Catalyst with organic waste gas catalytic oxidation function, and preparation method and application thereof

Abstract

The present application relates to the technical field of organic waste gas catalytic oxidation treatment, and discloses a catalyst with organic waste gas catalytic oxidation function and a preparation method and application thereof, wherein, taking 100 parts by weight of the catalyst as a basis, the catalyst contains: (a) 1-40 parts by weight of SAPO-34 molecular sieve; (b) 50-90 parts by weight of TiO2; (c) 0.01-1 parts by weight of noble metal; and (d) 0.1-20 parts by weight of rare earth oxide. The catalyst of the present application uses TiO2 and SAPO-34 as carriers, uses rare earth oxide as an additive, and uses noble metal as an active component, and has good catalytic activity, is particularly suitable for catalytic oxidation treatment of waste gas containing triethylamine, has a high removal rate of non-methane substances, and the conversion rate of triethylamine is more than 99%.

Description

Technical Field

[0001] This invention relates to the field of catalytic oxidation treatment technology for organic waste gas, specifically to a catalyst with catalytic oxidation function for organic waste gas, its preparation method, and its application. Background Technology

[0002] In the production of molecular sieves, such as ZSM-5, Y-type, and SAPO-34, large quantities of organic compounds, including template agents and structure-directing agents, are often used. During the crystallization, filtration, drying, and calcination processes, these organic compounds are mainly discharged in gaseous or liquid phases. Existing molecular sieve manufacturers typically have condensation systems to recover organic amines; however, due to limitations in condensation recovery efficiency, some organic amines still escape into the exhaust gas. If these organic amine template agents are discharged directly without treatment, they will inevitably cause serious environmental damage.

[0003] Due to its advantages such as high purification efficiency, low reaction temperature, low energy consumption, wide application range, and no secondary pollution, tail gas catalytic oxidation technology has been widely used in the organized emission processes of waste gas containing medium to high concentrations of VOCs in various industries. Organic waste gas is preheated to 200–400°C. In the presence of a catalyst, organic molecules and oxygen molecules are activated on the surface of the catalyst and are then rapidly oxidized to produce harmless substances such as carbon dioxide and water.

[0004] CN109289911A discloses a catalyst and method for treating nitrogen-containing volatile organic pollutants, particularly a catalyst and method for integrated selective oxidation-catalytic reduction treatment of nitrogen-containing organic waste gas. It includes a supported catalyst or a hydrotalcite-derived composite oxide catalyst. The composite oxide is (Cu... y M 1-y II ) x M Ⅲ O x+1.5 M II It is one or more of Mg, Co and Ni; M III It is one or more of Al, Mn, and Fe. This method uses an integrated device for selective oxidation and catalytic reduction of nitrogen-containing organic waste gas, which can simultaneously realize the dual-functional catalytic material of selective oxidation of nitrogen-containing organic waste gas and catalytic reduction of nitrogen oxides. It achieves efficient degradation of nitrogen-containing organic waste gas while ensuring that nitrogen oxides in the exhaust gas meet emission standards. However, the catalyst has low activity.

[0005] CN105745016A discloses a catalyst for purifying waste gas, comprising a catalyst support and cerium oxide supported thereon, for purifying nitrogen oxides. The catalyst support comprises at least one zeolite selected from chalcogenide, SAPO-34, and SSZ13, and 1 to 10 wt% copper or iron, or mixtures thereof, based on the catalyst. The cerium oxide is present in an amount of 1 to 30 wt% based on the catalyst and has a crystallite size of 0.1 nm or more and 2.5 nm or less. This catalyst is suitable for the removal of nitrogen oxides but not for the catalytic purification of triethylamine. Summary of the Invention

[0006] The technical problem this invention aims to solve is the low efficiency of organic waste gas removal in existing technologies. To address this, this invention provides a catalytic oxidation catalyst for organic waste gas, its preparation method, and its application in the catalytic oxidation treatment of organic amine waste gas. When used for the catalytic oxidation treatment of organic amine waste gas, this catalyst exhibits excellent catalytic activity, effectively reducing the concentration of organic amines in the waste gas while simultaneously inhibiting the formation of nitrogen oxides.

[0007] To achieve the above objectives, the first aspect of the present invention provides a catalyst with catalytic oxidation function for organic waste gas, wherein, based on 100 parts by weight of the catalyst, the catalyst contains: (a) 1 to 40 parts by weight of SAPO-34 molecular sieve; (b) 50 to 90 parts by weight of TiO2; (c) 0.01 to 1 part by weight of noble metal; and (d) 0.1 to 20 parts by weight of rare earth oxides.

[0008] A second aspect of the present invention provides a method for preparing a catalyst with catalytic oxidation function for organic waste gas, the method comprising:

[0009] S1. In the presence of a solvent and optional organic carboxylic acid, a precursor containing rare earth elements, SAPO-34 molecular sieve and TiO2 are mixed.

