A catalytic filter bag for removing dioxin at medium and low temperature and a preparation method and application thereof

Abstract

The application discloses a kind of low-temperature denitration removal dioxin catalytic filter bag and its preparation method and application, belong to waste incineration flue gas purification technical field.The method is mixed after catalyst fine powder and adjuvant is ground to particle size 5~15 μm, after mixing, water and nitric acid solution are added and mixed again, to obtain matrix supported catalyst sol slurry;Matrix supported catalyst sol slurry is sprayed on the filter bag after pretreatment, then dry and calcination are sequentially carried out, and catalyst filter material can be obtained.The catalyst sol slurry formed by the application has stronger adhesion with filter bag matrix and higher loading rate;Automatic spraying technology is used, and the production efficiency of catalytic filter bag is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste incineration flue gas purification, and particularly relates to a medium-low temperature denitration and dioxin removal catalytic filter bag and a preparation method and application thereof. BACKGROUND

[0002] Waste incineration flue gas contains NO x , particulate matter, dioxin and other pollutants, which need different flue gas purification technology combinations for treatment, and there are problems such as complex system, high cost and the like. The use of flue gas multi-pollutant simultaneous removal technology to replace two or more removal technologies in the existing process can effectively simplify the process system and reduce the floor area, and reduce the pollutant removal cost. The catalytic filter bag prepared by loading the dust removal filter material with the SCR denitration and dioxin removal catalyst can realize the simultaneous and efficient removal of dust, NO x and dioxin multi-pollutants.

[0003] In the existing catalytic filter bag technology for dust removal, denitration and dioxin removal, there are mainly two categories. One is to load the vanadium-titanium type SCR catalyst on the filter bag material to realize denitration and dioxin removal, but this type of catalyst has a use temperature exceeding 250 DEG C, and the temperature is relatively high, and the requirements for the filter bag material or flue gas temperature are relatively high. The second is to modify or prepare a denitration catalyst with a relatively low operating temperature, and then load it on the filter bag material, such as the patent CN104998467A discloses a filter material, which is prepared by mixing the catalyst with PTFE fibers to prepare a filter material containing the catalyst, so as to realize the denitration and dioxin removal of flue gas. In the preparation method of the filter material with the functions of denitration and dioxin removal disclosed in the patent CN112717556A, the high-temperature denitration and dioxin removal catalyst nanoparticles are sprayed on each layer of the laid net in the net stacking process of the traditional needle punching filter material production process, so that the catalyst nanoparticles melt part of the fiber body after contacting the fiber by using the heat of the catalyst nanoparticles, and the part of the nanoparticles and the fiber body are fused together and have a certain binding force to form the nano-particle composite fiber, and then the needle punching, singeing, polishing and heat setting processes are performed to prepare the dust removal filter material with the functions of denitration and dioxin removal. The patent CN116585885A discloses a catalytic filter bag with the functions of denitration and dioxin removal and a preparation method thereof, which comprises, from the outside to the inside, a gas permeable membrane layer, a first catalyst composite layer, a second catalyst composite layer and a third catalyst composite layer. Each layer is loaded with different catalysts, such as the first catalyst V2O5-MoO3-CeO2 / TiO2, the second catalyst is a high-efficiency collaborative denitration and dioxin removal catalyst prepared by taking cerium dioxide and zirconium oxide as the carrier, taking chromium source, ruthenium source and cobalt source as the active precursor, and taking praseodymium source and molybdenum source as the precursor; and the third catalyst is a V2O5-PdO-Nb2O5 / TiO2 catalyst.

[0004] The main problems in the above patents are: 1. The denitration process uses amino reducing agents such as ammonia water or urea, which has the risk of generating ammonium sulfate (and or ammonium bisulfate) and NH3 escape; 2. The operating temperature is relatively high; 3. The preparation process of the catalyst and the catalytic filter bag is too complex and long; 4. The combination strength of the catalyst and the filter material is not high, and the denitration and dioxin removal efficiency is relatively low. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the present application provides a catalytic filter bag for low-temperature denitration and removal of dioxin and a preparation method and application thereof.

[0006] In order to achieve the above-mentioned purpose, the following technical solutions are adopted in the present application:

[0007] A preparation method of a catalytic filter bag for low-temperature denitration and removal of dioxin, the method comprising the following steps:

[0008] (1) Catalyst fine powder: composed of perovskite and ternary talc structure with a weight fraction ratio of 35-65:20-75;

[0009] The perovskite is of a general formula RE x Co y Mn z O3, wherein RE is at least one of La, Ce, Pr and Nd, x=0-0.5, z=0-0.6, y≤1-(x+z);

[0010] The ternary talc structure is CuO-NiO-ZrO2; further preferably, the mass ratio of CuO:NiO:ZrO2 in CuO-NiO-ZrO2 is 0.5-2:0.5-2:0.5-2;

[0011] (2) Catalytic filter material: the catalyst fine powder and the additive are mixed and ground to a particle size of 5-15 µm, then water and nitric acid solution are added and mixed again to obtain a base-loaded catalyst sol slurry;

[0012] (3) The base-loaded catalyst sol slurry is sprayed on the pretreated filter bag, and then drying and calcination are sequentially performed to obtain the catalyst filter material.

