A process for the preparation of adipic acid from tetrahydrofurfurylic acid

Abstract

The application provides a method for preparing adipic acid from tetrahydrofurfurylic acid, and relates to the technical field of chemical synthesis.The method provided by the application can effectively reduce the synthesis cost and difficulty of adipic acid, can maintain stable production efficiency, is favorable for large-scale industrial production, and can separate the prepared mixed system more easily, has no excessive waste, and is more green and environment-friendly.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology, and in particular to a method for preparing adipic acid from tetrahydrofuranic acid. Background Technology

[0002] Adipic acid has the chemical formula C6H. 10 O4 is an important organic dicarboxylic acid, appearing as a white crystalline powder with good solubility and chemical stability. Adipic acid is also one of the most important dicarboxylic acids in industry, with a huge annual production volume, and is widely used in the production of nylon 66, polyurethane, plasticizers, food and pharmaceutical synthesis, resins, and coating additives.

[0003] In the existing technology, the industrial synthesis of adipic acid mainly adopts the chemical oxidation method. In an acidic environment, under the action of metal catalysts such as cobalt and manganese, cyclohexane is oxidized to produce KA oil, and the KA oil is further oxidized to adipic acid in an acidic environment. For example, Chinese patent with publication number CN114426472A provides a method for the direct oxidation of cyclohexane to prepare adipic acid. After mixing cyclohexane, acetic acid and catalyst, the mixture is oxidized in an air atmosphere to generate adipic acid synthesis liquid, and the adipic acid is evaporated and crystallized.

[0004] Meanwhile, in recent years, a relatively green and environmentally friendly method for producing adipic acid has been developed. This method involves modifying microorganisms using genetic engineering techniques to enable them to produce adipic acid during fermentation. Escherichia coli or yeast can be genetically engineered, and the modified strains can be cultured under suitable fermentation conditions to efficiently produce adipic acid. For example, Chinese patent CN105112436B provides a method for the complete biosynthesis of adipic acid. By metabolically modifying *Schizophyllum commune*, a mutant strain B6 capable of producing adipic acid was obtained, confirming the adipic acid synthesis pathway, and introducing the gene corresponding to this pathway into *E. coli* for modular expression.

[0005] Although chemical oxidation and bio-fermentation methods have made significant progress in adipic acid production, cyclohexane oxidation requires high temperature and pressure, resulting in high production costs and energy consumption. Furthermore, the oxidation process generates large amounts of wastewater and waste gas, easily causing environmental pollution. Additionally, the low selectivity of the oxidation process leads to the formation of numerous byproducts, affecting the purity and yield of adipic acid. On the other hand, modified microbial strains used in bio-fermentation are prone to gene mutations during long-term fermentation, leading to decreased acid production capacity. Moreover, bio-fermentation requires strict environmental conditions, increasing production difficulty and costs. Therefore, there is an urgent need to provide a solution to address these problems. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing adipic acid from tetrahydrofuranic acid.

[0007] The present invention provides a method for preparing adipic acid from tetrahydrofuranic acid. In a mixed atmosphere of hydrogen and carbon monoxide, tetrahydrofuranic acid undergoes a carbonylation reaction at 100-280°C in a solvent environment under the action of a noble metal catalyst and an iodine promoter to generate adipic acid.

[0008] The method for preparing adipic acid from tetrahydrofuranic acid provided by this invention can effectively reduce the synthesis cost and difficulty of adipic acid by using chemical catalytic synthesis, maintain stable production efficiency, and facilitate large-scale industrial production. In addition, the resulting mixed system is easier to separate, generates less waste, and is more environmentally friendly.

[0009] Optionally, when tetrahydrofuranic acid reacts to produce adipic acid under a mixed atmosphere, the pressure of the mixed atmosphere is 1-10 MPa.

[0010] Preferably, when tetrahydrofuranic acid reacts to produce adipic acid under a mixed atmosphere, the pressure of the mixed atmosphere is 2-6 MPa.

[0011] Optionally, the volume ratio of hydrogen to carbon monoxide in the mixed atmosphere is (0.1-10):1.

[0012] Preferably, the volume ratio of hydrogen to carbon monoxide in the mixed atmosphere is 1:1.

[0013] Optionally, the noble metal catalyst includes at least one of a supported catalyst and a metal salt catalyst; wherein the metal element supported on the supported catalyst includes at least one of rhodium, iridium, palladium and ruthenium, and the metal element in the metal salt catalyst includes at least one of rhodium, iridium, palladium and ruthenium.

[0014] Optionally, the molar ratio of the metal element to the tetrahydrofurfural is 1:(1-1000).

[0015] Preferably, the molar ratio of the metal element to the tetrahydrofurfural is 1:20.

[0016] Optionally, the iodine promoter includes at least one of elemental iodine, organic iodine, hydroiodic acid, and metal iodides.

[0017] Optionally, the molar ratio of iodine element in the iodine accelerator to tetrahydrofuranic acid is (0.2-5):1.

