Amino acid grafted modified porous solid materials, their preparation methods and CO2 adsorption and capture methods

Abstract

This invention relates to the field of gas purification technology, and discloses an amino acid-grafted modified porous solid material, its preparation method, and a method for CO2 adsorption and capture. The amino acid-grafted modified porous solid material comprises a porous material and amino acids grafted onto the porous material, wherein the content of the amino acids is 5-35% by weight of the porous material. This amino acid-grafted modified porous solid material improves CO2 adsorption efficiency.

Description

Technical Field

[0001] This invention relates to the field of gas purification technology, specifically to an amino acid grafted modified porous solid material, its preparation method, and a method for CO2 adsorption and capture. Background Technology

[0002] CO2 capture is a crucial pathway to achieving clean and low-carbon utilization of fossil fuels. To reduce emissions of greenhouse gases such as CO2, amine liquid decarbonizing agents are widely used in industrial waste gas treatment. Traditional coal-fired power plants, due to their low flue gas pressure and low CO2 concentration, typically employ chemical absorption as their post-combustion capture process. This method utilizes alkaline amine liquid to capture CO2 through chemical reactions, exhibiting good selectivity and absorption rate. However, the long-term operation of alkaline solvents corrodes equipment and pipelines, and the amine liquid itself undergoes thermal and oxidative degradation. Furthermore, the desorption process requires overcoming the latent and sensible heat of the solvent, consuming large amounts of steam, increasing equipment investment costs and safety risks, resulting in significant amine loss and high energy consumption. Therefore, there is an urgent need to develop a new, highly efficient CO2 capture technology that is applicable to low-partial-pressure, low-concentration CO2 feed gas while reducing equipment corrosion, amine loss, and regeneration energy consumption. Currently, solid adsorption is a method for removing CO2 that can absorb CO2 under low partial pressure and low concentration conditions. It is also less corrosive to equipment and has a low regeneration temperature. It has been widely studied in the fields of CO2 removal from flue gas and direct carbon capture in air, and is expected to become a new generation of CO2 capture technology.

[0003] Common solid adsorbents include molecular sieves, porous carbon, metal-organic frameworks, solid amine materials, and polymers. From an adsorption mechanism perspective, they can be divided into physical adsorption and chemical adsorption. Physical adsorption mainly utilizes the sieving effect of pore size and the van der Waals interaction between CO2 and the material's pores, while chemical adsorption utilizes the acidity of CO2, allowing it to react chemically with the amine functional groups in the material and be adsorbed. Chemical adsorption is generally more suitable for capturing low partial pressure and low concentration CO2, exhibiting higher selectivity and faster adsorption rates. Currently, various solid amine materials have been synthesized for CO2 adsorption and separation. However, flue gas and air contain water vapor, and under conditions of large amounts of feed gas, the water vapor content is substantial. Water molecules typically interact with the surface of solid materials, and the presence of water vapor can compete with CO2 for adsorption, reducing the adsorption rate and capacity of the solid material. It also increases the heat required for water evaporation during regeneration, increasing regeneration energy consumption.

[0004] Therefore, developing a hydrophobic solid amine material for CO2 removal from flue gas and direct carbon capture in air is of great practical significance. It can avoid the dehumidification and drying steps of the feed gas, reducing operating costs and equipment investment costs, and also avoid competitive adsorption of CO2 by water vapor, reducing feed gas pressure drop, saving costs, and improving adsorption efficiency, thus providing strong support for achieving the target. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem that traditional solid adsorbents have reduced adsorption efficiency when performing CO2 removal from flue gas and direct carbon capture from air, due to the large number of hydroxyl groups on the surface of traditional porous materials, which are hydrophilic to water. This invention provides an amino acid-grafted modified porous solid material, its preparation method, and a method for CO2 adsorption and capture. This amino acid-grafted modified porous solid material improves CO2 adsorption efficiency.

[0006] To achieve the above objectives, a first aspect of the present invention provides an amino acid grafted modified porous solid material, wherein the amino acid grafted modified porous solid material comprises a porous material and an amino acid grafted onto the porous material, and the content of the amino acid is 5-35% by weight of the porous material.

[0007] The second aspect of the present invention provides a method for preparing an amino acid-grafted modified porous solid material, wherein the preparation method includes: mixing and grinding a porous material and an amino acid, followed by an esterification reaction, and then cooling, washing with water and drying the product after the reaction to obtain the amino acid-grafted modified porous solid material.

[0008] A third aspect of the present invention provides an amino acid-grafted modified porous solid material prepared by the aforementioned preparation method.

[0009] The fourth aspect of the present invention provides a method for CO2 adsorption and capture, wherein the method uses the aforementioned amino acid grafted modified porous solid material as an adsorbent to adsorb and capture CO2.

[0010] The above-described technical solution, employing the technical solution of the present invention, has the following beneficial effects:

[0011] (1) The use of amino acid grafting modified porous solid material not only improves the hydrophobicity of the material surface, weakens the affinity of the material for water vapor, avoids the competitive adsorption of CO2 by water, reduces the pressure drop of the raw gas, lowers the desorption temperature, reduces operating costs, and reduces regeneration energy consumption, but also successfully introduces CO2 adsorption sites. Since the amino groups are introduced by grafting, they are very strong and not easy to be lost, thus improving the CO2 adsorption efficiency.

