Optimal Reactive Extraction of Valeric Acid from Aqueous Solutions Using Tri- n -propyl amine/Diluent and Dibenzyl amine/Diluent Systems

Reactive extraction of valeric acid from water by tri-n-propyl amine (TPA) and dibenzyl amine (DBA) dissolved in polar oxygenated aliphatic diluents (diethyl sebacate, diethyl succinate, diethyl malonate, ethyl caprylate, ethyl valerate and isoamyl alcohol) has been studied at T = 298 [+ or -] 0.2 K and P = 101.3 [+ or -] 0.7 kPa. Distribution data have been subjected to formulation of an optimization structure for effective acid separation. The optimization approach uses separation ratio R and synergistic enhancement SE factors to efficiently identify optimum extraction ranges. Among the examined aliphatic ester and alcohol diluents, monoesters exhibit higher solvation efficiency comprising [acid.sub.1]-[amine.sub.1] complex formation, while isoamyl alcohol yields larger loading factors. The uptake capacity of the amine/diluent system is ranging in the order TPA > DBA.Modeling efforts based on the mass-action law principles have shown considerable success. The mass action law chemodel and modified Langmuir approach are quite accurate yielding mean errors of 0.9 % and 0.7 %, respectively.Key words:extraction, valeric acid, amine, modeling, optimization