A method for increasing the yield of 5-hydroxymethylfurfural using ultra-high pressure homogenized formylated cellulose

Abstract

The application discloses a method for improving the yield of 5-hydroxymethylfurfural by using superhigh-pressure homogenization formylated cellulose, which comprises the following steps: mixing cellulose and formic acid, homogenizing the mixture for 5-25 times under the pressure of 600-1400 bar, performing solid-liquid separation to extract the precipitate, removing by-products by washing and drying; uniformly mixing 5-20 parts by weight of the treated cellulose, 0-1000 parts by weight of DMSO, 0-1000 parts by weight of deionized water, 25-125 parts by weight of metal ionic liquid and 0-80 parts by weight of acid, and reacting for 10-120 minutes under the temperature of 150-190 DEG C; and performing solid-liquid separation to obtain supernatant containing 5-hydroxymethylfurfural. The method for preparing formylated cellulose by performing superhigh-pressure homogenization pretreatment on the mixture of cellulose and formic acid and then catalytically converting the formylated cellulose into 5-hydroxymethylfurfural has good yield of reaction products, is simple in operation and easy to realize.

Description

Technical Field

[0001] This invention relates to the field of cellulose resource development and utilization technology, specifically to a method for improving the yield of 5-hydroxymethylfurfural by using ultra-high pressure homogenized formylated cellulose. Background Technology

[0002] In recent years, with the increasing prominence of resource crises and environmental problems, finding green and environmentally friendly alternatives to fossil resources has become an urgent issue. Biomass, as one of the most abundant renewable resources in nature, has attracted widespread attention. Biomass includes green, natural, and renewable resources such as cellulose and chitin, and the production of high-value chemicals such as formic acid, levulinic acid, ethylene glycol, and glucose from biomass resources has also become a hot topic.

[0003] Cellulose, as the world's largest biomass resource, is abundant and diverse, originating from sources such as potato tubers, wheat and corn stalks, sugarcane bagasse pith, fruit shells, and fruit peels. Cellulose is an organic polymer composed of D-glucose units linked by β-1,4-glycosides. Due to its excellent sustainability, biodegradability, and biocompatibility, cellulose is widely used in various industries, including food, pharmaceuticals, environment, and cosmetics. Glucose obtained through cellulose hydrolysis can serve as a common precursor for high-value chemicals such as 5-hydroxymethylfurfural (5-HMF) and biodegradable materials. This process provides a feasible pathway for the efficient utilization of resources, further promoting the application of cellulose and its derivatives in various fields.

[0004] 5-HMF, as one of the most representative high-value chemicals in biomass catalytic conversion, is considered a core raw material for the next generation of biofuels, and the U.S. Department of Energy lists it as one of the top ten general-purpose platform chemicals. 5-HMF is an important platform compound with excellent reactivity, and a key precursor for the production of compounds such as levulinic acid (LA), adipic acid, and dimethylfuran (DMF). Compared with traditional fossil fuels, 5-HMF derivatives have lower emissions of harmful gases and less environmental pollution, which is of great significance for promoting global sustainable development. 5-HMF is mainly obtained by the isomerization of sugars such as fructose, glucose, and cellulose. However, due to the high price of glucose and fructose, the production cost is high. Therefore, it is more ideal to use abundant and inexpensive natural cellulose to produce 5-HMF. In this process, cellulose first undergoes isomerization by cellulase, Lewis acid, and... Cellulose is hydrolyzed into glucose under the action of acids, then isomerized into fructose, and finally converted into 5-HMF. However, the efficient conversion of cellulose is limited by its inherent properties. The numerous hydrogen bonds and van der Waals forces between and within cellulose molecules endow it with significant rigidity, stability, and insolubility in water. These properties greatly increase the difficulty of converting cellulose into high-value chemicals such as 5-HMF. Therefore, improving cellulose conversion efficiency and developing more efficient catalytic methods are crucial to achieving this conversion process.

