Dividing wall distillation columns for separation of azeotropic mixtures: feasibility procedure and rigorous optimization

Abstract In this work, we propose the use of dividing wall distillation columns, DWC, to separate azeotropic mixtures. First, we present a procedure to guarantee the feasibility of the desired split, based on material balances. Once the feasibility is verified, a preliminary design is calculated considering the DWC as an arrangement of three disengaged conventional distillation columns. Then, this design is the initial solution of the optimization procedure: a multiobjective genetic algorithm with constraints coupled to Aspen Plus [1]. This algorithm is used to find optimal designs of DWC for two azeotropic mixtures of industrial importance, with just one distillation border at the operating pressure. Results show that use the DWC for separation of azeotropic mixtures is feasible, and important energy savings, until 50%, can be obtained in comparison with conventional sequences. In addition, tendencies in the location of interconnection, side and feed streams were founded. In general, results provide information that can be used for developing a short design method for these schemes.