A method for preparing adipic acid from furan-2,5-dicarboxylate derivatives

Abstract

The application discloses a method for preparing adipic acid. The method comprises the following steps: converting furan-2,5-dicarboxylic acid ester derivatives into adipic acid by a chemical catalytic method in water. Specifically, furan-2,5-dicarboxylic acid ester derivatives are reacted with hydrogen in an aqueous solution under the catalysis of a hydrogen-deoxidization catalyst, so that adipic acid is obtained. The method realizes the preparation of adipic acid from furan-2,5-dicarboxylic acid ester derivatives, has high product yield, and is simple in operation and green and environment-friendly.

Description

Technical Field

[0001] This invention relates to a method for preparing adipic acid, specifically a method for preparing adipic acid from furan-2,5-dicarboxylic acid ester derivatives. Background Technology

[0002] Adipic acid, commonly known as fatty acid, is a white monoclinic crystal at room temperature. It is an aliphatic dicarboxylic acid that polymerizes with hexamethylenediamine or polyols to form nylon 66 salt complexes or polyester polyols, primarily used in the production of nylon or polyurethane products. With the continued growth in demand for nylon 66 and the diversification of adipic acid's applications, the demand for adipic acid products is constantly increasing. Currently, global annual production of adipic acid exceeds 3.5 million tons and continues to grow at a rate of approximately 3% annually. my country, as a major consumer of adipic acid, accounts for about 30% of global consumption. Simultaneously, market competition is intensifying, and the adipic acid industry needs to fully meet current market demands and further achieve industrial transformation and innovation.

[0003] However, the existing production of adipic acid all uses petrochemical products as raw materials, and is therefore also known as petroleum-based adipic acid production technology. These technologies all have problems such as environmental pollution and equipment corrosion, and there is an urgent need to research and develop a greener and more environmentally friendly new route.

[0004] On the other hand, with the continuous depletion of fossil resources such as oil, developing and utilizing other renewable and abundant resources to produce bulk chemicals, fine chemicals, and polymer materials to supplement the shortage of oil resources is of great significance. Biomass is the only renewable organic carbon source on Earth that can simultaneously provide fuel and chemicals, playing a role in completely replacing fossil resources. Biomass energy is an important new energy source in the world, with mature technology and wide applications. It plays an important role in addressing global climate change, energy supply and demand imbalances, and protecting the ecological environment. It is the world's fourth largest energy source after oil, coal, and natural gas, becoming an important force in international energy transition. Developed countries and regions, including the United States and the European Union, have introduced various policies to support the development of biomass energy. my country has abundant biomass resources and great potential for energy utilization. During the "12th Five-Year Plan" period, my country's biomass energy industry developed rapidly, with the scale of development and utilization continuously expanding, and biomass power generation and liquid fuels reaching a certain scale. The "13th Five-Year Plan" period is an important period for realizing energy transformation and upgrading, and a key period for new urbanization construction, ecological civilization construction, and building a moderately prosperous society in all respects. Biomass energy faces important opportunities for industrial development. Therefore, developing a green production process for adipic acid based on biomass raw materials or platform molecules is of great significance to the sustainable development of human society.

[0005] Furan-2,5-dicarboxylic acid (FDCA) is considered a platform molecule for the conversion of cellulose, hemicellulose, and starch from biomass into fuels and downstream chemicals. In fact, as early as 2004, the U.S. Department of Energy listed FDCA as one of the "twelve most important platform molecules" for future biomass conversion and utilization. The U.S. government has solicited proposals for the use of FDCA in the production of industrial chemicals. Currently, chemical technologies for producing FDCA products are developing rapidly both domestically and internationally, laying a solid foundation for its downstream conversion.

[0006] CN102803196A discloses a two-step route for synthesizing adipic acid from furan-2,5-dicarboxylic acid. This route uses acetic acid as a solvent. First, furan-2,5-dicarboxylic acid is hydrogenated using a Pd / SiO2 catalyst to obtain tetrahydrofuran-2,5-dicarboxylic acid. Then, in the presence of HBr or HI, the tetrahydrofuran-2,5-dicarboxylic acid is hydrogenated and deoxygenated to obtain the adipic acid product. However, since HI is a highly corrosive acid, it significantly increases the corrosiveness of the above process to equipment and reduces its environmental friendliness. Therefore, this process is unlikely to meet the production requirements of future green chemical industries.

