Alkane dehydrogenation method, bimetallic oxide carrier, preparation method and application of bimetallic oxide carrier, non-noble metal dehydrogenation catalyst and preparation method of non-noble metal dehydrogenation catalyst

Abstract

The invention discloses an alkane dehydrogenation method, a bimetallic oxide carrier, a preparation method and application of the bimetallic oxide carrier, a non-noble metal dehydrogenation catalyst and a preparation method of the non-noble metal dehydrogenation catalyst. The carrier contains a first metal element and a second metal element, the first metal element comprises Al, the second metal element is selected from the IVB group, and the particle size distribution of the carrier is in a range of 15-50 microns in terms of Dx (90). The carrier is a composite carrier formed by two kinds of metal, and the average particle size distribution of the carrier is narrow. Therefore, the raw materials can enter the carrier, the product is desorbed quickly, and the catalyst has good activity. The preparation method of the carrier is relatively simple and easy to implement. The catalyst does not contain precious metal or elements harmful to the environment, and is easy to prepare, high in activity and good in stability.

Description

Technical Field

[0001] The invention relates to a bimetallic oxide carrier and a preparation method and application thereof, a non-noble metal dehydrogenation catalyst and a preparation method thereof, and an alkane dehydrogenation method. Background Art

[0002] Propylene is a very important organic chemical raw material, which can be used to produce chemical products such as polypropylene, acrylonitrile, acrolein, acrylic acid, isopropylbenzene, and polyols. With the rapid increase in the demand for propylene, the source of propylene can no longer be solved by refinery byproducts and steam cracking co-production. In this case, propane dehydrogenation to propylene has become one of the important ways to increase propylene production. The catalysts used in industrial propane dehydrogenation technology are mainly Cr-based catalysts and Pt-based catalysts. The Catofin process of Lummus, the Linde process of Linde & BASF, and the FBD process of Snamprogetti use Cr-based catalysts, and the Oleflex process of UOP and the Star process of Phillips use Pt-based catalysts. Cr-based catalysts are low in price but easy to deactivate, and metallic chromium can cause environmental pollution. Although Pt-based catalysts have higher selectivity and longer regeneration cycles, they are expensive and costly. Therefore, for the propane dehydrogenation process, the development of non-precious metal and environmentally friendly oxide catalysts is one of the main directions to solve 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 carrier, precious metal Pt as an active component, two or three of Sn, Ce, and Ca as auxiliary agents, and a Pt loading amount of 0.1-1.0%. The catalyst has high activity, but due to rapid carbon deposition, the conversion rate decreases rapidly after 2 hours of reaction.

[0004] CN114713276A discloses a catalyst for propane dehydrogenation aromatization, a preparation method and an application, and specifically discloses a catalyst for propane dehydrogenation aromatization, a preparation method and an application, wherein the catalyst is a nano alloy catalyst confined in a molecular sieve crystal, and the composition is recorded as Pt-M@zeolite, wherein the loading amount of metal Pt is 0.1% to 1%, the metal M is Zn / Ga / Sn, the loading amount is 0.1% to 2%, and zeolite is a molecular sieve carrier with different silicon-aluminum ratios. The Pt-M@zeolite catalyst prepared by ion exchange has a simple preparation method, and the synthesized catalyst can improve the yield of aromatics by strengthening the propane dehydrogenation process. During the reaction process, the propane conversion rate can reach 72%, the aromatics yield can reach 40%, and the byproduct methane selectivity is not higher than 5%. Compared with traditional Zn / HZSM-5 and Ga / HZSM-5, it has higher propane dehydrogenation and aromatization activity. Its disadvantages are low selectivity and low yield of target propylene.

