A process for the preparation of 2,5-furandicarboxylic acid

Abstract

The present application relates to the field of biomass high-value platform compound preparation, and relates to a method for preparing 2,5-furan dicarboxylic acid. The method comprises: under the condition of an oxidant and a catalyst, normal pressure reaction is carried out to obtain 2,5-furan dicarboxylic acid, wherein the catalyst is 2,2,6,6-tetramethylpiperidine oxide. The method uses a non-noble metal catalyst and does not need secondary treatment, the process is simple, the economy is high, the reaction condition is mild, the by-products are few, the alkaline additive is not added, the corrosion of alkaline substances to the equipment is effectively avoided, and the method has a wide industrial application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biomass high-value platform compound preparation, and in particular to a method for preparing 2,5-furan dicarboxylic acid. BACKGROUND

[0002] Biomass is a renewable resource with abundant reserves in nature, and it is of great significance to convert biomass into high-value chemicals through chemical catalysis. 5-hydroxymethylfurfural, which is obtained by hydrolysis-isomerization-dehydration of cellulose and hemicellulose, is an important platform compound. Its oxidation product, 2,5-furan dicarboxylic acid (FDCA), is a monomer for producing bio-based polyester polyfuran dicarboxylic acid ethylene glycol (PEF). PEF has a similar structure to petroleum-based polyethylene terephthalate (PET) and is biodegradable, and is expected to replace petroleum-based PET as the mainstream polyester product, and has broad application prospects.

[0003] FDCA can be oxidized from 5-hydroxymethylfurfural, and the catalyst used is a noble metal catalyst (CN117085701A) and a Cu / Mn catalyst (CN117417315A). However, due to the unstable nature of 5-hydroxymethylfurfural, the cost of separation and purification is high, thereby increasing the production cost of FDCA.

[0004]

[0005] FDCA can also be obtained by dehydration and cyclization of six-carbon sugar diacid. CN116768832A discloses an ionic liquid and an acidic catalyst for catalyzing the dehydration and cyclization of six-carbon sugar diacid compounds to convert them into FDCA.

[0006]

[0007] Currently, the conversion of 5-hydroxymethylfurfural into 2,5-furan dicarboxylic acid by catalytic oxidation is the most likely route to realize industrial production, but its catalysis depends on noble metal catalysts and requires high temperature and high pressure environment, and there are problems such as many by-products, low selectivity, the need to add alkaline substances, high production cost, etc. CN117085701A discloses a catalyst in which a noble metal (Ru, Pt, Pd, Au) active component is supported on a sulfur-doped nanocage, and a specific organic solvent and water are used as mixed solvents to catalyze the conversion of 5-hydroxymethylfurfural into FDCA at 1-3 MPa and 90-150 DEG C, and a FDCA yield of more than 78% can be obtained, but the use of organic solvents is inevitable and the cost of noble metal catalysts is relatively high, which limits the industrial application; CN116675660A discloses a method that can obtain a FDCA yield of up to 91.85 under the premise of using a solid base, but the use of alkali increases the difficulty of post-treatment and increases the cost. Therefore, it is of great significance to develop a method for the one-step catalytic oxidation of 5-hydroxymethylfurfural to 2,5-furan dicarboxylic acid under mild conditions, which is efficient, non-noble metal catalysis, has mild reaction conditions, is environmentally friendly, and is simple to operate. SUMMARY

[0008] In view of this, the purpose of the present application is to provide a method for preparing 2,5-furan dicarboxylic acid under mild conditions, which uses 2,2,6,6-tetramethylpiperidine oxide as a catalyst, potassium peroxymonosulfate or potassium peroxymonosulfate as an oxidant, and water as a solvent, and has mild reaction conditions and does not add alkaline additives, to solve the problems of high cost, high difficulty of subsequent treatment and product separation caused by the use of noble metal catalysts and alkaline additives in traditional synthesis methods, and has wide industrial application prospects. 2,2,6,6-tetramethylpiperidine oxide has the functions of capturing free radicals and quenching singlet oxygen, and can oxidize primary and secondary alcohols to the desired carbonyl compounds, with the advantages of high yield, good selectivity, good stability, recyclability, etc., and is widely used in the fields of chemistry, biology, food industry and agriculture. Potassium peroxymonosulfate has high stability, high water solubility, relatively low price, easy storage and transportation, non-flammable and non-explosive, long storage time at room temperature, etc., and after dissolving in water, it can release active oxygen and generate various high-energy, high-activity small molecule free radicals, new ecological atomic oxygen, oxygen free radicals, hydroxyl radicals and sulfuric acid radicals through chain reaction with the help of high-energy activators. It is a commonly used oxidant.

