CN-121991011-A - Method for extracting and separating 5-HMF from eutectic solvent

Abstract

The invention discloses a method for extracting and separating 5-HMF from a eutectic solvent, and belongs to the technical field of separation and purification. The method comprises the following steps of uniformly mixing acetonitrile, a eutectic solvent reaction liquid containing 5-HMF and an extracting agent, destroying a eutectic solvent system, and extracting and separating to obtain an extraction phase containing 5-HMF, wherein the eutectic solvent in the eutectic solvent reaction liquid comprises triethylbenzyl ammonium chloride, oxalic acid and water, and the volume dosage of the acetonitrile is not higher than that of the extracting agent. The separation method provided by the invention is simple and convenient to operate, has high separation efficiency, can obviously reduce the dosage of the extractant, and can effectively maintain the chemical stability of the 5-HMF, so that a high-purity product is obtained, and the problem of low efficiency of separating the 5-HMF from a eutectic solvent system in the prior art is solved.

Inventors

• LIN XIAOQING
• KE YUHAO
• Song Jiuhang
• SHI CHENXI
• FU XINYUAN
• FAN JIALIANG
• FANG SHU
• MAI XIAOYING

Assignees

• 广东工业大学

Dates

Publication Date

20260508

Application Date

20260212

Claims (10)

1. 1. A method for extracting and separating 5-HMF from a eutectic solvent is characterized by comprising the following steps of uniformly mixing acetonitrile, a eutectic solvent reaction liquid containing 5-HMF and an extractant, destroying a eutectic solvent system, and extracting and separating to obtain an extract phase containing 5-HMF; the eutectic solvent in the eutectic solvent reaction liquid comprises triethylbenzyl ammonium chloride, oxalic acid and water; the volume usage of acetonitrile is not higher than that of the extractant.
2. 2. The method of claim 1, wherein the volume ratio of the eutectic solvent reaction solution to acetonitrile is 1:1-2.
3. 3. The method according to claim 1, wherein the extractant is one or more of ethyl acetate, methyl isobutyl ketone, 2-methyltetrahydrofuran, diethyl succinate, methyl tert-butyl ether, butyl acetate, n-heptane, tetrahydrofuran or 1, 2-dichloroethane.
4. 4. The method of claim 1, wherein the extractant is 2-methyltetrahydrofuran.
5. 5. The method of claim 1, wherein the molar ratio of triethylbenzyl ammonium chloride to oxalic acid to water is (1-3): 0.5-1.5): 0-5.
6. 6. The method according to claim 1, wherein the eutectic solvent reaction solution is prepared by: S1, uniformly mixing triethylbenzyl ammonium chloride, oxalic acid and water, heating and stirring until liquid is clear, and obtaining a eutectic solvent; S2, mixing the eutectic solvent with biomass derived sugar, and performing airtight reaction to obtain a eutectic solvent reaction solution containing 5-HMF.
7. 7. The method of claim 1, wherein the volume ratio of the eutectic solvent reaction liquid to the extractant is 1:1-4.
8. 8. The method of claim 1, wherein the extraction separation temperature is 15-35 ℃.
9. 9. The method of claim 1, wherein the extraction separation time is 0.5 to 5 hours.
10. 10. Use of acetonitrile as a breaker for a eutectic solvent system comprising triethylbenzyl ammonium chloride, oxalic acid and water.

Description

Method for extracting and separating 5-HMF from eutectic solvent Technical Field The invention belongs to the technical field of separation and purification, and particularly relates to a method for extracting and separating 5-HMF from a eutectic solvent. Background In the field of biomass conversion, 5-hydroxymethylfurfural (5-HMF) is taken as a key platform compound with great value, and the derivative can further develop various resins, polymers, solvents and fuels, is an important platform compound for connecting petroleum-based chemicals and bio-based chemicals, and the efficient preparation and separation technology is always the focus of research. The eutectic solvent (DES) has become an ideal reaction medium for catalyzing biomass sugar to prepare 5-HMF due to the characteristics of environmental protection and strong designability. For example, patent CN118724846a catalyzes fructose to produce 5-HMF using DES formulated with triethylbenzyl ammonium chloride/acetic acid, its 5-HMF yield can reach 97.8%, patent CN119569685A catalyzes fructose to produce 5-HMF using DES formulated with triethylbenzyl ammonium chloride/oxalic acid/water, its 5-HMF yield can reach 87.8%, patent CN113651781a catalyzes glucose to produce 5-HMF using DES formulated with triethylbenzyl ammonium chloride/formic acid, and its 5-HMF yield can reach 36%. However, DES systems typically have extremely high viscosity and strong hydrogen bonding networks, which makes it difficult to efficiently separate the target product 5-HMF from the high viscosity system after the reaction is completed. This technical bottleneck severely limits the efficiency and economy of the overall process. At present, although various separation methods exist for separating 5-HMF, the problems of complex operation, high energy consumption, difficult DES circulation and the like are generally faced. For example, direct distillation is difficult to implement due to the thermal stability limitations of DES, whereas conventional organic solvent extraction methods often suffer from low extraction efficiency and poor selectivity due to the unique physicochemical properties of DES, resulting in loss of 5-HMF yield and difficulty in subsequent purification. Therefore, it is particularly important to develop a method for efficiently separating 5-HMF from a eutectic solvent. Disclosure of Invention The primary purpose of the invention is to overcome the defects or shortages of the existing method for separating 5-HMF from the eutectic solvent and provide a method for extracting and separating 5-HMF from the eutectic solvent. It is another object of the present invention to provide the use of acetonitrile as a breaking agent for eutectic solvent systems. In order to achieve the above purpose, the present invention is realized by the following technical scheme: A method for extraction separation of 5-HMF from a eutectic solvent, comprising the steps of: uniformly mixing acetonitrile, a eutectic solvent reaction liquid containing 5-HMF and an extracting agent, destroying a eutectic solvent system, and extracting and separating to obtain an extract phase containing 5-HMF; the eutectic solvent in the eutectic solvent reaction liquid comprises triethylbenzyl ammonium chloride, oxalic acid and water; the volume usage of acetonitrile is not higher than that of the extractant. The invention adopts triethylbenzyl ammonium chloride, oxalic acid and water to prepare the eutectic solvent. Wherein, the triethylbenzyl ammonium chloride contains benzene ring structure, has excellent phase transfer capability, can be accumulated with pi-pi of furan rings in biomass derived sugar, and has interaction to accelerate the reaction and increase the concentration of substrate sugar. Oxalic acid can improve more hydrogen protons, build a hydrogen bond network for reaction and provide an acidic environment. Water can regulate the hydrogen bonding network and the acidic environment. Based on the combined action of the three, the prepared eutectic solvent can be used as a reaction solvent for preparing 5-hydroxymethylfurfural from biomass-derived sugar, and can also be used as a catalyst for biomass-derived sugar, so that high-substrate sugar can be efficiently and rapidly converted into 5-hydroxymethylfurfural (5-HMF). However, the eutectic solvent has a hydrogen bond network structure similar to a bird nest structure, so that the system viscosity is higher and the extraction difficulty is higher. According to the invention, acetonitrile is added into the eutectic solvent system, so that the hydrogen bond network structure of the eutectic solvent can be effectively destroyed, an extraction channel is constructed, and the extractant is promoted to enter the eutectic solvent system, thereby remarkably improving the extraction efficiency of 5-HMF. Preferably, the volume ratio of the acetonitrile to the extractant is 1:1-2. More preferably, the volume ratio of acetonitrile to extractant is 1:1. W