A hierarchical guanidine resin-based CO2 adsorbent material and its preparation method

Abstract

This invention discloses a hierarchical guanidine resin-based CO2 adsorbent material and its preparation method, belonging to the field of polymer synthesis technology. The adsorbent material prepared by this invention has a composite spherical structure and a hierarchical pore structure, including micropores, mesopores, and macropores. By introducing a hierarchical pore structure, the adsorption capacity of the material for CO2 is effectively improved. The introduction of hierarchical pores can significantly reduce molecular diffusion resistance and increase the contact area between the adsorbent and CO2 molecules, thereby achieving rapid adsorption. Furthermore, pyridyl, polyamino compounds, and guanidine groups have strong basicity and chemical affinity for CO2. Through surface functionalization modification, the number of active sites on the material surface is significantly increased, thereby further improving the CO2 adsorption capacity and selectivity.

Description

Technical Field

[0001] This invention relates to the field of polymer synthesis technology, specifically to a hierarchical guanidine resin-based CO2 adsorbent material and its preparation method. Background Technology

[0002] With the acceleration of global industrialization, atmospheric CO2 concentrations have continued to rise, exacerbating the global greenhouse effect. Among various CO2 capture technologies, adsorption is considered a promising CO2 capture technology due to its advantages such as overcoming the problems of liquid amine solution evaporation and equipment corrosion in traditional organic amine solution absorption methods, as well as its high product purity and low energy consumption.

[0003] Currently, CO2 capture technologies are broadly classified into two categories: physical adsorption and chemical absorption. Physical adsorption has a lower heat of adsorption (15-50 kJ / mol) and lower regeneration energy consumption, but poor adsorption capacity and selectivity. Chemical adsorption has a higher heat of adsorption (60-110 kJ / mol) and higher adsorption capacity and selectivity, but higher regeneration energy consumption. Therefore, low-performance adsorption materials remain one of the main bottlenecks restricting the development of CO2 capture and separation technologies in greenhouse gas control. An ideal CO2 adsorption material should simultaneously possess high CO2 adsorption capacity, rapid adsorption kinetics, high CO2 selectivity, easy dissociation, and recyclability.

[0004] Chinese Patent 202210861324.9 discloses a highly efficient adsorbent material for carbon dioxide capture. This patent first prepares a porous magnesium carbonate material through a reaction between MgO and CO2, and then immobilizes amine modifiers such as tetraethylenepentamine and polyethyleneimine with high amine content onto the porous magnesium carbonate material. However, the loading of the ammonium modifier inevitably clogs the pores of the porous magnesium carbonate material, leading to a decrease in adsorption performance. Chinese Patent 202211539939.6 discloses a polyacrylic acid CO2-based adsorbent material and its preparation method. This patent first emulsifies and polymerizes substances such as acrylamide and glycidyl methacrylamide in an aqueous phase to obtain a porous spherical resin, and then grafts tetraethylenepentamine onto the porous spherical resin to avoid pore clogging. This material can achieve a CO2 adsorption capacity of 2.83 mmol / g. However, limited by its relatively small pore structure and amine group structure, this material may also suffer from drawbacks such as low adsorption rate and poor regeneration cycle performance. Therefore, most of the adsorption materials for carbon dioxide capture that have been reported so far still have drawbacks such as low adsorption rate and poor regeneration cycle performance. Summary of the Invention

[0005] The main objective of this invention is to propose a hierarchical guanidine resin-based CO2 adsorbent material and its preparation method. The adsorbent material prepared by this invention has a composite spherical structure and a multi-level pore structure, including micropores, mesopores and macropores. In particular, when guanidine groups and nano-boron nitride aerogel are present, the adsorption selectivity for CO2 is higher.

[0006] To achieve the above objectives, this invention proposes a hierarchical guanidine resin-based CO2 adsorbent material. The hierarchical guanidine resin-based CO2 adsorbent material is prepared by swelling and amylation modification of a nano-boron nitride aerogel-acrylic resin white sphere composite to obtain a nano-boron nitride aerogel-acrylic polyamino resin composite, and then by guanidine modification of the nano-boron nitride aerogel-acrylic polyamino resin composite.