[0013] In the above preparation method, in step (1), the RE y Mn z O3 perovskite structure composition is prepared by adding a precursor of a metal salt into deionized water to dissolve, then adding citric acid and stirring at 60-90°C for 4-8h, and then baking the obtained sol at 120-150°C for 6-10h; finally, calcining in a muffle furnace at 580-680°C for 4-8h to obtain the RE yMn z O3 perovskite structure composition;

[0014] Preferably: RE x Co y Mn z In the preparation method of the O3 perovskite structure composition: the metal salt precursor of RE, the metal salt precursor of Co and the metal salt precursor of Mn; the molar ratio of citric acid to the total metal ions in the metal salt precursors is 1-2:1.

[0015] The preparation method of CuO-NiO-ZrO2 is to add an alcohol solvent in a dodecylamine aqueous solution and stir to form a microemulsion; copper nitrate, nickel nitrate and zirconium nitrate are added into the microemulsion, and after complete dissolution, ammonia water is added, the pH of the solution is adjusted to 8-10, then the solution is hydrothermally crystallized at 120-140℃ for 15-28 hours, and then the precipitate is centrifuged, washed, dried at 110-150℃ for 4-8 hours, calcined at 600-700℃ for 5-10 hours, and naturally cooled to room temperature to obtain the CuO-NiO-ZrO2 ternary talc-like structure composition;

[0016] Preferably, in the preparation method of CuO-NiO-ZrO2, the drying condition is 110-150℃ for 4-8 hours, and the calcination condition is 600-700℃ for 6-10 hours; the alcohol solvent is n-butanol, and the mass ratio of dodecylamine, water and n-butanol is 1-2:10-20:5-15.

[0017] In the above preparation method, the auxiliary agent in step (2) is a combination of SB powder and carboxymethyl cellulose or a combination of SB powder and Tianjing powder with a mass ratio of 5-15:0.1-5; the catalyst fine powder and the auxiliary agent are 1-5:1-5.

[0018] In the above preparation method, the auxiliary agent in step (2) is a combination of SB powder and carboxymethyl cellulose or a combination of SB powder and Tianjing powder with a mass ratio of 5-15:0.1-2; the catalyst fine powder and the auxiliary agent are 1-3:1-3.

[0019] In the above preparation method, the mass concentration of the matrix loaded catalyst sol slurry is 1-10%.

[0020] In the above preparation method, the drying temperature in step (3) is 105-115℃, and the drying time is 4-8 hours; the calcination temperature is 150-250℃, and the calcination time is 2-4 hours.

[0021] In the preparation method, the filter bag after the pretreatment in step (3) is pretreated by 10-30% nitric acid on the filter bag substrate to remove the impurities on the surface, the temperature is 40-50℃, the immersion treatment is 1-3 hours, then the filter bag is washed by deionized water and dried in a blast drying oven at 100-110℃ for 1-2 hours to obtain the filter bag substrate after the pretreatment.

[0022] The filter bag substrate is polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS) or polyacyl (P84).

[0023] A catalytic filter bag for removing dioxin by medium and low temperature denitration, which is prepared by the method. 2 。

[0024] The application of the catalytic filter bag for removing dioxin by medium and low temperature denitration prepared by the method in dust removal, denitration and dioxin removal. The application includes (1) methanol catalytic partial decomposition into a mixture of methanol, H2 and CO steam; (2) introducing the steam mixture into the dust-containing, NO x and dioxin waste incineration flue gas, removing the dust by the filter bag substrate, and converting NO x and dioxin into N2, H2O and HCl by the catalyst on the filter bag, so as to realize the dust removal, denitration and dioxin removal of the catalytic filter bag.

[0025] The application provides a catalytic filter bag for removing dioxin by medium and low temperature denitration and a preparation method and application thereof. The double-catalyst composition is used as a denitration and dioxin removal catalyst, has high denitration and dioxin efficiency at a lower temperature, completely eliminates the generation of ammonium sulfate (or ammonium bisulfate) and NH3 escape, CO is converted into CO2 during the denitration process and does not need special treatment, the ball milling technology is used to make the catalyst and the binder more uniformly mixed and the particle size smaller, the formed catalyst sol slurry has higher adhesion to the filter bag substrate and higher loading rate, and the automatic spraying technology is used to improve the production efficiency of the catalytic filter bag. DETAILED DESCRIPTION

[0026] The application will be further described by specific examples below, and all the examples are completely operated according to the steps described in the application. Example 1

[0027] (1) Treatment of the filter bag substrate

[0028] Polytetrafluoroethylene (PTFE) filter bag material is placed in a beaker, and a 20% (mass concentration) nitric acid solution is added. The filter bag is immersed at 45°C for 2 hours, then washed with deionized water, and placed in a forced air drying oven at 105°C for 2 hours to obtain a pretreated filter bag substrate.

[0029] (2) La 0.2 Co 0.4 Mn 0.4 Preparation of a LaCoMnO3 perovskite structure composition

[0030] 1) 36.2.3g of La(NO3)3.6H2O (98.5%), 48.4g of Co(NO3)2.6H2O (99.0%), and 42.3g of Mn(NO3)2.4H2O (97.5%) are weighed into a beaker, 300mL of deionized water is added, and stirring is performed to completely dissolve the components;

[0031] 2) 23.2g of citric acid monohydrate (mass percentage concentration ≥98.5) is weighed into the beaker, and stirring is performed at 60°C for 5 hours to obtain a sol;

[0032] 3) The beaker is placed in a 120°C oven and dried for 8 hours, and then calcined at 650°C for 6 hours. After natural cooling to room temperature, a La 0.2 Co 0.4 Mn 0.4 O3 perovskite structure composition of the present application is obtained.