[0018] Preferably, the molar ratio of iodine element in the iodine accelerator to tetrahydrofuranic acid is 1:1.

[0019] Optionally, the solvent environment includes an organic acid, and the organic acid includes at least one of acetic acid, propionic acid, and trifluoroacetic acid.

[0020] Preferably, the solvent environment further includes deionized water.

[0021] Optionally, tetrahydrofuranic acid is carbonylated at 100-280℃ for 1-15 hours to produce adipic acid.

[0022] Preferably, tetrahydrofuranic acid is carbonylated at 100-280℃ for 10 hours to produce adipic acid.

[0023] Preferably, tetrahydrofuranic acid undergoes a carbonylation reaction at 100-180℃ to produce adipic acid. Attached Figure Description

[0024] Figure 1 This is the reaction formula for the carbonylation reaction of tetrahydrofuranic acid to produce adipic acid in this invention;

[0025] Figure 2 The above is the hydrogen NMR spectrum of the mixture containing adipic acid prepared in Example 1 of this invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0027] This invention provides a method for preparing adipic acid from tetrahydrofuranic acid. In a mixed atmosphere of hydrogen and carbon monoxide, tetrahydrofuranic acid undergoes a carbonylation reaction at 100-280°C in a solvent environment under the action of a noble metal catalyst and an iodine promoter to generate adipic acid.

[0028] In fact, under the action of noble metal catalyst and iodine accelerator, tetrahydrofuranic acid first reacts with iodine accelerator to generate 5-iodovalanoic acid, 5-iodovalanoic acid then undergoes carbonylation reaction to generate adipic acid, and iodine accelerator is regenerated.

[0029] Specifically, see Figure 1 When tetrahydrofuranic acid undergoes a carbonylation reaction to form adipic acid, the reaction formula is as follows:

[0030]

[0031] In some embodiments, when tetrahydrofuranic acid is carbonylated to produce adipic acid in a mixed atmosphere, the pressure environment of the mixed atmosphere during the reaction is 1-10 MPa. Reactions under this pressure environment are well promoted. In fact, variations in the mixed atmosphere within this range will affect the conversion rate of tetrahydrofuranic acid and the yield of adipic acid.

[0032] In some embodiments, when tetrahydrofuranic acid undergoes a carbonylation reaction to generate adipic acid under a mixed atmosphere at a pressure of 2-6 MPa, the conversion rate of tetrahydrofuranic acid and the yield of adipic acid can be improved.

[0033] In some embodiments, when tetrahydrofuranic acid is carbonylated in a mixed atmosphere to produce adipic acid, the volume ratio of hydrogen to carbon monoxide in the mixed atmosphere is 1:1. Adjusting the mixing ratio of hydrogen to carbon monoxide by increasing the CO pressure or the H2 pressure will lead to a decrease in the conversion rate of tetrahydrofuranic acid and the yield of adipic acid. Specifically, the mixing ratio of hydrogen to carbon monoxide during the tetrahydrofuranic acid reaction can be adjusted by controlling the gas pressure of hydrogen and carbon monoxide in the reaction atmosphere.

[0034] In some embodiments, the noble metal catalyst used in the reaction process includes at least one of a supported catalyst and a metal salt catalyst; wherein the metal element supported on the supported catalyst includes at least one of rhodium, iridium, palladium and ruthenium, and the metal element in the metal salt catalyst includes at least one of rhodium, iridium, palladium and ruthenium.

[0035] In practice, the molar ratio of the metal element to the tetrahydrofuranic acid is 1:(1-1000), preferably 1:20.

[0036] In some embodiments, the iodine accelerator used in the reaction process includes at least one of elemental iodine, organic iodine, hydroiodic acid, and metal iodides. Specifically, the molar ratio of elemental iodine in the iodine accelerator to the tetrahydrofuronic acid is (0.2-5):1, preferably 1:1.

[0037] In some embodiments, the solvent environment includes an organic acid, and the organic acid includes at least one of acetic acid, propionic acid, and trifluoroacetic acid; preferably, the solvent environment also includes deionized water.

[0038] In some embodiments, tetrahydrofuranic acid is carbonylated at 100-280°C for 1-15 hours to generate adipic acid. Preferably, the reaction time is 10 hours, and preferably, tetrahydrofuranic acid is carbonylated at 100-180°C.

[0039] Example 1

[0040] Example 1 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0041] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0042] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0043] The mixture obtained in Example 1 was characterized by proton NMR spectroscopy, and the proton NMR spectrum is shown below. Figure 1 As shown, D2O is the NMR test solvent, acetic acid is the reaction solvent in the mixture, and maleic acid is the internal standard. From Figure 1 As can be seen from the data, almost all of the tetrahydrofuranic acid in Example 1 was converted into adipic acid.

[0044] Example 2

[0045] Example 2 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0046] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of IrCl3, 0.5 mmol of I2, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0047] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0048] Example 3

[0049] Example 3 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0050] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RuCl3, 0.5 mmol of I2, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0051] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0052] Example 4

[0053] Example 4 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0054] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of PtCl2, 0.5 mmol of I2 and 5 mL of acetic acid into a 50 mL stainless steel autoclave and stir to mix, so as to obtain the reaction solution.

