Abstract
The pure virial coefficients of carbon dioxide, methane, ethylene and propylene at 125°C were measured with the Burnett method by an apparatus newly built for the high-temperature region. By use of the same apparatus, the excess second virial coefficients for the six binary systems composed of these components were measured at 125°C with a gas-mixing method.
The temperature and pressure measurements were performed with a high accuracy of 5 ppm and 3 ppm, respectively. The estimated errors of pure and excess second virial coefficients are within 0.5% and 1.5%, respectively. The pure third virial coefficients are obtained within an accuracy of 10 %.
The interaction second virial coefficients for the six binary systems are calculated from the results of the pure and excess virial coefficients obtained in this experiment. The estimated error of the interaction second virial coefficients for all systems is smaller than 0.5 %.