[0007] CN107011154A discloses a method for preparing adipic acid from furan-2,5-dicarboxylic acid in aqueous solution. The catalyst is a mixture of a supported noble metal catalyst and an unsupported metal oxide (or heteropolyacid), or a catalyst formed by co-supporting noble metal and metal oxide (or heteropolyacid). The reaction temperature is 60℃~140℃. The catalyst activity and selectivity are poor, and the yield of adipic acid can only reach a maximum of 75%. Summary of the Invention

[0008] The purpose of this invention is to provide a novel method for preparing adipic acid from furan-2,5-dicarboxylic acid ester derivatives, which is green and environmentally friendly and has a high yield.

[0009] The present invention provides a method for preparing adipic acid, comprising: reacting the furan-2,5-dicarboxylic acid ester derivative with hydrogen in an aqueous solution under the catalysis of a hydrodeoxygenation catalyst to obtain the adipic acid.

[0010] The furan-2,5-dicarboxylic acid ester derivatives mentioned herein are ester derivatives formed by furan-2,5-dicarboxylic acid and at least one C1-C4 alcohol, including but not limited to: monomethyl furan-2,5-dicarboxylic acid, dimethyl furan-2,5-dicarboxylic acid, monoethyl furan-2,5-dicarboxylic acid, diethyl furan-2,5-dicarboxylic acid, monopropyl furan-2,5-dicarboxylic acid, dipropyl furan-2,5-dicarboxylic acid, monobutyl furan-2,5-dicarboxylic acid, dibutyl furan-2,5-dicarboxylic acid, methyl ethyl furan-2,5-dicarboxylic acid, methyl propyl furan-2,5-dicarboxylic acid, methyl butyl furan-2,5-dicarboxylic acid, ethyl propyl furan-2,5-dicarboxylic acid, ethyl butyl furan-2,5-dicarboxylic acid, propyl butyl furan-2,5-dicarboxylic acid, etc.

[0011] Specifically, the hydrodeoxygenation catalyst may be one of the following (A), (B), or (C):

[0012] (A) A mixture of a supported noble metal catalyst and at least one metal oxide;

[0013] (B) A mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst or at least one supported heteropolyacid catalyst;

[0014] (C) A catalyst formed by co-supporting a noble metal with at least one metal oxide or at least one heteropolyacid.

[0015] The inventors of this application have unexpectedly discovered that using furan-2,5-dicarboxylic acid ester derivatives as reactants can provide a novel method for preparing adipic acid, achieving a total adipic acid yield of up to 93%, and the process is green and environmentally friendly, with significant social benefits. Detailed Implementation

[0016] A method for preparing adipic acid includes reacting a furan-2,5-dicarboxylic acid ester derivative with hydrogen in an aqueous solution in the presence of a hydrodeoxygenation catalyst to obtain the adipic acid.

[0017] Wherein: the furan-2,5-dicarboxylic acid ester derivatives are ester derivatives formed by furan-2,5-dicarboxylic acid and at least one C1-C4 alcohol, including but not limited to: dimethyl furan-2,5-dicarboxylic acid, diethyl furan-2,5-dicarboxylic acid, dipropyl furan-2,5-dicarboxylic acid, dibutyl furan-2,5-dicarboxylic acid, methyl ethyl furan-2,5-dicarboxylic acid, methyl propyl furan-2,5-dicarboxylic acid, methyl butyl furan-2,5-dicarboxylic acid, ethyl propyl furan-2,5-dicarboxylic acid, ethyl butyl furan-2,5-dicarboxylic acid, propyl butyl furan-2,5-dicarboxylic acid, etc.

[0018] Wherein: the hydrodeoxygenation catalyst is one or more of the following (A), (B), or (C):

[0019] (A) A mixture of a supported noble metal catalyst and at least one metal oxide;

[0020] (B) A mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst and / or at least one supported heteropolyacid catalyst;

[0021] (C) A catalyst formed by co-supporting a noble metal with at least one metal oxide and / or at least one heteropolyacid.

