Alkane dehydrogenation process and bimetallic oxide support and method of preparation and use thereof and non-noble metal dehydrogenation catalyst and method of preparation

Abstract

The application discloses an alkane dehydrogenation method and a bimetallic oxide carrier and a preparation method and application of the bimetallic oxide carrier and a non-noble metal dehydrogenation catalyst and a preparation method; the carrier contains a first metal element and a second metal element, the first metal element includes Al, the second metal element is selected from a group IVB, and a particle size distribution of the carrier ranges from 15 to 50 microns in terms of Dx(90). The carrier of the application is a composite carrier containing two metals, and the average particle size distribution is relatively narrow. Thus, the raw material can enter the carrier, and the product can be quickly desorbed, so that the catalyst has good activity. The preparation method of the carrier of the application is relatively simple and easy to realize. The catalyst of the application does not contain noble metals or elements harmful to the environment, and is easy to prepare, has high activity and good stability.

Description

Technical Field

[0001] This invention relates to bimetallic oxide supports, their preparation methods and applications, non-precious metal dehydrogenation catalysts and their preparation methods, and alkane dehydrogenation methods. Background Technology

[0002] Propylene is a crucial organic chemical raw material used to produce polypropylene, acrylonitrile, acrolein, acrylic acid, cumene, polyols, and other chemical products. With the rapid increase in propylene demand, relying solely on refinery byproducts and steam cracking co-production is no longer sufficient to address the propylene supply issue. In this context, propane dehydrogenation to propylene has become a vital pathway for increasing propylene production. Industrially applied propane dehydrogenation technologies primarily utilize two types of catalysts: Cr-based and Pt-based. Cr-based catalysts are used in Lummus's Catofin process, Linde & BASF's Linde process, and Snamprogetti's FBD process; Pt-based catalysts are used in UOP's Oleflex process and Phillips' Star process. Cr-based catalysts are inexpensive but prone to deactivation, and the metallic chromium causes environmental pollution. While Pt-based catalysts offer higher selectivity and longer regeneration cycles, they are expensive, resulting in higher costs. Therefore, for propane dehydrogenation processes, developing non-precious metal and environmentally friendly oxide catalysts is one of the main directions for solving the current problems.

[0003] CN201110283358.6 discloses a catalyst for the dehydrogenation of propane to propylene. The catalyst uses mesoporous molecular sieve MCM-41 as a support, noble metal Pt as the active component, and two or three of Sn, Ce and Ca as promoters. The loading of Pt is 0.1-1.0%. The catalyst has high activity, but the conversion rate drops rapidly after 2 hours of reaction due to rapid carbon deposition.

[0004] CN114713276A discloses a catalyst for propane dehydrogenation and aromatization, its preparation method, and its application. Specifically, it discloses a catalyst for propane dehydrogenation and aromatization, its preparation method, and its application. The catalyst is a nano-alloy catalyst confined within a molecular sieve crystal, with the composition designated Pt-M@zeolite. The loading of metallic Pt is 0.1%–1%, metallic M is Zn / Ga / Sn with a loading of 0.1%–2%, and zeolite is a molecular sieve support with a different silica-alumina ratio. The Pt-M@zeolite catalyst, prepared via ion exchange, has a simple preparation method. The synthesized catalyst can improve the aromatic yield by enhancing the propane dehydrogenation process. During the reaction, the propane conversion rate can reach 72%, the aromatic yield can reach 40%, and the selectivity of the byproduct methane is no higher than 5%. Compared with traditional Zn / HZSM-5 and Ga / HZSM-5 catalysts, it exhibits higher propane dehydrogenation and aromatization activity. Its drawbacks are low selectivity and low yield for the target propylene.

[0005] CN115155613A discloses a method for preparing an environmentally friendly novel propane dehydrogenation catalyst and its application. Specifically, it discloses a method for preparing an environmentally friendly novel propane dehydrogenation catalyst and its application. The catalyst comprises a support, a main active component, and a two-component active promoter. The support is a MgAl spinel structure, a ZnAl spinel structure, or a mesoporous Al₂O₃ composite support structure encapsulated in a hydrotalcite-like structure. The main active component is Ga and trace amounts of Pt, and the two-component active promoter is composed of transition metal oxides. The fluidized bed dehydrogenation catalyst prepared by this invention is environmentally friendly and exhibits excellent dehydrogenation activity and stability for propane dehydrogenation. Its drawback is that it still contains the noble metal Pt.

