Filter bag loaded with denitration catalyst and preparation method of filter bag

Abstract

The invention relates to the field of filter materials, and discloses a denitration catalyst-loaded filter bag and a preparation method thereof, the filter bag comprises interface modifier impregnated modified polytetrafluoroethylene fiber and a catalytic additive loaded on the modified polytetrafluoroethylene fiber, the interface modifier is prepared by carrying out hydrolysis-polycondensation on ethyl orthosilicate, perfluorooctyl ethyl trimethoxy silane, trimethyl borate and 3-(2, 3-epoxypropoxy) propyl trimethoxy silane, and the interface modifier is prepared by carrying out hydrolysis-polycondensation on ethyl orthosilicate, perfluorooctyl ethyl trimethoxy silane, trimethyl borate and 3-(2, 3-epoxypropoxy) propyl trimethoxy silane; the catalytic additive is prepared by using polyether PluronicF127, 1, 3, 5-trimethylbenzene and dopamine as raw materials through emulsion-induced interface assembly and externally introducing mesoporous silica to prepare a hollow spherical catalyst carrier, then loading cerium and manganese precursors onto the surface of the hollow spherical catalyst carrier, and coating with a titanium dioxide shell layer. The filter bag prepared by the invention has good denitration activity, sulfur resistance, water resistance, hydrophobicity and friction resistance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of filter materials, and particularly relates to a filter bag loaded with a denitration catalyst and a preparation method thereof. BACKGROUND

[0002] Industrial exhaust gas contains solid particles and toxic gas components, which not only destroy the ecological environment, but also seriously affect human health. The filter bag dust collector is currently recognized as one of the most effective technical equipment in treating the tail gas of a power plant. The polytetrafluoroethylene filter material has excellent properties such as high temperature resistance, acid and alkali resistance, hydrolysis resistance, and high flame resistance, and thus becomes the first choice for a coal-fired boiler and a waste incinerator filter bag. However, the polytetrafluoroethylene filter material has poor wear resistance. The denitration functional filter material refers to a filter material loaded with a denitration catalyst on the surface of the filter material fiber, so as to have the dual functions of dust removal and denitration.

[0003] NOx is an atmospheric pollutant that directly threatens the ecological environment and human health, and mainly comes from the fuel combustion process in fixed sources such as coal-fired power plants, coking plants, and industrial boilers. The ammonia selective catalytic reduction method is the most widely used NOx removal technology in industry, and the catalyst is the core of the technology. The V-Ti catalyst is the mainstream commercial catalyst in coal-fired power plants at home and abroad, and exhibits excellent denitration performance at medium and high temperatures (> 300 ℃). However, the traditional V-Ti catalyst has poor low-temperature activity, a narrow effective temperature window, and certain environmental toxicity, which limits its further development. The manganese-based catalyst has attracted widespread attention due to its strong low-temperature activity and rich valence state changes of Mn metal. However, the manganese-based catalyst with a single active component has poor stability and resistance to water and SO2. SUMMARY

[0004] To solve the problems mentioned in the background, the present application aims to provide a filter bag loaded with a denitration catalyst and a preparation method thereof. The prepared filter bag has good NOx catalytic removal performance, can maintain a NOx conversion rate of more than 85% and a N2 yield at 180-220 ℃, and has good water and sulfur resistance, hydrophobicity, and wear resistance.

[0005] The object of the present application can be achieved by the following technical solutions. A filter bag loaded with a denitration catalyst, comprising modified polytetrafluoroethylene fibers and a catalytic additive loaded on the modified polytetrafluoroethylene fibers, wherein the modified polytetrafluoroethylene fibers are prepared by immersing polytetrafluoroethylene fibers in an interfacial modifier and then taking them out and drying, and the interfacial modifier is prepared by hydrolysis-polycondensation reaction using tetraethyl orthosilicate, perfluorooctyl ethyl trimethoxysilane, trimethyl borate, and 3-(2,3-epoxypropoxy) propyl trimethoxysilane as raw materials. The catalytic additive is a hollow spherical catalyst carrier prepared by emulsion-induced interface assembly using polyether Pluronic F127 as a template agent, 1,3,5-trimethylbenzene as a pore swelling and interface modifier, dopamine as a carbon source and nitrogen source, and further using a sol-gel method by externally introducing mesoporous silica to prepare the hollow spherical catalyst carrier, and then precursors of cerium and manganese are loaded on the surface of the hollow spherical catalyst carrier and a titanium dioxide shell layer is prepared by a coprecipitation method.

