Preparation process of amine liquid purification resin for carbon capture system

Abstract

This application relates to the technical field of carbon capture, and specifically discloses a preparation process of an amine solution purification resin for a carbon capture system. The preparation process includes the following steps: S1: Mix styrene, divinylbenzene, acrylate, initiator, porogen, dispersant and water evenly, raise the temperature for reaction, cool down, perform solid-liquid separation, extract the porogen, and wash to obtain polystyrene microspheres; S2: Mix the polystyrene microspheres, chloromethyl methyl ether, Lewis acid catalyst and solvent evenly, raise the temperature for reaction, cool down, perform solid-liquid separation, and wash to obtain chloromethylated polystyrene microspheres; S3: Mix the chloromethylated polystyrene microspheres, triethylenetetramine, tetrabutylammonium bromide, antioxidant and ethanol evenly, raise the temperature for reaction, cool down, perform solid-liquid separation, wash, perform plasma treatment, soak in a silane coupling agent solution, perform solid-liquid separation, and wash to obtain the product. The purification resin prepared in this application has a good removal effect on heat stable salts in amine solution.

Description

Technical Field

[0001] The present application relates to the technical field of carbon capture, and more specifically, it relates to a preparation process of an amine solution purification resin for a carbon capture system. Background Art

[0002] As a commonly used chemical absorbent in a carbon capture system, amine solution will produce by-products such as heat-stable salts during long-term contact with complex components (such as oxygen, carbon dioxide, sulfur dioxide, nitrogen oxides, etc.) in flue gas. Especially during the carbon capture process of flue gas generated by the combustion of high-sulfur coal, due to the relatively high content of sulfur dioxide in the flue gas, a large amount of high-valence heat-stable salts such as sulfates will be generated.

[0003] The continuous increase in the concentration of heat-stable salts will cause many negative impacts on the carbon capture system. On the one hand, the carbon capture efficiency will decrease significantly; on the other hand, some heat-stable salts with strong acidity and chelating effect on metals will accelerate the corrosion of equipment, shorten the service life of equipment, and increase the maintenance cost.

[0004] To solve the problems caused by the accumulation of heat-stable salts, ion exchange technology is usually adopted. Among many purification devices, most choose functional styrene-based ion exchange resins. These resins are polymerized from styrene and divinylbenzene. The unique benzene ring and cross-linked structure endow it with good stability and mechanical strength. However, its pores are relatively narrow and fixed. Facing some high-valence complex anions, the diffusion and exchange of ions inside the resin are restricted, resulting in poor exchange effect, and then affecting the overall removal rate of heat-stable salts.

[0005] The patent application document with the publication number CN104725541A discloses a preparation method of an ion exchange resin for removing heat-stable salts in an alkanolamine solution, including adding styrene, divinylbenzene, etc. into a polymerization kettle for polymerization reaction to obtain polystyrene white balls, and then performing chloromethylation and reacting with trimethylamine to obtain fine particle resin.

[0006] In the fine particle resin in this patent application document, the formation of the pore structure only depends on the polymerization and cross-linking process of the polymer itself.

[0007] This kind of pore structure often has a smaller pore diameter and is difficult to control. And heat-stable salts often contain a variety of high-valence anions. The smaller pore diameter hinders the diffusion and entry of high-valence anions into the internal pores of the resin, resulting in the inability to fully carry out the ion exchange process and difficult to achieve an ideal exchange effect, thus affecting the overall removal rate of heat-stable salts in the amine solution. Summary of the Invention

[0008] In order to improve the removal rate of heat-stable salts in the amine solution, the present application provides a preparation process of an amine solution purification resin for a carbon capture system.

[0009] The present application provides a preparation process of an amine liquid purification resin for a carbon capture system, adopting the following technical solution:

[0010] A preparation process of an amine liquid purification resin for a carbon capture system, comprising the following steps:

[0011] S1: Mix styrene, divinylbenzene, acrylate, initiator, pore-forming agent, dispersant and water evenly, heat up to 65 - 100 °C, carry out polymerization reaction for 4 - 8 h, cool down, carry out solid-liquid separation, extract the pore-forming agent, wash and dry to obtain polystyrene microspheres;

[0012] S2: Mix polystyrene microspheres, chloromethyl methyl ether, Lewis acid catalyst and solvent evenly, heat up to 30 - 50 °C, react for 6 - 8 h, cool down, carry out solid-liquid separation, wash and dry to obtain chloromethylated polystyrene microspheres;

[0013] S3: Mix chloromethylated polystyrene microspheres, triethylenetetramine, tetrabutylammonium bromide, antioxidant and ethanol evenly, heat up to 80 - 100 °C, react for 10 - 20 h, cool down, carry out solid-liquid separation, wash and dry, after plasma treatment, immerse in a silane coupling agent solution with a pH of 8 - 10 for 2 - 4 h, carry out solid-liquid separation, wash and dry to obtain the purification resin;

[0014] The mass ratio of the styrene, divinylbenzene, acrylate and pore-forming agent is 1:(0.1 - 0.3):(0.1 - 0.15):(1 - 1.5); the pore-forming agent includes hyperbranched polyamide and dodecane.

[0015] By adopting the above technical solution, first, when acrylate copolymerizes with styrene and divinylbenzene, acrylate can participate in forming a more uniform and stable crosslinked network structure. Divinylbenzene, as a crosslinking agent, can form chemical bond connections between the molecular chains of styrene and acrylate. The reaction activity and structural characteristics of acrylate enable it to play a better regulating role in the crosslinked network, making the crosslinked network denser and more uniform. Its uniform crosslinked network can more effectively disperse stress and improve the overall mechanical properties of the microspheres. The pore-forming agents hyperbranched polyamide and dodecane form abundant nano-scale pores during the polymerization process, increasing the specific surface area of the polystyrene microspheres; the addition of dodecane further regulates the size and distribution of the pores, making the resin have an ideal specific surface area and pore size distribution. This optimized pore structure is beneficial to the diffusion of heat stable salts and improves the adsorption and exchange efficiency of the resin. Subsequently, through extraction treatment, the pore-forming agent and unreacted monomers are effectively removed, forming a uniform and stable pore structure.

[0016] Secondly, under the action of a Lewis acid catalyst, chloromethyl methyl ether is used to chloromethylate polystyrene microspheres, introducing chloromethyl groups onto the benzene ring, which provides active sites for subsequent functionalization.

[0017] Finally, the chloromethylated polystyrene microspheres react with triethylenetetramine and tetrabutylammonium bromide. The amino groups of the organic amine are introduced onto the surface of the polystyrene microspheres. Tetrabutylammonium bromide, as a phase transfer catalyst, can promote the transfer of the organic amine from the solvent phase to the resin surface, accelerating the reaction rate and enabling the reaction to proceed more fully. This not only improves the efficiency of the amination reaction but also ensures the uniform distribution of functional groups on the resin surface, which is beneficial to enhancing the overall adsorption performance and stability of the resin. Subsequently, through plasma treatment, oxygen-containing functional groups (such as hydroxyl groups, carboxyl groups, etc.) are introduced onto the resin surface, increasing the surface activity and roughness. These active groups can undergo chemical bonding with the silane coupling agent, improving the bonding strength and coverage rate of the silane coupling agent on the resin surface. The introduction of the silane coupling agent further enhances the surface chemical activity of the resin, optimizes the adsorption conditions, and improves the selectivity and efficiency of adsorption.

