Non-noble metal ethane dehydrogenation catalysts and ethane dehydrogenation processes

Abstract

The application discloses a non-noble metal ethane dehydrogenation catalyst and an ethane dehydrogenation method. The catalyst contains a carrier and a non-noble metal dehydrogenation active component loaded on the carrier. The carrier contains a first metal element and a second metal element. The first metal element includes Al, and the second metal element is selected from group IVB. The particle size distribution of the carrier ranges from 15 microns to 50 microns in terms of Dx(90). The catalyst of the application does not contain noble metals or environment-harmful elements, is easy to prepare, has high activity, and has good target product selectivity.

Description

Technical Field

[0001] This invention relates to a non-precious metal ethane dehydrogenation catalyst and a method for ethane dehydrogenation. Background Technology

[0002] Ethylene, as the most important olefin product, is a major raw material for downstream products such as synthetic fibers, synthetic rubber, and synthetic plastics. However, due to my country's lack of petroleum resources, rising crude oil prices, and environmental problems caused by traditional petroleum-based ethylene production, non-traditional petroleum-based ethylene production has a significant market prospect. Among these, the ethane dehydrogenation to ethylene route is an important source of ethylene.

[0003] Methods for producing ethylene from ethane through dehydrogenation mainly include steam cracking and catalytic dehydrogenation. Steam cracking of ethane is relatively mature, but it requires furnace temperatures of 1000-1200℃, making it a very energy-intensive process. Catalytic dehydrogenation of ethane can lower the reaction temperature, achieving high-efficiency, low-energy ethylene production. Therefore, it is necessary to prepare high-performance dehydrogenation catalysts and optimize the dehydrogenation process route. Currently, there are numerous research reports, including catalyst design and process route selection, such as choosing CO2 as the oxidant for the oxidative dehydrogenation of ethane. For example, CN201610134338.5 discloses a modified chromium trioxide catalyst with a special pore structure for the catalytic oxidative dehydrogenation of ethane to ethylene using carbon dioxide. Although it achieves a high ethylene yield, the catalyst's selectivity for ethylene during the reaction is limited.

[0004] Currently, catalysts for the dehydrogenation of ethane to ethylene are mainly concentrated on Pt and CrOx-based catalysts. However, due to the high cost of Pt metal and the high Cr content in CrOx catalysts... 6+ The presence of carcinogenic substances and environmental hazards significantly limits the development of these two types of dehydrogenation catalysts. Therefore, developing high-activity, inexpensive, safe, and environmentally friendly ethane dehydrogenation catalysts is of paramount importance.

[0005] CN105727978B discloses a method for preparing a catalyst for the oxidative dehydrogenation of ethane to ethylene. In order to improve the conversion rate of ethane and the selectivity of ethylene, the main active component of the catalyst is Ni and the support is alumina. However, the catalyst preparation requires the reduction treatment of the catalyst precursor. When using this catalyst to catalyze the dehydrogenation of ethane, the composition of the feed gas for the dehydrogenation reaction needs to include an ethane / oxygen ratio of 1:1 to 1:3. At the same time, the feed gas can contain diluent gases such as Ar, N2 or He. At the reaction temperature of 400 to 600 °C, due to the addition of more diluent gases, the ethane conversion rate is relatively high, but the ethylene selectivity is low, below 57.3%.

[0006] CN106984297A discloses a method for dehydrogenating ethane to ethylene under a carbon dioxide atmosphere. The catalyst uses SiO2-doped TiO2 as a support, with the SiO2 doping amount ranging from 1.0% to 20.0% by mass. Gallium oxide is used as the active component, prepared by an impregnation method, with the active component content ranging from 1.0% to 15.0%. The reaction is carried out in a fixed-bed reactor under atmospheric pressure at a temperature of 550–750°C. The total flow rate of the feed gas is 10–50 mL / min, and the molar percentages of the components in the feed gas are 1–5% ethane, 3–30% carbon dioxide, and the remainder nitrogen. The reaction results show that the ethylene yield is 30%, and the selectivity is higher than 80%. However, due to the low ethane content in the entire feed, the dehydrogenation economy is poor.

[0007] CN111013563A discloses a spinel catalyst for the dehydrogenation of ethane to ethylene under a carbon dioxide atmosphere and its preparation method. The catalyst is a gallium-doped magnesium aluminum spinel with the general formula: MgGa x Al 2-x O4 (x = 0.5~2), with gallium oxide doping content exceeding 50% in the preferred scheme. Although ethane catalytic dehydrogenation to ethylene under a carbon dioxide atmosphere exhibits high ethane conversion and ethylene selectivity, the ethane content in the mixed feed is low, accounting for only 1~5%. Although the ethylene yield reaches 43.9% and the selectivity reaches 87%, significant economic issues remain.

