Inert-Gas-Stripping Method for Measuring Solubilities of Sparingly Soluble Gases in Liquids. Solubilities of Some Gases in Protic Ionic Liquid 1-Butyl, 3-Hydrogen-imidazolium Acetate

The inert-gas stripping method is useful for rapidly measuring solubilities of moderately and sparingly soluble gases in liquids. Earlier versions of this method can give only solubilities of volatile-liquid solutes in low-volatile solvents. However, the modifications presented here enable measurement of very low solubilities of gases in liquids. Henry's constants are reported for carbon dioxide, krypton, oxygen, air, and nitrogen in n-dodecane and n-pentadecane, and for carbon dioxide in ethylene glycol at near-ambient conditions. The new Henry's constants compare well with those in the literature. Henry's constants are reported for carbon dioxide, ethane, ethylene, krypton, oxygen, air, and nitrogen at near-ambient conditions in the protic ionic liquid 1-butyl, 3-hydrogen-imidazolium acetate; we select this protic ionic liquid because, relative to other ionic liquids, it has low viscosity and because solubility data in protic ionic liquids are rare.