A comparison of the equilibrium and nonequilibrium models for a multicomponent reactive distillation column

Abstract Apropriate models and computational algorithms were developed and a series of simulations for a reactive distillation tray column were performed in order to compare the equilibrium and nonequilibrium model. The homogeneous liquid phase reversible reaction between acetic acid and ethanol in production of ethyl acetate was employed as a test chemical reaction. Both the Newton–Raphson and homotopy-continuation methods were applied to solve the set of model equations. The homotopy-continuation method was found superior to the Newton–Raphson method in guaranteeing the desired solution for the nonequilibrium model. The comparison between the equilibrium and the nonequilibrium model reveals that the nonequilibrium model is to be preferred for the simulation of a tray column for reactive distillation because of the difficulty in the accurate prediction of tray efficiency for the equilibrium model. Close agreement in the prediction of the two models arises only when the tray efficiency can be correctly guessed for the equilibrium model. The effects of reaction rate and reflux ratio on the column performance were illustrated using the nonequilibrium model. The use of the heat generated by the exothermic reaction as an internal heat source in the column is discussed.