Flue gas denitration catalyst as well as preparation method and application thereof

Abstract

The invention provides a flue gas denitration catalyst as well as a preparation method and application thereof. The flue gas denitration catalyst comprises a carrier and an active component, the carrier comprises a porous solid solution microsphere composed of TiO2, CeO2 and ZrO2, and the active component comprises WO3, MoO3, MnO2 and / or CuO; the mass ratio of ZrO2 to TiO2 is (1-10): 100, and the mass ratio of CeO2 to TiO2 is (2-10): 100; the mass ratio of WO3 to TiO2 is (1-8): 100, the mass ratio of MoO3 to TiO2 is (0.2-5): 100, and the mass ratio of MnO2 and / or CuO to TiO2 is (1-8): 100. The specific surface area of the catalyst is not less than 63.0 m < 2 > / g, the catalyst has relatively high high-temperature thermal stability, and the conversion rate of NOx at 400-500 DEG C is not less than 80.0%.

Description

Technical Field

[0001] The present invention belongs to the field of catalysts, and relates to a flue gas denitration catalyst, in particular to a flue gas denitration catalyst, a preparation method thereof and an application thereof. Background Art

[0002] As an important energy equipment for industrial production, gas boilers are indispensable in the process of petroleum refining. With the continuous improvement of the scale and process level of refining units, it is required that gas boilers can operate stably and meet the standards. Natural gas, as the main fuel of gas boilers, has the advantages of low nitrogen, low sulfur and low dust emissions during combustion. However, due to the large injection of combustion-supporting air, a large amount of nitrogen oxides (NO x ) will be generated from nitrogen in the air at high temperatures.

[0003] NO x is one of the main air pollutants, and the emission requirements are becoming increasingly strict. At present, the SCR technology is mostly used for denitration treatment. Among many flue gas denitration technologies, NH 3 -SCR is a currently relatively mature and widely used NO x formulation control method. In this control method, the denitration catalyst is the core of the SCR technology. Traditional industrial denitration catalysts mostly use V 2 O 5 as the active component and TiO 2 as the carrier. However, the anatase-type TiO 2 in this catalyst will slowly transform into rutile at high temperatures, resulting in the loss of denitration activity of the catalyst and poor thermal stability; and the active component V 2 O 5 will convert some SO 2 in the flue gas into SO 3 , and ammonium sulfate is produced and adhered to the surface of the heat exchanger tube bundle, affecting the normal operation of the subsequent low-temperature economizer.

[0004] Therefore, it is urgent to study a flue gas denitration catalyst that can solve the aforementioned problems. Summary of the Invention

[0005] In view of the above defects, the present invention provides a flue gas denitration catalyst, which has a high specific surface area and thermal stability, and can significantly improve the conversion rate of NO x at high temperatures.

[0006] The present invention provides a preparation method of the above flue gas denitration catalyst. The flue gas denitration catalyst prepared by this preparation method has a high specific surface area and thermal stability, and can achieve a high denitration efficiency under high-temperature reaction conditions.

[0007] The present invention provides a denitrification method. Using the above-mentioned flue gas denitrification catalyst or the flue gas denitrification catalyst prepared by the above-mentioned preparation method in the flue gas denitrification reaction can effectively improve the conversion rate of NO x .

[0008] The present invention provides a flue gas denitrification catalyst. The flue gas denitrification catalyst includes a carrier and an active component; the carrier includes a porous solid solution microsphere composed of TiO 2 , CeO 2 and ZrO 2 , and the active component includes WO 3 , MoO 3 , MnO 2 and / or CuO;

[0009] The mass ratio of ZrO 2 to TiO 2 is (1-10):100, and the mass ratio of CeO 2 to TiO 2 is (2-10):100;

[0010] The mass ratio of WO 3 to TiO 2 is (1-8):100, the mass ratio of MoO 3 to TiO 2 is (0.2-5):100, and the mass ratio of MnO 2 and / or CuO to TiO 2 is (1-8):100;

[0011] The specific surface area of the flue gas denitrification catalyst is not less than 63.0 m 2 / g;

[0012] In the flue gas denitrification reaction, the conversion rate of NO x is not less than 80.0% at 400-500 °C for the flue gas denitrification catalyst.

[0013] Furthermore, the flue gas denitrification catalyst is a corrugated plate type flue gas denitrification catalyst;

[0014] The corrugated plate of the corrugated plate type flue gas denitrification catalyst has a thickness of 0.2-0.6 mm, a corrugation width of 5-8 mm, and a corrugation height of 5-10 mm.

[0015] The present invention provides a preparation method of a flue gas denitrification catalyst, including the following steps:

[0016] (1) Mix a titanium source precursor, a zirconium source precursor, a cerium source precursor with an organic alcohol to obtain a first mixed solution, and perform a hydrothermal reaction to obtain a first product;

[0017] Among them, the titanium source precursor is calculated as TiO 2 The zirconium source precursor is calculated as ZrO 2 The cerium source precursor is calculated as CeO 2 The mass ratio of the zirconium source precursor to the titanium source precursor is (1-10):100, and the mass ratio of the cerium source precursor to the titanium source precursor is (2-10):100;

[0018] The volume ratio of the organic alcohol to the titanium source precursor is (1-10):1;

[0019] (2) After washing, solid-liquid separation, drying, and calcination of the first product, the porous solid solution microspheres are obtained; the calcination temperature is 420-500 °C, and the calcination time is 2-10 h;

[0020] (3) Mix the copper source precursor and / or manganese source precursor with water to obtain a second mixed solution, and soak the porous solid solution microspheres in the second mixed solution in an equal volume, and obtain a second product after drying;

[0021] Among them, the copper source precursor is calculated as CuO, the manganese source precursor is calculated as MnO 2 The titanium source precursor is calculated as TiO 2 The mass ratio of the copper source precursor and / or manganese source precursor to the titanium source precursor is (1-8):100;

[0022] (4) Mix the second product with the tungsten source precursor, molybdenum source precursor, polymer dispersant, binder, pore-forming agent, and water, and adjust the pH value to 7-12 to obtain a slurry, and obtain the flue gas denitration catalyst after extrusion to form a green body, drying, and calcination;

[0023] Among them, the tungsten source precursor is calculated as WO 3 The molybdenum source precursor is calculated as MoO 3 The titanium source precursor is calculated as TiO 2 The mass ratio of the tungsten source precursor to the titanium source precursor is (1-8):100, and the mass ratio of the molybdenum source precursor to the titanium source precursor is (0.2-5):100.

[0024] Further, in step (1), the temperature of the hydrothermal reaction is 140-220 °C, and the reaction time is 6-30 h.

[0025] Further, in step (3), the molar concentration of the copper source precursor and / or manganese source precursor in the second mixed solution is 0.5-4 mol / L;

[0026] And / or, the immersion time is 5 to 50 minutes.