[0018] Preferably, the mass ratio of the polystyrene microspheres, chloromethyl methyl ether, and Lewis acid catalyst is 1: (2 - 4): (0.1 - 0.2);

[0019] Preferably, the mass ratio of the chloromethylated polystyrene microspheres, triethylenetetramine, and tetrabutylammonium bromide is 1: (1 - 3): (0.008 - 0.02).

[0020] Preferably, the solvent is dichloromethane.

[0021] Preferably, the mass ratio of the hyperbranched polyamide to dodecane is (1 - 3): (1 - 2).

[0022] Preferably, in step S1, the initiator is benzoyl peroxide, and the dosage of benzoyl peroxide is 1% - 2.5% of the total mass of styrene, divinylbenzene, and acrylate.

[0023] Preferably, the acrylate is any one of methyl methacrylate and ethyl methacrylate.

[0024] Preferably, the Lewis acid catalyst is aluminum chloride.

[0025] Preferably, the dispersant is any one of polyvinyl alcohol and gelatin, and the dosage of the dispersant in water is (4 - 8) g / L.

[0026] Preferably, the power of the plasma treatment is 50 - 100 W, and the treatment time is 5 - 15 min.

[0027] Preferably, the antioxidant is antioxidant 2246, and the dosage of antioxidant 2246 accounts for 0.5% - 2% of the mass of triethylenetetramine.

[0028] Preferably, in step S3, when adding triethylenetetramine, a step of adding triethylamine is further included, and the dosage of triethylamine is 10% - 30% of the mass of triethylenetetramine.

[0029] Preferably, the silane coupling agent solution includes 3-aminopropyltriethoxysilane, ethanol and water, the mass fraction of the silane coupling agent solution is 4% - 6%, and the mass fraction of ethanol is 20% - 40%.

[0030] Preferably, in step S1, when adding styrene, a step of adding ion-imprinted polymer A is further included.

[0031] The preparation method of the ion-imprinted polymer A includes the following steps: Mix sodium sulfate, methacrylic acid and aqueous acetonitrile solution evenly, and under an inert atmosphere, add ethylene glycol dimethacrylate and azobisisobutyronitrile and mix evenly. Heat up to 60 - 80 °C, react for 12 - 24 h, cool down, perform solid-liquid separation, washing, pulverization, acid elution, washing, and drying to obtain ion-imprinted polymer A.

[0032] The molar ratio of sodium sulfate to methacrylic acid is 1:(1.5 - 2.5); the molar ratio of ethylene glycol dimethacrylate to methacrylic acid is (3 - 5):1; the dosage of ion-imprinted polymer A is 10% - 20% of the mass of styrene.

[0033] Preferably, the dosage of azobisisobutyronitrile is 1% - 2% of the total mass of methacrylic acid and ethylene glycol dimethacrylate.

[0034] Preferably, the particle size distribution of the ion-imprinted polymer A is 10 - 100 μm.

[0035] Preferably, in step S1, when adding styrene, a step of adding ion-imprinted polymer B is further included.

[0036] The preparation method of the ion-imprinted polymer B includes the following steps: Mix sodium carbonate, acrylic acid and water evenly, and under an inert atmosphere, add pentaerythritol tetraacrylate and redox initiator and mix evenly. Heat up to 60 - 80 °C, react for 6 - 8 h, cool down, perform solid-liquid separation, washing, pulverization, acid elution, washing, and drying to obtain ion-imprinted polymer B.

[0037] The molar ratio of sodium carbonate to acrylic acid is 1:(2 - 3); the molar ratio of pentaerythritol tetraacrylate to acrylic acid is (1 - 2):1; the dosage of ion-imprinted polymer B is 5% - 10% of the mass of styrene.

[0038] Preferably, the redox initiator includes potassium persulfate and sodium bisulfite, and the mass ratio of potassium persulfate to sodium sulfite is 1:(0.5 - 1).

[0039] Preferably, the dosage of the redox initiator is 1% - 3% of the total mass of acrylic acid and pentaerythritol tetraacrylate.

[0040] Preferably, the particle size distribution of the ion-imprinted polymer B is 10 - 100 μm.

[0041] By adopting the above technical solution, by adding ion-imprinted polymer A or B, the finally prepared amine liquid purification resin has the specific recognition ability for sulfate ions or carbonate ions. The ion-imprinted polymer is formed by polymerizing a template ion (such as sulfate or carbonate) with a functional monomer and then removing the template ion. Its surface has specific recognition sites that match the shape and chemical properties of the template ion. Through mechanisms such as hydrogen bonding and electrostatic interaction, these sites can quickly capture sulfate ions or carbonate ions, significantly improving the selective adsorption performance of the resin for specific heat-stable salt ions, thereby more effectively removing sulfate ions or carbonate ion impurities in the amine liquid and improving the purity of the amine liquid.

[0042] The ion-imprinted polymer A or B is combined with polymers such as polystyrene through covalent bonds or strong physical interactions and is uniformly dispersed in the resin matrix. This combination method not only ensures the stability of the ion-imprinted polymer but also enhances the mechanical strength of the resin, enabling it to better withstand the impact and pressure of the fluid during the amine liquid purification process and extending its service life.

[0043] In addition, due to the specific adsorption of the ion-imprinted polymer A or B for sulfate ions or carbonate ions, the regeneration process can be achieved through selective elution (such as using a low-concentration alkali solution). This targeted regeneration not only improves the regeneration efficiency but also reduces the usage amount of the eluent and lowers the operating cost.

[0044] Preferably, in step S1, after the polymerization reaction starts, it further includes the step of adding modified chitosan, and the preparation method of the modified chitosan includes the following steps:

[0045] Under an inert atmosphere, dissolve chitosan in a dilute acetic acid solution, cool down to 0 - 5°C, add acetic anhydride, react for 4 - 6 h, neutralize, perform solid-liquid separation, wash, dry, then add it to N,N-dimethylformamide, and then add pyridine and trimethylchlorosilane and mix evenly. React at 20 - 30°C for 2 - 4 h, perform solid-liquid separation, wash, and dry to obtain modified chitosan;

[0046] The mass ratio of the chitosan, acetic anhydride, pyridine and trimethylchlorosilane is 10: (1.5 - 2.5): (0.75 - 1): (0.9 - 1.2); the dosage of the modified chitosan is 4% - 8% of the mass of styrene.

[0047] Preferably, the mass fraction of the dilute acetic acid solution is 2% - 4%.

[0048] Preferably, the deacetylation degree of the chitosan is 70% - 80%, and the molecular weight distribution is 80,000 - 100,000.

[0049] By adopting the above technical solution, the modified chitosan is added in the middle stage of the polymerization reaction. At this time, some polystyrene chain segments have been formed in the system. A small amount of amino groups remaining on the molecular chain of the modified chitosan can interact with the polymer chain segments, promoting chain growth and crosslinking. The rigid backbone of the modified chitosan can also provide physical support, optimizing the pore structure of the microspheres. At the same time, its surface active groups promote the formation of the crosslinking network. In the subsequent process, by controlling the acidic or alkaline conditions, the protecting groups of the modified chitosan can be selectively hydrolyzed. This controllable hydrolysis can dynamically adjust the adsorption site density of the resin, balancing the adsorption capacity and regeneration performance.