[0005] CN115155613A discloses a method for preparing a new type of environmentally friendly propane dehydrogenation catalyst and its application, specifically discloses a method for preparing a new type of environmentally friendly propane dehydrogenation catalyst and its application. The catalyst comprises a carrier, a main active component and a two-component active auxiliary agent; wherein the carrier of the catalyst is a mesoporous Al2O3 composite carrier structure wrapped with a MgAl spinel structure, a ZnAl spinel structure, or a hydrotalcite-like structure; the main active component is Ga element and trace metal Pt, and the two-component active auxiliary agent is composed of transition metal oxides. The fluidized bed dehydrogenation catalyst prepared by the present invention is pollution-free to the environment and has excellent dehydrogenation activity and stability for propane dehydrogenation. Its defect is that it still contains precious metal Pt.

[0006] CN114984998A discloses a catalyst with KIT-6 as a carrier, a preparation method and an application thereof, and specifically discloses a catalyst with KIT-6 as a carrier, a mesoporous molecular sieve KIT-6 as a carrier, an active component of Ga, an auxiliary agent 1 of at least one of Li, Na, K, Rb, Mg and Ca, an auxiliary agent 2 of at least one of Mn, Ni, Zn, Co and La, the active component is calculated as 0.1-5.0% of the weight of the carrier in terms of elements, the auxiliary agent 1 is calculated as 0.1-3% of the weight of the carrier in terms of elements, and the auxiliary agent 2 is calculated as 0.1-3% of the weight of the carrier in terms of elements, the catalyst is synthesized by a one-step hydrothermal method, and the active component, auxiliary agent 1 and auxiliary agent 2 are loaded onto the carrier KIT-6 during the hydrothermal synthesis. The catalyst semi-encloses the active component gallium and other elements in the carrier, and the distribution of the active component on the carrier is more dispersed, which is beneficial to improving the activity of the catalyst. At the same time, since the active component is introduced during the crystallization of the carrier, it can enter the skeleton of the carrier, or present a semi-enclosed state, which is beneficial to inhibiting the generation of carbon deposition and extending the service life of the catalyst. Its disadvantages are low conversion rate and rapid inactivation.

[0007] In summary, the existing non-precious metal dehydrogenation catalysts all have certain defects, and it is very important to develop a new non-precious metal dehydrogenation catalyst. Summary of the invention

[0008] The purpose of the present invention is to overcome the problem of using precious metals or environmentally harmful catalysts in the prior art and to provide a non-precious metal or environmentally friendly catalyst which has the advantages of being easy to prepare, having good activity and not being easily deactivated.

[0009] In order to achieve the above objectives, the present invention provides a bimetallic oxide carrier, which contains 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 carrier is in the range of 15-50 microns based on Dx(90).

[0010] The second aspect of the present invention provides a method for preparing the carrier of the present invention, which comprises: mixing a first metal source, a second metal source, an optional boron source, and a hydroxyl-containing polymer, and then crystallizing, cooling, solid-liquid separation, drying, and roasting under alkaline conditions.

[0011] The third aspect of the present invention provides use of the carrier of the present invention in preparing a catalyst or use of the preparation method of the present invention in preparing a catalyst, preferably use of the carrier in preparing a dehydrogenation catalyst.

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

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

[0014] (1) preparing a carrier according to the method of the present invention;

[0015] (2) A non-precious metal dehydrogenation active component source and optionally a Group IIIA auxiliary agent source are loaded onto the carrier by an impregnation method, followed by drying and calcining.

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

[0017] The carrier of the present invention is a composite carrier formed by two metals, and its average particle size distribution is relatively narrow, so that the raw material can enter the carrier, the product can be quickly desorbed, and the catalyst has good activity.

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

[0019] The catalyst of the present invention does not contain precious metals or elements harmful to the environment, is easy to prepare, has high activity and good stability. DETAILED DESCRIPTION

[0020] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0021] The present invention provides a bimetallic oxide carrier, 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 Group IVB, and the particle size distribution of the carrier is in the range of 15-50 microns in terms of Dx(90). The average particle size distribution of the carrier of the present invention is relatively narrow.

[0022] According to a preferred embodiment of the present invention, the particle size distribution of the bimetallic oxide carrier is in the range of 18-35 microns in terms of Dx(90); the carrier having this characteristic can thus enable the raw material to enter the carrier and the product to be quickly desorbed, so that the catalyst has good activity.

