Industrial & Engineering Chemistry Research, Vol.54, No.18, 5165-5171, 2015
Ethane and Ethylene Solubility in an Imidazolium-Based Lipidic Ionic Liquid
The solubilities of ethane and ethylene in the lipidic ionic liquid 1-(Z-octadec-9-enyl)-3-methylimidazolium bistriflimide are measured at 298, 313, and 333 K from 0.1 MPa to about 2 MPa and are correlated and well reproduced with the Krichevsky-Kasarnovsky equation. Ethane is shown to have slightly higher solubility than ethylene, in agreement with results from other ionic liquids with significant nonpolar structural content, although fit Henrys constants are the same within experimental error. Additionally, this is the first example of an imidazolium-based ionic liquid with Henrys constants for ethane and ethylene that are below 5 MPa at room temperature. This supports the idea that these classes of solvents have "nonpolar-like" solvent properties and may be used as alternatives for reaction and separations processes that currently require volatile, nonpolar solvents, even though these species are ionic in nature. Experimental solubility data are compared to COSMO-RS predictions, which give good qualitative predictions of solubility but significantly overpredict the Henrys constant for both species.