A catalytic filter medium for the synergistic removal of dioxins and particulate matter at low temperature, its preparation method and its application

Abstract

This invention discloses a low-temperature synergistic removal catalytic filter material for dioxins and particulate matter, its preparation method, and its application. The method includes: Step 1: Using the filter material as a carrier, MnOx catalytic filter material is obtained through in-situ growth of a Mn-based organometallic framework; Step 2: Impregnation with the active component Ce; adding a Ce precursor at a certain loading rate to the MnOx catalytic filter material impregnation solution, stirring at room temperature for 12 hours, and then calcining at 260°C for 4 hours to obtain a Ce-MnOx composite catalytic filter material; Step 3: Redox etching; The composite catalytic filter material prepared by the in-situ growth method of this invention exhibits excellent low-temperature catalytic activity and selectivity for dioxins and good dust removal efficiency for flue gas particulate matter; The composite catalytic filter material prepared by the in-situ growth method of this invention incorporates Ce, an active component with multiple valence states and excellent resistance to chlorine poisoning, and uses POM functionalization on the catalyst surface, effectively improving catalytic activity while enhancing the catalyst's chlorine resistance.

Description

Technical Field

[0001] This invention belongs to the field of waste incineration flue gas treatment technology, and relates to a low-temperature synergistic removal of dioxins and particulate matter catalytic filter material, its preparation method and its application. Background Technology

[0002] Catalytic filter media integrates catalytic oxidation and dust removal functions, simultaneously removing dioxins and particulate matter from flue gas. The application of catalytic filtration technology only requires replacing the existing dust collector filter media in baghouse dust collectors with composite catalytic filter media, without requiring modification or the addition of new equipment or operating procedures. The catalyst is the core element for improving the catalytic performance of catalytic filter media. Patent CN116139595A, "PTFE Catalytic Filter Media and its Preparation Method," uses multiple impregnation methods to control the catalyst adhesion amount. While this method effectively increases the catalyst adhesion amount, the catalyst and filter media are bound by physical adsorption, resulting in low bonding strength and easy detachment. Patent CN111359673A, "MnO2 / PPS Composite Material and its Preparation Method and Application," prepares MnO2 / PPS catalytic filter media through atomized adhesion and in-situ oxidation. The catalytic filter media synthesized by this method exhibits good low-temperature denitrification performance and dust removal efficiency; however, the presence of hydrogen chloride and chlorinated organic pollutants in waste incineration flue gas easily leads to chlorine poisoning and deactivation of the Mn-based catalyst, limiting the service life of the catalytic filter media. Therefore, it is necessary to develop a catalytic filter media with high catalyst-to-filter media integration and strong low-temperature chlorine resistance. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention provides a catalytic filter material for the synergistic removal of dioxins and particulate matter at low temperature, its preparation method and its application.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing a catalytic filter material for the synergistic removal of dioxins and particulate matter at low temperature, comprising the following steps:

[0005] Step 1: Using filter media as a carrier, MnOx catalytic filter media is obtained through in-situ growth of Mn-based organometallic frameworks;

[0006] Step 2: Impregnation with the active ingredient Ce;

[0007] The precursor of the active component Ce was added to the solution impregnated with MnOx catalytic filter material at a certain loading, stirred at room temperature for 12 h, and then calcined at 260℃ for 4 h to obtain Ce-MnOx composite catalytic filter material.

[0008] Step 3: Oxidation-reduction etching;

[0009] Polyoxometalate (POM) precursors were dispersed in an aqueous solution with Ce-MnOx composite catalytic filter media at a certain loading. A certain concentration of hydrogen peroxide aqueous solution was added dropwise, and the reaction was carried out for 2 hours. The mixture was then washed with methanol and water, dried at 105°C for 8 hours, and calcined at 260°C for 4 hours to obtain Ce-MnOx-POM composite catalytic filter media.

[0010] Furthermore, step 1 includes the following steps:

[0011] Step 1.1: Wash the filter media with deionized water and dry it at 105℃ for 3 hours;

[0012] Step 1.2: Prepare a solution of N,N-dimethylformamide, methanol and water in a certain volume ratio, and add manganese nitrate and organic ligand in a certain molar ratio to the solution to form a mixed solution;

[0013] Step 1.3: Completely immerse the filter material in the mixed solution of Step 1.2, transfer it to the reactor, and react at 135℃ for 24 hours. After the reaction is completed, remove the filter material, wash it with methanol and water, dry it at 105℃ for 8 hours, and finally calcine it at 260℃ for 4 hours to obtain MnOx catalytic filter material.

