Journal of Chemical and Engineering Data, Vol.63, No.12, 4801-4806, 2018
Recovery of Lactic Acid from Dilute Aqueous Solutions Using a Binary Mixture of Tri-n-octylphosphine Oxide (TOPO) or Dioctylamine (DOA) with Different Solvents
The purpose of this investigation is to compare the extraction efficiency of lactic acid from dilute solutions using several extractant mixtures in order to determine the most efficient solution for the extraction processes. A phosphorus-based extractant, TOPO, has been chosen for the extraction experiments since it has low water solubility and is more environmentally friendly than the amine-type extractants. Also, amine-based extractant DOA is chosen due to the lack of study in the literature on lactic acid extraction using a DOA/solvent system. Organic phases were prepared by mixing TOPO or DOA with eight different solvents (n-octane, isobutyl methyl ketone, 1-octanol, ethyl methyl ketone, diisobutyl ketone, n-decane, diethly sabecate, and 1-decanol), and all experiments were performed at 298.15 K. The results were interpreted using the distribution coefficient (K-D), loading factor (Z), and extraction yield (E %) data. It has been observed that a considerable amount of lactic acid extraction can be achieved by using DOA in the organic phase compared to that attained by using TOPO. It is found that the maximum amount of extracted lactic acid (K-D = 56.331) was achieved with 1.654 mol.kg(-1) DOA dissolved in 1-octanol with an extraction efficiency of 98.26%, and thus especially the use of a DOA/1-octanol system is recommended for the lactic acid extraction processes.