[0010] S2. The mixture obtained in step S1 is dried and calcined sequentially;

[0011] S3. Load the precious metal onto the calcined product obtained in step S2;

[0012] The weight ratio of the rare earth element-containing precursor, SAPO-34 molecular sieve, TiO2 and noble metal is (0.1-20):(1-40):(50-90):(0.01-1), and the amount of the rare earth element-containing precursor is calculated as rare earth oxides.

[0013] A third aspect of the present invention provides a catalyst prepared by the method described in the second aspect.

[0014] The fourth aspect of the present invention provides the application of the organic waste gas catalytic oxidation catalyst described in the first and third aspects or the method described in the second aspect in the treatment of waste gas containing organic amines.

[0015] The fifth aspect of the present invention provides a method for treating waste gas containing organic amines, the method comprising: contacting the waste gas containing organic amines with the catalyst described in the first or third aspect under the presence of an oxygen atmosphere;

[0016] Alternatively, the catalyst can be prepared according to the method described in the second aspect, and then the waste gas containing organic amines can be contacted with the obtained catalyst in the presence of an oxygen atmosphere.

[0017] The catalyst of this invention uses TiO2 and SAPO-34 as supports, rare earth oxides as additives, and noble metals as active components. It has good catalytic activity and is particularly suitable for the catalytic oxidation treatment of waste gas containing triethylamine. It has a high removal rate of non-methane substances and a triethylamine conversion rate of over 99%.

[0018] Since organic amines produce nitrogen oxides during oxidation, the catalytic oxidation catalyst of this invention can effectively reduce the formation of nitrogen oxides, resulting in NOx content in the treated waste gas below 20 mg / m³. 3 This has yielded good technical results. Attached Figure Description

[0019] Figure 1 Scanning electron microscope image of the catalyst prepared in Example 3. Detailed Implementation

[0020] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0021] The first aspect of the present invention provides a catalyst with the function of catalytic oxidation of organic waste gas, wherein, based on 100 parts by weight of the catalyst, the catalyst contains: (a) 1 to 40 parts by weight of SAPO-34 molecular sieve; (b) 50 to 90 parts by weight of TiO2; (c) 0.01 to 1 part by weight of noble metal; and (d) 0.1 to 20 parts by weight of rare earth oxide.

[0022] According to the present invention, preferably, the weight ratio of TiO2 to SAPO-34 molecular sieve is (1.25 to 20): 1 (for example, it can be 1.25:1, 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1), more preferably (1.5 to 10): 1.

[0023] According to the present invention, preferably, the weight ratio of TiO2 to noble metal is (50-2000):1 (for example, it can be 50:1, 100:1, 103:1, 104:1, 108:1, 150:1, 158:1, 200:1, 250:1, 280:1, 300:1, 400:1, 500:1, 1500:1, 2000:1), more preferably (100-500):1, and even more preferably (100-300):1.

[0024] According to the present invention, preferably, the weight ratio of TiO2 to rare earth oxides is (5 to 100):1 (for example, it can be 5:1, 6:1, 7:1, 10:1, 11:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 50:1, 60:1, 100:1), more preferably (5.5 to 50):1, even more preferably (5.5 to 35):1, and even more preferably (6 to 11):1.

[0025] According to the present invention, the SAPO-34 molecular sieve can be any common SAPO-34 type molecular sieve, for example, prepared by hydrothermal method using triethylamine and tetraethylammonium hydroxide as template agents. Preferably, the average particle size of the SAPO-34 molecular sieve is less than 1 μm, more preferably less than 0.5 μm, and even more preferably 0.1-0.4 μm.

[0026] According to the present invention, the TiO2 can be a common type of TiO2 in the art. Preferably, the average particle size of the TiO2 is less than 100 nm, more preferably less than 50 nm, and even more preferably 12-40 nm. The crystal form of the TiO2 is anatase.

[0027] According to the present invention, preferably, the precious metal is selected from at least one of Pt, Pd and Ru, more preferably Pt and / or Ru, and even more preferably, the weight ratio of Pt and Ru is (0.01-1):1 (for example, it can be 0.01:1, 0.05:1, 0.1:1, 0.2:1, 0.3:1, 0.35:1, 0.4:1, 0.48:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 0.95:1, 1:1), and more preferably (0.1-0.5):1.

[0028] According to the present invention, preferably, the rare earth oxide is selected from at least one of cerium oxide and lanthanum oxide, more preferably, the weight ratio of cerium oxide and lanthanum oxide is (0.4-5):1 (for example, it can be 0.4:1, 0.5:1, 1:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 2:1, 3:1, 4:1, 5:1), and even more preferably (0.9-2):1.

[0029] A second aspect of the present invention provides a method for preparing a catalyst with catalytic oxidation function for organic waste gas, the method comprising:

[0030] S1. In the presence of a solvent and optional organic carboxylic acid, a precursor containing rare earth elements, SAPO-34 molecular sieve and TiO2 are mixed.