[0014] Furthermore, the volume ratio of the N,N-dimethylformamide, methanol, and water solution is 10–15:1–3:1.

[0015] Furthermore, the molar ratio of manganese nitrate to the organic ligand is 1:0.2 to 1.

[0016] Furthermore, the organic ligand is one of terephthalic acid, 2,5-dihydroxyterephthalic acid, and pyromellitic acid.

[0017] Furthermore, the precursor of the active component Ce is one of cerium nitrate, cerium acetate, and cerium sulfate.

[0018] Furthermore, the precursor of the active component Ce ranges from 0.1 wt% to 5 wt% of the MnOx catalyst loading.

[0019] Furthermore, the polyoxometalate precursor is one of silicotungstic acid, phosphotungstic acid, and silicotomolybdic acid.

[0020] A low-temperature synergistic catalytic filter media for removing dioxins and particulate matter includes the filter media and a Ce-MnOx-POM composite catalyst, wherein the Ce-MnOx-POM composite catalyst is grown in situ on the surface of the filter media; the Ce-MnOx-POM composite catalyst loading is 100–300 g / m³. 2 .

[0021] Furthermore, an MnOx catalyst is grown in situ on the surface of the filter material; the precursor of the active component Ce is adsorbed or deposited on the surface of the MnOx catalyst; under set conditions, the MnOx catalyst reacts with the precursor of the active component Ce to generate a Ce-MnOx composite catalyst; the Ce-MnOx catalyst forms a POM solid acid layer on its surface through a polyoxometalate precursor and hydrogen peroxide to generate a Ce-MnOx-POM composite catalyst.

[0022] Furthermore, the MnOx catalyst is grown in situ on the surface of the filter media to form MnOx catalytic filter media, which is obtained through the following steps:

[0023] Step 1.1: Wash the filter media with deionized water and dry it at 105℃ for 3 hours;

[0024] Step 1.2: Prepare a solution of N,N-dimethylformamide, methanol and water in a certain volume ratio, and add manganese nitrate and organic ligand in a certain molar ratio to the solution to form a mixed solution;

[0025] Step 1.3: Completely immerse the filter material in the mixed solution of Step 1.2, transfer it to the reactor, and react at 135℃ for 24 hours. After the reaction is completed, remove the filter material, wash it with methanol and water, dry it at 105℃ for 8 hours, and finally calcine it at 260℃ for 4 hours to obtain MnOx catalytic filter material.

[0026] Furthermore, the MnOx catalyst reacts with the precursor of the active component Ce to generate a Ce-MnOx composite catalyst, forming a Ce-MnOx composite catalytic filter media. The Ce-MnOx composite catalytic filter media is obtained through the following steps:

[0027] The precursor of the active component Ce was added to the solution impregnated with MnOx catalytic filter material at a certain loading, stirred at room temperature for 12 h, and then calcined at 260℃ for 4 h to obtain Ce-MnOx composite catalytic filter material.

[0028] Furthermore, the Ce-MnOx catalyst forms a POM solid acid layer on its surface through a polyoxometalate precursor and hydrogen peroxide, generating a Ce-MnOx-POM composite catalyst, which in turn forms a Ce-MnOx-POM composite catalytic filter material. The Ce-MnOx-POM composite catalytic filter material is obtained through the following steps:

[0029] Polyoxometalate (POM) precursors were dispersed in an aqueous solution with Ce-MnOx composite catalytic filter media at a certain loading. A certain concentration of hydrogen peroxide aqueous solution was added dropwise, and the reaction was carried out for 2 hours. The mixture was then washed with methanol and water, dried at 105°C for 8 hours, and calcined at 260°C for 4 hours to obtain Ce-MnOx-POM composite catalytic filter media.

[0030] The application of a low-temperature synergistic removal catalytic filter material for dioxin and particulate matter removal in flue gas treatment, wherein the catalytic filter material is prepared by the aforementioned method for preparing a low-temperature synergistic removal catalytic filter material for dioxin and particulate matter removal.

