Integrated ceramic filter tube and method of making and use thereof

Abstract

The application provides an integrated ceramic filter tube and a preparation method and application thereof. The integrated ceramic filter tube comprises a base body having a cavity structure, a pipe wall of the base body being formed by fiber lapping, and a high-entropy active component dispersed on the surface and / or inside of the pipe wall, and the high-entropy active component comprises metal oxides formed by five or more transition metals. The integrated ceramic filter tube breaks through the traditional segmented processing mode of dust removal first and catalytic purification later, integrates the functions of particulate matter capture and NO x , VOCs catalytic degradation into a single ceramic filter tube, and can simultaneously remove dust, nitrogen oxides and volatile organic compounds in industrial flue gas such as coking, steel and cement. The design simplifies the industrial tail gas treatment process, reduces the equipment area and system pipeline connection cost, reduces the difficulty of engineering transformation of the industrial end, and realizes efficient and collaborative removal of multiple pollutants.

Description

Technical Field

[0001] This invention relates to an integrated ceramic filter tube, its preparation method and application, belonging to the field of synergistic removal of multiple pollutants from industrial flue gas. Background Technology

[0002] Industrial flue gas treatment is one of the core issues in the field of ecological and environmental protection, especially in heavy industries such as coking, steel, and cement, where flue gas often carries particulate matter (dust) and nitrogen oxides (NOx). x Industrial flue gas contains a variety of pollutants, including volatile organic compounds (VOCs), which are characterized by their complex composition and cumulative hazards, posing a serious threat to the atmospheric environment and human health. With increasingly stringent environmental regulations, the synergistic removal of multiple pollutants from industrial flue gas has become an inevitable trend in the industry.

[0003] Currently, the industrial flue gas treatment field often adopts a "step-by-step treatment" model for the removal of the aforementioned multiple pollutants. This involves removing particulate matter using independent dust collection equipment (such as bag filters and electrostatic precipitators), followed by removing NO using denitrification devices (such as SCR denitrification systems). x VOCs require additional treatment units such as adsorption and catalytic combustion. This step-by-step treatment mode has many inherent drawbacks: First, the system structure is complex, the equipment occupies a large area, and the initial investment cost is high, while also increasing the difficulty of supporting engineering such as pipeline connection and control system integration; second, the operating parameters of each treatment unit are difficult to match precisely, which can easily lead to pollutant escape and affect the overall treatment efficiency; third, the equipment consumes a lot of energy and has high maintenance costs during operation, further increasing the environmental burden.

[0004] To address the drawbacks of step-by-step processing, the industry is gradually exploring "integrated collaborative processing" technology. Ceramic filter tubes, due to their advantages such as high temperature resistance, corrosion resistance, high mechanical strength, and high filtration accuracy, have become the core carrier of integrated processing equipment. Reference 1 discloses an integrated dust removal and denitrification ceramic filter material, its preparation method, and its application. The denitrification layer is a coated denitrification catalyst, achieving integrated dust removal and denitrification, suitable for high-temperature flue gas purification, and applicable to waste incineration, biomass power generation, and other fields. Reference 2 discloses a wear-resistant, large-size integrated dust removal and denitrification filter element and its preparation method. This involves a large-size integrated filter element (including ceramic filter tube structures) with a metal skeleton. It is manufactured by preparing a metal skeleton, aggregate, and catalyst slurry, followed by spraying, filling, and sealing processes. It exhibits good wear resistance, high denitrification efficiency, and recyclable ceramic fiber membrane material.

[0005] However, the above methods still have significant shortcomings. For example, on the one hand, the loading of catalytic components often involves a multi-step process: "first preparing a ceramic filter tube blank, then sintering it at high temperature, subsequently loading the catalytic solution, and then treating it again at low / high temperature." This process is cumbersome, and the catalytic components are prone to uneven distribution during the subsequent loading process, leading to unstable catalytic activity. On the other hand, the existing loaded catalytic components are mostly single or a few types of metal oxides, resulting in limited synergistic catalytic performance and making it difficult to simultaneously and efficiently remove NO. x And VOCs, cannot meet the treatment needs of complex industrial flue gas.

[0006] Therefore, developing an integrated ceramic filter tube preparation technology that is simple in process, has uniform catalytic component distribution, and high synergistic removal efficiency has become an urgent technical problem to be solved in the field of multi-pollutant treatment of industrial flue gas.

[0007] References:

[0008] Reference 1: CN116036729A

[0009] Reference 2: CN119607723A Summary of the Invention

[0010] The problem the invention aims to solve

[0011] In view of the technical problems existing in the prior art, the present invention first provides an integrated ceramic filter tube. The integrated ceramic filter tube of the present invention can achieve efficient and synergistic removal of dust, nitrogen oxides and volatile organic compounds under conditions of 150~400 °C.