[0022] The hydrodeoxygenation catalyst is preferably a mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst and / or at least one supported heteropolyacid catalyst, or a catalyst formed by co-supporting a noble metal with at least one heteropolyacid.

[0023] In the hydrodeoxygenation catalyst (A):

[0024] The supported noble metal catalyst comprises a support and a noble metal supported on the support. Based on the total mass of the support, the loading of the noble metal is 0.25% to 10%, preferably 0.5% to 5%, and more preferably 1% to 3%. The noble metal is selected from one or more of Ru, Rh, Pd, Os, Ir, and Pt. The support is selected from one or more of activated carbon, silica, zirconium oxide, and titanium dioxide.

[0025] The metal oxide is one or more of MoO3, WO3, or ReO3;

[0026] The mass ratio of the supported noble metal catalyst to the metal oxide is 1:0.1 to 100, preferably 1:0.2 to 10, and more preferably 1:0.5 to 5.

[0027] In the hydrodeoxygenation catalyst (B):

[0028] The supported noble metal catalyst comprises a support and a noble metal supported on the support. Based on the total mass of the support, the loading of the noble metal is 0.25% to 10%, preferably 0.5% to 5%, more preferably 1% to 3%; and / or the noble metal is selected from one or more of Ru, Rh, Pd, Os, Ir and Pt; the support is selected from one or more of activated carbon, silica, zirconium oxide and titanium dioxide.

[0029] The supported metal oxide catalyst comprises a support and a metal oxide supported on the support. Based on the total mass of the support, the loading of the metal oxide is 0.25% to 90%, preferably 1% to 60%, and more preferably 5% to 30%. The metal oxide is selected from one or more of MoO3, WO3, or ReO3. The support is selected from one or more of activated carbon, silica, zirconium oxide, or titanium dioxide.

[0030] The supported heteropolyacid catalyst comprises a support and a heteropolyacid supported on the support. Based on the total mass of the support, the loading of the heteropolyacid is 0.25%–90%, preferably 1–60%, more preferably 5–30%. The metal atoms in the heteropolyacid are selected from one or more of W, Mo, Re, V, Nb, and Ta, and the heteroatoms are selected from one or more of Si or P. Preferably, it contains one or more of tungsten-containing heteropolyacids, molybdenum-containing heteropolyacids, or rhenium-containing heteropolyacids, more preferably phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicotonic acid, and phosphorhenic acid. The support is selected from one or more of activated carbon, silicon dioxide, zirconium oxide, or titanium dioxide.

[0031] The hydrodeoxygenation catalyst (B) may be a mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst, or a mixture of a supported noble metal catalyst and at least one supported heteropolyacid catalyst, or a mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst and at least one supported heteropolyacid catalyst.

[0032] Wherein, (mass of supported noble metal catalyst): (mass of supported metal oxide catalyst and / or supported heteropolyacid catalyst) = 1:0.1 to 100, preferably 1:0.2 to 10, more preferably 1:0.5 to 5.

[0033] The hydrodeoxygenation catalyst (C) is a catalyst formed by co-supporting the noble metal with at least one metal oxide and / or at least one heteropolyacid. It includes a support and the noble metal, metal oxide, and / or heteropolyacid supported on the support. Based on the total mass of the support, the loading of the noble metal is 0.25%–10%, preferably 0.5%–5%, more preferably 1%–3%; the loading of the metal oxide is 0.25%–90%, preferably 1%–60%, more preferably 5%–30%; and the loading of the heteropolyacid is 0.25%–90%, preferably 1%–60%, more preferably 5%–30%.

[0034] The carrier is selected from one or more of activated carbon, silicon dioxide, zirconium oxide, and titanium dioxide; the noble metal is selected from one or more of Ru, Rh, Pd, Os, Ir, and Pt; and the metal oxide is selected from one or more of MoO3, WO3, or ReO3. The metal atoms in the heteropolyacid are selected from one or more of W, Mo, Re, V, Nb, and Ta, and the heteroatoms are selected from one or more of Si or P. Preferably, it is a tungsten-containing heteropolyacid, a molybdenum-containing heteropolyacid, or a rhenium-containing heteropolyacid, and more preferably, phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicotonic acid, and phosphorhenic acid.

