Method for producing linear hydrocarbon double acids using a cyclic hydrocarbon oxidation catalyst

Abstract

The present invention relates to a method for producing hydrocarbon double acid using a cyclic hydrocarbon oxidation catalyst, in which a vanadium phosphate oxide-based catalyst and / or a manganese cobalt oxide-based catalyst is used to oxidize a cyclohexane-cyclohexanone mixture, and adipic acid is used to oxidize a cyclododecane-cyclododecanone mixture, thereby solving the environmental pollution problem of dodecanedioic acid and producing it in high yield.

Description

[Technical field]

[0001] The present invention relates to a method for producing linear hydrocarbon double acids using a cyclic hydrocarbon oxidation catalyst, more particularly, to a method for producing linear hydrocarbon double acids such as adipic acid and dodecanedioic acid in high yields without generating nitrous oxide by oxidizing cyclic hydrocarbon compounds of C6-C12 cycloalkanes and / or C6-C12 cycloketones in the presence of a vanadium phosphate oxide-based catalyst and / or a manganese cobalt oxide-based catalyst. [Background technology]

[0002] Adipic acid, a dicarboxylic acid consisting of six carbons, is the raw material for nylon-6,6 polyamide, and since its commercial production by Dupont in the 1930s, its production method has been developed and improved. Currently, the reaction to produce adipic acid commercially uses cyclohexane as the reactant. When cyclohexane is first oxidized with oxygen, a mixture of cyclohexanol and cyclohexanone is obtained, and when this is further oxidized with nitric acid, adipic acid is finally obtained. However, nitrous oxide is also produced as a by-product, which, if emitted as is, rises into the stratosphere and becomes a greenhouse gas that destroys the ozone layer. Therefore, an additional process is required to separate nitrous oxide, which is a factor that reduces the economic viability of producing adipic acid. In addition, to produce adipic acid from cyclohexane, the ring structure of cyclohexane must be broken, but because cyclohexane is a stable substance, oxidation often does not proceed to adipic acid, which has the disadvantage of reducing the conversion rate of cyclohexane and the selectivity of adipic acid.

[0003] Dodecanedioic acid is a dicarboxylic acid consisting of 12 carbons and is used as a key raw material for polymer products such as polyamide, polyester, and polyurethane. The production of dodecanedioic acid is broadly divided into chemical production using cyclododecane as a reactant and biological production using biowaste. In the case of chemical production, nitric acid is also used to oxidize the intermediate cyclododecanone.

[0004] Therefore, many studies have been conducted on methods to oxidize cyclic hydrocarbons without using nitric acid as an oxidizing agent. A. Mazzi et al. showed that the reactivity of cyclohexane changes depending on the catalyst support using a VPO catalyst supported on a cerium oxide support (A. Mazzi, S. Paul, F. Cavani, and R. Wojcieszak, ChemCatChem, 10:3680-3682(2018)), but did not mention the type of phase of the synthesized VPO catalyst or its effect. F. Ivars-Barcelо et al. described that the product selectivity changes when the VPO phase changes and the oxidation number of vanadium changes, and presented a method to synthesize various VPO phases (F. Ivars-Barcelо, GJ Hutchings, JK Bartley, SH Taylor, P. Sutter, … and B. Solsona, Journal of catalysis, 354:236-249(2017)). Furthermore, M. Wu et al. oxidized cyclohexane using a Mn-Co catalyst, but the catalyst was not supported on a support, and the yield of adipic acid produced was very low (M. Wu, W. Zhan, Y. Guo, Y. Guo, Y. Wang, L. Wang, and G. Lu, Applied Catalysis A: General, 523:97-106(2016)).

[0005] Therefore, the present inventors have conducted extensive research to solve the above problems, and have confirmed that when cyclic hydrocarbon compounds, such as C6-C12 cycloalkanes and / or C6-C12 cycloketones, are oxidized in the presence of a catalyst based on vanadium phosphate oxide (VPO) supported on a mesoporous silica support or a catalyst based on manganese cobalt oxide, linear hydrocarbon double acids, such as adipic acid and dodecanedioic acid, can be produced in high yields without generating nitrous oxide, a greenhouse gas, and have completed the present invention. Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present invention to provide a method for producing linear hydrocarbon double acids, such as adipic acid and dodecanedioic acid, in high yields without producing nitrous oxide, a greenhouse gas.