[0006] Preferably, the preparation method of the interface modifier comprises the following steps: mixing deionized water, hydrochloric acid and isopropanol uniformly to obtain solution one, heating isopropanol, tetraethyl orthosilicate, perfluorooctyl ethyl trimethoxysilane, trimethyl borate and 3-(2,3-epoxypropoxy) propyl trimethoxysilane to 50-60°C and keeping constant temperature to obtain solution two, then slowly adding solution one into solution two within 1h, increasing the temperature to 75-85°C after the addition is completed, refluxing for 20-24h, decreasing the temperature to 45-55°C after the reaction is completed, adding sodium bicarbonate and stirring for 0.5-1h, and finally filtering to obtain the interface modifier.

[0007] Preferably, the molar ratio of the tetraethyl orthosilicate, perfluorooctyl ethyl trimethoxysilane, trimethyl borate and 3-(2,3-epoxypropoxy) propyl trimethoxysilane is 1.2-1.3:3.8-3.9:1-1.8:5-5.3.

[0008] Preferably, the preparation method of the catalytic additive comprises the following steps: (1) dispersing polyether F127 and hydrochloric acid dopamine in a reactor containing a mixed solution of anhydrous ethanol and distilled water, adding 1,3,5-trimethylbenzene and uniformly dispersing under ultrasonic at room temperature, placing the solution at 30-35°C after ultrasonic to form a uniform emulsion, adding concentrated ammonia water drop by drop and continuing to stir for 7-9h, then adding cetyltrimethylammonium bromide and stirring for 20-30min, then adding tetraethyl orthosilicate and continuously stirring for 4-4.5h, centrifuging, washing and drying the solid after the reaction, grinding the dried solid, placing it in a tube furnace in a nitrogen atmosphere for high-temperature calcination to prepare a hollow spherical catalyst carrier; (2) dispersing the hollow spherical catalyst carrier in anhydrous ethanol, adding cerium nitrate hexahydrate and manganese acetate tetrahydrate and stirring to mix uniformly, then magnetically stirring at room temperature for 3.5-4.5h, then removing ethanol by rotary evaporation, grinding the dried solid, ultrasonically dispersing it in anhydrous ethanol to obtain a suspension, and placing it in a water bath at 55-65°C and stirring, slowly adding ammonia water and titania sulfate solution into the suspension simultaneously until the pH value is 9-11, filtering, washing and drying the solid after the reaction, grinding the dried solid, and placing it in a tube furnace in a hydrogen-argon mixed gas atmosphere for high-temperature reduction to prepare the catalytic additive.

[0009] Preferably, the addition ratio of polyether F127, dopamine hydrochloride, anhydrous ethanol, distilled water, 1,3,5-trimethylbenzene, concentrated ammonia, cetyltrimethylammonium bromide and tetraethyl orthosilicate in step (1) is 0.1 g:0.12 g:5 mL:5 mL:0.1 mL:0.08 mL:0.1 g:0.6 mL.

[0010] Preferably, the high-temperature calcination in step (1) is set as follows: the temperature is raised to 520-550 DEG C at a temperature raising rate of 2-4 DEG C / min, and maintained for 2-3 h to remove the template agent, and then the temperature is further raised to 820-850 DEG C at a temperature raising rate of 2-4 DEG C / min, and maintained for 2-3 h.

