Ultra-microporous activated carbon based on gas separation and preparation method thereof

Abstract

The invention discloses ultra-microporous activated carbon based on gas separation and a preparation method, and belongs to the technical field of ultra-microporous activated carbon. Biomass raw materials and polymer raw materials are used as carbon sources and co-pyrolyzed to construct a biomass-polymer composite carbon skeleton with developed pore channels and a stable structure, and a molecular sieve material is grown on the surface of the biomass-polymer composite carbon skeleton in situ to prepare the ultra-microporous activated carbon. An integrated composite adsorption system with a continuous structure is formed, calcium ions are further introduced through ion exchange, the electric field environment and the adsorption energy level in a molecular sieve pore channel are regulated and controlled, the selective adsorption capacity on carbon dioxide molecules is enhanced, and the prepared ultra-microporous activated carbon has the high specific surface area of activated carbon and the separation selectivity of a molecular sieve, and has the advantages of high specific surface area and high adsorption efficiency. The problem of thermal failure of active adsorption sites of the molecular sieve caused by concentrated adsorption heat release in a traditional layered filling structure is effectively avoided, and the molecular sieve has excellent gas separation performance in complex gas systems such as coal-fired flue gas.

Description

Technical Field

[0001] This invention belongs to the field of ultra-microporous activated carbon technology, specifically an ultra-microporous activated carbon based on gas separation and its preparation method. Background Technology

[0002] Coal-fired power plants, due to their air-assisted combustion process, emit flue gas characterized by "high inert nitrogen and low carbon dioxide concentration." As carbon dioxide, as a major greenhouse gas, continues to accumulate, it will exacerbate global warming and ecological imbalance. Therefore, it is necessary to capture and separate it from the large amount of nitrogen. In the current field of industrial adsorption separation, activated carbon, due to its well-developed macroporous network and excellent hydrodynamic properties, and zeolite molecular sieves, due to their strong affinity and high selectivity for carbon dioxide, are often regarded as the two core materials for building efficient adsorption systems and are widely used in gas separation processes.

[0003] However, due to the performance limitations of single materials, a segmented filling mode of activated carbon layer and molecular sieve layer is usually adopted. That is, the gas first passes through the activated carbon layer for coarse separation, and then enters the molecular sieve layer for fine separation. However, when high-velocity carbon dioxide gas passes through the front activated carbon layer, a large amount of adsorption heat is released due to the rapid adsorption process, which causes the gas flow temperature to rise sharply. The heated high-temperature gas flow then directly impacts the rear molecular sieve layer. The heat energy will significantly inhibit the ability of the active sites in the molecular sieve to capture carbon dioxide, so that it cannot exert the proper separation efficiency, resulting in low utilization rate of activated carbon and molecular sieve and poor overall separation effect.

[0004] Therefore, in the application scenario of carbon capture of coal-fired flue gas, how to overcome the technical bottleneck of thermal failure of molecular sieve active chemical adsorption sites due to inter-stage thermal interference in the traditional layered filling process, and construct activated carbon composite materials that can maintain good separation performance under adsorption exothermic conditions, has become a key technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide an ultra-microporous activated carbon based on gas separation and its preparation method. By synergistically regulating the activated carbon carrier and the pore structure of the molecular sieve, the adsorption and separation efficiency is improved to meet the requirements of separation performance stability and practical application reliability in complex gas systems.

[0006] The objective of this invention can be achieved through the following technical solutions: An ultraporous activated carbon based on gas separation is prepared through the following steps: Step 1: Blend biomass char material with plastic char material and perform high-temperature pyrolysis carbonization to construct a basic carbon skeleton and obtain biomass-polymer char material. Then, use potassium hydroxide to perform high-temperature chemical etching and activation on the char material to obtain activated porous activated carbon.

[0007] Step 2: Add aluminum and silicon sources to a strongly alkaline reaction environment constructed with sodium hydroxide to undergo hydrolysis and condensation reactions to obtain molecular sieve precursor sol. Then, introduce activated porous activated carbon into the molecular sieve precursor sol system for in-situ hydrothermal crystallization to obtain a molecular sieve-supported activated carbon matrix.

