Enantioseparation of phenylethanol by distillative freezing

• Main Authors: Chien Ning Chiu, 邱健寧
• Other Authors: L. D. Shiau
• Format: Others
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/75479369376582896562

碩士 === 長庚大學 === 化工與材料工程學系 === 99 === Distillative freezing (DF) is a new separation technique which combines distillation and crystallization to produce pure crystals. In principle, DF is operated at a triple-point condition, in which the liquid mixture is simultaneously vaporized and crystallized due to the three-phase equilibrium. The process is continued until the liquid phase is completely eliminated and only the pure solid crystals remain in the feed. Thus, crystal washing is not required since no impurities are adhered on the crystal surfaces at the end of DF. Due to the close-boiling points, it is very difficult to separate enantiomers by distillation. DF is applied in this study to separate the phenylethanol enantiomers. The experiments confirm that seeding with magnetic stirring can be efficiently employed to break subcooling. S-phenylethanol can be purified from 95% to 96% with the recovery rate 79.3%, or from 97% to 98.3% with the recovery rate 77% by seeding with magnetic stirring.