[0023] According to a preferred embodiment of the present invention, the crystal characteristics of the bimetallic oxide carrier include: containing 1-10 weight % of γ-phase alumina, preferably containing 2-6 weight % of γ-phase alumina; the carrier having such characteristics can be used in a catalyst to improve the performance of the catalyst.

[0024] According to a preferred embodiment of the present invention, the physicochemical characteristics of the bimetallic oxide carrier further include: an average pore size distribution of 3-15 nm.

[0025] In the present invention, the molar ratio of the second metal element to the first metal element can be selected in a wide range. According to a preferred embodiment of the present invention, the molar ratio of the second metal element to the first metal element is 0.01 to 0.1.

[0026] In the present invention, the first metal element includes Al, but is not limited to Al, and other elements may be introduced as needed. In the embodiment of the present invention, the first metal element is Al as an example to illustrate the advantages of the present invention.

[0027] In the present invention, the second metal element is selected from one or more of Ti, Zr, and Hf, preferably Zr. Other elements may also be introduced as needed.

[0028] In the present invention, preferably, the carrier contains element B, and 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 carrier when applied to the catalyst.

[0029] The carriers with the characteristics of the present invention can achieve the purpose of the present invention, and there is no special requirement for their preparation methods. According to one embodiment of the present 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, and then crystallizing, cooling, solid-liquid separation, drying, and roasting under alkaline conditions. The target carrier of the present invention can be prepared by the above method, and the above method has simple steps and a wide range of material sources.

[0030] In the present invention, the dosage ratio of each material can be selected in a wide range. The following exemplary description is given, but the scope of the present invention is not limited thereto. According to a preferred embodiment of the present invention, the molar ratio of the first metal source: the second metal source: deionized water: the hydroxyl-containing polymer: the 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 the present invention, all hydroxyl-containing polymers are applicable to the present invention. According to the present invention, the average molecular weight of the hydroxyl-containing polymer is preferably 200-2500, preferably 400-1025. The above preferred technical solution can well achieve the purpose of the present invention.

[0032] In the present invention, various types of hydroxyl-containing polymers can be applied to the present invention. According to the present invention, the hydroxyl-containing polymer is preferably selected from polyethylene glycol and / or polyallyl alcohol.

[0033] In the present invention, polyethylene glycol is, for example: having a molecular weight of 200 to 600, being liquid at room temperature; and being a transparent, colorless or substantially colorless viscous liquid.

[0034] In the present invention, polyallyl alcohol is, for example, generally divided into three types according to average molecular weights of 425, 1025 and 2025, 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, preferably, the average molecular weight of the polyethylene glycol is 200-600.

[0036] According to a preferred embodiment of the present invention, preferably, the polyallyl alcohol is selected from one or more of those with 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 mixed polymer of polyethylene glycol with an average molecular weight of 400 and polyallyl alcohol with an average molecular weight of 1025, and the ratio of the two is 0.1-10:1. In the embodiment, 1:1 is used as an example to illustrate the advantages of the present invention, but the scope of the present invention is not limited thereby. This can further improve the performance of the carrier applied to the catalyst.

[0038] In the present invention, the crystallization conditions can be selected in a wide range. The following is an exemplary description, but the scope of the present invention is not limited thereto. Crystallization refers to a hydrothermal reaction in a reactor. According to a preferred embodiment of the present invention, the crystallization conditions include: a temperature of 150-200°C, preferably 150-180°C.

[0039] In the present invention, the crystallization time can be selected in a wide range and is determined specifically according to needs. According to a preferred embodiment of the present invention, the crystallization conditions include: the time is 12-48h, preferably 12-24h.

[0040] In the present invention, there is no special requirement for the conditions of drying and roasting, and the following is an exemplary description, but the scope of the present invention is not limited thereby.

[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 h; preferably, a temperature of 600-650° C. and a time of 4-6 h.

