SCR (Selective Catalytic Reduction) denitration catalyst, preparation method, sulfur-containing NOx flue gas treatment method and application

Abstract

The invention discloses an SCR (Selective Catalytic Reduction) denitration catalyst, a preparation method, a sulfur-containing NOx flue gas treatment method and application. The SCR denitration catalyst comprises a carrier and an active component, and the active component contains a compound and / or a composition with the following chemical general formula in atomic ratio: MnaGdbTiOz-(BaSO4) c, in the formula, a ranges from 0.01 to 0.95; the value range of b is 0.01 to 0.50; the value range of c is 0.01 to 0.50; and z is the total number of oxygen atoms required for meeting the valence of each element in the catalyst. The MnaGdbTiOz-(BaSO4) c denitration catalyst is prepared by adopting a coprecipitation method, the proportion of Mn < 4 + > / Mn < 3 + > can be adjusted by introducing a proper amount of Gd element, and when the valence state Mn < 4 + > / Mn < 3 + > of Mn in the catalyst is preferably (0.5-1.4): 1, the catalyst shows excellent catalytic activity. The introduction of BaSO4 can improve the SO2 resistance of the catalyst, and when the catalyst is in a reaction interval of 150-300 DEG C, the NOx conversion rate reaches 85% or above, preferably 90% or above, and the highest NOx conversion rate can reach 99% or above.

Description

Technical Field

[0001] The present invention relates to the technical field of SCR denitration, and specifically relates to an SCR denitration catalyst, a preparation method, and a sulfur-containing NO x flue gas treatment method and application. Background Technique

[0002] NO x emissions not only endanger human health but also damage the environment, such as forming acid rain or undergoing photochemical reactions with hydrocarbons to form photochemical smog. In recent years, the selective catalytic reduction (SCR) technology has played an important role in flue gas NO x removal. This technology reduces NO x to N 2 in the presence of a suitable catalyst and reducing agent, and no other pollutants are generated during the reaction process, which is a very environmentally friendly treatment method. Using ammonia as the reducing agent, V 2 O 5 / TiO 2 as the catalyst has been successfully industrialized around the world and is currently the most commonly used NO x removal method. However, V 2 O 5 has biological toxicity, and this catalyst needs to be at a relatively high reaction temperature (above 350 °C) to achieve efficient reduction of NO x Therefore, there is an urgent need to develop a denitration catalyst with low toxicity and a lower reaction temperature.

[0003] CN114538467A discloses an SSZ-13 molecular sieve and a method for regulating its crystal morphology. By mixing a silicon source, an aluminum source, an alkali, and a structure-directing agent in pure water and then further treating with a crystal morphology regulator, the crystal morphology and size of the SSZ-13 molecular sieve can be effectively controlled. After the developed SSZ-13 molecular sieve is loaded with Cu, it has high denitration performance and can achieve a NO x conversion efficiency of more than 90% in the range of 175-590 °C. However, the production cost of the SSZ-13 molecular sieve is relatively high, which is not conducive to its large-scale use in SCR denitration.

[0004] CN111841526A discloses a modified Ce-Ti medium and low temperature flue gas denitration catalyst powder and its preparation method. The rare earth content in the denitration catalyst powder is 8-15%, the specific surface area of the powder is more than 90 m 2 / g, and D50 is 1-2 μm. During the application of medium and low temperature industrial flue gas denitration, it is detected that the denitration efficiency is more than 90% at 250-350 °C. Although this catalyst avoids using V 2 O 5, but the reaction temperature is still relatively high. For example, when the inlet flue gas temperature is low, the energy consumption of the denitrification reaction is high.

[0005] Therefore, there is an urgent need for an SCR denitrification catalyst with low toxicity, low production cost, and lower reaction temperature. Summary of the Invention

[0006] To solve the problems existing in the prior art, the present invention provides an SCR denitrification catalyst, a preparation method, and a method for treating sulfur-containing NO x flue gas and its application.

[0007] One of the objectives of the present invention is to provide an SCR denitrification catalyst, including a carrier and an active component, and the active component contains a compound and / or composition with the following chemical general formula in terms of atomic ratio:

[0008] Mn a Gd b TiO z -(BaSO 4 ) c

[0009] In the formula, a is the molar ratio of Mn to Ti, b is the molar ratio of Gd to Ti, c is the molar ratio of BaSO 4 to Ti; the value range of a is 0.01 to 0.95; the value range of b is 0.01 to 0.50; the value range of c is 0.01 to 0.50; z is the total number of oxygen atoms required to satisfy the valence of each element in the catalyst. In the active component of the general formula, Mn a Gd b TiO z is a composite metal oxide, and BaSO 4 exists in the form of a mixture with the above composite metal oxide.

[0010] In a preferred embodiment of the present invention,

[0011] The valence states of Mn include Mn 4+ , Mn 3+ and Mn 2+ , where, Mn 4+ +Mn 3+ is preferably 92% to 99% of the total number of Mn atoms, more preferably 93% to 96% of the total number of Mn atoms, and / or, Mn 2+ is preferably 1% to 8% of the total number of Mn atoms, more preferably 4% to 7% of the total number of Mn atoms, and / or, Mn 4+ / Mn 3+ is preferably (0.5 to 1.4):1, more preferably (1.0 to 1.3):1; and / or,

[0012] The valence state of Gd is Gd3+ ; and / or,

[0013] The valence state of Ti is Ti 4+ ; and / or,

[0014] The value range of a is 0.05 to 0.90, preferably 0.3 to 0.90; and / or, the value range of b is 0.05 to 0.40, preferably 0.05 to 0.30; and / or, the value range of c is 0.05 to 0.40, preferably 0.05 to 0.20.

