Hydrophobic deep eutectic solvent effect on acrylic acid separation from aqueous media by using reactive extraction and modeling with response surface methodology

Abstract

Hydrophobic deep eutectic solvents (HDES) are new-generation green solvents that have emerged in recent years. In this study, the efficiency of using HDES as a solvent in separating acrylic acid from its aqueous solution by reactive extraction method was investigated. As a solvent, HDES prepared with a mixture of TOPO and menthol has been used for the recovery of acrylic acid for the first time. Physical properties of HDES mixtures such as density, viscosity, and refractive index were determined. In reactive extraction experiments, TOPO, one of the two basic components in the solvent, was also employed as an extractant. With the help of response surface methodology based on Box-Behnken design, the effect of the parameters of amount of extractant (0.1-0.9 g), Menthol/TOPO molar ratio (2-4), and initial acid concentration (3-9%) on the distribution coefficient was investigated and the model equation was formed. The highest distribution coefficient (D = 7.8) was achieved with the molar ratio of Menthol/TOPO is 2. Upon examining all the results obtained, it was seen that more than 90% of acrylic acid could be extracted from the aqueous phase to the organic phase.