A pretreatment method of a catalyst for benzyl alcohol hydrogenolysis, a pretreated catalyst obtained by the method, and a method for preparing cumene

Abstract

The application discloses a pretreatment method of a catalyst for benzyl alcohol hydrogenolysis, a pretreated catalyst obtained by the method and a preparation method of cumene. The pretreatment method comprises the following steps: under a hydrogen atmosphere, water vapor is used to pretreat the catalyst for benzyl alcohol hydrogenolysis, so as to obtain the pretreated catalyst. The pretreated catalyst obtained by the pretreatment method can be applied to the preparation of cumene by benzyl alcohol hydrogenolysis, especially the preparation of cumene by hydrogenolysis of benzyl alcohol material containing acetophenone. In the application, the conversion of acetophenone in the material can be effectively inhibited after the pretreatment of the catalyst for benzyl alcohol hydrogenolysis, and the hydrogenolysis reaction conversion rate and selectivity are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the preparation of cumene by hydrogenolysis of benzyl alcohol, in particular to a pretreatment method of catalyst for hydrogenolysis of benzyl alcohol, the pretreated catalyst obtained and a preparation method of cumene. BACKGROUND

[0002] Propylene oxide (PO) is an important organic chemical raw material, mainly used for the production of polyether polyols, propylene glycol, propylene glycol ether, etc. At present, the commercial production methods of PO mainly include chlorohydrination method, co-oxidation method (PO / SM), cumene hydroperoxide circulation method (CHP), and hydrogen peroxide direct oxidation method (HPPO). The CHP method for producing propylene oxide is not affected by the price fluctuation of associated products, and has no pollution to the environment, and the investment is less. It is an environmentally friendly clean production process, which was first developed by Sumitomo Chemical Company of Japan. The CHP method for producing PO includes the processes of cumene oxidation, propylene epoxidation, and α, α-dimethyl benzyl alcohol hydrogenolysis.

[0003] In the prior art, more attention is paid to improving the conversion rate of hydrogenolysis reaction by controlling the impurities in the raw materials, and less attention is paid to the technical problems of how to improve the conversion rate and selectivity through process modification.

[0004] CN105315236A patent points out that the high concentration of organic acids, alkali metal or alkaline earth metal ions and water in the cumene hydroperoxide oxidation solution will seriously affect the selectivity of the selective oxidation-reduction reaction and the service life of the catalyst. The weight percentage concentration of alkali metal or alkaline earth metal ions is required to be not more than 500ppm.

[0005] CN1860087A patent points out that the palladium catalyst is used as a hydrogenolysis or hydrogenation catalyst, with hydrogen gas having a carbon monoxide concentration of 0.1 to 10 volume percent, otherwise it may lead to hydrogenation of benzene ring, reducing the selectivity.

[0006] However, benzyl alcohol hydrogenolysis is often accompanied by the hydrogenation of by-product acetophenone, which is less concerned in the prior art. SUMMARY

[0007] In order to overcome the problems in the prior art, the application provides a pretreatment method of a catalyst for benzyl alcohol hydrogenolysis, a pretreated catalyst obtained by the method and a preparation method of cumene, wherein the pretreatment of the catalyst for benzyl alcohol hydrogenolysis by high-temperature water vapor can effectively improve the conversion rate and selectivity of the benzyl alcohol hydrogenolysis reaction (reduce the conversion of acetophenone), which may be due to the fact that the high-temperature water vapor causes the metal (such as Pd) grains on the hydrogenolysis catalyst (such as a Pd-based catalyst) to be rearranged, forming grains with more uniform size distribution and more suitable size for the hydrogenolysis reaction, which effectively inhibits the conversion of acetophenone in the material, thereby improving the selectivity of the reaction. As a high-value by-product of the hydrogenolysis unit, the inhibition of the hydrogenation reaction of acetophenone effectively improves the economy of the device.

[0008] In one aspect, the application provides a pretreatment method of a catalyst for benzyl alcohol hydrogenolysis, which is embodied as follows:

[0009] (1) A pretreatment method of a catalyst for benzyl alcohol hydrogenolysis, comprising: pretreating the catalyst for benzyl alcohol hydrogenolysis by water vapor under a hydrogen atmosphere to obtain a pretreated catalyst.

