Process for the preparation of a dehydrogenation catalyst carrier and use thereof

Abstract

The application discloses a preparation method of a dehydrogenation catalyst carrier. Pseudo-boehmite, esculin gum and alkali metal salt are mixed and then added into water to form a suspension, an acid solution is used to perform sol treatment on the suspension to obtain a sol solution, a gelling agent is added into the sol solution and then placed on a dispersion drop head above an oil column to perform oil column molding, and after aging, washing with water, drying and roasting, alumina small balls are obtained; wherein the pseudo-boehmite is composed of pseudo-boehmite A and pseudo-boehmite B with a mass ratio of 1: (0.1-10), the pore volume of the pseudo-boehmite A is 0.1-0.3 mL / g, and the pore volume of the pseudo-boehmite B is 1.0-2.0 mL / g. Meanwhile, the application also discloses application of the dehydrogenation catalyst carrier in a dehydrogenation catalyst and dehydrogenation application of the dehydrogenation catalyst. The prepared carrier makes the service life of the dehydrogenation catalyst better and the catalyst activity better.

Description

Technical Field

[0001] This invention belongs to the field of dehydrogenation catalyst technology, specifically relating to a method for preparing a dehydrogenation catalyst support and its application. Background Technology

[0002] With the gradual depletion of fossil fuels, the task of developing alternative, new green energy sources has emerged. Hydrogen energy, as a high-quality, sustainable, and clean energy source, is non-toxic and harmless in its use, making its development and utilization highly attractive to researchers. However, hydrogen storage remains a significant challenge during transportation and utilization. Currently, chemical hydrogen storage methods offer advantages such as safety, convenience, and large storage capacity, making them a new research direction in the field. Developing a highly efficient dehydrogenation catalyst is one of the key issues in the application of chemical hydrogen storage.

[0003] Platinum (Pt), a precious metal, is recognized as an excellent active component for dehydrogenation catalysts. The composition of the support and promoters significantly affects the catalyst's performance. Patent CN112707784A discloses a dehydrogenation method for organic liquids. This patent treats Pt / alumina, Pd / alumina, or composite catalysts with inhibitors to reduce their initial activity and suppress coking and deactivation. However, the final catalyst activity is generally low, with a product conversion rate of only 90%. Patent CN115231516A discloses a dehydrogenation method for methylcyclohexane. This patent coats a platinum alumina catalyst onto pretreated foamed iron, and uses electrical conductivity to rapidly and uniformly heat the catalyst, thereby improving its reaction performance. The highest methylcyclohexane conversion rate obtained in this patent's examples is 75%.

[0004] Currently, most data indicate that dehydrogenation reactions occur at relatively high temperatures, which easily leads to catalyst deactivation due to carbon buildup. Furthermore, high-temperature reactions increase energy consumption. Therefore, the catalyst's performance under low-temperature conditions directly impacts production costs. Supported alumina catalysts are typically prepared using commercially available alumina supports, requiring extensive screening and pretreatment to achieve optimal performance. Therefore, developing an integrated catalyst support and catalyst preparation technology for high-efficiency dehydrogenation reactions would allow for optimal gradation between the support and the active metal, thereby improving catalytic performance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing a dehydrogenation catalyst support, and also provides the application of the support prepared by the method in a dehydrogenation catalyst. The support prepared by this invention results in a longer lifespan and better catalyst activity for the dehydrogenation catalyst.

[0006] A method for preparing a dehydrogenation catalyst support: Boehmite, guar gum, and an alkali metal salt are mixed and added to water to form a suspension. The suspension is then sol-treated with an acid solution to obtain a gel solution. A gelling agent is added to the gel solution, and the solution is placed above an oil column using a dispersing dropper to form the oil column. The formed microspheres are aged, washed with water, dried, and calcined to obtain alumina microspheres. The boehmite is composed of boehmite A and boehmite B in a mass ratio of 1:(0.1-10), with boehmite A having a pore volume of 0.1-0.3 mL / g and boehmite B having a pore volume of 1.0-2.0 mL / g.

[0007] Preferably, the mass of the guar gum accounts for 0.01-5% of the boehmite, the mass of the alkali metal salt accounts for 0.1-15% of the boehmite, and the mass fraction of the boehmite in the suspension is 10-35%; the mass of the gelling agent is 1-50% of the boehmite; and the mass of the acid solution is 1-5 times that of the boehmite.

