Process for the oxidation of cyclopentanone

Abstract

The application belongs to the technical field of chemical industry, and particularly relates to a method for oxidizing cyclopentanone, which comprises the following steps: contacting an oxygen-containing gas with cyclopentanone in the presence of a solvent and a catalyst; and the catalyst contains a zirconium salt. By using the catalyst containing the zirconium salt, the conversion rate of the raw material cyclopentanone and the selectivity of the product glutaric acid in the method for preparing glutaric acid by oxidizing cyclopentanone are improved, the occurrence of a side reaction is reduced, the burden of separating impurities in a synthetic liquid is reduced, and a good technical effect is achieved.

Description

Technical Field

[0001] This invention belongs to the field of chemical technology, specifically relating to a method for the oxidation of cyclopentanone. Background Technology

[0002] Glutaric acid is an important chemical raw material and pharmaceutical intermediate with wide applications in fine chemicals, agriculture, medicine, and construction. In the plastics industry, glutaric acid is used to produce important polymer materials such as polyvinyl chloride, polyester, polyeneamines and resins, and synthetic rubber. In the pharmaceutical industry, glutaric acid serves not only as a crucial intermediate in the synthesis of cardiovascular drugs but also, due to its excellent broad-spectrum bactericidal properties, can be used to produce various disinfectants and related medicines to kill bacteria and insects parasitizing animals and plants, and can also be used for insect repellent. Furthermore, glutaric acid has important applications in the synthesis of polyester polyols, the formulation of descaling agents, sulfur-containing flue gas scrubbers, coolants, and hardeners. Therefore, large-scale production of glutaric acid has significant social and economic value.

[0003] There are many synthetic routes for glutaric acid. For example, using a metalloporphyrin biomimetic catalyst, cyclopentane can be directly oxidized to glutaric acid; cyclopentanol can be oxidized to glutaric acid using tungstic acid and hydrogen dioxide; or glutaraldehyde can be oxidized to glutaric acid using a Pd-supported solid catalyst. Another route uses adipic acid as a starting material, heating it to decarboxylate it to cyclopentanone, and then oxidizing it to glutaric acid using sodium tungstate, sulfosalicylic acid, and hexadecyltrimethylammonium bromide as catalysts. Cyclopentene can also be used to oxidize and prepare glutaric acid.

[0004] Glutamic acid can be obtained by oxidizing cyclopentanone with oxygen or air at 100°C using cobalt acetate at a concentration of 2% in acetic acid solution. Although the conversion rate of cyclopentanone can reach more than 80%, the selectivity of glutaric acid is only about 60%, which is not economical. In addition, due to the large number of impurities and byproducts in the reaction solution, as well as the large amount of catalyst used, the separation of the main product glutaric acid is also very difficult. Summary of the Invention

[0005] The main objective of this invention is to solve the problems of low conversion rate and low selectivity in the direct oxidation of cyclopentanone to produce glutaric acid in the prior art, as well as the difficulty in purifying the synthesis solution due to the presence of many impurities. This invention provides a method that requires less catalyst, has a higher conversion rate of cyclopentanone, and a higher selectivity for glutaric acid, making it suitable for the industrial production of glutaric acid.

[0006] To achieve the above objectives, the present invention provides a method for the oxidation of cyclopentanone, the method comprising: contacting an oxygen-containing gas with cyclopentanone in the presence of a solvent and a catalyst; wherein the catalyst contains a zirconium salt.

[0007] Preferably, the molar content of zirconium salt in the catalyst is 50% or more.

[0008] Preferably, the molar ratio of the total amount of catalyst to solvent is 0.01-0.2:100.

[0009] Preferably, the catalyst is a zirconium salt or a mixture of zirconium salt and cobalt salt; more preferably, the zirconium salt is zirconium acetate and / or zirconium chloride, and the cobalt salt is cobalt acetate.

