Control Strategy with Distributed Action for Minimization of Transients in Distillation Column

Abstract Distillation columns require well adjusted control systems to quickly reject disturbances. To assist this purpose, a new distributed control strategy using electrical resistances on intermediate plates of a distillation column was proposed. Usually the control of distillation columns is accomplished centralized at the bottom and at the top. In the present work the effect of the distributed control is evaluated, through the addition of thermal energy using an electric resistance located at an intermediate plate, when a disturbance is applied in the composition of the feeding stream. In order to validate the proposed strategy, a pilot distillation unit composed of 13 trays was used, processing an ethanol-water mixture with a feed flow rate of 300 L/h. The objective of this paper is a reduction in the operation transients. In addition, a thermal balance was used to verify if distribution of thermal energy occurs between the bottom of column and the plate where the distributed control is applied. The results showed that the introduction of the distributed heating along the column allows faster dynamics, representing a valid option for the reduction of transients.

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