Reactive Extraction of Levulinic Acid by Amberlite LA-2 Extractant

TLDR

Organic acids are produced at low concentrations in electrochemical and biochemical syntheses, and their recovery by solvent extraction—particularly reactive extraction of carboxylic acids—has attracted growing interest. The study performed reactive extraction of levulinic acid at 298.15 K using Amberlite LA‑2 dissolved in five esters, five alcohols, and two ketones, also testing pure solvents for physical extraction, and reported batch results as distribution coefficients, loading factors, stoichiometric loading factors, separation factors, and extraction efficiencies. Isoamyl alcohol proved the most effective solvent, achieving a maximum distribution coefficient of 68.017, and a linear solvation energy relationship model with R² = 0.98 accurately predicted loading factors for the alcohols.

Abstract

The production of organic acids at relatively low concentrations in aqueous solutions is typical of both electrochemical and biochemical syntheses. The recovery of these solute species can be achieved by solvent extraction, and the reactive recovery of carboxylic acids from aqueous solutions has received increasing attention. In this study the reactive extraction of levulinic acid was done at 298.15 K, and all experiments were reported on the extraction of levulinic acid by Amberlite LA-2 dissolved in five different esters (dimethyl phthalate, dimethyl adipate, dimethyl succinate, dimethyl glutarate, and diethyl carbonate), five different alcohols (isoamyl alcohol, hexan-1-ol, octan-1-ol, nonan-1-ol, and decan-1-ol) and two different ketones (diisobutyl ketone (DIBK) and methyl isobutyl ketone (MIBK)). Furthermore, single pure solvents (not containing Amberlite LA-2) were used for physical extraction. Experimental results of batch extraction experiments were calculated and reported as distribution coefficients (KD), loading factors (TT), stoichiometric loading factors (TS), separation factors (Sf) and extraction efficiencies (E). The isoamyl alcohol was found to be the most effective solvent with a maximum distribution value (KD) of 68.017. According to the data determined from the experiments, a linear solvation energy relationship (LSER) model equation was found to calculate loading factors (TT) for the alcohols with an R2 value of 0.98.