[0009] To achieve the above-mentioned purposes, the technical scheme adopted by the present application comprises:

[0010] The present application provides a method for preparing 2,5-furan dicarboxylic acid under mild conditions, comprising:

[0011] The 5-hydroxymethylfurfural, the oxidant and the catalyst are placed in the solvent water under an air atmosphere to prepare the above-mentioned 2,5-furan dicarboxylic acid through catalytic oxidation;

[0012] The catalyst is 2,2,6,6-tetramethylpiperidine oxide; the atmosphere is an air atmosphere; and the oxidant is at least one of potassium monopersulfate or potassium monopersulfate.

[0013] According to one embodiment of the present application, the molar ratio of 5-hydroxymethylfurfural to the catalyst is 1-50:1; preferably, the molar ratio of 5-hydroxymethylfurfural to the catalyst is 10-30:1.

[0014] According to one embodiment of the present application, the reaction temperature is 60-120℃; preferably, the reaction temperature is 80-120℃.

[0015] According to one embodiment of the present application, the reaction time is 2-16h; preferably, the reaction time is 8-14h.

[0016] According to the above technical solution, the present application has the following advantages:

[0017] The present application uses 2,2,6,6-tetramethylpiperidine oxide as the catalyst, avoids the use of noble metal catalysts, and does not further treat the catalyst, thereby greatly reducing the production cost; no alkaline substance is added, thereby simplifying the post-treatment steps of the product and avoiding the generation of a large amount of wastewater in the acidification process; at the same time, the present application uses green solvent water as the solvent and air as the oxygen source, thereby having the advantages of low cost and no pollution. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Fig. 1 is a 2,5-furan dicarboxylic acid yield-time trend chart for invention examples 1-7.

[0019] Figure 2 Fig. 2 is a 2,5-furan dicarboxylic acid yield-time trend chart for invention examples 8-9.

[0020] Figure 3 Fig. 3 is a 2,5-furan dicarboxylic acid yield-time trend chart for invention examples 10-14.

[0021] DETAILED EMBODIMENT

[0022] The present application is described in detail in combination with the specific embodiment, and the specific embodiment described herein is only used to illustrate and explain the present application, and is not used to limit the present application.

[0023] The raw materials in the embodiments of the present application are purchased through commercial channels.

[0024] For the numerical ranges recited in the description of the present application, the end points of the various ranges, the end points of the various ranges and the individual point values, and the individual point values can be combined with each other to give one or more new numerical ranges, which are to be considered as specifically disclosed in the present application.

[0025] Case 1

[0026] 5-hydroxymethylfurfural, oxidant (potassium monopersulfate salt), catalyst (2,2,6,6-tetramethylpiperidine oxide), solvent were added into a high-pressure reaction kettle, and reacted at 100°C under air atmosphere for 10h at normal pressure. Among them, the molar ratio of 5-hydroxymethylfurfural to catalyst 2,2,6,6-tetramethylpiperidine oxide was 20:1; the molar ratio of 5-hydroxymethylfurfural to potassium monopersulfate salt was 1:1; the molar volume (mmol / mL) ratio of 5-hydroxymethylfurfural to water was 1:6;

[0027] The yield of furan dicarboxylic acid in the reaction mixture was detected by HPLC method, and the detection conditions were as follows: the mobile phase was 0.1wt% acetic acid aqueous solution:methanol=50:50(v / v); the column temperature was 40°C; the flow rate was 0.5mL / min; the ultraviolet detector, the detection wavelength was 254nm; the C18 chromatographic column; the yield of 2,5-furan dicarboxylic acid was quantitatively determined by HPLC method standard curve as 88.4%.

[0028] Case 2

[0029] The catalytic time was changed to 2h, and the others were the same as in Case 1. The yield of 2,5-furan dicarboxylic acid was 60.3%.

