PPS melt-blown cloth-based integrated filter material for high-temperature flue gas and preparation method thereof

Abstract

The invention belongs to the technical field of high-temperature filter materials, and particularly relates to a PPS melt-blown cloth-based integrated filter material for high-temperature flue gas and a preparation method thereof.PPS melt-blown cloth with finer fibers is adopted as a base material, and a denitration catalyst (such as MnOx-CeO2) is firmly loaded inside and on the surfaces of the fibers through a unique catalyst inlaying and surface modification technology, so that the filter material is prepared; a composite structure with a gradient catalysis function is formed, and'surface fine dust catching 'and'internal deep catalysis' have a synergistic effect. The ultrafine melt-blown fiber network can efficiently intercept particulate matters such as PM2.5; then, harmful gas (such as NOx) in the flue gas is diffused into the fiber and the surface of the fiber, and is subjected to a catalytic reduction reaction with the embedded catalyst to be decomposed into harmless nitrogen and water, so that dust removal and denitration integration is realized.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature filtration material technology, specifically relating to an integrated PPS meltblown fabric filter material for high-temperature flue gas and its preparation method. Background Technology

[0002] Currently, the treatment of high-temperature industrial flue gas generally adopts a step-by-step process of "dust removal + denitrification," which has drawbacks such as large equipment size and high energy consumption. Therefore, the industry has shifted towards developing integrated dust removal and denitrification filter materials, with the catalyst-supported polyphenylene sulfide (PPS) needle-punched filter material being the most common solution. While this solution can achieve a certain degree of functional integration, its core materials and structure still have inherent defects, limiting further improvement in overall performance and application.

[0003] Existing technologies primarily employ methods such as in-situ growth on the substrate surface (in-situ growth in existing technologies typically refers to depositing and growing catalyst particles on the outer surface of pre-formed PPS needle-punched felt fibers through impregnation with a solution and chemical reactions (such as redox reactions). This is a post-processing step, where the catalyst and fiber are mainly physically attached or weakly chemically bonded, and it easily clogs the inherent pores of the material) to load oxide catalysts such as manganese, cerium, and vanadium onto the surface of PPS needle-punched felt. However, the needle-punched felt itself has relatively coarse fibers (10-20 micrometers) and large pores, resulting in limited filtration accuracy for fine particulate matter such as PM2.5. Simultaneously, the surface-loaded catalyst has weak bonding with the substrate, making it prone to detachment under high-temperature, high-flow-rate flue gas scouring, leading to rapid degradation of denitrification performance and a short lifespan. Furthermore, traditional processes for loading catalysts onto substrate surfaces often involve hazardous chemicals, are complex and difficult to control precisely, easily clogging filter media pores and significantly increasing system operating resistance. These shortcomings collectively lead to the prominent contradiction in existing PPS-based integrated filter media where it is difficult to simultaneously achieve filtration accuracy, catalytic efficiency, operating resistance, and lifespan. Summary of the Invention

[0004] To address the problem that the overall performance (including filtration performance, denitrification performance, stability, durability, high-temperature dimensional stability, catalyst loading capacity, etc.) of existing filter materials used for high-temperature PM2.5 and harmful gas treatment is not ideal, this invention provides an integrated PPS meltblown fabric-based filter material for high-temperature flue gas and its preparation method.

[0005] Existing technologies typically employ in-situ growth methods to load catalysts, specifically by impregnating the fiber with a solution and undergoing a chemical reaction (such as redox) to allow catalyst particles to deposit and grow on the outer surface of the fiber. This is a post-processing step, where the catalyst and fiber are primarily physically attached or weakly chemically bonded, and this process easily clogs the inherent pores of the material. In contrast, the "in-situ embedding" method in this solution is a synchronous process integrated with fiber forming: the catalyst precursor is pre-uniformly mixed into PPS resin and granulated, and the catalyst precursor is thermally decomposed into metal oxides. In the subsequent meltblown process, manganese and cerium oxide nanoparticles are directly encapsulated and locked inside the fiber by the instantaneously cooled and solidified PPS melt. This is not "growing" on the surface, but rather "embedding" or "precipitating" within the fiber matrix. This mechanism ensures a strong mechanical bond between the catalyst and the support, without additionally occupying or clogging the filtration pores between the fibers, thus achieving high catalytic activity while perfectly preserving the high filtration accuracy and low airflow resistance characteristics of the meltblown fabric itself.

[0006] The main concept of this invention is as follows: (1) It forms ultra-fine meltblown fabric fibers, which can form a dense three-dimensional network to achieve efficient and low-resistance capture of fine particulate matter such as PM2.5; (2) By blending the catalyst precursor with PPS resin and granulating, and then performing melt-blowing treatment after granulation, the nano-catalyst is embedded in the fiber during the melt-blowing process to achieve a firm bond; then a thin layer of catalyst active sites is constructed on the fiber surface by vapor deposition. (3) By innovatively combining materials and processes, the key performance of the filter material was successfully optimized. With the structural support of the catalyst, the long-term stability and durability of the filter material in harsh flue gas environments were significantly improved.

[0007] Compared with existing technologies that load catalysts through impregnation or in-situ growth, this invention uses finer PPS meltblown fabric as the substrate and employs a unique "catalyst embedding + surface modification" process to load denitrification catalysts (such as MnO) onto the substrate. x -CeO2) is firmly loaded inside and on the surface of the fiber, forming a composite structure with gradient catalytic function.

[0008] The synergistic effect of "dense surface dust capture" and "deep internal catalysis" allows the ultrafine meltblown fiber network to efficiently intercept PM2.5 and other particulate matter; subsequently, harmful gases in the flue gas (such as NO) are also captured. x The gas diffuses into the interior and surface of the fiber, where it undergoes a catalytic reduction reaction with the embedded catalyst, and is decomposed into harmless nitrogen and water, thus achieving integrated dust removal and denitrification.

[0009] More specifically, the integrated PPS meltblown fabric filter material for high-temperature flue gas includes a pre-filtration layer and a catalytic filtration layer, wherein the pre-filtration layer is a pure PPS meltblown fiber web, and the catalytic filtration layer is a PPS meltblown fiber web loaded with a catalyst, and the mass ratio of the two is 1:2.0-2.4. The catalytic filter layer is obtained by melt-blowing pure PPS resin with catalyst and carrier / PPS masterbatch, followed by chemical vapor deposition using precursor vapor.

[0010] Furthermore, in the preparation of the catalytic filter layer, the mass ratio of pure PPS resin to catalyst and support / PPS masterbatch is 3:1. The raw materials of the catalyst and support / PPS masterbatch include catalyst precursor, KH-550 surface-modified TiO2 powder and PPS resin. The catalyst precursor is manganese acetate and cerium nitrate with a Mn:Ce molar ratio of 2-4:1. The mass ratio of catalyst precursor to surface-modified TiO2 powder is 10:7-21, and the mass ratio of catalyst precursor to PPS resin is 1:3.7-6.4. The precursor vapor contains VO(OC3H7)3 and W(CO)6, and the atomic molar ratio of V to W in the precursor vapor is 1:30.

