Axially heat-conducting zeolite honeycomb material, method for producing same, and use thereof

Abstract

The application belongs to the technical field of zeolite materials, and particularly relates to an axial heat-conducting zeolite honeycomb material and a preparation method and application thereof. The preparation method provided by the application comprises the following steps: S1. filtering a first mud in the presence of a low-boiling-point organic solvent through n-stage filters, wedge-shaped filter holes are arranged in each filter, the size of the wedge-shaped filter holes gradually decreases along the filtering direction, and the size of the outlet of the wedge of each filter is smaller than the length of the fiber heat-conducting material, so that the fiber heat-conducting material is distributed in a directional manner, and a second mud is obtained; and S2. performing aging treatment on the second mud, and then performing extrusion molding, and then performing shaping and sintering treatment. The key of the application is to improve the axial heat-conducting performance and desorption efficiency of the zeolite honeycomb material through the synergistic effect of the low-boiling-point organic solvent and the n-stage filters with wedge-shaped filter holes.

Description

Technical Field

[0001] This invention belongs to the field of zeolite material technology, specifically relating to an axially heat-conducting zeolite honeycomb material, its preparation method, and its application. Background Technology

[0002] Zeolite is a type of aluminosilicate material, mainly composed of silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra with a regular nanoporous structure. Due to its porous structure and good thermal stability and acid resistance, it is widely used in catalysis, adsorption separation and other fields.

[0003] In the adsorption treatment of volatile organic pollutants (VOCs), zeolite honeycomb materials have received widespread attention and application due to their excellent adsorption performance and low pressure loss. However, traditional zeolite honeycomb materials suffer from poor thermal conductivity, which limits their efficiency in high-temperature desorption processes, leading to increased energy consumption and prolonged treatment time. Currently, the thermal conductivity is often improved by increasing the proportion of thermally conductive fillers in the zeolite honeycomb material; however, this method easily leads to a decrease in the adsorption performance of the zeolite honeycomb material. Therefore, improving the thermal conductivity of zeolite honeycomb materials while ensuring good adsorption performance is of great significance for improving the overall efficiency of the process system. Summary of the Invention

[0004] One of the objectives of this invention is to solve the problem of how to improve the thermal conductivity and desorption efficiency of zeolite honeycomb materials while ensuring good adsorption performance, and to provide a method for preparing axially thermally conductive zeolite honeycomb materials.

[0005] The second objective of this invention is to provide an axially conductive zeolite honeycomb material prepared by the above-mentioned preparation method.

[0006] A third objective of this invention is to provide the application of the aforementioned axially heat-conducting zeolite honeycomb material in the treatment of volatile organic pollutants.

[0007] Specifically, the preparation method of the axially heat-conducting zeolite honeycomb material includes: S1. Filtering a first slurry through an n-stage filter in the presence of a low-boiling-point organic solvent. The first slurry contains zeolite material, fiber thermally conductive material, binder, water, and optional additives. Each stage of the filter is provided with wedge-shaped filter holes. The pore size of the wedge-shaped filter holes gradually decreases along the filtration direction, and the outlet pore size of the wedge-shaped filter holes in each stage of the filter is smaller than the length of the fiber thermally conductive material, so that the fiber thermally conductive material in the first slurry is oriented to obtain a second slurry, wherein n≧2; S2. After aging the second slurry, extruding it into shape, and then performing shaping and sintering treatments to obtain the axially heat-conducting zeolite honeycomb material.

[0008] In a preferred embodiment, the outlet aperture size of the wedge-shaped filter holes in each of the n-stage filters is independently 10 to 60% of the length of the fiber thermally conductive material.

[0009] In a preferred embodiment, the outlet aperture size of the wedge-shaped filter orifice of the previous stage filter in the n-stage filter is larger than the outlet aperture size of the wedge-shaped filter orifice of the next stage filter.

[0010] In a preferred embodiment, based on the dry total amount of the first slurry, the content of the zeolite material is 50-70 wt%, the content of the fibrous thermal conductive material is 5-9 wt%, the content of the binder is 20-40 wt%, and the content of the additives is 3-8 wt%.

