Aperture-adjustable adsorption material, preparation method, RTO pretreatment device and process

Abstract

The invention discloses an adsorption material with adjustable aperture, a preparation method, an RTO pretreatment device and an RTO pretreatment process, and belongs to the technical field of waste gas treatment, the adsorption material takes a hydrophobic porous adsorption material as a matrix, and the surface of the matrix is coated with a layer of MOFs filter membrane. Furthermore, in the adsorption material, the matrix is a hydrophobic Y molecular sieve, and the MOFs filter membrane is MILs. According to the method, the pore size of the MILs porous membrane is controlled by utilizing humidity and temperature, so that the adsorption capacity of the hydrophobic Y molecular sieve under different concentrations is controlled, a peak-reducing and thickening RTO pretreatment process is provided by utilizing the adsorption material with the adjustable pore size, and stable and safe operation of an RTO device is ensured.

Description

Technical Field

[0001] This invention belongs to the field of waste gas treatment technology, and relates to a VOCs treatment process, particularly to an adsorption material with adjustable pore size, a preparation method, an RTO pretreatment device, and a process. Background Technology

[0002] Regenerative Thermal Oxidizer (RTO) is one of the most efficient VOCs treatment technologies currently available, boasting high purification and thermal efficiency. It is widely used in industries such as pharmaceuticals, chemicals, petrochemicals, and coating. While an RTO system can maintain self-heating under high influent gas concentrations, it struggles to do so under low concentrations, requiring an additional heat source such as natural gas or electric heating for combustion. In practical industrial applications, influent gas concentrations fluctuate significantly. High peak concentrations can lead to safety hazards if waste gas directly enters the RTO. Therefore, it is essential to add pretreatment facilities upstream of the RTO to reduce peak concentrations and ensure stable operation.

[0003] Currently, when using RTO systems to treat industrial organic waste gas, the bypass valve of the RTO equipment opens when the inlet gas concentration exceeds 25% LEL, discharging the high-concentration waste gas into the environment to avoid safety accidents. When the inlet gas concentration is below 8%~10% LEL, the inlet gas concentration is insufficient to maintain the RTO's self-heating, requiring additional natural gas combustion to supplement heat. How to store peak high-concentration waste gas and release it when the concentration drops, thereby reducing environmental pollution and minimizing fuel consumption, has long been a problem explored by environmental protection workers. Summary of the Invention

[0004] This invention provides an adsorbent material with adjustable pore size, a preparation method, an RTO pretreatment device, and a process to overcome the shortcomings of the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an adsorbent material with adjustable pore size, wherein the adsorbent material is based on a hydrophobic porous adsorbent material and a layer of MOF filter membrane is coated on the surface of the substrate.

[0006] Furthermore, in the adsorption material, the matrix is ​​a hydrophobic Y molecular sieve, and the MOF filter membrane is a MILs.

[0007] Secondly, the present invention also provides a method for preparing the above-mentioned tunable pore size adsorbent material, comprising the following steps: S1: mixing powdered hydrophobic Y molecular sieve with PDDA (polydiallyl dimethyl ammonium chloride) solution and stirring at room temperature for 1-3 h to obtain PDDA-modified Y molecular sieve; S2: adding the PDDA-modified Y molecular sieve to a mixed solution containing transition metal salt, organic ligand and deionized water, stirring and mixing, then adding HF solution and NaOH solution dropwise, and then reacting at 200-300℃ for 6-10 h to obtain Y molecular sieve-MILs powder.

[0008] Further, in S1, the concentration of the PDDA solution is 1.5~3 g / L; the solid-liquid ratio of the hydrophobic Y molecular sieve to the PDDA solution is 1:20~80.

[0009] Further, in S2, the transition metal salt is one or more of Cr(NO3)3•9H2O, Fe(NO3)3•9H2O, and Al(NO3)3•9H2O; the organic ligand is a binary amino-containing aromatic ring organic ligand; the binary amino-containing aromatic ring organic ligand is preferably a linear organic ligand and / or a flexible triangular organic ligand; the linear organic ligand is preferably one or more of 5-aminoisophthalic acid, di(4-amino-3-carboxyphenyl)methane, and 2,5-di[(4-methylphenyl)amino]-1,4-phthalic acid; the flexible triangular organic ligand is preferably one or more of 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine and 2-amino-5-4-carboxyphenyl-1,1,3,1-triphenyl-4,4-dicarboxylic acid.