[0006] CN114984998A discloses a catalyst supported on KIT-6, its preparation method, and its application. Specifically, it discloses a catalyst supported on KIT-6, using mesoporous molecular sieve KIT-6 as the support. The active component is Ga, and promoter 1 is at least one selected from Li, Na, K, Rb, Mg, and Ca. Promoter 2 is at least one selected from Mn, Ni, Zn, Co, and La. The active component, based on elemental composition, accounts for 0.1–5.0% of the support weight, promoter 1 accounts for 0.1–3% of the support weight, and promoter 2 accounts for 0.1–3% of the support weight. The catalyst is synthesized using a one-step hydrothermal method, where the active component, promoter 1, and promoter 2 are loaded onto the KIT-6 support during hydrothermal synthesis. The catalyst semi-encloses the active component, such as gallium, within the support, resulting in a more dispersed distribution of the active component on the support, which is beneficial for improving the catalyst's activity. Furthermore, since the active component is introduced during support crystallization, it can enter the support's framework or exist in a semi-enclosed state, which helps suppress carbon deposition and extend the catalyst's service life. Its drawbacks include a low conversion rate and rapid inactivation.

[0007] In summary, all existing non-precious metal dehydrogenation catalysts have certain shortcomings, making the development of a new non-precious metal dehydrogenation catalyst extremely important. Summary of the Invention

[0008] 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 catalyst that is easy to prepare, has good activity, and is not easily deactivated.

[0009] To achieve the above objectives, the present invention provides a bimetallic oxide support containing a first metal element and a second metal element, wherein the first metal element includes Al and the second metal element is selected from group IVB, and the particle size distribution of the support, in terms of Dx(90), ranges from 15 to 50 micrometers.

[0010] A second aspect of the present invention provides a method for preparing the carrier described herein, the method comprising: 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.

[0011] The third aspect of the present invention provides the application of the support described in the present invention in the preparation of catalysts or the preparation method described in the present invention in the preparation of catalysts, preferably in the preparation of dehydrogenation catalysts.

[0012] A fourth aspect of the present invention provides a non-precious metal dehydrogenation catalyst comprising a support and a non-precious metal dehydrogenation active component supported on the support, wherein the support includes the support described in the present invention.

[0013] The fifth aspect of this invention provides a method for preparing the non-noble metal dehydrogenation catalyst of this invention, the method comprising:

[0014] (1) Prepare the carrier according to the method described in this invention;

[0015] (2) The non-precious metal dehydrogenation active component source, optionally a group IIIA auxiliary agent source, is loaded onto the carrier by impregnation, and then dried and calcined.

[0016] A sixth aspect of the present invention provides a method for dehydrogenating alkane, the method comprising: subjecting an alkane to a dehydrogenation reaction, wherein the catalyst comprises the dehydrogenation catalyst described in the present invention.

[0017] 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.

[0018] The carrier preparation method of the present invention is relatively simple and easy to implement.

[0019] The catalyst of this invention does not contain precious metals or elements harmful to the environment, and is easy to prepare, highly active, and stable. 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] This invention provides a bimetallic oxide support containing 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 narrower average particle size distribution.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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).

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] According to a preferred embodiment of the present invention, the average molecular weight of polyethylene glycol is preferably 200 to 600.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] In this invention, the step of mixing the first metal source, the second metal source, and optionally the boron source containing the hydroxyl polymer has no special requirements; 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:

[0049] (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;

[0050] (2) Add the hydroxyl-containing polymer to the above mixed solution I and stir until homogeneous.

[0051] 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:

[0052] (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;

[0053] (2) Add the hydroxyl-containing polymer to the above mixed solution I and stir until homogeneous;

[0054] (3) Add an alkaline solution dropwise to the solution obtained in step (2), and continue stirring for 1-3 hours after adding the solution.

[0055] According to a preferred embodiment of the present invention, the method for preparing the carrier includes:

[0056] (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;

[0057] (2) Add the hydroxyl-containing polymer to the above mixed solution I and stir until homogeneous;

[0058] (3) Add an alkaline solution dropwise to the solution obtained in step (2), and continue stirring for 1-3 hours after adding the solution;

[0059] (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.

[0060] The present invention provides the application of the support described herein in the preparation of catalysts or the application of the preparation method described herein in the preparation of catalysts, preferably in the preparation of dehydrogenation catalysts.

[0061] This invention provides a non-precious metal dehydrogenation catalyst containing a support and a non-precious metal dehydrogenation active component supported on the support, wherein the support includes the support described in this invention.

[0062] 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.

[0063] 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%.

[0064] According to a preferred embodiment of the present invention, preferably, 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%.

[0065] 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.