[0008] CN115634678A provides an ethane dehydrogenation catalyst that uses a non-precious metal as the active component, comprising a first metal component, a second metal component, and a third metal component; wherein the first metal component is a combination of two or more elements selected from Fe, Zn, and Ga; the second metal component is one or more elements selected from alkali metals, alkaline earth metals, rare earth metals, Cu, and Mn; and the third metal component is one or more compounds containing V, Mo, W, Ni, and Zr; the catalyst, based on metal oxides, has a mass content of not less than 50%, 0-30%, and 0-20%, respectively. Although the dehydrogenation reaction has a high ethane conversion rate (above 33%) and good ethylene selectivity (above 83%), the reaction process requires water vapor and / or nitrogen as dilution gases, resulting in high operating costs and significant operational difficulties.

[0009] In summary, all existing ethane dehydrogenation catalysts have certain shortcomings, making the development of a new non-precious metal dehydrogenation catalyst extremely important. Summary of the Invention

[0010] The purpose of this invention is to overcome the problems of existing technologies that use precious metals or environmentally harmful catalysts, and to provide a non-precious metal or environmentally friendly ethane dehydrogenation catalyst that is easy to prepare and has good activity and good selectivity for target substances.

[0011] 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.

[0012] This invention provides a non-precious metal ethane dehydrogenation catalyst, which contains a support and a non-precious metal dehydrogenation active component supported on the support. The support contains a first metal element and a second metal element. The first metal element includes Al, and the second metal element is selected from Group IVB. The particle size distribution of the support, expressed as Dx(90), ranges from 15 to 50 micrometers. The support of this invention has a narrow average particle size distribution. The catalyst of this invention does not contain precious metals or environmentally harmful elements, and is easy to prepare, highly active, and stable.

[0013] According to a preferred embodiment of the present invention, preferably, the non-precious metal dehydrogenation active component is selected from one or more of Group VIII, Group IB, and Group IIB, more preferably from one or more of Zn, Fe, Co, Ni, and Cu, and more preferably from one or more of Zn, Fe, and Ni. In this embodiment of the present invention, Zn is used as an example to illustrate the advantages of the present invention, but this does not limit the scope of the present invention.

[0014] According to a preferred embodiment of the present invention, preferably, the non-precious metal dehydrogenation active component, based on the total weight of the catalyst, has an elemental content of 1-20%, preferably 2-15%.

[0015] According to a preferred embodiment of the present invention, preferably, the catalyst contains a Group IIIA auxiliary element, preferably, the content of the Group IIIA element is 0.1-5% by weight of the catalyst, and more preferably 0.2-3%.

[0016] According to a preferred embodiment of the present invention, preferably, preferably, the group IIIA element is at least one of B, Ga, and In, with Ga being the most preferred.

[0017] According to a preferred embodiment of the present invention, the particle size distribution of the bimetallic oxide support, in terms of Dx(90), ranges from 18 to 35 micrometers; the support with this characteristic enables the raw material to enter the support and the product to desorb rapidly, thereby giving the catalyst good activity.

[0018] According to a preferred embodiment of the present invention, the crystal structure of the bimetallic oxide support includes: containing 1-10% by weight of γ-phase alumina, preferably 2-6% by weight of γ-phase alumina; a support having this characteristic can improve the performance of a catalyst when used in a catalyst.

[0019] According to a preferred embodiment of the present invention, the physicochemical characteristics of the bimetallic oxide support further include: an average pore size distribution of 3-15 nm.

[0020] In this invention, the molar ratio of the second metal element to the first metal element can be selected within a wide range. According to a preferred embodiment of this invention, the molar ratio of the second metal element to the first metal element is 0.01 to 0.1.

[0021] In this invention, the first metallic element includes, but is not limited to, Al; other elements may be introduced as needed. In this embodiment, Al is used as the first metallic element to illustrate the advantages of the invention.

[0022] In this invention, the second metallic element is selected from one or more of Ti, Zr, and Hf, preferably Zr. Other elements may also be introduced as needed.

[0023] In this invention, preferably, the support contains element B; more preferably, the molar ratio of element B to the second metal element is 0.01-0.03:1. This can further improve the performance of the support when used in a catalyst.

