Aspectos estacionário e dinâmico de uma destilação azeotrópica não convencional.

Abstract

The occurrence of azeotropic mixtures in the industry of chemical processes is relatively common and a widely used method for separation of these is the azeotropic destination. This work presents the study for an azeotropic destination column of a vinyl chloride monomer industrial unit. The column of destination in question is labelled as nonconventional because it does not use an external component as separation agent and it does not form azeotrope, but presents an azeotropic behavior in the distillation process. In consulted literature no system with this characteristic was found. The primordial purpose of this column is the dehydration of a stream consisting of chlorinated organic. The aim of this work was to generate a dynamic model of this column, with intention to base the project of a new control system. The results obtained through the simulation (Aspen Plus™ and Aspen Dynamics™) have been validated against data of the plant. The dynamic results have shown that the column presents a long transient period, even for small disturbances. Beyond this fact, the control of the column is difficulted by the inversion in the behavior of some variables. In terms of product quality, the top product flow rate withdrawal showed to be a more appropriate control variable than reflux rate.