A hardening liquid for corrugated plate denitration catalyst and a preparation method and use method thereof

Abstract

The application discloses a corrugated plate denitration catalyst hardening liquid and a preparation method and use method thereof. The corrugated plate denitration catalyst hardening liquid comprises the following component raw materials in percentage by weight: deionized water 15-60%, phosphoric acid 12%-70%, copper oxide 1%-20%, Cu molecular sieve 3%-25%, polyvinyl alcohol 1.5%-5.5%, white carbon black 5%-15%, and polyethylene glycol 3%-6.5%. The corrugated plate denitration catalyst hardening liquid can not only improve the wear resistance of a catalyst hardening end surface, but also improve the denitration activity of the catalyst hardening end, prolong the service life of the catalyst, and ensure stable operation of the device for a longer time.

Description

Technical Field

[0001] The present invention belongs to the technical field of SCR denitration catalysts, and relates to a catalyst hardening solution, a preparation method thereof and a use method thereof, and particularly relates to a corrugated plate denitration catalyst hardening solution, a preparation method thereof and a use method thereof. Background Art

[0002] NO x is one of the main pollutants in the atmospheric environment. It can not only cause environmental problems such as haze, acid rain, photochemical smog, etc., but also have an adverse impact on human health. With the gradual improvement of national environmental protection policies, the emission control of NO x is becoming increasingly strict. At present, among many flue gas denitration technologies, the selective catalytic reduction (SCR) technology with NH3 as the reducing agent is the most mature and widely used, and the core of which is the denitration catalyst. The honeycomb catalyst is more commonly used in industrial applications. The corrugated plate catalyst has a large geometric specific surface area and is light in weight, and also occupies a certain market share in the denitration field.

[0003] The honeycomb catalyst is integrally extruded and formed, while the corrugated plate catalyst is a coated catalyst (with glass fiber as the substrate). Due to different preparation processes and compositions, the corrugated plate catalyst is more easily worn by dust scouring, which may cause problems such as catalyst breakage, collapse, and pore channel blockage, shortening the service life of the catalyst, and seriously leading to abnormal shutdown of the denitration device. In industrial production, the windward end of the catalyst is hardened, and the existing hardening technology mainly focuses on the honeycomb catalyst, and there are few reports on the hardening technology of the corrugated plate catalyst.

[0004] Chinese Patent CN201711347208.0 discloses a windward surface hardening process for an SCR denitration catalyst, which includes the following steps: (1) adding aluminum sulfate powder to a high-temperature melting kettle, adding deionized water according to a solid-liquid ratio of 1:4, and then raising the temperature of the melting kettle to 80°C and stirring at a constant temperature for 2 hours; (2) taking out the prepared solution after the constant-temperature stirring is completed and naturally cooling it to room temperature; (3) vertically inserting the calcined SCR denitration catalyst into the solution so that the windward surface of the catalyst is completely immersed in the solution; (4) putting the impregnated SCR denitration catalyst into a hot blast furnace for drying, thus completing the hardening of the catalyst. Although this hardening process can improve the anti-wear performance of the catalyst and extend the service life of the catalyst, the process is relatively cumbersome after the catalyst is calcined and then impregnated and dried, and the hardened part at the port has no denitration activity.

[0005] Chinese patent CN201410202244.8 discloses a method for end-hardening treatment of SCR denitrification catalyst, including the following steps: (1) preparing an active solution: weighing 1-5 parts of ammonium metatungstate, 0.5-1 parts of cerium nitrate, and 1-2 parts of ammonium heptamolybdate respectively, and dissolving them in 100 parts of deionized water; (2) weighing 20-35 parts of ammonium dihydrogen phosphate and dissolving them in 100 parts of deionized water; (3) mixing the two solutions from steps (1) and (2), heating to 80°C, and stirring evenly; (4) molding the honeycomb catalyst to be hardened. (3) Immerse one or both ends of the catalyst in the solution of step (3) for 5 to 10 seconds; (5) Take out the impregnated catalyst from step (4) and place it in a muffle furnace at 110°C for 30 minutes to allow the components and catalyst to react and ensure that the edges of one or both ends of the catalyst are hardened; However, the patented hardening liquid introduces active components, which can make the hardened part of the catalyst have denitrification activity and can improve the end hardness to a certain extent. Especially in the application range of 300 to 420°C, it is difficult to form an obvious protective film on the hardened part of the catalyst, and the wear resistance needs to be improved.