[0007] Preferably, the preparation method of the boron nitride nano-aerogel-acrylic resin white sphere composite is as follows:

[0008] The nano-boron nitride aerogel, acrylic monomer, crosslinking agent, 2-vinylpyridine, pore-forming agent, and initiator are mixed evenly to obtain an oil phase mixture. The oil phase mixture is added to a homogeneous aqueous solution obtained by mixing sodium chloride, polyvinyl alcohol, methylene blue, and water. The mixture is heated and stirred to react. After the reaction is completed, the reaction solution is extracted with toluene, dried, and sieved to obtain a nano-boron nitride aerogel-acrylic resin white ball composite.

[0009] Preferably, the mass ratio of the boron nitride nano-aerogel, acrylic monomer, crosslinking agent, 2-vinylpyridine, porogen, and initiator is 1:2-10:1-2:2-4:10-50:0.1-0.5; and the mass ratio of sodium chloride, polyvinyl alcohol, methylene blue, and water is 1:2-10:0.005-0.02:50-200.

[0010] Preferably, the preparation method of the nano-boron nitride aerogel is as follows: melamine, boric acid, dispersant and water are mixed and stirred until clear and transparent, dried and transferred to a tube furnace for calcination to obtain nano-boron nitride aerogel.

[0011] More preferably, the dispersant is polyvinylpyrrolidone and / or hydroxypropyl cellulose; the mass ratio of melamine, boric acid, dispersant, and water is 1:1-3:2-5:10-25; and the calcination temperature is 900-1300℃.

[0012] More preferably, the size of the boron nitride nano-aerogel is 50-200 nm; the boron nitride nano-aerogel contains a microporous structure.

[0013] Preferably, the acrylic monomer is methacrylic acid and / or acrylic acid.

[0014] Preferably, the crosslinking agent is divinylbenzene and / or trivinylbenzene.

[0015] Preferably, the pore-forming agent is a mixture of paraffin wax, polyethylene wax, and polypropylene wax.

[0016] Preferably, the initiator is azobisisobutyronitrile or benzoyl peroxide.

[0017] Preferably, the preparation method of the nano-boron nitride aerogel-acrylic polyamino resin composite is as follows: the nano-boron nitride aerogel-acrylic resin white sphere composite is added to N,N-dimethylformamide for swelling, a polyamino compound is added, the mixture is heated and stirred to react, after the reaction is completed, the mixture is cooled, filtered, and washed with water to obtain the nano-boron nitride aerogel-acrylic polyamino resin composite.

[0018] More preferably, the mass ratio of the boron nitride nano-aerogel-acrylic resin white sphere composite, N,N-dimethylformamide, and polyamino compound is 1:2-10:0.2-4.

[0019] More preferably, the polyamine compound is at least one of diethylenetriammonium, triethylenetetramine, and tetraethylenepentamine.

[0020] Preferably, the preparation method of the graded guanidine resin-based CO2 adsorbent material is as follows: the nano boron nitride aerogel-acrylic polyamino resin composite is added to N,N-dimethylformamide for swelling, dicyandiamide is added, the mixture is stirred, the pH value is adjusted to 3-4 with hydrochloric acid aqueous solution, the reaction is stirred, after the reaction is completed, the mixture is cooled, filtered, washed, and dried to obtain the graded guanidine resin-based CO2 adsorbent material.

[0021] More preferably, the mass ratio of the boron nitride nano-aerogel-acrylic polyamino resin composite, N,N-dimethylformamide and dicyandiamide is 1:2-10:0.1-0.4.

[0022] More preferably, the particle size of the hierarchical guanidine resin-based CO2 adsorbent material is 0.4-1.0 mm.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) The adsorbent material prepared by this invention has a composite spherical structure and a multi-level pore structure, including micropores, mesopores and macropores. By introducing a hierarchical pore structure, the adsorption capacity of the material for CO2 is effectively improved. The introduction of hierarchical pores can significantly reduce molecular diffusion resistance and increase the contact area between the adsorbent and CO2 molecules, thereby achieving rapid adsorption. Furthermore, pyridyl, polyamino compounds and guanidine groups have strong basicity and chemical affinity for CO2. Through surface functionalization modification, the active sites on the surface of the material are significantly increased, thereby further improving the adsorption capacity and selectivity of CO2.