[0008] Step 3: Place the molecular sieve-supported activated carbon matrix and calcium nitrate solution in deionized water to carry out a liquid-phase ion exchange reaction. Calcium ions are used to directionally replace sodium ions in the molecular sieve framework to obtain ultraporous activated carbon based on gas separation.

[0009] Furthermore, the ratio of molecular sieve-supported activated carbon matrix, calcium nitrate solution, and deionized water is 100-200g: 800-1000mL: 600-800mL.

[0010] Furthermore, the preparation process of the molecular sieve-supported activated carbon matrix is ​​as follows: Molecular sieve precursor sol and activated porous activated carbon are placed in a reaction vessel and stirred at 25-35℃ for 20-40 minutes. The reaction vessel is then fixed in a homogeneous reactor and reacted for 6-8 hours. After filtration, washing, and vacuum drying to constant weight, molecular sieve-supported activated carbon matrix is ​​obtained.

[0011] Furthermore, the mass ratio of molecular sieve precursor sol to activated porous activated carbon is 40-60:200-300.

[0012] This step involves mixing the molecular sieve precursor sol with activated porous carbon. The high specific surface area of ​​the activated carbon allows the oligomeric silica-alumina components to deeply penetrate into the mesopores, where they undergo in-situ nucleation and growth under subsequent hydrothermal conditions. By controlling the reaction temperature and rotation speed, the system remains in a uniformly dispersed state, preventing the precursor from crystallizing in the solution or depositing at the bottom of the container. This ensures that the molecular sieve preferentially grows on the surface and within the pores of the carbon material, achieving a tight bond between the crystals and the carbon framework. This allows the molecular sieve to perform shape-selective separation without clogging the mass transfer channels of the activated carbon, thus achieving an organic fusion of the high-throughput transport channels of the activated carbon and the highly shape-selective crystal layers of the molecular sieve at the microscale.

[0013] Furthermore, the preparation process of the molecular sieve precursor sol is as follows: Sodium hydroxide, sodium aluminate, and deionized water are placed in a reaction vessel and stirred at 25-35°C for 10-20 minutes. Sodium silicate nonahydrate is then added, and the reaction continues at the same temperature for 1-2 hours to obtain a molecular sieve precursor sol.

[0014] Furthermore, the ratio of sodium hydroxide, sodium aluminate, sodium silicate nonahydrate, and deionized water is 10-20g: 12-25g: 40-60g: 200-300mL.

[0015] This step involves stepwise feeding and low-temperature aging to regulate the hydrolysis and polycondensation rate of the silicon-aluminum source. This allows the aluminum source to first be converted into stable aluminate ions before reacting with the silicon source to form an oligomer sol rich in silicon-aluminum-oxygen bridging bonds. This prevents precipitation caused by excessively high local concentrations. The structure-directing effect of sodium ions is used to induce the framework to assemble into specific pore structures. At the same time, the silicon-aluminum ratio is controlled to regulate the density and polarity of acidic sites, providing highly reactive and crystal-controllable primary structural units for subsequent directional assembly on the activated carbon surface.

[0016] Furthermore, the preparation process of activated porous activated carbon is as follows: Biomass-polymer carbonized material, potassium hydroxide, and deionized water were placed in a reactor and stirred at 25-35℃ for 6-8 hours. The reaction solution was then vacuum dried at 100-120℃ to constant weight. The dried material was placed in a tube furnace under nitrogen atmosphere protection and heated to 700-800℃ at a heating rate of 5℃ / min and calcined at a constant temperature for 1-2 hours. 1 mol / L hydrochloric acid was added to adjust the pH to 7. The material was then filtered, washed, vacuum dried to constant weight, and sieved to obtain activated porous activated carbon.

[0017] Furthermore, the mass ratio of biomass-polymer carbonized material, potassium hydroxide, and deionized water is 300-400: 600-800: 600-800.