[0006] Chinese patents CN201310243987.5 and CN201310244764.0 disclose the formulation of a hardening liquid, which includes the following components, by weight percentage: aluminum hydroxide 2-5%, phosphoric acid 6-20%, vanadium pentoxide as the active component, accounting for 1-5%, and water as the remainder. The hardening process is as follows: (1) Prepare the hardening liquid according to the above composition; (2) Immerse both ends or one end of the already formed and dried or calcined catalyst in the hardening liquid for 10-30 seconds, remove it and air dry it at a temperature of 10-20°C and a humidity of 30-50%; (3) Calcine the impregnated catalyst at a temperature of 190-420°C. By using the above hardening liquid formulation and hardening process, the anti-wear performance and denitrification activity of the catalyst can be improved, and the service life of the catalyst can be extended. However, aluminum dihydrogen phosphate in the hardening solution is a thermosetting material that decomposes and dehydrates when heated, and generally shrinks significantly. This causes the adhesive layer to deform and the adhesive strength to decrease to varying degrees. Therefore, it is necessary to improve the adhesive strength and overall strength of the main component of the hardening solution to meet the requirements of different operating temperatures of the catalyst.

[0007] Chinese patent CN202110483224.2 discloses a copper-based SCR catalyst supported on a metal support, comprising a support and a coating. The support is a metal support, and the coating is a copper-containing molecular sieve. The copper-containing molecular sieve also contains rare earth elements, the content of which accounts for 0.1%-5% of the molecular sieve's weight. The crystal form of the copper-containing molecular sieve is one or a combination of ZSM-5, SAPO-34, SSZ-13, SAPO-11, SAPO-47, and SSZ-39. The rare earth elements in the copper-containing molecular sieve are one or a combination of cerium, zirconium, lanthanum, yttrium, and neodymium. The copper content in the copper-containing molecular sieve is 1.5wt%-4.0wt%, the silicon-to-aluminum ratio is 8-30, and the coating amount of the copper-containing molecular sieve is 60-160 g / L. However, this technology is mainly aimed at the preparation of copper-based SCR catalysts with metal supports as substrates. The metal supports have high wear resistance, and the catalyst will not collapse or break. However, the active components at the windward end of the catalyst are still at risk of being washed away and detached, which leads to a decrease in the denitrification performance of the catalyst.

[0008] The existing technologies mentioned above still have various shortcomings, so it is necessary to develop a hardening liquid suitable for corrugated plate catalysts to improve the wear resistance of corrugated plate catalysts. Summary of the Invention

[0009] The purpose of this invention is to provide a hardening liquid suitable for corrugated plate catalysts, as well as its preparation and application methods. This hardening liquid can not only improve the wear resistance of the hardened end face of the catalyst, but also improve the denitrification activity of the hardened end of the catalyst, and at the same time extend the service life of the catalyst, ensuring the stable operation of the device for a longer period of time.

[0010] To achieve the above objectives, the present invention provides a corrugated plate denitrification catalyst hardening liquid, which comprises the following raw materials in the following weight ratios: 15-60% deionized water, 12%-70% phosphoric acid, 1%-20% copper oxide, 3%-25% Cu molecular sieve, 1.5%-5.5% polyvinyl alcohol, 5%-15% silica, and 3%-6.5% polyethylene glycol.

[0011] The corrugated plate denitrification catalyst hardening liquid of the present invention comprises the following raw materials in the following weight ratios: water 25% to 45%, phosphoric acid 20% to 45%, copper oxide 3% to 15%, Cu molecular sieve 5% to 15%, polyvinyl alcohol 2% to 4%, silica 6% to 10%, and polyethylene glycol 3% to 5%.

[0012] The corrugated plate denitrification catalyst hardening liquid of the present invention, wherein the Cu molecular sieve is at least one of Cu / ZSM-5 molecular sieve, Cu / USY molecular sieve, and Cu / β molecular sieve.

