A process for the preparation of adipic acid
By using a mixture of supported noble metal catalysts and metal oxide and/or heteropolyacid catalysts in aqueous solution for hydrogenation, the problems of environmental pollution and poor catalyst activity in existing adipic acid production have been solved, achieving high-yield and environmentally friendly adipic acid preparation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2019-01-16
- Publication Date
- 2026-06-16
AI Technical Summary
Existing adipic acid production technologies suffer from environmental pollution and equipment corrosion. Furthermore, the HI corrosive acid used in the existing furan-2,5-dicarboxylic acid hydrodeoxygenation process enhances equipment corrosion, making it difficult to meet the requirements of green chemical production. In addition, the catalyst has poor activity and selectivity, resulting in low adipic acid yield.
A mixture of supported noble metal catalysts and supported metal oxide and/or heteropolyacid catalysts was used as a hydrogenation deoxygenation catalyst to carry out hydrogenation reactions in aqueous solution. By adjusting the dispersion and texture of the catalyst, the reaction conditions were optimized to achieve efficient preparation of adipic acid.
It achieved a total yield of up to 95% for adipic acid, the process was green and environmentally friendly, reduced production costs and equipment corrosion, and met the production requirements of green chemistry.
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Abstract
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 and / or tetrahydrofuran-2,5-dicarboxylic acid. 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 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. Therefore, developing a green production process for adipic acid based on biomass raw materials or platform molecules is of great significance for 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] The preparation of adipic acid via the hydrogenation and deoxygenation of furan-2,5-dicarboxylic acid has the advantages of relatively readily available raw materials, low total hydrogen consumption, and a green and environmentally friendly process. It provides a low-cost and environmentally friendly method for preparing adipic acid.
[0007] 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.
[0008] 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
[0009] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a method for preparing adipic acid, which is green and environmentally friendly and has a high yield.
[0010] This invention provides a method for preparing adipic acid, comprising:
[0011] (A): In an aqueous solution, in the presence of a hydrodeoxygenation catalyst, tetrahydrofuran-2,5-dicarboxylic acid is reacted with hydrogen gas to obtain the adipic acid; or...
[0012] (B): In aqueous solution, in the presence of a hydrogenation catalyst and a hydrogenation deoxygenation catalyst, furan-2,5-dicarboxylic acid is reacted with hydrogen gas to obtain the adipic acid; or...
[0013] (C): In an aqueous solution, in the presence of a hydrogenation catalyst, furan-2,5-dicarboxylic acid is reacted with hydrogen to obtain tetrahydrofuran-2,5-dicarboxylic acid; in an aqueous solution, in the presence of a hydrogenation deoxygenation catalyst, the tetrahydrofuran-2,5-dicarboxylic acid is reacted with hydrogen to obtain adipic acid.
[0014] 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.
[0015] The inventors of this application have unexpectedly discovered that using a mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst and / or at least one supported heteropolyacid catalyst as a hydrodeoxygenation catalyst can independently and effectively modulate the dispersion and texture of key deoxygenation components such as metal oxides and heteropolyacids on the support surface. By optimizing the reaction conditions, especially the reaction temperature, a total adipic acid yield of up to 95% can be achieved in the preparation of adipic acid from 2,5-furandicarboxylic acid. Moreover, the process is green and environmentally friendly, and has significant social benefits. Detailed Implementation
[0016] This invention provides a method for preparing adipic acid, comprising:
[0017] (A): In an aqueous solution, in the presence of a hydrodeoxygenation catalyst, tetrahydrofuran-2,5-dicarboxylic acid is reacted with hydrogen gas to obtain the adipic acid; or...
[0018] (B): In aqueous solution, in the presence of a hydrogenation catalyst and a hydrogenation deoxygenation catalyst, furan-2,5-dicarboxylic acid is reacted with hydrogen gas to obtain the adipic acid; or...