[0025] (2) This invention successfully constructed a hierarchical pore structure by combining nano-boron nitride aerogel with acrylic resin and using a pore-forming agent. The existence of hierarchical pores not only increases the specific surface area of ​​the material, but also optimizes the pore size distribution, enabling the material to simultaneously possess the functions of micropores for gas adsorption and mesopores / macropores for molecular diffusion. This hierarchical pore structure effectively overcomes the problem of pore blockage in traditional adsorption materials and significantly improves the adsorption rate and adsorption capacity.

[0026] (3) In this invention, boron nitride nanoparticles are introduced into the hierarchical guanidine resin-based CO2 adsorption material, which can improve the dispersion performance of boron nitride in the resin, give full play to the high thermal conductivity of boron nitride, improve the overall thermal conductivity of the material, thereby reducing the temperature difference inside and outside the system during the desorption heating process, promoting the desorption of CO2 gas in the adsorption material, and improving the regeneration and recycling performance of the material.

[0027] (3) In the adsorption material prepared by the present invention, the physical adsorption capacity of the adsorption material for CO2 is improved by utilizing the chemical adsorption between boron nitride, guanidine and 2-vinylpyridine and the physical adsorption performance of the hierarchical pore structure with cross-linking within the system; the adsorption selectivity of the adsorption material for CO2 is improved by utilizing the strong CO2 chemical adsorption selectivity of boron nitride material and guanidine resin.

[0028] (4) The present invention utilizes 2-vinylpyridine-modified acrylic resin to improve the crosslinking degree of the resin, improve the pore structure and mechanical strength of the resin, and improve the recyclability of the resin.

[0029] (5) The boron nitride and guanidine groups present in the acrylic resin of the present invention have stronger CO2 adsorption strength than the traditional amine groups, which can improve the adsorption capacity of the material for CO2 gas. At the same time, the introduction of boron nitride can improve the regeneration performance of the material for CO2 gas. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 An optical microscope image of the hierarchical guanidine resin-based CO2 adsorbent material obtained in Example 1 of this invention;

[0032] Figure 2 This is a nitrogen adsorption-desorption curve of the hierarchical guanidine resin-based CO2 adsorbent material obtained in Example 1 of the present invention.

[0033] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] To avoid unnecessary details, unless otherwise specified, all items used in the following examples are commercially available products, and all methods used are conventional methods unless otherwise specified.

[0035] Example 1

[0036] A hierarchical guanidine resin-based CO2 adsorbent material, the preparation method of which includes the following steps:

[0037] S1. Mix 20g melamine, 25g boric acid, 55g polyvinylpyrrolidone and 400mL deionized water, stir for 2h and dry at 80℃ for 12h. Then transfer to a tube furnace and calcine at 1100℃ for 5h to obtain nano boron nitride aerogel.

[0038] S2. Mix 10g of nano-boron nitride aerogel, 50g of acrylic acid, 10g of divinylbenzene, 20g of 2-vinylpyridine, 100g of paraffin wax, 100g of polyethylene wax and 2g of azobisisobutyronitrile to obtain an oil phase mixture. Add the oil phase mixture to a homogeneous aqueous solution obtained by mixing 30g of sodium chloride, 100g of polyvinyl alcohol, 0.3g of methylene blue and 3000mL of water. Stir for 0.5h, heat to 65℃, stir for 2h, heat to 83℃, stir for 3h, then heat to 95℃ and react for 12h. Extract with toluene, dry at 85℃, and sieve to obtain spheres with a particle size between 0.4-0.65mm to obtain nano-boron nitride aerogel-acrylic resin white sphere composite.