[0033] (3) Preparation of a CuO-NiO-ZrO ternary talc-like composition

[0034] 1) 120.5g of dodecylamine is weighed into a three-necked flask, dissolved in 1500mL of deionized water, and stirring is started;

[0035] 2) 1000mL of n-butanol (mass percentage concentration ≥99.5) is weighed into the three-necked flask, and stirring is performed to completely dissolve the dodecylamine in the n-butanol to obtain a microemulsion liquid;

[0036] 3) 47.3g of Cu(NO3)2.6H2O (98.0%), 99.2g of Ni(NO3)2.6H2O (98.0%), and 39.1g of Zr(NO3)4.3H2O (98.5%) are weighed into the three-necked flask;

[0037] 4) After the solids are completely dissolved, an appropriate amount of ammonia water is added to adjust the pH value to 8.5, and the liquid is placed in a 5000ml reaction kettle;

[0038] 5) Put the reactor into the 120°C oven, hydrothermal crystallization reaction for 24 hours, centrifugalize the product, water washing twice, alcohol washing twice, 120°C drying for 6 hours, 620°C calcination for 8 hours, after natural cooling to room temperature, the CuO-NiO-ZrO ternary hydrotalcite-like composition (weight ratio CuO: NiO: ZrO2=0.5:1.0:0.5) of the application is obtained.

[0039] (4) Preparation of the slurry of the matrix-supported catalyst

[0040] Weigh 3.5g of La 0.2 Co 0.4 Mn 0.4 O3 perovskite composition, 6.5g of CuO-NiO-ZrO ternary hydrotalcite catalyst composition prepared in step (3), 8.5g of SB powder, 0.2g of carboxymethyl cellulose, grind and mix in the ball mill for 4 hours, grind and mix thoroughly, the particle size reaches 10µm; add 300g of deionized water in a 1000mL beaker, under stirring, add the above ground and mixed powder, then slowly drop 6.5g of 10% nitric acid, and ultrasonic homogenize for 8 hours, to obtain a slurry of the matrix-supported catalyst sol with a mass concentration of 5.75%.

[0041] (5) Preparation of the catalytic filter material

[0042] Use the automatic spraying machine to coat the catalyst slurry on the polytetrafluoroethylene (PTFE) filter bag matrix treated in step (1), dry at 110°C for 4 hours, repeat the spraying for 3 times, and calcine at 200°C for 4 hours, to obtain the catalytic filter material 1 of the application with a catalyst loading of 528g / m 2 . Example 2

[0043] (1) Treatment of the filter bag matrix

[0044] Put the polyphenylene sulfide (PPS) filter bag material in a beaker, add 20% (mass concentration) nitric acid solution, immerse and treat at 45°C for 2 hours, then wash with deionized water, and place in the air drying oven at 105°C for 2 hours of drying, to obtain the pretreated filter bag matrix.

[0045] (2) Preparation of Ce 0.3 Co 0.4 Mn 0.3 O3 perovskite structure composition

[0046] 1) Respectively, 50.8g Ce(NO3)3.6H2O (98.5%), 45.1g Co(NO3)2.6H2O (99.0%) and 29.6g Mn(NO3)2.4H2O (97.5%) were weighed into a beaker, 300mL deionized water was added, stirred, and completely dissolved;

[0047] 2) 106.6g of citric acid monohydrate (mass percentage concentration ≥98.5) was weighed into the above beaker, and stirred at 70°C for 5 hours to obtain a sol;

[0048] 3) The beaker was placed in a 130°C oven and dried for 7 hours, and then calcined at 660°C for 8 hours, and then naturally cooled to room temperature to obtain the Ce 0.3 Co 0.4 Mn 0.3 O3 perovskite structure composition of the application.

[0049] (3) Preparation of CuO-NiO-ZrO ternary talc-like composition

[0050] 1) 120.5g of dodecylamine was weighed and dissolved in 1500mL deionized water, and then added to a three-necked flask and stirred; 2) 1000mL of n-butanol (mass percentage concentration ≥99.5) was added to the above three-necked flask, and the dodecylamine was completely dissolved in the n-butanol to obtain a microemulsion liquid; 3) 54.1g Cu(NO3)2.6H2O (98.0%), 113.4g Ni(NO3)2.6H2O (98.0%) and 22.3g Zr(NO3)4.3H2O (98.5%) were respectively weighed and added to the three-necked flask; 4) After the solid was completely dissolved, the pH value was adjusted to 9.0 by adding an appropriate amount of ammonia water, and the liquid was placed in a 5000ml reaction kettle; 5) The reaction kettle was placed in a 110°C oven, and hydrothermal crystallization reaction was carried out for 24 hours, and then the product was centrifuged, washed twice with water, twice with alcohol, dried at 125°C for 4 hours, and calcined at 650°C for 7 hours, and then naturally cooled to room temperature to obtain the CuO-NiO-ZrO ternary talc-like composition (weight ratio CuO:NiO:ZrO2=1.0:2.0:0.5) of the application.

[0051] (4) Preparation of matrix-supported catalyst slurry

[0052] 4.5g of the Ce 0.3 Co 0.4 Mn 0.3O3 perovskite structure composition, 2.5 g of CuO-NiO-ZrO ternary hydrotalcite catalyst composition prepared in step (3), 6.5 g of SB powder, 0.2 g of carboxymethyl cellulose, are mixed and ground in a ball mill for 4 hours, and the ground mixture is fully mixed and ground to a particle size of 10 µm; 300 g of deionized water is added to a 1000 mL beaker, the above ground mixture powder is added under stirring, and then 5.5 g of 10% nitric acid is slowly added dropwise, and ultrasonic homogenization is performed for 8 hours to obtain a matrix loaded catalyst sol slurry with a mass concentration of 4.21%.

