Method for efficiently preparing furfural and glucose from forest and grass biomass

Abstract

The application discloses a method for efficiently preparing furfural and glucose from forest and grass biomass, and comprises the following steps: mixing forest and grass biomass, a molten salt hydrate and an organic solvent to perform pretreatment reaction, obtaining a pretreatment liquid containing furfural and pretreatment residues; mixing the pretreatment residues, sulfuric acid and the molten salt hydrate to perform hydrolysis reaction, obtaining a hydrolysis liquid containing glucose. The method for preparing furfural and glucose from forest and grass biomass is simple, convenient, environmentally friendly, time-saving, high-yield, high-economical and efficient, and has a wide industrial application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biomass refining, and particularly relates to a method for efficiently preparing furfural and glucose from forest and grass biomass. BACKGROUND

[0002] As the most abundant renewable resource in the world, the high value of forest and grass biomass is the focus of bio-refining and green chemistry research. Cellulose and hemicellulose are important components of forest and grass biomass (accounting for 60-80% of the total content), which can be hydrolyzed into various multifunctional monosaccharides (xylose, glucose, mannose, arabinose) and biomass-based platform compounds (furfural, 5-hydroxymethyl furfural, levulinic acid). Among them, furfural is a very important intermediate in fine chemical and polymer industries, and is widely used in resins, plastics, pesticides, green solvents, fuel additives and other fine chemical products; glucose can be applied to medicine, food, microbial fermentation, leather and fuel, etc. Therefore, it is of great practical and strategic significance to study the catalytic conversion of forest and grass biomass into furfural and glucose.

[0003] Currently, there are mainly two methods to realize the synthesis of furfural and glucose using forest and grass biomass as raw materials: (1) direct one-step chemical catalysis to obtain furfural and glucose; (2) component separation through pretreatment: hemicellulose is converted into xylose, and xylose is converted into furfural through chemical catalysis; separated cellulose is converted into glucose through enzymatic hydrolysis. In the actual application process of direct one-step chemical catalysis method, a large amount of cellulose in forest and grass biomass is degraded into by-products (humus), and the yield of obtained glucose is low, thereby limiting its industrial application. For example, Li et al. (2023) used sulfuric acid as a catalyst, dichloromethane and LiBr·3H2O as solvents to catalyze corn stalk into furfural and glucose in one step, and only obtained 58.9% glucose yield and 72.5% furfural yield under the condition of 120℃, 90min (Y. Li, L. L. Sun, D. M. Cao, et al., One-step conversion of corn stalk to glucose and furfural in molten salt hydrate / organic solvent biphasic system, Bioresource Technology, 386 (2023) 129520). The research on component separation through pretreatment and further synthesis of furfural and glucose has been widely concerned by domestic and foreign researchers for a long time due to its wide universality and high yield of target products. For example, Zhang et al. in Chinese patent CN118086423A pretreated corn stalk with ethylenediamine and sodium carbonate solution, and obtained pretreated residue (cellulose content 65.1%, hemicellulose content 22.3%, lignin removal rate 85.2%) under the pretreatment condition of 80℃, 4h, then the pretreated residue was enzymatically hydrolyzed for 72h under the action of cellulase to obtain 92.3% glucose yield.Cheng et al. (2023) pretreated bamboo by PTSA-DES / GVL solvent system, obtained 68.6% furfural yield and pretreatment residue (90.0% of cellulose retention rate, 89.1% of lignin removal rate, 100% of hemicellulose removal rate) at 110℃ for 1h, and then the pretreatment residue was enzymatically hydrolyzed for 72h to achieve 91.2% glucose yield (J. Y. Cheng, C. Huang, Y. N. Zhan, et al., A novel mineral-acid free biphasic deep eutectic solvent / gamma-valerolactone system for furfural production and boosting the enzymatic hydrolysis of lignocellulosic biomass, Bioresource Technology, 387 (2023) 129653). Although the above research method shows good effect in preparing glucose or furfural, however, these methods require long enzymatic hydrolysis reaction time and expensive cellulase reagent, which increases the preparation cost and is not conducive to industrial production. Therefore, it is urgent to develop an environmentally friendly, simple operation and low production cost production technology to realize the industrial production of furfural and glucose. SUMMARY

[0004] In view of the problems and deficiencies of the prior art, the purpose of the present application is to provide a method for efficiently preparing furfural and glucose from forest and grass biomass. The method of the present application is simple in process, green and environmentally friendly in catalytic system, mild in reaction conditions, short in reaction time, and high in yield of target product.

