Key words: critical parameters, supercritical mixtures, concentration, equation of state, compressibility factor, reduced parameters, relative error
The p, ρ, T, x-relationshi ps for water + aliphatic alcohol (methanol, ethanol, n-propanol) mixtures in near-critical and supercritical conditions obtained by compressibility measurements using the piezometric setup are analyzed. It is demonstrated that thermodynamic surface (p, ρ,T)x or (Z, ρ,T)x in supercritical region can be satisfactory described (average relative error 0.83 %) by the equation of state in the form of polynomial decomposition of compressibility factor Z = p/RT to the series of degrees of density and temperature:
\(Z=1+\sum_{i=1}^{m}\sum_{j=0}^{n_i}a_{ij}\omega^i/\tau^j\), where
\(\omega=\rho_m/\rho_{m_{cr}}, \tau=T/T_{cr}\)
doi:10.1134/S1990793113080022