Metal organic framework adsorbent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of adsorbent cyanamide production, in particular to a metal organic framework adsorbent and a preparation method and application thereof, and the metal organic framework adsorbent comprises formic acid, aluminum hydroxide and a compound containing magnesium ions. The ALF material prepared by the method can efficiently adsorb, separate and purify a carbon dioxide component in a carbon dioxide / nitrogen system, shows more excellent selective adsorption performance compared with a previously reported ALF material, shows excellent capacity of adsorbing and separating carbon dioxide in a flue gas decarburization system, keeps high carbon dioxide equilibrium adsorption capacity, and has a good application prospect. The adsorption rate is higher, and desorption and regeneration are easier.

Description

Technical Field

[0001] The invention relates to the technical field of adsorbent cyanamide production, and in particular to a metal organic framework adsorbent and a preparation method and application thereof. Background Art

[0002] In recent decades, with the continuous progress of human society and the continuous development of industry, science and technology, and economy, a large amount of greenhouse gases have been emitted into the atmosphere, which has led to the occurrence and intensification of the greenhouse effect. Carbon dioxide is one of the most typical greenhouse gases, and its emissions account for 77.0% of global greenhouse gas emissions. It is one of the main factors leading to the greenhouse effect and a series of environmental problems. As the largest developing country and the world's second largest economy, my country also proposed on September 22, 2020 to achieve the goal of "carbon neutrality" by 2060. Flue gas generated by large-scale combustion equipment is the largest source of carbon dioxide emissions. If carbon dioxide emissions are to be controlled on a large scale to cope with its impact on the climate, it is necessary to focus on carbon dioxide capture from large-scale combustion equipment.

[0003] There are three main ways to capture carbon in large combustion equipment: pre-combustion capture, oxygen-enriched combustion technology, and post-combustion capture. Among them, post-combustion carbon capture does not require the modification of the equipment process itself and has a wider applicability. At present, the technologies for separating and capturing carbon dioxide that are being developed, researched, and applied in industry mainly include cryogenic separation technology, physical absorption technology, chemical absorption technology, membrane separation technology, and adsorption separation technology. Among them, the comprehensive energy consumption and investment of physical adsorption separation technology are much lower than those of other separation technologies; in industrial applications, physical adsorption separation technology can be subdivided into pressure swing adsorption technology (PSA), temperature swing adsorption technology (TSA), pressure swing-temperature swing coupled adsorption technology (PTSA), etc. Among them, pressure swing adsorption technology has many advantages such as low cost, economic energy saving, simple process, green environmental protection, and excellent separation and purification effect, and its core lies in the preparation and application of adsorbent materials.

[0004] Metal-organic frameworks (MOFs) are a class of crystalline porous materials with a periodic network structure formed by metal ions or metal clusters and organic ligands connected by self-assembly. Compared with many traditional adsorbent materials, metal-organic framework adsorbents have the advantages of high activity, high specific surface area, high adsorption capacity, uniform and modifiable pore structure, etc. They can show very good ability to adsorb and separate carbon dioxide in carbon dioxide / nitrogen mixed gas, and are easy to regenerate and reuse. In 2021, Svante cooperated with BASF to expand the production scale of CALF-20, a stable MOF with high post-combustion carbon dioxide capture capacity and excellent stability to water. CALF-20 is being tested in the CO2MENT project at the Lafarge-Hol cim cement plant in Canada, with an industrial capacity of one ton of carbon dioxide captured per day. It is also the world's first industrially demonstrated MOF material. The successful commercialization of CALF-20 provides new ideas for appropriate structures and adsorption indicators that are critical to carbon dioxide capture. However, it also has certain limitations: CALF-20 is synthesized from zinc ions, 1,2,4-triazole and oxalate ions as raw materials, and the high price of 1,2,4-triazole also determines that CALF-20 is not suitable for large-scale decarbonization equipment.

