Abstract
The sustainability of distillation operations could be maximized by implementation of four-product dividing wall columns (DWC), where appropriate, but this is hampered by the lack of related know-how and concerns about the controllability of a demanding separation process occurring within a complex internal configuration including up to three liquid and three vapor splits. Due to its unique design featuring two separate overhead condensers, the so-called 2-3-3 DWC configuration offers extra degrees of freedom compared to other feasible configurations of a four-product DWC, which, in theory, gives a possibility of manipulating directly one of the vapor splits. Present study is concerned with dynamic properties of a 2-3-3 DWC, and was carried out using established modelling methods and mathematical tools for the control system synthesis, but at the same time taking practical limitations and feasibility into consideration. Therefore, a realistic multicomponent feed composition was used, as well as simple, established means of control. Closed-loop performance was evaluated using a series of controlled disturbances. Although the operation could be successfully stabilized, using simple temperature control without active vapor split manipulation could prove insufficient in maintaining the desired product composition in certain scenarios.