[0012] (2) Amino acid grafted modified porous solid materials have high mechanical strength, good adsorption performance, stable structure and good cycle stability. They are suitable for adsorbing CO2 in fixed bed devices, fluidized bed devices and moving bed devices in industrial processes. The CO2 removal rate can reach more than 99%. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the adsorption curves of L-tert-leucine grafted modified Al2O3 prepared in Example 6 and L-tert-leucine impregnated modified Al2O3 prepared in Comparative Example 6.

[0014] Figure 2 The contact angles are those of the L-tert-leucine-grafted modified Al2O3 prepared in Example 6 and the L-tert-leucine-impregnated modified Al2O3 prepared in Comparative Example 6. Detailed Implementation

[0015] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0016] As previously stated, the first aspect of the present invention provides an amino acid grafted modified porous solid material, wherein the amino acid grafted modified porous solid material comprises a porous material and an amino acid grafted onto the porous material, and the content of the amino acid is 5-35% by weight of the porous material.

[0017] According to the present invention, preferably, the content of the amino acid is 21-34% by weight of the porous material.

[0018] The inventors of this invention discovered that porous materials have a large number of free hydroxyl functional groups on their surface, while amino acids contain carboxyl and amino groups. The carboxyl groups undergo esterification with the hydroxyl groups on the porous material surface, successfully grafting amino acids onto the porous material and introducing amino groups that adsorb CO2. Simultaneously, the generated ester groups are hydrophobic, weakening the competitive adsorption of CO2 by water vapor and thus facilitating CO2 absorption.

[0019] Furthermore, when a CO2 mixture containing water vapor passes through an amino acid-grafted porous solid material, the surface of the porous material is modified with amino acids, generating hydrophobic ester functional groups. This weakens water adsorption, avoids competitive adsorption of CO2 by water vapor, and increases the CO2 adsorption capacity and rate. Simultaneously, the reduced adsorption of water vapor significantly reduces the pressure drop of the feed gas during adsorption, thus lowering energy consumption. Moreover, the desorption process avoids the heat required for evaporating large amounts of water; desorption can be achieved at relatively low temperatures, utilizing low-grade heat waste from industrial processes for complete desorption, resulting in energy savings and reduced consumption.

[0020] Furthermore, when a CO2 mixture containing water vapor passes through an amino acid-grafted modified porous solid material, the ester groups on the material surface eliminate the competitive adsorption of water, while the introduced amine groups react chemically with CO2 for adsorption, which helps to improve the CO2 absorption efficiency.

[0021] According to the present invention, the pore volume of the amino acid grafted modified porous solid material is 0.1-2 cm³. 3 / g, pore size 10-100nm, specific surface area 300-865m² 3 / g; preferably, the pore volume of the amino acid-grafted modified porous solid material is 0.3-0.8 cm³. 3 / g, pore size 15-65nm, specific surface area 320-800m² 3 / g; More preferably, the pore volume of the amino acid-grafted modified porous solid material is 0.3-0.8 cm³. 3 / g, pore size 15-65nm, specific surface area 349-756m² 3 / g

[0022] According to the present invention, the porous material is a commercially available mesoporous or macroporous material with a large number of hydroxyl groups on its surface, used for modification; preferably, the porous material is selected from one or more of mesoporous activated carbon, macroporous activated carbon, MCM-41, SBA-15, SBA-16, titanium dioxide, aluminum oxide and macroporous resin.

[0023] According to the present invention, preferably, the pore volume of the porous material is 0.1-1.5 cm. 3 / g, pore size 2-85nm, specific surface area 300-850m² 3 / g; more preferably, the pore volume of the porous material is 0.3-0.8 cm³. 3 / g, pore size 15-65nm, specific surface area 320-800m² 3 / g; More preferably, the pore volume of the porous material is 0.3-0.8 cm³. 3 / g, pore size 15-65nm, specific surface area 349-756m² 3 / g.

[0024] According to the present invention, the amino acids used for modification are commercial products and do not require additional synthesis; preferably, the amino acids are selected from one or more of L-tert-leucine, glutamic acid, glycine, alanine, leucine, proline, serine and tyrosine.

[0025] According to the present invention, the adsorption capacity of the amino acid grafted modified porous solid material is 5.1-5.7 mmol / g.

[0026] The second aspect of the present invention provides a method for preparing an amino acid-grafted modified porous solid material, wherein the preparation method includes: mixing and grinding a porous material and an amino acid, followed by an esterification reaction, and then cooling, washing with water and drying the product after the reaction to obtain the amino acid-grafted modified porous solid material.

[0027] According to the present invention, a method for grafting and modifying porous materials with amino acids includes: thoroughly mixing and grinding amino acids and porous materials in a certain proportion; then placing the mixture in an oven for esterification reaction, wherein no additional catalyst is required for the esterification process; after the reaction is completed and the mixture has cooled completely, washing away any ungrafted amino acids with water, and then drying to obtain the amino acid-modified porous solid adsorbent material.

[0028] According to the present invention, the grinding time is 15-45 min, preferably 15-20 min.

[0029] According to the present invention, the conditions for the esterification reaction include: an esterification reaction temperature of 100-120°C and an esterification reaction duration of 8-12 h; preferably, the temperature is 105-110°C and the esterification reaction duration is 8-10 h.

