(431b) Process Intensification and Distillation: How to Control a Fixed Design Dividing Wall Distillation Column

An example of one of the emerging technologies in the field of process intensification is dividing wall distillation columns or DWCs. As part of an ongoing experimental study of dividing wall columns at The University of Texas at Austin, the design and selection of control strategies for a fixed design DWC will be presented. A dynamic process simulator was used to test various feed compositions on a dividing wall column to understand the operational flexibility of a fixed design DWC. A fourth trace component was added to the feed and the selection of and changes in manipulated variables necessary to move the trace component between product tanks was investigated. Conventional distillation temperature control techniques were tested on the dividing wall column as well as more advanced control strategies, such as model predictive control, thought to be better suited to capture the inherent interactions of the system caused by the intensified nature of the process. The ability of these control systems to handle setpoint changes and feed disturbances was compared. To verify the results from the simulation, the control systems were implemented on a pilot scale dividing wall distillation column from which dynamic responses were obtained.