Xylose production process

Abstract

The invention discloses a xylose production process. The xylose production process comprises the following steps: adding pretreated pentosan-enriched plant fiber into a 1.0%-1.5% sulfuric acid solution to generate hydrolysis reaction, and filtering liquid to obtain hydrolysate; decoloring the hydrolysate by virtue of activated carbon or decoloring resin until the transparency of the hydrolysate is 20%-80%, and filtering to remove impurities by virtue of membrane filter equipment; concentrating the filtered hydrolysate by virtue of membrane concentration equipment, and decoloring the hydrolysate until the transparency of the hydrolysate is 60%-90% to obtain feed liquid, wherein leachate of the membrane concentration equipment is used as inflow water of an electroosmosis concentrated water chamber; desalting the feed liquid by virtue of electroosmosis and ion exchange resin, wherein electroosmosis concentrated water is circularly applied to a hydrolysis step; concentrating the feed liquid until the refractive index is 80%, crystallizing in a crystallization tank, and centrifuging to separate mother liquid, so as to obtain xylose crystals. According to the xylose production process, the problem that the costs for sewage treatments including neutralization and ion exchange in the prior art are high is solved, and the problems of short service life, low desalting efficiency, poor stability and high power consumption of an electroosmosis manner in the production of xylose are solved.

Description

technical field [0001] The invention relates to the field of functional sugar production, in particular to a xylose production process. Background technique [0002] In traditional xylose production, sulfuric acid is needed to hydrolyze the plant fibers rich in pentosan (such as corncobs, etc.). The removal of sulfate ions usually uses neutralization precipitation and ion exchange. However, neutralization precipitation The introduced calcium ions reduce the exchange capacity of the cation exchange resin, and at the same time, the residual calcium salt precipitates and accumulates in the resin to block the pore size of the resin, affecting the performance and service life of the resin. The ion exchange method will produce a large amount of waste water containing acid and alkali, which increases the cost of sewage treatment. [0003] The technology of electrodialysis equipment for desalination has become increasingly mature, and its application in xylose production has also b...

AI Technical Summary

Problems solved by technology

[0003] The technology of electrodialysis equipment for desalination has become increasingly mature, and its application in xylose production has also been seen in academic papers, but no company has actually applied it to xylose production

The main reason is the limitation of technical bottlenecks. The content of organic impurities, organic acids and pigments in xylose hydrolyzate is large and miscellaneous, which is easy to contaminate the ion exchange membrane, cause scaling on the surface of the electrodialysis membrane, and cause polarization, which seriously affects the service life of electrodialysis. Shortening, desalination efficiency reduction, affecting stability and increasing power consumption

In addition, the electrodialysis concentrated water contains sulfate, and direct recycling for hydrolysis will lead to the accumulation of salt, resulting in insufficient hydrolysis and increased power consumption of electrodialysis