[0066] 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:

[0067] (1) Prepare the carrier according to the method described in this invention;

[0068] (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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] The dehydrogenation catalyst of the present invention has good activity and is particularly suitable for the dehydrogenation of propane, isobutane, n-butane and ethane.

[0074] This invention provides a method for dehydrogenating alkane, the method comprising: subjecting an alkane to a dehydrogenation reaction, wherein the catalyst comprises the dehydrogenation catalyst described in this invention.

[0075] 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.

[0076] According to one embodiment of the present invention, preferably, the conditions for the dehydrogenation reaction include: a reaction temperature of 500-650°C, a reaction pressure of 0.01-0.2 MPa, and a mass hourly space velocity of 0.4-1.0 h⁻¹. -1 .

[0077] The dehydrogenation reaction of the present invention is suitable for the dehydrogenation of various alkanes, such as C2-C4 alkanes, preferably propane.

[0078] 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.

[0079] 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.

[0080] Granularity testing methods include:

[0081] 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.

[0082] 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.

[0083] 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.

[0084] In the following examples, molecular weight refers to the average molecular weight.

[0085] Example 1

[0086] Carrier preparation:

[0087] 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.

[0088] 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.

[0089] Catalyst preparation:

[0090] 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.

[0091] Example 2

[0092] The method is the same as in Example 1, except that the preparation steps of the carrier are as follows:

[0093] 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.

[0094] Example 3

[0095] The method of Example 1 is followed, except that the preparation steps of the carrier are as follows: aluminum nitrate nonahydrate, zirconium nitrate, deionized water, polyethylene glycol (molecular weight 600) and ethylenediamine are weighed sequentially in a molar ratio of 100:1:300:0.5:30. The crystallization temperature is 180℃ and the time is 24h. The bioxide carrier is obtained by calcination in a muffle furnace at 650℃ for 6h. Its Dx(90) particle size is 27 micrometers, of which γ-Al2O3 accounts for 2.91% and the average pore size of the bioxide is 6.5nm.

[0096] Example 4

[0097] The method of Example 1 is different except that the molecular weight of polyethylene glycol is 900, and a bioxide carrier is obtained with a Dx(90) particle size of 18 micrometers, wherein γ-Al2O3 accounts for 2.31% and the average pore size of bioxide is 3.8 nm.

[0098] Example 5

[0099] The method of Example 1 is followed, except that the polymer is polyallyl alcohol with a molecular weight of 4100, and a bioxide carrier is obtained with a Dx(90) particle size of 23 micrometers, wherein γ-Al2O3 accounts for 2.45% and the bioxide average pore size is 4.5 nm.

[0100] Example 6

[0101] The method is the same as in Example 1, except that...

[0102] 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 the same, to obtain a bioxide carrier with a Dx(90) particle size of 45 micrometers, of which γ-Al2O3 accounted for 15% and the average pore size of the bioxide was 18 nm.

[0103] Example 7

[0104] 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 double oxide 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 double oxide was 19 nm.

[0105] Example 8

[0106] The method is the same as in Example 1, except that auxiliary agent B is introduced in the preparation process of the carrier:

[0107] 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.

[0108] 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.

[0109] Example 9

[0110] The method was the same as in Example 1, except that the carrier preparation process used the same 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.

[0111] Example 10

[0112] The method of Example 1 was followed, except that the carrier preparation process involved the simultaneous addition of polyethylene glycol with a molecular weight of 400 and polyallyl alcohol with a molecular weight of 1025 in a molar ratio of 1:1, 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.

[0113] Comparative Example 1

[0114] The method of Example 1 was followed, except that polyethylene glycol was not added to the preparation of the carrier, and the resulting carrier Dx(90) had a particle size distribution of 103 micrometers. All other conditions were the same.

[0115] Test case

[0116] The dehydrogenation method involves mixing propane and nitrogen gas at a 1:1 volume ratio, adjusting the flow rates using mass flow meters, and then preheating them in the 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 the predetermined temperatures. The reactor is a 400mm long quartz tube with an inner diameter of Ф8mm. After the reaction, the gas passes through a condenser and is then analyzed by gas chromatography.

[0117] 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, and the gas hourly space velocity is 1.0 h⁻¹. -1 The reaction temperature was 580℃. The content of each component in the post-reaction gas was analyzed by gas chromatography, and the conversion rate of propane and the selectivity of propylene were calculated. The results are shown in Table 1.

[0118] Regeneration test: After 100 hours of reaction, a 5% decrease in activity of the catalyst is considered as deactivation. The conversion rate and selectivity of the regenerated catalyst are compared with those of the fresh catalyst in Table 1.