[0011] In a preferred embodiment, the low-boiling-point organic solvent is selected from at least one of methanol, ethanol, and isopropanol.

[0012] In a preferred embodiment, the amount of the low-boiling-point organic solvent is such that the pressure when the first sludge passes through the n-stage wedge filter is 2 to 10 MPa.

[0013] In a preferred embodiment, the zeolite material is selected from at least one of ZSM5 zeolite, NaY zeolite, Beta zeolite, and Y zeolite.

[0014] In a preferred embodiment, the average particle size of the zeolite material is 150 to 300 mesh.

[0015] In a preferred embodiment, the fibrous thermally conductive material is selected from at least one of carbon fiber, metal fiber, silicon carbide fiber, aluminum nitride fiber, and alumina fiber.

[0016] In a preferred embodiment, the average length of the fibrous thermal conductive material is 1 to 3 mm.

[0017] In a preferred embodiment, the average diameter of the fibrous thermal conductive material is 0.02 to 0.05 mm.

[0018] In a preferred embodiment, prior to step S1, the first mud material is filtered through a first filter and a low-boiling-point organic solvent is added during this process to soften the first mud material.

[0019] In a preferred embodiment, the pore size of the filter holes in the first filter is 2 to 3 mm.

[0020] In a preferred embodiment, the outlet aperture size of the wedge-shaped filter holes in each of the n-stage filters is independently 0.1 to 1.8 mm.

[0021] In a preferred embodiment, the adhesive is a mixture of clay and cellulose.

[0022] In a preferred embodiment, the mass ratio of clay to cellulose is (3-9):1.

[0023] In a preferred embodiment, the additive is selected from at least one of humectants, lubricants, sintering aids, dispersants, stabilizers, flow agents, and antifoaming agents.

[0024] In a preferred embodiment, the sintering conditions include a temperature of 500–700°C and a time of 4–6 hours.

[0025] The key to this invention lies in controlling the softness of the slurry by adding a low-boiling-point organic solvent. Based on this, an n-stage filter with wedge-shaped pores ensures the directional distribution of the fibrous thermally conductive material within the slurry. This results in an axially distributed fibrous thermally conductive material in the resulting zeolite honeycomb material, enhancing its axial thermal conductivity. This improved axial thermal conductivity enhances heat transfer during VOCs desorption, increasing thermal efficiency and shortening the time to reach the desorption temperature, thus improving the desorption efficiency of the zeolite honeycomb material. The reason for this is likely that the combined effect of the low-boiling-point organic solvent and the n-stage filter with wedge-shaped pores ensures the directional distribution of the fibrous thermally conductive material. Compared to adding water or other high-boiling-point organic solvents, the low-boiling-point organic solvent in the filtered slurry evaporates quickly, allowing the fibrous thermally conductive material to maintain a good directional distribution during aging and subsequent operations. This prevents the slurry from retaining high softness due to delayed solvent evaporation, which would reduce the directional distribution of the fibrous thermally conductive material. Compared to existing technologies that often improve the thermal conductivity of zeolite honeycomb materials by increasing the proportion of thermally conductive materials, which leads to a decrease in the adsorption performance of zeolite honeycomb materials, the zeolite honeycomb materials prepared by the method provided in this invention not only have better thermal conductivity and higher desorption efficiency, but also maintain their original good adsorption performance, while maintaining the same proportion of fiber thermally conductive materials. Detailed Implementation

[0026] The preparation method of the axially heat-conducting zeolite honeycomb material provided by the present invention includes: S1. Filtering a first slurry through an n-stage filter in the presence of a low-boiling-point organic solvent. The first slurry contains zeolite material, fiber thermally conductive material, binder, water, and optional additives. Each stage of the filter is provided with wedge-shaped filter holes. The pore size of the wedge-shaped filter holes gradually decreases along the filtration direction, and the outlet pore size of the wedge-shaped filter holes in each stage of the filter is smaller than the length of the fiber thermally conductive material, so that the fiber thermally conductive material in the first slurry is oriented to obtain a second slurry, wherein n≧2, such as 2, 3, 4, 5, etc.; S2. After extruding and molding the second slurry, it is shaped and sintered to obtain the axially heat-conducting zeolite honeycomb material.

