Extraction of Lactic Acid from Fermentation Broth Using Long-Chain Alkanones

Abstract

The removal of lactic acid from fermentation broth aims at enhancing the fermentation process through acid reduction and also purifying the end product––lactic acid. In this work, the extraction of lactic acid from fermentation broth was carried out at 298.15, 303.15, and 308.15 K using hexanone, octanone, and nonanone, respectively. The solubility and extraction data were determined using titration and cell equilibration methods, respectively. The ternary systems exhibit type-1 behavior of LLE at all the studied temperatures. The reliability of the experimental extraction tie lines was ascertained by using both Hand and Othmer–Tobias correlations, and the standard deviations for reliability correlations were <0.05. The evaluated separation factors were >1 at all the studied temperatures. The yield of extraction ranged from 20.72 to 79.53%. Nonanone had the highest efficiency for the extraction process. The highest extraction factor (33.07) obtained from nonanone gave the corresponding optimum extraction temperature and solvent–broth ratio of 303.15 K and 7.70, respectively. The mass ratio of lactic acid to nonanone obtained as the extract was 0.3434. However, hexanone, octanone, and nonanone are good for lactic acid removal from fermentation broth.