Volumetric properties and virial coefficients of (water+methane)

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

“…The virial coefficients for pure components found in this way are listed in table 3. The mixture virial coefficients found from the analysis of the isotherms (1)(2)(3) for each isopleth are given in table 4. The second virial coefficients for some mixtures are shown in figures 5 and 6.…”

“…In this paper, we present new measurements of the gas-phase (p,r,T) surface for pure water, methane, n-hexane, n-octane and benzene. We have already published (1)(2)(3) measurements of the (p,r,T,x) properties for their aqueous mixtures in the same temperature and pressure range as the pure-component measurements discussed in this paper. The results were obtained using an existing apparatus, (1)(2)(3)(4) which has been proven to be capable of providing measurements of high precision and accuracy.…”

“…Values for the piezometer were a = 1.4·10 −5 K −1 and b = 3.06·10 −5 MPa −1 . The inner volume of the piezometer was calibrated carefully by using standard pure water with a well known (p,r,T) properties (23) and found to be V T 0 ,p 0 = (124 2 0.06) cm 3 at T 0 = 293.15 K and p 0 = 0.1 MPa. From an analysis of the maximum cumulative errors, the experimental uncertainties with respect to density were estimated to be E0.1 per cent, since those for the inner volume V and the mass m of the sample did not exceed 0.05 per cent and 0.01 per cent, respectively.…”

“…A schematic diagram of the apparatus is shown in figure 1. The cylindrical piezometer 1 was made of type 321 stainless steel (80 mm outer diameter, 30 mm inner diameter) and contained a volume of approximately 124 cm 3 . The diaphragm-type null indicator 2 was mounted on one end of the piezometer and valve 7 on the other end.…”

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

“…Abdulagatov et al, (5) and Shmonov et al (6) There are substantial regions of overlap between the results of the present work and these three sets of data. However, because the compositions involved in these various studies are not identical, it is impossible to make a direct comparison through smoothed fits to the data.…”