Purification of Styrene from a Styrene/Ethylbenzene Mixture by Stripping Crystallization

Abstract

Stripping crystallization (SC) was used to purify styrene (ST) from a liquid mixture of ST and ethylbenzene (EB). This new separation technology combines vaporization and crystallization to yield a crystalline product and a vaporous mixture from a liquid feed via three-phase equilibrium transformations. The three-phase equilibrium conditions for a liquid mixture determined by the thermodynamic calculations were adopted to direct the SC experiments. A unique apparatus was designed for SC experiments at low temperatures and pressures for a series of three-phase equilibrium conditions (from −33 °C and 9.0 Pa to −80 °C and 0.03 Pa). The experiments indicate that SC can be applied to the purification of ST from a liquid mixture of ST and EB with an initial ST concentration of 0.80–0.95.