Method for hydrolyzing vegetable fibre by solid acid

Abstract

The invention discloses a method for hydrolyzing vegetable fibre by solid acid, comprising the following steps: (1) adding smashed vegetable fibre and a solid-acid catalyst into water, mixing and dissolving; (2) carrying out hydro-thermal reaction at the temperature of 140-180DEG C for 6-10 hours after the smashed vegetable fibre and the solid-acid catalyst are evenly mixed and dissolved, and obtaining hydrolysate after the reaction; and (3) filtering the hydrolysate so as to separate target objects and the solid-acid catalyst, drying filter residues so as to be directly reused, and regulating the pH value of filter liquor to be within 6-8. The invention adopts solid sulfoacid with better hydrothermal stability and larger acid value to replace liquid acid, realizes the hydrolyzation of the cellulose under the moderate condition and solves the problem that the tradition catalyst is difficult to be separated from products; and after separation, the catalyst can be recycled, thereby avoiding lower economic benefit and acid contamination caused by the loss of liquid-acid catalysts.

Description

technical field [0001] The invention belongs to a method for preparing sugar by acid hydrolysis of plant fiber, and in particular relates to a method for hydrolyzing plant fiber with solid sulfonic acid. Background technique [0002] The use of biomass resources to produce liquid fuels and chemical products is to hydrolyze cellulose into sugars, such as oligosaccharides, monosaccharides, etc., and then use microorganisms (Candida, Saccharomyces cerevisiae, etc.) to produce liquid fuels and chemical products. Cellulose hydrolysis and saccharification methods mainly include dilute acid method, concentrated acid method, enzymatic method, and ultra-low acid hydrolysis and supercritical water hydrolysis, which are more popular in research. [0003] The traditional acid hydrolysis process is concentrated acid hydrolysis and dilute acid hydrolysis. Dilute acid hydrolysis has high requirements on the process conditions, excessive energy consumption in the reaction, and low sugar con...

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Problems solved by technology

[0003] The traditional acid hydrolysis process is concentrated acid hydrolysis and dilute acid hydrolysis. Dilute acid hydrolysis has high requirements on the process conditions, excessive energy consumption in the reaction, and low sugar conversion rate (about 25%). A large number of harmful intermediate products (such as furfural, organic acids) that inhibit microbial growth and other shortcomings; and concentrated acid hydrolysis, although the conversion rate of sugar is relatively high (90% or more), but the loss of concentrated acid of the catalyst is too serious, and the acid consumption is relatively large. The corrosion resistance requirements of the equipment are high, and the production cost is high; although the conversion rate of cellulase to the hydrolysis of cellulose is high, the cost of enzyme preparation is high, the pretreatment equipment is large, the operation cost is high, and the reaction cycle is relatively short. Long; ultra-low acid hydrolysis and supercritical water hydrolysis need to react under harsh conditions of high temperature and high pressure, the operation and process are difficult to control, and degradation products are easily produced, which affects subsequent fermentation

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