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CN-121992043-A - Method for efficiently producing ethanol by utilizing lignocellulose

CN121992043ACN 121992043 ACN121992043 ACN 121992043ACN-121992043-A

Abstract

The invention belongs to the technical field of biomass conversion and utilization, and particularly provides a method for efficiently producing ethanol by utilizing lignocellulose. According to the invention, additives such as tea saponin and the like are introduced in the synchronous saccharification and fermentation stage, so that the conversion efficiency of lignocellulose raw materials can be obviously improved, and the ethanol yield can be obviously improved. The method specifically comprises the steps of firstly preprocessing the lignocellulose raw material by adopting a eutectic solvent, combining a synchronous saccharification and fermentation technology, introducing a specific additive in a fermentation stage, and obviously improving the conversion efficiency of the lignocellulose raw material and the ethanol yield. The method for efficiently producing the ethanol has high ethanol yield and wide raw material sources, is suitable for lignocellulose raw materials with compact fiber structures such as pennisetum hydridum and the like, has sustainable development and provides powerful support for the industrial application of lignocellulose energy sources.

Inventors

  • ZHONG CHUNMEI
  • Pang Yandan
  • YANG SHUHAN

Assignees

  • 华南农业大学

Dates

Publication Date
20260508
Application Date
20251219

Claims (10)

  1. 1. A method for efficiently producing ethanol by utilizing lignocellulose is characterized by comprising the step of adding an additive into a fermentation substrate, and then carrying out synchronous saccharification and fermentation, wherein the additive is at least one of tea saponin, bovine serum albumin, tween 80, PEG8000 and rhamnolipid, and the fermentation substrate is a lignocellulose raw material.
  2. 2. The method of claim 1, wherein the additive is any one or two of tea saponin, bovine serum albumin, tween 80, PEG8000 and rhamnolipid, and preferably the mass ratio of the additive to the fermentation substrate is (0.01-0.2): 1.
  3. 3. The method of claim 1, wherein when the additive is any two of tea saponin, bovine serum albumin, tween 80, PEG8000 and rhamnolipid, the mass ratio of the two additives is (10-100).
  4. 4. The method of claim 1, wherein the fermentation substrate is a delignified lignocellulosic feedstock, and preferably wherein the delignification pretreatment is a pretreatment with a eutectic solvent.
  5. 5. The method of claim 4, wherein the eutectic solvent comprises choline chloride, p-toluenesulfonic acid and water, the mass of the water is 40% -60% of the total mass of the choline chloride and the p-toluenesulfonic acid, and the molar ratio of the choline chloride to the p-toluenesulfonic acid is 1 (2-3).
  6. 6. The method of claim 5, wherein the eutectic solvent comprises choline chloride, p-toluenesulfonic acid, alcohols and water, the mass of the water is 40% -60% of the total mass of the choline chloride and the p-toluenesulfonic acid, the molar ratio of the choline chloride, the p-toluenesulfonic acid and the alcohols is 1 (2-3): 0.5-3.5, and the alcohols are any one of ethylene glycol, propylene glycol, hexylene glycol and butylene glycol.
  7. 7. The method of claim 6, wherein the eutectic solvent comprises choline chloride, p-toluenesulfonic acid, alcohols and water, wherein the mass of the water is 40% -60% of the total mass of the choline chloride and the p-toluenesulfonic acid, the alcohols are any one of ethylene glycol, propylene glycol and hexylene glycol, and the molar ratio of the components meets one of the following conditions: (1) When the alcohol is ethylene glycol, the mol ratio of the choline chloride, the p-toluenesulfonic acid and the ethylene glycol is 1:2 (2.5-3.5); (2) When the alcohol is propylene glycol, the molar ratio of the choline chloride to the p-toluenesulfonic acid to the propylene glycol is 1:2 (1.5-3.5); (3) When the alcohol is hexanediol, the mol ratio of the choline chloride, the p-toluenesulfonic acid and the hexanediol is 1:2 (0.5-3.5).
  8. 8. The method of claim 7, wherein the molar ratio of the components satisfies one of the following conditions: (1) When the alcohol is propylene glycol, the molar ratio of the choline chloride to the p-toluenesulfonic acid to the propylene glycol is 1:2 (2-3); (2) When the alcohol is hexanediol, the mol ratio of the choline chloride, the p-toluenesulfonic acid and the hexanediol is 1:2 (1-3).
  9. 9. The method according to any one of claims 1 to 8, comprising the steps of: s1, pretreatment to remove lignin, namely mixing a pretreatment reagent with a lignocellulose raw material for reaction, and after treatment, separating solid from liquid, and collecting filter residues, wherein the pretreatment reagent is a eutectic solvent; and S2, fermenting to produce ethanol, namely taking filter residues obtained in the step S1 as a fermentation substrate, adding an additive into the filter residues, and then performing synchronous saccharification and fermentation.
  10. 10. The method of claim 9, wherein the mass to volume ratio of the lignocellulosic feedstock to the pretreatment reagent is 1g (5-15) mL; preferably, the reaction condition in the step S1 is 80-95 ℃ for 10-40 min; Preferably, the fermentation condition in the step S2 is 30-37 ℃ for 24-72 hours; preferably, the lignocellulose raw material is at least one of pennisetum hydridum, straw, bagasse and miscanthus sinensis.

