Recent work by Lucia and coworkers has shown that the most energy efficient distillation process has the shortest stripping line (this being the length in composition space) of the composition trajectory for the stripping section of a column when measured from the bottoms composition to the pinch point). Lucia and coworkers have demonstrated several advantages of this approach to the determination of minimum energy distillation systems that include the facts that the approach can handle any number of compounds, non-ideal systems, chemical reactions, and mass transfer effects.

In this paper we show how the concept of the shortest stripping line can be applied to the determination of minimum energy design of complex distillation configurations. We place particular emphasis on the modeling of dividing wall columns (DWC). In addition, we demonstrate the influence of mass transfer on the minimum energy design of a DWC.