[0055] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0056] Example 5

[0057] Example 5 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0058] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 1 mmol of LiI, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0059] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0060] Example 6

[0061] Example 6 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0062] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 1 mmol of HI, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix, so as to obtain the reaction solution.

[0063] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0064] Example 7

[0065] Example 7 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0066] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 1 mmol of CH3I, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0067] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0068] Example 8

[0069] Example 8 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0070] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 1 mmol of NaI, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0071] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0072] Example 9

[0073] Example 9 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0074] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of trifluoroacetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0075] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0076] Example 10

[0077] Example 10 of this invention provides a method for preparing adipic acid from tetrahydrofurfural, comprising the following steps:

[0078] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0079] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 180°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0080] Example 11

[0081] Example 11 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0082] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0083] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 100°C and stirred for 10 hours. After filtration, a mixture containing adipic acid is obtained.

[0084] Example 12

[0085] Example 12 of this invention provides a method for preparing adipic acid from tetrahydrofurfural, comprising the following steps:

[0086] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0087] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure are maintained at 3 MPa and 3 MPa respectively. The autoclave is then heated to 170°C and stirred for 1 hour. After filtration, a mixture containing adipic acid is obtained.

[0088] Example 13

[0089] Example 13 of this invention provides a method for preparing adipic acid from tetrahydrofurfural, comprising the following steps:

[0090] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0091] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure in the autoclave is maintained at 2 MPa and the carbon monoxide pressure is maintained at 4 MPa. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration and separation, a mixture containing adipic acid is obtained.

[0092] Example 14

[0093] Example 14 of this invention provides a method for preparing adipic acid from tetrahydrofuranic acid, comprising the following steps:

[0094] S1. Add 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of acetic acid and 2 mL of deionized water into a 50 mL stainless steel autoclave and stir to mix to obtain the reaction solution.

[0095] S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide are introduced into the autoclave. The hydrogen pressure in the autoclave is maintained at 4 MPa and the carbon monoxide pressure is maintained at 2 MPa. The autoclave is then heated to 170°C and stirred for 10 hours. After filtration and separation, a mixture containing adipic acid is obtained.

[0096] The concentration of adipic acid in the mixtures obtained in Examples 1 to 14 was detected using a Waters H-Class series high-performance liquid chromatograph (RID detector, Alltech OA-1000 OrganicAcids HPLC (300mm×6.5mm), flow rate 0.6mL / min, column temperature 60℃, mobile phase 0.1g / L dilute sulfuric acid), and the adipic acid yield was calculated as shown in Table 1 below.

[0097] Table 1. Adipic acid yield in Examples 1 to 14

[0098]

[0099]

[0100] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A method for preparing adipic acid from tetrahydrofurfural, characterized in that, Includes the following steps: S1. 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of acetic acid, and 2 mL of deionized water were added to a 50 mL stainless steel autoclave and stirred to prepare the reaction solution. S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide were introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure in the autoclave were maintained at 3 MPa and 3 MPa, respectively. The autoclave was then heated to 170 °C and stirred for 10 h. After filtration, a mixture containing adipic acid was obtained.

2. A method for preparing adipic acid from tetrahydrofurfural, characterized in that, Includes the following steps: S1. 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 1 mmol of HI, 3 mL of acetic acid, and 2 mL of deionized water were added to a 50 mL stainless steel autoclave and stirred to prepare the reaction solution. S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide were introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure in the autoclave were maintained at 3 MPa and 3 MPa, respectively. The autoclave was then heated to 170 °C and stirred for 10 h. After filtration, a mixture containing adipic acid was obtained.

3. A method for preparing adipic acid from tetrahydrofurfural, characterized in that, Includes the following steps: S1. 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of trifluoroacetic acid, and 2 mL of deionized water were added to a 50 mL stainless steel autoclave and stirred to prepare the reaction solution. S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide were introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure in the autoclave were maintained at 3 MPa and 3 MPa, respectively. The autoclave was then heated to 170 °C and stirred for 10 h. After filtration, a mixture containing adipic acid was obtained.

4. A method for preparing adipic acid from tetrahydrofurfural, characterized in that, Includes the following steps: S1. 1 mmol of tetrahydrofuranic acid, 0.1 mmol of RhCl3, 0.5 mmol of I2, 3 mL of acetic acid, and 2 mL of deionized water were added to a 50 mL stainless steel autoclave and stirred to prepare the reaction solution. S2. After replacing the air in the autoclave with hydrogen, hydrogen and carbon monoxide were introduced into the autoclave. The hydrogen pressure and carbon monoxide pressure in the autoclave were maintained at 3 MPa and 3 MPa, respectively. The autoclave was then heated to 180 °C and stirred for 10 h. After filtration, a mixture containing adipic acid was obtained.

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