An environmentally friendly method for removal of salts from produced water brine

Produced water is a complex mixture of organic and inorganic compounds and it is mainly salty water. It represents the largest volume of by-products generated during oil and gas recovery operations. As a result, water to oil ratio is around 3:1 that is water cut is 70%. Increasing volume of wastewater over the world has become a big issue of concern, and treatment of this wastewater can generate additional sources of potable water. Therefore, research efforts are devoted to developing a cost-effective technique to reduce high salinity of produced water to a lower value. A new approach is investigated, to remove/reduce salts from moderate to high concentration brine. This method is based on liquid-liquid extraction, and uses an organic phase containing ethanol, cyclohexane and sunflower oil. Experiments were successful to reduce the salinity of brine to approximately 27%–64%, in a single stage, with different concentrations of brine from 40,000 ppm up to 140,000 ppm. This method, is considered to be simple, efficient, environmentally-friendly and uses a sustainable system.