[0027] Further, in step (4), the titanium source precursor is TiO 2 The mass ratio of the polymer dispersant to the titanium source precursor is (0.5-3):100;

[0028] And / or, the mass ratio of the binder to the titanium source precursor solution is (2-8):100;

[0029] And / or, the mass ratio of the pore-forming agent to the titanium source precursor solution is (0.2-3):100.

[0030] Further, in step (4), the drying temperature is 30 to 90°C and the drying time is 5 to 15 days;

[0031] And / or, the calcination temperature is 450-620°C, and the calcination time is 6-38h.

[0032] Furthermore, the copper source precursor includes at least one of soluble nitrates, copper sulfate, and copper acetate;

[0033] And / or, the manganese source precursor includes at least one of soluble nitrates, manganese chloride, and manganese acetate;

[0034] And / or, the titanium source precursor includes tetraisopropyl titanate and / or tetrabutyl titanate;

[0035] And / or, the cerium source precursor includes at least one of soluble nitrates, cerium sulfate, and cerium chloride;

[0036] And / or, the zirconium source precursor includes at least one of zirconium acetate, zirconium nitrate and zirconium sulfate;

[0037] And / or, the organic alcohol includes at least one of ethanol, ethylene glycol, propanol, and isopropanol;

[0038] And / or, the tungsten source precursor includes ammonium paratungstate and / or ammonium metatungstate;

[0039] And / or, the molybdenum source precursor includes ammonium molybdate and / or ammonium heptamolybdate;

[0040] And / or, the polymer dispersant includes polyethylene glycol and / or polyacrylamide;

[0041] And / or, the binder comprises carboxymethyl cellulose and / or hydroxypropyl cellulose;

[0042] And / or, the pore-forming agent includes at least one of polyethylene oxide, polymethyl methacrylate, and Tianqing powder.

[0043] Further, the extrusion to form a green body in step (4) further includes stamping the slurry to form a corrugated sheet, spraying a resin adhesive between the corrugated sheets, and then laminating and assembling them to obtain a corrugated plate type denitration catalyst green body.

[0044] The present invention provides a flue gas denitration method, which uses the above-mentioned flue gas denitration catalyst, or the flue gas denitration catalyst prepared by the preparation method described in any one of the above, in the flue gas denitration reaction.

[0045] In the flue gas denitration catalyst of the present invention, the porous solid solution microspheres composed of TiO 2 , CeO 2 and ZrO 2 have a new crystal phase structure. When the mass ratio of ZrO 2 to TiO 2 and the mass ratio of CeO 2 to TiO 2 are within the above range, the high-temperature thermal stability can be significantly improved, so that the catalyst still maintains high activity in an environment of 400-500 °C; at the same time, the mass ratio of the active component WO 3 to TiO 2 , the mass ratio of MoO 3 to TiO 2 , the mass ratio of MnO 2 and / or CuO to TiO 2 are controlled, and the specific surface area of the catalyst is not less than 63.0 m 2 / g, which can further improve the reaction activity of the catalyst; thus, the denitration efficiency of the flue gas denitration catalyst in a high-temperature environment is comprehensively improved, and under the reaction conditions of 400-500 °C, the conversion rate of NO x is not less than 80.0%. Detailed Embodiments

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0047] The first aspect of the present invention provides a flue gas denitration catalyst, which includes a carrier and an active component; the carrier includes porous solid solution microspheres composed of TiO 2 , CeO 2 and ZrO 2 , and the active component includes WO 3 , MoO 3, MnO 2 and / or CuO;

[0048] ZrO 2 and TiO 2 have a mass ratio of (1 - 10):100, and CeO 2 and TiO 2 have a mass ratio of (2 - 10):100;

[0049] WO 3 and TiO 2 have a mass ratio of (1 - 8):100, MoO 3 and TiO 2 have a mass ratio of (0.2 - 5):100, MnO 2 and / or CuO and TiO 2 have a mass ratio of (1 - 8):100;

[0050] The specific surface area of the flue gas denitration catalyst is not less than 63.0 m 2 / g;

[0051] In the flue gas denitration reaction of the flue gas denitration catalyst, at 400 - 500 °C, the conversion rate of NO x is not less than 80.0%.

[0052] The conversion rate of NO x in the present invention being not less than 80.0% means that when the flue gas denitration catalyst in the present invention is used in the flue gas denitration reaction, it specifically includes:

[0053] NO x conversion rate evaluation conditions: space velocity 5000 h -1 , reaction temperature 480 °C, inlet NO x being 600 mg / Nm 3 , SO 2 being 100 mg / Nm 3 , ammonia - nitrogen ratio being 1, water content being 15%, O 2 content 3.0% (v).

[0054] Source of the raw gas: NO, SO 2 use standard gases, with specifications all being 5.0% (v), N 2 gas for balance, and the manufacturer is Dalian Dete Gas Co., Ltd.; O 2 comes from the utility air pipe network, with a pressure of 0.4 - 0.6 Mpa; N 2 comes from the utility nitrogen pipe network, with a purity of 99.0% (v) and a pressure of 0.4 - 0.6 Mpa.

[0055] NO concentration measurement method: continuous on-line flue gas analyzer, Siemens ULTRAMAT23.

[0056] The flue gas denitration catalyst in the present invention comprises porous solid solution microspheres composed of TiO 2 , CeO 2 and ZrO 2 . The active components include WO 3 , MoO 3 , MnO 2 and / or CuO; wherein, since the atomic radii of Ce 4+ and Zr 4+ are smaller than that of Ti 4+ , it is easy to displace Ti 2 in the lattice of TiO 4+ to form a new crystal phase structure, obtaining Ti-Ce-Zr porous solid solution microspheres. When the mass ratio of ZrO 2 to TiO 2 is (1-10):100 and the mass ratio of CeO 2 to TiO 2 is (2-10):100, the high-temperature thermal stability can be significantly improved, enabling the catalyst to maintain high activity in the environment of 400-500 °C; meanwhile, since the specific surface area of this catalyst is not less than 63.0 m 2 / g, and the mass ratio of the active component WO 3 to TiO 2 is (1-8):100, the mass ratio of MoO 3 to TiO 2 is (0.2-5):100, and the mass ratio of MnO 2 and / or CuO to TiO 2 is (1-8):100, so the reaction activity of the catalyst can be further improved; thereby comprehensively improving the reaction activity of the flue gas denitration catalyst in a high-temperature environment, making the conversion rate of NO x not less than 80.0% under the reaction conditions of 400-500 °C.

[0057] In addition, since the flue gas denitration catalyst in the present invention does not contain V 2 O 5 , it is possible to avoid the conversion of SO 2 in the flue gas into SO 3 , the production of ammonium sulfate adhering to the surface of the heat exchanger tube bank, affecting the normal operation of the subsequent low-temperature economizer; and due to TiO 2The lattice is doped with Ce, so the performance of the catalyst in resisting poisoning by alkali metals and alkaline earth metals can be improved; meanwhile, Ce can also cooperate with Cu and / or Mn to further improve the performance of the catalyst in resisting poisoning by alkali metals and alkaline earth metals and enhance the catalytic efficiency of the catalyst.