[0039] S3. Add 40g of boron nitride nano aerogel-acrylic resin white ball composite to 200mL of N,N-dimethylformamide, swell at 25℃ for 2h, add 60g of triethylenetetraammonium, stir at 25℃ for 1h, heat to 100℃, react for 18h, cool, filter to collect solids, wash with water, and dry to obtain boron nitride nano aerogel-acrylic polyamino resin composite.

[0040] S4. Add 40g of nano-boron nitride aerogel-acrylic polyamino resin composite to 40g of N,N-dimethylformamide, allow it to swell at 25℃ for 8h, add 5g of dicyandiamide, stir, adjust the pH to 4 with 5wt% hydrochloric acid aqueous solution, stir at 20℃ for 1h, raise the temperature to 95℃, reflux for 8h, cool, filter to collect the solids, wash, dry, and fractionate the guanidine resin-based CO2 adsorbent material.

[0041] Example 2

[0042] A hierarchical guanidine resin-based CO2 adsorbent material, the preparation method of which includes the following steps:

[0043] S1. Mix 20g melamine, 40g boric acid, 90g hydroxypropyl cellulose and 300mL water, stir for 3h, dry at 85℃ for 10h, transfer to tube furnace, and calcine at 1200℃ for 4h to obtain nano boron nitride aerogel.

[0044] S2. Mix 10g of nano-boron nitride aerogel, 80g of methacrylic acid, 15g of trivinylbenzene, 25g of 2-vinylpyridine, 200g of paraffin wax, 50g of polyethylene wax, 50g of polypropylene wax and 3g of benzoyl peroxide evenly to obtain an oil phase mixture. Add the oil phase mixture to a homogeneous aqueous solution composed of 90g of sodium chloride, 300g of polyvinyl alcohol, 0.72g of methylene blue and 9000mL of water. Stir for 1h, heat to 60℃, stir for 2.5h, heat to 80℃, stir for 4h, then heat to 90℃ and react for 16h. Extract with toluene, dry at 90℃, and sieve to obtain spheres with a particle size between 0.4-0.65mm to obtain a nano-boron nitride aerogel-acrylic resin white sphere composite.

[0045] S3. Add 50g of boron nitride nano aerogel-acrylic resin white ball composite to 350mL of N,N-dimethylformamide, swell at 25℃ for 2h, add 20g of triethylenetetraammonium, stir at 25℃ for 1h, raise the temperature to 110℃, react for 12h, cool, filter to collect solids, wash with water, and dry to obtain boron nitride nano aerogel-acrylic polyamino resin composite.

[0046] S4. Add 50g of nano-boron nitride aerogel-acrylic polyamino resin composite to 200g of N,N-dimethylformamide, allow it to swell at 30℃ for 6h, add 15g of dicyandiamide, stir, adjust the pH to 3.5 with 8wt% hydrochloric acid solution, stir at 30℃ for 1h, raise the temperature to 105℃, reflux for 7.5h, cool, filter to collect the solids, wash, dry, and fractionate the guanidine resin-based CO2 adsorbent material.

[0047] Example 3

[0048] A hierarchical guanidine resin-based CO2 adsorbent material, the preparation method of which includes the following steps:

[0049] S1. Mix 10g melamine, 10g boric acid, 45g hydroxypropyl cellulose and 250mL water, stir for 2h, dry at 85℃ for 12h, transfer to tube furnace, and calcine at 900℃ for 8h to obtain nano boron nitride aerogel.

[0050] S2. Mix 10g of nano-boron nitride aerogel, 100g of acrylic acid, 10g of divinylbenzene, 30g of 2-vinylpyridine, 50g of paraffin wax, 50g of polypropylene wax and 2g of benzoyl peroxide evenly to obtain an oil phase mixture. Add the oil phase mixture to a homogeneous aqueous solution composed of 60g of sodium chloride, 500g of polyvinyl alcohol, 0.6g of methylene blue and 3000mL of water. Stir for 2h, heat to 65℃, stir for 3h, heat to 85℃, stir for 5h, then heat to 95℃ and react for 10h. Extract with toluene, dry at 85℃, and sieve to obtain spheres with a particle size between 0.4-0.65mm to obtain a nano-boron nitride aerogel-acrylic resin white sphere composite.

