Water Content in Compressed Hydrogen at Low Temperatures: Experimental Measurements and Thermodynamic Modeling

Demand for hydrogen is increasing due to global warming concerns and the need to replace fossil fuels with cleaner energy sources. As production expands, efficient transport from production sites to end users becomes essential. While pipelines are preferred for short distances and large volumes, shipping is emerging as a flexible option for interregional and overseas hydrogen trade, especially where certain volume–distance combinations make pipelines impractical or uneconomical. Accurate thermodynamic models are therefore required to predict hydrogen behavior under varying pressures, temperatures, and impurity levels, particularly water vapor. This work presents new experimental data for the water content of hydrogen in equilibrium with ice and liquid water at temperatures from 233.15 to 283.15 K and pressures from 0.8 to 26.4 MPa using the Differential Scanning Hygrometry (DSH) technique. The data were compared with predictions from the Cubic Plus Association (CPA) and GERG-2008 equations of state and a dissymmetric model using the Peng–Robinson EoS with Henry’s law. All models showed similar deviations, with CPA giving the best predictions after parameter adjustment. The results extend existing data to higher pressures and confirm the capability of DSH for very low water contents.