[0007] To achieve the above object, the present invention provides a method for producing a hydrocarbon dual acid, comprising the step of oxidizing one or more cyclic hydrocarbon compounds selected from the group consisting of C6-C12 cycloalkanes and C6-C12 cycloketones in the presence of a vanadium phosphate oxide-based catalyst or a manganese cobalt oxide-based catalyst, or a mixture thereof. [Brief description of the drawings]

[0008] [Figure 1] 1 is a graph showing the outline of the XRD peak of the VOPO4·2H2O catalyst obtained in the step of synthesizing a VPO catalyst having a single phase according to Example 1 of the present invention. [Diagram 2] 1 is a graph showing the outline of the XRD peak of the (VO)2P2O7 catalyst obtained in the step of synthesizing a VPO catalyst having a single phase according to Example 1 of the present invention; [Diagram 3] 1 is a graph showing the outline of the XRD peak of the manganese oxide-cobalt catalyst obtained in Example 2 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Unless otherwise defined, all terms (technical and scientific) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Generally, the nomenclature used herein is that which is widely known and commonly used in the art.

[0010] The present invention recognizes that nitrous oxide, which is generated as a by-product in the existing production processes of adipic acid and dodecanedioic acid, has a negative impact on the environment as a greenhouse gas, and has confirmed that adipic acid and dodecanedioic acid can be produced from cyclohexane or cyclododecane, respectively, without producing the above-mentioned greenhouse gases, by using VPO or manganese oxide-cobalt catalyst supported on a mesoporous silica support. It has also been confirmed that when cyclohexanone and cyclododecanone are further input into the oxidation reaction of cyclohexane and cyclododecane, respectively, which are used as reactants, the yields of the respective products, adipic acid and dodecanedioic acid, increase.

[0011] Thus, the present invention relates to a method for producing a hydrocarbon double acid, comprising the step of oxidizing one or more cyclic hydrocarbon compounds selected from the group consisting of C6-C12 cycloalkanes and C6-C12 cycloketones in the presence of a vanadium phosphate oxide based catalyst or a manganese cobalt oxide based catalyst, or a mixture thereof.

[0012] In this specification, the term "C6-C12 cycloalkane" refers to a cyclic hydrocarbon in which 6 to 12 carbon atoms are bonded to a ring, and each carbon atom is bonded to a hydrogen atom. For example, cyclohexane (C 6 H 12 ), cycloheptane (C 7 H 14), cyclooctane (C 8 H 16 ), cyclononane (C 9 H 18 ), cyclodecane (C 10 H 20 ) is available.

[0013] In the present specification, a C6-C12 cycloketone refers to a cyclic hydrocarbon having a ketone group and 6 to 12 carbon atoms bonded to a ring, with each carbon atom bonded to a hydrogen atom. For example, cyclohexanone (C 6 H 10 Cycloheptanone of formula 2 (C 7 H 12 Cyclooctanone of formula 3 (C 8 H 14 Cyclononanone of formula 4 (C 9 H 16 Cyclodocanone of formula 5 (C 10 H 28 O).

[0014] [ka]

[0015] [ka]

[0016] [ka]

[0017] [ka]

[0018] [ka]

[0019] In the present invention, the cycloalkane may be cyclohexane or the cycloketone may be cyclohexanone, and the hydrocarbon double acid may be adipic acid (Formula 6).

[0020] [ka]

[0021] In the present invention, the cycloalkane may be cyclododecane or the cycloketone may be cyclododecanone, and in this case, the hydrocarbon diacid may be dodecanedioic acid (Formula 7).

[0022] [ka]

[0023] In the present invention, the cycloalkane is cyclohexane and cyclododecane, or the cycloketone is cyclohexanone and cyclododecanone, and the hydrocarbon diacid is adipic acid and dodecanedioic acid.

[0024] A preferred embodiment of the present invention can include the steps of: (a) oxidizing a mixture of cyclohexane and cyclohexanone in the presence of a vanadium phosphate oxide based catalyst or a manganese cobalt oxide based catalyst, or a mixture thereof, to obtain adipic acid; and (b) oxidizing a mixture of cyclododecane and cyclododecanone in the presence of a vanadium phosphate oxide based catalyst or a manganese cobalt oxide based catalyst, or a mixture thereof, to obtain dodecanedioic acid.

[0025] Another preferred embodiment of the present invention includes the steps of: (a) supporting two types of VPO having a single phase on a mesoporous silica support to prepare two types of VPO-based cyclic alkane oxidation catalysts and supporting a manganese oxide-cobalt precursor on a mesoporous silica support to prepare a manganese oxide-cobalt based cyclic alkane oxidation catalyst; (b) using the two types of VPO-based catalyst obtained in step (a) and a manganese oxide-cobalt based catalyst to prepare linear diacids from various cyclic alkane and ketone mixtures; (c) obtaining an optimal ratio of the two rings in the reaction mixture and optimal reaction pressure conditions in the VPO-based catalyst and the manganese oxide-cobalt based catalyst to maximize the yield of linear diacids.