[0005] Currently, research on 5-HMF production mainly focuses on optimizing catalysts, solvent systems, and reaction conditions. However, the high crystallinity, degree of polymerization, and insolubility of cellulose remain major obstacles to the efficient conversion of 5-HMF. According to reports, pretreatment methods such as acid, alkali, and mechanical treatment can effectively overcome the challenges of cellulose's physicochemical properties. Studies have shown that formic acid pretreatment of cellulose significantly increases the yield of 5-HMF, and ball milling pretreatment followed by formic acid treatment further improves the yield. Therefore, reducing crystallinity and degree of polymerization, as well as chemical treatment, can effectively increase the yield of 5-HMF. However, formic acid pretreatment requires high temperatures, long times, and high concentrations of formic acid, posing challenges such as demanding equipment requirements and significant safety risks. Furthermore, ball milling pretreatment also suffers from long processing times and high energy consumption. Combining both methods, while improving yield, also presents challenges such as stringent conditions and complex procedures. Summary of the Invention

[0006] This invention addresses the above-mentioned problems by researching and designing a method for improving the yield of 5-hydroxymethylfurfural using ultra-high pressure homogenization of formylated cellulose. The technical means employed in this invention are as follows:

[0007] A method for improving the yield of 5-hydroxymethylfurfural using ultra-high pressure homogenized formylated cellulose includes the following steps:

[0008] S1: Mix cellulose and formic acid, homogenize at 600-1400 bar for 5-20 times, perform solid-liquid separation to extract the precipitate, wash to remove by-products and dry.

[0009] S2: Mix 5-25 parts by weight of cellulose treated in step S1, 0-1000 parts by weight of DMSO, 0-1000 parts by weight of deionized water, 25-125 parts by weight of metal ion liquid and 0-80 parts by weight of acid evenly, and react at 150-190℃ for 10-120 minutes.

[0010] S3: Perform solid-liquid separation to obtain a supernatant containing 5-hydroxymethylfurfural.

[0011] Further, in step S1, the homogenization pressure is 1000-1400 bar, the ratio of cellulose to formic acid is 1 g: 50 mL, and the homogenization treatment is performed 15-20 times; in step S2, 5-20 parts by weight of the cellulose treated in step S1, 600-1000 parts by weight of DMSO, 0-400 parts by weight of deionized water, 50-100 parts by weight of metal ion liquid, and 10-80 parts by weight of acid are mixed evenly and reacted at 170-190°C for 30-120 minutes.

[0012] Further, in step S1, the homogenization pressure is 1200 bar, and the homogenization process is repeated 15 times; in step S2, 5-15 parts by weight of the cellulose treated in step S1, 800-900 parts by weight of DMSO, 100-200 parts by weight of deionized water, 50-75 parts by weight of metal ion liquid, and 20-40 parts by weight of acid are mixed evenly and reacted at 180-190°C for 60-120 minutes.

[0013] Further, in step S1, the homogenization is carried out in a homogenizer, the solid-liquid separation method is centrifugation, the precipitate is washed with ethanol to remove byproducts, and the drying method is vacuum drying; in step S2, the reaction is carried out in an oil bath preheated to a set temperature, the acid is an organic acid, and the metal ion liquid is 1-butyl-3-methylimidazolium chloroaluminate; in step S3, the solid-liquid separation method is centrifugation.

[0014] Furthermore, the organic acid is acetic acid.

[0015] Compared with existing technologies, the method for improving the yield of 5-hydroxymethylfurfural by using ultra-high pressure homogenization of cellulose to homogenize cellulose according to the present invention prepares formyl cellulose by ultra-high pressure homogenization pretreatment of a mixture of cellulose and formic acid, and then catalyzes the conversion of formyl cellulose to 5-hydroxymethylfurfural using DMSO-H2O solution as solvent and metal-based ionic liquid and organic weak acid as catalyst. This method has good product yield, simple operation and easy implementation. Attached Figure Description

[0016] Figure 1 These are the infrared spectra of cellulose after ultra-high pressure homogenization pretreatment with formic acid in Example 2 of this invention and the untreated cellulose.

[0017] Figure 2 This is a high-performance liquid chromatogram of the sample prepared in the embodiments of the present invention and the 5-HMF standard. Detailed Implementation

[0018] A method for improving the yield of 5-hydroxymethylfurfural using ultra-high pressure homogenized formylated cellulose includes the following steps:

[0019] S1: Mix cellulose and formic acid, homogenize at 600-1400 bar for 5-25 times, perform solid-liquid separation to extract the precipitate, wash to remove by-products and dry.

[0020] S2: Mix 5-25 parts by weight of cellulose treated in step S1, 0-1000 parts by weight of DMSO, 0-1000 parts by weight of deionized water, 25-125 parts by weight of metal ion liquid and 0-80 parts by weight of acid evenly, and react at 150-190℃ for 10-120 minutes.

[0021] S3: Perform solid-liquid separation to obtain a supernatant containing 5-hydroxymethylfurfural.

