Next Generation Ionic Liquid based Membranes for Dehydration of Bioethanol

Abstract

As the world looks for practical alternatives to fossil fuels, biofuels created from renewable energies have emerged as a promising solution. Bioethanol, in particular, has become the leading biofuel for transportation. But producing bioethanol can be challenging, especially when it comes to removing excess water. This study aims to explore a cutting-edge method for eliminating water from bioethanol: using solid dense membranes in a process called pervaporation. The use of Ionic liquid based membranes is particularly attractive because they can separate azeotropic mixtures with a high rate of molecular diffusion, low energy consumption, and no phase change or chemical reactions. To evaluate the performance of these membranes, we used Polydimethyl siloxane (PDMS) based membranes as a benchmark and studied the use of ionic liquids (ILs) as a way to improve ethanol selectivity. We synthesized three specific ILs, Tributyl methyl Phosphonium Bis [(trifluoromethyl) sulfonyl] imide, trihexyl tetradecyl phosphonium bis 2,4,4 trimethyl pentyl phosphinate and Tetrabutyl phosphonium bis [(trifluoromethyl) sulfonyl] imide and tested them in custom-built pervaporation se-up. We used various characterization methods like FTIR, BET, XRD, SEM and TEM to evaluate their performance in removing water from bioethanol. The study demonstrated that employing supported ionic liquid membranes (SLMs) effectively enhanced the dehydration process of bioethanol