Carbon capture microspheres, and methods of making and using the same

Abstract

The present application provides a kind of carbon capture microspheres and its preparation method and application, the carbon capture microspheres include degradable porous microspheres, and the component group of amine group containing substance component loaded on the porous microspheres, wherein, the porosity of carbon capture microspheres is 70~90%;Pore volume is 3~20cm 3 / g;Pore size is 100nm~10μm;Particle size is 10~500μm.The present application provides that the carbon capture microspheres are more than 1mmol / g to CO2 Absorption capture quantity, and it is a kind of green environmental protection performance excellent carbon adsorption material.

Description

Technical Field

[0001] This invention relates to the field of microsphere technology, and more specifically, to a carbon-capturing microsphere, its preparation method, and its application. Background Technology

[0002] Carbon capture and utilization (CCUS) is an essential technological pathway to achieving carbon neutrality, with enormous emission reduction potential and broad prospects for industrial application. Currently, carbon capture and utilization is a global research and industrialization hotspot as a crucial technological approach to achieving carbon neutrality.

[0003] Industrial CO2 emissions currently account for more than 50% of my country's total emissions. There are many methods for capturing CO2 from flue gas, such as liquid amine absorption, membrane separation, and solid amine adsorption. Among these methods, although liquid amine absorption is currently the most mature method for capturing CO2, this process not only consumes a large amount of energy during absorption but also suffers from drawbacks such as solvent evaporation, amine loss and degradation, and equipment corrosion.

[0004] Solid amine adsorption has attracted much attention due to its high adsorption capacity, low energy consumption, and high CO2 absorption rate under low CO2 partial pressure. It is typically achieved by loading liquid amines onto porous solid matrices. Chinese patent CN113171757A discloses a method for preparing a carbon dioxide adsorbent by loading polyethyleneimine onto a Si-Al porous material. However, the preparation process of this porous material requires high-temperature calcination, resulting in high energy consumption. (The last sentence appears to be a separate, unrelated statement.) Patent 107661748A discloses an organic amine-functionalized macroporous silica CO2 adsorbent and its preparation method, which loads organic amines onto porous silica materials. The preparation of the porous materials also requires prolonged high-temperature calcination. Chinese patent CN106902613A discloses a method for preparing amino-functionalized porous CO2 adsorbents, which involves shearing and pulverizing an amino modifier, a dispersant, and porous materials using a high-speed ultrafine pulverizer, followed by oven drying to obtain the amino-functionalized porous adsorbent. This method requires sophisticated equipment and generates a large amount of dust. Chinese patent CN103861557A discloses a novel solid amine carbon dioxide adsorbent, which supports PEI by forming a film on the inner wall of the pores, controlling the film thickness to control the pore size of the residual channels, resulting in micropores or small-to-medium pores. This technology uses resorcinol and formaldehyde as prepolymers and silica sol as a template to prepare spherical hybrid gels. The porous carriers reported in these patents are mostly inorganic materials, which will have a significant environmental impact after failure. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides carbon-capturing microspheres and their preparation method. The porous microspheres loaded with amine-based components are made from biodegradable materials, and the carbon dioxide adsorption material of this invention has the advantage of being green and environmentally friendly.

[0006] Firstly, one of the objectives of this invention is to provide a carbon-capturing microsphere.

[0007] Specifically, the carbon-capturing microspheres comprise biodegradable porous microspheres and an amine-containing component loaded on the porous microspheres. The porosity of the carbon-capturing microspheres is 70-90%, preferably 80-90%, and the pore volume is 3-20 cm³. 3 / g, preferably 8-20cm 3 / g; pore size is 100nm~10μm, preferably 100nm~800nm; particle size is 10~500μm, preferably 20~300μm.

[0008] Furthermore, in the carbon-capturing microspheres, based on the mass of the porous microspheres, the mass percentage of the amine-containing component loaded on the porous microspheres is 0.01–5%, preferably 0.1–3%.

