Method for producing cyclohexene

Abstract

The invention relates to the field of production of an organic chemical raw material cyclohexene, and discloses a production method of cyclohexene. The method comprises the following steps: carrying out cracking reaction on cyclohexylbenzene and / or dicyclohexylbenzene raw materials and a solid acid catalyst to obtain cyclohexene and benzene; the solid acid catalyst is selected from at least one of amorphous silica-alumina, a molecular sieve and immobilized inorganic acid. The method for preparing cyclohexene has the advantages of high raw material conversion rate, high cyclohexene yield, basically no byproduct cyclohexane and the like.

Description

Technical Field

[0001] The invention relates to the production field of cyclohexene, an organic chemical raw material, and in particular to a method for producing cyclohexene. Background Art

[0002] Cyclohexene is an important chemical raw material and intermediate. It can be used to synthesize lysine, cyclohexanol, cyclohexanone, 1,2-cyclohexanediol, adipic acid, cyclohexenone and cyclohexene oxide, etc. It has a wide range of industrial uses.

[0003] At present, cyclohexene is produced industrially by partial hydrogenation of benzene. Benzene is selectively hydrogenated with hydrogen under the action of a ruthenium-based catalyst to produce a mixture of cyclohexene and cyclohexane, which is then separated and purified by extraction, distillation and purification to obtain cyclohexene. The disadvantages of this method are: (1) The catalyst is a complex aqueous solution system with Ru-Zn as the main agent and zinc sulfate and zirconium oxide as auxiliary agents. The catalyst preparation stability is poor, which often brings difficulties to the stable operation of the process, and ruthenium is expensive; (2) The reaction conversion rate and selectivity of partial hydrogenation of benzene are not high. The most ideal result is a benzene conversion rate of 50%, a cyclohexene selectivity of 75%, and a large amount of low-priced cyclohexane as a by-product; (3) The reaction products are benzene, cyclohexene, and cyclohexane, which have basically the same boiling points. In particular, cyclohexene and cyclohexane are extremely difficult to separate. Therefore, the product separation process is complicated and the energy consumption is very high; (4) The benzene partial hydrogenation reactor needs to be made of expensive Hastelloy alloy, and the equipment investment is high. Due to the above factors, the production cost of cyclohexene has remained high for a long time. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems existing in the prior art and provide a method for producing cyclohexene. The method for preparing cyclohexene has the advantages of high raw material conversion rate, high cyclohexene yield and almost no by-product cyclohexane.

[0005] In order to achieve the above object, the present invention provides a method for producing cyclohexene, which comprises: subjecting cyclohexylbenzene and / or dicyclohexylbenzene raw materials to a cracking reaction with a solid acid catalyst to obtain cyclohexene and benzene;

[0006] The solid acid catalyst is selected from at least one of amorphous silica-alumina, molecular sieve and immobilized inorganic acid.

[0007] Further preferably, the solid acid catalyst is selected from at least one of amorphous silica-alumina, REY molecular sieve and MCM-41 molecular sieve, preferably amorphous silica-alumina.

[0008] Preferably, the mass ratio of cyclohexylbenzene to dicyclohexylbenzene is 0-100:100-0, more preferably 0-45:55-100.

[0009] Preferably, the cyclohexylbenzene and / or dicyclohexylbenzene is produced by a hydroalkylation reaction of benzene with hydrogen, and preferably at least part of the benzene is provided by benzene in a product obtained by a cracking reaction.

[0010] Through the above technical solution, the beneficial effects of the present invention include:

[0011] The method of the present invention is used to prepare cyclohexene, which has the advantages of high raw material conversion rate, high cyclohexene yield, and basically no by-product cyclohexane. Preferably, in the method provided by the present invention, the cyclohexylbenzene and / or dicyclohexylbenzene raw materials are prepared by a hydroalkylation reaction of benzene and hydrogen, and at least part of the benzene is provided by benzene in the product obtained by the cracking reaction, that is, the by-product is recycled, the process cycle is realized, the cost is saved, the energy consumption is reduced, and the economy is improved.

