NONLINEAR MODEL-BASED MULTIVARIABLE CONTROL OF A DEBUTANIZER

The debutanizer column control is a major economic incentive to a refi nery due to the importance of the product quality. The nonlinear model -based multivariable control on a debutanizer has shown to provide imp roved control performance of the top product and the bottom stream qua lities using a steady-state process model with approximate dynamics. T he control performance is much better than that achieved by the tradit ional PID-type control system. This paper outlines the non-linear cont rol method applied to an industrial debutanizer and discusses the use of inferential models to predict the iso-pentane contents in the overh ead stream and the Reid vapour pressure (RVP) in the bottom stream, in nonlinear control applications. (C) 1998 Elsevier Science Ltd. All ri ghts reserved.