(414b) Energy profile and life cycle assessment of an ethanol dehydration unit using an ionic liquid

Authors: 
Farahipour, R., University of Colorado Denver
Mehrkesh, A., University of Colorado Denver
Karunanithi, A. T., University of Colorado Denver

To date use of inorganic salts for ethanol dehydration (EDH) process has been studied. Although several benefits for EDH process using an inorganic salt have been reported, the limited solubility of salts is a big drawback which makes the process hardly feasible. Therefore, any improvement in this chemical process must be based on using new solvents having high selectivity. Ionic liquids (ILs) are a relatively new class of chemicals which can be developed to replace molecular compounds (e.g. solvents). They have a wide range of industrial applications from CO2 capture to aliphatic/aromatic separations. Based on their properties, ionic liquids can be a promising alternative for the EDH process. Ionic liquids are powerful solvents and they possess the benefits of inorganic salts and liquid solvents at the same time. Therefore, utilization of ILs for ethanol-water separation is widely being considered. In this work we used COSMO-RS method to design a functionalized ionic liquid which is suitable for EDT process. The designed ionic liquid is in liquid phase, with relatively low viscosity and high solvation power.A process simulation software is used to find the energy profile of the separation process using the selected ionic liquid. Based on raw materials and energy/electricity used for EDH process and all upstream processes prior to ethanol-water separation, a cradle-to-gate life cycle assessment for production of 1 kg ethanol, functional unit, is performed.
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