High purity separation for binary batch distillation: Optimal reflux policy and constant reflux policy

Batch distillation is an important operation in the small-scale of fine-chemicals. Since such processes often involve expensive materials, it is desirable to separate a product of high purity and in good yield. However, there are few reports on methods to determine theoretically the number of stages of batch distillation appropriate to achieve a specified separation, and the number is determined empirically. This study presents a method to determine the appropriate number of stages to achieve high purity separation and compare optimal reflux policy and constant reflux policy. Recently, small holdup regular packed columns are used in batch distillation, and adequate simulation is considered possible by assumption of no holdup. Here, a technical examination of batch distillation was performed using the McCabe-Thiele calculation method for a no-holdup model.