A synthesis method of MOF adsorbent and its application in purifying C3H6 in C3H4 / C3H6 / C3H8 mixture

Abstract

The present invention discloses a method for synthesizing a MOF adsorbent and its application in purifying C3H6 in a C3H4 / C3H6 / C3H8 mixture, belonging to the field of gas separation technology. A metal salt, 2,5-dimethylterephthalic acid, 1,4-diazabicyclo[2.2.2]octane and two drops of nitric acid are added to a solvent nitrogen and nitrogen-dimethylformamide, stirred and dissolved, and the mixed solution is transferred to a container and sealed. After high-temperature hydrothermal reaction, washing and drying, a metal organic framework adsorbent is obtained. The metal salt is one of zinc nitrate hexahydrate, cobalt nitrate hexahydrate and nickel nitrate hexahydrate. The adsorbent prepared by the present invention has good structural stability, thermal stability, hydrophobicity and water vapor stability, is easy to desorb after adsorption, and has strong reusability; the MOF material has excellent hydrophobicity and can achieve efficient separation of propyne / propylene / propane ternary gas mixture under high relative humidity (70%) conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of gas separation, and in particular to a method for synthesizing a MOF adsorbent and its application in purifying C3H6 in a C3H4 / C3H6 / C3H8 mixture. Background Art

[0002] Propylene (C3H6) is a key raw material for a variety of chemicals, including polymers. Global production exceeded 140 million tons in 2020, second only to ethylene (C2H4). Currently, the industrial production of C3H6 relies heavily on steam cracking of hydrocarbons or propane dehydrogenation, processes that inevitably produce impurities such as propyne (C3H4) and propane (C3H8). Trace amounts of C3H4 and high concentrations of C3H8 in C3H6 production can poison polymerization catalysts and lead to losses in polymer production efficiency. Therefore, removing C3H4 and C3H8 from C3H6 during chemical manufacturing is essential. Catalytic hydrogenation is a typical method for removing C3H4, but it suffers from high operating temperatures and low selectivity. Furthermore, separating C3H6 from C3H8 using current conventional separation methods requires energy-intensive distillation under harsh conditions (243K and 30 bar), resulting in high energy consumption. Pressure swing adsorption (PSA) separation technology is an attractive alternative, offering lower energy consumption and superior efficiency.

[0003] Metal-organic frameworks (MOFs) have become a promising adsorbent for PSA separations due to their strong tunability in pore shape, pore size, and functionality. Like most adsorbents, most MOF materials selectively adsorb C3H4 or C3H6 for C3H4 / C3H6 and C3H6 / C3H8 separations, while porous materials that preferentially adsorb both C3H8 and C3H4 are rarely reported. Therefore, there is an urgent need to develop a single MOF that can simultaneously capture C3H4 and C3H8 from a C3H4 / C3H6 / C3H8 ternary mixture, as it can directly produce ultra-high-purity C3H6 at the outlet through a single adsorption step on an adsorption column, thereby greatly reducing energy consumption.

[0004] In practical applications, since hydrocarbon raw materials need to be mixed with a certain amount of water vapor during the pyrolysis process and inevitably contain a small amount of water vapor during the cracking process, the development of MOF materials with the ability to purify C3H6 from the C3H4 / C3H6 / C3H8 ternary mixture in one step under humid conditions and good stability is more conducive to its industrial adsorption and separation. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for synthesizing a MOF adsorbent and its application in purifying C3H6 from a C3H4 / C3H6 / C3H8 mixture. The prepared MOF adsorption material has stable performance and can achieve efficient separation of C3H6 from a C3H4 / C3H6 / C3H8 ternary mixture under humid conditions.

[0006] To achieve the above objectives, the present invention provides a method for synthesizing a MOF adsorbent, comprising adding a metal salt, 2,5-dimethylterephthalic acid, 1,4-diazabicyclo[2.2.2]octane, and two drops of nitric acid to a solvent, nitrogen-dimethylformamide, stirring and dissolving the mixture, transferring the mixed solution to a sealed container, subjecting the mixture to a high-temperature hydrothermal reaction, washing, and drying to obtain a metal organic framework adsorbent.