[0031] In summary, the advantages of this invention are:

[0032] 1) The composite catalytic filter material prepared by the in-situ growth method of this invention has excellent low-temperature catalytic activity and selectivity for dioxins and good dust removal efficiency for flue gas particulate matter.

[0033] 2) The present invention prepares a composite catalytic filter material by in-situ growth method, adding Ce, an active component with multiple valence states and excellent resistance to chlorine poisoning, and uses POM to functionalize the catalyst surface, which effectively improves the catalytic activity and enhances the chlorine resistance of the catalyst.

[0034] 3) This invention achieves strong bonding between the catalyst and the filter media surface through in-situ growth, which avoids the catalyst being wrapped by fibers and improves the service life of the catalytic filter media and the efficiency of catalytic filtration. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the in-situ growth of the present invention.

[0036] Figure 2 This is a schematic diagram showing the change of catalyst loading on the catalytic filter media 1-5 of the present invention over time under a nitrogen flow of 2000 ml / min. Detailed Implementation

[0037] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0038] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0039] In this embodiment of the invention, all directional indicators (such as up, down, left, right, front, back, lateral, longitudinal, etc.) are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indicator will also change accordingly.

[0040] Due to installation errors and other reasons, the parallel relationship referred to in the embodiments of the present invention may actually be an approximate parallel relationship, and the perpendicular relationship may actually be an approximate perpendicular relationship.

[0041] Example:

[0042] Example 1:

[0043] This application provides a method for preparing a catalytic filter material for the synergistic removal of dioxins and particulate matter at low temperature. Using the filter material as a carrier, the method involves in-situ growth of a Mn-based organometallic framework, impregnation with the active component Ce, and redox etching steps to obtain a catalytic filter material with dust removal and dioxin catalytic degradation functions. The specific steps include:

[0044] Step 1: In-situ growth of Mn-based organometallic frameworks;

[0045] Step 1.1: Wash the filter media with deionized water and dry it at 105℃ for 3 hours;

[0046] Step 1.2: Prepare 150 ml of a solution of N,N-dimethylformamide, methanol and water in a volume ratio of 15:1:1. Add 0.02 mol of manganese nitrate and 0.01 mol of 2,5-dihydroxyterephthalic acid to the solution to form a mixed solution.

[0047] Step 1.3: The filter material is completely immersed in the mixed solution of Step 1.2, transferred to the reactor, and reacted at 135℃ for 24h. After the reaction is completed, the filter material is taken out, washed with methanol and water, dried at 105℃ for 8h, and finally calcined at 260℃ for 4h to obtain MnOx catalytic filter material.

[0048] MnOx catalytic filter media is a combination of MnOx catalyst (Mn-based catalyst) and filter media;

[0049] Step 2: Impregnation with the active ingredient Ce;

[0050] Add 5 wt% cerium nitrate of MnOx catalyst loading to 50 ml of aqueous solution impregnated with MnOx catalyst filter material, stir at room temperature for 12 h, and then calcine at 260 °C for 4 h to obtain Ce-MnOx composite catalyst filter material;

[0051] Ce-MnOx composite catalytic filter media is a combination of Ce-MnOx composite catalyst and filter media;

[0052] Step 3: Oxidation-reduction etching;

[0053] 50 ml of Ce-MnOx composite catalytic filter media obtained in step 2 and 3 wt% silicotungstic acid loaded with Ce-MnOx catalyst were dispersed in 50 ml of aqueous solution. 10 ml of 0.22 mol / L hydrogen peroxide solution was added dropwise, and the reaction was allowed to proceed for 2 h. The mixture was then washed with methanol and water, dried at 105 °C for 8 h, and calcined at 260 °C for 4 h to obtain a catalyst loading of 178 g / m³. 2 The Ce-MnOx-POM composite catalytic filter material is labeled as catalytic filter material 1.

[0054] Ce-MnOx-POM composite catalytic filter media is a combination of Ce-MnOx-POM composite catalyst and filter media.

