Material extraction potential of desalination brines: A technical and economic evaluation of brines as a possible new material source

Abstract

The environmental threat of discharging highly saline desalination brine into the sea and an expected growth in global demand for raw materials have increased interest in the idea of integrating desalination and material extraction. This paper examines the material extraction potential of desalination brines corresponding to the seawater desalination volume required to meet the projected global demand for freshwater. The results show that a growing use of seawater desalination techniques to solve the upcoming high water stress provides an increased material extraction potential by 2050, particularly for highly concentrated materials. For example, in the studied scenario, the extraction potential for magnesium and lithium in 2050 is approximately 2243 and 3.1 times the corresponding 2018 production, respectively. The analysis shows that the estimated lithium potential may be sufficient to ameliorate the expected shortage over this century, while the magnesium potential can significantly exceed the future demand. Several seawater materials with low concentrations do not have adequate 2050 extraction potential to be considered a viable resource even compared to present production. This study shows that the promising resource potential of desalination brines for elements such as lithium requires development of suitable extraction techniques that overcome the identified techno-economic challenges.