(177c) Process Intensification of Multicomponent Distillation Configurations Using Minimum Additional Number of Heat and Mass Integration Sections

We present a powerful and simple-to-use fact about heat and mass integration to consolidate distillation columns in a multicomponent distillation configuration. First, thermal couplings are introduced to all intermediate transfer streams in the distillation column. And then, distillation columns associated with a lighter final product reboiler and a heavier final product condenser are consolidated to produce a heat and mass integrated configuration. We call this novel set of configurations the HMP configurations.

Coupled with the already developed techniques¹ that enumerate all basic and thermally coupled distillation configurations, a systematic way of synthesizing all HMP configurations for n-component separations is introduced here. Also, we compare the energy savings of HMP configurations with the well-known fully thermally coupled (FTC) configuration using the state-of-the-art Global Minimization Algorithm (GMA)² developed based on Underwood equations. GMA provides a global optimization based rank-list of basic and thermally coupled configurations according to minimum total vapor duty requirement under minimum reflux conditions for separating any ideal or near-ideal multicomponent mixture. We demonstrate through case studies that HMP configurations can have very similar and sometimes even the same minimum total vapor duty requirement as the FTC configuration, while using far less number of column sections, intermediate transfer streams, and thermal couplings than the FTC configuration.

These findings not only intensify the search space of distillation configurations, but also provide industrial practitioners with insights in designing energy efficient distillation configurations that are easy to operate and control.