[0026] In the present invention, the vanadium phosphate oxide-based catalyst or the manganese cobalt oxide-based catalyst is preferably supported on a mesoporous silica support.

[0027] In the present invention, the catalyst based on vanadium phosphate oxide is VOPO 4 2H 2 O, (VO) 2 P 2 O 7 , or VOPO 4 2H 2 O and (VO) 2 P 2 O 7 It may also be a mixture of.

[0028] In the present invention, the manganese:cobalt molar ratio in the manganese cobalt oxide based catalyst may be from 2:0.5 to 2:4.

[0029] In the present invention, the amount of the vanadium phosphate oxide-based catalyst or the manganese cobalt oxide-based catalyst, or a mixture thereof, injected may be in a mass ratio of 0.02 to 2% relative to the mass of the cyclic hydrocarbon compound.

[0030] In the present invention, the oxidation may be carried out under an oxygen atmosphere at a pressure of 10 to 40 bar and a temperature of 120 to 250° C. for 2 to 15 hours.

[0031] In the present invention, the content of cyclohexanone in the mixture of cyclohexane and cyclohexanone may be 5 to 150% (molar ratio) relative to cyclohexane.

[0032] In the present invention, the content of cyclododecanone in the mixture of cyclododecane and cyclododecanone may be 10 to 300% (molar ratio) based on cyclododecane.

[0033] The present invention will be described in detail below.

[0034] The process for producing adipic acid and dodecanedioic acid according to the present invention may comprise the steps of: (a) supporting two types of VPOs having a single phase on a mesoporous silica support to prepare two types of VPO-based cyclic alkane oxidation catalysts, and supporting a manganese oxide-cobalt precursor on a mesoporous silica support to prepare a manganese oxide-cobalt based cyclic alkane oxidation catalyst; (b) obtaining adipic acid from various cyclohexane-cyclohexanone mixtures using the two VPO-based catalysts obtained in step (a) and a manganese oxide-cobalt-based catalyst, and obtaining the optimum ratios and optimum reaction pressure conditions of the two catalysts and the two reactants in the case of the VPO-based catalyst, and the optimum ratios and optimum reaction pressure conditions of the two reactants in the case of the manganese oxide-cobalt-based catalyst; and (c) obtaining dodecanedioic acid from various cyclododecane-cyclododecanone mixtures using the two VPO-based catalysts or manganese oxide-cobalt-based catalysts obtained in step (a), and obtaining the optimum ratios and optimum reaction pressure conditions for the two catalysts and two reactants in the case of the VPO-based catalyst, and the optimum ratios and optimum reaction pressure conditions for the two reactants in the case of the manganese oxide-cobalt-based catalyst.

[0035] The method for producing adipic acid and dodecanedioic acid according to the present invention may include the following steps:

[0036] (a) Catalyst synthesis step

[0037] The method for preparing the oxidation catalyst according to the present invention comprises the steps of synthesizing two single-phase VPO precursors and supporting them on a mesoporous silica support.

[0038] The method for producing an oxidation catalyst according to the present invention comprises the steps of synthesizing a manganese-cobalt oxide precursor and supporting it on a mesoporous silica support.

[0039] (b) Adipic acid production steps

[0040] The method for producing adipic acid according to the present invention comprises the step of oxidizing a cyclohexane-cyclohexanone mixture in the presence of the VPO-based catalyst obtained in step (a) or a manganese-cobalt oxide-based catalyst to obtain adipic acid.

[0041] The method for producing adipic acid according to the present invention can oxidize a cyclohexane-cyclohexanone mixture to adipic acid under an oxygen atmosphere using a VPO-based catalyst or a manganese-cobalt oxide-based catalyst.

[0042] In the cyclohexane-cyclohexanone mixture, cyclohexanone may be contained in a molar ratio of 5 to 150% relative to cyclohexane, preferably 25 to 50% relative to cyclohexane. Since both cyclohexane and cyclohexanone are involved in the reaction for producing adipic acid, if the amount of cyclohexanone is less than 5% or more than 150% relative to the moles of cyclohexane, there is a problem that adipic acid is not produced.

[0043] In the present invention, the VPO catalyst used in the oxidation reaction of a cyclohexane-cyclohexanone mixture is VOPO 4 2H 2 O or (VO) 2 P 2 O 7 In this case, each phase may have a mass ratio of 0 to 100% in the total catalyst amount. 4 2H 2 Only catalysts with O phases are used, or conversely, (VO) 2 P 2 O 7 Only catalysts having a VOPO phase can be used, but preferably 4 2H 2 The O phase may be contained in a mass ratio of 20 to 80%.

