Synthesis of hybrid membrane distillation processes with optimal structures for ethanol dehydration

Conventional distillation is the most used unit operation to separate zeotropic mixtures. However, it is combined other unit operations to separate azeotropic mixtures. This work proposes a synthesis and intensification framework to obtain hybrid membrane distillation process structures. The synthesis problem was represented by a low aggregation superstructure comprised of functional modules. Then, the superstructure was reformulated as a Mixed Integer Linear Programming (MILP) problem to derive the optimal structure. The synthesis problem does not consider any pre-established process structure or connectivity; therefore, the optimal solution must be interpreted, simulated, and validated to generate a known process structure. Finally, the validated structure was post-optimized to fine-tune the detailed design of the process structure. The presented framework was applied to separating an ethanol/water mixture. The obtained solutions attained high energy and cost savings compared to the typical pressure swing and extractive distillation.