2 was immersed in an ethanolamine methanol solution (weight ratio of ethanolamine: methanol 1:1.5) and reacted at 70°C for 0.5 h, and then dried at 80°C for 6 h to obtain a modified resin;

[0113] wherein the weight ratio of spherical macroporous resin B2: ethanolamine is 1:50;

[0114] (3) Template preparation: ethanolamine, epichlorohydrin (modifier) and methanol were mixed to obtain a mixed solution-III, the mixed solution-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 a liquid template;

[0115] wherein the weight ratio of ethanolamine: epichlorohydrin is 1:0.7; the weight ratio of methanol: (ethanolamine + epichlorohydrin + methanol) is 80:100;

[0116] The spherical particle product was separated after the reaction, and dried at 120°C for 24 hours to obtain a spherical core-shell structure composite material (denoted as P2, the average particle size of P2 was 800 μm, and the weight ratio of the resin shell to the inner core of the molecular sieve (NaX molecular sieve) in P2 was 100:620);

[0117] wherein the weight ratio of the modified resin: sodium hydroxide: template agent: sodium silicate nonahydrate: sodium aluminate was 100: 1170: 1560: 4740: 1420.

[0118] Example 3

[0119] (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 a mixed solution-I; then the mixed solution-I was mixed with water (stirring and mixing for 10 min at 6000 rpm) to obtain a mixed solution-II; then the mixed solution-II was slowly poured into an aqueous polyvinyl alcohol solution (polyvinyl alcohol concentration 0.01 g / mL) under continuous stirring (300 rpm) and nitrogen protection for polymerization, and polymerized at 60°C for 4 h; after the reaction, the polymerization product particles were separated and dried at 80°C for 6 h to obtain a spherical macroporous resin (denoted as B3, wherein the pore size distribution range was 4-5 μm);

[0120] wherein the weight ratio of the monomers: initiator: dispersant: water (including water in the aqueous polyvinyl alcohol solution) was 1:0.08:1:110; the weight ratio of the monomers: porogen was 1:1.2; the weight ratio of the monomers: crosslinking agent was 1:0.7; the weight ratio of the monomers: surfactant was 1:0.35; and the weight ratio of the monomers: reducing agent was 1:0.25;

[0121] (2) The spherical macroporous resin B3 was immersed in an ethylenediamine methanol solution (weight ratio of ethylenediamine: methanol was 1:4) and reacted at 60°C for 3 h, and then dried at 80°C for 6 h to obtain a modified resin;

[0122] wherein the weight ratio of the spherical macroporous resin B3: ethylenediamine was 1:40;

[0123] (3) Template preparation: ethylenediamine, ethylene glycol diglycidyl ether (modifier) and methanol were mixed to obtain a mixed solution-III, the mixed solution-III was reacted at 10°C for 48h, and the reaction product was dried in a vacuum drying oven at 60°C for 24h to obtain a liquid template;

[0124] wherein the weight ratio of ethylenediamine: ethylene glycol diglycidyl ether is 1:0.5; the weight ratio of methanol: (ethylenediamine + ethylene glycol diglycidyl ether + methanol) is 110:100;

[0125] Sodium hydroxide, the above template and an aqueous solution containing sodium silicate pentahydrate and sodium metaaluminate (the total concentration of sodium silicate pentahydrate and sodium metaaluminate is 26% by weight) were mixed to obtain a mixed solution-IV; the above modified resin was immersed in the mixed solution-IV and reacted at 90°C for 6h, after the reaction was completed, the spherical particle product was separated and dried at 120°C for 24h to obtain a spherical core-shell structure composite material (denoted as P3, the average particle size of P3 is 700μm, and the weight ratio of the resin shell: the molecular sieve inner core (NaX molecular sieve) in P3 is 100:607);

[0126] wherein the weight ratio of the modified resin: sodium hydroxide: template: sodium silicate pentahydrate: sodium metaaluminate is 100:780:1170:4740:830.