[0005] The purpose of the present application is achieved by the following technical solutions.

[0006] A method for efficiently preparing furfural and glucose from forest and grass biomass, comprising the following steps:

[0007] (1) mixing forest and grass biomass raw materials, molten salt hydrate and organic solvent for pretreatment reaction to obtain a pretreatment liquid containing furfural and a pretreatment residue;

[0008] (2) mixing the pretreatment residue of step (1), sulfuric acid and molten salt hydrate for hydrolysis reaction to obtain a hydrolysis liquid containing glucose.

[0009] Further, in step (1), the forest and grass biomass raw material is at least one of wheat straw, corn straw and eucalyptus wood.

[0010] Further, in step (1), the ratio of the mass of the forest and grass biomass raw material to the total volume of the molten salt hydrate and the organic solvent is 1:10-25 g / mL.

[0011] Further, in step (1), the molten salt hydrate is at least one of ZnCl2, LiCl, CaCl2, AlCl3, LiBr and water;

[0012] Further, in step (1), the concentration of the molten salt hydrate is 40-70 wt%.

[0013] Further, in step (1), the organic solvent is at least one of γ-valerolactone, dimethyl sulfoxide, methyl isobutyl ketone.

[0014] Further, in step (1), the volume ratio of the molten salt hydrate and the organic solvent is 0.25-4:1.

[0015] Further, in step (1), the temperature of the pretreatment reaction is 120-150°C, and the time of the pretreatment reaction is 10-120 min.

[0016] Further, in step (2), the molten salt hydrate is at least one of ZnCl2, LiCl, CaCl2, AlCl3, LiBr and water;

[0017] Further, in step (2), the concentration of the molten salt hydrate is 40-70 wt%.

[0018] Further, in step (2), the mass concentration of the sulfuric acid is 95% or more;

[0019] Further, in step (2), the ratio of the amounts of the pretreatment residue, the sulfuric acid and the molten salt hydrate is 1:0.01-0.05:50-150 g / moL / mL.

[0020] Further, in step (2), the temperature of the hydrolysis reaction is 70-100°C, and the time of the hydrolysis reaction is 10-30 min.

[0021] Further, in step (1), the yield of the furfural is 1.8%-67.3%, the retention rate of the cellulose in the pretreatment residue is 92.0%-99.6%, the removal rate of the hemicellulose is 75.2%-95.5%, and the removal rate of the lignin is 44.9%-80.1%;

[0022] Further, in step (2), the yield of the glucose is 42.6%-93.8%.

[0023] The present application can selectively obtain a pretreatment liquid with a furfural yield of 67.3% and a pretreatment residue with a cellulose retention rate of 98.5%, a hemicellulose removal rate of 93.5%, and a lignin removal rate of 71.2%; and can selectively hydrolyze to obtain a hydrolysis liquid with a glucose yield of 93.8%.

[0024] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0025] (1) The present application provides a method for preparing furfural and glucose, which realizes high yield of furfural and glucose from catalytic forest biomass.

[0026] (2) The present application uses molten salt hydrate as a pretreatment and catalytic reagent, which is cheap and easy to obtain, has good pretreatment separation effect, high catalytic activity, and mild reaction conditions.

[0027] (3) The present application uses γ-valerolactone as an organic solvent to obtain high yield of product furfural and pretreatment residue with high removal rate of hemicellulose and lignin, and the solvent has the advantages of green, easy storage, safety, etc.

[0028] (4) The present application realizes high glucose yield while obtaining high furfural yield through molten salt hydrate chemical catalysis method, reduces the generation of by-products, and has high economic benefits.

