Feasibility of Reactive Distillation for Ternary Systems with Azeotropic Mixtures: Decomposition Reaction

Systematic research on feasibility analysis for reactive distillation for ternary azeotropic systems has been conducted by Guo et al. [Quo, Z.; Chin, J.; Lee, J. W.; Feasibility of continuous reactive distillation with azeotropic mixtures. Ind. Eng. Chem. Res. 2004, 43, 3758-3769]. The analytical method they used was tray-by-tray calculations with difference point. There are two feasibility criteria, which are positive reaction extent is required on all trays and products can be reached by distillation or reactive distillation. In this work, we find that the feasibility analysis of reactive distillation using this method can be augmented by admitting the reverse reaction which can be compensated for by excess positive reaction on other trays. Two concepts that can accelerate the feasibility analysis are also shown. The first one is that the analysis of VLE vectors at the equilibrium line and the tray-by-tray calculation method with difference point are equivalent for determining the feasibility. Furthermore, the pinch point in the tray-by-tray calculation under chemical equilibrium and infinite reflux ratio is equivalent to a reactive azeotrope. The number of possibly feasible cases is increased by 21 from 27 to 48 out of all 113 possible ternary configurations. Nine of the 21 new cases are feasible regardless of the value of the equilibrium constant, and twelve cases may be feasible if the equilibrium constant is high enough. The result compares well with reactive distillation column simulations.