[0027] It should be noted that "axial direction" refers to the direction of the central axis of the pore structure of the zeolite honeycomb material. When the zeolite honeycomb material is used for the treatment of volatile organic pollutants, the "axial direction" is the same as the direction in which the gas passes through the zeolite honeycomb material.

[0028] Furthermore, the terms "first" and "second" are merely used to refer to clay materials that appear in different orders for easy distinction, and have no other special meaning and should not be interpreted as limitations on the composition and content of the clay materials.

[0029] In this invention, the outlet aperture size of the wedge-shaped filter holes in each stage of the n-stage filter is preferably 10% to 60% of the length of the fiber thermally conductive material, such as 10%, 20%, 30%, 40%, 50%, 60%, or any value between them. Controlling the outlet aperture size of the wedge-shaped filter holes in the final stage filter within the above-mentioned preferred range is more conducive to improving the directional distribution of the fiber thermally conductive material in the sludge after filtration through the n-stage filter, thereby further improving the axial thermal conductivity of the zeolite honeycomb material.

[0030] In this invention, the outlet aperture size of the wedge-shaped filter holes in each stage of the n-stage filter can be the same or different. More preferably, the outlet aperture size of the wedge-shaped filter holes in the previous stage of the n-stage filter is larger than that in the next stage. By designing the outlet aperture size of the wedge-shaped filter holes in the n-stage filter to decrease step by step, it is more beneficial to achieve the directional distribution of the fibrous thermally conductive material in the sludge obtained after filtration through the n-stage filter, thereby further improving the axial thermal conductivity of the zeolite honeycomb material. The outlet aperture size of the wedge-shaped filter holes in the next stage of the n-stage filter can be 65% to 100% of the outlet aperture size of the wedge-shaped filter holes in the previous stage, such as 65%, 68%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or any value between them. Values ​​smaller than the above preferred range may lead to excessive pressure during sludge filtration, which is not conducive to achieving the directional distribution of the fibrous thermally conductive material.

[0031] In this invention, based on the dry total weight of the first slurry, the content of the zeolite material is preferably 50-70 wt%, such as 50 wt%, 60 wt%, 70 wt%, or any value between them. The content of the fibrous thermally conductive material is preferably 5-9 wt%, such as 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or any value between them. The content of the binder is preferably 20-40 wt%, such as 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, or any value between them. The content of the additives is preferably 3-8 wt%, such as 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, or any value between them.

[0032] The present invention does not limit the specific type of the low-boiling-point organic solvent, as long as it is a substance that can soften the mud material after addition and is easily volatilized under normal temperature and pressure conditions. The boiling point of the low-boiling-point organic solvent is preferably below 85°C, and specific examples include, but are not limited to, at least one of methanol, ethanol, and isopropanol, with ethanol being more preferred.

[0033] The present invention does not specify the amount of the low-boiling-point organic solvent used, as long as it can soften the mud and cause the fibrous thermally conductive material in the mud to be directionally distributed through the n-stage filter. The preferred amount of the low-boiling-point organic solvent is such that the pressure of the first mud passing through the n-stage filter is 2 to 10 MPa, such as 2 MPa, 5 MPa, 8 MPa, 10 MPa or any value between them.

[0034] This invention does not specifically limit the type of zeolite material, as long as it has a porous structure formed by an aluminosilicate framework and can adsorb pollutants, it can be any existing natural zeolite material or any existing artificially prepared or modified zeolite material. Specific examples include, but are not limited to, at least one of ZSM5 zeolite, NaY zeolite, Beta zeolite, and Y zeolite. The average particle size of the zeolite material is preferably 150-300 mesh, such as 150 mesh, 180 mesh, 200 mesh, 220 mesh, 250 mesh, 280 mesh, 300 mesh, or any value between them. Within this preferred range, the zeolite material can be better mixed with the oriented fibrous thermally conductive material, thereby more effectively improving the desorption rate through the axial thermal conductivity of the fibrous thermally conductive material.

