Recovery of Valeric Acid Using Topo-Based Deep Eutectic Solvents

Abstract

Traditional industrial solvents often contain volatile organic compounds (VOCs) that are not environmentally friendly. Ionic liquids (ILs) and deep eutectic solvents (DESs) are being developed as sustainable alternatives. Some ILs are expensive, toxic, and non-biodegradable. On the other hand, DESs emerged as a new, greener solvent. The efficacy of hydrophobic deep eutectic solvents (HDESs) for the extraction of valeric acid (VA) was studied. A series of HDESs was prepared using menthol and trioctylphosphine oxide (TOPO) at various molar ratios (1.5M:1T, 2M:1T, 3M:1T). The efficiency of said solvents was assessed by means of reactive liquid-liquid extraction (RLLE) for the removal of valeric acid from an aqueous medium. Quantitative measurements of key performance parameters, including both extraction efficiency (E%) and the distribution coefficient (D), were obtained over a designated temperature range (303.15 - 308.15 K). The findings unequivocally indicate that this HDES system exhibits high performance, achieving high values for both extraction efficiency (98.99%) and the distribution coefficient (98.009) under specific operational conditions.