[0010] (2) The pretreatment method according to the above (1), wherein the catalyst for benzyl alcohol hydrogenolysis comprises a carrier and an active component supported on the carrier.

[0011] Preferably, the carrier is selected from at least one of alumina, silica and activated carbon; and / or the active component is selected from at least one of palladium, platinum, copper and nickel.

[0012] More preferably, in the catalyst for benzyl alcohol hydrogenolysis, the content of the active component is 0.01-70 wt%, preferably 0.05-60 wt%.

[0013] (3) The pretreatment method according to the above (1), wherein the temperature of the water vapor is 150-500°C, preferably 180-400°C.

[0014] (4) The pretreatment method according to any one of the above (1)-(3), wherein the mass space velocity of the water vapor is 2-20, preferably 5-15.

[0015] In a second aspect, the application provides:

[0016] (5) A pretreated catalyst obtained by the pretreatment method according to any one of the above (1)-(4).

[0017] In a third aspect, the application provides:

[0018] (6) The pretreatment method of any one of (1) to (4) above or the pretreated catalyst obtained by the pretreatment method for use in the preparation of cumene from benzyl alcohol by hydrogenolysis, in particular for use in the preparation of cumene from benzyl alcohol material containing acetophenone by hydrogenolysis.

[0019] The fourth aspect of the present application provides a method for preparing cumene, which is embodied as follows:

[0020] (7) A method for preparing cumene, comprising:

[0021] 1) pretreating a catalyst for hydrogenolysis of benzyl alcohol by steam in a hydrogen atmosphere to obtain a pretreated catalyst;

[0022] 2) reacting benzyl alcohol material with hydrogen in the presence of the pretreated catalyst to obtain cumene.

[0023] (8) The method according to (7) above, wherein the catalyst for hydrogenolysis of benzyl alcohol comprises a carrier and an active component supported on the carrier.

[0024] Preferably, the carrier is selected from at least one of alumina, silica and activated carbon; and / or the active component is selected from at least one of palladium, platinum, copper and nickel.

[0025] More preferably, in the catalyst for hydrogenolysis of benzyl alcohol, the content of the active component is 0.01 to 70 wt%, preferably 0.05 to 60 wt%.

[0026] (9) The method according to (7) above, wherein:

[0027] the temperature of the steam is 150 to 500°C, preferably 180 to 400°C; and / or

[0028] the mass space velocity of the steam is 2 to 20, preferably 5 to 15.

[0029] (10) The method according to (7) above, wherein the benzyl alcohol material contains acetophenone, preferably the content of acetophenone in the benzyl alcohol material is 0.01 to 5 wt%, preferably 0.1 to 1.5 wt%.

[0030] Preferably, the benzyl alcohol material contains benzyl alcohol, acetophenone and cumene, wherein the content of benzyl alcohol in the benzyl alcohol material is 20 to 80 wt%, preferably 40 to 60 wt%, the content of acetophenone is 0.01 to 5 wt%, preferably 0.1 to 1.5 wt%, and the content of cumene is 20 to 80 wt%, preferably 40 to 60 wt%.

[0031] (11) The method according to any one of (7) to (10) above, wherein,

[0032] In step 2), the temperature of the reaction is 120-240°C, preferably 150-200°C; and / or,

[0033] In step 2), the pressure of the reaction is 0.4-4.0 MPa, preferably 1.0-3.0 MPa; and / or,

[0034] In step 2), the benzyl alcohol material volume space velocity is 0.1-20 h -1 , preferably 0.5-10 h -1 ; and / or,

[0035] In step 2), the molar ratio of hydrogen to α,α-dimethylbenzyl alcohol is (1-20):1, preferably (1-10):1.

[0036] (12) The preparation method according to the above (11), wherein the benzyl alcohol material is derived from a process for producing propylene oxide, preferably the process for producing propylene oxide comprises an oxidation step and an epoxidation step.

[0037] The fifth aspect of the present application provides:

[0038] (13) Cumene obtained by the preparation method according to any one of the above (7)-(12).

