Three-phase crystallization (TPC) was applied to purify S-methyl-2-chloropropionate (S-M2CP) from liquid enantiomer mixtures. TPC combines melt crystallization and vaporization to produce S-M2CP crystalline solid along with the vapor from the liquid feed via a series of three-phase transformations. The proposed model can be efficiently applied in the TPC process design and optimization.

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.