[0029] (5) The catalytic system of the present application is green, the reaction conditions are mild, the economic benefits are high, the process operation is simple, and it has industrial application prospect. DETAILED DESCRIPTION

[0030] The technical solutions and effects of the present application will be further described below in combination with specific embodiments, but the embodiments of the present application are not limited thereto.

[0031] The yield is calculated according to the following formula by using high performance liquid chromatography (HPLC) detection:

[0032] (1) Furfural yield = (molar amount of furfural in pretreatment liquid / molar amount of hemicellulose in forest biomass) x 100%;

[0033] (2) Glucose yield = (molar amount of glucose in hydrolysis liquid / molar amount of cellulose in pretreatment residue) x 100%.

[0034] Example 1

[0035] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 67.3% is obtained, and the pretreatment residue has a cellulose retention rate of 98.5%, a hemicellulose removal rate of 93.5% and a lignin removal rate of 71.2%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the dosage ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with a glucose yield of 93.8% is obtained.

[0036] Example 2

[0037] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass eucalyptus, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of eucalyptus, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 56.8% is obtained, and the pretreatment residue has a cellulose retention rate of 93.5%, a hemicellulose removal rate of 90.5% and a lignin removal rate of 60.3%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the dosage ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with a glucose yield of 83.1% is obtained.

[0038] Example 3

[0039] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, LiBr 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of LiBr 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 3.7% is obtained, and the pretreatment residue has a cellulose retention rate of 93.2%, a hemicellulose removal rate of 79.7% and a lignin removal rate of 80.1%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the amount ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with a glucose yield of 88.6% is obtained.

[0040] Example 4

[0041] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 0.43:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 56.8% is obtained, and the pretreatment residue has a cellulose retention rate of 99.6%, a hemicellulose removal rate of 83.8% and a lignin removal rate of 70.1%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the amount ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with a glucose yield of 57.9% is obtained.

[0042] Example 5

[0043] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 150℃ for 40min, a pretreatment liquid with furfural yield of 58.6% is obtained, and the pretreatment residue with cellulose retention rate of 95.8%, hemicellulose removal rate of 95.5% and lignin removal rate of 62.0%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the dosage ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction at 80℃ for 20min, a hydrolysis liquid with glucose yield of 78.6% is obtained.

[0044] Example 6

[0045] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 140℃ for 20min, a pretreatment liquid with furfural yield of 59.0% is obtained, and the pretreatment residue with cellulose retention rate of 99.3%, hemicellulose removal rate of 85.4% and lignin removal rate of 65.6%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the dosage ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction at 80℃ for 20min, a hydrolysis liquid with glucose yield of 83.6% is obtained.

[0046] Example 7

[0047] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 67.3% is obtained, and the pretreatment residue has a cellulose retention rate of 98.5%, a hemicellulose removal rate of 93.5% and a lignin removal rate of 71.2%; then the pretreatment residue, ZnCl2 60wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the amount ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with a glucose yield of 81.7% is obtained.

[0048] Example 8

[0049] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 67.3% is obtained, and the pretreatment residue has a cellulose retention rate of 98.5%, a hemicellulose removal rate of 93.5% and a lignin removal rate of 71.2%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the amount ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.045:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with a glucose yield of 67.6% is obtained.

[0050] Example 9

[0051] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 67.3% is obtained, and the pretreatment residue has a cellulose retention rate of 98.5%, a hemicellulose removal rate of 93.5% and a lignin removal rate of 71.2%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the amount ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 90℃ for 20min, a hydrolysis liquid with a glucose yield of 78.9% is obtained.

[0052] Example 10

[0053] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 67.3% is obtained, and the pretreatment residue has a cellulose retention rate of 98.5%, a hemicellulose removal rate of 93.5% and a lignin removal rate of 71.2%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the amount ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 15min, a hydrolysis liquid with a glucose yield of 72.5% is obtained.