[0011] The specific steps for preparing the above-mentioned PPS meltblown fabric-based integrated filter material for high-temperature flue gas are as follows: (1) Preparation of catalyst and support / PPS masterbatch: Disperse nano TiO2 powder in anhydrous ethanol, add silane coupling agent KH-550 and stir, filter and dry to obtain surface-modified (surface hydrophobic) TiO2 powder; dissolve manganese acetate and cerium nitrate in ethanol-water mixed solvent to obtain solution, add the above surface-modified TiO2 powder to the solution, add appropriate amount of KH-550, ultrasonically disperse to form uniform suspension, mix the suspension with PPS resin powder in high-speed mixer to obtain mixture material, dry the mixture material and extrude it through twin screw extruder, cool and pelletize it. At this time, the precursor decomposes and the metal oxide is uniformly distributed in PPS to obtain catalyst and support / PPS masterbatch.

[0012] The removal of harmful gases from flue gas is mainly achieved through the selective catalytic reduction (NH3-SCR) of nitrates. In this reaction, NH3 molecules need to be adsorbed and activated on the catalyst surface. Anatase TiO2, with its abundant Lewis acid and Brønsted acid sites, is an excellent ammonia adsorbent. It can effectively adsorb and activate NH3, and synergistically interact with nearby active sites such as vanadium and tungsten, greatly enhancing the denitrification reaction rate and efficiency.

[0013] In this invention, TiO2 is first modified with a coupling agent to ensure that the surface of TiO2 is fully and uniformly coated with the coupling agent to form a stable organic modified layer. If it is added together with the manganese cerium precursor, it may lead to multiple problems such as incomplete coating of TiO2, ineffective consumption of the coupling agent, and system instability, which will ultimately affect the dispersion and binding of the catalyst in the fiber.

[0014] When mixing trace amounts of catalyst powder directly with resin powder, there are technical challenges such as difficulty in uniform dispersion, easy agglomeration, unstable feeding, and easy clogging of spinneret orifices. In this invention, the unique high temperature, high shear, and long-term melt blending environment of twin-screw extruder granulation is utilized. Under the assistance of solvent and strong mechanical action, the catalyst precursor is completely decomposed, dispersed, and homogenized into nanoscale particles, which are then uniformly coated in PPS matrix to produce a "functional masterbatch" with uniform composition and appropriate flowability.

[0015] (2) Meltblown molding: Pure PPS resin is meltblown to form a pure PPS meltblown fiber web (pre-filter layer before composite); the catalyst and carrier / PPS masterbatch obtained in step (1) are mixed with pure PPS resin and then meltblown to form a PPS meltblown fiber web loaded with the main catalyst and carrier.

[0016] (3) Surface vapor deposition: PPS meltblown fiber mesh loaded with main catalyst and support is placed in chemical vapor deposition (CVD) reactor, and precursor vapors of VO(OC3H7)3 and W(CO)6 are introduced. After high-temperature reaction in nitrogen atmosphere, it is calcined in air atmosphere to obtain PPS meltblown fiber mesh loaded with catalyst (catalytic filter layer before composite).

[0017] During the reaction in a nitrogen atmosphere, nitrogen purging is performed first, followed by the introduction of a vapor stream for chemical vapor deposition, which consists of three parts: 1. Carrier gas: Nitrogen (N2), used for stable transport of precursors, is the main component; 2. Precursor vapor: a mixture of VO(OC3H7)3 and W(CO)6 vapor; 3. Reaction gas: Contains a small amount of oxygen (O2) to ensure sufficient oxidation during the deposition or calcination stage; In some embodiments of the present invention, during the reaction in a nitrogen atmosphere, the vapor stream comprises 95% N2 as a carrier gas, 4.5% vanadium and tungsten metal organic precursor vapors, and 0.5% oxygen, by volume flow rate. The atomic molar ratio of V to W in the precursor vapor is 1:30, and the vapor temperature is 100-120°C, ensuring stable evaporation of the precursors without premature decomposition. Furthermore, VO(OC3H7)3 has a boiling point of 80°C, and W(CO)6 has a sublimation temperature of 50°C, ensuring that both precursors exist in vapor form at this vapor temperature.

[0018] (4) Hot rolling composite: The pure PPS meltblown fiber web obtained in step (2) and the PPS meltblown fiber web loaded with catalyst after vapor deposition obtained in step (3) are hot rolled using a web forming hot rolling device to obtain a double-layer composite PPS meltblown filter material.

[0019] (5) Post-processing: The filter material obtained in step (4) is subjected to electrostatic electret treatment.

[0020] Specifically, in step (1), nano-TiO2 powder is dispersed in anhydrous ethanol, with the mass of nano-TiO2 powder accounting for 15% of the mass of anhydrous ethanol. Silane coupling agent KH-550 is added, with the amount added being 8% of the mass of nano-TiO2 powder. After stirring for 4 hours, the suspension is filtered. At this time, the coupling agent is fully hydrolyzed and completes a condensation reaction with the TiO2 surface. The resulting solid is dried in a vacuum oven at 80°C and -0.1MPa for 3 hours to obtain surface-modified TiO2 powder. Manganese acetate and cerium nitrate were dissolved in an ethanol-water mixture with a Mn:Ce molar ratio of 2-4:1 and a volume ratio of anhydrous ethanol to water of 1:1. The total mass of manganese acetate and cerium nitrate accounted for 10% of the mass of the ethanol-water mixture. The surface-modified TiO2 powder was added to the solution to make the mass fraction of the surface-modified TiO2 powder 6-16%. A silane coupling agent KH-550 was added and ultrasonically dispersed to obtain a suspension. The mass of KH-550 added was 2-4% of the total mass of manganese acetate and cerium nitrate. The mass ratio of catalyst precursor (manganese acetate and cerium nitrate) to PPS resin was 1:3.7-6.4. The resulting suspension and PPS resin powder were mixed in a high-speed mixer at 50°C for 40 min to obtain a mixture. The melt flow rate (MFR) of the PPS resin powder was 300-500 g / 10 min (316°C, 5 kg).

[0021] Manganese and cerium require a specific synergistic ratio; the Mn:Ce ratio of 3:1 exhibits the best low-temperature denitrification activity. The addition of cerium allows it to enter the manganese oxide lattice or form a complex phase with it, introducing lattice defects and oxygen vacancies, significantly enhancing the catalyst's redox capacity and surface acidity. Excessive cerium may decrease the dispersion of the active component, manganese, and excessive cerium oxide may cover some of the manganese's active sites. While manganese is the main source of activity, excess cerium leads to a decrease in the catalyst's specific surface area and may form large-particle manganese oxides, reducing the effective active area and stability.

