A catalyst for preparing cyclohexylbenzene by hydrogenation of biphenyl, a preparation method and application thereof

Abstract

The application discloses a catalyst for preparing cyclohexylbenzene by hydrogenation of diphenyl and a preparation method and application thereof. The catalyst comprises a carrier and an active component loaded on the carrier in the form of eggshell. The active component comprises Ni, Zn and Cu. The content of Ni is 2wt%-8wt% based on the mass of the catalyst, the content of Zn is 0.5wt%-4wt%, and the content of Cu is 0.5wt%-4wt%. The catalyst has low active component loading, and is good in catalytic activity, high in selectivity and good in stability when used in the preparation of cyclohexylbenzene by hydrogenation of diphenyl.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of chemical technology, and particularly relates to a catalyst for preparing cyclohexylbenzene by hydrogenation of diphenyl and a preparation method thereof, and application of the catalyst in preparing high-purity cyclohexylbenzene by hydrogenation of diphenyl. BACKGROUND

[0002] Cyclohexylbenzene is an important chemical intermediate, is a high-boiling solvent for preparing coatings, plastics and adhesives, and has special physical and chemical properties. Cyclohexylbenzene can be prepared into phenol and cyclohexanone through oxidation reaction, phenol is an important chemical raw material, and cyclohexanone is an intermediate for producing caprolactam and nylon. Cyclohexylbenzene can also be used as a raw material for synthesizing TFT liquid crystal materials and can be used as an additive for lithium ion secondary battery electrolyte, and has overcharge prevention performance. As a raw material for electrolyte and the like, the purity of cyclohexylbenzene has a relatively high requirement, and is usually required to be more than 99.5%.

[0003] At present, cyclohexylbenzene is mostly prepared by benzene alkylation by hydrogenation, and is also prepared by benzene alkylation with styrene. The products prepared by these methods include cyclohexylbenzene, multi-alkylbenzene and methylcyclopentylbenzene, etc. Among them, methylcyclopentylbenzene has many isomers, and the boiling point is very close to that of cyclohexylbenzene (the difference is 2-8℃ under normal pressure). Therefore, the product needs to be separated and rectified in multiple stages to obtain high-purity cyclohexylbenzene.

[0004] Cyclohexylbenzene can also be prepared by selective hydrogenation of diphenyl, and CN107185548B discloses a catalyst for preparing cyclohexylbenzene by selective hydrogenation of diphenyl and a method thereof. The preparation process of the catalyst is as follows: first, a mixed solution containing a molybdenum compound, a nickel compound, a copper compound, deionized water, ammonia water and an additive is prepared, and then the mixed solution is reacted in an autoclave, shaped, dried and calcined to obtain a Ni-Mo-Cu oxidation state catalyst. Part of the oxidation state catalyst is partially reduced into a reduced state catalyst, and the catalyst is used in the reaction of selective hydrogenation of diphenyl to generate cyclohexylbenzene by using a fixed bed reactor. The catalyst has a large amount of active metals, high cost, and is easy to deactivate and has poor stability.

[0005] In the reaction process of preparing cyclohexylbenzene by selective hydrogenation of diphenyl, the raw material and the product are similar to liquid wax, and the reaction is an exothermic reaction, which leads to poor mass transfer and heat transfer. The existing catalysts are difficult to balance the catalyst activity and stability. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application provides a catalyst for preparing cyclohexylbenzene by hydrogenation of diphenyl and a preparation method and application thereof. The catalyst has a low active component loading, and is used in the preparation of cyclohexylbenzene by hydrogenation of diphenyl, has good catalytic activity, high selectivity and good stability.

[0007] The first aspect of the present application provides a catalyst for preparing cyclohexylbenzene by hydrogenation of biphenyl, comprising a carrier and an active component loaded on the carrier in the form of eggshell, wherein the active component comprises Ni, Zn and Cu, the content of Ni is 2wt%-8wt% based on the mass of the catalyst, the content of Zn is 0.5wt%-4wt% based on the mass of the catalyst, and the content of Cu is 0.5wt%-4wt% based on the mass of the catalyst.

[0008] Further, in the catalyst of the present application, the content of Ni is 2wt%-8wt% based on the mass of the catalyst, for example, 2%, 3%, 4%, 5%, 6%, 6.5%, 7%, 8%, and any value in the range constituted by any two of these values.