[0024] The carriers possessing the features of this invention can all achieve the objectives of this invention, and there are no special requirements for their preparation methods. According to one embodiment of this invention, the preparation method of the carrier includes: mixing a first metal source, a second metal source, an optional boron source, and a hydroxyl-containing polymer, followed by crystallization under alkaline conditions, cooling, solid-liquid separation, drying, and calcination. The target carrier of this invention can be prepared using the aforementioned method, which is simple in steps and uses widely available materials.

[0025] In this invention, the range of possible proportions of each material is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the molar ratio of first metal source: second metal source: deionized water: hydroxyl-containing polymer: alkali is (10-100): 1: (20-500): (0.1-10): (30-80), preferably (20-100): 1: (100-300): (0.2-5): (30-50).

[0026] In this invention, all hydroxyl-containing polymers are applicable. According to this invention, the average molecular weight of the hydroxyl-containing polymer is preferably 200-2500, more preferably 400-1025. The aforementioned preferred technical solutions can effectively achieve the objectives of this invention.

[0027] In this invention, various types of hydroxyl-containing polymers can be used. According to this invention, the preferred hydroxyl-containing polymers are selected from polyethylene glycol and / or polyallyl alcohol.

[0028] In this invention, polyethylene glycol is, for example, a liquid with a molecular weight of 200 to 600 at room temperature; a transparent, colorless or essentially colorless viscous liquid.

[0029] In this invention, polyallyl alcohol is generally classified into three types according to average molecular weights of 425, 1025 and 2025. It is non-volatile, soluble in water (low molecular weight) and organic solvents such as aliphatic ketones and alcohols, and insoluble in ether and most aliphatic hydrocarbons.

[0030] According to a preferred embodiment of the present invention, the average molecular weight of polyethylene glycol is preferably 200 to 600.

[0031] According to a preferred embodiment of the present invention, the polyallyl alcohol is preferably selected from one or more of the following: an average molecular weight of 425, 1025, and 2025.

[0032] According to a preferred embodiment of the present invention, preferably, the hydroxyl-containing polymer is selected from a mixture of polyethylene glycol with an average molecular weight of 400 and polyallyl alcohol with an average molecular weight of 1025, with a ratio of 0.1-10:1. In the examples, a 1:1 ratio is used as an example to illustrate the advantages of the present invention, but this does not limit the scope of the invention. This can further improve the performance of the support used in the catalyst.

[0033] In this invention, the crystallization conditions can be selected from a wide range. The following is an illustrative description, but it does not limit the scope of this invention. Crystallization refers to a hydrothermal reaction in a reaction vessel. According to a preferred embodiment of this invention, the crystallization conditions include a temperature of 150-200°C, preferably 150-180°C.

[0034] In this invention, the crystallization time can be selected within a wide range and is determined according to specific needs. According to a preferred embodiment of this invention, the crystallization conditions include a time of 12-48 hours, preferably 12-24 hours.

[0035] In this invention, there are no special requirements for the drying and calcination conditions. The following is an illustrative description, but it does not limit the scope of the invention.

[0036] According to one embodiment of the present invention, the drying conditions include a temperature of 80-120°C and a time of 12-24 hours.

[0037] According to a preferred embodiment of the present invention, the calcination conditions include: a temperature of 500-750°C and a time of 2-12 hours; preferably, a temperature of 600-650°C and a time of 4-6 hours.

[0038] In this invention, there are no special requirements for the type of the first metal source; various substances are applicable to this invention. The following is an illustrative description, but it does not limit the scope of this invention. According to one embodiment of this invention, the first metal source includes one or more of aluminum nitrate nonahydrate, aluminum sulfate, aluminum isopropoxide, and aluminum sol.

[0039] In this invention, there are no special requirements for the type of the second metal source; various substances are applicable to this invention. The following is an illustrative description, but it does not limit the scope of this invention. According to one embodiment of this invention, the second metal source is selected from a second metal soluble compound, preferably from a second metal soluble salt, and preferably zirconium nitrate and / or zirconium oxychloride.

[0040] In this invention, the range of boron sources is relatively wide, and commonly used substances can be used in this invention. For this invention, the preferred boron source is selected from one or more of boric acid and organoborides. Boric acid is used as an example in the embodiments to illustrate the advantages of this invention, but this invention is not limited thereto.

[0041] In this invention, the range of alkaline substances that can be selected is relatively wide, and commonly used alkaline substances can be applied to this invention. The main purpose is to provide an alkaline environment. The following is an illustrative description of this invention, but it does not limit the scope of this invention. Preferably, the alkaline substance is selected from organic amines and / or inorganic ammonia.