[0043] In the present invention, there is no special requirement for the type of the first metal source, and various substances are suitable for the present invention. The following exemplary description does not limit the scope of the present invention. According to one embodiment of the present invention, the first metal source includes one or more of aluminum nitrate nonahydrate, aluminum sulfate, aluminum isopropoxide and aluminum sol.

[0044] In the present invention, there is no special requirement for the type of the second metal source, and various substances are applicable to the present invention. The following exemplary description does not limit the scope of the present invention. According to one embodiment of the present invention, the second metal source is selected from a second metal soluble compound, preferably a second metal soluble salt, preferably zirconium nitrate and / or zirconium oxychloride.

[0045] In the present invention, the boron source can be selected from a wide range, and commonly used substances can be used in the present invention. For the present invention, the boron source is preferably selected from one or more of boric acid and organic boron compounds. Boric acid is used as an example to illustrate the advantages of the present invention, but the present invention is not limited to this.

[0046] In the present invention, the base used has a wide range of materials to be selected, and commonly used bases can be applied to the present invention, mainly used to provide an alkaline environment. The following exemplary description is given for the present invention, but the scope of the present invention is not limited thereto. Preferably, the base is selected from organic amines and / or inorganic ammonia.

[0047] In the present invention, the optional range of types of the organic amine substances is relatively wide, and commonly used organic amine substances can be applicable to the present invention, for example, 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-propylenediamine, 1,4-butylenediamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide or tetrapropylammonium hydroxide.

[0048] In the present invention, there is no special requirement for the step of mixing the first metal source, the second metal source, and the optional boron source hydroxyl-containing polymer. The main purpose is to mix them evenly. For example, the materials can be mixed evenly by appropriate heating and dripping. The following exemplary description, but not limiting the scope of the present invention, includes the following steps:

[0049] (1) adding the first metal source and the second metal source into deionized water in proportion at 20-50° C., stirring and dissolving the mixture to obtain a mixed solution I;

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

[0051] In the present invention, in order to achieve crystallization under alkaline conditions, the alkaline substance may be introduced during mixing, or after mixing. The present invention has no special requirements for this. According to one embodiment of the present invention, the alkaline substance is introduced after mixing, for example, the step of introducing the alkaline substance after mixing includes:

[0052] (1) adding the first metal source and the second metal source into deionized water in proportion at 20-50° C., stirring and dissolving the mixture to obtain a mixed solution I;

[0053] (2) adding a hydroxyl-containing polymer to the mixed solution I and stirring evenly;

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

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

[0056] (1) adding the first metal source and the second metal source into deionized water in proportion at 20-50° C., stirring and dissolving the mixture to obtain a mixed solution I;

[0057] (2) adding a hydroxyl-containing polymer to the mixed solution I and stirring evenly;

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

[0059] (4) The mixed solution obtained in step (3) is then poured into a crystallization kettle, crystallized at 150-200° C. for 12-48 hours, then cooled to room temperature, filtered, and the obtained solid product is dried at 80-120° C. for 12-24 hours, and then calcined at 500-750° C. for 2-12 hours to obtain a carrier.

[0060] The present invention provides application of the carrier in preparing a catalyst or application of the preparation method of the present invention in preparing a catalyst, preferably application in preparing a dehydrogenation catalyst.

[0061] The present invention provides a non-precious metal dehydrogenation catalyst, which comprises a carrier and a non-precious metal dehydrogenation active component loaded on the carrier, wherein the carrier comprises the carrier described in the present 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, preferably selected from one or more of Zn, Fe, Co, Ni, and Cu, and more preferably one or more of Zn, Fe, and Ni. In the embodiments of the present invention, Zn is used as an example to illustrate the advantages of the present invention, but the scope of the present invention is not limited thereby.

[0063] According to a preferred embodiment of the present invention, preferably, the content of the non-precious metal dehydrogenation active component as an element is 1 to 20%, preferably 2 to 15%, based on the total weight of the catalyst.

[0064] According to a preferred embodiment of the present invention, preferably, preferably, the catalyst contains a Group IIIA promoter element, preferably, based on the total weight of the catalyst, the Group IIIA element has an element content of 0.1-5%, 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, preferably Ga.

