Molecular Simulations As a Tool for Predicting Phase Equilibria and Transport Properties of Fluids

Abstract

Dans cet article, nous passons bri•vement en revue les mŽthodes de simulation molŽculaire applicables ˆ la prŽdiction des propriŽtŽs thermophysiques des fluides et des mŽlanges. Nous montrons, d'une part, comment la mŽthode de Monte-Carlo dans l'ensemble de Gibbs permet de prŽdire le comportement de phase de fluides rŽels dans des conditions telles que l'acquisition de donnŽes expŽrimen-tales serait difficile, voire impossible. D'autre part, nous dŽcrivons les mŽthodes de dynamique molŽculaire utilisŽes pour prŽdire les propriŽtŽs de transport de fluides molŽculaires. Enfin, nous discutons le potentiel de ces mŽthodes pour les applications futures. MOLECULAR SIMULATIONS AS A TOOL FOR PREDICTING PHASE EQUILIBRIA AND TRANSPORT PROPERTIES OF FLUIDSWe briefly review the molecular simulation methods which can be used to predict thermophysical properties of fluids and fluid mixtures. It is shown in this paper, on the one hand, how the Gibbs Ensemble Monte Carlo Method allows phase behavior predictions for real fluids under conditions for which experimental data are difficult or impossible to obtain. On the other hand, the molecular dynamics methods used for predicting transport properties of molecular fluids are described. Finally we discuss possible future applications of these methods. SIMULACIONES MOLECULARES UTILIZADAS COMO HERRAMIENTAS PARA LA PREDICCIîN DES LOS EQUILIBRIOS DE FASES Y LAS PROPIEDADES DE TRANSPORTE DE LOS FLUIDOSSe examinan breve y sucesivamente, los mŽtodos de simulaci-n molecular aplicables a la predicci-n del las propiedades termof'sicas de los fluidos y de las mezclas. En este art'culo se exponen, en primer lugar, c-mo el mŽtodo de Monte Carlo en el conjunto de Gibbs permite predecir el comportamiento de fase de fluidos reales en tales condiciones que la adquisici-n de datos experimentales ser'a dif'cil, por no decir imposible. En segundo lugar, se describen los mŽtodos de din ‡mica molecular utilizados utilizados para predecir las propiedades de transporte de fluidos moleculares, Finalmente, se pone en discusi-n el potencial de estos mŽtodos para las aplicaciones futuras. Copyright © 1998, Institut français du pétrole INTRODUCTIONMolecular simulation and molecular modeling techniques are profitably employed nowadays in several industrial sectors. The use of molecular simulation includes, for instance, the design of new molecules or phases through the prediction of their physical or chemical properties. Knowledge of phase equilibria and transport properties of multicomponent gases and oils is of great economic importance in reservoir modeling, as well as in the planning of transport and in the design of industrial plants. Although the physical properties have, in general, been well studied, certain areas remain extremely difficult to access by experimentation. These include systems under high pressure and temperature as well as molecules for which pure samples may not be readily available. However, there is a great deal of interest in studying these systems precisely because of the existence o...

Measurement and Prediction of Volumetric and Transport Properties of Reservoir Fluids At High Pressure

“…Monte Carlo simulation or molecular dynamics (Fuchs, 1998). Indeed, these techniques have the advantage of predicting equilibrium properties and transport properties as well, within a more rigorous framework.…”