Efficient optimization-based design of energy-integrated azeotropic distillation processes

The separation of azeotropic mixtures is frequently performed by extractive or heteroazeotropic distillation processes. The design of these processes requires careful selection of a suitable solvent and is specifically challenging since feasibility and optimality of the processes require consideration of the closed loop design including solvent recovery. Consideration of energy integration further complicates the design task and is usually conducted as post-evaluation step. The current publication proposes an efficient optimization-based design approach, which allows for the direct evaluation of several energy-integrated process concepts, while significantly reducing manual effort and computational time through a polylithic modeling and solution approach. The developed approach allows for a simultaneous evaluation of solvent selection and energy integration and is illustrated for different case studies, including the evaluation extractive and heteroazeotropic distillation for the dehydration of ethanol, as well as the evaluation of multiple solvent candidates for the extractive distillation of acetone and methanol.