Reactive extraction of d,l-α-phenylglycine with a quaternary ammonium salt: Effect of hydroxide anions and water coextraction

The extraction equilibria of α-phenylglycine in alkaline solutions with tri-n-octylmethylammonium chloride (TOMAC) (10%, v/v) in 1-decanol as diluent have been studied. Hydroxide anion and water co-extraction were also investigated. Equilibrium constants for the extraction of phenylglycine and OH- ions have been determined experimentally at 20 °C, being KePhg=1.09KePhg=1.09 and KeOH = 0.30. A mathematical model has been developed to predict the equilibrium concentrations from initial conditions, the equilibrium constants and mass balances to the system. The model takes into account the coextraction of water (3.5 ± 0.4%, v/v) that was determined to be independent of feed concentration.