Biomass pretreatment method
Patent Information
- Application Number
- CN202510650916.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-20
- Publication Date
- 2025-08-29
Smart Images
Figure CN120554656A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of biomass fermentation, and in particular to a biomass pretreatment method. Background Art
[0002] Biomass is generally composed of lignin, cellulose, and hemicellulose. Within the lignocellulose structure, cellulose, hemicellulose, and lignin form a complex cross-linked structure, which reduces the accessibility of cellulase during enzymatic hydrolysis, resulting in low sugar conversion efficiency. To improve enzymatic hydrolysis efficiency, appropriate pretreatment methods are necessary to break down the stubborn structure of lignocellulose and promote the enzymatic hydrolysis process.
[0003] Existing pretreatment methods include acidic pretreatment, alkaline pretreatment, organic solvent pretreatment, hydrothermal pretreatment, and steam explosion pretreatment. However, some of these pretreatment methods have complex processes, high reagent losses, harsh reaction conditions, and toxic and corrosive reagents, making them unfriendly to operators and equipment. Currently, deep eutectic solvent pretreatment, a type of organic solvent pretreatment, has attracted considerable attention in the relevant industry due to its environmental and efficiency. However, the removal efficiency of hemicellulose and lignin from biomass using deep eutectic solvents used in existing technologies still needs to be improved. Summary of the Invention
[0004] The purpose of the present invention is to overcome the problem in the prior art that the removal efficiency of deep eutectic solvents for hemicellulose and lignin in biomass needs to be improved, and to provide a biomass pretreatment method that can effectively reduce the content of hemicellulose and lignin in the biomass treated by the pretreatment method, thereby effectively improving the subsequent enzymatic saccharification efficiency of the biomass.
[0005] In order to achieve the above object, the present invention provides a biomass pretreatment method, the method comprising: mixing a biomass raw material and a deep eutectic solvent containing amino acids to react;
[0006] The amino acid is selected from at least one of glutamic acid, glycine, leucine, isoleucine, tyrosine and serine, the hydrogen bond acceptor of the deep eutectic solvent is ferric chloride hexahydrate, and the hydrogen bond donor is selected from at least one of p-toluenesulfonic acid monohydrate, methanesulfonic acid, propionic acid, malonic acid, sulfuric acid, oxalic acid dihydrate and glycolic acid.
[0007] Preferably, in the deep eutectic solvent, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1-5.
[0008] Further preferably, in the deep eutectic solvent, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:2-4.
[0009] Preferably, in the amino acid-containing deep eutectic solvent, the content of the amino acid is 2-20 wt %.
[0010] Further preferably, in the amino acid-containing deep eutectic solvent, the content of the amino acid is 5-15 wt %.
[0011] Preferably, the amino acid is glutamic acid and / or glycine.
[0012] More preferably, the amino acids are glutamic acid and glycine.
[0013] More preferably, the mass ratio of the glutamic acid to the glycine is 1:1-9.
[0014] More preferably, the mass ratio of the glutamic acid to the glycine is 1:2-5.
[0015] Preferably, the hydrogen bond donor is p-toluenesulfonic acid monohydrate.
[0016] Preferably, the biomass raw material is selected from at least one of crop straw, forestry processing waste, energy crops, fast-growing trees, aquatic plants and agricultural product processing by-products.
[0017] Further preferably, the crop straw is selected from at least one of corn straw, sorghum straw, wheat straw and rice straw; the forest processing waste is selected from at least one of branches, wood chips and bark; the energy crop is selected from at least one of sugarcane, cassava and oil palm; the fast-growing trees are poplar and / or willow; the aquatic plants are algae; and the agricultural product processing by-products are selected from at least one of rice husks, bran, oil residue and sugarcane bagasse.
[0018] Preferably, the amount of the amino acid-containing deep eutectic solvent used is 1-40 g relative to 1 g of the biomass raw material.
[0019] Preferably, the method further comprises: crushing the biomass raw material before mixing the biomass raw material and the low eutectic solvent containing amino acids.
[0020] Further preferably, the particle size of the crushed biomass raw material is less than or equal to 0.6 mm.