[0022] In an ethanol-water mixed solvent, a 1:1 solution exhibits moderate polarity, effectively dissolving inorganic salts such as manganese acetate and cerium nitrate, as well as the silane coupling agent KH-550. Ethanol reduces the surface tension of water, improving the wettability of the solution on hydrophobic PPS powder and facilitating the uniform coating of the precursor solution onto the resin particle surface for finer dispersion. Water ensures salt dissolution and silane hydrolysis, while also facilitating subsequent vacuum drying removal. Insufficient water content leads to inadequate salt dissolution, while excessive water content results in high drying energy consumption or resin adhesion.

[0023] The two ends of the KH-550 molecular structure can interact with the catalyst precursor and PPS resin, respectively. Its amino group can coordinate with metal ions or be electrostatically attracted, while its siloxane end can form hydrogen bonds or chemical bonds with trace polar points on the PPS surface after hydrolysis, which can improve the binding strength of the final catalyst inside the fiber.

[0024] MFR is tested according to GB / T 3682.1-2008. The reason for this MFR range is as follows: The essence of meltblown process is to use high temperature and high speed airflow to extremely stretch the melt into ultrafine fibers in a very short time. This places certain requirements on the flowability of the melt. If the resin's MFR is too low (i.e., large molecular weight and high melt viscosity), the melt flowability in the spinneret will be poor, making it difficult to be effectively stretched. This can easily lead to extruder blockage and production failure, and it will also be impossible to form a uniform ultrafine fiber web. If the resin's MFR is too high, it may lead to a decrease in the mechanical strength (such as breaking strength) of the resulting fibers. For filter materials that need to be used for a long time in a certain flue gas environment, the fibers must have sufficient mechanical strength and durability. An MFR range of 300-500 g / 10 min can meet the demanding processing requirements of ultrafine fiber forming while also taking into account the mechanical strength of the final product.

[0025] Preferably, in step (1), the mixture is heated and dried at 105°C to constant weight (the drying is repeated until the mass difference between two weighings is less than 0.0003g, which is considered constant weight; test method: national standard GB / T 6284-2006).

[0026] Preferably, in step (1), the melting temperature of the twin-screw extruder is set according to the following temperature gradient from the feed port to the die head: 280-300℃ in the feeding section, 300-310℃ in the melting section, 310-320℃ in the mixing section, and 305-315℃ in the die head section. The screw speed is 300 rpm, and the die head is equipped with a vacuum exhaust pressure of -0.10 MPa.

[0027] Specifically, the specific process of step (2) is as follows: (a) First layer meltblown: Pure PPS resin is meltblown. The meltblown process parameters are: feeding section 290-300℃, melting section 305-315℃, homogenization section 310-320℃, die head connection section 315-325℃, die head temperature 320-325℃, hot air temperature 320-330℃, metering pump flow rate 10L / h (the quantitative amount of meltblown fiber web is controlled by adjusting the flow meter), receiving distance (DCD) 25 cm, and the quantitative amount formed after meltblowing is 50 g / m³. 2 Pure PPS meltblown fiber mesh; (b) Second layer meltblown: The catalyst and carrier / PPS masterbatch are mixed with pure PPS resin at a mass ratio of 1:3 and then meltblown (using the same equipment as the first layer meltblown). The meltblown process parameters are: feeding section 290-300℃, melting section 305-315℃, homogenization section 310-320℃, die head connection section 315-325℃, die head temperature 320-325℃, hot air temperature 320-330℃, metering pump flow rate 20-40 L / h, receiving distance (DCD) 25cm, resulting in a quantitative yield of 90-110 g / m³. 2 The PPS meltblown fiber web is loaded with the main catalyst and support; In an embodiment of the present invention, a meltblown testing machine is used for meltblown testing. The meltblown testing machine includes a twin-screw extruder, a metering pump, a meltblown die head, and a receiving device, which are commonly used equipment in the art. The key to this process lies in the uniform embedding of MnOx-CeO2 nanoparticles into the PPS fiber matrix, forming a robust "embedded" structure.

[0028] The catalyst and support / PPS masterbatch contain inorganic catalyst components, which fundamentally alters the melt rheology. The presence of inorganic substances significantly increases melt viscosity and disrupts melt elasticity. If 100% catalyst and support / PPS masterbatch is used directly for meltblowing, the melt becomes too viscous and brittle, unable to be effectively drawn by the airflow. This easily leads to problems such as spinneret blockage, uneven fiber diameter, fiber breakage, and the generation of a large number of poorly drawn beads, making continuous production impossible. Secondly, even if the catalyst is well dispersed within the catalyst and support / PPS masterbatch, the addition of pure PPS resin during the secondary melting and mixing process in the meltblown screw provides additional shearing and homogenizing effects. This helps to further break down any potentially small agglomerates, ensuring that catalyst nanoparticles are more uniformly distributed throughout the entire PPS matrix of the final fiber, thereby achieving more efficient and stable catalytic performance.

[0029] Preferably, the specific process of step (3) is as follows: the PPS meltblown fiber mesh loaded with the main catalyst and the support is placed in a chemical vapor deposition (CVD) reactor. First, all inlets and outlets are closed, and the reaction chamber is repeatedly purged and evacuated three times with high-purity nitrogen (purity ≥99.999%) to ensure that the chamber is in an inert atmosphere that is completely free of oxygen and water. Thereafter, nitrogen is continuously flowed through the system as the carrier gas, and the system temperature is raised to a preset 250°C. After the temperature stabilizes, a vapor stream containing precursor vapors of VO(OC3H7)3 and W(CO)6 is introduced. The atomic molar ratio of V to W in the precursor vapor is 1:30, and the vapor temperature is 100-120°C (to ensure stable evaporation of the precursor and to prevent premature decomposition). The reaction is carried out at 250°C in a nitrogen atmosphere for 20-40 min, and then calcined at 320°C in an air atmosphere for 1 h. After step (3), a V2O5-WO3 / TiO2 layer was generated on the surface of the PPS meltblown fiber web loaded with the main catalyst and the support, and the PPS meltblown fiber web loaded with the catalyst was obtained.

[0030] (4) Hot rolling composite: The pure PPS meltblown fiber web obtained in step (2) and the PPS meltblown fiber web loaded with catalyst after vapor deposition obtained in step (3) are hot rolled using a web forming hot rolling device. The roll surface temperature is 110℃ and the roll pressure is 4 kN / m to obtain a double-layer composite PPS meltblown filter material.