[0031] S2. The mixture obtained in step S1 is dried and calcined sequentially;

[0032] S3. Load the precious metal onto the calcined product obtained in step S2;

[0033] The weight ratio of the rare earth element-containing precursor, SAPO-34 molecular sieve, TiO2 and noble metal is (0.1-20):(1-40):(50-90):(0.01-1), and the amount of the rare earth element-containing precursor is calculated as rare earth oxides.

[0034] According to the present invention, preferably, the weight ratio of TiO2 to SAPO-34 molecular sieve is (1.25 to 20): 1 (for example, it can be 1.25:1, 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1), more preferably (1.5 to 10): 1.

[0035] According to the present invention, preferably, the weight ratio of TiO2 to noble metal is (50-2000):1 (for example, it can be 50:1, 100:1, 103:1, 104:1, 108:1, 150:1, 158:1, 200:1, 250:1, 280:1, 300:1, 400:1, 500:1, 1500:1, 2000:1), more preferably (100-500):1, and even more preferably (100-300):1.

[0036] According to the present invention, preferably, the weight ratio of TiO2 to the rare earth element-containing precursor (calculated as rare earth oxide) is (5-100):1 (for example, it can be 5:1, 6:1, 7:1, 10:1, 11:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 50:1, 60:1, 100:1), more preferably (5.5-50):1, further preferably (5.5-35):1, and even more preferably (6-11):1.

[0037] According to the present invention, preferably, the solvent in step S1 is water.

[0038] According to the present invention, preferably, the weight ratio of the sum of TiO2 and SAPO-34 molecular sieve to the weight of organic carboxylic acid is (1-100):1, more preferably (4-50):1.

[0039] According to the present invention, the SAPO-34 molecular sieve can be any common SAPO-34 type molecular sieve. Preferably, the average particle size of the SAPO-34 molecular sieve is less than 1 μm, more preferably less than 0.5 μm, and even more preferably 0.1-0.4 μm.

[0040] According to the present invention, the TiO2 can be a common type of TiO2 in the art. Preferably, the average particle size of the TiO2 is less than 100 nm, more preferably less than 50 nm, and even more preferably 12-40 nm. The crystal form of the TiO2 is anatase.

[0041] According to the present invention, preferably, the precious metal is selected from at least one of Pt, Pd and Ru, more preferably Pt and / or Ru, and even more preferably, the weight ratio of Pt and Ru is (0.01-1):1 (for example, it can be 0.01:1, 0.05:1, 0.1:1, 0.2:1, 0.3:1, 0.35:1, 0.4:1, 0.48:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 0.95:1, 1:1), more preferably (0.1-0.5):1.

[0042] According to the present invention, preferably, the rare earth element in the rare earth element-containing precursor is selected from at least one of cerium and lanthanum; more preferably, the weight ratio of cerium and lanthanum, calculated as oxides, is (0.4-5):1 (for example, it can be 0.4:1, 0.5:1, 1:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 2:1, 3:1, 4:1, 5:1), and even more preferably (0.9-2):1.

[0043] According to the present invention, there is no particular limitation on the specific type of rare earth element-containing precursor, and it can be any substance containing rare earth elements. For example, rare earth cerium can be provided by at least one of cerium nitrate, cerium ammonium nitrate, cerium sulfate and cerium acetate; rare earth lanthanum can be provided by at least one of lanthanum nitrate, lanthanum acetate and lanthanum chloride.

[0044] According to the present invention, in order to better disperse rare earth elements in the catalyst, preferably, the organic carboxylic acid is selected from C1-10 aliphatic carboxylic acids and / or C7-10 aromatic carboxylic acids, more preferably at least one of formic acid, acetic acid, tartaric acid, citric acid, benzoic acid, and salicylic acid, and even more preferably a mixture of acetic acid and citric acid in a weight ratio of (0.1-1):1, preferably (0.1-0.5):1.

[0045] According to the present invention, preferably, step S1 further includes drying the obtained mixture, wherein the drying conditions include: a drying temperature of 40 to 120°C, more preferably 60 to 100°C; and / or a drying time of 4 to 12 hours, more preferably 6 to 12 hours.

[0046] According to the present invention, preferably, the mixing conditions in step S1 include: a mixing temperature of 20 to 90°C, more preferably 40 to 80°C; and / or a mixing time of 1 to 12 hours, more preferably 2 to 8 hours.

[0047] According to the present invention, preferably, the drying conditions in step S2 include: a drying temperature of 20 to 120°C, more preferably 40 to 100°C; and / or a drying time of 4 to 48 hours, more preferably 8 to 24 hours.

[0048] According to the present invention, preferably, the calcination conditions in step S2 include: a calcination temperature of 300-600°C, more preferably 350-550°C; and / or a calcination time of 1-8 hours, more preferably 2-6 hours.

[0049] According to the present invention, preferably, step S2 further includes mixing the mixture obtained in step S1 with a release agent and a solvent, and then drying and calcining them in sequence.