[0009] Further, in the catalyst of the present application, the content of Zn is 0.5wt%-4wt% based on the mass of the catalyst, for example, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, and any value in the range constituted by any two of these values.

[0010] Further, in the catalyst of the present application, the content of Cu is 0.5wt%-4wt% based on the mass of the catalyst, for example, 0.5%, 1.0%, 1.5%, 1.7%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, and any value in the range constituted by any two of these values.

[0011] Further, the catalyst of the present application further comprises an auxiliary agent selected from one or more of Co, Fe and Mo, preferably Mo. The content of the auxiliary agent is 0-2wt% based on the mass of the catalyst, preferably 0.2wt%-2wt%, for example, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.5%, 1.8%, 2.0%, and any value in the range constituted by any two of these values. The auxiliary agent and the active component are loaded on the carrier in the form of eggshell.

[0012] Further, in the catalyst of the present application, the carrier is an alumina carrier. The carrier can be spherical or strip-shaped. The diameter of the spherical carrier is preferably 2-10mm, more preferably 3-5mm. The diameter of the strip-shaped carrier is preferably 0.5-3.0mm, and the length is preferably 3-8mm. Preferably, the specific surface area of the alumina carrier is 150m 2 / g or more, preferably 200-350m 2 / g, the pore volume is 0.5-1.0ml / g, preferably 0.65-1.0ml / g, and the bulk density is not more than 0.6kg / m 3 , preferably not more than 0.5kg / m 3, further preferably 0.3-0.5 kg / m 3 .

[0013] Further, in the catalyst of the present application, the thickness of the shell layer is less than 10% of the radius of the catalyst, preferably less than 7%, and further preferably 1-7%.

[0014] The second aspect of the present application provides a method for preparing the above-mentioned catalyst, comprising the step of loading the active component in the form of an eggshell on the carrier; preferably, the carrier is first treated with an alkali solution, and then the active component is loaded on the carrier in the form of an eggshell.

[0015] Further, the active component is loaded on the carrier in the form of an eggshell by impregnation, i.e. the carrier is impregnated with a solution containing a precursor of the active component, and then dried and calcined to obtain the catalyst.

[0016] Further, preferably, the carrier is first treated with an alkali solution, and then impregnated with a solution containing a precursor of the active component, and then dried and calcined to obtain the catalyst.

[0017] Further, in the present application, the carrier is an alumina carrier, and the carrier is a shaped carrier, which can have a conventional shape, including but not limited to a spherical shape or a strip shape. The carrier can be spherical or strip-shaped. The diameter of the spherical carrier is preferably 2-10 mm, and more preferably 3-5 mm. The diameter of the strip-shaped carrier is preferably 0.5-3.0 mm, and the length is 3-8 mm. Preferably, the specific surface area of the alumina carrier is 150 m 2 / g or more, preferably 200-350 m 2 / g, the pore volume is 0.5-1.0 ml / g, preferably 0.65-1.0 ml / g, and the bulk density is not more than 0.6 kg / m 3 , preferably not more than 0.5 kg / m 3 , and further preferably 0.3-0.5 kg / m 3 .

[0018] Further, the alkali solution is an alkaline earth metal solution, which is preferably prepared by dissolving an alkaline earth metal soluble salt (such as a nitrate salt, etc.) in water, and the alkaline earth metal is preferably magnesium and / or calcium. The process for treating the carrier with the alkali solution is as follows: the carrier is impregnated with the alkali solution (preferably equal-volume impregnation), and then washed with water, dried and calcined. The loading amount of the alkaline earth metal, calculated as an oxide, is 5-15% by mass of the carrier. The impregnation, washing with water, drying and calcination can all be carried out by conventional methods. Generally, the drying conditions are 50-150°C for 2-24 h, and the calcination conditions are 500-600°C for 2-10 h.

[0019] Further, the impregnation of the carrier with a solution containing a precursor of the active component is preferably carried out by equal-volume impregnation.

[0020] Further, the solution containing the active component precursor further contains an assistant precursor. The assistant is selected from one or more of Co, Fe and Mo. The content of the assistant is 0-2wt%, preferably 0.2wt%-2wt% based on the mass of the catalyst.