[0050] The rigid backbone structure of the modified chitosan synergistically acts with the pore-forming agent during the polymerization process to form a hierarchical pore structure (micropores - mesopores), increasing the specific surface area and providing more adsorption sites for the thermally stable salt ions, thereby enhancing the adsorption effect on the thermally stable salt.

[0051] Preferably, in step S1, when adding divinylbenzene, the step of adding triallyl isocyanurate is further included, and the dosage of the triallyl isocyanurate is 3% - 6% of the mass of styrene.

[0052] By adopting the above technical solution, the addition of triallyl isocyanurate makes the network structure of the polystyrene microspheres more complex and diverse. This complex network structure helps to improve the mechanical properties and thermal stability of the polystyrene microspheres, enabling them to maintain better morphology and performance under different environmental conditions. At the same time, during the polymerization process, the presence of triallyl isocyanurate can affect the dispersion and effect of the pore-forming agent, thus affecting the pore structure of the microspheres. An appropriate dosage of triallyl isocyanurate can make the microspheres form a more uniform and richer pore structure, increasing the specific surface area of the microspheres, and improving the adsorption capacity and loading capacity of the subsequent purification resin for the target substance.

[0053] In summary, the present application has the following beneficial effects:

[0054] 1. In this application, styrene is used as the main monomer, and divinylbenzene and diallylamine are used as auxiliaries to synthesize a three-dimensional network polymer with certain mechanical strength and flexibility. At the same time, a hyperbranched polyamide and dodecane are used as a compounding porogen to form pores with specific sizes and distributions inside the resin. After the polymerization reaction is completed, the porogen is removed, and then chloromethylation and amination treatments are carried out, greatly improving the adsorption efficiency and adsorption capacity of the purification resin.

[0055] 2. Preferably, when synthesizing polystyrene microspheres in this application, ionic imprinted polymer A or B is added, which improves the selective adsorption performance for specific thermally stable salt ions. At the same time, it can also increase the adsorption capacity of the purification resin for sulfate ions or carbonate ions, enabling the purification resin to adsorb more sulfate ions or carbonate ions per unit mass or volume, and improving the removal rate of thermally stable salts in the amine solution.

[0056] 3. Preferably, during the mid-stage of polystyrene microsphere synthesis in this application, modified chitosan is also added, which enriches the thermally stable salt adsorption sites of the subsequent purification resin, improves the adsorption capacity and adsorption efficiency of the purification resin, and ultimately improves the removal rate of thermally stable salts by the purification resin. Specific Embodiments

[0057] The following further elaborates on this application in conjunction with examples.

[0058] The raw materials of the examples and comparative examples of this application are all ordinary commercially available products unless otherwise specified.

[0059] The hyperbranched polyamide is an amino-terminated hyperbranched polyamide with a molecular weight distribution of 350 - 2200 and a purity of 99%, purchased from Wuhan Huaxiang Kejie Biotechnology Co., Ltd.;

[0060] The linear polyamide is purchased from Suzhou Huida Plastic Import and Export Co., Ltd.

[0061] Preparation Examples 1 - 3 of Ionic Imprinted Polymer A

[0062] Preparation Example 1

[0063] This preparation example provides a preparation method for ionic imprinted polymer A, including the following steps:

[0064] Add 0.1 mol of sodium sulfate and 0.15 mol of methacrylic acid into a reactor, then add a mixed solvent composed of 140 ml of acetonitrile and 60 ml of deionized water, stir and mix evenly. Under a nitrogen atmosphere, add 0.45 mol of ethylene glycol dimethacrylate and azobisisobutyronitrile, stir and mix evenly, heat up to 60 °C, react for 24 h, naturally cool to room temperature, filter by suction, and wash with acetonitrile three times. Crush the product until it completely passes through a 200-mesh sieve, then pass through a 1250-mesh sieve and take the oversize. Transfer the oversize to an acid elution container, add 550 ml of 0.2 mol / L hydrochloric acid solution, and carry out acid elution at a stirring speed of 200 rpm at room temperature. Take a small amount of eluate every 1 h to detect the sulfate ion concentration. When the change in sulfate ion concentration detected continuously twice is less than 5%, stop elution, then filter by suction, wash with a large amount of deionized water until neutral, then transfer to a vacuum drying oven at 40 °C and dry for 4 h, then heat up to 60 °C and dry to constant weight to obtain ion-imprinted polymer A.

[0065] Among them, the dosage of azobisisobutyronitrile is 2% of the total mass of methacrylic acid and ethylene glycol dimethacrylate, about 2.1 g.

[0066] Preparation Example 2

[0067] Add 0.1 mol of sodium sulfate and 0.25 mol of methacrylic acid into a reactor, then add a mixed solvent composed of 280 ml of acetonitrile and 120 ml of deionized water, stir and mix evenly. Under a nitrogen atmosphere, add 1.25 mol of ethylene glycol dimethacrylate and azobisisobutyronitrile, stir and mix evenly, heat up to 80 °C, react for 12 h, naturally cool to room temperature, filter by suction, and wash with acetonitrile three times. Crush the product until it completely passes through a 200-mesh sieve, then pass through a 1250-mesh sieve and take the oversize. Transfer the oversize to an acid elution container, add 600 ml of 0.2 mol / L hydrochloric acid solution, and carry out acid elution at a stirring speed of 200 rpm at room temperature. Take a small amount of eluate every 1 h to detect the sulfate ion concentration. When the change in sulfate ion concentration detected continuously twice is less than 5%, stop elution, then filter by suction, wash with a large amount of deionized water until neutral, then transfer to a vacuum drying oven at 40 °C and dry for 4 h, then heat up to 60 °C and dry to constant weight to obtain ion-imprinted polymer A.

[0068] Among them, the dosage of azobisisobutyronitrile is 1% of the total mass of methacrylic acid and ethylene glycol dimethacrylate, about 2.7 g.

[0069] Preparation Example 3

[0070] Add 0.1 mol of sodium sulfate and 0.2 mol of methacrylic acid to a reactor, then add a mixed solvent composed of 210 ml of acetonitrile and 90 ml of deionized water, stir and mix evenly. Under a nitrogen atmosphere, add 0.8 mol of ethylene glycol dimethacrylate and azobisisobutyronitrile, stir and mix evenly. Heat up to 70 °C and react for 18 h. Naturally cool to room temperature, filter by suction, and wash with acetonitrile 3 times. Crush the product until it completely passes through a 200-mesh sieve, then pass through a 1250-mesh sieve and take the oversize. Transfer the oversize to an acid elution container, add 570 ml of 0.2 mol / L hydrochloric acid solution, and carry out acid elution at a stirring speed of 200 rpm at room temperature. Take a small amount of eluate every 1 h to detect the sulfate ion concentration. When the change in sulfate ion concentration is less than 5% for two consecutive detections, stop elution, then filter by suction, wash with a large amount of deionized water until neutral, then transfer to a vacuum drying oven at 40 °C and dry for 4 h, then heat up to 60 °C and dry to constant weight to obtain ion-imprinted polymer A.

[0071] Among them, the dosage of azobisisobutyronitrile is 1.5% of the total mass of methacrylic acid and ethylene glycol dimethacrylate, about 2.6 g.