[0012] The method of the present invention has a simple and easy-to-control reaction process, does not require production equipment to use special materials, has low process energy consumption, is environmentally friendly, can significantly reduce equipment investment, energy consumption and operating costs, and significantly reduce the production cost of cyclohexene. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic flow diagram of the process of the present invention. DETAILED DESCRIPTION

[0014] 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.

[0015] The pressure mentioned in the present invention is absolute pressure.

[0016] In one aspect, the present invention provides a method for producing cyclohexene, the method comprising: subjecting cyclohexylbenzene and / or dicyclohexylbenzene raw materials to a cracking reaction with a solid acid catalyst to obtain cyclohexene and benzene;

[0017] The solid acid catalyst is selected from at least one of amorphous silica-alumina, molecular sieve and immobilized inorganic acid.

[0018] At present, cyclohexene is mainly prepared by partial hydrogenation of benzene on a ruthenium-based catalyst in industry, which has the disadvantages of poor catalyst preparation repeatability, large amount of low-value cyclohexane produced as a by-product of the reaction, and extremely stringent requirements on the materials of raw materials and reaction equipment, resulting in high production costs of cyclohexene. The method provided by the present invention effectively overcomes the above disadvantages, has the advantages of high raw material conversion rate, high cyclohexene yield, and almost no by-product cyclohexane, and is expected to significantly reduce the production cost of cyclohexene.

[0019] The inventors found during the research that in the method of the present invention, the use of a specific type of solid acid catalyst is beneficial to improving the cracking performance of cyclohexylbenzene and / or dicyclohexylbenzene raw materials, and can almost quantitatively crack cyclohexylbenzene and dicyclohexylbenzene into cyclohexene and benzene.

[0020] In the present invention, the ratio of the raw materials cyclohexylbenzene and dicyclohexylbenzene can be adjusted arbitrarily, that is, cyclohexylbenzene can be used alone, dicyclohexylbenzene can be used alone, or a mixed raw material of any ratio of the two can be used. Preferably, the mass ratio of cyclohexylbenzene to dicyclohexylbenzene is 0-100:100-0, more preferably 0-45:55-100. By adopting this preferred embodiment, the efficiency of producing cyclohexene can be improved.

[0021] According to the present invention, preferably, the molecular sieve is at least one of Y-type molecular sieve, Beta-type molecular sieve and MCM-type molecular sieve, more preferably REY molecular sieve and / or MCM-41 molecular sieve. This preferred embodiment is conducive to improving the cracking performance of the raw material.

[0022] In the present invention, the immobilized inorganic acid refers to a catalyst obtained by loading an inorganic acid on a solid carrier.

[0023] The present invention has a wide range of choices for the type of the immobilized inorganic acid. Preferably, the immobilized inorganic acid is H3PW 12 O 40 / SiO2 and / or H3PO4 / diatomaceous earth.

[0024] Further preferably, the solid acid catalyst is selected from at least one of amorphous silica-alumina, REY molecular sieve and MCM-41 molecular sieve, and amorphous silica-alumina is particularly preferred.

[0025] The inventors have found that the use of an amorphous silicon-alumina catalyst has significantly higher raw material cracking performance, and can more completely crack cyclohexylbenzene and dicyclohexylbenzene into cyclohexene and benzene. Moreover, the catalyst can still maintain high activity and stability at high temperatures, and can easily recover its activity completely through high-temperature calcination after deactivation, and the regeneration method is simple.

[0026] According to the present invention, preferably, in the amorphous silicon-alumina, the mass fraction of aluminum oxide is 10-40%, preferably 15-30%. The amorphous silicon-alumina having the above characteristics has stronger acidity and thus has higher cracking activity.

[0027] According to the present invention, preferably, the pore volume of the amorphous silica-alumina is 0.3-1 mL / g, preferably 0.5-1 mL / g.

[0028] According to the present invention, preferably, the specific surface area of ​​the amorphous silicon aluminum is 50-1000m 2 / g, preferably 100-400m 2 / g.

[0029] The amorphous silicon-alumina having the above-mentioned specific surface area and pore volume characteristics has higher cracking activity and stability.

[0030] The present invention has no particular limitation on the source of the solid acid catalyst, which can be obtained from commercial sources or prepared by conventional methods.