[0010] Further, in step S2, the mass ratio of the transition metal salt, the organic ligand, and the deionized water in the mixed solution is 20:200 to 400:750; the solid-liquid mass ratio of the PDDA-modified Y molecular sieve to the mixed solution is 1:10 to 20; the concentration of the HF solution is 0.5 to 3 M, preferably 1 M; the volume ratio of the mixed solution with the added PDDA-modified Y molecular sieve to the HF solution is 10 to 20:1, preferably 15:1; the concentration of the NaOH solution is 0.5 to 3 M, preferably 1 M; the volume ratio of the mixed solution with the added PDDA-modified Y molecular sieve to the NaOH solution is 5 to 15:1, preferably 10:1.

[0011] Thirdly, the present invention also provides an RTO pretreatment device, wherein the RTO pretreatment device is disposed before the RTO equipment, and VOCs first enter the RTO pretreatment device and then enter the RTO equipment; the RTO pretreatment device is filled with the aforementioned adjustable pore size adsorbent material, and an atomizing spray device and a gas mixing device are provided at the inlet end; the atomizing spray device is used to increase the humidity of the inlet VOCs; the gas mixing device is used to mix the inlet VOCs with high-temperature gas to increase the temperature of the inlet VOCs, wherein the high-temperature gas refers to the gas with a temperature higher than that of the inlet VOCs, preferably the high-temperature flue gas purified by the RTO.

[0012] Furthermore, the adsorbent material is made into honeycomb-shaped blocks and filled into the RTO pretreatment device. The preparation method of the honeycomb-shaped blocks is as follows: the adsorbent material is mixed with a binder, an extrusion aid and an acid solution, and then the plasticity of the water-based clay is adjusted with water to obtain a clay material; the clay material is coarsely refined, vacuum refined to remove air bubbles, and then formed into a honeycomb integral wet base blank by a high-pressure extruder; the blank is heated and dried to obtain a dried blank; the dried blank is cut and polished, and then calcined at 500~550 ℃ for 6~10 h to obtain the honeycomb-shaped blocks.

[0013] Furthermore, in the method for preparing the honeycomb block, the binder is one or more of silica solution, alumina, boehmite, and kaolin; the extrusion aid is one or more of glycerol, polyvinyl alcohol, and liquid paraffin; the acid solution is a solution of one or more of citric acid, oxalic acid, and nitric acid; the concentration of the acid solution is 5-10 wt%; and the mass ratio of the adsorbent material, the binder, the extrusion aid, and the acid solution is 50-70:15:4:5.

[0014] Fourthly, the present invention also provides an RTO pretreatment process, implemented using the aforementioned RTO pretreatment device; the RTO pretreatment process is as follows: when the inlet VOCs concentration is below 15% LEL, the atomizing spray device is turned on to control the inlet VOCs humidity to 70~90%; when the inlet VOCs concentration is 15~25% LEL, the gas mixing device is turned on to control the inlet VOCs temperature to 50~60℃.

[0015] The beneficial effects of this invention are as follows: This invention provides an adsorption material using a hydrophobic Y molecular sieve as the substrate, with a layer of MILs filter membrane coated on its surface to achieve adjustable pore size. Specifically, MILs are flexible porous materials. Increasing humidity enhances the hydrogen bonding between organic ligands, causing the MILs pores to shrink, making it difficult for VOCs molecules to enter the internal hydrophobic Y molecular sieve pores. Conversely, increasing temperature and decreasing inlet humidity causes the hydrogen bonds between pores to break, resulting in MILs pore expansion and allowing VOCs molecules to enter the interior of the hydrophobic Y molecular sieve pores.