[0044] In the present invention, the manganese oxide-cobalt catalyst used in the oxidation reaction of a cyclohexane-cyclohexanone mixture may have a manganese:cobalt molar ratio of 2:0.5 to 2:4, and preferably has a manganese:cobalt molar ratio of 2:2 to 2:3.

[0045] The oxidation reaction may be carried out using oxygen as an oxidizing agent at an absolute pressure of 10 to 40 bar, preferably 10 to 20 bar, more preferably 13 to 15 bar. When the reaction is carried out at a pressure of less than 10 bar, there is a problem that the amount of the oxidizing agent is insufficient, resulting in a decrease in the yield of adipic acid. Conversely, when the pressure exceeds 40 bar, there is a problem that the production of undesired by-products increases, resulting in a decrease in the yield of adipic acid.

[0046] In the oxidation reaction, the amount of catalyst may be 0.02 to 2% by mass relative to the mass of the reactants cyclohexane-cyclohexanone. If the catalyst is used at a mass ratio of less than 0.02%, the reactants cannot be sufficiently oxidized due to the relatively insufficient amount of catalyst, and if the catalyst is used at a mass ratio of more than 2%, the conversion rate of adipic acid does not increase with the increased amount of catalyst, resulting in economic inefficiency.

[0047] In the oxidation reaction, the temperature of the reactants may be 120 to 250° C., preferably 120 to 160° C., and more preferably 135 to 145° C. If the temperature of the reactants is lower than 120° C., adipic acid is not produced, and conversely, if the temperature of the reactants is higher than 250° C., a reaction in which the produced adipic acid is decomposed may occur.

[0048] In the oxidation reaction, the reaction time may be 2 to 15 hours after the temperature is increased.

[0049] In the oxidation reaction, the conversion of cyclohexane-cyclohexanone or the yield of adipic acid can vary depending on the temperature of the reaction, the oxygen pressure, the amount of catalyst, and the relative ratio of cyclohexane and cyclohexanone.

[0050] (c) Production steps of dodecanedioic acid

[0051] The method for producing dodecanedioic acid according to the present invention comprises the step of oxidizing a cyclododecane-cyclododecanone mixture in the presence of the VPO-based catalyst or manganese-cobalt oxide-based catalyst obtained in step (a) to obtain dodecanedioic acid.

[0052] The method for producing dodecanedioic acid according to the present invention can oxidize a cyclododecane-cyclododecanone mixture to dodecanedioic acid under an oxygen atmosphere using a VPO-based catalyst or a manganese-cobalt oxide-based catalyst.

[0053] In the cyclododecane-cyclododecanone mixture, cyclododecanone may be contained in a molar ratio of 10 to 300% relative to cyclododecane, and preferably in a molar ratio of 25 to 50% relative to cyclododecane.

[0054] In the present invention, the VPO catalyst used in the oxidation reaction of the cyclododecane-cyclododecanone mixture is VOPO 4 2H 2 O or (VO) 2 P 2 O 7 In this case, each phase may have a mass ratio of 0 to 100% in the total catalyst amount. 4 2H 2 Only catalysts with O phases are used, or conversely, (VO) 2 P 2 O 7 Only catalysts having a VOPO phase can be used, but preferably 4 2H 2 The O phase may be contained in a mass ratio of 20 to 80%.

[0055] In the present invention, the manganese oxide-cobalt catalyst used in the oxidation reaction of the cyclododecane-cyclododecanone mixture may have a manganese:cobalt molar ratio of 2:0.5 to 2:4, and preferably has a manganese:cobalt molar ratio of 2:2 to 2:3.

[0056] The oxidation reaction may be carried out using oxygen as an oxidizing agent at an absolute pressure of 10 to 20 bar, preferably 13 to 15 bar. If the reaction is carried out at a pressure of less than 10 bar, there is a problem that the amount of oxidizing agent is insufficient, resulting in a decrease in the yield of dodecanedioic acid, while if the pressure exceeds 20 bar, there is a problem that the production of undesired by-products increases, resulting in a decrease in the yield of dodecanedioic acid.

[0057] In the oxidation reaction, the amount of catalyst may be 0.02 to 2% by mass relative to the mass of the reactants cyclododecane-cyclododecanone. If the catalyst is used at a mass ratio of less than 0.02%, the reactants are not sufficiently oxidized due to the relatively insufficient amount of catalyst, and if the catalyst is used at a mass ratio of more than 2%, the conversion rate of dodecanedioic acid does not increase with the increased amount of catalyst, which is economically inefficient.