[0022] As a preferred embodiment, in step S1, the homogenization pressure is 1000-1400 bar, and the ratio of cellulose to formic acid is 1g:50mL, that is, in this embodiment of the invention, 1g of cellulose reacts with 50mL of formic acid, and the homogenization process is repeated 15-20 times; in step S2, 5-20 parts by weight of the cellulose treated in step S1, 600-1000 parts by weight of DMSO, 0-400 parts by weight of deionized water, 50-100 parts by weight of metal ion liquid and 10-80 parts by weight of acid are mixed evenly and reacted at 170-190°C for 30-120 minutes.

[0023] As a more preferred embodiment, in step S1, the homogenization pressure is 1200 bar, the ratio of cellulose to formic acid is 1 g: 50 mL, and the homogenization treatment is performed 15 times; in step S2, 5-15 parts by weight of the cellulose treated in step S1, 800-900 parts by weight of DMSO, 100-200 parts by weight of deionized water, 50-75 parts by weight of metal ion liquid, and 20-40 parts by weight of acid are mixed evenly and reacted at 180-190°C for 60-120 minutes.

[0024] The raw material cellulose in this invention is sourced from Shanghai Aladdin Biochemical Technology Co., Ltd. This invention utilizes cellulose, the most abundant biomass resource in nature, as a raw material. It prepares formyl cellulose by mixing cellulose with formic acid and undergoing ultra-high pressure homogenization pretreatment to disrupt intermolecular forces and reduce crystallinity. Simultaneously, grafting formyl groups onto cellulose enhances the catalytic activity for the conversion of cellulose to 5-HMF. The resulting formyl cellulose is then subjected to hydrothermal treatment in an H2O-DMSO mixed solution to prepare 5-hydroxymethylfurfural, expanding the research scope of effective biomass utilization. The pretreatment of cellulose before the reaction, and the catalytic system formed by the combination of metal ionic liquid and organic acid, significantly improves the formation rate of 5-hydroxymethylfurfural.

[0025] The metal ionic liquid described in this embodiment of the invention is 1-butyl-3-methylimidazolium chloroaluminate. Ionic liquids (ILs) are widely used in the catalytic conversion of 5-HMF due to their flexible designability, recyclability, and low toxicity. ILs can act as both catalysts and solvents in biomass conversion, and their recyclability further highlights their green and sustainable chemistry characteristics, expanding their application range in catalytic conversion. Against this backdrop, this invention discloses a method for producing 5-HMF through a combination of mechanical and chemical pretreatment of cellulose, and optimizes various process conditions to achieve efficient 5-HMF production. First, a mixture of cellulose and formic acid is homogenized under ultra-high pressure homogenization to prepare cellulose formate (CF). Subsequently, in this embodiment, CF is converted to 5-HMF in a mixed solvent of DMSO and water using a metal-based ionic liquid and an organic acid as catalysts. The reaction conditions were investigated and optimized in detail, including reaction temperature, reaction time, mass fraction of DMSO, optimal amount of substrate CF, and amounts of IL and organic acid added.

[0026] Example 1: By comparing four cellulose pretreatment methods, the pretreatment method with the best 5-HMF yield was selected. The four pretreatment methods are: (1) no treatment, (2) ball milling, (3) ball milling + formic acid treatment, and (4) ultra-high pressure homogenization treatment of cellulose and formic acid mixture. In this example, the pressure of ultra-high pressure homogenization treatment is 1200 bar. In this example, 15 parts by weight of cellulose after step S1 treatment, 800 parts by weight of DMSO, 200 parts by weight of deionized water, 50 parts by weight of metal ion liquid, and 40 parts by weight of acid were taken. Specifically, four hard glass tubes of the same type with a volume of 35 mL were taken, and the treated cellulose (0.150 g), DMSO (8.000 g), deionized water (2.000 g), 1-butyl-3-methylimidazolium chloroaluminate (0.5 g), and acetic acid (0.400 g) were added and mixed. The glass tubes were placed in an oil bath preheated to 180°C and reacted for 0.5 hours. The glass tube was then removed and quickly immersed in ice water to stop the reaction. The mixture was centrifuged at 10,000 rpm and 25 °C for 5 minutes, and the supernatant was diluted to a volumetric flask with the mobile phase. The 5-HMF content was detected by high performance liquid chromatography, and the yields of 5-hydroxymethylfurfural obtained by the four different treatment methods were calculated using the standard regression equation as (1) 4.12% (2) 7.12% (3) 7.78% (4) 13.85%. It can be seen that ultra-high pressure homogenization treatment can significantly improve the yield of 5-hydroxymethylfurfural.