[0016] This invention also proposes a peak-reduction and concentration-enhancing RTO pretreatment process using tunable pore size adsorbent materials. The process controls the pore size of the MILs (Metal Injection Layers) by adjusting humidity and temperature, thereby controlling the adsorption capacity of the hydrophobic Y molecular sieve at different concentrations. Specifically, at lower concentrations, water vapor is introduced at the inlet to increase humidity, causing the MOF (Metal Injection Facility) material pores to contract, thus preventing VOC molecules from entering the internal pores of the hydrophobic Y molecular sieve. When the inlet concentration is higher, purified high-temperature flue gas or other high-temperature gases are mixed at the inlet to increase the inlet temperature and reduce humidity, thereby expanding the MOF material pores and allowing VOCs to enter the hydrophobic Y molecular sieve, reducing the peak concentration and ensuring the safe and stable operation of the downstream RTO. Attached Figure Description

[0017] Figure 1 This is a structural diagram of a linear organic ligand; Figure 2 This is a structural diagram of a flexible triangular organic ligand; Figure 3 This is a diagram of the pore structure of MILs material; Figure 4 This is the XPS spectrum of aluminum in the Y molecular sieve-MILs material sample of Example 1. Detailed Implementation

[0018] The present invention will be further described in detail below through specific embodiments, but it should not be construed as limiting the scope of the present invention to the following embodiments. All technologies implemented based on the above content of the present invention fall within the scope of the present invention.

[0019] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the reagents, methods and equipment used are conventional reagents, methods and equipment in this technical field.

[0020] The present invention provides an adsorbent material with adjustable pore size, which uses a hydrophobic porous adsorbent material as a matrix and coats the surface of the matrix with a layer of MOF filter membrane.

[0021] Specifically, hydrophobic Y-type molecular sieves are used as the matrix. Hydrophobic Y-type molecular sieves with a high Si / Al ratio (SiO2 / Al2O3>40) are selected. These sieves possess a three-dimensional twelve-membered ring pore structure with an average pore size of 0.74 nm. Most organic molecules can enter and be adsorbed through these pores. Furthermore, the hydrophobic Y-type molecular sieves have a large specific surface area and a high Si / Al ratio, enabling them to effectively adsorb VOCs molecules while reducing the adsorption of water molecules.

[0022] Flexible MILs (Metal-Organic Frameworks) materials are used as MOF (Metal-Organic Facility) filter membranes. MOFs are organic-inorganic hybrid materials with intramolecular pores, formed by the self-assembly of organic ligands and metal ions or clusters through coordination bonds, characterized by high surface area and high porosity. MILs are a type of MOF material, composed of trivalent transition metals and carboxylic acid ligands, and possess the characteristic of tunable pore size.

[0023] The present invention also provides a method for preparing the above-mentioned tunable pore size adsorbent material, comprising the following steps: S1: Grind the hydrophobic Y molecular sieve into powder, mix it with 1.5~3 g / L PDDA solution, the solid-liquid mass ratio is 1:20~80, stir at room temperature for 1~3 h, wash by centrifugation, and dry at 60~120 ℃ for 2~6 h to obtain PDDA modified Y molecular sieve.

[0024] S2: Y molecular sieve-MILs powder was prepared by the "phase separation-hydrothermal method", and MILs materials were synthesized by self-assembly of transition metal salt solution and organic ligand. PDDA-modified Y molecular sieves were added to a mixed solution comprising transition metal salts, organic ligands, and deionized water, with a mass ratio of 20:200–400:750. The solid-liquid mass ratio of the PDDA-modified Y molecular sieves to the mixed solution was 1:10–20. The mixture was ultrasonically stirred until homogeneous, and then 1 M HF solution and 1 M NaOH solution were added dropwise. The volume ratio of the mixed solution containing the PDDA-modified Y molecular sieves to the HF solution was 15:1, and the volume ratio of the mixed solution containing the PDDA-modified Y molecular sieves to the NaOH solution was 10:1. The mixture was then placed in an electrically heated stainless steel hydrothermal reactor and reacted at 200–300 °C for 6–10 h. After cooling to room temperature, the mixture was thoroughly washed and filtered with DMF and ethanol. The filter cake was dried at 60–120 °C for 5–10 h to obtain Y molecular sieve-MILs powder.

