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CN-122012651-A - Method for strengthening degradation and conversion of lignocellulose by photo Fenton treatment

CN122012651ACN 122012651 ACN122012651 ACN 122012651ACN-122012651-A

Abstract

The invention discloses a method for strengthening degradation and conversion of lignocellulose by photo Fenton treatment, which comprises the following steps of (1) mixing crushed straws with hydrogen peroxide solution, activated carbon doped nickel ferrite nano particles and deionized water to obtain mixed solution, (2) carrying out white light irradiation on the mixed solution while carrying out oscillation treatment, then carrying out solid-liquid separation to obtain supernatant and residues, and (3) carrying out enzymolysis saccharification on the residues. The straw is pretreated in a photocatalysis and Fenton reaction synergistic mode, so that the effects of lignin degradation and removal, good retention of cellulose and efficient enzymolysis and saccharification are obtained.

Inventors

  • ZHANG QIN
  • WU BO
  • CHENG QIANZI
  • LI YANBIN
  • Suo Liheng
  • ZHOU JIALE
  • DUAN QIAN

Assignees

  • 安徽工程大学

Dates

Publication Date
20260512
Application Date
20260202

Claims (10)

  1. 1. A method of photo-Fenton treatment for enhancing lignocellulose degradation and conversion, comprising the steps of: (1) Mixing the crushed straw with hydrogen peroxide solution, activated carbon doped nickel ferrite nano particles and deionized water to obtain mixed solution; (2) Carrying out white light irradiation on the mixed solution while carrying out oscillation treatment, and then carrying out solid-liquid separation to obtain supernatant and residues; (3) And (5) carrying out enzymolysis saccharification on the residues.
  2. 2. The method for enhancing degradation and conversion of lignocellulose by photo Fenton treatment according to claim 1, wherein in the step (1), the grain size of the straw is 20-40 meshes.
  3. 3. The method for reinforcing degradation and conversion of lignocellulose by photo Fenton treatment according to claim 1, wherein in the step (1), the mass concentration of hydrogen peroxide in the mixed solution is 1.0-3.5%, the concentration of activated carbon doped nickel ferrite nano particles is 2-6 g/L, and the concentration of straw is 0.1 g/mL.
  4. 4. The method for enhancing degradation and conversion of lignocellulose by photo Fenton treatment according to claim 1, wherein in the step (2), the illumination intensity of the white light is 3000-7000W/m 2, and the illumination time is 24-72 h.
  5. 5. The method for enhancing the degradation and conversion of lignocellulose according to any one of claims 1-4, wherein in the step (1), the mass concentration of hydrogen peroxide in the mixed solution is 2.5%, and the concentration of the activated carbon doped nickel ferrite nano particles is 4g/L.
  6. 6. The method for enhancing the degradation and conversion of lignocellulose according to any one of claims 1-4, wherein in step (2), the white light has an illumination intensity of 5000W/m 2 and an illumination time of 36 h.
  7. 7. The method for enhancing degradation and transformation of lignocellulose as recited in any one of claims 1-4, wherein in the step (3), the enzymatic saccharification is performed by dispersing the residue in a citric acid buffer, adding Cellic v CTec HS cellulase, and oscillating at 50 ℃ for reaction 72 h.
  8. 8. The method for enhancing the degradation and conversion of lignocellulose according to claim 7, wherein the concentration of the citric acid buffer is 0.05M, the pH is 4.8, and the mass concentration of the residue in the citric acid buffer is 5%.
  9. 9. The method for enhancing the degradation and conversion of lignocellulose according to claim 7, wherein Cellic: CTec3 HS cellulase is added in an amount of 10 FPU/g residue.
  10. 10. The method for strengthening degradation and conversion of lignocellulose by photo Fenton treatment according to claim 7, wherein the retention rate of cellulose in straw treated by the method is more than 80%, the lignin degradation removal rate is more than 20%, the total phenol content is less than 15 mg/L, and the enzymatic hydrolysis rate is more than 60%.