[0055] In this embodiment, the volume ratio of N,N-dimethylformamide, methanol and water is 10-15:1-3:1;

[0056] In this embodiment, 2,5-dihydroxyterephthalic acid is an organic ligand, and the molar ratio of manganese nitrate to the organic ligand is 1:0.2-1;

[0057] In this embodiment, cerium nitrate is the precursor of the active component Ce, and silicotungstic acid is the precursor of a polyoxometalate.

[0058] The precursor of the active component Ce ranges from 0.1 wt% to 5 wt% of the MnOx catalyst loading;

[0059] The range of polyoxometalate precursors is 0.1 wt% to 3 wt% of the Ce-MnOx catalyst loading;

[0060] In this embodiment, the concentration of hydrogen peroxide (H2O2) solution is 0.05–0.5 mol / L;

[0061] In this embodiment, the calcination atmosphere in the preparation step is nitrogen or air.

[0062] In this embodiment, the catalyst loading of the Ce-MnOx-POM composite catalytic filter media is 100–300 g / m³. 2 ;

[0063] In this embodiment, the filter media is one of polytetrafluoroethylene filter media, polyimide filter media, and polyphenylene sulfide filter media;

[0064] In other embodiments, the organic ligand may also be one of terephthalic acid and pyromellitic acid;

[0065] In other embodiments, the polyoxometalate precursor may also be one of phosphotungstic acid and molybdic acid;

[0066] In other embodiments, the precursor of the active component Ce may also be one of cerium acetate or cerium sulfate.

[0067] Step 1 involves linking Mn with the filter material using organic ligands to prepare MnOx (Mn-based) catalytic filter material. After calcination, the organic ligands decompose, and Mn and the filter material are linked by chemical bonds, thereby achieving a stronger bonding strength between the Mn-based catalyst and the filter material, thus improving the service life of the catalytic filter material.

[0068] The form in which Mn-based catalysts are grown on the surface of filter media through in-situ growth is called MnOx catalytic filter media.

[0069] In this application, the Mn-based catalyst is grown directly on the surface of the filter media using an in-situ growth method, which avoids the catalyst being wrapped inside the filter media fibers and reducing its contact area with dioxins, thereby improving the catalytic effect.

[0070] In step 2, after the MnOx catalytic filter material is impregnated, the precursor of the active component Ce is adsorbed or deposited on the surface of the Mn-based catalyst. At high temperature, the precursor of the active component Ce is oxidized to CeO2 and forms Ce-Mn bonds with Mn in the Mn-based catalyst to form Ce-MnOx compounds, thus forming Ce-MnOx composite catalytic filter material.

[0071] This application utilizes polyoxometalate precursors to form a POM solid acid layer on the surface of Ce-MnOx catalysts, promoting the formation of bransted acid on the catalyst surface and further improving the catalyst's service life. Simultaneously, the polyoxometalates combine with the catalyst on the surface of Ce-MnOx composite catalytic filter media under the oxidation of hydrogen peroxide to form Ce-MnOx-POM composite catalytic filter media.

[0072] The Ce-MnOx-POM composite catalytic filter material prepared by the in-situ growth method in this application uses MnOx as the main active phase. It has a large specific surface area, oxygen vacancies, uniformly distributed active sites and three-dimensional pore structure, which can effectively improve the adsorption and activation of oxygen in the reaction process, and make the catalytic filter material have excellent low-temperature catalytic activity for dioxins.

[0073] This application utilizes Ce-MnOx-POM composite catalytic filter media prepared by in-situ growth method to selectively catalytically oxidize dioxins into CO2 and CO. Through the interaction of Mn-Ce, the catalyst's large specific surface area, abundant oxygen vacancies, uniformly distributed active sites, and three-dimensional pore structure, the catalytic activity of the catalyst is improved, thereby achieving selective oxidation.

[0074] Example 2:

[0075] This application also provides a method for preparing a catalytic filter material for the synergistic removal of dioxins and particulate matter at low temperature. Using the filter material as a carrier, the method involves in-situ growth of a Mn-based organometallic framework, impregnation with the active component Ce, and redox etching steps to obtain a catalytic filter material with dust removal and dioxin catalytic degradation functions. The specific steps include:

[0076] Step 1: In-situ growth of Mn-based organometallic frameworks;

[0077] Step 1.1: Wash the filter media with deionized water and dry it at 105℃ for 3 hours;

[0078] Step 1.2: Prepare 150 ml of a solution of N,N-dimethylformamide, methanol and water in a volume ratio of 15:1:1. Add 0.02 mol of manganese nitrate and 0.018 mol of 2,5-dihydroxyterephthalic acid to the solution to form a mixed solution.

