Patent ID: 9573925
Date: 2017-02-21
CPC Classifications: B01D,C07D

Claim:
1. A process for the recovery and production of meso-lactide from a crude lactide containing stream, the process comprising: subjecting a starting crude lactide stream (A) to a first distillation step under distillation conditions comprising a temperature ranging from 80 to 180° C., a pressure ranging from 3 to 50 mbara and a number of theoretical stages of distillation (NTS) between 6 and 30 to obtain: recovering the side stream (D) and subjecting the side stream (D) to a melt crystallization step to obtain: recovering the top stream (B) and the drain stream (F); and subjecting the top stream (B) and the drain stream (F) to a second distillation step in a distillation column (20) operated at a temperature ranging from 100 to 185° C., a pressure ranging from 3 to 50 mbara and containing from 20 to 50 NTS to obtain a second purified stream (G) containing L-lactide and meso-lactide.