[0008] Preferably, the alkali metal salt is one or two of potassium carbonate, sodium carbonate, potassium chloride, sodium chloride, potassium nitrate, and sodium nitrate.

[0009] Preferably, the acid solution is a 5-30 wt% nitric acid solution or hydrochloric acid solution; the gelling agent is a mixture of urea and hexamethylenetetramine in a mass ratio of (0.1-10):1.

[0010] Preferably, the sol treatment is performed at a temperature of 40-80°C for 5-20 hours.

[0011] Preferably, the oil column forming temperature is 80-100℃, and the forming oil used for oil column forming is any one of heat transfer oil, lubricating oil, and machine oil.

[0012] Preferably, the aging temperature is 100℃-180℃, the time is 10-40h, and the pressure is 0-1MPa; the drying is vacuum drying at 120-150℃ to constant weight; and the calcination temperature is 800-1100℃ and the time is 3-8h.

[0013] A dehydrogenation catalyst, comprising a support, an active component Pt supported on the support, and an auxiliary component, wherein the auxiliary component is at least one selected from Na, K, Zn, and Zr, and the support is a dehydrogenation catalyst support prepared by the preparation method according to any one of claims 1-7; the content of each component of the catalyst, based on 100% by weight, is as follows: Pt 0.1-5%, auxiliary component 0.5-5%.

[0014] The dehydrogenation catalyst is prepared by an equal-volume impregnation method, specifically as follows: a platinum chloride solution or platinum nitrate solution and a precursor solution of the auxiliary component are mixed, a support is added, the mixture is impregnated at room temperature for 5-20 hours, vacuum dried, calcined at 400-550°C for 2-5 hours, and then reduced to obtain the dehydrogenation catalyst.

[0015] Preferably, the precursor of the auxiliary component is sodium citrate, sodium metavanadate, potassium oxalate, dipotassium hydrogen phosphate, zinc nitrate, or zirconium nitrate.

[0016] Preferably, in the preparation method of the dehydrogenation catalyst, the vacuum drying conditions are vacuum drying at 100-120℃ to constant weight; the reduction conditions are reduction at 200-400℃ for 2-10 hours under a hydrogen atmosphere, with a hydrogen flow rate of 100-500 mL·min. -1 .

[0017] The dehydrogenation catalyst is applied in the dehydrogenation reaction of methylcyclohexane, cyclohexane, cyclopentane, or tetrahydronaphthalene, specifically as follows: the dehydrogenation catalyst is packed into a fixed-bed reactor, the feedstock is any one of methylcyclohexane, cyclohexane, cyclopentane, or tetrahydronaphthalene, the reaction temperature is 290-400℃, the pressure is atmospheric pressure, and the feed space velocity is 0.1-3 h⁻¹. -1 .

[0018] Advantages of this invention:

[0019] (1) The present invention regulates the pore size and strength of the support by adding boehmite with different pore sizes. At the same time, alkali metals are doped during the preparation process to make the reaction products desorb better and inhibit the formation of carbon deposits, thereby making the catalyst life better and the activity better.

[0020] (2) The dehydrogenation catalyst support prepared in this invention is used in the dehydrogenation catalyst. The additives and active metals are combined to make the metal dispersion more uniform and the catalyst has better activity and selectivity.

[0021] (3) The dehydrogenation catalyst described in this invention can be applied to the continuous catalytic dehydrogenation reaction of methylcyclohexane, cyclohexane, cyclopentane or tetrahydronaphthalene. The process is highly continuous and automated, with less waste, and has good economic and social benefits.

[0022] (4) This invention provides a process method for the integrated preparation of dehydrogenation catalyst support and catalyst for dehydrogenation reaction performance. This application provides guidance for the subsequent production of the entire industrial chain in the factory. Implementation

[0023] Example 1

[0024] 1. A method for preparing a dehydrogenation catalyst support: 35g of boehmite A with a pore volume of 0.23mL / g, 65g of boehmite B with a pore volume of 1.76mL / g, 1g of guar gum, and 5.3g of potassium nitrate are mechanically mixed for 0.5h, 200g of pure water is added, and the mixture is stirred to form a suspension. 150g of 10wt% nitric acid solution is added dropwise to the suspension, and the suspension is sol-gelled at 50℃ for 15h to obtain a gel solution. 5g of urea and 15g of hexamethylenetetramine are added to the gel solution, and the mixture is stirred for another 2h. The gel solution is then placed above an oil column using a dispersing dropper to form an oil column at a temperature of 85℃. The forming oil is a heat-conducting oil. The formed microspheres are aged in an aging vessel at 120℃ and 0.3MPa for 18h, washed with pure water, vacuum dried at 120℃ for 12h, and then calcined at 900℃ for 6h to obtain alumina microspheres, which are the dehydrogenation catalyst support.

