Energy consumption in pervaporation, conventional and hybrid processes to separate toluene and i-octane

Chemical industries need to employ new process designs due to environmental policies and energy optimization because of the global energy challenge. Pervaporation has been introduced as a promising alternative for conventional processes such as distillation, known as energy intensive process, in chemical plants. In this work, the energy consumption of different processes for separation of toluene and i-octane (representatives of aromatics and aliphatic mixtures) has been evaluated, based on our previous laboratory pervaporation experiments using Polyvinyl alcohol/Graphene oxide mixed matrix membranes. Accordingly, hybrid distillation-pervaporation and cascade pervaporation systems have been compared with distillation and extractive distillation (conventional process). The results indicated that although the energy demand of hybrid system is much less than distillation, but it is not comparative with extractive distillation. However, when purification of aliphatics is required, cascade pervaporation system is more effective than extractive distillation and the energy demand for purification of i-octane is 56.1% lower in cascade pervaporation process. The results can assist engineers to design novel and low energy consumer process plants for removing aromatics from aliphatic mixtures.