[0127] Example 4

[0128] (1) Monomers (glycidyl methacrylate, cyclohexyl methacrylate and γ-(methacryloyloxy) propyl triethoxysilane, weight ratio 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 a mixed solution-I; then the mixed solution-I was mixed with water (stirring and mixing for 10 min at 6000 rpm) to obtain a mixed solution-II; then the mixed solution-II was slowly poured into an aqueous polyvinyl alcohol solution (polyvinyl alcohol concentration 0.01 g / mL) under continuous stirring (250 rpm) and nitrogen protection for polymerization, and polymerized at 60°C for 3h; after the reaction was completed, the polymerization product particles were separated and dried at 80°C for 6h to obtain a spherical macroporous resin (denoted as B4, wherein the pore size distribution range is 3-5μm);

[0129] wherein the weight ratio of monomers: initiator: dispersant: water (including water in the aqueous polyvinyl alcohol solution) is 1:0.08:1:112; the weight ratio of monomers: porogen is 1:1.5; the weight ratio of monomers: crosslinking agent is 1:0.8; the weight ratio of monomers: surfactant is 1:0.4; the weight ratio of monomers: reducing agent is 1:0.25;

[0130] (2) The spherical macroporous resin B4 was immersed in a methanol solution of 2-amino-2-methyl-l-propanol (the weight ratio of 2-amino-2-methyl-l-propanol : methanol was 1 : 4) and reacted at 60°C for 3 h, and then dried at 80°C for 6 h to obtain a modified resin;

[0131] wherein the weight ratio of the spherical macroporous resin B4 : 2-amino-2-methyl-l-propanol was 1 : 45;

[0132] (3) Template preparation: 2-amino-2-methyl-l-propanol, 1,2-epoxy cyclopentane (a modifier) and methanol were thoroughly mixed to obtain a mixed solution-III, the mixed solution-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 a liquid template;

[0133] wherein the weight ratio of 2-amino-2-methyl-l-propanol : 1,2-epoxy cyclopentane was 1 : 0.7; the weight ratio of methanol : (2-amino-2-methyl-l-propanol + 1,2-epoxy cyclopentane + methanol) was 115 : 100;

[0134] Sodium hydroxide, the above template and an aqueous solution containing silica sol and sodium alumininate (the total concentration of silica sol and sodium alumininate was 22% by weight) were mixed to obtain a mixed solution-IV; the above modified resin was immersed in the mixed solution-IV and reacted at 80°C for 12 h, after the reaction was completed, the spherical particle product was separated and dried at 120°C for 24 h to obtain a spherical core-shell composite material (denoted as P4, the average particle size of P4 was 700 μm, and the weight ratio of the resin shell : the molecular sieve core (NaX molecular sieve) in P4 was 100 : 566);

[0135] wherein the weight ratio of the modified resin : sodium hydroxide : template : silica sol : sodium alumininate was 100 : 740 : 740 : 4120 : 780.

[0136] Example 5

[0137] (1) monomers (isodecyl methacrylate, vinyl trimethoxysilane and styrene, weight ratio 1:0.9:1.1), divinylbenzene (crosslinking agent), Span 80 (surfactant), azobisisobutyronitrile (initiator), toluene (porogen) were mixed to obtain a mixed solution-I; then the mixed solution-I was mixed with water (stirring and mixing for 10 min at 6000 rpm) to obtain a mixed solution-II; then the mixed solution-II was slowly poured into a polyvinyl alcohol aqueous solution (polyvinyl alcohol concentration 0.01 g / mL) under continuous stirring (200 rpm) and nitrogen protection for polymerization, and polymerization was carried out 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 a spherical macroporous resin (denoted as B5, wherein the pore size distribution range is 3-5 μm);

[0138] wherein the weight ratio of monomer: initiator: dispersant: water (including water in the 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; the weight ratio of monomer: surfactant is 1:0.5;