[0031] According to the present invention, preferably, the conditions of the cracking reaction include: temperature of 300-500°C, preferably 350-450°C; pressure of 0.1-0.5MPa, preferably 0.1-0.3MPa; mass space velocity of 0.1-5h -1 , preferably 0.5-2h -1 The use of this preferred embodiment is beneficial to improving the yield of cyclohexene.

[0032] The cracking reaction of the present invention can be carried out in the presence of a carrier gas or not. Preferably, the cracking reaction is carried out under the condition of a carrier gas, and the carrier gas is selected from at least one of nitrogen, argon, neon, helium and water vapor. By adopting this preferred embodiment, the reaction conversion rate can be improved and the deactivation rate of the catalyst can be reduced.

[0033] According to the present invention, preferably, the volume usage of the carrier gas is 1-20 times, preferably 1-5 times, the total volume of the raw materials.

[0034] According to the present invention, preferably, the cleavage reaction is carried out in a cleavage reactor. The present invention has no particular restrictions on the type of cleavage reactor, and various reactor types conventionally used in the art such as a fixed bed reactor, a fluidized bed reactor, and a suspended bed reactor can be used. The present invention preferably uses a fixed bed reactor. With this preferred embodiment, the reactor manufacturing cost is low and the reaction process is easier to operate.

[0035] In the present invention, the cleavage reaction may also produce a small amount of heavy components such as polycyclohexylbenzenes and cyclohexene polymers.

[0036] Preferably, the method further comprises: separating the cracking products to obtain cyclohexene and benzene.

[0037] The present invention has no particular limitation on the separation method, and various conventional separation methods can be used. Preferably, the separation is carried out by distillation.

[0038] The present invention has no particular limitation on the distillation method, and the distillation can be carried out according to conventional methods in the art.

[0039] According to the present invention, preferably, the cyclohexylbenzene and / or dicyclohexylbenzene are prepared by a hydroalkylation reaction of benzene and hydrogen, and preferably at least part of the benzene is provided by benzene in the product obtained by the cracking reaction. By adopting the above preferred embodiment, cyclohexylbenzene and / or dicyclohexylbenzene can be obtained by a one-step reaction, and the raw materials are simple and easy to obtain. At least part of the benzene is provided by benzene in the product obtained by the cracking reaction, and the by-product is recycled to achieve process circulation, save costs, reduce energy consumption, and improve economic efficiency.

[0040] According to the present invention, preferably, the process of the hydroalkylation reaction comprises: a hydroalkylation reaction of benzene with hydrogen under the action of a metal / solid acid catalyst.

[0041] The present invention has a wide range of conditions for the hydroalkylation reaction. In order to improve the single-pass conversion rate of benzene and the selectivity of cyclohexylbenzene and dicyclohexylbenzene raw materials, preferably, the conditions for the hydroalkylation reaction include: temperature of 100-200°C, preferably 110-160°C; pressure of 1-5MPa, preferably 1-4MPa; mass space velocity of 0.1-5h -1 , preferably 0.2-2h -1 ; Hydrogen to benzene molar ratio 1-10:1, preferably 3-6:1.

[0042] The present invention has no particular limitation on the type of the metal / solid acid catalyst, and it can be any metal / solid acid catalyst conventionally used in the art. Preferably, the metal / solid acid catalyst comprises a solid acid component and a metal hydrogenation component.

[0043] In the present invention, the present invention has a wide range of selection of the type of the solid acid component, which can be various molecular sieves conventionally used in the art. Preferably, the solid acid component is a molecular sieve, preferably selected from at least one of MCM type molecular sieve, Y type molecular sieve and β type molecular sieve, more preferably selected from at least one of MCM-49 molecular sieve, Y type molecular sieve and β type molecular sieve.

[0044] According to the present invention, preferably, the silicon to aluminum molar ratio of the solid acid component is 3-100:1.

[0045] The present invention has a wide range of selection for the type of the metal hydrogenation component, which can be a noble metal, such as palladium, ruthenium, etc.; or a non-noble metal, such as nickel, etc.

[0046] When the metal hydrogenation component is a non-precious metal, preferably, based on the metal / solid acid catalyst, the content of the metal hydrogenation component in the metal / solid acid catalyst is 1-5 wt %.

