Hydrogen Recombiners for Non-nuclear Hydrogen Safety Applications

Hydrogen recombiners are catalyst-based, hydrogen mitigation systems that have been successfully implemented in the nuclear industry, but have not yet received serious interest from the hydrogen industry. Recombiners have been installed in the containment buildings of many nuclear power plants to prevent the accumulation of hydrogen in potential accidents. The attractiveness of hydrogen recombiners for the nuclear industry is due to the confined state of the containment building, where hydrogen cannot be vented easily, and its passive design, where no power or actions are needed for the unit to operate. Alternatively, in the hydrogen industry, most applications utilize ventilation to mitigate potential hydrogen accumulation in confined areas and passive safety is not essential. However, many applications in the hydrogen industry may utilize hydrogen recombiners from a different approach. For instance, recombiners could be utilized in emerging hydrogen areas to minimize the costs of ventilation upgrades, or built into hydrogen appliances to avoid vent connections. The potential applications for recombiners in the hydrogen industry have different atmospheric conditions than the nuclear industry, which may impact the catalyst in the units and render them less effective. Thus, experiments have been performed to investigate the limits of the recombiner catalyst and if modifications to the catalyst can extend their use to the hydrogen industry. This paper will present and discuss the applications of interest, conditions that may affect the catalyst and results from experiments investigating the catalyst behaviour at temperatures less than 0 °C and carbon monoxide concentrations up to 1000 ppm.