[0119] The catalyst to be regenerated was subjected to the following conditions: a carbonization reaction was carried out for 30-60 minutes at an air flow rate of 150 mL / min and at the reaction temperature to complete the regeneration process, and the regenerator was used for propane dehydrogenation according to Test Example 1.

[0120] Table 1

[0121]

[0122]

[0123] In this invention, the conversion rate is calculated as follows: the conversion rate of propane (%) = (amount of propane used - content of propane in the reaction product) ÷ amount of propane used × 100%;

[0124] The selectivity is calculated as follows: propylene selectivity (%) = actual propylene yield ÷ theoretical propylene yield × 100%.

[0125] 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 bimetallic oxide support, characterized in that, The carrier contains a first metal element and a second metal element, the first metal element including Al, and the second metal element selected from group IVB. The particle size distribution of the carrier is in the form of Dx (90) and ranges from 31 to 35 micrometers. The carrier contains element B; The crystal structure of the bimetallic oxide support includes: containing 2.48-6% by weight of γ-phase alumina; The physicochemical characteristics of the bimetallic oxide support include: an average pore size distribution of 4.6-15 nm; The molar ratio of the second metallic element to the first metallic element is 0.01 to 0.1; The molar ratio of element B to the second metallic element is 0.01-0.03:

1.

2. The carrier 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.

3. The carrier according to claim 2, wherein, The second metallic element is Zr.

4. The method for preparing the carrier according to any one of claims 1-3, characterized in that, The method 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; The average molecular weight of hydroxyl-containing polymers is 200-2500; The hydroxyl-containing polymers are selected from polyethylene glycol and polyallyl alcohol.

5. The preparation method according to claim 4, wherein, First metal source: Second metal source: Deionized water: Hydroxyl-containing polymer: Alkali molar ratio of (10~100):1:(20~500):(0.1~10):(30~80); and / or The average molecular weight of hydroxyl-containing polymers is 400-1025.

6. The preparation method according to claim 5, wherein, First metal source: Second metal source: Deionized water: Hydroxyl-containing polymer: Alkali molar ratio is (20~100):1:(100~300):(0.2~5):(30~50).

7. The preparation method according to claim 4, wherein, 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.

8. The preparation method according to claim 4, 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.

9. The preparation method according to claim 4, 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; and / or 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 boron source is selected from one or more of boric acid and organoborides; and / or The base is selected from organic amines and / or inorganic ammonia.

10. The preparation method according to claim 9, 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; and / or The second metal source is selected from a soluble salt of the second metal.

11. The preparation method according to claim 10, wherein, The second metal source is zirconium nitrate and / or zirconium oxychloride.

12. The preparation method according to claim 9, wherein, 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, 1,2-propanediamine, 1,4-butanediamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrapropylammonium hydroxide.

13. The preparation method according to claim 4, wherein, The method includes: (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.

14. The use of the support according to any one of claims 1-3 in the preparation of catalysts or the use of the preparation method according to any one of claims 4-13 in the preparation of catalysts.

15. A non-precious metal dehydrogenation catalyst, characterized in that, The catalyst contains a support and a non-precious metal dehydrogenation active component supported on the support, wherein the support includes the support described in any one of claims 1-3.

16. The catalyst according to claim 15, wherein, The non-precious 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.

17. The catalyst according to claim 16, 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.

18. The catalyst according to claim 17, wherein, The non-precious metal dehydrogenation active component is one or more of Zn, Fe, and Ni.

19. The catalyst according to claim 15, wherein, The catalyst contains Group IIIA auxiliary elements.

20. The catalyst according to claim 19, 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.

21. The catalyst according to claim 20, 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.

22. A method for preparing a non-noble metal dehydrogenation catalyst according to any one of claims 15-21, characterized in that, The preparation method includes: (1) The carrier is prepared according to any one of claims 4-13; (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.

23. The preparation method according to claim 22, wherein, The impregnation method is an equal-volume impregnation method; 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.

24. A method for dehydrogenating alkane, characterized in that, The method includes: subjecting an alkane to a dehydrogenation reaction, wherein the catalyst comprises the dehydrogenation catalyst according to any one of claims 15-21.

25. The method according to claim 24, wherein, The conditions for the dehydrogenation reaction include: a reaction temperature of 500-650℃, a reaction pressure of 0.01-0.2 MPa, and a mass hourly space velocity of 0.4-1.0 h⁻¹. -1 ; and / or The alkane is a C2-C4 alkane.

26. The method of claim 25, wherein, The alkane is propane.

Images