EXTRACTION OF CARBOXYLIC-ACIDS WITH AMINE EXTRACTANTS .3. EFFECT OF TEMPERATURE, WATER COEXTRACTION, AND PROCESS CONSIDERATIONS

Coextraction of water during extraction of succinic acid by Alamine 336 in different diluents has been measured. The amounts of coextracted water lie in the same order as the solubilities of water in the diluents without amine present. Water coextraction with different acids follows the order fumaric >malonic >maleic = succinic >lactic >acetic. The effects of temperature on extraction of succinic and lactic acids by Alamine 336 with chloroform and methyl isobutyl ketone (MIBK) diluents have been measured. Enthalpies and entropies of complex formation have been derived from the results and are interpreted in terms of the differences in interactions among the species involved. Two approaches for regeneration through back-extraction into an aqueous phase are considered. These involve changes in the equilibrium relationship through a swing of temperature and a swing of diluent composition, respectively. The factors underlying the utility of each are explored and contrasted. The two approaches may be used in combination. © 1990, American Chemical Society. All rights reserved.