[0053] (5) Preparation of catalytic filter material

[0054] The catalyst slurry is coated on the polyphenylene sulfide (PPS) filter bag matrix treated in step (1) by using an automatic spraying machine, dried at 110°C for 5 hours, and the spraying is repeated 4 times, and then calcined at 180°C for 4 hours to obtain the catalytic filter material 2 of the application with a catalyst loading of 468 g / m 2 . Example 3

[0055] (1) Treatment of filter bag matrix

[0056] The polyacyl (P84) filter bag material is placed in a beaker, a 20% (mass concentration) nitric acid solution is added, and the material is immersed and treated at 45°C for 2 hours, then washed with deionized water, and placed in a forced air drying oven at 105°C for 2 hours to obtain the pretreated filter bag matrix.

[0057] (2) Preparation of Pr 0.5 Co 0.4 Mn 0.1 O3 perovskite structure composition

[0058] 1) 74.9 g of Pr(NO3)3.6H2O (98.5%), 37.4 g of Co(NO3)2.6H2O (99.0%), and 9.3 g of Mn(NO3)2.4H2O (97.5%) are weighed into a beaker, 300 mL of deionized water is added, and stirring is performed to completely dissolve them;

[0059] 2) 94.0 g of citric acid monohydrate (mass percentage concentration ≥98.5) is weighed into the above beaker, and stirring is performed at 80°C for 4 hours to obtain a sol;

[0060] 3) The beaker is placed in an oven at 140°C and dried for 9 hours, and then calcined at 680°C for 6 hours, and then naturally cooled to room temperature to obtain the Pr 0.5 Co 0.4 Mn 0.1 O3 perovskite structure composition of the application.

[0061] (3) Preparation of CuO-NiO-ZrO ternary hydrotalcite-like composition

[0062] 1) Weigh 120.5g of dodecylamine, dissolve it in 1500mL of deionized water, and add it to a three-necked flask, and start stirring; 2) Weigh 1000mL of n-butanol (mass percentage concentration ≥99.5), and add it to the above three-necked flask, and stir to make the dodecylamine completely dissolved in the n-butanol, to obtain a microemulsion liquid; 3) Respectively weigh 71.0g of Cu(NO3)2.6H2O (98.0%), 74.4g of Ni(NO3)2.6H2O (98.0%), and 39.1g of Zr(NO3)4.3H2O (98.5%) and add them to the three-necked flask; 4) After the solid is completely dissolved, add an appropriate amount of ammonia water to adjust the pH value to 9.5, and place the liquid in a 5000ml reaction kettle; 5) Place the reaction kettle in a 135°C oven, and hydrothermally crystallize for 20 hours, centrifuge the product, wash it with water twice, wash it with alcohol twice, dry it at 110°C for 8 hours, and calcine it at 680°C for 5 hours, and then naturally cool it to room temperature, to obtain the CuO-NiO-ZrO ternary hydrotalcite-like composition (weight ratio CuO:NiO:ZrO2=1.5:1.5:1.0) of the present application.

[0063] (4) Preparation of catalyst slurry loaded on the matrix

[0064] Weigh 1.5g of the Pr 0.5 Co 0.4 Mn 0.1 O3 perovskite structure composition, 1.5g of the CuO-NiO-ZrO ternary hydrotalcite-like catalyst composition prepared in step (3), 5.5g of SB powder, and 0.3g of carboxymethyl cellulose, and grind and mix them in a ball mill for 3 hours, fully mix and grind, and make the particle size reach 15µm; add 300g of deionized water into a 1000mL beaker, add the above ground and mixed powder under stirring, then slowly drop 3.5g of 10% nitric acid, and ultrasonically homogenize for 8 hours, to obtain a catalyst sol slurry loaded on the matrix with a mass concentration of 2.87%.

[0065] (5) Preparation of catalytic filter material

[0066] Use an automatic spraying machine to coat the catalyst slurry on the polyacyl (P84) filter bag matrix treated in step (1), dry it at 110°C for 5 hours, repeat the spraying for 5 times, and calcine it at 170°C for 4 hours, to obtain the catalytic filter material 3 of the present application with a catalyst loading of 502g / m 2 . Example 4

[0067] (1) Treatment of filter bag matrix

[0068] Polytetrafluoroethylene (PTFE) filter bag material is placed in a beaker, a 20% (mass concentration) nitric acid solution is added, and the material is immersed at 45°C for 2 hours. After washing with deionized water, the material is placed in a blast drying oven at 105°C for 2 hours to obtain a pretreated filter bag substrate.

[0069] (2) Nd 0.3 Co 0.3 Mn 0.4 Preparation of an O3 perovskite structure composition

[0070] 1) 50.3 g of Nd(NO3)3.6H2O (98.5%), 33.2 g of Co(NO3)2.6H2O (99.0%), and 41.6 g of Mn(NO3)2.4H2O (97.5%) are weighed into a beaker, 300 mL of deionized water is added, and stirring is performed to completely dissolve the materials;

[0071] 2) 107.7 g of citric acid monohydrate (mass percentage concentration ≥98.5%) is weighed into the beaker, and stirring is performed at 80°C for 6 hours to obtain a sol;

[0072] 3) The beaker is placed in a 150°C oven and dried for 6 hours, and then calcined at 580°C for 8 hours. After natural cooling to room temperature, the Nd 0.3 Co 0.3 Mn 0.4 O3 perovskite structure composition of the present application is obtained.