[0066] The present invention has no special requirements for the preparation method of the catalyst. According to the present invention, a preparation method of the non-precious metal dehydrogenation catalyst is provided, and the preparation method comprises:

[0067] (1) preparing a carrier according to the method of the present invention;

[0068] (2) The non-noble metal dehydrogenation active component source and optionally the IIIA group auxiliary agent source are loaded onto the carrier by an impregnation method, followed by drying and calcining.

[0069] In the present invention, there is no special requirement for the impregnation method, which is exemplary but not intended to limit the scope of the present invention. The impregnation method is an equal volume impregnation method.

[0070] In the present invention, there is no special requirement for the conditions of drying and roasting, and the following is an exemplary description, but the scope of the present invention is not limited thereby.

[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 h.

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

[0074] The present invention provides an alkane dehydrogenation method, which comprises: subjecting the alkane to a dehydrogenation reaction, wherein the catalyst comprises the dehydrogenation catalyst described in the present invention.

[0075] In the present invention, there is no special requirement for the dehydrogenation reaction conditions, which are described below for exemplary purposes, but the scope of the present invention is not limited thereby.

[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 space velocity of 0.4-1.0 h -1 .

[0077] The dehydrogenation reaction of the present invention is suitable for the dehydrogenation of various alkanes, for example, the alkane is a C2-C4 alkane, 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 carrier is obtained by dry method testing using a Malvern particle size analyzer, the crystal form of the bimetallic oxide carrier is obtained by XRD analysis combined with instrument configuration identification software, and the average pore size distribution of the oxide is obtained by the BET method; all raw materials used are analytically pure products commercially available from China Pharmaceutical Group.

[0079] In the present invention, particle size distribution (particle size) is what is shown by particles or particle aggregates, and pore size distribution is the size inside particles.

[0080] Particle size testing methods include:

[0081] The particle size of the carrier was analyzed by Malvern 3000 particle size analyzer. The test method was as follows: first clean the particle size analyzer and set the test parameters, where the Venturi tube was set 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 powder parallel tests. 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 test method for the γ-alumina crystal phase content is: using the German BRUKER X-ray powder diffractometer (XRD), model D8 Advance SS (18kW), rotating target (copper target) X-ray generator: maximum power 18KW, voltage and current 60KV*300mA, conventional test. Crystal phase analysis uses system software to automatically perform peak identification and analysis.

[0083] The test method for the average pore size of the double oxide carrier is to use the physical adsorption instrument ASAP2020M+C of Micromeritics Instruments, USA, to perform fully automatic specific surface area and mesopore / micropore analysis.

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

[0085] Example 1

[0086] Preparation of vector:

[0087] Aluminum isopropoxide, zirconium nitrate, deionized water, polyethylene glycol (molecular weight 400), and diethanolamine were weighed according to a molar ratio of 20:1:100:5:30;

[0088] At 25°C, dissolve aluminum isopropoxide and zirconium nitrate in deionized water and stir thoroughly to dissolve. Then slowly drop polyethylene glycol liquid and stir for 1 hour to mix evenly. Then drop diethanolamine into the solution and continue stirring for 2 hours. The obtained mixed solution is introduced into a crystallization kettle and crystallized at 150°C for 12 hours. The obtained solution is centrifuged, and the filter cake is transferred to an oven and dried at 80°C for 12 hours. It is then placed in a muffle furnace and calcined at 600°C for 4 hours to obtain a ZrO2-Al2O3 dual oxide carrier. The Dx(90) particle size of the dual oxide carrier is 35 microns, of which the γ-alumina content is 2.41%, and the average pore size of the dual oxide is 4.9nm.

[0089] Preparation of catalyst:

[0090] Weigh 2.33 g of zinc nitrate and 0.16 g of gallium nitrate, dissolve in 8 g of deionized water to obtain a solution containing active components, add solution I to 20 g of the above-mentioned carrier to allow sufficient contact, then dry in an oven at 80°C for 12 h, transfer to a muffle furnace and calcine at 600°C for 4 h to obtain a catalyst sample.

