Solubilities of Gases in the Ionic Liquid 1-n-Butyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide

Solubility data of carbon dioxide, propane, propene, butane, and 1-butene in the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (bmimTf2N) are presented as a function of pressure at temperatures between 280 K and 340 K. The equilibrium pressure at a given temperature and the amount of gas dissolved into the ionic liquid phase were measured with an experimental technique based on a saturation method at constant volume by use of an apparatus equipped with a cylindrical equilibrium view cell. All measured solubilities were between 0.1 and 0.5 mole fraction gas in ionic liquid. 1-Butene had the highest solubility, followed by butane, propene, and then propane. Carbon dioxide and propane are similarly the least soluble in the bmimTf2N. Alkene gases were more soluble than alkane gases. From the experimental solubility data, the Henry's constants of each gas in the ionic liquid were estimated as a function of temperature.