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

• Published in: Industrial & engineering chemistry research Vol. 60; no. 7; pp. 3027 - 3037
• Main Authors: Yan, Lingqing, Witt, Paul M, Edgar, Thomas F, Baldea, Michael
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 24-02-2021; American Chemical Society (ACS)
• Subjects: Alcohols; Distillation; Energy; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Mixtures; Process Systems Engineering; Separation science
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.0c06139

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.