Description

Method for strengthening degradation and conversion of lignocellulose by photo Fenton treatment Technical Field The invention belongs to the technical field of pretreatment of lignocellulose raw materials, and particularly relates to a method for strengthening degradation and conversion of lignocellulose by photo-Fenton treatment. Background Lignocellulosic biomass is the most abundant renewable resource on earth, can be used for the production of various high-value products and energy sources, is considered as a good alternative fuel or energy source, and has important supporting effect on the development of carbon zero emission and circular economy. Lignocellulosic biomass is a natural organic material with a complex structure mainly formed by cross-linking cellulose, hemicellulose and lignin, and a certain pretreatment mode is generally needed to promote depolymerization of the lignocellulose and enhance enzymolysis accessibility of the cellulose and the hemicellulose. There have been a great deal of reports on ways of pretreatment of lignocellulose, and in recent years, there has been a gradual shift to low energy consumption, low cost, high efficiency and mild conditions, the most prominent of which is the photocatalytic treatment. As a high-grade oxidation treatment mode, the photocatalysis process can stimulate the generation of active oxygen, the active oxygen can attack lignin structure, and O-H bonds are activated to form alkoxy, so that adjacent C-C bonds are weakened, aromatic rings are cracked, and the decomposition of lignocellulose biomass is promoted. However, due to the firm crystalline structure characteristic of lignocellulose, the photocatalysis technology has a common mass transfer limiting problem in the conversion of lignocellulose biomass, so that active oxygen is not easy to contact lignocellulose macromolecules, and the degradation efficiency is low. Disclosure of Invention In order to solve the technical problems, the invention provides a method for strengthening degradation and conversion of lignocellulose by photo-Fenton treatment, which adopts a photocatalysis and Fenton reaction synergistic mode to pretreat straws, obtains the effects of lignin degradation and removal, good retention of cellulose and efficient enzymolysis saccharification, and is a novel green method for realizing efficient pretreatment of lignocellulose. The technical scheme adopted by the invention is as follows: The invention provides a method for strengthening lignocellulose degradation and conversion by photo Fenton treatment, which comprises the following steps: (1) Mixing the crushed straw with hydrogen peroxide solution, activated carbon doped nickel ferrite nano particles and deionized water to obtain mixed solution; (2) The mixed solution is subjected to white light irradiation while being stirred, and then solid-liquid separation is carried out to obtain supernatant and residues; (3) And (5) carrying out enzymolysis saccharification on the residues. In the step (1), the grain size of the straw is 20-40 meshes. In the step (1), the mass concentration of hydrogen peroxide in the mixed solution is 1.0-3.5%, the concentration of the activated carbon doped nickel ferrite nano particles is 2-6 g/L, and the concentration of the straws is 0.1 g/mL. Preferably, the mass concentration of the hydrogen peroxide is 2.5 percent, and the concentration of the activated carbon doped nickel ferrite nano particles is 4g/L. In the step (2), the illumination intensity of the white light is 3000-7000W/m < 2 >, and the illumination time is 24-72 h. Preferably, the illumination intensity of the white light is 5000W/m 2, and the illumination time is 36 h. In the step (3), the enzymolysis saccharification method comprises the steps of dispersing residues in a citric acid buffer solution, adding Cellic ℃ CTec HS cellulase, and stirring and reacting for 65-75 hours at 45-55 ℃. Further, the concentration of the citric acid buffer solution is 0.05M, the pH is 4.8, and the mass concentration of the residue in the citric acid buffer solution is 5%. Cellic% CTec HS cellulase was added in an amount of 10 FPU/g of residue. According to the method for reinforcing lignocellulose degradation and conversion by photo-Fenton treatment, provided by the invention, the straw is pretreated in a synergistic manner of photocatalysis and Fenton reaction, so that the effects of lignin degradation removal, good retention of cellulose and efficient enzymolysis saccharification are obtained, the retention rate of cellulose in the straw is above 80%, the lignin degradation removal rate is above 20%, the total phenol content is below 15 mg/L, and the enzyme hydrolysis rate is above 60%. Under the preferable treatment condition of the invention, the retention rate of cellulose in the straw is above 90%, the lignin degradation removal rate is above 30%, the total phenol content is lower than 8 mg/L, and the enzymatic hydrolysis rate is above 85%. Is a gr