[0021] Further, the active component precursor and the assistant precursor can be at least one of soluble salts, such as nitrate, sulfate, chloride, preferably chloride.

[0022] Further, after impregnating the carrier with the solution containing the active component precursor, the drying condition is as follows: drying at 50-160℃ for 1-24h, and the calcination is preferably as follows: calcination at 250-350℃ for 1-8h, and calcination at 400-600℃ for 2-10h.

[0023] Further, after impregnating the carrier with the solution containing the active component precursor, before drying, it is preferred to first air dry, i.e. air dry to surface dry.

[0024] The third aspect of the present application provides the use of the above-mentioned catalyst in the hydrogenation of diphenyl to prepare cyclohexylbenzene.

[0025] Further, the catalyst needs to be reduced and activated before use. The reducing gas can be hydrogen, and the reduction condition is as follows: temperature is 150-350℃, hydrogen space velocity is 200-2000h -1 , and activation time is 0.5-5h.

[0026] Further, the use includes: contacting diphenyl with the catalyst in the presence of hydrogen to obtain cyclohexylbenzene.

[0027] Further, the reaction is carried out by feeding the mixture of diphenyl and solvent, preferably cyclohexane. In the mixture of diphenyl and solvent, the mass concentration of diphenyl is 5%-50%, preferably 15%-35%.

[0028] Further, the reaction uses a fixed bed reactor.

[0029] Further, the reaction condition is as follows: reaction temperature is 90-120℃, hydrogen / oil (diphenyl) volume ratio is 0.2-2.0, liquid volume space velocity is 0.5-10h -1 , and pressure is 0.6-2.0MPa.

[0030] Further, the mass purity of the diphenyl is above 99.5%.

[0031] Furthermore, the reaction products are separated (preferably using two towers: the first tower recovers the solvent cyclohexane, the second tower outputs dicyclohexane from the top and cyclohexylbenzene from the side stream, and the biphenyl from the bottom is reused) to obtain the solvent, cyclohexylbenzene, and dicyclohexane. The separated solvent can be recycled. The resulting cyclohexylbenzene has a purity of over 99.5%.

[0032] Furthermore, the conversion rate of the biphenyl reaches over 95%, and the selectivity of the cyclohexylbenzene reaches over 95%.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] 1. Existing catalysts for the hydrogenation of biphenyl to cyclohexylbenzene are high-activity metal catalysts. Although they have high initial activity, they are prone to deactivation and have poor stability. Through extensive research, the inventors discovered that loading the active components Ni, Zn, and Cu onto a support in the form of eggshells not only results in a low loading of active components but also effectively solves the problem of poor catalyst stability, while ensuring good activity and selectivity.

[0035] 2. In the preparation method of the catalyst of the present invention, it is preferable to first treat the support with an alkaline solution and then impregnate and load the active component, which can make the active component form a more uniform eggshell on the surface of the support, so that the catalyst prepared can have better activity, selectivity and stability when used in the process of biphenyl hydrogenation to prepare cyclohexylbenzene.

[0036] 3. The catalyst of this invention, when used in the hydrogenation of biphenyl to prepare cyclohexylbenzene, not only exhibits good activity and selectivity for cyclohexylbenzene, but also good stability. Attached Figure Description

[0037] Figure 1 This is a photograph of a section of the catalyst obtained in Example 1 that has been cut open. Detailed Implementation

[0038] To provide a clearer understanding of the technical solution, objectives, and beneficial effects of the present invention, the present invention will be described in detail below with reference to specific embodiments. However, it should be understood that the scope of protection of the present invention is not limited by the specific embodiments.

[0039] In this invention, specific surface area and pore volume were measured using an ASAP2600 surface analyzer (USA). Samples were degassed under vacuum at 400°C for 2 hours, followed by adsorption and desorption under liquid nitrogen conditions. Specific surface area was calculated using the BET method.

[0040] In this invention, the bulk density is measured using a Canta bulk density meter from the United States.

