EFFECT OF KINETICS ON RESIDUE CURVE MAPS FOR REACTIVE DISTILLATION

A class of models is derived for studying the effects of chemical kine tics on residue curve maps for reactive distillation. Activity-based r ate and phase equilibrium expressions provide an accurate and thermody namically consistent description of composition changes in nonideal, r eacting vapor-liquid mixtures. For certain strategies of operation, wh ich dictate the rate of product removal, the model equations are nonau tonomous, leading to unusual dynamic behavior. However, for a certain special product removal policy, the effects of kinetics can be describ ed by a single parameter, the Damkohler number, which measures the rat e of reaction relative to product removal. For small values of the Dam kohler number, the nonreactive simple distillation residue curve map i s recovered and the singular points are the pure components and azeotr opes in the nonreactive mixture. A bifurcation analysis shows the defo rmation and, in some cases, the disappearance of these singular points as the Damkohler number is increased until the equilibrium reactive r esidue curve map is recovered at large values. This bifurcation analys is reveals the limitations of the equilibrium analysis. A model proble m for the reactive distillation of methyl tert-butyl ether from isobut ene and methanol is solved.