Automatic Synthesis of Distillation Processes for the Separation of Heterogeneous Azeotropic Multi-component Mixtures

The separation of azeotropic mixtures is a complex task that is frequently addressed by means of graphical analysis of residue curve maps and trial-and-error flowsheet simulations. While miscibility gaps in heterogeneous mixtures result in considerably more complex phase behaviour, the possible exploitation of a combination of decantation and distillation bears the potential for efficient separation processes. In order to enable an automatic generation of alternative separation sequences with closed recycle loops the current article presents an extension of a previously developed algorithmic framework for process synthesis of homogeneous distillation processes. This extension includes the computation and characterization of heterogeneous azeotropes and the analysis of the topology of the system, as well as an extended split feasibility algorithm, which also accounts for decantation at different temperature levels. The approach is fully algorithmic and includes a shortcut-based computation of the energy demand of the generated flowsheet variants.