Application of crossflow ultrafiltration to emulsion separation in the extraction of valeric acid with tri-n-butyl phosphate

Extractive ultrafiltration (EUF) of valeric acid from aqueous solutions wit h tri-n-butyl phosphate dissolved in kerosene, at two different phase ratio s and using two ceramic membranes, was studied. The membranes used were ZrO 2 supported on ct-alumina and ZrO2 + TiO2, supported on carbon with an aver age pore size of 20 and 45 nm, respectively. Permeation rates and degree of extraction were determined under three different modes of operation of the membrane unit: total recirculation, permeate removal, and continuous opera tion.