[0039] Compared with the prior art, the present application has the following beneficial effects:

[0040] (1) After the pretreatment of the benzyl alcohol hydrogenolysis catalyst according to the present application, the conversion of acetophenone in the material can be effectively inhibited, and the hydrogenolysis reaction conversion rate and selectivity are improved;

[0041] (2) Acetophenone is a high-value by-product of the hydrogenolysis unit, and the inhibition of the acetophenone hydrogenation reaction effectively improves the economic efficiency of the device. DETAILED DESCRIPTION

[0042] The present application will be specifically described below in combination with specific examples. It is necessary to point out here that the following examples are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Some non-essential improvements and adjustments of the present application made by those skilled in the art according to the content of the present application still fall within the protection scope of the present application.

[0043] In addition, it should be noted that each specific technical feature described in the following specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0044] Besides, the various embodiments of the present application can be combined arbitrarily, as long as the idea of the present application is not deviated, and the technical solutions formed by the combination belong to the original disclosure of the present specification and fall within the protection scope of the present application.

[0045] One of the objects of the present application is to provide a pretreatment method of a benzyl alcohol hydrogenolysis catalyst, comprising: pretreating the benzyl alcohol hydrogenolysis catalyst with steam under a hydrogen atmosphere to obtain a pretreated catalyst.

[0046] Among them, the high-temperature steam treatment of the catalyst can effectively improve the conversion rate and selectivity of the hydrogenolysis reaction. The reason may be that the high-temperature steam treatment makes the metal crystal grains on the hydrogenolysis catalyst rearrange, form a more uniform size distribution, and the size particles are more suitable for hydrogenolysis reaction, effectively inhibiting the conversion of acetophenone in the material, thereby improving the selectivity of the reaction. As a high-value by-product of hydrogenolysis unit, the inhibition of acetophenone hydrogenation reaction effectively improves the economic efficiency of the device.

[0047] In a preferred embodiment, the benzyl alcohol hydrogenolysis catalyst comprises a carrier and an active component supported on the carrier.

[0048] In a further preferred embodiment, the carrier is selected from at least one of alumina, silica, and activated carbon; and / or, the active component is selected from at least one of palladium, platinum, copper, and nickel.

[0049] In a still further preferred embodiment, in the benzyl alcohol hydrogenolysis catalyst, the content of the active component is 0.01-70wt%, preferably 0.05-60wt%.

[0050] Preferably, when the active component is selected from noble metals (such as palladium and / or platinum), its content is 0.01-5wt% (such as 0.05wt%, 0.1wt%, 0.2wt%, 0.4wt%, 0.6wt%, 0.8wt% or 1wt%), preferably 0.05-1wt%; and / or, when the active component is selected from non-noble metals (such as copper and / or nickel), its content is 20-70wt% (such as 20wt%, 30wt%, 40wt%, 50wt%, 60wt% or 70wt%), preferably 30-60wt%.

[0051] For example, the benzyl alcohol hydrogenolysis catalyst is selected from at least one of the commonly used palladium-based catalysts, platinum-based catalysts, copper-based catalysts, and nickel-based catalysts in the art, preferably a palladium-based catalyst.

[0052] In a preferred embodiment, the temperature of the steam is 150-500℃, preferably 180-400℃, more preferably 180-280℃.

[0053] For example, the temperature of the water vapor is 150°C, 180°C, 200°C, 220°C, 250°C, 280°C, 300°C, 350°C, 400°C, 450°C or 500°C.

[0054] In a preferred embodiment, the mass space velocity of the water vapor is 2-20, preferably 5-15.

[0055] For example, the space velocity of the water vapor is 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18 or 20.

[0056] The second object of the present application is to provide a pretreated catalyst obtained by the pretreatment method according to the first object of the present application.

[0057] The third object of the present application is to provide the use of the pretreatment method according to the first object of the present application or the pretreated catalyst obtained by the pretreatment method in the preparation of cumene by hydrogenolysis of benzyl alcohol, especially in the preparation of cumene by hydrogenolysis of benzyl alcohol containing acetophenone.

[0058] The fourth object of the present application is to provide a method for preparing cumene, comprising:

[0059] (1) pretreating a catalyst for hydrogenolysis of benzyl alcohol by water vapor under a hydrogen atmosphere to obtain a pretreated catalyst.

[0060] (2) reacting a benzyl alcohol material with hydrogen in the presence of the pretreated catalyst to obtain cumene.

[0061] In a preferred embodiment, the catalyst for hydrogenolysis of benzyl alcohol comprises a carrier and an active component supported on the carrier.