[0015] In a preferred embodiment of the present invention,

[0016] The average particle size of the active component is 0.2 to 20 μm, preferably 0.2 to 10 μm; and / or,

[0017] The carrier is selected from at least one of alumina, silica, activated carbon, and cordierite.

[0018] In a preferred embodiment of the present invention,

[0019] By weight percentage, the carrier is 60% to 95% of the total weight of the catalyst, preferably 70% to 95%, more preferably 75% to 90%; and / or, the active component is 5% to 40% of the total weight of the catalyst, preferably 5% to 30%, more preferably 10% to 25%.

[0020] The second object of the present invention is to provide a preparation method of the SCR denitration catalyst of the first object of the present invention, including the steps of mixing and stirring a mixed solution containing a manganese compound, a gadolinium compound, a barium compound, and titanyl sulfate with an alkaline aqueous solution, drying and calcining to obtain an active component, and loading the active component onto a carrier.

[0021] In a preferred embodiment of the present invention,

[0022] The method includes:

[0023] S1. Mix a manganese compound and a gadolinium compound with water to obtain a mixed solution A;

[0024] S2. Under stirring conditions, dropwise add an aqueous solution of a barium-containing compound to an aqueous solution of titanyl sulfate for mixing to form a mixed solution B;

[0025] S3. Under stirring conditions, dropwise add the mixed solution A to the mixed solution B for mixing to form a mixed solution C;

[0026] S4. Mix and stir the mixed solution C with an alkaline aqueous solution, and the obtained precipitate is washed, dried, and calcined to obtain the active component;

[0027] S5. Mix the active component with water, grind the mixture, coat it onto the carrier, and then obtain the SCR denitration catalyst after drying and calcination.

[0028] In a preferred embodiment of the present invention,

[0029] In step S1,

[0030] The manganese compound is selected from at least one of soluble manganese compounds, preferably at least one of divalent soluble manganese compounds, more preferably at least one of manganese nitrate, manganese acetate, manganese sulfate, and manganese chloride; and / or,

[0031] The gadolinium compound is selected from at least one of soluble gadolinium compounds, preferably at least one of trivalent soluble gadolinium compounds, more preferably at least one of gadolinium nitrate, gadolinium chloride, and gadolinium acetate; and / or,

[0032] The concentration of manganese element in the mixed solution A is 0.1 - 5 mol / L; and / or,

[0033] The concentration of gadolinium element in the mixed solution A is 0.1 - 5 mol / L; and / or,

[0034] The molar ratio of the manganese compound to the gadolinium compound is (0.02 - 95):1, preferably (0.1 - 18):1; and / or,

[0035] The mixing temperature is 10 - 80 °C, preferably 20 - 60 °C; and / or the mixing time is 5 - 30 min.

[0036] In a preferred embodiment of the present invention,

[0037] In step S2,

[0038] The barium compound is selected from at least one of soluble barium compounds, preferably at least one of barium nitrate and barium chloride; and / or,

[0039] The concentration of the aqueous solution of the barium-containing compound is 0.01 - 1 mol / L; and / or,

[0040] The concentration of the aqueous solution of titanyl sulfate is 0.01 - 2 mol / L; and / or,

[0041] The molar ratio of the barium-containing compound to titanyl sulfate is (0.01 - 0.5):1, preferably (0.05 - 0.4):1; and / or,

[0042] The stirring rate is 300 - 1200 rmp; and / or,

[0043] The conditions for the mixing include: the temperature is 10 to 100 °C, preferably 20 to 80 °C; and / or, the time is 5 to 180 min, preferably 10 to 60 min.

[0044] In a preferred embodiment of the present invention,

[0045] In step S3,

[0046] In the mixed solution C, the molar ratio of manganese element to titanium element is (0.01 to 0.95):1, preferably (0.05 to 0.90):1; and / or,

[0047] The stirring rate is 300 to 1200 rmp; and / or,

[0048] The conditions for the mixing include: the temperature is 10 to 90 °C, preferably 20 to 60 °C; and / or, the time is 1 to 180 min, preferably 10 to 60 min.

[0049] In a preferred embodiment of the present invention,

[0050] In step S4,

[0051] The basic compound in the basic aqueous solution is selected from at least one of ammonia water, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate; and / or,

[0052] The mass concentration of the basic compound in the basic aqueous solution is 1 to 25%; and / or,

[0053] The pH after mixing the mixed solution C and the basic aqueous solution is 7.0 to 9.5, preferably 7.5 to 9.2; the addition of the basic aqueous solution is to adjust the pH to precipitate the metal salt, so the addition amount of the basic aqueous solution only needs to ensure that the pH after mixing is within the above range; and / or,

[0054] The stirring rate is 300 to 1200 rmp; and / or, the stirring time is 30 to 240 min, preferably 60 to 180 min; and / or,

[0055] The mixing temperature is 10 to 90 °C, preferably 20 to 60 °C; and / or,

[0056] The drying temperature is 40 to 120 °C, preferably 50 to 100 °C; and / or, the drying time is 4 to 48 h, preferably 8 to 24 h; and / or,

[0057] The calcination temperature is 300 to 650 °C, preferably 350 to 600 °C; and / or, the calcination time is 0.5 to 8 h, preferably 1 to 6 h.