[0035] This invention does not limit the specific type of the fibrous thermal conductive material, and it can be any existing fibrous material capable of conducting heat, including but not limited to at least one of carbon fiber, metal fiber, silicon carbide fiber, aluminum nitride fiber, and alumina fiber. The average length of the fibrous thermal conductive material is preferably 1–3 mm, such as 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or any value between them. Controlling the average length of the fibrous thermal conductive material within the above-mentioned preferred range is more conducive to the directional distribution of the fibrous thermal conductive material through the n-stage filter, and avoids fiber breakage during n-stage filter processing due to excessive fiber length, or easy clogging of the n-stage filter with a small wedge-shaped filter outlet aperture due to excessively short fiber length, which is not conducive to achieving the directional distribution of the fibrous thermal conductive material. This is more beneficial to improving the axial thermal conductivity of the zeolite honeycomb material. The average diameter of the fibrous thermal conductive material is preferably 0.02–0.05 mm, such as 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, or any value between them.

[0036] This invention does not limit the specific type of adhesive, as long as it is a substance capable of binding various added raw materials. Specific examples include, but are not limited to, at least one of: boehmite, polyurethane-based adhesive, epoxy resin-based adhesive, clay, and cellulose. The adhesive is preferably a mixture of clay and cellulose. The mass ratio of clay to cellulose is preferably (3-9):1, such as 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or any value between them. The clay can be at least one of palygorskite, kaolin, bentonite, and activated clay. The cellulose can be at least one of carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl methyl cellulose.

[0037] In this invention, the additive is preferably selected from at least one of humectants, lubricants, sintering aids, dispersants, stabilizers, flow agents, and antifoaming agents.

[0038] In this invention, in step S1, the first raw material can be obtained by mixing zeolite material, fiber thermal conductive material, binder, water, and optional additives in any order. The mixing order of the components is not fixed; they can be added simultaneously and then mixed together, or at least one of the components other than water can be mixed with water first, and then the remaining components can be added simultaneously or sequentially. Preferably, step S1 of this invention is performed as follows: the zeolite material and a portion of the binder are premixed, then the remaining binder and water are added and stirred, and then the fiber thermal conductive material and additives are added and stirred to obtain the first mud material.

[0039] In this invention, before step S1, the process may further include filtering the first slurry through a first filter and adding a low-boiling-point organic solvent during this process to soften the first slurry. The function of the first filter is to first form the first slurry into small, fine strips, making it easier for the first slurry to pass through the subsequent n-stage filters for directional distribution of the fiber thermal conductive material. The filter holes in the first filter can be wedge-shaped or conventional filter holes with the same inlet and outlet diameter. This invention does not specifically limit the diameter of the filter holes in the first filter, but it is preferably 2–3 mm, such as 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, or any value between them. The outlet diameter of the wedge-shaped filter holes in the final stage filter of the n-stage filter is preferably 0.1–1.8 mm, such as 0.1 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, or any value between them.

[0040] In this invention, the aging process in step S2 preferably includes placing the second mud material in a constant temperature and humidity environment. The placement time can be determined according to the actual situation, preferably 12 to 36 hours, such as 12 hours, 15 hours, 18 hours, 20 hours, 24 hours, 30 hours, 36 hours or any value between them.

[0041] In this invention, the shaping process in step S2 can be achieved by naturally drying the extruded semi-finished zeolite honeycomb material, or by microwave shaping, or other shaping methods in the prior art, preferably by microwave shaping. The conditions for the microwave shaping can be conventionally chosen in the art, preferably including a total microwave power of 10–15 kW, such as 10 kW, 11 kW, 12 kW, 13 kW, 14 kW, 15 kW, or any value between them; a microwave frequency of 0.5–10 GHz, such as 0.5 GHz, 1 GHz, 2 GHz, 5 GHz, 8 GHz, 10 GHz; a time of 1–5 min, such as 1 min, 2 min, 3 min, 4 min, 5 min, or any value between them; and a temperature of 90–150 °C, such as 90 °C, 100 °C, 120 °C, 150 °C, or any value between them.

[0042] In this invention, the sintering conditions include a temperature preferably of 500–700°C, such as 500°C, 550°C, 600°C, 650°C, 700°C or any value between them; and a time preferably of 4–6 h, such as 4 h, 4.5 h, 5 h, 5.5 h, 6 h or any value between them.