[0079] Step 1.3: The filter material is completely immersed in the mixed solution of Step 1.2, transferred to the reactor, and reacted at 135℃ for 24h. After the reaction is completed, the filter material is taken out, washed with methanol and water, dried at 105℃ for 8h, and finally calcined at 260℃ for 4h to obtain MnOx catalytic filter material.

[0080] Step 2: Impregnation with the active ingredient Ce;

[0081] Add 3 wt% cerium nitrate of MnOx catalyst loading to 50 ml of aqueous solution impregnated with MnOx catalyst filter material, stir at room temperature for 12 h, and then calcine at 260 °C for 4 h to obtain Ce-MnOx composite catalyst filter material;

[0082] Step 3: Oxidation-reduction etching;

[0083] 50 ml of Ce-MnOx catalyst-loaded with 5 wt% silicotungstic acid and Ce-MnOx composite catalytic filter media obtained in step 2 were dispersed in 50 ml of aqueous solution. 10 ml of 0.22 mol / L hydrogen peroxide solution was added dropwise, and the reaction was allowed to proceed for 2 h. The mixture was then washed with methanol and water, dried at 105 °C for 8 h, and calcined at 260 °C for 4 h to obtain a catalyst loading of 228 g / m³. 2 The Ce-MnOx-POM composite catalytic filter material is labeled as catalytic filter material 2.

[0084] Example 3:

[0085] This application also provides a method for preparing a catalytic filter material for the synergistic removal of dioxins and particulate matter at low temperature. Using the filter material as a carrier, the method involves in-situ growth of a Mn-based organometallic framework, impregnation with the active component Ce, and redox etching steps to obtain a catalytic filter material with dust removal and dioxin catalytic degradation functions. The specific steps include:

[0086] Step 1: In-situ growth of Mn-based organometallic frameworks;

[0087] Step 1.1: Wash the filter media with deionized water and dry it at 105℃ for 3 hours;

[0088] Step 1.2: Prepare 150 ml of a solution of N,N-dimethylformamide, methanol and water in a volume ratio of 15:1:1. Add 0.02 mol of manganese nitrate and 0.018 mol of 2,5-dihydroxyterephthalic acid to the solution to form a mixed solution.

[0089] Step 1.3: The filter material is completely immersed in the mixed solution of Step 1.2, transferred to the reactor, and reacted at 135℃ for 24h. After the reaction is completed, the filter material is taken out, washed with methanol and water, dried at 105℃ for 8h, and finally calcined at 260℃ for 4h to obtain MnOx catalytic filter material.

[0090] Step 2: Impregnation with the active ingredient Ce;

[0091] Add 5 wt% cerium nitrate of MnOx catalyst loading to 50 ml of aqueous solution impregnated with MnOx catalyst filter material, stir at room temperature for 12 h, and then calcine at 260 °C for 4 h to obtain Ce-MnOx composite catalyst filter material;

[0092] Step 3: Oxidation-reduction etching;

[0093] 50 ml of Ce-MnOx catalyst-loaded with 5 wt% silicotungstic acid and Ce-MnOx composite catalytic filter media obtained in step 2 were dispersed in 50 ml of aqueous solution. 10 ml of 0.22 mol / L hydrogen peroxide solution was added dropwise, and the reaction was allowed to proceed for 2 h. The mixture was then washed with methanol and water, dried at 105 °C for 8 h, and calcined at 260 °C for 4 h to obtain a catalyst loading of 233 g / m³. 2 The Ce-MnOx-POM composite catalytic filter material is labeled as catalytic filter material 3.

[0094] Example 4:

[0095] This application also provides a method for preparing a catalytic filter material for the synergistic removal of dioxins and particulate matter at low temperature. Using the filter material as a carrier, the method involves in-situ growth of a Mn-based organometallic framework, impregnation with the active component Ce, and redox etching steps to obtain a catalytic filter material with dust removal and dioxin catalytic degradation functions. The specific steps include:

[0096] Step 1: In-situ growth of Mn-based organometallic frameworks;

[0097] Step 1.1: Wash the filter media with deionized water and dry it at 105℃ for 3 hours;

[0098] Step 1.2: Prepare 150 ml of a solution of N,N-dimethylformamide, methanol and water in a volume ratio of 15:1:1. Add 0.02 mol of manganese nitrate and 0.018 mol of 2,5-dihydroxyterephthalic acid to the solution to form a mixed solution.