[0058] In a preferred embodiment of the present invention,

[0059] In step S5,

[0060] the mass ratio of the active component to water is (0.05 - 0.8):1; and / or,

[0061] the average particle size of the active component after grinding is 0.2 - 20 μm, preferably 0.2 - 10 μm; and / or,

[0062] the mass ratio of the active component to the carrier is (0.05 - 0.7):1, preferably (0.05 - 0.4):1; and / or,

[0063] the drying temperature is 40 - 120°C, preferably 50 - 100°C; and / or, the drying time is 4 - 48 h, preferably 8 - 24 h; and / or,

[0064] the calcination temperature is 300 - 650°C, preferably 350 - 600°C; and / or, the calcination time is 0.5 - 8 h, preferably 1 - 6 h.

[0065] The third object of the present invention is to provide a method for treating sulfur - containing NOx flue gas, including the step of contacting and reacting a flue gas containing NO x , NH 3 , SO 2 and oxygen with a catalyst; the catalyst includes the SCR denitration catalyst of the first object of the present invention or the SCR denitration catalyst obtained by the preparation method of the second object of the present invention.

[0066] In a preferred embodiment of the present invention,

[0067] the NO x includes NO; and / or,

[0068] in the sulfur - containing NO x flue gas, the content of NO x is 100 - 5000 ppm, preferably 500 - 5000 ppm; and / or,

[0069] in the sulfur - containing NO x flue gas, the content of NH 3 is 100 - 5000 ppm, preferably 500 - 5000 ppm; and / or,

[0070] in the sulfur - containing NO x flue gas, the molar ratio of NO x to NH 3 is (0.9 - 1.1):1; and / or,

[0071] in the sulfur - containing NO x flue gas, the content of SO 2The content is greater than 0 ppm. Preferably, the content of SO 2 is less than 100 ppm. More preferably, the content of SO 2 is 5 to 80 ppm; and / or,

[0072] In the sulfur-containing NO x flue gas, the volume fraction of oxygen is 2 to 20%, preferably 5 to 20%; and / or,

[0073] The contact reaction conditions include: the temperature is 100 to 300 °C, preferably 150 to 280 °C; and / or, the volume space velocity is 2000 to 100000 h -1 , preferably 5000 to 60000 h -1 .

[0074] The fourth object of the present invention is to provide an SCR denitration catalyst of one of the objects of the present invention, or an SCR denitration catalyst obtained by the preparation method of the second object of the present invention, or the treatment method of the third object of the present invention in the treatment of sulfur-containing NO x flue gas.

[0075] The present invention prepares a Mn a Gd b TiO z -(BaSO 4 ) c denitration catalyst. By introducing an appropriate amount of Gd element, the ratio of Mn 4+ / Mn 3+ can be adjusted. When the valence state of Mn in the catalyst Mn 4+ / Mn 3+ is (0.5 to 1.4):1, it shows good catalytic activity. The introduction of BaSO 4 can improve the SO 2 resistance of the catalyst. In the reaction range of 150 to 300 °C, the NO x conversion rate reaches more than 85%, preferably more than 90%, and can reach up to more than 99%. Specific Embodiments

[0076] The present invention will be specifically described below in conjunction with specific embodiments. It is necessary to point out here that the following embodiments are only used for further illustration of the present invention and cannot be understood as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the protection scope of the present invention.

[0077] The raw materials used in the examples and comparative examples of the present invention are all conventional commercially available products.

[0078] In the examples and comparative examples of the present invention, the surface metal valence state of the samples was analyzed using a PHI5000CESCASystem X-ray photoelectron spectrometer from PHI, USA, with an Al target, a high voltage of 14.0 kV, a power of 300 W, and calibrated using the C1s energy spectrum peak (284.5 eV).

[0079] In the slurries of the examples and comparative examples of the present invention, the particle size of the catalyst active components was measured using a Mastersizer3000E laser particle size analyzer from Malvern, USA.

[0080] Example 1

[0081] Catalyst preparation:

[0082] S1. At 30 °C, 10.4 g of manganese acetate tetrahydrate and 2.3 g of gadolinium nitrate hexahydrate were mixed in 20 g of water to form solution A.

[0083] S2. At 30 °C, 100 mL of an aqueous solution containing 0.6 g of barium nitrate was added dropwise to 100 mL of an aqueous solution containing 8 g of titanyl sulfate while stirring at 600 rpm for 60 min to form a mixed solution B.

[0084] S3. At 20 °C, solution A was added dropwise to mixed solution B while stirring at 600 rpm for 20 min to form a mixed solution C.

[0085] S4. At 20 °C, Na 2 CO 3 with a concentration of 0.1 mol / L was added dropwise to mixed solution C until the pH reached 8.6, and the mixture was stirred at 600 rpm for 120 min. The precipitate was filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 400 °C for 2 h to obtain the catalyst active components.

[0086] S5. 80 g of water was added to 20 g of the obtained catalyst active component powder, and wet ball milling was carried out for 4 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of the active component of 6.2 μm, which was uniformly coated on the surface of alumina balls (particle size 2 - 4 mm). It was dried at 100 °C for 8 h and calcined at 400 °C for 2 h to obtain the SCR denitration catalyst. The content of the active component in the obtained catalyst was 16% of the total mass of the catalyst, and the balance was the carrier alumina. In the catalyst active components, the valence states of Mn included Mn 4+ 、Mn 3+ and Mn 2+ , among which, Mn 4+ +Mn 3+ was 94.1% of the total number of Mn atoms, and Mn 2+ was 5.9% of the total number of Mn atoms; the valence state of Gd was Gd 3+ ; the valence state of Ti was Ti 4+; The composition of the active components in the catalyst is shown in Table 1.

