In our lab, we are doing experiments about the excess enthalpy of refrigerant and organic absorbent mixtures. With obtained excess enthalpy data at different temperatures, would it be possible to predict the vapor-liquid equilibrium behavior of the mixtures and how ?
Thanks!
The following information may be useful for your research
Abstract:he molecular interactions between the ionic liquid trimethylbutylammomium bis(trifluoromethylsulfonyl)imide, [N1114][Tf2N], and three common solvents, including short chain alcohols (ethanol and 1-propanol) and an aprotic solvent (N,N-dimethylformamide or DMF) were investigated through experimental properties. The excess enthalpies were measured by calorimetry at temperatures from 308.15 K to 323.15 K over the whole composition range and excess volumes were calculated from density measurements. The vapor–liquid equilibrium (VLE) measurements of the [N1114][Tf2N] + DMF mixture were obtained using a headspace gas chromatography instrument. It was determined that hydrogen bonds between the alcohol molecules contribute to the positive excess enthalpies, while the favorable interactions between DMF and [N1114][Tf2N] might be explained by electrostatic interactions between the ionic liquid and the zwitterionic resonance structure of DMF. The nonrandom two liquid (NRTL) equation was successfully used to correlate the excess enthalpy and VLE results.
Ref:hase Equilibrium, Excess Enthalpies, and Densities of Binary Mixtures of Trimethylbutylammonium Bis(trifluoromethylsulfonyl)imide with Ethanol, 1-Propanol, and Dimethylformamide
Massel, M et al,.
. Chem. Eng. Data, Article ASAP,2014
American Chemical Society
pubs.acs.org/doi/pdfplus/10.1021/je500696p
Yes, but you need a suitable constitutive equation and computational setup to do this. See links to sample publications.
http://link.springer.com/article/10.1007/BF00650760#page-1
http://www.tandfonline.com/doi/abs/10.1080/00986440701244317
If your pure fluids can be described by equations of state, it is possible to determine the binary interaction parameters from HE. You can probably do this with the ThermoC software via your browser (http://thermoc.uni-koeln.de/index.html).
But do not expect miracles: The excess enthalpy captures only a part of the nonidealities in a mixture.
Agree with the last two comments. Can suggest usage of recent publication:
FPE, 376(2014), 141-153
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