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CN-121975147-A - Functionalized lignin and preparation method and application thereof

CN121975147ACN 121975147 ACN121975147 ACN 121975147ACN-121975147-A

Abstract

The application discloses a preparation method of functional lignin, which is characterized in that lignocellulose is modified in situ by using p-toluenesulfonic acid and glycol to obtain the functional lignin with surface activity, and meanwhile, the functional lignin is used as a surfactant to effectively improve the concentration and the yield of ethanol in the saccharification and fermentation process, and the yield of ethanol can reach more than 90%. The functionalized lignin can be synchronously prepared when the lignocellulose raw material is pretreated, the whole process from raw material to product is simplified, and the functionalized lignin is derived from byproducts in the pretreatment process of the lignocellulose raw material, compared with commercial surface activity, the functionalized lignin is cheaper, and the comprehensive cost for producing ethanol by saccharification and fermentation can be effectively reduced.

Inventors

  • Fan Meishan
  • PEI XIAOYU
  • XIE JUN

Assignees

  • 华南农业大学

Dates

Publication Date
20260505
Application Date
20251218

Claims (10)

  1. 1. The preparation method of the functionalized lignin is characterized by comprising the following steps of: S1, uniformly mixing a lignocellulose raw material, ethylene glycol and p-toluenesulfonic acid according to the ratio of 10-30 g to 100-300 mL to 2.5-7.5 g, fully reacting, and then carrying out solid-liquid separation, and collecting liquid; S2, adding the liquid obtained in the step S1 into water with pH value of 2-4 for sufficient precipitation, carrying out solid-liquid separation, collecting solids, sufficiently cleaning the solids with water, and freeze-drying to obtain the functional lignin.
  2. 2. The method according to claim 1, wherein the lignocellulosic feedstock in step S1 is wheat straw, corn stover, corn cob or miscanthus.
  3. 3. The preparation method according to claim 1, wherein in the step S1, the lignocellulose raw material, the ethylene glycol and the p-toluenesulfonic acid are uniformly mixed according to 25g:250mL:6.25 g.
  4. 4. The method according to claim 1, wherein the sufficient reaction in step S1 is performed at 140-170 ℃ for 20-60 min.
  5. 5. The functionalized lignin prepared by the preparation method of any one of claims 1 to 4.
  6. 6. Use of the functionalized lignin according to claim 5 for increasing the yield of ethanol produced by saccharification and fermentation.
  7. 7. The method for improving the yield of ethanol produced by saccharification and fermentation is characterized by comprising the following steps of: S11, uniformly mixing a lignocellulose raw material, ethylene glycol and p-toluenesulfonic acid according to the ratio of 10-30 g to 100-300 mL to 2.5-7.5 g, and carrying out solid-liquid separation after full reaction to obtain a liquid and a pretreated lignocellulose raw material; S12, adding the liquid obtained in the step S11 into water with pH value of 2-4 for sufficient precipitation, carrying out solid-liquid separation, collecting solids, sufficiently cleaning the solids with water, and freeze-drying to obtain the functionalized lignin; S13, uniformly mixing the pretreated lignocellulose raw material obtained in the step S11 with a nutrient salt solution according to a ratio of 5-15 g to 50-100 mL, and adding cellulase with a final concentration of 10-30 FPU/g and Saccharomyces cerevisiae with a final concentration of 1-4 g/L into the mixture to obtain a fermentation system; The nutrient salt solution contains 1-3 g/L of yeast extract, 0.5-1.5 g/L of NH 4 Cl, 0.5-1.5 g/L of KH 2 PO 4 and 0.2-0.4 g/L of MgSO 4 ·7H 2 O; s14, adding the functional lignin obtained in the step S12 into the fermentation system obtained in the step S13, performing saccharification and fermentation, and collecting ethanol; Wherein the mass ratio of the functionalized lignin to the pretreated lignocellulose raw material in the fermentation system is 1-5 mg/1 g.
  8. 8. The method of claim 7, wherein the pretreated lignocellulosic feedstock obtained in step S11 and the nutrient salt solution are mixed uniformly in a ratio of 5-12.5 g to 50ml in step S13.
  9. 9. The method according to claim 7, characterized in that the mass ratio of functionalized lignin to pretreated lignocellulosic feedstock in the fermentation system in step S14 is 2 mg/1 g.
  10. 10. The method of claim 7, wherein the saccharification and fermentation in step S14 is performed at 30-35 ℃ for 24-96 hours.