[0054] Comparative Example 1

[0055] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate, gamma-valerolactone and concentrated sulfuric acid (98wt%) are sequentially mixed and added into a reaction kettle, no pressure setting, the amount ratio of wheat straw, sulfuric acid, molten salt hydrate and gamma-valerolactone is 1:0.006:20 (g / moL / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; reaction at 140℃ for 40min, the reaction liquid with furfural yield of 30.1% and glucose yield of 26.9% is obtained, the reaction residue with cellulose retention rate of 46.3%, hemicellulose removal rate of 95.7% and lignin removal rate of 82.5% is obtained.

[0056] Comparative Example 2

[0057] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, LiCl 40wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of LiCl 40wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 140℃ for 40min, the pretreatment liquid with furfural yield of 1.8% is obtained, the pretreatment residue with cellulose retention rate of 92.0%, hemicellulose removal rate of 75.2% and lignin removal rate of 48.9% is obtained; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into a reaction kettle, the amount ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), hydrolysis reaction at 80℃ for 20min, the hydrolysis liquid with glucose yield of 45.8% is obtained.

[0058] Comparative Example 3

[0059] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, CaCl2 50wt% molten salt hydrate and γ-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and γ-valerolactone is 1:20 (g / mL); the volume ratio of CaCl2 50wt% molten salt hydrate and γ-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with furfural yield of 14.5% is obtained, and the pretreatment residue with cellulose retention rate of 94.3%, hemicellulose removal rate of 76.7% and lignin removal rate of 44.9%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the dosage ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction at 80℃ for 20min, a hydrolysis liquid with glucose yield of 39.1% is obtained.

[0060] Comparative Example 4

[0061] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, AlCl3 60wt% molten salt hydrate and γ-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and γ-valerolactone is 1:20 (g / mL); the volume ratio of AlCl3 60wt% molten salt hydrate and γ-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with furfural yield of 45.3% is obtained, and the pretreatment residue with cellulose retention rate of 32.2%, hemicellulose removal rate of 89.1% and lignin removal rate of 65.1%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the dosage ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction at 80℃ for 20min, a hydrolysis liquid with glucose yield of 12.3% is obtained.

[0062] Comparative Example 5

[0063] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and dimethyl sulfoxide are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and dimethyl sulfoxide is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and dimethyl sulfoxide is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with furfural yield of 35.6% is obtained, and the pretreatment residue with cellulose retention rate of 76.2%, hemicellulose removal rate of 86.7% and lignin removal rate of 56.3% is obtained; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the amount ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with glucose yield of 21.3% is obtained.

[0064] Comparative example 6

[0065] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and dimethyl sulfoxide are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and dimethyl sulfoxide is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and dimethyl sulfoxide is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with furfural yield of 35.6% is obtained, and the pretreatment residue with cellulose retention rate of 76.2%, hemicellulose removal rate of 86.7% and lignin removal rate of 56.3% is obtained; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the amount ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with glucose yield of 21.3% is obtained.

[0066] Comparative example 7

[0067] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 0.25:1; pretreatment at 140℃ for 40min, a pretreatment liquid with furfural yield of 43.2% is obtained, the pretreatment residue with cellulose retention rate of 97.8%, hemicellulose removal rate of 78.0% and lignin removal rate of 54.1%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the dosage ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), hydrolysis reaction at 80℃ for 20min, a hydrolysis liquid with glucose yield of 51.3% is obtained.

[0068] Comparative Example 8

[0069] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and gamma-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and gamma-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and gamma-valerolactone is 1:1; pretreatment at 150℃ for 120min, a pretreatment liquid with furfural yield of 44.6% is obtained, the pretreatment residue with cellulose retention rate of 78.1%, hemicellulose removal rate of 98.9% and lignin removal rate of 34.7%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the dosage ratio of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.03:100 (g / moL / mL), hydrolysis reaction at 80℃ for 20min, a hydrolysis liquid with glucose yield of 41.7% is obtained.

[0070] Comparative Example 9

[0071] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and γ-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and γ-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and γ-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 67.3% is obtained, and the pretreatment residue has a cellulose retention rate of 98.5%, a hemicellulose removal rate of 93.5% and a lignin removal rate of 71.2%; then the pretreatment residue, ZnCl2 65wt% molten salt hydrate are sequentially mixed and added into the reaction kettle, the solid-liquid ratio of the pretreatment residue and the molten salt hydrate is 1:100 (g / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with a glucose yield of 26.3% is obtained.

