I.J. Halvorsen, M. Serra and S. Skogestad, `` Evaluation of Self-Optimizing Control Structures for an Integrated Petlyuk Distillation Column'', Proc. Symposium PRES'99, 30 May-2 June 1999, Budapest, Hungary.

Abstract.
In a Petlyuk distillation column, two extra degrees of freedom can be used for optimisation purposes. It has been reported that a typical energy saving of 30% is achievable with a Petlyuk distillation column, compared to conventional distillation arrangements. However, the optimal steady-state operation point can be difficult to maintain in practice. In this work we have studied the performance of some self-optimising control configurations for the Petlyuk distillation column in presence of disturbances and uncertainties. The results show that self-optimising control can be used to improve the robustness of optimal operation by adjusting a degree of freedom in a feedback control loop by keeping a suitable measurement variable at a setpoint.