[0012] The present invention also provides a method for preparing an integrated ceramic filter tube, wherein a high-entropy active component is introduced before the tubular blank is sintered, and the high-entropy active component and the ceramic filter tube are formed simultaneously through the sintering process. The preparation method is simple and has excellent performance.

[0013] Solution for solving the problem

[0014] [1] An integrated ceramic filter tube, comprising:

[0015] A matrix having a hollow structure, and the tube walls of the matrix being formed by overlapping fibers, and

[0016] A high-entropy active component, said high-entropy active component being dispersed on the surface and / or inside the tube wall; and...

[0017] The high-entropy active component includes metal oxides formed from five or more transition metals.

[0018] [2] According to the integrated ceramic filter tube described in [1] above, the transition metal includes Cu, Co, Ni, Fe, Mn, V or W;

[0019] Preferably, the molar ratio between different transition metals is 0.9~1.1:0.9~1.1.

[0020] [3] According to the integrated ceramic filter tube described in [1] or [2] above, the loading of the high-entropy active component is 5% to 15% based on the total mass of the substrate as 100%.

[0021] [4] The integrated ceramic filter tube according to any one of [1] to [3] above, wherein the raw materials for preparing the matrix include aggregate and binder.

[0022] [5] The integrated ceramic filter tube according to any one of [1] to [4] above, wherein the content of the binder is 10% to 30% based on the total mass of the aggregate as 100%.

[0023] [6] A method for preparing an integrated ceramic filter tube according to any one of [1] to [5] above, wherein the method includes the step of loading a high-entropy active component onto the surface of the substrate; preferably, the preparation method includes the following steps:

[0024] A tubular preform was prepared;

[0025] Prepare a metal precursor solution containing a high-entropy active component;

[0026] After the metal precursor solution is present on the surface and / or inside the tubular preform, it is dried and then sintered to obtain an integrated ceramic filter tube.

[0027] [7] According to the preparation method described in [6] above, the concentration of the metal precursor in the metal precursor solution is 0.5 mol / L to 4 mol / L.

[0028] [8] According to the preparation method described in [6] or [7] above, the metal precursor solution is present on the surface and / or inside the tubular preform by spraying; preferably, the spraying rate is 0.05 m / s to 0.1 m / s, and the number of spraying times is 2 to 4.

[0029] [9] The preparation method according to any one of [6] to [8] above, wherein the drying temperature is 50℃ to 120℃, the sintering temperature is 1000℃ to 1300℃, and the sintering time is 1 h to 2 h.

[0030]

[10] A method for using an integrated ceramic filter tube according to any one of [1] to [5] above for dust removal and synergistic removal of nitrogen oxides and volatile organic compounds.

[0031] The effects of the invention

[0032] The integrated ceramic filter tube of this invention breaks through the traditional segmented treatment mode of first removing dust and then catalytic purification, and captures particulate matter and NO. x The VOCs synergistic catalytic degradation function is integrated into a single ceramic filter tube, which can simultaneously remove dust, nitrogen oxides, and volatile organic compounds from industrial flue gas from coking, steel, and cement industries. This design simplifies the industrial exhaust gas treatment process, reduces equipment footprint and system piping connection costs, lowers the difficulty of engineering modifications at the industrial end, and achieves efficient synergistic removal of multiple pollutants.

[0033] The integrated ceramic filter tube of this invention constructs a high-entropy active system by using high-entropy active components. The high-entropy effect can regulate the electronic structure of active sites, improve the dispersion and stability of metal oxides, and simultaneously enhance the removal of NO. x Activity of reduction and VOCs catalytic oxidation.

[0034] The integrated ceramic filter tube of the present invention is based on a mature ceramic filter tube extrusion molding process. It does not require the introduction of complex equipment or special process conditions, and is easy to scale up for industrial production, which greatly reduces the threshold and cost of technology transfer. Attached Figure Description

[0035] Figure 1 The NO content of the integrated ceramic filter tubes of Examples 1-7 of the present invention as a function of temperature is shown. x Synergistic C7H8 decomposition reaction activity.

[0036] Figure 2 The following are scanning electron microscope (SEM) images of the ceramic filter tube of Comparative Example 1 and the ceramic filter tube A of Example 1 of the present invention; wherein, a and b are the ceramic filter tube of Comparative Example 1 at different magnifications, and c and d are the ceramic filter tubes of Example 1 at different magnifications.

[0037] Figure 3 The EDS elemental distribution diagram of the ceramic filter tube F of Embodiment 6 of the present invention is shown. Detailed Implementation

[0038] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0039] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the spirit of the present invention.

