A crystallization control agent for a water-based liquid-solid phase CO2 capture system, and a preparation method and application thereof

Abstract

The application provides a crystallization control agent for a water-based liquid-solid phase change CO2 trapping system and a preparation method and application thereof, and relates to the technical field of CO2 trapping. The crystallization control agent is a steric alkylated fatty amine with an asymmetric structure, which is prepared by taking an alkyl amine as raw material, and through a nucleophilic substitution reaction and separation and purification. The prepared steric alkylated fatty amine with an asymmetric structure has a large polar cosolvent property, is compounded with a symmetric structure steric alkylated ethylenediamine with strong hydrophobic characteristics, and is applied to the water-based liquid-solid phase change CO2 trapping system, so that the formation and growth of carbamate crystals in the CO2 trapping process can be effectively controlled, and the crystallization process is controllable, the energy consumption for desorption is low, and the cyclic stability is good, and the industrial application prospect is wide.

Description

Technical Field

[0001] This invention relates to the field of organic amine CO2 capture technology, and in particular to a crystallization control agent for an aqueous liquid-solid phase change CO2 capture system, its preparation method, and its application. Background Technology

[0002] The massive carbon dioxide emissions from fossil fuel combustion exacerbate the greenhouse effect and have become a major challenge for global environmental governance. Against this backdrop, developing efficient CO2 capture technologies has become a crucial aspect of industrial emission reduction. Among existing carbon capture technologies, organic amine chemical absorption has been widely used in industrial flue gas treatment due to its advantages such as fast absorption rate, large absorption capacity, and recyclability. However, problems such as the inability to synergistically enhance the absorption and desorption capacities of traditional monoamine absorbents and the excessively high energy consumption of the desorption and regeneration process severely restrict the large-scale application and industrial promotion of this technology.

[0003] To address the aforementioned issues, paper 200710011508.1 proposed a composite decarbonization solution for recovering CO2 from waste gas. This solution employs a combination of fast-reaction-rate amines and slow-reaction-rate amines, with the addition of polyol ethers to enhance selective CO2 absorption. Sodium vanadate is used as a corrosion inhibitor, and sodium acetate and copper acetate as antioxidants. This composite decarbonization solution exhibits excellent overall CO2 absorption-desorption performance.

[0004] CN 107261766 A discloses a flue gas decarbonization composition, its preparation method, and a flue gas decarbonization method. The composition uses diazabicyclooctane as the main absorbent, and adds one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and triethylenediamine as activators, while also incorporating antioxidants and corrosion inhibitors. Although this absorbent has a good CO2 removal effect, its recirculation performance is still insufficient.

[0005] CN 114699899 A discloses a hydroxyalkylpiperazine-based composite organic amine carbon scavenger. This carbon scavenger uses hydroxyalkylpiperazine and aminoalkylpiperazine, which have steric hindrance effects, as the main absorbents, and is compounded with primary / secondary amino alcohol amines, bis-tertiary amino alicyclic amines, and various additives. Utilizing the synergistic effect of different amino functional groups, it exhibits good overall CO2 absorption-desorption performance.

[0006] The carbon capture agents based on the traditional homogeneous absorption process mentioned above have improved regeneration performance to some extent, but have not yet reduced it to an industrially acceptable level.

[0007] CN 120437788 A discloses a piperazine-based sterically hindered liquid-solid phase change carbon capture agent and its preparation method. This method achieves efficient liquid-solid separation of CO2 absorption products in an aqueous system, exhibiting significant energy-saving advantages and good stability. However, the presence of tertiary amine groups weakens the basicity and reactivity of the amine molecules, thereby significantly inhibiting the CO2 capture capacity and capture rate.

[0008] To address the problems of existing technologies, this invention provides a sterically hindered liquid-solid phase carbon scavenger with excellent overall scavenging performance, outstanding energy-saving advantages, and controllable reaction crystallization. Summary of the Invention

[0009] To address the problems of low capture efficiency and high energy consumption for desorption and regeneration of organic amines mentioned in the background, this invention provides a crystallization control agent for an aqueous liquid-solid phase change CO2 capture system. This crystallization control agent is a sterically hindered alkylated aliphatic amine with an asymmetric structure containing two secondary amine groups. It is compounded with a sterically hindered alkylated ethylenediamine main absorber with a symmetric structure to obtain a sterically hindered liquid-solid phase carbon capture agent with controllable reaction crystallization process. R8 and R9 have electron-donating effects, and the symmetric structure enhances the synergistic effect between the two secondary amine groups of the sterically hindered alkylated ethylenediamine, enabling rapid CO2 absorption. Furthermore, the sterically hindered alkyl group weakens the hydrogen bonding between the carbamate and the solvent, achieving CO2-induced solid-liquid phase separation, causing the absorption products to be mainly enriched in the solid phase. The highly polar solubilizing properties of the asymmetric structure and the electron-donating effect of the sterically hindered alkyl group allow for a controllable delay of the phase change node, improving mass transfer efficiency.