[0058] In a specific embodiment, the flue gas denitration catalyst is a corrugated plate type flue gas denitration catalyst; the thickness of the corrugated plate of the corrugated plate type flue gas denitration catalyst is 0.2 - 0.6 mm, the corrugation width is 5 - 8 mm, and the corrugation height is 5 - 10 mm. When the flue gas denitration catalyst is a corrugated plate type catalyst and the thickness, corrugation width and corrugation height of the catalyst are within the above ranges, it can be applied to the flue gas denitration reaction at a high space velocity and still have a high denitration efficiency at a high space velocity.

[0059] The second aspect of the present invention provides a preparation method of a flue gas denitration catalyst, including the following steps:

[0060] (1) Mix a titanium source precursor, a zirconium source precursor, a cerium source precursor with an organic alcohol to obtain a first mixed solution, and carry out a hydrothermal reaction to obtain a first product;

[0061] Among them, the titanium source precursor is calculated as TiO 2 The zirconium source precursor is calculated as ZrO 2 The cerium source precursor is calculated as CeO 2 The mass ratio of the zirconium source precursor to the titanium source precursor is (1 - 10):100, and the mass ratio of the cerium source precursor to the titanium source precursor is (2 - 10):100;

[0062] The volume ratio of the organic alcohol to the titanium source precursor is (1 - 10):1;

[0063] (2) Wash, solid-liquid separate, dry, and calcine the first product to obtain a porous solid solution microsphere; the calcination temperature is 420 - 500 °C, and the calcination time is 2 - 10 h;

[0064] (3) Mix a copper source precursor and / or a manganese source precursor with water to obtain a second mixed solution, impregnate the porous solid solution microsphere with an equal volume in the second mixed solution, and dry to obtain a second product;

[0065] Among them, the copper source precursor is calculated as CuO, the manganese source precursor is calculated as MnO 2 The titanium source precursor is calculated as TiO 2 The mass ratio of the copper source precursor and / or the manganese source precursor to the titanium source precursor is (1 - 8):100;

[0066] (4) Mix the second product with a tungsten source precursor, a molybdenum source precursor, a polymer dispersant, a binder, a pore former, and water, and adjust the pH value to 7 - 12 to obtain a slurry. After extrusion to form a green body, drying, and calcination, a flue gas denitrification catalyst is obtained;

[0067] Among them, the tungsten source precursor is calculated based on WO 3 The source precursor is calculated based on MoO 3 The titanium source precursor is calculated based on TiO 2 The mass ratio of the tungsten source precursor to the titanium source precursor is (1 - 8):100, and the mass ratio of the molybdenum source precursor to the titanium source precursor is (0.2 - 5):100.

[0068] Specifically, in step (1), mix the titanium source precursor calculated based on TiO 2 The zirconium source precursor calculated based on ZrO 2 The cerium source precursor calculated based on CeO 2 with an organic alcohol to obtain a first mixed solution. Among them, the mass ratio of the zirconium source precursor to the titanium source precursor is (1 - 10):100, the mass ratio of the cerium source precursor to the titanium source precursor is (2 - 10):100, and the volume ratio of the organic alcohol to the titanium source precursor is (1 - 10):1. Carry out a hydrothermal reaction to obtain a first product.

[0069] Furthermore, the mass ratio of the zirconium source precursor to the titanium source precursor is (1 - 4):100, the mass ratio of the cerium source precursor to the titanium source precursor is (3 - 7):100, and the volume ratio of the organic alcohol to the titanium source precursor is (3 - 6):1.

[0070] The present invention does not specifically limit the sources of the titanium source precursor, zirconium source precursor, cerium source precursor, and organic alcohol. Commercially available products or products prepared by conventional preparation methods well-known to those skilled in the art can be used.

[0071] The titanium source precursor of the present invention refers to the raw material providing Ti element, the zirconium source precursor refers to the raw material providing Zr element, and the cerium source precursor refers to the raw material providing Ce element. As long as it contains the target element (Ti, Zr, Ce), it falls within the scope of the present invention.

[0072] The present invention does not specifically limit the type of organic alcohol, as long as it can completely dissolve the titanium source precursor, zirconium source precursor, and cerium source precursor to form a mixed solution.

[0073] The present invention does not specifically limit the mixing method, as long as the titanium source precursor, zirconium source precursor, and cerium source precursor are completely dissolved in the organic alcohol. For example, mixing can be carried out by stirring or ultrasonic oscillation.

[0074] The present invention does not specifically limit the temperature and reaction time of the hydrothermal reaction.

[0075] In step (2), after the first product is washed, subjected to solid-liquid separation, and dried, it is calcined. The calcination temperature is 420-500 °C, and the calcination time is 2-10 h, to obtain porous solid solution microspheres.

[0076] The present invention does not specifically limit the washing method, and it is only necessary to wash the porous solid solution microspheres clean.

[0077] The present invention does not specifically limit the method of solid-liquid separation. For example, solid-liquid separation can be carried out by filtration and / or centrifugation.

[0078] The present invention does not specifically limit the temperature and time during the drying process, and it is only necessary to completely evaporate the moisture in the separated solid phase. For example, the drying temperature is 80-110 °C, and the drying time is 1-8 h.

[0079] In step (3), a copper source precursor in terms of CuO and / or a manganese source precursor in terms of MnO 2 are mixed and dissolved in water to obtain a second mixed solution. Among them, the mass ratio of the copper source precursor and / or the manganese source precursor to the titanium source precursor is (1-8):100; the porous solid solution microspheres are impregnated in the second mixed solution in an equal volume, and after drying, a second product is obtained.

[0080] The equal volume impregnation in the present invention means that the pore volume of the porous solid solution microspheres is consistent with the volume of the impregnating solution, the second mixed solution, so that the impregnating solution can just completely enter the pores.

[0081] The copper source precursor of the present invention refers to a raw material that provides Cu element, and the manganese source precursor refers to a raw material that provides Mn element. As long as it contains the target elements (Cu, Mn), it belongs to the definition of the present invention.

[0082] The present invention does not specifically limit the sources of the copper source precursor and the manganese source precursor, and commercially available products or products prepared by conventional preparation methods well-known to those skilled in the art can be used.

[0083] The present invention does not specifically limit the molar concentration of the second mixed solution.

[0084] The present invention does not specifically limit the temperature and time of drying, and it is only necessary to completely evaporate the moisture in the impregnated porous solid solution microspheres.

[0085] In step (4), the second product is combined with a tungsten source precursor in terms of WO 3 and a molybdenum source precursor in terms of MoO 3Mix a tungsten source precursor, a polymer dispersant, a binder, a pore former, and water. Among them, the mass ratio of the tungsten source precursor to the titanium source precursor is (1-8):100, and the mass ratio of the molybdenum source precursor to the titanium source precursor is (0.2-5):100; adjust the pH of the mixed system to 7-12, and the obtained slurry is extruded to form a green body, which is dried and calcined to obtain a flue gas denitrification catalyst.

