A method for preparing alkyladamantane by hydrogenation cycloisomerization of acenaphthene

Abstract

The invention belongs to the technical field of alkyl adamantane preparation, and is a method for preparing alkyl adamantane by hydrogenation cycloisomerization of acenaphthene. Under the action of hydrogenation isomerization bifunctional Pt / USY catalyst, polycyclic aromatic hydrocarbon acenaphthene is converted into alkyl adamantane compounds, and the main products are hexahydro acenaphthene, perhydro acenaphthene, carbon 12 alkyl adamantane compounds and other cracking products, carbon 12 alkyl adamantane compounds include 1,3-dimethyl adamantane, 1,4-dimethyl adamantane, 1-ethyl adamantane and 2-ethyl adamantane, and the target product is carbon 12 alkyl adamantane compounds, and the total yield of alkyl adamantane is 66% to 74%. In the present invention, the carrier USY is modified by different methods to improve the catalytic performance of the catalyst, thereby improving the yield of alkyl adamantane. The method of the present invention is suitable for continuous fixed bed reaction, has a simple process flow, mild reaction conditions, realizes the continuous production of alkyl adamantane, and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of alkyladamantane preparation, and specifically relates to a method for preparing alkyladamantane by hydrogenation cycloisomerization of acenaphthene. Background Art

[0002] Adamantane is a cage-like compound composed of 10 carbon atoms and 16 hydrogen atoms. The structure of Adamantane is highly symmetrical, with high density and high calorific value, making it a very promising candidate for high-density hydrocarbon fuels. Although the unsubstituted Adamantane molecule has a high density and calorific value, it is difficult to use it directly as a high-energy fuel main body or additive due to its high melting point and poor solubility in fuel. The alkyl-substituted Adamantane destroys the high symmetry of the Adamantane molecule due to the introduction of the alkyl functional group. At the same time, the alkyl substituent also plays a role in efficient solubilization, which can promote the dissolution of solid components in the solution, and thus has excellent low-temperature performance.

[0003] At present, the synthesis method of adamantane mainly uses tetrahydrocyclopentadiene as the starting material to synthesize adamantane and its alkyl derivatives through rearrangement isomerization, including AlCl3 catalytic isomerization method, superacid method, zeolite catalytic isomerization method and room temperature ionic liquid synthesis method. These methods have their own advantages and disadvantages. The main problem is that the yield of adamantane is low and it is difficult to industrialize.

[0004] The Chinese patent, publication number: CN101125791A, introduces a method for synthesizing adamantane on a solid acid catalyst. The solid acid catalyst is a halogenide, including chloride or bromide of aluminum, titanium, zinc or iron, which is immobilized on a carrier such as a mesoporous silica-alumina molecular sieve, and tetrahydrodicyclopentadiene is used as a raw material to synthesize adamantane through an isomerization reaction, and the adamantane yield is 27.06%.

[0005] Chinese patent, publication number: CN112341307A, introduces a method for preparing alkyladamantane from phenanthrene in coal tar, using high-content phenanthrene in coal tar as raw material to synthesize alkyladamantane, and realizing the synthesis of alkyladamantane on Pt catalyst supported on mesoporous Y molecular sieve. However, the yield of adamantane is low, less than 10%. Summary of the invention

[0006] The present invention provides a method for preparing alkyladamantane by hydrogenation cycloisomerization of acenaphthene, wherein the raw material acenaphthene can be separated from high-temperature coal tar, which not only effectively utilizes the components in the high-temperature coal tar, but also provides a new way to prepare alkyladamantane. The raw materials of the method are cheap and easy to obtain, the process flow is simple to operate, and has good industrial prospects.

[0007] The technical solution of the present invention:

[0008] A method for preparing alkyladamantane by hydrogenation cycloisomerization of acenaphthene, comprising the following steps:

[0009] The hydroisomerization bifunctional Pt / USY catalyst is prepared by an impregnation method. The hydroisomerization bifunctional Pt / USY catalyst needs to be reduced in a hydrogen atmosphere at 400°C for 2h for activation. The catalytic reaction is carried out in a continuous fixed bed reactor. The reaction raw material acenaphthene is diluted with n-heptane as a solvent to a solution with a mass concentration of 10-20wt% and enters the continuous fixed bed reactor. The hydroisomerization reaction temperature is 260-280°C, the hydrogen pressure is 4-6MPa, the hydrogen-to-oil ratio is 300-600, and the reaction The contact time of the liquid with the hydroisomerization bifunctional Pt / USY catalyst is 0.18 to 2.44 min. The main products are hexahydroacenaphthene, perhydroacenaphthene, alkyladamantanes with carbon 12 and other cracking products. The alkyladamantanes with carbon 12 include 1,3-dimethyladamantane, 1,4-dimethyladamantane, 1-ethyladamantane and 2-ethyladamantane. The target product is an alkyladamantanes with carbon 12, and the total yield of alkyladamantanes is 66% to 74%.