[0050] According to the present invention, preferably, the release agent is selected from at least one of silicone oil, paraffin wax, graphite, methylcellulose and sodium stearate. The weight ratio of TiO2 to the release agent can be (20-200):1.

[0051] According to the present invention, noble metals can be loaded onto a carrier using conventional methods. Preferably, in step S3, the noble metal is loaded onto the calcined product by immersing the calcined product in a solution containing a precursor of the noble metal element, followed by drying and reduction.

[0052] In this preferred embodiment, the impregnation can be saturated impregnation or excessive impregnation, without particular limitation.

[0053] According to the present invention, the precursor containing the noble metal element can be any substance capable of providing the desired noble metal. The noble metal Pt can be provided by at least one of ammonium hexachloroplatinate, chloroplatinic acid, potassium hexachloroplatinate, and platinum acetylacetonate; the noble metal Pd can be provided by at least one of palladium chloride, palladium acetate, ammonium chloride palladiumate, and palladium acetylacetonate; and the noble metal Ru can be provided by at least one of ruthenium trichloride, ruthenium acetylacetonate, and ruthenium nitrite.

[0054] According to the present invention, preferably, the solvent in the solution of the precursor containing the noble metal element is selected from at least one of water, acetone, methanol and ethanol, more preferably a mixture of ethanol and water, with a volume ratio of (0.05 to 20):1.

[0055] According to the present invention, preferably, in step S3, the conditions for impregnation include: an impregnation temperature of 20 to 90°C, more preferably 40 to 80°C; and / or an impregnation time of 0.5 to 24 hours, more preferably 2 to 12 hours.

[0056] According to the present invention, preferably, the drying conditions in step S3 include: a drying temperature of 20 to 120°C, more preferably 40 to 90°C; and / or a drying time of 1 to 24 hours, more preferably 4 to 12 hours.

[0057] According to the present invention, the reduction in step S3 mainly results in the noble metal existing in a reduced state. Preferably, the conditions for the reduction in step S3 include: being carried out in a reducing atmosphere containing hydrogen, a reduction temperature of 150–600°C, more preferably 250–500°C; and / or a reduction time of 1–12 h, more preferably 2–8 h.

[0058] According to the present invention, preferably, the reducing atmosphere containing hydrogen is provided by hydrogen and an inert gas in a volume ratio of 1:(1-50), preferably 1:(1-20), wherein the inert gas is selected from nitrogen and / or an inert gas. The inert gas may be selected from at least one of helium, argon and neon.

[0059] A third aspect of the present invention provides a catalyst prepared by the method described in the second aspect.

[0060] The fourth aspect of the present invention provides the application of the organic waste gas catalytic oxidation catalyst described in the first and third aspects or the method described in the second aspect in the treatment of waste gas containing organic amines.

[0061] The fifth aspect of the present invention provides a method for treating waste gas containing organic amines, the method comprising: contacting the waste gas containing organic amines with the catalyst described in the first or third aspect under the presence of an oxygen atmosphere;

[0062] Alternatively, the catalyst can be prepared according to the method described in the second aspect, and then the waste gas containing organic amines can be contacted with the obtained catalyst in the presence of an oxygen atmosphere.

[0063] According to the present invention, preferably, the content of organic amines in the waste gas containing organic amines is 50-2000 mg / m³. 3 Preferably 50–1000 mg / m³ 3 .

[0064] According to the present invention, preferably, the waste gas containing organic amines also contains C2-C4 hydrocarbons, wherein the mass ratio of hydrocarbon components to organic amines is (0.1-10):1. The C2-C4 hydrocarbons can be at least one of ethylene, propylene, and butene.

[0065] According to the present invention, preferably, the organic amine is selected from at least one of aliphatic amines, alkanolamines, amides, and aromatic amines. The aliphatic amine may be triethylamine and / or diethylamine.

[0066] According to the present invention, preferably, the contact conditions include: an initial temperature of the exhaust gas of 180–400°C, more preferably 180–350°C; a pressure of 0.1–0.5 MPa, more preferably 0.1–0.35 MPa; and an exhaust gas volume hourly space velocity of 2000–30000 h⁻¹. -1 .

[0067] According to the present invention, preferably, the oxygen volume content in the oxygen-enriched atmosphere is 0.1-10%, more preferably 2-5%. The oxygen-enriched atmosphere can be provided by a mixture of oxygen and an inert gas, wherein the inert gas in the oxygen-enriched atmosphere can be selected from nitrogen and / or an inert gas. The inert gas can be selected from at least one of helium, argon, and neon. The oxygen in the oxygen-enriched atmosphere can also be provided by air, i.e., the oxygen-enriched atmosphere is provided by a mixture of air and an inert gas.

[0068] The present invention will be described in detail below through embodiments. In the following embodiments,

[0069] The manufacturer of SAPO-34 molecular sieve is Sinopec Nanjing Catalyst Company.

[0070] The manufacturer of SSZ13 molecular sieve is Zhuoran Environmental Protection Technology (Dalian) Co., Ltd.

[0071] All other raw materials are commercially available.

