Plant-Wide Control of a Complete Ethyl Acetate Reactive Distillation Process

Abstract

By combining chemical reaction and multi-stage distillation in one column, a reactive distillation (RD) column can significantly save capital investment and make chemical conversion reach a much higher level. In a previous study, an optimal steady state design for the production of ethyl acetate (EtAc), consisting of two columns (one for RD and one for stripping column) and an overhead decanter, was reported. As a continuous study to that previous work, four alternative plant-wide control strategies for this designed process are studied in this paper. Feed compositions of both Acetic acid (HAc) and ethanol (EtOH) streams are treated as disturbances. These disturbances are used to test the closed-loop performance of each control scheme. It is found that control of the product qualities by modulating two tray temperatures in the RD column and one tray temperature in the stripper is most appropriate. By this control scheme, both of HAc and EtOH impurities in the product stream can be kept effectively within the acceptable product specifications.