[0030] According to the present invention, the amount of amino acid used is 10-100 parts by weight, preferably 20-35 parts by weight, relative to 100 parts by weight of the mesoporous material.

[0031] A third aspect of the present invention provides an amino acid-grafted modified porous solid material prepared by the aforementioned preparation method.

[0032] The fourth aspect of the present invention provides a method for CO2 adsorption and capture, wherein the method uses the aforementioned amino acid grafted modified porous solid material as an adsorbent to adsorb and capture CO2.

[0033] According to the present invention, the aforementioned amino acid grafted modified porous solid material is applied to CO2 adsorption and capture. Preferably, the application is suitable for absorption or capture devices for low partial pressure CO2, and is applicable to industrial waste gas treatment, flue gas CO2 removal, and direct carbon capture of air.

[0034] According to the present invention, the adsorption and capture method includes: filling an amino acid-grafted modified porous solid material into a temperature-controlled area of ​​a custom-made quartz glass tube; controlling the flow rate of the raw gas through the solid material by a flow meter and a regulating valve; wrapping the outside of the quartz tube with an electric heating system and a heat insulation layer; and connecting CO2 detection devices to the inlet and outlet of the quartz tube respectively.

[0035] According to the present invention, the main equipment for adsorbing CO2 by the amino acid grafted modified porous solid material includes a custom-made quartz glass tube, in which the porous material is filled in the middle constant temperature zone of the quartz tube; wherein, the middle constant temperature zone is provided with a temperature control device to maintain the adsorption temperature at 20-50℃ and control the desorption temperature at 80-120℃; specifically, the temperature control device includes a constant temperature electric heating system to control the adsorption temperature at 20-50℃ and the desorption temperature at 80-120℃.

[0036] Furthermore, the main equipment for adsorbing CO2 by the amino acid grafted modified porous solid material also includes a humidity generator, a gas phase CO2 detection device, a gas phase flow control device, and a purified gas carbon dioxide detection device.

[0037] The humidity generator is used to regulate and control the humidity changes of the raw material gas.

[0038] Among them, the gas phase CO2 detection device is used to monitor the CO2 concentration in the gas to be treated, ensuring it is around 10-15% (v / v).

[0039] The gas inlet control device is used to control the flow rate of the raw material gas (phase). Preferably, the gas inlet control device includes a regulating valve and a flow meter to ensure that the gas inlet flow rate is stable at 80 mL / min-200 mL / min and the raw material gas concentration is in the range of 0-85%. Furthermore, in this invention, when ensuring that the gas inlet flow rate is stable at 80 mL / min-200 mL / min, the loading mass of the amino acid grafted modified porous solid material is 5-15 g.

[0040] Among them, the purified gas carbon dioxide detection device is used to detect the carbon dioxide concentration in the purified gas, and the detection value is less than 0.1%.

[0041] In this invention, the adsorption device can be a conventional choice for those skilled in the art. The CO2 adsorption and capture device used in this invention includes:

[0042] Amino acid-grafted modified porous solid material is placed in a temperature-controlled zone within a custom-designed quartz glass tube. The quartz tube is surrounded by an electric heating device and insulation material, maintaining the adsorption temperature at 45°C. One end of the quartz tube is connected to an inlet, and the other end to an outlet. The feed gas is a 15% / 85% (v / v) CO2 / N2 mixture. This mixture is first humidified to 25% using a humidity generator, and then the flow rate is controlled at 120 mL / min using a flow meter and regulating valve. The feed gas flows out through the adsorbent material in the quartz tube from the other end. Both ends of the quartz tube are equipped with gas and flow detection devices to monitor the gas concentration and flow rate in real time. The adsorption process is complete when the CO2 concentration at the outlet no longer changes. After adsorption, N2 is introduced into the other end of the quartz tube for backflushing, while the desorption temperature is controlled at 100°C. The desorption process is complete when the CO2 concentration in the outflowing gas no longer changes. The relationship between CO2 adsorption and CO2 desorption over time can be obtained from the recorded data.

[0043] The present invention will be described in detail below through embodiments.

[0044] In the following examples and comparative examples:

[0045] Pore ​​size parameters were measured using the BET method; activated carbon, MCM-41, SBA-15, SBA-16, and Al2O3 raw materials were commercially available from McLean Company, and various amino acids were commercially available from Aladdin Company.

[0046] Example 1

[0047] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0048] (1) The preparation process of amino acid grafted modified porous solid materials is as follows:

[0049] Take 10g of mesoporous activated carbon (pore volume 0.3cm³). 3 / g, pore size 15nm, specific surface area 349m² 3 1 g of L-tert-leucine was ground in a mortar for 15 min to ensure thorough mixing. The mixture was then placed in an oven at 115 °C for 10 h. After the esterification reaction was completed, the sample was removed, cooled to room temperature, and thoroughly washed with water to remove unreacted L-tert-leucine. The sample was then vacuum dried at 120 °C for later use. This yielded an amino acid-grafted modified porous solid material, namely, L-tert-leucine-grafted modified mesoporous activated carbon.

