Essential oil terpenless by extraction using organic solvents or ionic liquids

Ionic liquids are gaining attention as potential substitutes for classic organic solvents in many different applications, especially as reaction media and separation agents. Search for an effective method for essential oils terpenless is necessary. Organic solvents are volatile substances, which contribute to environmental pollution and lead to important operating costs due to losses by evaporation. Thus, use of a green-solvent would avoid those difficulties. In this work, the possibility of using two organic solvents and an ionic liquid to carry out the citrus essential oil deterpenation is studied and the obtained results are compared. Citrus essential oil is simulated as a mixture of limonene and linalool; the solvents studied are 2-butene-1,4-diol, ethylene glycol, and the 1-ethyl-3-methylimidazolium methanesulfonate ionic liquid; and LLE data for the three ternary systems are reported. Data correlation is done by means of the NRTL equation. Solvent selection is studied by means of the solute distribution ratio and the selectivity, and compared to other solvents from the literature. The ionic liquid presents the highest selectivity, but close to other organic solvents, and results for solute distribution ratio depend on concentration range of extraction. Extraction process simulations using these solvents are carried out and the results are shown for comparison. Despite the fact that the ionic liquid does not get the highest linalool recovery, it provides the highest purity. (c) 2006 American Institute of Chemical Engineers.