Ideal gas solubilities and solubility selectivities in a binary mixture of room-temperature ionic liquids

Alexia Finotello; Jason E Bara; Suguna Narayan; Dean Camper; Richard D Noble

doi:10.1021/jp075572l

Ideal gas solubilities and solubility selectivities in a binary mixture of room-temperature ionic liquids

J Phys Chem B. 2008 Feb 28;112(8):2335-9. doi: 10.1021/jp075572l. Epub 2008 Feb 2.

Authors

Alexia Finotello¹, Jason E Bara, Suguna Narayan, Dean Camper, Richard D Noble

Affiliation

¹ Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309-0424, USA.

PMID: 18247501
DOI: 10.1021/jp075572l

Abstract

This study focuses on the solubility behaviors of CO2, CH4, and N2 gases in binary mixtures of imidazolium-based room-temperature ionic liquids (RTILs) using 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][Tf2N]) and 1-ethyl-3-methylimidazolium tetrafluoroborate ([C2mim][BF4]) at 40 degrees C and low pressures (approximately 1 atm). The mixtures tested were 0, 25, 50, 75, 90, 95, and 100 mol % [C2mim][BF4] in [C2mim][Tf2N]. Results show that regular solution theory (RST) can be used to describe the gas solubility and selectivity behaviors in RTIL mixtures using an average mixture solubility parameter or an average measured mixture molar volume. Interestingly, the solubility selectivity, defined as the ratio of gas mole fractions in the RTIL mixture, of CO2 with N2 or CH4 in pure [C2mim][BF4] can be enhanced by adding 5 mol % [C2mim][Tf2N].