Determining the Hydrogen Conversion Rates of a Passive Catalytic Recombiner for Hydrogen Risk Mitigation

Hydrogen can play a key role as short- and long-term energy storage solution in an energy grid with fluctuating renewable sources. In technologies using hydrogen, there is always the risk of unintended leakages due to the low density of gaseous hydrogen. The risk becomes specifically high in confined areas where leaking hydrogen could easily mix with air and form flammable gas mixtures. In the maritime transportation, large and congested geometries can be subject to accumulation of hydrogen. A mitigation measure for areas where venting is insufficient or even impossible is the installation of catalytic recombiners. The operational behavior can be described with numerical models which are required to optimize the location and to assess the efficiency of the mitigation solution. In the present study, we established an experimental procedure in the REKO-4 facility, a 5.5 m³ vessel, to determine the recombination rate obtained from a recombiner. Based on the experimental data, an engineering correlation was developed to be used for simulations in safety assessments.