Flow-calorimetric results for the specific heat capacity cp of CO2, of C2H6, and of (0.5CO2 + 0.5C2H6) at high pressures

The speed of sound and derived thermodynamic properties of ethane at temperatures between 220 K and 450 K and pressures up to 10.5 MPa

“…The agreement with the values calculated from spectroscopic data by Chao et al (20) is always within 0.1 per cent. The calorimetric results of Ernst and Hochberg (21) deviate by between −0.1 per cent and −0.3 per cent, but this is reasonable in the light of their claimed maximum uncertainty of 20.3 per cent. The acoustic results of Esper et al (22) deviate by between 0.3 per cent and −0.4 per cent; these authors make no statement about their overall uncertainty but clearly the observed deviations greatly exceed the available precision in an acoustic determination.…”

“…The observed differences lie between −1.2 per cent and 0.4 per cent. Finally, in figure 10 we compare the isobaric heat capacities with those of Ernst and Hochberg (21) which have claimed uncertainties of between 0.2 to 0.4 per cent. The agreement is within 0.5 per cent in all cases.…”

Experimental determination of the critical line for (carbon dioxide + ethane) and calculation of various thermodynamic properties for (carbon dioxide +n-alkane) using the PSRK model

“…Typically, an extensive set of experimental data on the systems over a wide temperature range is required for obtaining these parameters by regression. Ernst and Hochberg (3) have stated that in this process the lack of experimental values seems to become more and more the limiting factor.…”

Excess enthalpies and volumes for (carbon dioxide + ethane) atT= 291.6 K, close to the minimum in the critical locus

“…measurements with a Burnett apparatus, a continuously weighed pyknometer, and an enthalpy increment flow calorimeter. Isobaric heat capacities of carbon dioxide, ethane, and of the binary mixture, measured in the temperature range 303 K to 393 K, at pressures up to 50 MPa, have been published by Ernst et al (16,17) A feature of the measurements made by the Bristol group (7,8) was that an attempt was made to reach as close to the critical points of the mixture as possible. Work to date concentrated on making measurements close to the critical temperatures of the pure components, while this paper focuses on measurements close to the minimum temperature of the critical locus.…”