DYNAMIC SIMULATION OF AN EXTRACTIVE DISTILLATION COLUMN

Abstract

A mathematical model, based on heat transfer, mass transfer and fluid dynamics principles, has been developed to represent the dynamics of an extractive distillation column. The column simulation subroutine was incorporated into the recent dynamic System Simulator executive package (DYNSYS 2.1), created at McMaster University, which uses Rear's method of integration. Simulation runs were performed with step and pulse disturbances in the feed composition, feed flowrate and reflux ratio variables. Calculated results were compared with available experimental data obtained from a laboratory-scale (2 inch diameter), fifteen-stage extractive distillation column which used distilled water as the solvent to separate a binary mixture of acetone-methanol. Fairly good consistency was found within the normal operating conditions of the column. A preliminary simulation study of the dynamics of the column (overhead composition transient behaviour) subject to controlled-cycling of the feed flowrate showed a substantial improvement in the separation efficiency of the column