CN108689790B

CN108689790B - Method for preparing cyclopentene by selective hydrogenation of cyclopentadiene

Info

Publication number: CN108689790B
Application number: CN201710224457.4A
Authority: CN
Inventors: 祁彦平; 柴忠义; 任玉梅; 宁淑娟; 熊凯; 张富春
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2017-04-07
Filing date: 2017-04-07
Publication date: 2021-07-30
Anticipated expiration: 2037-04-07
Also published as: CN108689790A

Abstract

The invention provides a method for preparing cyclopentene by selective hydrogenation of cyclopentadiene, which comprises the following steps: mixing cyclopentadiene, hydrogen, a liquid phase diluent and a regulator, and then carrying out selective hydrogenation reaction in the presence of a nickel-copper-based catalyst to prepare cyclopentene, wherein the regulator is carbon monoxide. The catalyst is used for a cyclopentadiene selective hydrogenation process, overcomes the defects of difficult timely removal of reaction heat, poor reaction selectivity, short service life of the catalyst and the like in the prior art under the combined action of the catalyst, a regulator and an ester liquid phase diluent, can be used for preparing cyclopentene with high selectivity, has high catalyst activity and stability, greatly prolongs the service life of the catalyst, and can resist poisoning of impurities such as sulfur, arsenic and the like to the catalyst.

Description

Method for preparing cyclopentene by selective hydrogenation of cyclopentadiene

Technical Field

The invention relates to the field of cyclopentene preparation, and in particular relates to a method for preparing cyclopentene through selective hydrogenation of cyclopentadiene.

Background

Cyclopentene is an important organic chemical raw material, and can be widely applied to the fields of pharmaceutical industry, organic synthesis, synthetic rubber and fine chemical industry. Because cyclopentene has active double bonds, high-value-added medical intermediates such as cyclopentanol, cyclopentanone, bromocyclopentane and the like can be prepared from the cyclopentene as a raw material; in addition, cyclopentene is an important raw material for preparing polycyclopentene rubber.

In the prior art, cyclopentene can be obtained by various methods, however, the production method by selective hydrogenation of cyclopentadiene has the most industrial prospect. However, in the selective hydrogenation process, cyclopentadiene is very easy to be completely hydrogenated to generate cyclopentane, and because the boiling points of cyclopentane and cyclopentene are relatively close and are difficult to separate, whether the high-selectivity generation of cyclopentene is a key index for evaluating the quality of the catalyst and the process conditions is determined. In addition, the existing preparation method of cyclopentadiene also has the defects of difficult separation of catalyst and cyclopentene, difficult timely removal of reaction heat, low yield of reaction products, poor selectivity and the like. Even with the use of expensive noble metals, the above-mentioned disadvantages are not significantly improved.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a method for preparing cyclopentene by selective hydrogenation of cyclopentadiene, which can remarkably improve the activity, selectivity and stability of a catalyst, and particularly greatly increase the service cycle and service life of the catalyst by using a specific catalyst, a liquid-phase diluent and a regulator in the selective hydrogenation reaction of cyclopentadiene and hydrogen.

Accordingly, it is an object of the present invention to provide a process for the preparation of cyclopentene by the selective hydrogenation of cyclopentadiene comprising: mixing cyclopentadiene, hydrogen, a liquid-phase diluent and a regulator, and then carrying out selective hydrogenation reaction in the presence of a nickel-copper-based catalyst to prepare cyclopentene; wherein the regulator is carbon monoxide (CO).

The inventor of the application has conducted extensive and intensive research on a process for preparing cyclopentene by selective hydrogenation of cyclopentadiene, and as a result, the inventor has found that when CO is matched with a nickel-copper-based catalyst and a regulator, the activity of the catalyst can be reasonably regulated, so that the phenomenon that a large amount of reaction heat is rapidly released in a reaction region can be avoided, and the defect that the reaction heat is difficult to remove in time is caused, and further the selectivity of a reaction product and the stability of the catalyst can be greatly improved. The present invention has been completed based on the above findings.

In a preferred embodiment of the invention, the nickel-copper based catalyst comprises nickel and copper supported on a carrier, optionally with a co-active metal.

