No abstract

Cyclic distillation is a novel process intensification of distillation with higher separation efficiency. However, its efficient simulation and rigorous optimization have been challenging because a coupled boundary value problem must be solved. This study proposes a novel simulation and optimization approach for cyclic distillation based on the pseudo-transient modeling-assisted discretization method. This method involves discretizing the original dynamic model as an algebraic equation system and then reformulating it as a pseudo-transient model to address the convergence difficulty. Optimization of cyclic distillation was achieved for the first time using a gradient-based optimization method while considering tray hydraulics. The proposed method is shown by illustrating examples more efficiently than conventional methods. Optimization results indicate that the process cost is negatively correlated with the vapor flow period duration, one of the decision variables; however, the process cost could not further reduce at the optimal point due to activation of the weeping constraint provided by the hydraulic model.