[0072] The elemental composition of the catalysts obtained in the examples was analyzed by X-ray fluorescence spectroscopy. The elemental composition obtained by X-ray fluorescence spectroscopy was basically close to that of the feedstock, and therefore will not be shown again. Cerium oxide was calculated as CeO2, and lanthanum oxide was calculated as La2O3.

[0073] The scanning electron microscope is a FEI Nova Nano SEM field emission scanning electron microscope.

[0074] Example 1

[0075] S1. Dissolve 2.5g of cerium nitrate hexahydrate, 2g of lanthanum nitrate, 0.5g of acetic acid and 1g of citric acid in 50g of water to prepare a solution. Add 10g of SAPO-34 molecular sieve with an average particle size of 0.4μm and 20g of anatase TiO2 with an average particle size of 12nm to the solution. Mix and stir at 60℃ for 4h, and dry at 80℃ for 12h to obtain rare earth modified TiO2 and SAPO-34 powder.

[0076] S2. Mix 20g of the powder obtained in step S1 with 1g of methylcellulose and 2g of water at room temperature, and form into sheets. Dry at 40℃ for 24h, and calcine at 500℃ for 4h to obtain the catalyst support.

[0077] S3. Dissolve 0.1 g of chloroplatinic acid hexahydrate and 0.2 g of ruthenium chloride hydrate (RuCl3·3H2O) in 10 mL of ethanol aqueous solution to obtain a noble metal solution, wherein the volume ratio of ethanol to water is 20:1. Under 60 °C, 20 g of catalyst support is immersed in the above noble metal solution for 12 h, then dried at 80 °C for 12 h, and then reduced at 500 °C under an atmosphere of 5 vol% H2-95 vol% N2 for 8 h to obtain the catalyst.

[0078] The catalyst prepared in Example 1 has similar scanning electron microscope (SEM) images to the catalyst prepared in Example 3. The SEM images show that the catalyst prepared in Example 1 has a mixed structure of nanocubes and nanoparticles.

[0079] Example 2

[0080] S1. Dissolve 4.5g of cerium nitrate hexahydrate, 2g of lanthanum nitrate, 0.4g of acetic acid and 4g of citric acid in 30g of water to prepare a solution. Add 5g of SAPO-34 molecular sieve with an average particle size of 0.2μm and 20g of anatase TiO2 with an average particle size of 20nm to the solution. Mix and stir at 40℃ for 8h and dry at 80℃ for 12h to obtain rare earth modified TiO2 and SAPO-34 powder.

[0081] S2. Mix 20g of the powder obtained in step S1 with 0.5g of methylcellulose and 4g of water at room temperature, and form into sheets. Dry at 60℃ for 12h, and calcine at 350℃ for 6h to obtain the catalyst support.

[0082] S3. Dissolve 0.08 g of chloroplatinic acid hexahydrate and 0.22 g of ruthenium chloride hydrate in 10 mL of ethanol aqueous solution to obtain a noble metal solution, wherein the volume ratio of ethanol to water is 10:1. Under 40 °C, 20 g of catalyst support is impregnated in the above noble metal solution for 12 h, then dried at 80 °C for 12 h, and then reduced at 400 °C under an atmosphere of 10 vol% H2-90 vol% N2 for 6 h to obtain the catalyst.

[0083] The catalyst prepared in Example 2 has similar scanning electron microscope (SEM) images to the catalyst prepared in Example 3. The SEM images show that the catalyst prepared in Example 2 has a mixed structure of nanocubes and nanoparticles.

[0084] Example 3

[0085] S1. Dissolve 5g of cerium nitrate hexahydrate, 2.5g of lanthanum nitrate, 1g of acetic acid and 5g of citric acid in 20g of water to prepare a solution. Add 8g of SAPO-34 molecular sieve with an average particle size of 0.1μm and 20g of anatase TiO2 with an average particle size of 20nm to the solution. Mix and stir at 80℃ for 2h, and dry at 80℃ for 12h to obtain rare earth modified TiO2 and SAPO-34 powder.

[0086] S2. Mix 20g of the powder obtained in step S1 with 0.5g of methylcellulose and 5g of water at room temperature, and form into sheets. Dry at 100℃ for 8 hours, and calcine at 550℃ for 2 hours to obtain the catalyst support.

[0087] S3. Dissolve 0.01 g of chloroplatinic acid hexahydrate and 0.1 g of ruthenium chloride hydrate in 10 mL of ethanol aqueous solution to obtain a noble metal solution, wherein the volume ratio of ethanol to water is 1:1. Under 80 °C, 20 g of catalyst support is immersed in the above noble metal solution for 2 h, then dried at 90 °C for 10 h, and then reduced at 250 °C under an atmosphere of 5 vol% H2-95 vol% N2 for 8 h to obtain the catalyst.

[0088] Figure 1 The image shows a scanning electron microscope (SEM) image of the catalyst prepared in Example 3. As can be seen from the image, the catalyst prepared in Example 3 has a mixed structure of nanocubes and nanopowders.

