COMPOSITION CONTROL OF DISTILLATION COLUMNS: A VARIETY OF OBJECTIVES AND STRATEGIES

摘要

Many of the difficulties of closed-loop analyzer control of distillation columns relate to large process gain variations, long lags, and poor basic control loops. Further questions relate to the value of steadier composition and the determination of the proper composition setpoint. This tutorial paper describes a variety of process and business objectives for distillation composition control. Ways to achieve them are recommended with computer regulatory control and steady-state optimization of material and energy balances. Criteria for the relative importance of these two methods reveal situations where tight regulation is not needed.