[0051] S3. Add 20g of boron nitride nano aerogel-acrylic resin white ball composite to 60mL of N,N-dimethylformamide, swell at 25℃ for 1.5h, add 8g of triethylenetetraammonium, stir at 30℃ for 1.5h, raise the temperature to 115℃, react for 18h, cool, filter to collect solids, wash with water, and dry to obtain boron nitride nano aerogel-acrylic polyamino resin composite.

[0052] S4. Add 20g of nano-boron nitride aerogel-acrylic polyamino resin composite to 50g of N,N-dimethylformamide, allow it to swell at 30℃ for 7h, add 5g of dicyandiamide, stir, adjust the pH to 3.5 with 5wt% hydrochloric acid aqueous solution, stir at 20℃ for 1.5h, raise the temperature to 100℃, reflux for 8.5h, cool, filter to collect the solid, wash, dry, and fractionate the guanidine resin-based CO2 adsorbent material.

[0053] Example 4

[0054] A hierarchical guanidine resin-based CO2 adsorbent material, the preparation method of which includes the following steps:

[0055] S1. Mix 10g melamine, 20g boric acid, 50g polyvinylpyrrolidone and 100mL water, stir for 5h, dry at 85℃ for 11h, transfer to tube furnace and calcine at 1250℃ for 4h to obtain nano boron nitride aerogel.

[0056] S2. Mix 10g of boron nitride nano aerogel, 50g of methacrylic acid, 15g of divinylbenzene, 40g of 2-vinylpyridine, 100g of polyethylene wax, 200g of polypropylene wax and 4g of azobisisobutyronitrile to obtain an oil phase mixture. Add the oil phase mixture to a homogeneous aqueous solution composed of 25g of sodium chloride, 150g of polyvinyl alcohol, 0.2g of methylene blue and 5000mL of water. Stir for 2h, heat to 70℃, stir for 1h, heat to 82℃, stir for 4h, then heat to 90℃ and react for 14h. Extract with toluene, dry at 90℃, and sieve to obtain spheres with a particle size between 0.4-0.65mm to obtain a boron nitride nano aerogel-acrylic resin white sphere composite.

[0057] S3. Add 10g of boron nitride nano aerogel-acrylic resin white ball composite to 80mL of N,N-dimethylformamide, swell at 20℃ for 3h, add 35g of triethylenetetraammonium, stir at 25℃ for 1h, heat to 100℃, react for 20h, cool, filter to collect solids, wash with water, and dry to obtain boron nitride nano aerogel-acrylic polyamino resin composite.

[0058] S4. Add 20g of nano-boron nitride aerogel-acrylic polyamino resin composite to 150g of N,N-dimethylformamide, swell at 30℃ for 5h, add 8g of dicyandiamide, stir, adjust pH to 3.0 with 7.5wt% hydrochloric acid aqueous solution, stir at 20℃ for 2h, raise the temperature to 110℃, reflux for 8h, cool, filter to collect solids, wash, dry, and fractionate guanidine resin-based CO2 adsorbent material.

[0059] Comparative Example 1

[0060] A guanidine resin-based CO2 adsorbent material is prepared using a method similar to that in Example 1, except that boron nitride nano-aerogel is not introduced. The preparation method includes the following steps:

[0061] S1. Mix 50g acrylic acid, 10g divinylbenzene, 20g 2-vinylpyridine, 100g paraffin wax, 100g polyethylene wax and 2g azobisisobutyronitrile evenly to obtain an oil phase mixture. Add the oil phase mixture to a homogeneous aqueous solution composed of 30g sodium chloride, 100g polyvinyl alcohol, 0.3g methylene blue and 3000mL water. Stir for 0.5h, heat to 65℃, stir for 2h, heat to 83℃, stir for 3h, then heat to 95℃ and react for 12h. Extract with toluene, dry at 85℃, and sieve to obtain spheres with a particle size between 0.4-0.65mm to obtain acrylic resin white spheres.