[0025] 2. A dehydrogenation catalyst, comprising a support, an active component Pt supported on the support, and auxiliary components Na and Zr, wherein the content of each component is as follows (based on 100% weight of the catalyst): Pt 1%, Na 2%, Zr 1%, with the balance being the support, wherein the support is the aforementioned dehydrogenation catalyst support;

[0026] The dehydrogenation catalyst was prepared by the following method: Platinum nitrate solution, sodium citrate, and zirconium nitrate were weighed into a beaker according to the weight ratio of Pt, Na, and Zr in the catalyst, and diluted with 80g of pure water. 100g of the above dehydrogenation catalyst support was weighed and poured into the beaker for impregnation at room temperature for 12h. After impregnation, the catalyst was vacuum dried at 120℃ for 12h. The dried catalyst was calcined at 450℃ for 3h, and then reduced at 300℃ under a hydrogen atmosphere for 3h at a hydrogen flow rate of 200mL·min. -1 A dehydrogenation catalyst was obtained.

[0027] Example 2

[0028] 1. A method for preparing a dehydrogenation catalyst support: 50g of boehmite A with a pore volume of 0.15mL / g, 50g of boehmite B with a pore volume of 1.93mL / g, 0.1g of guar gum, and 8.6g of sodium carbonate are mechanically mixed for 0.5h. 200g of pure water is added, and the mixture is stirred to form a suspension. 200g of 8wt% hydrochloric acid solution is added dropwise to the suspension, and the suspension is sol-gelled at 70℃ for 10h to obtain a gel solution. 10g of urea and 10g of hexamethylenetetramine are added to the gel solution, and the mixture is stirred for another 2h. The gel solution is then placed above an oil column using a dispersing dropper to form an oil column at a temperature of 90℃. The forming oil is a heat-conducting oil. The formed microspheres are aged in an aging vessel at 100℃ and 0.5MPa for 30h, washed with pure water, vacuum dried at 120℃ for 12h, and then calcined at 950℃ for 4h to obtain alumina microspheres, which are the dehydrogenation catalyst support.

[0029] 2. A dehydrogenation catalyst, comprising a support, an active component Pt supported on the support, and auxiliary components K and Zn, wherein the content of each component is as follows (based on 100% weight): Pt 2%, K 3%, Zn 1%, with the balance being the support, wherein the support is the aforementioned dehydrogenation catalyst support;

[0030] The dehydrogenation catalyst was prepared by the following method: Platinum nitrate solution, dipotassium hydrogen phosphate, and zinc nitrate were weighed into a beaker according to the weight ratio of Pt, K, and Zn in the catalyst, and 80g of pure water was added for dilution. 100g of the above dehydrogenation catalyst support was weighed and poured into the beaker for impregnation at room temperature for 12h. After impregnation, the catalyst was vacuum dried at 120℃ for 12h. The dried catalyst was calcined at 500℃ for 3h, and then reduced at 300℃ under a hydrogen atmosphere for 3h at a hydrogen flow rate of 200mL·min. -1 A dehydrogenation catalyst was obtained.

[0031] Example 3

[0032] 1. A method for preparing a dehydrogenation catalyst support: 60g of boehmite A with a pore volume of 0.22mL / g, 40g of boehmite B with a pore volume of 1.46mL / g, 0.05g of guar gum, and 4.9g of potassium chloride are mechanically mixed for 0.5h. 200g of pure water is added, and the mixture is stirred to form a suspension. 300g of 5wt% hydrochloric acid solution is added dropwise to the suspension, and the suspension is sol-gelled at 60℃ for 15h to obtain a gel solution. 5g of urea and 25g of hexamethylenetetramine are added to the gel solution, and the mixture is stirred for another 2h. The gel solution is then placed above an oil column using a dispersing dropper to form an oil column at a temperature of 90℃. The forming oil is a lubricating oil. The formed microspheres are aged in an aging vessel at 150℃ and 0.2MPa for 12h, washed with pure water, vacuum dried at 120℃ for 12h, and then calcined at 850℃ for 6h to obtain alumina microspheres, which are the dehydrogenation catalyst support.