[0021] Preferably, the reaction conditions include at least: temperature of 25-90° C. and time of 1-12 h.
[0022] Through the above technical scheme, the pretreatment method provided by the present invention mixes the biomass raw material and the deep eutectic solvent containing amino acids for reaction, and the amino acids are limited to at least one selected from glutamic acid, glycine, leucine, isoleucine, tyrosine and serine, the hydrogen bond acceptor of the deep eutectic solvent is limited to ferric chloride hexahydrate, and the hydrogen bond donor is limited to at least one selected from p-toluenesulfonic acid monohydrate, methanesulfonic acid, propionic acid, malonic acid, sulfuric acid, oxalic acid dihydrate and glycolic acid, which can effectively reduce the hemicellulose content and lignin content in the biomass raw material, increase the cellulose content, and thus effectively improve the subsequent enzymatic saccharification efficiency of the biomass. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 These are SEM images of the straw obtained by the method of Example 1 of the straw raw material, wherein (a) and (b) are SEM images of the straw raw material, and (c) and (d) are SEM images of the straw obtained by the method of Example 1. DETAILED DESCRIPTION
[0024] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.
[0025] As described above, the present invention provides a method for pretreating biomass, comprising: mixing a biomass raw material and a deep eutectic solvent containing an amino acid to react; wherein the amino acid is selected from at least one of glutamic acid, glycine, leucine, isoleucine, tyrosine and serine, the hydrogen bond acceptor of the deep eutectic solvent is ferric chloride hexahydrate, and the hydrogen bond donor is selected from at least one of p-toluenesulfonic acid monohydrate, methanesulfonic acid, propionic acid, malonic acid, sulfuric acid, oxalic acid dihydrate and glycolic acid.
[0026] During the research process, the inventors unexpectedly discovered that when pre-treating biomass, the biomass raw material and a low eutectic solvent containing amino acids are mixed and reacted, and the amino acids are limited to at least one selected from glutamic acid, glycine, leucine, isoleucine, tyrosine and serine, the hydrogen bond acceptor of the low eutectic solvent is limited to ferric chloride hexahydrate, and the hydrogen bond donor is limited to at least one selected from p-toluenesulfonic acid monohydrate, methanesulfonic acid, propionic acid, malonic acid, sulfuric acid, oxalic acid dihydrate and glycolic acid, which can effectively reduce the hemicellulose content and lignin content in the biomass raw material, and thus effectively improve the subsequent enzymatic saccharification efficiency of the biomass.
[0027] Preferably, in the deep eutectic solvent, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1-5, and can be 1:1, 1:2, 1:3, 1:4, 1:5, or any value within the range formed by any two of these ratios. Studies have found that controlling the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor in the deep eutectic solvent within the above range can further reduce the hemicellulose content and lignin content in the biomass raw material. In order to further reduce the hemicellulose content and lignin content in the biomass raw material, it is further preferred that in the deep eutectic solvent, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:2:4.
[0028] Preferably, in the deep eutectic solvent containing amino acids, the content of the amino acids is 2-20wt%, which can be 2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt%, 16wt%, 18wt%, 20wt%, or any value within the range formed by any two of these values. Controlling the content of amino acids within the above range can further reduce the hemicellulose content and lignin content in the biomass feedstock. In order to further reduce the hemicellulose content and lignin content in the biomass feedstock, it is further preferred that the content of the amino acids in the deep eutectic solvent containing amino acids is 5-15wt%.
[0029] In order to further reduce the hemicellulose content and lignin content in the biomass raw material, preferably, the amino acid is glutamic acid and / or glycine.
[0030] Preferably, the amino acids are glutamic acid and glycine. Studies have found that the combination of glutamic acid and glycine has a better interaction effect with the deep eutectic solvent, thereby further reducing the hemicellulose and lignin contents in the biomass feedstock. To further reduce the hemicellulose and lignin contents in the biomass feedstock, it is further preferred that the mass ratio of glutamic acid to glycine is 1:1-9. Even more preferably, the mass ratio of glutamic acid to glycine is 1:2-5.