[0018] This step utilizes the strong chemical etching effect of potassium hydroxide on biomass-polymer carbonized materials at high temperatures. Through potassium metal intercalation and carbonate decomposition reactions, a large number of micropores and mesopores are formed in the carbon skeleton, significantly increasing the specific surface area. By controlling the alkali-to-carbon ratio, the activation intensity is kept within a reasonable range, which can fully open the pore structure without causing the carbon skeleton to collapse or decrease in strength. This provides a key structural basis for achieving high-capacity and high-flux composite adsorption performance.

[0019] Furthermore, the preparation process of biomass-polymer carbonized material is as follows: Biomass raw materials and polymer raw materials are crushed in a high-speed pulverizer, sieved with a 60-100 mesh screen, the materials are collected and ground and mixed for 10-30 minutes, the mixed materials are placed in a tube furnace under nitrogen atmosphere protection, heated to 500-600℃ at a heating rate of 8℃ / min, and calcined at a constant temperature for 1-2 hours, the product is collected and ground to obtain biomass-polymer carbonized material.

[0020] Furthermore, the mass ratio of biomass feedstock to polymer feedstock is 600-800:300-400.

[0021] Furthermore, the biomass raw material is any one of corn cobs, coconut shells, and wheat straw, and the polymer raw material is any one of polyethylene terephthalate, polybutylene terephthalate, and polystyrene.

[0022] This step utilizes the physical impact and shearing action generated during high-speed mechanical crushing and mixing to disrupt the lignin structure and polymer crystalline regions of biomass, achieving uniform dispersion at the microscopic level and co-carbonizing them. This fully leverages the synergistic advantages of the natural porous structure of biomass and the high carbon content of polymers. During the pyrolysis of corn cobs, a multi-level porous framework is formed, while the aromatic carbon structure generated by the pyrolysis of polyethylene terephthalate fills the defects in biochar, improving the density and stability of the overall carbon framework. This provides a structurally stable and uniformly reactive carbon source for subsequent high-temperature chemical activation.

[0023] The beneficial effects of this invention are: 1. The ultraporous activated carbon based on gas separation prepared in this invention uses activated porous carbon co-constructed from biomass and polymers as a carrier. Through in-situ hydrothermal crystallization of molecular sieve precursor sol within the carbon framework channels, a strong nanoscale interface bond is established between the molecular sieve and the carbon matrix during the nucleation and growth stage. This unique "embedded" structure achieves functional coupling of the high selectivity of the molecular sieve and the excellent thermal conductivity of the activated carbon at the microscale. When carbon dioxide flows through at high flow rates in coal-fired flue gas, the physical adsorption of activated carbon and the selective adsorption of the molecular sieve can occur simultaneously. This allows the adsorption exothermic process to be rapidly dispersed and slowly released by the carbon framework, weakening the impact of adsorption heat on the active sites of the molecular sieve and effectively alleviating the problem of decreased separation efficiency due to thermal effects under high flow rate conditions.

[0024] 2. The ultraporous activated carbon based on gas separation prepared in this invention introduces calcium ions for directional ion exchange after the activated carbon is stably loaded onto a molecular sieve. This regulates the cation composition in the molecular sieve framework, thereby optimizing the adsorption energy distribution and gas selectivity within the molecular sieve. The substitution of sodium ions in the framework by calcium ions alters the electric field environment within the molecular sieve channels, which enhances the adsorption affinity for polar gas molecules such as carbon dioxide while suppressing the competitive adsorption behavior of non-target gases. This ion modification process, carried out under a stable carbon support structure, avoids the risk of framework collapse or grain agglomeration that may occur when directly treating pure molecular sieve powder with liquid phase. It ensures that the material can maintain the integrity of the ultraporous structure and the long-term stability of its separation performance even after high-temperature calcination and complex chemical modification.