[0042] In this invention, the range of types of organic amines is relatively wide, and commonly used organic amines can be used in this invention, such as ethylamine, propylamine, dimethylamine, ethylenediamine, diethylamine, diisopropylamine, hexamethylenediamine, monoethanolamine, diethanolamine, triethanolamine, 3-propanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, 1,2-dimethylpropylamine, sec-butylamine, ethylenediamine, 1,2-propanediamine, 1,4-butanediamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, or tetrapropylammonium hydroxide, or one or more of these.

[0043] In this invention, the step of mixing the first metal source, the second metal source, and optionally the boron source containing the hydroxyl polymer is not particularly required; the main purpose is to achieve uniform mixing. For example, this can be achieved by appropriate heating or dropwise mixing. The following is an illustrative description, but it does not limit the scope of the invention. The mixing step includes:

[0044] (1) Under the conditions of 20-50℃, the first metal source and the second metal source are added to deionized water in proportion and stirred thoroughly to dissolve, so as to obtain mixed solution I;

[0045] (2) Add the hydroxyl-containing polymer to the above mixed solution I and stir until homogeneous.

[0046] In this invention, to achieve crystallization under alkaline conditions, an alkaline substance can be introduced during mixing or after mixing. This invention does not have special requirements in this regard. According to one embodiment of the invention, the step of introducing an alkaline substance after mixing, for example, includes:

[0047] (1) Under the conditions of 20-50℃, the first metal source and the second metal source are added to deionized water in proportion and stirred thoroughly to dissolve, so as to obtain mixed solution I;

[0048] (2) Add the hydroxyl-containing polymer to the above mixed solution I and stir until homogeneous;

[0049] (3) Add an alkaline solution dropwise to the solution obtained in step (2), and continue stirring for 1-3 hours after adding the solution.

[0050] According to a preferred embodiment of the present invention, the method for preparing the carrier includes:

[0051] (1) Under the conditions of 20-50℃, the first metal source and the second metal source are added to deionized water in proportion and stirred thoroughly to dissolve, so as to obtain mixed solution I;

[0052] (2) Add the hydroxyl-containing polymer to the above mixed solution I and stir until homogeneous;

[0053] (3) Add an alkaline solution dropwise to the solution obtained in step (2), and continue stirring for 1-3 hours after adding the solution;

[0054] (4) Then pour the mixture obtained in step (3) into a crystallization vessel and crystallize it at 150-200℃ for 12-48h. Then cool it to room temperature, filter it, dry the resulting solid product at 80-120℃ for 12-24h, and then calcine it at 500-750℃ for 2-12h to obtain the carrier.

[0055] This invention does not impose any special requirements on the preparation method of the catalyst. Specifically, this invention provides a method for preparing the non-noble metal dehydrogenation catalyst, which includes:

[0056] (1) Prepare the carrier according to the method described in this invention;

[0057] (2) The non-precious metal dehydrogenation active component source, optionally a group IIIA auxiliary agent source, is loaded onto the carrier by impregnation, followed by drying and calcination.

[0058] In this invention, there are no special requirements for the impregnation method. The impregnation method is an equal-volume impregnation method, which is illustrative but does not limit the scope of the invention.

[0059] In this invention, there are no special requirements for the drying and calcination conditions. The following is an illustrative description, but it does not limit the scope of the invention.

[0060] According to one embodiment of the present invention, the drying conditions include a temperature of 80-120°C and a time of 12-24 hours.

[0061] According to a preferred embodiment of the present invention, the calcination conditions include: a temperature of 500-750°C and a time of 2-12 hours.

[0062] The present invention provides a method for ethane dehydrogenation, the method comprising: subjecting ethane to a dehydrogenation reaction, wherein the catalyst comprises the dehydrogenation catalyst described in the present invention.

[0063] In this invention, there are no special requirements for the dehydrogenation reaction conditions. The following is an illustrative description, but it does not limit the scope of the invention.

[0064] According to one embodiment of the present invention, preferably, the conditions for the dehydrogenation reaction include: a reaction temperature of 500-850°C, a reaction pressure of 0.01-0.2 MPa, and a volume hourly space velocity of 0.4-0.8 h⁻¹. -1 .

[0065] The support of this invention is a composite support composed of two metals, with a narrow average particle size distribution. This enables the raw materials to enter the support and the products to desorb rapidly, resulting in good catalyst activity.