[0013] This invention also provides a method for preparing a corrugated plate SCR denitrification catalyst hardening liquid, the method comprising the following steps:

[0014] (1) Dissolve phosphoric acid in water to form a phosphoric acid solution;

[0015] (2) Add copper oxide to the phosphoric acid solution to prepare copper dihydrogen phosphate solution;

[0016] (3) Add Cu molecular sieve to copper dihydrogen phosphate solution to form copper dihydrogen phosphate-Cu molecular sieve mixture;

[0017] (4) Add polyethylene glycol to the mixture in step (3) to obtain a copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixture;

[0018] (5) Dissolve polyvinyl alcohol in water to obtain a polyvinyl alcohol solution;

[0019] (6) Mix the mixture from step (4) and the polyvinyl alcohol solution from step (5) to obtain a mixture;

[0020] (7) Add silica to the mixture from step (6), mix, and obtain the corrugated plate denitrification catalyst hardening solution.

[0021] In the preparation method of the corrugated plate SCR denitrification catalyst hardening liquid of the present invention, in step (1), during the process of dissolving phosphoric acid in water, the mixture is stirred at a constant speed and heated to 70-80°C.

[0022] In the preparation method of the corrugated plate SCR denitrification catalyst hardening liquid of the present invention, in step (3), during the process of adding Cu molecular sieve to copper dihydrogen phosphate solution, the mixture is stirred at a constant speed and heated to 80-90°C.

[0023] In the preparation method of the corrugated plate SCR denitrification catalyst hardening liquid of the present invention, in step (4), during the process of adding polyethylene glycol to the mixture in step (3), the mixture is stirred at a constant speed and heated to 70-80°C.

[0024] In the preparation method of the corrugated plate SCR denitrification catalyst hardening liquid of the present invention, in step (5), during the process of adding polyvinyl alcohol to water, the mixture is stirred at a constant speed and heated to 95-98°C.

[0025] In the preparation method of the corrugated plate SCR denitrification catalyst hardening liquid of the present invention, in step (7), during the process of adding fumed silica to the mixture in step (6), the mixture is stirred at a constant speed and heated to 70-80°C.

[0026] The present invention provides a method for using a corrugated SCR denitrification catalyst hardening liquid. The method includes: vertically immersing the pre-hardened end of the corrugated SCR catalyst substrate in the corrugated SCR denitrification catalyst hardening liquid, air-drying it at room temperature to obtain a corrugated SCR catalyst substrate with hardened end face, coating the corrugated SCR catalyst substrate with an active material, and then drying and calcining it to obtain a hardened catalyst.

[0027] The method for using the corrugated plate SCR denitrification catalyst hardening liquid of the present invention includes the following steps: the impregnation time is 1-3 min; the drying temperature is 180-240℃ and the time is 2-4 h; the calcination temperature is 300-400℃ and the time is 8-10 h.

[0028] The corrugated plate SCR denitrification catalyst hardening solution provided by this invention is formulated from phosphoric acid, copper oxide, Cu molecular sieve, polyethylene glycol, polyvinyl alcohol, and silica in a specific ratio. Specifically, copper dihydrogen phosphate, prepared from phosphoric acid and copper oxide, forms a phosphate polymer by bridging O-Cu-O bonds with polyphosphoric acid molecules, increasing cohesion and improving adhesion, in addition to hydrogen bonds and van der Waals forces. Cu molecular sieve exhibits good denitrification performance and strong erosion resistance; its introduction into the hardening solution ensures denitrification activity at the hardened end face while improving wear resistance. Polyethylene glycol promotes uniform dispersion of the components in the hardening solution and has strong viscosity adjustment capabilities. Polyvinyl alcohol forms a protective film on the surface of the glass fiber substrate. Silica is mainly used to adjust the rheological properties of the hardening solution to improve its overall performance. After the SCR catalyst substrate is treated with a hardening solution, it is coated with active material. During the drying and calcination process, phosphoric acid, copper oxide, Cu molecular sieve, polyethylene glycol, polyvinyl alcohol, and silica in the hardening solution interact, and the components of the hardening solution, active components, and substrate are integrated, which is beneficial to improving the hardening capacity of the catalyst port. The corrugated plate SCR denitrification catalyst hardening solution prepared by this invention can improve the denitrification activity and wear resistance of the corrugated plate catalyst, extend the catalyst life, and ensure the stable operation of the denitrification unit. Detailed Implementation

[0029] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and processes. However, the scope of protection of the present invention is not limited to the following embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions.

