A semicontinuous approach for heterogeneous azeotropic distillation processes

•A semicontinuous design of heterogeneous azeotropic distillation system is proposed.•MATLAB simulation interfaced with Aspen Hysys on acetic acid dehydration process.•Sensitivity analyses and process optimization carried out on design variables.•Comparisons with heterogeneous azeotropic distillation and dividing wall column.•Results show that the proposed process is better than the above two. The separation of azeotropes has substantial energy and investment costs, and the available methods require high capital costs for reconstruction of process plants. As an alternative, a semicontinuous configuration that utilizes an existing plant with minor modifications has been explored. In this paper, a semicontinuous, heterogeneous azeotropic distillation process is proposed and acetic acid dehydration process is used as a case study. To carry out the simulation work, Aspen HYSYS® simulation software is used along with MATLAB® and an interface program to handle the mode-transition of the semicontinuous process. Sensitivity analyses on operating parameters are performed to identify the process limits. Comparisons are made to conventional heterogeneous azeotropic distillation, and dividing-wall distillation column on the annual cost. The results proved that the semicontinuous system is the best setup in terms of total annual costs and energy requirements.