Demonstration and experimental model validation of the DME synthesis by reactive distillation in a pilot-scale pressure column

Abstract

The dehydration of methanol to produce the hydrogen carrier and alternative fuel dimethyl ether (DME) is an equilibrium limited reaction, resulting in a relatively complex and expensive production process. A promising method for process intensification is reactive distillation (RD), as this allows the synthesis and purification of DME in a single unit operation. However, existing kinetic models for liquid phase DME synthesis have never been validated in an industrially relevant reactive distillation environment, preventing a detailed model-based design of industrial-scale applications. In this work, a pilot-scale pressure distillation column was used to successfully demonstrate the feasibility of the process involving pure and crude MeOH feed using the catalyst Amberlyst 36. Based on the measured composition and temperature profiles, a kinetic model could successfully be validated for the RD system. A process simulation model was developed in Aspen Plus to analyze an industrial-scale process and validated on the pilot scale. Hereby the influences of column size, methanol feed purity and catalyst selection were examined in detail.