CN108940313B - Biomass carbon-based solid acid catalyst and preparation method and application thereof - Google Patents

Abstract

The invention provides a preparation method and application of a biomass carbon-based solid acid catalyst, comprising: A) impregnating biomass containing nitrogen compounds in an acid solution, and filtering to obtain a solid product; B) carbonizing the solid product to obtain a porous carbon carrier ; C) the porous carbon carrier is reacted with p-aminobenzenesulfonic acid and isoamyl nitrite, and sulfonated to obtain a catalyst. In the present invention, the nitrogen-containing biomass is impregnated and carbonized to obtain a porous carbon carrier; after carbonization, the diverse surface chemical components have better sulfonic acid group loading capacity than the highly carbonized surface, and the Bronsted acid is improved. load, and promote the conversion efficiency of various sugars. The adjustable carbon-based carrier porous structure formed by the invention enables the sulfonic acid group to be firmly loaded inside the pores, and the pores are mesopores and macropores after loading, which is conducive to the contact between the substrate and the acid site and maintains better recycling. sex. The biomass carbon-based solid acid catalyst of the invention has high catalytic activity, good stability and high catalytic conversion efficiency.

Description

A kind of biomass carbon-based solid acid catalyst and its preparation method and application

technical field

The invention relates to the technical field of biomass chemical utilization, in particular to a biomass carbon-based solid acid catalyst and a preparation method and application thereof.

Background technique

With the increasingly serious problems of environmental pollution and energy shortage caused by the use of traditional fossil energy, the production of chemicals and liquid fuels from renewable biomass raw materials has attracted great attention. 5-Hydroxymethylfurfural (HMF) is an important biomass-based platform compound that can be converted into levulinic acid, 2,5-dimethylfuran, 2,5-furandicarboxylic acid, 2,5-dimethylfuran through various chemical reactions. , 5-furandimethanol, 1,6-hexanediol and maleic anhydride and other chemicals that can be used in medicine, fuel, plastic products and fine chemicals.

5-Hydroxymethylfurfural is mainly obtained through the catalytic dehydration conversion of carbohydrate acids. Carbohydrates can be six-carbon monosaccharides, polysaccharides, or even direct biomass raw materials. Among them, fructose and glucose are the most widely studied. The acid catalysts used for the catalytic conversion of six-carbon sugars to prepare HMF are mainly divided into homogeneous catalysts and solid catalysts. Homogeneous catalysts commonly include inorganic acids (hydrochloric acid, sulfuric acid, and nitric acid), organic acids (formic acid, acetic acid, and citric acid), and metal chlorides (aluminum chloride, chromium chloride, and copper chloride), but homogeneous catalysts are used. Unsustainable due to equipment corrosion, difficulty in recycling and environmental pollution.

acid)和路易斯酸(Lewis acid)才能实现较好催化效果，而常规的固体酸往往只包含单类型酸性位。Solid catalysts have attracted more attention from researchers due to their high reactivity, recyclability, and environmental friendliness. Currently, solid catalysts used include resins, carbon-based solid acids, zeolites, and metal oxides, which have achieved good results. However, many solid catalysts have the problems of unstable activity, unstable structure, low cyclability and low efficiency. And in order to improve the yield, expensive or toxic substances such as ionic liquids and dimethyl sulfoxide are often used as solvents, and the industrial availability is not strong. In addition, for the conversion of glucose to HMF, it requires a strong brynkast acid (

acid) and Lewis acid can achieve better catalytic effect, while conventional solid acids often only contain a single type of acid site.

The cyclic effect of the existing biomass carbon-based solid acid catalysts is general. In the process of catalyzing the preparation of HMF, the initial effect is often only good, and generally only contains brynkast acid, and the yield of converting glucose into HMF is too low. Therefore, the search for an efficient and stable solid acid and an environmentally friendly catalytic method plays a key role in promoting the industrialized preparation of HMF.

SUMMARY OF THE INVENTION

In view of this, the technical problem to be solved by the present invention is to provide a biomass carbon-based solid acid catalyst. The biomass carbon-based solid acid catalyst of the present invention has high catalytic activity, good stability and high catalytic conversion efficiency.

The invention provides a preparation method of a biomass carbon-based solid acid catalyst, comprising:

A) dipping the biomass containing nitrogen compounds in acid solution and filtering to obtain solid product;

B) carbonizing the solid product to obtain a porous carbon support;

C) The porous carbon support is reacted with p-aminobenzenesulfonic acid and isoamyl nitrite, and the catalyst is obtained by sulfonation.