[0033] 2. A dehydrogenation catalyst, comprising a support, an active component Pt supported on the support, and auxiliary components Na and Zn, wherein the content of each component is as follows (based on 100% weight): Pt 2.5%, Na 1.5%, Zn 1.5%, with the balance being the support, wherein the support is the aforementioned dehydrogenation catalyst support;

[0034] The dehydrogenation catalyst was prepared by the following method: Platinum nitrate solution, sodium metavanadate, and zinc nitrate were weighed into a beaker according to the weight ratio of Pt, Na, and Zn in the catalyst, and diluted with 80g of pure water. 100g of the above dehydrogenation catalyst support was weighed and poured into the beaker for impregnation at room temperature for 20h. After impregnation, the catalyst was vacuum dried at 120℃ for 12h. The dried catalyst was calcined at 500℃ for 3h, and then reduced at 250℃ under a hydrogen atmosphere for 5h at a hydrogen flow rate of 300mL·min. -1 A dehydrogenation catalyst was obtained.

[0035] Example 4

[0036] 1. A method for preparing a dehydrogenation catalyst support: 25g of pseudoboehmite A with a pore volume of 0.28mL / g, 75g of pseudoboehmite B with a pore volume of 1.55mL / g, 4.5g of guar gum, and 9.3g of potassium carbonate are mechanically mixed for 0.5h, 200g of pure water is added, and the mixture is stirred to form a suspension. 350g of a 10wt% hydrochloric acid solution is added dropwise to the suspension, and the suspension is sol-gel treated at 50℃ for 10h to obtain a gel solution. After adding 10g of urea and 10g of hexamethylenetetramine to the gel solution, the mixture was stirred for 2 hours. Then, the solution was placed above an oil column using a dispersing dropper to form the oil column. The oil column forming temperature was 90℃, and the forming oil was a lubricating oil. The formed microspheres were aged in an aging vessel at 150℃ and 0.5MPa for 10 hours, washed with pure water, vacuum dried at 120℃ for 12 hours, and then calcined at 1000℃ for 3.5 hours to obtain alumina microspheres, which are the dehydrogenation catalyst support.

[0037] 2. A dehydrogenation catalyst, comprising a support, an active component Pt supported on the support, and auxiliary components Na and K, wherein the content of each component, based on 100% by weight, is as follows: Pt 0.5%, Na 0.5%, K 1.2%, with the balance being the support, wherein the support is the aforementioned dehydrogenation catalyst support;

[0038] The dehydrogenation catalyst was prepared by the following method: Platinum nitrate solution, sodium citrate, and potassium oxalate were weighed into a beaker according to the Pt, Na, and K weight ratio in the catalyst, and diluted with 80g of pure water. 100g of the above dehydrogenation catalyst support was weighed and poured into the beaker for impregnation at room temperature for 6 hours. After impregnation, the catalyst was vacuum dried at 120℃ for 12 hours. The dried catalyst was calcined at 550℃ for 3 hours, and then reduced at 300℃ under a hydrogen atmosphere for 2 hours at a hydrogen flow rate of 100mL·min. -1 A dehydrogenation catalyst was obtained.

[0039] Example 5

[0040] 1. A method for preparing a dehydrogenation catalyst support: 35g of boehmite A with a pore volume of 0.11mL / g, 65g of boehmite B with a pore volume of 1.38mL / g, 3g of guar gum, and 3g of potassium carbonate are mechanically mixed for 0.5h, 200g of pure water is added, and the mixture is stirred to form a suspension. 300g of 20wt% hydrochloric acid solution is added dropwise to the suspension, and the suspension is sol-gelled at 70℃ for 8h to obtain a gel solution. 0.5g of urea and 5g of hexamethylenetetramine are added to the gel solution, and the mixture is stirred for another 2h. The gel solution is then placed above an oil column using a dispersing dropper to form an oil column at a temperature of 85℃. The forming oil is a lubricating oil. The formed microspheres are aged in an aging vessel at 130℃ and 0.2MPa for 10h, washed with pure water, vacuum dried at 120℃ for 12h, and then calcined at 1000℃ for 4h to obtain alumina microspheres, which are the dehydrogenation catalyst support.