[0025] The transition metal salt is one or more of Cr(NO3)3•9H2O, Fe(NO3)3•9H2O, and Al(NO3)3•9H2O. These trivalent transition metal ions form strong coordination bonds, are not easily hydrolyzed / acidified, and can maintain good structural stability above 280 °C.

[0026] The organic ligand is a binary amino-containing aromatic ring organic ligand; preferably, it is a linear organic ligand and / or a flexible triangular organic ligand; such as Figure 1 As shown, the linear organic ligand is preferably one or more of 5-aminoisophthalic acid, bis(4-amino-3-carboxyphenyl)methane, and 2,5-bis[(4-methylphenyl)amino]-1,4-phthalic acid; Figure 2 As shown, the flexible triangular organic ligand is preferably one or more of 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine and 2-amino-5-4-carboxyphenyl-1,1,3,1-triphenyl-4,4-dicarboxylic acid.

[0027] By introducing amino side groups through the benzene ring of terephthalic acid ligands, the material significantly enhances its hydrophilicity while maintaining the stability of its porous structure. When combined with hydrophobic Y molecular sieves, it can form a hydrogen bond network structure, creating a sealing effect that prevents VOCs molecules from entering the pores of the Y molecular sieves.

[0028] Furthermore, the strong acidity of HF can suppress side reactions, ensuring the formation of a regular cage-like structure in the material. NaOH increases the pH environment, promoting the coordination of metal ions with organic ligands and forming stable polyhedral metal clusters.

[0029] In one specific embodiment, a MILs material is formed using Cr(NO3)3•9H2O as a transition metal element and bis(4-amino-3-carboxyphenyl)methane as an organic ligand to form a linearly connected pore structure, such as... Figure 3 As shown, at an ambient temperature of 20℃ and humidity >100%RH (no liquid water), water molecules form hydrogen bonds with the amino groups on the benzene ring. Under the influence of hydrogen bond attraction, the pore length of the MILs-101 material is 17~20 Å, the longitudinal length is 5~8 Å, and the pores have a flat, rhomboid shape. When the ambient temperature rises to 50℃ and the humidity <60%RH, the hydrogen bonds break, water molecules are lost, and the pore length of the MILs-101 material changes to 15~18 Å, the longitudinal length is 12~14 Å, and the pore flux doubles.

[0030] To further enhance the breathing effect of MILs series materials, linear organic ligands of different lengths and flexible triangular organic ligands can be selected to form mixed ligands, thereby achieving the desired pore size in MILs series porous framework materials.

[0031] This invention also provides an RTO pretreatment device, installed before the RTO equipment. VOCs first enter the RTO pretreatment device and then enter the RTO equipment. The RTO pretreatment device is filled with the aforementioned adjustable-pore-size adsorbent material, and an atomizing spray device and a gas mixing device are provided at the inlet end. The atomizing spray device is used to increase the humidity of the inlet VOCs. The gas mixing device is used to mix the inlet VOCs with high-temperature gas to increase the temperature of the inlet VOCs. The high-temperature gas refers to gas with a temperature higher than that of the inlet VOCs, preferably the high-temperature flue gas purified by the RTO.

[0032] Specifically, the adsorbent material is made into honeycomb-shaped blocks and filled into the RTO pretreatment device. The preparation method of the honeycomb blocks is as follows: the adsorbent material is mixed with binder, extrusion aid and acid solution, and then the plasticity of the water-based clay is adjusted with water to obtain clay; the clay is coarsely refined, vacuum refined to remove air bubbles, and then formed into a honeycomb integral wet base blank by a high-pressure extruder; the blank is heated to 120 ℃ at 5~10 ℃ / min and dried, and the water loss rate is controlled to be ≤20% / h to obtain a dried blank; after the dried blank is cut and polished, it is calcined at 500~550 ℃ for 6~10 h to obtain the honeycomb blocks.