[0031] This invention constructs a two-layer composite filter material, wherein the first layer is a pure PPS meltblown fiber web, and the second layer is a PPS meltblown fiber web loaded with a main catalyst and a secondary functional catalyst, constructed by meltblowing. To ensure that the secondary functional catalyst can be accurately constructed without damaging the core structure of the filter material, a vapor deposition method is used for its introduction. The composite filter material is constructed by vapor deposition of an ultrathin catalytic functional layer on the surface of the second layer (the meltblown fabric loaded with the main catalyst). If a conventional impregnation method is used, the entire filter material needs to be immersed in the precursor solution, which would prevent the precursor from selectively depositing on the surface, causing it to penetrate and fill the fiber gaps and pores inside the filter material, resulting in pore blockage after calcination.

[0032] Preferably, in step (5), the double-layer composite PPS meltblown filter material obtained in step (4) is subjected to electrostatic electret treatment using a high-voltage electrostatic electret machine with a voltage of 40-50 kV and a time of 30 s, which imparts electrostatic adsorption capacity to the filter material and further improves the collection efficiency of ultrafine particles.

[0033] The above method can be used to obtain PPS meltblown fabric-based integrated filter material with a total basis weight of 150-170 g / m³. 2 .

[0034] The PPS meltblown fabric-based integrated filter material is used for the filtration of high-temperature flue gas. In use, the pure PPS meltblown fiber web layer (pre-filter layer) faces the flue gas inflow direction, and the flue gas flows out sequentially through the PPS meltblown fiber web layer (pre-filter layer) and the PPS meltblown fiber web loaded with catalyst (catalytic filter layer).

[0035] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. Thanks to the inherent ultra-fine fiber three-dimensional network structure of PPS meltblown fabric, this filter material has excellent filtration efficiency for PM2.5 fine particulate matter, which is far superior to traditional needle-punched felt filter material (usually <85%), achieving highly efficient interception of inhalable particulate matter. 2. This invention utilizes an "in-situ catalyst embedding" process to embed the main catalyst (MnO) into the substrate. x -CeO2) is locked inside the PPS fiber during the melt-blowing process, realizing mechanical interlocking and chemical bonding between the catalyst and the support at the microscale; 3. A V2O5-WO3 / TiO2 nanolayer constructed on the surface of the second layer of fibers using chemical vapor deposition (CVD) technology forms a functional gradient with the internal main catalyst. This surface catalyst greatly optimizes the denitrification activity and sulfur poisoning resistance in the medium and high temperature range, and its vapor deposition process avoids pore blockage caused by traditional coating methods, fully preserving the low-resistivity characteristics of the filter material; 4. High synergy and seamless coordination of functional layers in space and mechanism: The first layer of pure PPS fiber performs primary physical interception; the main catalyst inside the second layer of fiber intercepts particles while performing deep catalytic reduction of gaseous pollutants; the secondary functional catalyst loaded on its surface further broadens the temperature window for efficient denitrification (main catalyst (Mn-Ce-Ox): typically has excellent low-temperature activity, capable of efficiently initiating the reaction at 200-250℃ or even lower temperatures. Auxiliary catalyst (VW-Ox / TiO2): deposited on the surface through vapor phase, characterized by good high-temperature activity, strong thermal stability, and strong resistance to poisoning, ensuring high activity even at 300-400℃ or even higher temperatures. The synergy of the two allows the filter material to maintain a NOx purification efficiency of over 90% within a wide temperature range of 200-280℃, significantly better than single-component catalysts, thus adapting to complex and variable actual industrial flue gas conditions); while the electrostatic electret field distributed throughout the entire fiber network preferentially adsorbs ultrafine particles that are difficult to mechanically intercept, providing more sufficient contact opportunities for subsequent catalytic reactions. This multi-stage synergistic purification system of "physical interception-electrostatic adsorption-gradient catalysis" is the fundamental reason why this filter material can simultaneously achieve ultra-high filtration efficiency, ultra-low airflow resistance, high stable denitrification performance, and long service life. Attached Figure Description

[0036] Figure 1This is a schematic diagram of the structure of the PPS meltblown fabric-based integrated filter material of the present invention. Detailed Implementation

[0037] The technical solution of the present invention will be further described below with reference to specific embodiments. These embodiments are only used to illustrate the technical solution of the present invention in more detail and should not be construed as limiting the scope of protection of the present invention.

[0038] In the following examples and comparative examples, the nano-TiO2 powder has a particle size of 30 nm and is manufactured by Aladdin.

[0039] In the following embodiments, comparative examples, and experimental examples, the meltblown process uses a meltblown testing machine, which was custom-made by Changzhou Lingxian Textile Machinery Co., Ltd. This equipment is conventional in the field, and the use of other models of meltblown testing lines or meltblown production lines is also applicable to this invention.

[0040] The filter media performance testing bench is used for filtration performance testing. It was purchased from Shanghai Qingji and its model number is QJ706C. The catalytic fixed-bed reactor system, customized by Shanghai Fuding Technology, was used for denitrification performance testing. The chemical vapor deposition reactor, purchased from KingKee Instruments, is model JKCH-CVD and is used for chemical vapor deposition. The equipment used for electrostatic electret treatment is a high-voltage electrostatic electret machine, purchased from Wuhan Sanxin Electric Power, model SXDL(JZ).

[0041] The PPS meltblown fabric-based integrated filter material is used for the filtration of high-temperature flue gas. In use, the pure PPS meltblown fiber web layer (pre-filter layer) faces the flue gas inflow direction, and the flue gas flows out sequentially through the PPS meltblown fiber web layer (pre-filter layer) and the catalyst-loaded meltblown fabric layer (catalytic filter layer).

[0042] The instruments and equipment listed above are merely examples and are all conventional equipment in the prior art, which can be obtained through various channels.

[0043] In the following examples and comparative examples, deionized water was used; quantitative analysis was performed according to the national standard GB / T24218.1 2009.

[0044] Unless otherwise specified, the substances, equipment, reagents, etc. used in the following examples, comparative examples, and experimental cases are all commercially available products.

[0045] Example 1: A PPS meltblown fabric-based integrated filter material for high-temperature flue gas, the structure of which is as follows: Figure 1 As shown, it is prepared by the following method.

[0046] The melt flow rate (MFR) of the PPS resin powder used in this embodiment is 300-500 g / 10 min (316℃, 5 kg) (according to GB / T 3682.1-2008, qualified PPS resin products that meet this melt flow rate range can be used).