Description

Functionalized lignin and preparation method and application thereof Technical Field The application relates to the technical field of biomass energy, in particular to a functionalized lignin and a preparation method and application thereof. Background The high-solid-content fermentation technology refers to a process of performing bioconversion by using high-concentration solids (usually with total solid content of > 15%) as a substrate in a fermentation process, and compared with the traditional liquid fermentation technology, the technology can remarkably improve the concentration of a product and the fermentation efficiency when processing viscous materials, and particularly has great potential in the fields of processing agricultural wastes, producing biofuels and chemicals. In the process of producing ethanol by saccharification and fermentation of lignin, the high-solid-content fermentation technology can improve the production efficiency and economy of bioethanol, but the high viscosity caused by a high-solid-content system can generate serious mass transfer limitation, and the non-productive adsorption of the pretreated lignin to cellulose can obviously reduce the enzymolysis efficiency. Currently, in order to solve the above problems, commercial surfactants such as whey protein, tween system, etc. are usually added during the fermentation production process. However, such exogenous surfactants are costly and their use adds additional investment and complexity to the production process, resulting in undesirable economics of lignin saccharification fermentation to ethanol. Therefore, there is an urgent need for a method capable of effectively improving the yield of ethanol produced by saccharification and fermentation under high-solid fermentation conditions. Disclosure of Invention The invention aims to overcome the defects in the prior art and provides a functionalized lignin, a preparation method and application thereof. The first aim of the invention is to provide a method for preparing functionalized lignin. The second aim of the invention is to provide the functionalized lignin prepared by the preparation method. The third object of the invention is to provide the application of the functionalized lignin in improving the yield of ethanol produced by saccharification and fermentation. The fourth object of the invention is to provide a method for improving the yield of ethanol produced by saccharification and fermentation. In order to achieve the above object, the present invention is realized by the following means: The invention discloses a preparation method of functionalized lignin, which comprises the following steps: S1, uniformly mixing a lignocellulose raw material, ethylene glycol and p-toluenesulfonic acid according to the ratio of 10-30 g to 100-300 mL to 2.5-7.5 g, fully reacting, and then carrying out solid-liquid separation, and collecting liquid; S2, adding the liquid obtained in the step S1 into water with pH value of 2-4 for sufficient precipitation, carrying out solid-liquid separation, collecting solids, sufficiently cleaning the solids with water, and freeze-drying to obtain the functional lignin. Preferably, the lignocellulose raw material in step S1 is wheat straw, corn cob or miscanthus. More preferably, the lignocellulosic feedstock in step S1 is wheat straw. Preferably, in step S1, the lignocellulosic feedstock, ethylene glycol and p-toluenesulfonic acid are mixed uniformly in 25g:250mL:6.25 g. More preferably, the volume concentration of the ethylene glycol is 50-100%. Further preferably, the volume concentration of the ethylene glycol is 60%. Preferably, the sufficient reaction is carried out at 140-170 ℃ for 20-60 min. More preferably, the reaction is carried out at 160℃for 30min. Preferably, before the step S2 is performed for sufficient precipitation, the pH of the liquid obtained in the step S1 is adjusted to 5.5-5.8. Preferably, in step S2, the liquid obtained in step S1 is added to water having ph=2. Preferably, the sufficient washing in step S2 is to wash the solid with water to a neutral pH of the wash solution. In the preparation method, the lignocellulose is subjected to in-situ modification by using the p-toluenesulfonic acid and the ethylene glycol, so that the functionalized lignin with surface activity can be obtained, and the functionalized lignin is used as the surfactant to effectively improve the concentration of ethanol and the yield of ethanol in the saccharification and fermentation process. Therefore, the invention also claims the functionalized lignin prepared by the preparation method. The invention also claims the application of the functionalized lignin in improving the yield of ethanol produced by saccharification and fermentation. The invention also claims a method for improving the yield of ethanol produced by saccharification and fermentation, which comprises the following steps: S11, uniformly mixing a lignocellulose raw material, ethylen