[0099] Step 1.3: The filter material is completely immersed in the mixed solution of Step 1.2, transferred to the reactor, and reacted at 135℃ for 24h. After the reaction is completed, the filter material is taken out, washed with methanol and water, dried at 105℃ for 8h, and finally calcined at 260℃ for 4h to obtain MnOx catalytic filter material.

[0100] Step 2: Impregnation with the active ingredient Ce;

[0101] Add 5 wt% cerium nitrate of MnOx catalyst loading to 50 ml of aqueous solution impregnated with MnOx catalyst filter material, stir at room temperature for 12 h, and then calcine at 260 °C for 4 h to obtain Ce-MnOx composite catalyst filter material;

[0102] Step 3: Oxidation-reduction etching;

[0103] 50 ml of Ce-MnOx composite catalytic filter media obtained in step 2 and 10 wt% silicotungstic acid loaded with Ce-MnOx catalyst were dispersed in 50 ml of aqueous solution. 10 ml of 0.22 mol / L hydrogen peroxide solution was added dropwise, and the reaction was allowed to proceed for 2 h. The mixture was then washed with methanol and water, dried at 105 °C for 8 h, and calcined at 260 °C for 4 h to obtain a catalyst loading of 242 g / m³. 2 The Ce-MnOx-POM composite catalytic filter media is labeled as catalytic filter media 4.

[0104] Comparative example:

[0105] The comparative example uses filter media as a carrier to prepare composite catalytic filter media by impregnation method, specifically including the following steps:

[0106] Step 1: Preparation of MnOx catalyst;

[0107] Step 1.1: Prepare 150 ml of a solution of N,N-dimethylformamide, methanol and water in a volume ratio of 15:1:1. Then dissolve 0.02 mol manganese nitrate and 0.018 mol 2,5-dihydroxyterephthalic acid in the above solution to form a mixed solution.

[0108] Step 1.2: Transfer the mixed solution to the reactor and react at 135℃ for 24h. After the reaction is completed, take out the catalyst, wash it with methanol and water, dry it at 105℃ for 8h, and finally calcine it at 260℃ and air for 4h to obtain the MnOx catalyst.

[0109] Step 2: Impregnation with the active ingredient Ce;

[0110] Add 5 wt% cerium nitrate of MnOx catalyst loading to 50 ml of aqueous solution of MnOx catalyst, stir at room temperature for 12 h, and then calcine at 260 °C for 4 h to obtain Ce-MnOx composite catalyst;

[0111] Step 3: Oxidation-reduction etching;

[0112] Step 3.1: Disperse the Ce-MnOx composite catalyst with 10wt% silicotungstic acid and the Ce-MnOx composite catalyst obtained in step 2 in 50 ml of aqueous solution, add 10 ml of 0.22 mol / L hydrogen peroxide solution dropwise, react for 2 h, then wash with methanol and water, dry at 105 °C for 8 h after washing, and calcine at 260 °C for 4 h to obtain Ce-MnOx-POM composite catalyst;

[0113] Step 3.2: Wash the filter media with deionized water and dry it at 105℃ for 3 hours; ready for use.

[0114] Step 3.3: Dissolve the Ce-MnOx-POM composite catalyst from Step 3.1 in 50 ml of aqueous solution, add the filter material to the aqueous solution for impregnation, stir at room temperature for 12 h, and then calcine at 260℃ for 4 h to obtain a catalyst loading of 140 g / m³. 2 The Ce-MnOx-POM composite catalytic filter material is designated as catalytic filter material 5.