[0019] (C)(1) In an aqueous solution, in the presence of a hydrogenation catalyst, furan-2,5-dicarboxylic acid is reacted with hydrogen to obtain tetrahydrofuran-2,5-dicarboxylic acid; (2) In an aqueous solution, under the catalysis of a hydrogenation deoxygenation catalyst, the tetrahydrofuran-2,5-dicarboxylic acid is reacted with hydrogen to obtain adipic acid.
[0020] The hydrogenation catalyst is a supported noble metal catalyst.
[0021] 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. Specifically, it can be a mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst, 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.
[0022] 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.
[0023] The supported noble metal catalyst in the hydrogenation catalyst can be the same as or different from the supported noble metal catalyst in the hydrodeoxygenation catalyst.
[0024] The supported noble metal catalyst includes 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 support is selected from one or more of activated carbon, silica, zirconium oxide, and titanium dioxide. The noble metal is selected from one or more of Ru, Rh, Pd, Os, Ir, and Pt.
[0025] The supported metal oxide catalyst includes 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 support is selected from one or more of activated carbon, silicon dioxide, zirconium oxide, or titanium dioxide. The metal oxide is one or more of MoO3, WO3, or ReO3.
[0026] 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% to 90%, preferably 1% to 60%, and more preferably 5% to 30%. The support is one or more of activated carbon, silicon dioxide, zirconium oxide, or titanium dioxide. 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 one or more of tungsten-containing heteropolyacid, molybdenum-containing heteropolyacid, or rhenium-containing heteropolyacid, and more preferably such as phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicotonic acid, phosphorhenic acid, etc.
[0027] According to one embodiment of the present invention, when method (A) is used, the process conditions are as follows:
[0028] In the aqueous solution formed by the tetrahydrofuran-2,5-dicarboxylic acid and water, the mass percentage of the tetrahydrofuran-2,5-dicarboxylic acid can be 0.1% to 40%, preferably 0.5% to 25%, and more preferably 1% to 10%.
[0029] The molar ratio of the noble metal in the supported noble metal catalyst to the tetrahydrofuran-2,5-dicarboxylic acid in the hydrodeoxygenation catalyst can be 1:1 to 1000, preferably 1:5 to 500, and more preferably 1:10 to 100.
[0030] The reaction can be carried out at a pressure of 1 MPa to 10 MPa, preferably at 1 to 8 MPa, and more preferably at 2 to 5 MPa.
[0031] The reaction temperature can be 140℃~250℃, preferably 150℃~240℃, and more preferably 180℃~220℃.
[0032] The reaction time can be 1 to 40 hours, preferably 5 to 30 hours, and more preferably 10 to 20 hours.
[0033] According to one embodiment of the present invention, when method (B) (one-pot process) is used, the process conditions are as follows:
[0034] In the aqueous solution formed by furan-2,5-dicarboxylic acid and water, the mass percentage of furan-2,5-dicarboxylic acid can be 0.1% to 40%, preferably 0.5% to 25%, and more preferably 1% to 10%.
[0035] The molar ratio of the noble metal in the hydrogenation catalyst to the furan-2,5-dicarboxylic acid can be 1:1 to 1000, preferably 1:5 to 500, and more preferably 1:10 to 100.
[0036] The molar ratio of the noble metal in the supported noble metal catalyst to the furan-2,5-dicarboxylic acid in the hydrodeoxygenation catalyst can be 1:10 to 1000, preferably 1:5 to 500, and more preferably 1:10 to 100.
[0037] The reaction can be carried out at a pressure of 1 MPa to 10 MPa, preferably at 1 to 8 MPa, and more preferably at 2 to 5 MPa.
[0038] The reaction temperature can be 140℃~250℃, preferably 160℃~240℃, and more preferably 180℃~220℃.
[0039] The reaction time can be 1 to 40 hours, preferably 5 to 30 hours, and more preferably 10 to 20 hours.
[0040] According to one embodiment of the present invention, when method (C) (two-step method) is used, the process conditions are as follows:
[0041] In step (1), the mass percentage of furan-2,5-dicarboxylic acid in the aqueous solution formed by furan-2,5-dicarboxylic acid and water can be 0.1% to 40%, preferably 0.5% to 25%, and more preferably 1% to 10%.
