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CN-121975883-A - Method for strengthening saccharification of corn straw based on mixed solution slow release treatment

CN121975883ACN 121975883 ACN121975883 ACN 121975883ACN-121975883-A

Abstract

The invention provides a method for strengthening saccharification of corn straws based on mixed liquor slow-release treatment, which aims to solve the problems of strong pH dependency, difficult control of reaction process, reagent waste, high ecological risk and the like in AHP pretreatment. After the corn straw is treated by the method, the corn straw is subjected to enzymolysis saccharification to produce reducing sugar. Compared with the conventional alkaline hydrogen peroxide pretreatment, the method solves the problems of strong pH dependency, difficult control of reaction process, reagent waste, high ecological risk and the like in the alkaline hydrogen peroxide pretreatment. The pretreatment method provided by the invention is efficient, energy-saving, easy to operate and environment-friendly, and is beneficial to promoting the recycling utilization of lignocellulose. The invention relates to the technical field of lignocellulose pretreatment.

Inventors

  • XING DEFENG
  • LIU QIANG
  • LI YITIAN
  • YUAN YI

Assignees

  • 哈尔滨工业大学

Dates

Publication Date
20260505
Application Date
20251219

Claims (10)

  1. 1. The method for strengthening saccharification of corn straw based on mixed liquor slow release treatment is characterized by comprising the following steps: Step 1, crushing, sieving, washing and drying corn stalks; Step 2, putting the straw obtained in the step 1 into a mixed solution of potassium hydroxide and urea, stirring, adding hydrogen peroxide solution at a constant rate in the stirring process, filtering, washing and drying the straw after the reaction is finished for later use; And step 3, mixing the straw pretreated in the step 2 with a buffer solution containing cellulase for enzymolysis reaction to obtain the corn straw saccharification liquid.
  2. 2. The method for enhancing saccharification of corn stalks based on the slow release treatment of the mixed liquor according to claim 1, wherein in the step 2, the treatment temperature is 25 ℃, the stirring speed is 300 rpm, and the reaction system is 100 mL.
  3. 3. The method for enhancing saccharification of corn stalks based on the mixed solution slow-release treatment according to claim 2, wherein in the step 2, the concentration of potassium hydroxide is 2% -10% (w/v), the concentration of urea is 2% -10% (w/v), the addition rate of hydrogen peroxide is 6.94-83.33 mg/min, the treatment time is 2-24 h, and the treatment load is 5-20% (w/v).
  4. 4. The method for enhancing saccharification of corn stalks by a mixed solution based on a slow-release treatment according to claim 3, wherein in the step 2, the concentration of potassium hydroxide is 2% (w/v), the concentration of urea is 2% (w/v), the addition rate of hydrogen peroxide is 16.67 mg/min, the treatment time is 2 hours, and the treatment load is 5% (w/v).
  5. 5. The method for enhancing saccharification of corn stalks by a mixed solution based on a slow-release treatment according to claim 3, wherein in the step 2, the concentration of potassium hydroxide is 4% (w/v), the concentration of urea is 2% (w/v), the addition rate of hydrogen peroxide is 41.67 mg/min, the treatment time is 2 hours, and the treatment load is 5% (w/v).
  6. 6. The method for enhancing saccharification of corn stalks by a mixed solution based on a slow-release treatment according to claim 3, wherein in the step 2, the concentration of potassium hydroxide is 4% (w/v), the concentration of urea is 2% (w/v), the addition rate of hydrogen peroxide is 6.94 mg/min, the treatment time is 12 hours, and the treatment load is 5% (w/v).
  7. 7. The method for enhancing saccharification of corn stalks by a mixed solution based on a slow-release treatment according to claim 3, wherein in the step 2, the concentration of potassium hydroxide is 4% (w/v), the concentration of urea is 2% (w/v), the addition rate of hydrogen peroxide is 6.94 mg/min, the treatment time is 12 hours, and the treatment load is 20% (w/v).
  8. 8. The method for enhancing saccharification of corn stalks based on a slow release treatment of a mixed liquor according to claim 1, wherein the stalks washed with clean water in step 2 are subsequently dried at 80 ℃.
  9. 9. The method for enhancing saccharification of corn stalks based on the slow-release treatment of the mixed liquor according to claim 1, wherein in the step 3, the cellulase buffer is 50mM citric acid buffer with the pH of 4.8, the concentration of the cellulase is 0.3 FPU/mL, the stalk treatment load is 2% (w/v), and the final dosage of the cellulase is 15 FPU/g stalk.
  10. 10. The method for enhancing saccharification of corn stalks based on the slow release treatment of the mixed liquor according to claim 9, wherein in the step 3, the enzymolysis temperature is 50 ℃, the enzymolysis rotating speed is 150 rpm, and the enzymolysis time is 72 hours.