[0031] Preferably, the hydrogen bond donor is p-toluenesulfonic acid monohydrate. Studies have found that p-toluenesulfonic acid monohydrate has a good interaction effect with ferric chloride hexahydrate and amino acids, thereby further reducing the hemicellulose and lignin content in biomass raw materials.
[0032] According to the present invention, preferably, the biomass raw material is selected from at least one of crop straw, forestry processing waste, energy crops, fast-growing trees, aquatic plants, and agricultural product processing by-products. Further preferably, the crop straw is selected from at least one of corn straw, sorghum straw, wheat straw, and rice straw; the forestry processing waste is selected from at least one of branches, sawdust, and bark; the energy crop is selected from at least one of sugarcane, cassava, and oil palm; the fast-growing trees are poplar and / or willow; the aquatic plants are algae; and the agricultural product processing by-products are selected from at least one of rice husks, bran, oil residue, and sugarcane bagasse.
[0033] In order to further reduce the hemicellulose content and lignin content in the biomass feedstock, preferably, the amount of the amino acid-containing deep eutectic solvent is 1-40 g relative to 1 g of the biomass feedstock, and can be 1 g, 5 g, 10 g, 15 g, 20 g, 25 g, 30 g, 35 g, 40 g, or any value within the range formed by any two of these values. In order to further reduce the hemicellulose content and lignin content in the biomass feedstock, it is further preferred that the amount of the amino acid-containing deep eutectic solvent is 5-20 g relative to 1 g of the biomass feedstock.
[0034] Preferably, the method further comprises crushing the biomass feedstock before mixing the biomass feedstock with the amino acid-containing deep eutectic solvent. Crushing the biomass feedstock can enhance the interaction between the biomass feedstock and the amino acid-containing deep eutectic solvent, thereby further reducing the hemicellulose and lignin contents in the biomass feedstock. To further reduce the hemicellulose and lignin contents in the biomass feedstock, the particle size of the crushed biomass feedstock is preferably less than or equal to 0.6 mm.
[0035] Preferably, the reaction conditions include at least: a temperature of 25-90°C, which can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, or any value within the range formed by any two of these values; a time of 1-12h, which can be 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, or any value within the range formed by any two of these values. Under the above reaction conditions, the reaction effect between the biomass raw material and the deep eutectic solvent containing amino acids can be improved, thereby further reducing the hemicellulose content and lignin content in the biomass raw material.
[0036] According to a particularly preferred embodiment of the present invention, a method for pretreating biomass is provided, the method comprising:
[0037] (1) The biomass raw material is crushed to obtain biomass powder with a particle size less than or equal to 0.6 mm.
[0038] (2) mixing the biomass powder with a deep eutectic solvent containing amino acids and reacting the mixture at a temperature of 25-90° C. for 1-12 h;
[0039] The biomass raw material is selected from at least one of crop straw, forestry processing waste, energy crops, fast-growing trees, aquatic plants and agricultural product processing by-products; the crop straw is selected from at least one of corn straw, sorghum straw, wheat straw and rice straw; the forestry processing waste is selected from at least one of branches, wood chips and bark; the energy crop is selected from at least one of sugarcane, cassava and oil palm; the fast-growing trees are poplar and / or willow; the aquatic plants are algae; and the agricultural product processing by-products are selected from at least one of rice husks, bran, oil residue and sugarcane bagasse;
[0040] The amount of the amino acid-containing deep eutectic solvent is 1-40 g relative to 1 g of the biomass raw material;
[0041] The preparation method of a deep eutectic solvent containing amino acids comprises: in a liquid state, mixing ferric chloride hexahydrate and a hydrogen bond donor in a molar ratio of 1:1-5, and then adding the amino acid so that its mass proportion in the deep eutectic solvent containing amino acids is 2-20wt%; the hydrogen bond donor of the deep eutectic solvent is selected from at least one of p-toluenesulfonic acid monohydrate, methanesulfonic acid, propionic acid, malonic acid, sulfuric acid, oxalic acid dihydrate and glycolic acid; the amino acids are glutamic acid and glycine, and the mass ratio of the glutamic acid to the glycine is 1:1-9.