[0042] The molar ratio of the noble metal in the hydrogenation catalyst to the furan-2,5-dicarboxylic acid can be 1:1 to 1000, preferably 1:5 to 500, and more preferably 1:10 to 100.
[0043] The reaction can be carried out at a pressure of 1 MPa to 10 MPa, preferably at 1 to 8 MPa, and more preferably at 2 to 5 MPa.
[0044] The reaction temperature can be 140℃~250℃, preferably 150℃~240℃, and more preferably 180℃~220℃.
[0045] The reaction time can be 1 to 40 hours, preferably 5 to 30 hours, and more preferably 10 to 20 hours.
[0046] In step (2), the mass percentage of the tetrahydrofuran-2,5-dicarboxylic acid in the aqueous solution formed by the tetrahydrofuran-2,5-dicarboxylic acid can be 0.1% to 40%, preferably 0.5% to 25%, and more preferably 1% to 10%.
[0047] The molar ratio of the noble metal in the supported noble metal catalyst to the furan-2,5-dicarboxylic acid in the hydrodeoxygenation catalyst can be 1:10 to 1000, preferably 1:5 to 500, and more preferably 1:10 to 100.
[0048] The reaction can be carried out at a pressure of 1 MPa to 10 MPa, preferably at 1 to 8 MPa, and more preferably at 2 to 5 MPa.
[0049] The reaction temperature can be 140℃~250℃, preferably 150℃~240℃, and more preferably 180℃~220℃.
[0050] The reaction time can be 1–40 hours, preferably 5–30 hours, and more preferably 10–20 hours. The supported noble metal catalyst used in the method of the present invention can be prepared according to existing methods, such as isochoric impregnation, initial wet impregnation, ion exchange, deposition-precipitation, or vacuum impregnation. Specifically, after metal deposition, the solid powder is dried in an oven at 100–140°C for about 6–24 hours. The resulting supported catalyst precursor is first calcined in air at 300–800°C for a period of time, 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.
[0051] The hydrodeoxygenation catalyst used in the method of this invention is a mixture of a supported noble metal catalyst and at least one supported metal oxide catalyst or at least one supported heteropolyacid catalyst, which can be prepared by simple mechanical mixing. 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.
[0052] 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 reaction system, or they can be added to the reaction system separately in a certain proportion.
[0053] When preparing adipic acid using the method of this invention, the reaction can be carried out in a reaction vessel. After the reaction is complete, 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, 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.
[0054] The method for preparing adipic acid provided by this invention uses water as a solvent, does not introduce other impurities except for the heterogeneous catalyst used, and has a high yield of adipic acid. Therefore, the method of this invention not only further reduces production costs, but is also more environmentally friendly.
[0055] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.
[0056] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.
[0057] Preparation Example 1
[0058] Preparation of supported noble metal catalyst 2% Ru / ZrO2:
[0059] 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 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 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 / TiO2 catalyst.
[0060] Supported noble metal catalysts were prepared according to the above method, with 2% Rh / TiO2, 4% Pt / C, 1% Pd / SiO2, and 2% Ir / TiO2 respectively.
[0061] Preparation Example 2
[0062] Preparation of 10% WO3 / TiO2 supported metal oxide catalyst:
[0063] 0.19 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] Supported metal oxide catalysts were prepared according to the above method, with supports of 20% WO3 / TiO2, 30% WO3 / TiO2, 40% WO3 / TiO2, 2% ReO3 / SiO2, and 20% MoO3 / ZrO2, respectively. Different supported metal oxide catalysts can be prepared using precursors corresponding to their supporting components, as per the example. For instance, 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.
[0065] Preparation Example 3
[0066] Preparation of supported heteropolyacid catalysts:
[0067] 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.
[0068] Supported heteropolyacid catalysts were prepared according to the above method, and 20% PWO was loaded onto them respectively. x / TiO2, 2% PReO x / SiO2 and 10% SiMoO3 / ZrO2.
