LACTIC ACID PRODUCTION METHOD Russian patent published in 2019 - IPC C07C51/43 C07C59/08 C08G63/06 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing lactic acid, comprising the following steps: carrying out distillation of lactic acid-containing solution to remove lactic acid from steam side (step A); carrying out crystallisation of lactic acid obtained at step A (step B); performing separation of the lactic acid suspension obtained at step B into lactic acid crystals and a mother liquid containing oligomers of lactic acid (step C); and organizing recycling of mother liquid obtained at step C to step B (step D).

EFFECT: in the process of crystallisation of lactic acid and extraction of crystals of purified lactic acid during recycling of mother liquid to the crystallisation step, by using lactic acid withdrawn from the steam side after distillation of lactic acid-containing solution as liquid supplied to crystallization step, it is possible to prevent accumulation of multimeric lactic acid in system of crystallization step recycling, thereby providing stable production of lactic acid crystals with high output; thus, using said lactic acid, polylactic acid is obtained, characterized by excellent physical properties.

5 cl, 1 dwg, 2 tbl, 3 ex