[0041]

Example 1

[0042] Using alumina as a carrier (strips with a radius of 1 mm and a length of 3 mm, and a specific surface area of ​​300 m²), 2 / g, pore volume is 0.70ml / g, bulk density is 0.42kg / m³ 3 The catalyst A1 was prepared by impregnation with an equal volume of calcium nitrate solution, drying at 90°C for 3 hours, and then calcining in air at 550°C for 3 hours. The loading amount of calcium oxide was 10.5 wt% of the alumina support mass. A mixed precursor solution was prepared using nickel nitrate, zinc sulfate, and copper sulfate, and the active components Ni, Zn, and Cu were loaded by an equal volume impregnation method. The Ni loading was 4.8 wt%, and the Zn and Cu loadings were 1.0 wt% and 1.7 wt%, respectively, based on the catalyst mass. After standing and drying, the catalyst was dried at 150°C at 20°C / min for 2 hours, calcined at 300°C at 10°C / min for 2 hours, and then calcined at 400°C at 5°C / min for 6 hours.

[0043] See the photo of catalyst A1 after it was cut open. Figure 1 ,Depend on Figure 1 It is evident that the outer surface of the carrier consists of eggshell-shaped active components.

[0044] In catalyst A1, the shell thickness is approximately 0.07 mm.

[0045] Before use, activate with hydrogen gas at 250°C and a hydrogen space velocity of 300 h⁻¹. -1 The activation time is 1 hour. After activation, it is ready for use.

[0046] A fixed-bed reactor was used, with biphenyl dissolved in cyclohexane as feed, wherein the mass concentration of biphenyl was 18%. The reaction conditions were as follows: reaction temperature 95℃, hydrogen-to-oil volume ratio 1.0, and liquid hourly space velocity 3 h⁻¹. -1 The pressure was 1 MPa. The reaction results are as follows: the initial biphenyl conversion rate was 97.4%, and the cyclohexylbenzene selectivity was greater than 99.3%. After 100 h of reaction, the biphenyl conversion rate was 97.1%, and the cyclohexylbenzene selectivity was 98.8%.

[0047]

Example 2

[0048] Using alumina spheres as a carrier (radius 3mm, specific surface area 310m²) 2 / g, pore volume is 0.68ml / g, bulk density is 0.40kg / m³ 3The catalyst A2 was prepared by impregnation with an equal volume of magnesium nitrate solution, drying at 90°C for 3 hours, and then calcining in air at 550°C for 4 hours. The magnesium oxide loading was 15.5 wt% of the alumina support mass. A mixed precursor solution was prepared using nickel nitrate, zinc sulfate, and copper sulfate, and the active components Ni, Zn, and Cu were loaded using an equal volume impregnation method. The Ni loading was 6.2 wt%, and the Zn and Cu loadings were 0.6 wt% and 0.6 wt%, respectively, based on the catalyst mass. After standing and drying, the temperature was increased to 150°C at 10°C per minute and held for 2 hours, then calcined at 300°C at 10°C per minute for 2 hours, and finally calcined at 450°C at 8°C per minute for 3 hours.

[0049] When catalyst A2 is cut open, it can be seen that the outer surface of the support is composed of eggshell-shaped active components.

[0050] In catalyst A2, the shell thickness is approximately 0.10 mm. Before use, it is activated with hydrogen at 250°C and a hydrogen space velocity of 300 h⁻¹. -1 The activation time is 1 hour. After activation, it is ready for use.

[0051] A fixed-bed reactor was used, with biphenyl dissolved in cyclohexane as feed, wherein the mass concentration of biphenyl was 18%. The reaction conditions were as follows: reaction temperature 95℃, hydrogen-to-oil volume ratio 1.0, and liquid hourly space velocity 3 h⁻¹. -1 The pressure was 2 MPa. The reaction results are as follows: the initial biphenyl conversion rate was 97.6%, and the cyclohexylbenzene selectivity was greater than 99.1%. After 100 h of reaction, the biphenyl conversion rate was 97.5%, and the cyclohexylbenzene selectivity was 98.4%.