[0009] Secondly, another objective of the present invention is to provide a method for preparing carbon-capturing microspheres, which is one of the objectives of the present invention.

[0010] Specifically, the method includes the following steps: adding preheated polyol to a solution containing degraded polyester, stirring to form an emulsion and then performing thermal phase separation, drying the separated precipitate to obtain porous microspheres, and impregnating the porous microspheres in a solution containing amine components to obtain carbon-capturing microspheres.

[0011] More specifically, the method includes the following steps:

[0012] Step 1: Dissolve the degraded polyester in an organic solvent and heat and stir until completely dissolved;

[0013] Step 2: Add the preheated polyol to the solution from Step 1 and stir to form an emulsion;

[0014] Step 3: Place the emulsion formed in Step 2 into a low-temperature environment to allow for thermal phase separation;

[0015] Step 4: Remove the frozen emulsion and pour it into deionized water, stirring to form a white precipitate;

[0016] Step 5: Repeatedly soak and wash the white precipitate with deionized water, filter, and vacuum dry to constant weight to obtain porous microspheres;

[0017] Step 6: Place the porous microspheres obtained in Step 5 into an aqueous solution containing amine substances under negative pressure and inject them in portions until the microspheres are completely immersed in the aqueous solution containing amine substances. Allow them to stand at normal pressure and dry to obtain the carbon capturing microspheres.

[0018] Specifically, the method includes the following steps:

[0019] Step 1: Dissolve a certain amount of degraded polyester in an organic solvent, and heat and stir until completely dissolved;

[0020] Step 2: Add the preheated polyol to the solution from Step 1, and stir vigorously at a certain speed and temperature to form a white emulsion.

[0021] Step 3: After stirring for a certain period of time, quickly place the emulsion formed in Step 2 into a low-temperature environment to allow the thermally induced phases to separate.

[0022] Step 4: Take out the frozen emulsion and slowly pour it into a large amount of deionized water, stirring slowly with a glass rod to form a white precipitate;

[0023] Step 5: Soak and wash the white precipitate repeatedly with deionized water 3 to 5 times, filter, and vacuum dry to constant weight to obtain porous microspheres;

[0024] Step Six: Place the porous microspheres obtained in Step Five into a colorimetric tube, seal the top with a sponge, first evacuate the colorimetric tube, then inject an aqueous solution containing amine substances under negative pressure. Pause after injecting a certain amount, introduce air, shake, and repeat 3-5 times until the liquid level in the colorimetric tube is higher than the sponge, so that the microspheres are completely immersed in the aqueous solution containing amine substances. Leave it open and stand under load for a period of time, then take out the microspheres and freeze-dry them to constant weight to obtain carbon capturing microspheres.

[0025] It is worth mentioning that the present invention uses a polyol and an organic solution for degrading polyester to form an emulsion, wherein the polyol is the continuous phase and the organic solution is the dispersed phase. The polyol is dispersed in droplets in the continuous phase. During the freezing process, the degrading polyester and the organic solvent undergo phase separation and crystallization to precipitate out as porous microspheres.

[0026] More notably, this invention involves adding polyols to degrade polyester into spheres, followed by a thermally induced phase separation-crystallization method to obtain porous microspheres. These porous microspheres are then loaded with amine groups via impregnation to obtain a functionalized carbon dioxide adsorption material. The microspheres provided by this invention possess a suitable pore structure, enabling them to effectively capture CO2.

[0027] Furthermore, in step one,

[0028] The degradable polyester is selected from one or a combination of poly(L-lactic acid), poly(D-lactic acid), glycolide-lactide copolymer, and caprolactone-lactide copolymer;

[0029] The organic solvent is selected from one or a combination of tetrahydrofuran, dioxane, N,N-dimethylformamide;

[0030] The concentration of the organic solution for degrading polyester is 1–8 wt%, preferably 3–6 wt%;

[0031] The heating temperature is 60-70℃, preferably 65-70℃.