[0030] The catalyst wear rate of the present invention was tested according to the standard "Technical Specification for Testing Corrugated Plate Denitrification Catalysts" GB / T39703-2020.

[0031] Evaluation conditions for the denitrification performance of the catalyst of this invention: space velocity 4000 h⁻¹-1 The reaction temperature is 320℃, and the inlet NO is... x 300 mg / Nm 3 The O2 content is 3.0%, the H2O content is 6%, and the ammonia-nitrogen ratio is 1.

[0032] Catalyst dimensions: 30×30×300mm (cut from industrial sample).

[0033] The wear rate of the catalyst without hardening treatment was 0.15% / kg.

[0034] Source of raw materials for preparing the hardening solution in this embodiment of the invention:

[0035] Phosphoric acid: Sinopharm Chemical Reagent Co., Ltd.;

[0036] Copper oxide: Sinopharm Chemical Reagent Co., Ltd.;

[0037] Cu molecular sieve: homemade;

[0038] Polyvinyl alcohol: Sinopharm Chemical Reagent Co., Ltd.;

[0039] Silica: Sinopharm Chemical Reagent Co., Ltd.;

[0040] Polyethylene glycol: Sinopharm Chemical Reagent Co., Ltd.

[0041] Example 1:

[0042] Weigh 65g of phosphoric acid and dissolve it in 70g of deionized water to obtain a phosphoric acid solution. Stir the mixture at a constant speed and heat it to 75℃. Then, slowly add 10g of copper oxide to the phosphoric acid solution to obtain a copper dihydrogen phosphate solution, stirring the mixture at a constant speed. Continue to add 15g of Cu / ZSM-5 molecular sieve to the copper dihydrogen phosphate solution to obtain a copper dihydrogen phosphate-Cu molecular sieve mixed solution, stirring the mixture at a constant speed and heating it to 85℃. Continue to add 7.5g of polyethylene glycol to the copper dihydrogen phosphate-Cu molecular sieve mixed solution to obtain a copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution, stirring the mixture at a constant speed and heating it to 80℃. Weigh 4.2g of polyvinyl alcohol and dissolve it in 20g of deionized water to obtain a polyvinyl alcohol solution, stirring the mixture at a constant speed and heating it to 95℃. Mix the copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution and the polyvinyl alcohol solution, then add 15g of silica, stirring the mixture at a constant speed and heating it to 75℃ to obtain a corrugated plate SCR denitration catalyst hardening solution.

[0043] A 30×30×300mm corrugated SCR catalyst substrate with a pre-hardened end was vertically immersed in a hardening solution to a depth of 10mm for 1 minute. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 200℃ for 2 hours and calcined at 350℃ for 8 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.07% / kg.

[0044] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1 minute. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification efficiency of approximately 51.5%.

[0045] Comparative Example 1:

[0046] Weigh 65g of phosphoric acid and dissolve it in 70g of deionized water to obtain a phosphoric acid solution. Stir the solution at a constant speed and heat it to 75℃. Then, slowly add 10g of copper oxide to the phosphoric acid solution to obtain a copper dihydrogen phosphate solution, and stir the solution at a constant speed. Continue to add 7.5g of polyethylene glycol to the copper dihydrogen phosphate solution to obtain a copper dihydrogen phosphate-polyethylene glycol mixture, and stir the solution at a constant speed and heat it to 80℃. Weigh 4.2g of polyvinyl alcohol and dissolve it in 20g of deionized water to obtain a polyvinyl alcohol solution, and stir the solution at a constant speed and heat it to 95℃. Mix the copper dihydrogen phosphate-polyethylene glycol mixture and the polyvinyl alcohol solution, and then add 15g of silica. Stir the solution at a constant speed and heat it to 75℃ to obtain a corrugated plate SCR denitrification catalyst hardening solution.

[0047] Compared with Example 1, Cu / ZSM-5 molecular sieve was not added in the preparation steps of the catalyst hardening solution.

[0048] A 30×30×300mm corrugated SCR catalyst substrate with a pre-hardened end was vertically immersed in a hardening solution to a depth of 10mm for 1 minute. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 200℃ for 2 hours and calcined at 350℃ for 8 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.08% / kg.

[0049] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1 minute. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification efficiency of approximately 14.2%.

