Separation of the Cresol Isomers by a New Technique Combining Distillation and Crystallization
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A new separation technology, called stripping crystallization (SC) or distillative freezing (DF), has been recently developed in our laboratory to separate the mixtures with close boiling temperatures, including the mixed xylenes [1-3] and the benzene/cyclohexane mixture . In principle, SC is operated at a triple-point condition, in which the liquid mixture is simultaneously vaporized and crystallized due to the three-phase equilibrium. Thus, SC combines distillation and crystallization to produce pure crystals. Due to the close boiling points of p-cresol (201.98°C) and m-cresol (202.27°C), it is very difficult to separate them by conventional distillation. The experiments show that the SC operation can be applied to purify p-cresol from the cresol isomer while it is rather difficult to purify m-cresol. In the purification of p-cresol by SC, the recovery rate increases with increasing operating pressure while the final purity of the product decreases with increasing operating pressure.
 L.D. Shiau, C.C. Wen, B.S. Lin, Ind. Eng. Chem. Res., 2005; 44, 2258-2265.
 L.D. Shiau, C.C. Wen, B.S. Lin, AIChE J., 2006; 52, 1962-1967.
 L.D. Shiau, C.C. Wen, B.S. Lin, AIChE J., 2008; 54, 337-342.
 L.D. Shiau, C.C. Yu, Sep. Purif. Technol., 2009; 66, 422-426.