[0087] Catalyst evaluation:

[0088] The denitration catalyst obtained in Example 1 was evaluated in a stainless steel reactor. The flue gas composition was 1000 ppm of NH 3 , 1000 ppm of NO, 50 ppm of SO 2 , 10% by volume of O 2 , and the rest was nitrogen. The reaction conditions were: reaction temperature 150 °C, atmospheric pressure, and the volume space velocity of the catalyst was 50000 h -1 . The concentration of NO x in the tail gas was measured using an infrared analyzer. The experimental results are shown in the data of Table 1.

[0089] Example 2

[0090] Catalyst preparation:

[0091] S1. At 30 °C, 10.4 g of manganese acetate tetrahydrate and 2.3 g of gadolinium nitrate hexahydrate were mixed in 20 g of water to form solution A.

[0092] S2. At 30 °C, 100 mL of an aqueous solution containing 0.6 g of barium nitrate was added dropwise to 100 mL of an aqueous solution containing 8 g of titanyl sulfate while stirring at 600 rpm for 60 min to form a mixed solution B.

[0093] S3. At 20 °C, solution A was added dropwise to mixed solution B while stirring at 600 rpm for 20 min to form a mixed solution C.

[0094] S4. At 20 °C, an aqueous ammonia solution with a mass concentration of 25% was added dropwise to mixed solution C until the pH reached 8.6, and the mixture was stirred at 600 rpm for 120 min. The precipitate was filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 400 °C for 2 h to obtain the active components of the catalyst.

[0095] S5. 80 g of water was added to 20 g of the obtained catalyst active component powder, and wet ball milling was carried out for 4.5 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of 3.4 μm of the active component, which was uniformly coated on the surface of alumina balls (particle size 2 - 4 mm). It was dried at 100 °C for 8 h and calcined at 400 °C for 2 h to obtain the SCR denitration catalyst. The content of the active component in the obtained catalyst was 16% of the total mass of the catalyst, and the balance was carrier alumina. In the catalyst active component, the valence states of Mn included Mn 4+ , Mn 3+ and Mn 2+ , among which, Mn 4+ +Mn 3+ was 94.6% of the total number of Mn atoms, and Mn 2+is 5.4% of the total number of Mn atoms; the valence state of Gd is Gd 3+ ; the valence state of Ti is Ti 4+ ; the composition of the active components in the catalyst is shown in Table 1.

[0096] The catalyst was evaluated in the same manner as in Example 1. The experimental results are shown in the data of Table 1.

[0097] Example 3

[0098] Catalyst preparation:

[0099] S1. At 30 °C, 9.2 g of manganese acetate tetrahydrate and 4.5 g of gadolinium nitrate hexahydrate were mixed in 20 g of water to form solution A.

[0100] S2. At 30 °C, 100 mL of an aqueous solution containing 0.6 g of barium nitrate was added dropwise to 100 mL of an aqueous solution containing 8 g of titanium oxysulfate while stirring at 600 rpm for 60 min to form a mixed solution B.

[0101] S3. At 20 °C, solution A was added dropwise to mixed solution B, and the mixture was stirred at 600 rpm for 20 min to form a mixed solution C.

[0102] S4. At 20 °C, an aqueous ammonia solution with a mass concentration of 25% was added dropwise to mixed solution C until the pH reached 8.6, and the mixture was stirred at 600 rpm for 120 min. The precipitate was filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 450 °C for 2 h to obtain the active components of the catalyst.

[0103] S5. 80 g of water was added to 20 g of the obtained catalyst active component powder, and wet ball milling was carried out for 4.5 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of the active component of 3.5 μm, which was uniformly coated on the surface of alumina balls (particle size 2 - 4 mm). It was dried at 100 °C for 8 h and calcined at 400 °C for 2 h to obtain the SCR denitration catalyst. The content of the active components in the obtained catalyst was 16% of the total mass of the catalyst, and the balance was the carrier alumina. In the active components of the catalyst, the valence states of Mn include Mn 4+ , Mn 3+ and Mn 2+ , among which, Mn 4+ +Mn 3+ is 93.8% of the total number of Mn atoms, and Mn 2+ is 6.2% of the total number of Mn atoms; the valence state of Gd is Gd 3+ ; the valence state of Ti is Ti 4+ ; the composition of the active components in the catalyst is shown in Table 1.

[0104] The catalyst was evaluated in the same manner as in Example 1. The experimental results are shown in the data of Table 1.

[0105] Example 4

[0106] Catalyst preparation:

[0107] S1. At 30 °C, 11.0 g of manganese acetate tetrahydrate and 1.1 g of gadolinium nitrate hexahydrate are mixed in 25 g of water to prepare solution A.

[0108] S2. At 30 °C, 100 mL of an aqueous solution containing 0.6 g of barium nitrate is added dropwise to 100 mL of an aqueous solution containing 8 g of titanyl sulfate while stirring at 600 rpm for 60 min to form mixture B.

[0109] S3. At 20 °C, solution A is added dropwise to mixture B while stirring at 600 rpm for 20 min to form mixture C.