[0010] The technical solution of the present invention is as follows:

[0011] This invention provides a crystallization control agent for an aqueous liquid-solid phase change CO2 capture system, wherein the crystallization control agent is a sterically hindered alkylated fatty amine A containing a di-secondary amine group and having an asymmetric structure;

[0012] The preparation method involves using alkylamines as raw materials, followed by nucleophilic substitution reactions with chloroalkyl secondary alcohols, thionyl chloride, and alkylamines to obtain a crude solution of sterically hindered alkylated fatty amines. After separation and purification, sterically hindered alkylated fatty amine A is obtained. This A is then homogenized with sterically hindered alkylated ethylenediamine G (with a symmetrical structure), water, and functional additives to obtain a sterically hindered liquid-solid phase carbon capture agent with controllable reaction crystallization. Utilizing the highly polar solubilizing properties of the asymmetric structure, combined with the significant electron-donating effect of the alkyl group, this method effectively solves the problems of low solubility of sterically hindered alkylated ethylenediamine with a symmetrical structure in aqueous systems and premature phase transition during CO2 capture. It combines the advantages of high-efficiency capture, controllable crystallization, and enhanced phase separation.

[0013] The main absorbent is a sterically hindered alkylated ethylenediamine G with a symmetrical structure, and the crystallization control agent is a sterically hindered alkylated fatty amine A with an asymmetrical structure.

[0014]

[0015] Among them, R1, R2, R3, R4, R5, and R7 are C1-C3 alkyl groups, R6 is a C1-C4 carbon chain, R8 and R9 are C1-C5 alkyl groups, and R... 10 It is an H proton or a C1~C3 alkyl group.

[0016] Preferably, the main absorbent G accounts for 5 wt% to 70 wt%, the crystallization control agent A accounts for 5 wt% to 70 wt%, the water accounts for 25 wt% to 90 wt%, and the functional additive accounts for 0 to 15 wt%.

[0017] This invention provides a method for synthesizing and purifying the sterically hindered alkylated fatty amine A described above, with the specific steps as follows:

[0018] S1: Chloroalkyl secondary alcohol C is added dropwise to alkylamine B dissolved in a polar solvent. After the addition is complete, the mixture is heated to reflux to carry out a nucleophilic substitution reaction. After the reaction, the solvent is removed, and then saturated sodium hydroxide solution is added for extraction and separation. The upper phase is then distilled under reduced pressure to obtain hydroxyalkylamine intermediate D. The reaction equation is as follows:

[0019]

[0020] The molar ratio of the alkylamine B to the chloroalkyl secondary alcohol C is 1:1 to 5:1, preferably 1.5:1 to 3:1; the polar solvent is one or a combination of methanol, ethanol, n-propanol, isopropanol, and acetonitrile, preferably methanol or ethanol.

[0021] S2: The hydroxyalkylamine intermediate D obtained in S1 was reacted with thionyl chloride in a chloroalkane under reflux for a nucleophilic substitution reaction for 2 h. After cooling to 5-10 °C, the mixture was filtered to obtain the chloroalkylamine intermediate E. The reaction equation is as follows:

[0022]

[0023] The molar ratio of the hydroxyalkylamine intermediate D to thionyl chloride is 1:1 to 1:5, preferably 1:1 to 1:2; the chloroalkane is one of CH3Cl, CH2Cl2, CHCl3 and CCl4, preferably CH2Cl2 or CCl4;

[0024] S3: The chloroalkylamine intermediate E obtained in S2 is reacted with alkylamine F in a polar solvent to undergo a substitution reaction, yielding a crude product containing a sterically hindered alkylated aliphatic amine A. The reaction equation is as follows:

[0025]

[0026] The molar ratio of the chloroalkylamine intermediate E to F is 1:1 to 1:5, preferably 1:1.5 to 1:3, and the polar solvent is one or a combination of water, methanol, ethanol, isopropanol, and acetonitrile, preferably water or ethanol.