[0073] (3) Preparation of a CuO-NiO-ZrO ternary talc-like composition

[0074] 1) 120.5 g of dodecylamine is weighed into a three-necked flask, dissolved in 1500 mL of deionized water, and stirring is started; 2) 1000 mL of n-butanol (mass percentage concentration ≥99.5%) is added to the three-necked flask, and stirring is performed to completely dissolve the dodecylamine in the n-butanol to obtain a microemulsion liquid; 3) 108.2 g of Cu(NO3)2.6H2O (98.0%), 56.7 g of Ni(NO3)2.6H2O (98.0%), and 22.3 g of Zr(NO3)4.3H2O (98.5%) (weight ratio CuO:NiO:ZrO2=2.0:1.0:0.5) are weighed into the three-necked flask; 4) after the solids are completely dissolved, an appropriate amount of ammonia water is added to adjust the pH value to 9.5, and the liquid is placed in a 5000 mL reaction kettle; 5) the reaction kettle is placed in a 140°C oven, and hydrothermal crystallization is performed for 15 hours. The product is centrifuged, washed with water twice, washed with alcohol twice, dried at 130°C for 6 hours, calcined at 700°C for 10 hours, and then naturally cooled to room temperature to obtain the CuO-NiO-ZrO ternary talc-like composition of the present application.

[0075] (4) Preparation of matrix-supported catalyst slurry

[0076] Weigh 8.5 g of Nd 0.3 Co 0.3 Mn 0.4 O3 perovskite structure composition, 2.5 g of CuO-NiO-ZrO ternary hydrotalcite catalyst composition prepared in step (3), 12.5 g of SB powder, and 0.2 g of carboxymethyl cellulose are mixed and ground in a ball mill for 6 hours, and the mixture is ground to a particle size of 20 μm; 300 g of deionized water is added to a 1000 mL beaker, and the ground mixture powder is added under stirring, and then 10.5 g of 10% nitric acid is slowly added dropwise, and ultrasonic homogenization is performed for 8 hours to obtain a matrix-supported catalyst sol slurry with a mass concentration of 7.09%.

[0077] (5) Preparation of catalytic filter material

[0078] The catalyst slurry is coated on the polytetrafluoroethylene (PTFE) filter bag substrate treated in step (1) by using an automatic spraying machine, dried at 110°C for 6 hours, and the spraying is repeated 3 times, and then calcined at 210°C for 4 hours to obtain the catalytic filter material 4 of the present application with a catalyst loading of 573 g / m 2 . Example 5

[0079] (1) Treatment of filter bag substrate

[0080] The polytetrafluoroethylene (PTFE) filter bag material is placed in a beaker, and a 20% (mass concentration) nitric acid solution is added, and the material is immersed at 45°C for 2 hours, and then washed with deionized water and placed in a forced air drying oven at 105°C for 2 hours to obtain the pretreated filter bag substrate.

[0081] (2) Preparation of La 0.3 Co 0.3 Mn 0.4 O3 perovskite structure composition

[0082] 1) 51.0 g of La(NO3)3.6H2O (98.5%), 34.0 g of Co(NO3)2.6H2O (99.0%), and 39.7 g of Mn(NO3)2.4H2O (97.5%) are weighed into a beaker, 300 mL of deionized water is added, and stirring is performed to completely dissolve them;

[0083] 2) 107.2 g of citric acid monohydrate (mass percentage concentration ≥98.5) is weighed into the above beaker, and stirring is performed at 90°C for 6 hours to obtain a sol;

[0084] 3) The beaker is placed in a 135°C oven and dried for 10 hours, and then calcined at 650°C for 8 hours, and then naturally cooled to room temperature to obtain the La 0.3 Co 0.3 Mn 0.4 O3 perovskite structure composition.

[0085] (3) Preparation of CuO-NiO-ZrO ternary talc-like composition

[0086] 1) 120.5 g of dodecylamine is weighed and dissolved in 1500 mL of deionized water and added to a three-necked flask, and stirring is started; 2) 1000 mL of n-butanol (mass percentage concentration ≥ 99.5) is weighed and added to the above three-necked flask, and stirring is performed to completely dissolve the dodecylamine in the n-butanol to obtain a microemulsion liquid; 3) 27.1 g of Cu(NO3)2.6H2O (98.0%), 113.4 g of Ni(NO3)2.6H2O (98.0%), and 44.6 g of Zr(NO3)4.3H2O (98.5%) (weight ratio CuO:NiO:ZrO2=0.5:2.0:1.0) are weighed and added to the three-necked flask; 4) after the solids are completely dissolved, an appropriate amount of ammonia water is added to adjust the pH value to 9.0, and the liquid is placed in a 5000 mL reaction kettle; 5) the reaction kettle is placed in a 120°C oven, and hydrothermal crystallization reaction is performed for 22 hours, and the product is centrifuged, washed with water twice, washed with alcohol twice, dried at 135°C for 6 hours, calcined at 680°C for 8 hours, and then naturally cooled to room temperature to obtain the CuO-NiO-ZrO ternary talc-like composition of the present application.

[0087] (4) Preparation of matrix-loaded catalyst slurry

[0088] 7.0 g of the La 0.3 Co 0.3 Mn 0.4 O3 perovskite structure composition prepared in step (2), 12.5 g of the CuO-NiO-ZrO ternary hydrotalcite catalyst composition prepared in step (3), 12.5 g of SB powder, and 0.4 g of Tianqin powder are weighed and mixed in a ball mill for 4 hours, and the particle size is 10 µm after grinding; 300 g of deionized water is added to a 1000 mL beaker, the above mixed powder after ball milling is added under stirring, and then 15.5 g of concentrated nitric acid with a concentration of 10% is slowly added dropwise, and ultrasonic homogenization is performed for 8 hours to obtain a matrix-loaded catalyst sol slurry with a mass concentration of 9.31%.