[0086] Furthermore, the water content of the slurry is 20-40%.

[0087] The tungsten source precursor in the present invention refers to the raw material that provides the W element, and the molybdenum source precursor refers to the raw material that provides the Mo element. As long as it contains the target element (W, Mo), it belongs to the definition of the present invention.

[0088] The present invention does not specifically limit the molecular weight of the polymer dispersant.

[0089] The present invention does not specifically limit the types of the polymer dispersant, the binder, and the pore former, and the types commonly used by those skilled in the art can be adopted.

[0090] The present invention does not specifically limit the sources of the tungsten source precursor, the molybdenum source precursor, the polymer dispersant, the binder, and the pore former, and commercially available products well-known to those skilled in the art or products prepared by conventional preparation methods can be adopted.

[0091] The present invention does not specifically limit the method of pH adjustment. For example, ammonia water can be used to adjust the pH value of the mixed system to 7-12.

[0092] The present invention does not specifically limit the conditions of drying and calcination.

[0093] In the preparation method of the flue gas denitrification catalyst in the present invention, first, use the hydrothermal method to dope CeO 2 and ZrO 2 into TiO 2 . In the TiO 2 lattice, Ti 4+ is easily replaced by Ce 4+ and Zr 4+ with smaller atomic radii to form a new Ti-Zr-Ce solid solution structure. By controlling the mass ratio of the zirconium source precursor to the titanium source precursor, the mass ratio of the cerium source precursor to the titanium source precursor, and the volume ratio of the organic alcohol to the titanium source precursor, the thermal stability of the porous solid solution microspheres can be significantly improved; secondly, by calcining the product after the hydrothermal reaction, the lattice defects of the doped TiO 2 become more stable, and at the same time, the lattice defects and specific surface area of the TiO 2 substrate are increased. This can not only make the active components more evenly dispersed, but also increase the specific surface area of the catalyst, making it not less than 63.0m2 / g helps to fully exert the catalytic activity of the catalyst and improve the denitrification efficiency; finally, by controlling the mass ratio of the copper source precursor and / or manganese source precursor to the titanium source precursor, the mass ratio of the tungsten source precursor to the titanium source precursor, and the mass ratio of the molybdenum source precursor to the titanium source precursor, the content of the active components in the catalyst is further controlled, and the catalytic activity of the catalyst is further improved; through the above preparation method, the thermal stability and denitrification efficiency of the catalyst can be comprehensively improved, so that the catalyst in the flue gas denitrification reaction has a NO x conversion rate of not less than 80.0% at 400-500 °C.

[0094] In a specific embodiment, in step (1), the temperature of the hydrothermal reaction is 140-220 °C, and the reaction time is 6-30 h. Within this range, the increase in side reactions caused by too fast reaction rate can be avoided, and at the same time, the efficiency decline caused by too slow reaction rate can also be avoided.

[0095] Furthermore, the temperature of the hydrothermal reaction is 150-180 °C, and the reaction time is 12-23 h.

[0096] In a specific embodiment, in step (3), the molar concentration of the copper source precursor and / or manganese source precursor in the second mixed solution is 0.5-4 mol / L. Within this range, the copper source precursor and / or manganese source precursor in the second mixed solution can be completely absorbed by the porous solid solution microspheres, and the active components can be evenly distributed inside and on the surface of the porous solid solution microspheres, thereby further improving the reaction activity of the catalyst.

[0097] When the second mixed solution contains both the copper source precursor and the manganese source precursor at the same time, the present invention does not specifically limit the ratio between the copper source precursor and the manganese source precursor.

[0098] In a specific embodiment, in step (3), the impregnation time is 5-50 min. Within this range, it can ensure that the second mixed solution completely infiltrates the inside and surface of the porous solid solution microspheres, and at the same time improve the uniformity of the distribution of the copper source precursor and / or manganese source precursor in the second mixed solution inside and on the surface of the microspheres, so that the catalyst has high reaction activity.

[0099] In a specific embodiment, in step (4), taking the titanium source precursor as TiO 2 calculated, the mass ratio of the polymer dispersant to the titanium source precursor is (0.5-3):100. At this time, it helps to evenly disperse the active components, improve the aggregation and agglomeration problems of the active components, and fully exert the role of the active components in catalysis.

[0100] In a specific embodiment, in step (4), taking the titanium source precursor as TiO 2It is calculated that the mass ratio of the binder to the titanium source precursor solution is (2-8):100. Since the flue gas denitration catalyst contains a variety of inorganic components and the connection is relatively loose, when the mass ratio of the binder to the titanium source precursor solution is within the aforementioned range, the catalyst cracking and shedding can be prevented.

[0101] In a specific embodiment, the titanium source precursor is TiO 2 It is calculated that the mass ratio of the pore-forming agent to the titanium source precursor solution is (0.2-3):100. The pore-forming agent is generally a macromolecular organic compound, which decomposes after calcination, leaving pores to provide a reaction space for the catalytic reaction. When the mass ratio of the pore-forming agent to the titanium source precursor solution is within the aforementioned range, it can not only ensure the microspace and pores required for the catalyst reaction, but also ensure the content of the active components of the catalyst, further improving the catalytic efficiency.

[0102] In a specific embodiment, in step (4), the drying temperature is 30-90 °C and the drying time is 5-15 days. Within this range, it can not only prevent the dehydration from being too fast due to too high drying temperature, resulting in cracking of the catalyst during drying, but also improve the production efficiency.

[0103] In a specific embodiment, in step (4), the calcination temperature is 450-620 °C and the calcination time is 6-38 h. Within this range, it can be avoided that the active components are not fully activated due to too low calcination temperature and the low strength of the catalyst finished product; at the same time, it can also be avoided that TiO 2 is transformed from anatase to rutile due to too high temperature, resulting in the loss of denitration activity of the catalyst; in addition, it can effectively prevent sintering of some micropores inside the catalyst, resulting in a decrease in the specific surface area of the catalyst and a reduction in catalytic activity.

[0104] In a specific embodiment, the copper source includes at least one of soluble nitrates, copper sulfate, and copper acetate, preferably copper nitrate; and / or, the manganese source precursor includes at least one of soluble nitrates, manganese chloride, and manganese acetate, preferably manganese nitrate; and / or, the titanium source precursor includes tetra-isopropyl titanate and / or tetra-butyl titanate; and / or, the cerium source precursor includes at least one of soluble nitrates, cerium sulfate, and cerium chloride, preferably cerium nitrate; and / or, the zirconium source precursor includes at least one of zirconium acetate, zirconium nitrate, and zirconium sulfate, preferably zirconium nitrate; and / or, the organic alcohol includes at least one of ethanol, ethylene glycol, propanol, and isopropyl alcohol, preferably ethylene glycol; and / or, the tungsten source precursor includes ammonium paratungstate and / or ammonium metatungstate; and / or, the molybdenum source precursor includes ammonium molybdate and / or ammonium heptamolybdate; and / or, the polymer dispersant includes polyethylene glycol and / or polyacrylamide; and / or, the binder includes carboxymethyl cellulose and / or hydroxypropyl cellulose; and / or, the pore former includes at least one of polyethylene oxide, polymethyl methacrylate, and sesbania powder. When the foregoing several types of compounds are respectively mixtures of multiple specific compounds, the present invention does not overly limit the ratio between the individual specific compounds.