[0040] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0041] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0042] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0043] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0044] <First Aspect>

[0045] A first aspect of the present invention provides an integrated ceramic filter tube, comprising:

[0046] A matrix having a hollow structure, and the tube walls of the matrix being formed by overlapping fibers, and

[0047] A high-entropy active component, said high-entropy active component being dispersed on the surface and / or inside the tube wall; and...

[0048] The high-entropy active component includes metal oxides formed from five or more transition metals.

[0049] The integrated ceramic filter tube of this invention directly loads high-entropy active components onto the surface and / or interior of the substrate tube wall, enabling the integrated ceramic filter tube to break through the traditional segmented treatment mode of first dust removal and then catalytic purification, and to capture particulate matter and NO. xThe VOCs synergistic catalytic degradation function is integrated into a single ceramic filter tube, which can simultaneously remove dust, nitrogen oxides, and volatile organic compounds from industrial flue gas from coking, steel, and cement industries. This design simplifies the industrial exhaust gas treatment process, reduces equipment footprint and system piping connection costs, and lowers the difficulty of engineering modifications at the industrial level.

[0050] matrix

[0051] In this invention, the substrate has a hollow structure, and the tube wall of the substrate is formed by overlapping fibers. This invention uses ceramic fiber filter tubes as the substrate, which are lighter, more flexible, stronger, and less prone to breakage during use. The tubular preform forming the substrate of this invention can be purchased or prepared.

[0052] In some specific embodiments, the raw materials for preparing the matrix may include aggregates and binders. In this invention, the binder is only used when preparing the tubular preform of the matrix to enable the tubular preform of the matrix to take shape. Even when tubular preforms are purchased directly, a binder needs to be added during their preparation to form the tubular preform.

[0053] Furthermore, the present invention does not impose any particular limitation on the aggregate, which can be some aggregates commonly used in the art. Specifically, the aggregate may include alumina and / or silicon carbide.

[0054] In some specific embodiments, in order to obtain the desired matrix, the binder content is 10% to 30% based on the total mass of the aggregate, for example: 12%, 15%, 18%, 20%, 22%, 25%, 28%, etc. When the binder content is 10% to 30%, the desired tubular preform can be formed.

[0055] Specifically, the present invention does not impose particular limitations on the adhesive, and it can be any adhesive commonly used in the art. The adhesive includes cellulose-based adhesives, preferably including one or more combinations of carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, and cellulose acetyl.

[0056] High-entropy active components

[0057] The high-entropy active component of this invention is dispersed on the surface and / or inside the tube wall of the substrate. The high-entropy active component comprises metal oxides formed from five or more transition metals. Generally, only three or fewer metal oxides can be loaded onto a substrate, while the high-entropy active component of this invention comprises five or more metal oxides. By directly dispersing the high-entropy active component on the surface and / or inside the tube wall of the substrate, the NO removal efficiency can be improved. xReduction and VOCs catalytic oxidation activity.

[0058] The integrated ceramic filter tube of this invention constructs a high-entropy active system by using high-entropy active components. The high-entropy effect can regulate the electronic structure of active sites, improve the dispersion and stability of metal oxides, and simultaneously enhance the removal of NO. x Activity of reduction and VOCs catalytic oxidation.

[0059] In some specific embodiments, the transition metal includes Cu, Co, Ni, Fe, Mn, V, or W. Specifically, the high-entropy active component can be Cu, Co, Ni, Fe, and Mn; the high-entropy active component can be Cu, Co, Ni, Fe, Mn, and V; the high-entropy active component can be Cu, Co, Ni, Fe, Mn, and W; the high-entropy active component can be Cu, Co, Fe, Mn, and V; the high-entropy active component can be Cu, Co, Fe, Mn, and W.

[0060] Preferably, the molar ratio between different transition metals is 0.9~1.1:0.9~1.1, and more preferably it can be close to 1:1. For example, when the high-entropy active component is Cu, Co, Ni, Fe and Mn, the molar ratio of Cu, Co, Ni, Fe and Mn is 0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1; when the high-entropy active component is Cu, Co, Ni, Fe, Mn and V, the molar ratio of Cu, Co, Ni, Fe, Mn and V is 0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1; when the high-entropy active component is Cu, Co, Ni, Fe, Mn and W, the molar ratio of Cu... The molar ratio of Cu, Co, Ni, Fe, Mn and W is 0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1; when Cu, Co, Fe, Mn and W are present, the molar ratio of Cu, Co, Fe, Mn and W is 0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1; when Cu, Co, Fe, Mn and V are present, the molar ratio of Cu, Co, Fe, Mn and V is 0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1:0.9~1.1.

[0061] In some specific implementations, based on the total mass of the matrix as 100%, the loading of the high-entropy active component is 5% to 15%, preferably 8% to 14%, for example: 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, etc. When the loading of the high-entropy active component is 5% to 15%, the function of the high-entropy active component can be exerted more effectively.

