Wei Ren1, Azita Ahosseini1, Aaron M. Scurto1, Mark B. Shiflett2, and Akimichi Yokozeki3. (1) Chemical and Petroleum Engineering & NSF-ERC Center for Environmentally Beneficial Catalysis, University of Kansas, 1530 W. 15th St., 4132 Learned Hall, Lawrence, KS 66045, (2) Central Research and Development, The DuPont Company, Experimental Station, Wilmington, DE 19880-0304, (3) DuPont, Fluoroproducts, Wilmington, DE 19880-0711
Recently, the solubility and selectivity of ionic liquid for the dissolution and separation of gases, in particular refrigerant gases, has been reported. A number of potential applications for these systems are possible. However, accurate thermodynamic and transport properties are needed for further development. Here, the global phase behavior and phase equilibrium (vapor-liquid, liquid-liquid, vapor-liquid-liquid, and critical points) have been determined for several imidazolium ionic liquids with CO2 and several refrigerant gases. High solubility of gas was observed with all of the refrigerants investigated. The viscosity and diffusivity in these systems has also been measured and modeled and indicate significant augmentation of the mass transport properties with dissolved gas. Both low and high-pressure solubility (pressure-temperature-composition) data have been well correlated with an equation-of-state (EOS) model.