Equilibria and kinetics for reactive extraction of lactic acid using Alamine 336 in decanol

Lactic acid is an important commercial product and extracting this from aqueous solution is a growing requirement in fermentation-based industries. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid-amine (solvent) system used. The equilibrium complexation constants for ratios of (1:1) and (2:1) have been estimated. The kinetics of extraction of lactic acid by Alamine 336 in decanol has also been determined. The reaction between lactic acid and Alamine 336 in decanol in a stirred cell falls in Regime 3, ie extraction accompanied by a fast chemical reaction occurring in the diffusion film. The reaction has been found to be zero order in Alamine 336 and first order in lactic acid with a rate constant of 0.21 s(-1). These data will be useful in the design of extraction processes. (C) 2002 Society of Chemical Industry.