[0041] 2. A dehydrogenation catalyst, wherein the support is the dehydrogenation catalyst support prepared in Example 5, and the rest is the same as in Example 1.

[0042] Example 6

[0043] 1. A method for preparing a dehydrogenation catalyst support: 35g of boehmite A with a pore volume of 0.23mL / g, 65g of boehmite B with a pore volume of 1.76mL / g, 1g of guar gum, and 5.3g of potassium nitrate are mechanically mixed for 0.5h, 200g of pure water is added, and the mixture is stirred to form a suspension. 150g of 10wt% hydrochloric acid solution is added dropwise to the suspension, and the suspension is sol-gelled at 80℃ for 5h to obtain a gel solution. 5g of urea and 15g of hexamethylenetetramine are added to the gel solution, and the mixture is stirred for another 2h. The gel solution is then placed above an oil column using a dispersing dropper to form an oil column at a temperature of 100℃. The forming oil is a lubricating oil. The formed microspheres are aged in an aging vessel at 170℃ and 0.8MPa for 11h, washed with pure water, vacuum dried at 120℃ for 12h, and then calcined at 1100℃ for 3h to obtain alumina microspheres, which are the dehydrogenation catalyst support.

[0044] 2. A dehydrogenation catalyst, wherein the support is the dehydrogenation catalyst support prepared in Example 6, and the rest is the same as in Example 1.

[0045] Example 7

[0046] 1. A method for preparing a dehydrogenation catalyst support: 35g of boehmite A with a pore volume of 0.23mL / g, 65g of boehmite B with a pore volume of 1.76mL / g, 1.5g of guar gum, and 3.9g of sodium chloride are mechanically mixed for 0.5h. 200g of pure water is added, and the mixture is stirred to form a suspension. 150g of 15wt% hydrochloric acid solution is added dropwise to the suspension, and the suspension is sol-gelled at 75℃ for 10h to obtain a gel solution. 18g of urea and 2g of hexamethylenetetramine are added to the gel solution, and the mixture is stirred for another 2h. The gel solution is then placed above an oil column using a dispersing dropper to form an oil column at 100℃ using a lubricating oil. The formed microspheres are aged in an aging vessel at 100℃ and 0.5MPa for 35h, washed with pure water, vacuum dried at 120℃ for 12h, and then calcined at 900℃ for 6h to obtain alumina microspheres, which are the dehydrogenation catalyst support.

[0047] 2. A dehydrogenation catalyst, wherein the support is the dehydrogenation catalyst support prepared in Example 7, and the rest is the same as in Example 1.

[0048] Example 8

[0049] 1. A method for preparing a dehydrogenation catalyst support: 65g of boehmite A with a pore volume of 0.20mL / g, 35g of boehmite B with a pore volume of 1.63mL / g, 0.1g of guar gum, and 4.9g of potassium chloride are mechanically mixed for 0.5h. 200g of pure water is added, and the mixture is stirred to form a suspension. 500g of 5wt% hydrochloric acid solution is added dropwise to the suspension, and the suspension is sol-gelled at 80℃ for 20h to obtain a gel solution. 27g of urea and 3g of hexamethylenetetramine are added to the gel solution, and the mixture is stirred for another 2h. The gel solution is then placed above an oil column using a dispersing dropper to form an oil column at a temperature of 120℃. The forming oil is a lubricating oil. The formed microspheres are aged in an aging vessel at 160℃ and 0.4MPa for 18h, washed with pure water, vacuum dried at 120℃ for 12h, and then calcined at 960℃ for 8h to obtain alumina microspheres, which are the dehydrogenation catalyst support.

[0050] 2. A dehydrogenation catalyst, wherein the support is the dehydrogenation catalyst support prepared in Example 8, and the rest is the same as in Example 1.

[0051] Example 9

[0052] A dehydrogenation catalyst is composed of a support, an active component Pt supported on the support, and an auxiliary component Na. The content of each component is as follows (based on 100% weight): Pt 5%, Na 4.5%, and the balance is the support. The support is the same as in Example 1.

[0053] The dehydrogenation catalyst was prepared by the following method: Platinum nitrate solution and sodium citrate were weighed into a beaker according to the Pt:Na weight ratio in the catalyst, and 80g of pure water was added for dilution. 100g of the support was weighed and poured into the beaker for impregnation at room temperature for 20h. After impregnation, the catalyst was vacuum dried at 120℃ for 12h. The dried catalyst was calcined at 450℃ for 3h, and then reduced at 280℃ under a hydrogen atmosphere for 6h at a hydrogen flow rate of 200mL·min. -1 A dehydrogenation catalyst was obtained.

