Controllability analysis of thermally coupled distillation sequences for five—Component mixtures

Abstract

The control properties of thermally coupled distillation sequences for the separation of five -component mixtures of hydrocarbons were compared to those of conventional distillation sequences. Seven thermally coupled arrangements were investigated. The preliminary steady -state designs of complex schemes were obtained by starting from conventional distillation sequences and then optimizing for minimum energy consumption. The control properties of the sequences considered were obtained by using the singular value decomposition technique at zero frequency and analyzing rigorous dynamic simulations. It was found that, in general, the coupled schemes present theoretical control properties similar or better than those of conventional distillation sequences. This result establishes that the energy savings predicted for thermally coupled distillation sequences can be achieved in practice.