Batch Distillation in a Batch Stripper with a Side Withdrawal for Purification of Heat-Unstable Compounds

Batch distillation in a batch stripper with a side withdrawal (BSS) for the purification of heat-unstable compounds from light and heavy impurities was investigated. The batch distillation process was simulated by a dimensionless dynamic model and optimized by simulated annealing algorithm. Batch distillation in a BSS was compared with that in a batch stripper (BS) for the purification of heat-unstable compounds with different types of degradation reactions. The recovery of heat-unstable compounds in a BSS is larger than that in a BS, especially in the case of the heat-unstable compound converting to a heavy impurity. Compared with batch distillation in a batch rectifier with a side withdrawal (BRS), batch distillation in a BSS is more suitable for purification of heat-unstable compounds that convert to a light impurity. The effects of operational and design parameters for batch distillation in a BSS were discussed according to the simulation results, such as the temperature in the top storage vessel, the location of the side withdrawal stage, the holdup in the reboiler, the reboiler ratio, and the side reflux ratio.