[0007] Preferably, the metal salt is one of zinc nitrate hexahydrate, cobalt nitrate hexahydrate, and nickel nitrate hexahydrate.

[0008] Preferably, the molar ratio of the metal salt to 2,5-dimethylterephthalic acid is 1:1; the molar ratio of the 1,4-diazabicyclo[2.2.2]octane to the metal salt is 1:2.

[0009] Preferably, the amount of the solvent nitrogen, nitrogen-dimethylformamide is 15 to 20 mL.

[0010] Preferably, the hydrothermal reaction temperature is 110-130° C., and the reaction time is 24-48 hours.

[0011] The present invention also provides the use of the MOF adsorbent obtained by the above synthesis method in one-step purification of C3H6 from a C3H4 / C3H6 / C3H8 ternary mixture under humid conditions.

[0012] Preferably, the specific application steps are to pass the C3H4 / C3H6 / C3H8 ternary mixed gas into an adsorption column filled with MOF adsorption material, adjust the gas flow rate with a pressure valve and a flow meter at the inlet of the adsorption column, and perform a dynamic adsorption penetration experiment under a certain temperature, pressure and different relative humidity; and use gas chromatography at the outlet of the adsorption column to monitor the concentrations of propyne, propylene and propane in real time.

[0013] Preferably, the volume fraction of C3H4 in the C3H4 / C3H6 / C3H8 ternary mixed gas is 1%, and the volume fraction of C3H8 is 0-50%.

[0014] Preferably, the mass of the MOF adsorption material filled in the adsorption column is 0.5 to 1 g, and the gas flow rate of the C3H4 / C3H6 / C3H8 ternary mixed gas entering the adsorption column is 0 to 5 mL / min.

[0015] Preferably, the adsorption temperature is 0-25° C., the pressure is ≥1 bar, and the relative humidity is one of 20%, 40%, and 70%.

[0016] Therefore, the present invention provides a method for synthesizing a MOF adsorbent and its application in purifying C3H6 in a C3H4 / C3H6 / C3H8 mixture, and the beneficial effects achieved are as follows:

[0017] (1) The present invention adopts a hydrothermal method, and MOF adsorbent materials can be prepared by simple stirring, heating, and drying in a glass bottle. By scaling up the metal and ligand in equal proportions, hundreds of grams of products can be obtained at a time, which can realize the industrial synthesis of MOF materials.

[0018] (2) The adsorbent prepared by the present invention has good structural stability, thermal stability, hydrophobicity and water vapor stability, is easy to desorb after adsorption, has strong reusability, and is better suitable for industrialization;

[0019] (3) Compared with traditional adsorption materials (molecular sieves, carbon materials), the adsorbent prepared by the present invention has a stronger adsorption force for propyne and propane, and has high propyne and propane adsorption capacity and propyne-propylene and propane-propylene separation selectivity. The adsorbent can achieve efficient separation of propyne / propylene / propane ternary gas mixtures, and can generate polymerization-grade propylene product gas (>99.99%) through a single-step adsorption separation. The yield of high-purity propylene obtained in a single breakthrough experiment is 90-160 L / Kg.

[0020] (4) Compared with other propane selective materials, the adsorbent prepared by the present invention has more excellent hydrophobicity, can achieve efficient separation of propyne / propylene / propane ternary gas mixture under high relative humidity (70%) conditions, and is more suitable for industrial adsorption separation.

[0021] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 These are SEM images of M-DMOF-DM obtained in Examples 1-3 of the present invention, wherein (a) is Zn-DMOF-DM; (b) is Co-DMOF-DM; and (c) is Ni-DMOF-DM.

[0023] Figure 2 XRD comparison diagram of M-DMOF-DM obtained in Examples 1-3 of the present invention and the simulated peak;

[0024] Figure 3 : This is the nitrogen adsorption-desorption curve of M-DMOF-DM obtained in Examples 1-3 of the present invention at 77K;

[0025] Figure 4 The adsorption curves of propyne, propylene, and propane of M-DMOF-DM obtained in Examples 1-3 of the present invention at 298K are shown, where (a) is Zn-DMOF-DM; (b) is Co-DMOF-DM; and (c) is Ni-DMOF-DM.