[0050] In the L-tert-leucine-grafted modified mesoporous activated carbon, the content of L-tert-leucine is 25% by weight of the mesoporous activated carbon; and the pore volume of the L-tert-leucine-grafted modified mesoporous activated carbon is 0.3 cm³. 3 / g, pore size 15nm, specific surface area 349m² 3 / g;

[0051] (2) The CO2 adsorption and desorption process is as follows:

[0052] Using the adsorption device of this invention, 5g of L-tert-leucine-grafted modified mesoporous activated carbon is placed as the adsorbent in a constant-temperature zone within a custom-made quartz glass tube. The quartz tube is surrounded by an electric heating device and insulation material, and the adsorption temperature is controlled at 45°C. One end of the quartz tube is connected to the inlet, and the other end is connected to the outlet. The feed gas is a 15% / 85% (v / v) CO2 / N2 mixture. This mixture is first adjusted to a humidity of 25% by a humidity generator, and then the flow rate is controlled at 120mL / min by a flow meter and regulating valve. The feed gas flows out from the other end of the quartz tube after passing through the adsorbent material. Both ends of the quartz tube are equipped with gas detection devices and flow detection devices to monitor the gas concentration and flow rate in real time. The adsorption process is complete when the CO2 concentration at the outlet no longer changes. After adsorption is complete, N2 is introduced into the other end of the quartz tube for backflushing, while the desorption temperature is controlled at 100°C. The desorption process is complete when the CO2 concentration in the outflowing gas no longer changes. The relationship between CO2 adsorption and CO2 desorption over time can be obtained from the recorded data.

[0053] The results showed that the adsorption capacity was 5.2 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0054] Example 2

[0055] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0056] (1) The amino acid grafted modified porous solid material was prepared according to the same method as in Example 1, except that in the preparation process of the amino acid grafted modified porous solid material, "10g mesoporous activated carbon" was replaced with "10g macroporous activated carbon (pore volume of 0.4cm)". 3 / g, with a macropore diameter of 65nm and a specific surface area of ​​368m². 3 The remaining steps and methods were the same, and L-tert-leucine grafted modified macroporous activated carbon was prepared.

[0057] In the L-tert-leucine-grafted modified macroporous activated carbon, the content of L-tert-leucine is 28% by weight of the macroporous activated carbon; and the pore volume of the L-tert-leucine-grafted modified macroporous activated carbon is 0.4 cm³. 3 / g, pore size 65nm, specific surface area 368m² 3 / g;

[0058] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of L-tert-leucine-grafted modified macroporous activated carbon as adsorbent”. The adsorption temperature was 30°C and the desorption temperature was 80°C. All other steps were the same.

[0059] The result showed an adsorption capacity of 5.1 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0060] Example 3

[0061] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0062] (1) The amino acid grafted modified porous solid material was prepared according to the same method as in Example 1, except that in the preparation process of the amino acid grafted modified porous solid material, "10g mesoporous activated carbon" was replaced with "10g MCM-41 (pore volume of 0.5cm³)". 3 / g, pore size 16nm, specific surface area 535m² 3 The remaining steps and methods were the same, and L-tert-leucine grafted modified MCM-41 was prepared.

[0063] In the L-tert-leucine-grafted modified MCM-41, the content of L-tert-leucine is 29% by weight of the MCM-41; and the pore volume of the L-tert-leucine-grafted modified MCM-41 is 0.5 cm³. 3 / g, pore size 16nm, specific surface area 535m² 3 / g;

[0064] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of L-tert-leucine-grafted modified MCM-41 as adsorbent”. The adsorption temperature was 40°C and the desorption temperature was 95°C. All other steps were the same.

[0065] The adsorption capacity was 5.4 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0066] Example 4

[0067] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0068] (1) The amino acid grafted modified porous solid material was prepared according to the same method as in Example 1, except that in the preparation process of the amino acid grafted modified porous solid material, "10g mesoporous activated carbon" was replaced with "10g SBA-15 (pore volume of 0.6cm³)". 3 / g, pore size 23nm, specific surface area 612m² 3 The remaining steps and methods were the same, and SBA-15 modified with L-tert-leucine grafting was prepared.

[0069] In the L-tert-leucine-grafted modified SBA-15, the content of L-tert-leucine is 30% by weight of the SBA-15; and the pore volume of the L-tert-leucine-grafted modified SBA-15 is 0.6 cm³. 3 / g, pore size 23nm, specific surface area 612m² 3 / g;

[0070] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between Example 1 and Example 2 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of L-tert-leucine-grafted modified SBA-15 as adsorbent”. The adsorption temperature was 35°C and the desorption temperature was 105°C. All other steps were the same.

[0071] The result showed an adsorption capacity of 5.5 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0072] Example 5

[0073] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0074] (1) The amino acid grafted modified porous solid material was prepared according to the same method as in Example 1, except that in the preparation process of the amino acid grafted modified porous solid material, "10g mesoporous activated carbon" was replaced with "10g SBA-16 (pore volume of 0.7cm³)". 3 / g, pore size 32nm, specific surface area 656m² 3The remaining steps and methods were the same, and L-tert-leucine grafted modified SBA-16 was prepared.

[0075] In the L-tert-leucine-grafted modified SBA-16, the content of L-tert-leucine is 23% by weight of the SBA-16; and the pore volume of the L-tert-leucine-grafted modified SBA-16 is 0.7 cm³. 3 / g, pore size 32nm, specific surface area 656m² 3 / g;

[0076] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of L-tert-leucine-grafted modified SBA-16 as adsorbent”. The adsorption temperature was 25°C and the desorption temperature was 115°C. All other steps were the same.

