Vapor recompression distillation is an energy integrated distillation configuration which works on the principle of a heat pump. The tight material and energy integration in such columns shows a potential for intricate dynamics. In this paper, a systematic modeling framework is developed which explicitly captures the discrepancies between different material and energy flows present in such columns. This feature is documented to lead to stiff dynamic equations and multiple time-scale dynamics. Through a nested application of singular perturbations, reduced order non-stiff models are derived which capture the dynamics in each time-scale. A hierarchical control strategy is then proposed exploiting this time-scale multiplicity. A case of propane-propylene separation is considered to illustrate these results and demonstrate the effectiveness of the proposed control strategy via a simulation case study.
Bibliographical noteFunding Information:
Partial financial support for this work by the National Science Foundation, Grant CBET-0756363 is gratefully acknowledged. We would also like to thank Dr. Michael Baldea for his comments and suggestions.
- Hierarchical control
- Model reduction
- Propanepropylene separation
- Vapor recompression distillation