Influence of the Location of the Internal Temperature Control Loop on the Performance of the Dual Temperature Control for Feed Temperature Disturbance

Abstract

A control strategy with distributed corrective action for distillation has been proposed and consists of a conventional dual temperature control combined with an additional column tray. In this work, we evaluated the influence of the location of this internal loop as part of the new proposal, compared to a conventional system. Tests were carried out in a 13-column tray distillation equipment and feed temperature was disturbed. Two different column trays from the stripping section were used (11 and 12) for internal decentralized temperature control, each one separately, plus the dual control of top and bottom temperatures. The results demonstrated that this proposed control approach with distributed corrective action is faster than the conventional one, regardless of the column tray in use. It was also determined that the internal loop close to the feed (disturbance) is more interesting as a way to minimize transients.

Dynamic Control of Sensor and Actuator failures in Multivariable Distillation Column

“…In a typical distillation operation, set points are fixed and control tasks are therefore associated with disturbances rejection functions to deal with external disturbances and interactions introduced due to actions of other control loops. Various different strategies have been developed and reported in the literature [4][5][6][7]. While these techniques offer solutions for dealing with small disturbances, larger process upsets resulting from failures of instruments, and other auxiliary equipment are often difficult to handle.…”