Method for preparing 2, 5-furandicarboxylic acid from 5-hydroxymethylfurfural

Abstract

The invention provides a method for preparing 2, 5-furandicarboxylic acid from 5-hydroxymethylfurfural, and belongs to the field of chemistry and chemical engineering. The method comprises the following steps: uniformly mixing a 5-hydroxymethylfurfural solution and an alkali solution, adding a first catalyst, a second catalyst, an auxiliary agent and an oxidizing agent, and carrying out oxidation reaction to generate 2, 5-furandicarboxylic acid. The method is simple to operate and mild in condition, the yield of the 2, 5-furandicarboxylic acid is as high as 95.4%, the reaction does not need a high-pressure environment, the reaction can be carried out in air, the requirement on the pressure resistance of equipment is reduced, the production cost of FDCA is reduced, and the method has a good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of chemical engineering, and specifically to a method for preparing 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural. Background Technology

[0002] 2,5-Furfurandicarboxylic acid (FDCA) is a furan derivative with an aromatic heterocyclic structure. Synthesized from biomass such as straw sugars and starch sugars, it possesses both green attributes and renewable characteristics, making it a highly promising biomass-based new material. Structurally, FDCA is highly similar to the petrochemical derivative 1,4-terephthalic acid (PTA), thus it can serve as a PTA substitute and is widely used in the preparation of various polymers, such as polyesters, polyamides, polyimides, and polyurethanes. It can also be used in the synthesis of whitening agents, plasticizers, and surfactants. Due to its enormous potential in replacing fossil resources and promoting a low-carbon circular economy, FDCA was recognized by the U.S. Department of Energy in 2004 as one of the 12 most valuable chemical products from biomass, indicating a huge market potential.

[0003]

[0004] Currently, FDCA is typically prepared by oxidizing 5-hydroxymethylfurfural (HMF), a product of fructose dehydration. HMF oxidation generally follows two reaction pathways: Pathway A usually involves the preferential oxidation of the aldehyde group of HMF to a carboxyl group, generating 5-hydroxymethyl-2-furanoic acid (HMFCA), followed by the oxidation of the hydroxymethyl group of HMFCA to a carboxyl group, yielding FDCA; Pathway B usually involves the preferential oxidation of the hydroxymethyl group of HMF to an aldehyde group, generating 2,5-furandicarboxaldehyde (DFF), followed by the oxidation of the two aldehyde groups of DFF to carboxyl groups, yielding FDCA. The choice between these two reaction pathways is usually based on the type of catalyst and its activation ability for specific functional groups. The intermediate HMFCA in Pathway A has higher stability than DFF and is currently a key focus of industrial research. However, HMFCA oxidation requires multiple electron transfer steps and oxygen insertion processes, resulting in slow reaction kinetics. It is the rate-determining step in the entire oxidation process, often leading to byproduct accumulation, decreased selectivity, and limited yield.

[0005] Therefore, developing a reaction process with efficient and selective catalytic reaction system to improve the yield of FDCA has become an urgent technical problem to be solved. Summary of the Invention

[0006] To address the problems mentioned above, the main objective of this invention is to provide a method for preparing 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural. This method is simple to operate, operates under mild reaction conditions, has low production costs, and achieves high product yield, thus possessing promising prospects for industrial application.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for preparing 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural includes: dissolving 5-hydroxymethylfurfural in a solvent to obtain a 5-hydroxymethylfurfural solution, adding an alkaline solution and mixing evenly to form a reaction mixture; adding a first catalyst, a second catalyst, an auxiliary agent and an oxidant to the reaction mixture to carry out an oxidation reaction, thereby obtaining 2,5-furandicarboxylic acid.

[0008] Preferably, the solvent is selected from at least one of water, an organic solvent, or a mixture of water and an organic solvent; the organic solvent is at least one of dimethyl sulfoxide, acetonitrile, dioxane, acetone, and N,N-dimethylformamide; the volume ratio of water to organic solvent is 1:0.1-10; and the concentration of the 5-hydroxymethylfurfural solution is 1-200 g / L.

[0009] Preferably, the alkaline solution is a solution composed of one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate, mixed with water; the concentration of the alkaline solution is 1-100 g / L. The sodium carbonate solution provides alkaline conditions, which not only neutralizes the acidic intermediates generated in the reaction and prevents catalyst deactivation, but also promotes the deprotonation of hydroxyl groups in the HMF molecule, enhancing its reactivity and accelerating the conversion to FDCA.

[0010] Preferably, the volume ratio of the 5-hydroxymethylfurfural solution to the alkaline solution is 1:0.5-5.