[0050] Example 2:

[0051] 95g of phosphoric acid was dissolved in 100g of deionized water to obtain a phosphoric acid solution. The mixture was stirred at a constant speed and heated to 80℃. Then, 15g of copper oxide was slowly added to the phosphoric acid solution to obtain a copper dihydrogen phosphate solution, and the mixture was stirred at a constant speed. Next, 15g of Cu / β molecular sieve was added to the copper dihydrogen phosphate solution to obtain a copper dihydrogen phosphate-Cu molecular sieve mixed solution, and the mixture was stirred at a constant speed and heated to 85℃. Finally, 8.5g of polyethylene glycol was added to the copper dihydrogen phosphate-Cu molecular sieve mixed solution to obtain a copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution, and the mixture was stirred at a constant speed and heated to 75℃. 5.5g of polyvinyl alcohol was dissolved in 15g of deionized water to obtain a polyvinyl alcohol solution, and the mixture was stirred at a constant speed and heated to 98℃. The copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution and the polyvinyl alcohol solution were mixed, and then 20g of silica was added, and the mixture was stirred at a constant speed and heated to 80℃ to obtain a corrugated plate SCR denitration catalyst hardening solution.

[0052] A 30×30×300mm corrugated SCR catalyst substrate was vertically immersed in a hardening solution to a depth of 10mm for 1 minute. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 200℃ for 4 hours and calcined at 380℃ for 9 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.06% / kg.

[0053] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1 minute. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification efficiency of approximately 56.3%.

[0054] Comparative Example 2:

[0055] 95g of phosphoric acid was dissolved in 100g of deionized water to obtain a phosphoric acid solution. The mixture was stirred at a constant speed and heated to 80℃. Then, 15g of copper oxide was slowly added to the phosphoric acid solution to obtain a copper dihydrogen phosphate solution, and the mixture was stirred at a constant speed. Next, 8.5g of polyethylene glycol was added to the copper dihydrogen phosphate solution to obtain a copper dihydrogen phosphate-polyethylene glycol mixture, and the mixture was stirred at a constant speed and heated to 75℃. 5.5g of polyvinyl alcohol was dissolved in 15g of deionized water to obtain a polyvinyl alcohol solution, and the mixture was stirred at a constant speed and heated to 98℃. The copper dihydrogen phosphate-polyethylene glycol mixture and the polyvinyl alcohol solution were mixed, and then 20g of silica was added. The mixture was stirred at a constant speed and heated to 80℃ to obtain a corrugated plate SCR denitrification catalyst hardening solution.

[0056] Compared with Example 2, Cu / β molecular sieve was not added in the preparation steps of the catalyst hardening solution.

[0057] A 30×30×300mm corrugated SCR catalyst substrate with a pre-hardened end was vertically immersed in a hardening solution to a depth of 10mm for 1 minute. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 200℃ for 4 hours and calcined at 380℃ for 9 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.07% / kg.

[0058] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1 minute. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification efficiency of approximately 17.4%.

[0059] Example 3:

[0060] Weigh 80g of phosphoric acid and dissolve it in 80g of deionized water to obtain a phosphoric acid solution. Stir the mixture at a constant speed and heat it to 70℃. Then, slowly add 20g of copper oxide to the phosphoric acid solution to obtain a copper dihydrogen phosphate solution, stirring the mixture at a constant speed. Continue to add 20g of Cu / ZSM-5 molecular sieve to the copper dihydrogen phosphate solution to obtain a copper dihydrogen phosphate-Cu molecular sieve mixed solution, stirring the mixture at a constant speed and heating it to 85℃. Continue to add 8.4g of polyethylene glycol to the copper dihydrogen phosphate-Cu molecular sieve mixed solution to obtain a copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution, stirring the mixture at a constant speed and heating it to 80℃. Weigh 7.2g of polyvinyl alcohol and dissolve it in 35g of deionized water to obtain a polyvinyl alcohol solution, stirring the mixture at a constant speed and heating it to 96℃. Mix the copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution and the polyvinyl alcohol solution, then add 20.5g of silica, stirring the mixture at a constant speed and heating it to 75℃ to obtain a corrugated plate SCR denitration catalyst hardening solution.

