Abstract
Experimental solubilities are reported for carbon dioxide in four ionic liquids: trihexyl tetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate [P(14)666][TMPP], tetrabutylphosphonium bis(2,4,4-trimethylpentyl) phosphinate [P4444][TMPP], trimethyloctylphosphonium bis(2,4,4-trimethylpentyl) phosphinate [P8111][TMPP], and trihexyl tetradecylphosphonium dicyanamide [P(14)666][DCA] from 298 K to 334 K up to 4 MPa. Tetraalkyl phosphonium bis(2,4,4-trimethylpentyl) phosphinate ionic liquids show solubilities for carbon dioxide higher than those in other ionic liquids. In these phosphonium-based ionic liquids, the anion appears to have a larger influence on carbon-dioxide solubility than the cation. Water or 1-butyl-3-H-imidazolium acetate ([BHMIM][AC]) are used as diluents to reduce the large viscosity of [P(14)666][TMPP]. Viscosities are reported for mixtures of [P(14)666][TMPP] with varying content of water or [BHMIM][AC] from 298 K to 343 K at atmospheric pressure. Solubilities for carbon dioxide are reported in mixtures of [P(14)666][TMPP] with varying content of water or [BHMIM][AC] from 298 K to 323 K up to 4 MPa. These diluents very much reduce the viscosity. The addition of [BHMIM][AC] does not seriously lower the solubility of carbon dioxide.
Original language | English |
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Pages (from-to) | 954-960 |
Number of pages | 7 |
Journal | Journal of Chemical and Engineering Data |
Volume | 59 |
Issue number | 4 |
Early online date | 21 Feb 2014 |
DOIs | |
Publication status | Published - 10 Apr 2014 |