[0139] (2) The spherical macroporous resin B5 was immersed in a methanol solution of N-(aminoethyl) piperazine (weight ratio of N-(aminoethyl) piperazine:methanol 1:4.5) and reacted at 55°C for 2.5 h, and then dried at 80°C for 6 h to obtain a modified resin;

[0140] wherein the weight ratio of spherical macroporous resin B5:N-(aminoethyl) piperazine is 1:60;

[0141] (3) Template preparation: N-(aminoethyl) piperazine, 2,3-epoxy-1-cyclohexanone (modifier) and methanol were mixed to obtain a mixed solution-III, the mixed solution-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 a liquid template;

[0142] wherein the weight ratio of N-(aminoethyl) piperazine:2,3-epoxy-1-cyclohexanone is 1:1.5; the weight ratio of methanol:(N-(aminoethyl) piperazine+2,3-epoxy-1-cyclohexanone+methanol) is 123:100;

[0143] A mixture of sodium hydroxide, the above template agent, and an aqueous solution of water glass and sodium metaaluminate (the total concentration of water glass and sodium metaaluminate is 19% by weight) was mixed to obtain a mixed solution-IV; the above modified resin was impregnated in the mixed solution-IV, and reacted at 90°C for 6h, after the reaction was completed, the spherical particle product was separated, and dried at 120°C for 24h to obtain a spherical core-shell structure composite material (denoted as P5, the average particle size of P5 is 800μm, and the weight ratio of the resin shell to the inner core of the molecular sieve (NaX molecular sieve) in P5 is 100:496);

[0144] wherein the weight ratio of the modified resin: sodium hydroxide: template agent: water glass: sodium metaaluminate is 100:719:725:3890:736.

[0145] Example 6

[0146] (1) A mixture of monomers (isopropyl methacrylate, vinyltrimethoxysilane, and α-methylstyrene, the weight ratio is 1:0.7:1.3), divinylbenzene (crosslinking agent), Span 80 (surfactant), azobisisobutyronitrile (initiator), and toluene (porogen) was mixed to obtain a mixed solution-I; then the mixed solution-I was mixed with water (stirring and mixing for 10 min at 6000rpm) to obtain a mixed solution-II; then the mixed solution-II was slowly poured into an aqueous polyvinyl alcohol solution (the concentration of polyvinyl alcohol is 0.01g / mL) under continuous stirring (250rpm) and nitrogen protection for polymerization, and polymerized at 70°C for 24h; after the reaction was completed, the polymerization product particles were separated, and dried at 80°C for 6h to obtain a spherical macroporous resin (denoted as B6, wherein the pore size distribution range is 4-6μm);

[0147] wherein the weight ratio of the monomer: initiator: dispersant: water (including the water in the aqueous polyvinyl alcohol solution) is 1:0.12:1:110; the weight ratio of the monomer: porogen is 1:1.3; the weight ratio of the monomer: crosslinking agent is 1:0.7; and the weight ratio of the monomer: surfactant is 1:0.6;

[0148] (2) The spherical macroporous resin B6 was impregnated in an isobutanolamine methanol solution (the weight ratio of isobutanolamine: methanol is 1:5), and reacted at 50°C for 3h, and then dried at 80°C for 6h to obtain a modified resin;

[0149] wherein the weight ratio of the spherical macroporous resin B6: isobutanolamine is 1:70;

[0150] (3) Template preparation: 1-(2-aminoethyl)piperidine, glycidol (modifier) and methanol were mixed to obtain a mixed solution-III, which was reacted at 30°C for 36h, and the reaction product was dried in a vacuum drying oven at 60°C for 24h to obtain a liquid template;

[0151] wherein the weight ratio of 1-(2-aminoethyl)piperidine: glycidol is 1:1.9; the weight ratio of methanol: (1-(2-aminoethyl)piperidine + glycidol + methanol) is 132:100;