[0072] Preparation Examples 4 to 6 of ion-imprinted polymer B

[0073] Preparation Example 4

[0074] This preparation example provides a method for preparing ion-imprinted polymer B, which includes the following steps:

[0075] Add 0.1 mol of sodium carbonate and 0.2 mol of acrylic acid to a reactor, then add 300 ml of deionized water, stir and mix evenly. Under a nitrogen atmosphere, add 0.2 mol of pentaerythritol tetraacrylate and an oxidation-reduction initiator, stir and mix evenly. Heat up to 60 °C and react for 8 h. Naturally cool to room temperature, filter by suction, and wash with deionized water 3 times. Crush the product until it completely passes through a 200-mesh sieve, then pass through a 1250-mesh sieve and take the oversize. Transfer the oversize to an acid elution container, add 550 ml of 0.2 mol / L hydrochloric acid solution, and carry out acid elution at a stirring speed of 200 rpm at room temperature. Take a small amount of eluate every 1 h to detect the carbonate ion concentration. When the change in carbonate ion concentration is less than 5% for two consecutive detections, stop elution, then filter by suction, wash with a large amount of deionized water until neutral, then transfer to a vacuum drying oven at 40 °C and dry for 4 h, then heat up to 60 °C and dry to constant weight to obtain ion-imprinted polymer B.

[0076] Among them, the dosage of the oxidation-reduction initiator is 3% of the total mass of acrylic acid and pentaerythritol tetraacrylate. The oxidation-reduction initiator includes 1.70 g of potassium persulfate and 0.85 g of sodium bisulfite.

[0077] Preparation Example 5

[0078] This preparation example provides a method for preparing ion-imprinted polymer B, which includes the following steps:

[0079] Add 0.1 mol of sodium carbonate and 0.3 mol of acrylic acid into a reactor, then add 600 ml of deionized water, stir and mix evenly. Under a nitrogen atmosphere, add 0.6 mol of pentaerythritol tetraacrylate and a redox initiator, stir and mix evenly, heat up to 80 °C, react for 6 h, naturally cool to room temperature, filter by suction, and wash with deionized water 3 times. Crush the product until it completely passes through a 200-mesh sieve, then pass through a 1250-mesh sieve and take the oversize. Transfer the oversize to an acid elution container, add 600 ml of 0.2 mol / L hydrochloric acid solution, and carry out acid elution at a stirring speed of 200 rpm at room temperature. Take a small amount of eluate every 1 h to detect the carbonate ion concentration. When the change in carbonate ion concentration is less than 5% for two consecutive detections, stop elution, then filter by suction, wash with a large amount of deionized water until neutral, then transfer to a vacuum drying oven at 40 °C and dry for 4 h, then heat up to 60 °C and dry to constant weight to obtain ion-imprinted polymer B.

[0080] Among them, the dosage of the redox initiator is 1% of the total mass of acrylic acid and pentaerythritol tetraacrylate. The redox initiator includes 1.33 g of potassium persulfate and 1.0 g of sodium bisulfite.

[0081] Preparation Example 6

[0082] This preparation example provides a method for preparing ion-imprinted polymer B, which includes the following steps:

[0083] Add 0.1 mol of sodium carbonate and 0.25 mol of acrylic acid into a reactor, then add 500 ml of deionized water, stir and mix evenly. Under a nitrogen atmosphere, add 0.375 mol of pentaerythritol tetraacrylate and a redox initiator, stir and mix evenly, heat up to 70 °C, react for 7 h, naturally cool to room temperature, filter by suction, and wash with deionized water 3 times. Crush the product until it completely passes through a 200-mesh sieve, then pass through a 1250-mesh sieve and take the oversize. Transfer the oversize to an acid elution container, add 570 ml of 0.2 mol / L hydrochloric acid solution, and carry out acid elution at a stirring speed of 200 rpm at room temperature. Take a small amount of eluate every 1 h to detect the carbonate ion concentration. When the change in carbonate ion concentration is less than 5% for two consecutive detections, stop elution, then filter by suction, wash with a large amount of deionized water until neutral, then transfer to a vacuum drying oven at 40 °C and dry for 4 h, then heat up to 60 °C and dry to constant weight to obtain ion-imprinted polymer B.

[0084] Among them, the dosage of the redox initiator is 2% of the total mass of acrylic acid and pentaerythritol tetraacrylate, and the redox initiator includes 1.94 g of potassium persulfate and 1.94 g of sodium bisulfite.

[0085] Preparation Examples 7-9 Modified Chitosan

[0086] Preparation Example 7

[0087] This preparation example provides a method for preparing modified chitosan, which includes the following steps:

[0088] Under a nitrogen atmosphere, 20 g of chitosan and 100 g of dilute acetic acid with a mass fraction of 2% are added to a reactor, and stirred until the chitosan is completely dissolved. Then it is transferred to an ice-salt bath, and the temperature is maintained between 0 and 5 °C. 3 g of acetic anhydride is slowly added, and the reaction is carried out for 4 h. The pH is adjusted to neutral with 5% ammonia water by mass, centrifuged, washed 3 times with deionized water, dried to constant weight at 50 °C, then added to 150 g of N,N-dimethylformamide, stirred and mixed evenly. Then 1.5 g of pyridine and 1.8 g of trimethylchlorosilane are added and stirred and mixed evenly. After reacting at 20 °C for 4 h, methanol is added until no precipitation occurs, filtered, washed 3 times with absolute ethanol, transferred to a vacuum drying oven and dried to constant weight at 50 °C to obtain modified chitosan.

[0089] Among them, the deacetylation degree of chitosan is 70% - 80%, and the molecular weight distribution is 80,000 - 100,000.

[0090] Preparation Example 8

[0091] This preparation example provides a method for preparing modified chitosan, which includes the following steps:

[0092] Under a nitrogen atmosphere, 20 g of chitosan and 100 g of dilute acetic acid with a mass fraction of 3% are added to a reactor, and stirred until the chitosan is completely dissolved. Then it is transferred to an ice-salt bath, and the temperature is maintained between 0 and 5 °C. 5 g of acetic anhydride is slowly added, and the reaction is carried out for 5 h. The pH is adjusted to neutral with 5% ammonia water by mass, centrifuged, washed 3 times with deionized water, dried to constant weight at 50 °C, then added to 150 g of N,N-dimethylformamide, stirred and mixed evenly. Then 2 g of pyridine and 2.4 g of trimethylchlorosilane are added and stirred and mixed evenly. After reacting at 30 °C for 2 h, methanol is added until no precipitation occurs, filtered, washed 3 times with absolute ethanol, transferred to a vacuum drying oven and dried to constant weight at 50 °C to obtain modified chitosan.

[0093] Among them, the deacetylation degree of chitosan is 70% - 80%, and the molecular weight distribution is 80,000 - 100,000.

[0094] Preparation Example 9

[0095] This preparation example provides a method for preparing modified chitosan, which comprises the following steps:

[0096] Under a nitrogen atmosphere, 20 g of chitosan and 100 g of dilute acetic acid with a mass fraction of 4% are added to a reactor, and stirred until the chitosan is completely dissolved. Then it is transferred to an ice-salt bath, and the temperature is maintained between 0 and 5 °C. 4 g of acetic anhydride is slowly added, and the reaction is carried out for 6 h. The pH is adjusted to neutral with ammonia water with a mass fraction of 5%. After centrifugal separation, it is washed 3 times with deionized water, dried to a constant weight at 50 °C, then added to 150 g of N,N-dimethylformamide, stirred and mixed evenly. Then 1.8 g of pyridine and 2.2 g of trimethylchlorosilane are added and stirred and mixed evenly. At 25 °C, after reacting for 3.5 h, methanol is added until no precipitate is formed. After filtration, it is rinsed 3 times with absolute ethanol, transferred to a vacuum drying oven and dried to a constant weight at 50 °C to obtain modified chitosan.