[0066] The carrier preparation method of the present invention is relatively simple and easy to implement.

[0067] The catalyst of this invention does not contain precious metals or environmentally harmful elements, and is easy to prepare, highly active, and has good selectivity for target substances. Detailed Implementation

[0068] The present invention will be described in detail below through examples. In the following examples, the particle size distribution of the bimetallic oxide support was obtained by dry testing using a Malvern particle size analyzer, the crystal form of the bimetallic oxide support was obtained by XRD analysis combined with instrument configuration identification software, and the average pore size distribution of the oxide was obtained by the BET method; all raw materials used were commercially available analytical grade products from China National Pharmaceutical Group.

[0069] In this invention, particle size distribution (particle size) is what the particles or particle aggregates exhibit, while pore size distribution is the internal size of the particles.

[0070] Granularity testing methods include:

[0071] The particle size of the carrier was analyzed using a Malvern 3000 particle size analyzer. The test method is as follows: First, the particle size analyzer was cleaned, and the test parameters were set. The Venturi tube was set according to the standard value, the test pressure was 2 bar, the test powder was added, the file name was set, and the test was started. The instrument automatically completed the background scan and three parallel tests of the powder. After the test, the test data was processed through the editing option to obtain the Dx(90) particle size of the double oxide carrier.

[0072] The method for testing the γ-alumina crystalline phase content was as follows: A BRUKER X-ray powder diffractometer (XRD), model D8 Advance SS (18kW), was used, with a rotating target (copper target) X-ray generator: maximum power 18kW, voltage and current 60KV*300mA, and routine testing was performed. Crystalline phase analysis was conducted automatically using system software for peak identification and analysis.

[0073] Method for testing the average pore size of the dual oxide support: The ASAP2020M+C physical adsorption instrument from Micron Instruments, Inc. was used for fully automated analysis of specific surface area and mesopore / micropore size.

[0074] In the following examples, molecular weight refers to the average molecular weight.

[0075] The dehydrogenation method involves mixing ethane and nitrogen gas at a 1:1 volume ratio, adjusting the flow rates using mass flow meters, and then preheating them in a preheating zone before introducing them into the reaction zone. Both the heating and reaction sections of the reactor are heated by heating wires to reach predetermined temperatures. The reactor is constructed using a 400mm long quartz tube with an inner diameter of Ф8mm. The reacted gases are then condensed and analyzed by gas chromatography.

[0076] The catalyst evaluation conditions in the isothermal fixed-bed reactor are as follows: Weigh 1g of catalyst (20-40 mesh after sieving) and 1g of 20-40 mesh quartz sand, mix them evenly, and load them into the above-mentioned isothermal fixed-bed reactor. The reaction pressure is atmospheric pressure, the feed is pure ethane, and the gas hourly space velocity is 0.4h. -1 The reaction temperature was 720℃. After 12 minutes of reaction, the content of each component in the gas was analyzed by gas chromatography, and the conversion rate of ethane and the selectivity of ethylene were calculated.

[0077] In this invention, the conversion rate is calculated as follows: Ethane conversion rate (%) = (Amount of ethane used - Content of ethane in the reaction product) ÷ Amount of ethane used × 100%;

[0078] The selectivity is calculated as follows: Selectivity of ethylene (%) = Actual yield of ethylene ÷ Theoretical yield of ethylene × 100%.

[0079] Example 1

[0080] Carrier preparation:

[0081] Weigh aluminum isopropoxide, zirconium nitrate, deionized water, polyethylene glycol (molecular weight 400) and diethanolamine according to a molar ratio of 20:1:100:5:30.

[0082] At 25°C, aluminum isopropoxide and zirconium nitrate were dissolved in deionized water and stirred thoroughly. Then, polyethylene glycol liquid was slowly added dropwise and stirred for 1 hour to mix evenly. Diethanolamine was then added dropwise to the solution and stirring was continued for 2 hours. The resulting mixture was introduced into a crystallization vessel and crystallized at 150°C for 12 hours. The resulting solution was centrifuged, and the filter cake was transferred to an oven and dried at 80°C for 12 hours. Then, it was placed in a muffle furnace and calcined at 600°C for 4 hours to obtain a ZrO2-Al2O3 bioxide support. The Dx(90) particle size of the bioxide support was 35 micrometers, with a γ-alumina content of 2.41% and an average pore size of 4.9 nm.

