Predictions of the Joule−Thomson Inversion Curve for the n-Alkane Series and Carbon Dioxide from the Soft-SAFT Equation of State

In this work, we use a molecular based equation of state, the Soft-SAFT equation, to predict complete Joule−Thomson inversion curves for carbon dioxide and the n-alkane series, including heavy n-alkanes up to octatetracontane (n-C<INF>48</INF>H<INF>98</INF>). Comparisons with available experimental and correlation data, for carbon dioxide and the lighter n-alkanes, show good quantitative agreement. We observe a strong dependence of the inversion curve on the set of molecular parameters used in the calculations, especially near the inversion point and in the high-temperature region. The equation is able to predict the general trend of inversion curves even for extreme conditions, with reduced pressure, P<INF>r</INF> = P/P<INF>c</INF>, values up to 40, and reduced temperatures, T<INF>r</INF> = T/T<INF>c</INF>, of almost 5.