Critical Assessment of CO2 Solubility in Volatile Solvents at 298.15 K

Abstract

Fifteen different low molar mass compounds are assessed as CO2 solvents based on bubble-point loci on the solvent-rich end (0.6 to 1.0 solvent wt fraction) of the CO2-solvent pressure−composition diagram at 298.15 K. Four of the five best solvents (in descending order of solvent strength on a mass fraction CO2 dissolved basis), acetone, methyl acetate, 1,4-dioxane, and 2-methoxyethyl acetate, are oxygen-rich, low molar mass species possessing one or more oxygen atoms in carbonyl, ether, and/or acetate groups that can interact favorably with CO2 via Lewis acid/Lewis base interactions. Methanol, a very low molar mass solvent, is comparable to 1,4-dioxane in solvent strength. The remaining solvents, in descending order of solvent strength on a mass basis, include 2-nitropropane, N,N-dimethylacetamide, acetylacetone, 1-nitropropane, iso-octane, 2-(2-butoxyethoxy)ethyl acetate, N-formylmorpholine, propylene carbonate, 2-butoxyethyl acetate, and N-tert-butylformamide. When compared on a molar basis, each of the...