Atmospheric pre-treatment method of plant fiber material

Abstract

The invention discloses a normal pressure pre-treatment method for a plant fibrous material. Under normal pressure conditions, the plant fibrous material is cooked by dilute sulfuric acid first to hydrolyze hemicellulose into a pentaose solution; then a remaining part is cooked by dilute alkali solution to separate out most of lignin to obtain single fibriform cellulose; and the sulfuric acid and the alkali solution are recovered for circulating use. The single fibriform cellulose has a loose structure due to the fact that no hemicellulose is contained and only a small amount of lignin is contained, which can ensure that the rate of concentrated acid hydrolysis or enzyme hydrolysis of the cellulose is greatly accelerated. The pretreatment is finished under normal pressure, so the huge investment for a pressure vessel during high-temperature pretreatment is saved; the cooking temperature is basically lower than 100 DEG C, and the cheap heat energy obtained by the light-heat conversion of solar energy can be utilized as the heat energy for heating, so the using amount of coal is reduced; and process reagents, namely the sulfuric acid and sodium hydroxide can be recycled, so the method is a method which has less investment and is environment-friendly.

Description

[0001] Field [0002] The invention belongs to the field of biochemical industry, and relates to a method for utilizing plant fiber raw materials, in particular to a method for preparing sugar liquid, lignin and single fiber by normal-pressure pretreatment of plant fiber raw materials. Background technique [0003] Plant fiber raw materials are extremely abundant renewable resources in nature. If plant fiber raw materials can be well utilized, it will greatly reduce the cost of chemical raw materials and automobile fuel. But up to now, people are very insufficient to the utilization of plant fiber raw material. This is because the main components of plant fiber raw materials, cellulose, hemicellulose, and lignin are tightly combined, and their processing performance is also poor. The melting temperature of cellulose is higher than the decomposition temperature, so it does not have solubility and fluidity when heated to decomposition. To use plant fiber raw materials, a certa...

AI Technical Summary

Problems solved by technology

Dilute alkaline treatment alone cannot dissolve all the hemicelluloses, which will cause the peeling reaction of cellulose and hemicelluloses at the same time, and the monosaccharides produced will be isomerized into organic acids under alkaline conditions, reducing the yield of pentoses ; Only with the dilute acid method, the plant fiber material cannot be made into a single fiber-like cellulose material that is easily hydrolyzed by concentrated acid or enzyme during normal pressure hydrolysis, and acid-resistant and pressure-resistant containers are required during high-temperature and high-pressure hydrolysis; organic solvent method and Pressure vessels are required for both steam explosion methods

Both pressure-resistant and acid-resistant and pressure-resistant containers will greatly increase the investment, thereby increasing the cost of the product through depreciation; another disadvantage of high-temperature and high-pressure hydrolysis is that it requires high-temperature and high-pressure primary steam, and it is difficult to use low-temperature secondary steam and solar light. The low-temperature heat energy generated by thermal conversion is difficult to meet the requirements of energy saving