[0097] Among them, the degree of deacetylation of chitosan is 70% - 80%, and the molecular weight distribution is 80,000 - 100,000.

[0098] Example 1

[0099] This example provides a preparation process for amine liquid purification resin for a carbon capture system, which comprises the following steps:

[0100] S1: After mixing 100 g of styrene, 10 g of divinylbenzene, 10 g of ethyl methacrylate, 3 g of benzoyl peroxide, 50 g of terminal amino hyperbranched polyamide and 50 g of dodecane evenly, an organic phase is obtained; 4 g of polyvinyl alcohol and 1000 ml of deionized water are mixed evenly to obtain an aqueous phase; the organic phase is slowly dropped into the aqueous phase, and continuously stirred at a speed of 200 rpm. After the addition is completed, the temperature is raised to 65 °C, and the polymerization reaction is carried out for 8 h. It is naturally cooled to room temperature, and vacuum filtered to collect the filter cake;

[0101] Then the filter cake is immersed in a container filled with petroleum ether, the ultrasonic equipment is turned on to assist stirring, the ultrasonic power is set to 200 W, the stirring speed is 200 rpm, and stirring is continued for 20 min, followed by vacuum filtration; then it is immersed again in a new container filled with petroleum ether, the ultrasonic equipment is turned on to assist stirring, the ultrasonic power is set to 200 W, the stirring speed is 200 rpm, and stirring is continued for 20 min, followed by vacuum filtration;

[0102] The filter cake treated with petroleum ether was immersed in a container filled with N,N-dimethylformamide. Similarly, an ultrasonic device was turned on to assist stirring. The ultrasonic power was set at 200 W, the stirring speed was 200 rpm, and stirring was continued for 20 min. Then, vacuum filtration was carried out. After that, it was immersed again in a new container filled with N,N-dimethylformamide. Similarly, an ultrasonic device was turned on to assist stirring. The ultrasonic power was set at 200 W, the stirring speed was 200 rpm, and stirring was continued for 20 min. Then, vacuum filtration was carried out;

[0103] After that, it was washed 3 times with deionized water. After vacuum filtration, it was transferred to a vacuum drying oven and dried to a constant weight at 40 °C to obtain polystyrene microspheres;

[0104] S2: 100 g of polystyrene microspheres and 300 ml of dichloromethane were stirred and mixed evenly in a reactor. Then, 200 g of chloromethyl methyl ether was added and stirred and mixed evenly. Then, aluminum chloride was added in 5 portions, with an interval of 10 - 15 min between each addition, and the amount added each time was 2 g. The reaction temperature was controlled at 30 °C. After stirring and reacting for 8 h, it was naturally cooled to room temperature. It was neutralized with an ammonia water solution with a mass fraction of 5%. After standing and separating layers, the organic phase was taken, washed with deionized water until neutral, and then vacuum filtered. It was transferred to a vacuum drying oven and dried to a constant weight at 40 °C to obtain chloromethylated polystyrene microspheres;

[0105] S3: 100 g of chloromethylated polystyrene microspheres, 100 g of triethylenetetramine, 0.8 g of tetrabutylammonium bromide, 0.5 g of antioxidant 2246, and 500 ml of ethanol were stirred and mixed evenly. The temperature was raised to 80 °C and the reaction was carried out for 20 h. Then, it was naturally cooled to room temperature. Vacuum filtration was carried out, and it was washed 2 times with ethanol. It was transferred to a vacuum drying oven and dried to a constant weight at 40 °C. Then, it was evenly spread on the sample stage of a plasma treatment device. The nitrogen gas flow rate was 30 sccm, the power was 50 W, and the treatment was carried out for 15 min. Then, it was immersed in a prepared 3-aminopropyltriethoxysilane solution with a pH between 8 - 8.5 and a mass fraction of 4% and soaked for 4 h. Vacuum filtration was carried out, and it was washed 2 times with ethanol. It was transferred to a vacuum drying oven and dried to a constant weight at 40 °C to obtain a purification resin.

[0106] Among them, the 3-aminopropyltriethoxysilane solution includes 3-aminopropyltriethoxysilane, ethanol, and water, and the mass fraction of ethanol is 20%.

[0107] Example 2

[0108] S1: After uniformly mixing 100 g of styrene, 30 g of divinylbenzene, 15 g of methyl methacrylate, 1.45 g of benzoyl peroxide, 90 g of amino-terminated hyperbranched polyamide, and 60 g of dodecane, an organic phase is obtained; 8 g of gelatin and 1000 ml of deionized water are uniformly mixed to obtain an aqueous phase; the organic phase is slowly added dropwise to the aqueous phase, and stirring is continuously carried out at a speed of 200 rpm. After the addition is completed, the temperature is raised to 100 °C, and a polymerization reaction is carried out for 4 h. It is naturally cooled to room temperature, and vacuum filtration is carried out to collect the filter cake;

[0109] Then, the filter cake is immersed in a container filled with petroleum ether, and an ultrasonic device is turned on to assist stirring. The ultrasonic power is set to 200 W, the stirring speed is 200 rpm, and stirring is continuously carried out for 30 min, followed by vacuum filtration; then it is immersed again in a new container filled with petroleum ether, an ultrasonic device is turned on to assist stirring, the ultrasonic power is set to 200 W, the stirring speed is 200 rpm, and stirring is continuously carried out for 30 min, followed by vacuum filtration;

[0110] The filter cake treated with petroleum ether is immersed in a container filled with N,N-dimethylformamide. Similarly, an ultrasonic device is turned on to assist stirring. The ultrasonic power is set to 200 W, the stirring speed is 200 rpm, and stirring is continuously carried out for 30 min, followed by vacuum filtration; then it is immersed again in a new container filled with N,N-dimethylformamide. Similarly, an ultrasonic device is turned on to assist stirring, the ultrasonic power is set to 200 W, the stirring speed is 200 rpm, and stirring is continuously carried out for 30 min, followed by vacuum filtration;

[0111] After that, it is washed 3 times with deionized water. After vacuum filtration, it is transferred to a vacuum drying oven and dried to a constant weight at 40 °C to obtain polystyrene microspheres;

[0112] S2: 100 g of polystyrene microspheres and 300 ml of dichloromethane are stirred and mixed uniformly in a reactor, then 400 g of chloromethyl methyl ether is added and stirred and mixed uniformly. Then, aluminum chloride is added in 5 portions, with an interval of 10 - 15 min between each addition, and the amount added each time is 4 g. The reaction temperature is controlled at 50 °C. After stirring and reacting for 6 h, it is naturally cooled to room temperature, neutralized with an ammonia water solution with a mass fraction of 5%, the organic phase is taken after standing and separating layers, washed with deionized water until neutral, vacuum filtered, transferred to a vacuum drying oven, and dried to a constant weight at 40 °C to obtain chloromethylated polystyrene microspheres;

[0113] S3: Stir and mix 100 g of chloromethylated polystyrene microspheres, 300 g of triethylenetetramine, 30 g of triethylamine, 2 g of tetrabutylammonium bromide, 2 g of antioxidant 2246, and 500 ml of ethanol evenly. Heat up to 100 °C, react for 10 h, cool naturally to room temperature, perform vacuum filtration, wash twice with ethanol, transfer to a vacuum drying oven, dry to constant weight at 40 °C, then evenly spread on the sample stage of the plasma treatment equipment. With a nitrogen gas flow rate of 30 sccm and a power of 100 W, treat for 5 min, then immerse in the prepared 3-aminopropyltriethoxysilane solution with a pH between 9.5 and 10 and a mass fraction of 6%, soak for 2 h, perform vacuum filtration, wash twice with ethanol, transfer to a vacuum drying oven, dry to constant weight at 40 °C to obtain the purified resin.