[0091] Example 2

[0092] The method of Example 1 is followed, except that the steps for preparing the carrier are as follows:

[0093] Aluminum sol, zirconium oxychloride, deionized water, polyethylene glycol (molecular weight 200) and propylamine were weighed according to the molar ratio of 50:1:200:0.2:50. The crystallization temperature was 180°C for 18 hours; the double oxide carrier was calcined at 650°C for 4 hours in a muffle furnace to obtain a Dx (90) particle size of 29 microns, of which γ-Al2O3 accounted for 2.51%, and the average pore size of the double oxide was 5.3nm.

[0094] Example 3

[0095] According to the method of Example 1, the difference is 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 in sequence according to the molar ratio of aluminum nitrate nonahydrate, zirconium nitrate, deionized water, polyethylene glycol (molecular weight 600) and ethylenediamine of 100:1:300:0.5:30. The crystallization temperature is 180°C and the time is 24h; the double oxide carrier is calcined in a muffle furnace at 650°C for 6h to obtain a double oxide carrier, whose Dx(90) particle size is 27 microns, of which γ-Al2O3 accounts for 2.91%, and the average pore size of the double oxide is 6.5nm.

[0096] Example 4

[0097] The method of Example 1 is followed, except that the molecular weight of polyethylene glycol is 900, and a double oxide carrier is obtained, whose Dx(90) particle size is 18 microns, of which γ-Al2O3 accounts for 2.31%, and the average pore size of the double oxide 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, to obtain a double oxide carrier with a Dx(90) particle size of 23 microns, of which γ-Al2O3 accounts for 2.45%, and the average pore size of the double oxide is 4.5 nm.

[0100] Example 6

[0101] According to the method of Example 1, the difference is 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 other conditions were the same to obtain a double oxide carrier with a Dx(90) particle size of 45 microns, of which γ-Al2O3 accounted for 15%, and the average pore size of the double oxide was 18 nm.

[0103] Example 7

[0104] According to the same preparation method as Example 3, but with a crystallization temperature of 240°C and a treatment time of 36h, a double oxide carrier was obtained, whose Dx(90) particle size was 49 microns, of which γ-Al2O3 accounted for 21%, and the average pore size of the double oxide was 19nm.

[0105] Example 8

[0106] The method of Example 1 is followed, except that an auxiliary agent B is introduced during the preparation of the carrier:

[0107] Boric acid, aluminum isopropoxide, zirconium nitrate, deionized water, polyethylene glycol and diethanolamine were weighed 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, dissolve boric acid, aluminum isopropoxide and zirconium nitrate in deionized water and stir thoroughly to dissolve. Then slowly add polyethylene glycol liquid and stir for 1 hour to mix evenly, then add diethanolamine to the solution and continue stirring for 2 hours. The obtained mixed solution is introduced into a crystallization kettle, and the crystallization conditions remain unchanged to obtain a double oxide carrier containing B, wherein the double oxide carrier has a Dx (90) particle size of 33 microns, of which γ-Al2O3 accounts for 5.6%, and the average pore size of the double oxide is 7.1nm. In the catalyst preparation, Zn and Ga are introduced in the same way, and finally a non-precious metal dehydrogenation catalyst containing B and Ga is obtained.

[0109] Example 9

[0110] The method of Example 1 is followed, except that the carrier preparation process uses the same molar amount of polyallyl alcohol with a molecular weight of 425. The Dx(90) particle size of the double oxide carrier is 25 microns, the γ-alumina content is 3.41%, and the average pore size of the double oxide is 4.4 nm.

[0111] Example 10

[0112] The method of Example 1 is followed, except that in the carrier preparation process: polyethylene glycol with a molecular weight of 400 and polyallyl alcohol with a molecular weight of 1025 are added simultaneously at a molar ratio of 1:1, and the total molar amount of the two is the same as the amount of polymer used in Example 1. The Dx (90) particle size of the double oxide carrier is 31 microns, wherein the γ-alumina content is 2.48%, and the average pore size of the double oxide is 4.6 nm.