[0062] In a further preferred embodiment, the carrier is selected from at least one of alumina, silica, activated carbon; and / or, the active component is selected from at least one of palladium, copper, platinum, copper, nickel.

[0063] For example, the catalyst for hydrogenolysis of benzyl alcohol is selected from at least one of the commonly used palladium-based catalyst, platinum-based catalyst, copper-based catalyst, nickel-based catalyst in the art, preferably a palladium-based catalyst.

[0064] In a preferred embodiment, the temperature of the water vapor is 150-500°C, preferably 180-400°C, more preferably 180-280°C.

[0065] For example, the temperature of the water vapor is 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C or 500°C.

[0066] In a preferred embodiment, the mass space velocity of the water vapour is in the range of 2 to 20, preferably in the range of 5 to 15.

[0067] For example, the space velocity of the water vapour is 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18 or 20.

[0068] In a preferred embodiment, the benzyl alcohol feedstock comprises acetophenone.

[0069] In a further preferred embodiment, the benzyl alcohol feedstock comprises acetophenone in an amount in the range of 0.01 to 5 wt%, preferably in the range of 0.1 to 1.5 wt%.

[0070] For example, the benzyl alcohol feedstock comprises acetophenone in an amount of 0.01 wt%, 0.05 wt%, 0.5 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, or 5 wt%.

[0071] In a further preferred embodiment, the benzyl alcohol feedstock comprises benzyl alcohol, acetophenone and cumene, wherein the benzyl alcohol feedstock comprises benzyl alcohol in an amount in the range of 20 to 80 wt%, preferably in the range of 40 to 60 wt%, acetophenone in an amount in the range of 0.01 to 5 wt%, preferably in the range of 0.1 to 1.5 wt%, and cumene in an amount in the range of 20 to 80 wt%, preferably in the range of 40 to 60 wt%.

[0072] For example, the benzyl alcohol feedstock comprises benzyl alcohol in an amount of 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt% or 80 wt%, acetophenone in an amount of 0.01 wt%, 0.05 wt%, 0.5 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, or 5 wt%, and cumene in an amount of 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt% or 80 wt%.

[0073] In a preferred embodiment, the benzyl alcohol feedstock is derived from a process for producing propene oxide, in particular a CHP process for producing propene oxide.

[0074] In a further preferred embodiment, the process for producing propene oxide comprises an oxidation step, an epoxidation step.

[0075] In a further preferred embodiment, the process for producing propene oxide comprises:

[0076] the oxidation step: oxidation of cumene to cumene hydroperoxide;

[0077] Epoxidation step: reaction of cumene hydroperoxide with propene to give propene oxide and the benzyl alcohol material.

[0078] wherein the oxidation step and the epoxidation step are carried out using conditions disclosed in the prior art.

[0079] In a preferred embodiment, in step (2) the reaction is carried out at a temperature of from 120 to 240 °C, preferably from 150 to 200 °C.

[0080] For example, in step (2) the reaction is carried out at a temperature of 120 °C, 150 °C, 180 °C, 200 °C, 220 °C or 240 °C.

[0081] In a preferred embodiment, in step (2) the reaction is carried out at a pressure of from 0.4 to 4.0 MPa, preferably from 1.0 to 3.0 MPa.

[0082] For example, in step (2) the reaction is carried out at a pressure of 0.4 MPa, 0.8 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa or 4.0 MPa.

[0083] In a preferred embodiment, in step (2) the benzyl alcohol material is carried out at a volume hourly space velocity of from 0.1 to 20 h -1 , preferably from 0.5 to 10 h -1 .

[0084] For example, in step (2) the benzyl alcohol material is carried out at a volume hourly space velocity of 0.1 h -1 , 0.5 h -1 , 1 h -1 , 2 h -1 , 3 h -1 , 4 h -1 , 5 h -1 , 6 h -1 , 7 h -1 , 8 h -1 , 9 h -1 , 10 h -1 , 12 h -1 , 14 h -1 , 16 h -1 , 18 h -1 or 20 h -1 .

[0085] In a preferred embodiment, in step (2) the molar ratio of hydrogen to a,a-dimethylbenzyl alcohol is from (1 to 20) : 1, preferably from (1 to 10) : 1.

[0086] For example, in step (2), the molar ratio of hydrogen and α,α-dimethylbenzyl alcohol is 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 12:1, 14:1, 16:1, 18:1 or 20:1.

