Development of a start-up operation and dynamic behavior of a thermally coupled extractive distillation scheme

Abstract

The startup operation of distillation columns is one of the most complex steps performed in the industry. This complexity becomes even greater for thermally coupled extractive distillation systems. Thermally coupled confgurations are commonly used in order to minimize the excessive amount of energy required to perform distillation. In view of this, this study aimed to develop a startup procedure for the thermally coupled extractive distillation system to obtain anhydrous ethanol by simulation using the computational package Aspen Plus Dynamics. From the startup procedure developed, the complex dynamic behavior of the system under study was analyzed (strong interaction between variables). Large variations in the stripping section of the extractive column were observed, resulting from the variation of the molar density of the liquid mixture in addition to the delay in the startup operation when the amount of ethanol in the recovery column increases.