Method for preparing fermentable sugar co-produced xylooligosaccharide by using wheat bran as raw material

Abstract

The application discloses a method for preparing fermentable sugar co-produced xylooligosaccharide by using wheat bran as a raw material. The method comprises the steps of raw material pretreatment and enzyme hydrolysis; in the raw material pretreatment step, after the wheat bran and hydrogen peroxide solution are mixed, a mixture is cooked to obtain a solid material easy to hydrolyze by an enzyme and soluble xylooligosaccharide. According to the application, after the wheat bran and the hydrogen peroxide solution are mixed, the mixture is cooked, and hydrogen peroxide eliminates the acid buffer effect caused by high-content free ash in the wheat bran in the pretreatment process, so that the weak acid environment in the wheat bran pretreatment process can be effectively enhanced, the method is beneficial to degradation and dissolution of xylan in the pretreatment process to generate the xylooligosaccharide, meanwhile, the enzyme hydrolysis performance of a pretreated material can be effectively improved, and efficient preparation of the fermentable sugar co-produced xylooligosaccharide by the wheat bran is implemented. The method effectively solves the problem how to eliminate a buffer system in the currently reported hydrothermal pretreatment process of cellulose waste with high ash content, and has the advantages of obvious greenness, environmental protection, high efficiency and the like.

Description

technical field [0001] The invention relates to a process for preparing fermentable sugars and xylo-oligosaccharides, in particular to a method for preparing fermentable sugars and co-producing xylo-oligosaccharides from wheat straw pulping waste bran. Background technique [0002] Wheat straw is a common raw material in my country's pulp and paper industry. In the pulp and paper industry using wheat straw as raw material, in order to ensure that the quality of wheat straw pulp meets the relevant standards, wheat straw must be screened before being used for pulping to remove the adsorbed ash in wheat straw. , wheat ears, wheat roots and some leaves, etc., the parts of these wheat straws that are not suitable for papermaking form wheat straw pulping waste, collectively referred to as "wheat bran". Wheat bran usually accounts for about 20% of the raw material of wheat straw, and is a very considerable resource of cellulosic waste. The rational utilization of these cellulose wa...

AI Technical Summary

Problems solved by technology

During the hydrothermal pretreatment process of wheat bran, the acetyl groups on the wheat bran hemicellulose xylan fall off under high temperature conditions to form acetic acid, and the hydrogen ions generated by the acetic acid are adsorbed by the adsorbed ash, so that the hydrothermal pretreatment of wheat bran The weak acidic environment of the liquid is weakened, which is not conducive to the degradation and dissolution of hemicellulose in wheat bran, resulting in a decrease in the amount of xylooligosaccharides dissolved in the hydrothermal pretreatment of wheat bran and a decrease in the enzymatic hydrolysis performance of the pretreated material

The methods to overcome the effect of adsorption ash in wheat bran on the effect of wheat bran pretreatment mainly include: one is to use washing method to remove the free adsorption ash in wheat bran, but this method has the disadvantage of large water consumption; Adding a small amount of metal ions with strong exchange properties in the hydrothermal pretreatment system can effectively eliminate the buffer system of wheat bran hydrothermal pretreatment, but the residue of metal salts has obvious effects on the enzyme activity of cellulase and the subsequent fermentation process of sugar solution. At the same time, the addition of metal salts will also cause certain difficulties to the subsequent wastewater treatment

It can be seen that the existing technology cannot effectively solve the technical problems of the reduction of the amount of xylo-oligosaccharides dissolved in the hydrothermal pretreatment of wheat bran and the reduction of the enzymatic hydrolysis performance of the pretreated materials.

Images