[0062] <Second aspect>

[0063] A second aspect of the present invention provides a method for preparing an integrated ceramic filter tube according to the first aspect of the present invention, comprising the step of loading a high-entropy active component onto the surface of the substrate.

[0064] Preferably, the preparation method includes the following steps:

[0065] A tubular preform was prepared;

[0066] Prepare a metal precursor solution containing a high-entropy active component;

[0067] After the metal precursor solution is present on the surface and / or inside the tubular preform, it is dried and then sintered to obtain an integrated ceramic filter tube.

[0068] Specifically, aggregates, binders, and solvents are mixed to form a homogeneous slurry, which serves as the raw material for the green body. Then, a tubular green body is prepared using an extrusion molding process. Preferably, to balance the density of the green body with subsequent sintering stability, medium-high pressure, low-speed extrusion can be employed. Specifically, the extrusion pressure can be 15 MPa to 40 MPa, for example: 18 MPa, 20 MPa, 22, 25 MPa, 28 MPa, 30 MPa, 32 MPa, 35 MPa, 38 MPa, etc.; the extrusion speed is 0.3 mm / s to 1.2 mm / s, for example: 0.5 mm / s, 0.7 mm / s, 0.9 mm / s, 1 mm / s, 1.1 mm / s, etc.

[0069] Furthermore, to facilitate subsequent loading, drying can be performed after extrusion molding. Specifically, the drying temperature can be 50℃~120℃, such as 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, etc.

[0070] In some specific implementations, to better load the high-entropy active component, the concentration of the metal precursor in the metal precursor solution can be from 0.5 mol / L to 4 mol / L, for example: 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, etc. In this invention, the concentration of the metal precursor refers to the sum of the molar amounts of all metal precursors.

[0071] In this invention, the metal precursor solution does not contain binders, plasticizers, or other chemical components; it only contains the metal precursor. That is, in the preparation method of this invention, the loading of high-entropy active components can be achieved without using binders, plasticizers, or other chemical components.

[0072] Furthermore, the present invention can make the high-entropy active component exist on the surface and / or inside of the tubular preform by means of spraying, coating, casting, etc. In the present invention, the metal precursor solution has excellent permeability to the tube wall of the tubular preform. Therefore, the metal precursor solution can be applied only to the inner wall of the tubular preform to disperse the high-entropy active component on the surface and / or inside the tube wall of the substrate.

[0073] To achieve a more uniform distribution of the high-entropy active components, this invention preferably utilizes a spraying method to ensure the metal precursor solution exists on the inner wall of the tubular preform. Specifically, the spraying rate is 0.05 m / s to 0.1 m / s, for example: 0.06 m / s, 0.07 m / s, 0.08 m / s, or 0.09 m / s; and the number of spraying passes is 2 to 4.

[0074] Furthermore, through drying and sintering, the integrated ceramic filter tube of this application can be obtained. Drying and sintering allow for a strong bond between particles, while simultaneously creating the desired pore structure.

[0075] In some specific embodiments, the drying temperature is 50℃~120℃, for example: 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, etc.; the sintering temperature is 1000℃~1300℃, for example: 1050℃, 1100℃, 1150℃, 1200℃, 1250℃, etc.; the sintering time is 1h~2h, for example: 1.2h, 1.4h, 1.6h, 1.8h, etc. The inventors of this invention have discovered that by using ultra-high temperature sintering, high-entropy active components can be uniformly present on the surface and / or inside the substrate tube wall. Furthermore, after sintering, there is no need to reduce it to a high-entropy alloy; the effects of the high-entropy active components can be effectively exerted.

[0076] The integrated ceramic filter tube manufacturing process provided by this invention is based on a mature ceramic filter tube extrusion molding process. It only requires the addition of simple operations such as molten metal spraying and low-temperature drying before sintering, without the need for complex equipment or special process conditions. The low-temperature drying (50℃~120℃) and high-temperature sintering (1000℃~1300℃) are highly compatible with existing ceramic filter tube production processes, facilitating large-scale industrial production and significantly reducing the barriers and costs of technology transfer.

[0077] <Third aspect>

[0078] A third aspect of the present invention provides a method for dust removal and synergistic removal of nitrogen oxides and volatile organic compounds using an integrated ceramic filter tube according to the present invention. By using the integrated ceramic filter tube of the present invention, highly efficient synergistic removal of dust, nitrogen oxides, and volatile organic compounds is achieved under conditions of 150°C to 400°C.

[0079] Specifically, the temperature range for the synergistic removal of nitrogen oxides and volatile organic compounds can be 150℃~400℃, and the mass hourly space velocity (WHSV) can be 30000 mL·g. -1 ·h -1 ~90000 mL·g -1 ·h -1 .

