Extraction of phenolic compounds from aqueous solution using choline bis(trifluoromethylsulfonyl)imide

The efficiency of choline bis(trifluoromethylsulfonyl)imide [choline][NTf2] was evaluated as extractant media for the extraction of phenolic compounds from aqueous solution. Solid-liquid and liquid-liquid equilibria of the ternary mixtures {water + phenolic compounds (phenol, guaiacol, syringol or pyrocatechol) + ionic liquid} were first measured at 295.15 K at atmospheric pressure. The selectivity and the solute distribution ratio values calculated from experimental data indicate that [choline][NTf2] is suitable for the extraction of phenolic compounds. Thermodynamic data of ternary mixtures were used to regress the parameters of the NRTL and UNIQUAC thermodynamic models. The influence of experimental conditions on the extraction of phenolic compounds from aqueous solutions using [choline][NTf2] were evaluated. Process design shows that phenol, guaiacol and syringol are easily extractable with few amount of solvent, number of theoretical steps and energy.