Preferably, the biomass containing nitrogen compounds in step A) is tobacco stems, eggplant straws or bean straws; the acid solution is phosphoric acid or pyrophosphoric acid solution with a concentration of 10% to 50% by mass.

Preferably, the immersion time in step A) is 1-24h; the mass ratio of the nitrogen-containing compound biomass to the acid solution is: 1:(0.4-2); the p-aminobenzenesulfonic acid and nitrous acid are The mass ratio of pentyl ester is 1:3～3:1.

Preferably, the reaction in step B) is carried out under the protection of an inert gas; the carbonization temperature is 300-700° C.; the carbonization time is 1-10 h.

Preferably, the reaction temperature in step C) is 60-100° C.; the reaction time is 4-24 h.

The present invention provides a biomass carbon-based solid acid catalyst, which is prepared by the preparation method described in any one of the above technical solutions.

The invention provides a preparation method of 5-hydroxymethyl furfural, comprising:

A catalyst is prepared by mixing glucose or fructose, a solvent and the preparation method described in any one of the above technical solutions, and a catalyst is mixed and stirred to obtain 5-hydroxymethylfurfural.

Preferably, the reaction temperature is 80-250°C, and the catalytic dehydration time is 1-600 min.

The invention provides a preparation method of furfural, comprising:

The xylose, the solvent and the catalyst prepared by the preparation method according to any one of claims 1 to 5 are mixed and stirred to obtain furfural.

The present invention provides the application of the catalyst prepared by the preparation method described in any one of the above technical solutions in the preparation of 5-hydroxymethylfurfural or furfural.

acid)负载量，促进各类糖的转化效率；而后采用亚硝酸异戊脂水解和对氨基苯磺酸磺化反应制备得到催化剂。本发明形成的可调控的碳基载体多孔结构，使磺酸基团牢固的负载在孔道及表面内部，负载后孔道都为介孔和大孔结构，利于底物与酸性位接触，同时保持更好的循环回收性。本发明的生物质碳基固体酸催化剂催化活性高，稳定性好，催化转换效率高。Compared with the prior art, the present invention provides a method for preparing a biomass carbon-based solid acid catalyst, comprising: A) dipping the biomass containing nitrogen compounds in an acid solution, and filtering to obtain a solid product; The product is carbonized to obtain a porous carbon support; C) the porous carbon support is reacted with p-aminobenzenesulfonic acid and isoamyl nitrite, and the catalyst is obtained by sulfonation. In the present invention, the nitrogen-containing biomass is impregnated and carbonized to obtain a porous carbon carrier; after carbonization, the diverse surface chemical components have better sulfonic acid group loading capacity than the highly carbonized surface, and the Bronsted acid is improved. (

acid) loading capacity to promote the conversion efficiency of various sugars; and then the catalyst is prepared by hydrolysis of isoamyl nitrite and sulfonation of p-aminobenzenesulfonic acid. The controllable carbon-based carrier porous structure formed by the invention enables the sulfonic acid group to be firmly loaded in the pores and inside the surface. After loading, the pores are all mesoporous and macroporous structures, which is conducive to the contact between the substrate and the acid site, and at the same time keeps more Good recyclability. The biomass carbon-based solid acid catalyst of the invention has high catalytic activity, good stability and high catalytic conversion efficiency.

Detailed ways

The present invention provides a biomass carbon-based solid acid catalyst and a preparation method and application thereof, and those skilled in the art can learn from the content of this article and appropriately improve the process parameters to achieve. It should be particularly pointed out that all similar replacements and modifications are obvious to those skilled in the art, and they all belong to the protection scope of the present invention. The method and application of the present invention have been described through the preferred embodiments, and it is obvious that relevant persons can make changes or appropriate changes and combinations of the methods and applications herein without departing from the content, spirit and scope of the present invention, so as to realize and apply the present invention. Invention technology.

The invention provides a preparation method of a biomass carbon-based solid acid catalyst, comprising:

A) dipping the biomass containing nitrogen compounds in acid solution and filtering to obtain solid product;

B) carbonizing the solid product to obtain a porous carbon support;

C) The porous carbon support is reacted with p-aminobenzenesulfonic acid and isoamyl nitrite, and the catalyst is obtained by sulfonation.

The present invention first impregnates biomass containing nitrogen compounds in an acid solution.

