Operation and control of dividing wall distillation columns - Part 1: Degrees of freedom and dynamic simulation

The dividing wall distillation column has been known now for some 50 years. Despite its potential to make major savings in energy and capital costs in distillation, it has not been widely used in practice. One of the major fears in applying the technology is uncertainty regarding the control and operation of the arrangement. This paper investigates theoretically the operation and control of the dividing wall column. A degrees of freedom analysis was performed to determine the number of control loops required. Possible control configurations were then investigated using Relative Gain Array Analysis and dynamic simulation. The results of these theoretical studies indicate that simple control schemes are capable of providing stable control.