[0083] Catalyst preparation:

[0084] Weigh 2.33 g of zinc nitrate and 0.16 g of gallium nitrate, dissolve them in 8 g of deionized water to obtain a solution containing the active components. Add solution I to 20 g of the above-mentioned support to ensure full contact, then dry in an oven at 80 °C for 12 h, and then calcine in a muffle furnace at 600 °C for 4 h to obtain a catalyst sample.

[0085] The ethane conversion rate was 29%, and the ethylene selectivity was 88%.

[0086] Example 2

[0087] The method is the same as in Example 1, except that the preparation steps of the carrier are as follows:

[0088] Aluminum sol, zirconium oxychloride, deionized water, polyethylene glycol (molecular weight 200), and propylamine were weighed according to a molar ratio of 50:1:200:0.2:50. Crystallization was carried out at 180℃ for 18 hours; the bioxide support was obtained by calcination in a muffle furnace at 650℃ for 4 hours, with a Dx(90) particle size of 29 micrometers, of which γ-Al₂O₃ accounted for 2.51%, and the average pore size of the bioxide was 5.3 nm.

[0089] The ethane conversion rate was 27%, and the ethylene selectivity was 89%.

[0090] Example 3

[0091] The method of Example 1 was followed, except that the preparation steps of the support were as follows: aluminum nitrate nonahydrate, zirconium nitrate, deionized water, polyethylene glycol (molecular weight 600), and ethylenediamine were weighed sequentially in a molar ratio of 100:1:300:0.5:30. The crystallization temperature was 180℃, and the time was 24h. The bioxide support was obtained by calcination in a muffle furnace at 650℃ for 6h, with a Dx(90) particle size of 27 micrometers, a γ-Al₂O₃ content of 2.91%, and an average pore size of 6.5 nm. The ethane conversion rate was 28%, and the ethylene selectivity was 87%.

[0092] Example 4

[0093] Following the method of Example 1, except that the polyethylene glycol molecular weight was 900, a bioxide support was obtained with a Dx(90) particle size of 18 micrometers, of which γ-Al₂O₃ accounted for 2.31%, and the average pore size of the bioxide was 3.8 nm. The ethane conversion rate was 26%, and the ethylene selectivity was 85%.

[0094] Example 5

[0095] The method was followed in Example 1, except that the polymer was polyallyl alcohol with a molecular weight of 4100, resulting in a bioxide support with a Dx(90) particle size of 23 micrometers, of which γ-Al₂O₃ accounted for 2.45%, and the average pore size of the bioxide was 4.5 nm. The ethane conversion rate was 25%, and the ethylene selectivity was 86%.

[0096] Example 6

[0097] The method is the same as in Example 1, except that...

[0098] Aluminum nitrate nonahydrate, zirconium nitrate, deionized water, polyethylene glycol, and diethanolamine were weighed according to a molar ratio of 200:1:200:0.2:50, and all other conditions were kept the same to obtain a bioxide support with a Dx(90) particle size of 45 μm, of which γ-Al₂O₃ accounted for 15%, and the average pore size of the bioxide was 18 nm. The ethane conversion rate was 24%, and the ethylene selectivity was 88%.

[0099] Example 7

[0100] Following the same preparation method as in Example 3, but with a crystallization temperature of 240°C and a processing time of 36 hours, a bioxide support was obtained with a Dx(90) particle size of 49 micrometers, of which γ-Al₂O₃ accounted for 21%, and the average pore size of the bioxide was 19 nm. The ethane conversion rate was 24%, and the ethylene selectivity was 85%.

[0101] Example 8

[0102] The method is the same as in Example 1, except that auxiliary agent B is introduced in the preparation process of the carrier:

[0103] Weigh boric acid, aluminum isopropoxide, zirconium nitrate, deionized water, polyethylene glycol (molecular weight 400), and diethanolamine according to a molar ratio of boric acid to zirconium nitrate of 0.01:1 and a molar ratio of aluminum isopropoxide, zirconium nitrate, deionized water, polyethylene glycol (molecular weight 400), and diethanolamine of 20:1:100:5:30.

[0104] At 25°C, boric acid, aluminum isopropoxide, and zirconium nitrate were dissolved in deionized water and stirred thoroughly. Then, liquid polyethylene glycol was slowly added dropwise, and the mixture was stirred for 1 hour to ensure homogeneity. Diethanolamine was then added dropwise to the solution, and stirring continued for 2 hours. The resulting mixture was introduced into a crystallization vessel under unchanged crystallization conditions to obtain a boron-containing bioxide support. The bioxide support had a Dx(90) particle size of 33 micrometers, with γ-Al₂O₃ comprising 5.6% and an average pore size of 7.1 nm. In the catalyst preparation, Zn and Ga were introduced in the same manner, ultimately yielding a non-noble metal dehydrogenation catalyst containing B and Ga. The ethane conversion rate was 30%, and the ethylene selectivity was 91%.

