Integrated Valorization of Desalination Brine through NaOH Recovery: Opportunities and Challenges

Abstract

The rising use of seawater desalination for fresh water production is driving a parallel rise in the discharge of high-salinity brine into the ocean. Better utilization of this brine would have a positive impact on the energy use, cost, and environmental footprint of desalination. Furthermore, intermittent renewable energy can easily power the brine utilization and, for reverse osmosis technology, the entire desalination plant. One pathway toward these goals is to convert the otherwise discharged brine into useful chemicals; waste could be transformed into sodium hydroxide or caustic soda (NaOH) and hydrochloric acid (HCl). In this Minireview, we discuss opportunities and challenges for integrated valorization of desalination brine through NaOH and HCl recovery.

Keywords: HCl recovery; NaOH recovery; bipolar membrane electrodialysis; desalination brine; sustainable chemistry.