[0026] Figure 5 This is the water vapor adsorption curve of M-DMOF-DM obtained in Examples 1-3 of the present invention at 298K;

[0027] Figure 6 The XRD patterns of M-DMOF-DM obtained in Examples 1-3 of the present invention after being treated under different conditions, wherein (a) is Zn-DMOF-DM; (b) is Co-DMOF-DM; (c) is Ni-DMOF-DM;

[0028] Figure 7 The single-component adsorption isotherms of multiple propyne, propylene, and propane cycles of Ni-DMOF-DM obtained in Example 3 of the present invention, wherein (a) is C3H4; (b) is C3H6; (c) is C3H8;

[0029] Figure 8 Figures 1 and 2 are diagrams of the adsorption column and penetration test apparatus used under different conditions of the present invention, wherein (a) is the apparatus used under dry conditions, and (b) is the apparatus used under wet conditions;

[0030] Figure 9 The breakthrough curves of M-DMOF-DM obtained in Examples 1-3 of the present invention for propane-propylene mixtures with different ratios at room temperature, pressure, and dry conditions are shown, where (a) is propane / propylene = 1 / 1 (v / v); (b) is propane / propylene = 1:9 (v / v); and (c) is propane:propylene = 1 / 15 (v / v).

[0031] Figure 10 This is the breakthrough curve of Ni-DMOF-DM obtained in Example 3 of the present invention for a propyne / propylene / propane mixture (propyne / propylene / propane = 1 / 90 / 9 (v / v / v)) at room temperature, pressure, and different relative humidity conditions;

[0032] Figure 11 Schematic diagram of the application principle of the MOF adsorbent prepared in the present invention. DETAILED DESCRIPTION

[0033] The present invention provides a method for synthesizing a MOF adsorbent, comprising the following steps: adding zinc nitrate hexahydrate (cobalt, nickel), 2,5-dimethylterephthalic acid, 1,4-diazabicyclo[2.2.2]octane and two drops of nitric acid to nitrogen-dimethylformamide (DMF), stirring evenly until completely dissolved, transferring the obtained mixed solution to a glass bottle, sealing, performing a high-temperature hydrothermal reaction, washing, and drying to obtain a series of M-DMOF-DM (M=Zn, Co, Ni) metal organic framework (MOF) adsorbents.

[0034] The present invention also provides a production process for purifying C3H6 from a ternary mixture of propyne / propylene / propane (C3H4 / C3H6 / C3H8) using the above-prepared MOF adsorbent under humid conditions in one step, comprising the following steps: passing a ternary mixture of propyne, propylene and propane into an adsorption column filled with an M-DMOF-DM adsorbent prepared by the synthesis method of the M-DMOF-DM, wherein the flow rate is adjusted by a pressure valve and a flowmeter at the inlet of the adsorption column, and a dynamic adsorption penetration experiment is performed under a certain temperature, pressure and different relative humidity; the concentrations of propyne, propylene and propane are monitored in real time by gas chromatography at the outlet of the adsorption column; and desorption and regeneration of the adsorbent are completed by purging with an inert gas at room temperature or under vacuum negative pressure.

[0035] During the synthesis process, the amounts of metal salt, ligand, and solvent are adjusted to minimize synthesis costs. Furthermore, the synthesis is simple, requiring only a simple hydrothermal method and a glass bottle reaction to produce M-DMOF-DM. The present invention's efficient method for separating low-concentration propyne and propane from a ternary mixture of propyne, propylene, and propane has simple steps and a wide range of applications. It can achieve efficient separation of propyne, propylene, and propane at high relative humidity (70%), and generates polymerization-grade propylene product gas (>99.99%) through a one-step adsorption separation, promising industrial applications for M-DMOF-DM materials.

[0036] In the present invention, zinc nitrate hexahydrate (cobalt, nickel) and 2,5-dimethylterephthalic acid are in equimolar amounts, the molar amount of 1,4-diazabicyclo[2.2.2]octane is half the molar amount of zinc nitrate hexahydrate, the amount of DMF solvent used is controlled at 15-20 mL, the reaction temperature is controlled at 110-130° C., and the reaction time is 24-48 hours.