[0025] 3. The gas separation-based ultraporous activated carbon prepared by this invention constructs an activated porous carbon framework using biomass and plastic polymers as carbon sources, and then grows molecular sieves in situ on it and performs ion regulation to form an integrated composite adsorption material system with continuous structure and synergistic function. This realizes a low-cost, high-value-added adsorption material construction path, significantly reducing material preparation costs and environmental burden. On this basis, by constructing a structurally continuous and functionally synergistic ultraporous activated carbon material, the problem of separation efficiency decay caused by concentrated adsorption heat release, uneven mass transfer, and discontinuous material interface in traditional layered packing structures is avoided, thus improving the long-term operational reliability of the material in complex systems such as coal-fired flue gas. Detailed Implementation

[0026] The technical solutions 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1: This example provides an ultraporous activated carbon based on gas separation, which is prepared through the following steps: S1: Place 600g of corn cob (i.e., biomass raw material) and 300g of polyethylene terephthalate (i.e., polymer raw material) in a high-speed pulverizer for pulverization, sieve with a 60-mesh sieve, collect the material and grind and mix for 10 minutes. Place the mixed material in a tube furnace under nitrogen atmosphere protection, heat to 500℃ at a heating rate of 8℃ / min, and calcine at a constant temperature for 1 hour. After the reaction is completed, cool to room temperature, collect the product and grind it to obtain biomass-polymer carbonized material.

[0028] S2: Place 300g of biomass-polymer carbonized material, 600g of potassium hydroxide and 600mL of deionized water in a reactor and stir at 400r / min for 6h at 25℃. Vacuum dry the reaction solution at 100℃ to constant weight. Load the dried material into a crucible and place it in a tube furnace under nitrogen atmosphere protection. Heat to 700℃ at a heating rate of 5℃ / min and calcine at a constant temperature for 1h. After the reaction is completed, cool to room temperature and add 1mol / L hydrochloric acid to the crucible to adjust the pH value of the carbonized product to 7. Filter and wash the filter cake twice with deionized water. Vacuum dry at 100℃ to constant weight and sieve through an 80-mesh sieve to obtain activated porous activated carbon.

[0029] S3: Place 10g sodium hydroxide, 15g sodium aluminate and 200mL deionized water in a reaction vessel, stir at 400r / min for 10 minutes at 25℃, add 40g sodium silicate nonahydrate, and continue stirring at the same temperature and stirring rate for 1h. After the reaction is completed, molecular sieve precursor sol is obtained.

[0030] S4: Place 40g of molecular sieve precursor sol and 200g of activated porous activated carbon in a reaction vessel, stir at 400r / min for 20 minutes at 25℃, fix the reaction vessel in a homogeneous reactor, set the rotation speed to 12r / min, and react at 80℃ for 6 hours. After the reaction is completed, cool to room temperature, filter, wash the filter cake twice with deionized water, and vacuum dry at 100℃ to constant weight to obtain the molecular sieve supported activated carbon matrix.

[0031] S5: Place 100g of molecular sieve-supported activated carbon matrix and 600mL of deionized water in a reaction vessel, stir at 200r / min for 10 minutes at 25℃, add 800mL of 1mol / L calcium nitrate tetrahydrate solution, and continue the reaction at 70℃ with the same stirring rate for 20h. After the reaction is completed, cool to room temperature, filter, wash the filter cake twice with deionized water, and vacuum dry at 60℃ to constant weight to obtain gas separation-based ultraporous activated carbon.

[0032] Example 2: This example provides an ultraporous activated carbon based on gas separation, prepared through the following steps: S1: 700g of corn cobs and 350g of polyethylene terephthalate were placed in a high-speed pulverizer for pulverization. The mixture was sieved through an 80-mesh sieve, collected, and ground for 20 minutes. The mixture was then placed in a tube furnace under nitrogen atmosphere protection and heated to 550°C at a heating rate of 8°C / min. The mixture was then calcined at a constant temperature for 1.5 hours. After the reaction was completed, the mixture was cooled to room temperature, and the product was collected and ground to obtain biomass-polymer carbonized material.