[0047] The integrated PPS meltblown fabric filter material for high-temperature flue gas is prepared by the following method: (1) Preparation of catalyst and support / PPS masterbatch: Nano TiO2 powder was dispersed in anhydrous ethanol, with the mass of nano TiO2 powder accounting for 15% of the mass of anhydrous ethanol. Silane coupling agent KH-550 was added, with the amount added being 8% of the mass of nano TiO2 powder. After stirring for 4 h, the suspension was filtered (filter diameter 0.02 μm). The resulting solid was dried in a vacuum oven at 80 °C and -0.1 MPa for 3 h to obtain surface-modified TiO2 powder. Manganese acetate and cerium nitrate were dissolved in an ethanol-water mixture (Mn:Ce molar ratio 2:1) in anhydrous ethanol and water (volume ratio 1:1), with the sum of the mass of manganese acetate and cerium nitrate accounting for 10% of the mass of the ethanol-water mixture. Surface-modified TiO2 powder was added to the solution to achieve a mass fraction of 6%. A silane coupling agent, KH-550, was added and ultrasonically dispersed to obtain a suspension. The mass of KH-550 added was 2% of the sum of the mass of manganese acetate and cerium nitrate. The mass ratio of the catalyst precursor (manganese acetate and cerium nitrate) to PPS resin was 1:6.4. The resulting suspension and PPS resin powder were mixed in a high-speed mixer at 50°C for 40 min to obtain a mixture. The mixture was then dried at 105°C to constant weight (testing method: GB / T). After drying, the product is extruded through a twin-screw extruder, cooled, and pelletized. At this time, the precursor decomposes and the metal oxide is evenly distributed in PPS to obtain the catalyst and support / PPS masterbatch. The twin-screw extruder has a melting temperature gradient from the feed port to the die head: 280°C in the feeding section, 300°C in the melting section, 310°C in the mixing section, and 305°C in the die head section. The screw speed is 300 rpm, and the die head is equipped with a vacuum exhaust system with a pressure of -0.10 MPa.

[0048] (2) Meltblown molding: (a) First layer meltblown: Pure PPS resin is meltblown. The meltblown process parameters are: feeding section 290℃, melting section 305℃, homogenization section 310℃, die head connection section 315℃, die head temperature 320℃, hot air temperature 320℃, metering pump flow rate 10L / h, receiving distance (DCD) 25cm. The resulting product has a basis weight of 50 g / m³. 2Pure PPS meltblown fiber web (the ratio of the first and second layers is determined based on the quantitative determination); (b) Second layer meltblown: The catalyst and carrier / PPS masterbatch are mixed with pure PPS resin at a mass ratio of 1:3 and then meltblown. The meltblown process parameters are: feeding section 290°C, melting section 305°C, homogenization section 310°C, die head connection section 315°C, die head temperature 320°C, hot air temperature 320°C, metering pump flow rate 20L / h, receiving distance (DCD) 25cm, resulting in a quantitative yield of 90 g / m³. 2 The PPS meltblown fiber web is loaded with a main catalyst and a support.

[0049] (3) Surface vapor deposition: The PPS meltblown fiber mesh loaded with the main catalyst and support is placed in the chemical vapor deposition (CVD) reactor. First, all inlet and outlet are closed, and the reaction chamber is repeatedly purged and evacuated three times with high-purity nitrogen (purity ≥99.999%) to ensure that the chamber is in an inert atmosphere that is completely free of oxygen and water. Thereafter, nitrogen is continuously flowed through the system as the carrier gas, and the system temperature is raised to the preset 250℃. After the temperature stabilizes, precursor vapors of VO(OC3H7)3 (CAS:1686-23-3) and W(CO)6 (CAS:14040-11-0) are introduced. The vapor flow consists of three parts by volume flow rate: nitrogen carrier gas (95%), precursor vapor (4.5%), and a small amount of reactant gas (oxygen) (0.5%). The atomic molar ratio of V to W in the precursor vapor is 1:30. The steam temperature was 100℃, and the reaction was carried out at 250℃ under a nitrogen atmosphere for 20 min, followed by calcination at 320℃ in an air atmosphere for 1 h. After step (3), a V2O5-WO3 / TiO2 layer was generated on the surface of the PPS meltblown fiber web loaded with the main catalyst and the support, and the PPS meltblown fiber web loaded with the catalyst was obtained.

[0050] (4) Hot rolling composite: The pure PPS meltblown fiber web obtained in step (2) and the PPS meltblown fiber web loaded with catalyst after vapor deposition obtained in step (3) are hot rolled using a web forming hot rolling device. The roll surface temperature is 110℃ and the roll pressure is 4 kN / m to obtain a double-layer composite PPS meltblown filter material.

[0051] (5) Post-processing: The filter material obtained in step (4) is subjected to electrostatic electret treatment using a high-voltage electrostatic electret machine. The voltage of the electrostatic electret treatment is 45 kV and the time is 30 s.

[0052] The PPS meltblown fabric-based integrated filter material prepared by the above process has a total basis weight of 150 g / m³. 2 (Tested according to national standard GB / T24218.1 2009).

[0053] Example 2 A PPS meltblown fabric-based integrated filter material for high-temperature flue gas was prepared using a method basically the same as that in Example 1, except that the Mn:Ce molar ratio in step (1) was changed to 4:1; the amount of silane coupling agent KH-550 was changed to 4% of the sum of the mass of manganese acetate and cerium nitrate, and the other conditions remained unchanged.

[0054] Example 3 A PPS meltblown cloth-based integrated filter material for high-temperature flue gas is prepared using a method that is basically the same as that in Example 1, except that in step (1), surface-modified TiO2 powder is added to the solution so that the mass fraction of surface-modified TiO2 powder in the solution is 16%, and the other conditions remain unchanged.

[0055] Example 4 A PPS meltblown fabric-based integrated filter material for high-temperature flue gas was prepared using a method that was basically the same as that in Example 1, except that the mass ratio of the catalyst precursor to the PPS resin in step (1) was changed to 1:3.7, while the other conditions remained unchanged.

[0056] Example 5: A PPS meltblown fabric-based integrated filter material for high-temperature flue gas was prepared using a method essentially the same as in Example 1, except that the metering pump flow rate in step (2)(b) was changed to 40 L / h, resulting in a metering density of 110 g / m³. 2 The PPS meltblown fabric was finally obtained with a total basis weight of 170 g / m³. 2 The integrated filter media; all other conditions remain unchanged.

[0057] Example 6: A PPS meltblown fabric-based integrated filter material for high-temperature flue gas was prepared using a method essentially the same as in Example 1, except that: in step (3), the reaction time of the precursor vapors VO(OC3H7)3 and W(CO)6 under a nitrogen atmosphere was changed to 40 min, and the vapor temperature was changed to 120℃, resulting in a V2O5-WO3 / TiO2 layer. The total basis weight of the integrated filter material was 160 g / m³. 2 All other conditions remain unchanged.

[0058] Example 7 A PPS meltblown fabric-based integrated filter material for high-temperature flue gas was prepared using a method basically the same as that in Example 1, except that: in step (1), the melting temperature of the twin-screw extruder was changed to a temperature gradient from the feed port to the die head: 300°C for the feeding section, 310°C for the melting section, 320°C for the mixing section, and 315°C for the die head section; the meltblown process parameters in steps (2)(a) and (b) were: 300°C for the feeding section, 315°C for the melting section, 320°C for the homogenization section, 325°C for the die head connection section, 325°C for the die head temperature, and 330°C for the hot air temperature; the other conditions remained unchanged.

