No abstract

Extractive distillation (ED) can be combined with divided wall column (DWC) schemes to separate azeotropic mixtures within one column shell. Traditional extractive divided wall columns (EDWCs) have the dividing wall placed at the top of the column, eliminating the common rectifying section. This review covers the design schemes, entrainer selection process, simulation design methods, and control schemes for EDWCs. There is an emphasis on the 33 azeotropic systems that have been separated using EDWCs. Successful case studies and ongoing research challenges are highlighted in the review. As with switching from conventional distillation schemes to a DWC, the motivation to use EDWCs over ED is economic savings and environmental benefits.

As a preliminary step in the development of a reactive dividing wall distillation process, a reactive distillation experimental and modeling effort was conducted. A novel aldol condensation process was chosen to demonstrate many of the complex behaviors associated with industrial chemical systems. The first portion of the experimental program was focused on determining the phase equilibria and reaction kinetics of the chemical system. Next, a laboratory scale reactive distillation column (RDC) was built and tested. Finally, a steady-state model of the RDC was developed. Through these accomplishments, this work provided a roadmap to use the tools of laboratory scale experimentation and modeling to evaluate the commercial potential of a reactive dividing wall column process.