[0113] Comparative Example 1

[0114] The method of Example 1 was followed, except that polyethylene glycol was not added in the preparation of the carrier, and the particle size distribution of the obtained carrier Dx(90) was 103 μm. The other conditions were the same.

[0115] Test Case

[0116] The dehydrogenation method is as follows: propane gas and nitrogen are adjusted by mass flow meter at a volume ratio of 1:1, enter the preheating zone for preheating, and then enter the reaction zone. The heating section and reaction section of the reactor are heated by electric heating wire to reach a predetermined temperature. The inner diameter of the reactor is a quartz tube with a length of 400mm and an inner diameter of 8mm. The reacted gas passes through a condenser and enters a gas chromatograph to analyze its composition.

[0117] The catalyst evaluation conditions in the isothermal fixed bed reactor are as follows: 1 g of catalyst with a mesh size of 20-40 and 1 g of quartz sand with a mesh size of 20-40 are weighed and mixed evenly, and then loaded into the above isothermal fixed bed reactor. The reaction pressure is atmospheric pressure, and the gas mass space velocity is 1.0 h -1 , reaction temperature 580°C. The content of each component of the gas after the reaction 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 the catalyst reacted for 100 hours, a 5% decrease in activity was considered deactivated. The comparison of the reaction conversion rate and selectivity of the regenerated catalyst with those of the fresh catalyst is shown in Table 1.

[0119] The catalyst to be regenerated is subjected to regeneration conditions, which include: performing a charcoal burning reaction for 30-60 minutes at a reaction temperature at an air flow rate of 150 mL / min, that is, completing the regeneration process, and using the regenerating agent to perform propane dehydrogenation according to Test Example 1.

[0120] Table 1

[0121]

[0122]

[0123] In the present invention, the conversion rate is calculated as follows: 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: selectivity of propylene (%) = actual production of propylene / theoretical production of propylene × 100%.

[0125] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A bimetallic oxide carrier, characterized in that: The carrier contains 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. The particle size distribution of the carrier is in the range of 15-50 microns in terms of Dx(90).

2. The carrier according to claim 1, wherein The particle size distribution of the bimetallic oxide carrier is in the range of 18-35 microns based on Dx(90); and / or The crystal characteristics of the bimetallic oxide carrier include: containing 1-10 wt% of γ-phase alumina, preferably containing 2-6 wt% of γ-phase alumina; and / or The physicochemical characteristics of the bimetallic oxide carrier include: an average pore size distribution of 3-15 nm.

3. The vector according to claim 1 or 2, wherein The molar ratio of the second metal element to the first metal element is 0.01 to 0.1; and / or The first metal element is Al; and / or The second metal element is selected from one or more of Ti, Zr, and Hf, preferably Zr; Preferably, the carrier contains element B, and the molar ratio of element B to the second metal element is 0.01-0.03:

1.

4. The method for preparing a carrier according to any one of claims 1 to 3, characterized in that: The method comprises: mixing a first metal source, a second metal source, an optional boron source, and a hydroxyl-containing polymer, and then crystallizing, cooling, solid-liquid separation, drying, and calcining under alkaline conditions; Preferably, The molar ratio of the first metal source: the second metal source: deionized water: the hydroxyl-containing polymer: the base is (10-100): 1: (20-500): (0.1-10): (30-80), preferably (20-100): 1: (100-300): (0.2-5): (30-50); and / or The average molecular weight of the hydroxyl-containing polymer is 200-2500, preferably 400-1025; and / or The hydroxyl-containing polymer is selected from polyethylene glycol and / or polyallyl alcohol; Preferably, the average molecular weight of polyethylene glycol is 200 to 600; The polyallyl alcohol is selected from one or more of those having an average molecular weight of 425, 1025 and 2025; Preferably, the hydroxyl-containing polymer is selected from a mixed polymer of polyethylene glycol with an average molecular weight of 400 and polyallyl alcohol with an average molecular weight of 1025, and the usage ratio of the two is 0.1-10:

1.