[0105] Further, the number-average molecular weight of the polymer dispersant polyethylene glycol is 190 to 420, and the number-average molecular weight of the polymer dispersant polyacrylamide is 6 million to 12 million.

[0106] Further, the average molecular weight of polyethylene oxide is 3 million to 8 million, the number-average molecular weight of polymethyl methacrylate is 100,000 to 1 million, and sesbania powder is a polysaccharide polymer substance extracted from the seed endosperm of the leguminous plant Sesbania cannabina, with an average molecular weight of 206,000.

[0107] In a specific embodiment, the extrusion to form the green body in step (4) further includes stamping the slurry to form a corrugated sheet, spraying a resin adhesive between the corrugated sheets, and then laminating and assembling to obtain a corrugated plate type denitration catalyst green body. By extruding the green body to make a corrugated plate type denitration catalyst green body, the catalyst can still have a high denitration efficiency at a high space velocity.

[0108] The third aspect of the present invention provides a flue gas denitration method, using the flue gas denitration catalyst of the first aspect, or the flue gas denitration catalyst prepared by the preparation method of the second aspect, in the flue gas denitration reaction. Since this flue gas denitration catalyst has a high specific surface area and good thermal stability, it can still achieve a high denitration efficiency at a reaction temperature of 400 to 500 °C, making the conversion rate of NO x not less than 80%.

[0109] Hereinafter, the flue gas denitration catalyst of the present invention will be introduced in detail through specific examples, and "%" in the examples and comparative examples refers to mass percentage.

[0110] Example 1

[0111] (1) Mix 100 g of tetra-isopropyl titanate calculated as TiO 2 , 2 g of zirconium acetate calculated as ZrO 2 , 4 g of cerium nitrate calculated as CeO 2 with 500 mL of ethylene glycol and stir to obtain a first mixed solution. Among them, the volume ratio of ethylene glycol to tetra-isopropyl titanate is 1.35:1. Place the first mixed solution in a reaction kettle, with a reaction temperature of 170 °C, and obtain a first product after reacting for 23 h;

[0112] (2) Wash and filter the first product, then dry it at 80 °C for 6 h. Take out the sample and calcine it in an environment of 450 °C for 6 h to obtain porous solid solution microspheres;

[0113] (3) Dissolve 5 g of copper nitrate calculated as CuO and 3 g of manganese nitrate calculated as MnO 2 in water to form a second mixed solution with a concentration of 0.5 mol / L. Immerse the above porous solid solution microspheres in the second mixed solution with equal volume for 30 min, then take them out and dry to obtain a second product;

[0114] (4) Mix the second product with 1 g of ammonium metatungstate calculated as WO 3 , 5 g of ammonium heptamolybdate calculated as MoO 3 , 7.0 g of carboxymethyl cellulose, 0.8 g of polyethylene glycol (number average molecular weight is 190), 1.0 g of polyethylene oxide (average molecular weight is 5 million) and deionized water by mechanical stirring, adjust the pH value to 10.0, make a mud with a moisture content of 26%, punch out corrugated plates, spray epoxy resin glue between the corrugated sheets and then stack and assemble them to obtain a corrugated plate type denitration catalyst blank. Dry the blank at 50 °C for 7 days, and then calcine it at 550 °C for 8 h according to the heating program to obtain the flue gas denitration catalyst of this example. The corrugated plate thickness of this catalyst is 0.4 mm, the corrugated width is 6 mm, and the corrugated height is 6 mm.

[0115] Example 2

[0116] (1) Mix 100 g of tetra-isopropyl titanate calculated as TiO 2 , 4 g of zirconium nitrate calculated as ZrO 2 , 4 g of cerium nitrate calculated as CeO 2 with 400 mL of ethylene glycol and stir to obtain a first mixed solution. Among them, the volume ratio of ethylene glycol to tetra-isopropyl titanate is 1.08:1. Place the first mixed solution in a reaction kettle, with a reaction temperature of 170 °C, and obtain a first product after reacting for 20 h;

[0117] (2) Wash and filter the first product, then dry it at 90 °C for 5 h. After taking out the sample, calcine it in an environment of 460 °C for 8 h to obtain porous solid solution microspheres;

[0118] (3) Dissolve 3 g of copper nitrate in terms of CuO and 3 g of manganese nitrate in terms of MnO 2 in water to form a second mixed solution with a concentration of 0.5 mol / L. Immerse the above-mentioned porous solid solution microspheres in the second mixed solution with equal volume for 30 min, then take them out and dry to obtain a second product;

[0119] (4) Mix the second product with 5 g of ammonium metatungstate in terms of WO 3 , 1 g of ammonium molybdate in terms of MoO 3 , 5.0 g of carboxymethyl cellulose, 1.2 g of polyethylene glycol (number average molecular weight is 190), 1.0 g of polyethylene oxide (average molecular weight is 6 million) and deionized water by mechanical stirring, adjust the pH value to 9.0, make a mud with a water content of 30%, punch out corrugated plates, spray epoxy resin glue between the corrugated sheets and then stack and assemble them to obtain a corrugated plate type denitration catalyst green body. After drying the green body at 60 °C for 5 days, calcine it according to the heating program at 520 °C for 20 h to obtain the flue gas denitration catalyst of this example. The corrugated plate thickness of this catalyst is 0.3 mm, the corrugated width is 5 mm, and the corrugated height is 6 mm.

[0120] Example 3

[0121] (1) Mix 100 g of tetra-isopropyl titanate in terms of TiO 2 , 3 g of zirconium acetate in terms of ZrO 2 , 7 g of cerium nitrate in terms of CeO 2 and 600 mL of ethylene glycol and stir to obtain a first mixed solution. Among them, the volume ratio of ethylene glycol to tetra-isopropyl titanate is 1.62:1. Place the first mixed solution in a reaction kettle, the reaction temperature is 180 °C, and after reacting for 20 h, obtain a first product;

[0122] (2) Wash and filter the first product, then dry it at 110 °C for 2 h. After taking out the sample, calcine it in an environment of 480 °C for 10 h to obtain porous solid solution microspheres;

[0123] (3) Dissolve 2 g of copper sulfate in terms of CuO and 3 g of manganese nitrate in terms of MnO 2 in water to form a second mixed solution with a concentration of 4 mol / L. Immerse the above-mentioned porous solid solution microspheres in the second mixed solution with equal volume for 50 min, then take them out and dry to obtain a second product;

[0124] (4) Mix the second product with 1 g of ammonium metatungstate in terms of WO 3 , 1 g of ammonium molybdate in terms of MoO 32 g of ammonium molybdate, 4.0 g of carboxymethyl cellulose, 0.8 g of polyethylene glycol (number average molecular weight of 420), 1.2 g of polymethyl methacrylate (number average molecular weight of 100,000), and deionized water were mixed by mechanical stirring, the pH value was adjusted to 10.0, a mud with a moisture content of 25% was made, corrugated plates were punched out, epoxy resin glue was sprayed between the corrugated sheets and then laminated and assembled to obtain a corrugated plate type denitration catalyst blank. After drying the blank at 30 °C for 15 days, it was calcined at 620 °C for 6 h according to the heating program to obtain the flue gas denitration catalyst of this example. The corrugated plate of this catalyst has a thickness of 0.6 mm, a corrugated width of 8 mm, and a corrugated height of 6 mm.