[0047] When the metal hydrogenation component is a noble metal, preferably, based on the metal / solid acid catalyst, the content of the metal hydrogenation component in the metal / solid acid catalyst is 0.1-1 wt %.

[0048] In the present invention, in order to improve the reaction activity, preferably, the metal hydrogenation component is a noble metal, preferably palladium and / or ruthenium.

[0049] According to a preferred embodiment of the present invention, the metal / solid acid catalyst comprises a solid acid component and a metal hydrogenation component, the metal hydrogenation component is palladium and / or ruthenium; the solid acid component is selected from at least one of MCM-49 molecular sieve, Y molecular sieve and β molecular sieve, and the silicon-aluminum molar ratio of the solid acid component is 3-100: 1. This preferred embodiment is conducive to further improving the single-pass conversion rate of benzene and the selectivity of cyclohexylbenzene and dicyclohexylbenzene raw materials.

[0050] According to the present invention, the reactor used in the hydroalkylation reaction includes one or more reactors, and the reactor type can be various reactor types such as fixed bed reactor, suspended bed reactor, continuous stirred tank, etc., preferably a fixed bed reactor, and more preferably a shell-and-tube fixed bed reactor.

[0051] The hydroalkylation product of the present invention comprises cyclohexylbenzene, dicyclohexylbenzene, a trace amount of cyclohexane, methylcyclopentylbenzene, and heavy components such as dicyclohexylcyclohexane and tricyclohexylbenzene, as well as unreacted benzene or excess hydrogen.

[0052] The hydroalkylation product of the present invention can be separated by conventional separation methods, and the present invention does not impose any limitation on the separation method.

[0053] Preferably, cyclohexylbenzene and / or dicyclohexylbenzene in the hydroalkylation product is sent to a cracking reaction for use as a raw material.

[0054] Preferably, unreacted benzene is returned to the hydroalkylation reaction and used as a feedstock.

[0055] The present invention will be described in detail below through examples.

[0056] In the following examples, the yield of the reaction product was analyzed by gas chromatography. The chromatographic analysis conditions were: chromatograph: Agilent 7890A; injector temperature 250°C; detector: FID, detector temperature 250°C; analytical column: HP-PONA column, 50m×0.25mm×1μm; column phase program: 40°C for 2 minutes, then heated to 240°C at a rate of 5°C / min, and stayed for 60 minutes.

[0057] Example 1

[0058] The tubular fixed bed reactor used was a stainless steel tube with an inner diameter of 20 mm and a length of 1000 mm, which contained 30 g of amorphous silica-alumina catalyst (alumina mass fraction of 22.5%, pore volume of 0.56 mL / g, specific surface area of ​​298.5 m 2 / g) raw materials (cyclohexylbenzene 70 mass%, dicyclohexylbenzene 30 mass%) were introduced into the reactor at 30g / h, and carrier nitrogen was introduced into the reactor at 300mL / min. The reaction temperature was 400°C and normal pressure to obtain a cleavage reaction product, which was separated by rectification to obtain cyclohexene and benzene. The reaction results are shown in Table 1.

[0059] Under the action of a metal / solid acid catalyst, benzene and hydrogen undergo a hydroalkylation reaction in a solid bed reactor, and at least part of the benzene is provided by benzene in the product obtained by the cracking reaction.

[0060] The metal / solid acid catalyst comprises a Y-type molecular sieve (silicon-aluminum molar ratio of 5.5) and a noble metal Pd; based on the metal / solid acid catalyst, the content of the noble metal in the metal / solid acid catalyst is 0.15wt%. The conditions of the hydroalkylation reaction include: a temperature of 120°C; a pressure of 2MPa; a space velocity of 1h -1 The molar ratio of hydrogen to benzene is 5:1, and cyclohexylbenzene and dicyclohexylbenzene are separated. The single-pass conversion rate of benzene is 54.2%, and the total selectivity of cyclohexylbenzene and dicyclohexylbenzene is 98.5%.

