METHOD OF PRODUCING HIGH-PURITY HYDRAZINE Russian patent published in 2016 - IPC C01B21/16 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical engineering processes, particularly, to technology of hydrazine compounds. Method of producing hydrazine of high purity from hydrazine-hydrate and aqueous hydrazine, which includes step of dehydration using solid alkali, step for rectification at low pressure and step of fractional crystallisation, wherein step of dehydration is carried out in conditions of intensive mixing and emulsification of produced liquid phases; step of rectification is carried out in continuous mode after separation of main part of alkali-sodium hydroxide to residual content of not more than 0.5 wt% by cooling and settling, pressure during rectification maintained in range 50-200 mm Hg, with number of theoretical plates of column of not less than 6, reflux ratio 2-4; and crystallisation of hydrazine is carried out in conditions of mixing and removing crystals from walls of crystalliser with transfer of crystallisation process into volume of apparatus, to crystallisation of not more than 80 % at a rate of crystallisation of not more than 30 kg/hour per 1 m² area of cooled surface of apparatus.

EFFECT: reduced power consumption and higher safety of production.

3 cl, 2 dwg, 1 tbl, 11 ex