METHOD AND DEVICE FOR PRODUCING LACTIDE Russian patent published in 2024 - IPC B01D3/14 C07D319/12 C07B63/00 B01D5/00 B01D3/12 

FIELD: chemical or physical processes.

SUBSTANCE: present invention relates to a method for continuous production of optically pure lactide from an aqueous solution of lactic acid. Method comprises a first reactive distillation system, a second reactive distillation system, a main distillation system and a side cut refluxer and characterized by the fact that HTM-condensers are horizontally mounted in the upper part of the distillation columns, each of which is a modified horizontal shell-and-tube heat exchanger. HTM-condensers are used to ensure low pressure drops and to reduce side reactions associated with high still temperatures. For concentration of the purge stream from the second reaction distillation system for removal of metal contaminants contained in the purge stream, preventing accumulation of metals in the system and extracting crude lactide by depolymerization of the contained unreacted lactic acid oligomers, a concentration device is used.

EFFECT: providing a method and a device for producing an end product based on two reaction distillations and two traditional distillations, reducing the total pressure drop, reduced racemization of lactic acid and side reactions of lactic acid with lactide, removal of accumulated metal contaminants and increased output of lactide in the second reaction distillation system.

15 cl, 2 dwg, 4 ex