[0033] S2: Place 350g of biomass-polymer carbonized material, 700g of potassium hydroxide and 700mL of deionized water in a reactor and stir at 500r / min for 7h at 30℃. Vacuum dry the reaction solution at 110℃ to constant weight. Load the dried material into a crucible and place it in a tube furnace under nitrogen atmosphere protection. Heat to 750℃ at a heating rate of 5℃ / min and calcine at a constant temperature for 1.5h. After the reaction is completed, cool to room temperature and add 1mol / L hydrochloric acid to the crucible to adjust the pH of the carbonized product to 7. Filter and wash the filter cake three times with deionized water. Vacuum dry at 110℃ to constant weight and sieve through an 80-mesh sieve to obtain activated porous activated carbon.

[0034] S3: Place 15g sodium hydroxide, 20g sodium aluminate and 250mL deionized water in a reaction vessel, stir at 450r / min for 15 minutes at 30℃, add 50g sodium silicate nonahydrate, and continue stirring at the same temperature and stirring rate for 1.5h. After the reaction is completed, molecular sieve precursor sol is obtained.

[0035] S4: Place 50g of molecular sieve precursor sol and 250g of activated porous activated carbon in a reaction vessel, stir at 450r / min for 30 minutes at 30℃, fix the reaction vessel in a homogeneous reactor, set the rotation speed to 13r / min, and react at 90℃ for 7 hours. After the reaction is completed, cool to room temperature, filter, wash the filter cake three times with deionized water, and vacuum dry at 110℃ to constant weight to obtain the molecular sieve supported activated carbon matrix.

[0036] S5: Place 150g of molecular sieve-supported activated carbon matrix and 700mL of deionized water in a reaction vessel, stir at 250r / min for 15 minutes at 30℃, add 900mL of 1mol / L calcium nitrate tetrahydrate solution, and continue the reaction at 80℃ with the same stirring rate for 22h. After the reaction is completed, cool to room temperature, filter, wash the filter cake three times with deionized water, and vacuum dry at 70℃ to constant weight to obtain gas separation-based ultraporous activated carbon.

[0037] Example 3: This example provides an ultraporous activated carbon based on gas separation, which is prepared through the following steps: S1: Place 800g of corn cob and 400g of polyethylene terephthalate in a high-speed pulverizer for pulverization, sieve with a 100-mesh sieve, collect the material and grind and mix for 30min. Place the mixed material in a tube furnace under nitrogen atmosphere protection, heat to 600℃ at a heating rate of 8℃ / min, and calcine at a constant temperature for 2h. After the reaction is completed, cool to room temperature, collect the product and grind it to obtain biomass-polymer carbonized material.

[0038] S2: Place 400g of biomass-polymer carbonized material, 800g of potassium hydroxide and 800mL of deionized water in a reactor and stir at 600r / min for 8h at 35℃. Vacuum dry the reaction solution at 120℃ to constant weight. Put the dried material into a crucible and place it in a tube furnace under nitrogen atmosphere protection. Heat to 800℃ at a heating rate of 5℃ / min and calcine at a constant temperature for 2h. After the reaction is completed, cool to room temperature and add 1mol / L hydrochloric acid to the crucible to adjust the pH value of the carbonized product to 7. Filter and wash the filter cake 4 times with deionized water. Vacuum dry at 120℃ to constant weight and sieve through an 80-mesh sieve to obtain activated porous activated carbon.

[0039] S3: Place 20g sodium hydroxide, 25g sodium aluminate and 300mL deionized water in a reaction vessel, stir at 500r / min for 20 minutes at 35℃, add 60g sodium silicate nonahydrate, and continue stirring at the same temperature and stirring rate for 2 hours. After the reaction is completed, molecular sieve precursor sol is obtained.

[0040] S4: Place 60g of molecular sieve precursor sol and 300g of activated porous activated carbon in a reactor and stir at 500r / min for 40 minutes at 35℃. Fix the reactor in a homogeneous reactor and set the rotation speed to 14r / min. React at 100℃ for 8 hours. After the reaction is completed, cool to room temperature, filter, wash the filter cake 4 times with deionized water, and vacuum dry at 120℃ to constant weight to obtain the molecular sieve supported activated carbon matrix.

