Xylitol refining crystallization process

Abstract

The invention relates to a method for refining and crystallizing xylitol. The xylitol solution with a mass concentration of 85% to 92% is sent into a crystallizer, and the initial temperature of the raw material liquid is 65°C to 85°C, and then cooling and crystallization is carried out; at 55°C to 70 Add seed crystals at ℃ to control the nucleation of refined xylitol crystals, and grow crystals at a constant temperature for 15 to 60 minutes after adding seeds; the cooling rate of the entire refined crystallization process is controlled at 1°C / hr to 10°C / hr; the end point temperature of crystallization is 30°C ~45°C; the operation time of the crystallization process is less than 10 hours, the crystal slurry is centrifuged, washed, and dried at 40°C~80°C for 1~8 hours to obtain the crystal product. The invention greatly improves the quality of crystallization products and the yield of the process, is economical and practical, has short production cycle, and is especially suitable for applications in the fields of food and other fine chemicals. The particle size distribution of the xylitol crystal product obtained by the method is concentrated, the main particle size is adjustable from 150 μm to 1000 μm, the product crystal purity is greater than 99.5 percent, the fluidity is good, and the crystallization single-pass yield is more than 60 percent.

Description

technical field

[0001] The invention belongs to the technical field of crystallization, in particular to a method for refining and crystallizing xylitol. Background technique

[0002] Xylitol (Xylitol), scientific name pentapentyl alcohol, is a five-hydroxy polyol. Because it is first made from birch bark, it is commonly known as xylitol. The molecular formula of xylitol is C 5 h 12 o 5 , the molecular weight is 152.14, the melting point is 92 ° C ~ 96 ° C, the crystal is very soluble in water, the solubility in water at 20 ° C is about 16.8g / 100g, the chemical stability is good, hygroscopic, and it is a white orthorhombic under normal conditions Crystalline or crystalline powder, it has a unique refreshing feeling when eaten.

[0003] Xylitol is a normal intermediate of carbohydrate metabolism in the human body and one of the indispensable substances in human life activities. It has been identified as a grade A (safety grade) food additi...

Images