[0115] The catalytic filter media obtained in Examples 1-4 and the comparative example were subjected to performance testing using a conventional dioxin catalytic removal device. The test results for the composite catalytic filter media are shown in Table 1. The bonding strength between the catalyst and the filter media surface was tested by varying the catalyst loading on the composite catalytic filter media under a nitrogen flow of 2000 ml / min. The results are as follows: Figure 2 As shown;

[0116] Table 1 Test results of composite catalytic filter media

[0117]

[0118] A comparison of Example 1 and Example 2 shows that increasing the amount of organic ligand from 0.01 mol to 0.018 mol significantly increases the formation of the MnOx catalyst, resulting in a catalyst loading of 178 g / m³. 2 Increased to 228g / m 2 In other words, increasing the amount of organic ligands can increase the catalyst loading.

[0119] By comparing Examples 2, 3 and 4, it can be seen that increasing the precursor of active component Ce and the precursor of polyoxometalate can increase the catalyst loading, but the effect is relatively small compared to the amount of organic ligands.

[0120] By comparing Examples 2, 3, and 4 with the comparative examples, it can be seen that a higher catalyst loading on the catalytic filter media does not necessarily lead to better dioxin removal. A higher catalyst loading can cover the active sites of the catalyst, thus inhibiting catalytic performance. A lower catalyst loading provides little or no improvement in chlorine resistance. According to Table 1, catalytic filter media 2 achieves a dioxin removal efficiency of over 95.43%, a degradation efficiency of over 84.76%, and a dust removal efficiency of over 99% within the temperature range of 180–220℃. Catalytic filter media 2 exhibits the best catalytic performance, with a catalyst loading of 228 g / m³. 2 This indicates that the active components Ce, MnOx catalyst and polyoxometalate precursor of catalytic filter material 2 have a good ratio, resulting in better performance in terms of surface area and oxygen vacancies, thus achieving a better catalytic effect.

[0121] The temperature of the flue gas from waste incineration entering the bag filter is about 180-220℃. Therefore, in this embodiment, the removal efficiency, degradation efficiency and dust removal efficiency of different catalyst filter media within the temperature range of 180-220℃ are selected to determine the removal effect of the catalyst filter media.

[0122] The preparation method of the comparative catalytic filter media differs from that of Examples 1-4; the catalyst loading of the comparative catalytic filter media is 140 g / m³. 2 Compared to the catalyst loading and catalytic effect of Examples 1-4, the catalyst loading is lower.

[0123] The bonding strength between the catalyst and the filter media surface was tested by varying the catalyst loading on the composite catalytic filter media under a nitrogen flow rate of 2000 ml / min. The results are as follows: Figure 2 As shown;

[0124] Figure 2 The curves showing the change of catalyst loading on catalytic filter media 1-5 over time under a nitrogen flow of 2000 ml / min are shown. As can be seen from the figure, the catalyst loading of catalytic filter media 5 prepared by the impregnation method decreases significantly over time compared to catalytic filter media 1-4 prepared by the in-situ growth method, indicating that the catalytic filter media prepared by the in-situ growth method has a stronger catalyst-filter media bonding strength than the catalytic filter media prepared by the impregnation method. In addition, the catalyst loading of the catalytic filter media prepared by the in-situ growth method remains basically unchanged over time, indicating that the catalytic filter media prepared by the in-situ growth method has a stronger catalyst-filter media bonding strength.

[0125] The calculation of catalyst loading in this embodiment is a conventional calculation and will not be described in detail here.

[0126] This application also provides a low-temperature synergistic removal catalytic filter media for dioxins and particulate matter, comprising the filter media and a Ce-MnOx-POM composite catalyst, wherein the Ce-MnOx-POM composite catalyst is grown in situ on the surface of the filter media; the Ce-MnOx-POM composite catalyst loading is 100–300 g / m³. 2 ;

[0127] MnOx catalyst is grown in situ on the surface of the filter media;

[0128] The precursor of active component Ce is adsorbed or deposited on the surface of the MnOx catalyst. Under certain conditions, the MnOx catalyst reacts with the precursor of active component Ce to form a Ce-MnOx composite catalyst.

[0129] Ce-MnOx catalysts form a POM solid acid layer on their surface through the formation of polyoxometalate precursors and hydrogen peroxide, thus generating Ce-MnOx-POM composite catalysts.

[0130] This application also provides the application of a low-temperature synergistic removal catalytic filter material for dioxin and particulate matter removal in flue gas treatment.

