A Tale of Two Columns: Integrating Dynamic Simulation in Conceptual Design

Steady-state simulators in conjunction with standard column sizing methodologies have been used extensively in industry to design distillation columns. Steady-state simulators, when based on reliable underlying physical property data and models, are invaluable in identifying optimal designs and configurations for distillation. However, steady-state simulations do not consider the impact of hold-ups, operation in certain regimes e.g. vacuum, or commonly encountered perturbations such as feed conditions and utilities. Dynamic simulation has been used widely in industry as a tool to diagnose operability issues for operating plants and equipment and less commonly in earlier stages of process design.Dynamic simulation can also be used as an effective screening tool to identify potential control schemes. Two case studies involving new intensified designs for solvent recovery separations are presented, where dynamic simulation is used as a tool to evaluate operability in the conceptual design stage.