[0114] Among them, the 3-aminopropyltriethoxysilane solution includes 3-aminopropyltriethoxysilane, ethanol, and water, and the mass fraction of ethanol is 40%.

[0115] Example 3

[0116] S1: After mixing 100 g of styrene, 20 g of divinylbenzene, 12 g of methyl methacrylate, 2.6 g of benzoyl peroxide, 80 g of terminal amino hyperbranched polyamide, and 60 g of dodecane evenly, an organic phase is obtained; mix 6 g of polyvinyl alcohol and 1000 ml of deionized water evenly to obtain an aqueous phase; slowly drip the organic phase into the aqueous phase, and continuously stir at a speed of 200 rpm. After adding, heat up to 85 °C, perform a polymerization reaction for 6 h, cool naturally to room temperature, perform vacuum filtration, and collect the filter cake;

[0117] Then immerse the filter cake in a container filled with petroleum ether, turn on the ultrasonic equipment to assist stirring, set the ultrasonic power to 200 W, the stirring speed to 200 rpm, continuously stir for 25 min, and perform vacuum filtration; then immerse again in a new container filled with petroleum ether, turn on the ultrasonic equipment to assist stirring, set the ultrasonic power to 200 W, the stirring speed to 200 rpm, continuously stir for 25 min, and perform vacuum filtration;

[0118] Immerse the filter cake treated with petroleum ether in a container filled with N,N-dimethylformamide, also turn on the ultrasonic equipment to assist stirring, set the ultrasonic power to 200 W, the stirring speed to 200 rpm, continuously stir for 25 min, and perform vacuum filtration; then immerse again in a new container filled with N,N-dimethylformamide, also turn on the ultrasonic equipment to assist stirring, set the ultrasonic power to 200 W, the stirring speed to 200 rpm, continuously stir for 25 min, and perform vacuum filtration;

[0119] After that, wash 3 times with deionized water, perform vacuum filtration, then transfer to a vacuum drying oven, dry to constant weight at 40 °C to obtain polystyrene microspheres;

[0120] S2: Stir and mix 100 g of polystyrene microspheres and 300 ml of dichloromethane evenly in a reactor, then add 300 g of chloromethyl methyl ether and stir to mix evenly. Then add aluminum chloride in 5 portions, with an interval of 10 - 15 min between each addition, and the amount added each time is 3 g. Control the reaction temperature at 40 °C, stir and react for 7 h, then naturally cool to room temperature. Neutralize with an ammonia water solution with a mass fraction of 5%, let it stand for layering and take the organic phase, wash with deionized water until neutral, filter by vacuum suction, transfer to a vacuum drying oven, and dry at 40 °C until constant weight to obtain chloromethylated polystyrene microspheres;

[0121] S3: Stir and mix 100 g of chloromethylated polystyrene microspheres, 200 g of triethylenetetramine, 60 g of triethylamine, 1.2 g of tetrabutylammonium bromide, 1.5 g of antioxidant 2246 and 500 ml of ethanol evenly, heat up to 90 °C, react for 16 h, naturally cool to room temperature, filter by vacuum suction, wash with ethanol 2 times, transfer to a vacuum drying oven, dry at 40 °C until constant weight, then evenly spread on the sample stage of the plasma treatment equipment, with a nitrogen gas flow rate of 30 sccm, a power of 100 W, treat for 10 min, then immerse in a prepared 3 - aminopropyltriethoxysilane solution with a pH between 8.5 - 9.5 and a mass fraction of 5%, soak for 3 h, filter by vacuum suction, wash with ethanol 2 times, transfer to a vacuum drying oven, dry at 40 °C until constant weight to obtain the purification resin.

[0122] Among them, the 3 - aminopropyltriethoxysilane solution includes 3 - aminopropyltriethoxysilane, ethanol and water, and the mass fraction of ethanol is 30%.

[0123] Example 4

[0124] The difference between this example and Example 3 is that:

[0125] In step S1, when adding styrene, 10 g of ion - imprinted polymer A is also added;

[0126] In step S3, the dosage of triethylamine is 40 g;

[0127] The ion - imprinted polymer A comes from Preparation Example 1.

[0128] Others are the same as Example 3.

[0129] Example 5

[0130] The difference between this example and Example 4 is that:

[0131] In step S1, when adding styrene, 15 g of ion - imprinted polymer A is also added;

[0132] The ion - imprinted polymer A comes from Preparation Example 2.

[0133] The rest is the same as in Example 4.

[0134] Example 6

[0135] The difference between this example and Example 5 lies in:

[0136] In step S1, when adding styrene, 15 g of ion-imprinted polymer A and 5 g of ion-imprinted polymer B were also added;

[0137] Ion-imprinted polymer A is from Preparation Example 3; ion-imprinted polymer B is from Preparation Example 4.

[0138] The rest is the same as in Example 5.

[0139] Example 7

[0140] The difference between this example and Example 6 lies in:

[0141] In step S1, when adding styrene, 15 g of ion-imprinted polymer A and 10 g of ion-imprinted polymer B were also added;

[0142] Ion-imprinted polymer A is from Preparation Example 3; ion-imprinted polymer B is from Preparation Example 5.

[0143] The rest is the same as in Example 6.

[0144] Example 8

[0145] The difference between this example and Example 7 lies in:

[0146] S1: Mix 100 g of styrene, 15 g of ion-imprinted polymer A, 10 g of ion-imprinted polymer B, 20 g of divinylbenzene, 12 g of methyl methacrylate, 2.6 g of benzoyl peroxide, 80 g of amino-terminated hyperbranched polyamide, and 60 g of dodecane evenly to obtain an organic phase; mix 6 g of polyvinyl alcohol and 1000 ml of deionized water evenly to obtain an aqueous phase; slowly drop the organic phase into the aqueous phase and continuously stir at a speed of 200 rpm. After the addition is completed, heat up to 85 °C. When the polymerization reaction is carried out for 3 h, add 4 g of modified chitosan, maintain 85 °C, continue the reaction for 3 h, then naturally cool to room temperature, and perform vacuum filtration to collect the filter cake;

[0147] Then immerse the filter cake in a container filled with petroleum ether, turn on the ultrasonic device to assist stirring, set the ultrasonic power to 200 W, the stirring speed to 200 rpm, continuously stir for 25 min, and perform vacuum filtration; immerse it again in a new container filled with petroleum ether, turn on the ultrasonic device to assist stirring, set the ultrasonic power to 200 W, the stirring speed to 200 rpm, continuously stir for 25 min, and perform vacuum filtration;

[0148] The filter cake treated with petroleum ether was immersed in a container filled with N,N-dimethylformamide. The ultrasonic device was also turned on to assist stirring. The ultrasonic power was set at 200 W, the stirring speed was 200 rpm, and stirring was continued for 25 min, followed by vacuum filtration. It was then immersed again in a new container filled with N,N-dimethylformamide. The ultrasonic device was also turned on to assist stirring. The ultrasonic power was set at 200 W, the stirring speed was 200 rpm, and stirring was continued for 25 min, followed by vacuum filtration.