[0059] Comparative Example 1: A commercially available PPS needle-punched felt with a fiber diameter of 20 μm, loaded with MnO by an impregnation method.x -CeO2 catalyst, catalyst precursor (manganese acetate and cerium nitrate) to PPS needle-punched felt mass ratio 1:28.6, quantitative amount 150 g / m 2 The fiber diameter is 20μm.

[0060] Comparative Example 2: A pure PPS meltblown fabric, prepared using the same method as step (2)(a) of Example 1.

[0061] Comparative Example 3: A PPS meltblown fabric filter material with in-situ catalyst embedding, the preparation method of which is as follows: (1) Preparation of catalyst and support / PPS masterbatch: The catalyst and support were prepared using the same method as in step (1) of Example 1; (2) Single-layer meltblown: The catalyst and carrier / PPS masterbatch are mixed with pure PPS resin at a mass ratio of 1:3 and then meltblown. The meltblown process parameters are: feeding section 290℃, melting section 305℃, homogenization section 310℃, die head connection section 315℃, die head temperature 320℃, hot air temperature 320℃, metering pump flow rate 20L / h, receiving distance (DCD) 25cm, resulting in a quantitative yield of 90g / m³. 2 Meltblown fabric filter material.

[0062] Comparative Example 4: A PPS meltblown fabric-based integrated filter material was prepared using a method that was basically the same as that in Example 1, except that the PPS meltblown fiber web loaded with the main catalyst and carrier obtained in step (2)(b) was not subjected to the vapor deposition treatment in step (3), while the other conditions remained unchanged.

[0063] Comparative Example 5: A PPS meltblown fabric filter material with a catalyst supported by impregnation, the preparation method of which is as follows: (1) First layer meltblown: Pure PPS resin is meltblown. The meltblown process parameters are: feeding section 300℃, melting section 310℃, homogenization section 315℃, die head connection section 320℃, die head temperature 320℃, hot air temperature 325℃, metering pump flow rate 10L / h, receiving distance (DCD) 25cm. After meltblowing, the quantitative amount formed is 50 g / m³. 2 The pure PPS meltblown fiber web is kept at a temperature of 110°C. (2) Second layer meltblown: Pure PPS resin is meltblown. The meltblown process parameters are: feeding section 300℃, melting section 310℃, homogenization section 315℃, die head connection section 320℃, die head temperature 320℃, hot air temperature 325℃, metering pump flow rate 30L / h, receiving distance (DCD) 25cm. The resulting product has a basis weight of 90g / m³. 2 Pure PPS meltblown fiber mesh; (3) Impregnation of catalyst: Surface-modified TiO2 powder support was prepared using the method in Example 1, and suspension was prepared using catalyst precursor, ethanol-water mixed solvent and surface-modified TiO2 powder according to the method in Example 1; The PPS meltblown fabric obtained in step (2) was immersed in the suspension (complete immersion, no quality requirements), and treated at 50°C for 2 h. It was then dried at 105°C to constant weight (test method: GB / T 6284-2006) to obtain a PPS meltblown fabric loaded with catalyst precursor and TiO2. This meltblown fabric was calcined at 320°C in air for 1 h to obtain a PPS meltblown fabric functional material loaded with Mn-Ce / TiO2 catalyst. (4) Surface vapor deposition: Performed using the same method as step (3) in Example 1; (5) Hot rolling composite: The pure PPS meltblown fiber web obtained in step (1) and the PPS meltblown fiber web loaded with catalyst after vapor deposition obtained in step (4) are hot rolled using a web forming hot rolling device. The roll surface temperature is 110℃ and the roll pressure is 4 kN / m to obtain a double-layer composite PPS meltblown filter material. (6) Post-processing: The same method as step (5) in Example 1 is used.

[0064] The total basis weight of the PPS meltblown fabric functional material prepared by the above process is 150 g / m³. 2 .

[0065] Comparative Example 6: A PPS meltblown fabric-based integrated filter material, prepared using a method essentially the same as that in Example 1, except that in the second meltblown layer, the catalyst and carrier / PPS masterbatch are mixed with pure PPS resin at a mass ratio of 1:1.

[0066] Comparative Example 7: A PPS meltblown fabric-based integrated filter material, prepared using a method essentially the same as that in Example 1, except that in the second meltblown layer, the catalyst and carrier / PPS masterbatch are mixed with pure PPS resin at a mass ratio of 1:6.

[0067] Comparative Example 8: A PPS meltblown fabric-based integrated filter material, prepared using a method essentially the same as that in Example 1, except that in the second meltblown layer, the catalyst and carrier / PPS masterbatch are mixed with pure PPS resin at a mass ratio of 1:0 (i.e., pure PPS resin is not used in the second composite layer).

[0068] Experiment Example 1: Filtration Performance Test Using an automated filter media testing station, under a filtration rate of 5 cm / s, the filtration efficiency and resistance were tested using KCl aerosol (median diameter 0.26 μm) (obtained by processing KCl aqueous solution through an aerosol generator) and Arizona test dust (Shanghai Ruibei Trading Co., Ltd., A2 fine ash) (tested according to national standard GB / T 14295-2019). The results are shown in Table 1.

[0069] Table 1. Filtration efficiency and resistance test results As shown in Table 1, the PM2.5 filtration efficiency of Comparative Example 1 is significantly lower than that of all other examples, and its initial resistance is also much higher than that of all other experimental examples. This is because the fibers of the needle-punched felt are coarser than those of the meltblown fibers, and the three-dimensional network pores formed are insufficient in their mechanical interception ability for PM2.5 fine particles, resulting in low filtration efficiency. Secondly, the post-treatment impregnation loading process coats and blocks the catalyst slurry on the already sparse coarse fiber surface and pores, which seriously hinders the airflow and increases the system resistance.

[0070] Comparative Example 2 uses a single-layer PPS meltblown material, which has a much lower filtration efficiency for KCl aerosol than all other examples, and a slightly lower filtration efficiency for PM2.5 than all other examples.

[0071] Comparative Example 3 uses PPS meltblown fabric filter material with a single-layer catalyst embedded in situ. Without a clean pre-filtration layer for protection, the catalyst layer is easily clogged by particles, and the filtration efficiency for KCl aerosol and PM2.5 is lower than that of Example 1.

[0072] Comparative Example 4 shows that the presence or absence of the second functional catalyst layer does not affect the basic physical filtration performance.

[0073] Comparative Example 5 sacrificed its greatest advantage of low resistance due to severe blockage of the meltblown fabric pores by the impregnation liquid. Compared with all examples, the resistance increased dramatically, and the efficiency decreased due to structural damage.