[0052]

Example 3

[0053] Using alumina spheres as a carrier (radius 5mm, specific surface area 350m²) 2 / g, pore volume is 0.65ml / g, bulk density is 0.38kg / m³ 3 The catalyst A3 was obtained by impregnating the alumina support with an equal volume of calcium nitrate solution, drying at 90°C for 3 hours, and then calcining in air at 550°C for 4 hours. The loading amount of calcium oxide accounted for 13.6 wt% of the alumina support mass. A mixed precursor solution was prepared using nickel nitrate, zinc sulfate, molybdenum nitrate, and copper sulfate, and the active components Ni, Zn, Mo, and Cu were loaded using an equal volume impregnation method. The Ni loading was 3.0 wt%, and the loadings of Zn, Mo, and Cu were 0.5 wt%, 0.4 wt%, and 0.9 wt%, respectively, based on the catalyst mass. After standing and drying, the catalyst was dried at 150°C at a rate of 10°C / min for 2 hours, calcined at 300°C at a rate of 10°C / min for 2 hours, and then calcined at 450°C at a rate of 8°C / min for 3 hours.

[0054] When catalyst A3 is cut open, it can be seen that the outer surface of the support is composed of eggshell-shaped active components.

[0055] In catalyst A3, the shell thickness is approximately 0.11 mm.

[0056] Before use, activate with hydrogen gas at 280°C and a hydrogen space velocity of 100 h⁻¹. -1 The activation time is 3 hours. After activation, it is ready for use.

[0057] A fixed-bed reactor was used, with biphenyl dissolved in cyclohexane as feed, wherein the mass concentration of biphenyl was 18%. The reaction conditions were as follows: reaction temperature 95℃, hydrogen-to-oil volume ratio 0.6, and liquid hourly space velocity 2 h⁻¹. -1 The pressure was 2 MPa. The reaction results are as follows: the initial biphenyl conversion rate was 97.1%, and the cyclohexylbenzene selectivity was greater than 99.3%. After 100 h of reaction, the biphenyl conversion rate was 96.6%, and the cyclohexylbenzene selectivity was 98.9%.

[0058] Comparative Example 1

[0059] First, nickel nitrate, zinc sulfate, copper sulfate, and deionized water were mixed to form a solution, which was then reacted in an autoclave, dried, and calcined to obtain a Ni-Zn-Cu oxidized catalyst solid solution (the mass ratio of Ni, Zn, and Cu was the same as in Example 1). The solid solution was ground, pulverized, and mixed into a paste, then kneaded, extruded, dried, and calcined at 450°C for 3 hours to obtain the catalyst. Its specific surface area was measured to be 85 m². 2 / g.

[0060] The oxidized catalyst was reduced to a reduced state and activated with hydrogen gas at 250°C and a hydrogen space velocity of 300 h⁻¹. -1 The activation time is 1 hour. After activation, it is ready for use.

[0061] In a fixed-bed reactor, at 95℃ and 1 MPa, with a hydrogen-to-oil volume ratio of 1.0 and a liquid hourly space velocity of 3 h⁻¹, the following conditions were met: -1 Under certain conditions, biphenyl selectively hydrogenates to cyclohexylbenzene, with an initial biphenyl conversion of 97.8% and a cyclohexylbenzene selectivity of 97.2%. After 100 h of reaction, the biphenyl conversion is 85.1% and the cyclohexylbenzene selectivity is 94.8%.

[0062] The embodiments described above are merely detailed descriptions of the technical solutions of the present invention, but the present invention is not limited to the above embodiments, that is, the present invention does not depend on the steps described in the above embodiments to be implemented. In summary, any improvements made to the present invention by those skilled in the art, including the substitution of the raw materials and additives described in the present invention, the selection of specific implementation methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A catalyst for preparing cyclohexylbenzene by hydrogenation of diphenyl, comprising a carrier and an active component loaded on the carrier in the form of eggshell, the active component comprising Ni, Zn and Cu, the content of Ni being 2wt%-8wt% and the content of Zn being 0.5wt%-4wt% and the content of Cu being 0.5wt%-4wt% based on the mass of the catalyst.

2. The catalyst according to claim 1, characterized in that, The carrier is an alumina carrier.

3. The catalyst of claim 2, wherein The specific surface area of the alumina support is 150 m 2 / g or more, the pore volume is 0.5 to 1.0 mL / g, and the bulk density is not more than 0.6 kg / m 3 .

4. The catalyst of claim 3, wherein The alumina support has a specific surface area of 200 to 350 m 2 / g, a pore volume of 0.65 to 1.0 mL / g, and a bulk density of not more than 0.5 kg / m 3 .