[0027] Example 2: 3 g of cellulose (CE) was mixed with 150 mL of formic acid in a 300 mL beaker and magnetically stirred at room temperature for 3 minutes to ensure homogeneity. The mixture was then slowly poured into an ultra-high pressure homogenizer at 1200 bar and homogenized 15 times consecutively. The resulting cellulose mixture was collected, washed with anhydrous ethanol, and centrifuged at 4000 r / min for 10 min, repeated three times to extract the precipitate. The precipitate was washed with sufficient deionized water to remove byproducts, filtered, and vacuum dried for 24 h to obtain formicyl cellulose. Unless otherwise specified, the formicyl cellulose used in the following examples is the same as that obtained in this example; specific details shall prevail.

[0028] Example 3: Take five identical 35 mL hard glass tubes and add the same amounts of DMSO (8.000 g), deionized water (2.000 g), 1-butyl-3-methylimidazolium chloroaluminate (0.500 g), and acetic acid (0.400 g). Under these conditions, add 0.150 g of formicocellulose obtained after treatment at five different homogenization pressures (600 bar, 800 bar, 1000 bar, 1200 bar, and 1400 bar) and react for 0.5 hours. After the reaction, remove the glass tubes and quickly immerse them in ice water to stop the reaction. Centrifuge the mixture at 10,000 rpm and 25°C for 5 minutes, and dilute the supernatant to a 100 mL volumetric flask with the mobile phase. The content of 5-HMF was detected by high performance liquid chromatography. The yields of 5-hydroxymethylfurfural under five different homogenization pressures were calculated using the standard regression equation as follows: (1) 12.63% (2) 13.03% (3) 16.34% (4) 20.09% (5) 17.93%. Therefore, a homogenization pressure of 1200 bar was selected as the optimal parameter for subsequent experimental condition optimization.

[0029] Example 4: Take five identical 35 mL hard glass tubes and add the same amounts of DMSO (8.000 g), deionized water (2.000 g), 1-butyl-3-methylimidazolium chloroaluminate (0.500 g), and acetic acid (0.400 g). Add 0.150 g of formicocellulose obtained after five different homogenization cycles (0, 5, 10, 15, and 20 cycles) at the optimal homogenization pressure of 1200 bar as selected in Example 3, and react at 180°C for 0.5 hours. After the reaction, remove the glass tubes and quickly immerse them in ice water to stop the reaction. Centrifuge the mixture at 10,000 rpm at 25°C for 5 minutes, and dilute the supernatant to a 100 mL volumetric flask with the mobile phase. The content of 5-HMF was detected by high performance liquid chromatography. The yields of 5-hydroxymethylfurfural under five different homogenization times were calculated using the standard regression equation as (1) 4.12%, (2) 18.39%, (3) 18.73%, (4) 22.35%, and (5) 19.51%. Therefore, 15 homogenization times were selected as the optimal parameter for subsequent experimental condition optimization.

[0030] Example 5: Take 10 identical 35 mL hard glass tubes and add the same amount of formyl cellulose (0.150 g), DMSO (8.000 g), deionized water (2.000 g), 1-butyl-3-methylimidazolium chloroaluminate (0.500 g), and acetic acid (0.400 g). Divide the 10 tubes into two groups of five each and place them in oil baths preheated to two different temperatures (180°C and 190°C). Under these conditions, each group of five tubes reacts for different times (10 min, 30 min, 60 min, 90 min, 120 min). After the reaction, remove the glass tubes and quickly immerse them in ice water to stop the reaction. Centrifuge the mixture at 10,000 rpm at 25°C for 5 minutes, and dilute the supernatant to a 100 mL volumetric flask with the mobile phase. The 5-HMF content was detected by high performance liquid chromatography (HPLC). The yields of 5-hydroxymethylfurfural at 180℃ for five different reaction times were calculated using the standard regression equation: (1) 9.16% (2) 14.13% (3) 17.31% (4) 19.01% (5) 18.36%; and at 190℃ for the same five reaction times: (1) 10.28% (2) 21.8% (3) 23.14% (4) 23.96% (5) 22.09%. Therefore, a reaction time of 90 min was selected as the optimal parameter for subsequent experimental condition optimization.