According to the invention, the co-active metal is selected from one or more of Li, Na, K, Cs, Ca, Mg, Ba, La, Ce, Nd and Zn, preferably from one or more of K, Mg, Ba and Cs. According to the invention, the support is a titanium oxide-alumina composite. Preferably, the surface area of the titanium oxide-alumina composite (before loading the active component) is 120-150m²The pore volume is 0.5-1.0ml/g, and the most probable pore diameter is 10-14 nm. Further, the shape of the titanium oxide-alumina composite is not particularly limited, and may be, for example, a spherical shape, a clover shape, a columnar shape, a bar shape, a zigzag shape, and preferably a clover shape.

According to the present invention, the titanium oxide-alumina composite material may be prepared by a method conventional in the art, for example, may be prepared according to a method disclosed in chinese patent CN 1184289C.

According to the present invention, the titania-alumina composite support has a titania content of 3 to 25wt%, preferably 5 to 20wt%, more preferably 6 to 16 wt%, based on the weight of alumina.

To obtain the catalyst used in the present invention, nickel and copper as catalytically active metal components, and optionally a co-active metal, may be dispersed on the titania-alumina composite support, in one or more batches, by methods well known in the art, such as impregnation, co-precipitation, co-gelation, or ion exchange, usually by impregnation followed by calcination to obtain a catalyst precursor.

Further, the supported catalyst precursor may be reductively activated with hydrogen, and in order to realize the reductive activation process, it is usually maintained at a temperature of 100 ℃ and 180 ℃, a hydrogen pressure of 1.5 to 3.5MPa, and a hydrogen flow rate per unit volume of the catalyst of 8 to 16L/min for 3 to 8 hours.

In addition, the catalyst precursor can be optionally not subjected to special hydrogen reduction activation, and when the catalyst precursor is used for catalyzing the selective hydrogenation reaction of cyclopentadiene, active components of the catalyst can be gradually reduced from an oxidation state to a metal elementary substance form in the catalytic reaction process, so that the purpose of activating the catalyst can be achieved.

In a more preferred embodiment of the invention, the nickel content is from 1 to 30 wt.%, preferably from 3 to 25 wt.%, more preferably from 4 to 20 wt.%, based on 100% by weight of the total catalyst; the content of copper is 0.1-8 wt%; the content of the co-active metal is 0 to 3wt%, preferably 0 to 2.0wt%, more preferably 0.01 to 1.0 wt%.

In another preferred embodiment of the present invention, the liquid phase diluent is an ester compound, preferably one or more of methyl formate, butyl formate, ethyl acetate, butyl acetate, isopropyl acetate, sec-butyl acetate, amyl acetate, isoamyl acetate, methyl amyl acetate, n-butyl propionate, isopropyl acetoacetate, and ethyl acetoacetate, more preferably one or more of ethyl acetate, amyl acetate, and ethyl acetoacetate.

In another preferred embodiment of the present invention, the molar ratio of carbon monoxide to hydrogen is 1 (20-100), preferably 1 (30-80), more preferably 1 (40-70).

In another preferred embodiment of the present invention, the molar ratio of hydrogen to cyclopentadiene is (0.5-8):1, preferably (1-5):1, more preferably (1.2-3.0): 1.

In another preferred embodiment of the present invention, the weight ratio of cyclopentadiene to liquid-phase diluent is 1 (5-10); the catalyst load is 3-20h^-1Preferably 5-15h^-1。

In another preferred embodiment of the present invention, the temperature of the selective hydrogenation reaction is in the range of 0 to 150 ℃, preferably 15 to 100 ℃, more preferably 40 to 100 ℃; the reaction pressure is 0.1-5.0MPa, preferably 0.5-3.0 MPa.

In a specific embodiment of the invention, amyl acetate is taken as a liquid-phase diluent, CO is taken as a regulator, amyl acetate, cyclopentadiene, hydrogen and CO are mixed in an oil-gas mixer at the inlet of a reactor and then enter the reactor filled with a catalyst bed layer of a nickel-copper-based catalyst, cyclopentadiene is subjected to selective hydrogenation reaction under the reaction conditions that the hydrogenation temperature is 40-100 ℃ and the hydrogen pressure is 0.5-3.0MPa to generate a reaction product containing cyclopentene, and the reaction product is discharged from the discharge hole of the reactor. Taking materials and sending the materials to a gas chromatograph for composition analysis, and sending the other materials to a separation section.