[0010] Preferably, the solvent is one or more of acetic acid, acetone, and acetonitrile.

[0011] Preferably, the catalyst is a mixture of zirconium acetate and cobalt acetate, wherein the molar ratio of cobalt acetate to zirconium acetate is 0.1-1:1.

[0012] Preferably, the oxygen content in the oxygen-containing gas is 5-18% by volume, more preferably 6-12% by volume.

[0013] Preferably, the molar flow ratio of the oxygen-containing gas to the solvent is 10-30:1.

[0014] Preferably, the molar ratio of cyclopentanone to solvent is 0.5-2:1.

[0015] Preferably, the contact temperature is 80-110°C.

[0016] Preferably, the contact pressure is 3-8 MPa.

[0017] Preferably, the contact time is 2-6 hours.

[0018] Preferably, the method includes:

[0019] I) The catalyst, cyclopentanone, and solvent are added to the oxidation reactor to form a reaction mixture;

[0020] II) Introduce oxygen-containing gas into the reactor and heat the reactor to the reaction temperature and pressure;

[0021] III) Oxygen-containing gas under working pressure is continuously fed into the reactor for contact;

[0022] IV) Stop feeding and end the reaction.

[0023] Preferably, the contact is carried out in the presence of an auxiliary agent, more preferably the auxiliary agent is a C5-C6 alcohol and / or a C6 ketone.

[0024] Preferably, the molar ratio of the additive to the solvent is 0.01-0.05:100.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] By employing a catalyst containing zirconium salt, the conversion rate of cyclopentanone and the selectivity of glutaric acid in the oxidation of cyclopentanone to glutaric acid were improved, side reactions were reduced, and the burden of separating impurities in the synthesis liquid was lessened, achieving better technical results. Detailed Implementation

[0027] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0028] The present invention provides a method for the oxidation of cyclopentanone, the method comprising: contacting an oxygen-containing gas with cyclopentanone in the presence of a solvent and a catalyst; wherein the catalyst contains a zirconium salt.

[0029] By employing a catalyst containing zirconium salt, the conversion rate of cyclopentanone and the selectivity of glutaric acid in the oxidation of cyclopentanone to glutaric acid were improved, the occurrence of side reactions was reduced, and the burden of impurities in the synthesis liquid was alleviated.

[0030] In this invention, as long as the objective of this invention can be achieved, the content of zirconium salt in the catalyst is not particularly required. According to a preferred embodiment of this invention, the molar content of zirconium salt in the catalyst is 50% or more, preferably 50-95%. By adopting the aforementioned technical solution, the conversion rate of cyclopentanone and the selectivity of the product glutaric acid can be further improved, the occurrence of side reactions can be reduced, and the burden of impurities in the synthesis liquid separation can be reduced.

[0031] In this invention, as long as the objective of the invention can be achieved, the molar ratio of the total catalyst to the solvent is not particularly required. According to a preferred embodiment of the invention, the molar ratio of the total catalyst to the solvent is 0.01-0.2:100. By adopting the aforementioned technical solution, the conversion rate of cyclopentanone and the selectivity of the product glutaric acid can be further improved, the occurrence of side reactions can be reduced, and the burden of impurities in the synthesis liquid separation can be reduced.

[0032] In order to further improve the conversion rate of cyclopentanone and the selectivity of the product glutaric acid, reduce the occurrence of side reactions, and reduce the burden of impurities in the synthesis liquid separation, according to a preferred embodiment of the present invention, the catalyst is a zirconium salt or a mixture of zirconium salt and cobalt salt.

[0033] In this invention, the zircon salt and cobalt salt can be conventional choices in the art as long as the purpose of this invention can be achieved. According to a preferred embodiment of this invention, the zircon salt is zirconium acetate and / or zirconium chloride, and the cobalt salt is cobalt acetate.