[0062] S2. Add 40g of acrylic resin white balls to 200mL of N,N-dimethylformamide and swell at 25℃ for 2h. Add 60g of triethylenetetraammonium and stir at 25℃ for 1h. Heat to 100℃ and react for 18h. Cool, filter to collect solids, wash with water and dry to obtain acrylic polyamino resin.

[0063] S3. Add 40g of polyamino acrylic resin to 40g of N,N-dimethylformamide and allow it to swell at 25℃ for 8h. Add 5g of dicyandiamide, stir, adjust the pH to 4 with 5wt% hydrochloric acid aqueous solution, stir at 20℃ for 1h, raise the temperature to 95℃, reflux for 8h, cool, filter to collect the solids, wash, dry, and classify the guanidine resin-based CO2 adsorbent material with fractionated pores.

[0064] Comparative Example 2

[0065] A resin-based CO2 adsorbent material is prepared using a method similar to that in Example 1, except that it is not guanidineized. The preparation method specifically includes the following steps:

[0066] S1. Mix 20g melamine, 25g boric acid, 55g polyvinylpyrrolidone and 400mL water, stir for 2h, dry at 80℃ for 12h, transfer to tube furnace and calcine at 1100℃ for 5h to obtain nano boron nitride aerogel.

[0067] S2. Mix 10g of nano-boron nitride aerogel, 50g of acrylic acid, 10g of divinylbenzene, 20g of 2-vinylpyridine, 100g of paraffin wax, 100g of polyethylene wax and 2g of azobisisobutyronitrile to obtain an oil phase mixture. Add the oil phase mixture to a homogeneous aqueous solution containing 30g of sodium chloride, 100g of polyvinyl alcohol, 0.3g of methylene blue and 3000mL of water. Stir for 0.5h, heat to 65℃, stir for 2h, heat to 83℃, stir for 3h, then heat to 95℃ and react for 12h. Extract with toluene, dry at 85℃, and sieve to obtain spheres with a particle size between 0.4-0.65mm to obtain a nano-boron nitride aerogel-acrylic resin white sphere composite.

[0068] S3. Add 40g of the nano-boron nitride aerogel-acrylic resin white ball composite to 200mL of N,N-dimethylformamide, swell at 25℃ for 2h, add 60g of triethylenetetraammonium, stir at 25℃ for 1h, raise the temperature to 100℃, react for 18h, cool, filter to collect the solid, wash with water, and dry to obtain the nano-boron nitride aerogel-acrylic polyamino resin adsorbent material, i.e., resin-based CO2 adsorbent material.

[0069] Comparative Example 3

[0070] A hierarchical guanidine resin-based CO2 adsorbent material is prepared by a method similar to that in Example 1, except that 2-vinylpyridine is not added. The specific steps include:

[0071] S1. Disperse 20g melamine, 25g boric acid and 55g polyvinylpyrrolidone in 400mL deionized water, mix and stir for 2h, dry at 80℃ for 12h, transfer to tube furnace and calcine at 1100℃ for 5h to obtain boron nitride nano aerogel.

[0072] S2. Mix 10g of nano-boron nitride aerogel, 50g of acrylic acid, 10g of divinylbenzene, 100g of paraffin wax, 100g of polyethylene wax and 2g of azobisisobutyronitrile evenly to obtain an oil phase mixture. Add the oil phase mixture to a homogeneous aqueous solution composed of 30g of sodium chloride, 100g of polyvinyl alcohol, 0.3g of methylene blue and 3000mL of water. Stir for 0.5h, heat to 65℃, stir for 2h, heat to 83℃, stir for 3h, then heat to 95℃ and react for 12h. Extract with toluene, dry at 85℃, and sieve to obtain spheres with a particle size between 0.4-0.65mm to obtain nano-boron nitride aerogel-acrylic resin white sphere composite.

[0073] S3. Add 40g of boron nitride nano aerogel-acrylic resin white ball composite to 200mL of N,N-dimethylformamide, swell at 25℃ for 2h, add 60g of triethylenetetraammonium, stir at 25℃ for 1h, heat to 100℃, react for 18h, cool, filter to collect solids, wash with water, and dry to obtain boron nitride nano aerogel-acrylic polyamino resin composite.

