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

• Published in: Fluid phase equilibria 2017-12, Vol.454, p.78-90
• Main Authors: Nath, Devjyoti, Sumon, Kazi Z., Tagiuri, Ali, Henni, Amr
• Format: Article
• Language: English
• Subjects: Carbon capture; Equation of state; Ionic liquids; Solubility
• ISSN: 0378-3812; 1879-0224
• DOI: 10.1016/j.fluid.2017.08.011

The solubility of ethane (C2H6) in three ionic liquids (ILs) with the same anion, [C3C1pip][FSI], [C3C1pyrr][FSI] and [N1223][FSI], was measured at (303.15, 323.15, and 343.15) K and at pressures up to 1.1 MPa. Experimental data were correlated with Peng-Robinson (PR) equation of state using three different mixing rules: (i) van der Waals one (vdW1, based on a single binary interaction parameter), (ii) van der Waals two (vdW2, based on two binary interaction parameters), and (iii) Wong-Sandler mixing rules combined with NRTL model. Henry's law constants, enthalpy and entropy for the absorption of ethane in these ILs were also estimated. No significant change was found in the values of Henry's law constants of C2H6 in these three ILs which indicates a negligible effect of cations of these ILs on C2H6 solubility. The selectivity towards carbon dioxide (CO2) over C2H6 for these ILs was also reported. [FSI]-based ILs seem to have higher selectivity than all the other ILs, except for [C4C1Im][BF4] and possibly [C4C1Im][PF6], which may qualify them as promising solvents for CO2 removal from natural gas streams. [Display omitted] •Solubility of ethane in three bis(fluorosulfonyl)imide ([FSI]) based ionic liquids were measured.•Three piperidinium, pyrrolidinium and ammonium based cations were tested.•Solubility data were correlated with Peng-Robinson EoS using three different mixing rules.•Henry's law constants of C2H6 absorption were estimated at different temperatures.•Selectivity of these ILs towards CO2 over C2H6 were calculated at 303.15 K and 343.15 K.