Modeling and Predictive Control of Pellet Reactors for Water Softening

A nonlinear chemical/physical dynamic model in the form of partial differential equations was adopted and further developed to serve as a basis for model predictive control of a pellet reactor for drinking water softening. The model was calibrated using full-scale process measurements. A linear predictive controller based on a lineralization of the model has been designed to achieve the desired hardness of the effluent water through cost-effective operation of the reactor. This controller has been extensively validated in nonlinear simulations. The results are promising and the strategy found by the predictive controller leads to a smoother operation compared to the currently used heuristic controller. Copyright c © 2005 IFAC