[0074] Comparative Example 6 showed a significant increase in resistance and a decrease in overall filtration performance due to an excessively high catalyst and carrier / PPS masterbatch ratio, indicating that excessive catalyst leads to poor fiber spinnability and reduced porosity. Comparative Example 7 had a lower catalyst and carrier / PPS masterbatch content and did not affect the filtration performance of the filter media. Comparative Example 8, consisting of 100% pure catalyst and carrier / PPS masterbatch, had extremely poor melt rheology due to its excessively high inorganic content, making stable meltblown spinning impossible.

[0075] Experiment Example 2: Denitrification Performance Test Flue gas conditions were simulated in a fixed-bed reactor (NO: 500 ppm, NH3: 550 ppm, O2: 5% (volume concentration), N balance (using high-purity nitrogen as the packing gas, the components of the simulated flue gas (such as NO, O2, etc.) were mixed in proportion and then replenished to a total volume of 100%), with a space velocity of 10000 h⁻¹. -1 The denitrification rate was tested at different flue gas temperatures (referencing national standard GB / T 38219-2019), and the results are shown in Table 2.

[0076] Table 2. Denitrification rate test results at different temperatures As shown in Table 2, all examples achieved a denitrification rate of over 90% at 200-280℃, which is superior to Comparative Example 1 in terms of performance. The needle-punched felt has a lower denitrification rate due to its coarse fibers, large pores, and low catalyst contact efficiency.

[0077] Comparative Example 2 has no denitrification capability because it does not contain any catalyst.

[0078] Comparative Example 3 lacks a pre-filter layer and large dust particles can easily clog the pores of the catalyst layer, resulting in poor denitrification activity; the absence of a second functional catalyst also leads to a low denitrification rate at high temperatures.

[0079] Comparative Example 4 was not supported on a second functional catalyst (V2O5-WO3 / TiO2). This catalyst was used to improve the denitrification efficiency in the higher temperature range of 250-300℃ and enhance the resistance to sulfur poisoning. Therefore, its denitrification rate at 250℃ and 280℃ was lower than that of all other examples.

[0080] Comparative Example 5 showed a significantly lower denitrification rate at all temperatures compared to all other examples. Post-impregnation treatment of the meltblown PPS membrane only allows the catalyst precursor to adhere to its surface through simple immersion, resulting in an unstable and uneven bond between the catalyst precursor and the PPS meltblown fabric, which can clog the pores between fibers.

[0081] The comparison between Comparative Examples 6-7 and Example 1 illustrates that the catalyst concentration needs to be appropriate: If the catalyst concentration is too low (Comparative Example 7), it will lead to insufficient catalytic activity and poor denitrification performance; if the catalyst concentration is too high (Comparative Example 6), it will lead to blockage of fiber pores and affect the fiber forming effect.

[0082] Experimental Example 3: Catalyst Stability and Durability Test Simulated flue gas containing SO2 (100 ppm) at 280℃ (NO: 500 ppm, NH3: 550 ppm, O2: 5% (volume concentration), N balance, space velocity 10000 h⁻¹) -1After running continuously for 500 hours, the denitrification rate retention rate was compared (refer to T / CSTM00359-2021), and the results are shown in Table 3.

[0083] Table 3 Catalyst stability test results As can be seen from Table 3, the denitrification rate retention rate of Comparative Example 1 and Comparative Example 5 after 500 hours of operation is much lower than that of all examples. This indicates that the impregnation method catalyst is severely detached under long-term high-temperature scouring and its stability is much worse than that of the embedding process.

[0084] Comparative Example 4 did not undergo vapor deposition and was not loaded with a secondary functional catalyst (V2O5-WO3 / TiO2). It exhibited weak denitrification activity at high temperatures and poor sulfur resistance. Under SO2-containing conditions at 280℃, the main catalyst was prone to sulfur poisoning, and its high-temperature activity was insufficient, with significant degradation.

[0085] Experiment Example 4: High Temperature Dimensional Stability Test After placing the sample in an oven at 280℃ for 24 h, its area shrinkage rate was tested (refer to the paper: Preparation of polyphenylene sulfide meltblown microfiber and its oil absorption performance study, Wuhan Textile University, 2018). The results are shown in Table 4.

[0086] Table 4. Detection results of area shrinkage rate The area shrinkage rate of all embodiments is less than that of Comparative Example 1. Meltblown filter material is spun into fibers in a high-temperature molten state, and the fibers cool naturally and bond thermally. Its structure has already completed "thermal setting" during the manufacturing process, with low internal residual stress. Therefore, it is dimensionally stable and has an extremely low shrinkage rate when heated. In contrast, needle-punched filter material is made by forcibly entangled short fibers together by mechanical force at room temperature. A large amount of residual stress accumulates inside the fibers. When heated for the first time, this stress is released, causing the fiber network to shrink back, exhibiting a larger thermal shrinkage rate.

[0087] Comparative Example 5 is a filter material with a catalyst loaded by impregnation. The catalyst and carrier are mainly attached to the fiber surface in the form of physical adhesion, with weak bonding force and no internal anchoring effect on the PPS molecular chain. Secondly, impregnation will cause swelling or stress on the already shaped fiber network structure, which will damage its thermal stability.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any equivalent substitutions or modifications made by those skilled in the art within the spirit and principle of the present invention without any creative effort should be included within the protection scope of the present invention.

Claims

1. A PPS meltblown fabric-based integrated filter material for high-temperature flue gas, characterized in that, The integrated PPS meltblown fabric filter material for high-temperature flue gas includes a pre-filtration layer and a catalytic filtration layer. The pre-filtration layer is a pure PPS meltblown fiber web, and the catalytic filtration layer is a PPS meltblown fiber web loaded with a catalyst. The mass ratio of the two is 1:2.0-2.

4. The total basis weight of the integrated PPS meltblown fabric filter material is 150-170 g / m³. 2 ; The catalytic filter layer is obtained by melt-blowing pure PPS resin with catalyst and carrier / PPS masterbatch, followed by chemical vapor deposition using precursor vapor.

2. The integrated PPS meltblown fabric filter material for high-temperature flue gas as described in claim 1, characterized in that, In the preparation of the catalytic filter layer, the mass ratio of pure PPS resin to catalyst and support / PPS masterbatch is 3:

1. The raw materials of the catalyst and support / PPS masterbatch include catalyst precursor, KH-550 surface-modified TiO2 powder and PPS resin. The catalyst precursor is manganese acetate and cerium nitrate with a Mn:Ce molar ratio of 2-4:

1. The mass ratio of catalyst precursor to surface-modified TiO2 powder is 10:7-21, and the mass ratio of catalyst precursor to PPS resin is 1:3.7-6.

4. The precursor vapor contains VO(OC3H7)3 and W(CO)6, and the atomic molar ratio of V to W in the precursor vapor is 1:

30.

