ELECTRICAL DEMULSIFICATION OF SUBMICRON W O EMULSION IN LIQUID SURFACTANT MEMBRANE PROCESSES/

In the ordinary high-voltage A.C. electric demulsification of W/0 emul sion for liquid surfactant membranes, the breaking of the submicron dr oplets has been reported to be difficult. In this work, by making the distance between the electrodes short in an A.C. electric demulsifier the submicron droplets were successfully broken. In the experiments, t he oil phase was kerosene with Span 80 as the surfactant, and the inne r aqueous phase was NaCl solution for the non-extraction system and H2 SO4 solution for the extraction system. The original W/0 emulsion, whi ch was made with a disperser, was demulsified by an ordinary A.C. elec tric demulsifier. The oil phase containing unbroken submicron droplets was used as the sample emulsion. For the extraction system, W/O emuls ion which experienced the extraction of Cu was used as the original em ulsion. It was found experimentally that the submicron emulsion can be demulsified by making the distance between the electrodes as short as 10 mm. The effects of water concentration C[mol.m-3], surfactant volu me fraction Cs [-], electrical potential E[V.m-1] and temperature T[K] on the demulsification rate, dC/dtheta, was correlated by the experim ental equation. dC/dtheta = -k.E.Cs-1,8.C3.exp (-E0.R-1.T-1) Where the ta[s] is time, R[J.mol-1.K-1] is gas constant, E0[J.mol-1] is apparent activation energy and k[m7.mol-2.V-1.s-1] is constant; E0 = 43.0 x 10 (3), k = 1.54 x 10(-8), for the non-extraction system and E0 = 53.9 x 10(3), k = 4.4 x 10(-6) for the extraction system.