METHOD OF CLEANING PROCESS STREAMS DURING PRODUCTION OF DILACTIDE OR POLYLACTIDE Russian patent published in 2013 - IPC C07D319/12 B01D53/14 C08G63/08 C08G63/78 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of condensing and washing vaporous biodegradable intermolecular cyclic diester of alpha-hydroxycarboxylic acid of formula II , where R is selected from hydrogen or linear or branched aliphatic radicals containing 1-6 carbon atoms, from a vaporous mixture containing a diester of formula II, alpha-hydroxycarboxylic acid of formula I which corresponds to the diester of formula II, and water, wherein the stream of condensation and washing liquid (3), which contains aqueous solution of alpha-hydroxycarboxylic acid which corresponds to the diester of formula II, having formula I, is brought into contact, at least once, with the vaporous mixture, wherein the diester of formula II contained in the vaporous mixture dissolves in the condensation and washing liquid (3). The invention also relates to possible applications of said method.

EFFECT: improved method of condensing and washing vaporous biodegradable intermolecular cyclic diester of alpha-hydroxycarboxylic acid.

20 cl, 2 dwg