Xylose hydrolysate preparation pre-treatment method for papermaking wastewater

Abstract

The invention provides a xylose hydrolysate preparation pre-treatment method for papermaking wastewater, and belongs to the technical field of functional sugar preparation. The method comprises the following steps: 1. concentrating, wherein raw materials are concentrated in vacuum at a temperature of between 60 and 80 DEG C until the mass concentration is between 10 and 60 percent; and 2. hydrolyzing, wherein a solution with sulfuric acid mass concentration of between 0.5 and 3.0 percent is prepared from concentrated sulfuric acid with the concentrate of 98 percent, hydrolyzing for 90 to 120 minutes at a temperature of between 110 and 120 DEG C until hydrolysate is clean and transparent, and the xylose content in the dry matter of the hydrolysate is between 50 and 70 percent. According to the method, the papermaking wastewater is concentrated, so that inherent organic acidity of the wastewater is improved, organic acid in the wastewater is utilized, partial impurities are removed, the quality of the hydrolysate and the content of xylose can be improved, the hydrolysis efficiency is improved, the transportation is facilitated, and the transportation cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of functional sugar preparation and relates to a method for pretreatment of papermaking wastewater before preparation of xylose hydrolyzate. Background technique [0002] Many paper mills that use wood chips such as eucalyptus and birch as raw materials for papermaking produce a large amount of paper-making wastewater during the cooking process of wood chips. These paper-making wastewater contains a large amount of cellulose, hemicellulose, oligosaccharides, pigments, etc. Impurities, if the papermaking wastewater is directly hydrolyzed to produce xylose, the quality of the obtained hydrolyzate is not high, and the xylose mass content in the dry matter of the hydrolyzate is about 45%. Such a low-xylose hydrolyzate will make wood Sugar is difficult to crystallize; moreover, the direct hydrolysis of these papermaking wastewater is inefficient and causes certain difficulties in transportation, thus greatly incr...

AI Technical Summary

Problems solved by technology

[0002] Many paper mills that use wood chips such as eucalyptus and birch as raw materials for papermaking produce a large amount of paper-making wastewater during the cooking process of wood chips. These paper-making wastewater contains a large amount of cellulose, hemicellulose, oligosaccharides, pigments, etc. Impurities, if the papermaking wastewater is directly hydrolyzed to produce xylose, the quality of the obtained hydrolyzate is not high, and the xylose mass content in the dry matter of the hydrolyzate is about 45%. Such a low-xylose hydrolyzate will make wood Sugar is difficult to crystallize; moreover, the direct hydrolysis of these papermaking wastewater is inefficient and causes certain difficulties in transportation, thus greatly increasing the cost of xylose