Purification of C9 Arenes by Stripping Crystallization

A new separation technique called stripping crystallization (SC) is applied for purification of a mesitylene/pseudoumene mixture. SC combines distillation and crystallization to produce pure crystals due to the three-phase equilibrium. The experiments demonstrate that a batch SC operation can purify pseudoumene from 85% to 95% for the pseudoumene-rich mixture with a recovery rate of 51% while it can only purify mesitylene from 85% to 88% for the mesitylene-rich mixture with a recovery rate of 34%. Compared to azeotropic distillation, SC is a clean separation technology as no chemicals are added. SC can be continued until the liquid phase is completely eliminated and only pure crystals remain in the feed. Compared to conventional crystallization, filtration or centrifugation is not needed to separate the solid crystals from the mother liquor since no mother liquor is present together with the crystals. In addition, crystal washing is not required since no impurities adhere to the crystal surfaces at the end of operation. Stripping crystallization (SC) is applied as a new separation technique for purification of a mesitylene/pseudoumene mixture. SC combines distillation and crystallization to produce pure crystals due to the three-phase equilibrium and can be continued until the liquid phase is completely eliminated and only pure crystals remain in the feed.