[0089] Example 4

[0090] S1. Dissolve 1g of cerium nitrate hexahydrate, 0.5g of lanthanum nitrate, 1g of acetic acid and 1g of citric acid in 10g of water to prepare a solution. Add 2g of SAPO-34 molecular sieve with an average particle size of 0.7μm and 20g of anatase TiO2 with an average particle size of 40nm to the solution. Mix and stir at 20℃ for 12h, and dry at 80℃ for 12h to obtain rare earth modified TiO2 and SAPO-34 powder.

[0091] S2. Mix 20g of the powder obtained in step S1 with 1g of methylcellulose and 5g of water at room temperature, and form into sheets. Dry at 20℃ for 48h, and calcine at 300℃ for 8h to obtain the catalyst support.

[0092] S3. Dissolve 0.01 g of chloroplatinic acid hexahydrate and 0.2 g of ruthenium chloride hydrate in 10 mL of ethanol aqueous solution to obtain a noble metal solution, wherein the volume ratio of ethanol to water is 20:1. Under 20°C, 20 g of catalyst support is immersed in the above noble metal solution for 24 h, then dried at 20°C for 24 h, and then reduced at 200°C under an atmosphere of 20 vol% H2-80 vol% N2 for 12 h to obtain the catalyst.

[0093] The catalyst prepared in Example 4 has a similar scanning electron microscope (SEM) image to the catalyst prepared in Example 3. The SEM images show that the catalyst prepared in Example 4 has a mixed structure of nanocubes and nanoparticles.

[0094] Example 5

[0095] S1. Dissolve 2.5g of cerium nitrate hexahydrate, 5g of lanthanum nitrate, 1g of acetic acid and 4g of citric acid in 20g of water to prepare a solution. Add 4g of SAPO-34 molecular sieve with an average particle size of 0.8μm and 20g of anatase TiO2 with an average particle size of 60nm to the solution. Mix and stir at 90℃ for 1h, and dry at 80℃ for 12h to obtain rare earth modified TiO2 and SAPO-34 powder.

[0096] S2. Mix 20g of the powder obtained in step S1 with 1g of methylcellulose and 4g of water at room temperature, and form into sheets. Dry at 120℃ for 4h, and calcine at 600℃ for 1h to obtain the catalyst support.

[0097] S3. Dissolve 0.15 g of chloroplatinic acid hexahydrate and 0.15 g of ruthenium chloride hydrate in 10 mL of ethanol aqueous solution to obtain a noble metal solution, wherein the volume ratio of ethanol to water is 20:1. Under 90 °C, 20 g of catalyst support is impregnated in the above noble metal solution for 0.5 h, then dried at 120 °C for 1 h, and then reduced at 600 °C under an atmosphere of 20 vol% H2-80 vol% N2 for 1 h to obtain the catalyst.

[0098] The catalyst prepared in Example 5 has a similar scanning electron microscope (SEM) image to the catalyst prepared in Example 3. The SEM images show that the catalyst prepared in Example 5 has a mixed structure of nanocubes and nanoparticles.

[0099] Example 6

[0100] The catalyst was prepared according to the method of Example 1, except that lanthanum nitrate was replaced with an equal mass of cerium nitrate hexahydrate.

[0101] Example 7

[0102] The catalyst was prepared according to the method of Example 1, except that ruthenium chloride hydrate was replaced with an equal mass of chloroplatinic acid hexahydrate.

[0103] Example 8

[0104] The catalyst was prepared according to the method of Example 1, except that ruthenium chloride hydrate was replaced with an equal mass of silver nitrate.

[0105] Example 9

[0106] The catalyst was prepared according to the method of Example 1, except that the average particle size of the SAPO-34 molecular sieve was 2 μm.

[0107] Example 10

[0108] The catalyst was prepared according to the method of Example 1, except that the TiO2 was rutile and the average particle size was 15 nm.

[0109] Example 11

[0110] The catalyst was prepared according to the method of Example 1, except that cerium nitrate hexahydrate and lanthanum nitrate were not added in step S1, and equal masses of cerium nitrate hexahydrate and lanthanum nitrate were added in step S3.

[0111] Example 12

[0112] The catalyst was prepared according to the method of Example 1, except that the calcination temperature in step S2 was 700°C.

[0113] Comparative Example 1

[0114] The catalyst was prepared according to the method of Example 1, except that cerium nitrate hexahydrate and lanthanum nitrate were not used in the preparation of the support.

[0115] Comparative Example 2

[0116] The catalyst was prepared according to the method of Example 1, except that SAPO-34 molecular sieve was replaced with an equal mass of SSZ13 molecular sieve.

[0117] Comparative Example 3

[0118] The catalyst was prepared according to the method of Example 1, except that anatase TiO2 was replaced with an equal mass of SAPO-34 molecular sieve.

[0119] Comparative Example 4

[0120] The catalyst was prepared according to the method of Example 1, except that SAPO-34 molecular sieve was replaced with an equal mass of anatase TiO2.