[0035] According to the method of the present invention, the molar ratio of the noble metal in the hydrodeoxygenation catalyst to the furan-2,5-dicarboxylic acid ester derivative is 1:1 to 1000, preferably 1:5 to 500, and more preferably 1:20 to 80.

[0036] The reaction is carried out at a pressure of 1 MPa to 10 MPa, preferably 1 to 8 MPa, and more preferably 2 to 5 MPa.

[0037] The reaction temperature is 100℃~300℃, preferably 150℃~240℃, and more preferably 180℃~220℃.

[0038] The reaction time can be 1 to 40 hours, preferably 5 to 30 hours, and more preferably 10 to 20 hours.

[0039] According to the method of the present invention, the supported noble metal catalyst can be prepared according to existing methods, such as isochoric impregnation, initial wet impregnation, ion exchange, deposition-precipitation, or vacuum impregnation. For example, in the specific preparation by isochoric impregnation, the metal precursor solution is diluted and stirred evenly. Then, a certain mass of support is added to the mixture, and after stirring and impregnation at room temperature for 6-24 hours, the water is evaporated, and then dried in an oven at 100-140°C for about 6-24 hours to obtain the catalyst precursor. The precursor prepared in the above steps is placed in a quartz tube and calcined in air at 300-800°C for about 6-24 hours, and then reduced in a reducing atmosphere (such as H2 or a mixture of H2 and N2) at 200-500°C for about 6-24 hours to obtain the supported noble metal catalyst.

[0040] According to one embodiment of the present invention, the mixture of the supported noble metal catalyst and at least one metal oxide can be prepared by simple mechanical mixing. The metal oxide and the supported noble metal catalyst can be ground evenly in a certain proportion before being added to the reactor, or they can be added to the reactor separately in a certain proportion.

[0041] According to the method of the present invention, the supported metal oxide catalyst or supported heteropolyacid catalyst can be prepared according to existing methods, such as isochoric impregnation, initial wet impregnation, ion exchange, deposition-precipitation, or vacuum impregnation. Specifically, after the metal oxide precursor or heteropolyacid precursor is deposited, the solid powder is dried in an oven at 100–140°C for approximately 6–24 hours. The resulting supported catalyst precursor is then calcined in air at 300–800°C for approximately 6–24 hours to obtain the supported metal oxide catalyst or supported heteropolyacid catalyst. The metal oxide precursor is typically an ammonium salt that can decompose into the metal oxide at the calcination temperature. For example, when the supporting component is ReO3, ammonium perrhenate can be selected as the precursor; when the supporting component is MoO3, ammonium molybdate can be selected as the precursor; and when the supporting component is WO3, ammonium metatungstate can be selected as the precursor. The precursors of heteropoly acids are usually water-soluble heteropoly acid crystals that can decompose at calcination temperature. For example, when the supporting component is a tungsten-containing heteropoly acid, such as phosphotungstic acid or silicotungstic acid, the corresponding tungsten-containing heteropoly acid, such as phosphotungstic acid or silicotungstic acid, can be selected as the precursor. When the supporting component is a molybdenum-containing heteropoly acid, the corresponding molybdenum-containing heteropoly acid, such as phosphotungstic acid or silicotungstic acid, can be selected as the precursor.

[0042] According to one embodiment of the present invention, a mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst or at least one supported heteropolyacid catalyst can be prepared by simple mechanical mixing. The supported metal oxide catalyst or the supported heteropolyacid catalyst and the supported noble metal catalyst can be ground evenly in a certain proportion before being added to the reactor, or they can be added to the reactor separately in a certain proportion.

[0043] According to one embodiment of the present invention, the catalyst formed by co-supporting the noble metal with at least one metal oxide or at least one heteropolyacid can be prepared by a stepwise loading method: firstly, a precursor of the target metal oxide or heteropolyacid is deposited on a support, dried, and then calcined in air at a temperature of 300-800°C for about 6-24 hours to obtain a support modified with the target metal oxide or heteropolyacid; then, a certain proportion of noble metal is loaded on the support using the method for preparing the supported catalyst, and finally the co-supported catalyst is obtained.

