Operation and control of dividing wall distillation columns - Part 2: Simulation and pilot plant studies using temperature control

This paper follows on from preliminary work to investigate the theoretical aspects of control of dividing wall columns in Part I of this paper. Two different control arrangements have been investigated using temperature control. Dynamic simulation was first used to test the control configurations. These were then investigated in a large-scale pilot plant. The simulation and pilot plant runs show the same basic trends from the control arrangements. In all cases, the control arrangements investigated proved to give a stable response to fluctuations in the feed to the column. Temperature control resulted in an off-set in one of the product purities. This was demonstrated in both simulation and practical runs. A procedure has been suggested to overcome this off-set by over-refluxing the column. The procedure allows the column to be designed for minimum over-refluxing.