[0121] Test Example 1

[0122] 5 mL of the catalyst from the above examples or comparative examples was loaded into a fixed-bed reactor, and then waste gas containing triethylamine, ethylene, air, and nitrogen was introduced into the reactor (the concentration of triethylamine in the waste gas was 852 mg / m³). 3 The ethylene concentration was 1520 mg / m³. 3 The oxygen content is 5% by volume, and the NOx concentration is < 0.01 mg / m³. 3 The volumetric space velocity of the exhaust gas is 15000 h⁻¹. -1 The initial temperature of the exhaust gas was controlled at 250℃, and the internal pressure of the reactor was 0.1MPa. After 0.5 hours of reaction, the concentration of non-methane substances in the outlet gas was tested using gas chromatography (Agilent 6890). Non-methane substances mainly include unreacted triethylamine, ethylene, and the reaction intermediate acetic acid. The concentration of NOx (NOx mainly includes NO and N2O) was determined using a Thermo Fisher Nicolet Antaris IGS infrared online analyzer. The triethylamine conversion rate was calculated using the formula: Conversion rate % = 100% - (triethylamine concentration after reaction ÷ triethylamine concentration before reaction) × 100%. The results are shown in Table 1.

[0123] Table 1

[0124]

[0125]

[0126] As shown in Table 1, the catalyst prepared by the method of this invention can effectively remove triethylamine and ethylene from the waste gas containing triethylamine, and the concentrations of non-methane substances and NOx are low after the reaction. Furthermore, it can be seen that the catalysts prepared by the methods in Examples 1-5 can achieve a triethylamine conversion rate of over 96% while ensuring that the concentration of non-methane substances after the reaction is below 50 mg / m³. 3 After the reaction, the NOx concentration was below 55 mg / m³. 3Particularly preferred is the catalyst prepared using the methods of Examples 1-3, which enables a triethylamine conversion rate of over 98% while ensuring that the concentration of non-methane substances after the reaction is below 20 mg / m³. 3 After the reaction, the NOx concentration was less than 20 mg / m³. 3 .

[0127] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst with catalytic oxidation function for organic amine waste gas, characterized in that, Based on 100 parts by weight of catalyst, the catalyst contains: (a) 1 to 40 parts by weight of SAPO-34 molecular sieve; (b) 50 to 90 parts by weight of TiO2; (c) 0.01 to 1 part by weight of noble metal; and (d) 0.1 to 20 parts by weight of rare earth oxide; The TiO2 has anatase crystal form; The average particle size of the SAPO-34 molecular sieve is less than 1 μm; The average particle size of the TiO2 is less than 100 nm; The precious metal is selected from at least one of Pt, Pd and Ru; The rare earth oxide is selected from at least one of cerium oxide and lanthanum oxide.

2. The catalyst according to claim 1, wherein, The weight ratio of TiO2 to SAPO-34 molecular sieve is (1.25~20):1; And / or, the weight ratio of TiO2 to precious metals is (50~2000):1; And / or, the weight ratio of TiO2 to rare earth oxides is (5~100):

1.

3. The catalyst according to claim 2, wherein, The weight ratio of TiO2 to SAPO-34 molecular sieve is (1.5~10):1; And / or, the weight ratio of TiO2 to precious metals is (100~500):1; And / or, the weight ratio of TiO2 to rare earth oxides is (5.5~50):

1.

4. The catalyst according to claim 1, wherein, The average particle size of the SAPO-34 molecular sieve is less than 0.5 μm; And / or, the average particle size of the TiO2 is less than 50 nm.

5. A method for preparing a catalyst with catalytic oxidation function for organic amine waste gas, characterized in that, The method includes: S1. In the presence of a solvent and optional organic carboxylic acid, a precursor containing rare earth elements, SAPO-34 molecular sieve and TiO2 are mixed. S2. The mixture obtained in step S1 is dried and calcined sequentially; S3. Load the precious metal onto the calcined product obtained in step S2; The weight ratio of the rare earth element-containing precursor, SAPO-34 molecular sieve, TiO2 and noble metal is (0.1~20):(1~40):(50~90):(0.01~1), and the amount of the rare earth element-containing precursor is based on rare earth oxides. The TiO2 has anatase crystal form; The average particle size of the SAPO-34 molecular sieve is less than 1 μm; The average particle size of the TiO2 is less than 100 nm; The precious metal is selected from at least one of Pt, Pd and Ru; The rare earth element in the rare earth element-containing precursor is selected from at least one of cerium and lanthanum.

6. The method according to claim 5, wherein, The weight ratio of TiO2 to SAPO-34 molecular sieve is (1.25~20):1; And / or, the weight ratio of TiO2 to precious metals is (50~2000):1; And / or, the weight ratio of TiO2 to the rare earth element-containing precursor (calculated as rare earth oxides) is (5~100):1; And / or, the sum of the weights of TiO2 and SAPO-34 molecular sieves to the weight ratio of the organic carboxylic acid is (1~100):

1.