[0152] The sodium hydroxide, the above-mentioned template and the aqueous solution containing silica sol and sodium metaaluminate (the total concentration of silica sol and sodium metaaluminate is 17% by weight) were mixed to obtain a mixed solution-IV; the above-mentioned modified resin was immersed in the mixed solution-IV, which was reacted at 80°C for 6h, after the reaction was completed, the spherical particle product was separated, and was dried at 120°C for 24h to obtain a spherical core-shell structure composite material (denoted as P6, the average particle size of P6 is 850μm, the weight ratio of the resin shell: the inner core of molecular sieve (NaX molecular sieve) in P6 is 100:451);

[0153] wherein the weight ratio of modified resin: sodium hydroxide: template: silica sol: sodium metaaluminate is 100:699:708:3788:619.

[0154] Example 7

[0155] (1) The spherical macroporous resin (denoted as B6) was prepared according to the step (1) of Example 6;

[0156] (2) The spherical macroporous resin B6 was immersed in a methanol solution of 1-(2-aminoethyl)piperidine (the weight ratio of 1-(2-aminoethyl)piperidine: methanol is 1:5), which was reacted at 50°C for 3h, and then was dried at 80°C for 6h to obtain a modified resin;

[0157] wherein the weight ratio of the spherical macroporous resin B6: 1-(2-aminoethyl)piperidine is 1:70;

[0158] (3) Template preparation: 1-(2-aminoethyl)piperidine, glycidol (modifier) and methanol were mixed to obtain a mixed solution-III, which was reacted at 30°C for 36h, and the reaction product was dried in a vacuum drying oven at 60°C for 24h to obtain a liquid template;

[0159] wherein the weight ratio of 1-(2-aminoethyl)piperidine: glycidol is 1:1.9; the weight ratio of methanol: (1-(2-aminoethyl)piperidine + glycidol + methanol) is 132:100;

[0160] The mixture of sodium hydroxide, the above-mentioned template agent, and an aqueous solution of silica sol and sodium metaaluminate (the total concentration of silica sol silicon and sodium metaaluminate was 17% by weight) was mixed to obtain a mixed solution-IV; the above-mentioned modified resin was immersed in the mixed solution-IV and reacted at 80°C for 6 hours, after the reaction was completed, the spherical particle product was separated and dried at 120°C for 24 hours to obtain a spherical core-shell structure composite material (denoted as P7, the average particle size of P7 was 840 μm, and the weight ratio of the resin shell to the molecular sieve inner core (NaX molecular sieve) in P7 was 100:446);

[0161] The weight ratio of the modified resin: sodium hydroxide: template agent: silica sol: sodium metaaluminate was 100:699:708:3788:619.

[0162] Example 8

[0163] (1) The spherical macroporous resin (denoted as B6) was prepared according to the same procedure as step (1) of Example 6;

[0164] (2) The spherical macroporous resin B6 was immersed in the methanol solution of 1-(2-aminoethyl)piperidine (the weight ratio of 1-(2-aminoethyl)piperidine:methanol was 1:5) and reacted at 50°C for 3 hours, and then dried at 80°C for 6 hours to obtain a modified resin;

[0165] The weight ratio of the spherical macroporous resin B6: 1-(2-aminoethyl)piperidine was 1:70;

[0166] (3) Template agent preparation: the piperazine, 3-[(2,3)-epoxypropoxy]propyl methyl dimethoxysilane (modifier), and methanol were mixed to obtain a mixed solution-III, reacted at 30°C for 36 hours, and the reaction product was dried in a vacuum drying oven at 60°C for 24 hours to obtain a liquid template agent;

[0167] The weight ratio of piperazine: 3-[(2,3)-epoxypropoxy]propyl methyl dimethoxysilane was 1:1.9; the weight ratio of methanol: (piperazine + 3-[(2,3)-epoxypropoxy]propyl methyl dimethoxysilane + methanol) was 132:100;