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

[0044] Example 1

[0045] The raw materials include: 140kg ZSM5 zeolite (average particle size of 200 mesh), 14kg silicon carbide fiber (average length of 2mm and average diameter of 0.03mm), 40kg clay material (palmitite), 12kg methylcellulose, 2kg humectant, 2kg lubricant, 6kg sintering aid, and 72kg pure water.

[0046] S1. ZSM5 zeolite and clay materials are premixed by ball milling, transferred to a mixing tank, and methylcellulose and pure water are added. After stirring for 20 minutes, a humectant is added and stirring is continued for 10 minutes. Then, a lubricant, silicon carbide fiber and sintering aid are added and stirring is continued for 10 minutes to form small spherical clay. The clay is then kneaded by a twin-screw extruder, and the kneading cycle is repeated 3 times and then extruded into a cylindrical shape to obtain the first clay material.

[0047] The first slurry is filtered through a first filter (with an inlet diameter of 5.0 mm and an outlet diameter of 2.5 mm for the wedge-shaped filter holes). During this process, ethanol is sprayed to soften the slurry. The amount of ethanol added is the amount used when the pressure gauge drops to 5 MPa. At this point, the slurry is extruded from a cylindrical shape into small strips. Then, the slurry is subjected to directional treatment through a first-stage filter (with an inlet diameter of 2.5 mm and an outlet diameter of 1.0 mm for the wedge-shaped filter holes) and a second-stage filter (with an inlet diameter of 1.5 mm and an outlet diameter of 0.7 mm for the wedge-shaped filter holes), thus obtaining a second slurry with directional distribution of fiber thermal conductive material.

[0048] S2. By placing the second clay material in a constant temperature and humidity space for 24 hours for aging treatment, the ethanol and excess water evaporate. When the humidity of the clay material is tested by a hygrometer and is about 80%, and the extrusion pressure of the clay material is verified to be 5 MPa by a small extrusion device, the clay material can be extruded into a semi-finished zeolite honeycomb material through a mold. Then, it is microwave treated (total microwave power 14kW, microwave frequency 5GHz, time 2min, temperature 120℃), and then sintered at 600℃ for 4 hours to obtain axially heat-conducting zeolite honeycomb material.

[0049] Example 2

[0050] The raw materials include: 100kg NaY zeolite (average particle size of 250 mesh), 18kg carbon fiber (average length of 1mm and average diameter of 0.02mm), 64kg clay material (palmitite), 8kg carboxymethyl cellulose, 2kg humectant, 2kg lubricant, 6kg sintering aid, and 72kg pure water.

[0051] S1. NaY zeolite and clay materials are premixed by ball milling, transferred to a mixing tank, and carboxymethyl cellulose and 72 kg of pure water are added. After stirring for 20 min, a humectant is added and stirring is continued for 10 min. Then, a lubricant, carbon fiber and sintering aid are added and stirring is continued for 10 min to form small spherical clay. The clay is then kneaded by a twin-screw extruder, and the kneading cycle is repeated 3 times and then extruded into a cylindrical shape to obtain the first clay material.

[0052] The first slurry is filtered through a first filter (with an inlet diameter of 4.0 mm and an outlet diameter of 2.0 mm in a wedge-shaped filter hole). During this process, ethanol is sprayed to soften the slurry. The amount of ethanol added is the amount used when the pressure gauge drops to 5 MPa. At this point, the slurry is extruded from a cylindrical shape into small strips. Then, the slurry is subjected to directional treatment through a first-stage filter (with an inlet diameter of 2.0 mm and an outlet diameter of 0.3 mm in a wedge-shaped filter hole) and a second-stage filter (with an inlet diameter of 0.5 mm and an outlet diameter of 0.2 mm in a wedge-shaped filter hole), which yields a second slurry with directional distribution of fiber thermal conductive material.

[0053] S2. By placing the second clay material in a constant temperature and humidity space for 24 hours for aging treatment, the ethanol and excess water evaporate. When the humidity of the clay material is tested by a hygrometer and is about 80%, and the extrusion pressure of the clay material is verified to be 5 MPa by a small extrusion device, the clay material can be extruded into a semi-finished zeolite honeycomb material through a mold. Then, it is microwave treated (total microwave power 14kW, microwave frequency 5GHz, time 2min, temperature 120℃), and then sintered at 500℃ for 6 hours to obtain axially heat-conducting zeolite honeycomb material.