[0033] The binder is one or more of silica solution, alumina, boehmite, and kaolin. The extrusion aid is one or more of glycerol, polyvinyl alcohol, and liquid paraffin. The acid solution is a solution of one or more of citric acid, oxalic acid, and nitric acid. The concentration of the acid solution is 5-10 wt%, and the mass ratio of the adsorbent, binder, extrusion aid, and acid solution is 50-70:15:4:5.

[0034] The present invention also provides a pretreatment process for the above-mentioned RTO pretreatment device: when the inlet gas concentration is low, the adsorption amount of the adsorbent material is small; when the inlet gas concentration is high, the adsorption amount of the adsorbent material is increased by controlling the inlet gas temperature; when the inlet gas concentration decreases, the VOCs adsorbed in the material are released by taking measures to continue to increase the inlet gas temperature, thereby achieving the effect of peak reduction and concentration increase.

[0035] Specifically, when the intake VOCs concentration is below 15% LEL, the atomizing spray device is turned on to control the intake VOCs humidity to 70-90%; when the intake VOCs concentration is 15-25% LEL, the gas mixing device is turned on to control the intake VOCs temperature to 50-60℃.

[0036] Example 1 This embodiment provides an adsorbent material with tunable pore size, Y molecular sieve-MILs, whose preparation method includes the following steps: S1: The hydrophobic Y molecular sieve was ground into powder and mixed with 2 g / L PDDA solution at a solid-liquid mass ratio of 1:50. The mixture was stirred at room temperature for 2 h, washed by centrifugation, and dried at 90 ℃ for 4 h to obtain PDDA-modified Y molecular sieve.

[0037] S2: PDDA-modified Y molecular sieve was added to a mixed solution comprising Cr(NO3)3•9H2O, bis(4-amino-3-carboxyphenyl)methane, and deionized water. The mass ratio of Cr(NO3)3•9H2O, bis(4-amino-3-carboxyphenyl)methane, and deionized water was 20:300:750. The solid-liquid mass ratio of PDDA-modified Y molecular sieve to the mixed solution was 1:15. The mixture was ultrasonically stirred and mixed thoroughly. Then, 1 M HF solution and 1 M NaOH solution were added dropwise. The volume ratio of the mixed solution containing PDDA-modified Y molecular sieve to HF solution was 15:1, and the volume ratio of the mixed solution containing PDDA-modified Y molecular sieve to NaOH solution was 10:1. The mixture was then placed in an electrically heated stainless steel hydrothermal reactor and reacted at 250 °C for 8 h. After cooling to room temperature, the mixture was thoroughly washed and filtered with DMF and ethanol. The filter cake was dried at 90 °C for 8 h to obtain Y molecular sieve-MILs powder.

[0038] Example 2 This embodiment provides an adsorbent material with tunable pore size, Y molecular sieve-MILs, whose preparation method includes the following steps: S1: The hydrophobic Y molecular sieve was ground into powder and mixed with 1.5 g / L PDDA solution at a solid-liquid mass ratio of 1:80. The mixture was stirred at room temperature for 1 h, washed by centrifugation, and dried at 60 ℃ for 6 h to obtain PDDA-modified Y molecular sieve.

[0039] S2: PDDA-modified Y molecular sieve was added to a mixed solution comprising Cr(NO3)3•9H2O, bis(4-amino-3-carboxyphenyl)methane, and deionized water. The mass ratio of Cr(NO3)3•9H2O, bis(4-amino-3-carboxyphenyl)methane, and deionized water was 20:200:750, and the solid-liquid mass ratio of PDDA-modified Y molecular sieve to the mixed solution was 1:20. The mixture was ultrasonically stirred and homogenized. Then, 1 M HF solution and 1 M NaOH solution were added dropwise. The volume ratio of the mixed solution containing PDDA-modified Y molecular sieve to HF solution was 15:1, and the volume ratio of the mixed solution containing PDDA-modified Y molecular sieve to NaOH solution was 10:1. The mixture was then placed in an electrically heated stainless steel hydrothermal reactor and reacted at 200 °C for 10 h. After cooling to room temperature, the mixture was thoroughly washed and filtered with DMF and ethanol. The filter cake was dried at 120 °C for 5 h to obtain Y molecular sieve-MILs powder.