[0027] S4: The sterically hindered alkylated fatty amine A crude product obtained in S3 was added to a saturated sodium hydroxide solution for extraction and separation. The upper phase liquid was then subjected to vacuum distillation to obtain sterically hindered alkylated fatty amine A.

[0028] The functional additives of this invention are composed of corrosion inhibitors, antioxidants, and defoamers, as shown in Table 1 below:

[0029] Table 1

[0030] corrosion inhibitor 0~50 antioxidants 0~60 Defoamer 0~50

[0031] The corrosion inhibitor is composed of a metal oxide (70-95 wt%) and a mono-oil imidazoline (5-30 wt%); wherein the metal oxide is one or more of basic copper carbonate, metavanadate, vanadate, and potassium antimony tartrate.

[0032] The antioxidant is one or more of acetone oxime, N,N-bis(2-hydroxyethyl)glycine, dodecyl hydroquinone, anthraquinone, sodium anthraquinone disulfonate, and 4-tert-butylcatechol.

[0033] The defoamer is one or more of polydimethylsiloxane, ethylene glycol siloxane, and polyoxypropylene ethylene glycerol ether.

[0034] The method for absorbing and desorbing CO2 from a mixed gas provided by this invention includes: introducing the mixed gas and a sterically hindered liquid-solid phase carbon scavenger with controllable reaction crystallization from the bottom and top of an absorption tower at 30-50 °C, respectively; after countercurrent contact, the decarbonized gas is drawn out from the top of the absorption tower; after cooling and crystallizing in the bottom of the absorption tower, the decarbonized carbon scavenger introduces the solid phase into a phase separator for further phase separation, and then enters the desorption tower to desorb and remove CO2 at 50-110 °C; the reactivated carbon scavenger is mixed and homogenized with the liquid phase in the bottom of the absorption tower and then sent to the top of the absorption tower for recycling.

[0035] The sterically hindered liquid-solid phase carbon capture agent with controllable reaction crystallization described in this invention can be applied to the capture, recovery and utilization of CO2 in industrial flue gas from industries such as coal-fired power generation, metal smelting, cement building materials, and petrochemicals.

[0036] This carbon capture agent uses sterically hindered alkylated ethylenediamine as the main absorbent and an asymmetric sterically hindered alkylated fatty amine as the crystallization control agent. Utilizing the highly polar solubilizing properties and alkyl electron-donating effect of the asymmetric crystallization control agent, efficient CO2 capture, controllable crystallization, and phase separation enhancement in an aqueous system can be simultaneously achieved, effectively solving the problem of crystallization control in liquid-solid-liquid-solid phase CO2 capture processes. Furthermore, this carbon capture agent exhibits high absorption efficiency, low desorption energy consumption, and excellent cycle stability; its absorption capacity is 35% higher than that of traditional hydroxyethyl ethylenediamine carbon capture agents. After phase separation, only the CO2-enriched solid phase needs desorption, and the regeneration energy consumption is as low as 1.15 GJ / t CO2, only 39.4% of that of commercial hydroxyethyl ethylenediamine carbon capture agents, making it suitable for industrial flue gas CO2 capture.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] 1. Using sterically hindered alkylated fatty amines with asymmetric structures as crystallization control agents, the crystallization slow-release process is controlled, solid crystallization in the absorption tower is eliminated, pipeline blockage is avoided, and mass transfer efficiency is reduced.

[0039] 2. The solubility of the main absorbent in water can be increased by the solubility properties of the crystallization control agent, promoting its combination with CO2. Furthermore, the electron-donating effect of the sterically hindered alkyl group further enhances the reactivity with CO2: the CO2 absorption capacity (1.32 mol / mol) and circulation capacity (0.30 g / g) of Example 1 are significantly higher than those of N,N'-diethylethylenediamine carbon scavenger (Comparative Example 2) and N,N'-diisopropylethylenediamine carbon scavenger (Comparative Example 3), and the solid phase CO2 content (0.32 g / g) is also slightly increased; and compared with hydroxyethylethylenediamine carbon scavenger, the absorption rate is increased by 34.6% (Comparative Example 1).

