A general simulation model and a heating/cooling strategy to improve controllability of batch reactors

This paper describes the development of a dynamic simulation model for stir red tank batch or semi-batch chemical reactor and its heating/cooling syste m. Heat and mass balances are established for the reactor and its jacket. A s the general purpose is the thermal control of the reactor, special attent ion is devoted to the behaviour of the heating/cool-cooling system. The con trol strategy is based on the use of the thermal flux as manipulated variab le. At each sampling time, the controller computes the thermal flux to be e xchanged with the fluid flowing inside the jacket to get the desired reacto r temperature set-point. This information is then used to select the therma l fluid on the basis of the maximal and minimal thermal flux capacities of each utility. The computer simulation program is flexible, enabling simulat ion of a batch or semi-batch reactor vessel, ranging from a laboratory pilo t plant to full-scale production plant. To demonstrate the good performance of both simulation model and control methodology, experimental results are presented for a pilot plant and simulation studies have been performed for both pilot plant and industrial reactors.