[0032] Furthermore, in step two,

[0033] The polyol is selected from polyols that are miscible with water, preferably from one or a combination of ethylene glycol, glycerol, butanediol, polyethylene glycol, and isopropanol;

[0034] The preheating temperature of the polyol is 30–70°C, preferably 40–60°C;

[0035] The amount of polyol used is 3 to 6 times the total mass of the degraded polyester solution, preferably 4 to 5 times;

[0036] The stirring temperature is 25–70℃, preferably 30–60℃;

[0037] The stirring speed is 300–1500 rpm, preferably 700–1200 rpm;

[0038] The stirring time is 1 to 6 hours, preferably 2 to 4 hours.

[0039] Furthermore, in step three,

[0040] The low temperature is -15 to -30°C, preferably -20 to -30°C; and / or,

[0041] The separation time is 24–72 h, preferably 24–48 h.

[0042] Furthermore, in step six,

[0043] The amine-containing substance is selected from basic polyamine compounds; preferably from one or a combination of ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, polyethylene polyamine, polyacrylamide, arginine, lysine, histidine, polyarginine, polylysine, and polyhistidine.

[0044] The mass ratio of the added amine-containing substance to the porous microspheres is 0.5:1 to 3:1, preferably 1:1 to 2:1;

[0045] The concentration of the aqueous solution containing the amine group is 0.1–50 wt%, preferably 0.5–20 wt%.

[0046] The static load time under normal pressure is 3 min to 5 h, preferably 5 min to 1 h.

[0047] Furthermore, a third objective of this invention is to provide the application of the carbon-capturing microspheres, which is one of the objectives of this invention.

[0048] The carbon capture microspheres provided by the present invention are used to capture CO2, wherein the CO2 adsorption and capture capacity is >1 mmol / g, preferably >2 mmol / g.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0050] 1. The polymer carbon trapping microspheres provided by this invention have a high pore volume, a large number of macropores and a good interconnected pore structure, which effectively reduces the gas diffusion resistance; the basic N atoms have a strong interaction with the acidic CO2 gas, and when the flue gas passes through the adsorption material, the CO2 gas can be selectively adsorbed and trapped.

[0051] 2. The biodegradable polyester material used in this invention has strong hydrophobicity and poor water adsorption capacity, which can effectively prevent the pores from being blocked and causing a decrease in adsorption capacity.

[0052] 3. After the carbon capture microsphere material provided by this invention fails, the matrix degraded polyester material can be regenerated into a new microsphere carrier or degraded under suitable conditions, which has obvious advantages of being recyclable, low-carbon and environmentally friendly, and low in processing cost.

[0053] 4. The carbon capture microsphere material preparation method provided by this invention is simple and easy to implement, green, low-carbon and environmentally friendly; the amount of organic solvent used is small and can be recycled and reused; the preparation process does not require high temperature and high pressure; and for the first time, it is proposed to use basic amino acids from non-fossil raw materials as amine modifiers. Attached Figure Description

[0054] Figure 1 This is an overall view of the SEM image of the porous microspheres provided in Embodiment 1 of the present invention;

[0055] Figure 2 This is a partially magnified view of the SEM image of the porous microspheres provided in Embodiment 1 of the present invention. Detailed Implementation

[0056] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0057] In the following examples and comparative examples, the raw materials were all commercially available products.

[0058] In the test methods of the following embodiments, porosity and CO2 adsorption capacity are obtained using the BET test method. The test method is as follows: A certain amount of microspheres are placed in a sample tube, and the sample tube is placed in a fully automated physical adsorption instrument for degassing. Then, the sample tube is placed in the analysis station for nitrogen adsorption-desorption isotherm analysis, and the porosity and CO2 adsorption capacity of the microspheres are calculated using the BET method.

[0059] Example 1

[0060] This embodiment illustrates the preparation of carbon-capturing microspheres, and the specific steps are as follows:

[0061] Step 1: Weigh 1.5g of poly-L-lactic acid (PLLA), add dioxane to 30g, heat to 70℃, and stir until completely dissolved.

