Robust Model Based Control of Dividing Wall Column

In this paper, a robust model based control has been studied for BTX (Benzene-Toluene-Xylene) separation system in a dividing wall column. Compositions of the three products are indirectly controlled by regulating the corresponding temperatures by manipulating reflux rate, side-stream flow rate, and reboiler heat duty. It has been observed that the model based control shows good performance even in the presence of +/- 10% change in the feed flow rate, feed composition, and liquid split factor in comparison to conventional controllers. This controller has less settling time (almost 1.5 hrs) as compared to PI controller (approximately 3-4 hrs).