MINES ParisTech CAS - Centre automatique et systèmes


22 janvier 2007, Salle V107, à l'Ecole des Mines, Paris
15h30 : Dr. Veit HAGENMEYER, WLE/ED - Automation Technology, BASF.
The control of industrial semibatch reactors is a challenging task, especially if multi-product plants are considered. For this task, advanced control strategies are employed at BASF Aktiengesellschaft for respective reactor geometries, i.e. from a certain size upwards. So-called ``flatness-based two-degrees-of-freedom-control structures'' lead to a significantly better temperature control, a higher reproducibility of the batches and a shorter dosing time. This augments the space-time yield of the plant. In the talk firstly two-degrees-of-freedom-control structures are briefly recalled in general. Then, the property of differential flatness is also recalled and we show how it facilitates the design of the feedforward part of the aforementioned control structures via system inversion. Thereafter the modelling of industrial-scale semi-batch reactors is addressed, especially the modelling of the cooling system is considered in light of the methods of finite differences and orthogonal collocation. Based on this, an Extended Kalman Filter for the estimation of the reaction heat and the overall heat transfer coefficient is presented. These two time-varying parameters are adaptively used in the flatness-based feedforward part of the two-degrees-of-freedom-control structure. The talk is concluded by a discussion of production results obtained with the presented control structure.