The nitrogen-containing biomass of the present invention includes, but is not limited to, tobacco stems or bean straw; in the embodiment of the present invention, tobacco stems are used.

In the present invention, preferably, the biomass containing nitrogen compounds is preferably dried and ground at 100-105°C. The present invention does not limit the specific manner of the grinding, as long as those skilled in the art are well-known; the present invention does not limit the number of the grinding, preferably 40-60 mesh.

The milled biomass containing nitrogen compounds is dipped in an acid solution.

According to the present invention, the acid solution is preferably a phosphoric acid or pyrophosphoric acid solution with a mass concentration of 10% to 50%; more preferably a phosphoric acid or pyrophosphoric acid solution with a mass concentration of 15% to 48%. The immersion time is preferably 1-24h; more preferably 5-20h; most preferably 6-15h.

Wherein, the mass ratio of the nitrogen-containing compound biomass to the acid solution is preferably 1:(0.4-2); more preferably 1:(0.8-1.8); most preferably 1:(1-1.6).

The present invention does not limit the specific method of the impregnation, and those skilled in the art are well-known.

Filtration after impregnation gave a filtrate and a solid product.

The solid product was carbonized to obtain a porous carbon support.

The carbonization in the present invention is preferably carried out under the protection of an inert gas; the inert gas can be nitrogen, helium and the like.

The carbonization in the present invention is preferably carbonization at 300-700°C for 1-10 hours; more preferably, carbonization at 300-600°C for 1-8 hours; most preferably, carbonization at 300-500°C for 1-6 hours.

After carbonization, a black solid is obtained, which is washed with water until the pH value is neutral. The present invention does not limit the number and method of the washing, which is well known to those skilled in the art.

According to the present invention, the porous carbon carrier is obtained by drying to remove moisture after washing.

The porous carbon support was reacted with p-aminobenzenesulfonic acid and isoamyl nitrite, and the catalyst was obtained by sulfonation.

Specifically, the porous carbon is first immersed in water and stirred, and then p-aminobenzenesulfonic acid and isoamyl nitrite are added in sequence.

The present invention does not limit the specific manner of the stirring, and those skilled in the art are well-known.

The mass ratio of p-aminobenzenesulfonic acid and isoamyl nitrite according to the present invention is preferably 1:3-3:1; more preferably 1:0.5-1. The mass ratio of the porous carbon carrier of the present invention to p-aminobenzenesulfonic acid and isoamyl nitrite is preferably 1:1-6:0.5-3; most preferably 1:4:2.

After stirring, the reaction is heated and refluxed at 60-100°C for 4-24 hours; more preferably, the reaction is heated and refluxed at 80-90°C for 10-20 hours; most preferably, the reaction is heated and refluxed at 80-85°C for 12-18 hours. After the end, solid-liquid separation and washing are carried out, and the catalyst is obtained by drying under vacuum conditions of 60-120° C. for 2-24 hours. More preferably, the catalyst is obtained by drying under vacuum at 80-100°C for 12-20 hours.

The present invention provides a biomass carbon-based solid acid catalyst, which is prepared by the preparation method described in any one of the above technical solutions.

acid)负载量，促进各类糖的转化效率；而后采用亚硝酸异戊脂水解和对氨基苯磺酸磺化反应制备得到催化剂。本发明形成的可调控的碳基载体多孔结构，使磺酸基团牢固的负载在孔道及表面内部，负载后孔道都为介孔和大孔结构，利于底物与酸性位接触，同时保持更好的循环回收性。本发明的生物质碳基固体酸催化剂催化活性高，稳定性好，催化转换效率高。The present invention provides a method for preparing a biomass carbon-based solid acid catalyst, comprising: A) immersing biomass containing nitrogen compounds in an acid solution, and filtering to obtain a solid product; B) carbonizing the solid product to obtain a porous carbon carrier; C) The porous carbon carrier is reacted with p-aminobenzenesulfonic acid and isoamyl nitrite, and the catalyst is obtained by sulfonation. In the present invention, the nitrogen-containing biomass is impregnated and carbonized to obtain a porous carbon carrier; after carbonization, the diverse surface chemical components have better sulfonic acid group loading capacity than the highly carbonized surface, and the Bronsted acid is improved. (

acid) loading capacity to promote the conversion efficiency of various sugars; and then the catalyst is prepared by hydrolysis of isoamyl nitrite and sulfonation of p-aminobenzenesulfonic acid. The controllable carbon-based carrier porous structure formed by the invention enables the sulfonic acid group to be firmly loaded in the pores and inside the surface. After loading, the pores are all mesoporous and macroporous structures, which is conducive to the contact between the substrate and the acid site, and at the same time keeps more Good recyclability. The biomass carbon-based solid acid catalyst of the invention has high catalytic activity, good stability and high catalytic conversion efficiency.

