NONDISPERSIVE MEMBRANE SOLVENT BACK EXTRACTION OF PHENOL

Nondispersive back extraction of phenol from methyl isobutyl ketone into caustic solutions has been studied using microporous polymeric membranes in flat as well as hollow‐fiber form. Dispersion‐free reactive back extraction was successfully achieved using the correct phase pressure difference. The predictive capabilities of the mathematical models developed for such a system have been investigated. This study indicates that the overall mass transfer can be controlled by boundary layer resistance and/or the membrane transfer resistance, depending on the flow configuration, the nature of the membrane, and the regime of caustic concentration. Individual film transfer coefficients on the shell side and the tube side have been isolated for different hollow‐fiber modules. A commercially available 15 cm long module containing hydrophobic microporous hollow fibers has provided very low values of height of transfer unit (HTU) and very high phenol recoveries. The experimentally obtained HTUs of this module have been predicted with significant accuracy. Copyright © 1990 American Institute of Chemical Engineers