The selective hydrogenation process for cyclopentadiene overcomes the defects of difficult timely removal of reaction heat, poor reaction selectivity, short service life of the catalyst and the like in the prior art under the combined action of the catalyst, the regulator CO and the ester liquid phase diluent, can prepare cyclopentene with high selectivity, and has the advantages of high catalyst activity, high stability, greatly prolonged catalyst service life and resistance to poisoning of impurities such as sulfur, arsenic and the like on the catalyst.

Drawings

FIG. 1 is a process flow diagram of example 1.

Detailed Description

The present invention is further described in the following examples, which should be construed as merely illustrative and not a limitation of the spirit and scope of the present invention.

The reactor is a fixed bed reactor, and the positions of the material inlet and outlet are not limited to those shown in the figure. The catalyst loading volumes were all 200ml, the cyclopentadiene feed used was obtained commercially, and hydrogen was obtained commercially for pipeline hydrogen, CO. In the following examples, catalyst loading, conversion and selectivity are defined as:

the catalyst is defined as failed when the cyclopentadiene conversion is less than 85% and the cyclopentene selectivity is less than 90%. Catalyst life refers to the time that the catalyst remains in an unexpired state.

Example 1

The catalyst takes a titanium oxide-aluminum oxide composite material as a carrier and nickel-copper as an active component, and based on the total weight of the catalyst, the content of nickel is 15 wt%, the content of copper is 3.8 wt%, and the content of the auxiliary active metal K is 0.5 wt%. Amyl acetate, cyclopentadiene, hydrogen and CO are mixed in an oil-gas mixer at the inlet of a reactor and then enter the reactor filled with a catalyst bed layer of a nickel-copper-based catalyst, under the reaction conditions shown in Table 1, cyclopentadiene is subjected to selective hydrogenation to generate a reaction product containing cyclopentene, and the reaction product is discharged from the discharge hole of the reactor. Taking materials and sending the materials to a gas chromatograph for composition analysis, and sending the other materials to a separation section.

Example 2

The catalyst takes titanium oxide-alumina composite material as a carrier and nickel-copper as an active component, and based on the total weight of the catalyst, the content of nickel is 10 wt%, and the content of copper is 8 wt%. The selective hydrogenation was carried out as in example 1, and the specific process conditions and reaction results are shown in Table 1.

Example 3

The catalyst takes titanium oxide-alumina composite material as a carrier and nickel-copper as an active component, and based on the total weight of the catalyst, the content of nickel is 15 wt%, the content of copper is 0.2 wt%, and the content of coactive metal Mg is 0.5 wt%. The selective hydrogenation was carried out as in example 1, and the specific process conditions and reaction results are shown in Table 1.

Example 4

The catalyst takes a titanium oxide-aluminum oxide composite material as a carrier and nickel-copper as an active component, and based on the total weight of the catalyst, the content of nickel is 15 wt%, the content of copper is 5wt%, and the content of a co-active metal Ba is 0.6 wt%. The selective hydrogenation was carried out as in example 1, and the specific process conditions and reaction results are shown in Table 1.

Example 5

The catalyst takes a titanium oxide-aluminum oxide composite material as a carrier and nickel-copper as an active component, and based on the total weight of the catalyst, the content of nickel is 15 wt%, the content of copper is 3.8 wt%, and the content of co-active metal Cs is 0.5 wt%. The selective hydrogenation was carried out as in example 1, and the specific process conditions and reaction results are shown in Table 1.

Example 6

The selective hydrogenation reaction was carried out in the same manner as in example 1 using the catalyst provided in example 1, and the specific process conditions and reaction results are shown in table 1.

Example 7

The catalyst takes titanium oxide-alumina composite material as a carrier and nickel-copper as an active component, and based on the total weight of the catalyst, the content of nickel is 20wt%, the content of copper is 3wt%, and the content of the auxiliary active metal K is 0.3 wt%. The selective hydrogenation was carried out as in example 1, and the specific process conditions and reaction results are shown in Table 1.

Example 8

The catalyst uses titanium oxide-alumina composite material as carrier, nickel-copper as active component, based on the total weight of the catalyst, nickel content is 4 wt%, copper content is 8wt%, and auxiliary active metal K content is 0.5 wt%, the selective hydrogenation reaction is carried out according to the method of example 1, and the specific process conditions and reaction results are shown in Table 1.

Comparative example 1

The catalyst provided in example 1 was used and a selective hydrogenation reaction was carried out as in example 1, except that the liquid phase diluent was n-octane and no carbon monoxide modifier was used, and the specific process conditions and reaction results are shown in table 1.