[0040] 3. The sterically hindered alkyl groups linked by secondary amino groups significantly reduce the energy required for carbamate breakage during regeneration, thereby improving desorption performance and reducing regeneration energy consumption: The CO2 desorption capacity (0.31 g / g) of Example 1 is 344% of that of hydroxyethyl ethylenediamine carbon trap (Comparative Example 1), and also shows a slight improvement compared to N,N'-diisopropylethylenediamine carbon trap (Comparative Example 3); its desorption regeneration energy consumption is as low as 1.15 GJ / t CO2, which is 39.4% of that of hydroxyethyl ethylenediamine carbon trap (Comparative Example 1), and is 45.0% lower than that of N,N'-diethylethylenediamine carbon trap (Comparative Example 2).

[0041] In summary, this invention has significant energy-saving advantages and promising prospects for industrial applications. Attached Figure Description

[0042] Figure 1 The N-tert-butyl-N'-isopropyl-1,2-propanediamine prepared in Example 1 of this invention 1 H NMR spectrum;

[0043] Figure 2 The N-tert-butyl-N'-isopropyl-1,2-propanediamine prepared in Example 1 of this invention 13 C10 NMR spectrum. Detailed Implementation

[0044] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Example 1

[0046] Synthesis of sterically hindered alkylated fatty amines: When R1=R2=R3=R4=R5=R6=R7 are methyl, R8=R9 are isopropyl, R 10 When the proton is H, the sterically hindered alkylated ethylenediamine is N,N'-diisopropylethylenediamine having the following structure, and the sterically hindered alkylated aliphatic amine is N-tert-butyl-N'-isopropyl-1,2-propanediamine having the following structure:

[0047]

[0048] The specific synthesis steps are as follows:

[0049] tert-butylamine (0.15 mol, 10.97 g) was reacted with 1-chloro-2-propanol (0.1 mol, 9.45 g) in anhydrous methanol (50 ml) for a nucleophilic substitution reaction (reaction equation shown in I). After solvent removal, saturated sodium hydroxide solution was added for extraction and separation. The supernatant was distilled under reduced pressure and then reacted with thionyl chloride (0.15 mol, 17.84 g) in dichloromethane (50 ml) under reflux for a nucleophilic substitution reaction for 2 h (reaction equation shown in II). After cooling to 5–10 °C, the mixture was filtered. The filtered solid was dissolved in anhydrous ethanol (50 ml) and reacted with isopropylamine (0.2 mol, 11.82 g) to undergo a nucleophilic substitution reaction (reaction equation shown in III). The mixture was heated under reflux for 16 h, and saturated sodium hydroxide solution was added to separate the layers. The upper phase was collected to obtain a crude product containing sterically hindered alkylated fatty amines. The fraction collected at 150–160 °C was obtained by vacuum distillation to give N-tert-butyl-N'-isopropyl-1,2-propanediamine.

[0050]

[0051]

[0052]

[0053] Preparation of a sterically hindered liquid-solid phase carbon scavenger with controllable reaction crystallization: In a 25 ml three-necked flask, N,N'-diisopropylethylenediamine (2 g) and N-tert-butyl-N'-isopropyl-1,2-propanediamine (2 g) were added to water (6 g), followed by the addition of dimethoxysiloxane (0.05 g), mono-imidazoline (0.05 g), and acetone oxime (0.1 g). After mixing and homogenization, a sterically hindered liquid-solid phase carbon scavenger with controllable reaction crystallization was obtained.

[0054] Carbon capture agent absorption performance test: 10 g of carbon capture agent was placed in a three-necked flask, and the temperature was controlled at 40 ℃ and the pressure at 101.3 kPa under magnetic stirring. A CO2-N2 mixture with a CO2 content of 15% was introduced at a flow rate of 100 ml / min and continued for 120 min. The CO2 content in the outlet tail gas was measured in real time using a gas chromatograph.

[0055] CO2-rich solid phase composition test: After the carbon capture agent above was saturated, a CO2-rich solid phase was obtained by filtration. The contents of amines and CO2 in the solid phase were measured by potentiometric titration and volumetric method, respectively.

[0056] Carbon scavenger desorption performance test: 3 g of solid phase was placed in a 25 ml three-necked flask and placed in a 120 ℃ oil bath. The stirring speed was 300 r / min, and the pressure was 101.3 kPa. Desorption was carried out in a reflux apparatus for 120 min. The volume of desorbed CO2 was measured in real time using a flow meter. The desorption regeneration energy consumption was obtained by measuring the latent heat, sensible heat, and heat of reaction of the carbon scavenger during desorption. After desorption, the carbon scavenger was mixed with the absorbent liquid phase, and the absorption and desorption processes were repeated 10 times. The results are listed in Table 2.

