Feasibility of Reactive Distillation for Ternary Systems with Azeotropic Mixtures: The Role of Reverse Reaction

摘要

The reactive distillation offers significant economic advantages in some systems, especially when reactions are reversible and/or when azeotropes are presented. The feasibility analysis helps us to check whether a process is feasible or not [1-3]. It is crucial and important because there are fewer methods for shortcut designs and the iterative design is always time-consuming in reactive distillation column. We can save a lot of time for the design procedures of reactive distillation by getting rid of infeasible cases and focusing on the feasible ones. Systematical research on feasibility analysis of ternary azeotropic systems has been done by Guo et al [1]. The analysis method they used is tray-by-tray calculations with difference point. There are two feasibility criteria, which are positive reaction extent is required and products can be reached by distillation or reactive distillation. In this work, we find that the feasibility analysis of reactive distillation in the method of [1] can be augmented by admitting the reverse reaction which can be demanded by excess positive reaction. And we also find that the vectors at equilibrium line and tray-by-tray calculations method with difference point are equivalent in feasibility analysis. The number of feasible cases are increased from 27 to 48 in 113 all possible ternary configurations. Nine cases are feasible with low equilibrium constants, and twelve cases could be feasible with proper equilibrium constants. Those results are compared well with rigorous reactive distillation column simulations.