We and others (Hasebe et al., 1992; Meski et;al., 1993; Davidyan et al., 1994) have previously developed insights into batch distillation when using a "middle vessel" batch column. We extended earlier work on reachable product regions for continuous columns to this and other batch column configurations. Our work also examined the use of a continuously flowing extractive agent to facilitate the separation of azeotropic mixtures. A middle vessel batch column has both an enriching and stripping section and thus both a distillate and bottoms product. In many ways it is just like a traditional continuous column, but we feed it by charging st middle tray having a very large holdup (a pot or still) with the initial feed. Our work compared running this column with running a batch rectifier for an azeotropic mixture when using an extractive agent. We showed that both are often able in theory to recover all of the distillate component in relatively pure form, with the middle vessel accomplishing this by "steering" the still pot composition against time through the choice of reflux, reboil, entrainer, and product rates. The middle vessel also requires a much smaller pot, as we can continually remove and recycle the extractive agent. In this work we show the sensitivity of the separation’s profit to the entrainer now rate, the operation’s switching times between fractions, and the bottom flow rate policy for an extractive middle vessel batch column. We illustrate with an example problem.