The invention provides a preparation method of 5-hydroxymethyl furfural, comprising:

A catalyst is prepared by mixing glucose or fructose, a solvent and the preparation method described in any one of the above technical solutions, and a catalyst is mixed and stirred to obtain 5-hydroxymethylfurfural.

In the present invention, preferably in a pressure-resistant reaction vessel, glucose or fructose, a solvent, and the preparation method described in any one of the above technical solutions are prepared to obtain a catalyst for mixing and stirring reaction.

The solvent described in the present invention includes, but is not limited to, γ-valerolactone (GVL), γ-butyrolactone (GBL) and other pure organic solvents or their mixed solvents formed with water. The present invention does not limit its source, and it can be commercially available.

The present invention adopts a non-toxic green solvent which can be obtained from biomass conversion, which is beneficial to environmental protection and circular economy.

The mass ratio of the sugar (glucose or fructose) of the present invention to the solvent is preferably 0.01-0.05) The mass ratio of the sugar (glucose or fructose) of the present invention to the catalyst is preferably 20-1, more preferably 2-5, and the organic The mass ratio of solvent to water is preferably 1-200:1; more preferably 5-100:1; most preferably 10-50:1.

The mixed solvent of the present invention can also be a pure organic solvent without adding water.

The reaction temperature is preferably 80～250°C, more preferably 100～200°C, most preferably 120～180°C, and the catalytic dehydration time is preferably 1～600min; more preferably 10～300min; most preferably 20～180°C 60min.

The reaction is preferably a stirring reaction, and the stirring speed is preferably 300-600 r/min; more preferably 400-500 r/min.

After the reaction, the reaction solution was filtered to obtain 5-hydroxymethylfurfural.

The invention provides a preparation method of furfural, comprising:

The xylose, the solvent and the catalyst prepared by the preparation method according to any one of claims 1 to 5 are mixed and stirred to obtain furfural.

In the present invention, preferably in a pressure-resistant reaction vessel, xylose, a solvent and the preparation method described in any one of the above technical solutions are prepared to obtain a catalyst for mixing and stirring reaction.

The solvent described in the present invention includes, but is not limited to, pure organic solvents such as γ-valerolactone, γ-butyrolactone (GBL), or a mixed solvent formed with water. The present invention does not limit its source, and it can be commercially available.

The mass ratio of the sugar (glucose or fructose) of the present invention to the solvent may preferably be 0.01-0.05), and the mass ratio of the sugar (glucose or fructose) of the present invention to the catalyst is preferably 20-1, most preferably 2-5), and the mixing of the present invention The mass ratio of organic solvent to water in the solvent is preferably 1-200:1; more preferably 5-100:1; most preferably 10-50:1. The mixed solvent of the present invention can also be a pure organic solvent without adding water.

The reaction temperature (for sugar conversion) is preferably 80-250°C, more preferably 100-200°C, most preferably 120-180°C, and the catalytic dehydration time is preferably 1-600min; more preferably 10-300min; Most preferably, it is 20 to 60 minutes.

The reaction is preferably a stirring reaction, and the stirring speed is preferably 300-600 r/min; more preferably 400-500 r/min.

After completion of the reaction, the reaction solution was filtered to obtain furfural.

The present invention provides the application of the catalyst prepared by the preparation method described in any one of the above technical solutions in the preparation of 5-hydroxymethylfurfural or furfural.

The catalyst prepared by the invention is prepared by using primary biomass, turns waste into treasure, and has good economy. It uses primary biomass rich in nitrogen-containing compounds as raw materials, and the surface of the prepared carbon-based carrier has abundant hydroxyl groups, carboxyl groups and various Nitrogen-containing functional groups, which have a good catalytic synergistic effect on the preparation of HMF by acid-catalyzed dehydration of sugars.

