Extraction of Sodium Chloride from Water and Solubility of Water in Hydrophobic Trialkylammonium Alkanoate-Based Ionic Liquids

Abstract

The sodium chloride extraction from aqueous solutions by using hydrophobic trialkylammonium alkanoate ionic liquids (ILs) is studied experimentally. The water solubility in these ILs is also determined. It is found that trialkylammonium alkanoate ILs show sodium chloride extraction efficiencies up to 0.101 g NaCl extracted/g NaCl start. This efficiency cannot be explained by the low water uptake (up to 0.02 g water /g IL ) in the IL. Instead, the sodium chloride extraction must be attributed to other factors, such as steric hindrance considerations. Steric hindrance considerations also explain the dependence of sodium chloride extraction efficiency on the IL structure. Kinetic experiments were performed to ensure a state of chemical equilibrium.

A Novel Mechanism for the Extraction of Metals from Water to Ionic Liquids

“…OMIM concentrations were determined in the (deuterated) aqueous phase by 1 H NMR spectroscopy using a Bruker AVANCE 400 MHz spectrometer. The 1 H NMRspectra for BMIM and HMIM NTf 2 were obtained by using a Varian 500 MHz spectrometer.…”

“…An area that has seen significant study over the past decade is the extraction of metal salts from aqueous solutions. [1][2][3][4][5][6][7][8] Such processes can be applied either to purify water streams by removing toxic materials or to recover metals of interest from an aqueous phase. ILs are nonvolatile, nonflammable and offer good thermal stability.…”

Product engineering and sustainability

“…Hazardous components should already in the design phase of the product be avoided as much as possible. VOS can sometimes be substituted by more benign solvents like ionic liquids [2,3] or supercritical carbon dioxide [4]. A very well-known example of VOS substitution is water based paint, where the irreversible solidification of the binder occurs by a chemical reaction after the water has evaporated.…”

Sodium-ion electrolytes based on ionic liquids: a role of cation-anion hydrogen bonding

“…RTILs are actively used as electrolytes, reaction media, for gas capture, protein and cellulose solubilization, extraction, nuclear fuel reprocessing, waste recycling, etc. Properties of the lithium and sodium ions in RTILs are currently under active investigation [13][14][15][16].…”

“…Witkamp and coworkers [13] considered sodium chloride extraction from aqueous solutions by a specifically selected hydrophobic RTIL, trialkylammonium alkanoate. Extraction efficiencies of up to 10.1 % were found, while water solubility in the discussed RTIL is negligible, 2 %.…”