[0037] In the present invention, the M-DMOF-DM material can be produced in a single reaction in a glass bottle by simple stirring, heating, and drying. The present invention is not limited to this specific yield at this ratio; scaling up the metal and ligand ratios to produce hundreds of grams of product in a single reaction is also applicable to the present invention.

[0038] In the present invention, the volume fraction of propyne in the mixed gas is 1%, and the volume fraction of propane is 0-50%, excluding zero.

[0039] In the present invention, the sample loaded in the adsorption column is 0.5 to 1 g, the flow rate of the ternary mixture of propyne, propylene and propane entering the adsorption column is 0 to 5 mL / min, and when the gas is adsorbed on the adsorbent, the adsorption temperature is 0 to 25°C, the pressure is 1 bar and above, and the relative humidity is 20%, 40% and 70% respectively.

[0040] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort shall fall within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment provides a method for synthesizing a MOF adsorbent, comprising the following steps: adding 0.119 mg of zinc nitrate, 0.121 mg of 2,5-dimethylterephthalic acid, 0.023 mg of 1,4-diazabicyclo[2.2.2]octane, and two drops of nitric acid to 15.0 mL of DMF, stirring until completely dissolved to obtain a mixed solution; transferring the resulting mixed solution to a 20 mL glass bottle, placing it in a constant temperature drying oven, and performing a hydrothermal reaction at a temperature of 110°C to 130°C; filtering, washing, and drying the resulting sample to obtain Zn-DMOF-DM. Washing with DMF and centrifugal drying yield a highly pure product.

[0043] Example 2

[0044] This example provides a method for synthesizing a MOF adsorbent, comprising the following steps: adding 0.119 mg of cobalt nitrate, 0.121 mg of 2,5-dimethylterephthalic acid, 0.023 mg of 1,4-diazabicyclo[2.2.2]octane, and two drops of nitric acid to 15.0 mL of DMF, stirring until completely dissolved to obtain a mixed solution; transferring the resulting mixed solution to a 20 mL glass bottle, placing it in a constant temperature drying oven, and performing a hydrothermal reaction at a temperature of 110°C to 130°C; filtering, washing, and drying the resulting sample to obtain Co-DMOF-DM. Washing with DMF and centrifugal drying yield a highly pure product.

[0045] Example 3

[0046] This embodiment provides a method for synthesizing a MOF adsorbent, comprising the following steps: adding 0.119 mg of nickel nitrate, 0.121 mg of 2,5-dimethylterephthalic acid, 0.023 mg of 1,4-diazabicyclo[2.2.2]octane, and two drops of nitric acid to 15.0 mL of DMF, stirring until completely dissolved to obtain a mixed solution; transferring the resulting mixed solution to a 20 mL glass bottle, placing it in a constant temperature drying oven, and performing a hydrothermal reaction at a temperature of 110°C to 130°C; filtering, washing, and drying the resulting sample to obtain Ni-DMOF-DM. Washing with DMF and centrifugal drying yield a highly pure product.

[0047] The MOF adsorbents prepared in Examples 1-3 were tested for their separation effects on a ternary gas mixture of propyne / propylene / propane (C3H4 / C3H6 / C3H8) in a humid environment. Figure 11 shown.

[0048] Before testing the adsorption and separation performance of the prepared samples, solvent exchange and washing were performed with dichloromethane. The prepared samples were then subjected to Soxhlet extraction with dichloromethane for 12 hours. The test samples were activated at 60°C and degassed under vacuum for 12 hours. The gas adsorption and separation performance of the samples was then tested at a pressure range of 0-1 bar.

[0049] In order to evaluate the actual separation effect of Ni-DMOF-DM on the ternary mixture of propyne, propylene and propane, Figure 8 The apparatus shown in Figure 1 was used to conduct dynamic penetration experiments on a ternary mixture of propyne, propylene, and propane under dry and wet conditions, respectively. (a) shows the apparatus used under dry conditions, and (b) shows the apparatus used under wet conditions. Approximately 0.5 to 1 g of sample was loaded into a stainless steel adsorption column with an inner diameter of 4 mm and a length of 125 mm. A high-purity inert gas purge was used to remove residual gases from the pipe. The sample adsorption column was fixed in the chamber, and the flow rates of propyne, propylene, and propane were regulated by a pressure valve and flowmeter at the adsorption column inlet. A gas chromatograph (Agilent-490 Micro GC) was used to monitor the concentrations of propyne, propylene, and propane at the column outlet in real time. The entire experiment was conducted at 0 to 25°C, with a propyne / propylene / propane mixture (1 / 90 / 9, v / v / v) flowing at a rate of 0 to 5 mL / min.