5. Catalyst according to claim 3 or 4, characterized in that The bulk density of the alumina support is 0.3-0.5 kg / m 3 .

6. The catalyst of claim 2, wherein The carrier is spherical or strip-shaped.

7. The catalyst of claim 6, wherein The diameter of the spherical carrier is 2-10 mm and the diameter of the strip-shaped carrier is 0.5-3.0 mm and the length of the strip-shaped carrier is 3-8 mm.

8. The catalyst of claim 7, wherein The diameter of the spherical carrier is 3-5 mm.

9. The catalyst according to claim 1 or 6, characterized in that, The thickness of the shell layer accounts for less than 10% of the radius of the catalyst.

10. The catalyst of claim 9, wherein The thickness of the shell layer accounts for less than 7% of the radius of the catalyst.

11. The catalyst of claim 10, wherein The thickness of the shell layer accounts for 1%-7% of the radius of the catalyst.

12. The catalyst of claim 1, wherein The catalyst further comprises an auxiliary agent selected from one or more of Co, Fe and Mo, the content of the auxiliary agent being 0-2wt% based on the mass of the catalyst, wherein the auxiliary agent and the active component are loaded on the carrier in the form of eggshell.

13. The catalyst of claim 12, wherein, The content of the auxiliary agent is 0.2wt%-2wt% based on the mass of the catalyst.

14. A method for preparing the catalyst of any one of claims 1-11, comprising the step of loading the active component on the carrier in the form of eggshell.

15. The preparation method according to claim 14, characterized in that, The method comprises the step of first treating the carrier with an alkali solution and then loading the active component on the carrier in the form of eggshell.

16. The method of claim 15, wherein, The alkali solution is an alkaline earth metal solution.

17. The preparation method according to claim 16, characterized in that, The alkaline earth metal is magnesium and / or calcium.

18. The production method according to claim 15 or 16, characterized by, The treatment of the carrier with the alkali solution is as follows: the carrier is impregnated with the alkali solution, then washed with water, dried and calcined; the loading amount of the alkaline earth metal in the form of oxide is 5wt%-15wt% based on the mass of the carrier.

19. The method of claim 18, wherein, The carrier is impregnated with the alkali solution in an equal volume.

20. The method of manufacturing according to claim 14 or 15, wherein, The carrier is impregnated with a solution containing a precursor of the active component in an equal volume.

21. The method of claim 20, wherein, The solution containing the precursor of the active component further contains a precursor of an auxiliary agent selected from one or more of Co, Fe and Mo, the content of the auxiliary agent being 0-2wt% based on the mass of the catalyst.

22. The method of claim 21, wherein, The content of the auxiliary agent is 0.2wt%-2wt% based on the mass of the catalyst.

23. The method of manufacturing according to claim 14 or 15, wherein, After the carrier is impregnated with the solution containing the precursor of the active component, the catalyst is obtained by drying and calcining; the drying conditions are as follows: drying at 50-160°C for 1-24 h, and the calcining conditions are as follows: calcining at 250-350°C for 1-8 h and calcining at 400-600°C for 2-10 h.

24. Use of the catalyst of any one of claims 1-13 or the catalyst prepared by the method of any one of claims 14-23 in the preparation of cyclohexylbenzene by hydrogenation of diphenyl.

25. The use according to claim 24, characterized in that, The use comprises: contacting diphenyl with the catalyst in the presence of hydrogen to obtain cyclohexylbenzene; and feeding the diphenyl after mixing with a solvent.

26. The use according to claim 25, characterized in that, The solvent is cyclohexane.

27. The use according to claim 25, characterized in that, The mass concentration of diphenyl in the mixture of diphenyl and solvent is 5wt%-50wt%.

28. The use according to claim 27, characterized in that, The mass concentration of diphenyl in the mixture of diphenyl and solvent is 15wt%-35wt%.

29. The use of claim 25, wherein, The reaction is carried out in a fixed bed reactor.

30. The use according to claim 29, characterized in that, The reaction conditions are as follows: the reaction temperature is 90-120℃, the volume ratio of hydrogen to biphenyl is 0.2-2.0, the liquid volume space velocity is 0.5-10 h -1 , and the pressure is 0.6-2.0 MPa.

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