Separation of Ionic Liquid Dispersions in Centrifugal Solvent Extraction Contactors

Abstract

Separations of dispersions formed by mixing immiscible organic roomtemperature ionic liquids (IL)/hydrocarbon/and aqueous systems using a centrifugal solvent-extraction contactor have been successfully demonstrated in proof-ofconcept testing. This accomplishment is significant in that physical property factors that are typical of ionic liquid systems (e.g., similar densities of the bulk phases, low interfacial tensions, and high viscosities) are typically unfavorable for dispersion separation, particularly in continuous processes. Efficient separation of dispersions containing ionic liquid solvents is essential for utilization of these compounds in liquid-liquid extraction applications to maximize both solute transfer efficiency and solvent recovery. Efficient solvent recovery is of particular concern in IL applications because of the high cost of most IL solvents. This paper presents the results of initial experiments with three hydrophobic ionic liquids to determine how their physical properties affect phase mixing and phase disengagement in contact with an aqueous solution using a centrifugal contactor. While the results of the reported work are promising, additional work is needed to optimize existing mathematical models of contactor hydraulics to address special considerations involved in IL-based processes and to optimize the equipment itself for IL applications.

Novel highly integrated biodiesel production technology in a centrifugal contactor separator device

“…for cleaning oils spills [28]), for extraction of fermentation broths [29] and several other extraction processes [30][31][32][33]. We recently demonstrated the use of the CCS for enantioselective extractions of amino acid derivatives [34] and reported process integration in the CCS by combining biphasic (bio)catalytic conversions with the separation of the catalyst and the reaction products in the device [35].…”

Recycling and recovery of ammonium-based ionic liquids after extraction of metal cations from aqueous solutions

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