[0005] Anthony K. Cheetham's research group reported in its research (world patent WO2022 / 260592A2) that the ultra-microporous material Al(HCOO)3 (ALF) can capture CO2 from hydrocarbon mixtures, including hydrocarbon mixtures containing C2H2 and CH4, and the equilibrium adsorption capacity for carbon dioxide at room temperature and pressure conditions reaches about 3.85 mmol / g (about 86.2 mL / g). Current studies have shown that although its equilibrium adsorption capacity for carbon dioxide is very high, its narrow pores are only the size of carbon dioxide, and the ALF grains produced by the currently reported synthesis method are large, making the mass transfer and diffusion of carbon dioxide adsorbent molecules extremely difficult, the adsorption rate is very slow, and it takes a long time to reach adsorption equilibrium. It is also difficult to desorb and regenerate, which limits its large-scale industrial application in removing carbon dioxide from flue gas. Summary of the invention

[0006] The purpose of the present invention is to provide a metal organic framework adsorbent and a preparation method and application thereof, so as to solve the technical problems in the prior art of low heat exchange efficiency of the liquid in the reactor, uneven heat distribution, slow temperature adjustment control, low product output and difficulty in achieving automation.

[0007] The invention discloses a metal organic framework adsorbent, which comprises formic acid, aluminum hydroxide and a compound containing magnesium ions.

[0008] Furthermore, the anions in the compound containing magnesium ions are one or more of hydroxide ions, nitrate ions, sulfate ions, phosphate ions, carbonate ions, formate ions, acetate ions, oxalate ions, fluoride ions, chloride ions, bromide ions or iodide ions.

[0009] Furthermore, the mass ratio of the aluminum hydroxide to the compound containing magnesium ions is 10 to 3:1.

[0010] Furthermore, the mass ratio of formic acid to aluminum hydroxide is 60 to 244:1, preferably 52 to 215:1.

[0011] A method for preparing a metal organic framework adsorbent comprises the following steps:

[0012] S1. Mixing formic acid, aluminum hydroxide and a compound containing magnesium ions;

[0013] S2. The mixture was heated and stirred in an oil bath, condensed and refluxed, and then the white solid was separated by filtration and washed until the clear liquid was neutral;

[0014] S3. After sufficient drying, the product is pressed into tablets and granules, and then ground and sieved to obtain the product.

[0015] Furthermore, the oil bath temperature in step S2 is 90-120°C.

[0016] Furthermore, the co-heating stirring rate in step S2 is 500-1000 r / min.

[0017] Furthermore, the co-heating and stirring treatment in step S2 lasts for 12 to 72 hours.

[0018] Furthermore, in step S2, anhydrous ethanol is used for washing until the clear liquid is neutral.

[0019] Furthermore, the drying is carried out at 120-200° C. for 12-48 hours.

[0020] Furthermore, the grinding and screening is performed into particles of 10 to 20 meshes.

[0021] An application of a metal organic framework adsorbent for removing carbon dioxide from flue gas.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The metal organic framework adsorbent prepared according to the above method can efficiently adsorb and separate and purify the carbon dioxide component in the carbon dioxide / nitrogen system. Compared with the previously reported ALF material, it shows more excellent selective adsorption performance and exhibits excellent ability to adsorb and separate carbon dioxide in the flue gas decarbonization system. While maintaining a high carbon dioxide equilibrium adsorption capacity, the adsorption rate is faster and it is easier to desorb and regenerate;

[0024] 2. The metal organic framework adsorbent prepared according to the above method has a very good ability to adsorb and separate carbon dioxide, is less affected by nitrogen oxides and water vapor in flue gas, and is easy to regenerate and reuse;

[0025] 3. The process flow for preparing metal organic framework adsorbents according to the above method is simple, the raw materials used are simple, cheap and easy to obtain, and it is a process technology that can be quickly transformed into engineering, and has a very broad application prospect in industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only represent some embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 It is a comparison chart of the adsorption rate of Example 1 of the present invention and Comparative Example 1, in which a. is the adsorption curve of the unmodified ALF material; b. is the adsorption curve of the material modified by adding metal magnesium ions with a mass ratio of Al(OH)3 to Mg(OH)2 of 5:1.

