EXPERIMENTAL DESIGN AND COMPARATIVE ANALYSIS OF DESALINATION OF HYPERSALINE BRINES USING TEMPERATURE SWING SOLVENT EXTRACTION
With the increase in world populations, sourcing purified, potable water continues to become a challenge. Hypersaline brines are readily available and, when desalinated, could provide a source for clean drinking water. Current desalination techniques include evaporative distillation and reverse osmosis, but high energy consumption and an inability to efficiently process high total dissolved solids levels, make them less attractive options. Temperature swing solvent extraction provides a promising alternative method characterized by membrane-less, low-energy, and cost-effective desalination. The technique utilizes temperature swing and a low-polarity solvent with temperature-dependent water solubility. Amines have properties desirable for solvent as they have both of hydrophilic and hydrophobic moieties and the water solubility in the amines varies at high and low temperatures. This study aimed at designing the experiments to evaluate the desalination effectiveness of amines and optimize the solvent-specific extraction conditions. The main parameters included the calculation basis (mole, volume, and mass), solvents with varying degree of substitution (secondary versus tertiary) and different hydrophobicity (chain length), hypersalinity of the feed, and the schemes of temperature swing. The effects of varying substituents and different concentrations of salts on the final volume of the product water were examined. In addition, the quality of the desalination product was evaluated for residual amine and salt concentrations as well as the parameters. Secondary amines extracted the largest quantities of product water from both 1M and 4M brines, compared to tertiary amines. Molar basis comparison accounted for the varying densities of amines and thereby was most relevant when comparing the solvent/feed ratio. The optimal conditions for solvent-feed specific desalination and the cost analysis of corresponding temperature swing processes will provide the stakeholders including academic research groups, local and federal governments, and industries with both the scientific and practical information for feasible and reliable scale-up applications.
Colona*, Cristin; Tarnowski, Voytek; Archer, Favor; and Lee, Seungjin Dr.
"EXPERIMENTAL DESIGN AND COMPARATIVE ANALYSIS OF DESALINATION OF HYPERSALINE BRINES USING TEMPERATURE SWING SOLVENT EXTRACTION,"
Georgia Journal of Science, Vol. 81, No. 1, Article 93.
Available at: https://digitalcommons.gaacademy.org/gjs/vol81/iss1/93