Chiral Purification of S‐Methyl‐2‐chloropropionate from Enantiomer Mixtures by Three‐Phase Crystallization

Abstract

Three‐phase crystallization (TPC) was applied to purify S‐methyl‐2‐chloropropionate (S‐M2CP) from liquid enantiomer mixtures with various initial concentrations. TPC combines melt crystallization and vaporization to produce the desired crystalline solid along with the vapor from the liquid feed via a series of three‐phase transformations. The three‐phase states during TPC were calculated in terms of the thermodynamic properties of M2CP. Basically, the liquid mixture was gradually transformed to the S‐M2CP crystalline solid and vapor mixture at reduced temperature and pressure during TPC. A model was proposed based on the material and energy balances to determine the variations of the masses of the remained liquid mixture, of the produced S‐M2CP crystalline solid, and of the produced vapor mixture during the batch TPC operation. The results indicated that the experimental yield and purity for the final S‐M2CP product obtained during TPC were consistent with those predicted by the model.