[0080] During dust removal, the gas flow rate can be 0.5 m / min to 1.0 m / min, and the dust supply rate can be 3000 mg / m³. 3 ~6000mg / m 3 .

[0081] Example

[0082] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0083] Example 1

[0084] 6 kg of silicon carbide, 4 kg of alumina, and 6 kg of water were poured into a 30 L mixing drum and stirred until homogeneous. Then, 2 kg of carboxymethyl cellulose was gradually added and stirred at high speed (1000 r / min) for 60 min to form a uniformly dispersed slurry. The slurry was then extruded using a mold at a pressure of 30 MPa and a speed of 0.8 mm / s to obtain a tubular preform with a wall thickness of approximately 20 mm and an inner diameter of approximately 10 cm. Add 3 kg of deionized water to a container, then add 544.5 g of Cu(NO3)2·3H2O, 657 g of Co(NO3)2·6H2O, 909 g of Fe(NO3)3·9H2O, and 567 g of Mn(NO3)2·4H2O in sequence. Stir to dissolve and then bring the volume to 6 kg. This solution is denoted as solution A1. Weigh 652.5 g of Ni(NO3)2·6H2O, dissolve it in 1 kg of deionized water, stir to dissolve and then bring the volume to 2 kg. This solution is denoted as solution B1. Mix solution A1 and solution B1 and shake well to obtain solution C1. After drying the tubular preform in a 100 ℃ drying oven, solution C1 was sprayed onto the inner wall of the ceramic filter tube at a rate of 0.08 m / s for a total of 3 rounds. After standing for 30 min, it was dried at a low temperature (80 ℃) and then sintered in a high-temperature furnace (1000 ℃) for 1 h to obtain ceramic filter tube A. The loading of the high-entropy active component is about 8.8% based on the total mass of the matrix as 100%.

[0085] Example 2

[0086] 6 kg of silicon carbide, 4 kg of alumina, and 6 kg of water were poured into a 30 L mixing drum and stirred until homogeneous. Then, 2 kg of carboxymethyl cellulose was gradually added and stirred at high speed (1000 r / min) for 60 min to form a uniformly dispersed slurry. The slurry was then extruded using a mold at a pressure of 30 MPa and a speed of 0.8 mm / s to obtain a tubular preform with a wall thickness of approximately 20 mm and an inner diameter of approximately 10 cm. Add 2 kg of deionized water to a container, then add 363 g of Cu(NO3)2·3H2O, 438 g of Co(NO3)2·6H2O, 606 g of Fe(NO3)3·9H2O, and 378 g of Mn(NO3)2·4H2O in sequence. Stir to dissolve and then bring the volume to 4 kg. This solution is denoted as solution A2. Weigh 435 g of Ni(NO3)2·6H2O and dissolve it in 500 g of deionized water. Stir to dissolve and then bring the volume to 1.5 kg. This solution is denoted as solution B2. Mix solution A2 and solution B2 and shake well to obtain solution C2. After drying the tubular preform in a 110 ℃ drying oven, solution C2 was sprayed onto the inner wall of the ceramic filter tube at a rate of 0.1 m / s for two rounds. After standing for 30 min, it was dried at a low temperature (70 ℃) and then sintered in a high-temperature furnace (1100 ℃) for 1 h to obtain ceramic filter tube B. The loading of the high-entropy active component is about 5.8% based on the total mass of the matrix as 100%.

[0087] Example 3

[0088] 6 kg of silicon carbide, 4 kg of alumina, and 6 kg of water were poured into a 30 L mixing drum and stirred until homogeneous. Then, 2 kg of carboxymethyl cellulose was gradually added and stirred at high speed (1000 r / min) for 60 min to form a uniformly dispersed slurry. The slurry was then extruded using a mold at a pressure of 30 MPa and a speed of 0.8 mm / s to obtain a tubular preform with a wall thickness of approximately 20 mm and an inner diameter of approximately 10 cm. Add 5 kg of deionized water to a container, then add 878.46 g of Cu(NO3)2·3H2O, 1059.96 g of Co(NO3)2·6H2O, 1466.52 g of Fe(NO3)3·9H2O, and 914.76 g of Mn(NO3)2·4H2O in sequence. Stir to dissolve and then bring the volume to 10 kg. This solution is recorded as solution A3. Weigh 1052.7 g of Ni(NO3)2·6H2O and dissolve it in 1.5 kg of deionized water. Stir to dissolve and then bring the volume to 3 kg. This solution is recorded as solution B3. Mix solution A3 and solution B3 and shake well to obtain solution C3. After drying the tubular preform in a 105 ℃ drying oven, solution C3 was sprayed onto the inner wall of the ceramic filter tube at a rate of 0.08 m / s for a total of 4 rounds. After standing for 60 min, it was dried at a low temperature (90 ℃) and then sintered in a high-temperature furnace (1200 ℃) for 1 h to obtain ceramic filter tube C. The loading of the high-entropy active component is approximately 14.15% based on the total mass of the matrix as 100%.

