(506d) Solubilities and Diffusivities of Carbon Dioxide in Ionic Liquids

Ionic Liquids (ILs) are being considered as alternative solvents for capturing carbon dioxide from power plant emissions. The successful utilization of ILs requires fundamental understanding of solubilities and diffusivities of CO2. Recent work in our lab has focused on measurements of CO2 solubility and diffusivity using a gas uptake technique. The experimental system used for these measurements involves tracking the decrease in pressure that results following the introduction of target gas into a small closed chamber containing a thin film of IL. In this presentation, we report low pressure solubility and diffusivity of CO2 in different ILs at temperatures between 10C and 40C. Solubility results are interpreted using regular solution theory and with the solubility parameter of the ILs estimated from the activation energy of viscosity using Eyring's absolute reaction rate theory. Measured diffusivities are on the order of 10^-6 cm2/sec, and vary inversely with the square root of viscosity of IL. Diffusivity correlations, based on Tf2N anion and non Tf2N anion, relating the carbon dioxide diffusivity and IL properties will be presented.