[0011] Preferably, the concentration of the titanyl sulfate solution in step (2) is 0.1-0.4 mol / L; and the addition ratio of the hollow spherical catalyst carrier, cerium nitrate hexahydrate, manganese acetate tetrahydrate and the titanyl sulfate solution is 0.1 g:15-16 mg:48-49 mg:1-1.5 mL.

[0012] Preferably, the volume fraction of hydrogen in the hydrogen-argon mixed gas atmosphere in step (2) is 15%, and the volume fraction of argon is 85%; and the high-temperature reduction is set as follows: the temperature is raised to 520-550 DEG C at a temperature raising rate of 2-3 DEG C / min, and maintained for 4-5 h.

[0013] The preparation method of the filter bag loaded with the denitration catalyst as described above comprises the following steps: S1, dispersing the catalytic additive in the aqueous acrylic resin, then adding the PTFE emulsion binder, and mechanically stirring for 30-40 min to form a well-dispersed mixed solution; S2, depositing the mixed solution containing the catalytic additive on the cut modified polytetrafluoroethylene fiber by the impregnation-calendering method, 1 impregnation-1 calendering, then setting at 175-190 DEG C for 2-3 min, and curing at 230-250 DEG C for 2-3 min to prepare the filter bag loaded with the denitration catalyst.

[0014] The beneficial effects of the present application are as follows: The application utilizes tetraethyl orthosilicate, perfluorooctyl ethyl trimethoxysilane, trimethyl borate and 3-(2,3-epoxypropoxy) propyl trimethoxysilane as raw materials to generate hydrolysis-polycondensation reaction, to prepare an interface modifier, then the interface modifier is used to impregnate polytetrafluoroethylene fibers to prepare modified polytetrafluoroethylene fibers, wherein 3-(2,3-epoxypropoxy) propyl trimethoxysilane is a reactive main chain to ensure the bonding force with the polytetrafluoroethylene fibers, perfluorooctyl ethyl trimethoxysilane is a core functional group to provide super-hydrophobic performance, tetraethyl orthosilicate and trimethyl borate are auxiliary adjusting agents to optimize mechanical properties and thermal properties, and tetraethyl orthosilicate and trimethyl borate form a hard Si-O-Si and B-O-Si inorganic network to interweave with organic components into a dense hybrid coating, which significantly improves the wear resistance of the polytetrafluoroethylene fibers, and the epoxy groups introduced in the interface modifier can form covalent bond with the subsequent loaded catalytic additives, so that the catalytic additives can be firmly and durably loaded on the modified polytetrafluoroethylene fibers, avoiding the falling off of the catalytic additives in the process of airflow scouring and pulse ash removal, greatly prolonging the service life of the filter bag.

[0015] The application utilizes polyether Pluronic F127 as a template agent, 1,3,5-trimethylbenzene as a pore swelling and interface adjusting agent, and dopamine as a carbon source and nitrogen source to synthesize polydopamine balls, and further utilizes a sol-gel method to prepare a hollow spherical catalyst carrier with a larger pore size and a higher nitrogen content by externally introducing mesoporous silica, the larger pore size makes mass transfer more convenient, and the high nitrogen content promotes more dispersed active component metal nanoparticles, manganese and cerium ions are fixed through metal-nitrogen coordination to prevent migration and agglomeration, thereby achieving high dispersion at a nanoscale, then the precursors of cerium and manganese are loaded on the large surface of the hollow spherical catalyst carrier, and a catalytic additive coated with a titanium dioxide shell is prepared by a coprecipitation method, the B acid sites and the rich L acid sites formed by the titanium dioxide shell increase the adsorption and activation of ammonia, the high-valence active component manganese ions and the high proportion of manganese ions and cerium ions ensure the activation rate of ammonia and nitric oxide, improve the low-temperature oxidation-reduction cycle efficiency of the catalyst, and inhibit the deep oxidation of sulfur dioxide, so that the catalytic additive exhibits excellent denitration activity and good sulfur and water resistance in a wide temperature range. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the application.