[0069] Example 1: Two-step method for preparing adipic acid from furan-2,5-dicarboxylic acid
[0070] I. Preparation of Tetrahydrofuran-2,5-Dicarboxylic Acid (THFDCA)
[0071] A 2% Ru / ZrO2 catalyst was used as the hydrogenation catalyst.
[0072] In a 30 mL high-pressure reactor, 0.2 g of the prepared 2% Ru / ZrO2 catalyst, 1 g of FDCA, and 10 mL of water (FDCA mass percentage 10%) 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 150 °C. The reaction was stirred at 700 rpm for 6 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 resulting liquid was diluted to 50 mL and analyzed by high-performance liquid chromatography (HPLC). The conversion rate and product yield were calculated. Under these conditions, the conversion rate of FDCA reached 100%, and the selectivity of THFDCA was >99%. Therefore, a 2% (mass fraction) THFDCA aqueous solution can be obtained for further conversion to adipic acid.
[0073] II. Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0074] The catalyst obtained by mechanically mixing 2% Rh / TiO2 and 10% WO3 / TiO2 was used as the hydrodeoxygenation catalyst.
[0075] In a 30 mL high-pressure reactor, 0.2 g of 2% Rh / TiO2 catalyst (where the molar ratio of Rh to THFDCA is approximately 1:30), 0.4 g of 10% WO3 / TiO2 catalyst, and 10 mL of the aforementioned 2% THFDCA aqueous solution 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 heating 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 heating furnace, cooled to room temperature, and 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 2: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0077] The catalyst obtained by mechanically mixing 2% Rh / TiO2 and 20% WO3 / TiO2 was used as the hydrodeoxygenation catalyst.
[0078] In a 30 mL high-pressure reactor, 0.2 g of 2% Rh / TiO2 catalyst (where the molar ratio of Rh to THFDCA is approximately 1:30), 0.2 g of 20% WO3 / TiO2 catalyst, and 10 mL of the aforementioned 2% THFDCA aqueous solution 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 heating 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 heating furnace, cooled to room temperature, and 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 3: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0080] The catalyst obtained by mechanically mixing 2% Rh / TiO2 and 20% WO3 / TiO2 was used as the hydrodeoxygenation catalyst.
[0081] In a 30 mL high-pressure reactor, 0.2 g of 2% Rh / TiO2 catalyst (where the molar ratio of Rh to THFDCA is approximately 1:30), 0.2 g of 20% WO3 / TiO2 catalyst, and 10 mL of the aforementioned 2% THFDCA aqueous solution 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 heating 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 heating furnace, cooled to room temperature, and 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 4: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0083] The catalyst obtained by mechanically mixing 2% Rh / TiO2 and 20% WO3 / TiO2 was used as the hydrodeoxygenation catalyst.
[0084] In a 30 mL high-pressure reactor, 0.2 g of 2% Rh / TiO2 catalyst (where the molar ratio of Rh to THFDCA is approximately 1:30), 0.2 g of 20% WO3 / TiO2 catalyst, and 10 mL of the aforementioned 2% THFDCA aqueous solution 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 210 °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 5: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0086] The catalyst obtained by mechanically mixing 2% Rh / TiO2 and 30% WO3 / TiO2 was used as the hydrodeoxygenation catalyst.
[0087] In a 30 mL high-pressure reactor, 0.2 g of 2% Rh / TiO2 catalyst (where the molar ratio of Rh to THFDCA is approximately 1:30), 0.13 g of 30% WO3 / TiO2 catalyst, and 10 mL of the aforementioned 2% THFDCA aqueous solution 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 heating 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 heating furnace, cooled to room temperature, and 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 6: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0089] The catalyst obtained by mechanically mixing 2% Rh / TiO2 and 40% WO3 / TiO2 was used as the hydrodeoxygenation catalyst.
[0090] In a 30 mL high-pressure reactor, 0.2 g of 2% Rh / TiO2 catalyst (where the molar ratio of Rh to THFDCA is approximately 1:30), 0.1 g of 40% WO3 / TiO2 catalyst, and 10 mL of the aforementioned 2% THFDCA aqueous solution 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 heating 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 heating furnace, cooled to room temperature, and 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 7: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0092] 4% Pt / C + 2% ReO3 / SiO2 was used as the hydrodeoxygenation catalyst.