[0028] Figure 2 1 is an XRD comparison diagram of the samples before and after modification of Example 1 of the present invention and Comparative Example 1, wherein a. is the XRD diagram of the unmodified ALF material; b. is the XRD diagram of the material modified by adding metal magnesium ions with a mass ratio of Al(OH)3 to Mg(OH)2 of 5:1.

[0029] Figure 3 The electron microscope comparison diagram of the samples before and after modification of Example 1 of the present invention and Comparative Example 1, in which a. is the electron microscope diagram of the ALF raw powder without adding additives; b. is the SEM diagram of the material modified by adding metal magnesium ions with a mass ratio of Al(OH)3 to Mg(OH)2 of 5:1. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0031] Example 1

[0032] This embodiment discloses a metal organic framework adsorbent and a preparation method thereof, comprising the following steps:

[0033] (1) 1 L of formic acid, 12 g of aluminum hydroxide and 2.4 g of magnesium hydroxide were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 100° C. The stirring rate was 750 r / min;

[0034] (2) After 48 h, the white solid was separated by filtration and washed with anhydrous ethanol until the clear liquid was neutral;

[0035] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into particles of 10 to 20 mesh, to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as sample No. 1 in Example 1.

[0036] Under normal temperature and pressure conditions, the equilibrium adsorption capacity of the sample for CO2 and N2 was measured by an isothermal adsorption-desorption instrument and the separation coefficient was calculated. The results are shown in Table 1.

[0037] Under normal temperature and pressure conditions, a manual static adsorption instrument was used to measure the adsorption capacity of the sample for CO2 and N2 within 3 minutes and the separation coefficient was calculated. The results are shown in Table 2.

[0038] Example 2

[0039] A metal organic framework adsorbent for removing carbon dioxide from flue gas and a preparation method thereof, comprising the following steps:

[0040] (1) 1 L of formic acid, 12 g of aluminum hydroxide and 2.4 g of magnesium nitrate were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 100° C. The stirring rate was 750 r / min;

[0041] (2) After 48 h, the white solid was separated by filtration and washed with anhydrous ethanol until the clear liquid was neutral;

[0042] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into particles of 10 to 20 mesh, to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as sample No. 2 in Example 2.

[0043] Under normal temperature and pressure conditions, the equilibrium adsorption capacity of the sample for CO2 and N2 was measured by an isothermal adsorption-desorption instrument and the separation coefficient was calculated. The results are shown in Table 1.

[0044] Under normal temperature and pressure conditions, a manual static adsorption instrument was used to measure the adsorption capacity of the sample for CO2 and N2 within 3 minutes and the separation coefficient was calculated. The results are shown in Table 2.

[0045] Example 3

[0046] A metal organic framework adsorbent for removing carbon dioxide from flue gas and a preparation method thereof, comprising the following steps:

[0047] (1) 1 L of formic acid, 12 g of aluminum hydroxide and 2.4 g of magnesium acetate were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 100° C. The stirring rate was 750 r / min;

[0048] (2) After 48 h, the white solid was separated by filtration and washed with anhydrous ethanol until the clear liquid was neutral;

[0049] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into 10-20 mesh particles to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as sample No. 3 in Example 3.

[0050] Under normal temperature and pressure conditions, the equilibrium adsorption capacity of the sample for CO2 and N2 was measured by an isothermal adsorption-desorption instrument and the separation coefficient was calculated. The results are shown in Table 1.

[0051] Under normal temperature and pressure conditions, a manual static adsorption instrument was used to measure the adsorption capacity of the sample for CO2 and N2 within 3 minutes and the separation coefficient was calculated. The results are shown in Table 2.

[0052] Example 4

[0053] A metal organic framework adsorbent for removing carbon dioxide from flue gas and a preparation method thereof, comprising the following steps:

[0054] (1) 1 L of formic acid, 12 g of aluminum hydroxide and 2.4 g of magnesium hydroxide were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 100° C. The stirring rate was 750 r / min;

[0055] (2) After 24 hours, separate the white solid by filtration and wash with anhydrous ethanol until the clear liquid is neutral;

[0056] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into particles of 10 to 20 mesh, to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as sample No. 4 in Example 4.

