Investigations into the Effects of the Cooling Rate on Stripping Crystallization

Abstract

This study investigates how the cooling rate affects the performance of stripping crystallization (SC) for purification of a p-xylene (PX)/o-xylene (OX) mixture to elucidate the rate process of three-phase equilibrium. A thermodynamic model is developed to simulate the three-phase equilibrium conditions during the batch SC operation. Experimental results indicate that SC can be used to purify both PX from the PX-rich mixture and OX from the OX-rich mixture. A slower cooling rate generally gives rise to a longer operating time, leading to a product with a higher purity and lower recovery ratio. We conclude that the three-phase equilibrium can be achieved quickly, even at a cooling rate of 0.50 °C/min. Importantly, the results of this study demonstrate that the proposed thermodynamic model can reliably determine the three-phase equilibrium conditions for the studied system.