[0054] Example 10

[0055] A dehydrogenation catalyst comprises a support, an active component Pt supported on the support, and auxiliary components Na and K. The catalyst is based on 100% by weight, and the contents of each component are as follows: Pt 0.1%, Na 0.5%, K 0.5%, with the balance being the support. The support is the same as in Example 1.

[0056] The dehydrogenation catalyst was prepared by the following method: Platinum chloride solution, sodium citrate, and potassium oxalate were weighed into a beaker according to the weight ratio of Pt, Na, and K in the catalyst, and diluted with 80g of pure water. 100g of the support was weighed and poured into the beaker for impregnation at room temperature for 12h. After impregnation, the catalyst was vacuum dried at 120℃ for 12h. The dried catalyst was calcined at 500℃ for 3h, and then reduced at 400℃ under a hydrogen atmosphere for 2h at a hydrogen flow rate of 200mL·min. -1 A dehydrogenation catalyst was obtained.

[0057] Example 11

[0058] A dehydrogenation catalyst comprises a support, an active component Pt supported on the support, and auxiliary components Na and Zr. The content of each component is as follows (based on 100% weight): Pt 3.5%, Na 3.5%, Zr 1%, with the balance being the support. The support is the same as in Example 2.

[0059] The dehydrogenation catalyst was prepared by the following method: Platinum nitrate solution, sodium metavanadate, and zirconium nitrate were weighed into a beaker according to the weight ratio of Pt, Na, and Zr in the catalyst, and diluted with 80g of pure water. 100g of the support was weighed and poured into the beaker for impregnation at room temperature for 15h. After impregnation, the catalyst was vacuum dried at 120℃ for 12h. The dried catalyst was calcined at 400℃ for 5h, and then reduced at 300℃ under a hydrogen atmosphere for 3h at a hydrogen flow rate of 500mL·min. -1 A dehydrogenation catalyst was obtained.

[0060] Example 12

[0061] 1. A method for preparing a dehydrogenation catalyst support: 9g of boehmite A with a pore volume of 0.23mL / g, 90g of boehmite B with a pore volume of 1.76mL / g, 5g of guar gum, and 15g of potassium nitrate are mechanically mixed for 0.5h, 850g of pure water is added, and the mixture is stirred to form a suspension. 100g of 30wt% nitric acid solution is added dropwise to the suspension, and the suspension is sol-gelled at 40℃ for 15h to obtain a gel solution. 0.5g of urea and 0.49g of hexamethylenetetramine are added to the gel solution, and the mixture is stirred for another 2h. The gel solution is then placed above an oil column using a dispersing dropper to form an oil column at a temperature of 85℃. The forming oil is a heat-conducting oil. The formed microspheres are aged in an aging vessel at 180℃ and 0.3MPa for 40h, washed with pure water, vacuum dried at 150℃ for 12h, and then calcined at 800℃ for 6h to obtain alumina microspheres, which are the dehydrogenation catalyst support.

[0062] 2. A dehydrogenation catalyst, comprising a support, an active component Pt supported on the support, and an auxiliary component Na, wherein the content of each component is as follows (based on 100% weight of the catalyst): Pt 1%, Na 0.5%, with the balance being the support, wherein the support is the aforementioned dehydrogenation catalyst support;

[0063] The dehydrogenation catalyst was prepared by the following method: Platinum nitrate solution and sodium metavanadate were weighed into a beaker according to the Pt:Na weight ratio in the catalyst, and 80g of pure water was added for dilution. 100g of the above dehydrogenation catalyst support was weighed and poured into the beaker for impregnation at room temperature for 5 hours. After impregnation, the catalyst was vacuum dried at 120℃ for 12 hours. The dried catalyst was calcined at 400℃ for 5 hours, and then reduced at 200℃ under a hydrogen atmosphere for 10 hours at a hydrogen flow rate of 200mL·min. -1 A dehydrogenation catalyst was obtained.