acid)负载量，促进各类糖的转化效率；本发明原料原生生物质富含的一些矿物金属，碳化后可形成路易斯酸(Lewis acid)位，而无需外加负载，对葡萄糖催化转化有良好作用；本发明形成的可调控的碳基载体多孔结构，使磺酸基团牢固的负载在孔道及表面内部，负载后孔道都为介孔和大孔结构，利于底物与酸性位接触，同时保持更好的循环回收性。本发明催化反应迅速，在反应时间10～30min内，对果糖转化其HMF的收率可达到93.7％，对葡萄糖转化其HMF的收率可达到43.8％。After the solid product of the present invention is carbonized, its diverse surface chemical composition has better sulfonic acid group loading than the highly carbonized surface, which improves its Bronsted acid (

acid) loading capacity to promote the conversion efficiency of various sugars; some mineral metals rich in the raw biomass of the present invention can form Lewis acid sites after carbonization without additional loading, which has a good effect on the catalytic conversion of glucose The controllable carbon-based carrier porous structure formed by the present invention enables the sulfonic acid group to be firmly loaded in the pore channels and the inside of the surface, and the pores after loading are all mesoporous and macroporous structures, which is conducive to the contact between the substrate and the acid site, while maintaining Better recycling. The invention has rapid catalytic reaction, and within 10 to 30 minutes of reaction time, the yield of HMF for fructose conversion can reach 93.7%, and the yield of HMF for glucose conversion can reach 43.8%.

The present invention adopts a non-toxic green solvent that can be converted from biomass, or a mixed solvent with water, and the process is green and the yield is high. Combining the above features, the present invention turns waste biomass into treasure, and the prepared carbon-based solid acid catalyst can efficiently catalyze sugars to obtain HMF, the target product yield is high, the catalyst cycle is good, the reaction system is green and environmentally friendly, and has very good performance. industrial application value.

In order to further illustrate the present invention, a biomass carbon-based solid acid catalyst provided by the present invention and its preparation method and application are described in detail below with reference to the examples.

Example 1-4. Preparation of catalysts A-D

Take 10 g of ground tobacco stem powder as the raw biomass raw material rich in nitrogen-containing compounds, immerse it in a 45% pyrophosphoric acid solution for 12 hours, and the mass ratio of pyrophosphoric acid to tobacco stem is 1.3:1, and then filter the filtrate; The obtained solids were carbonized at 350, 400, 450, and 500 °C for 1 h under the protection of inert gas to obtain black solids numbered 1 to 4, respectively, washed with deionized water until the pH value was neutral, and then dried to remove moisture to obtain the number of porous carbon carriers. 1 to 4. In the sulfonation process, a certain amount of porous carbon was first immersed in water and stirred, and then p-aminobenzenesulfonic acid and isoamyl nitrite (mass: 2:1) were added in sequence and refluxed at 80 °C for 12 hours. Washed clean, dried under vacuum at 80°C for 12 hours to obtain the corresponding catalyst numbers A-D in sequence.

Examples 5-8

Add 0.1g of fructose, 4.7ml of γ-valerolactone, 0.3ml of water, and 0.05g of catalyst into a 15ml pressure-resistant tube, react at a temperature of 130°C for 30min at a rotating speed of 500r/min, filter the reaction solution after the end, and use Sugar and HMF products were detected by HPLC. The specific results are shown in Table 1.

Table 1. Conversion of fructose, yield and selectivity of HMF under different catalysis

catalyst Conversion rate(%) Yield (%) Selectivity (%) A 99.95 93.69 93.73 B 99.42 91.26 91.79 C 99.27 90.28 90.95 D 99.06 89.70 90.55

Examples 9-12

Add 0.1g of glucose, 4.7ml of γ-valerolactone, 0.3ml of water, and 0.05g of catalyst into a 15ml pressure-resistant tube, react at a temperature of 180°C for 30min at a rotational speed of 500r/min, filter the reaction solution after the end, and use Sugar and HMF products were detected by HPLC. The specific results are shown in Table 2.

Table 2. Conversion of glucose, yield and selectivity of HMF under different catalysis

Examples 13 to 16

Add 0.1g xylose, 5.0ml γ-valerolactone, and 0.05g catalyst to a 15ml pressure-resistant tube, react at a temperature of 170°C for 30min at a rotating speed of 500r/min, filter the reaction solution after the end, and use HPLC to detect sugar and HMF product. The specific results are shown in Table 3.

