APPLICATION OF PREDICTIVE CONTROL TO A BATCH REACTOR

The REPSOL company had in mind the improvement of the control on one of their chemical reactors. A feasibility study for the implementation of an Advanced Control technique (Predictive Control for temperature control for chemical Reactors PCR) for a batch reactor for Polyols production has been performed. The proposed technique PCR is based on a dynamic model of the unit which makes the prediction of the process variables behaviour. That behaviour is specified in terms of closed loop time response through a desired future trajectory. The control system shows a substantial improvement in the reactor temperature controllability and a notorious elimination of the competition between the cooling and heating actuators. The improvement is partially explained by the distinction made by the model and the control modules between the heating and the cooling dynamic effects which are usually quite different. Among the origins of the benefits obtained by such a model based predictive control, energy savings come from a smaller consumption of utilities, a higher availability of the unit comes from less activated valves are non negligible aspects. But the better handling of the temperature profile provides more significant improvements on quality stability and on batch duration. ERTC Computing 2003, Milan, Italy Page 2 Repsol / Soteica / Adersa Application of Predictive Control to A Batch Reactor