[0077] The adsorption capacity was 5.6 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0078] Example 6

[0079] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0080] (1) Amino acid grafted modified porous solid materials were prepared using the same method as in Example 1, except that in the preparation of the amino acid grafted modified porous solid materials, "10g mesoporous activated carbon" was replaced with "10g Al2O3 (pore volume of 0.8cm³)". 3 / g, pore size 45nm, specific surface area 756m² 3 The remaining steps and methods were the same, and L-tert-leucine grafted modified Al2O3 was prepared.

[0081] In the L-tert-leucine-grafted Al2O3, the content of L-tert-leucine is 27% by weight of the Al2O3; and the pore volume of the L-tert-leucine-grafted Al2O3 is 0.8 cm³. 3 / g, pore size 45nm, specific surface area 756m² 3 / g;

[0082] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that "5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent" was replaced with "5g of L-tert-leucine-grafted modified Al2O3 as adsorbent". The adsorption temperature was 20°C and the desorption temperature was 120°C. All other steps were the same.

[0083] The adsorption capacity was 5.7 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0084] Example 7

[0085] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0086] (1) The amino acid grafted modified porous solid material was prepared according to the same method as in Example 2, except that in the preparation process of the amino acid grafted modified porous solid material, "1g L-tert-leucine" was replaced with "1g proline (pore volume 0.4cm)". 3 / g, pore size 65nm, specific surface area 368m² 3 The remaining steps and methods are the same, and proline-grafted modified macroporous activated carbon is prepared.

[0087] In the proline-grafted macroporous activated carbon, the proline content is 21% by weight of the macroporous activated carbon; and the pore volume of the proline-grafted macroporous activated carbon is 0.4 cm³. 3 / g, pore size 65nm, specific surface area 368m² 3 / g;

[0088] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between Example 2 and Example 2 was that "5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent" was replaced with "5g of proline-grafted modified macroporous activated carbon as adsorbent". The adsorption temperature was 20°C and the desorption temperature was 95°C. All other steps were the same.

[0089] The result showed an adsorption capacity of 5.3 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0090] Example 8

[0091] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0092] (1) The amino acid grafted modified porous solid material was prepared according to the same method as in Example 3, except that in the preparation process of the amino acid grafted modified porous solid, "1g L-tert-leucine" was replaced with "1g proline (pore volume of 0.5cm)". 3 / g, pore size 16nm, specific surface area 535m² 3 The remaining steps and methods were the same, and proline-grafted modified MCM-41 was prepared.

[0093] In the proline-grafted modified MCM-41, the proline content is 26% by weight of the MCM-41; and the pore volume of the proline-grafted modified MCM-41 is 0.5 cm³. 3 / g, pore size 16nm, specific surface area 535m² 3 / g;

[0094] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of proline-grafted modified MCM-41 as adsorbent”. The adsorption temperature was 30°C and the desorption temperature was 105°C. All other steps were the same.

[0095] The adsorption capacity was 5.4 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0096] Example 9

[0097] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0098] (1) The amino acid grafted modified porous solid material was prepared according to the same method as in Example 4, except that in the preparation process of the amino acid grafted modified porous solid material, "1g L-tert-leucine" was replaced with "1g proline (pore volume of 0.6cm)". 3 / g, pore size 23nm, specific surface area 612m² 3 The remaining steps and methods were the same, and proline-grafted modified SBA-15 was prepared.

[0099] In the proline-grafted modified SBA-15, the proline content is 29% by weight of the SBA-15; and the pore volume of the proline-grafted modified SBA-15 is 0.6 cm³. 3 / g, pore size 23nm, specific surface area 612m² 3 / g;

[0100] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that "5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent" was replaced with "5g of proline-grafted modified SBA-15 as adsorbent". The adsorption temperature was 25°C and the desorption temperature was 105°C. All other steps were the same.

[0101] The adsorption capacity was 5.6 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0102] Example 10

[0103] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0104] (1) The amino acid grafted modified porous solid material was prepared according to the same method as in Example 5, except that in the preparation process of the amino acid grafted modified porous solid material, "1g L-tert-leucine" was replaced with "1g proline (pore volume 0.7cm)". 3 / g, pore size 32nm, specific surface area 656m² 3 The remaining steps and methods were the same, and proline-grafted modified SBA-16 was prepared.

[0105] In the proline-grafted modified SBA-16, the proline content is 22% by weight of the SBA-16; and the pore volume of the proline-grafted modified SBA-16 is 0.7 cm³. 3 / g, pore size 32nm, specific surface area 656m² 3 / g;

[0106] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between Example 1 and Example 2 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of proline-grafted modified SBA-16 as adsorbent”. The adsorption temperature was 25°C and the desorption temperature was 100°C. All other steps were the same.

[0107] The adsorption capacity was 5.7 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0108] Example 11

[0109] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0110] (1) The amino acid grafted modified porous solid material was prepared according to the same method as in Example 6, except that in the preparation process of the amino acid grafted modified porous solid material, "1L-tert-leucine" was replaced with "1g proline (pore volume of 0.8cm)". 3 / g, pore size 45nm, specific surface area 756m² 3 The remaining steps and methods are the same, and proline-grafted modified Al2O3 is prepared.