[0168] The mixture of sodium hydroxide, the above-mentioned template agent, and an aqueous solution of silica sol and sodium metaaluminate (the total concentration of silica sol silicon and sodium metaaluminate was 17% by weight) was mixed to obtain a mixed solution-IV; the above-mentioned modified resin was immersed in the mixed solution-IV and reacted at 80°C for 6 hours, after the reaction was completed, the spherical particle product was separated and dried at 120°C for 24 hours to obtain a spherical core-shell structure composite material (denoted as P7, the average particle size of P7 was 840 μm, and the weight ratio of the resin shell to the molecular sieve inner core (NaX molecular sieve) in P7 was 100:446);

[0169] wherein the weight ratio of modified resin: sodium hydroxide: template agent: silica sol: sodium metaaluminate is 100:699:708:3788:619.

[0170] Comparative Example 1

[0171] The core-shell structure composite material (denoted as DP1) was prepared according to the method of steps (2) and (3) disclosed in Example 1 of CN117160429A.

[0172] Comparative Example 2

[0173] According to the method of Example 8, the difference is that in step (3), an equal weight of tetrapropylammonium bromide is used as the template agent, and other steps and conditions are the same as those of 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 the resin shell to the molecular sieve core in DP2 is 100:370).

[0174] Comparative Example 3

[0175] According to the method of Example 8, the difference is that in step (3), the sodium hydroxide, the above-mentioned template agent, and the aqueous solution containing the silica sol (the concentration of the silica sol is 9% by weight) are mixed to obtain a mixed solution; the modified resin is immersed in the mixed solution and reacted at 80°C for 3h, after the reaction is completed, the spherical particle product is separated out and dried at 120°C for 6h; then the dried spherical particle product is further immersed in an aqueous solution containing sodium metaaluminate (the concentration of the sodium metaaluminate is 8% by weight) and reacted at 80°C for 3h, after the reaction is completed, the spherical particle product is separated out and dried at 120°C for 24h, 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 the resin shell to the molecular sieve core in PD3 is 100:388); wherein the weight ratio of modified resin: sodium hydroxide: template agent: silica sol: sodium metaaluminate is 100:699:708:3788:619. Other steps and conditions are the same as those of Example 8.

[0176] Test Example

[0177] 1. Hydrophobicity test

[0178] The composite materials P1-P8 prepared in Examples 1-8 were subjected to water absorption tests, and the test process was as follows:

[0179] A certain mass of sample was vacuum dried at 150°C for 12h, and the dried sample was placed in a steam adsorption instrument for water absorption test (40°C, relative humidity of 20%RH), and the water absorption was calculated according to the following formula:

[0180]

[0181] The results are shown in Table 1.

[0182] Table 1

[0183] Composite material Water uptake / wt% at 40°C, 20% RH P1 11.0 P2 12.6 P3 14.1 P4 15.7 P5 17.2 P6 19.1 P7 20.2 P8 21.6 NaX molecular sieve 29.1

[0184] Note: The chemical composition of the inner core of the molecular sieve in Table 1 is the same as that in P1

[0185] As can be seen from the data in Table 1, the water absorption of the core-shell structure composite materials P1-P8 prepared by the preparation method of the application is not higher than 22 wt% under the condition of 40℃ and 20% RH, and has excellent hydrophobic performance. Compared with the NaX molecular sieve, the water absorption of P1 is greatly reduced, indicating that the resin shell of P1 has a strong hydrophobic barrier effect.

[0186] 2. CO2 adsorption performance test

[0187] 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 process was as follows:

[0188] A certain amount of sample was placed in a vacuum at 120℃ for 3h, and the dried sample was placed in a gravimetric adsorption analyzer, and the CO2 adsorption capacity of the sample was tested by introducing a mixed gas of 10% by volume CO2, 20% by volume water vapor (the remaining components were balanced with nitrogen) at 40℃, and then desorbing in a CO2 atmosphere at 120℃. The amount of CO2 desorbed was the CO2 working adsorption capacity of the sample, and the results are shown in Table 2.

