Treatment of Oilfield Produced Water: A Cleaner Process for Producing Sodium Carbonate (Soda Ash)

Abstract

The objective of this research was to obtain soda ash from oilfield produced water. The association between produced water and the conditions to produce soda ash, its processes and reactions, inspired the development of this innovative research. With the goal of transforming this wastewater in a high value product, this research performed and compared different treatment processes. An anionic surfactant was used in the flotation process of the dispersed oil phase, and sodium carbonate was employed to promote calcium and magnesium precipitations. The relationship between the liquid effluents and solid wastes with the quality of the soda ash produced was established. The quality parameters for treated water were determined, and the different streams derived from these treatments were used in the production of soda ash. The soda ash obtained in this research presented physicochemical composition similar to the one of a carbonate mineral (trona ore). The yields were as high as 80%. This process allowed to treat and to transform produced water, an effluent that is harmful to the environment, into soda ash which is largely used in the industry.