[0042] Preferably, the ferric chloride hexahydrate may be heated to a molten state before mixing.
[0043] The biomass raw materials obtained by the above-mentioned treatment method have lower hemicellulose and lignin, which can effectively improve the subsequent enzymatic saccharification efficiency of the biomass.
[0044] The present invention will be described in detail below by way of examples. In the following examples, the raw materials, such as p-toluenesulfonic acid monohydrate, methanesulfonic acid, oxalic acid dihydrate, glycolic acid, glutamic acid, glycine, leucine, tyrosine, serine, aspartic acid, proline, and ferric chloride hexahydrate, are commercially available products from Aladdin.
[0045] Example 1
[0046] (1) Wash the corn stalks, dry them, grind them, and pass them through a 60-mesh sieve to obtain corn stalk powder.
[0047] (2) Ferric chloride hexahydrate was melted in a 50°C water bath in advance and added to a 50 mL conical flask after becoming a molten liquid. P-toluenesulfonic acid monohydrate was ground into powder and added to the flask. The mixture was thoroughly mixed and ultrasonicated in a 50°C water bath until the solution was dark red and uniform. The total mass of the low eutectic solvent was 30 g, and the molar ratio of p-toluenesulfonic acid monohydrate to ferric chloride hexahydrate was 1:1. Amino acids were then added (the mass ratio of glutamic acid to glycine was 1:3) to obtain a low eutectic solvent containing 5 wt% amino acids.
[0048] (3) 3 g of corn straw powder was placed in a 75 mL pressure bottle and mixed with 30 g of the aforementioned deep eutectic solvent containing amino acids. The pressure bottle was placed in a water bath and reacted at 50°C for 6 h. The mixture was further washed with water through a 400-mesh filter cloth until the washing liquid was colorless and transparent. The solid was then dried in an oven at 50°C overnight.
[0049] The SEM images of the straw raw material and the straw treated by the method of Example 1 are as follows: Figure 1 As shown, Figure 1 As shown in Figures (a) and (b), the fibers of the straw raw material are compact and regular, arranged in bundles, and the surface is relatively smooth, which is not conducive to enzymatic hydrolysis. However, after being treated by the method of Example 1, the surface of the corn straw is severely damaged, the cell wall is broken and porous, and the specific surface area is significantly increased. Figure 1 (c) and (d) in the glycosylation reaction, making it easier to combine with the enzyme and improving the saccharification efficiency.
[0050] Example 2
[0051] Corn straw was pretreated according to the method of Example 1, except that the molar ratio of p-toluenesulfonic acid monohydrate to ferric chloride hexahydrate was 2:1.
[0052] Example 3
[0053] Corn straw was pretreated according to the method of Example 1, except that the molar ratio of p-toluenesulfonic acid monohydrate to ferric chloride hexahydrate was 3:1.
[0054] Example 4
[0055] Corn straw was pretreated according to the method of Example 1, except that the molar ratio of p-toluenesulfonic acid monohydrate to ferric chloride hexahydrate was 4:1.
[0056] Example 5
[0057] Corn straw was pretreated according to the method of Example 1, except that the molar ratio of p-toluenesulfonic acid monohydrate to ferric chloride hexahydrate was 5:1.
[0058] Example 6
[0059] Corn straw was pretreated according to the method of Example 1, except that the amount of amino acid added was adjusted to obtain a deep eutectic solvent containing 10 wt % amino acids, and the mass ratio of glutamic acid to glycine was 1:5.
[0060] Example 7
[0061] Corn straw was pretreated according to the method of Example 1, except that the amount of amino acid added was adjusted to obtain a deep eutectic solvent containing 15 wt % amino acids, and the mass ratio of glutamic acid to glycine was 1:2.
[0062] Example 8
[0063] Corn straw was pretreated according to the method of Example 6, except that the mass ratio of glutamic acid to glycine was 1:9.
[0064] Example 9
[0065] Corn straw was pretreated according to the method of Example 7, except that the mass ratio of glutamic acid to glycine was 1:1.
[0066] Example 10
[0067] Corn straw was pretreated according to the method of Example 6, except that glycine was replaced by glutamic acid.
