No 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.

A new separation technique, called stripping crystallization (SC), is applied here in the purification of the cresol isomer. Basically, SC combines distillation and crystallization to produce pure crystals because of the three-phase equilibrium. The experiments show that the SC operation can be applied to purify p-cresol from the cresol isomer whereas it is rather difficult to purify m-cresol. In the purification of p-cresol using SC, the recovery rate increases with increasing operating pressure whereas the final purity of the product decreases with increasing operating pressure.

No abstract

No abstract