[0044] When preparing adipic acid and its derivatives using the method of this invention, the reaction can be carried out in a reaction vessel. After the reaction is completed, the reaction vessel is removed, cooled to room temperature, the pressure is released, the vessel lid is opened, and the liquid-solid mixture is removed for filtration separation. The obtained liquid is analyzed by liquid chromatography or gas chromatography, and the conversion rate and product yield are calculated. The method of this invention can also use other conventional reactors, such as fixed-bed reactors.

[0045] The method for preparing adipic acid provided by this invention uses furan-2,5-dicarboxylic acid ester derivatives as reactants and water as a solvent. Except for the heterogeneous catalyst used, no other impurities are introduced. Therefore, the method of this invention not only further reduces production costs, but is also more environmentally friendly.

[0046] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0047] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0048] Preparation Example 1

[0049] Preparation of hydrogenation catalyst with 2% Ru / C:

[0050] 2.1 mL of a 0.1 mol / L RuCl2 solution and 3.0 mL of deionized water were mixed and stirred until homogeneous. Then, 1.00 g of activated carbon support was added to the mixture. After stirring and impregnation at room temperature for 10 hours, the water was evaporated, and then the mixture was dried in an oven at 110 °C for 12 hours to obtain the catalyst precursor RuCl2 / C. The Ru loading was 2% (mass percentage). The precursor prepared in the above steps was placed in a quartz tube and calcined in air at 500 °C for 4 hours, followed by reduction in 20% H2 + N2 at 200 °C for 3 hours to obtain the supported 2% Ru / C catalyst.

[0051] Supported noble metal catalysts were prepared according to the above method, with 2% Rh / ZrO2 and 2% Ir / TiO2 respectively.

[0052] Preparation Example 2

[0053] Preparation of 20% MoO3 / TiO2 supported metal oxide catalyst:

[0054] 0.46 g of ammonium molybdate and 5.0 mL of water were mixed and stirred until homogeneous. Then, 1.00 g of TiO2 support was added to the mixture. After stirring and impregnation at room temperature for 10 hours, the water was evaporated, and then the mixture was dried in an oven at 110 °C for 12 hours to obtain the catalyst precursor. The MoO3 loading was 20% (mass percentage). The precursor prepared in the above steps was placed in a quartz tube and calcined in air at 500 °C for 3 hours to obtain 20% MoO3 / TiO2.

[0055] The supported metal oxide catalyst 10% ReO3 / SiO2 was prepared according to the above method. Different supported metal oxide catalysts can be prepared by selecting the precursor corresponding to their supporting components. For example, when the supporting component is ReO3, ammonium perrhenate can be selected as the precursor.

[0056] Preparation Example 3

[0057] Supported heteropolyacid catalyst 40% PWO x Preparation of ZrO2:

[0058] 0.44 g of phosphomolybdic acid and 5.0 mL of water were mixed and stirred until homogeneous. Then, 1.00 g of TiO2 support was added to the mixture. After stirring and impregnation at room temperature for 10 hours, the water was evaporated, and then the mixture was dried in an oven at 110 °C for 12 hours to obtain the catalyst precursor. The MoO3 loading was 20% (mass percentage). The precursor prepared in the above steps was placed in a quartz tube and calcined in air at 500 °C for 3 hours to obtain 40% PWO3. x / ZrO2.

[0059] The preparation methods for different supported heteropolyacid catalysts are similar to those for supported metal oxides. The precursors corresponding to the supported components can be selected and prepared accordingly. For example, when the supported component is a tungsten-containing heteropolyacid, such as phosphotungstic acid or silicotungstic acid, the corresponding tungsten-containing heteropolyacid, such as phosphotungstic acid or silicotungstic acid, can be selected as the precursor. When the supported component is a molybdenum-containing heteropolyacid, the corresponding molybdenum-containing heteropolyacid, such as phosphotungstic acid or silicotungstic acid, can be selected as the precursor.