[0034] In this invention, the solvent can be any conventional choice in the art, as long as it achieves the objective of the invention. According to a preferred embodiment of the invention, the solvent is one or more of acetic acid, acetone, and acetonitrile. By adopting the aforementioned preferred method, the conversion rate of cyclopentanone and the selectivity of the product glutaric acid can be further improved, the occurrence of side reactions can be reduced, and the burden of impurities in the synthesis liquid separation can be lessened.

[0035] To further improve the conversion rate of cyclopentanone and the selectivity of the product glutaric acid, reduce the occurrence of side reactions, and alleviate the burden of impurities in the synthesis liquid, according to a preferred embodiment of the present invention, the catalyst is a mixture of zirconium acetate and cobalt acetate, wherein the molar ratio of cobalt acetate to zirconium acetate is 0.1-1:1, for example, 0.1:1, 0.2:1, 0.3:1, 0.1-0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, or 1:1.

[0036] To further improve the conversion rate of cyclopentanone and the selectivity of the product glutaric acid, reduce the occurrence of side reactions, and alleviate the burden of impurities in the synthesis liquid separation, according to a preferred embodiment of the present invention, the oxygen content in the oxygen-containing gas is 5-18% by volume, preferably 6-12% by volume.

[0037] In this invention, as long as the objective of the invention can be achieved, the molar flow ratio of the oxygen-containing gas to the solvent is not particularly required. According to a preferred embodiment of the invention, the molar flow ratio of the oxygen-containing gas to the solvent is 10-30:1. By adopting the aforementioned preferred scheme, the conversion rate of cyclopentanone and the selectivity of the product glutaric acid can be further improved, the occurrence of side reactions can be reduced, and the burden of impurities in the synthesis liquid separation can be reduced.

[0038] In this invention, the feed molar ratio of oxygen-containing gas to solvent refers to the ratio of the flow rate of oxygen-containing gas (mol / h) to the feed flow rate of the solvent solution (mol / h) (based on the amount of acetic acid in the feed solution).

[0039] In this invention, as long as the objective of this invention can be achieved, there are no special requirements for the molar ratio of cyclopentanone to solvent. According to a preferred embodiment of this invention, the molar ratio of cyclopentanone to solvent is 0.4-2:1, for example, 0.5:1, 1:1, 1.5:1, or 2:1.

[0040] In this invention, the contact conditions can be conventionally selected in the art. According to a preferred embodiment of the invention, the contact temperature is 80-110°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, or 110°C.

[0041] According to a preferred embodiment of the present invention, the contact pressure is 3-8 MPa, for example, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, or 8 MPa.

[0042] According to a preferred embodiment of the present invention, the contact time is 2-6 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, or 6 hours.

[0043] By adopting the aforementioned preferred scheme, the conversion rate of cyclopentanone and the selectivity of the product glutaric acid can be further improved, the occurrence of side reactions can be reduced, and the burden of impurities in the synthesis liquid separation can be lessened.

[0044] In this invention, the method for cyclopentanone oxidation can be a conventional method in the art. According to a preferred embodiment of this invention, the method includes:

[0045] I) The catalyst, cyclopentanone, and solvent are added to the oxidation reactor to form a reaction mixture;

[0046] II) Introduce oxygen-containing gas into the reactor and heat the reactor to the reaction temperature and pressure;

[0047] III) Oxygen-containing gas under working pressure is continuously fed into the reactor for contact;

[0048] IV) Stop feeding to end the reaction.

[0049] By adopting the aforementioned technical solution, the conversion rate of cyclopentanone and the selectivity of the product glutaric acid can be further improved, the occurrence of side reactions can be reduced, and the burden of impurities in the synthesis liquid separation can be lessened.

[0050] To further improve the conversion rate of cyclopentanone and the selectivity of the product glutaric acid, reduce the occurrence of side reactions, and alleviate the burden of impurities in the synthesis solution, according to a preferred embodiment of the present invention, the contact is carried out in the presence of an auxiliary agent, preferably a C5-C6 alcohol and / or a C6 ketone; preferably, the molar ratio of the auxiliary agent to the solvent is 0.01-0.05:100, more preferably 0.01-0.03:100.