[0017] The preparation method of the interface modifier of Example 1 comprises the following steps: uniformly mixing 28 mL of deionized water, 10 g of hydrochloric acid and 100 g of isopropyl alcohol to obtain solution one, heating 53 g of isopropyl alcohol, 7.5 g of tetraethyl orthosilicate, 62.5 g of perfluorooctyl ethyl trimethoxysilane, 4.2 g of trimethyl borate and 35.4 g of 3-(2,3-epoxypropoxy) propyl trimethoxysilane to 55°C and keeping constant temperature to obtain solution two, then slowly adding solution one into solution two within 1 h, increasing the temperature to 80°C after the addition is completed, refluxing for 24 h, decreasing the temperature to 50°C after the reaction is completed, adding 23 g of sodium bicarbonate and stirring for 1 h, and finally filtering to obtain the interface modifier.

[0018] The preparation method of the catalytic additive of Example 2 comprises the following steps: (1) dispersing 0.1 g of polyether F127 and 0.12 g of dopamine hydrochloride in a reactor containing 5 mL of anhydrous ethanol and 5 mL of distilled water mixed solution, adding 0.1 mL of 1,3,5-trimethylbenzene and then uniformly dispersing under ultrasonic at room temperature, placing the solution at 30°C after the ultrasonic is completed to form a uniform emulsion, adding 0.08 mL of concentrated ammonia water drop by drop and continuing to stir for 8 h, then adding 0.1 g of cetyltrimethylammonium bromide and stirring for 25 min, adding 0.6 mL of tetraethyl orthosilicate and continuously stirring for 4 h, centrifuging, washing and drying the solid after the reaction is completed, grinding the dried solid, placing it in a tube furnace in a nitrogen atmosphere and calcining at a temperature increasing rate of 3°C / min to 550°C and keeping for 2 h to remove the template, further increasing the temperature to 850°C at a temperature increasing rate of 3°C / min and keeping for 2 h to obtain a hollow spherical catalyst carrier; (2) dispersing 0.1 g of the hollow spherical catalyst carrier in 25 mL of anhydrous ethanol, adding 15.3 mg of cerium nitrate hexahydrate and 48.3 mg of manganese acetate tetrahydrate and stirring to mix uniformly, then magnetically stirring at room temperature for 4 h, removing the ethanol by rotary evaporation, grinding the dried solid, ultrasonically dispersing it in anhydrous ethanol to obtain a suspension and placing it in a water bath at 60°C and stirring, slowly adding ammonia water and 1.3 mL of titania sulfate solution with a concentration of 0.2 mol / L to the suspension until the pH value is 10, filtering, washing and drying the solid after the reaction is completed, grinding the dried solid, placing it in a tube furnace in a hydrogen (15%) -argon (85%) mixed gas atmosphere and reducing at a temperature increasing rate of 2°C / min to 550°C and keeping for 4 h to obtain a catalytic additive.

[0019] The preparation method of the catalytic additive of Example 3 comprises the following steps: (1) 0.1 g of polyether F127 and 0.12 g of dopamine hydrochloride were dispersed in a reactor containing a mixture of 5 mL of anhydrous ethanol and 5 mL of distilled water, 0.1 mL of 1,3,5-trimethylbenzene was added, and then ultrasonic dispersion was performed at room temperature until uniformity was achieved. After the ultrasonic dispersion was completed, the solution was stirred at 30°C to form a uniform emulsion, 0.08 mL of concentrated ammonia was added dropwise, and stirring was continued for 8 h. Then, 0.1 g of cetyltrimethylammonium bromide was added and stirred for 25 min, and then 0.6 mL of tetraethyl orthosilicate was added, and stirring was continued for 4 h. After the reaction was completed, centrifugation, washing, and drying were performed, the dried solid was ground, and then placed in a tube furnace in a nitrogen atmosphere for high-temperature calcination. The temperature was increased to 520°C at a rate of 2°C / min, and maintained for 2 h to remove the template, and then further increased to 820°C at a rate of 2°C / min, and maintained for 2 h, thereby preparing a hollow spherical catalyst carrier; (2) 0.1 g of the hollow spherical catalyst carrier was dispersed in 25 mL of anhydrous ethanol, 15.6 mg of cerium nitrate hexahydrate and 48.5 mg of manganese acetate tetrahydrate were added, and stirred until uniformity was achieved. Then, magnetic stirring was performed at room temperature for 4 h, and then the ethanol was removed by rotary evaporation. The dried solid was ground and ultrasonically dispersed in anhydrous ethanol to obtain a suspension, and then placed in a water bath at 60°C and stirred. Ammonia and 1.5 mL of a titania sulfate solution having a concentration of 0.1 mol / L were simultaneously and slowly added to the suspension until the pH value was 10. After the reaction was completed, filtration, washing, and drying were performed, the dried solid was ground, and then placed in a tube furnace in a hydrogen (15%) -argon (85%) mixed gas atmosphere for high-temperature reduction. The temperature was increased to 520°C at a rate of 2°C / min, and maintained for 5 h, thereby preparing a catalytic additive.