[0060] The supported heteropolyacid catalyst 40% PWO was prepared according to the above method. x / ZrO2.

[0061] Preparation Example 4

[0062] Preparation of a hydrodeoxygenation catalyst of 2% Ir / 40% WO3 / TiO2 (co-supported):

[0063] 0.76 g of ammonium metatungstate and 5.0 mL of water were mixed and stirred until homogeneous. Then, 1.00 g of TiO2 support was added to the mixture. After stirring and impregnation at room temperature for 10 hours, the water was evaporated, and then the mixture was dried in an oven at 110 °C for 12 hours to obtain the catalyst precursor. The WO3 loading was 40% (mass percentage). The precursor prepared in the above steps was placed in a quartz tube and calcined in air at 500 °C for 3 hours to obtain 40% WO3 / TiO2.

[0064] 2.1 mL of a 0.1 mol / L H₂IrCl₆ aqueous solution and 3.0 mL of deionized water were mixed and stirred until homogeneous. Then, 1.00 g of the 40% WO₃ / TiO₂ obtained in the previous step was added to the mixture. After stirring and impregnation at room temperature for 10 hours, the water was evaporated, and then the mixture was dried in an oven at 110 °C for 12 hours to obtain the catalyst precursor H₂IrCl₆ / 40% WO₃ / TiO₂. The Ir loading was 2% (mass percentage). The precursor prepared in the above steps was placed in a quartz tube and calcined in air at 500 °C for 3 hours, followed by reduction in 20% H₂ + N₂ at 200 °C for 3 hours to obtain the supported 2% Ir / 40% WO₃ / TiO₂ catalyst.

[0065] Prepare 2% Rh / 10% ReO3 / SiO2 and 2% Pt / 20% SiMoO2 according to the above method. x / ZrO2.

[0066] Different co-supported components can be prepared by selecting their corresponding precursors. For example, when the co-supported component is ReO3, ammonium perrhenate can be selected as the precursor; when the co-supported component is silicomolybdenum heteropolyacid, silicomolybdenum heteropolyacid can be selected as the precursor.

[0067] Example 1: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0068] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0069] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.2 g of commercial WO3, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0070] Example 2: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0071] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0072] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.2 g of commercial WO3, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 100 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0073] Example 3: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0074] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0075] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.2 g of commercial WO3, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 150 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0076] Example 4: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0077] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0078] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.2 g of commercial WO3, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to a reaction temperature of 240 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0079] Example 5: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0080] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0081] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.2 g of commercial WO3, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 2 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to a reaction temperature of 280 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0082] Example 6: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0083] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0084] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.15 g of commercial WO3, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0085] Example 7: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0086] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0087] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.5 g of commercial WO3, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0088] Example 8: Preparation of adipic acid from diethyl furan-2,5-dicarboxylic acid

[0089] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0090] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.2 g of commercial WO3, 0.5 g of diethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0091] Example 9: Preparation of adipic acid from di-n-butyl furan-2,5-dicarboxylic acid

[0092] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0093] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.2 g of commercial WO3, 0.5 g of di-n-butyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to a reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0094] Example 10: Preparation of adipic acid from methyl ethyl furan-2,5-dicarboxylic acid

[0095] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 was used as the catalyst.

[0096] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.2 g of commercial WO3, 0.5 g of methyl ethyl furan-2,5-dicarboxylic acid, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0097] Example 11: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0098] 2% Rh / ZrO2+MoO3 was used as the catalyst.

[0099] In a 30 mL high-pressure reactor, 0.2 g of 2% Rh / ZrO2 catalyst (where the molar ratio of Rh to reactants is approximately 1:30), 0.2 g of commercial MoO3, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0100] Example 12: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0101] 2% Ru / C + 20% MoO3 / TiO2 was used as the catalyst.

[0102] In a 30 mL high-pressure reactor, 0.2 g of 2% Ru / C catalyst (where the molar ratio of Ru to reactants is approximately 1:30), 0.2 g of 20% MoO3 / TiO2 catalyst, 0.5 g of dimethyl furan-2,5-dicarboxylic acid, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 6 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 180 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0103] Example 13: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0104] 2% Ru / C + 20% MoO3 / TiO2 was used as the catalyst.

