EMULSION LIQUID MEMBRANE EXTRACTION OF ORGANIC-ACIDS .1. A THEORETICAL-MODEL FOR LACTIC-ACID EXTRACTION WITH EMULSION SWELLING

A new quantitative model is developed which describes the transport mechanisms and kinetics of organic acid extraction using emulsion liquid membranes. The model includes the contributions from facilitated transport of the acid by a tertiary amine carrier, and convective acid transport resulting from water transport to the emulsion. The facilitated transport model considers mass transfer in the external phase, the solute-carrier chemical reaction, diffusion in the globule as described by a shrinking-core model, and the stripping reaction. Convective transport is accounted for in terms of solute dissolved in the transported water. The effects of swelling on globule size and diffusion distance are also considered.