Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Sorption of trifluoromethane in zeolites and ionic liquid

Shiflett, M. B.[Mark B.], Corbin, D. R.[David R.], Elliott, B. A.[Beth A.], Yokozeki, A.
J. Chem. Thermodyn. 2013, 64, 40-49
ABSTRACT
Sorption isotherms for trifluoromethane (R-23) on three zeolites, Na-Y, K,H-Y, and Rb,Na-Y and ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [emim][Tf2N] have been measured at ca. 298 and 323 K, using a gravimetric microbalance. The adsorption on the zeolites reaches about 3 mol kg 1 at 0.025 MPa and 298 K while in the ionic liquid the absorption reaches 3 mol kg 1 at about 2.5 MPa (100 times higher pressure). Three different adsorption models (Langmuir, multi-site Langmuir, and BET equations) have been used to analyze the zeolite sorption data, with a particular interest in the heat of adsorption ( DH). The heat of adsorption for zeolites Na-Y, K,H-Y, and Rb,Na-Y were about 35 +- 3 kJ mol 1, 29 +- 3 kJ mol 1, and 34 +- 5 kJ mol 1, respectively. These values are within the range of typical physical adsorption. According to the IUPAC classification, the zeolites exhibit Type II adsorption and according to the Scott and van Konynenburg classification the ionic liquid is predicted to be Type V phase behavior. The adsorption process on the zeolites took more time than the absorption process in the ionic liquid to reach the thermodynamic equilibrium and both processes were reversible.
Compounds
# Formula Name
1 CHF3 trifluoromethane
2 C8H11F6N3O4S2 1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 2
  • Mole fraction - 1 ; Liquid
  • Pressure, kPa; Liquid
  • Temperature, K; Liquid
  • Liquid
  • Gas
  • gravimetric microbalance
  • 35