Researchers from the University of Stuttgart and the University of Valladolid have conducted a study to better understand the behavior of natural gas mixtures when hydrogen is added, a process that could play a significant role in the decarbonization of the heat and power supply. The team, led by Daniel Lozano-Martín and including Fatemeh Pazoki, Heinrich Kipphardt, Peyman Khanipour, Dirk Tuma, Alfonso Horrillo, and César R. Chamorro, published their findings in the International Journal of Thermophysics.
The study focuses on the thermodynamic properties of a high-calorific natural gas mixture when hydrogen is added up to 20% by volume. As the energy industry explores ways to reduce carbon emissions, blending hydrogen into natural gas networks has emerged as a promising strategy. However, this approach requires a thorough understanding of how hydrogen affects the thermophysical properties of natural gas.
The researchers prepared three mixtures: a hydrogen-free natural gas mixture and two hydrogen-enriched versions with 10% and 20% hydrogen by volume. They then measured the density of these mixtures at temperatures ranging from 250 to 350 Kelvin and pressures up to 20 MPa using a high-precision densimeter. The experimental data were compared with predictions from three widely used equations of state for natural gas: the AGA8-DC92 EoS, the GERG-2008 EoS, and an improved version of the GERG-2008 EoS.
The results showed that the equations of state performed well for the hydrogen-free mixture, with deviations within their claimed uncertainty. However, for the hydrogen-enriched mixtures, especially at the lowest temperatures and highest pressures, the deviations were larger. This indicates that current models may need to be refined to accurately predict the behavior of hydrogen-enriched natural gas mixtures.
For the energy industry, this research highlights the importance of validating and potentially updating the equations of state used for natural gas when hydrogen is introduced. Accurate modeling of these mixtures is crucial for the safe and efficient operation of gas networks, as well as for designing equipment and infrastructure that can handle hydrogen-enriched natural gas. As the sector moves towards decarbonization, understanding these thermophysical properties will be key to integrating hydrogen into existing natural gas infrastructure.
This article is based on research available at arXiv.