[0020] Example 4 A method for preparing a catalytic additive includes the following steps: (1) 0.1 g of polyether F127 and 0.12 g of dopamine hydrochloride were dispersed in a reactor containing a mixture of 5 mL of anhydrous ethanol and 5 mL of distilled water, 0.1 mL of 1,3,5-trimethylbenzene was added, and then ultrasonic dispersion was performed at room temperature until uniformity was achieved. After the ultrasonic dispersion was completed, the solution was stirred at 30°C to form a uniform emulsion, 0.08 mL of concentrated ammonia was added dropwise, and stirring was continued for 8 h. Then, 0.1 g of cetyltrimethylammonium bromide was added and stirred for 25 min, and then 0.6 mL of tetraethyl orthosilicate was added, and stirring was continued for 4 h. After the reaction was completed, centrifugation, washing, and drying were performed, the dried solid was ground, and then placed in a tube furnace in a nitrogen atmosphere for high-temperature calcination. The temperature was increased to 520°C at a rate of 2°C / min, and maintained for 2 h to remove the template, and then further increased to 820°C at a rate of 2°C / min, and maintained for 2 h, thereby preparing a hollow spherical catalyst carrier; (2) Take 0.1 g of hollow spherical catalyst carrier and disperse it in 25 mL of anhydrous ethanol, add 16 mg of cerium nitrate hexahydrate and 49 mg of manganese acetate tetrahydrate, stir and mix uniformly, then magnetically stir at room temperature for 4 h, then remove the ethanol by rotary evaporation, disperse the dried solid in anhydrous ethanol by grinding and ultrasonic dispersion, obtain a suspension, and place it in a 60°C water bath for stirring, slowly add ammonia water and 1.5 mL of titania sulfate solution with a concentration of 0.3 mol / L to the suspension at the same time until the pH value is 10, after the reaction is completed, filter, wash and dry, grind the dried solid, and place it in a hydrogen (15%) - argon (85%) mixed gas atmosphere tube furnace for high temperature reduction, increase the temperature to 540°C at a rate of 3°C / min and maintain for 5 h, to prepare the catalytic additive.

[0021] Example 5 A preparation method of a filter bag loaded with a denitration catalyst, comprising the following steps: S1, disperse 10 g of the catalytic additive prepared in Example 2 in 20 g of an aqueous acrylic resin, then add 30 g of a PTFE emulsion binder (solid content 18%), mechanically stir for 35 min to form a well-dispersed mixture; immerse the polytetrafluoroethylene fiber in the interfacial modifier prepared in Example 1 and dry to obtain modified polytetrafluoroethylene fiber; S2, deposit the mixture containing the catalytic additive on the cut modified polytetrafluoroethylene fiber by the impregnation and rolling method, 1 rolling after 1 impregnation, then 180°C setting for 2 min, 240°C curing for 3 min, to prepare the filter bag loaded with the denitration catalyst.