[0050] In order to characterize the micromorphology of the M-DMOF-DM material, the products obtained in Examples 1-3 were subjected to SEM characterization. The results are as follows: Figure 1 As shown. Figure 1 It can be seen that all samples are in cubic form, indicating that the prepared samples have high purity.

[0051] In order to confirm the crystal structure of the synthesized samples, XRD characterization was performed on the samples synthesized in Examples 1-3, and the results were compared with the simulated peaks of the theoretical crystal structure of Zn-DMOF-DM. The comparison results are shown in FIG. Figure 2 As shown in the figure, it can be seen that the XRD diffraction peaks of the M-DMOF-DM prepared by the method of the present invention are consistent with the simulated peaks of the theoretical crystal structure of the original structure, indicating that the method has successfully synthesized the M-DMOF-DM material.

[0052] In order to characterize the adsorption capacity of M-DMOF-DM materials for different gases, the products obtained in Examples 1-3 were tested for their adsorption performance for different gases using a Micromeritics ASAP2020 instrument. At 298K, the adsorption curves of the products in Examples 1-3 for each gas were measured. Figure 3 is the nitrogen adsorption-desorption curve of the material at 77K, Figure 4 are the corresponding adsorption and desorption curves of propyne, propylene and propane. Figure 3-4 It can be seen that M-DMOF-DM has a high BET specific surface area and exhibits selective adsorption and separation performance of propyne and propane that is stronger than propylene within the test pressure range, indicating that M-DMOF-DM is a selective adsorbent for propyne and propane.

[0053] In order to test the stability of M-DMOF-DM materials, the water vapor adsorption, water stability, air stability and stability under different relative humidity conditions of the products prepared in Examples 1-3 were tested. Figure 5 The water vapor adsorption isotherm shown in Figure 2 shows that Ni-DMOF-DM still has a low water vapor adsorption capacity (0.015g / cm2) even at high relative humidity (70%). -1 ), indicating that the material has good hydrophobicity. Figure 6 The XRD patterns shown show that when the samples are exposed to different humidity environments, the samples still maintain their original crystal structure. Figure 7 Shown are the single-component adsorption isotherms of Ni-DMOF-DM for multiple propyne, propylene and propane cycles. It can be seen that the performance of Ni-DMO F-DM material is fully maintained after multiple adsorption and desorption cycle experiments.

[0054] To test the effectiveness of the M-DMOF-DM material in separating propane-propylene mixtures with varying ratios, propane / propylene and propyne / propylene / propane mixture separation experiments were conducted using the products obtained in Examples 1-3 as examples. The specific process involved precisely controlling the pressure (1.0 bar) and flow rate (2 mL / min) of the mixed gas through an adsorption column (Ø4 × 95 mm) packed with adsorbent (sample size: 0.75 g) using a pressure reducing valve and a gas mass flowmeter. The column temperature was maintained at 298 K. A timer was started as the mixed gas began to enter the column, and the tail gas concentration at the tail of the column was monitored in real time using a chromatograph (Agilent-490 Micro GC). Data was recorded until the gas concentration reached the initial concentration, indicating complete gas expulsion and adsorption.

[0055] When the mixed gas is C3H8 / C3H6 (volume fraction ratio is 1 / 1, 1 / 9 and 1 / 15), the breakthrough curves of the adsorbent material are as follows: Figure 9 ,from Figure 9 It can be seen that this series of materials can effectively remove low-concentration propane from propane-propylene mixture and achieve effective separation of low-concentration C3H8 / C3H6.