[0057] Example 2

[0058] Synthesis of sterically hindered alkylated fatty amines: When R1=R2=R3=R4=R5=R7 are methyl, R6 is ethyl, R8=R9 are isopropyl, R... 10 When the proton is H, the sterically hindered alkylated ethylenediamine is N,N'-diisopropylethylenediamine having the following structure, and the sterically hindered alkylated aliphatic amine is N-tert-butyl-N'-isopropyl-1,3-butanediamine having the following structure:

[0059]

[0060] The specific synthesis steps differ from those in Example 1 in that the starting material 1-chloro-2-propanol is replaced with 4-chlorobutane-2-ol. The specific reaction equations are shown in I-III.

[0061]

[0062]

[0063]

[0064] In a 25 ml three-necked flask, N,N'-diisopropylethylenediamine (2 g) and N-tert-butyl-N'-isopropyl-1,3-butanediamine (2 g) were added to water (6 g), followed by the addition of dimethoxysiloxane (0.05 g), imidazoline monooleate (0.05 g), and acetone oxime (0.1 g). After mixing and homogenization, a sterically hindered liquid-solid phase carbon scavenger with controllable reaction crystallization was obtained. The performance evaluation of the carbon scavenger was performed using the same procedure as in Example 1, and the results are listed in Table 2.

[0065] Comparative Example 1

[0066] In a 25 ml three-necked flask, 4 g of commercially available hydroxyethyl ethylenediamine (Macklin, 99%, N810760) was added to 6 g of water, followed by the addition of dimethoxysiloxane (0.05 g), imidazoline monooleate (0.05 g), and acetone oxime (0.1 g). After mixing and homogenization, a homogeneous hydroxyethyl ethylenediamine carbon trap was prepared. The performance evaluation of the carbon trap was conducted following the same procedure as in Example 1, and the results are listed in Table 2.

[0067] Comparative Example 2

[0068] In a 25 ml three-necked flask, 4 g of N,N'-diisopropylethylenediamine (Macklin, 99%, N835022) was added to 6 g of water, followed by the addition of dimethoxysiloxane (0.05 g), imidazoline monooleate (0.05 g), and acetone oxime (0.1 g). After mixing and homogenization, the N,N'-diisopropylethylenediamine liquid-solid phase change carbon capture agent was prepared. The performance evaluation of the carbon capture agent was conducted in accordance with the procedures in Example 1, and the results are listed in Table 2.

[0069] Comparative Example 3

[0070] In a 25 ml three-necked flask, 4 g of N,N'-diethylethylenediamine (Macklin, 98%, N687064) was added to 6 g of water, followed by the addition of dimethoxysiloxane (0.05 g), imidazoline monooleate (0.05 g), and acetone oxime (0.1 g). After mixing and homogenization, N,N'-diethylethylenediamine liquid-solid phase change carbon capture agent was prepared. The performance evaluation of the carbon capture agent was conducted in accordance with the procedures in Example 1, and the results are listed in Table 2.

[0071] Table 2 CO2 capture performance of different carbon capture agents

[0072] Example 1 1.32 0.035 ─ 0.32 0.31 96.9 0.30 1.08 Example 2 1.40 0.037 ─ 0.29 0.27 93.1 0.26 1.15 Comparative Example 1 0.98 0.026 ─ ─ 0.09 71.4 0.08 2.92 Comparative Example 2 1.08 0.037 ─ ─ 0.09 71.6 0.07 2.09 Comparative Example 3 1.09 0.039 ─ 0.27 0.25 92.6 0.23 1.28

[0073] In summary, the carbon capture agent provided by this invention has higher saturation absorption capacity, faster initial absorption rate, higher desorption capacity, larger cycle capacity, and significantly lower desorption regeneration energy consumption compared with commercial carbon capture agents and other similar carbon capture agents.

[0074] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A crystallization control agent for an aqueous liquid solid phase CO2 capture system, characterized by, The crystallization control agent is a sterically hindered alkylated fatty amine A containing a di-secondary amine group and having an asymmetric structure, with the following structural formula: ； Among them, R1, R2, R3, R4, R5, and R7 are C1~C3 alkyl groups, and R6 is a C1~C4 carbon chain.

