A Five Stage Extraction Cascade with Backmixing and Control

PID control of a five stage extraction column with backmixing using Simulink.

PID control over the exit raffinate composition (x5) of a five stages column is obtained by changing solvent flow rate (G). The set point is equal to 0.1. The model equations include backmixing effects. This problem is solved using Berkeley-Madonna in Chemical Engineering Dynamics, Ingham et al., Wiley-VCH, 2000. The program ExtractionCascade.m runs the simulink file ExtCont.mdl and plots the composition versus time of the five stages as well as the solvent flow rate versus time.