In the present study, an analytical model is developed to investigate the dehydration efficiency of NATCO Dual Polarity® electrostatic treater at steady state conditions using population balance equations (PBE). To investigate the effect of frequency on dehydration performance and electric field strength between electrodes, a detailed electrical model is considered. In the developed electrical model, electrodes are virtualized as simple ideal capacitors, with emulsion acting as dielectric. Proving the model’s accuracy, gathered industrial data were compared with simulation results. In addition, current frequency as the main electrical parameter besides power supply electrical potential was proved to be effective on the strength of the applied electric field, the electrical potential profile on electrodes, and the outlet water cut in the treated crude oil. The results indicated that increasing the current frequency from 50 to 500 Hz, by enhancing DC field strength, reduces the water cut by 0.03%. Although, high temperatures and frequencies, increase the electrical conductivity of the emulsion, electrical power lost during the disconnection of the power supply on electrodes, will be retrieved by increasing frequency. Finally, the performance of different electric fields on crude oil dehydration was compared.

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