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Speed of Sound Measurements of Binary Mixtures of trans-1,2-difluoroethylene (R-1132(E)) with Difluoromethane (R-32) or 2,3,3,3-Tetrafluoropropene (R-1234yf)
Published
Author(s)
Aaron Rowane
Abstract
The speed of sound of two binary mixtures containing 33.6 mole % trans-1,2-difluoroethylene (R-1132(E)) with difluoromethane (R-32) and 43.5 mole % R-1132(E) with 2,3,3,3-tetrafluoropropene (R-1234yf) were measured with a dual-path pulse-echo instrument. The speed of sound was measured along several pseudo-isochores for each blend at temperatures ranging from 230 K to 325 K for blends with R-32 and to 342 K for blends with R-1234yf. Measurements started at pressures just above each mixtures bubble point pressure and were limited to 8 MPa to avoid potential disproportionation reactions of the R-1132(E). The data were compared to multifluid models incorporating Helmholtz-energy-explicit equations of state (EOS) for each pure fluid. No binary interaction parameters for either the R-1132(E)/32 or R-1132(E)/1234yf system are currently available. Therefore, binary interaction parameters for chemically similar systems suggested by REFPROP version 10.0 were used. Deviations from the measured data to the EOS ranged from 5.5% to 11.0% for the R-1132(E)/32 system and 0.4% to 1.8% for the R-1132(E)/1234yf system. These results were unsurprising for several reasons: 1) The R-1132(E) EOS is preliminary and no liquid phase speed of sound data were fit to it, 2) there are known weaknesses in speed of sound calculations with the current EOS for R-32, and 3) binary interaction parameters fit to experimental data are needed to obtain reference quality thermodynamic property values. These data will be used to refit the R-1132(E) EOS and fit mixture models for R-1132(E) blends with R-32 and R-1234yf.
Rowane, A.
(2025),
Speed of Sound Measurements of Binary Mixtures of trans-1,2-difluoroethylene (R-1132(E)) with Difluoromethane (R-32) or 2,3,3,3-Tetrafluoropropene (R-1234yf), Journal of Chemical and Engineering Data, [online], https://doi.org/10.1021/acs.jced.4c00531, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958769
(Accessed October 7, 2025)