Thermodynamics of solvent-driven water extraction from hypersaline brines using dimethyl ether

Solvent-driven water extraction (SDWE) has promising applications in hypersaline brine desalination, including zero-liquid discharge processing for industrial wastewaters, and resource recovery, such as the of lithium rare earth elements from solution mining leachates. In this study, we develop a computational thermodynamic framework to analyze liquid–liquid brines using dimethyl ether (DME), an aprotic solvent that is partially miscible with water. The high volatility DME enables its rapid separation water–DME mixtures after absorption, while low polarity minimizes organic-phase solubility electrolytes, sodium chloride (NaCl). We first build model based on LIQUAC excess Gibbs free energy water–DME–NaCl mixtures. Maximum likelihood estimators interaction parameters are calculated through nonlinear regression fluid phase equilibrium osmotic coefficient data metaheuristic global optimization techniques. A multistage counter-current separator (LLS) then developed explore recovery concentration ratios achievable function feed molality flow rate ratio. For saline 2 . 0 mol kg − 1 (over three times salinity seawater) our analysis demonstrates one-stage LLS can achieve ratio 0.51 initial molar 4.0, rising 0.63 second stage. conclude by quantifying amount required reach salinities analyzing impact staging temperature performance. Our evaluation SDWE systems emerging desalination valorization applications. • Thermodynamic solvent-driven (SDWE). (DME) extract brines. Computational quantifies DME-based calculated. Excess be extended other solvents.