Chiral Purification of S-2-Phenylpropionic Acid from an Enantiomer Mixture by Stripping Crystallization

Stripping crystallization (SC) was applied in this study to purify S-2-phenylpropionic acid (S-2-PPA) from enantiomer mixtures. According to the solid–liquid equilibrium predicted by the Schroder–Van Laar equation and the vapor–liquid equilibrium predicted by Raoult's law, a series of three-phase transformation conditions were determined to perform the batch SC experiments. As opposed to the solid–liquid transformation in melt crystallization, a series of three-phase transformations occur operated at low pressures during the SC cooling process. The experimental yield and purity for the final S-2-PPA product obtained during SC were investigated. A comparison was made between the experimental results and the calculated results based on the material and energy balances.