Short-cut method for the design of reactive distillation columns

The design of reactive distillation (RD) has received significant attention because of the technological and economic advantages obtained from the simultaneous occurrence of reaction and separation. Although the advantages of RD are well-documented in the literature, the commercial applications of RD are still limited because of the control and operation complexity of these separation systems and the need for improved software tools to reliably model and design RD columns. In this study, a robust short-cut method for the design of multicomponent reactive distillation is presented. This method is based on distillation lines and tray-by-tray calculations defined in terms of reaction-invariant composition variables. Our method provides the number of theoretical stages, the operating reflux ratio, the feed tray location, and the top or bottom flow. We use three case studies to demonstrate the effectiveness of the proposed strategy, namely, the reactive systems for the syntheses of ETBE and MTBE in the presence of inert components and of TAME without inert components. The results obtained with our strategy show good agreement with those obtained using the rigorous model of the commercial simulator AspenONE Aspen Plus.