[0010] The hydrogenation isomerization bifunctional Pt / USY catalyst uses precious metal Pt as the hydrogenation active component, and the carrier uses USY molecular sieve, including parent USY and / or modified USY; wherein the Pt content is 0.1-1%, the silicon-aluminum ratio of the USY molecular sieve is 9-13, the crystallinity is ≥90%, and the unit cell constant is Specific surface area ≥750m 2 / g, pore volume ≥0.40ml / g.

[0011] The modified USY is treated with alkali, hydrothermally and / or alkali-hydrothermally.

[0012] Beneficial effects of the present invention:

[0013] (1) This method effectively solves the problem of utilizing acenaphthene as a fraction in high-temperature coal tar in coal chemical industry, and converts cheap and readily available acenaphthene into alkyl adamantane compounds with high added value.

[0014] (2) The USY molecular sieve as the carrier of the hydroisomerization catalyst was modified to improve the catalyst activity and thereby increase the yield of alkyl adamantane.

[0015] (3) The yield of alkyl adamantane in this method is relatively high, reaching 66.04% to 73.12%, and the synthesis method is simple, being produced by one-step hydrogenation cycloisomerization of acenaphthene. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a graph showing the yield of acenaphthene hydrogenation isomerization products at different contact times on a Pt / USY catalyst with a loading of 1 wt%.

[0017] Figure 2This is a graph showing the yields of isomeric alkyl adamantane products from hydrogenation of acenaphthene at different contact times over a Pt / USY catalyst with a loading of 1 wt%. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0019] Example 1: Alkali-treated modified USY molecular sieve. Prepare a certain amount of 0.3 mol / L NaOH solution, with a solid-liquid ratio of 1:30, add 5g USY molecular sieve and 150ml NaOH solution in a round-bottom flask, stir at 85℃ for 2h, filter, wash and dry. Perform ammonium exchange three times with 2mol / L ammonium chloride solution at 80℃, filter, wash and dry, and calcine at 550℃ to obtain the alkali-treated modified USY molecular sieve, which is recorded as USY-B.

[0020] Example 2: USY molecular sieve modified by hydrothermal treatment. A certain amount of USY molecular sieve was weighed and loaded into a tube furnace. The temperature was heated to 700°C and hydrothermally treated in a water vapor and argon atmosphere to obtain a USY molecular sieve modified by hydrothermal treatment, which was recorded as USY-H.

[0021] Example 3: Alkali-treated-hydrothermal-treated composite modified USY molecular sieve. First, an alkali-treated modified USY molecular sieve was prepared according to the method of Example 1, and then the obtained alkali-treated modified USY molecular sieve was subjected to a hydrothermal secondary modification treatment according to the method of Example 2, and finally an alkali-treated-hydrothermal-treated composite modified USY molecular sieve was obtained, which was recorded as USY-BH.

[0022] Example 4: Preparation of Pt / USY catalyst by impregnation method. Prepare a certain amount of H2PtCl6 solution with a concentration of 0.02 mol / L, add a measured amount of USY carrier to the solution at room temperature, and stir for 18 hours. Rotate on a rotary evaporator until the liquid is completely evaporated, dry in an oven at 80°C overnight, roast in a mixture of argon and oxygen (Ar / O2=40 / 20, volume ratio) at 400°C for 3 hours, and reduce with hydrogen at 400°C for 2 hours to obtain a Pt / USY catalyst. There are 4 types of parent USY and modified USY, and the prepared catalysts are respectively recorded as Pt / USY, Pt / USY-B, Pt / USY-H, and Pt / USY-BH.

[0023] Example 5: The acenaphthene hydrogenation isomerization reaction was carried out using the Pt / USY catalyst with a loading of 1 wt% prepared in Example 4. The reaction pressure was 4 MPa, the contact time was 0.5 min, and the hydrogen-to-oil ratio was 300. The effect of temperature on the reaction results was investigated. The reaction results are shown in Table 1 below.

[0024]

[0025] As shown in Table 1, the optimal reaction temperature of the Pt / USY catalyst for the hydrogenation cycloisomerization of acenaphthene to alkyladamantanes is 260-280°C.

[0026] Example 6: The acenaphthene hydrogenation isomerization reaction was carried out using the Pt / USY catalyst with a loading of 1 wt% prepared in Example 4. The reaction temperature was 260°C, the contact time was 0.5 min, and the hydrogen-to-oil ratio was 300. The effect of pressure on the reaction results was investigated. The reaction results are shown in Table 2 below.

