Speed of sound and phase equilibria for ($CO_{2}$ + $C_{3}H_{8}$) mixtures

TL;DR

This study measures phase equilibria and speed of sound in CO₂ + C₃H₈ mixtures, comparing experimental data with models, and deriving thermodynamic properties relevant for industrial applications.

Contribution

It provides new experimental phase and sound speed data for specific CO₂+C₃H₈ mixtures and evaluates model performance against these measurements.

Findings

Average deviations: 0.24% in pressure, 0.025% in speed of sound

Derived thermodynamic properties include heat capacities and virial coefficients

Model comparisons show good agreement with experimental data

Abstract

This work presents phase envelope and speed of sound data for the (0.60 $CO_{2}$ + 0.40 $C_{3}H_{8}$) and (0.80 $CO_{2}$ + 0.20 $C_{3}H_{8}$) binary mixtures. Phase equilibria was measured using a cylindrical resonator working in the microwave band whereas an acoustic resonator was used for speed of sound measurements. The experimental results were compared with GERG-2008 equation of state, obtaining average absolute deviations by 0.24% in pressure for phase equilibria data and 0.025% for speed of sound data. Speed of sound values were used to derive perfect-gas heat capacities, acoustic virial coefficients, and second density virial coefficients. In addition, AGA8-DC92 equation of state performance was checked for the results derived from speeds of sound.