Title: Chemical process sliding mode control

Authors: Malik Sekher, Mohammed M'Saad, Mondher Farza, O. Gehan

Addresses: Control Group of GREYC, UMR 6072 CNRS, ENSICAEN, 6 Boulevard Marechal Juin, Caen Cedex 14050, France. ' Control Group of GREYC, UMR 6072 CNRS, ENSICAEN, 6 Boulevard Marechal Juin, Caen Cedex 14050, France. ' Control Group of GREYC, UMR 6072 CNRS, ENSICAEN, 6 Boulevard Marechal Juin, Caen Cedex 14050, France. ' Control Group of GREYC, UMR 6072 CNRS, ENSICAEN, 6 Boulevard Marechal Juin, Caen Cedex 14050, France

Abstract: The temperature control involved in chemical reactors has proved to be of fundamental importance from product quality and cost points of view. This paper presents a likely sliding mode control approach to deal with the temperature servo problem in exothermic stirred tank batch reactors. Two design features are worth to be emphasised. Firstly, an engineering control design framework is developed in the sliding mode control spirit. This involves a design function satisfying an adequate reachability condition and allows to incorporate a filtered integral action into the design for free offset performance considerations. Secondly, a high gain observer providing an accurate estimation of the reaction heat is used to improve the control performances while monitoring the chemical reactor operation. The control as well as the monitoring features of the proposed approach are illustrated in a realistic simulation framework involving an exothermic stirred tank reactor.

Keywords: process control; chemical reactor; sliding mode control; state feedback control; high gain observer; integral action; temperature control; exothermic stirred tank reactors; batch reactors; chemical industry; simulation.

DOI: 10.1504/IJMIC.2008.023510

International Journal of Modelling, Identification and Control, 2008 Vol.5 No.4, pp.260 - 267

Published online: 25 Feb 2009 *

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