LIQUID-LIQUID EXTRACTION EQUILIBRIUM FOR PYRUVIC ACID RECOVERY: EXPERIMENTAL DATA AND MODELING

Physical extraction studies of pyruvic acid from dilute aqueous solutions (0.025 kmol.m(-3) to 0.200 kmol.m(-3)) using several pure solvents (tri-n-butylphosphate (TBP), 1-decanol, 1-octanol, toluene, Methylisobutylketone (MIBK), and n-heptane) and their binary mixtures are reported in this work. All the batch extraction experiments were carried out at isothermal conditions (T=303 +/- 1K) and the results are reported in terms of distribution coefficient (K-D). The results obtained by the equilibrium studies of the different extraction system were correlated with solvatochromic parameters of the solvents. A linear solvation energy relationship (LSER) model was applied to interpret the extraction equilibrium which specifically considers physical interactions. The values of the LSER model parameters for the extraction system were optimized by regression technique and the model equations have been proposed. Experimental and model values were in good agreement (RMSD < 0.1). Reported outcomes are useful in the selection of a suitable extraction system and understanding the extraction mechanism for the separation of pyruvic acid from dilute aqueous solutions.