Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

CO2/H2O partition coefficients () of 18 compounds have been measured at t = 300 K and P = 80 bar, which is equivalent to a carbon dioxide fluid density of 0.76 g cm-3. This expands the range of compounds for which such data are available to include aldehydes, ketones, esters, and halides. With this contribution, data for 49 compounds are now available. Three correlation methods were tested to estimate partition coefficients based on molecular structure and/or physicochemical properties: (1) comparison to water solubility; (2) comparison to solvent/water partition coefficients; and (3) linear solvation energy relationship (LSER) estimation. Correlations (to within +/-0.30 log units) between and either water solubility or octanol/water partition coefficients were found using the first two methods provided that hydrogen-bond donors were excluded from the regression. A correlation (+/-0.30 log units) was found between and carbon disulfide/water partitioning, with benzyl alcohol as the lone exception. The LSER approach was relatively robust, with good agreement (to within +/-0.20 log units) between measurements and predictions for all compounds analyzed. Solute acidity, basicity, and molecular volume were important LSER parameters, reflecting the limited hydrogen bonding opportunities possible in carbon dioxide as compared to water.