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CN-122013579-A - Green wood fiber dissociation method based on peroxide

CN122013579ACN 122013579 ACN122013579 ACN 122013579ACN-122013579-A

Abstract

The invention discloses a green dissociation method of wood fiber based on peroxide. The dissociation method comprises the following steps of stirring peroxide and wood fiber raw materials in a solvent to obtain a dissociation product, wherein the peroxide is selected from sodium percarbonate. According to the invention, partial lignin of an intermediate layer in the lignocellulose cell wall of sodium percarbonate is subjected to transverse permeation and depolymerization, and a method of longitudinally dissociating the lignocellulose cell wall by combining mechanical stirring is adopted, so that dissociated products with high lignin content components and high crystallinity are prepared under the condition of low power consumption.

Inventors

  • CHEN WENSHUAI
  • GUO XINPENG
  • SHI MENGJIAO
  • LI QING
  • Su Fangtian

Assignees

  • 东北林业大学

Dates

Publication Date
20260512
Application Date
20260320

Claims (10)

  1. 1. A peroxide-based green dissociation method for wood fibers, comprising the steps of: The peroxide and the wood fiber raw material are stirred in a solvent to obtain a dissociation product, wherein the peroxide is selected from sodium percarbonate.
  2. 2. The dissociation method of claim 1, wherein said lignocellulosic feedstock is selected from wood chips; and/or the solvent is selected from water.
  3. 3. The dissociation method of claim 2, wherein said wood chips have a length of 0.3 to 1.8mm; And/or the wood chips are derived from one or more of poplar, bamboo and grass.
  4. 4. The dissociation method of claim 1, wherein the mass ratio of the lignocellulosic feedstock to sodium percarbonate is 1 (1.0-7.0).
  5. 5. The dissociation method of claim 1, wherein the temperature of said treatment is 0-100 ℃; and/or the treatment time is 6-30 h.
  6. 6. The method of claim 1, wherein the rotational speed of the stirring process is 1000 to 3000r/s.
  7. 7. A dissociation product obtained by the dissociation method according to any one of claims 1 to 6.
  8. 8. The dissociation product of claim 7, wherein said dissociation product has a lignin retention of 80% to 90% and cellulose retention of 85% to 95%; and/or the crystallinity of the dissociated product is 50-70%.
  9. 9. A product comprising the dissociation product of claim 7 or 8.
  10. 10. Use of sodium percarbonate for increasing the retention of lignin and/or cellulose in the dissociation products of lignocellulosic feedstock.

Description

Green wood fiber dissociation method based on peroxide Technical Field The invention relates to the technical field of materials, in particular to a green wood fiber dissociation method based on peroxide. Background The green high-valued utilization of wood fiber is a key path for realizing the efficient and high-quality conversion of low-quality artificial forest wood resources, and plays an important role in promoting national economy development and improving the quality of life of people. Lignocellulosic cell walls are highly ordered three-dimensional composite structures formed by crosslinking Cellulose (Cellulose), hemicellulose (Hemicellulose), and Lignin (Lignin) through non-covalent and covalent interactions. The cellulose exists in a microfibril form, a highly crystallized framework (the crystallinity is 40% -60%) is formed through a hydrogen bond network, surface hydroxyl groups of the cellulose are connected with hemicellulose (such as xylan and glucomannan) through hydrogen bonds or ester bonds, the hemicellulose is filled among the cellulose microfibrils in an amorphous state to form a net-shaped supporting structure, lignin is covalently crosslinked with the hemicellulose through phenolic groups (such as ferulic acid and p-coumaric acid) through ester bonds to form a hemicellulose-lignin complex (LCC), the hemicellulose-lignin complex is filled between cellulose net-shaped structures as a filler, and finally the cellulose framework-hemicellulose supporting-lignin filled compact complex is formed. Cellulose accounts for 30-50% of the dry weight of the plant, and is a framework substance of the cell wall. The supramolecular structure of cellulose can be divided into crystalline and amorphous regions, the proportions of which affect the mechanical properties and chemical reactivity of the material. The crystallization area is formed by forming bundle-shaped structure 'microfibrils' with diameters of 3-5 nm by parallel arrangement of 36-120 cellulose chains, and the inside of the crystallization area is tightly combined by hydrogen bonds and Van der Waals force. The rigid chain structure causes that cellulose is difficult to dissolve in water and common organic solvents, only dissolves in strong polar solvents (such as ionic liquid and concentrated sulfuric acid), cellulose chains in an amorphous region are disordered in arrangement, a hydrogen bond network is incomplete, and the cellulose chains are easy to attack by hydrolytic enzymes or chemical reagents, so that the cellulose is a main action site for biological transformation and utilization. Hemicellulose is the second largest component next to cellulose in plant cell walls, accounting for 15-35% of plant dry weight, is filled between cellulose microfibrils, enhances cell wall toughness, and forms a complex network structure of plant cell walls together with cellulose and lignin. The hemicellulose and lignin are crosslinked by covalent linkage with phenylpropane units of lignin mainly through ester bonds or ether bonds of phenolic acid (such as ferulic acid) to form a three-dimensional network structure of lignin-carbohydrate complex (LCC), so that the mechanical strength and degradation resistance of cell walls are enhanced. One of the keys to release the lignocellulosic degradation barrier to achieve maximum resource utilization of the components is how to disrupt LCC structure and reduce hemicellulose loss, reducing inhibitor production. Lignin represents 15-30% of the dry weight of plants, mainly providing mechanical support and resistance to microbial degradation. The structure of lignin is very specific, being present in the plant cell wall in a complex three-dimensional network. The structure ensures that lignin has high stability and strength and can effectively support and protect plant cells. Meanwhile, the structure of lignin also gives good biocompatibility and degradability to the lignin, so that the lignin has wide application prospects in various fields. The three components (cellulose, hemicellulose and lignin) forming the wood fiber form a cell wall polymerization structure through chemical bonds and interaction force, so that not only can the structural damage caused by water, acid, alkali and the like be avoided, but also the entry of microorganisms can be prevented, and enzymolysis is prevented. Therefore, if the lignin is to be separated on the basis of maintaining the original structure of the lignin, the basic structure of the cell wall is required to be destroyed, and then the lignin is obtained through solvent dissolution or enzymatic hydrolysis, so that the extraction efficiency can be greatly improved. Various pretreatment methods have been developed over the years to overcome and reduce the recalcitrance of biomass, and currently existing pretreatment methods mainly include physical methods, chemical methods, physicochemical combinations and biological methods to destroy the cell wall structure of wood fibers and