Influence of Constant Wave and Pulsatile Electric Field on Water Droplets Coalescence in Crude Oil Emulsions

In this study, the coalescence of water droplets in crude oil under electric field was assessed numerically. The impact of different electrical field waveforms on the separation performance was evaluated. The pulsatile electric fields studied include sinusoidal, square wave, saw-tooth wave and triangular waves. In addition, the effect of several process conditions and emulsion properties on coalescence were assessed. The effect of electric potential (0-30kV), crude oil viscosity (10.6-212mPa.s), interfacial tension (20-250mN/m) and flow inlet velocity (10-100mm/s) under electric field application was investigated. The order of coalescence time followed: constant wave $\sim$ square wave < sinusoidal wave < saw-tooth wave $\sim$ triangular wave. The lowest performance for the coalescence was 160ms for saw-tooth and triangular waves. The energy consumed increased from 204. 8mJ to 5. 12J with the elevation of the applied electric potential from 2kV to 20kV. However, the consumed coalescence energy reduced to 2. SSJ at 30kV from 5. 12J at 20kV.