Extraction of Lactic Acid from Fermentation Broth Using Long Chain Alkanoates

Liquid–liquid equilibrium data of the ternary systems of water + lactic acid + hexyl acetate (heptyl acetate and octyl acetate) were determined at T = (298, 303, and 308) K and atmospheric pressure. Complete phase diagrams show that the ternary systems exhibit type-1 behavior of LLE. The reliability of the LLE data was ascertained, using Hand and Othmer–Tobias correlations, at standard deviation < 0.05. The calculated separation factor, at values greater than 1, shows that the solvents have the ability to extract lactic at the three studied temperatures. The yield of the extraction ranged between 39.99 and 81.81%; octyl acetate had the highest yield. The highest extraction factor (21.8886) obtained with octyl acetate gave the corresponding optimum extraction temperature and solvent–broth ratio of 308 K and 3.18, respectively. The lactic acid–octyl acetate extract mass ratio was 0.4834. Hexyl acetate, heptyl acetate, and octyl acetate are good solvents for lactic acid extraction from fermentation broth.