Optimal Operation of Vapor-recompressed Batch Distillation Column under Total Reflux

Abstract

This article addresses optimal operation of a vapor recompressed batch distillation (VRBD) column under total reflux. This system allows us to obtain high purity top and bottom products simultaneously, which is usually not possible in a VRBD system with product removal. In this paper, we propose a novel approach wherein trajectory optimization is combined with model-based control to achieve optimal operation. Specifically, key performance indices are defined to characterize operation and assess the trade-off between production and energy efficiency. Subsequently, one of these indices is maximized, in closed-loop, using a model predictive controller. The effectiveness and robustness of this approach is demonstrated using a simulation case study of benzene/toluene separation.