Tables of methane, ethane, propane, isobutane, and normal butane thermodynamic and transport properties are presented. The mathematical relations from which these thermophysical properties are obtained are described. The tables list pressure, density, temperature, internal energy, enthalpy, entropy, specific heat at constant pressure and at constant volume, sound speed, viscosity, thermal conductivity, and dielectric constant.

A model for the prediction of the viscosity of nonpolar fluid mixtures over the entire range of PVT states is presented. The model is an extension of an earlier version (Hanley, 1976) to molecular weights which roughly correspond to that of Ch-The proposed model Is based on an extended corresponding states principle and requires only critical constants and Pltzer's acentric factor for each component as input. Extensive comparisons with experimental data for pure fluids and binary mixtures are presented. The average deviation between experiment and prediction is 8% for pure species and 7% for mixtures.

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In this paper we develop a crossover modification of the statistical associating fluid theory (SAFT) equation of state for macromolecular chain fluids which incorporates the scaling laws asymptotically close to the critical point and is transformed into the original classical SAFT equation of state far away from the critical point. A comparison is made with experimental data for pure methane, ethane, n-hexane, n-decane, and n-eicosane in the one- and two-phase regions. We also present comparisons with experimental single-phase data for n-triacontane and n-tetracontane. We show that, over a wide range of states, the crossover SAFT model yields a much better representation of the thermodynamic properties of pure fluids than the original SAFT equation of state. The crossover SAFT equation of state reproduces the saturated pressure data in the entire temperature range from the triple point to the critical temperature with an average absolute deviation (AAD) of about 3.8%, the saturated liquid densities with an AAD of about 1.5%, and the saturated vapor densities with an AAD of about 3.4%. In the one-phase region, the crossover SAFT equation represents the experimental values of pressure in the critical region with an AAD of about 2.9% in the region bounded by 0.05ρc ≤ ρ ≤ 2.5ρc and T c ≤ T ≤ 2T c, and the liquid density data with an AAD of about 3% at the pressures up to P = 2000 bar. For the n-alkanes C m H2 m +2 with the molecular weight M w > 142 (m > 10), the crossover SAFT model contains no adjustable parameters and can be used for the pure prediction of the fluid thermodynamic surface.

New correlations for the thermophysical properties of fluid methane are presented. The correlations are based on a critical evaluation of the available experimental data and have been developed to represent these data over a broad range of the state variables. Estimates for the accuracy of the equations and comparisons with measured properties are given. The reasons for this new study of methane include significant new and more accurate data, and improvements in the correlation functions which allow increased accuracy of the con.-elations especially in the extended critical region. For the thermodynamic properties, a classical equation for the molar Helmholtz energy, which contains terms multiplied by the exponential of the quadratic and quartic powers of the system density, is used. The resulting equation of state is accurate from about 91 to 600 K for pressures < 100 MPa and was developed by considering PVT, second virial coefficient, heat capacity, and sound speed data. Tables of coefficients and equations are presented to allow the calculation of these and other thermodynamic quantities. Ancillary equations for properties along the liquid-vapor phase boundary, which are consistent with the equation of state and lowest order scaling theory, are also given. For the viscosity of fluid methane, a low-density contribution based on theory is combined with an empirical representation of the excess contribution. The approximate range of the resulting correlation is 91 to 400 K for pressures < 55 MPa. The correlation for the thermal conductivity includes a theoretically based expression for the critical enhancement; the range for the resulting correlation is about 91 to 700 K for pressures below 100 MPa.