2011XXXVII JEEP – 37th Conference on Phase Equilibria
|Number of page(s)||5|
|Published online||05 October 2011|
PPR78, a thermodynamic model for the prediction of petroleum fluid-phase behaviour
ENSIC – LRGP (UPR CNRS 3349), 1 rue Grandville – BP20451 – 54001 Nancy Cedex - France
Nowadays, design and optimization of chemical engineering processes are carried out using process simulators. However, the accuracy of the obtained results strongly depends on the choice of an appropriate thermodynamic model. In most of the cases, chemical engineers need information about phase equilibria of multicomponent systems for which few or no data are available. It is thus essential to dispose of a reliable thermodynamic model (i) predicting the equilibrium properties without the preliminary use of experimental data; (ii) yielding accurate results in both the sub-critical and critical regions. In order to meet these challenges, the predictive thermodynamic model PPR78 is developed since 2004. This equation of state combines the model proposed by Peng and Robinson in 1978 with classical Van der Waals mixing rules involving a temperature-dependent binary interaction parameter kij(T). These kij coefficients are predicted by PPR78 from the mere knowledge of chemical structures of molecules within the mixture. Today, the PPR78 model is able to represent the fluid phase behaviour of any fluid containing alkanes, alkenes, aromatic compounds, cycloalkanes, permanent gases (CO2, N2, H2S, H2), mercaptans and water. In order to test the predictive capabilities of the PPR78 model, fluid phase behaviour of synthetic petroleum fluids including natural gases, gas condensate, crude oils etc. were predicted. In many cases, the PPR78 model allows a fine prediction of fluid phase behaviours with an accuracy close to the experimental uncertainty.
© Owned by the authors, published by EDP Sciences, 2011