Separation of ternary heteroazeotropic mixtures in a closed multivessel batch distillation–decanter hybrid

The feasibility of a novel multivessel batch distillation–decanter hybrid for simultaneous separation of ternary heterogeneous azeotropic mixtures is addressed both theoretically and by simulations. The multivessel column is operated as a closed system without product withdrawal and the three components are accumulated in the vessels during one closed operation. The closed mode (total reflux) operation of the column enables us to make direct use of the distillation line (or residue curve) map. Simple rules for predicting the products in the vessels and identifying feasible separation regions are developed and applied on three common classes of azeotropic mixtures. This theoretical distillation line map analysis shows that Serafimov’s classes 1.0-2, 1.0-1a and 2.0-2b can be separated in the proposed process. Dynamic simulations verify the feasibility of the novel process in separating heterogeneous azeotropic mixtures of these three topological classes.