[0061] Example 2

[0062] The tubular fixed bed reactor used was a stainless steel tube with an inner diameter of 20 mm and a length of 1000 mm, containing 30 g of amorphous silica-alumina catalyst (alumina mass fraction of 25%, pore volume of 0.6 mL / g, specific surface area of ​​275 m 2 / g) raw materials (cyclohexylbenzene 70 mass%, dicyclohexylbenzene 30 mass%) were introduced into the reactor at 30g / h, and carrier nitrogen was introduced into the reactor at 300mL / min. The reaction temperature was 425°C and normal pressure to obtain a cleavage reaction product, which was separated by rectification to obtain cyclohexene and benzene. The reaction results are shown in Table 1.

[0063] Under the action of a metal / solid acid catalyst, benzene and hydrogen undergo a hydroalkylation reaction in a solid bed reactor, and at least part of the benzene is provided by benzene in the product obtained by the cracking reaction.

[0064] The metal / solid acid catalyst comprises a Y-type molecular sieve (silicon-aluminum molar ratio of 5.5) and a noble metal Pd; based on the metal / solid acid catalyst, the content of the noble metal in the metal / solid acid catalyst is 0.2wt%. The conditions of the hydroalkylation reaction include: a temperature of 115°C; a pressure of 2MPa; a space velocity of 1.2h -1The molar ratio of hydrogen to benzene is 5.5:1, and cyclohexylbenzene and dicyclohexylbenzene are separated. The single-pass conversion rate of benzene is 50.6%, and the total selectivity of cyclohexylbenzene and dicyclohexylbenzene is 98.2%.

[0065] Example 3

[0066] The tubular fixed bed reactor used was a stainless steel tube with an inner diameter of 20 mm and a length of 1000 mm, containing 30 g of amorphous silica-alumina catalyst (alumina mass fraction of 17.9%, pore volume of 0.55 mL / g, specific surface area of ​​300.2 m 2 / g) raw materials (cyclohexylbenzene 70 mass %, dicyclohexylbenzene 30 mass %) prepared according to the method described in Example 1 were passed into the reactor at 30g / h, and carrier nitrogen was passed into the reactor at 300mL / min. The reaction temperature was 450°C and normal pressure to obtain a cleavage reaction product, which was separated by rectification to obtain cyclohexene and benzene. The reaction results are shown in Table 1.

[0067] Under the action of metal / solid acid catalyst, benzene and hydrogen are subjected to hydroalkylation reaction in a solid bed reactor, and at least part of the benzene is provided by benzene recovered from the cracking reaction product. The specific method is as in Example 1.

[0068] Example 4

[0069] The method of Example 2 was followed, except that the reaction temperature was changed to 375° C. The reaction results are shown in Table 1.

[0070] Example 5

[0071] The method of Example 2 was followed, except that the carrier gas was changed to water vapor, which was introduced into the reactor at a rate of 30 g / h. The reaction results are shown in Table 1.

[0072] Example 6

[0073] The method of Example 2 was followed, except that no carrier gas was introduced. The reaction results are shown in Table 1.

[0074] Example 7

[0075] The method of Example 2 was followed, except that 30 g of REY molecular sieve catalyst (silicon-aluminum ratio of 5, lanthanum oxide mass fraction of 2.5%) was used as the catalyst. The reaction results are shown in Table 1.

[0076] It should be noted that, compared with the catalyst of Example 2, since the cage-shaped pores of the molecular sieve are easily clogged by carbon deposits, the catalyst is easily deactivated and has poor stability.

[0077] Example 8

[0078] The method of Example 2 was followed, except that cyclohexylbenzene was used as the raw material and 30 g / h was introduced into the reactor. The results are shown in Table 1.

[0079] Example 9

[0080] The method of Example 2 was followed, except that dicyclohexylbenzene was used as the raw material and introduced into the reactor at a rate of 30 g / h. The reaction results are shown in Table 1.

[0081] Example 10

[0082] The method of Example 2 was followed, except that the mass fraction of aluminum oxide in the amorphous silica-alumina catalyst was 8%, the pore volume was 0.45 mL / g, and the specific surface area was 420.6 m 2 / g. The reaction results are shown in Table 1.

[0083] Comparative Example 1

[0084] The method of Example 2 was followed, except that the catalyst was changed to γ-alumina. The reaction results are shown in Table 1.