[0062] Step 2: Add 135g of glycerol preheated to 45℃ to the solution in Step 1, and emulsify by stirring at 1000rpm for 3 hours at 50℃.

[0063] Step 3: Quickly place the emulsion formed in Step 2 into -20℃ to allow thermal phase separation for 30 hours.

[0064] Step 4: After 30 hours, remove the frozen emulsion and slowly pour it into a large amount of deionized water, stirring slowly with a glass rod to form a white precipitate.

[0065] Step 5: Soak and wash the white precipitate repeatedly with deionized water 3 times, filter, and vacuum dry to constant weight to obtain biodegradable polyester porous microspheres.

[0066] Step Six: Weigh 1g of the microspheres obtained in Step Five and place them in a colorimetric tube. Seal the top with a sponge. First, evacuate the colorimetric tube and inject a total of 10g of 10% polylysine aqueous solution under negative pressure. Pause every 3ml of liquid, introduce air, shake, and repeat 3 times until the liquid level in the colorimetric tube is higher than the sponge, so that the microspheres are completely immersed in the modified solution. Let it stand open for 50min, take out the microspheres, freeze-dry them to constant weight, and obtain amine-loaded functionalized carbon-capturing microspheres with a particle size of 20-130μm.

[0067] Figure 1 and Figure 2 SEM images of the carbon-capturing microspheres prepared in this example are shown. As can be seen from the images, the microspheres have abundant pore structures with diverse pore sizes and high porosity.

[0068] The specific evaluation results of the porosity, pore volume, pore size, CO2 adsorption capacity and amine loading rate of the carbon trapping microspheres provided in this embodiment are detailed in Table 1.

[0069] Example 2

[0070] This embodiment illustrates the preparation of carbon-capturing microspheres, and the specific steps are as follows:

[0071] Step 1: Weigh 2g of poly(D-lactic acid) PDLA, add tetrahydrofuran to 30g, heat to 60℃, and stir until completely dissolved.

[0072] Step 2: Add 150g of butanediol preheated to 50℃ to the solution in Step 1, and emulsify by stirring at 1200rpm for 2 hours at 35℃.

[0073] Step 3: Quickly place the emulsion formed in Step 2 into -25℃ to allow thermal phase separation for 24 hours.

[0074] Step 4: After 24 hours, remove the frozen emulsion and slowly pour it into a large amount of deionized water, stirring slowly with a glass rod to form a white precipitate.

[0075] Step 5: Soak and wash the white precipitate repeatedly with deionized water 5 times, filter, and vacuum dry to constant weight to obtain biodegradable polyester porous microspheres.

[0076] Step Six: Weigh 1g of the porous microspheres obtained in Step Five and place them in a colorimetric tube. Seal the top with a sponge. First, evacuate the colorimetric tube and inject a total of 20g of 5% polyethyleneimine aqueous solution under negative pressure. Pause after each injection, introduce air, shake, and repeat 5 times until the liquid level in the colorimetric tube is higher than the sponge, so that the microspheres are completely immersed in the modified solution. Let it stand open for 20min, then take out the microspheres and freeze-dry them to constant weight to obtain amine-loaded functionalized carbon trapping microspheres with a particle size of 50-180μm.

[0077] The specific evaluation results of the porosity, pore volume, pore size, CO2 adsorption capacity and amine loading rate of the carbon trapping microspheres provided in this embodiment are detailed in Table 1.

[0078] Example 3

[0079] This embodiment illustrates the preparation of carbon-capturing microspheres, and the specific steps are as follows:

[0080] Step 1: Weigh 1g of glycolide-lactide copolymer (10:90), add N,N dimethylformamide to 30g, heat to 65℃, and stir until completely dissolved.

[0081] Step 2: Add 120g of preheated polyethylene glycol (molecular weight 200) to the solution in Step 1, and emulsify by stirring at 800rpm for 4 hours at 40℃.

[0082] Step 3: Quickly place the emulsion formed in Step 2 into -30℃ to allow thermal phase separation for 40 hours.

