Industrial & Engineering Chemistry Research, Vol.59, No.38, 16751-16761, 2020
Highly Efficient Dehydration of Ethyl Acetate using Strong Hydrophilic Ionic Liquids
Ethyl acetate (EA) is a widely used solvent and raw material in chemical and pharmaceutical industries. The removal of the low water content (<2%) in EA is difficult using the conventional separation method. The strong hydrophilicity of ionic liquids (ILs) can provide a new opportunity for highly efficient EA dehydration, and the water can be easily removed through liquid-liquid extraction. In this work, several kinds of hydrophilic ILs with the carboxylate group for EA dehydration were designed and prepared. The liquid-liquid equilibrium of ILs with EA-water was measured. Among the ILs, 1-ethyl-3-methylimidazolium acetate ([C(2)mim]OAc) showed the best extraction performance for EA dehydration. The water removal efficiency was 99% by single-stage extraction. The partition coefficient of water was 711.26, and the selectivity of water to EA was 2.64 x 10(4). After three stages of extraction, the water content of EA was as low as 84 ppm. Hydrogen bonding played an important role in the dehydration of EA with [C(2)mim]OAc, as determined from quantum chemical calculations.