[0057] Under normal temperature and pressure conditions, the equilibrium adsorption capacity of the sample for CO2 and N2 was measured by an isothermal adsorption-desorption instrument and the separation coefficient was calculated. The results are shown in Table 1.

[0058] Under normal temperature and pressure conditions, a manual static adsorption instrument was used to measure the adsorption capacity of the sample for CO2 and N2 within 3 minutes and the separation coefficient was calculated. The results are shown in Table 2.

[0059] Example 5

[0060] A metal organic framework adsorbent for removing carbon dioxide from flue gas and a preparation method thereof, comprising the following steps:

[0061] (1) 1 L of formic acid, 12 g of aluminum hydroxide and 2.4 g of magnesium hydroxide were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 100° C. The stirring rate was 750 r / min;

[0062] (2) After 12 h, the white solid was separated by filtration and washed with anhydrous ethanol until the clear liquid was neutral;

[0063] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into particles of 10 to 20 mesh, to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as sample No. 5 in Example 5.

[0064] Comparative Example 1

[0065] A metal organic framework adsorbent for removing carbon dioxide from flue gas and a preparation method thereof, comprising the following steps:

[0066] (1) 1 L of formic acid and 12 g of aluminum hydroxide were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 100° C. The stirring rate was 750 r / min;

[0067] (2) After 48 h, the white solid was separated by filtration and washed with anhydrous ethanol until the clear liquid was neutral;

[0068] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into particles of 10 to 20 mesh, to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as comparative example sample No. 1.

[0069] Under normal temperature and pressure conditions, the equilibrium adsorption capacity of the sample for CO2 and N2 was measured by an isothermal adsorption-desorption instrument and the separation coefficient was calculated. The results are shown in Table 1.

[0070] Under normal temperature and pressure conditions, a manual static adsorption instrument was used to measure the adsorption capacity of the sample for CO2 and N2 within 3 minutes and the separation coefficient was calculated. The results are shown in Table 2.

[0071] Comparative Example 2

[0072] A metal organic framework adsorbent for removing carbon dioxide from flue gas and a preparation method thereof, comprising the following steps:

[0073] (1) 1 L of formic acid, 12 g of aluminum hydroxide and 4.8 g of magnesium hydroxide were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 100° C. The stirring rate was 750 r / min;

[0074] (2) After 48 h, the white solid was separated by filtration and washed with anhydrous ethanol until the clear liquid was neutral;

[0075] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into particles of 10 to 20 mesh, to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as comparative example sample No. 2.

[0076] Under normal temperature and pressure conditions, the equilibrium adsorption capacity of the sample for CO2 and N2 was measured by an isothermal adsorption-desorption instrument and the separation coefficient was calculated. The results are shown in Table 1.

[0077] Under normal temperature and pressure conditions, a manual static adsorption instrument was used to measure the adsorption capacity of the sample for CO2 and N2 within 3 minutes and the separation coefficient was calculated. The results are shown in Table 2.

[0078] Comparative Example 3

[0079] A metal organic framework adsorbent for removing carbon dioxide from flue gas and a preparation method thereof, comprising the following steps:

[0080] (1) 1 L of formic acid, 12 g of aluminum hydroxide and 2.4 g of magnesium hydroxide were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 80° C. The stirring rate was 750 r / min;

[0081] (2) After 48 h, the white solid was separated by filtration and washed with anhydrous ethanol until the clear liquid was neutral;

[0082] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into particles of 10 to 20 mesh, to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as comparative example sample No. 3.

[0083] Under normal temperature and pressure conditions, the equilibrium adsorption capacity of the sample for CO2 and N2 was measured by an isothermal adsorption-desorption instrument and the separation coefficient was calculated. The results are shown in Table 1.

[0084] Under normal temperature and pressure conditions, a manual static adsorption instrument was used to measure the adsorption capacity of the sample for CO2 and N2 within 3 minutes and the separation coefficient was calculated. The results are shown in Table 2.