Comparative example 2

The catalyst provided in example 1 was used and a selective hydrogenation reaction was carried out as in example 1, except that the molar ratio of carbon monoxide regulator to hydrogen was 1:18, and the specific process conditions and reaction results are shown in table 1.

Comparative example 3

The catalyst provided in example 1 was used and a selective hydrogenation reaction was carried out as in example 1, except that the molar ratio of carbon monoxide regulator to hydrogen was 1:110, and the specific process conditions and reaction results are shown in table 1.

Although the present invention has been described in detail, modifications within the spirit and scope of the invention will be apparent to those skilled in the art. Further, it should be understood that the various aspects recited herein, portions of different embodiments, and various features recited may be combined or interchanged either in whole or in part. In the various embodiments described above, those embodiments that refer to another embodiment may be combined with other embodiments as appropriate, as will be appreciated by those skilled in the art. Furthermore, those skilled in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention.

Claims

1. A process for the preparation of cyclopentene by the selective hydrogenation of cyclopentadiene comprising: mixing cyclopentadiene, hydrogen, a liquid-phase diluent and a regulator, and then carrying out selective hydrogenation reaction in the presence of a nickel-copper-based catalyst to prepare cyclopentene; wherein the regulator is carbon monoxide; the liquid phase diluent is an ester compound, and the ester compound is one or more of methyl formate, butyl formate, ethyl acetate, butyl acetate, isopropyl acetate, sec-butyl acetate, amyl acetate, isoamyl acetate, methyl amyl acetate, n-butyl propionate, isopropyl acetoacetate and ethyl acetoacetate;

the molar ratio of the carbon monoxide to the hydrogen is 1 (30-80);

the content of nickel is 1-30wt% based on the total weight of the nickel-copper-based catalyst being 100%; the copper content is 0.1-8 wt%.

2. The method of claim 1, wherein the molar ratio of carbon monoxide to hydrogen is 1 (40-70).

3. A process according to claim 1 or 2, wherein the nickel-copper based catalyst comprises nickel and copper on a support, optionally with a promoter metal.

4. A method according to claim 3, wherein the co-active metal is selected from one or more of Li, Na, K, Cs, Ca, Mg, Ba, La, Ce, Nd and Zn.

5. The method of claim 4, wherein the co-active metal is one or more of K, Mg, Ba, and Cs.

6. The process of claim 3, wherein the amount of the co-active metal is 0 to 3wt% based on 100 wt% of the total weight of the nickel-copper based catalyst.

7. The method of claim 6, wherein the amount of said co-active metal is 0-2.0 wt%.

8. The method of claim 6, wherein the amount of said co-active metal is 0.01 to 1.0 wt%.

9. The process according to claim 1 or 2, wherein the nickel is present in an amount of 3 to 25 wt.%, based on 100% by weight of the total nickel-copper based catalyst.

10. The process according to claim 1 or 2, wherein the nickel is present in an amount of 4 to 20 wt.%, based on 100% by weight of the total nickel-copper based catalyst.

11. The process according to claim 1 or 2, wherein the liquid phase diluent is one or more of ethyl acetate, amyl acetate and ethyl acetoacetate.

12. The process according to claim 1 or 2, characterized in that the molar ratio of hydrogen to cyclopentadiene is (0.5-8): 1.

13. The method of claim 12, wherein the molar ratio of hydrogen to cyclopentadiene is (1-5): 1.

14. The process of claim 12, wherein the molar ratio of hydrogen to cyclopentadiene is (1.2-3.0): 1.

15. The method of claim 1 or 2, wherein the weight ratio of cyclopentadiene to liquid phase diluent is 1 (5-10); the catalyst load is 3-20h^-1。

16. The method of claim 15, wherein the catalyst loading is from 5 to 15 hours^-1。

17. The process according to claim 1 or 2, characterized in that the temperature of the selective hydrogenation reaction is between 0 and 150 ℃; the reaction pressure is 0.1-5.0 MPa.

18. The process of claim 17, wherein the temperature of the selective hydrogenation reaction is in the range of 15 ℃ to 120 ℃.

19. The process of claim 17, wherein the temperature of the selective hydrogenation reaction is in the range of 40 ℃ to 100 ℃.

20. The process of claim 17, wherein the reaction pressure is from 0.5 to 3.0 MPa.