[0087] In the present application, the benzyl alcohol refers to α,α-dimethylbenzyl alcohol.

[0088] The fifth object of the present application is to provide cumene obtained by the preparation method according to the fourth object of the present application.

[0089] The endpoints of the ranges and any values disclosed in the present application are not limited to the precise values stated. The ranges and values are meant to serve as a guideline to the scope of the application. The endpoints of the ranges and values are not to be understood as being limited to the precise values. The ranges and values are to be understood to encompass values approximately around the end point of the range or value. For numeric value ranges, the end point values of each range, the end point values of each range and individual point values, and individual point values can be combined with each other to form one or more new numeric value ranges, which should be considered as being specifically disclosed herein. In the following, each technical solution can be combined with each other in principle to form a new technical solution, which should also be considered as being specifically disclosed herein.

[0090]

Examples and Comparative Examples

[0091] The raw materials used in the examples and comparative examples are, if not particularly limited, publicly known in the art, for example, can be directly purchased or prepared according to the publicly known preparation methods.

[0092] In the following examples and comparative examples, the palladium-based benzyl alcohol hydrogenolysis catalyst is Pd / Al2O3, and the specific preparation method is shown in patent CN112569972A, Comparative Example 1.

[0093] In the following examples, the nickel-based benzyl alcohol hydrogenolysis catalyst is Ni / Al2O3, and the specific preparation method is shown in patent CN103418386A, Example 1.

[0094] In the following examples, the platinum-based benzyl alcohol hydrogenolysis catalyst is Pd / Al2O3, and the specific preparation method is shown in patent CN1044571C, Example 1.

[0095]

Example 1

[0096] The benzyl alcohol hydrogenolysis catalyst is pretreated by water vapor to obtain a pretreated catalyst. The temperature of the water vapor is 150°C, and the water vapor mass space velocity is 10.

[0097]

Example 2

[0098] The benzyl alcohol hydrogenolysis catalyst is pretreated with steam to obtain a pretreated catalyst. The temperature of the steam is 200°C, and the steam mass space velocity is 10.

[0099] [Example 3] Pretreatment of a palladium-based benzyl alcohol hydrogenolysis catalyst

[0100] The benzyl alcohol hydrogenolysis catalyst is pretreated with steam to obtain a pretreated catalyst. The temperature of the steam is 300°C, and the steam mass space velocity is 10.

[0101] [Example 4] Pretreatment of a palladium-based benzyl alcohol hydrogenolysis catalyst

[0102] The benzyl alcohol hydrogenolysis catalyst is pretreated with steam to obtain a pretreated catalyst. The temperature of the steam is 200°C, and the steam mass space velocity is 20.

[0103] [Example 5] Isopropylbenzene preparation

[0104] In a 50 mL autoclave, a benzyl alcohol feedstock containing 55 wt% α,α-dimethylbenzyl alcohol, 1.5 wt% acetophenone and 43 wt% isopropylbenzene (remainder 0.5 wt%) is reacted with hydrogen in the presence of the pretreated catalyst obtained in Example 1, the molar ratio of hydrogen to α,α-dimethylbenzyl alcohol being 8, at a reaction temperature of 150°C, a pressure of 2.0 MPa and a feedstock volume space velocity of 2.0 h -1 , the conversion of α,α-dimethylbenzyl alcohol being 98% and the conversion of acetophenone being 66%.

[0105] [Example 6] Isopropylbenzene preparation

[0106] In a 50 mL autoclave, a benzyl alcohol feedstock containing 55 wt% α,α-dimethylbenzyl alcohol, 1.5 wt% acetophenone and 43 wt% isopropylbenzene (remainder 0.5 wt%) is reacted with hydrogen in the presence of the pretreated catalyst obtained in Example 2, the molar ratio of hydrogen to α,α-dimethylbenzyl alcohol being 8, at a reaction temperature of 150°C, a pressure of 2.0 MPa and a feedstock volume space velocity of 2.0 h -1 , the conversion of α,α-dimethylbenzyl alcohol being 99% and the conversion of acetophenone being 10%.