[0085] Comparative Example 4

[0086] A metal organic framework adsorbent for removing carbon dioxide from flue gas and a preparation method thereof, comprising the following steps:

[0087] (1) 1 L of formic acid, 12 g of aluminum hydroxide and 2.4 g of magnesium hydroxide were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 100° C. The stirring rate was 750 r / min;

[0088] (2) After 8 h, the white solid was separated by filtration and washed with anhydrous ethanol until the clear liquid was neutral;

[0089] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into particles of 10 to 20 mesh, to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as comparative example sample No. 4.

[0090] Under normal temperature and pressure conditions, the equilibrium adsorption capacity of the sample for CO2 and N2 was measured by an isothermal adsorption-desorption instrument and the separation coefficient was calculated. The results are shown in Table 1.

[0091] Under normal temperature and pressure conditions, a manual static adsorption instrument was used to measure the adsorption capacity of the sample for CO2 and N2 within 3 minutes and the separation coefficient was calculated. The results are shown in Table 2.

[0092] Comparative Example 5

[0093] A metal organic framework adsorbent for removing carbon dioxide from flue gas and a preparation method thereof, comprising the following steps:

[0094] (1) 1 L of formic acid, 12 g of aluminum hydroxide and 2.4 g of magnesium hydroxide were added to a three-necked flask and mixed evenly, and the mixture was heated, stirred, condensed and refluxed in an oil bath at 100° C. The stirring rate was 250 r / min;

[0095] (2) After 48 h, the white solid was separated by filtration and washed with anhydrous ethanol until the clear liquid was neutral;

[0096] (3) The white solid was transferred to a forced air drying oven, dried at 180° C. for 24 h, and then pressed into tablets and granulated, and ground and sieved into particles of 10 to 20 mesh, to finally obtain a metal organic framework adsorbent for removing carbon dioxide from flue gas, which was recorded as comparative example sample No. 5.

[0097] Under normal temperature and pressure conditions, the equilibrium adsorption capacity of the sample for CO2 and N2 was measured by an isothermal adsorption-desorption instrument and the separation coefficient was calculated. The results are shown in Table 1.

[0098] Under normal temperature and pressure conditions, a manual static adsorption instrument was used to measure the adsorption capacity of the sample for CO2 and N2 within 3 minutes and the separation coefficient was calculated. The results are shown in Table 2.

[0099] Table 1 Results of equilibrium adsorption capacity determination of metal organic framework adsorbents for CO2 and N2

[0100]

[0101]

[0102] Table 2 Results of the adsorption capacity of metal organic framework adsorbents for CO2 and N2 within 3 min in the examples

[0103]

[0104] From the results in Table 1 and Table 2, it can be found that adding an appropriate amount of a compound containing magnesium ions to the raw materials for preparing the metal organic framework adsorbent, such as adding magnesium hydroxide, magnesium nitrate, and magnesium acetate in Examples 1 to 3 and the blank samples in Comparative Example 1 without adding a compound containing magnesium ions, all have a higher equilibrium adsorption capacity for carbon dioxide, but the adsorption capacity of carbon dioxide in Examples 1 to 4 at 3 min is significantly better than that of the sample without Mg modification in Comparative Example 1 (see Table 2), among which the effect of adding aluminum hydroxide to the magnesium-containing compound in a mass ratio of 5:1 is the most significant. Figure 1 The comparison of the adsorption rate test results also shows that the modified sample has a faster adsorption rate; Figure 2 This is the XRD test analysis result of the sample. It can be found in the figure that the diffraction peak of the adsorbent material has shifted to the left as a whole after doping modification, which proves that Mg atoms larger than Al are doped into the sample, the unit cell parameters increase, and the crystal plane spacing also increases, causing all the diffraction peaks of the XRD spectrum to shift to small angles. Figure 3Comparison of electron microscope images also shows that after adding aluminum hydroxide and magnesium hydroxide in a mass ratio of 5:1, the crystal size of the material is significantly reduced and the twinning phenomenon is also improved.

