Flatness-based two-degree-of-freedom control of industrial semi-batch reactors using a new observation model for an extended Kalman filter approach

A flatness-based two-degree-of-freedom control is applied to industrial semi-batch reactors. Thereby a new observation model for an extended Kalman filter approach based on the results of Graichen et al. (2006) is used in order to estimate the reaction heat and the overall heat transfer coefficient. The flatness-based advanced process control scheme makes use of a calorimetric model of the reactor in order to calculate the nominal non-linear feedforward; the feedback part consists of a linear PID control. Results from production are presented including the heat up phase of the process. The performance and effectiveness of the applied flatness-based two-degree-of-freedom control are shown: a significant reduction of the batch time is achieved.