[0083] Step 4: After 40 hours, remove the frozen emulsion and slowly pour it into a large amount of deionized water, stirring slowly with a glass rod to form a white precipitate.

[0084] Step 5: Soak and wash the white precipitate repeatedly with deionized water 3 times, filter, and vacuum dry to constant weight to obtain biodegradable polyester porous microspheres.

[0085] Step Six: Weigh 1g of the porous microspheres obtained in Step Five and place them in a colorimetric tube. Seal the top with a sponge. First, evacuate the colorimetric tube and inject a total of 13g of 15% polyethylene polyamine aqueous solution under negative pressure. Pause after each injection, introduce air, shake, and repeat 5 times until the liquid level in the colorimetric tube is higher than the sponge, so that the microspheres are completely immersed in the modified solution. Let it stand open for 10 minutes, take out the microspheres, freeze-dry them to constant weight, and obtain amine-loaded functionalized carbon trapping microspheres with a particle size of 30-150μm.

[0086] The specific evaluation results of the porosity, pore volume, pore size, CO2 adsorption capacity and amine loading rate of the carbon trapping microspheres provided in this embodiment are detailed in Table 1.

[0087] Example 4

[0088] This embodiment illustrates the preparation of carbon-capturing microspheres, and the specific steps are as follows:

[0089] Step 1: Weigh 1.2g of caprolactone-lactide copolymer (20:80), add tetrahydrofuran to 30g, heat to 68℃, and stir until completely dissolved.

[0090] Step 2: Add 140g of isopropanol preheated to 50℃ to the solution in Step 1, and emulsify by stirring at 1100rpm for 2.5h at 50℃.

[0091] Step 3: Quickly place the emulsion formed in Step 2 into -20℃ to allow thermal phase separation for 48 hours.

[0092] Step 4: After 48 hours, remove the frozen emulsion and slowly pour it into a large amount of deionized water, stirring slowly with a glass rod to form a white precipitate.

[0093] Step 5: Soak and wash the white precipitate repeatedly with deionized water 3 times, filter, and vacuum dry to constant weight to obtain biodegradable polyester porous microspheres.

[0094] Step 6: Weigh 1g of the microspheres obtained in Step 5 and place them in a colorimetric tube. Seal the top with a sponge. First, evacuate the colorimetric tube and inject 18g of 8% polylysine aqueous solution under negative pressure. Pause every 3ml of liquid, introduce air, shake, and repeat 3 times until the liquid level in the colorimetric tube is higher than the sponge, so that the microspheres are completely immersed in the modified solution. Let it stand open for 30min, then take out the microspheres and freeze-dry them to constant weight to obtain amine-loaded functionalized carbon trapping microspheres with a particle size of 80-260μm.

[0095] The specific evaluation results of the porosity, pore volume, pore size, CO2 adsorption capacity and amine loading rate of the carbon trapping microspheres provided in this embodiment are detailed in Table 1.

[0096] Table 1 shows the test data of porosity, average pore size, pore volume and amine loading rate of the carbon capture microspheres provided in Examples 1-4; and the evaluation results of the carbon capture microspheres provided in Examples 1-4 on the carbon dioxide absorption performance at 80°C (simulated flue gas temperature) using the BET test.

[0097] Table 1:

[0098] Example 1 2 3 4 Average pore size (nm) 406.11 1779.54 967.63 714.25 <![CDATA[Pore volume (cm 3 / g)]]> 7.0530 10.1976 16.2541 8.9257 Porosity (%) 80.5126 84.6150 78.1240 81.7234 <![CDATA[CO2 adsorption capacity mmol / g]]> 2.96 3.58 4.15 3.14 Amine loading rate (%) 1.28 2.07 2.95 2.11

[0099] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A carbon-capturing microsphere, comprising biodegradable porous microspheres and an amine-containing material component loaded on the porous microspheres, wherein the porosity of the carbon-capturing microspheres is 70-90% and the pore volume is 3-20 cm³. 3 / g; pore size is 100nm~10μm; particle size is 10~500μm.