[0125] Example 4

[0126] (1) 100 g of tetrabutyl titanate calculated as TiO 2 , 3 g of zirconium acetate calculated as ZrO 2 , 1 g of cerium nitrate calculated as CeO 2 were mixed and stirred with 500 mL of ethylene glycol to obtain a first mixed solution. Among them, the volume ratio of ethylene glycol to tetraisopropyl titanate is 1.41:1; the first mixed solution was placed in a reaction kettle, the reaction temperature was 170 °C, and after reacting for 23 h, a first product was obtained;

[0127] (2) The first product was washed, filtered, then dried at 80 °C for 6 h, and after taking out the sample, it was calcined in an environment of 450 °C for 6 h to obtain porous solid solution microspheres;

[0128] (3) 6 g of manganese nitrate calculated as MnO 2 was dissolved in water to form a second mixed solution with a concentration of 0.5 mol / L; the above-mentioned porous solid solution microspheres were impregnated in the second mixed solution with equal volume for 30 min and then taken out and dried to obtain a second product;

[0129] (4) The second product was mixed with 1 g of ammonium metatungstate calculated as WO 3 , 5 g of ammonium heptamolybdate calculated as MoO 3 , 7.0 g of carboxymethyl cellulose, 0.8 g of polyethylene glycol (number average molecular weight of 420), 1.0 g of polyethylene oxide (average molecular weight of 3,000,000), and deionized water were mixed by mechanical stirring, the pH value was adjusted to 10.0, a mud with a moisture content of 26% was made, corrugated plates were punched out, epoxy resin glue was sprayed between the corrugated sheets and then laminated and assembled to obtain a corrugated plate type denitration catalyst blank. After drying the blank at 40 °C for 11 days, it was calcined at 480 °C for 18 h according to the heating program to obtain the flue gas denitration catalyst of this example. The corrugated plate of this catalyst has a thickness of 0.5 mm, a corrugated width of 5 mm, and a corrugated height of 7 mm.

[0130] Example 5

[0131] (1) TiO 2 100g of tetraisopropyl titanate, ZrO 2 1g of zirconium nitrate, as CeO 2 2g of cerium nitrate and 1200mL of ethylene glycol were mixed and stirred to obtain a first mixed solution, wherein the volume ratio of ethylene glycol to tetraisopropyl titanate was 3.24:1; the first mixed solution was placed in a reactor, the reaction temperature was 170°C, and the first product was obtained after the reaction for 23h;

[0132] (2) washing and filtering the first product and drying it at 100°C for 6 hours, taking out the sample and calcining it at 500°C for 6 hours to obtain porous solid solution microspheres;

[0133] (3) 1g of copper nitrate (CuO) and 1g of MnO 2 7g of manganese nitrate was dissolved in water to form a second mixed solution of 0.5mol / L; an equal volume of the porous solid solution microspheres was immersed in the second mixed solution for 30min, then taken out and dried to obtain a second product;

[0134] (4) The second product is reacted with WO 3 1g of ammonium paratungstate, MoO 3 5g of ammonium molybdate, 7.0g of carboxymethyl cellulose, 0.8g of polyethylene glycol (number average molecular weight of 190), 1.0g of polyethylene oxide (average molecular weight of 3 million) and deionized water were mixed by mechanical stirring, and the pH value was adjusted to 10.5 to make a mud material with a moisture content of 26%. Corrugated plates were punched out, and epoxy resin glue was sprayed between the corrugated plates and stacked and assembled to obtain a corrugated plate type denitration catalyst blank. The blank was dried at 60°C for 6 days, and then calcined at 580°C for 30 hours according to the heating program to obtain the flue gas denitration catalyst of this embodiment. The thickness of the corrugated plate of the catalyst is 0.2mm, the width of the corrugation is 5mm, and the height of the corrugation is 10mm.

[0135] Example 6

[0136] (1) TiO 2 100g of tetraisopropyl titanate, ZrO 2 10g of zirconium acetate, CeO 2 10g of cerium nitrate and 800mL of ethylene glycol were mixed and stirred to obtain a first mixed solution, wherein the volume ratio of ethylene glycol to tetraisopropyl titanate was 2.16:1; the first mixed solution was placed in a reaction kettle, the reaction temperature was 140°C, and the first product was obtained after the reaction for 30 hours;

[0137] ​​(2) Wash and filter the first product, then dry it at 80 °C for 2 h. After taking out the sample, calcine it in an environment of 450 °C for 4 h to obtain porous solid solution microspheres;

[0138] (3) Dissolve 1 g of copper nitrate (calculated as CuO) in water to form a second mixed solution with a concentration of 2.5 mol / L. Immerse the above-mentioned porous solid solution microspheres in the second mixed solution with equal volume for 5 min, then take them out and dry to obtain a second product;

[0139] (4) Mix the second product with 8 g of ammonium metatungstate (calculated as WO 3 ), 0.2 g of ammonium heptamolybdate (calculated as MoO 3 ), 7.0 g of carboxymethyl cellulose, 3 g of polyethylene glycol (number average molecular weight is 190), 3.0 g of polyethylene oxide (average molecular weight is 5 million) and deionized water by mechanical stirring, adjust the pH value to 7.0, make a mud with a water content of 26%, punch out corrugated plates, spray epoxy resin glue between the corrugated sheets and then stack and assemble them to obtain a corrugated denitration catalyst blank. After drying the blank at 30 °C for 15 days, calcine it according to the heating program at 450 °C for 38 h to obtain the flue gas denitration catalyst of this example. The corrugated plate of this catalyst has a thickness of 0.5 mm, a corrugation width of 7 mm, and a corrugation height of 10 mm.

[0140] Example 7

[0141] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (4), the mud is extruded into a 30×30 hole denitration catalyst blank. After drying the blank at 50 °C for 7 days, calcine it according to the heating program at 550 °C for 8 h to obtain the honeycomb flue gas denitration catalyst of this example.

[0142] Example 8

[0143] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (4), the corrugated plate of this catalyst has a thickness of 0.7 mm, a corrugation width of 9 mm, and a corrugation height of 4 mm.

[0144] Example 9

[0145] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (1), the reaction temperature is adjusted to 240 °C and the reaction time is adjusted to 35 h.

[0146] Example 10

[0147] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (2), the drying temperature is adjusted to 70 °C and the drying time is adjusted to 0.5 h.

