A Thermodynamic Model to Calculate the Solubilities of Heavy Oils in Supercritical Carbon Dioxide

摘要

Over the past few years, significant interest has been expressed in a separation concept wherein a condensed phase is contacted with a supercritical fluid phase in a solvent extraction process, which is the basis for several industrial processes, such as the petroleum refining. The thermodynamic formulations for correlating and predicting phase equilibrium behavior in the supercritical fluid region are in a crescent development as can be found in several works in the literature. So, there is a frequently necessity for a correct characterization of the phase behavior of this kind of systems, calculating the solubilities of heavy oils in the supercritical fluids. The aim of this work is to present a thermodynamic model to correlate and predict the experimental data available in the literature for two selected systems formed by supercritical carbon dioxide with decane and hexadecane. This model was based on the Peng - Robinson equation of state and two different mixing rules, Heideman and Kokal (HK) and LCVM, were tested. The results show a satisfactory characterization of the phase behavior of the selected systems.