CN-122012647-A - Method for hydrolyzing and saccharifying lignocellulose biomass

Abstract

The invention discloses a method for hydrolyzing and saccharifying lignocellulose biomass, which is characterized by comprising the following steps of (1) washing and drying materials, (2) crushing the materials, (3) preparing a material pretreatment solvent, (4) delignifying the materials in the pretreatment solvent, (5) filtering a reaction solution at normal temperature and normal pressure to separate liquid from solid to obtain cellulose, (6) adding the cellulose and polypeptide into deionized water according to a ratio of 2:1-1:2, wherein the solid-liquid ratio is 1:50-1:100, adding a NaOH solution to adjust the pH of the solution to 3-8, and reacting for 6-16 hours under the protection of nitrogen at 40- o ℃ to obtain glucose.

Inventors

• LIU YING
• SHI NING
• LAN YAQUAN
• CHEN ZHENLING
• YANG LIUTAO

Assignees

• 贵州理工学院

Dates

Publication Date

20260512

Application Date

20251229

Claims (8)

1. 1. A method for hydrolyzing and saccharifying lignocellulose biomass is characterized by comprising the following steps of (1) washing and drying materials, (2) crushing the materials, (3) preparing a material pretreatment solvent, (4) delignifying the materials in the pretreatment solvent, (5) filtering a reaction liquid at normal temperature and normal pressure to separate liquid from solid to obtain cellulose, (6) adding the cellulose and polypeptide into deionized water according to a ratio of 2:1-1:2, wherein the solid-to-liquid ratio is 1:50-1:100, adding a NaOH solution to adjust the pH of the solution to 3-8, and reacting for 6-16 hours under the protection of nitrogen at 40-95 o ℃ to obtain the product glucose.
2. 2. The method of claim 1, wherein the material in the step (1) comprises corn stalks, rice stalks, wheat straw, tea tree pruning, wood, branches, shells and bamboo.
3. 3. The method of claim 1, wherein the size of the pulverized material in the step (2) is 80-120. Mu.m.
4. 4. The method for hydrolyzing and saccharifying lignocellulose biomass is characterized in that the material pretreatment solvent is prepared from organic acid and hydrogen peroxide in a volume ratio of 7:1-10:1, and the organic acid comprises saturated monocarboxylic acids such as formic acid, acetic acid and propionic acid.
5. 5. The method for hydrolyzing and saccharifying lignocellulosic biomass as claimed in claim 1, wherein the step (4) is to pretreat the material at a mechanical stirring speed of 90-150 rpm for a depolymerization time of 6-12h under normal pressure at a temperature of 50-90 o C and a solid-to-liquid ratio of the material to the pretreatment solvent of 1:12-1:60. The lignin and hemicellulose of the material are depolymerized into low molecular weight organics in solution.
6. 6. A method of hydrolytic saccharification of lignocellulosic biomass as claimed in claim 1, wherein: the polypeptide comprises histidine-glutamic acid hexapeptide (His-Glu-His-Glu-His-Glu), tyrosine-glutamic acid hexapeptide (Tyr-Glu-Tyr-Glu-Tyr-Glu), lysine-glutamic acid hexapeptide (Lys-Glu-Lys-Glu), tyrosine-histidine hexapeptide (Tyr-His-Tyr-His-Tyr-His), lysine-histidine hexapeptide (Lys-His-Lys-His-Lys-His), dodecyl histidine-glutamic acid hexapeptide (C 12 H 25 -His-Glu-His-Glu-His-Glu-His) dodecyl tyrosine-glutamic acid hexapeptide (C 12 H 25 -Tyr-Glu-Tyr-Glu-Tyr-Glu), dodecyl lysine-glutamic acid hexapeptide (C 12 H 25 -Lys-Glu-Lys-Glu-Lys-Glu), dodecyl tyrosine-histidine hexapeptide (C 12 H 25 -Tyr-His-Tyr-His-Tyr-His), dodecyl lysine-histidine hexapeptide (C 12 H 25 -Lys-His-Lys-His-Lys-His).
7. 7. The method of claim 1 wherein the reacted glucose solution is used in a fermentation process to produce bioethanol.
8. 8. The pretreated lignin depolymerized solution of the process for the hydrolytic saccharification of lignocellulosic biomass of claim 1 as a conventional liquid fuel.