[0022] Example 6 A preparation method of a filter bag loaded with a denitration catalyst, compared with Example 5, the catalytic additive prepared in Example 2 is replaced by an equal amount of the catalytic additive prepared in Example 3, and the preparation method of the remaining components is the same as that of Example 5.

[0023] Example 7 A preparation method of a filter bag loaded with a denitration catalyst, compared with Example 5, the catalytic additive prepared in Example 2 is replaced by an equal amount of the catalytic additive prepared in Example 4, and the preparation method of the remaining components is the same as that of Example 5.

[0024] Comparative Example 1 A preparation method of a catalytic additive, comprising the following steps: (1) 0.1 g of polyether F127 and 0.12 g of dopamine hydrochloride were taken and dispersed in a reactor containing a mixture of 5 mL of anhydrous ethanol and 5 mL of distilled water, 0.1 mL of 1,3,5-trimethylbenzene was added and ultrasonic dispersion was carried out uniformly at room temperature, after ultrasonic dispersion, the solution was placed in a 30°C water bath and stirred to form a uniform emulsion, 0.08 mL of concentrated ammonia was then added dropwise and stirred for 8 h, then 0.1 g of cetyltrimethylammonium bromide was added and stirred for 25 min, and then 0.6 mL of tetraethyl orthosilicate was added, and the stirring was continued for 4 h, after the reaction was completed, the solid was centrifuged, washed and dried, the dried solid was ground and placed in a tube furnace in a nitrogen atmosphere, and heated to 550°C at a heating rate of 3°C / min, and kept for 2 h to remove the template, and then heated to 850°C at a heating rate of 3°C / min, and kept for 2 h, to obtain a hollow spherical catalyst carrier; (2) 0.1 g of the hollow spherical catalyst carrier was taken and dispersed in 25 mL of anhydrous ethanol, 15.3 mg of cerium nitrate hexahydrate and 48.3 mg of manganese acetate tetrahydrate were added and stirred to mix uniformly, and then magnetic stirring was carried out at room temperature for 4 h, then the ethanol was removed by rotary evaporation, the dried solid was ground and placed in a tube furnace in a hydrogen (15%) -argon (85%) mixed gas atmosphere, and heated to 550°C at a heating rate of 2°C / min, and kept for 4 h, to obtain a catalytic additive.

[0025] The preparation method of the catalytic additive of Comparative Example 2 comprises the following steps: 15.3 mg of cerium nitrate hexahydrate, 48.3 mg of manganese acetate tetrahydrate and 25 mL of deionized water were taken and stirred to mix uniformly, ammonia was added dropwise until the pH value was 10, and then water bath heating and stirring were carried out, and after aging, the mixture was filtered, washed and dried, the dried solid was ground and ultrasonically dispersed in anhydrous ethanol to obtain a suspension, and the suspension was placed in a 60°C water bath and stirred, ammonia and 1.3 mL of a titanium sulfate solution with a concentration of 0.2 mol / L were simultaneously and slowly added dropwise to the suspension until the pH value was 10, after the reaction was completed, the mixture was filtered, washed and dried, the dried solid was ground and placed in a tube furnace in a hydrogen (15%) -argon (85%) mixed gas atmosphere, and heated to 550°C at a heating rate of 2°C / min, and kept for 4 h, to obtain a catalytic additive.

[0026] The preparation method of the filter bag loaded with the denitration catalyst of Comparative Example 3 is similar to that of Example 5, except that the catalytic additive prepared in Example 2 is replaced by an equal amount of the catalytic additive prepared in Comparative Example 1.

[0027] The preparation method of the filter bag loaded with the denitration catalyst of Comparative Example 4 is similar to that of Example 5, except that the catalytic additive prepared in Example 2 is replaced by an equal amount of the catalytic additive prepared in Comparative Example 2.

[0028] Comparative Example 5 Preparation of a filter bag loaded with a denitration catalyst, compared with Example 5, the modified polytetrafluoroethylene fiber in step S2 is replaced with polytetrafluoroethylene fiber in equal amount, and the modified polytetrafluoroethylene fiber is not impregnated with the interfacial modifier, and the preparation method of the remaining components is the same as that of Example 5.