[0131] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

Claims

1. A method for preparing a catalytic filter media for the synergistic removal of dioxins and particulate matter at low temperature, characterized in that: Includes the following steps: Step 1: Using filter media as a carrier, MnOx catalytic filter media is obtained through in-situ growth of Mn-based organometallic frameworks; Step 2: Impregnation with the active ingredient Ce; The precursor of the active component Ce was added to the solution impregnated with MnOx catalytic filter material at a certain loading, stirred at room temperature for 12 h, and then calcined at 260℃ for 4 h to obtain Ce-MnOx composite catalytic filter material. Step 3: Oxidation-reduction etching; Polyoxometalate precursors were dispersed in an aqueous solution with Ce-MnOx composite catalytic filter media at a certain loading. A certain concentration of hydrogen peroxide aqueous solution was added dropwise, and the reaction was carried out for 2 hours. Then, the mixture was washed with methanol and water, dried at 105℃ for 8 hours after washing, and calcined at 260℃ for 4 hours to obtain Ce-MnOx-POM composite catalytic filter media. The precursor of the polyoxometalate is one of silicotungstic acid, phosphotungstic acid, and silicotomolybdic acid.

2. The method for preparing a low-temperature synergistic removal catalytic filter material for dioxins and particulate matter according to claim 1, characterized in that: Step 1 includes the following steps: Step 1.1: Wash the filter media with deionized water and dry it at 105℃ for 3 hours; Step 1.2: Prepare a solution of N,N-dimethylformamide, methanol and water in a certain volume ratio, and add manganese nitrate and organic ligand in a certain molar ratio to the solution to form a mixed solution; Step 1.3: Completely immerse the filter material in the mixed solution of Step 1.2, transfer it to the reactor, and react at 135℃ for 24 hours. After the reaction is completed, remove the filter material, wash it with methanol and water, dry it at 105℃ for 8 hours, and finally calcine it at 260℃ for 4 hours to obtain MnOx catalytic filter material.

3. The method for preparing a low-temperature synergistic removal catalytic filter material for dioxins and particulate matter according to claim 2, characterized in that: The volume ratio of the N,N-dimethylformamide, methanol, and water solution is 10–15:1–3:

1.

4. The method for preparing a low-temperature synergistic removal catalytic filter material for dioxins and particulate matter according to claim 2, characterized in that: The molar ratio of manganese nitrate to the organic ligand is 1:0.2 to 1.

5. The method for preparing a low-temperature synergistic removal catalytic filter material for dioxins and particulate matter according to claim 2, characterized in that: The organic ligand is one of terephthalic acid, 2,5-dihydroxyterephthalic acid, and pyromellitic acid.

6. The method for preparing a low-temperature synergistic removal catalytic filter material for dioxins and particulate matter according to claim 1, characterized in that: The precursor of the active component Ce is one of cerium nitrate, cerium acetate, and cerium sulfate.

7. The method for preparing a low-temperature synergistic removal catalytic filter material for dioxins and particulate matter according to claim 1, characterized in that: The precursor of the active component Ce ranges from 0.1 wt% to 5 wt% of the MnOx catalyst loading.

8. A catalytic filter media for low-temperature synergistic removal of dioxins and particulate matter obtained by the preparation method according to any one of claims 1-7, characterized in that: This includes filter media and a Ce-MnOx-POM composite catalyst, with the Ce-MnOx-POM composite catalyst grown in situ on the surface of the filter media; the Ce-MnOx-POM composite catalyst loading is 100–300 g / m³. 2 .

9. The catalytic filter media for low-temperature synergistic removal of dioxins and particulate matter according to claim 8, characterized in that: MnOx catalyst is grown in situ on the surface of the filter material; the precursor of active component Ce is adsorbed or deposited on the surface of the MnOx catalyst; under set conditions, the MnOx catalyst reacts with the precursor of active component Ce to generate Ce-MnOx composite catalyst. Ce-MnOx catalysts form a POM solid acid layer on their surface through the formation of polyoxometalate precursors and hydrogen peroxide, thus generating Ce-MnOx-POM composite catalysts.

10. The application of a low-temperature synergistic catalytic filter material for removing dioxins and particulate matter in flue gas treatment, characterized in that: The catalytic filter material is prepared by a method for preparing a low-temperature synergistic removal catalytic filter material for dioxins and particulate matter as described in any one of claims 1-7.

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