5. The preparation method according to claim 4, wherein The crystallization conditions include: a temperature of 150-200°C, preferably 150-180°C; and / or a time of 12-48h, preferably 12-24h; and / or Drying conditions include: temperature of 80-120°C, time of 12-24h; and / or 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; and / or The first metal source comprises 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, preferably a second metal soluble salt, preferably zirconium nitrate and / or zirconium oxychloride; and / or The boron source is selected from one or more of boric acid and organic boron compounds; and / or The base is selected from organic amines and / or inorganic ammonia; Preferably, the organic amine is selected from one or more of ethylamine, propylamine, dimethylamine, ethylenediamine, diethylamine, diisopropylamine, hexyldiamine, monoethanolamine, diethanolamine, triethanolamine, 3-propanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, 1,2-dimethylpropylamine, sec-butylamine, ethylenediamine, 1,2-propylenediamine, 1,4-butylenediamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and tetrapropylammonium hydroxide.

6. The preparation method according to claim 4 or 5, wherein: The method includes: (1) adding the first metal source, the second metal source, and optionally the boron source into deionized water in proportion at 20-50° C., stirring and dissolving the mixture to obtain a mixed solution I; (2) adding a hydroxyl-containing polymer to the mixed solution I and stirring evenly; (3) adding an alkaline solution dropwise to the solution obtained in step (2), and continuing stirring for 1-3 hours after the addition; (4) The mixed solution obtained in step (3) is then poured into a crystallization kettle, crystallized at 150-200° C. for 12-48 hours, then cooled to room temperature, filtered, and the obtained solid product is dried at 80-120° C. for 12-24 hours, and then calcined at 500-750° C. for 2-12 hours to obtain a carrier.

7. Use of the carrier according to any one of claims 1 to 3 in preparing a catalyst or use of the preparation method according to any one of claims 4 to 6 in preparing a catalyst, preferably in preparing a dehydrogenation catalyst.

8. A non-precious metal dehydrogenation catalyst, characterized in that: The catalyst comprises a carrier and a non-precious metal dehydrogenation active component supported on the carrier, wherein the carrier comprises the carrier according to any one of claims 1 to 3; Preferably, the non-precious metal dehydrogenation active component is selected from one or more of Group VIII, Group IB, and Group IIB, preferably selected from one or more of Zn, Fe, Co, Ni, and Cu, and more preferably selected from one or more of Zn, Fe, and Ni; The non-precious metal dehydrogenation active component is present in an amount of 1 to 20%, preferably 2 to 15%, based on the total weight of the catalyst, calculated as an element; Preferably, the catalyst contains a group IIIA promoter element, preferably, the content of the group IIIA element as an element is 0.1 to 5%, preferably 0.2 to 3%, based on the total weight of the catalyst; Preferably, the Group IIIA element is at least one of Ga and In, preferably Ga.

9. A method for preparing the non-precious metal dehydrogenation catalyst according to claim 8, characterized in that: The preparation method comprises: (1) preparing the carrier according to any one of claims 4 to 6; (2) loading a non-noble metal dehydrogenation active component source and optionally a Group IIIA auxiliary agent source onto the carrier by an impregnation method, followed by drying and calcining; Preferably, The impregnation method is an equal volume impregnation method; and / or Drying conditions include: temperature of 80-120°C, time of 12-24h; and / or The calcination conditions include: temperature of 500-750°C and time of 2-12h.

10. A method for dehydrogenating alkanes, characterized in that: The method comprises: subjecting an alkane to a dehydrogenation reaction, wherein the catalyst comprises the dehydrogenation catalyst according to claim 8; Preferably, The conditions for the dehydrogenation reaction include: reaction temperature of 500-650°C, reaction pressure of 0.01-0.2MPa, mass space velocity of 0.4-1.0h -1 ; and / or The alkane is a C2-C4 alkane, preferably propane.

Images