[0110] S4. At 20 °C, an aqueous ammonia solution with a mass concentration of 10% is added dropwise to mixture C until the pH reaches 8.6, and then stirred at 600 rpm for 120 min. The precipitate is filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 500 °C for 2 h to obtain the catalyst active component.

[0111] S5. 80 g of water is added to 20 g of the obtained catalyst active component powder, and wet ball milling is carried out for 6 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of the active component of 1.2 μm, which is uniformly coated on the surface of alumina balls (particle size 2 - 4 mm). It is dried at 100 °C for 8 h and calcined at 400 °C for 2 h to obtain the SCR denitration catalyst. The content of the active component in the obtained catalyst is 16% of the total mass of the catalyst, and the balance is the carrier alumina. In the catalyst active component, the valence states of Mn include Mn 4+ , Mn 3+ and Mn 2+ , where Mn 4+ +Mn 3+ is 94.8% of the total number of Mn atoms, and Mn 2+ is 5.2% of the total number of Mn atoms; the valence state of Gd is Gd 3+ ; the valence state of Ti is Ti 4+ ; the composition of the active component in the catalyst is shown in Table 1.

[0112] The catalyst evaluation is the same as that in Example 1. The experimental results are shown in the data of Table 1.

[0113] Example 5

[0114] Catalyst preparation:

[0115] S1. At 30 °C, 7.4 g of manganese acetate tetrahydrate and 6.8 g of gadolinium nitrate hexahydrate are mixed in 25 g of water to prepare solution A.

[0116] S2. At 30 °C, a 100 mL aqueous solution containing 1.3 g of barium nitrate was added dropwise to a 100 mL aqueous solution containing 8 g of titanium oxysulfate, and stirred at 600 rpm for 60 min to form a mixed solution B.

[0117] S3. At 20 °C, solution A was added dropwise to the mixed solution B, and stirred at 600 rpm for 20 min to form a mixed solution C.

[0118] S4. At 20 °C, an ammonia water with a mass concentration of 10% was added dropwise to the mixed solution C until the pH reached 8.2, and stirred at 600 rpm for 120 min. The precipitate was filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 350 °C for 2 h to obtain the catalyst active component.

[0119] S5. 80 g of water was added to the above-obtained 20 g of catalyst active component powder, and wet ball milling was carried out for 8 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of the active component of 0.6 μm, which was uniformly coated on the surface of alumina balls (particle size 2 - 4 mm). It was dried at 100 °C for 8 h and calcined at 350 °C for 2 h to obtain the SCR denitration catalyst. The content of the active component in the obtained catalyst was 16% of the total mass of the catalyst, and the balance was carrier alumina. In the catalyst active component, the valence states of Mn included Mn 4+ 、Mn 3+ and Mn 2+ ,wherein, Mn 4+ +Mn 3+ was 94.2% of the total number of Mn atoms, and Mn 2+ was 5.8% of the total number of Mn atoms; the valence state of Gd was Gd 3+ ; the valence state of Ti was Ti 4+ ; the composition of the active component in the catalyst was shown in Table 1.

[0120] Catalyst evaluation:

[0121] The denitration catalyst obtained in Example 5 was evaluated in a stainless steel reactor. The flue gas composition was 1000 ppm of NH 3 , 1000 ppm of NO, 50 ppm of SO 2 , 10% by volume of O 2 , and the rest was nitrogen. The reaction conditions were: reaction temperature 300 °C, atmospheric pressure, and the volume space velocity of the catalyst was 50000 h -1 . An infrared analyzer was used to measure the concentration of NO x in the tail gas. The experimental results are shown in the data of Table 1.

[0122] Example 6

[0123] Catalyst preparation:

[0124] S1. At 30 °C, dissolve 4.9 g of manganese acetate tetrahydrate and 11.3 g of gadolinium nitrate hexahydrate in 40 g of water to prepare solution A.

[0125] S2. At 30 °C, add 100 mL of an aqueous solution containing 1.3 g of barium nitrate dropwise to 100 mL of an aqueous solution containing 8 g of titanium oxysulfate, and stir at 600 rpm for 60 min to form mixture B.

[0126] S3. At 20 °C, add solution A dropwise to mixture B, and stir at 600 rpm for 20 min to form mixture C.

[0127] S4. At 20 °C, add ammonia water with a mass concentration of 10% dropwise to mixture C until the pH reaches 9.1, and stir at 600 rpm for 120 min. The precipitate is filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 350 °C for 2 h to obtain the catalyst active component.

[0128] S5. Add 80 g of water to 20 g of the obtained catalyst active component powder, perform wet ball milling for 4 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of the active component of 2.4 μm, and uniformly coat it on the surface of alumina balls (particle size 2 - 4 mm). Dry at 100 °C for 8 h and calcine at 350 °C for 2 h to obtain the SCR denitration catalyst. The content of the active component in the obtained catalyst is 16% of the total mass of the catalyst, and the balance is the carrier alumina. In the catalyst active component, the valence states of Mn include Mn 4+ 、Mn 3+ and Mn 2+ , where, Mn 4+ +Mn 3+ is 94.7% of the total number of Mn atoms, and Mn 2+ is 5.3% of the total number of Mn atoms; the valence state of Gd is Gd 3+ ; the valence state of Ti is Ti 4+ ; the composition of the active component in the catalyst is shown in Table 1.

[0129] The catalyst evaluation is the same as in Example 1. The experimental results are shown in the data of Table 1.