[0074] S4. Add 40g of boron nitride nano-aerogel-acrylic polyamino resin composite to 40g of N,N-dimethylformamide, swell at 25℃ for 8h, add 5g of dicyandiamide, stir, adjust pH to 4 with 5wt% hydrochloric acid solution, stir at 20℃ for 1h, raise temperature to 95℃, reflux reaction for 8h, cool, filter to collect solids, wash, dry, and fractionate guanidine resin-based CO2 adsorbent material.

[0075] 1. Structural characterization

[0076] This application presents optical microscopy observations and nitrogen adsorption-desorption tests on the hierarchical guanidine resin-based CO2 adsorbent material prepared in Example 1. The optical micrographs are shown below. Figure 1 As shown, it can be clearly seen that the adsorbent material prepared in Example 1 has a composite spherical structure and a multi-level porous structure, including micropores, mesopores, and macropores. The nitrogen adsorption-desorption test results are as follows... Figure 2 As shown, the multi-level pore characteristics of the adsorbent material are further verified, indicating that it simultaneously possesses microporous, mesoporous, and macroporous structures.

[0077] 2. Saturated adsorption capacity test

[0078] The test used a fixed-bed method, in which a mixed gas containing a certain concentration of CO2 was passed through a fixed bed filled with a fully moistened sample. The CO2 concentration at the outlet was continuously measured by gas chromatography to obtain the CO2 adsorption breakthrough curve. The adsorption capacity of the adsorbent materials prepared in Examples 1-4 and Comparative Examples 1-3 was calculated by Formula 1.

[0079]

[0080] Where Q is the equilibrium adsorption capacity of the adsorbent material (mmol / g), t is the adsorption time (min), and C is the equilibrium adsorption capacity of the adsorbent material. in C represents the inlet concentration (vol%) of the adsorbed gas. eff V is the outlet concentration of the adsorbed gas (vol%), V is the flow rate of the mixed gas (mL / min), and W is the mass of the adsorbent material (g). The results are shown in Table 1.

[0081] Table 1. Experimental results of adsorption capacity of the adsorbent material obtained in this invention.

[0082] Adsorption capacity (mmol / g) Example 1 20.74 Example 2 19.09 Example 3 19.78 Example 4 18.20 Comparative Example 1 10.35 Comparative Example 2 8.62 Comparative Example 3 14.11

[0083] As can be seen from the data in Table 1, the hierarchical guanidine resin-based CO2 adsorbent material prepared by the present invention has a high adsorption capacity.

[0084] 3. Adsorption selectivity test

[0085] The fixed-bed method was used for testing. A CO2 / CH4 mixed gas stream containing 50% CO2 volume fraction was passed through a fixed bed (pressure 1 MPa) filled with 20g of fully moistened sample at a flow rate of 300 mL / min. The CO2 and CH4 concentrations at the outlet were continuously measured by gas chromatography. The adsorption selectivity of the adsorbent materials prepared in Examples 1-4 and Comparative Examples 1-3 for CO2 was calculated according to Formula 2.

[0086]

[0087] in, For adsorption selectivity, These represent the mole fractions of CO2 and CH4 in the adsorbed phase, respectively. The values ​​are the mole fractions of CO2 and CH4 in the gas phase, respectively, and the results are shown in Table 2.

[0088] Table 2. Adsorption selectivity test results of the adsorption material obtained in this invention.

[0089] Adsorption selectivity Example 1 862 Example 2 724 Example 3 799 Example 4 706 Comparative Example 1 256 Comparative Example 2 308 Comparative Example 3 681

[0090] As can be seen from the data in Table 2, the hierarchical guanidine resin-based CO2 adsorbent material prepared in the embodiments of the present invention has high adsorption selectivity, especially when guanidine and nano boron nitride aerogel are present, the adsorption selectivity for CO2 is even higher.

[0091] 4. Adsorption-regeneration cycle performance test

[0092] The adsorption and regeneration performance of the adsorbent materials prepared in Examples 1-4 and Comparative Examples 1-3 were tested at 70°C and 80°C, respectively.