[0105] Example 9

[0106] The method was followed as in Example 1, except that the carrier preparation process used an equal molar amount of polyallyl alcohol with a molecular weight of 425. The Dx(90) particle size of the bioxide carrier was 25 micrometers, with a γ-alumina content of 3.41% and an average pore size of 4.4 nm. The ethane conversion rate was 28%, and the ethylene selectivity was 88%.

[0107] Example 10

[0108] The method of Example 1 was followed, except that the carrier preparation process involved the simultaneous addition of polyethylene glycol (molecular weight 400) and polyallyl alcohol (molecular weight 1025) in a 1:1 molar ratio, with the total molar amount being the same as that of the polymer used in Example 1. The Dx(90) particle size of the bioxide carrier was 31 micrometers, with a γ-alumina content of 2.48% and an average pore size of 4.6 nm. The ethane conversion rate was 32%, and the ethylene selectivity was 93%.

[0109] Comparative Example 1

[0110] The method of Example 1 was followed, except that polyethylene glycol was not added to the prepared support, and the resulting support Dx(90) had a particle size distribution of 103 micrometers. All other conditions were the same. The ethane conversion rate was 19%, and the ethylene selectivity was 81%.

[0111] 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 non-precious metal ethane dehydrogenation catalyst, characterized in that, The catalyst contains a support and a non-precious metal dehydrogenation active component supported on the support. The support contains a first metal element and a second metal element. The first metal element includes Al, and the second metal element is selected from Group IVB. The particle size distribution of the support is in the form of Dx (90) and ranges from 15 to 50 micrometers. The molar ratio of the second metallic element to the first metallic element is 0.01 to 0.1; The crystal structure characteristics of the carrier include: containing 1-10% by weight of γ-phase alumina; The physicochemical characteristics of the support include: an average pore size distribution of 3-15 nm; and the non-noble metal dehydrogenation active component is selected from one or more of Group VIII, Group IB, and Group IIB. The non-precious metal dehydrogenation active component, calculated by element, has a content of 1-20% based on the total weight of the catalyst.

2. The catalyst according to claim 1, wherein, The non-precious metal dehydrogenation active component is selected from one or more of Zn, Fe, Co, Ni, and Cu; The non-precious metal dehydrogenation active component, calculated by element, comprises 2-15% of the total weight of the catalyst.

3. The catalyst according to claim 2, wherein, The non-precious metal dehydrogenation active component is one or more of Zn, Fe, and Ni.

4. The catalyst according to claim 1, wherein, The catalyst contains Group IIIA auxiliary elements.

5. The catalyst according to claim 4, wherein, Based on the total weight of the catalyst, the content of Group IIIA elements is 0.1% to 5% (elemental basis). Group IIIA elements are at least one of Ga and In.

6. The catalyst according to claim 5, wherein, Based on the total weight of the catalyst, the content of Group IIIA elements is 0.2% to 3% (elemental basis). The element in Group IIIA is Ga.

7. The catalyst according to claim 1, wherein, The particle size distribution of the carrier, expressed as Dx(90), ranges from 18 to 35 micrometers; and / or The crystal structure of the carrier includes: containing 2-6% by weight of γ-phase alumina.

8. The catalyst according to claim 1, wherein, The first metallic element is Al; and / or The second metallic element is selected from one or more of Ti, Zr, and Hf.

9. The catalyst according to claim 8, wherein, The second metallic element is Zr.

10. The catalyst according to claim 8, wherein, The carrier contains element B, and the molar ratio of element B to the second metal element is 0.01-0.03:

1.

11. The catalyst according to any one of claims 1-9, wherein, The preparation method of the carrier includes: mixing a first metal source, a second metal source, and a hydroxyl-containing polymer, followed by crystallization under alkaline conditions, cooling, solid-liquid separation, drying, and calcination; First metal source: Second metal source: Deionized water: Hydroxyl-containing polymer: Alkali molar ratio = (10~100): 1: (20~500): (0.1~10): (30~80); The average molecular weight of hydroxyl-containing polymers is 200-2500; The hydroxyl-containing polymer is selected from polyethylene glycol and / or polyallyl alcohol.

