Self-Tuning Control Applied to an Industrial Distillation Column

Abstract

The control of industrial distillation columns usually involves the implementation of dead-time compensation techniques. These compensators make use of a model of the process to eliminate the effects of the dead-time inherent in the process. Under most conditions, the implementation of such techniques brings about a noticeable improvement in the overall performance of the closed loop system. However, distillation columns are subject to changes in feed compositions, feed flow rates and various disturbances and, as a result, are forced to run under variety of operating conditions. Hence, the process characteristics change and the dead-time compensator which employs a fixed parameter model can no longer cope and a degradation in control performance is usually experienced. Therefore, the opportunity exists for employing self-tuning control strategy to ensure tight control under all operating conditions.