[0027]

[0028]

[0029] As shown in Table 2, the optimal reaction pressure of Pt / USY catalyst for the hydrogenation cycloisomerization of acenaphthene to alkyladamantanes is 4-6 MPa.

[0030] Example 7: The acenaphthene hydrogenation isomerization reaction was carried out using the Pt / USY catalyst with a loading of 1 wt% prepared in Example 4. The reaction temperature was 260°C, the reaction pressure was 4 MPa, and the hydrogen-to-oil ratio was 300. The effect of the contact time on the reaction results was investigated. The reaction results are shown in Table 3 below.

[0031]

[0032] As shown in Table 3, when the Pt / USY catalyst is used for the acenaphthene hydrogenation cycloisomerization reaction, the reactant acenaphthene can be completely converted, and the maximum total yield of alkyl adamantane can reach 66.04%.

[0033] Example 8: Acenaphthene hydrocycloisomerization reaction was carried out using the Pt / USY-B catalyst with a loading of 1 wt% prepared in Example 4. The reaction temperature was 260°C, the reaction pressure was 4 MPa, and the hydrogen-to-oil ratio was 300. The effect of the contact time on the reaction results was investigated. The reaction results are shown in Table 4 below.

[0034]

[0035] As shown in Table 4, the alkali-treated modified Pt / USY-B catalyst is used for the acenaphthene hydrocycloisomerization reaction, and the reactant acenaphthene is completely converted, and the maximum total yield of alkyl adamantane can reach 72.06%.

[0036] Example 9: Acenaphthene hydrocycloisomerization reaction was carried out using the Pt / USY-H catalyst with a loading of 1 wt% prepared in Example 4. The reaction temperature was 260°C, the reaction pressure was 4 MPa, and the hydrogen-to-oil ratio was 300. The effect of the contact time on the reaction results was investigated. The reaction results are shown in Table 5 below.

[0037]

[0038]

[0039] As shown in Table 5, the hydrothermal treatment modified Pt / USY-H catalyst is used for the acenaphthene hydrogenation cycloisomerization reaction, the reactant acenaphthene is completely converted, and the highest total yield of alkyl adamantane can reach 69.21%.

[0040] Example 10: Acenaphthene hydrocycloisomerization reaction was carried out using the Pt / USY-BH catalyst with a loading of 1 wt% prepared in Example 4. The reaction temperature was 260°C, the reaction pressure was 4 MPa, and the hydrogen-to-oil ratio was 300. The effect of the contact time on the reaction results was investigated. The reaction results are shown in Table 6 below.

[0041]

[0042] As shown in Table 6, the alkali-treated-hydrothermal-treated composite modified Pt / USY-BH catalyst is used for the acenaphthene hydrogenation cycloisomerization reaction, and the reactant acenaphthene is completely converted, and the highest total yield of alkyl adamantane can reach 73.12%.

Claims

1. A method for preparing alkyladamantanes by hydrogenation cycloisomerization of acenaphthene, characterized in that: Here are the steps: The hydroisomerization bifunctional Pt / USY catalyst is prepared by an impregnation method. The hydroisomerization bifunctional Pt / USY catalyst needs to be reduced at 400° C. for 2 hours in a hydrogen atmosphere for activation. The catalytic reaction is carried out in a continuous fixed bed reactor. The reaction raw material acenaphthene is diluted with n-heptane as a solvent to a solution with a mass concentration of 10-20wt% and enters the continuous fixed bed reactor. The hydroisomerization reaction temperature is 260-280° C., the hydrogen pressure is 4-6MPa, the hydrogen-to-oil ratio is 300-600, and the contact time between the reaction liquid and the hydroisomerization bifunctional Pt / USY catalyst is 0.18-2.44min. The main products are hexahydroacenaphthene, perhydroacenaphthene, alkyl adamantane compounds of carbon 12 and other cracking products. The alkyl adamantane compounds of carbon 12 include 1,3-dimethyladamantane, 1,4-dimethyladamantane, 1-ethyladamantane and 2-ethyladamantane. The target product is an alkyl adamantane compound of carbon 12. The hydrogenation isomerization bifunctional Pt / USY catalyst uses the noble metal Pt as the hydrogenation active component, and the carrier uses USY molecular sieve, which is selected from parent USY and / or modified USY; The Pt content is 0.1-1%, the silicon-aluminum ratio of USY molecular sieve is 9-13, the crystallinity is ≥90%, and the unit cell constant is Specific surface area ≥750m 2 / g, pore volume ≥ 0.40ml / g; The modified USY molecular sieve is treated with alkali, hydrothermally and / or alkali-hydrothermally.

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