The electrostatic – misfit energy arise from repulsive interaction of CH4 plays a dominant role in determining its solubility in ILs. Modelling using COSMO-RS shows that IL size and van der Walls forces only have marginal influences on CH4 solubility.
The solubility of ethane is not only governed by the electrostatic–misfit of the solute toward ionic liquids, but also the existence of a preferential site for ethane to interact with the ionic liquid's non-polar moiety.
Ionic liquids (ILs) are promising solvents for gas absorption and separation processes. In this work, the solubility of methane in four alkylpyridinium-based ILs, namely, 1butylpyridinium bis(trifluoromethylsulfonyl)imide ([C 4 py][Tf 2 N]), 1-hexylpyridinium bis-(trifluoromethylsulfonyl)imide ([C 6 py][Tf 2 N]), 1-butylpyridinium tetrafluoroborate ([C 4 py]-[BF 4 ]), and 1-hexylpyridinium tetrafluoroborate ([C 6 py][BF 4 ]), was measured at temperatures 298.15 to 343.15 K and pressures up to 4 MPa using a pressure drop method. The result showed that the solubility of methane increases with increasing pressure and decreasing temperature. In addition, the solubility of methane in ILs can be ranked as follows: [C 4 py][BF 4 ] < [C 6 py][BF 4 ] < [C 4 py][Tf 2 N] < [C 6 py][Tf 2 N]. Furthermore, Henry's law constant (K H ) and thermodynamic properties, namely, enthalpy and entropy at an infinite dilution, were estimated from the experimental solubility data. The estimated thermodynamic properties revealed that the solubility of methane in alkylpyridinium-based ILs is not only governed by a favorable solute−solvent interaction but also balanced by an unfavorable entropy of solution.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.