[0029] Performance detection The filter bags prepared in Examples 5-7 and Comparative Examples 3-5 were subjected to performance detection. (1) Water contact angle: the static water contact angle of the sample was measured by a DSA30 type contact angle measuring instrument, and the detection results are shown in Table 1.

[0030] (2) Abrasion resistance: according to the GB 3960-83 standard, the friction and wear properties of the sample were determined on a MM-200 type friction and wear tester, and the detection results are shown in Table 1.

[0031] (3) Denitration performance: NH3-SCR performance test was carried out under the conditions of 8% O2, 1000 ppm NH3, 1000 ppm NO, and gas velocity 0.8 m / min, and the detection results are shown in Table 1.

[0032] (4) Water and sulfur resistance: the nitrogen oxide conversion rate of the catalytic filter material was determined at 200°C for 6h by introducing 200ppm of SO2 and 10% of H2O into the reaction gas, and the detection results are shown in Table 1.

[0033] Table 1 Performance detection results of samples

[0034] As can be seen from the data in Table 1, the filter bags prepared in Examples 5-7 have good NOx catalytic removal performance, and can maintain a NOx conversion rate of more than 85% and a N2 yield at 180-220°C, and also have good water and sulfur resistance, hydrophobicity and abrasion resistance. The catalytic additive added in Comparative Example 3 does not form a titanium dioxide shell layer, and the catalytic additive added in Comparative Example 4 does not introduce a hollow spherical catalyst carrier, and the measured NOx conversion rate and N2 yield, water and sulfur resistance of Comparative Examples 3-4 are lower than those of Examples 5-7, which shows that the catalytic additive formed by the titanium dioxide shell layer and the hollow spherical catalyst carrier can synergistically improve the denitration activity and sulfur and water resistance of the material. The modified polytetrafluoroethylene fiber in Comparative Example 5 is not impregnated with the interfacial modifier, and the measured water contact angle and abrasion resistance grade are lower than those of Examples 5-7, which shows that the introduction of the interfacial modifier is beneficial to improving the hydrophobicity and abrasion resistance of the material.

[0035] In the description of the specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0036] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A filter bag loaded with a de-NOx catalyst, characterized by, The catalytic additive is prepared by emulsion-induced interface assembly using polyether Pluronic F127 as a template agent, 1,3,5-trimethylbenzene as a pore swelling and interface adjusting agent, and dopamine as a carbon source and nitrogen source to synthesize polydopamine balls, and then a hollow spherical catalyst carrier is prepared by further introducing mesoporous silica outside through a sol-gel method, and then a precursor of cerium and manganese is loaded on the surface of the hollow spherical catalyst carrier and a titanium dioxide shell layer is coated by a coprecipitation method. The preparation method of the interface modifier comprises the following steps: mixing deionized water, hydrochloric acid and isopropanol uniformly to obtain solution one, heating isopropanol, tetraethyl orthosilicate, perfluorooctyl ethyl trimethoxysilane, trimethyl borate and 3-(2,3-epoxypropoxy) propyl trimethoxysilane to 50-60 DEG C and keeping constant temperature to obtain solution two, then slowly drop solution one into solution two within 1h, after drop completion, temperature is raised to 75-85 DEG C, reflux reaction is carried out for 20-24h, after reaction completion, temperature is lowered to 45-55 DEG C, sodium bicarbonate is added and stirred for 0.5-1h, finally, the interface modifier is prepared by filtration.

2. The load de-NOx catalyst-equipped filter bag according to claim 1, characterized by, The molar ratio of the tetraethyl orthosilicate, perfluorooctyl ethyl trimethoxysilane, trimethyl borate and 3-(2,3-epoxypropoxy) propyl trimethoxysilane is 1.2-1.3:3.8-3.9:1-1.8:5-5.

3.

