A Review of Experimental Researches on the Thermophysical Properties of Hydrogen-Containing Mixtures at High Temperatures and High Pressures

Hydrogen is a promising energy carrier compared with the direct burning of coal or oil. The gasification processes of coal, oil, and other organic substances in supercritical water (>647 K and 22.1 MPa) produce hydrogen-containing mixtures. The mixtures mainly contain H₂, CO₂, CH₄, and CO. Knowledge of the thermophysical properties which mainly include the PVT property, viscosity, and thermal conductivity is significant for the design and optimization of the relevant equipment. Currently available experimental researches on the thermophysical properties of hydrogen-containing mixtures at high temperatures and high pressures are reviewed. The review describes the progress in developing the measurement apparatuses, obtaining the thermophysical data, and observing the abnormal phenomena for the PVT property, viscosity, and thermal conductivity along with proposing the equation of state and transport property correlations of hydrogen-containing mixtures at high temperatures and high pressures. In addition, the possible advancements in both experiment and theory in the future are discussed.