[0064] Example 13

[0065] 1. A method for preparing a dehydrogenation catalyst support: 90g of pseudoboehmite A with a pore volume of 0.23mL / g, 9g of pseudoboehmite B with a pore volume of 1.76mL / g, 0.0099g of guar gum, and 0.099g of potassium nitrate are mechanically mixed for 0.5h, 190g of pure water is added, and the mixture is stirred to form a suspension. 100g of 30wt% nitric acid solution is added dropwise to the suspension, and the suspension is sol-gelled at 40℃ for 15h to obtain a gel. Solution; 45g urea and 4.5g hexamethylenetetramine were added to the gel solution and stirred for 2 hours. Then, the solution was placed above an oil column and a dispersing dropper was used to form the oil column. The oil column forming temperature was 85℃, and the forming oil was a heat transfer oil. The formed pellets were aged in an aging kettle at 100℃ and 1MPa for 20 hours, washed with pure water, vacuum dried at 150℃ for 12 hours, and then calcined at 800℃ for 8 hours to obtain alumina pellets, which are the dehydrogenation catalyst support.

[0066] 2. A dehydrogenation catalyst, comprising a support, an active component Pt supported on the support, and an auxiliary component Na, wherein the content of each component is as follows (based on 100% weight): Pt 5%, Na 5%, with the balance being the support, wherein the support is the aforementioned dehydrogenation catalyst support;

[0067] The dehydrogenation catalyst was prepared by the following method: Platinum nitrate solution and sodium metavanadate were weighed into a beaker according to the Pt:Na weight ratio in the catalyst, and 80g of pure water was added for dilution. 100g of the above dehydrogenation catalyst support was weighed and poured into the beaker for impregnation at room temperature for 5 hours. After impregnation, the catalyst was vacuum dried at 120℃ for 12 hours. The dried catalyst was calcined at 550℃ for 2 hours, and then reduced at 400℃ under a hydrogen atmosphere for 2 hours at a hydrogen flow rate of 200mL·min. -1 A dehydrogenation catalyst was obtained.

[0068] Comparative Example 1

[0069] A dehydrogenation catalyst, supported on commercially available alumina (BET=89.7m). 2 / g, pore volume = 0.642m 3 / g), the catalyst is prepared in the same way as in Example 1.

[0070] Comparative Example 2

[0071] A dehydrogenation catalyst support, identical to that in Example 1;

[0072] A dehydrogenation catalyst, comprising a dehydrogenation catalyst support and an active component Pt supported on the support, is prepared as follows: 10 mL of platinum nitrate solution (platinum content 0.1 g / mL) is placed in a beaker, and 80 g of pure water is added for dilution. 100 g of the above dehydrogenation catalyst support is weighed and poured into the beaker for impregnation at room temperature for 12 h. After impregnation, it is vacuum dried at 120 °C for 12 h. After drying, it is reduced at 300 °C under a hydrogen atmosphere for 3 h at a hydrogen flow rate of 200 mL / min. -1 A dehydrogenation catalyst was obtained.

[0073] Comparative Example 3

[0074] A dehydrogenation catalyst comprises a support and an active component Pt supported on the support, wherein the support is commercially available alumina (BET=89.7m). 2 / g, pore volume = 0.642m 3 / g);

[0075] The catalyst is prepared as follows: 10 mL of platinum nitrate solution (platinum content 0.1 g / mL) is placed in a beaker, and 80 g of pure water is added for dilution. 100 g of the above dehydrogenation catalyst support is weighed and poured into the beaker for impregnation at room temperature for 12 h. After impregnation, it is vacuum dried at 120 °C for 12 h. After drying, it is reduced at 300 °C under a hydrogen atmosphere for 3 h at a hydrogen flow rate of 200 mL / min. -1 A dehydrogenation catalyst was obtained.

[0076] Comparative Example 4

[0077] A dehydrogenation catalyst support: potassium nitrate is not added during the preparation process, and the rest is the same as the preparation of the dehydrogenation catalyst support in Example 1;

[0078] A dehydrogenation catalyst, the support used is the support prepared in Comparative Example 4, and the rest is the same as in Example 1.

[0079] Comparative Example 5

[0080] A dehydrogenation catalyst is composed of a support and an active component Pt supported on the support, wherein the support is the dehydrogenation catalyst support described in Comparative Example 4.

