Vapor–Liquid Equilibrium of Three Hydrofluorocarbons with [HMIM][Tf₂N]

Abstract

New experimental data for the vapor−liquid equilibrium of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIM][Tf 2 N]) with difluoromethane (R-32), 1,1-difluoroethane (R-152a), and pentafluoroethane (R-125) were presented. Measurements were performed using an isochoric saturation method at temperatures from (302.3 to 344.1) K and at pressures between (0.03 to 1.22) MPa. The relative expanded uncertainty in solubility measurement is less than 4 %. Within the investigated temperature and pressure range, the order of the solubilities for R-32, R-152a, and R-125 in [HMIM][Tf 2 N] is R-152a > R-32 > R-125. The experimental results were successfully correlated with the Krichevsky−Kasarnovsky equation. The AAD between the experimental data and calculated values for the solubilities of R-152a, R-32, and R-125 in [HMIM][Tf 2 N] are 1.4 %, 1.5 %, and 0.8 %, respectively.

The isobaric vapor liquid equilibria of ethyl acetate + acetonitrile + bis(trifluoromethylsulfonyl)imide-based ionic liquids at 101.3 kPa

“…Ionic liquids (ILs), not only due to their remarkable physicochemical properties but also for their recyclability, have attracted researchers' interest for their application on azeotropic distillation [2e18]. He et al [5] investigated the solubility of difluoromethane (R-32), 1,1-difluoroethane (R-152a), and pentafluoroethane (R-125) in [HMIM][NTf 2 ], and found that the solubility are in sequence of R-152a > R-32 > R-125. By means of studying the vapor liquid equilibria (VLE) data, excess enthalpies (H E ) of binary systems with 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ( ]), and prediction of g ∞ using modified UNIFAC(Dortmund), Gmehling et al [11] proposed that ionic liquids can be used to separate the azeotropic mixtures.…”

Gaseous absorption of fluorinated ethanes by ionic liquids

“…The solubilities increase with the increasing of pressure and decrease with the increasing of temperature. In order to investigate [21,22], indicating that replacing some hydrogen atoms of ethane by fluorine atoms will increase its solubility in ionic liquids. This phenomenon may due to the hydrogen bonds interactions between the fluorine atoms of the HFCs and the hydrogen atoms of ionic liquids.…”

“…From Table 5, we can find that the order of the absolute values of the partial molar enthalpies and the partial molar entropies at infinite dilution limit for the five fluorinated ethanes in [P14666][TMPP] is R143a < R134a < R152a < R125 < R161 which exhibits the same trend of the solubilities, indicating that larger values of the partial molar enthalpy and partial molar entropy at . Solubilities of gas in ionic liquids can be accurately correlated by the modified Krichevsky-Kasarnovsky (KK) equation [21] which is given by…”

“…The change in the mass of gas yields the solubility of gas in the solvent. A detailed description of apparatus and experimental procedure were given in our previous papers [21,22], we just give a brief introduction in this work. The apparatus mainly consists of the equilibrium cell, the gas reservoir, the magnetic stirrer and the temperature and pressure sensors.…”

“…Recently, lots of work have been carried out on the solubility behaviors of hydrofluorocarbons (HFCs) in ionic liquids which are important for applying ionic liquids + HFCs as working pairs for the absorption refrigeration cycles [2][3][4] or using ionic liquids as solvents for separation of hydrofluorocarbon mixtures [5]. Most of these work are on the solubilities of HFCs in imidazolium-based ionic liquids [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. There are little experimental data for the solubilities of HFCs in phosphonium-based ionic liquids although phosphonium-based ionic liquids have some advantages such as high thermal stability and low cost.…”