Description

Method for efficiently producing ethanol by utilizing lignocellulose Technical Field The invention belongs to the technical field of biomass conversion and utilization. And more particularly, to a method for efficiently producing ethanol using lignocellulose. Background With the urgent need for global energy structure transformation and sustainable development, a rich, renewable lignocellulosic feedstock is considered as a key feedstock to replace fossil fuels. Lignocellulose (lignocellulose) is a natural biomass material consisting of lignin, cellulose and hemicellulose, which is widely present in plant cell walls. The preparation of ethanol by using lignocellulose has become an effective method for solving the energy structure, and the method has the advantages of wide sources of raw materials (such as respective straws, bagasse, leaves, fallen leaves, forestry leftover materials and other agricultural and forestry wastes), no competition with grains, resource reuse and contribution to reducing the emission of greenhouse gases. At present, the production of ethanol by lignocellulose also has the restriction problem of low efficiency. Lignin severely hinders the efficient hydrolysis of cellulose wrapped by cellulose due to the intractable chemical structure and physical barrier effect, and restricts the production efficiency of subsequent biofuels (such as ethanol). It is therefore often desirable to pretreat the lignocellulosic feedstock to remove lignin, thereby increasing ethanol yield. Eutectic solvents (Deep Eutectic Solvents, DESs) as a green and efficient pretreatment reagent have great potential in breaking lignocellulose. However, practice shows that, on the one hand, even after the lignocellulose raw material is subjected to such DES pretreatment, the pretreatment residue is used as a substrate for fermenting to produce ethanol, and the ethanol yield is still not ideal, which severely restricts the efficient conversion and utilization of lignocellulose resources. On the other hand, the treatment efficiency difference of different lignocellulose raw materials is obvious, certain raw materials with compact fiber structures, such as pennisetum hydridum (Pennisetum sinese Roxb.), are difficult to obtain ideal pretreatment effect, and researches show that when the existing optimized DESs system for common straws is directly applied to pennisetum hydridum pretreatment, ideal lignin removal rate and cellulose retention rate are difficult to obtain, which directly leads to unsatisfactory subsequent enzymolysis efficiency and ethanol yield, and severely restricts the efficient conversion and utilization of high-quality biomass resources of pennisetum hydridum. The specific DES system developed by the Chinese patent CN119531164B (the molar ratio of the choline chloride to the p-toluenesulfonic acid to the 1, 4-butanediol is 1-2:3-6:2-8, and the mass ratio of the total mass of the choline chloride and the p-toluenesulfonic acid to the water is 20:9-11) can effectively remove lignin in the pennisetum hydridum, and the enzymolysis efficiency of cellulose is obviously improved. However, the technology has not solved the problem that the ethanol yield is still not high enough when residues obtained by pretreatment of lignocellulose raw materials are used as fermentation substrates. Therefore, developing a new method for producing ethanol by efficiently converting lignocellulose resources while further improving the ethanol yield when residues obtained by DES pretreatment of lignocellulose raw materials are used as fermentation substrates, and developing a eutectic solvent (DESs) which is also applicable to lignin removal pretreatment of lignocellulose raw materials with compact fiber structures such as pennisetum hydridum becomes a problem to be solved urgently in the field. Disclosure of Invention Aiming at the defects that the yield of ethanol is still not high enough when residues obtained by preprocessing lignocellulose raw materials with the eutectic solvent are used as fermentation substrates and the lignin removal rate of the existing eutectic solvent on lignocellulose raw materials with compact fiber structures such as pennisetum hydridum is low, the invention aims to provide a method for producing ethanol by using lignocellulose more efficiently. The above object of the present invention is achieved by the following technical scheme: The invention provides a method for efficiently producing ethanol by utilizing lignocellulose, which comprises the step of adding an additive into a fermentation substrate and then carrying out synchronous saccharification and fermentation, wherein the additive is at least one of tea saponin, bovine serum albumin, tween 80, PEG8000 and rhamnolipid, and the fermentation substrate is a lignocellulose raw material. Preferably, the additive is any one or two of tea saponin, bovine serum albumin, tween 80, PEG8000 and rhamnolipid. Further preferably, the mass ratio of the addit