[0081] The catalyst is prepared as follows: 10 mL of platinum nitrate solution (platinum content 0.1 g / mL) is placed in a beaker, and 80 g of pure water is added for dilution. 100 g of the above dehydrogenation catalyst support is weighed and poured into the beaker for impregnation at room temperature for 12 h. After impregnation, it is vacuum dried at 120 °C for 12 h. After drying, it is reduced at 300 °C under a hydrogen atmosphere for 3 h at a hydrogen flow rate of 200 mL / min. -1 A dehydrogenation catalyst was obtained.

[0082] Catalyst performance evaluation

[0083] The catalyst described in this invention is used in the dehydrogenation of methylcyclohexane to prepare 2-toluene, specifically as follows: The dehydrogenation catalyst is packed into a fixed-bed reactor, and the dehydrogenation feedstock methylcyclohexane is pumped into the reaction tube through a plunger pump and passes through the catalyst bed for the dehydrogenation reaction. The reaction temperature is 290-400℃, the pressure is atmospheric pressure, and the space velocity of the feedstock is 0.1-3 h⁻¹. -1 The reaction products were detected by liquid chromatography. The specific reaction conditions and results are shown in Table 1. The stabilization period is the stabilization reaction time when the yield drops to below 90% of the initial value.

[0084] Table 1. Specific reaction conditions and results

[0085] .

Claims

1. A dehydrogenation catalyst characterized by: The dehydrogenation catalyst comprises a support, an active component Pt supported on the support, and an auxiliary component. The auxiliary component is at least one selected from Na, K, Zn, and Zr. The content of each component, based on 100% of the catalyst weight, is as follows: Pt 0.1-5%, auxiliary component 0.5-5%. The carrier is a dehydrogenation catalyst carrier, which is prepared by the following method: Boehmite, guar gum, and alkali metal salt are mixed and added to water to form a suspension. The suspension is then sol-treated with an acid solution to obtain a gel solution. A gelling agent is added to the gel solution, and the gel is placed above an oil column using a dispersing dropper to form the oil column. The formed microspheres are aged, washed with water, dried, and calcined to obtain alumina microspheres. The boehmite is composed of boehmite A and boehmite B in a mass ratio of 1:(0.1-10), with boehmite A having a pore volume of 0.1-0.3 mL / g and boehmite B having a pore volume of 1.0-2.0 mL / g.

2. The dehydrogenation catalyst of claim 1, wherein: The mass of the guar gum is 0.01-5% of the boehmite, the mass of the alkali metal salt is 0.1-15% of the boehmite, and the mass fraction of the boehmite in the suspension is 10-35%; the mass of the gelling agent is 1-50% of the boehmite; and the mass of the acid solution is 1-5 times that of the boehmite.

3. The dehydrogenation catalyst of claim 2, wherein: The alkali metal salt is one or two of potassium carbonate, sodium carbonate, potassium chloride, sodium chloride, potassium nitrate, and sodium nitrate.

4. The dehydrogenation catalyst according to claim 3, characterized in that: The acid solution is a 5-30 wt% nitric acid solution or hydrochloric acid solution; the gelling agent is a mixture of urea and hexamethylenetetramine in a mass ratio of (0.1-10):

1.

5. The dehydrogenation catalyst according to claim 4, characterized in that: The sol treatment is performed at a temperature of 40-80℃ for 5-20 hours.

6. The dehydrogenation catalyst according to claim 5, characterized in that: The oil column forming temperature is 80-100℃, and the forming oil used for oil column forming is any one of heat transfer oil, lubricating oil, or machine oil.

7. The dehydrogenation catalyst according to claim 6, characterized in that: The aging temperature is 100℃-180℃, the time is 10-40h, and the pressure is 0-1MPa; the drying is vacuum drying at 120-150℃ to constant weight; the calcination temperature is 800-1100℃, and the time is 3-8h.

8. The method for preparing the dehydrogenation catalyst according to claim 1, characterized in that: The dehydrogenation catalyst is obtained by mixing a platinum chloride solution or platinum nitrate solution and a precursor solution of the auxiliary component using an equal-volume impregnation method, adding a support, impregnating at room temperature for 5-20 hours, vacuum drying, calcining at 400-550℃ for 2-5 hours, and then reducing.

9. The application of the dehydrogenation catalyst according to claim 1, characterized in that: The dehydrogenation catalyst is packed in a fixed bed reactor, the raw material is any one of methylcyclohexane, cyclohexane, cyclopentane, tetrahydronaphthalene, the reaction temperature is 290-400℃, the pressure is normal pressure, the space velocity of the raw material is 0.1-3h -1 .