Dynamic and Steady State Behaviour of an Extractive Distillation Column

Abstract

<p>This project was the second part of a long-term study into the control of an extractive distillation unit. A fifteen stage extractive distillation column was re-built and operated over a range of operating levels. Overhead product acetone composition was limited to approximately 0.94 mole fraction acetone due to tray liquid priming. A steady state simulation was developed to aid in a better understanding of the process. Murphree vapour tray efficiencies were adjusted within the simulation to match experimental and simulated product composition results. The simulation was used to accurately predict unfitted experimental results. Dynamic behaviour of the column was studied by relating product composition responses to changes in disturbance and manipulated variables. Dynamic behaviour was analysed by frequency response and real time response fitting. Experimental data was relatively noisy. First order transfer function models with dead time, fitted in the real time domain, were satisfactory.</p>