The excess enthalpy of (water + hydrogen) vapour and (water + methane) vapour

Measurements of the (p, ρ,T) properties and virial coefficients of pure water, methane,n-hexane,n-octane, benzene, and of their aqueous mixtures in the supercritical region

“…Once again, as for B 12 , the C 112 , and C 221 may be regressed using B mix , C mix and x values over several components. The interaction second and third virial coefficients values are presented in table 5 and shown in figure 7 together with selected data from the literature.…”

“…Previously, Rigby and Prausnitz (10) used solubility measurements of water in compressed methane and nitrogen to extract interaction second virial coefficients at T = (298.15, 323, 348, and 373) K. Aoyagi et al (11) used a regression technique to extract interaction second and third virial coefficients at T = (240, 250, 260, and 270) K. Smith et al (12) have measured excess enthalpies of (water + methane) vapour. Using these excess enthalpies and assuming second virial coefficients, they also extracted interaction second virial coefficients at six temperatures ranging from T = 373.2 K to T = 423.2 K. Recently, Joffrion and Eubank (13) presented smoothed compression factors, densities, and residual thermodynamic properties for (water + methane) containing 50, 25, and 10 mole per cent of water.…”

Excess enthalpies and cross-term second virial coefficients for mixtures containing water vapour

“…where p12 is the dipole moment appropriate to the cross-term interaction. With t = 1, eqn (10) is equivalent to the rule t,*, = (t:t$ usually used with the Stockmayer potential.…”

“…We continued to use the Orbey-Vera correlation for the calculation of the v/ term even though it was not designed for polar fluids. Eqn (10) was now included in the combining rules. No attempt to take account of dipole-induced-dipole interactions was made, it was assumed that the energies were negligible compared with other terms.…”

“…3. Because of the additional combining rule (10) the valley runs in a different direction to curve (a). The standard deviation at the minimum of the valley is 2.5%.…”