[0068] Example 11
[0069] Corn straw was pretreated according to the method of Example 7, except that glutamic acid was replaced by glycine.
[0070] Example 12
[0071] Corn straw was pretreated according to the method of Example 6, except that glycine was replaced by leucine.
[0072] Example 13
[0073] Corn straw was pretreated according to the method of Example 7, except that glutamic acid was replaced by tyrosine.
[0074] Example 14
[0075] Corn straw was pretreated according to the method of Example 6, except that glycine was replaced by tyrosine.
[0076] Example 15
[0077] Corn straw was pretreated according to the method of Example 7, except that glutamic acid was replaced by serine.
[0078] Example 16
[0079] Corn straw was pretreated according to the method of Example 1, except that the amount of amino acid added was adjusted to obtain a deep eutectic solvent containing 2 wt % of amino acids.
[0080] Example 17
[0081] Corn straw was pretreated according to the method of Example 7, except that the amount of amino acid added was adjusted to obtain a deep eutectic solvent containing 20 wt % of amino acids.
[0082] Example 18
[0083] Corn straw was pretreated according to the method of Example 1, except that p-toluenesulfonic acid monohydrate was replaced by propionic acid.
[0084] Example 19
[0085] Corn straw was pretreated according to the method of Example 1, except that p-toluenesulfonic acid monohydrate was replaced by oxalic acid dihydrate and methanesulfonic acid in a molar ratio of 1:1.
[0086] Example 20
[0087] Corn straw was pretreated according to the method of Example 1, except that p-toluenesulfonic acid monohydrate was replaced by malonic acid and glycolic acid in a molar ratio of 1:2.
[0088] Example 21
[0089] Corn straw was pretreated according to the method of Example 1, except that p-toluenesulfonic acid monohydrate was replaced by sulfuric acid.
[0090] Example 22
[0091] The pretreatment was performed according to the method of Example 1, except that the corn straw was replaced with sugarcane bagasse.
[0092] Example 23
[0093] The pretreatment was carried out according to the method of Example 1, except that in step (3), the amount of the low eutectic solvent containing amino acids was 5 g, the reaction temperature was 90° C., and the reaction time was 1 h.
[0094] Example 24
[0095] The pretreatment was carried out according to the method of Example 1, except that in step (3), the amount of the low eutectic solvent containing amino acids was 20 g, the reaction temperature was 25° C., and the reaction time was 12 h.
[0096] Example 25
[0097] The pretreatment was carried out according to the method of Example 23, except that in step (3), the amount of the low eutectic solvent containing amino acids was 1 g.
[0098] Example 26
[0099] The pretreatment was carried out according to the method of Example 24, except that in step (3), the amount of the low eutectic solvent containing amino acids was 40 g.
[0100] Comparative Example 1
[0101] The pretreatment was performed according to the method of Example 11, except that glycine was replaced by aspartic acid.
[0102] Comparative Example 2
[0103] The pretreatment was performed according to the method of Example 12, except that glutamic acid was replaced by proline.
[0104] Comparative Example 3
[0105] The pretreatment was performed according to the method of Example 1, except that ferric chloride hexahydrate was replaced by choline chloride.
[0106] Comparative Example 4
[0107] The pretreatment was carried out according to the method of Example 1, except that p-toluenesulfonic acid monohydrate was replaced by boric acid.
[0108] Comparative Example 5
[0109] Pretreatment was performed according to the method of Example 1, except that step (2) included: placing ferric chloride hexahydrate in a 50°C water bath in advance for melting, and adding the molten liquid into a 50 mL conical flask, and amino acids (glutamic acid and glycine in a mass ratio of 1:3) were also added to the flask and thoroughly mixed. The total mass of the deep eutectic solvent was 30 g, and the molar ratio of amino acids to ferric chloride hexahydrate was 1:1.
[0110] Test Case
[0111] Accurately weigh 300 mg of absolute dry sample and add it to a 100 mL pressure bottle. Add 3 mL of 72% (w / w) concentrated sulfuric acid to the bottle, mix well, place it in a 30°C shaker, and react at 150 pm for one hour. After the reaction is completed, add 84 mL of ultrapure water to the pressure bottle, mix well, and place it in an autoclave at 121°C for 1 hour.