[0189] Table 2

[0190] Composite material CO2 working adsorption capacity / mmol / g P1 0.94 P2 0.91 P3 0.89 P4 0.86 P5 0.84 P6 0.80 P7 0.76 P8 0.73 DP1 0.38 DP2 0.41 DP3 0.26 NaX molecular sieve 0.49

[0191] Note: The chemical composition of the inner core of the molecular sieve in Table 2 is the same as that in P1

[0192] As can be seen from the data in Table 2, the CO2 working adsorption capacity of the core-shell structure composite materials P1-P8 prepared by the preparation method of the application is not lower than 0.7mmol / g under the conditions of 40℃ and 10% by volume CO2 flue gas adsorption and 120℃ and 100% by volume CO2 regeneration, which is much higher than that of DP1-DP3. By comparing the CO2 working adsorption capacity of the composite material P1 with that of the NaX molecular sieve, it can be seen that the CO2 adsorption performance of the adsorbent is not reduced after hydrophobic modification by the method of the application, and still exhibits excellent CO2 working adsorption capacity, and the CO2 working adsorption capacity is better than that of the corresponding NaX molecular sieve.

[0193] 3. CO2 / N2 adsorption selectivity test

[0194] The composite materials P1-P8 and DP1-DP3 prepared in Examples 1-8 and Comparative Examples 1-3 were subjected to CO2 / N2 adsorption selectivity test, the process being as follows:

[0195] A certain mass of sample was vacuum heated at 120℃ for 3h, and the dried sample was placed in a static volumetric adsorption analyzer, and CO2 and N2 containing gas (containing 10% CO2 and 70% N2 by volume) was introduced at 40℃, and 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

[0197] Composite material CO2 / N2 adsorption selectivity P1 262 P2 259 P3 255 P4 239 P5 233 P6 229 P7 213 P8 201 DP1 180 DP2 185 DP3 177 NaX molecular sieve 187

[0198] Note: The chemical composition of the inner core of the molecular sieve in P1 is the same as that of NaX molecular sieve in Table 3

[0199] As can be seen from the data in Table 3, the core-shell structure composite materials P1-P8 prepared by the preparation method of the present application have a CO2 / N2 adsorption selectivity not less than 200 at 40℃ and 10% CO2 and 70% N2, and the selectivity of adsorbing CO2 is significantly higher than that of DP1-DP3 and NaX molecular sieve, and exhibit excellent CO2 / N2 selectivity.

[0200] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all fall within the protection scope of the present application.

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 alcohols, epoxy-containing ketones, and epoxy-containing silane coupling agents. 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; The silicon source and aluminum source are fed in the form of an aqueous solution containing both silicon and aluminum sources. The weight ratio of the modified resin, alkali, template agent, silicon source, and aluminum source is 100:(195-1560):(390-1660):(1360-6162):(315-1560). The conditions for the third reaction include: a reaction temperature of 60-120℃ and a reaction time of 6-24h; The core-shell composite material comprises: a resin shell and a molecular sieve core encapsulated within the resin shell; wherein the weight ratio of the resin shell to the molecular sieve core is 100:(300-800).

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, The modifier is selected from at least one of ethylene glycol diglycidyl ether, epichlorohydrin, epichlorohydrin, 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).

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

12. A core-shell composite material prepared by any one of claims 1-11.

13. The core-shell composite material according to claim 12, wherein, The core-shell composite material comprises: a resin shell and a molecular sieve core encapsulated 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; And / or, the water absorption of the core-shell composite material is ≤22g by weight at 40°C and 20%RH relative humidity.

14. The application of the core-shell composite material of claim 12 or 13 as a carbon dioxide adsorbent in the purification of carbon dioxide-containing flue gas.

15. The application according to claim 14, wherein, The water content in the carbon dioxide-containing flue gas is 10-50% by volume.

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