[0085] Table 1

[0086]

[0087]

[0088] It can be seen from the results in Table 1 that the method of the present invention has a significantly higher raw material conversion rate and a higher cyclohexene yield.

[0089] Moreover, the method of the present invention produces almost no by-product cyclohexane, effectively overcoming the defect of complicated subsequent product separation process and reducing energy consumption; the reaction equipment used in the method of the present invention does not need to use special materials, which can greatly reduce the production cost of cyclohexene.

[0090] In addition, the by-product benzene obtained by the method of the present invention can be used as a raw material to produce cyclohexylbenzene and / or dicyclohexylbenzene, thereby realizing process circulation, saving costs, reducing energy consumption, and improving economic efficiency.

[0091] 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 method for producing cyclohexene, the method comprising: The cyclohexylbenzene and / or dicyclohexylbenzene raw materials are subjected to a cracking reaction with a solid acid catalyst to obtain cyclohexene and benzene; The solid acid catalyst is selected from at least one of amorphous silica-alumina, molecular sieve and immobilized inorganic acid.

2. The method according to claim 1, wherein: The raw material is dicyclohexylbenzene.

3. The method according to claim 1, wherein: The molecular sieve is at least one of a Y-type molecular sieve, a Beta-type molecular sieve and an MCM-type molecular sieve; Preferably, the immobilized inorganic acid is H3PW 12 O 40 / SiO2 and / or H3PO4 / diatomaceous earth; Further preferably, the solid acid catalyst is selected from at least one of amorphous silica-alumina, REY molecular sieve and MCM-41 molecular sieve, preferably amorphous silica-alumina.

4. The method according to any one of claims 1 to 3, wherein: In the amorphous silicon aluminum, the mass fraction of aluminum oxide is 10-40%, preferably 15-30%; Preferably, the pore volume of the amorphous silicon aluminum is 0.3-1 mL / g, preferably 0.5-1 mL / g; the specific surface area is 50-1000 m 2 / g, preferably 100-400m 2 / g.

5. The method according to any one of claims 1 to 4, wherein: The conditions of the cracking reaction include: temperature of 300-500°C, preferably 350-450°C; pressure of 0.1-0.5MPa, preferably 0.1-0.3MPa; mass space velocity of 0.1-5h -1 , preferably 0.5-2h -1 .

6. The method according to any one of claims 1 to 5, wherein: The cracking reaction is carried out under the condition of a carrier gas, and the carrier gas is selected from at least one of nitrogen, argon, neon, helium and water vapor; Preferably, the volume of the carrier gas is 1-20 times, preferably 1-5 times, the total volume of the raw materials.

7. The method according to any one of claims 1 to 6, wherein: The cleavage reaction is carried out in a cleavage reactor, and the cleavage reactor is selected from at least one of a fluidized bed reactor, a suspended bed reactor and a fixed bed reactor, preferably a fixed bed reactor.

8. The method according to claim 1, wherein: The cyclohexylbenzene and / or dicyclohexylbenzene are prepared by a hydroalkylation reaction of benzene with hydrogen, and preferably at least part of the benzene is provided by benzene in a product obtained by a cracking reaction; Preferably, the hydroalkylation reaction process comprises: hydroalkylation reaction of benzene with hydrogen under the action of metal / solid acid catalyst; Preferably, the conditions of the hydroalkylation reaction include: temperature of 100-200°C; pressure of 1-5 MPa; mass space velocity of 0.1-5 h -1 ; Hydrogen to benzene molar ratio 1-10:

1.

9. The method according to claim 8, wherein: The metal / solid acid catalyst comprises a solid acid component and a metal hydrogenation component, wherein the metal hydrogenation component is a noble metal; and the solid acid component is selected from at least one of an MCM molecular sieve, a Y molecular sieve and a Beta molecular sieve.

10. The method according to claim 9, wherein: The silicon to aluminum molar ratio of the solid acid component is 3-100:1; Preferably, the solid acid component is selected from at least one of MCM-49 molecular sieve, Y-type molecular sieve and Beta-type molecular sieve; Preferably, the metal hydrogenation component is palladium and / or ruthenium; Preferably, based on the metal / solid acid catalyst, the content of the metal hydrogenation component in the metal / solid acid catalyst is 0.1-1 wt %.

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