[0105] From the performance evaluation results of the samples in Table 1 and Table 2, it can be found that when the mass ratio of aluminum hydroxide to magnesium hydroxide is less than 3:1, the adsorption of CO2 will be reduced, but the separation result is still better than that of Example 1; at the same time, when the synthesis temperature is reduced to 80°C and the synthesis speed is reduced to 250r / min, the adsorption and separation performance of the prepared adsorbent is significantly reduced when the synthesis temperature is reduced to 80°C and the synthesis speed is reduced to 250r / min when comparing the samples of Example 1, Example 4, Example 5 and Example 4. The too short synthesis time will affect the transformation and growth of the crystals, and also reduce the adsorption performance of the adsorbent. The appropriate range of preparation process parameters is also a key influencing factor in improving the performance of the adsorbent.

[0106] The above results show that the metal organic framework adsorbent prepared by adding an appropriate amount of a compound containing magnesium ions to the raw material through the method of the present invention, and after co-heating stirring, condensation reflux, suction filtration washing, and tableting, has smaller grains and a pore structure that is conducive to adsorption, desorption and mass transfer. It can exhibit a better ability to adsorb and separate carbon dioxide in a carbon dioxide / nitrogen system, while maintaining a high carbon dioxide equilibrium adsorption capacity, the adsorption rate is improved, and it is easier to desorb and regenerate.

[0107] The above basic examples of the present invention and their further selected examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed by the present invention. In the scheme of the present invention, each selected example can be arbitrarily combined with any other basic example and selected example. Those skilled in the art will know that there are many combinations.

[0108] The above are the implementation methods listed in this embodiment, but this embodiment is not limited to the above optional implementation methods. Those skilled in the art can arbitrarily combine the above methods to obtain other various implementation methods. Anyone can derive other various forms of implementation methods under the inspiration of this embodiment. The above specific implementation methods should not be understood as limiting the scope of protection of this embodiment. The scope of protection of this embodiment shall be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. A metal organic framework adsorbent, characterized in that: These include formic acid, aluminum hydroxide, and compounds containing magnesium ions.

2. A metal organic framework adsorbent according to claim 1, characterized in that: The anions in the compound containing magnesium ions are one or more of hydroxide ions, nitrate ions, sulfate ions, phosphate ions, carbonate ions, formate ions, acetate ions, oxalate ions, fluoride ions, chloride ions, bromide ions or iodide ions.

3. A metal organic framework adsorbent according to claim 1, characterized in that: The mass ratio of the aluminum hydroxide to the compound containing magnesium ions is 10 to 3:

1.

4. A metal organic framework adsorbent according to claim 1, characterized in that: The mass ratio of formic acid to aluminum hydroxide is 60 to 244:1, preferably 52 to 215:

1.

5. A method for preparing a metal organic framework adsorbent, characterized in that: The following steps are involved: S1. Mixing formic acid, aluminum hydroxide and a compound containing magnesium ions; S2. The mixture was heated and stirred in an oil bath, condensed and refluxed, and then the white solid was separated by filtration and washed until the clear liquid was neutral; S3. After sufficient drying, the product is pressed into tablets and granules, and then ground and sieved to obtain the product.

6. The method for preparing a metal organic framework adsorbent according to claim 5, characterized in that: The oil bath temperature in step S2 is 90-120°C.

7. The method for preparing a metal organic framework adsorbent according to claim 5, characterized in that: The co-heating stirring rate in step S2 is 500-1000 r / min.

8. The method for preparing a metal organic framework adsorbent according to claim 5, characterized in that: The time of the co-heating and stirring treatment in step S2 is 12 to 72 hours.

9. The method for preparing a metal organic framework adsorbent according to claim 5, characterized in that: The drying is carried out at 120-200° C. for 12-48 hours.

10. An application of a metal organic framework adsorbent, characterized in that: The adsorbent prepared by the preparation method of a metal organic framework adsorbent as described in any one of claims 1 to 3 or a metal organic framework adsorbent as described in any one of claims 4 to 9 is used for removing carbon dioxide from flue gas.

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