[0051] The present invention will be further described below through specific embodiments, but the scope of the present invention is not limited to the scope covered by the embodiments. In the following embodiments, the raw materials are all commercially available products. The specific calculation methods for cyclopentanone conversion rate and glutaric acid selectivity are as follows:

[0052] Cyclopentanone conversion rate = (molar amount of cyclopentanone before reaction - molar amount of cyclopentanone after reaction) / molar amount of cyclopentanone before reaction

[0053] Glutaric acid selectivity = Molar amount of glutaric acid produced in the reaction / (Molar amount of cyclopentanone before the reaction - Molar amount of cyclopentanone after the reaction)

[0054] Example 1

[0055] 1) Dissolve 0.05 mol of cobalt acetate and 0.05 mol of zirconium acetate in 100 mol of acetic acid, add 0.02 mol of cyclohexanone as an auxiliary agent, and add 100 mol of cyclopentanone as a reaction raw material. Mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel.

[0056] 2) Oxygen-deficient air (oxygen volume content 10%, the remainder being mainly nitrogen) is continuously introduced into the oxidation reactor at a flow rate of 20 mol / h. The reactor is heated to a reaction temperature of 90℃ and a reaction pressure of 6.0 MPa.

[0057] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The acetic acid solution feed flow rate is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the oxygen-deficient air flow rate is 20 mol / h.

[0058] 4) After 5 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 98.9%, and the glutaric acid selectivity was 93.8%.

[0059] Example 2

[0060] 1) Dissolve 0.025 mol of cobalt acetate and 0.05 mol of zirconium acetate in 100 mol of acetic acid, add 0.01 mol of cyclohexanone as an auxiliary agent, and add 100 mol of cyclopentanone as a reaction raw material. Mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel.

[0061] 2) Oxygen-deficient air (oxygen volume content 10%, the remainder mainly nitrogen) is continuously introduced into the oxidation reactor at a gas flow rate of 20 mol / h. The reactor is heated to the reaction temperature of 90℃ and the reaction pressure is 6.0 MPa.

[0062] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The acetic acid solution feed flow rate is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the oxygen-deficient air flow rate is 20 mol / h.

[0063] 4) After 5 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 97.7%, and the glutaric acid selectivity was 92.5%.

[0064] Example 3

[0065] 1) Dissolve 0.01 mol of cobalt acetate and 0.1 mol of zirconium acetate in 100 mol of acetic acid, add 0.03 mol of cyclohexanone as an auxiliary agent, and add 100 mol of cyclopentanone as a reaction raw material. Mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel.

[0066] 2) Oxygen-deficient air (oxygen volume content 10%, the remainder mainly nitrogen) is continuously introduced into the oxidation reactor at a gas flow rate of 20 mol / h. The reactor is heated to the reaction temperature of 90℃ and the reaction pressure is 6.0 MPa.

[0067] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The acetic acid solution feed flow rate is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the oxygen-deficient air flow rate is 20 mol / h.

[0068] 4) After 5 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 98.1%, and the glutaric acid selectivity was 91.6%.

[0069] Example 4

[0070] The difference from Example 1 is that an equal amount of a single zirconium acetate catalyst as in Example 1 is used, and an auxiliary agent is added, specifically:

[0071] 1) Dissolve 0.1 mol of zirconium acetate in 100 mol of acetic acid, add 0.02 mol of cyclohexanol as an auxiliary agent, and add 100 mol of cyclopentanone as a reaction raw material. Mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel.

[0072] 2) Oxygen-deficient air (oxygen volume content 10%, the remainder mainly nitrogen) is continuously introduced into the oxidation reactor at a gas flow rate of 20 mol / h. The reactor is heated to the reaction temperature of 80℃ and the reaction pressure is 6.0 MPa.

