Accuracy of the volumetric predictions of some important equations of state for hydrocarbons, including a modified version of the Lee-Kesler method

The present study evaluates the accuracy of five equations of state for the determination of the volumetric properties of pure hydrocarbon compounds. The equations examined are Peng-Robinson, Simonet-Behar-Rauzy, Lee-Kesler, Chain of Rotators and a modified version of the Lee-Kesler method. The accuracy of density calculations for alkanes up to butane are expressed as deviation maps in (P, T), coordinates. For higher alkanes, deviation graphs are presented along isobars and isotherms. The analysis stresses the behavior in the high pressure (up to 2000 bar) and high temperature (up to 500 K) region. The modified version of the Lee-Kesler method provides good results for hydrocarbons up to n-butane, but not for heavier components.