Method for removing colloid in xylitol solution by utilizing carbon dioxide gas

Abstract

The invention relates to the technical field of production of xylitol and discloses a method for removing colloid in a xylitol solution by utilizing carbon dioxide gas. The method comprises the following steps: (1) dissolving calcium oxide into water to prepare lime milk; (2) carrying out heating treatment on the xylitol solution and then adding the prepared lime milk to adjust the pH (Potential of Hydrogen) value of the xylitol solution, so as to obtain a mixed solution a; (3) introducing CO2 gas into the mixed solution a and stirring to sufficiently dissolve; regulating the pH value of the mixed solution a; then standing and reacting, filtering and centrifuging and separating to obtain the xylitol solution. The method disclosed by the invention has the advantages of simple technology, low cost, obvious impurity removal effect, strong stability and easiness in operation and large-scale production; compared with traditional activated carbon adsorption or cation and anion resin exchangeresin purification methods and the like, the content of colloid impurities in the xylitol solution can be effectively improved and the subsequent purification cost of xylitol is reduced.

Description

technical field [0001] The patent of the invention relates to the technical field of xylitol production, in particular to a method for removing colloids in xylitol solution with carbon dioxide gas. Background technique [0002] With the rapid development of social economy and the continuous improvement of people's living standards, the problems of environmental pollution and energy shortage are becoming more and more serious, and people's requirements for energy conservation and environmental protection are also getting higher and higher. Lignocellulosic raw materials are extremely abundant and cheap renewable resources in nature. How to extract and recycle their active components to realize the rational utilization of resources has become the focus of research. [0003] As we all know, xylitol is a five-carbon sugar alcohol, a functional natural sweetener. In nature, it widely exists in various fruits, vegetables, and grains. It can not only adjust abnormal glucose metabol...

AI Technical Summary

Problems solved by technology

However, due to its low natural content and high production cost, its application space is greatly limited.

In industrial production, xylitol is mainly prepared by hydrogenation of xylose, and xylose is generally obtained from lignocellulosic corncobs or wood through acid hydrolysis, separation and purification, but because corncobs or wood often contain crude protein, Crude fat, soil, sand or lignin (belonging to aromatic compounds), resins, volatile oils, tannins, pectin and other substances, so these substances tend to remain in the xylitol solution during acid hydrolysis In the process, colloidal impurities such as silicic acid or silicate are formed. As the xylitol liquid enters the next process, the concentration of these substances will increase with the increase in the concentration of the xylitol liquid during the evaporation and concentration process, which seriously affects the follow-up process. Crystalline Purity and Quality of Xylitol

[0004] At present, activated carbon adsorption, anion and cation exchange resins, filter aid filtration or 0.45 micron precision filtration are often used in actual production to remove silicic acid or silicate and lignin (belonging to aromatic compounds) in xylitol liquid. , resin, volatile oil, tannin, pectin and other colloidal impurities, but there are often disadvantages such as complex process, cumbersome operation, high cost, and unsatisfactory impurity removal effect

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