3. The load deNOx catalysted filter bag of claim 2, wherein, The preparation method of the catalytic additive comprises the following steps:

4. The load de-NOx catalysted filter bag of claim 1, wherein, (1) polyether F127 and hydrochloric acid dopamine are dispersed in a reactor containing a mixed solution of anhydrous ethanol and distilled water, 1,3,5-trimethylbenzene is added, and then ultrasonic dispersion is carried out uniformly at room temperature, after ultrasonic dispersion, the solution is stirred at 30-35 DEG C to form a uniform emulsion, concentrated ammonia is added drop by drop and stirred for 7-9h, then cetyltrimethylammonium bromide is added and stirred for 20-30min, then tetraethyl orthosilicate is added, and continuous stirring is carried out for 4-4.5h, after reaction completion, centrifugation, washing and drying are carried out, the dried solid is ground and placed in a nitrogen atmosphere tube furnace for high temperature calcination to prepare a hollow spherical catalyst carrier; ​ (2) The hollow spherical catalyst carrier is dispersed in anhydrous ethanol, and cerium nitrate hexahydrate and manganese acetate tetrahydrate are added and stirred to mix uniformly, and then magnetic stirring is carried out at room temperature for 3.5-4.5 h, and then the ethanol is removed by rotary evaporation, and the dried solid is ground and dispersed in anhydrous ethanol by ultrasonic dispersion to obtain a suspension, and the suspension is stirred in a water bath at 55-65 ℃, and ammonia water and titania sulfate solution are simultaneously and slowly added to the suspension until the pH value is 9-11, and after the reaction is completed, the solid is filtered, washed and dried, and then the dried solid is ground and placed in a tube furnace in a hydrogen-argon mixed gas atmosphere for high-temperature reduction to prepare the catalytic additive.

5. The load deNOx catalysted filter bag of claim 4, wherein, The addition ratio of polyether F127, dopamine hydrochloride, anhydrous ethanol, distilled water, 1,3,5-trimethylbenzene, concentrated ammonia water, cetyltrimethylammonium bromide and tetraethyl orthosilicate in step (1) is 0.1 g:0.12 g:5 mL:5 mL:0.1 mL:0.08 mL:0.1 g:0.6 mL.

6. The load deNOx catalysted filter bag of claim 4, wherein, The high-temperature calcination conditions in step (1) are set as follows: the temperature is raised to 520-550 ℃ at a rate of 2-4 ℃ / min, and maintained for 2-3 h to remove the template agent, and then the temperature is further raised to 820-850 ℃ at a rate of 2-4 ℃ / min, and maintained for 2-3 h.

7. The load deNOx catalysted filter bag of claim 4, wherein, The concentration of the titania sulfate solution in step (2) is 0.1-0.4 mol / L; and the addition ratio of the hollow spherical catalyst carrier, cerium nitrate hexahydrate, manganese acetate tetrahydrate and titania sulfate solution is 0.1 g:15-16 mg:48-49 mg:1-1.5 mL.

8. The load deNOx catalysted filter bag of claim 4, wherein, The volume fraction of hydrogen in the hydrogen-argon mixed gas atmosphere in step (2) is 15%, and the volume fraction of argon is 85%; and the high-temperature reduction conditions are set as follows: the temperature is raised to 520-550 ℃ at a rate of 2-3 ℃ / min, and maintained for 4-5 h.

9. The method of producing a filter bag loaded with a denitration catalyst according to any one of claims 1 to 8, characterized by, The following steps are included: S1, disperse the catalytic additive in the aqueous acrylic resin, then add the PTFE emulsion binder, mechanically stir for 30-40 min to form a well-dispersed mixture; S2, deposit the mixture containing the catalytic additive on the cut modified polytetrafluoroethylene fiber by the impregnation and rolling method, roll once after 1-time impregnation, then set at 175-190 ℃ for 2-3 min, and cure at 230-250 ℃ for 2-3 min to prepare the filter bag loaded with the denitration catalyst.

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