(539c) Recent Advances in Reactive Distillation

The integration of tasks in one unit has attracted considerable academic and industrial interest using synergistic effects of this integration as a potential means of process improvement. The most studied and applied operation in that field is Reactive Distillation (RD) comprising simultaneously chemical reaction and vapor (gas)-liquid phase separation in one column. RD has the ability to separate difficult separation mixtures in one column such as azeotropic or close boiling points mixtures as well as increasing the conversion of the reaction beyond its equilibrium and suppressing side-reactions through product removal into the non-reactive phase. This enables a number of potential process improvements such as lower capital and operational costs, a simplified flowsheet by replacing a series of separation steps, higher energy efficiency through usage of exothermic heat of reaction for evaporation, higher raw material efficiency, higher selectivity as well as improving safety due to usage of heat of reaction for evaporation.

Even though many applications are reported, design decisions have been made mostly case-based, so one may conclude that RD has not reached its full potential yet. Therefore, in order to support a wider implementation of RD in industry, a systematic framework for design/synthesis of reactive distillation systems is valuable.

This contribution presents recent industrial as well as academic research in application of reactive distillation and discusses the design decisions reported through application of a systematic design framework considering operational design and synthesis as well as potential selection of different (catalytic) column devices. First of all, a set of criteria/ rules is used in order to establish for which systems RD might be potentially advantageous. Next, a synthesis/ design framework is applied to generate alternative RD-designs from a superstructure; create models for each alternative; analyze/ evaluate the most promising alternatives to identify the best; and finally design experiments for verification of design.

The application of the model-based synthesis design framework will be illustrated through examples of industrial interest.