[0030] Case 3

[0031] The catalytic time was changed to 4h, and the others were the same as in Case 1. The yield of 2,5-furan dicarboxylic acid was 65.2%.

[0032] Case 4

[0033] The catalytic time was changed to 6h, and the others were the same as in Case 1. The yield of 2,5-furan dicarboxylic acid was 73.6%.

[0034] Case 5

[0035] The catalytic time was changed to 8h, and the others were the same as in Case 1. The yield of 2,5-furan dicarboxylic acid was 78.7%.

[0036] Case 6

[0037] The catalytic time was changed to 12h, and the others were the same as in Case 1. The yield of 2,5-furan dicarboxylic acid was 88.6%.

[0038] Case 7

[0039] The catalysis time was changed to 14 h, and the other conditions were the same as in Example 1. The yield of 2,5-furan dicarboxylic acid was 88.5%.

[0040] Example 8

[0041] The catalysis temperature was changed to 80°C, and the other conditions were the same as in Example 1. The yield of 2,5-furan dicarboxylic acid was 75.6%.

[0042] Example 9

[0043] The catalysis temperature was changed to 120°C, and the other conditions were the same as in Example 1. The yield of 2,5-furan dicarboxylic acid was 86.2%.

[0044] Example 10

[0045] The molar ratio of 5-hydroxymethylfurfural to 2,2,6,6-tetramethylpiperidine oxide was changed to 1:1, and the other conditions were the same as in Example 1. The yield of 2,5-furan dicarboxylic acid was 98.3%.

[0046] Example 11

[0047] The molar ratio of 5-hydroxymethylfurfural to 2,2,6,6-tetramethylpiperidine oxide was changed to 10:1, and the other conditions were the same as in Example 1. The yield of 2,5-furan dicarboxylic acid was 93.5%.

[0048] Example 12

[0049] The molar ratio of 5-hydroxymethylfurfural to 2,2,6,6-tetramethylpiperidine oxide was changed to 30:1, and the other conditions were the same as in Example 1. The yield of 2,5-furan dicarboxylic acid was 80.7%.

[0050] Example 13

[0051] The molar ratio of 5-hydroxymethylfurfural to 2,2,6,6-tetramethylpiperidine oxide was changed to 40:1, and the other conditions were the same as in Example 1. The yield of 2,5-furan dicarboxylic acid was 72.3%.

[0052] Example 14

[0053] The molar ratio of 5-hydroxymethylfurfural to 2,2,6,6-tetramethylpiperidine oxide was changed to 50:1, and the other conditions were the same as in Example 1. The yield of 2,5-furan dicarboxylic acid was 60.5%.

[0054] Example 15

[0055] The oxidant was changed to potassium monopersulfate, and the other conditions were the same as in Example 1. The yield of 2,5-furan dicarboxylic acid was 70.3%.

[0056] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical solution and inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for preparing 2,5-furandicarboxylic acid, characterized in that, The process includes the following steps: mixing 5-hydroxymethylfurfural, catalyst, oxidant, and solvent, and catalyzing the reaction at a temperature of 60-120℃, a reaction time of 2-16h, at atmospheric pressure, and with a molar ratio of 5-hydroxymethylfurfural to catalyst of 1-50:1 to obtain 2,5-furandicarboxylic acid. The catalyst is 2,2,6,6-tetramethylpiperidine oxide, and the oxidant is potassium peroxide monosulfate or potassium peroxide monosulfonate.

2. The method for preparing 2,5-furandicarboxylic acid according to claim 1, characterized in that, The solvent is water.

3. The method for preparing 2,5-furandicarboxylic acid according to claim 1, characterized in that, The atmosphere used in this method is an air atmosphere.

4. The method for preparing 2,5-furandicarboxylic acid according to claim 1, characterized in that, The reaction temperature is 80-120℃.

5. The method for preparing 2,5-furandicarboxylic acid according to claim 1, characterized in that, The reaction time is 8-14 hours.

6. The method for preparing 2,5-furandicarboxylic acid according to claim 1, characterized in that, The molar ratio of 5-hydroxymethylfurfural to the catalyst is 10-30:1.

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