[0061] A 30×30×300mm corrugated SCR catalyst substrate with a pre-hardened end was vertically immersed in a hardening solution to a depth of 10mm for 1.2 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 220℃ for 3 hours and calcined at 360℃ for 8 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.06% / kg.

[0062] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1.2 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification efficiency of approximately 54.9%.

[0063] Comparative Example 3:

[0064] Weigh 80g of phosphoric acid and dissolve it in 80g of deionized water to obtain a phosphoric acid solution. Stir the mixture at a constant speed and heat it to 70℃. Then, slowly add 20g of copper oxide to the phosphoric acid solution to obtain a copper dihydrogen phosphate solution, stirring the mixture at a constant speed. Continue to add 20g of Cu / ZSM-5 molecular sieve to the copper dihydrogen phosphate solution to obtain a copper dihydrogen phosphate-Cu molecular sieve mixed solution, stirring the mixture at a constant speed and heating it to 85℃. Weigh 7.2g of polyvinyl alcohol and dissolve it in 35g of deionized water to obtain a polyvinyl alcohol solution, stirring the mixture at a constant speed and heating it to 96℃. Mix the copper dihydrogen phosphate-Cu molecular sieve mixed solution and the polyvinyl alcohol solution, then add 20.5g of silica, stirring the mixture at a constant speed and heating it to 75℃ to obtain a corrugated plate SCR denitration catalyst hardening solution.

[0065] Compared with Example 3, polyethylene glycol was not added in the preparation steps of the catalyst hardening solution.

[0066] A 30×30×300mm corrugated SCR catalyst substrate was vertically immersed in a hardening solution to a depth of 10mm for 1.2 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 220℃ for 3 hours and calcined at 360℃ for 8 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.08% / kg.

[0067] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1.2 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification efficiency of approximately 44.5%.

[0068] Example 4:

[0069] 110g of phosphoric acid was dissolved in 80g of deionized water to obtain a phosphoric acid solution. The mixture was stirred at a constant speed and heated to 70℃. Then, 20g of copper oxide was slowly added to the phosphoric acid solution to obtain a copper dihydrogen phosphate solution, stirred at a constant speed. Next, 30g of Cu / USY molecular sieve was added to the copper dihydrogen phosphate solution to obtain a copper dihydrogen phosphate-Cu molecular sieve mixed solution, stirred at a constant speed and heated to 80℃. Finally, 7.5g of polyethylene glycol was added to the copper dihydrogen phosphate-Cu molecular sieve mixed solution to obtain a copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution, stirred at a constant speed and heated to 75℃. 10g of polyvinyl alcohol was dissolved in 50g of deionized water to obtain a polyvinyl alcohol solution, stirred at a constant speed and heated to 97℃. The copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution and the polyvinyl alcohol solution were mixed, and then 22.5g of silica was added, stirred at a constant speed and heated to 75℃ to obtain a corrugated plate SCR denitration catalyst hardening solution.

[0070] A 30×30×300mm corrugated SCR catalyst substrate was vertically immersed in a hardening solution to a depth of 10mm for 1.5 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 180℃ for 3.5 hours and then calcined at 400℃ for 8 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.05% / kg.

[0071] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1.5 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification efficiency of approximately 58.9%.

[0072] Comparative Example 4:

[0073] 110g of phosphoric acid was dissolved in 80g of deionized water to obtain a phosphoric acid solution. The mixture was stirred at a constant speed and heated to 70℃. Then, 20g of copper oxide was slowly added to the phosphoric acid solution to obtain a copper dihydrogen phosphate solution. The mixture was stirred at a constant speed. 7.5g of polyethylene glycol was added to the copper dihydrogen phosphate solution to obtain a copper dihydrogen phosphate-polyethylene glycol mixture. The mixture was stirred at a constant speed and heated to 75℃. 10g of polyvinyl alcohol was dissolved in 50g of deionized water to obtain a polyvinyl alcohol solution. The mixture was stirred at a constant speed and heated to 97℃. The copper dihydrogen phosphate-polyethylene glycol mixture and the polyvinyl alcohol solution were mixed to obtain a corrugated plate SCR denitrification catalyst hardening solution.

[0074] Compared with Example 4, Cu / USY molecular sieve and silica were not added in the preparation steps of the catalyst hardening solution.