12. The catalyst according to claim 10, wherein, The preparation method of the carrier includes: mixing a first metal source, a second metal source, a boron source, and a hydroxyl-containing polymer, followed by crystallization under alkaline conditions, cooling, solid-liquid separation, drying, and calcination.

13. The catalyst according to claim 11, wherein, First metal source: Second metal source: Deionized water: Hydroxyl polymer: Alkali molar ratio = (20~100): 1: (100~300): (0.2~5): (30~50).

14. The catalyst according to claim 11, wherein, The average molecular weight of hydroxyl-containing polymers is 400-1025; and / or The average molecular weight of polyethylene glycol is 200–600; Polyallyl alcohol is selected from one or more of the following: average molecular weight 425, 1025, and 2025.

15. The catalyst according to claim 14, wherein, The hydroxyl-containing polymer is selected from a mixture of polyethylene glycol with an average molecular weight of 400 and polyallyl alcohol with an average molecular weight of 1025, with a ratio of 0.1-10:

1.

16. The catalyst according to claim 11, wherein, Crystallization conditions include: a temperature of 150-200℃; and / or a time of 12-48 hours; and / or Drying conditions include: a temperature of 80-120℃ and a time of 12-24 hours; and / or The roasting conditions include a temperature of 500-750℃ and a time of 2-12 hours.

17. The catalyst according to claim 16, wherein, Crystallization conditions include: a temperature of 150-180℃; and / or a time of 12-24 hours; and / or The roasting conditions include a temperature of 600-650℃ and a time of 4-6 hours.

18. The catalyst according to claim 11, wherein, The first metal source includes one or more of aluminum nitrate nonahydrate, aluminum sulfate, aluminum isopropoxide, and aluminum sol; and / or The second metal source is selected from a second metal-soluble compound; and / or The base is selected from organic amines and / or inorganic ammonia.

19. The catalyst according to claim 12, wherein, The boron source is selected from one or more of boric acid and organoborides.

20. The catalyst according to claim 18, wherein, The second metal source is selected from a soluble salt of a second metal; and / or The organic amine is selected from one or more of ethylamine, propylamine, dimethylamine, ethylenediamine, diethylamine, diisopropylamine, hexamethylenediamine, monoethanolamine, diethanolamine, triethanolamine, 3-propanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, 1,2-dimethylpropylamine, sec-butylamine, ethylenediamine, 1,2-propanediamine, 1,4-butanediamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrapropylammonium hydroxide.

21. The catalyst according to claim 20, wherein, The second metal source is zirconium nitrate and / or zirconium oxychloride.

22. The catalyst according to claim 11, wherein, Methods for preparing the carrier include: (1) Under the conditions of 20-50℃, the first metal source and the second metal source are added to deionized water in proportion and stirred thoroughly to dissolve, so as to obtain mixed solution I; (2) Add the hydroxyl-containing polymer to the above mixed solution I and stir until homogeneous; (3) Add an alkaline solution dropwise to the solution obtained in step (2), and continue stirring for 1-3 hours after adding the solution; (4) Then pour the mixture obtained in step (3) into a crystallization vessel, crystallize at 150-200℃ for 12-48h, then cool to room temperature, filter, dry the obtained solid product at 80-120℃ for 12-24h, and then calcine at 500-750℃ for 2-12h to obtain the carrier.

23. The catalyst according to claim 12, wherein, Methods for preparing the carrier include: (1) Under the conditions of 20-50℃, the first metal source, the second metal source, and the boron source are added to deionized water in proportion and stirred thoroughly to dissolve, so as to obtain mixed solution I; (2) Add the hydroxyl-containing polymer to the above mixed solution I and stir until homogeneous; (3) Add an alkaline solution dropwise to the solution obtained in step (2), and continue stirring for 1-3 hours after adding the solution; (4) Then pour the mixture obtained in step (3) into a crystallization vessel, crystallize at 150-200℃ for 12-48h, then cool to room temperature, filter, dry the obtained solid product at 80-120℃ for 12-24h, and then calcine at 500-750℃ for 2-12h to obtain the carrier.

24. A method for ethane dehydrogenation, characterized in that, The method includes: subjecting ethane to a dehydrogenation reaction, wherein the catalyst comprises the dehydrogenation catalyst according to any one of claims 1-23.

25. The method according to claim 24, wherein, The conditions for the dehydrogenation reaction include: a reaction temperature of 500-850℃, a reaction pressure of 0.01-0.2 MPa, and a mass hourly space velocity of 0.4-0.8 h⁻¹. -1 .