[0093] In a 30 mL high-pressure reactor, 0.2 g of 4% Pt / C catalyst (where the molar ratio of Pt to THFDCA is approximately 1:30), 0.2 g of 2% ReO3 / SiO2 catalyst, and 10 mL of the 2% THFDCA aqueous solution prepared in Example 1 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 220 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the furnace, cooled to room temperature, and 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 8: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0095] The catalyst obtained by mechanically mixing 2% Ru / ZrO2 and 20% MoO3 / ZrO2 was used as the hydrodeoxygenation catalyst.
[0096] In a 30 mL high-pressure reactor, 0.2 g of 2% Ru / ZrO2 catalyst (where the molar ratio of Ru to THFDCA is 1:30), 0.2 g of 20% MoO3 / ZrO2 catalyst, and 10 mL of the 2% THFDCA aqueous solution prepared in Example 1 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 heating furnace and heated to the reaction temperature of 220 °C. The reaction was stirred at 700 rpm for 20 hours. After the reaction was completed, the reactor was removed from the heating furnace, cooled to room temperature, and 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 9: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0098] The catalyst obtained by mechanically mixing 2% Rh / TiO2 and 40% PWO3 / TiO2 was used as the hydrodeoxygenation catalyst.
[0099] In a 30 mL high-pressure reactor, 0.2 g of 2% Rh / TiO2 catalyst (where the molar ratio of Rh to THFDCA is approximately 1:30), 0.2 g of 40% PWO3 / TiO2 catalyst, and 10 mL of the 2% THFDCA aqueous solution prepared in Example 1 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 heating 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 heating furnace, cooled to room temperature, and 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 10: One-pot preparation of adipic acid from furan-2,5-dicarboxylic acid
[0101] Using 2% Ru / ZrO2 catalyst as the hydrogenation catalyst, 4% Pt / C + 2% PReO x The catalyst obtained by mechanical mixing of / SiO2 is a hydrodeoxygenation catalyst.
[0102] In a 30 mL high-pressure reactor, add 0.5 g of 2% Ru / ZrO2 catalyst (where the molar ratio of Ru to FDCA is 1:60), 0.5 g of 4% Pt / C catalyst (where the molar ratio of Ru to FDCA is 1:60), and 0.5 g of 2% PReO2 catalyst. x The reactor was prepared using SiO2 catalyst, 1g FDCA, and 10mL water (FDCA content 10% by mass). After sealing, the reactor was purged with 4MPa hydrogen gas to replace the residual air. This process was repeated three times. Then, 2MPa hydrogen gas was introduced into the reactor, and the reactor was placed on a furnace and heated to a reaction temperature of 220℃. The mixture was stirred at 700rpm 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 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.
[0103] Example 11: One-pot preparation of adipic acid from furan-2,5-dicarboxylic acid
[0104] A 1% Pd / SiO2 catalyst was used as the hydrogenation catalyst, and a 2% Rh / TiO2 + 20% SiMoO3 / ZrO2 mechanically mixed catalyst was used as the hydrogenation deoxygenation catalyst.
[0105] In a 30 mL high-pressure reactor, add 0.2 g of 1% Pd / SiO2 catalyst (where the molar ratio of Pd to FDCA is 1:60), 0.4 g of pre-mixed 2% Rh / TiO2 + 20% SiMoO3 / ZrO2 mixed catalyst (containing 0.2 g of 2% Rh / ZrO2 and 0.2 g of 20% SiMoO3 / ZrO2, where the molar ratio of Rh to FDCA is 1:30), 0.2 g of FDCA, and 10 mL of water (FDCA mass percentage is 2%). After sealing the reactor, purge the residual air in the reactor with 4 MPa of hydrogen gas. Repeat this process three times. Then, purge the reactor with 4 MPa of hydrogen gas and place it on a heating furnace to heat it to the reaction temperature of 220 °C. Stir the reaction at 700 rpm for 20 hours. After the reaction was complete, 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 12: One-pot preparation of adipic acid from furan-2,5-dicarboxylic acid
[0107] A 1% Pd / SiO2 catalyst was used as the hydrogenation catalyst, and a mechanically mixed catalyst of 2% Rh / TiO2 + 20% SiMoO3 / ZrO2 was used as the hydrogenation deoxygenation catalyst. The reaction temperature was 160℃, the reaction pressure was 4MPa, and the remaining operations were the same as in Example 11. The reaction results are listed in Table 1.