[0058] The temperature of the reactants in the oxidation reaction may be 120 to 160° C., preferably 135 to 145° C. If the temperature of the reactants is lower than 120° C., dodecanedioic acid is not produced, whereas if the temperature of the reactants is higher than 160° C., a reaction in which the produced dodecanedioic acid is decomposed may occur.

[0059] In the oxidation reaction, the reaction time may be 2 to 15 hours after the temperature is increased.

[0060] In the oxidation reaction, the conversion of cyclododecane-cyclododecanone or the yield of dodecanedioic acid can vary depending on the reaction temperature and oxygen pressure, the amount of catalyst, and the relative ratio of cyclododecane and cyclododecanone.

[0061] In the following, preferred examples are presented to facilitate understanding of the present invention. However, the following examples are merely illustrative of the present invention, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope of the scope and technical spirit of the present invention. Naturally, such changes and modifications also fall within the scope of the appended claims.

[0062] [Example]

[0063] Example 1: Preparation of VPO catalyst supported on mesoporous silica support

[0064] Two single-phase VPO precursors were synthesized and supported on mesoporous silica supports with high surface areas.

[0065] In a 250 mL round bottom flask, add vanadium(V) oxide (V 2 O 5 , ≥99.6%, Sigma-Aldrich) 6 g and phosphoric acid (H 3 PO 4 8.3g of toluene (min. 89.0w / w%, TCI) and 125mL of isobutanol (>99%, TCI) were added and refluxed at 100℃ for 16 hours. The solution was then filtered using 0.8μm filter paper, and 100mL of acetone (>99.5%, TCI) was added to a 250mL beaker and washed by stirring at 300 rpm at room temperature for 30 minutes. The above washing-filtration process was then repeated a total of three times, and the mixture was dried at 90℃ for 12 hours.

[0066] The dried solid was placed in an alumina crucible and then placed in a reactor, and the crucible was opened at both ends to allow air to circulate, and the firing process was carried out. The temperature of the reactor was raised from 20°C to 550°C at a rate of 5°C / min, and then maintained at 550°C for 3 hours. Then, it was cooled to room temperature to obtain VOPO. 4 2H 2 O catalyst was obtained.

[0067] In this process, the dried solid was placed in an alumina crucible and then placed in a reactor, where it was sintered while flowing helium (He, >99.999%, Samwo Specialty Gas) at a flow rate of 50 mL / min. The temperature of the reactor was raised from 20°C to 550°C at a rate of 5°C / min, and then maintained at 550°C for 3 hours, after which it was cooled to room temperature (VO). 2 P 2 O 7 The catalyst was obtained.

[0068] In the above process, the solid and mesoporous silica (MCM-41, 4.5-4.8 nm, Sigma-Aldrich) were placed in a 250 mL beaker so that the content of the dried solid was 5 wt%, and then 30 mL of distilled water per 1 g of solid was added and stirred at room temperature for 24 hours. Then, all of the distilled water was evaporated and the remaining solid was dried at 100°C. The solid was placed in an alumina crucible and then placed in a reactor and subjected to a firing process with both ends of the crucible open to allow air to circulate. During this time, the temperature of the reactor was raised from 20°C to 550°C at a rate of 5°C / min, and then maintained at 550°C for 3 hours, and then cooled to room temperature to obtain VOPO supported on a mesoporous silica support. 4 2H 2 The solid that had been dried was placed in an alumina crucible and then placed in a reactor, where it was calcined while flowing helium (He, >99.999%, Samwo Specialty Gas) at a flow rate of 50 mL / min. The temperature of the reactor was raised from 20°C to 550°C at a rate of 5°C / min, and then maintained at 550°C for 3 hours, after which it was cooled to room temperature and supported on a mesoporous silica support (VO). 2 P 2 O 7 The catalyst was obtained.

[0069] The synthesized catalyst was analyzed by XRD (Smartlab). 4 2H 2 The outline of the XRD peaks of the O catalyst is shown in Figure 1. 2 P 2 O 7 The outlines of the XRD peaks of the catalysts are shown in FIG.

[0070] Example 2: Preparation of manganese-cobalt oxide catalyst supported on mesoporous silica support

[0071] A manganese-cobalt oxide precursor was synthesized and supported on a high surface area mesoporous silica support.

