METHOD OF PURIFICATION OF THERMOLABILE LIQUIDS Russian patent published in 2021 - IPC B01D9/02 C01B21/16 C01B15/01 C01B15/17 

FIELD: chemical industry.

SUBSTANCE: invention relates to the field of chemical technology processes and can be used for the isolation and purification of individual unstable liquids from water and other impurities by the method of fractional countercurrent crystallization. The purification of thermolabile liquids is carried out by the method of countercurrent fractional crystallization. The thermolabile liquid is hydrazine or hydrogen peroxide. Purification is carried out when the ratio of the flows of crystals of the thermolabile liquid in the apparatus to its purified melt withdrawn from the apparatus is not less than 5, as well as when the ratio of flows of the purified melt withdrawn from the melting zone of the apparatus and the mother liquor withdrawn from the zone above the crystallizer is no more than 10. The melt flow conditions are approaching the plug-flow regime. The temperature in the crystallizer is below the equilibrium melting point of the initial product by at least 3°C, but not more than by 25°C. The temperature in the washing zone is in the range from the crystallization temperature of the initial solution to a temperature above the melting point of the pure product, but not more than by 2°C, and the temperature in the melting zone is in the range of 1-5°C above the melting point of the pure product. In the upper part of the crystallizer above the crystallization zone, the temperature of the mother liquor is maintained not less than the equilibrium crystallization temperature of the initial crude product.

EFFECT: invention makes it possible to obtain highly concentrated products of special purity, without the product being in the zone of elevated temperatures, and also ensures a decrease in energy consumption and an increase in production safety.

1 cl, 3 dwg, 1 tbl, 15 ex