[0108] Example 13: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0109] The catalyst obtained by mechanically mixing 2% Ir / TiO2 and 40% WO3 / TiO2 was used as the hydrodeoxygenation catalyst.
[0110] In a 30 mL high-pressure reactor, 0.2 g of 2% Ir / TiO2 catalyst (where the molar ratio of Ir to THFDCA is approximately 1:60), 0.2 g of 40% WO3 / TiO2 catalyst, and 10 mL of the 2% THFDCA aqueous solution prepared in Example 1 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 heating 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 heating furnace, cooled to room temperature, and 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.
[0111] Comparative Example 1: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0112] The catalyst obtained by mechanically mixing 2% Ir / TiO2+WO3 as reported in patent CN 107011154 A was used as a hydrodeoxygenation catalyst.
[0113] First, a supported noble metal catalyst of 2% Ir / TiO2 was prepared according to the method disclosed in patent CN 107011154 A. The difference between the method disclosed in patent CN 107011154 A and the method disclosed in patent CN 107011154 A is that the reaction temperature was increased to 180℃. The specific reaction process is as follows:
[0114] In a 30 mL high-pressure reactor, 0.2 g of the prepared 2% Ir / TiO2 catalyst (where the molar ratio of Ir to THFDCA is approximately 1:60), 0.2 g of commercial WO3, and 10 mL of the above-mentioned 2% THFDCA aqueous solution 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 heating 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 heating furnace, cooled to room temperature, and 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.
[0115] Comparative Example 2: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0116] The 2% Ir / 40% WO3 / TiO2 catalyst reported in patent CN 107011154 A was used as the hydrodeoxygenation catalyst.
[0117] First, a noble metal and metal oxide co-supported catalyst of 2% Ir / 40% WO3 / TiO2 was prepared according to the method disclosed in patent CN 107011154 A. The difference between the method disclosed in patent CN 107011154 A and the method itself is that the reaction temperature is increased to 180℃. Specifically:
[0118] In a 30 mL high-pressure reactor, 0.2 g of the 2% Ir / 40% WO3 / TiO2 catalyst prepared above (where the molar ratio of Ir to THFDCA is approximately 1:60) and 10 mL of the 2% THFDCA aqueous solution prepared in Example 1 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 heating 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 heating furnace, cooled to room temperature, and 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.
[0119] Comparative Example 3: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0120] A 2% Rh / 20% WO3 / TiO2 catalyst was used as the hydrodeoxygenation catalyst.
[0121] First, a noble metal and metal oxide co-supported catalyst of 2% Rh / 20% WO3 / TiO2 was prepared according to the method disclosed in patent CN 107011154 A. Following the method of Example 2, except that this 2% Rh / 20% WO3 / TiO2 catalyst was used for the reaction, specifically:
[0122] In a 30 mL high-pressure reactor, 0.2 g of the 2% Rh / 20% WO3 / TiO2 catalyst prepared above (where the molar ratio of Rh to THFDCA is approximately 1:30) and 10 mL of the 2% THFDCA aqueous solution prepared in Example 1 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 heating 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 heating furnace, cooled to room temperature, and 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.
[0123] Comparative Example 4: Preparation of adipic acid from tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)
[0124] The catalyst obtained by mechanically mixing 2% Rh / TiO2 and 20% WO3 / TiO2 was used as the hydrodeoxygenation catalyst.
