Phase equilibria of long chain n-alkanes in supercritical ethane: Review, measurements and prediction

The available sets of data for the phase equilibrium of long chain n-alkanes with 10 or more carbon atoms in supercritical ethane were studied to determine if the phase equilibrium pressure can be predicted from the number of carbon atoms and system temperature. It has previously been shown that for the phase equilibria of heavy n-alkanes in supercritical propane there exists, at constant temperature and mass fraction, a linear relationship between the number of carbon atoms and the bubble/dew point pressure. Published data in the temperature range 310–360 K was obtained from a literature survey and, where required, additional data was measured using a high-pressure equilibrium cell. It was found that linear relationships exist and that these relationships can be used to predict the phase equilibrium pressure within 4% of experimental values.