Study of the polysaccharides obtaining process from wheat processing waste

Abstract

The article presents the results of the study of the enzymatic combined (hybrid) hydrolysis-hydrogenation process
for the production of sorbitol. This article describes the results of the pre-treatment and enzymatic hydrolysis of wheat straw,
as well as the synthesis of sorbitol in order to increase the yield of valuable products needed for industry. Pretreatment of straw
carried out in the temperature range 190-250 ◦ C with a variation in the concentration of sulfuric acid from 0.6 to 2.5% by
weight. The optimum temperature and duration of hydrolysis of straw with sulfurous acid at 160 ◦ C- 170 ◦ C and in 30-80
minutes, respectively. In all straw hydrolysis experiments, the best results achieved with a sulfuric acid concentration of 1.6%
by weight and an experimental temperature of 150-160 ◦ C. Studies of the processes of enzymatic hydrolysis of straw carried
out. As well as, the paper is practically pure cellulose, then, with the same kinetic parameters of the fermentolysis processes,
the amount of formed sugars in the case of fermentolysis of straw would be 1.49 times less than when using paper. The resulting
purified glucose hydrolyzate was subjected to hydrogenation in the presence of a nickel-aluminum-iron-chromium catalyst. The
catalyst of the alloy with 7.0% chromium exhibits the greatest activity, the yield of sorbitol at which at 100 ◦ C and 6MPa for
60 minutes of hydrogenation is 50.5%, and the rate of hydrogenation of glucose is 1.46 times higher than for skeleton nickel
without an additive. It is shown that with increasing hydrogen pressure from 2 to 12 MPa and from 40-120 ◦ C, the rate of
hydrogenation of glucose on titanium-promoted nickel-aluminum-iron catalysts increases.