[0054] Example 3

[0055] The raw materials include: 120kg Beta zeolite (average particle size of 200 mesh), 10kg aluminum nitride fiber (average length of 3mm and average diameter of 0.04mm), 50kg clay material (palmitite), 14kg hydroxypropyl cellulose, 2kg humectant, 2kg lubricant, 2kg sintering aid, and 72kg pure water.

[0056] S1. Beta zeolite and clay materials are premixed by ball milling, transferred to a mixing tank, and hydroxypropyl cellulose and 72 kg of pure water are added. After stirring for 20 min, a humectant is added and stirring is continued for 10 min. Then, a lubricant, aluminum nitride fiber and sintering aid are added and stirring is continued for 10 min to form small spherical clay. The clay is then kneaded by a twin-screw extruder, and the kneading cycle is repeated 3 times and then extruded into a cylindrical shape to obtain the first clay material.

[0057] The first mud material is filtered through a first filter (with an inlet diameter of 5.5 mm and an outlet diameter of 3.0 mm for the wedge-shaped filter holes). During this process, ethanol is sprayed to soften the mud material. The amount of ethanol added is the amount used when the pressure gauge drops to 5 MPa. At this point, the mud material is extruded from a cylindrical shape into small strips. Then, the mud material is subjected to directional treatment through a primary filter device (with an inlet diameter of 3.2 mm and an outlet diameter of 1.5 mm for the wedge-shaped filter holes) and a secondary filter (with an inlet diameter of 2.0 mm and an outlet diameter of 1.2 mm for the wedge-shaped filter holes), thus obtaining a second mud material with directional distribution of fiber thermal conductive material.

[0058] S2. By placing the second clay material in a constant temperature and humidity space for 24 hours for aging treatment, the ethanol and excess water evaporate. When the humidity of the clay material is tested by a hygrometer and is about 80%, and the extrusion pressure of the clay material is verified to be 5 MPa by a small extrusion device, the clay material can be extruded into a semi-finished zeolite honeycomb material through a mold. Then, it is microwave treated (total microwave power 14kW, microwave frequency 5GHz, time 2min, temperature 120℃), and then sintered at 550℃ for 5 hours to obtain axially heat-conducting zeolite honeycomb material.

[0059] Example 4

[0060] Axially heat-conducting zeolite honeycomb material was prepared according to the method of Example 1, except that silicon carbide fibers with an average length of 6 mm and an average diameter of 0.03 mm of the same mass were used instead of silicon carbide fibers with an average length of 2 mm and an average diameter of 0.03 mm. All other conditions were the same, and thus the axially heat-conducting zeolite honeycomb material was obtained.

[0061] Comparative Example 1

[0062] The reference zeolite honeycomb material was prepared according to the method of Example 1, except that the inlet and outlet aperture sizes of the wedge-shaped filter holes in the first filter, primary filter and secondary filter were all 5 mm (the average length of the silicon carbide fiber was 2 mm), and all other conditions were the same, thus obtaining the reference zeolite honeycomb material.

[0063] Comparative Example 2

[0064] The reference zeolite honeycomb material was prepared according to the method of Example 1, except that in step S1, the same mass of water was used instead of ethanol, and all other conditions were the same, thus obtaining the reference zeolite honeycomb material.

[0065] Test case

[0066] The zeolite honeycomb materials prepared in the above examples and comparative examples were tested for axial thermal conductivity and adsorption-desorption efficiency using the following methods. The results are shown in Table 1.

[0067] (1) Axial thermal conductivity: The axial thermal conductivity is calculated by applying heat flow through the zeolite honeycomb material in the axial direction using a heat flow meter and measuring the heat energy flowing through the material.