[0089] (5) Preparation of catalytic filter material

[0090] The catalyst slurry is coated on the polytetrafluoroethylene (PTFE) filter bag substrate treated in step (1) by using an automatic spraying machine, dried at 110°C for 8 hours, repeated spraying 3 times, and baked at 240°C for 2 hours to obtain the catalyst-loaded filter material 5 of the application with a catalyst loading of 586 g / m 2 . Example 6

[0091] (1) Treatment of filter bag substrate

[0092] The polyacyl (P84) filter bag material is placed in a beaker, a nitric acid solution with a concentration of 20% (mass concentration) is added, and the material is immersed at 45°C for 2 hours, then washed with deionized water, and placed in a forced air drying oven at 105°C for 2 hours to obtain the pretreated filter bag substrate.

[0093] (2) Preparation of Ce 0.2 Co 0.3 Mn 0.5 O3 perovskite structure composition

[0094] 1) 36.3g of Ce(NO3)3.6H2O (98.5%), 56.4g of Co(NO3)2.6H2O (99.0%), and 53.0g of Mn(NO3)2.4H2O (97.5%) are weighed into a beaker, 300mL of deionized water is added, and stirred to completely dissolve;

[0095] 2) 114.4g of citric acid monohydrate (mass percentage concentration ≥98.5) is weighed into the above beaker, and stirred vigorously at 90°C for 6 hours to obtain a sol;

[0096] 3) The beaker is placed in a 130°C oven and dried for 8 hours, and then baked at 650°C for 7 hours, and naturally cooled to room temperature to obtain the Ce 0.2 Co 0.3 Mn 0.5 O3 perovskite structure composition of the application.

[0097] (3) Preparation of CuO-NiO-ZrO ternary talc-like composition

[0098] 1) Weigh 120.5g of dodecylamine, dissolve it in 1500mL of deionized water, add it to a three-necked flask, and start stirring; 2) Weigh 1000mL of n-butanol (mass percentage concentration ≥99.5), add it to the above three-necked flask, and stir until the dodecylamine is completely dissolved in the n-butanol to obtain a microemulsion liquid; 3) Weigh 71.0g of Cu(NO3)2.6H2O (98.0%), 99.2g Ni(NO3)2.6H2O (98.0%), and 19.5g Zr(NO3)4.3H2O (98.5%) (weight ratio of CuO:NiO:ZrO2=1.5:2.0:0.5) were added to a three-necked flask; 4) after the solid was completely dissolved, an appropriate amount of ammonia water was added to adjust the pH to 9.5, and the liquid was placed in a 5000ml reactor; 5) the reactor was placed in a 120°C oven for hydrothermal crystallization reaction for 26 hours, the product was centrifuged, washed twice with water, twice with alcohol, dried at 125°C for 6 hours, calcined at 650°C for 8 hours, and naturally cooled to room temperature to obtain the CuO-NiO-ZrO ternary talc-like composition of the present invention.

[0099] (4) Preparation of substrate-loaded catalyst slurry

[0100] Weigh 7.0 g of Ce obtained in step (2) 0.2 Co 0.3 Mn 0.5 The O3 perovskite structure composition, 8.5 g of the CuO-NiO-ZrO ternary hydrotalcite catalyst composition prepared in step (3), 12.5 g of SB powder, and 0.4 g of Tianqing powder were ground and mixed in a ball mill for 6 hours, and the mixture was fully mixed and ground to a particle size of 15 μm. 300 g of deionized water was added to a 1000 mL beaker, and the ball-milled mixture powder was added while stirring. Then, 12.5 g of 10% nitric acid was slowly added dropwise, and ultrasonic homogenization was performed for 8 hours to obtain a matrix-loaded catalyst sol slurry with a mass concentration of 8.33%.

[0101] (5) Preparation of catalytic filter material

[0102] The catalyst slurry was coated on the polyimide (P84) filter bag substrate treated in step (1) using an automatic sprayer, dried at 110°C for 7 hours, sprayed 4 times, and calcined at 175°C for 4 hours to obtain a catalyst loading of 516 g / m 2 Catalytic filter material 6. Comparative Example 1

[0103] (1) Treatment of the filter bag substrate and (2) Preparation of the CuO-NiO-ZrO ternary talc-like composition are the same as in Example 1.

[0104] (3) Preparation of substrate-loaded catalyst slurry

[0105] Take 10.0 g of CuO-NiO-ZrO ternary hydrotalcite catalyst composition prepared in step (3), 8.5 g of SB powder, and 0.2 g of carboxymethyl cellulose, and mix and grind in a ball mill for 4 hours. After grinding, the particle size reaches 10 μm. Add 300 g of deionized water into a 1000 mL beaker, and then add the above mixed and ground powder under stirring. Then, slowly add 6.5 g of 10% nitric acid, and ultrasonically homogenize for 8 hours to obtain a matrix-supported catalyst sol slurry with a mass concentration of 5.75%.

