Scholarly record

THE FORMATION OF CRYSTALL CENTERS IN A GLUCOSE SOLUTION

Lyudmila Khvorova

Abstract

Glucose on an industrial scale is obtained in anhydride (at a temperature above 50 0C) or hydrate form (at a temperature below 50 0C). The crystallization process is conventionally divided into two stages: nucleation ? the formation of nucleus and their growth to crystals of technical dimensions. The most difficult stage is the formation of nucleus during the crystallization of hydrate glucose. Spontaneous formation of nucleus is slow and they have a fragile needle shape, from which it is difficult to grow technical crystals, easily separated from the mother liquid. The successful crystallization process is facilitated by the introduction of glucose seed crystals into the glucose solution. The aim of the research was to determine the effect of priming seed crystals on the crystallization process. For studies, solutions were prepared by dissolving glucose in water, that a crystal seeds was added. A setup for conducting experiments on the crystallization was used rotary evaporator and laboratory crystallizers. The induction period was determined as changing the transparency of the solutions by the photocolorimeter. The size and shape of crystals were controlled by a microscope DMLN. The concentration of solids in the syrup and the massecuite was determined by refractometer. Studies have shown that seed crystals significantly reduced the induction period for formation of glucose nanoparticles (nuclei). In the experiment, the induction period in pure glucose solutions was 210 min, and in the presence of seed crystals was reduced to 15 min. The main role of the seed is to provide the crystallization process with the necessary number of crystallization centers to carry out the process at a high speed, to obtain the maximum yield of high quality glucose. Calculations have shown that the number of crystals in 1 g of glucose depending on the size differs from 103 (at the size of 250 ?m) to 106 particle (at the size of 30 ?m). Using seed with crystals of different sizes, that is possible to adjust the seed mass, which is of practical importance, because the dosage of seed crystals in production conditions reaches 10-15% by weight of the solution and significantly reduces the capacity of crystallizers.

Publication Impact Profile

• Captures
• Mendeley - Readers: 1

PLUMX see details

DOI resolver: doi.org/10.5593/sgem2019/6.1/s25.126

Publication details

Back to publication list