[0075] A 30×30×300mm corrugated SCR catalyst substrate with a pre-hardened end was vertically immersed in a hardening solution to a depth of 10mm for 1.5 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 180℃ for 3.5 hours and calcined at 400℃ for 8 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.08% / kg.

[0076] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1.5 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification rate of approximately 13.6%.

[0077] Example 5:

[0078] 60g of phosphoric acid was dissolved in 40g of deionized water to obtain a phosphoric acid solution. The mixture was stirred at a constant speed and heated to 75℃. Then, 20g of copper oxide was slowly added to the phosphoric acid solution to obtain a copper dihydrogen phosphate solution, while stirring at a constant speed. Next, 25g of Cu / ZSM-5 molecular sieve was added to the copper dihydrogen phosphate solution to obtain a copper dihydrogen phosphate-Cu molecular sieve mixed solution, while stirring at a constant speed and heating to 80℃. Finally, 8.5g of polyethylene glycol was added to the copper dihydrogen phosphate-Cu molecular sieve mixed solution to obtain a copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution, while stirring at a constant speed and heating to 75℃. 6.0g of polyvinyl alcohol was dissolved in 55g of deionized water to obtain a polyvinyl alcohol solution, while stirring at a constant speed and heating to 98℃. The copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixed solution and the polyvinyl alcohol solution were mixed, and then 16.5g of silica was added, while stirring at a constant speed and heating to 80℃ to obtain a corrugated plate SCR denitration catalyst hardening solution.

[0079] A 30×30×300mm corrugated SCR catalyst substrate with a pre-hardened end was vertically immersed in a hardening solution to a depth of 10mm for 1.2 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 240℃ for 3 hours and calcined at 350℃ for 8 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.08% / kg.

[0080] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1.2 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification efficiency of approximately 56.5%.

[0081] Comparative Example 5:

[0082] Weigh 60g of phosphoric acid and dissolve it in 40g of deionized water to obtain a phosphoric acid solution. Stir the mixture at a constant speed and heat it to 75℃. Continue to add 25g of Cu / ZSM-5 to the phosphoric acid solution to obtain a phosphoric acid-Cu molecular sieve mixed solution. Stir the mixture at a constant speed and heat it to 80℃. Continue to add 8.5g of polyethylene glycol to the phosphoric acid-Cu molecular sieve mixed solution to obtain a phosphoric acid-Cu molecular sieve-polyethylene glycol mixed solution. Stir the mixture at a constant speed and heat it to 75℃. Weigh 6.0g of polyvinyl alcohol and dissolve it in 55g of deionized water to obtain a polyvinyl alcohol solution. Stir the mixture at a constant speed and heat it to 98℃. Mix the phosphoric acid-Cu molecular sieve-polyethylene glycol mixed solution and the polyvinyl alcohol solution, and then add 16.5g of silica. Stir the mixture at a constant speed and heat it to 80℃ to obtain a corrugated plate SCR denitration catalyst hardening solution.

[0083] Compared with Example 5, no copper oxide was added in the preparation steps of the catalyst hardening solution.

[0084] A 30×30×300mm corrugated SCR catalyst substrate was vertically immersed in a hardening solution to a depth of 10mm for 1.2 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. Subsequently, an active material was coated onto this substrate, and it was dried at 240℃ for 3 hours and calcined at 350℃ for 8 hours to obtain the hardened catalyst. The wear resistance was then evaluated, and the results showed that the catalyst wear rate was 0.12% / kg.

[0085] The corrugated SCR catalyst substrate, measuring 30×30×300mm, was vertically immersed in the hardening solution for 1.2 minutes. After immersion, it was air-dried at room temperature to complete end-face hardening. The denitrification performance was then evaluated, showing a catalyst denitrification efficiency of approximately 40.5%.

[0086] Through the examples and comparative examples, it was found that each component of the present invention causes changes in wear resistance or denitrification performance to varying degrees. The interaction of the components of the hardening liquid collectively promotes the performance changes. Compared with the comparative examples, the catalyst treated with the hardening liquid in the examples exhibits superior denitrification and wear resistance performance. In summary, the corrugated plate SCR denitrification catalyst hardening liquid of the present invention, formulated in proportion by phosphoric acid, copper oxide, Cu molecular sieve, polyethylene glycol, polyvinyl alcohol, and silica, can not only improve the wear resistance of the hardened end face of the catalyst but also enhance the denitrification activity of the hardened end of the catalyst.