[0056] To test the effectiveness of the M-DMOF-DM material for separating propyne, propylene, and propane mixtures under humid conditions, a propyne / propylene / propane mixture (1 / 90 / 9, v / v / v) separation experiment was conducted using the product obtained in Example 3. The specific process involved passing the mixed gas through an adsorption column (Ø4 × 95 mm) packed with adsorbent (sample weight: 0.75 g) at a pressure of 1.0 bar and a flow rate of 2 mL / min, precisely controlled by a pressure reducing valve and a gas mass flowmeter. The column temperature was maintained at 298 K. The dried mixed gas was then passed through saturated brine at different relative humidities (20%, 40%, and 70%) to simulate a wet gas mixture. Within a sealed humid chamber at 298 K, saturated CH₃COOK, K₂CO₃, and NaCl solutions were used to create relative humidities of 20%, 40%, and 70%, respectively. When the mixed gas begins to enter the adsorption column, the timer starts at the same time, and the tail gas concentration is monitored in real time by chromatography (Agilent-490 Micro GC) at the end of the adsorption column. The data is recorded until the concentration of the three components of the gas reaches the initial concentration, which is considered to be the complete exit of the gas and the adsorption is considered complete.

[0057] When the mixed gas is at different relative humidity (20%, 40% and 70%), the breakthrough curves of the adsorbent material are as follows: Figure 10 ,from Figure 10It can be seen that Ni-DMOF-DM can achieve efficient separation of propyne, propylene and propane ternary mixture at high relative humidity (70%), and can generate polymerization-grade propylene product gas (>99.99%) through one-step adsorption separation. The yield of high-purity propylene obtained in a single breakthrough experiment is 90-160L / Kg.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An application of a MOF adsorbent, characterized in that: MOF adsorbents were used for one-step purification of C3H6 from C3H4 / C3H6 / C3H8 ternary mixtures under humid conditions; The MOF adsorbent is synthesized by adding a metal salt, 2,5-dimethylterephthalic acid, 1,4-diazabicyclo[2.2.2]octane and two drops of nitric acid to a solvent of nitrogen-dimethylformamide, stirring and dissolving the mixture, transferring the mixed solution to a container, sealing the container, performing a high-temperature hydrothermal reaction, washing, and drying to obtain a metal organic framework adsorbent. The metal salt is one of zinc nitrate hexahydrate, cobalt nitrate hexahydrate and nickel nitrate hexahydrate.

2. The use of a MOF adsorbent according to claim 1, characterized in that: The molar ratio of the metal salt to 2,5-dimethylterephthalic acid is 1:1; the molar ratio of the 1,4-diazabicyclo[2.2.2]octane to the metal salt is 1:

2.

3. The use of a MOF adsorbent according to claim 1, characterized in that: The amount of the solvent nitrogen, nitrogen-dimethylformamide is 15-20 mL.

4. The use of a MOF adsorbent according to claim 1, characterized in that: The hydrothermal reaction temperature is 110-130° C., and the reaction time is 24-48 hours.

5. The use of a MOF adsorbent according to claim 1, characterized in that: The MOF adsorbent is used to purify C3H6 in a C3H4 / C3H6 / C3H8 ternary mixture. The specific application steps are: passing the C3H4 / C3H6 / C3H8 ternary mixed gas into an adsorption column filled with MOF adsorption material, adjusting the gas flow rate with a pressure valve and a flow meter at the adsorption column inlet, conducting a dynamic adsorption penetration experiment under a certain temperature, pressure and different relative humidity; and using gas chromatography at the adsorption column outlet to monitor the concentrations of propyne, propylene and propane in real time.

6. The use of a MOF adsorbent according to claim 5, characterized in that: The volume fraction of C3H4 in the C3H4 / C3H6 / C3H8 ternary mixed gas is 1%, and the volume fraction of C3H8 is 0-50%.

7. The use of a MOF adsorbent according to claim 5, characterized in that: The mass of the MOF adsorption material filled in the adsorption column is 0.5-1 g, and the gas flow rate of the C3H4 / C3H6 / C3H8 ternary mixed gas entering the adsorption column is 0-5 mL / min.

8. The use of a MOF adsorbent according to claim 5, characterized in that: The adsorption temperature is 0-25° C., the pressure is ≥1 bar, and the relative humidity is one of 20%, 40%, and 70%.

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