[0040] Example 3 This embodiment provides an adsorbent material with tunable pore size, Y molecular sieve-MILs, whose preparation method includes the following steps: S1: The hydrophobic Y molecular sieve was ground into powder and mixed with 3 g / L PDDA solution at a solid-liquid mass ratio of 1:20. The mixture was stirred at room temperature for 3 h, washed by centrifugation, and dried at 120 ℃ for 2 h to obtain PDDA-modified Y molecular sieve.

[0041] S2: PDDA-modified Y molecular sieve was added to a mixed solution comprising Cr(NO3)3•9H2O, bis(4-amino-3-carboxyphenyl)methane, and deionized water. The mass ratio of Cr(NO3)3•9H2O, bis(4-amino-3-carboxyphenyl)methane, and deionized water was 20:400:750, and the solid-liquid mass ratio of PDDA-modified Y molecular sieve to the mixed solution was 1:10. The mixture was ultrasonically stirred and mixed thoroughly. Then, 1 M HF solution and 1 M NaOH solution were added dropwise. The volume ratio of the mixed solution containing PDDA-modified Y molecular sieve to HF solution was 15:1, and the volume ratio of the mixed solution containing PDDA-modified Y molecular sieve to NaOH solution was 10:1. The mixture was then placed in an electrically heated stainless steel hydrothermal reactor and reacted at 300 °C for 6 h. After cooling to room temperature, the mixture was thoroughly washed and filtered with DMF and ethanol. The filter cake was dried at 60 °C for 10 h to obtain Y molecular sieve-MILs powder.

[0042] Example 4 This embodiment provides an adsorbent material with tunable pore size, Y molecular sieve-MILs, whose preparation method includes the following steps: S1: The hydrophobic Y molecular sieve was ground into powder and mixed with 2 g / L PDDA solution at a solid-liquid mass ratio of 1:50. The mixture was stirred at room temperature for 2 h, washed by centrifugation, and dried at 90 ℃ for 4 h to obtain PDDA-modified Y molecular sieve.

[0043] S2: PDDA-modified Y molecular sieve was added to a mixed solution comprising Fe(NO3)3•9H2O, 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine, and deionized water. The mass ratio of Cr(NO3)3•9H2O, di(4-amino-3-carboxyphenyl)methane, and deionized water was 20:300:750. The solid-liquid mass ratio of the PDDA-modified Y molecular sieve to the mixed solution was 1:15. The mixture was ultrasonically stirred until homogeneous. Then, 1 M HF solution and 1 M NaOH solution were added dropwise. The volume ratio of the mixed solution containing the PDDA-modified Y molecular sieve to the HF solution was 15:1, and the volume ratio of the mixed solution containing the PDDA-modified Y molecular sieve to the NaOH solution was 10:1. The mixture was then placed in an electrically heated stainless steel hydrothermal reactor and reacted at 250 °C for 8 h. After cooling to room temperature, the mixture was thoroughly washed and filtered with DMF and ethanol. The filter cake was dried at 90 °C for 8 h. h, Y molecular sieve-MILs powder was obtained.

[0044] Example 5 This embodiment provides an adsorbent material with tunable pore size, Y molecular sieve-MILs, whose preparation method includes the following steps: S1: The hydrophobic Y molecular sieve was ground into powder and mixed with 2 g / L PDDA solution at a solid-liquid mass ratio of 1:50. The mixture was stirred at room temperature for 2 h, washed by centrifugation, and dried at 90 ℃ for 4 h to obtain PDDA-modified Y molecular sieve.

[0045] S2: PDDA-modified Y molecular sieve was added to a mixed solution comprising Al(NO3)3•9H2O, 5-aminoisophthalic acid, and deionized water. The mass ratio of Cr(NO3)3•9H2O, di(4-amino-3-carboxyphenyl)methane, and deionized water was 20:300:750. The solid-liquid mass ratio of PDDA-modified Y molecular sieve to the mixed solution was 1:15. The mixture was ultrasonically stirred and homogenized. Then, 1 M HF solution and 1 M NaOH solution were added dropwise. The volume ratio of the mixed solution containing PDDA-modified Y molecular sieve to HF solution was 15:1, and the volume ratio of the mixed solution containing PDDA-modified Y molecular sieve to NaOH solution was 10:1. The mixture was then placed in an electrically heated stainless steel hydrothermal reactor and reacted at 250 °C for 8 h. After cooling to room temperature, the mixture was thoroughly washed and filtered with DMF and ethanol. The filter cake was dried at 90 °C for 8 h to obtain Y molecular sieve-MILs powder.