[0149] After that, it was washed 3 times with deionized water. After vacuum filtration, it was transferred to a vacuum drying oven and dried to a constant weight at 40 °C to obtain polystyrene microspheres.

[0150] Ion-imprinted polymer A was from Preparation Example 3; ion-imprinted polymer B was from Preparation Example 6; modified chitosan was from Preparation Example 7.

[0151] Other conditions were the same as in Example 7.

[0152] Example 9

[0153] The difference between this example and Example 8 was that:

[0154] In step S1, the amount of modified chitosan used was 8 g, and the modified chitosan was from Preparation Example 8.

[0155] Other conditions were the same as in Example 8.

[0156] Example 10

[0157] The difference between this example and Example 9 was that:

[0158] In step S1, the amount of modified chitosan used was 6 g, and the modified chitosan was from Preparation Example 9.

[0159] In step S1, when adding divinylbenzene, 3 g of triallyl isocyanurate was also added.

[0160] Other conditions were the same as in Example 9.

[0161] Example 11

[0162] The difference between this example and Example 10 was that:

[0163] In step S1, when adding divinylbenzene, 6 g of triallyl isocyanurate was also added.

[0164] Other conditions were the same as in Example 10.

[0165] Comparative Example 1

[0166] The difference between this comparative example and Example 1 was that:

[0167] An equal mass of linear polyamide was used to replace the amino-terminated hyperbranched polyamide;

[0168] Others are the same as in Example 1.

[0169] Comparative Example 2

[0170] The difference between this comparative example and Example 1 is that:

[0171] Methyl methacrylate was not added.

[0172] Others are the same as in Example 1.

[0173] Comparative Example 3

[0174] The difference between this comparative example and Example 1 is that:

[0175] S3: Stir and mix 100 g of chloromethylated polystyrene microspheres, 300 g of triethylenetetramine, 90 g of triethylamine, 2 g of tetrabutylammonium bromide, 2 g of antioxidant 2246 and 500 ml of ethanol evenly, heat up to 100 °C, react for 10 h, cool naturally to room temperature, carry out vacuum filtration, wash with ethanol twice, transfer to a vacuum drying oven, and dry to constant weight at 40 °C to obtain the purified resin.

[0176] Others are the same as in Example 1.

[0177] Performance detection

[0178] (1) Detection object: For a coal-fired power plant, for the amine solution after flue gas treatment after high-sulfur coal combustion, test the removal rate of heat-stable salts after treatment with the purified resins in Examples 1 to 11 and Comparative Examples 1 to 3.

[0179] In the flue gas treatment system, on the circulation pipeline between the absorption tower and the regeneration tower, a sampling point is set at 1 / 3 of the pipeline length from the outlet of the absorption tower. The amine solution at this position can better reflect the properties and heat-stable salt content of the overall amine solution. Sampling starts after the coal-fired power plant has been operating stably for 24 hours. Samples are collected every 2 hours, 2000 mL each time, and a total of 5 times are collected. The 5 collected samples are fully mixed to obtain a representative amine solution sample. The collected amine solution is filtered using a filter membrane with a pore size of 0.45 μm to avoid interference from impurities in subsequent detection and purification experiments, and an amine solution sample to be purified is obtained, with a density of about 1.13 g / cm 3 ³. The initial mass concentration of heat-stable salts in the amine solution sample is detected using an ion chromatograph, and the detection results are shown in Table 1.

[0180] Table 1 Detection data of the initial mass concentration of heat-stable salts in the amine solution

[0181]

[0182] (2) Purification treatment: Pass the amine liquid sample through the ion exchange columns filled with the purification resins prepared in Examples 1 - 11 and Comparative Examples 1 - 3, which are marked, at a flow rate of 7 BV / h (bed volume per hour). Collect the purified amine liquid flowing out from each ion exchange column, ensuring no external contamination during the collection process. Analyze the purified amine liquid using an ion chromatograph to determine the concentration of each thermally stable salt anion. Conduct 3 parallel experiments for each experiment, using a newly filled ion exchange column each time. Take the average value as the result and calculate the removal rate of thermally stable salts in the amine liquid sample. The test results are shown in Table 2. Among them, record the operating temperature, pressure, and other parameters of each ion exchange column, and try to keep the operating conditions of all columns consistent. The temperature can be controlled at 40 ± 2 °C, and the pressure is maintained at 0.2 ± 0.01 MPa.

[0183] Table 2 Performance test data of amine liquid purification resins in Examples 1 - 11 and Comparative Examples 1 - 3

[0184]

[0185] (3) Fill Example 9 and Example 11 into different ion exchange columns respectively, and conduct purification operations on the amine liquid sample at a flow rate of 7 BV / h (bed volume per hour) and recycle it 10 times. Each time, use a new amine liquid sample, and purify the ion exchange column after each use and then recycle it. Among them, the purification operation is as follows: Pass sodium hydroxide with a mass fraction of 3% three times the volume of the purification resin in the ion exchange column for 30 minutes, and then rinse with deionized water until neutral. Record the operating temperature, pressure, and other parameters of each ion exchange column, and try to keep the operating conditions of all columns consistent. The temperature can be controlled at 40 ± 2 °C, and the pressure is maintained at 0.2 ± 0.01 MPa. Detect and record the total removal rate of thermally stable salts and the change in the appearance of the purification resin for the 1st and 10th times. The results are shown in Table 3.

[0186] Table 3 Performance test data of amine liquid purification resins after recycling in Example 9 and Example 11

[0187]

[0188] Based on the data in Tables 1 - 3, the following analysis is carried out:

[0189] Through comprehensive analysis, when the purification resin in Examples 1 - 11 is used for the amine liquid sample, after purification treatment, the mass concentration of the total amount of thermally stable salts in the amine liquid is not higher than 0.85%, the mass concentration of SO4 2- is not higher than 0.24%, the mass concentration of SO3 2- is not higher than 0.20%, the mass concentration of S2O3 2- is not higher than 0.07%, and the mass concentration of CO3 2-The mass concentration content is not higher than 0.14%.

[0190] It can be seen from Example 1 and Comparative Examples 1-3 that when synthesizing polystyrene microspheres, by using amino-terminated hyperbranched polyamide to compound with the pore-forming agent, more adsorption sites and diffusion channels are provided for the thermally stable salt ions, greatly increasing the contact area between the purification resin and the thermally stable salt, thereby significantly improving the removal rate of the thermally stable salt.

[0191] When synthesizing polystyrene microspheres, by adding methyl methacrylate or ethyl methacrylate, the polymer main chain structure of the polystyrene microspheres is optimized. According to the principle of similar solubility, the affinity between the polymer with polar ester groups and the thermally stable salt is enhanced, so that the adsorption and removal ability of the resin for the thermally stable salt is improved.

