15th Triennial World Congress of the International Federation of Automatic Control
  Barcelona, 21–26 July 2002 
CONTROL STRUCTURE SELECTION FOR A REACTIVE DISTILLATION COLUMN
K. Dadhe*, S. Engell*, R. Gesthuisen*, S. Pegel*,
M. Völker*
* Process Control Laboratory, Department of Chemical
Engineering, University of Dortmund, D-44221 Dortmund,
Germany,
Tel: +49/231/755-5127, Fax: +49/231/755-5129

In recent years integrated processes have attracted considerable attention in both academic research and industrial applications. The integration, for instance of reaction and separation, reduces the degrees of freedom and requires tight control to operate the processes at optimal conditions. From the available number of measurements and input variables, a control structure has to be identified which guarantees the best performance. In this paper, we discuss the application of a systematic control structure selection consisting of pre-screening of structures and calculation of the attainable performance for the heterogenous catalyzed esterification of methyl acetate in a batch reactive distillation column. The approach is applied to a linearized model of 85th order of the nonlinear system. To verify the predictions of the control structure selection method, linear controllers are designed for the favorable structures by using a frequency response approximation method. The resulting linear controller is applied to the nonlinear model and shows good performance.
Keywords: Reactive distillation column, control structure selection, attainable performance computation, convex optimization, multiv ariable systems
Session slot T-We-M11: Process Modeling and Analysis Tools/Area code 7a : Chemical Process Control