[0073] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The acetic acid solution feed flow rate is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the oxygen-deficient air flow rate is 20 mol / h.

[0074] 4) After 5 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 91.6%, and the glutaric acid selectivity was 88.9%.

[0075] Example 5

[0076] The difference from Example 1 is that no additives were added, specifically:

[0077] 1) Dissolve 0.05 mol of cobalt acetate and 0.05 mol of zirconium acetate in 100 mol of acetic acid, add 100 mol of cyclopentanone as a reaction raw material, mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel.

[0078] 2) Oxygen-deficient air (oxygen content 16% by volume, the remainder mainly nitrogen) is continuously introduced into the oxidation reactor at a flow rate of 20 mol / h. The reactor is heated to the reaction temperature of 90℃ and the reaction pressure is 6.0 MPa.

[0079] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The acetic acid solution feed flow rate is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the oxygen-deficient air flow rate is 20 mol / h.

[0080] 4) After 5 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 90.4%, and the glutaric acid selectivity was 80.8%.

[0081] Example 6

[0082] The difference from Example 1 is that an equal amount of zirconium acetate as a catalyst was used in Example 1, and no additives were added. Specifically:

[0083] 1) Dissolve 0.1 mol of zirconium acetate in 100 mol of acetic acid, add 100 mol of cyclopentanone as a reaction raw material, mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel;

[0084] 2) Oxygen-deficient air (oxygen volume content 18%, the remainder mainly nitrogen) is continuously introduced into the oxidation reactor at a flow rate of 30 mol / h. The reactor is heated to the reaction temperature of 90℃ and the reaction pressure is 8.0 MPa.

[0085] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The feed flow rate of acetic acid solution is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the flow rate of oxygen-deficient air is 30 mol / h.

[0086] 4) After 2 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 88.3%, and the glutaric acid selectivity was 76.9%.

[0087] Example 7

[0088] 1) Dissolve 0.05 mol of cobalt acetate and 0.15 mol of zirconium acetate in 100 mol of acetic acid, add 0.05 mol of cyclopentanol as an auxiliary agent, and add 100 mol of cyclopentanone as a reaction raw material. Mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel.

[0089] 2) Air (oxygen content 21% by volume, the remainder mainly nitrogen) is continuously introduced into the oxidation reactor at a flow rate of 10 mol / h. The reactor is heated to a reaction temperature of 110℃ and a reaction pressure of 3.0 MPa.

[0090] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The feed flow rate of acetic acid solution is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the flow rate of oxygen-deficient air is 10 mol / h.

[0091] 4) After 5 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 97.9%, and the glutaric acid selectivity was 89.7%.

[0092] Example 8

[0093] 1) Dissolve 0.12 mol of cobalt acetate and 0.02 mol of zirconium acetate in 100 mol of acetic acid, add 0.02 mol of cyclohexanone as an auxiliary agent, and add 100 mol of cyclopentanone as a reaction raw material. Mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel.

[0094] 2) Oxygen-deficient air (oxygen volume content 10%, the remainder mainly nitrogen) is continuously introduced into the oxidation reactor at a gas flow rate of 20 mol / h. The reactor is heated to the reaction temperature of 90℃ and the reaction pressure is 6.0 MPa.

[0095] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The acetic acid solution feed flow rate is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the oxygen-deficient air flow rate is 20 mol / h.

[0096] 4) After 5 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 90.5%, and the glutaric acid selectivity was 83.1%.

[0097] Example 9

[0098] 1) Dissolve 0.05 mol of cobalt acetate and 0.05 mol of zirconium acetate in 100 mol of acetic acid, add 0.02 mol of cyclohexanone as an auxiliary agent, and add 40 mol of cyclopentanone as a reaction raw material. Mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel.

