Design of hybrid separation processes incorporating membrane technologies

Abstract

This doctoral thesis work is aimed to design new separation processes that result from the integration of conventional operations (such as distillation) with other membrane separation operations (such as pervaporation) leading to new hybrid processes that allow the separation of complex mixtures (such as azeotropic mixtures) to achieve energy savings compared to conventional processes with the consequent economic profit. In order to achieve the proposed objectives, the ETBE production process has been adopted as a case study, which is of great industrial importance and where energy costs have a great impact on the final product price. Based on previous studies by the PAS research group, experimental information on the separation process of ethanol/ETBE mixtures was used to develop a new mathematical model that reliably describes the pervaporation process using commercial membranes according to the operating conditions. In the next stage this model together with the material and energy balance equations were used to develop a user model in the Aspen Custom Modeler simulator. After validation, this model was exported to the Aspen Plus environment, in order to be able to implement in this simulation environment the different flowsheets that describe the alternative hybrid processes that have been proposed.