Evaluation of extractability of 2,4,6-trinitrophenol by secondary amine extractant in alcohols: Equilibrium and molecular dynamic study

Extractive separation of 2,4,6-trinitrophenol (picric acid, PAH) from its aqueous solutions was examined at constant temperature of 298.2 K. The experiments were studied on the extraction of PAH (0.061 mol kg−1) by Amberlite LA2, a secondary amine diluted in five different alcohols such as isopropyl alcohol, isoamyl alcohol, hexanol, heptanol, and decanol. In addition to reactive extraction, experiments on physical extraction were also performed by pure diluents. Experimental results obtained from batch extraction were evaluated in terms of distribution coefficients (KD), extraction efficiency (E), and loading factors (Z). The highest synergistic effect was achieved with isopropyl alcohol in LA-2 at a concentration of 0.588 mol kg−1 as 98.36%. The highest value of probable equilibrium constants for the complex between acid and amine (1:1), K11 was calculated to be 11.62 for isopropyl alcohol at 0.588 mol kg−1 LA-2 concentration. Kinetic and potential energies of components during reactive extraction in the organic phase have been determined by molecular dynamic modeling for picric acid + isopropyl alcohol + secondary amine. The values of energy, per atom, for mixture picric acid + isopropyl + secondary amine were respectively: ∼30,000 kcal/mol, ∼15,000 kcal/mol, ∼−50,000 kcal/mol and ∼−60,000 kcal/mol.