[0107] [Example 7] Isopropylbenzene preparation

[0108] In a 50 mL autoclave, a benzyl alcohol feedstock containing 55 wt% α,α-dimethylbenzyl alcohol, 1.5 wt% acetophenone and 43 wt% isopropylbenzene (remainder 0.5 wt%) is reacted with hydrogen in the presence of the pretreated catalyst obtained in Example 3, the molar ratio of hydrogen to α,α-dimethylbenzyl alcohol being 8, at a reaction temperature of 150°C, a pressure of 2.0 MPa and a feedstock volume space velocity of 2.0 h -1, the conversion of α,α-dimethylbenzyl alcohol was 98.5%, and the conversion of acetophenone was 31%.

[0109] Example 8: Preparation of cumene

[0110] In a 50 mL autoclave, a benzyl alcohol feedstock containing 55 wt% of α,α-dimethylbenzyl alcohol, 1.5 wt% of acetophenone and 43 wt% of cumene (the rest 0.5 wt%) was reacted with hydrogen in the presence of the pretreated catalyst obtained in Example 4, the molar ratio of hydrogen to α,α-dimethylbenzyl alcohol was 8, the reaction temperature was 150°C, the pressure was 2.0 MPa, and the raw material volume space velocity was 2.0 h -1 , the conversion of α,α-dimethylbenzyl alcohol was 97%, and the conversion of acetophenone was 19%.

[0111] Example 9: Pretreatment of platinum-based benzyl alcohol hydrogenolysis catalyst

[0112] The platinum-based benzyl alcohol hydrogenolysis catalyst was pretreated by using steam to obtain a pretreated catalyst. The temperature of the steam was 250°C, and the steam mass space velocity was 8.

[0113] Example 10: Pretreatment of nickel-based benzyl alcohol hydrogenolysis catalyst

[0114] The copper-based benzyl alcohol hydrogenolysis catalyst was pretreated by using steam to obtain a pretreated catalyst. The temperature of the steam was 180°C, and the steam mass space velocity was 12.

[0115] Example 11: Preparation of cumene

[0116] In a 50 mL autoclave, a benzyl alcohol feedstock containing 55 wt% of α,α-dimethylbenzyl alcohol, 1.5 wt% of acetophenone and 43 wt% of cumene (the rest 0.5 wt%) was reacted with hydrogen in the presence of the pretreated catalyst obtained in Example 9, the molar ratio of hydrogen to α,α-dimethylbenzyl alcohol was 8, the reaction temperature was 200°C, the pressure was 2.0 MPa, and the raw material volume space velocity was 2.0 h -1 , the conversion of α,α-dimethylbenzyl alcohol was 90%, and the conversion of acetophenone was 70%.

[0117] Example 12: Preparation of cumene

[0118] In a 50 mL autoclave, a benzyl alcohol feedstock containing 55 wt% of α,α-dimethylbenzyl alcohol, 1.5 wt% of acetophenone and 43 wt% of cumene (the rest 0.5 wt%) was reacted with hydrogen in the presence of the pretreated catalyst obtained in Example 10, the molar ratio of hydrogen to α,α-dimethylbenzyl alcohol was 8, the reaction temperature was 130°C, the pressure was 2.0 MPa, and the raw material volume space velocity was 2.0 h -1 , the conversion of α,α-dimethylbenzyl alcohol was 97%, and the conversion of acetophenone was 55%.

[0119] Comparative Example 1

[0120] The procedure of Example 5 was repeated except that the catalyst used was a benzyl alcohol hydrogenolysis catalyst which had not been pretreated and the other reaction conditions were unchanged.

[0121] As a result, the conversion of α,α-dimethylbenzyl alcohol was greater than 94.0% and the conversion of acetophenone was 85%.

[0122] The above detailed description of the application has been given in conjunction with specific embodiments and illustrative examples, but these are not to be understood as limiting the application. It is understood by those skilled in the art that various equivalent substitutions, modifications or improvements can be made to the technical solutions and embodiments of the application without departing from the spirit and scope of the application, and these all fall within the scope of the application. The scope of protection of the application is defined by the appended claims.