[0106] (4) Preparation of the catalytic filter material

[0107] Use an automatic spraying machine to coat the catalyst slurry on the polytetrafluoroethylene (PTFE) filter bag matrix treated in step (1), dry at 110°C for 5 hours, repeat the spraying for 3 times, and then calcine at 200°C for 4 hours to obtain the comparative catalytic filter material 1 with a catalyst loading of 536 g / m 2 . Comparative Example 2

[0108] (1) Treatment of the filter bag matrix and (2) Preparation of La 0.3 Co 0.3 Mn 0.4 O3 perovskite composition according to Example 5,

[0109] (3) Preparation of the matrix-supported catalyst slurry

[0110] Take 19.5 g of La 0.3 Co 0.3 Mn 0.4 O3 perovskite composition, 12.5 g of SB powder, and 0.4 g of tianq powder, and mix and grind in a ball mill for 4 hours. After grinding, the particle size reaches 10 μm. Add 300 g of deionized water into a 1000 mL beaker, and then add the above mixed and ground powder under stirring. Then, slowly add 15.5 g of 10% nitric acid, and ultrasonically homogenize for 8 hours to obtain a matrix-supported catalyst sol slurry with a mass concentration of 9.31%.

[0111] (4) Preparation of the catalytic filter material

[0112] Use an automatic spraying machine to coat the catalyst slurry on the polytetrafluoroethylene (PTFE) filter bag matrix treated in step (1), dry at 110°C for 6 hours, repeat the spraying for 3 times, and then calcine at 240°C for 2 hours to obtain the comparative catalytic filter material 2 with a catalyst loading of 512 g / m 2 . Comparative Example 3

[0113] (1) Treatment of the filter bag matrix, (2) Preparation of La 0.2 Co 0.4 Mn0.4 The preparation of the O3 perovskite composition and (3) the preparation of the CuO-NiO-ZrO ternary talc-like composition were exactly the same as the first three steps of Example 1;

[0114] (4) Weigh 3.5g La 0.2 Co 0.4 Mn 0.4 The perovskite composition of O3, 6.5 g of the CuO-NiO-ZrO ternary hydrotalcite catalyst composition prepared in step (2), and 8.7 g of carboxymethyl cellulose were ground and mixed in a ball mill for 4 hours, and the mixture was fully mixed and ground until the particle size reached 10 μm; then 6.5 g of 10% nitric acid was slowly added dropwise, and ultrasonic homogenization was performed for 8 hours to obtain a matrix-supported catalyst sol slurry with a mass concentration of 5.75%.

[0115] (5) Preparation of catalytic filter material

[0116] The catalyst slurry was coated on the polytetrafluoroethylene (PTFE) filter bag substrate treated in step (1) using an automatic sprayer, dried at 110°C for 7 hours, sprayed three times, and calcined at 160°C for 6 hours to obtain a catalyst loading of 211 g / m 2 Comparative catalytic filter material 3. Comparative Example 4

[0117] (1) Treatment of filter bag matrix, (2) Nd 0.3 Co 0.3 Mn 0.4 The preparation of the perovskite composition of O3 and (3) the preparation of the CuO-NiO-ZrO ternary talc-like composition were exactly the same as the first three steps of Example 4;

[0118] (4) Weigh 8.5gNd 0.3 Co 0.3 Mn 0.4 The perovskite composition of O3, 2.5g of the CuO-NiO-ZrO ternary hydrotalcite catalyst composition prepared in step (2), and 12.7g of Tianqing powder were ground and mixed in a ball mill for 6 hours, and the mixture was fully mixed and ground to a particle size of 20µm; 300g of deionized water was added to a 1000mL beaker, and the ball-milled mixture powder was added under stirring, and then 10.5g of 10% nitric acid was slowly added dropwise, and ultrasonic homogenization was performed for 8 hours to obtain a matrix-supported catalyst sol slurry with a mass concentration of 7.09%;

[0119] (5) Preparation of catalytic filter material

[0120] The catalyst slurry is coated on the polytetrafluoroethylene (PTFE) filter bag substrate treated in step (1) by using an automatic spraying machine, dried at 110℃ for 8 hours, repeated spraying 3 times, and baked at 210℃ for 4 hours to obtain the catalyst-loaded filter bag of the application with a catalyst loading of 285g / m 2 of the comparative catalyst filter 4. Comparative Example 5

[0121] The performance evaluation of the catalyst filter bag for low-temperature denitration and dioxin removal prepared in the above examples and comparative examples is carried out by sleeving the catalyst filter bag on a sleeve. The evaluation conditions are: the NO concentration in the flue gas is 450mg / m 3 , the O2 volume fraction is 10%, the water vapor content is 15% (volume ratio), the SO2 concentration is 350mg / m 3 , the dioxin concentration (replaced by chlorobenzene) is 10mg / m 3 , the dust concentration is 2000mg / m 3 , the methanol is carried by water vapor into the methanol pre-decomposition bed, the methanol / NO range is 1.05~1.40, the carrier gas is N2, the evaluation temperature range is 140~220℃, the evaluation temperature is 195℃, the methanol / NO is 1.15, the filtration air speed is 0.75m / min (filter bag size). The performance of the catalyst filter bag is evaluated by the changes of NO, dioxin and dust concentrations at the inlet and outlet. The results are shown in Table 1.

[0122] Table 1 Performance evaluation of catalyst filter bag for denitration, dioxin removal and dust removal

[0123]

[0124] The above examples are only used to illustrate the technical ideas and characteristics of the application, and the purpose is to enable those skilled in the art to understand the content of the application and to implement it, and cannot be limited to the patent scope of the application only by the above examples, i.e. any equivalent changes or modifications made in the spirit disclosed by the application still fall within the patent scope of the application.