[0072] In a 250 mL beaker, add Co(NO 3 )2 6H 2 O and Mn(NO 3 ) 2 After that, distilled water was added until all the solids were completely dissolved. The temperature of the solution was raised to 60°C using a hot plate and stirred at a speed of 300 rpm. Then, while measuring the pH of the solution using a pH meter, 1 mol / L sodium hydroxide aqueous solution was dropped into the solution one drop at a time using a burette until the pH reached 8. The temperature of the solution was kept at 60°C and the solution was continuously stirred for 4 hours for aging, and the completed solution was filtered using a 0.8 μm filter paper. Then, 100 mL of distilled water was added to a 250 mL beaker and washed by stirring at 300 rpm at room temperature for 30 minutes. Then, the above washing-filtration process was repeated a total of three times, and dried at 120°C for 12 hours.

[0073] The solid and mesoporous silica (MCM-41, 4.5-4.8 nm, Sigma-Aldrich) were placed in a 250 mL beaker so that the content of the dried solid was 5 wt%, and then 30 mL of distilled water per 1 g of solid was added and stirred at room temperature for 24 hours. Then, all the distilled water was evaporated and the remaining solid was dried at 100 ° C. The dried solid was placed in an alumina crucible and then placed in a reactor, and a firing process was performed with both ends of the crucible open to allow air to pass through. At this time, the temperature of the reactor was raised from 20 ° C to 400 ° C at a rate of 5 ° C / min, and then maintained at 400 ° C for 4 hours, and then cooled to room temperature to obtain a manganese oxide-cobalt catalyst supported on a mesoporous silica support.

[0074] The synthesized catalyst was analyzed by XRD (Smartlab). The outline of the XRD peak of the synthesized manganese oxide-cobalt catalyst is shown in Figure 3.

[0075] Example 3: Determination of the optimal ratio of two-phase VPO catalyst and the optimal ratio of cyclohexane-cyclohexanone mixture in the reaction for the production of adipic acid

[0076] The relative amounts of two single-phase VPO catalysts and the ratio of the cyclohexane-cyclohexanone mixture were varied to determine the optimum for the conversion of the cyclohexane-cyclohexanone mixture to adipic acid under the catalyst.

[0077] 10 mL of cyclohexane and 0, 25, 50, 100, 150, and 200% cyclohexanone based on the moles of cyclohexane were injected into the reactor. Then, VOPO was added while maintaining the total catalyst amount at 15 mg. 4 2H 2 The mass ratio of VPO catalyst with O phase was increased to 0, 50, 80, and 100%, respectively, and reaction experiments were carried out. The temperature of the reactants was increased to 135°C, and when the temperature reached the set value, the reactor was filled with 13 bar of oxygen, after which the reactants were oxidized for 5 hours.

[0078] The reaction product was quantitatively analyzed by online GC (Agilent 7890A). 4 2H 2 The conversion of cyclohexane and the yield of adipic acid when the mass ratio of the VPO catalyst having an O phase was 0, 50, 80, and 100%, respectively, are shown in Tables 1 to 4, respectively.

[0079] VOPO 4 2H 2 (VO) than the O / MCM-41 catalyst. 2 P 2 O 7 The amount of adipic acid produced was higher when the VOPO / MCM-41 catalyst was used. The amount of adipic acid produced was also higher when both catalysts were used than when only one phase was used as a catalyst. When the ratio of the two catalysts was 1:1, the amount of adipic acid produced was highest when the molar ratio of cyclohexane to cyclohexanone was 1:0.25, and the amount of adipic acid produced was highest when the molar ratio of VOPO 4 2H 2 When the ratio of O / MCM-41 accounted for 80% of the total catalyst amount, the largest amount of adipic acid was produced when the molar ratio of cyclohexane to cyclohexanone was 1:0.5.

[0080] In addition, when only cyclohexane was present or the ratio of cyclohexanone was too high, adipic acid was not produced. This means that when using the current catalyst system, if cyclohexanone is not present, the reaction will not proceed to adipic acid. In addition, it was confirmed that adipic acid cannot be obtained unless cyclohexane and cyclohexanone are present in the correct ratio, and that adipic acid cannot be obtained simply because cyclohexanone is present.

[0081] Example 4: Effect of oxygen pressure on the reaction for the production of adipic acid using VPO catalyst supported on mesoporous silica

[0082] In the oxidation reaction of cyclohexane-cyclohexanone mixture using both single-phase VPO catalysts, the effect of increasing oxygen pressure on the production of adipic acid was examined.

[0083] 10 mL of cyclohexane and 50% of cyclohexanone per mole of cyclohexane were injected into the reactor. Then, VOPO was added while maintaining the total catalyst amount at 15 mg. 4 2H 2 The reaction experiments were carried out with mass ratios of VPO catalyst with O phase of 50 and 80%, respectively. The temperature of the reactants was increased to 135°C, and when the temperature reached the set value, the reactor was filled with oxygen at 13, 15 or 17 bar, after which the reactants were oxidized for 5 hours.

