Extraction of Carboxylic Acids from Aqueous Solutions by Using [BMim][NTf₂] and Salting-out Agents

Abstract

Levulinic and lactic acids are important feedstock in a wide range of different industries such as polymer, pharmaceutical, or food manufacture. In this work, a study about levulinic acid and lactic acid recovery from their aqueous solutions was carried out using the hydrophobic ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonil)imide, [BMim][NTf 2 ]. Liquid−liquid equilibria data for the ternary systems water + levulinic acid or lactic acid + IL were determined. The obtained experimental data were correlated by using the nonrandom two-liquid (NRTL) equation. An analysis of the influence of the acid structure and the addition of salting-out agents (potassium phosphate, ammonium sulfate, and saccharose) on the phase equilibria, was also carried out. [BMim][NTf 2 ] was found to be a good extractant for the recovery of levulinic acid and the extraction process was improved by the addition ammonium sulfate.

Cleaning Phenolic Compounds Present in Water Using Salting-Out Effect with DCA-Based Ionic Liquids

“…Since its consumption of energy is lower, it is a simple process and allows the removal of contaminants even at low concentrations [6][7][8]. The most commonly used solvents to remove substances from aqueous systems by liquid-liquid extraction are volatile organic compounds (VOCs); these solvents is volatile, flammable, and toxic-all undesirable properties-therefore, they must be replaced by other solvents with more suitable characteristics [13,14].…”