PRESSURE-COMPENSATED TEMPERATURE CONTROL IN RECTIFICATION COLUMN

Abstract

The focus of this work is to study the control of a rectification column (RC) for separating n-butane (nC4) and n-pentane (nC5) mixtures. Two control structures based on conventional temperature control (TC) and pressure-compensated control (PTC) structures are studied and compared using Aspentech software. The control performance of TC and PTC are investigated in terms of the control of component purities in both distillate and bottoms streams, under various disturbances in feed and pressure conditions. Due to pressure compensation, PTC is superior to TC in terms of purity and impurity control under disturbances in feed and pressure conditions. Accordingly, simulation results, from the point of view of industrial operation, the pressure-compensated temperature control (PTC) scheme provides potential solutions for a bicomponent RC.