[0031] Example 6: Take five 35 mL hard glass tubes of the same type and add the same amount of formyl cellulose (0.150 g), DMSO (8.000 g), deionized water (2.000 g), 1-butyl-3-methylimidazolium chloroaluminate (0.500 g), and acetic acid (0.400 g). Immerse the five glass tubes in oil baths preheated to (1) 150℃ (2) 160℃ (3) 170℃ (4) 180℃ (5) 190℃, respectively, and react for 90 min at the optimal reaction time selected in Example 5. After the reaction is complete, remove the glass tubes from the oil bath and immediately immerse them in an ice-water bath to terminate the reaction. Centrifuge at 10000 rpm and 25℃ for 5 minutes, and dilute the supernatant to a 100 mL volumetric flask with the mobile phase. The 5-HMF content was detected by high performance liquid chromatography. The yields of 5-hydroxymethylfurfural at five different reaction temperatures were calculated using the standard regression equation: (1) 6.33%, (2) 10.56%, (3) 13.74%, (4) 19.00%, and (5) 23.96%. Therefore, a reaction temperature of 190 ℃ was selected as the optimal parameter for subsequent experimental condition optimization.

[0032] Example 7: Take five 35 mL hard glass tubes of the same type and add the same 1-butyl-3-methylimidazolium chloroaluminate (0.500 g), acetic acid (0.400 g), DMSO (8.000 g), deionized water (2.000 g), and the optimal reaction temperature of 190 °C selected in Example 6. Add the following amounts of formyl cellulose to the five tubes respectively: (1) 0.05 g, (2) 0.100 g, (3) 0.150 g, (4) 0.200 g, and (5) 0.250 g. Place the glass tubes in an oil bath preheated to 190 °C and react for 90 min. After the reaction is complete, remove the glass tubes from the oil bath and quickly immerse them in an ice-water bath to stop the reaction. Centrifuge at 10,000 rpm and 25 °C for 5 min, and dilute the supernatant to a 100 mL volumetric flask with the mobile phase. The 5-HMF content was detected by high performance liquid chromatography. The yields of 5-hydroxymethylfurfural were calculated by standard regression equations for five different amounts of formyl cellulose: (1) 27.82% (2) 24.62% (3) 22.31% (4) 21.54% (5) 18.90%. Therefore, 0.050 g of formyl cellulose was selected as the optimal parameter for subsequent experimental condition optimization.

[0033] Example 8: Take five 35 mL hard glass tubes of the same type and add the same amount of DMSO (8.000 g), deionized water (2.000 g), acetic acid (0.400 g), and the optimal formyl cellulose (0.050 g) selected in Example 7. Add 1-butyl-3-methylimidazolium chloroaluminate to each of the five tubes in the following quantities: (1) 0.250 g, (2) 0.500 g, (3) 0.750 g, (4) 1.000 g, and (5) 1.250 g. Place the glass tubes in an oil bath preheated to 190 °C and react for 90 min. After the reaction is complete, remove the glass tubes and immediately immerse them in an ice-water bath to terminate the reaction. Centrifuge at 10,000 rpm and 25 °C for 5 min, and dilute the supernatant to a 100 mL volumetric flask with the mobile phase. The content of 5-HMF was determined by high performance liquid chromatography. The yields of 5-hydroxymethylfurfural were calculated based on the standard regression equation for five different masses of 1-butyl-3-methylimidazolium chloroaluminate: (1) 16.09%, (2) 27.82%, (3) 25.16%, (4) 21.91%, and (5) 17.78%. Therefore, a mass of 0.5 g of 1-butyl-3-methylimidazolium chloroaluminate was selected as the optimal parameter for subsequent experimental condition optimization.

[0034] Example 9: Take 7 identical 35 mL hard glass tubes and add the same amount of formyl cellulose (0.050 g), 1-butyl-3-methylimidazolium chloroaluminate (0.500 g), and acetic acid (0.400 g). Fix the total mass of deionized water and DMSO to 10 g. Add DMSO and deionized water to 6 tubes in the following ratios: (1) 0:2 (2) 2:8 (3) 4:6 (4) 6:4 (5) 8:2 (6) 9:1 (7) 10:0. Place the glass tubes in an oil bath preheated to the reaction temperature of 190 °C and react for 90 min. After the reaction is complete, remove the glass tubes from the oil bath and quickly immerse them in an ice-water bath to stop the reaction. Centrifuge at 10,000 rpm and 25 °C for 5 minutes, and dilute the supernatant to 100 mL in a volumetric flask with the mobile phase. The 5-HMF content was detected by high performance liquid chromatography. The yields of 5-hydroxymethylfurfural were calculated using the standard regression equation for seven different DMSO:deionized water ratios: (1) 4.53%, (2) 8.57%, (3) 12.20%, (4) 26.03%, (5) 28.43%, (6) 33.43%, and (7) 26.90%. Therefore, a DMSO:deionized water ratio of 9:1 was selected as the optimal parameter for subsequent experimental condition optimization.