[0046] Example 6 This embodiment provides an adsorbent material with tunable pore size, Y molecular sieve-MILs, whose preparation method includes the following steps: S1: The hydrophobic Y molecular sieve was ground into powder and mixed with 2 g / L PDDA solution at a solid-liquid mass ratio of 1:50. The mixture was stirred at room temperature for 2 h, washed by centrifugation, and dried at 90 ℃ for 4 h to obtain PDDA-modified Y molecular sieve.

[0047] S2: Add PDDA-modified Y molecular sieve to the mixed solution, which includes Cr(NO3)3•9H2O, bis(4-amino-3-carboxyphenyl)methane, 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine, and deionized water. The mass ratio of Cr(NO3)3•9H2O, bis(4-amino-3-carboxyphenyl)methane, 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine, and deionized water is 20:150:150:750. The solid-liquid mass ratio of PDDA-modified Y molecular sieve to the mixed solution is 1:15. Mix thoroughly by ultrasonic stirring, then add 1 M HF solution and 1... A mixture of PDDA-modified Y molecular sieve and HF solution was added to a NaOH solution at a volume ratio of 15:1, and the mixture of PDDA-modified Y molecular sieve and NaOH solution was added at a volume ratio of 10:1. The mixture was then placed in an electrically heated stainless steel hydrothermal reactor and reacted at 250 °C for 8 h. After cooling to room temperature, the mixture was thoroughly washed and filtered with DMF and ethanol. The filter cake was dried at 90 °C for 8 h to obtain Y molecular sieve-MILs powder.

[0048] Adsorption performance of Y-zeolite-MILs material for VOCs under different humidity and temperature conditions: Xylene was selected as the VOC molecule, and the adsorption was tested using a pilot-scale adsorption platform filled with the Y-zeolite-MILs material from Example 1. The humidity was 50%RH and 90%RH, and the imported xylene concentration was 2000~2500 mg / m³. 3 Using the similarity between inlet and outlet concentrations as the breakthrough index, the dynamic adsorption amount was measured as shown in Table 1.

[0049] Table 1

[0050] The results show that under low humidity and elevated temperature conditions, the adsorption performance of the same material for xylene is improved by 50.5%.

[0051] In-situ variable-temperature XPS was used to test the aluminum content on the surface of the Y molecular sieve-MILs material in Example 1 at different temperatures (25 °C, 50 °C). The results are as follows: Figure 4 As shown in the results, a characteristic peak of Al 2p binding energy of 75 eV was found in the XPS spectrum. Moreover, the signal intensity of the characteristic peak detected at 50 °C was higher than that at 25 °C. This is because as the temperature increases, the respiration of MILs is enhanced, the pore size of MILs increases, and the range of detected Y molecular sieves increases.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the technical solution of the present invention, based on the technical essence of the present invention, shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. An adsorbent material with adjustable pore size, characterized in that: The adsorbent material is based on a hydrophobic porous adsorbent material, and a layer of MOF filter membrane is coated on the surface of the substrate.

2. The pore size-adjustable adsorbent material according to claim 1, characterized in that: In the adsorption material, the matrix is ​​a hydrophobic Y molecular sieve, and the MOF filter membrane is a MILs.

3. The method for preparing the tunable pore size adsorbent material as described in claim 2, characterized in that: Includes the following steps: S1: Mix powdered hydrophobic Y molecular sieve with PDDA solution and stir at room temperature for 1-3 h to obtain PDDA-modified Y molecular sieve; S2: Add the PDDA-modified Y molecular sieve to a mixed solution containing transition metal salt, organic ligand and deionized water, stir and mix well, then add HF solution and NaOH solution dropwise, and then react at 200~300℃ for 6~10 h to obtain Y molecular sieve-MILs powder.