[0148] Example 11

[0149] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (3), the molar concentration of the second mixed solution is adjusted to 0.4 mol / L.

[0150] Example 12

[0151] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (3), the impregnation time is adjusted to 4 min.

[0152] Example 13

[0153] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (4), the mass of the polymer dispersant polyethylene glycol is adjusted to 0.4 g, and the mass ratio of the polymer dispersant to the titanium source precursor tetra-isopropyl titanate (calculated as TiO 2 is 0.4:100.

[0154] Example 14

[0155] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (4), the mass of the binder carboxymethyl cellulose is adjusted to 1.0 g, and the mass ratio of the binder to the titanium source precursor tetra-isopropyl titanate (calculated as TiO 2 is 1.0:100.

[0156] Example 15

[0157] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (4), the mass of the pore former polyethylene oxide is adjusted to 0.1 g, and the mass ratio of the pore former to the titanium source precursor tetra-isopropyl titanate (calculated as TiO 2 is 0.1:100.

[0158] Example 16

[0159] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (4), the drying temperature is adjusted to 100 °C and the drying time is adjusted to 4 days.

[0160] Example 17

[0161] The preparation method of the flue gas denitration catalyst in this example is basically the same as that in Example 1, except that in step (4), the calcination temperature is adjusted to 400 °C and the calcination time is adjusted to 5 h.

[0162] Comparative Example 1

[0163] The preparation method of the flue gas denitration catalyst in this comparative example is basically the same as that in Example 1, except that in step (2), after washing and drying the first product, it is not calcined.

[0164] Comparative Example 2

[0165] It is prepared by the catalyst preparation method in CN109513438B, and the main components and dosage ratios of the catalyst remain unchanged, including the following steps:

[0166] (1) Preparation of the promoter precursor ion solution: Screen and weigh 5 g of copper nitrate (calculated as CuO), 3 g of manganese nitrate (calculated as MnO 2 calculated) and 4 g of cerium nitrate (calculated as CeO 2 calculated) and mix with deionized water, and stir and dissolve until the solution is clear and transparent to obtain the promoter precursor ion solution;

[0167] (2) Preparation of the promoter ion-modified composite support: Impregnate 100 g of titanium dioxide with the promoter precursor ion solution prepared in step (1) in an equal volume, and obtain the catalyst mixed support through drying and pulverization;

[0168] (3) Preparation of the tungsten-zirconium composite ion precursor solution: Screen and weigh 1 g of ammonium metatungstate (calculated as WO 3 calculated) and mix with deionized water, then stir evenly until the solution is clear and transparent to obtain solution A; Screen and weigh 2 g (calculated as ZrO 2 calculated) of zirconium acetate and mix with deionized water, then stir evenly until the solution is clear and transparent to obtain solution B; Add solution B to solution A, and stir during the dropping process to obtain the tungsten-zirconium composite ion precursor solution;

[0169] (4) Preparation and pretreatment of the catalyst green body: Based on the mass of 100 g of titanium dioxide, mix the tungsten-zirconium composite ion precursor solution prepared in step (3) with the catalyst mixed support prepared in step (2), as well as 1 g of ammonium metatungstate (calculated as WO 3 calculated), 5 g of ammonium heptamolybdate (calculated as MoO 3 calculated), 7.0 g of carboxymethyl cellulose, 0.8 g of polyethylene glycol (number average molecular weight is 190), 1.0 g of polyethylene oxide (average molecular weight is 5 million) and deionized water through mechanical stirring, adjust the pH value to 10.0, pour the agent into the mixer and mix and knead the mud, knead repeatedly with a kneader, after the mud is aged, place it in a molding machine for pre-extrusion to prepare a catalyst mud with uniform humidity and containing 26% water;

[0170] (5) Preparation of corrugated denitration catalyst: The catalyst mud obtained in step (4) is kneaded and pre-extruded, then put into a molding machine to punch out corrugated plates. After spraying epoxy resin glue between the corrugated sheets, they are stacked and assembled to obtain a corrugated denitration catalyst blank. After the blank is dried, it is calcined at 520 °C for 20 h according to the heating program to obtain a high-temperature non-vanadium corrugated denitration catalyst.

[0171] Comparative Example 3

[0172] The preparation method of the flue gas denitration catalyst in this comparative example is basically the same as that in Example 3, except that in step (1), there is no cerium nitrate.

[0173] Comparative Example 4

[0174] The preparation method of the flue gas denitration catalyst in this comparative example is basically the same as that in Example 4, except that in step (1), there is no zirconium nitrate.

[0175] Comparative Example 5

[0176] The preparation method of the flue gas denitration catalyst in this comparative example is basically the same as that in Example 1, except that in step (1), no cerium source and zirconium source are doped.

[0177] Comparative Example 6

[0178] The preparation method of the flue gas denitration catalyst in this comparative example is basically the same as that in Example 1, except that in step (1), 100 g of tetra-isopropyl titanate calculated as TiO 2 , 15 g of zirconium acetate calculated as ZrO 2 , 0.5 g of cerium nitrate calculated as CeO 2 and 300 mL of ethylene glycol are mixed and stirred to obtain a first mixed solution, where the volume ratio of ethylene glycol to tetra-isopropyl titanate is 0.81:1.

[0179] Comparative Example 7

[0180] The preparation method of the flue gas denitration catalyst in this comparative example is basically the same as that in Example 1, except that in step (2), the calcination temperature is adjusted to 350 °C and the calcination time is adjusted to 2 h.

[0181] Comparative Example 8

[0182] The preparation method of the flue gas denitration catalyst in this comparative example is basically the same as that in Example 1, except that in step (3), the mass of copper nitrate is adjusted to 0.5 g (calculated as CuO), and the mass of manganese nitrate is adjusted to 12 g (calculated as MnO 2 ).

[0183] Comparative Example 9

[0184] The preparation method of the flue gas denitration catalyst in this comparative example is basically the same as that in Example 1, except that in step (4), the mass of ammonium metatungstate is adjusted to 0.5 g (calculated as WO 3 ), and the mass of ammonium heptamolybdate is adjusted to 8 g (calculated as MoO 3 ).

[0185] Test Example

[0186] The flue gas denitration catalysts prepared in the above examples and comparative examples were applied to the flue gas denitration reaction, and the specific surface area and NO x conversion rate of the catalysts were tested. The specific conditions are as follows:

[0187] NO x Conversion rate evaluation conditions: Space velocity 5000 h -1 , reaction temperature 480 °C, inlet NO x is 600 mg / Nm 3 , SO 2 is 100 mg / Nm 3 , ammonia-nitrogen ratio is 1, water content is 15%, O 2 content 3.0% (v).

[0188] Source of raw gas: NO, SO 2 Adopt standard gas, the specifications are all 5.0% (v), N 2 gas balance, and the manufacturer is Dalian Dete Gas Co., Ltd.; O 2 comes from the utility engineering air pipe network, and the pressure is 0.4 - 0.6 Mpa; N 2 comes from the utility engineering nitrogen pipe network, with a purity of 99.0% (v) and a pressure of 0.4 - 0.6 Mpa.

