Effect of cation on the solubility of carbon dioxide in three bis(fluorosulfonyl)imide low viscosity ([FSI]) ionic liquids

The solubility of carbon dioxide in three bis(fluorosulfonyl)imide-based ionic liquids: N-propyl-n-methyl-piperidinium bis(fluorosulfonyl)imide ([p(3)mpip][FSI]), N-propyl-n-methyl-pyrrolidinium bis(fluorosulfonyl)imide ([p(3)mpyrr][FSI]) and N-propyl-n-methyl-n,n-dimethyl-ammonium bis(fluorosulfonyl)imide ([N-4441][FSI]) was measured at (298.15, 313.15, and 343.15)K and pressure up to about 2 MPa. The Henry's law constants for CO2 in the three ILs, ([P(3)mPiPl[FSI], [p(3)mpyrr][FSI] and([N-4441][FSI])at 298 K are (4.1, 4.0, and 3.8)MPa respectively, indicating the negligible effect of change of cation precursors on CO2 solubility. Solubility of CO2 in the present ILs with [FSI] anion is comparable with those in the ILs containing a more fluorinated common anion, [Tf2N]. The solubility data were correlated well with the Soave-Redlich-Kwong equation of state (SRK-EoS). (C) 2014 Elsevier B.V. All rights reserved.