4. The method for preparing the tunable pore size adsorbent material according to claim 3, characterized in that: In step S1, the concentration of the PDDA solution is 1.5~3 g / L; The solid-liquid ratio of the hydrophobic Y molecular sieve to the PDDA solution is 1:20~80.

5. The method for preparing the tunable pore size adsorbent material according to claim 3, characterized in that: In S2, the transition metal salt is one or more of Cr(NO3)3•9H2O, Fe(NO3)3•9H2O, and Al(NO3)3•9H2O; The organic ligand is a binary amino-containing aromatic ring organic ligand; the binary amino-containing aromatic ring organic ligand is preferably a linear organic ligand and / or a flexible triangular organic ligand; the linear organic ligand is preferably one or more of 5-aminoisophthalic acid, di(4-amino-3-carboxyphenyl)methane, and 2,5-di[(4-methylphenyl)amino]-1,4-phthalic acid; the flexible triangular organic ligand is preferably one or more of 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine and 2-amino-5-4-carboxyphenyl-1,1,3,1-triphenyl-4,4-dicarboxylic acid.

6. The method for preparing the tunable pore size adsorbent material according to claim 3, characterized in that: In S2, the mass ratio of the transition metal salt, the organic ligand, and the deionized water in the mixed solution is 20:200 to 400:

750. The solid-liquid mass ratio of the PDDA-modified Y molecular sieve to the mixed solution is 1:10~20; The concentration of the HF solution is 0.5~3 M; The volume ratio of the mixed solution containing the PDDA-modified Y molecular sieve to the HF solution is 10~20:1; The concentration of the NaOH solution is 0.5~3 M; The volume ratio of the mixed solution containing the PDDA-modified Y molecular sieve to the NaOH solution is 5~15:

1.

7. An RTO pretreatment apparatus, characterized in that: The RTO pretreatment device is located before the RTO equipment. VOCs first enter the RTO pretreatment device and then enter the RTO equipment. The RTO pretreatment device is filled with an adsorbent material with adjustable pore size as described in claim 1 or 2, and an atomizing spray device and a gas mixing device are provided at the inlet end; the atomizing spray device is used to increase the humidity of the intake air VOCs; the gas mixing device is used to mix the intake air VOCs with high-temperature gas to increase the temperature of the intake air VOCs.

8. The RTO pretreatment apparatus according to claim 7, characterized in that: The adsorbent material is made into a honeycomb-shaped block and filled into the RTO pretreatment device. The method for preparing the honeycomb-shaped block is as follows: The adsorbent material is mixed with a binder, an extrusion aid, and an acid solution. The plasticity of the water-based clay is then adjusted with water to obtain a clay material. The clay material is coarsely refined, vacuum refined to remove air bubbles, and then formed into a honeycomb integral wet-based green body using a high-pressure extruder. The green body is heated and dried to obtain a dried green body. After the dried green body is cut and polished, it is calcined at 500~550 ℃ for 6~10 h to obtain the honeycomb block.

9. The RTO pretreatment apparatus according to claim 8, characterized in that: In the method for preparing the honeycomb block, the binder is one or more of the following: silica solution, alumina, boehmite, and kaolin. The extrusion aid is one or more of glycerin, polyvinyl alcohol, and liquid paraffin; The acid solution is a solution of one or more of citric acid, oxalic acid, and nitric acid; The concentration of the acid solution is 5-10 wt%; the mass ratio of the adsorbent material, the binder, the extrusion aid, and the acid solution is 50-70:15:4:

5.

10. An RTO pretreatment process, characterized in that: Implemented using the RTO pretreatment apparatus as described in any one of claims 7 to 9; The RTO pretreatment process is as follows: when the inlet VOCs concentration is below 15% LEL, the atomizing spray device is turned on to control the humidity of the inlet VOCs to 70~90%; when the inlet VOCs concentration is 15~25% LEL, the gas mixing device is turned on to control the temperature of the inlet VOCs to 50~60℃.

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