Demulsification of stable emulsions from produced water using a phase separator with inclined parallel arc coalescing plates

A novel and highly efficient oil-water separator equipped with a series of inclined multiple arc coalescence plates is developed and optimized for the removal of stable oil emulsions from produced water. The synthetic high salinity produced water with stable emulsions was prepared by mixing Catenex oil and the emulsifying surfactant (Armac T) with brine water. A series of experiments were performed to evaluate the effects of the arc coalescence plate geometry, produced water volumetric flow rate, influent oil concentration, and treatment temperature on the oil removal efficiency using the developed separator. Optimal coalescence plate arc geometry for maximum oil removal at different operating conditions was determined. Using the optimal coalescence plate arc geometry, strong correlations between oil removal efficiency from produced water, volumetric flow rate, and treatment temperature were established. The results demonstrated that the developed oil-water separator is highly effective in the treatment of stable emulsions in produced waters due to the combined effects of chemical demulsification and oil droplet coalescence.