Design and optimization of combined pervaporation/distillation processes for the production of MTBE

The purification of product streams in the production of MTBE requires complex processes due to the thermodynamic behaviour of the mixtures (i.e. formation of azeotropes). Combined processes consisting of distillation and pervaporation/vapour permeation might offer economically attractive alternatives as they can simplify the process structure, reduce the energy consumption and avoid entrainers. The paper presents possible process configurations and design strategies for an integration of pervaporation and vapour permeation into the Huels process. For all process calculations, the commercial simulation software ASPEN PLUS was used in combination with a compatible FORTRAN routine allowing the design and simulation of complete pervaporation units in ASPEN PLUS.