[0084] The reaction product was quantitatively analyzed by online GC (Agilent 7890A). 4 2H 2 The conversion of cyclohexane and the yield of adipic acid under various oxygen pressures (13-17 bar) when the mass ratio of VPO catalyst with O phase was 50 and 80%, respectively, are shown in Tables 5-6, respectively.

[0085] When the oxygen pressure was increased from 13 bar to 15 bar, the amount of adipic acid produced increased. This indicates that the supply of oxygen is very important in the production of adipic acid. However, when the oxygen pressure was further increased to 17 bar, the selectivity of adipic acid decreased, and the overall production of adipic acid decreased. Therefore, it was confirmed that when the amount of oxygen supplied exceeds a certain level, undesirable side reactions occur.

[0086] Example 5: Effect of oxygen pressure on the production of adipic acid using manganese oxide-cobalt catalyst supported on mesoporous silica

[0087] In the oxidation reaction of a cyclohexane-cyclohexanone mixture using a manganese-cobalt oxide catalyst supported on mesoporous silica, the effect of increasing oxygen pressure on the production of adipic acid was investigated.

[0088] 10 mL of cyclohexane and 50% of cyclohexanone per mole of cyclohexane were injected into the reactor. Then, 15 mg of manganese-cobalt oxide catalyst was injected and the temperature of the reaction was increased to 135° C. Once the temperature reached the set point, the reactor was filled with oxygen at 13, 15 or 17 bar and the reaction was then oxidized for 5 hours.

[0089] The reaction product was quantitatively analyzed by on-line GC (Agilent 7890A). The effect of various oxygen pressures (13-17 bar) on the conversion of cyclohexane and the yield of adipic acid in the presence of the manganese oxide-cobalt catalyst supported on the mesoporous silica support confirmed by this analysis is shown in Table 7.

[0090] In the case of using the manganese oxide-cobalt catalyst, as in the case of the VPO catalyst described above, when the oxygen pressure was increased from 13 bar to 15 bar, the amount of adipic acid produced increased, but when the oxygen pressure was increased to 17 bar, the selectivity to adipic acid decreased, and the overall amount of adipic acid produced decreased.

[0091] Example 6: Determination of the optimal ratio of VPO catalysts supported on two-phase mesoporous silica supports in the reaction for the production of dodecanedioic acid

[0092] The relative amounts of VPO catalyst loaded onto two single-phase mesoporous silica supports were varied to determine the optimum for the conversion of a cyclododecane-cyclododecanone mixture to dodecanedioic acid.

[0093] The two substances were injected into the reactor with the sum of the moles of cyclododecane and cyclododecanone being 92.45 mmol, with the molar ratio of cyclododecane being 25% and the molar ratio of cyclododecanone being 75%. Then, while maintaining the total catalyst amount at 15 mg, VOPO 4 2H 2 Reaction experiments were carried out with increasing mass ratios of VPO catalyst with O phase at 0, 50, and 100%, respectively. The temperature of the reactants was increased to 135°C, and when the temperature reached the set value, the reactor was filled with 13 bar of oxygen, after which the reactants were oxidized for 5 h.

[0094] The reaction product was quantitatively analyzed by NMR. In this case, 1 mL of chloroform-D and 20 μL of dimethyl sulfoxide-D6 were used as the solvent, and 0.01 mmol of ethylene carbonate was used as the standard solution. 4 2H 2 The effect of the mass ratio of O phase on the yield of dodecanedioic acid is shown in Table 8.

[0095] VOPO 4 2H 2 (VO) than the O / MCM-41 catalyst. 2 P 2 O 7 The amount of dodecanedioic acid produced was higher when the VOPO / MCM-41 catalyst was used. Compared to when only a single phase was used as a catalyst, the amount of dodecanedioic acid produced when the two catalysts were mixed at a mass ratio of 50% each was higher than that produced when the VOPO / MCM-41 catalyst was used.4 2H 2 It was almost the same as when the O / MCM-41 catalyst was used.

[0096] Example 7: Determination of the optimal ratio of cyclododecane-cyclododecanone mixture in the production of dodecanedioic acid using manganese oxide-cobalt catalyst supported on mesoporous silica

[0097] In the oxidation reaction of a cyclododecane-cyclododecanone mixture using a manganese oxide-cobalt catalyst supported on a mesoporous silica support, the optimum ratio in the reaction of converting the cyclododecane-cyclododecanone mixture to dodecanedioic acid under the catalyst was determined while changing the ratio of the cyclododecane-cyclododecanone mixture.

