I&EC 81 |
| CO2-expanded liquids are attractive media for reactions and separations. However, investigations of the solubility of oxygen and other reactant gases in CO2-expanded acetone, methanol and acetonitrile over a range of compositions and at 40 C and at pressures to 90 bar show very little enhancement, if any, in the solubility of the oxygen. While the oxygen solubility is greater than for 1 bar of pure oxygen, it is not significantly greater than the pure gas at the same oxygen partial pressure. In many cases, the solubility is less than if the entire applied pressure was pure oxygen. The situation is very different for the ionic liquid 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, where the presence of CO2 does significantly increase the solubility of oxygen, especially at total pressures above 30 bar. Comparison at the same thermodynamic conditions of temperature and pressure reveals the significant differences between the phase behavior of the molecular and ionic solvents. |
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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 |