[0068] (2) Adsorption-desorption efficiency: The honeycomb prepared in the comparative example was cut into 4 small pieces of 3*3*10cm and placed in a glass tube. During adsorption, VOCs (concentration of 1000ppm, flow rate of 1m / s) were introduced into the inlet, and the VOCs concentration curve at the tube outlet was recorded. During desorption, hot air at 180℃ (flow rate of 0.2m / s) was introduced into the inlet, and the VOCs concentration curve and temperature curve at the tube outlet were recorded. The adsorption efficiency was calculated based on the VOCs adsorption concentration curve, VOCs desorption concentration curve and desorption temperature curve, and the desorption temperature and the time required to reach the desorption temperature were recorded.

[0069] Wherein, adsorption efficiency = (adsorption inlet concentration - adsorption outlet concentration) / adsorption inlet concentration * 100%.

[0070] Table 1

[0071]

[0072] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A method for preparing a zeolite honeycomb material, characterized in that, The preparation method includes: S1. Filtering a first clay material through an n-stage filter in the presence of a low-boiling-point organic solvent. The first clay material contains zeolite material, fiber thermal conductive material, binder, water, and optional additives. Each stage of the filter has wedge-shaped filter holes, the pore size of which gradually decreases along the filtration direction, and the outlet pore size of each wedge-shaped filter hole is smaller than the length of the fiber thermal conductive material, so that the fiber thermal conductive material in the first clay material is directionally distributed to obtain a second clay material, wherein n ≥ 2; S2. After aging the second clay material, extruding it into shape, and then performing shaping and sintering treatment to obtain zeolite honeycomb material. Based on the dry total amount of the first clay material, the content of the zeolite material is 50~70wt%, the content of the fiber thermal conductive material is 5~9wt%, the content of the binder is 20~40wt%, and the content of the additives is 3~8wt%.

2. The method for preparing zeolite honeycomb material according to claim 1, characterized in that, The outlet aperture size of the wedge-shaped filter holes in each of the n-stage filters is independently 10 to 60% of the length of the fiber thermal conductive material.

3. The method for preparing zeolite honeycomb material according to claim 2, characterized in that, In the n-stage filter, the outlet diameter of the wedge-shaped filter orifice of the previous stage filter is larger than that of the wedge-shaped filter orifice of the next stage filter.

4. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The low-boiling-point organic solvent is selected from at least one of methanol, ethanol, and isopropanol.

5. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The amount of the low-boiling-point organic solvent used is such that the pressure of the first sludge passing through the n-stage filter is 2~10 MPa.

6. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The zeolite material is selected from at least one of ZSM5 zeolite, NaY zeolite, Beta zeolite, and Y zeolite.

7. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The average particle size of the zeolite material is 150~300 mesh.

8. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The fibrous thermal conductive material is selected from at least one of carbon fiber, metal fiber, silicon carbide fiber, aluminum nitride fiber, and alumina fiber.

9. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The average length of the fiber thermal conductive material is 1~3mm; the average diameter of the fiber thermal conductive material is 0.02~0.05mm.

10. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, Prior to step S1, the process further includes filtering the first mud material through a first filter and adding a low-boiling-point organic solvent during the filtration of the first mud material through the first filter to soften the first mud material.

11. The method for preparing zeolite honeycomb material according to claim 10, characterized in that, The pore size of the filter holes in the first filter is 2~3mm.

12. The method for preparing zeolite honeycomb material according to claim 11, characterized in that, The outlet aperture size of the wedge-shaped filter holes in each of the n-stage filters is independently 0.1~1.8mm.

13. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The adhesive is a mixture of clay and cellulose.

14. The method for preparing zeolite honeycomb material according to claim 13, characterized in that, The mass ratio of clay to cellulose is (3~9):

1.

15. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The additive is selected from at least one of humectants, lubricants, sintering aids, dispersants, stabilizers, flow agents, and antifoaming agents.

16. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The aging process includes placing the second mud material in a constant temperature and humidity environment.

17. The method for preparing zeolite honeycomb material according to any one of claims 1 to 3, characterized in that, The sintering conditions include a temperature of 500~700℃ and a time of 4~6h.

18. An axially conductive zeolite honeycomb material prepared by the method for preparing zeolite honeycomb material according to any one of claims 1 to 17.

19. The application of the zeolite honeycomb material according to claim 18 in the treatment of volatile organic pollutants.

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