[0130] Example 7

[0131] Catalyst preparation:

[0132] S1. At 30 °C, dissolve 10.4 g of manganese acetate tetrahydrate and 2.3 g of gadolinium nitrate hexahydrate in 20 g of water to prepare solution A.

[0133] S2. At 30 °C, add 100 mL of an aqueous solution containing 0.6 g of barium nitrate dropwise to 100 mL of an aqueous solution containing 8 g of titanium oxysulfate, and stir at 600 rpm for 60 min to form mixture B.

[0134] S3. At 20 °C, solution A was added dropwise to mixture B, and stirred at 600 rpm for 20 min to form mixture C.

[0135] S4. At 20 °C, Na with a concentration of 0.1 mol / L was added dropwise to mixture C until the pH reached 8.6, and stirred at 600 rpm for 120 min. The precipitate was filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 400 °C for 2 h to obtain the catalyst active component. 2 CO 3 S5. 80 g of water was added to 20 g of the obtained catalyst active component powder, and wet ball milling was carried out for 2 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of the active component of 26.8 μm, which was uniformly coated on the surface of alumina balls (particle size 2 - 4 mm). It was dried at 100 °C for 8 h and calcined at 400 °C for 2 h to obtain the SCR denitration catalyst. The content of the active component in the obtained catalyst was 16% of the total mass of the catalyst, and the balance was the carrier alumina. In the catalyst active component, the valence states of Mn included Mn

[0136] , Mn 4+ , and Mn 3+ , and Mn 2+ . Among them, Mn 4+ + Mn 3+ was 94.1% of the total number of Mn atoms, and Mn 2+ was 5.9% of the total number of Mn atoms; the valence state of Gd was Gd 3+ ; the valence state of Ti was Ti 4+ ; the composition of the active component in the catalyst was shown in Table 1.

[0137] The catalyst was evaluated in the same way as in Example 1. The experimental results are shown in the data of Table 1.

[0138] Example 8

[0139] Catalyst preparation:

[0140] S1. At 30 °C, 7.4 g of manganese acetate tetrahydrate and 11.3 g of gadolinium nitrate hexahydrate were mixed in 40 g of water to prepare solution A.

[0141] S2. At 30 °C, a 100 mL aqueous solution containing 1.3 g of barium nitrate was added dropwise to a 100 mL aqueous solution containing 8 g of titanyl sulfate, and stirred at 600 rpm for 60 min to form mixture B.

[0142] S3. At 20 °C, solution A was added dropwise to mixture B, and stirred at 600 rpm for 20 min to form mixture C.

[0143] S4. At 20 °C, ammonia water with a mass concentration of 10% was added dropwise to the mixed solution C until the pH reached 9.1, and it was stirred at 600 rpm for 120 min. The precipitate was filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 350 °C for 2 h to obtain the catalyst active component.

[0144] S5. 80 g of water was added to the above-obtained 20 g of catalyst active component powder, and wet ball milling was carried out for 4 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of the active component of 2.4 μm, which was uniformly coated on the surface of alumina balls (particle size 2 - 4 mm). It was dried at 100 °C for 8 h and calcined at 350 °C for 2 h to obtain the SCR denitration catalyst. The content of the active component in the obtained catalyst was 16% of the total mass of the catalyst, and the balance was the carrier alumina. In the catalyst active component, the valence states of Mn included Mn 4+ 、Mn 3+ and Mn 2+ , among which, Mn 4+ +Mn 3+ was 94.6% of the total number of Mn atoms, and Mn 2+ was 5.4% of the total number of Mn atoms; the valence state of Gd was Gd 3+ ; the valence state of Ti was Ti 4+ ; the composition of the active component in the catalyst is shown in Table 1.

[0145] The catalyst evaluation was the same as in Example 1. The experimental results are shown in the data of Table 1.

[0146] Comparative Example 1

[0147] Catalyst preparation:

[0148] S1. At 30 °C, 10.4 g of manganese acetate tetrahydrate and 2.3 g of gadolinium nitrate hexahydrate were mixed in 20 g of water to prepare solution A.

[0149] S2. At 30 °C, 8 g of titanium oxysulfate was dissolved in 100 mL of water and stirred at 600 rpm for 60 min to form mixed solution B.

[0150] S3. At 20 °C, solution A was added dropwise to mixed solution B and stirred at 600 rpm for 20 min to form mixed solution C.

[0151] S4. At 20 °C, Na with a concentration of 0.1 mol / L 2 CO 3 was added dropwise to mixed solution C until the pH reached 8.6, and it was stirred at 600 rpm for 120 min. The precipitate was filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 400 °C for 2 h to obtain the catalyst active component.

[0152] S5. Add 80 g of water to the obtained 20 g of the catalyst active component powder, carry out wet ball milling for 4 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of the active component of 6.1 μm, and uniformly coat it on the surface of alumina balls (with a particle size of 2 - 4 mm). Dry at 100 °C for 8 h and calcine at 400 °C for 2 h. The content of the active component in the obtained catalyst is 16% of the total mass of the catalyst, and the balance is the carrier alumina. In the catalyst active component, the valence states of Mn include Mn 4+ 、Mn 3+ and Mn 2+ , among which, Mn 4+ +Mn 3+ is 93.9% of the total number of Mn atoms, and Mn 2+ is 6.1% of the total number of Mn atoms; the valence state of Gd is Gd 3+ ; the valence state of Ti is Ti 4+ ; the composition of the active component in the catalyst is shown in Table 1.