[0111] In the proline-grafted Al2O3, the proline content is 26% by weight of the Al2O3; and the pore volume of the proline-grafted Al2O3 is 0.8 cm³. 3 / g, pore size 45nm, specific surface area 756m² 3 / g;

[0112] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that "5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent" was replaced with "5g of proline-grafted modified Al2O3 as adsorbent". The adsorption temperature was 30°C and the desorption temperature was 90°C. All other steps were the same.

[0113] The adsorption capacity was 5.2 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0114] Example 12

[0115] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0116] (1) Prepare amino acid grafted modified porous solid materials according to the same method as in Example 11, except that in the preparation process of amino acid grafted modified porous solid materials, "1g proline" is replaced with "1g tyrosine (pore volume of 0.8cm)". 3 / g, pore size 45nm, specific surface area 756m² 3 The remaining steps and methods are the same, and tyrosine-grafted modified Al2O3 is prepared.

[0117] In the tyrosine-grafted Al2O3, the tyrosine content is 27% by weight of the Al2O3; and the pore volume of the tyrosine-grafted Al2O3 is 0.8 cm³. 3 / g, pore size 45nm, specific surface area 756m² 3 / g;

[0118] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of tyrosine-grafted modified Al2O3 as adsorbent”. The adsorption temperature was 30°C and the desorption temperature was 85°C. All other steps were the same.

[0119] The result showed an adsorption capacity of 5.3 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0120] Example 13

[0121] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0122] (1) An amino acid-grafted modified porous solid material was prepared using the same method as in Example 12, except that in the preparation process of the amino acid-grafted modified porous solid material, "1g tyrosine" was replaced with "1g serine (pore volume 0.8cm)". 3 / g, pore size 45nm, specific surface area 756m² 3 The remaining steps and methods are the same, and serine-grafted modified Al2O3 is prepared.

[0123] In the serine-grafted Al2O3, the serine content is 26% by weight of the Al2O3; and the pore volume of the serine-grafted Al2O3 is 0.8 cm³. 3 / g, pore size 45nm, specific surface area 756m² 3 / g;

[0124] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of serine-grafted modified Al2O3 as adsorbent”. The adsorption temperature was 25°C and the desorption temperature was 85°C. All other steps were the same.

[0125] The result showed an adsorption capacity of 5.5 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0126] Example 14

[0127] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0128] (1) An amino acid-grafted modified porous solid material was prepared using the same method as in Example 13, except that in the preparation of the amino acid-grafted modified porous solid material, "1g serine" was replaced with "1g glycine (pore volume 0.8cm)". 3 / g, pore size 45nm, specific surface area 756m² 3 The remaining steps and methods are the same, and glycine-grafted modified Al2O3 is prepared.

[0129] In the glycine-grafted Al2O3, the glycine content is 34% by weight of the Al2O3; and the pore volume of the glycine-grafted Al2O3 is 0.8 cm³. 3 / g, pore size 45nm, specific surface area 756m² 3 / g;

[0130] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between Example 1 and Example 2 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of glycine-grafted modified Al2O3 as adsorbent”. The adsorption temperature was 35°C and the desorption temperature was 95°C. All other steps were the same.

[0131] The adsorption capacity was 5.6 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0132] Example 15

[0133] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0134] (1) An amino acid-grafted modified porous solid material was prepared using the same method as in Example 14. The difference from Example 14 was that, in the preparation of the amino acid-grafted modified porous solid material, "1g glycine" was replaced with "1g alanine (pore volume 0.8cm³)". 3 / g, pore size 45nm, specific surface area 756m² 3 The remaining steps and methods are the same, and alanine-grafted modified Al2O3 is prepared.

[0135] In the alanine-grafted Al2O3, the alanine content is 27% by weight of the Al2O3; and the pore volume of the alanine-grafted Al2O3 is 0.8 cm³. 3 / g, pore size 45nm, specific surface area 756m² 3 / g;

[0136] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that "5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent" was replaced with "5g of alanine-grafted modified Al2O3 as adsorbent". The adsorption temperature was 35°C and the desorption temperature was 105°C. All other steps were the same.

[0137] The result showed an adsorption capacity of 5.1 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0138] Example 16

[0139] This embodiment illustrates the amino acid-grafted modified porous solid material prepared according to the present invention and its adsorption and capture of CO2.

[0140] (1) An amino acid-grafted modified porous solid material was prepared using the same method as in Example 15, except that in the preparation process of the amino acid-grafted modified porous solid material, "1g alanine" was replaced with "1g leucine (pore volume 0.8cm)". 3 / g, pore size 45nm, specific surface area 756m² 3 The remaining steps and methods are the same, and leucine-grafted modified Al2O3 is prepared.

[0141] In the leucine-grafted Al2O3, the leucine content is 32% by weight of the Al2O3; and the pore volume of the leucine-grafted Al2O3 is 0.8 cm³. 3 / g, pore size 45nm, specific surface area 756m² 3 / g;

[0142] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1, except that in the CO2 adsorption and desorption process, the difference from Example 15 was that “5g of L-tert-leucine-grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of leucine-grafted modified Al2O3 as adsorbent”, the adsorption temperature was 30°C and the desorption temperature was 110°C, and the rest of the steps were the same.