[0105] In a 30 mL high-pressure reactor, 0.2 g of 2% Ru / C catalyst (where the molar ratio of Ru to reactants is approximately 1:30), 0.15 g of 20% MoO3 / TiO2 catalyst, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 6 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 180 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0106] Example 14: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0107] 2% Ru / C + 20% MoO3 / TiO2 was used as the catalyst.

[0108] In a 30 mL high-pressure reactor, 0.2 g of 2% Ru / C catalyst (where the molar ratio of Ru to reactants is approximately 1:30), 0.5 g of 20% MoO3 / TiO2 catalyst, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 6 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 180 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0109] Example 15: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0110] 2% Ir / TiO2 + 10% ReO3 / SiO2 was used as the catalyst.

[0111] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.2 g of 10% ReO3 / SiO2 catalyst, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0112] Example 16: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0113] With 2% Rh / ZrO2 + 40% PWO x / ZrO2 as a catalyst.

[0114] In a 30 mL high-pressure reactor, add 0.2 g of 2% Rh / ZrO2 catalyst (where the molar ratio of Rh to reactants is approximately 1:30) and 0.2 g of 40% PWO4. xThe reaction vessel was prepared using ZrO2 catalyst, 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water. After sealing the vessel, residual air was replaced by 2 MPa of hydrogen gas. This process was repeated three times. Then, 2 MPa of hydrogen gas was introduced into the vessel, and it was heated to 220 °C in a furnace. The mixture was stirred at 700 rpm for 20 hours. After the reaction, the vessel was removed from the furnace and cooled to room temperature. The pressure inside the vessel was reduced to atmospheric pressure, the lid was opened, and the liquid-solid mixture was removed and separated by filtration. The resulting liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are shown in Table 1.

[0115] Example 17: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0116] 2% Ir / 40% WO3 / TiO2 was used as the catalyst.

[0117] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / 40% WO3 / TiO2 catalyst (where the molar ratio of Ir to reactants is approximately 1:60), 0.5 g of dimethyl furan-2,5-dicarboxylate, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to the reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0118] Example 18: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0119] 2% Rh / 10% ReO3 / SiO2 was used as the catalyst.

[0120] In a 30 mL high-pressure reactor, 0.2 g of 2% Rh / 10% ReO3 / SiO2 catalyst (where the molar ratio of Rh to reactants is approximately 1:30), 0.5 g of dimethyl furan-2,5-dicarboxylic acid, and 10 mL of water were added. After sealing the reactor, 2 MPa of hydrogen gas was introduced to replace the residual air in the reactor. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to a reaction temperature of 200 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace and cooled to room temperature. The pressure inside the reactor was reduced to atmospheric pressure, the reactor lid was opened, and the liquid-solid mixture was removed and separated by vacuum filtration. The obtained liquid was analyzed by liquid chromatography, and the conversion rate and product yield were calculated. The reaction results are listed in Table 1.

[0121] Example 19: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0122] With 2% Pt / 20% SiMoO x / ZrO2 as a catalyst.

[0123] In a 30 mL high-pressure reactor, add 0.2 g of 2% Pt / 20% SiMoO. x The reaction vessel was prepared using ZrO2 catalyst (with a Pt molar ratio of approximately 1:60 to the reactants), 0.5 g of dimethyl furan-2,5-dicarboxylic acid, and 10 mL of water. After sealing the vessel, residual air was replaced by 2 MPa of hydrogen gas. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the vessel, and it was heated to 200 °C in a furnace. The mixture was stirred at 700 rpm for 20 hours. After the reaction, the vessel was removed from the furnace and cooled to room temperature. The pressure inside the vessel was reduced to atmospheric pressure, the lid was opened, and the liquid-solid mixture was removed and separated by filtration. The resulting liquid was analyzed by liquid chromatography, and the conversion and product yield were calculated. The reaction results are shown in Table 1.

[0124] Example 20: Preparation of adipic acid from dimethyl furan-2,5-dicarboxylic acid ester

[0125] With 2% Rh / 40% PWO x / ZrO2 as a catalyst.