Description

Method for strengthening saccharification of corn straw based on mixed solution slow release treatment Technical Field The invention relates to the technical field of lignocellulose pretreatment, in particular to a method for strengthening saccharification of corn straws based on mixed liquor slow-release treatment. Background With the acceleration of global industrialization progress and the over exploitation of fossil fuels, the problem of energy shortage is increasingly remarkable, a large amount of greenhouse gases are discharged along with the problem, and the energy crisis and the climate crisis are solved. Lignocellulose is regarded as the only sustainable biomass energy source capable of realizing emission reduction and carbon fixation by virtue of abundant reserves and recycling. The biological energy source or bio-based chemical is converted by the biological conversion technology, and has far-reaching significance for promoting the energy structure transformation and protecting the ecological environment. However, lignin in lignocellulose such as straw can form a wrapping layer to wrap cellulose and hemicellulose therein, and the stable and intractable structure greatly prevents degradation and saccharification processes of cellulose and hemicellulose by microorganisms and enzymes, so that the subsequent conversion efficiency is limited. Therefore, developing an economically feasible pretreatment method breaks the intractable structure of lignocellulose, improves the accessibility of fibers and becomes a key for promoting the efficient progress of hydrolysis and saccharification reactions. Alkaline Hydrogen Peroxide (AHP) pretreatment is widely focused on the characteristics of high delignification efficiency, moderate reaction conditions, low inhibitor yield and the like. AHP pretreatment typically uses NaOH to adjust a hydrogen peroxide (H 2O2) solution to alkaline conditions. Then, H 2O2 is decomposed under alkaline condition to generate free radicals, and the free radicals can selectively act with lignin through various reaction paths, so that high-efficiency delignification is finally realized. The AHP pretreatment technology has obvious limitations that on one hand, the dependence on the pH value is extremely strong, the optimal reaction pH range is only 11.5-11.6, the narrow interval is difficult to accurately control in practical operation, the reagent utilization rate is easy to reduce to cause waste, and on the other hand, the additionally introduced Na + can increase the ecological risk in the pretreatment process and can potentially influence the subsequent process and environment. Based on the above, the optimization and improvement of the existing AHP pretreatment process become necessary measures for promoting the efficient conversion of lignocellulose. Disclosure of Invention The invention aims to solve the problems of strong pH dependency, difficult control of reaction process, reagent waste, high ecological risk and the like in AHP pretreatment, and further provides a method for strengthening saccharification of corn straws based on mixed liquor slow release treatment. The technical scheme adopted by the invention for solving the problems is as follows: the invention provides a method for strengthening saccharification of corn straw based on mixed liquor slow release treatment, which comprises the following steps: Step 1, crushing, sieving, washing and drying the corn straw, sieving the crushed straw with a 40-100-mesh sieve, washing the crushed straw with clear water, and drying at 80 ℃. Step 2, placing the straw obtained in the step 1 into a mixed solution of potassium hydroxide and urea and stirring, adding hydrogen peroxide solution (hydrogen peroxide is added through a microfluidic injection pump or a peristaltic pump) at a constant speed in the stirring process, and filtering, washing and drying the straw for later use after the reaction is finished; And step 3, mixing the straw pretreated in the step 2 with a buffer solution containing cellulase for enzymolysis reaction to obtain the corn straw saccharification liquid. Further, in step 2, the treatment temperature was 25 ℃, the stirring speed was 300 rpm, and the reaction system was 100 mL. Further, in the step 2, the concentration of potassium hydroxide is 2% -10% (w/v), the concentration of urea is 2% -10% (w/v), the adding rate of hydrogen peroxide is 6.94-83.33 mg/min, the treatment time is 2-24: 24 h, and the treatment load is 5-20% (w/v). Further, in step 2, the concentration of potassium hydroxide was 2% (w/v), the concentration of urea was 2% (w/v), the rate of addition of hydrogen peroxide was 16.67 mg/min, the treatment time was 2 hours, and the treatment load was 5% (w/v). Further, in step 2, the concentration of potassium hydroxide was 4% (w/v), the concentration of urea was 2% (w/v), the rate of addition of hydrogen peroxide was 41.67 mg/min, the treatment time was 2 hours, and the treatment load was 5% (w/v)