[0125] The reaction was carried out according to the operating procedure of Example 2, except that the reaction temperature was 100°C. The reaction results are listed in Table 1.
[0126] As can be seen from the data in Table 1, the method for preparing adipic acid provided by this invention can effectively convert THFDCA or FDCA into adipic acid, an important chemical raw material, in aqueous solution. A maximum adipic acid yield of 96% can be obtained from THFDCA, and a maximum adipic acid yield of 95% can be obtained from FDCA.
[0127] As can be seen from Comparative Examples 1, 2, and 3, according to the method reported in CN 107011154 A, using a mixture of supported noble metal catalyst and unsupported metal oxide catalyst, or using a co-supported catalyst of noble metal and metal oxide, even with increased reaction temperature, the yield of adipic acid is still significantly lower than that of the method of this invention.
[0128] As can be seen from Comparative Example 4, when the catalyst of this invention is used and the reaction is carried out at the reaction temperature reported in CN 107011154 A, the reaction yield is also very low, indicating that the catalyst of this invention cannot be used to carry out the reaction according to the method in CN 107011154 A.
[0129] 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.
[0130] 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.
[0131] 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.
[0132] Table 1. Reaction conditions, conversion rates, and adipic acid yields of the examples and comparative examples.
[0133]
Claims
1. A method for preparing adipic acid, comprising: (A): In an aqueous solution, in the presence of a hydrodeoxygenation catalyst, tetrahydrofuran-2,5-dicarboxylic acid is reacted with hydrogen to obtain the adipic acid; or, (B): In aqueous solution, in the presence of a hydrogenation catalyst and a hydrodeoxygenation catalyst, furan-2,5-dicarboxylic acid is reacted with hydrogen to obtain the adipic acid; or, (C): (1) In an aqueous solution, in the presence of a hydrogenation catalyst, furan-2,5-dicarboxylic acid is reacted with hydrogen to obtain tetrahydrofuran-2,5-dicarboxylic acid; (2) In an aqueous solution, under the catalysis of a hydrogenation deoxygenation catalyst, the tetrahydrofuran-2,5-dicarboxylic acid is reacted with hydrogen to obtain adipic acid; The hydrogenation catalyst is a supported noble metal catalyst, and the hydrogenation deoxygenation catalyst is a mixture of the 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 noble metal is selected from one or more of Ru, Rh, Pd, Ir and Pt, the metal oxide is selected from one or more of MoO3 and WO3, and the heteropolyacid is selected from one or more of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, and silicotomolybdic acid. In method (A), (B) or (C), the reaction is carried out at a pressure of 1 MPa to 8 MPa; the temperature of the reaction is 150°C to 220°C. The supported noble metal catalyst comprises a support and a noble metal supported on the support, wherein the loading of the noble metal is 1% to 5% based on the total mass of the support; the supported metal oxide catalyst comprises a support and a metal oxide supported on the support, wherein the loading of the metal oxide is 5% to 30% based on the total mass of the support; the supported heteropolyacid catalyst comprises a support and a heteropolyacid supported on the support, wherein the loading of the heteropolyacid is 5% to 30% based on the total mass of the support; the support is one or more of activated carbon, silica, zirconium oxide, or titanium dioxide; In step (2) of methods (A) and (C), the mass percentage of the tetrahydrofuran-2,5-dicarboxylic acid in the aqueous solution is 1% to 10%; in step (1) of methods (B) and (C), the mass percentage of the furan-2,5-dicarboxylic acid in the aqueous solution is 1% to 10%. In step (2) of methods (A) and (C), the molar ratio of the noble metal in the supported noble metal catalyst to the tetrahydrofuran-2,5-dicarboxylic acid in the hydrodeoxygenation catalyst is 1:10~100; in step (1) of methods (B) and (C), the molar ratio of the noble metal in the hydrogenation catalyst to the furan-2,5-dicarboxylic acid 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, In method (A), (B) or (C), the reaction is carried out at a pressure of 2 to 5 MPa.
4. The method according to claim 1, wherein, In method (A), (B) or (C), the temperature of the reaction is 180°C to 220°C.