[0089] Example 4

[0090] 6 kg of silicon carbide, 4 kg of alumina, and 6 kg of water were poured into a 30 L mixing drum and stirred until homogeneous. Then, 2 kg of carboxymethyl cellulose was gradually added and stirred at high speed (1000 r / min) for 60 min to form a uniformly dispersed slurry. The slurry was then extruded using a mold at a pressure of 30 MPa and a speed of 0.8 mm / s to obtain a tubular preform with a wall thickness of approximately 20 mm and an inner diameter of approximately 10 cm. Add 3 kg of deionized water to a container, then add 544.5 g of Cu(NO3)2·3H2O, 657 g of Co(NO3)2·6H2O, 909 g of Fe(NO3)3·9H2O, and 567 g of Mn(NO3)2·4H2O in sequence. Stir to dissolve and then bring the volume to 6 kg. This solution is labeled A4. Weigh 652.5 g of Ni(NO3)2·6H2O and dissolve it in 1 kg of deionized water. Stir to dissolve and then bring the volume to 2 kg. This solution is labeled B4. Weigh 263.1 g of ammonium metavanadate and dissolve it in 500 g of deionized water. Stir to dissolve and then bring the volume to 1 kg. This solution is labeled B. 4# Solution A4, solution B4 and solution B 4#After mixing and shaking, solution C4 was obtained. The tubular preform was dried in a drying oven at 120 °C. Solution C4 was then sprayed onto the inner wall of the ceramic filter tube at a rate of 0.08 m / s for a total of 3 rounds. After standing for 60 min, it was dried at low temperature (80 °C) and then sintered in a high-temperature furnace (1000 °C) for 1 h to obtain ceramic filter tube D. The loading of the high-entropy active component was approximately 10.8% based on the total mass of the matrix (100%).

[0091] Example 5

[0092] 6 kg of silicon carbide, 4 kg of alumina, and 6 kg of water were poured into a 30 L mixing drum and stirred until homogeneous. Then, 2 kg of carboxymethyl cellulose was gradually added and stirred at high speed (1000 r / min) for 60 min to form a uniformly dispersed slurry. The slurry was then extruded using a mold at a pressure of 30 MPa and a speed of 0.8 mm / s to obtain a tubular preform with a wall thickness of approximately 20 mm and an inner diameter of approximately 10 cm. Add 3 kg of deionized water to a container, then add 544.5 g of Cu(NO3)2·3H2O, 657 g of Co(NO3)2·6H2O, 909 g of Fe(NO3)3·9H2O, and 567 g of Mn(NO3)2·4H2O in sequence. Stir to dissolve and then bring the volume to 6 kg, which is recorded as solution A5. Weigh 652.5 g of Ni(NO3)2·6H2O and dissolve it in 1 kg of deionized water. Stir to dissolve and then bring the volume to 2 kg, which is recorded as solution B5. Weigh 558 g of ammonium metatungstate and dissolve it in 1 kg of deionized water. Stir to dissolve and then bring the volume to 2 kg, which is recorded as solution B. 5# Solution A5, solution B5 and solution B 5# After mixing and shaking, solution C5 was obtained. The tubular preform was dried in a drying oven at 100 °C. Solution C5 was then sprayed onto the inner wall of the ceramic filter tube at a rate of 0.1 m / s for a total of 4 rounds. After standing for 45 min, it was dried at a low temperature (70 °C) and then sintered in a high-temperature furnace (1100 °C) for 1 h to obtain ceramic filter tube E. The loading of the high-entropy active component was approximately 14% based on the total mass of the matrix (100%).

[0093] Example 6

[0094] 6 kg of silicon carbide, 4 kg of alumina, and 6 kg of water were poured into a 30 L mixing drum and stirred until homogeneous. Then, 2 kg of carboxymethyl cellulose was gradually added and stirred at high speed (1000 r / min) for 60 min to form a uniformly dispersed slurry. The slurry was then extruded using a mold at a pressure of 30 MPa and a speed of 0.8 mm / s to obtain a tubular preform with a wall thickness of approximately 20 mm and an inner diameter of approximately 10 cm. Add 3 kg of deionized water to a container, then add 544.5 g of Cu(NO3)2·3H2O, 657 g of Co(NO3)2·6H2O, 909 g of Fe(NO3)3·9H2O, and 567 g of Mn(NO3)2·4H2O in sequence. Stir to dissolve and then bring the volume to 6 kg. This solution is designated as solution A6. Weigh 263.1 g of ammonium metavanadate and dissolve it in 500 g of deionized water. Stir to dissolve and then bring the volume to 1 kg. This solution is designated as solution B6. Mix solution A6 and solution B6 and shake well to obtain solution C6. After drying the tubular preform in an 80 ℃ drying oven, solution C6 was sprayed onto the inner wall of the ceramic filter tube at a rate of 0.05 m / s for a total of 4 rounds. After standing for 60 min, it was dried at a low temperature (80 ℃) and then sintered in a high-temperature furnace (1300 ℃) for 1 h to obtain ceramic filter tube F. The loading of the high-entropy active component is about 9.1% based on the total mass of the matrix as 100%.