7. The method according to claim 6, wherein, The weight ratio of TiO2 to SAPO-34 molecular sieve is (1.5~10):1; And / or, the weight ratio of TiO2 to precious metals is (100~500):1; And / or, the weight ratio of TiO2 to rare earth element-containing precursors (calculated as rare earth oxides) is (5.5~50):1; And / or, the sum of the weights of TiO2 and SAPO-34 molecular sieves to the weight ratio of the organic carboxylic acid is (5~50):

1.

8. The method according to claim 5 or 6, wherein, The organic carboxylic acid is selected from C1-10 aliphatic carboxylic acids and / or C7-10 aromatic carboxylic acids.

9. The method according to claim 5, wherein, The average particle size of the SAPO-34 molecular sieve is less than 0.5 μm; And / or, the average particle size of the TiO2 is less than 50 nm.

10. The method according to claim 8, wherein, The organic carboxylic acid is at least one of formic acid, acetic acid, tartaric acid, citric acid, benzoic acid, and salicylic acid.

11. The method according to claim 10, wherein, The organic carboxylic acid is a mixture of acetic acid and citric acid in a weight ratio of (0.1~1):

1.

12. The method according to claim 5 or 6, wherein, The mixing conditions described in step S1 include: a mixing temperature of 20~90℃; and / or a mixing time of 1~12h; And / or, the drying conditions described in step S2 include: a drying temperature of 20~120℃; and / or a drying time of 4~48h; And / or, the calcination conditions in step S2 include: a calcination temperature of 300~600℃; and / or a calcination time of 1~8h.

13. The method according to claim 12, wherein, The mixing conditions described in step S1 include: a mixing temperature of 40~80℃; and / or a mixing time of 2~8h; And / or, the drying conditions described in step S2 include: a drying temperature of 40~100℃; and / or a drying time of 8~24h; And / or, the calcination conditions in step S2 include: a calcination temperature of 350~550℃; and / or a calcination time of 2~6h.

14. The method according to claim 5 or 6, wherein, In step S3, the method of loading the precious metal onto the calcined product is as follows: the calcined product is immersed in a solution containing a precursor of precious metal elements, and then dried and reduced.

15. The method according to claim 14, wherein, In step S3, the conditions for impregnation include: an impregnation temperature of 20~90℃; and / or an impregnation time of 0.5~24h; And / or, the drying conditions described in step S3 include: a drying temperature of 20~120℃; and / or a drying time of 1~24h; And / or, the reduction conditions in step S3 include: being carried out in a reducing atmosphere containing hydrogen, with a reduction temperature of 150~600℃; and / or a reduction time of 1~12h.

16. The method according to claim 15, wherein, In step S3, the conditions for impregnation include: an impregnation temperature of 40~80℃; and / or an impregnation time of 2~12h; And / or, the drying conditions described in step S3 include: a drying temperature of 40~90℃; and / or a drying time of 4~12h; And / or, the reduction conditions in step S3 include: being carried out in a reducing atmosphere containing hydrogen, with a reduction temperature of 250~500℃; and / or a reduction time of 2~8h.

17. The method according to claim 15, wherein, The reducing atmosphere containing hydrogen is provided by a volume ratio of hydrogen to inert gas of 1:(1-50), wherein the inert gas is selected from nitrogen and / or inert gases.

18. The catalyst prepared by the method of any one of claims 5-17.

19. The use of the organic amine waste gas catalytic oxidation catalyst according to any one of claims 1-4 and 18 or the method according to any one of claims 5-17 in the treatment of waste gas containing organic amines.

20. A method for treating waste gas containing organic amines, characterized in that, The method includes: contacting the waste gas containing organic amines with the catalyst described in any one of claims 1-4 and 18 in the presence of an oxygen atmosphere; Alternatively, the catalyst may be prepared according to the method described in any one of claims 5-17, and then the waste gas containing organic amines may be contacted with the obtained catalyst in the presence of an oxygen atmosphere.

21. The method according to claim 20, wherein, The organic amine content in the waste gas is 50~2000 mg / m³. 3 ; And / or, the organic amine is selected from at least one of aliphatic amines, alkanolamines, amides, and aromatic amines; And / or, the contact conditions include: an initial temperature of the exhaust gas of 180~400℃; and / or a pressure of 0.1~0.5MPa; and / or an exhaust gas volume hourly space velocity of 2000~30000h. -1 ; And / or, the oxygen volume content in the oxygenated atmosphere is 0.1~10%.

22. The method according to claim 21, wherein, The organic amine content in the waste gas is 50~1000 mg / m³. 3 ; And / or, the contact conditions include: an initial temperature of the exhaust gas of 180~350℃; and / or a pressure of 0.1~0.35MPa; and / or an exhaust gas volume hourly space velocity of 2000~30000h. -1 ; And / or, the oxygen volume content in the oxygenated atmosphere is 2-5%.

Images