Phase equilibrium, structure and transport properties of carbon-dioxide expanded liquids: A molecular simulation study

I&EC 79

Brian B Laird, blaird@ku.edu, Department of Chemistry, University of Kansas, 1251 Wescoe Hall Dr, Lawrence, KS 66045, Yao Houndonougbo, yaoh@ku.edu, Center for Environmetally Beneficial Catalysis, University of Kansas, 1251 Wescoe Hall Dr, Lawrence, KS 66045, and Krzysztof Kuczera, kkuczera@ku.edu, Departments of Chemistry and Molecular Biosciences, University of Kansas, 1251 Wescoe Hall Dr, Lawrence, KS 66045.
Carbon-dioxide expanded liquids (CXL's) are mixed solvents composed of carbon dioxide condensed into an organic solvent that have potential application as environmentally benign catalyst support media. We present molecular-simulation studies of the phase equilibrium, structure and transport properties for a number of CO2-expanded organic solvents, including acetonitrile, acetone, acetic acid, toluene, methanol, ethanol and 1-octene. In these studies, the CO2 mole fraction was varied by changing the pressure at a constant temperature. Gibbs ensemble Monte Carlo (GEMC) was used to obtain phase equilibrium (volume expansion) and structural information. In addition, Molecular-Dynamics simulations were used to determine translational diffusion coefficients, rotational correlation times and shear viscosities for some of these mixtures. The GEMC results for the volume expansion were found to be superior to the predictions based on the Peng-Robinson equation of state. The MD simulation results for the transport properties are in good agreement with the available experimental data for the pure components and provide interesting insights into the largely unknown dynamical properties of these mixtures.
 

Green Chemistry and Engineering with Gas Expanded Liquids and Near-Critical Media
8:00 AM-11:25 AM, Wednesday, August 22, 2007 Boston Park Plaza -- Clarendon Rm, Oral

Division of Industrial & Engineering Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007