[0112] After the reaction, the supernatant was filtered through a 0.22 μm aqueous membrane into a liquid phase vial. Reducing sugar content was determined by HPLC using a 5 mM aqueous sulfuric acid solution as the mobile phase at a flow rate of 0.6 mL / min. The corresponding cellulose, hemicellulose, and lignin contents were calculated according to the following formulas and are reported in Table 1.
[0113]
[0114] in,
[0115] m0 is the sample volume, in grams (g)
[0116] m1 is the mass of the glass sand core crucible (G4), in grams (g)
[0117] m2 is the mass of the glass sand core crucible and the acid-insoluble residue, in grams (g)
[0118] m3 is the mass of the glass sand core crucible and ash, in grams (g).
[0119] Table 1
[0120]
[0121]
[0122] It can be seen from the results in Table 1 that the cellulose content of the pretreated products obtained in Examples 1-22 is much higher than that in Comparative Examples 1-5, and the hemicellulose content and lignin content of the pretreated products obtained in Examples 1-22 are lower than those in Comparative Examples 1-5, indicating that the pretreatment method of the present invention can effectively increase the cellulose content of biomass and reduce the lignin and hemicellulose contents of biomass, thereby effectively improving the subsequent enzymatic saccharification efficiency of biomass.
[0123] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.
Claims
1. A method for pretreating biomass, characterized in that: The method comprises: mixing a biomass raw material and a deep eutectic solvent containing amino acids to react; The amino acid is selected from at least one of glutamic acid, glycine, leucine, isoleucine, tyrosine and serine, the hydrogen bond acceptor of the deep eutectic solvent is ferric chloride hexahydrate, and the hydrogen bond donor is selected from at least one of p-toluenesulfonic acid monohydrate, methanesulfonic acid, propionic acid, malonic acid, sulfuric acid, oxalic acid dihydrate and glycolic acid.
2. The pretreatment method according to claim 1, characterized in that In the deep eutectic solvent, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1-5, preferably 1:2-4.
3. The pretreatment method according to claim 1, characterized in that In the amino acid-containing deep eutectic solvent, the content of the amino acid is 2-20 wt%, preferably 5-15 wt%.
4. The pretreatment method according to any one of claims 1 to 3, characterized in that The amino acids are glutamic acid and / or glycine.
5. The pretreatment method according to claim 4, characterized in that The amino acids are glutamic acid and glycine; Preferably, the mass ratio of the glutamic acid to the glycine is 1:1-9, more preferably 1:2-5.
6. The pretreatment method according to any one of claims 1 to 3, characterized in that The hydrogen bond donor is p-toluenesulfonic acid monohydrate.
7. The pretreatment method according to any one of claims 1 to 3, characterized in that The biomass raw material is selected from at least one of crop straw, forest processing waste, energy crops, fast-growing trees, aquatic plants and agricultural product processing by-products; Preferably, the crop straw is selected from at least one of corn straw, sorghum straw, wheat straw and rice straw; the forest processing waste is selected from at least one of branches, wood chips and bark; the energy crop is selected from at least one of sugarcane, cassava and oil palm; the fast-growing trees are poplar and / or willow; the aquatic plants are algae; and the agricultural product processing by-products are selected from at least one of rice husks, bran, oil residue and sugarcane bagasse.
8. The pretreatment method according to any one of claims 1 to 3, characterized in that Relative to 1 g of the biomass raw material, the amount of the amino acid-containing deep eutectic solvent used is 1-40 g.
9. The pretreatment method according to any one of claims 1 to 3, characterized in that: The method further comprises: crushing the biomass raw material before mixing the biomass raw material and the deep eutectic solvent containing amino acids; Preferably, the particle size of the crushed biomass raw material is less than or equal to 0.6 mm.
10. The pretreatment method according to any one of claims 1 to 3, characterized in that: The reaction conditions at least include: temperature of 25-90° C. and time of 1-12 h.