Compressibility factors, densities, and residual thermodynamic properties for methane-water mixtures

Abstract

Smoothed compressibility factors and residual thermodynamic properties for mixtures of 50, 25, and 10 mol % water vapor In methane are presented along with experimental densities. Pressure-enthalpy diagrams for the three mixtures are also provided. The measured densities cover a temperature range of 498.15-398.15 K and a pressure range of 72 kPa to 12 MPa. These densities were measured by use of a Burnett-isochoric (B-I) apparatus and are accurate to ±0.08%. The adsorption phenomenon normally present In vapor measurements of polar components was taken into account during the B-I data analysis. Thus the densities, and therefore the residual properties, presented here are free of the errors caused by the adsorption process.

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

“…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. Richards et al (14) used excess enthalpy measurements of (water + nitrogen) vapour to derive cross-term second virial coefficients over the temperature range from 373.15 K to 423.15 K. In 1984, Rettich et al (15) measured the solubility of nitrogen in water at pressures from 45 kPa to 115 kPa.…”

Densities of (water + methane) in the temperature range 430 K to 699 K and at pressures up to 30 MPa

“…(4) The relative deviations of the present experimental results and those of Joffrion and Eubank (4) from the calculated values are shown in figures 1 and 2. In figure 1, the deviations (4) are plotted against pressure. Figure 2 shows the deviations as a function of the amount-of-substance fraction of H 2 O.…”

“…In this work, the methane used (Linde Gas UK Ltd) had a stated mole fraction of 0.99995 of CH 4 . The water (BDH Laboratory Supplies) was of AnalaR quality (conductivity: 5.005 mS·m −1 at T=293.1 K).…”

“…The predicted values were calculated using the Peng-Robinson equation of state with the optimum interaction binary parameter determined from an analysis of the density results of this work and those of Joffrion and Eubank. (4) The mixing rules adopted are the usual rules associated with the cubic equations of state. The optimum binary interaction parameter d ij of the Peng-Robinson equation of state was found to be 0.399.…”

“…In this paper we present the results of measurements of the density of nine mixtures {xH 2 O+(1−x)CH 4 } with amount-of-substance fractions x r ranging from 0.0760 to 0.6761. The measurements extend over the temperature range 430 K to 699 K, at pressures from 7.5 MPa to 30 MPa.…”