An electrostatic coalescer apparatus for separating water from a crude oil emulsion comprises a vessel housing having a cavity, an inlet for receiving a crude oil emulsion and outlets for water and purified crude oil. First and second pairs of electrodes are positioned in the vessel cavity. A first Scott-T transformer circuit is coupled to the first pair of electrodes and a second Scott-T transformer circuit is coupled to the second pair of electrodes. The first and second Scott-T transformer circuit receive as an input a 3-phase power supply and output a 2-phase high voltage signal pairs of electrodes. The 2-phase voltage generated between the first pair of electrodes is of the same amplitude and phase as the voltage generated between the second pair of electrodes via the respective Scott-T transformer circuits. A method comprises steps performed during operation of the apparatus.

Embodiments discussed herein relate to systems and methods for separating two or more phases of an emulsion or other mixture. The methods include providing the mixture with a net and unipolar charge (e.g., such that adjacent droplets therein acquire net and unipolar charges), thereby enhancing coalescence of like-phase droplets therein and producing, or enhancing the production of, two or more consolidated phases; and collecting the two or more consolidated phases.

Systems and methods for separating water from an oil and water mixture are provided. A free water knockout vessel includes a mechanical separation section, an electrostatic coalescence section, and a gravitational separation section. A process for separating water from an oil and water mixture includes mechanical separation of the free water, electrostatic coalescence of emulsified water via one or more electrode assemblies, and separation of the coalesced water.