[0189] NO concentration measurement method: Flue gas continuous online analyzer, Siemens ULTRAMAT23.

[0190] Specific surface area test method: BET adsorption method. The test results are shown in Table 1.

[0191] Table 1

[0192]

[0193]

[0194] As can be seen from Table 1:

[0195] The flue gas denitration catalysts in Examples 1 - 17 have higher NO x conversion rates compared with the flue gas denitration catalysts in Comparative Examples 1 - 9. The highest conversion rate can reach 85.7%, while the NO in Comparative Examples 1 - 9 xThe highest conversion rate is only 74.8%. It can be seen from this that the flue gas denitration catalyst of the present invention can significantly improve the conversion rate of NO x at high temperatures.

[0196] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flue gas denitration catalyst, characterized in that: The flue gas denitration catalyst comprises a carrier and an active component; the carrier comprises porous solid solution microspheres composed of TiO2, CeO2 and ZrO2, and the active component comprises WO3, MoO3, MnO2 and / or CuO; The mass ratio of ZrO2 to TiO2 is (1-10):100, and the mass ratio of CeO2 to TiO2 is (2-10):100; The mass ratio of the WO3 to the TiO2 is (1-8):100, the mass ratio of the MoO3 to the TiO2 is (0.2-5):100, and the mass ratio of the MnO2 and / or CuO to the TiO2 is (1-8):100; The specific surface area of ​​the flue gas denitration catalyst is not less than 63.0 m 2 / g; The flue gas denitration catalyst is used in the flue gas denitration reaction at 400-500°C to reduce NO x The conversion rate is not less than 80.0%.

2. The flue gas denitration catalyst according to claim 1, characterized in that: The flue gas denitration catalyst is a corrugated plate type flue gas denitration catalyst; The corrugated plate of the corrugated plate type flue gas denitration catalyst has a thickness of 0.2 to 0.6 mm, a corrugation width of 5 to 8 mm, and a corrugation height of 5 to 10 mm.

3. A method for preparing a flue gas denitration catalyst according to claim 1 or 2, characterized in that: The following steps are involved: (1) mixing a titanium source precursor, a zirconium source precursor, a cerium source precursor and an organic alcohol to obtain a first mixed solution, and performing a hydrothermal reaction to obtain a first product; Wherein, the titanium source precursor is calculated as TiO2, the zirconium source precursor is calculated as ZrO2, the cerium source precursor is calculated as CeO2, the mass ratio of the zirconium source precursor to the titanium source precursor is (1-10):100, and the mass ratio of the cerium source precursor to the titanium source precursor is (2-10):100; The volume ratio of the organic alcohol to the titanium source precursor is (1-10):1; (2) washing, solid-liquid separation, drying and calcining the first product to obtain the porous solid solution microspheres; the calcination temperature is 420 to 500° C. and the calcination time is 2 to 10 hours; (3) mixing a copper source precursor and / or a manganese source precursor with water to obtain a second mixed solution, immersing an equal volume of the porous solid solution microspheres in the second mixed solution, and drying to obtain a second product; Wherein, the copper source precursor is calculated as CuO, the manganese source precursor is calculated as MnO2, the titanium source precursor is calculated as TiO2, and the mass ratio of the copper source precursor and / or the manganese source precursor to the titanium source precursor is (1-8):100; (4) mixing the second product with a tungsten source precursor, a molybdenum source precursor, a polymer dispersant, a binder, a pore-forming agent, and water, and adjusting the pH value to 7 to 12 to obtain a slurry, extruding the slurry to form a green body, drying the green body, and calcining the green body to obtain the flue gas denitration catalyst; Among them, the tungsten source precursor is calculated as WO3, the molybdenum source precursor is calculated as MoO3, and the titanium source precursor is calculated as TiO2. The mass ratio of the tungsten source precursor to the titanium source precursor is (1-8):100, and the mass ratio of the molybdenum source precursor to the titanium source precursor is (0.2-5):

100.

4. The method for preparing a flue gas denitration catalyst according to claim 3, characterized in that: In step (1), the temperature of the hydrothermal reaction is 140 to 220° C., and the reaction time is 6 to 30 hours.

5. The method for preparing a flue gas denitration catalyst according to claim 3 or 4, characterized in that: In step (3), the molar concentration of the copper source precursor and / or the manganese source precursor in the second mixed solution is 0.5 to 4 mol / L; And / or, the immersion time is 5 to 50 minutes.

6. The method for preparing a flue gas denitration catalyst according to any one of claims 3 to 5, characterized in that: In step (4), the titanium source precursor is calculated as TiO2, and the mass ratio of the polymer dispersant to the titanium source precursor is (0.5-3):100; And / or, the mass ratio of the binder to the titanium source precursor solution is (2-8):100; And / or, the mass ratio of the pore-forming agent to the titanium source precursor solution is (0.2-3):

100.

7. The method for preparing a flue gas denitration catalyst according to any one of claims 3 to 6, characterized in that: In step (4), the drying temperature is 30 to 90° C. and the drying time is 5 to 15 days; And / or, the calcination temperature is 450-620° C. and the calcination time is 6-38 hours.

8. The method for preparing a flue gas denitration catalyst according to any one of claims 3 to 7, characterized in that: The copper source precursor includes at least one of soluble nitrates, copper sulfate, and copper acetate; And / or, the manganese source precursor includes at least one of soluble nitrates, manganese chloride, and manganese acetate; And / or, the titanium source precursor includes tetraisopropyl titanate and / or tetrabutyl titanate; And / or, the cerium source precursor includes at least one of soluble nitrates, cerium sulfate, and cerium chloride; And / or, the zirconium source precursor includes at least one of zirconium acetate, zirconium nitrate and zirconium sulfate; And / or, the organic alcohol includes at least one of ethanol, ethylene glycol, propanol, and isopropanol; And / or, the tungsten source precursor includes ammonium paratungstate and / or ammonium metatungstate; And / or, the molybdenum source precursor includes ammonium molybdate and / or ammonium heptamolybdate; And / or, the polymer dispersant includes polyethylene glycol and / or polyacrylamide; and / or, the binder comprises carboxymethyl cellulose and / or hydroxypropyl cellulose; And / or, the pore-forming agent includes at least one of polyethylene oxide, polymethyl methacrylate, and Tianqing powder.

9. The method for preparing a flue gas denitration catalyst according to any one of claims 3 to 8, characterized in that: The extrusion to form the blank in step (4) also includes stamping the slurry to obtain corrugated sheets, spraying resin glue between the corrugated sheets and stacking and assembling them to obtain a corrugated plate type denitration catalyst blank.

10. A flue gas denitrification method, characterized in that: The flue gas denitration catalyst according to claim 1 or 2, or the flue gas denitration catalyst prepared by the preparation method according to any one of claims 3 to 9 is used in a flue gas denitration reaction.

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