Design/optimization of ternary heterogeneous azeotropic distillation sequences

Various strategies for sequencing heterogeneous azeotropic distillations have been explored. The design and optimization of these systems by simulation-based methods is generally acknowledged to be a very difficult problem (Kingsley and Lucia, 1988). In this article, a simple and accurate design and optimization procedure has been developed. The method does not involve any recycle convergence loops and has been applied successfully to several test problems. Unlike the simulation-based methods, our method is robust to changes in the system optimization variables (e.g., reflux ratio in the azeotropic column). In order to demonstrate the method, we present design and optimization results for the dehydration of ethanol using a benzene entrainer. Our optimal designs consume significantly less energy than state-of-the-art designs reported in the literature.