Thermodynamics of solvent-driven water extraction from hypersaline brines using dimethyl ether
Name
SDWE_Manuscript01_v35_Preprint.pdf
Size
18.4 MB
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Unknown
Checksum (MD5)
30f8e804a3ab96c446de4a5afce283aa
Author(s)
Deshmukh, Akshay
Foo, Zi Hao
Stetson, Caleb
Lee, Hyeonseok
Orme, Christopher J.
Wilson, Aaron D.
Lienhard, John H
Date Issued
April 2022
Journal
Chemical Engineering Journal
Publisher
Elsevier BV
Citation
Deshmukh, Akshay et al. "Thermodynamics of solvent-driven water extraction from hypersaline brines using dimethyl ether." Forthcoming in Chemical Engineering Journal (2022).
Version
Author's final manuscript
Abstract
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 extraction of lithium and rare earth elements from solution mining leachates. In this study, we develop a computational thermodynamic framework to analyze the liquid–liquid extraction of water from hypersaline brines using dimethyl ether (DME), an aprotic solvent that is partially miscible with water. The high volatility of DME enables its rapid separation from water–DME mixtures after water absorption, while its low polarity minimizes the organic-phase solubility of electrolytes, such as sodium chloride (NaCl). We first build a thermodynamic model based on the LIQUAC excess Gibbs free energy model for water–DME–NaCl mixtures. Maximum likelihood estimators for water–DME–NaCl interaction parameters are calculated through the nonlinear regression of fluid phase equilibrium and osmotic coefficient data using metaheuristic global optimization techniques. A multistage counter-current liquid–liquid separator (LLS) model is then developed to explore the water recovery and brine concentration ratios achievable as a function of feed molality and DME to feed water flow rate ratio. For a saline feed with a molality of (over three times the salinity of seawater) our analysis demonstrates that a one-stage LLS can achieve a water recovery ratio of 0.51 with an initial DME to saline feed molar flow rate ratio of 4.0, rising to 0.63 with a second equilibrium stage. We conclude by quantifying the amount of DME required to reach zero-liquid discharge brine salinities and analyzing the impact of staging and temperature on separation performance. Our thermodynamic model enables the rapid evaluation of SDWE systems for emerging hypersaline brine desalination and valorization applications.
MIT Department
Rohsenow Kendall Heat Transfer Laboratory (Massachusetts Institute of Technology)
Massachusetts Institute of Technology. Department of Mechanical Engineering
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Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1016/j.cej.2021.134391
