A group-contribution equation of state for predicting vapor-liquid equilibria and volumetric properties of carbon dioxide-hydrocarbons systems

In order to predict the solubility of carbon dioxide in heavy solvents the model excess function-equation of state is applied. It combines an accurate equation of state for carbon dioxide, a Peng-Robinson-type one for hydrocarbons and a Van Laar-like excess function defined at constant packing fraction in which interaction parameters are estimated from contribution-group method. It is shown that the model proposed leads to a good correlation and prediction of vapour-liquid equilibria of binary systems composed of carbon dioxide and hydrocarbons. Its ability for estimating volumetric properties is also analyzed.