[0041] S5: Place 200g of molecular sieve-supported activated carbon matrix and 800mL of deionized water in a reaction vessel, stir at 300r / min for 20 minutes at 35℃, add 1000mL of 1mol / L calcium nitrate tetrahydrate solution, and continue the reaction at 90℃ with the same stirring rate for 24h. After the reaction is completed, cool to room temperature, filter, wash the filter cake 4 times with deionized water, and vacuum dry at 80℃ to constant weight to obtain gas separation-based ultraporous activated carbon.

[0042] Comparative Example 1: Based on Example 2, commercially available activated carbon was used instead of the activated porous activated carbon prepared in step S2. The remaining steps remained unchanged.

[0043] Comparative Example 2: Based on Example 2, the molecular sieve-supported activated carbon matrix prepared in S4 was used instead of the gas separation-based ultraporous activated carbon in S5, while the other steps remained unchanged.

[0044] Comparative Example 3: Based on Example 2, the activated porous activated carbon prepared in S2 was used instead of the molecular sieve-supported activated carbon matrix prepared in S4, while the other steps remained unchanged.

[0045] The corn cobs used in the above embodiments and comparative examples were taken from discarded corn cobs in farmland, and were washed and dried before the experiment; the polyethylene terephthalate was taken from recycled waste polyethylene terephthalate beverage bottles, and after washing and drying, it was cut into fragments with a size of less than 5 mm for later use; the activated carbon was produced by Sinopharm Chemical Reagent Co., Ltd., and was coconut shell-based activated carbon, which was ground and sieved before the experiment, with an average particle size of 80 mesh.

[0046] The performance of the gas separation-based ultraporous activated carbons prepared in Examples 1-3 and Comparative Examples 1-3 was tested, and the test results are shown in Table 1.

[0047] Sample preparation: Referring to standard GB / T 7702.1-1997, the gas separation-based ultraporous activated carbon prepared in the above examples and comparative examples was placed in a vacuum degassing station and continuously degassed for 12 hours at 150°C and a vacuum degree of less than 10 Pa to completely remove the pre-adsorbed moisture and impurity gases in the pores. After cooling to room temperature, it was ready for testing.

[0048] Adsorption performance: In accordance with standard GB / T 19587-2017, a fully automated gas adsorption analyzer was used to conduct tests at room temperature (25℃) and at high temperature (60℃) under simulated adsorption exothermic conditions. The saturated adsorption capacity of carbon dioxide at a pressure of 100 kPa was recorded. The larger the saturated adsorption capacity, the better the adsorption performance.

[0049] Separation performance: The carbon dioxide adsorption data measured above were calculated using the Ideal Adsorption Solution Theory (IAST) model. The volume ratio of the simulated flue gas components was set as CO2:N2=15:85, and the total pressure was 100kPa. The separation coefficients of carbon dioxide and nitrogen were calculated. The larger the separation coefficient value, the more preferentially the material adsorbs carbon dioxide in the mixed gas flow, and the better the separation performance.

[0050] Table 1 Performance Test Table of Ultraporous Activated Carbon Based on Gas Separation As shown in Table 1, the performance of the gas separation-based ultraporous activated carbon prepared in Examples 1-3 is superior to that of Comparative Examples 1-3. Moreover, under the simulated adsorption exothermic condition at 60℃, it still maintains a high adsorption and separation effect. This indicates that by constructing a composite pore structure with the synergistic effect of molecular sieve and activated carbon and effectively controlling the pore environment, the present invention can enhance the adsorption stability of the material under high temperature conditions and the selective separation ability of carbon dioxide, thereby improving its practical application adaptability in complex gas systems such as coal-fired flue gas.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A method for preparing ultraporous activated carbon based on gas separation, characterized in that, Includes the following steps: Step 1: Blend biomass raw materials and polymer raw materials and perform high-temperature pyrolysis carbonization to construct a basic carbon skeleton and obtain biomass-polymer carbonized material. Then, use potassium hydroxide to perform high-temperature chemical etching and activation on the carbonized material to obtain activated porous activated carbon. Step 2: Add aluminum source and silicon source to a strongly alkaline reaction environment constructed with sodium hydroxide to undergo hydrolysis and condensation reaction to obtain molecular sieve precursor sol. Then, introduce activated porous activated carbon into the molecular sieve precursor sol system for in-situ hydrothermal crystallization to obtain molecular sieve supported activated carbon matrix. Step 3: Place the molecular sieve-supported activated carbon matrix and calcium nitrate solution in deionized water to carry out a liquid-phase ion exchange reaction. Calcium ions are used to directionally replace sodium ions in the molecular sieve framework to obtain ultraporous activated carbon based on gas separation.