[0095] Example 7

[0096] 6 kg of silicon carbide, 4 kg of alumina, and 6 kg of water were poured into a 30 L mixing drum and stirred until homogeneous. Then, 2 kg of carboxymethyl cellulose was gradually added and stirred at high speed (1000 r / min) for 60 min to form a uniformly dispersed slurry. The slurry was then extruded using a mold at a pressure of 30 MPa and a speed of 0.8 mm / s to obtain a tubular preform with a wall thickness of approximately 20 mm and an inner diameter of approximately 10 cm. Add 3 kg of deionized water to a container, then add 544.5 g of Cu(NO3)2·3H2O, 657 g of Co(NO3)2·6H2O, 909 g of Fe(NO3)3·9H2O, and 567 g of Mn(NO3)2·4H2O in sequence. Stir to dissolve and then bring the volume to 6 kg. This solution is designated as solution A7. Weigh 558 g of ammonium metatungstate and dissolve it in 1 kg of deionized water. Stir to dissolve and then bring the volume to 2 kg. This solution is designated as solution B7. Mix solution A7 and solution B7 and shake well to obtain solution C7. After drying the tubular preform in an 80 ℃ drying oven, solution C7 was sprayed onto the inner wall of the ceramic filter tube at a rate of 0.05 m / s for a total of 4 rounds. After standing for 60 min, it was dried at a low temperature (80 ℃) and then sintered in a high-temperature furnace (1300 ℃) for 1 h to obtain ceramic filter tube G. The loading of the high-entropy active component is about 12.3% based on the total mass of the matrix as 100%.

[0097] Comparative Example 1

[0098] 6 kg of silicon carbide, 4 kg of alumina, and 6 kg of water were poured into a 30 L mixing drum and stirred until homogeneous. Then, 2 kg of carboxymethyl cellulose was gradually added, and the mixture was stirred at high speed (1000 r / min) for 60 min to form a uniformly dispersed slurry. The slurry was then extruded using a mold at a pressure of 30 MPa and a speed of 0.8 mm / s to obtain a tubular preform with a wall thickness of approximately 20 mm and an inner diameter of approximately 10 cm. The preform was then sintered in a high-temperature furnace (1000 °C) for 1 h to obtain a blank ceramic filter tube.

[0099] Performance testing

[0100] 1. Catalytic performance test

[0101] Cut the integrated ceramic filter tube into 2mm×2mm×2mm pieces, and weigh out the corresponding masses (ceramic filter tube A: 1.1364g, ceramic filter tube B: 1.7241g, ceramic filter tube C: 0.7067g, ceramic filter tube D: 0.9259g, ceramic filter tube E: 0.7143g, ceramic filter tube F: 1.0989g, ceramic filter tube G: 0.8130g) of the ceramic filter tubes and add them to the quartz tube reactor. Then, introduce 500ppm NH3 and 500ppm NO.x 100ppm C7H8, 5% O2, 5% H2O, with N2 as the equilibrium gas; total flow rate 100 ml / min; mass hourly space velocity 60000 ml·g. -1 ·h -1 The test was conducted using Gasmate. Before the test, the reactant gas was switched to bypass the ceramic filter and enter the detection system directly to ensure that the configured gas concentration reached the set value. Then, the reactant gas was switched back to pass through the ceramic filter. Finally, the temperature control program was set with a heating rate of 10 °C / min. -1 The gas was kept at each temperature point for 30 minutes, and the composition of the exhaust gas was detected in real time using infrared spectroscopy. The test results are as follows: Figure 1 As shown.

[0102] Depend on Figure 1 It can be seen that the integrated ceramic filter tubes of Examples 1-7 are all quite excellent. Among them, in Examples 1-3, since the loading of the high-entropy active component in Example 2 is 5.8% and the loading of the catalyst in Example 1 is 8.8%, even if more ceramic filter tubes of Example 2 are used to make the amount of high-entropy active component the same, the catalytic performance of Example 1 is still higher than that of Example 2. However, the loading of the high-entropy active component in Example 3 is too high. Therefore, at temperatures below 300°C, NO... x It has high catalytic oxidation performance, but as the temperature increases, especially above 300℃, NO... x Its catalytic oxidation performance decreases.

