Phase state of ternary mixture methane-propane-decane with low decane concentration
The present work shows the accurate calorimetric measurements of phase equilibrium of a ternary hydrocarbon mixture methane-propane-decane with low decane content in the range from 0.06 to 1.05 % mol. The heat capacity, temperature derivative of pressure at constant volume, internal energy and pressure as a function of temperature for ternary systems have been measured in the temperature range from 100 to 370 K and in the pressure range from 0.1 to 40 MPa. Based on experimental data of heat capacity and temperature derivative of pressure at constant volume, the phase diagrams for ternary hydrocarbon mixtures have been constructed. To show a method of precision adiabatic calorimetry the phase envelope construction of a classical shape for the ternary hydrocarbon mixture 79.79С1 +17.16С3+3.05C7 is presented in detail.Investigations show that if the decane content is less than 1 % mol., the phase behavior of hydrocarbon mixturedrastically transforms compared to the classical concepts. The hydrocarbon mixture is separated into a macrophase