[0153] The catalyst evaluation is the same as that in Example 1. The experimental results are shown in the data of Table 1.

[0154] Comparative Example 2

[0155] Catalyst preparation:

[0156] S1. At 30 °C, dissolve 10.4 g of manganese acetate tetrahydrate in 20 g of water to form solution A.

[0157] S2. At 30 °C, drop 100 mL of an aqueous solution containing 0.6 g of barium nitrate into 100 mL of an aqueous solution containing 8 g of titanyl sulfate, and stir at 600 rpm for 60 min to form a mixed solution B.

[0158] S3. At 20 °C, drop solution A into the mixed solution B, and stir at 600 rpm for 20 min to form a mixed solution C.

[0159] S4. At 20 °C, drop Na 2 CO 3 with a concentration of 0.1 mol / L into the mixed solution C until the pH is 8.6, and stir at 600 rpm for 120 min. The precipitate is filtered, washed with distilled water, dried at 80 °C for 12 h, and calcined at 400 °C for 2 h to obtain the catalyst active component.

[0160] S5. Add 80 g of water to the obtained 20 g of catalyst active component powder, carry out wet ball milling for 4 h at a rotation speed of 160 rpm to obtain a slurry with an average particle size of the active component of 6.2 μm, and uniformly coat it on the surface of alumina balls (particle size 2 - 4 mm). Dry at 100 °C for 8 h and calcine at 400 °C for 2 h. The content of the active component in the obtained catalyst is 16% of the total mass of the catalyst, and the balance is carrier alumina. In the catalyst active component, the valence states of Mn include Mn 4+ 、Mn 3+ and Mn 2+ , among which, Mn 4+ +Mn 3+ is 94.5% of the total number of Mn atoms, and Mn 2+ is 5.5% of the total number of Mn atoms; the valence state of Ti is Ti 4+ ; the composition of the active component in the catalyst is shown in Table 1.

[0161] The catalyst evaluation is the same as that in Example 1. The experimental results are shown in the data of Table 1.

[0162] Table 1

[0163]

[0164] It can be seen from Examples 1 - 8, Comparative Examples 1 - 2 and Table 1 that for the denitration catalyst of the present invention, by introducing an appropriate amount of Gd element into the active component, the ratio of Mn 4+ / Mn 3+ can be adjusted. When the valence state ratio of Mn in this catalyst Mn 4+ / Mn 3+ is preferably (0.5 - 1.4):1, it shows more excellent catalytic activity. The introduction of BaSO 4 can improve the SO 2 resistance of the catalyst. In the reaction range of 150 - 300 °C, the NO x conversion rate of the catalyst reaches more than 85%, preferably more than 90%, and can reach up to more than 99%. In addition, the catalytic activity of the active component in the present invention is higher within the range of 0.2 - 20 μm of the average particle size.

Claims

1. An SCR denitration catalyst, comprising a carrier and an active component, wherein the active component contains a compound and / or composition with the following chemical formula in terms of atomic ratio: Mn a Gd b TiO z -(BaSO 4 ) c In the formula, the value range of a is 0.01 to 0.95; the value range of b is 0.01 to 0.50; the value range of c is 0.01 to 0.50; z is the total number of oxygen atoms required to satisfy the valence of each element in the catalyst.

2. The SCR denitration catalyst according to claim 1, characterized in that: The valence states of Mn include Mn 4+ , Mn 3+ and Mn 2+ , wherein, Mn 4+ + Mn 3+ is preferably 92% to 99% of the total number of Mn atoms, more preferably 93% to 96% of the total number of Mn atoms, and / or, Mn 2+ is preferably 1% to 8% of the total number of Mn atoms, more preferably 4% to 7% of the total number of Mn atoms, and / or, Mn 4+ / Mn 3+ is preferably (0.5 to 1.4):1, more preferably (1.0 to 1.3):1; and / or, The valence state of Gd is Gd 3+ ; and / or, The valence state of Ti is Ti 4+ ; and / or the value range of a is 0.05 to 0.90; and / or, the value range of b is 0.05 to 0.40; and / or, the value range of c is 0.05 to 0.

40.

3. The SCR denitration catalyst according to claim 1, characterized in that: the average particle size of the active component is 0.2 to 20 μm, preferably 0.2 to 10 μm; and / or, the carrier is selected from at least one of alumina, silica, activated carbon, and cordierite.

4. The SCR denitration catalyst according to any one of claims 1-3, characterized in that: by weight percentage, the carrier is 60% to 95% of the total weight of the catalyst, preferably 70% to 95%; and / or, the active component is 5% to 40% of the total weight of the catalyst, preferably 5% to 30%.

5. A preparation method of an SCR denitration catalyst according to any one of claims 1-4, comprising the steps of mixing and stirring a mixed solution containing a manganese compound, a gadolinium compound, a barium compound, and titanyl sulfate with an alkaline aqueous solution, drying and calcining to obtain an active component, and loading the active component onto a carrier.

6. The preparation method according to claim 5, characterized in that the method includes: S1. Mixing a manganese compound and a gadolinium compound with water to obtain a mixed solution A; S2. Under stirring conditions, dropping an aqueous solution of a barium-containing compound into an aqueous solution of titanyl sulfate for mixing to form a mixed solution B; S3. Under stirring conditions, dropping the mixed solution A into the mixed solution B for mixing to form a mixed solution C; S4. Mixing and stirring the mixed solution C with an alkaline aqueous solution, and washing, drying, and calcining the obtained precipitate to obtain the active component; S5. Mixing and grinding the active component with water, then coating it onto a carrier, and after drying and calcining, obtaining the SCR denitration catalyst.