[0087] This invention is not limited to the specific embodiments described above. Any changes or modifications made by those skilled in the art within the scope of this invention are covered by the patent scope of this invention.

Claims

1. A corrugated plate SCR denitrification catalyst hardening liquid, characterized in that, The raw materials include the following components in the indicated weight ratios: deionized water 15-60%, phosphoric acid 12-70%, copper oxide 1-20%, Cu molecular sieve 3-25%, polyvinyl alcohol 1.5-5.5%, silica 5-15%, and polyethylene glycol 3-6.5%. In the preparation of the corrugated plate SCR denitrification catalyst hardening liquid, phosphoric acid is first dissolved in water to form a phosphoric acid solution, and then copper oxide is added to the phosphoric acid solution to prepare a copper dihydrogen phosphate solution; and then other component raw materials are added.

2. The corrugated plate SCR denitrification catalyst hardening liquid according to claim 1, characterized in that, The raw materials include the following components in the following weight ratios: water 25%~45%, phosphoric acid 20%~45%, copper oxide 3%~15%, Cu molecular sieve 5%~15%, polyvinyl alcohol 2%~4%, silica 6%~10%, and polyethylene glycol 3%~5%.

3. The corrugated plate SCR denitrification catalyst hardening liquid according to claim 1, characterized in that, The Cu molecular sieve is at least one of Cu / ZSM-5 molecular sieve, Cu / USY molecular sieve, and Cu / β molecular sieve.

4. A method for preparing the corrugated plate SCR denitrification catalyst hardening liquid according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Dissolve phosphoric acid in water to form a phosphoric acid solution; (2) Add copper oxide to the phosphoric acid solution to prepare copper dihydrogen phosphate solution; (3) Add Cu molecular sieve to copper dihydrogen phosphate solution to form copper dihydrogen phosphate-Cu molecular sieve mixture; (4) Add polyethylene glycol to the mixture in step (3) to obtain a copper dihydrogen phosphate-Cu molecular sieve-polyethylene glycol mixture; (5) Dissolve polyvinyl alcohol in water to obtain a polyvinyl alcohol solution; (6) Mix the mixture from step (4) and the polyvinyl alcohol solution from step (5) to obtain a mixture; (7) Add silica to the mixture in step (6), mix, and obtain the corrugated plate SCR denitrification catalyst hardening solution.

5. The method for preparing the corrugated plate SCR denitrification catalyst hardening liquid according to claim 4, characterized in that, In step (1), while dissolving phosphoric acid in water, the mixture is stirred at a constant speed and heated to 70~80℃.

6. The method for preparing the corrugated plate SCR denitrification catalyst hardening liquid according to claim 4, characterized in that, In step (3), during the process of adding Cu molecular sieve to the copper dihydrogen phosphate solution, the mixture is stirred at a constant speed and heated to 80~90℃.

7. The method for preparing the corrugated plate SCR denitrification catalyst hardening liquid according to claim 4, characterized in that, In step (4), during the process of adding polyethylene glycol to the mixture in step (3), the mixture is stirred at a constant speed and heated to 70~80℃.

8. The method for preparing the corrugated plate SCR denitrification catalyst hardening liquid according to claim 4, characterized in that, In step (5), when polyvinyl alcohol is added to water, it is stirred at a constant speed and heated to 95~98℃; in step (7), when silica is added to the mixture from step (6), it is stirred at a constant speed and heated to 70~80℃.

9. A method for using a corrugated plate SCR denitrification catalyst hardening liquid, characterized in that, include: The pre-hardened end of the corrugated SCR catalyst substrate is vertically inserted into the hardening liquid of the corrugated SCR denitrification catalyst according to any one of claims 1-3 for immersion, and then air-dried at room temperature to complete the end-face hardening of the corrugated SCR catalyst substrate. Active material is coated on the corrugated SCR catalyst substrate, and then dried and calcined to obtain the hardened catalyst.

10. The method of using the corrugated plate SCR denitrification catalyst hardening liquid according to claim 9, characterized in that, The soaking time is 1-3 minutes; the drying temperature is 180-240℃ and the time is 2-4 hours; the calcination temperature is 300-400℃ and the time is 8-10 hours.