Claims

1. The application of a pretreatment method for a catalyst used in the hydrogenolysis of benzyl alcohol in the preparation of cumene by the hydrogenolysis of benzyl alcohol, wherein the benzyl alcohol refers to α,α-dimethylbenzyl alcohol, and the pretreatment method includes: The catalyst for benzyl alcohol hydrogenolysis is pretreated with steam under a hydrogen atmosphere to obtain a pretreated catalyst. The temperature of the steam is 150-500°C and the mass hourly space velocity of the steam is 2-20. The catalyst for benzyl alcohol hydrogenolysis includes a support and an active component supported on the support. The support is selected from at least one of alumina, silicon oxide, and activated carbon, and the active component is selected from at least one of palladium, platinum, copper, and nickel.

2. The application according to claim 1, characterized in that, In the benzyl alcohol hydrogenolysis catalyst, the content of the active component is 0.01~70wt%.

3. The application according to claim 1, characterized in that, In the benzyl alcohol hydrogenolysis catalyst, the content of the active component is 0.05~60wt%.

4. The application according to claim 1, characterized in that, The temperature of the water vapor is 180-400℃.

5. The application according to any one of claims 1 to 4, characterized in that, The mass hourly space velocity of the water vapor is 5 to 15.

6. The application according to claim 5, characterized in that, Application in the hydrogenolysis of benzyl alcohol containing acetophenone to prepare cumene.

7. A method for preparing cumene, comprising: (1) In a hydrogen atmosphere, the catalyst for the hydrogenolysis of benzyl alcohol is pretreated with water vapor to obtain a pretreated catalyst. The benzyl alcohol refers to α,α-dimethylbenzyl alcohol. The temperature of the water vapor is 150-500℃ and the mass hourly space velocity of the water vapor is 2-20. (2) In the presence of the pretreatment catalyst, benzyl alcohol reacts with hydrogen to obtain cumene; The catalyst for benzyl alcohol hydrogenolysis includes a support and an active component supported on the support. The support is selected from at least one of alumina, silica, and activated carbon, and the active component is selected from at least one of palladium, platinum, copper, and nickel.

8. The preparation method according to claim 7, characterized in that, In the benzyl alcohol hydrogenolysis catalyst, the content of the active component is 0.01~70wt%.

9. The preparation method according to claim 7, characterized in that, In the benzyl alcohol hydrogenolysis catalyst, the content of the active component is 0.05~60wt%.

10. The preparation method according to claim 7, characterized in that, The temperature of the water vapor is 180-400℃; and / or, The mass hourly space velocity of the water vapor is 5 to 15.

11. The preparation method according to claim 7, characterized in that, The benzyl alcohol material contains acetophenone.

12. The preparation method according to claim 11, characterized in that, In the benzyl alcohol material, the content of acetophenone is 0.01~5wt%.

13. The preparation method according to claim 11, characterized in that, In the benzyl alcohol material, the content of acetophenone is 0.1~1.5 wt%.

14. The preparation method according to claim 7, characterized in that, The benzyl alcohol material contains benzyl alcohol, acetophenone and cumene, wherein the benzyl alcohol content is 20-80 wt%, the acetophenone content is 0.01-5 wt%, and the cumene content is 20-80 wt%.

15. The preparation method according to claim 7, characterized in that, The benzyl alcohol material contains benzyl alcohol, acetophenone and cumene, wherein the benzyl alcohol content is 40-60 wt%, the acetophenone content is 0.1-1.5 wt%, and the cumene content is 40-60 wt%.

16. The preparation method according to any one of claims 7 to 15, characterized in that, In step (2), the reaction temperature is 120~240℃; and / or, In step (2), the reaction pressure is 0.4~4.0 MPa; and / or, In step (2), the volume hourly space velocity (VHSV) of the benzyl alcohol material is 0.1~20 h⁻¹. -1 ; and / or, In step (2), the molar ratio of hydrogen to benzyl alcohol is (1~20):

1.

17. The preparation method according to claim 16, characterized in that, In step (2), the reaction temperature is 150~200℃; and / or, In step (2), the reaction pressure is 1.0~3.0 MPa; and / or, In step (2), the volume hourly space velocity (VHSV) of the benzyl alcohol material is 0.5~10 h⁻¹. -1 ; and / or, In step (2), the molar ratio of hydrogen to benzyl alcohol is (1~10):

1.

18. The preparation method according to claim 16, characterized in that, The benzyl alcohol material is derived from the process of producing propylene oxide.

19. The preparation method according to claim 18, characterized in that, The process for producing propylene oxide includes an oxidation step and an epoxidation step.