Density, Speed of Sound, and Other Derived Properties of Ethanol at Pressures up to 65 MPa

A vibrating tube densitometer (VTD) and a high-pressure high-temperature (HPHT) acoustic cell were used to measure the density and speed of sound in ethanol for 5 isotherms at a temperature range of (323–423) K and pressures ranging up to 65 MPa. The measured sound velocities were used to calculate density and other derived properties, employing the initial value method (IVM). The computed values were compared with the predictions of Schroeder et al. equation of state for the thermodynamic properties of ethanol. The overall average absolute deviations (% AAD) of the measured properties in comparison to predictions of the model were found to be 0.05 and 0.30% for the density and speed of sound, respectively. The overall expanded uncertainties (k = 2) associated with the measured densities and sound velocities were found to be 0.03 and 0.09%, respectively. Moreover, the overall % AAD of the calculated properties in comparison to the predicted values of the model were calculated to be 0.05, 0.74, 0.58, and 3.16% for density, isobaric and isochoric heat capacities, and Joule–Thomson coefficient, respectively. The overall expanded uncertainties (k = 2) of the obtained properties were found to be 0.06, 0.04, 0.42, and 0.32% for density, isobaric and isochoric heat capacities, and Joule–Thomson coefficient, respectively.