[0011] Preferably, the first catalyst is a microspherical noble metal catalyst supported by Ir, Ru, Pt or Au, with an average particle size of 100-150 μm; the support for the noble metal catalyst is Al2O3 or SiO2; more preferably, the first catalyst is Au / Al2O3 with a loading of 2%.

[0012] Preferably, the second catalyst is at least one of manganese sulfate, manganese nitrate, manganese acetate, manganese oxalate, manganese chloride, manganese monoxide, manganese dioxide, manganese tetroxide, and potassium permanganate; more preferably, the second catalyst is manganese tetroxide.

[0013] Preferably, the auxiliary agent is a cationic surfactant, and the cationic surfactant is at least one selected from tetramethylammonium bromide, tetraethylammonium bromide, dodecyltrimethylammonium bromide, and hexadecyltrimethylammonium bromide; more preferably, the auxiliary agent is hexadecyltrimethylammonium bromide.

[0014] Preferably, the oxidant is air or oxygen, and the gas flow rate is 10-200 mL / min.

[0015] Preferably, the mass ratio of the first catalyst, the second catalyst, the auxiliary agent, and 5-hydroxymethylfurfural is 0.1-0.5:0.05-0.25:0.01-0.1:1.

[0016] Preferably, the oxidation reaction temperature is 60-110℃ and the reaction time is 20-30h.

[0017] In this invention, the first catalyst efficiently activates the hydroxyl and aldehyde groups in the HMF molecule, and the second catalyst promotes oxygen adsorption and the generation of reactive oxygen species. The two work synergistically to improve the oxidation reaction rate and selectivity and reduce the generation of by-products. The surfactant improves the contact efficiency between HMF and the catalyst surface, and in the mixed solvent, it can reduce the interfacial resistance and improve the reaction uniformity. Dimethyl sulfoxide can enhance the solubility of HMF, prevent it from precipitating during the reaction, and ensure that the raw materials and catalyst are in full contact.

[0018] The method of this invention is carried out in an open reaction system, and the reaction does not require the introduction of high-pressure oxygen; it can occur in air or oxygen alone. This method significantly reduces the operational risks of the reaction and greatly reduces the need for special reaction equipment, thereby reducing equipment investment and operating costs. Under this mild reaction system, the yield of 2,5-furandicarboxylic acid (FDCA) is still as high as 95.4%, demonstrating that the catalytic system of this invention has high activity and excellent selectivity.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention utilizes the high efficiency of noble metal catalysis in conjunction with the selectivity of manganese-based materials to form active sites at the interface between noble metal and manganese, thereby achieving high efficiency catalytic oxidation and regulation of oxygen transfer pathways. This enables the efficient and selective oxidation of HMF to FDCA. The surfactant introduced in the reaction reduces the surface tension between the solid and liquid interfaces and regulates the properties of the gas-liquid interface, allowing the oxidant and HMF to be more uniformly dispersed in the solvent, thus promoting the reaction.

[0020] 2. By optimizing the proportions of each group and the reaction parameters, this invention achieves efficient and selective oxidation of HMF to FDCA, with an HMF conversion rate of up to 99.3% and an FDCA yield of up to 95.4%. It also results in high raw material utilization and reduced product production costs.

[0021] 3. The method of the present invention is simple to operate, the reaction conditions are mild, and no high temperature and high pressure equipment is required, which reduces production energy consumption and equipment investment costs; moreover, water or water-dimethyl sulfoxide is used as a solvent, which is in line with the trend of green chemical industry and has industrial application prospects. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings: Figure 1This is a liquid chromatogram of the reaction solution in Example 2 of the present invention.

[0023] Figure 2 This is a graph showing the yield of 2,5-furandicarboxylic acid versus reaction time in Example 2 of this invention. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0025] Example 1: 10 g of 5-hydroxymethylfurfural was dissolved in 100 ml of water to obtain a 5-hydroxymethylfurfural solution. A 10 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to obtain a homogeneous solution. 1 g of 2%-Au / Al₂O₃ catalyst, 1 g of manganese tetroxide, and 0.1 g of hexadecyltrimethylammonium bromide were added to the solution, and oxygen was bubbled through at a flow rate of 20 mL / min. The reaction was carried out at 100 °C for 24 h. After the reaction was complete, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 97.4%, and the yield of 2,5-furandicarboxylic acid was 92.3%.

[0026] Example 2: 10 g of 5-hydroxymethylfurfural was dissolved in 100 ml of water to obtain a 5-hydroxymethylfurfural solution. 300 ml of a 10 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to obtain a homogeneous solution. 2 g of 2%-Au / Al₂O₃ catalyst, 2 g of manganese tetroxide, and 0.5 g of hexadecyltrimethylammonium bromide were added to the solution, and oxygen was bubbled through at a flow rate of 20 mL / min. The reaction was carried out at 100 °C for 24 h. After the reaction was complete, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 99.3%, and the yield of 2,5-furandicarboxylic acid was 95.4%.

