A PREDICTIVE EQUATION OF STATE
A new methodology to improve predictive capability
To use the Peng and Robinson equation of state to predict the phase and volumetric behavior of mixtures, one must be able to provide the critical pressure, the critical temperature, and the acentric factor for each component in the mixture. For pure compounds, the required properties are well defined and known. Nearly all naturally occurring petroleum fluids contain a quantity of heavy fractions that are not well defined. These heavy fractions are often lumped together as heptanes-plus fraction. The problem of how to adequately characterize the C7+ fractions in terms of their critical properties and acentric factors has been long recognized in the petroleum industry. Changing the characterization of C7+ fractions present in even small amounts can have a profound effect on the PVT properties and the phase equilibria of a hydrocarbon system as predicted by the Peng and Robinson equation of state.
The usual approach for such situations is to “tune” the parameters in the EOS in an attempt to improve the accuracy of prediction. During the tuning process, the critical properties of the heptanes-plus fraction and the binary interaction coefficients are adjusted to obtain a reasonable match with experimental data available on the hydrocarbon mixture.
The main objective of the presentation is to review recent developments in equations of state and to present a new methodology that improves the predictive capability of PREOS.
Those registering on the day of the event will be charged $35 regardless of memebership status.