[0192] In the subsequent preparation process of Step 3, by using plasma treatment and soaking in a silane coupling agent solution, a molecular chain containing functional groups such as siloxy groups is grafted on the resin surface. The siloxy groups can form chemical bonds or complexes with certain ions in the thermally stable salt, enhancing the adsorption of the thermally stable salt; in addition, the grafted silane coupling agent molecular chain can change the hydrophilicity and hydrophobicity of the resin surface, making it more conducive to the interaction with the thermally stable salt ions, thereby improving the removal efficiency of the thermally stable salt.

[0193] It can be seen from Examples 1-3 that by optimizing the component ratios and reaction conditions, the removal rate of the thermally stable salt in the amine solution is maintained within a good range.

[0194] It can be seen from Examples 3-8 that by introducing ion-imprinted polymer A and ion-imprinted polymer B, the adsorption function and active sites of the purification resin are enriched. They cooperate with the resin matrix to form a more powerful adsorption system. This system can not only specifically remove sulfate and carbonate thermally stable salts, but also have a certain adsorption effect on other thermally stable salt ions, improving the overall removal ability of the resin for different types of thermally stable salt ions, and further improving the removal rate of the total amount of thermally stable salts in the amine solution.

[0195] It can be seen from Examples 8-11 that by adding modified chitosan in the middle stage of polystyrene microsphere synthesis, the modified chitosan can be fully combined with the polystyrene microspheres to form a dispersion system with a special microstructure, increasing the specific surface area and providing more adsorption sites for the thermally stable salt ions, thereby enhancing the adsorption effect on the thermally stable salt.

[0196] When synthesizing polystyrene microspheres, adding triallyl isocyanurate can significantly improve the mechanical strength and hardness of polystyrene microspheres. Through the observation of the ion exchange column during the experiment, under the same operating conditions, for the column filled with the purification resin prepared by adding triallyl isocyanurate, no obvious resin breakage or deformation occurred during the long-term operation, making it less likely to be damaged or deformed during subsequent applications, enabling it to maintain a good shape and performance under different environmental conditions, and improving the adsorption stability and adsorption efficiency of the subsequent purification resin.

[0197] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A process for preparing an amine liquid purification resin for a carbon capture system, characterized in that: The steps include: S1: Styrene, divinylbenzene, acrylate, initiator, porogen, dispersant and water are mixed evenly, heated to 65-100°C, polymerized for 4-8 hours, cooled, solid-liquid separated, porogen extracted, washed and dried to obtain polystyrene microspheres; S2: uniformly mix polystyrene microspheres, chloromethyl methyl ether, Lewis acid catalyst and solvent, heat to 30-50°C, react for 6-8h, cool, separate solid from liquid, wash and dry to obtain chloromethylated polystyrene microspheres; S3: uniformly mix chloromethylated polystyrene microspheres, triethylenetetramine, tetrabutylammonium bromide, antioxidant and ethanol, heat to 80-100°C, react for 10-20 hours, cool, separate solid from liquid, wash, dry, and after plasma treatment, immerse in a silane coupling agent solution with a pH of 8-10 for 2-4 hours, separate solid from liquid, wash, and dry to obtain a purification resin; The mass ratio of styrene, divinylbenzene, acrylate and porogen is 1:(0.1-0.3):(0.1-0.15):(1-1.5); the porogen includes hyperbranched polyamide and dodecane.

2. The process for preparing the amine liquid purification resin for carbon capture system according to claim 1, characterized in that: The mass ratio of the polystyrene microspheres, chloromethyl methyl ether and Lewis acid catalyst is 1:(2-4):(0.1-0.2).

3. The process for preparing the amine liquid purification resin for carbon capture system according to claim 2, characterized in that: The mass ratio of the chloromethylated polystyrene microspheres to triethylenetetramine and tetrabutylammonium bromide is 1:(1-3):(0.008-0.02).

4. The process for preparing the amine liquid purification resin for carbon capture system according to claim 1, characterized in that: The mass ratio of the hyperbranched polyamide to dodecane is (1-3):(1-2).

5. The process for preparing the amine liquid purification resin for carbon capture system according to claim 3, characterized in that: In step S3, when adding triethylenetetramine, the step of adding triethylamine is also included, and the amount of triethylamine used is 10% to 30% of the mass of triethylenetetramine.

6. The process for preparing the amine liquid purification resin for carbon capture system according to claim 1, characterized in that: The silane coupling agent solution comprises 3-aminopropyltriethoxysilane, ethanol and water. The mass fraction of the silane coupling agent solution is 4% to 6%, and the mass fraction of the ethanol is 20% to 40%.

7. The process for preparing the amine liquid purification resin for carbon capture system according to claim 1, characterized in that: In step S1, when adding styrene, the step of adding ion-imprinted polymer A is also included. The preparation method of the ion-imprinted polymer A comprises the following steps: after uniformly mixing sodium sulfate, methacrylic acid and acetonitrile aqueous solution, adding ethylene glycol dimethacrylate and azobisisobutyronitrile in an inert atmosphere and uniformly mixing, heating to 60-80° C., reacting for 12-24 hours, cooling, solid-liquid separation, washing, crushing, acid eluting, washing, and drying to obtain the ion-imprinted polymer A; The molar ratio of sodium sulfate to methacrylic acid is 1:(1.5-2.5); the molar ratio of ethylene glycol dimethacrylate to methacrylic acid is (3-5):1; and the amount of the ion-imprinted polymer A is 10%-20% of the mass of styrene.

8. The process for preparing the amine liquid purification resin for carbon capture system according to claim 1, characterized in that: In step S1, when adding styrene, the step of adding ion-imprinted polymer B is also included; The preparation method of the ion-imprinted polymer B comprises the following steps: after sodium carbonate, acrylic acid and water are uniformly mixed, pentaerythritol tetraacrylate and an oxidation-reduction initiator are added and mixed uniformly under an inert atmosphere, the temperature is raised to 60-80° C., reacted for 6-8 hours, cooled, solid-liquid separation, washing, crushing, acid elution, washing, and drying to obtain the ion-imprinted polymer B; The molar ratio of sodium carbonate to acrylic acid is 1:(2-3); the molar ratio of pentaerythritol tetraacrylate to acrylic acid is (1-2):1; and the amount of the ion-imprinted polymer B is 5%-10% of the mass of styrene.

9. The process for preparing the amine liquid purification resin for carbon capture system according to claim 1, characterized in that: In step S1, after the polymerization reaction starts, a step of adding modified chitosan is also included. The preparation method of the modified chitosan includes the following steps: Under an inert atmosphere, chitosan is dissolved in a dilute acetic acid solution, cooled to 0-5°C, acetic anhydride is added, reacted for 4-6 hours, neutralized, solid-liquid separated, washed, dried, added to N,N-dimethylformamide, and then pyridine and trimethylsilyl chloride are added and mixed evenly, reacted at 20-30°C for 2-4 hours, solid-liquid separated, washed, and dried to obtain modified chitosan; The mass ratio of chitosan, acetic anhydride, pyridine and trimethylchlorosilane is 10: (1.5-2.5): (0.75-1): (0.9-1.2); the amount of modified chitosan is 4%-8% of the mass of styrene.

10. The process for preparing the amine liquid purification resin for carbon capture system according to claim 1, characterized in that: In step S1, when adding divinylbenzene, the step of adding triallyl isocyanurate is also included, and the amount of triallyl isocyanurate is 3% to 6% of the mass of styrene.

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