Logic-Sequential Approach to the Synthesis of Complex Thermally Coupled Distillation Systems.

Abstract

Abstract In this work a methodology is presented for the rigorous optimization of complex thermally coupled distillation systems using a sequential logic-mathematical programming approach. In order to explicitly include in the search space the possibility of divided wall columns (that are thermodynamically equivalent to three fully thermally coupled separations tasks) we use an hybrid logical representation of the system that takes into account the separation tasks, the states (mixtures) produced by the tasks and the possibilities of tasks (states) aggregation to generate divided wall columns (DWC). Once the sequence of tasks, and the DWC that these tasks produces, is determined it is possible to synthesize the sequence of actual columns searching in the space of thermodynamically equivalent configurations. An example of a five component mixture illustrates the procedure.