Method for extracting low-molecular-weight lignin from biomass

Abstract

The invention relates to a method for extracting low-molecular-weight lignin from biomass. The preparation method comprises the following steps of (1) preparing an extraction agent: preparing cholinechloride and hydrogen bond donors into a mixed solution at a certain mol mass ratio; then, performing reaction under a certain condition to form a uniform solution, namely the extraction agent; (2) adding the extraction agent into the biomass raw materials; adding catalysts; performing reaction for a certain time under the stirring condition at a certain temperature; performing filtering; adding deionized water; performing precipitation and centrifugation to obtain solid substances; then, cleaning the solid substances by absolute ethyl alcohol and deionized water; performing drying; obtaininga finished product. According to the method, poplar, bamboo-willow, wheat straw and the like are used as the biomass raw materials; the solvent prepared at a specific proportion under the specific conditions is used as the extraction agent for extracting the low-molecular-weight lignin. The method has the advantages that the reaction conditions are mild; the process is simple; green effect and high efficiency are realized; the extraction cost is low; the method is suitable for large-scale production application.

Description

technical field [0001] The invention relates to the technical field of separation of biomass components, in particular to a method for extracting low molecular weight lignin from biomass. Background technique [0002] On the earth, plant resources are abundant, which are mainly composed of cellulose, hemicellulose, lignin and a small amount of ash and extractives. After a long period of research and test applications, woody plant resources have been widely used in the field of pulp and paper. With the gradual maturity of biomass refining technology, plants, as a rich renewable biomass resource, have been closely watched by enterprises and researchers in the fields of biomass energy and materials. In my country, biomass raw materials such as poplar, bamboo willow, corn stalks, and rice straw are quite abundant, widely distributed, and have a short growth cycle, which is a sustainable source of biomass. [0003] Lignocellulosic biomass can not only be used for pulping and pa...

AI Technical Summary

Problems solved by technology

The traditional chemical pulping method can effectively extract lignin by using chemicals such as strong alkali and sulfate, but this traditional pulping method has harsh conditions and will cause environmental pollution, and the isolated alkali lignin is highly polycondensed and active. Functional groups are lost and difficult to be used

Organic solvents such as methanol, acetone, dioxane, etc. can also extract lignin, but the efficiency is low, and the relative price of organic solvents is relatively high, and it will also cause environmental pollution

Traditional ionic liquids, especially imidazole-based ionic liquids, can effectively extract lignin from biomass raw materials, but their development is limited due to their potential biotoxicity, high cost and poor biodegradability.

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