Description

Method for hydrolyzing and saccharifying lignocellulose biomass Technical Field The invention belongs to the field of comprehensive utilization of lignocellulose waste, and particularly relates to a method for improving hydrolysis saccharification efficiency of lignocellulose raw materials. Background With the continuous expansion of energy demands of human beings and the increasing demands of chemicals and materials using petroleum as raw materials, fossil resources as main energy sources and industrial raw materials of human society are facing to the serious challenges of increasing exhaustion for a long time, and the problems of environmental pollution and global climate abnormality caused by the excessive development and utilization of fossil energy are also increasingly prominent. Therefore, there is an urgent need to find and develop new renewable energy sources and petroleum feedstock alternatives. Lignocellulosic biomass such as straw, branch and the like is the most abundant renewable resource on the earth at present, and the conversion of the lignocellulosic biomass into chemicals or biofuels has very important significance for solving the problems of energy exhaustion, resource deficiency, environmental pollution and the like faced by human beings at present. Glucose is an important platform compound (e.g., bioethanol, lactic acid, 3-hydroxypropionic acid, furfural, etc.) capable of producing biofuels, chemicals, and macromolecules. Lignocellulosic biomass hydrolytic saccharification is therefore considered one of the key bottlenecks in lignocellulosic biomass development. Lignocellulosic biomass has lignin, hemicellulose, and cellulose as the main chemical components. The lignin and hemicellulose are combined in a covalent bond mode and tightly surround the cellulose, so that a catalyst or enzyme is difficult to contact with the cellulose to influence hydrolysis and saccharification of the cellulose, and therefore, partial lignin and hemicellulose are required to be separated or removed through pretreatment, the porosity of the lignocellulose raw material is increased, and the contact specific surface area and accessibility of the enzyme to the cellulose are improved. Therefore, the saccharification of the lignocellulose biomass mainly comprises two steps of pretreatment, hydrolysis and saccharification. Existing physicochemical pretreatment methods, such as steam explosion, acid/alkali treatment and the like, often involve severe conditions such as high temperature, high pressure, strong acid, strong alkali and the like. The conditions are easy to cause excessive degradation or structural damage of cellulose while destroying the intractable structure of lignocellulose, so that a great deal of cellulose raw material is lost, and byproducts such as furfural, hydroxymethyl furfural and the like can be generated in the pretreatment process, so that the subsequent saccharification efficiency of cellulose is influenced. In addition, in order to eliminate the influence of residual strong acid, strong alkali and byproducts on subsequent cellulose saccharification, a large amount of water washing or neutralization treatment is needed to be carried out on the pretreated material, and the step not only remarkably increases the water consumption, energy consumption and wastewater treatment cost of the process, but also generates a large amount of wastewater containing acid, alkali and organic matters so as to bring pressure to the environment. Therefore, the development of a novel pretreatment technology which is mild in condition, high in selectivity, environment-friendly and free from a large amount of water washing is one of key challenges to be broken through in the field of lignocellulose biorefinery. Currently, the most common methods for hydrolytic saccharification of cellulose are acid hydrolysis and enzymatic hydrolysis. Acid hydrolysis is classified into concentrated acid hydrolysis and dilute acid hydrolysis. The concentrated acid has strong hydrolysis corrosiveness and high requirements on the reactor. The dilute acid hydrolysis reaction condition is mild, the reaction rate is high, the cost is low, the industrial application is easy, but the hydrolysis product sugar is easy to degrade in an acidic medium, so that the hydrolysis product is complex, the selectivity of the target product is low, and meanwhile, the separation and purification of the product sugar are difficult, so that the directional accurate control of the target product is difficult to realize. The enzyme hydrolysis process has mild conditions, fewer hydrolysis byproducts and high saccharification yield, but the cellulase has poor stability and high cost, and the enzyme hydrolysis pretreatment process is complex and has higher cost. In order to overcome the disadvantages of acid hydrolysis and enzymatic hydrolysis, solid acid catalysts have been increasingly used in recent years in the field of catalyzing the hydrolysis of cell