[0027] Example 3: 10 g of 5-hydroxymethylfurfural was dissolved in a mixed solvent of 80 ml dimethyl sulfoxide and 20 ml water to obtain a 5-hydroxymethylfurfural solution. 300 ml of a 10 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to form a homogeneous solution. 2 g of 2%-Au / Al₂O₃ catalyst, 2 g of manganese tetroxide, and 0.1 g of hexadecyltrimethylammonium bromide were added to the solution, and oxygen was bubbled through at a flow rate of 20 mL / min. The reaction was carried out at 100 °C for 24 h. After the reaction was complete, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 98.7%, and the yield of 2,5-furandicarboxylic acid was 94.1%.

[0028] Example 4: 20 g of 5-hydroxymethylfurfural was dissolved in a mixed solvent of 80 ml dimethyl sulfoxide and 20 ml water to obtain a 5-hydroxymethylfurfural solution. 400 ml of 10 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min until homogeneous, forming a homogeneous solution. 2 g of 2%-Au / Al₂O₃ catalyst, 1 g of manganese tetroxide, and 0.5 g of hexadecyltrimethylammonium bromide were added to the homogeneous solution. Oxygen was bubbled through the solution at a flow rate of 20 mL / min, and the reaction was carried out at 100 °C for 24 h. After the reaction was complete, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 95.2%, and the yield of 2,5-furandicarboxylic acid was 87.8%.

[0029] Example 5: 20 g of 5-hydroxymethylfurfural was dissolved in 100 mL of dimethyl sulfoxide to obtain a 5-hydroxymethylfurfural solution. 300 mL of a 20 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to form a homogeneous solution. 2 g of 2%-Au / Al₂O₃ catalyst, 2 g of manganese tetroxide, and 0.5 g of hexadecyltrimethylammonium bromide were added to the solution, and oxygen was bubbled through at a flow rate of 20 mL / min. The reaction was carried out at 100 °C for 24 h. After the reaction was complete, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 94.9%, and the yield of 2,5-furandicarboxylic acid was 92.1%.

[0030] Example 6: 5 g of 5-hydroxymethylfurfural was dissolved in a mixed solvent of 80 ml dimethyl sulfoxide and 20 ml water to obtain a 5-hydroxymethylfurfural solution. 100 ml of a 10 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to form a homogeneous solution. 1 g of 2%-Au / Al₂O₃ catalyst, 1 g of manganese tetroxide, and 0.25 g of hexadecyltrimethylammonium bromide were added to the solution, and oxygen was bubbled through at a flow rate of 50 mL / min. The reaction was carried out at 80 °C for 24 h. After the reaction was complete, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 99.1%, and the yield of 2,5-furandicarboxylic acid was 91.8%.

[0031] Example 7: 20 g of 5-hydroxymethylfurfural was dissolved in a mixed solvent of 80 ml of dimethyl sulfoxide and 20 ml of water to obtain a 5-hydroxymethylfurfural solution. 300 ml of 20 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to form a homogeneous solution. 2 g of 2%-Au / Al₂O₃ catalyst, 0.5 g of manganese tetroxide, and 0.5 g of hexadecyltrimethylammonium bromide were added to the solution, and oxygen was introduced at a flow rate of 20 mL / min. The reaction was carried out at 80 °C for 24 h. After the reaction was completed, the conversion rate of 5-hydroxymethylfurfural was calculated to be 89.5% and the yield of 2,5-furandicarboxylic acid was 80.1% by liquid chromatography.

[0032] Example 8: 20 g of 5-hydroxymethylfurfural was dissolved in 100 mL of dimethyl sulfoxide to obtain a 5-hydroxymethylfurfural solution. 200 mL of a 10 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to form a homogeneous solution. 5 g of 2%-Au / Al₂O₃ catalyst, 4 g of manganese tetroxide, and 0.2 g of hexadecyltrimethylammonium bromide were added to the solution, and oxygen was bubbled through at a flow rate of 20 mL / min. The reaction was carried out at 100 °C for 24 h. After the reaction was complete, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 92.7%, and the yield of 2,5-furandicarboxylic acid was 87.9%.

[0033] Comparative Example 1: 10 g of 5-hydroxymethylfurfural was dissolved in 100 mL of dimethyl sulfoxide to obtain a 5-hydroxymethylfurfural solution. 300 mL of a 10 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to form a homogeneous solution. 2 g of 2%-Pd / Al₂O₃ catalyst, 2 g of manganese tetroxide, and 0.5 g of hexadecyltrimethylammonium bromide were added to the solution, and oxygen was bubbled through at a flow rate of 20 mL / min. The reaction was carried out at 100 °C for 24 h. After the reaction was complete, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 97.4%, and the yield of 2,5-furandicarboxylic acid was 77.9%.

