Solubility Differences of Halocarbon Isomers in Ionic Liquid [emim][Tf₂N]

Abstract

Solubility behaviors of CFC-113 (CFCl 2 -CF 2 Cl), CFC-113a (CCl 3 -CF 3 ), CFC-114 (CF 2 Cl-CF 2 Cl), CFC-114a (CFCl 2 -CF 3 ), HCFC-123 (CHCl 2 -CF 3 ), HCFC-123a (CHClF-CF 2 Cl), HCFC-124 (CHFCl-CF 3 ), HCFC-124a (CHF 2 -CF 2 Cl), HFC-134 (CHF 2 -CHF 2 ), and HFC-134a (CH 2 F-CF 3 ) in room-temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf 2 N]) have been investigated using a gravimetric microbalance method from (283 to 348) K or volumetric and cloud-point methods. In the case of the perhalogenated compounds (CFC-113, CFC-114, and their isomers), the solubility behavior between isomers in the ionic liquid is practically identical with large immiscibility gaps. This suggests that the (present) ionic liquid cannot be used for these isomer separations. However, the monohydrogen substituted halocarbons (HCFC-123, HCFC-124, and their isomers) begin to show some difference (liquid-liquid immiscibility gap) in the ionic liquid. The isomer effect on the solubility in the ionic liquid becomes significant for the dihydrogen-substituted halocarbons (HFC-134 and HFC-134a), and these isomers can be separated using [emim][Tf 2 N] as an entrainer in an extractive distillation. This observation is consistent with our earlier findings for various HFCs in ionic liquids.

Phase Behavior of N2O and CO2 in Room-Temperature Ionic Liquids [bmim][Tf2N], [bmim][BF4], [bmim][N(CN)2], [bmim][Ac], [eam][NO3], and [bmim][SCN]

“…[13] b Ref. [14] have been successfully applied for refrigerant/lubricant oil mixtures [16,17], and various hydrofluorocarbons, NH 3 , and CO 2 mixtures with ionic liquids [18][19][20][21][22][23][24][25][26][27]. We have also successfully modeled ternary systems of CO 2 [14].…”

“…We model the phase behavior using our well established cubic equation-of-state (EOS) method [16][17][18][19][20][21][22][23][24][25][26][27] and show that the N 2 O (and CO 2 ) binary systems demonstrate both Type III and Type V phase behavior [11,12]. In addition, Henry's law constants for the present systems are analyzed and discussed.…”

Global phase behavior of imidazolium ionic liquids and compressed 1,1,1,2‐tetrafluoroethane (R‐134a)

“…To determine the effect of the anion, three ILs were compared based on the cation 1-hexyl-3-metyl-imidazolium ( 4,9 This trend scales with the diameter of the anion or charge density as larger anions can have more disperse negative charge. Ions with more disperse charge can be more readily solvated by the polar compressed hydrofluorocarbon, and thus become miscible at lower temperatures.…”

“…Shiflett et al, [6][7][8][9] have reported the majority of known data. They have measured the low-pressure (\10 bar) vapor-liquid equilibrium (VLE) and vapor-liquid-liquid equilibrium (VLLE) data of a large series of refrigerants and ILs; see Shiflett and Yokozeki 9 and Ren et al 10 14 …”

Synthesis and Sorption Analysis of Task-specific Fluorous Ionic Liquids

“…For an analogous series of 1,2,4-triazolium-based ILs, miscibility data have been reported only for common organic solvents [19,20]. Phase equilibria between the common hydrophobic IL 1-ethyl-3-methyl-imidazolium triflimide and HFE [21], halocarbon isomers [22], and (refrigerant) fluorocarbons [23,24] have been studied, revealing large differences in the solubilities. Based on this unique phase behavior of fluorocarbons in RTILs, they have been proposed as extractants for separation and purification.…”