2. A method for preparing a crystallization control agent for an aqueous liquid solid phase CO2 capture system, characterized by, Includes the following steps: Using alkylamine B as a raw material, a nucleophilic substitution reaction is carried out with chloroalkyl secondary alcohol C. After solvent removal, extraction, and vacuum distillation, hydroxyalkylamine intermediate D is obtained. Thionyl chloride is added to hydroxyalkylamine intermediate D to carry out a nucleophilic substitution reaction, and filtration is used to obtain chloroalkylamine intermediate E. Then, a nucleophilic substitution reaction is carried out with alkylamine F to obtain a crude product containing sterically hindered alkylated fatty amine A. After extraction and vacuum distillation, sterically hindered alkylated fatty amine A, i.e., crystallization control agent, is obtained.

3. The method for preparing a crystallization control agent for an aqueous liquid-solid phase change CO2 capture system according to claim 2, characterized in that, The synthesis method of the crystallization control agent specifically includes the following steps: S1: Chloroalkyl secondary alcohol C is added dropwise to alkylamine B dissolved in a polar solvent. After the addition is complete, the mixture is heated to reflux to carry out a nucleophilic substitution reaction. After the reaction, the solvent is removed, and then saturated sodium hydroxide solution is added for extraction and separation. The upper phase is then distilled under reduced pressure to obtain hydroxyalkylamine intermediate D. The reaction equation is as follows: ； S2: The hydroxyalkylamine intermediate D obtained in S1 is slowly added dropwise to thionyl chloride dissolved in chloroalkanes. After the addition is complete, the mixture is heated to reflux to carry out a nucleophilic substitution reaction. The reaction is then filtered to obtain chloroalkylamine intermediate E. The reaction equation is as follows: ； S3: The chloroalkylamine intermediate E obtained in S2 is reacted with alkylamine F in a polar solvent to undergo a substitution reaction, yielding a crude product containing a sterically hindered alkylated aliphatic amine A. The reaction equation is as follows: ； S4: The sterically hindered alkylated fatty amine A crude product obtained in S3 was added to a saturated sodium hydroxide solution for extraction and separation. The upper phase liquid was then subjected to vacuum distillation to obtain sterically hindered alkylated fatty amine A.

4. The method for preparing a crystallization control agent for an aqueous liquid-solid phase change CO2 capture system according to claim 3, characterized in that, The molar ratio of alkylamine B to chloroalkyl secondary alcohol C in S1 is 1:1 to 5:1; The polar solvent mentioned in S1 is one or a combination of methanol, ethanol, n-propanol, isopropanol and acetonitrile.

5. The method for preparing a crystallization control agent for an aqueous liquid-solid phase change CO2 capture system according to claim 3, characterized in that, The molar ratio of the hydroxyalkylamine intermediate D to thionyl chloride in S2 is 1:1 to 1:5; The chloroalkane mentioned in S2 is one of CH3Cl, CH2Cl2, CHCl3, and CCl4.

6. The method for preparing a crystallization control agent for an aqueous liquid-solid phase change CO2 capture system according to claim 3, characterized in that, The molar ratio of the chloroalkylamine intermediate E to the alkylamine F in S3 is 1:1 to 1:5; The polar solvent mentioned in S3 is one or a combination of several of the following: water, methanol, ethanol, isopropanol, and acetonitrile.

7. The use of a crystallization control agent for a water-based liquid solid phase CO2 capture system according to claim 1, characterized in that, Crystallization control agent A is compounded with sterically hindered alkylated ethylenediamine main absorbent G with symmetrical structure, water, and functional additives to prepare a sterically hindered liquid-solid phase carbon capture agent with controllable reaction crystallization. When applied to CO2 capture process, it can achieve slow-release control of the crystallization process and eliminate solid crystallization in the absorption tower.

8. The use of a crystallization control agent for a water-based liquid solid phase CO2 capture system according to claim 7, characterized in that, The main absorbent G accounts for 5-70%, the crystallization control agent A accounts for 5-70%, water accounts for 25-90%, and functional additives account for 0-15%.

9. The use of a crystallization control agent for a water-based liquid solid phase CO2 capture system according to claim 7, characterized in that, The functional additives consist of corrosion inhibitors, antioxidants, and defoamers.

10. The use of a crystallization control agent for a water-based liquid solid phase CO2 capture system according to claim 7, characterized in that, The structural formula of the main absorbent G is: ； wherein R8, R9are C1-C5 alkyl, R 10 is H proton or C1-C3 alkyl.

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