Analysis of Microwave-Assisted Heating and Water Extraction from Imidazolium and Phosphonium Based Ionic Liquids
29 Pages Posted: 23 Mar 2022
Abstract
Ionic liquids have attracted much attention with their low melting point, low vapor pressure, and non-flammability. However, their application in industrial processes is not common due to the high economic cost and low efficiency of recovering ILs. To reduce costs and environmental effects, this study proposes to use industrial microwave irradiation to recover eight different water/ILs. The heating kinetics and identification between dielectric and convective heat properties were studied. Imidazolium-based ionic liquids demonstrated higher temperatures in short time periods (1-butyl-3-methylimidazolium methylsulfate ([bmim][CH3OSO3]) at 417 K in 150 s) than Phosphonium-based LIs (bis(trifluoromethylsulfonyl) trihexyl(tetradecyl) phosphonium imide ([P6,6,6,14][Tf2N]) at 398 K in 360 s). Microwave-assisted heating water extraction experiments (water/ionic liquids) demonstrated 90% recovery in ~200 s for 1-octyl-3-methylimidazolium chloride ([omim][Cl]). Finally, microwave irradiation demonstrated a 15 times shorter time reduction than vacuum-assisted distillation (~90% recovery). Therefore, microwave-assisted heating has shown to be an excellent form to heat ionic liquids to decrease the cost of the extraction process.
Keywords: ionic liquid, microwave heating, Heat Capacity, Water extraction
Suggested Citation: Suggested Citation