[0093] Table 3. Test results of the adsorption capacity reduction rate of the adsorbent material obtained by the present invention after 8 consecutive regeneration cycles.

[0094]

[0095]

[0096] As can be seen from Table 3, the adsorption capacity of Examples 1-4 changed little after 8 cycles at 70℃ and 80℃, while the adsorption capacity of Comparative Examples 1-3, especially Comparative Example 1, changed much more after 8 cycles at 70℃.

[0097] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A hierarchical guanidine resin-based CO2 adsorbent material, characterized in that: The hierarchical pore guanidine resin-based CO2 adsorbent material is prepared by swelling and amylation of a nano-boron nitride aerogel-acrylic resin white sphere composite to obtain a nano-boron nitride aerogel-acrylic polyamino resin composite, and then by guanidine modification of the nano-boron nitride aerogel-acrylic polyamino resin composite. The preparation method of the boron nitride nano-aerogel-acrylic resin white sphere composite is as follows: The nano-boron nitride aerogel, acrylic monomer, crosslinking agent, 2-vinylpyridine, pore-forming agent, and initiator are mixed evenly to obtain an oil phase mixture. The oil phase mixture is added to a homogeneous aqueous solution obtained by mixing sodium chloride, polyvinyl alcohol, methylene blue, and water. The mixture is heated and stirred to react. After the reaction is completed, the reaction solution is extracted with toluene, dried, and sieved to obtain a nano-boron nitride aerogel-acrylic resin white ball composite. The mass ratio of the boron nitride nano-aerogel, acrylic monomer, crosslinking agent, 2-vinylpyridine, porogen, and initiator is 1:2-10:1-2:2-4:10-50:0.1-0.5; the mass ratio of sodium chloride, polyvinyl alcohol, methylene blue, and water is 1:2-10:0.005-0.02:50-200. The pore-forming agent is a mixture of paraffin wax, polyethylene wax, and polypropylene wax.

2. The CO2 adsorption material according to claim 1, characterized in that, The preparation method of the nano-boron nitride aerogel is as follows: melamine, boric acid, dispersant and water are mixed and stirred until clear and transparent, dried and transferred to a tube furnace for calcination to obtain nano-boron nitride aerogel.

3. The CO2 adsorption material according to claim 2, characterized in that: The dispersant is polyvinylpyrrolidone and / or hydroxypropyl cellulose; the mass ratio of melamine, boric acid, dispersant and water is 1:1-3:2-5:10-25; the calcination temperature is 900-1300℃.

4. The CO2 adsorption material according to claim 2, characterized in that: The size of the boron nitride nanogel is 50-200 nm.

5. The CO2 adsorption material according to claim 1, characterized in that: The acrylic monomer is methacrylic acid and / or acrylic acid; the crosslinking agent is divinylbenzene and / or trivinylbenzene; and the initiator is azobisisobutyronitrile or benzoyl peroxide.

6. The CO2 adsorption material according to claim 1, characterized in that, The preparation method of the nano-boron nitride aerogel-acrylic polyamino resin composite is as follows: the nano-boron nitride aerogel-acrylic resin white ball composite is added to N,N-dimethylformamide for swelling, a polyamino compound is added, the mixture is heated and stirred to react, after the reaction is completed, it is cooled, filtered, and washed with water to obtain the nano-boron nitride aerogel-acrylic polyamino resin composite.

7. The CO2 adsorption material according to claim 6, characterized in that: The mass ratio of the boron nitride nano-aerogel-acrylic resin white sphere composite, N,N-dimethylformamide, and polyamino compound is 1:2-10:0.2-4.

8. The CO2 adsorption material according to claim 1, characterized in that, The preparation method is as follows: The nano boron nitride aerogel-acrylic polyamino resin composite is added to N,N-dimethylformamide for swelling, dicyandiamide is added, and the mixture is stirred. The pH value is adjusted to 3-4 with hydrochloric acid aqueous solution, and the reaction is stirred. After the reaction is completed, the mixture is cooled, filtered, washed, and dried to obtain fractionated guanidine resin-based CO2 adsorbent material.

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