2. The carbon capture microspheres of claim 1, wherein, The carbon-capturing microspheres have a porosity of 80–90% and a pore volume of 8–20 cm³. 3 / g; pore size is 100nm~800nm; particle size is 20~300μm.

3. The carbon capture microspheres of claim 1, wherein, The mass percentage of the amine-containing component loaded on the porous microspheres is 0.01–5%, preferably 0.1–3%.

4. The method of claim 1-3 for the preparation of carbon capture microspheres, comprising the steps of: Preheated polyol is added to a solution containing degraded polyester. After stirring to form an emulsion, thermal phase separation is performed. The separated precipitate is dried to obtain porous microspheres. The porous microspheres are then impregnated in a solution containing amine components to obtain the carbon-capturing microspheres.

5. The method of claim 4, wherein the carbon capture microspheres are prepared by a process comprising: The method includes the following steps: Step 1: Dissolve the degraded polyester in an organic solvent and heat and stir until completely dissolved; Step 2: Add the preheated polyol to the solution from Step 1 and stir to form an emulsion; Step 3: Place the emulsion formed in Step 2 into a low-temperature environment to allow for thermal phase separation; Step 4: Remove the frozen emulsion and pour it into deionized water, stirring to form a white precipitate; Step 5: Soak and wash the white precipitate with deionized water, filter, and vacuum dry to constant weight to obtain biodegradable polyester porous microspheres. Step 6: Place the porous microspheres obtained in Step 5 into an aqueous solution containing amine substances under negative pressure and inject them in portions until the microspheres are completely immersed in the aqueous solution containing amine substances. Allow them to stand at normal pressure and dry to obtain the carbon capturing microspheres.

6. The method of claim 5, wherein the carbon capture microspheres are prepared by a process comprising: In step one, The degraded polyester is selected from one or a combination of poly(L-lactic acid), poly(D-lactic acid), glycolide-lactide copolymer, and caprolactone-lactide copolymer; and / or, The organic solvent is selected from one or a combination of tetrahydrofuran, dioxane, N,N-dimethylformamide; and / or, The concentration of the organic solution used to degrade the polyester is 1–8 wt%, preferably 3–6 wt%; and / or, The heating temperature is 60-70℃, preferably 65-70℃.

7. The method for preparing carbon-capturing microspheres according to claim 5, characterized in that, In step two, The polyol is selected from one or a combination of ethylene glycol, glycerol, butylene glycol, polyethylene glycol, and isopropanol; and / or, The preheating temperature of the polyol is 30–70°C, preferably 40–60°C; and / or, The amount of the polyol used is 3 to 6 times the total mass of the degraded polyester solution, preferably 4 to 5 times; and / or, The stirring temperature is 25–70°C, preferably 30–60°C; and / or, The stirring speed is 300–1500 rpm, preferably 700–1200 rpm; and / or, The stirring time is 1 to 6 hours, preferably 2 to 4 hours.

8. The method for preparing carbon-capturing microspheres according to claim 5, characterized in that, In step three, The low temperature is -15 to -30°C, preferably -20 to -30°C; and / or, The separation time is 24–72 h, preferably 24–48 h.

9. The method for preparing carbon-capturing microspheres according to claim 5, characterized in that, In step six, The amine-containing component is selected from one or a combination of ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, polyethylenepolyamine, polyacrylamide, arginine, lysine, histidine, polyarginine, polylysine, and polyhistidine; and / or, The mass ratio of the added amine-containing substance to the porous microspheres is 0.5:1 to 3:1, preferably 1:1 to 2:1; and / or, The concentration of the aqueous solution containing the amine group is 0.1–50 wt%, preferably 0.5–20 wt%; and / or, The static load time under normal pressure is 3 min to 5 h, preferably 5 min to 1 h.

10. The application of the carbon capture microspheres according to any one of claims 1 to 3 for capturing CO2, wherein the CO2 adsorption and capture capacity is >1 mmol / g, preferably >2 mmol / g.

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