Assessment Of Density And Volume Data Of Fluid Methane And Hydrogen

The pressure-volume-temperature（PVT）data from experiments and molecular dynamics（MD）and Monte Carlo（MC）simulations of CH₄ and H₂ are assessed carefully in this work.The reference data are taken from the free energy model of CH₄developed by Setzmann and Wagner（1991）and that of H₂ developed by Leachman et al.（2009）,or their appropriate extrapolation.Among the experimental PVT data of CH₄,the data of Trusler and Zarari（1992）,Atilhan（2007）,Cristancho et al.（2010）,Ejaz（2007）and Le No?et al.（1996）are accurate.The data of Evers et al.（2001）have large deviations at low pressures,but their other results are very accurate.The data of Fenghour et al.（1995）and Patil（2005）have small systematic deviations.The density data of Biswas and ten Seldam（1992）derived from sound velocity measurements and those of Obriot et al.（1993）derived from refractive index measurements have notable deviations.The density data of St-Arnaud et al.（1994）,Obriot et al.（1993）and Malbrunot et al.（1994）derived from dielectric constant measurements are good,but those of the third group have small systematic deviations.There are 6 sets of simulated data for CH₄.The data of Abbaspour（2011）have obvious systematic deviation,but their volume deviation is within 2.5%.The deviations simulated volumes of Aimoli et al.（2014）is within 1.1%.In the simulated results of Kadoura（2011）,the volume deviations of supercritical CH₄ from LJ model are mostly within 2%;the other simulation results are inaccurate or very inaccurate.The data of Belonoshko and Saxena（1991）show lage deviations.The simulated volumes of Duan et al.（1992）have obvious negative deviations.The simulated volumes of Zhang et al.（2007）have significant positive deviations,but their results below 1 GPa are good.There are 5 sets of experimental or MD simulation data for shock compressed CH₄.The experimental volumes of Radousky et al.（1990）are obviously larger than those of Nellis et al.（2001）.The simulated results of Li et al.（2011）are quite different from experimental values above 36 GPa,but they agree well with the experimental results of Nellis et al.（2001）below 36 GPa.The simulated results of Goldman et al.（2009）are in good agreement with the experimental data of Radousky et al.（1990）.The simulated results of Bolesta et al.（2007）are obviously unreasonable.The two sets of experimental data of Sakoda et al.（2012）have small systematic deviation,but their volume deviations are within 0.17%and 0.24%,respectvely.The experimental results of Supriatno（2018）and the MD simulation results of Belonoshko and Saxena（1991）show obvious systematic deviations.