Model predictive control of integrated unit operations: Control of a divided wall column

The integration of several unit operations into one common apparatus (process intensification) has the potential to substantially improve the economics of chemical processes if applied to adequate problems. On the other hand, the integration typically causes strong interactions of different process quantities and a loss in degrees of freedom. This may require a more elaborate automatic control scheme. In this study, the control of a divided wall column has been investigated in comparison to the control with a single loop PI controller concept. Although the PI controller concept can be implemented successfully, the model predictive controller shows a considerably improved control behaviour in respect to maximum deviations of the controlled variables and the time to reach steady state.