3. The preparation method of the integrated PPS meltblown fabric filter material for high-temperature flue gas as described in claim 1, characterized in that, The steps are as follows: (1) Preparation of catalyst and support / PPS masterbatch: Disperse nano titanium dioxide powder in anhydrous ethanol, add silane coupling agent KH-550 and stir, filter and dry to obtain surface-modified TiO2 powder. Manganese acetate and cerium nitrate were dissolved in an ethanol-water mixture to obtain a solution. The surface-modified TiO2 powder was added to the solution, and an appropriate amount of KH-550 was added. The mixture was ultrasonically dispersed to form a uniform suspension. The suspension was mixed with PPS resin powder in a high-speed mixer to obtain a mixture. After drying, the mixture was extruded through a twin-screw extruder, cooled, and pelletized to obtain the catalyst and support / PPS masterbatch. (2) Meltblown molding: Pure PPS resin is meltblown to form a pure PPS meltblown fiber web; the catalyst and carrier / PPS masterbatch obtained in step (1) are mixed with pure PPS resin and then meltblown to form a PPS meltblown fiber web loaded with the main catalyst and carrier. (3) Surface vapor deposition: PPS meltblown fiber mesh loaded with main catalyst and support is placed in chemical vapor deposition reactor, and precursor vapors of VO(OC3H7)3 and W(CO)6 are introduced. After high-temperature reaction under nitrogen atmosphere, it is calcined in air atmosphere to obtain PPS meltblown fiber mesh loaded with catalyst. (4) Hot rolling composite: The pure PPS meltblown fiber web obtained in step (2) and the PPS meltblown fiber web loaded with catalyst after vapor deposition obtained in step (3) are hot rolled using a web forming hot rolling device to obtain a double-layer composite PPS meltblown filter material. (5) Post-processing: The filter material obtained in step (4) is subjected to electrostatic electret treatment.

4. The method for preparing the integrated PPS meltblown fabric filter material for high-temperature flue gas according to claim 3, characterized in that, In step (1), nano-TiO2 powder is dispersed in anhydrous ethanol, with the mass of nano-TiO2 powder accounting for 15% of the mass of anhydrous ethanol. Silane coupling agent KH-550 is added at an amount of 8% of the mass of nano-TiO2 powder. After stirring for 4 hours, the suspension is filtered. The resulting solid is dried in a vacuum oven at 80°C and -0.1 MPa for 3 hours to obtain surface-modified TiO2 powder. Manganese acetate and cerium nitrate were dissolved in an ethanol-water mixture with a Mn:Ce molar ratio of 2-4:1 and a volume ratio of anhydrous ethanol to water of 1:

1. The total mass of manganese acetate and cerium nitrate accounted for 10% of the mass of the ethanol-water mixture. The surface-modified TiO2 powder was added to the solution to make the mass fraction of the surface-modified TiO2 powder 6-16%. Silane coupling agent KH-550 was added and ultrasonically dispersed to obtain a suspension. The mass of KH-550 added was 2-4% of the total mass of manganese acetate and cerium nitrate. The mass ratio of catalyst precursor to PPS resin was 1:3.7-6.

4. The resulting suspension and PPS resin powder were mixed in a high-speed mixer at 50°C for 40 min to obtain a mixture. The mixture was then dried at 105°C to constant weight.

5. The method for preparing the integrated PPS meltblown fabric filter material for high-temperature flue gas according to claim 4, characterized in that, In step (1), the melting temperature of the twin-screw extruder is set according to the following temperature gradient from the feed port to the die head: 280-300℃ in the feeding section, 300-310℃ in the melting section, 310-320℃ in the mixing section, and 305-315℃ in the die head section. The screw speed is 300 rpm, and the die head is equipped with a vacuum exhaust pressure of -0.10 MPa.

6. The method for preparing the integrated PPS meltblown fabric filter material for high-temperature flue gas according to claim 3, characterized in that, The specific process of step (2) is as follows: (a) First layer meltblown: Pure PPS resin is meltblown. The meltblown process parameters are: feeding section 290-300℃, melting section 305-315℃, homogenization section 310-320℃, die head connection section 315-325℃, die head temperature 320-325℃, hot air temperature 320-330℃, metering pump flow rate 10L / h, receiving distance 25 cm. The resulting product has a quantitative density of 50 g / m³. 2 Pure PPS meltblown fiber mesh; (b) Second layer meltblowing: The catalyst and carrier / PPS masterbatch are mixed with pure PPS resin at a mass ratio of 1:3 and then meltblown. The meltblowing process parameters are: feeding section 290-300℃, melting section 305-315℃, homogenization section 310-320℃, die head connection section 315-325℃, die head temperature 320-325℃, hot air temperature 320-330℃, metering pump flow rate 20-40 L / h, receiving distance 25cm, resulting in a quantitative yield of 90-110 g / m³. 2 The PPS meltblown fiber web is loaded with a main catalyst and a support.

7. The method for preparing the integrated PPS meltblown fabric filter material for high-temperature flue gas according to claim 3, characterized in that, The specific process of step (3) is as follows: the PPS meltblown fiber mesh loaded with the main catalyst and the carrier is placed in a chemical vapor deposition reactor, chemical vapor deposition is performed on the surface of the second meltblown fiber layer, precursor vapors of VO(OC3H7)3 and W(CO)6 are introduced, and the reaction is carried out at 250°C and nitrogen atmosphere for 20-40 min, and then calcined at 320°C for 1 h in air atmosphere.

8. The method for preparing the integrated PPS meltblown fabric filter material for high-temperature flue gas according to claim 7, characterized in that, During the reaction in a nitrogen atmosphere, nitrogen replacement is performed first, followed by the introduction of a vapor stream for chemical vapor deposition. The vapor stream consists of carrier gas nitrogen, precursor vapor, and reactant gas oxygen. The precursor vapor includes VO(OC3H7)3 and W(CO)6. The precursor vapor has an atomic molar ratio of V to W of 1:30 and a vapor temperature of 100-120℃. During the reaction in a nitrogen atmosphere, the vapor stream of the chemical vapor deposition comprises 95% nitrogen, 4.5% precursor vapor, and 0.5% oxygen by volumetric flow rate.

9. The method for preparing the integrated PPS meltblown fabric filter material for high-temperature flue gas according to claim 3, characterized in that, The specific process of step (4) is as follows: the first layer of pure PPS meltblown fiber web and the obtained PPS meltblown fiber web loaded with catalyst after vapor deposition are hot rolled using a web forming hot rolling device, with a roll surface temperature of 110℃ and a roll pressure of 4 kN / m, to obtain a double-layer composite PPS meltblown filter material.

10. The method for preparing the integrated PPS meltblown fabric filter material for high-temperature flue gas according to any one of claims 3-9, characterized in that, In step (5), the double-layer composite PPS meltblown filter material obtained in step (4) is subjected to electrostatic electret treatment at a voltage of 40-50 kV for 30 s; the melt flow rate of the PPS resin powder is 300-500 g / 10 min; the total basis weight of the resulting PPS meltblown fabric-based integrated filter material is 150-170 g / m³. 2 .

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