Extension of the Equilibrium Stage Model to Include Rigorous Liquid Holdup Calculations for Reactive Distillation

Abstract

An extension of the equilibrium stage model to improve its applicability to reactive distillation is presented. The significant aeration of the liquid holdup on trays leads to the amount of clear liquid present being significantly less than the volume available. Tray hydraulic correlations are incorporated by leveraging the existing inside-out algorithm to rigorously calculate the liquid holdup on distillation trays, turning this parameter into an additional model output and eliminating the need to estimate this parameter beforehand. Application of this extended model shows that the aeration of the liquid holdup cannot be neglected for systems where the reaction kinetics limit the reactive productivity, and leads to column designs where additional reactive trays are needed to provide adequate reactive capacity. The workflow of this model provides a more robust path to obtaining reactive distillation column and tray designs that comply with liquid holdup requirements and tray hydraulic limitations.