[0143] The adsorption capacity was 5.2 mmol / g, and the adsorption capacity did not decrease after 10 adsorption-desorption cycles.

[0144] Comparative Example 1

[0145] The preparation process of amino acid-impregnated modified porous solid materials is as follows:

[0146] (1) 1g of L-tert-leucine was dissolved in water and loaded onto 10g of mesoporous activated carbon using the equal volume impregnation method. The sample was then vacuum dried at 120℃ for later use. As a result, L-tert-leucine impregnated modified mesoporous activated carbon was prepared.

[0147] In the L-tert-leucine-impregnated mesoporous activated carbon, the content of L-tert-leucine is 25% by weight of the mesoporous activated carbon; and the pore volume of the L-tert-leucine-impregnated mesoporous activated carbon is 0.3 cm³. 3 / g, pore size 15nm, specific surface area 349m² 3 / g;

[0148] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between Example 1 and Example 2 was that “5g of L-tert-leucine grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of L-tert-leucine impregnated modified mesoporous activated carbon as adsorbent”. All other steps were the same.

[0149] The results showed that the adsorption capacity was 2.2 mmol / g, and the adsorption capacity decreased by 70% after 10 adsorption-desorption cycles.

[0150] Comparative Example 2

[0151] (1) Prepare amino acid impregnated modified porous solid material according to the same method as Comparative Example 1. The difference from Comparative Example 1 is that in the preparation process of amino acid impregnated modified porous solid material, "10g mesoporous activated carbon" is replaced with "10g macroporous activated carbon". The other steps are the same, and L-tert-leucine impregnated modified macroporous activated carbon is prepared.

[0152] In the L-tert-leucine-impregnated macroporous activated carbon, the content of L-tert-leucine is 28% by weight of the macroporous activated carbon; and the pore volume of the L-tert-leucine-impregnated macroporous activated carbon is 0.4 cm³. 3 / g, pore size 65nm, specific surface area 368m² 3 / g;

[0153] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that “5g of L-tert-leucine grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of L-tert-leucine impregnated modified macroporous activated carbon as adsorbent”. The adsorption temperature was 30°C and the desorption temperature was 80°C. All other steps were the same.

[0154] The results showed that the adsorption capacity was 1.8 mmol / g, and after 10 adsorption-desorption cycles, the adsorption capacity decreased by 63%.

[0155] Comparative Example 3

[0156] 1) Prepare amino acid impregnated modified porous solid material according to the same method as Comparative Example 1. The difference from Comparative Example 1 is that in the preparation process of amino acid impregnated modified solid porous material, "10g mesoporous activated carbon" is replaced with "10g MCM-41". The remaining steps are the same, and L-tert-leucine impregnated modified MCM-41 is obtained.

[0157] In the L-tert-leucine-impregnated MCM-41, the content of L-tert-leucine is 29% by weight of the MCM-41; and the pore volume of the L-tert-leucine-impregnated MCM-41 is 0.5 cm³. 3 / g, pore size 16nm, specific surface area 535m² 3 / g;

[0158] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between Example 1 and Example 2 was that “5g of L-tert-leucine grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of L-tert-leucine impregnated modified MCM-41 as adsorbent”. The adsorption temperature was 40°C and the desorption temperature was 95°C. All other steps were the same.

[0159] The results showed that the adsorption capacity was 2.1 mmol / g, and after 10 adsorption-desorption cycles, the adsorption capacity decreased by 72% (Comparative Example 4).

[0160] (1) The amino acid impregnated modified porous solid material was prepared in the same way as Comparative Example 1. The difference from Comparative Example 1 was that in the preparation process of the amino acid impregnated modified porous solid material, “10g mesoporous activated carbon” was replaced with “10g SBA-15”. The other steps were the same, and L-tert-leucine impregnated modified SBA-15 was obtained.

[0161] In the L-tert-leucine-impregnated SBA-15, the content of L-tert-leucine is 30% by weight of the SBA-15; and the pore volume of the L-tert-leucine-impregnated SBA-15 is 0.6 cm³. 3 / g, pore size 23nm, specific surface area 612m² 3 / g;

[0162] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between Example 1 and Example 2 was that “5g of L-tert-leucine grafted modified mesoporous activated carbon as adsorbent” was replaced with “5g of L-tert-leucine impregnated modified SBA-15 as adsorbent”. The adsorption temperature was 35°C and the desorption temperature was 105°C. All other steps were the same.

[0163] The results showed that the adsorption capacity was 2.3 mmol / g, and after 10 adsorption-desorption cycles, the adsorption capacity decreased by 71% (Comparative Example 5).

[0164] (1) The amino acid impregnated modified porous solid material was prepared in the same way as Comparative Example 1. The difference from Comparative Example 1 was that in the preparation process of the amino acid impregnated modified porous solid material, “10g mesoporous activated carbon” was replaced with “10g SBA-16”. The other steps were the same, and L-tert-leucine impregnated modified SBA-16 was prepared.

[0165] In the L-tert-leucine-impregnated SBA-16, the content of L-tert-leucine is 23% by weight of the SBA-16; and the pore volume of the L-tert-leucine-impregnated SBA-16 is 0.7 cm³. 3 / g, pore size 32nm, specific surface area 656m² 3 / g;

[0166] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that "5g of L-tert-leucine grafted modified mesoporous activated carbon as adsorbent" was replaced with "5g of L-tert-leucine impregnated modified SBA-16 as adsorbent". The adsorption temperature was 25°C and the desorption temperature was 115°C. All other steps were the same.