2. The method for preparing ultraporous activated carbon based on gas separation according to claim 1, characterized in that, In step three, the ratio of the molecular sieve-supported activated carbon matrix, calcium nitrate solution, and deionized water is 100-200g: 800-1000mL: 600-800mL.

3. The method for preparing ultraporous activated carbon based on gas separation according to claim 1, characterized in that, The molecular sieve-supported activated carbon matrix described in step two is prepared through the following steps: Molecular sieve precursor sol and activated porous activated carbon are placed in a reaction vessel and stirred at 25-35℃ for 20-40 minutes. The reaction vessel is then fixed in a homogeneous reactor and reacted for 6-8 hours. After filtration, washing, and vacuum drying to constant weight, molecular sieve-supported activated carbon matrix is ​​obtained.

4. The method for preparing ultraporous activated carbon based on gas separation according to claim 3, characterized in that, The mass ratio of the molecular sieve precursor sol to the activated porous activated carbon is 40-60:200-300.

5. The method for preparing ultraporous activated carbon based on gas separation according to claim 4, characterized in that, The molecular sieve precursor sol was prepared via the following steps: Sodium hydroxide, sodium aluminate, and deionized water are placed in a reaction vessel and stirred at 25-35°C for 10-20 minutes. Sodium silicate nonahydrate is then added, and the reaction continues at the same temperature for 1-2 hours to obtain a molecular sieve precursor sol.

6. The method for preparing ultraporous activated carbon based on gas separation according to claim 5, characterized in that, The ratio of sodium hydroxide, sodium aluminate, sodium silicate nonahydrate, and deionized water is 10-20g: 12-25g: 40-60g: 200-300mL.

7. The method for preparing ultraporous activated carbon based on gas separation according to claim 1, characterized in that, The activated porous activated carbon mentioned in step one is prepared through the following steps: Biomass-polymer carbonized material, potassium hydroxide, and deionized water were placed in a reactor and stirred at 25-35℃ for 6-8 hours. The reaction solution was then vacuum dried at 100-120℃ to constant weight. The dried material was placed in a tube furnace under nitrogen atmosphere protection and heated to 700-800℃ at a heating rate of 5℃ / min and calcined at a constant temperature for 1-2 hours. 1 mol / L hydrochloric acid was added to adjust the pH to 7. The material was then filtered, washed, vacuum dried to constant weight, and sieved to obtain activated porous activated carbon.

8. The method for preparing ultraporous activated carbon based on gas separation according to claim 1, characterized in that, The mass ratio of the biomass-polymer carbonized material, potassium hydroxide, and deionized water is 300-400: 600-800: 600-800.

9. The method for preparing ultraporous activated carbon based on gas separation according to claim 8, characterized in that, The biomass-polymer carbonized material is prepared through the following steps: Biomass raw materials and polymer raw materials are crushed in a high-speed pulverizer, sieved with a 60-100 mesh screen, the materials are collected and ground and mixed for 10-30 minutes, the mixed materials are placed in a tube furnace under nitrogen atmosphere protection, heated to 500-600℃ at a heating rate of 8℃ / min, and calcined at a constant temperature for 1-2 hours, the product is collected and ground to obtain biomass-polymer carbonized material; The mass ratio of the biomass raw material to the polymer raw material is 600-800:300-400.

10. A type of ultraporous activated carbon based on gas separation, characterized in that, It is prepared by the gas separation-based method for preparing ultraporous activated carbon according to any one of claims 1-9.

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