[0034] Comparative Example 2: 10 g of 5-hydroxymethylfurfural was dissolved in 100 mL of dimethyl sulfoxide to obtain a 5-hydroxymethylfurfural solution. 300 mL of a 10 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to form a homogeneous solution. 2 g of 2%-Au / Al₂O₃ catalyst and 2 g of manganese tetroxide were added to the solution, and oxygen was bubbled through at a flow rate of 20 mL / min. The reaction was carried out at 100 °C for 24 h. After the reaction was complete, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 98.2%, and the yield of 2,5-furandicarboxylic acid was 85.3%.

[0035] Comparative Example 3: 10 g of 5-hydroxymethylfurfural was dissolved in 100 mL of dimethyl sulfoxide to obtain a 5-hydroxymethylfurfural solution. 300 mL of a 10 g / L sodium carbonate solution was added, and the mixture was stirred for 30 min to form a homogeneous solution. 2 g of a 2%-Au / Al₂O₃ catalyst was added to the solution, and oxygen was introduced at a flow rate of 20 mL / min. The reaction was carried out at 100 °C for 24 h. After the reaction was completed, the reaction solution was obtained. Liquid chromatography showed that the conversion rate of 5-hydroxymethylfurfural was 97.9%, and the yield of 2,5-furandicarboxylic acid was 82.2%.

[0036] As can be seen from the above examples and comparative examples, Au / Al2O3, Mn3O4, and CTAB of the present invention exhibit excellent synergistic catalytic performance in DMSO / H2O and Na2CO3. In Example 2, Au / Al2O3 and Mn3O4 were used as catalysts, and CTAB was added as an auxiliary agent. In a DMSO / H2O mixed solvent, an appropriate amount of sodium carbonate was used to adjust the pH. The reaction was carried out at 100°C and atmospheric pressure under oxygen for 24 hours, achieving an HMF conversion rate of greater than 99% and an FDCA yield of greater than 95%.

[0037] In summary, this invention significantly improves the yield of the target product FDCA while maintaining a high HMF conversion rate by optimizing the catalyst combination, solvent system, alkali dosage, surfactant, and reaction conditions. This process offers advantages such as mild reaction conditions, safe operation, high selectivity, and high efficiency, demonstrating promising prospects for industrial application.

[0038] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for preparing 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural, characterized in that: 5-Hydroxymethylfurfural is dissolved in a solvent to obtain a 5-hydroxymethylfurfural solution. An alkaline solution is added and mixed evenly to form a mixture. A first catalyst, a second catalyst, an auxiliary agent, and an oxidant are added to the mixture to induce an oxidation reaction, thereby obtaining 2,5-furandicarboxylic acid.

2. The method according to claim 1, characterized in that: The solvent is selected from at least one of water, organic solvent, or a mixture of water and organic solvent; the organic solvent is at least one of dimethyl sulfoxide, acetonitrile, dioxane, acetone, and N,N-dimethylformamide; the volume ratio of water to organic solvent is 1:0.1-10; and the concentration of the 5-hydroxymethylfurfural solution is 1-200 g / L.

3. The method according to claim 1, characterized in that: The alkaline solution is a solution composed of one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate with water; the concentration of the alkaline solution is 1-100 g / L.

4. The method according to claim 1, characterized in that: The volume ratio of the 5-hydroxymethylfurfural solution to the alkaline solution is 1:0.5-5.

5. The method according to claim 1, characterized in that: The first catalyst is a microspherical noble metal catalyst supported by Ir, Ru, Pt or Au, with an average particle size of 100-150 μm, and the support for the noble metal catalyst is Al2O3 or SiO2.

6. The method according to claim 1, characterized in that: The second catalyst is at least one of manganese sulfate, manganese nitrate, manganese acetate, manganese oxalate, manganese chloride, manganese monoxide, manganese dioxide, manganese tetroxide, and potassium permanganate.

7. The method according to claim 1, characterized in that: The auxiliary agent is a cationic surfactant, and the cationic surfactant is at least one of tetramethylammonium bromide, tetraethylammonium bromide, dodecyltrimethylammonium bromide, and hexadecyltrimethylammonium bromide.

8. The method according to claim 1, characterized in that: The oxidant is air or oxygen, and the gas flow rate is 10-200 mL / min.

9. The method according to claim 1, characterized in that: The mass ratio of the first catalyst, the second catalyst, the auxiliary agent, and 5-hydroxymethylfurfural is 0.1-0.5:0.05-0.25:0.01-0.1:

1.

10. The method according to claim 1, characterized in that: The oxidation reaction temperature is 60-110℃, and the reaction time is 20-30h.

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