Claims

1. A method for preparing a catalytic filter bag for removing dioxins at a medium-low temperature, characterized in that, The method comprises the following steps: (1) Catalyst fine powder: composed of perovskite and ternary talc structure with a weight fraction ratio of 35-65:20-75; The perovskite is of a general formula of RE x Co y Mn z O3, wherein RE is at least one of La, Ce, Pr and Nd, x=0~0.5, z=0~0.6, y≤1-(x+z). The ternary talc structure is CuO-NiO-ZrO2, and the mass ratio of CuO:NiO:ZrO2 in CuO-NiO-ZrO2 is 0.5-2:0.5-2:0.5-2; The preparation method of CuO-NiO-ZrO2 is to add an alcohol solvent to a dodecylamine aqueous solution to form a microemulsion liquid; add copper nitrate, nickel nitrate and zirconium nitrate to the microemulsion liquid, add ammonia water after complete dissolution, adjust the pH of the solution to 8-10, then perform hydrothermal crystallization on the solution at 120-140°C for 15-28 hours, centrifuge, wash and dry the precipitated product at 110-150°C for 4-8 hours, and calcine at 600-700°C for 5-10 hours, and then naturally cool to room temperature to obtain the CuO-NiO-ZrO2 ternary talc structure composition; (2) Catalyst filter material: mix the catalyst fine powder and the additive, grind to a particle size of 5-15 µm, mix with water and nitric acid solution, and mix again to obtain a matrix-supported catalyst sol slurry; (3) Spray the matrix-supported catalyst sol slurry on the pretreated filter bag, and then dry and calcine in sequence to obtain the catalytic filter bag.

2. The method according to claim 1, wherein the catalyst filter bag is prepared by the steps of: (1) mixing the catalyst and the binder to form a mixture; (2) adding the mixture into the filter bag; (3) drying the filter bag; and (4) calcining the filter bag. RExCo in step (1) y Mn z The method for preparing the O3 perovskite structure composition is as follows: a precursor of a metal salt is dissolved in deionized water, then citric acid is added and stirred at 60-90°C for 4-8 hours, the obtained sol is baked at 120-150°C for 6-10 hours, and finally the RExCo y Mn z O3 perovskite structure composition is obtained by calcining in a muffle furnace at 580-680°C for 4-8 hours.

3. The method according to claim 2, wherein the catalyst filter bag is prepared by the steps of: (1) mixing the catalyst and the binder to form a mixture; (2) adding the mixture into the filter bag; and (3) drying the filter bag. In the preparation method of CuO-NiO-ZrO2, the drying conditions are 110-150°C for 4-8 hours, and the calcining conditions are 600-700°C for 6-10 hours; the alcohol solvent is n-butanol, and the mass ratio of dodecylamine, water and n-butanol is 1-2:10-20:5-15.

4. The method according to claim 1, wherein the catalyst filter bag is prepared by the steps of: (1) mixing the catalyst and the binder to form a mixture; (2) adding the mixture into the filter bag; and (3) drying the filter bag. In step (2), the additive is a combination of SB powder and carboxymethyl cellulose or a combination of SB powder and Tianjing powder with a mass ratio of 5-15:0.1-5; and the mass ratio of the catalyst fine powder and the additive is 1-5:1-5.

5. The method according to claim 4, wherein the catalyst filter bag is prepared by the steps of: (1) mixing the catalyst and the binder to form a mixture; (2) adding the mixture into the filter bag; (3) drying the filter bag; and (4) calcining the filter bag. In step (2), the additive is a combination of SB powder and carboxymethyl cellulose or a combination of SB powder and Tianjing powder with a mass ratio of 5-15:0.1-2; and the mass ratio of the catalyst fine powder and the additive is 1-3:1-3.

6. The method according to claim 1, wherein the catalyst filter bag is prepared by the steps of: (1) mixing the catalyst with the filter material; (2) forming the catalyst filter bag; (3) drying the catalyst filter bag; and (4) calcining the catalyst filter bag. The mass concentration of the matrix-supported catalyst sol slurry is 1-10%.

7. The method according to claim 1, wherein the catalyst filter bag is prepared by the steps of: (1) mixing the catalyst with the filter material; (2) forming the catalyst filter bag; (3) drying the catalyst filter bag; (4) calcining the catalyst filter bag; and (5) coating the catalyst filter bag with the coating material. In step (3), the drying temperature is 105-115°C, and the drying time is 4-8 hours; the calcining temperature is 150-250°C, and the calcining time is 2-4 hours.

8. The method according to claim 1, wherein the catalyst filter bag is prepared by the steps of: (1) mixing the catalyst with the filter material; (2) forming the catalyst filter bag; (3) drying the catalyst filter bag; (4) calcining the catalyst filter bag; and (5) coating the catalyst filter bag with the catalyst. In step (3), the pretreated filter bag is pretreated with 10-30% nitric acid to remove impurities on the surface of the filter bag matrix, the temperature is 40-50°C, the immersion treatment time is 1-3 hours, then the filter bag is washed with deionized water, dried in a forced air drying oven at 100-110°C for 1-2 hours, and the pretreated filter bag matrix is obtained; The filter bag matrix is polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS) or polyacyl (P84).

9. A catalytic filter bag for removing dioxins by low-medium temperature denitration, characterized in that, The catalytic filter bag is prepared by the method of any one of claims 1-5.

10. Application of the catalytic filter bag for removing dioxins at medium and low temperatures prepared by the method of claim 1 in dust removal, denitration and dioxin removal.

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