Modeling and optimization of reactive extraction equilibria and kinetic study of gallic acid using tributyl phosphate in isoamyl alcohol

Equilibrium and kinetic experiments were performed for gallic acid recovery using tributyl phosphate dissolved in isoamyl alcohol as a diluent. Employing an extractive-reaction system results in significantly higher acid recovery in comparison to physical extraction. Overall equilibrium extraction complexation constant K-E was found to be in the range 4.325-6.896. 1:1 acid: extractant complexes are proposed from the results obtained from mass action law model. Adsorption isotherm models (Langmuir, Freundlich, Temkin) and Response Surface Methodology was used, Mass transfer coefficient (k(L)) and diffusivity coefficient were also calculated. Extraction kinetics was observed to be very slow based on the Hatta number.