Solubility of the Single Gases Methane and Xenon in the Ionic Liquid [hmim][Tf₂N]

Abstract

This work reports new experimental results for the solubility of two single gases (methane and xenon) in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([hmim][Tf2N]). The solubility was measured with a high-pressure view-cell technique operating on the synthetic method. The temperature ranged from 293.3 to 413.3 K, and the maximum pressure (the maximum gas molality) was 9.3 MPa (0.51 mol·kg-1) for methane and 9.6 MPa (2.08 mol·kg-1) for xenon. Xenon shows a significantly higher solubility than methane at all conditions investigated. Both gases become less soluble in [hmim][Tf2N] with rising temperature. An extension of Henry's law is employed to correlate the solubility pressures. The final results for the Henry's constants (at zero pressure) of methane and xenon in [hmim][Tf2N] (on the molality scale) are represented within the experimental uncertainty (about 1.2% for methane and 1% for xenon) by ln( /MPa) = 6.4929 − 835.9/(T/K) − 0.003471(T/K) and ln( /MPa) = 6.3357 − 1321.4/(T/K) − 0.00265(T/K), respectively.

Phase equilibria of imidazolium ionic liquids and the refrigerant gas, 1,1,1,2-tetrafluoroethane (R-134a)

“…This single phase behavior is quite unique for hydrofluorocarbon refrigerant gases and ionic liquids, as most compressed gases (CO 2 , CO, ethane, etc.) have no reported miscibility with ILs [6][7][8][9]. For instance, Brennecke and coworkers [10] indicate that [BMIm][PF 6 ] and CO 2 represent a two-phase system even beyond 3.1 kbar at 40 • C. For comparison, we have measured the critical point of this IL with R-134a at approximately 110 bar at 50 • C [3].…”

Modeling imidazolium-based ionic liquids with ePC-SAFT

“…This can be seen also from Table 8, which summarizes the ARD values of the ePC-SAFT predicted CO 2 solubilities in ILs. [65,92,93]. In general, the CH 4 solubility in ILs is much lower than the CO 2 solubility.…”

Modeling imidazolium-based ionic liquids with ePC-SAFT. Part II. Application to H2S and synthesis-gas components

“…The solubility data of CH4 stem from [45] and those for CO2 from [46]. Curves will guide the reader's eye.…”