[0098] The mixture was varied in proportions with increasing molar ratios of cyclododecanone at 0, 25, 50, 75, and 100%, with the sum of the moles of cyclododecane and cyclododecanone being 92.45 mmol. 15 mg of manganese oxide-cobalt catalyst was injected along with the mixture, and the temperature of the reaction was increased to 135° C. Once the temperature had reached the set point, the reactor was filled with 13 bar of oxygen, after which the reaction was oxidized for 5 hours.

[0099] The reaction product was quantitatively analyzed by NMR. In this case, 1 mL of chloroform-D and 20 μL of dimethyl sulfoxide-D6 were used as the solvent, and 0.01 mmol of ethylene carbonate was used as the standard solution. The effect of various ratios of cyclododecane-cyclododecanone mixtures on the yield of dodecanedioic acid in the presence of manganese oxide-cobalt catalyst supported on mesoporous silica support confirmed by this method is shown in Table 9.

[0100] Although dodecanedioic acid was formed when cyclododecane and cyclododecanone were used alone, the yield of dodecanedioic acid increased when a mixture of cyclododecane and cyclododecanone was used, confirming that in the reaction of converting cyclododecane to dodecanedioic acid, the additional addition of cyclododecanone, which is an intermediate in the reaction, promotes the production of dodecanedioic acid by reducing the induction time.

[0101] [Table 1]

[0102] [Table 2]

[0103] [Table 3]

[0104] [Table 4]

[0105] [Table 5]

[0106] [Table 6]

[0107] [Table 7]

[0108] [Table 8]

[0109] [Table 9]

[0110] According to the process of the present invention, linear diacids such as adipic acid and dodecanedioic acid can be obtained without producing nitrous oxide, a greenhouse gas by-product, as a catalyst using VPO or manganese-cobalt oxide supported on a mesoporous silica support in the conventional process. In addition, by adding a cyclic ketone to a cyclic alkane as a reactant, each diacid can be obtained in a higher yield than when the cyclic alkane is used as the sole reactant.

[0111] Although the specific parts of the present invention have been described in detail above, it is clear to those skilled in the art that such specific techniques are merely preferred embodiments and do not limit the scope of the present invention. Therefore, the substantial scope of the present invention should be defined by the claims and their equivalents.

Claims

1. 1. A method for producing a dibasic acid, comprising the step of oxidizing a cyclic hydrocarbon compound comprising C6-C12 cycloalkanes and C6-C12 cycloketones in the presence of a vanadium phosphate oxide based catalyst or a manganese cobalt oxide based catalyst, or a mixture thereof, the cycloalkane is cyclododecane or the cycloketone is cyclododecanone and the diacid is dodecanedioic acid; or The method for producing a dibasic acid, wherein the cycloalkane is a mixture of cyclohexane and cyclododecane or the cycloketone is a mixture of cyclohexanone and cyclododecanone, and the dibasic acid is a mixture of adipic acid and dodecanedioic acid.

2. oxidizing a mixture of cyclododecane and cyclododecanone to give dodecanedioic acid in the presence of a vanadium phosphate oxide based catalyst or a manganese cobalt oxide based catalyst, or a mixture thereof; The method for producing the dibasic acid according to claim 1, comprising:

3. 2. The method for producing a dibasic acid according to claim 1, wherein the vanadium phosphate oxide-based catalyst or the manganese cobalt oxide-based catalyst is supported on a mesoporous silica support.

4. The vanadium phosphate oxide-based catalyst is VOPO ４ ・2H ２ O, (V.O.) ２ P ２ O ７ , or VOPO ４ ・2H ２ O and (VO) ２ P ２ O ７ The method for producing a dibasic acid according to claim 1, characterized in that the dibasic acid is a mixture of

5. 2. The method for producing a dibasic acid according to claim 1, wherein the manganese:cobalt molar ratio in the manganese cobalt oxide-based catalyst is from 2:0.5 to 2:

4.

6. 2. The method for producing a dibasic acid according to claim 1, wherein the amount of the vanadium phosphate oxide-based catalyst or the manganese cobalt oxide-based catalyst, or a mixture thereof, injected is in a mass ratio of 0.02 to 2% relative to the mass of the cyclic hydrocarbon compound.

7. 2. The method for producing a dibasic acid according to claim 1, wherein the oxidation is carried out under an oxygen atmosphere at a pressure of 10-40 bar and a temperature of 120-250° C. for 2-15 hours.

8. 3. The method for producing a dibasic acid according to claim 2, wherein the content of cyclododecanone in the mixture of cyclododecane and cyclododecanone is 10 to 300% (molar ratio) of cyclododecane.

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