7. The preparation method according to claim 6, characterized in that: In step S1, the manganese compound is selected from at least one of soluble manganese compounds, preferably at least one of divalent soluble manganese compounds, more preferably at least one of manganese nitrate, manganese acetate, manganese sulfate, and manganese chloride; and / or, the gadolinium compound is selected from at least one of soluble gadolinium compounds, preferably at least one of trivalent soluble gadolinium compounds, more preferably at least one of gadolinium nitrate, gadolinium chloride, and gadolinium acetate; and / or, the concentration of manganese element in the mixed solution A is 0.1 to 5 mol / L; and / or, the concentration of gadolinium element in the mixed solution A is 0.1 to 5 mol / L; and / or, The molar ratio of the manganese compound to the gadolinium compound is (0.02 to 95):1, preferably (0.1 to 18):1; and / or, The mixing temperature is 10 to 80 °C, preferably 20 to 60 °C.

8. The preparation method according to claim 6, characterized in that: In step S2, the barium compound is selected from at least one of soluble barium compounds, preferably at least one of barium nitrate and barium chloride; and / or, the concentration of the aqueous solution of the barium-containing compound is 0.01 to 1 mol / L; and / or, the concentration of the aqueous solution of titanium oxysulfate is 0.01 to 2 mol / L; and / or, the molar ratio of the barium-containing compound to titanium oxysulfate is (0.01 to 0.5):1, preferably (0.05 to 0.4):1; and / or, the stirring rate is 300 to 1200 rmp; and / or, the mixing conditions include: the temperature is 10 to 100 °C, preferably 20 to 80 °C; and / or, the time is 5 to 180 min, preferably 10 to 60 min.

9. The preparation method according to claim 6, characterized in that: In step S3, in the mixed solution C, the molar ratio of manganese element to titanium element is (0.01 to 0.95):1, preferably (0.05 to 0.90):1; and / or, the stirring rate is 300 to 1200 rmp; and / or, the mixing conditions include: the temperature is 10 to 90 °C, preferably 20 to 60 °C; and / or, the time is 1 to 180 min, preferably 10 to 60 min.

10. The preparation method according to claim 6, characterized in that: In step S4, the basic compound in the basic aqueous solution is selected from at least one of ammonia water, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate; and / or, the mass concentration of the basic compound in the basic aqueous solution is 1 to 25%; and / or, the pH after mixing the mixed solution C with the basic aqueous solution is 7.0 to 9.5, preferably 7.5 to 9.2; and / or, the stirring rate is 300 to 1200 rmp; and / or, the stirring time is 30 to 240 min, preferably 60 to 180 min; and / or, the mixing temperature is 10 to 90 °C, preferably 20 to 60 °C; and / or, the drying temperature is 40 to 120 °C, preferably 50 to 100 °C; and / or, the drying time is 4 to 48 h, preferably 8 to 24 h; and / or, the calcination temperature is 300 to 650 °C, preferably 350 to 600 °C; and / or, the calcination time is 0.5 to 8 h, preferably 1 to 6 h.

11. The preparation method according to claim 6, characterized in that: In step S5, the mass ratio of the active component to water is (0.05 to 0.8):1; and / or, the average particle size of the active component after grinding is 0.2 to 20 μm, preferably 0.2 to 10 μm; and / or, the mass ratio of the active component to the carrier is (0.05 to 0.7):1, preferably (0.05 to 0.4):1; and / or, The drying temperature is 40 to 120 °C, preferably 50 to 100 °C; and / or, the drying time is 4 to 48 h, preferably 8 to 24 h; and / or, The roasting temperature is 300 to 650 °C, preferably 350 to 600 °C; and / or, the roasting time is 0.5 to 8 h, preferably 1 to 6 h.

12. A sulfur-containing NO x flue gas treatment method, comprising the step of contacting and reacting a flue gas containing NO x , NH 3 , SO 2 and oxygen with a catalyst; the catalyst includes the SCR denitration catalyst according to any one of claims 1-4 or the SCR denitration catalyst obtained by the preparation method according to any one of claims 5-11.

13. The method according to claim 12, characterized in that: The NO x includes NO; and / or, The sulfur-containing NO x in the flue gas, NO x has a content of 100 to 5000 ppm, preferably 500 to 5000 ppm; and / or, The sulfur-containing NO x in the flue gas, NH 3 content is 100 to 5000 ppm, preferably 500 to 5000 ppm; and / or, The sulfur-containing NO x in the flue gas, NO x and NH 3 have a molar ratio of (0.9 to 1.1):1; and / or, The sulfur-containing NO x in the flue gas, SO 2 content is greater than 0 ppm, preferably, SO 2 content is less than 100 ppm, more preferably, SO 2 content is 5 - 80 ppm; and / or, The sulfur-containing NO x In the flue gas, the volume fraction of oxygen is 2-20%, preferably 5-20%; and / or, The contact reaction conditions include: the temperature is 100 to 300 °C, preferably 150 to 280 °C; and / or, the volume space velocity is 2000 to 100000 h -1 , preferably 5000 to 60000 h -1 .

14. An SCR denitration catalyst as described in any one of claims 1-4, or an SCR denitration catalyst obtained by the preparation method as described in any one of claims 5-11, or the method as described in any one of claims 12-13 in the treatment of sulfur-containing NO x flue gas.

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