An experimental investigation of the critical state of aqueous solutions of aliphatic alcohols

The ballast-free constant-volume piezometer technique is used for measuring the $p$, $\rho$, $T$ dependences of aqueous solutions of aliphatic alcohols (methanol, ethanol, and 1-propanol) with $0.2$, $0.5$, and $0.8$ mole fraction of alcohol in the temperature range from $373.15$ to $623.15$ K and at pressures up to $50$ MPa for different values of density. The data of $p$, $\rho$, $T$ measurements in the near-critical region are used to determine the parameters of critical state of solutions as a function of composition. Diagrams are constructed of projections of lines of critical points of thermodynamic surface in different planes.