Analysis of Experimental Studies from European Projects on the Safety of Liquefied Hydrogen Storage Tanks: Insights and Research Directions

Liquefied hydrogen (LH₂) is increasingly regarded as a promising energy carrier for decarbonizing transport due to its high energy density and zero carbon emissions at the point of use. In particular, the application of LH₂ in maritime systems requires large-scale cryogenic storage tanks, which introduce safety challenges that differ fundamentally from those of conventional marine fuels. Although numerous European projects have addressed LH₂ technologies, a structured synthesis of experimental safety knowledge relevant to shipboard LH₂ storage tanks is still lacking. This study systematically reviews European projects related to the safety of LH₂ storage, transfer, and operation, with the objective of identifying safety-relevant knowledge gaps that limit the riskinformed design and safe implementation of LH₂ storage tanks in maritime applications. The review primarily focuses on physical experiments investigating safety-critical phenomena, which are analyzed across key hazard domains, including LH₂ release and dispersion, pool formation and evaporation, ignition and explosion behavior, fire exposure, boiling liquid expanding vapour explosion (BLEVE), and mitigation technologies. In addition, selected non-experimental European projects are considered to provide system-level context and to support the interpretation of experimental findings within a risk-based safety framework. The cross-project analysis shows that most existing experiments are limited to static or quasi-static conditions, revealing a critical gap in experimental evidence for dynamic effects that are particularly relevant to large-scale LH₂ storage tanks in maritime environments. Based on the identified gaps, this study outlines key research directions to support riskinformed design and the safe maritime implementation of LH₂ storage tanks.

Keywords: Experimental studies, Liquefied hydrogen storage tanks, Safety, Research direction.