[0167] The results showed that the adsorption capacity was 2.5 mmol / g, and after 10 adsorption-desorption cycles, the adsorption capacity decreased by 75%. (Comparative Example 6)

[0168] (1) Amino acid impregnated modified porous solid material was prepared in the same way as Comparative Example 1. The difference from Comparative Example 1 was that in the preparation process of amino acid impregnated modified porous solid material, “10g mesoporous activated carbon” was replaced with “10g Al2O3”. The other steps and methods were the same, and L-tert-leucine impregnated modified Al2O3 was prepared.

[0169] In the L-tert-leucine-impregnated Al2O3, the content of L-tert-leucine is 27% by weight of the Al2O3; and the pore volume of the L-tert-leucine-impregnated Al2O3 is 0.8 cm³. 3 / g, pore size 45nm, specific surface area 756m² 3 / g;

[0170] (2) CO2 adsorption and desorption were carried out in the same manner as in Example 1. However, the difference between the CO2 adsorption and desorption process and that in Example 1 was that "5g of L-tert-leucine grafted modified mesoporous activated carbon as adsorbent" was replaced with "5g of L-tert-leucine impregnated modified Al2O3 as adsorbent". The adsorption temperature was 20°C and the desorption temperature was 120°C. All other steps were the same.

[0171] The results showed that the adsorption capacity was 2.4 mmol / g, and after 10 adsorption-desorption cycles, the adsorption capacity decreased by 76%. Figure 1 This is a schematic diagram of the adsorption curves of L-tert-leucine-grafted modified Al2O3 prepared in Example 6 and L-tert-leucine-impregnated modified Al2O3 prepared in Comparative Example 6; Figure 1 It can be seen that, even among Al2O3 modified with L-tert-leucine, their CO2 adsorption performance varies greatly. Al2O3 modified by grafting L-tert-leucine via esterification exhibits a faster adsorption rate and larger adsorption capacity than Al2O3 modified by simple impregnation. This is mainly because the grafted Al2O3 surface contains a large number of ester groups. These ester groups are hydrophobic, which can significantly inhibit the competitive adsorption of CO2 by water, thereby improving its adsorption capacity and rate.

[0172] Figure 2 The contact angles were compared between the L-tert-leucine-grafted modified Al2O3 prepared in Example 6 and the L-tert-leucine-impregnated modified Al2O3 prepared in Comparative Example 6; from Figure 2 It can be seen that porous materials modified with grafted amino acids have stronger hydrophobicity.

[0173] 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. An amino acid-grafted modified porous solid material, characterized in that, The amino acid grafted modified porous solid material comprises a porous material and amino acids grafted onto the porous material, wherein the content of the amino acids is 5-35% by weight of the porous material.

2. The amino acid grafted modified porous solid material according to claim 1, wherein, The amino acid content is 21-34% by weight of the porous material; and / or the pore volume of the amino acid-grafted porous solid material is 0.1-2 cm 3 / g, the pore size is 10-100 nm, and the specific surface area is 300-865 m 3 / g; Preferably, the pore volume of the amino acid-grafted modified porous solid material is 0.3-0.8 cm³. 3 / g, pore size 15-65nm, specific surface area 320-800m² 3 / g.

3. The amino acid grafted modified porous solid material according to claim 1 or 2, wherein, The porous material is selected from one or more of mesoporous activated carbon, macroporous activated carbon, MCM-41, SBA-15, SBA-16, titanium dioxide, aluminum oxide and macroporous resin; Preferably, the pore volume of the porous material is 0.1-1.5 cm. 3 / g, pore size 2-85nm, specific surface area 300-850m² 3 / g; More preferably, the pore volume of the porous material is 0.3-0.8 cm³. 3 / g, pore size 15-65nm, specific surface area 320-800m² 3 / g.

4. The amino acid grafted modified porous solid material according to claim 1 or 2, wherein, The amino acid is selected from one or more of L-tert-leucine, glutamic acid, glycine, alanine, leucine, proline, serine, and tyrosine.

5. The amino acid grafted modified porous solid material according to any one of claims 1-4, wherein, The adsorption capacity of the amino acid-grafted modified porous solid material is 5.1-5.7 mmol / g.

6. A method for preparing an amino acid-grafted modified porous solid material, characterized in that, The preparation method includes: mixing and grinding porous materials and amino acids, followed by esterification reaction, and then cooling, washing with water and drying the reaction product to obtain amino acid grafted modified porous solid material.

7. The preparation method according to claim 6, wherein, The grinding time is 15-45 minutes; And / or, the conditions for the esterification reaction include: an esterification reaction temperature of 100-120°C and an esterification reaction time of 8-12 h.

8. The preparation method according to claim 6 or 7, wherein, The amount of amino acid used is 10-100 parts by weight relative to 100 parts by weight of the mesoporous material.

9. An amino acid-grafted modified porous solid material prepared by the preparation method according to any one of claims 6-8.

10. A method for CO2 adsorption and capture, characterized in that, The method uses the amino acid-grafted modified porous solid material as described in any one of claims 1-5 and 9 as an adsorbent to adsorb and capture CO2.

Images