Impact of Mass Transfer on Modelling and Simulation of Reactive Distillation Columns

Abstract

1.1 Reactive distillation In chemical process industries, chemical reaction and purification of the desired products by distillation are usually carried out sequentially. In many cases, the performance of this classic chemical process structure can be significantly improved by an integration of reaction and distillation in a single multifunctional process unit. This integration concept is called ‘reactive distillation’ (RD); when heterogeneous catalysts are applied, the term ‘catalytic distillation’ is often used. As to the advantages of this integration, chemical equilibrium limitations can be overcome, higher selectivity achieved, by-product formation reduced, heat of the reaction can be used for distillation in-situ, hot spots and run-away effect can be avoided, and azeotropic or closely boiling mixtures can be separated more easily than in a non-RD process. Some of these advantages are realised using a reaction to improve the separation; others are realised using separation to improve the reaction (Sundmacher & Kienle, 2002). Technological advantages as well as financial benefit resulting from this integration are important. Simplification or elimination of the separation system can lead to significant capital savings, increased conversion and total efficiency, which then result in reduced operating costs (Taylor & Krishna, 2000).