Page 70 - Handbook of Natural Gas Transmission and Processing Principles and Practices

Abstract
Natural gases have so many industrial applications that a major challenge is to develop a
thermodynamic model able to predict the phase equilibrium of these mixtures. Such
predictions are indeed essential for the processing of natural gases and the design of
transportation facilities. The most commonly used models for this purpose are cubic equations
of state (EoS) and especially the ones issued from the Redlich-Kwong and Peng-Robinson
classes. The SAFT-type models are a promising class of EoS emerging since the late 1980s.
Although no industrialized version of SAFT EoS really exists nowadays, proof has been given
that the Perturbed-Chain-SAFT EoS can be successfully used to model natural-gas phase
envelopes. The goal of this chapter is to describe and analyze the various EoS models usable for
the correlation and prediction of phase-equilibrium and energetic properties (enthalpy, heat
capacities, etc.) of natural gases. In the last part of this chapter, some of these models are
compared on the basis of the reproduction of experimental phase-envelope data of real or
synthetic natural gases.

Keywords
Natural gas; Phase behavior; Phase-equilibrium; Energetic properties; Thermodynamic
models; Equations of state

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