INTERFACIAL KINETICS OF THE STRIPPING OF ACETIC AND CITRIC ACIDS FROMTRI-N-OCTYLAMINE COMPLEXES

A rotating diffusion cell (RDC) was used to measure the kinetics of ac etic and citric acids stripping from an organic solvent phase to water . It has been proved that the carboxylic acid transfer is rate control led by a diffusion process. The rate constant for acetic acid was foun d to be (3.43 +/- 0.18) x 10(-5) m . s(-1) at 298 +/- 0.1 K. For citri c acid, the rate constant determined as a function of temperature was k = (0.043 +/- 0.002)e(-3680/T) for which the activation energy is 30. 6 +/- 1.0 kJ . mol(-1). The stripping resistance depends on the number of carboxylic acid groups in the acid and is largely entropic in natu re.