Comprehensive utilization method of lignocellulose biomass

Abstract

A comprehensive utilization method of lignocellulose biomass comprises the following steps: (a) performing alkaline hydrolysis processing; (b) performing acid hydrolysis of the alkaline hydrolysis residues, separating to obtain a pentose solution and acid hydrolysis residues; (c) performing enzymatic hydrolysis of the acid hydrolysis residues by using cellulase to obtain a glucose solution and enzymatic hydrolysis residues; (d) returning the enzymatic hydrolysis residues to step (b) for acid hydrolysis, or combining the enzymatic hydrolysis residues with new alkaline hydrolysis residues and performing acid hydrolysis processing in step (b), then orderly performing steps (c) and (d), cycling the steps so as to further convert the hemicelluloses into pentose and to perform enzymatic hydrolysis of the celluose into glucose. The method realizes the maximum resource utilization of lignocellulose biomass.

Description

technical field [0001] The invention relates to a method for comprehensively utilizing lignocellulosic biomass, in particular to a method for comprehensively utilizing cellulose, hemicellulose and lignin in lignocellulosic biomass. Background technique [0002] With the depletion of fossil fuel resources and the increasing environmental pollution, the use of renewable energy as a substitute for petrochemical products has become increasingly important. Fuel ethanol is the main form of biomass liquid energy and the most likely substitute for fossil fuels. At present, the world's ethanol production mainly uses starches (corn, cassava, etc.) and sugars (sugar cane, sugar beets, etc.) as raw materials for fermentation. The technology of producing ethanol by microbial fermentation is mature, but the high cost of raw materials restricts the industrial application of grain fermentation to produce ethanol. At the same time, there are disadvantages such as competition with people for...

AI Technical Summary

Problems solved by technology

The hemicellulose hydrolyzate is fermented to obtain 2,3-butanediol, the cellulose residue is fermented to obtain fuel ethanol, and the cellulose and hemicellulose are finally converted into industrial products for utilization, but the purpose of this process is to convert the Cellulose and hemicellulose are converted into fuel ethanol and 2,3-butanediol. The purpose of alkaline pretreatment is to remove lignin to the greatest extent, and lignin is used as a removal product, without considering the purity of lignin and other quality issues And the follow-up utilization of lignin, the alkali concentration is relatively high, and the activity of lignin is greatly damaged. Therefore, the separation of the three substances in this method ignores the extraction effect of lignin, and only cellulose and hemicellulose are tested. Effective industrial utilization, there is no guarantee that lignin can be effectively utilized industrially

[0007] The Chinese patent document with the publication number CN101725068A discloses a method and device for fractionating lignocellulosic biomass, providing lignocellulosic biomass, adding the first solvent capable of dissolving lignin, namely an alkaline solvent, from the obtained The above biomass extracts lignin, and then adds a second solvent that can dissolve hemicellulose, that is, an acidic solvent to extract xylose, and then extracts the cellulose remaining in the biomass; lignin, cellulose, and hemicellulose can all be separated. But when using dilute acid in this process, hemicellulose is not degraded into pentose, but exists in the form of oligomers; when using high-concentration acid, although the recovery rate of pentose is high, the amount of furfural generated is relatively small. High, therefore, the operation process has strict requirements on pH

At the same time, the concentration of lye used in the process of separating lignin is relatively high, and the activity of lignin is relatively large. The separated lignin can only be used as fuel for steam boilers or power plant boilers, or as phenolic chemicals through degradation treatment. low added value

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