Table 3 The conversion rate of xylose under different catalysis The yield and selectivity of furfural

catalyst Conversion rate(%) Yield (%) Selectivity (%) A 98.95 83.52 84.41 B 98.28 82.32 83.77 C 97.67 79.64 81.54 D 97.18 77.27 79.52

Examples 17-20

In a 15ml pressure-resistant tube, add 0.1g fructose or glucose, 0.05g catalyst A, and use 5ml pure GVL, 4.55ml GVL and 0.45ml water mixed solvent as the solvent. The reaction was carried out for 30 min, and the glucose was reacted at a temperature of 180° C. for 30 min. After the reaction, the reaction solution was filtered, and HPLC was used to detect the sugar and HMF products. The specific results are shown in Table 4.

Table 4. Conversion of sugar, yield and selectivity of HMF under different reaction solvents

Examples 21-24

In a 15ml pressure-resistant tube, add 0.1g fructose or glucose, 4.7ml γ-valerolactone, and 0.3ml water. The dosage of catalyst A is 0.06g and 0.03g respectively. At a rotating speed of 500r/min, fructose is at a temperature of 130°C. The reaction was carried out for 30 min, and the glucose was reacted at a temperature of 180° C. for 30 min. After the reaction, the reaction solution was filtered, and HPLC was used to detect the sugar and HMF products. The specific results are shown in Table 5.

Table 5. Conversion of sugar, yield and selectivity of HMF under different catalyst dosages

Amount of catalyst (g) sugar Conversion rate(%) Yield (%) Selectivity (%) 0.06 fructose 99.96 91.62 91.66 0.03 fructose 98.63 87.87 89.09 0.06 glucose 96.79 43.05 44.48 0.03 glucose 89.41 38.55 43.11

Examples 25-29

Add 0.1g of fructose, 4.7ml of γ-valerolactone, 0.3ml of water, and 0.05g of catalyst into a 15ml pressure-resistant tube, react at a temperature of 130°C for 30min at a rotating speed of 500r/min, filter the reaction solution after the end, and use Sugar and HMF products were detected by HPLC. After the solid product was filtered, washed repeatedly with ethanol, dried at 110 °C for 2 h, and used directly for the reaction. The specific results are shown in Table 6.

Table 6. Conversion of fructose, yield and selectivity of HMF under catalyst recycle

Cycles Conversion rate(%) Yield (%) Selectivity (%) 1 99.95 93.69 93.73 2 99.83 92.82 92.98 3 99.22 90.33 91.04 4 98.87 89.47 90.49 5 98.13 86.62 88.27

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (9)

1. A preparation method of a biomass carbon-based solid acid catalyst comprises the following steps:

A) drying and grinding biomass containing nitrogen compounds at 100-105 ℃, soaking in an acid solution, and filtering to obtain a solid product; the biomass containing the nitrogen compounds is tobacco stems, eggplant straws or bean straws; the ground mesh number is 40-60 meshes;

B) carbonizing the solid product to obtain a porous carbon carrier; the reaction is carried out under the protection of inert gas; the carbonization temperature is 300-700 ℃; the carbonization time is 1-10 h;

C) and reacting the porous carbon carrier with sulfanilic acid and isoamyl nitrite, and sulfonating to obtain the catalyst.

2. The method according to claim 1, wherein the acid solution in step a) is a phosphoric acid or pyrophosphoric acid solution having a concentration of 10 to 50% by mass.

3. The preparation method according to claim 1, wherein the dipping time in the step A) is 1-24 h; the mass ratio of the biomass containing the nitrogen compounds to the acid solution is as follows: 1: (0.4-2); the mass ratio of the sulfanilic acid to the isoamyl nitrite is 1: 3-3: 1.

4. the method according to claim 1, wherein the reaction temperature in step C) is 60 to 100 ℃; the reaction time is 4-24 h.

5. A biomass carbon-based solid acid catalyst, which is prepared by the preparation method of any one of claims 1 to 4.

6. A preparation method of 5-hydroxymethylfurfural comprises the following steps:

mixing glucose or fructose, a solvent and the catalyst prepared by the preparation method of any one of claims 1-4, stirring and reacting to obtain the 5-hydroxymethylfurfural.

7. The preparation method according to claim 6, wherein the reaction temperature is 80-250 ℃ and the catalytic dehydration time is 1-600 min.

8. A method for preparing furfural, comprising:

mixing xylose, a solvent and the catalyst prepared by the preparation method of any one of claims 1 to 4, stirring and reacting to obtain furfural.

9. The application of the catalyst prepared by the preparation method according to any one of claims 1 to 4 in the preparation of 5-hydroxymethylfurfural or furfural.