[0072] Comparative example 10

[0073] A method for efficiently preparing furfural and glucose from forest biomass, the specific steps are as follows: forest biomass wheat straw, ZnCl2 60wt% molten salt hydrate and γ-valerolactone are sequentially mixed and added into a reaction kettle, no pressure setting, the solid-liquid ratio of wheat straw, molten salt hydrate and γ-valerolactone is 1:20 (g / mL); the volume ratio of ZnCl2 60wt% molten salt hydrate and γ-valerolactone is 1:1; pretreatment at 140℃ for 40min, a pretreatment liquid with a furfural yield of 67.3% is obtained, and the pretreatment residue has a cellulose retention rate of 98.5%, a hemicellulose removal rate of 93.5% and a lignin removal rate of 71.2%; then the pretreatment residue, deionized water and concentrated sulfuric acid (98wt%) are sequentially mixed and added into the reaction kettle, the amount ratio of the pretreatment residue, sulfuric acid and deionized water is 1:0.03:100 (g / moL / mL), and hydrolysis reaction is carried out at 80℃ for 20min, a hydrolysis liquid with a glucose yield of 6.2% is obtained.

[0074] The specific embodiments of the application are described in detail above, but the application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application.

Claims

1. A method for efficiently preparing furfural and glucose from forest and grassland biomass, characterized in that, Includes the following steps: (1) Forest and grassland biomass raw materials, molten salt hydrate and organic solvent are mixed and pretreated to obtain furfural-containing pretreated solution and pretreated residue; the mass ratio of the forest and grassland biomass raw materials to the total volume of molten salt hydrate and organic solvent is 1:10-25 g / mL; the molten salt hydrate is at least one of ZnCl2, LiCl, CaCl2, AlCl3, LiBr and water; The concentration of the molten salt hydrate is 40–70 wt%; the volume ratio of the molten salt hydrate to the organic solvent is 0.25–4:1; the temperature of the pretreatment reaction is 120–150 °C, and the pretreatment reaction time is 10–120 min; the yield of furfural is 1.8%–67.3%; the retention rate of cellulose in the pretreatment residue is 92.0%–99.6%, the removal rate of hemicellulose is 75.2%–95.5%, and the removal rate of lignin is 44.9%–80.1%; (2) After mixing the pretreatment residue from step (1), sulfuric acid and molten salt hydrate, hydrolyze the mixture to obtain a hydrolysate containing glucose.

2. The method for efficiently preparing furfural and glucose from forest and grassland biomass according to claim 1, characterized in that, In step (1), the forestry and grassland biomass raw materials are at least one of wheat straw, corn straw and eucalyptus wood.

3. The method for efficiently preparing furfural and glucose from forest and grassland biomass according to claim 1, characterized in that, In step (1), the organic solvent is at least one of γ-valerolactone, dimethyl sulfoxide, and methyl isobutyl ketone.

4. The method for efficiently preparing furfural and glucose from forest and grassland biomass according to claim 1, characterized in that, In step (2), the molten salt hydrate is at least one of ZnCl2, LiCl, CaCl2, AlCl3, and LiBr, plus water; In step (2), the concentration of the molten salt hydrate is 40–70 wt%.

5. The method for efficiently preparing furfural and glucose from forestry and grassland biomass according to claim 1, characterized in that, In step (2), the mass concentration of the sulfuric acid is 95% or higher; In step (2), the ratio of the amount of pretreatment residue, sulfuric acid and molten salt hydrate is 1:0.01~0.05:50~150g / mol / mL.

6. The method for efficiently preparing furfural and glucose from forest and grassland biomass according to claim 1, characterized in that, In step (2), the temperature of the hydrolysis reaction is 70-100℃ and the time of the hydrolysis reaction is 10-30 min.

7. The method for efficiently preparing furfural and glucose from forest and grassland biomass according to claim 1, characterized in that, In step (2), the yield of glucose is 42.6% to 93.8%.