Static and Dynamic Intensification of Water–Ethylene Glycol Separation Using a Dividing Wall Column

This
paper makes several first-of-a-kind contributions toward “double
intensification” (static/dynamic) of distillation systems,
focusing in particular on the energy-intensive separation of a mixture
of water and ethylene glycols. First, we demonstrate that a dividing
wall column (DWC) can be an appropriate choice for separating wide-boiling
zeotropic mixtures. Additionally, we show that the conventional DWC
configuration where the wall is in the “middle” should
be discarded in favor of a less frequently encountered “common-bottom”
setup. For the mixture considered, choosing a DWC in lieu of a conventional
two-column sequence can lead to over 6% energy cost savings and a
5% reduction in the number of stages compared to the conventional
direct sequence two-column counterpart. The second part of this paper
focuses on applying the previously introduced concept of dynamic process
intensification to the DWC, the first time that such an effort is
reported in the literature, to our knowledge. We show that an additional
1.4% energy savings can be unlocked in this way, and confirm the stable
operation of the column via dynamic simulation.