[0035] Example 10: Take seven 35 mL hard glass tubes of the same type and add the same amount of formyl cellulose (0.050 g), DMSO (9.000 g), deionized water (1.000 g), and 1-butyl-3-methylimidazolium chloroaluminate (0.500 g). Add acetic acid to each of the seven tubes in the following quantities: (1) 0.000 g, (2) 0.1000 g, (3) 0.200 g, (4) 0.300 g, (5) 0.400 g, (6) 0.600 g, and (7) 0.800 g. Place the glass tubes in an oil bath preheated to 190 °C and react for 90 min. After the reaction is complete, remove the glass tubes and immediately immerse them in an ice-water bath to terminate the reaction. Centrifuge at 10,000 rpm and 25 °C for 5 min, and dilute the supernatant to a 100 mL volumetric flask with the mobile phase. The content of 5-HMF was detected by high performance liquid chromatography. The yields of 5-hydroxymethylfurfural were calculated according to the standard regression equation for seven different masses of acetic acid, and were (1) 18.11%, (2) 26.34%, (3) 35.29%, (4) 33.80%, (5) 33.43%, (6) 24.68%, and (7) 23.92%. Therefore, 0.200 g of acetic acid was selected as the optimal parameter for subsequent experimental condition optimization.

[0036] Characterization analysis

[0037] (1) FTIR

[0038] like Figure 1 As shown, Fourier transform infrared spectroscopy (FTIR) was used to obtain the 3600-500 cm⁻¹... 1 The spectrum is within the range of [specific parameters]. The spectra show that after ultra-high pressure homogenization pretreatment with formic acid, the formation of formyl groups leads to a decrease in hydroxyl groups, causing the OH peak to shift to a higher wavenumber and become weaker. It can be seen that, unlike the untreated peak, the 1712 cm⁻¹ peak after formic acid treatment [is significantly higher / lower / lower]. 1 A new peak appears at the point, which is attributed to the C=O stretching vibration caused by the formyl group, thus proving the introduction of the formyl group.

[0039] (2) High Performance Liquid Chromatography

[0040] like Figure 2As shown, qualitative and quantitative analysis of 5-HMF was performed using a high-performance liquid chromatography (HPLC) system. The system was a Hitachi Scientific Instruments Chromaster 5000, equipped with a reversed-phase C18 column (250 mm × 4.6 mm × 5 μm) and a 287 nm UV detector for 5-HMF detection. The product was separated using a mobile phase of methanol and water (15:85, v / v) at a flow rate of 0.6 mL / min. The column temperature was maintained at 30 °C throughout the detection process, and the injection volume for each detection cycle was 5 μL. The chromatograms show that the peak of the 5-HMF standard appeared at 9.8 min, and a similar peak was detected in the sample at 9.8 min, indicating consistent peak times and confirming the formation of 5-HMF.

[0041] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for improving the yield of 5-hydroxymethylfurfural using ultra-high pressure homogenization of formylated cellulose, characterized in that, Includes the following steps: S1: Mix cellulose and formic acid at room temperature, homogenize 15 times at 1200 bar, perform solid-liquid separation to extract the precipitate, wash to remove by-products and dry. S2: Mix 5-15 parts by weight of cellulose treated in step S1, 800-900 parts by weight of DMSO, 100-200 parts by weight of deionized water, 50-75 parts by weight of metal ion liquid and 20-40 parts by weight of acetic acid evenly, and react at 180-190°C for 60-120 minutes. The reaction is carried out in an oil bath preheated to the set temperature. The metal ion liquid is 1-butyl-3-methylimidazolium chloroaluminate. S3: Perform solid-liquid separation to obtain a supernatant containing 5-hydroxymethylfurfural. The solid-liquid separation method is centrifugation. In step S1, homogenization is carried out in a homogenizer, solid-liquid separation is performed by centrifugation, precipitate is washed with ethanol to remove byproducts, and drying is performed by vacuum drying.

Images