Ionic liquids have potential applications on separation technologies, as solvents for liquid extraction, gas absorbers and others. In this work, the ability of 1-ethyl-3-methyl imidazolium ethyl sulfate, [emim][EtSO4], to carry out the separation of tert-amyl ethyl ether and ethanol mixtures has been studied. New experimental LLE data for the ternary system are reported. Data correlation was done by means of the NRTL equation with satisfactory results (rmsd = 0.429%). Extraction process was studied by means of solute distribution ratio and selectivity of the ionic liquid. Results were compared to other solvents from the literature. Solute distribution ratio for [emim][EtSO4] was acceptable (higher than 1) and selectivity was better than for other solvents. Then, extraction processes were also simulated using conventional software and obtained results are shown for comparison. Best TAEE recovery was obtained with [emim][EtSO4] and water. (c) 2006 Elsevier Ltd. All rights reserved.