Two-Point Temperature Control Structure Selection for Dividing-Wall Distillation Columns

Two-point temperature control structures of dividing-wall columns (DWCs) were investigated to overcome difficulties arising from their complicated natures. The control performance of DWCs was assessed for nine different feed conditions characterized by the composition of an intermediate component and their relative volatility. Steady-state and dynamic simulations were performed to analyze the closed-loop responses for various two-point temperature control structures of DWCs. It is shown that proper control strategies depend strongly on feed characteristics, particularly on the relative volatilities of the feed components. Control structure evaluations follow from the rigorous simulations, and basic guidelines for selecting proper control structures for DWCs are proposed in relation to the feed conditions.