Searching for green solvents is imperative for the sustainable development of liquid-liquid extraction. Liquid-liquid equilibrium data for two ternary systems of methyl tert-butyl ether (MTBE) + methanol + N-methylimidazolium hydrosulfate ([MIM][HSO4]) and MTBE + methanol + 1-butyl-3- methylimidazolium hydrosulfate ([BMIM][HSO4]) were measured at 278.15 K, 298.15 K and 318.15 K at 101.325 kPa for this study. The values of the distribution coefficient and the separation factor were calculated based on the experimental data, and then, the extraction ability was determined. Factors affecting the phase behavior such as the nature of the ionic liquid and the temperature were discussed. NRTL and UNIQUAC models were applied to correlate the experimental tie-line data. (C) 2018 Elsevier Ltd.