[0099] 2) Oxygen-deficient air (oxygen volume content 4% and the remainder mainly nitrogen) is continuously introduced into the oxidation reactor at a flow rate of 40 mol / h. The reactor is heated to a reaction temperature of 120°C and a reaction pressure of 2.0 MPa.

[0100] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The feed flow rate of acetic acid solution is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the flow rate of oxygen-deficient air is 40 mol / h.

[0101] 4) After 7 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 84.9%, and the glutaric acid selectivity was 85.2%.

[0102] Comparative Example 1

[0103] The difference from Example 1 is that an equal amount of cobalt acetate as a catalyst was used, without the addition of any auxiliary agents. Specifically:

[0104] 1) Dissolve 0.1 mol of cobalt acetate in 100 mol of acetic acid, add 100 mol of cyclopentanone as a reaction raw material, mix the above materials to prepare an acetic acid solution and add it to the oxidation reaction vessel.

[0105] 2) Oxygen-deficient air (oxygen content 10% by volume, the remainder mainly nitrogen) is continuously introduced into the oxidation reactor at a flow rate of 20 mol / h. The reactor is heated to the reaction temperature of 90℃ and the reaction pressure is 6.0 MPa.

[0106] 3) Acetic acid solution and oxygen-deficient air are continuously fed into the reactor. The acetic acid solution feed flow rate is 1 mol / h (calculated based on the amount of acetic acid in the solution), and the oxygen-deficient air flow rate is 20 mol / h.

[0107] 4) After 5 hours of reaction, stop feeding to end the reaction. Take a sample of the glutaric acid oxidation reaction solution from the synthesis liquid collection tank for analysis of its composition. The cyclopentanone conversion rate was calculated to be 68.3%, and the glutaric acid selectivity was 56.5%.

[0108] As shown in Table 1, the method for producing glutaric acid by cyclopentanone oxidation provided by the present invention improves the conversion rate of cyclopentanone and the selectivity of glutaric acid.

[0109] Table 1

[0110]

[0111]

[0112] If the data in the table is inconsistent with the data in the embodiments, the data in the embodiments shall prevail.

[0113] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for oxidizing cyclopentanone, characterized in that, The method includes contacting an oxygen-containing gas with cyclopentanone in the presence of a solvent and a catalyst; The molar ratio of the total catalyst to the solvent is 0.01-0.2:100; The oxygen content in the oxygen-containing gas is 5-18% by volume, and the contact pressure is 3-8 MPa. The contact is carried out in the presence of an auxiliary agent, which is a C5-C6 alcohol and / or a C6 ketone; the molar ratio of the auxiliary agent to the solvent is 0.01-0.05:

100. The solvent is acetic acid, and the catalyst is a mixture of zirconium acetate and cobalt acetate, with a molar ratio of cobalt acetate to zirconium acetate of 0.1-1:1; the molar ratio of cyclopentanone to solvent is 0.4-2:

1.

2. The method according to claim 1, wherein, The oxygen content in oxygen-containing gas is 6-12% by volume.

3. The method according to claim 1, wherein, The molar flow ratio of oxygen-containing gas to solvent is 10-30:

1.

4. The method according to claim 1, wherein, The contact temperature is 80-110℃.

5. The method according to claim 4, wherein, The contact temperature is 85-110℃.

6. The method according to claim 1, wherein, Contact time: 2-6 hours.

7. The method according to claim 6, wherein, Contact time is 4-6 hours.

8. The method according to claim 1, wherein, The method includes: I) The catalyst, cyclopentanone, and solvent are added to the oxidation reactor to form a reaction mixture; II) Introduce oxygen-containing gas into the reactor and heat the reactor to the reaction temperature and pressure; III) Oxygen-containing gas under working pressure is continuously fed into the reactor for contact; IV) Stop feeding to end the reaction.

9. The method according to claim 1, wherein, The molar ratio of additive to solvent is 0.01-0.03:100.

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