[0126] Add 0.2g of 2% Rh / 40% PWO to a 30mL high-pressure reactor. x The reaction vessel was prepared using ZrO2 catalyst (with a molar ratio of Rh to reactants of approximately 1:30), 0.5 g of dimethyl furan-2,5-dicarboxylic acid, and 10 mL of water. After sealing the vessel, residual air was replaced by 2 MPa of hydrogen gas. This process was repeated three times. Then, 4 MPa of hydrogen gas was introduced into the vessel, and it was heated to 200 °C in a furnace. The mixture was stirred at 700 rpm for 20 hours. After the reaction, the vessel was removed from the furnace and cooled to room temperature. The pressure inside the vessel was reduced to atmospheric pressure, the lid was opened, and the liquid-solid mixture was removed and separated by filtration. The resulting liquid was analyzed by liquid chromatography, and the conversion and product yield were calculated. The reaction results are shown in Table 1.

[0127] As can be seen from the data in Table 1, the method for preparing adipic acid provided by this invention can effectively convert furan-2,5-dicarboxylic acid ester derivatives into adipic acid, an important chemical raw material, in aqueous solution. Starting from dimethyl furan-2,5-dicarboxylic acid ester, adipic acid yield of up to 93% can be obtained.

[0128] As can be seen from the examples, this method is applicable to a wide temperature range, but the reaction temperature has a significant impact on the yield of adipic acid. Too low or too high a reaction temperature will lead to a decrease in the yield of adipic acid.

[0129] As can be seen from the examples, this method is applicable to different types of furan-2,5-dicarboxylic acid ester derivatives. When furan-2,5-dicarboxylic acid dimethyl ester is used as the reactant, the yield of adipic acid is relatively high.

[0130] As can be seen from the examples, the catalysts of types (A), (B) and (C) described in this method can all achieve the catalytic conversion of furan-2,5-dicarboxylic acid ester derivatives to adipic acid. Among them, the catalyst of type (B), namely the mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst and / or at least one supported heteropolyacid catalyst, generally has a high adipic acid yield.

[0131] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0132] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0133] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

[0134] Table 1 Reaction conditions and adipic acid yield of the examples

[0135]

[0136]

Claims

1. A method for preparing adipic acid, comprising reacting a furan-2,5-dicarboxylic acid ester derivative with hydrogen in an aqueous solution in the presence of a hydrodeoxygenation catalyst to obtain the adipic acid, wherein the furan-2,5-dicarboxylic acid ester derivative is an ester derivative formed by furan-2,5-dicarboxylic acid and at least one C1-C4 alcohol; the reaction is carried out at a pressure of 1-8 MPa and a temperature of 180°C-220°C; the hydrodeoxygenation catalyst is a mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst and / or at least one supported heteropolyacid catalyst, wherein the mass ratio of the supported noble metal catalyst to the supported metal oxide catalyst and / or the supported heteropolyacid catalyst is 1:0.5-5; the supported noble metal catalyst consists of a support and a noble metal supported on the support, wherein the loading of the noble metal is 0.5-5% based on the total mass of the support. The noble metal is selected from one or more of Ru, Rh, and Ir, and the support is selected from one or more of activated carbon, silica, zirconium oxide, and titanium dioxide; the supported metal oxide catalyst consists of a support and a metal oxide supported on the support, with the loading of the metal oxide being 5-30% based on the total mass of the support, the metal oxide being selected from one or more of MoO3 and ReO3, and the support being selected from one or more of activated carbon, silica, zirconium oxide, and titanium dioxide; the supported heteropolyacid catalyst consists of a support and a heteropolyacid supported on the support, with the loading of the heteropolyacid being 5-60% based on the total mass of the support, the heteropolyacid being selected from phosphotungstic acid, and the support being selected from one or more of activated carbon, silica, zirconium oxide, and titanium dioxide; the molar ratio of the noble metal to the furan-2,5-dicarboxylic acid ester derivative in the hydrodeoxygenation catalyst is 1:10-100.

2. The method according to claim 1, wherein, The loading of the precious metal is 1-3%.

3. The method according to claim 1, wherein the reaction time is 1 to 40 hours.

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