DEMULSIFICATION KINETICS OF W/0 EMULSION IN AN A.C. ELECTRIC FIELD

抄録

The demulsification kinetics of W/O emulsion in a high A.C. electric field was investigated by using a batch cylindrical demulsifier in which a glass-sealed electrode was placed above a grounded copper disk electrode. The effects of emulsion preparation conditions (oil-phase viscosity, water drop size, water-phase holdup and surfactant concentration) and demulsifying conditions (agitation speed and temperature) on the demulsification rates were examined experimentally while keeping the applied voltage constant. The demulsification rates varied considerably with slight change of these conditions. The rate equation that expressed the above contributions in suitable functional forms gave satisfactory agreement with observed rates over a wide range of experimental conditions. Based on comparison with thermal demulsification without electric field, the accelerating effect of temperature rise was thought to be caused by the decrease of oil-phase viscosity and emulsion stability. Mixing of the demulsifier contents during the operation was found to be effective in promoting demulsification together with temperature rise.