[0103] As can be seen from Examples 1 and 4-7, the presence of lum or tungsten, especially lum, is more conducive to achieving NO. x Co-catalytic removal with toluene. Furthermore, compared to Examples 3 and 5, when the loading of the high-entropy active component is comparable and contains a greater amount of the high-entropy active component, but when the transition metal vanadium is present, it is more conducive to achieving NO removal. x Co-catalytic removal with toluene.

[0104] 2. Dust removal performance test

[0105] The dust removal performance of ceramic filter tubes was tested using a DLC-2004 dynamic filtration performance tester, which consists of a dust supply device, a main body, and a control and recording device. During the test, filter media samples were mounted on the filter media fixture, and the gas flow rate (0.8 m³ / min) and dust supply rate (5000 mg / m³) were adjusted according to the testing conditions. 3 The vacuum pump was started, and the dust filtration performance experiment was conducted at room temperature. The results are shown in Table 1 below.

[0106] Table 1

[0107]

[0108] As can be seen from Table 1, the integrated ceramic filter tubes of the present invention all have excellent dust removal performance, and the dust removal performance of the ceramic filter tubes in Examples 1 to 7 is consistently maintained at around 99.80%.

[0109] 3. Morphological observation

[0110] The morphology of the ceramic filter tube of Example 1 and ceramic filter tube A of Example 1 was compared using scanning electron microscopy, and the elemental distribution of the ceramic filter tube F of Example 6 was observed using X-ray energy dispersive spectroscopy. The results are as follows: Figure 2 and Figure 3 As shown.

[0111] Figure 2 The following are scanning electron microscope (SEM) images of the ceramic filter tube of Comparative Example 1 and the ceramic filter tube A of Example 1 of the present invention; wherein, a and b are the ceramic filter tube of Comparative Example 1 at different magnifications, and c and d are the ceramic filter tubes of Example 1 at different magnifications. Figure 3 The EDS elemental distribution diagram of the ceramic filter tube F of Embodiment 6 of the present invention is shown.

[0112] Depend on Figure 2 It can be seen that the blank ceramic filter tube in Comparative Example 1 exhibits a coarse fibrous morphology, while the surface of ceramic filter tube A is uniformly covered with catalyst particles, indicating the uniform formation of the catalyst on its surface. Figure 3 It can be seen that the catalyst components are uniformly dispersed on the surface of the ceramic filter tube fibers.

[0113] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that the present invention should not be limited thereto.

[0114] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An integrated ceramic filter tube, characterized in that, include: A matrix having a hollow structure, and the tube walls of the matrix being formed by overlapping fibers, and A high-entropy active component, said high-entropy active component being dispersed on the surface and / or inside the tube wall; and... The high-entropy active component includes metal oxides formed from five or more transition metals.

2. The integrated ceramic filter tube according to claim 1, characterized in that, The transition metal includes Cu, Co, Ni, Fe, Mn, V, or W; Preferably, the molar ratio between different transition metals is 0.9~1.1:0.9~1.

1.

3. The integrated ceramic filter tube according to claim 1 or 2, characterized in that, Based on the total mass of the matrix as 100%, the loading of the high-entropy active component is 5% to 15%.

4. The integrated ceramic filter tube according to any one of claims 1 to 3, characterized in that, The raw materials used to prepare the matrix include aggregates and binders.

5. The integrated ceramic filter tube according to claim 4, characterized in that, The content of the binder is 10% to 30% based on the total mass of the aggregate (100%).

6. A method for preparing an integrated ceramic filter tube according to any one of claims 1 to 5, characterized in that, The method includes the step of loading a high-entropy active component onto the surface of the matrix; preferably, the preparation method includes the following steps: A tubular preform was prepared; Prepare a metal precursor solution containing a high-entropy active component; After the metal precursor solution is present on the surface and / or inside the tubular preform, it is dried and then sintered to obtain an integrated ceramic filter tube.

7. The preparation method according to claim 6, characterized in that, The concentration of the metal precursor in the metal precursor solution is 0.5 mol / L to 4 mol / L.

8. The preparation method according to claim 6 or 7, characterized in that, The metal precursor solution is present on the surface and / or inside the tubular preform by spraying; preferably, the spraying rate is 0.05 m / s to 0.1 m / s, and the number of sprayings is 2 to 4.

9. The preparation method according to any one of claims 6 to 8, characterized in that, The drying temperature is 50℃~120℃, the sintering temperature is 1000℃~1300℃, and the sintering time is 1 h~2 h.

10. A method for using an integrated ceramic filter tube according to any one of claims 1 to 5 for dust removal and synergistic removal of nitrogen oxides and volatile organic compounds.

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