Hydrogen Recombiners: An Alternative Strategy for Hydrogen Mitigation

Hydrogen recombiners exploit a noble metal catalyst that enables the oxidation of hydrogen by oxygen (in air) reaction for non-flammable hydrogen-air mixtures at room temperatures. They can be used to remove hydrogen in confined spaces during accidental release, preventing the potential for accumulation, fire, and explosions, or they can be used as part of ventilation systems in controlled releases. The most common hydrogen recombiner found in the market – the passive autocatalytic recombiner (PAR) – has been widely adopted in the nuclear industry to prevent hydrogen explosions in nuclear containment buildings. To-date, despite their usefulness, hydrogen recombiners are not widely known outside the nuclear industry.

More recent studies have focused on the application of hydrogen recombiners for the hydrogen industry, which can take advantage of years of research experience. A new study has been performed at Canadian Nuclear Laboratories (CNL) to compare the economics of retrofitting a hydrogen installation with an upgraded active ventilation system versus the installation of recombiners to prevent the accumulation of hydrogen. This paper will provide details on the relevant studies of recombiners, including an economic analysis, to demonstrate the applicability of hydrogen recombiners as an alternative or redundant approach for hydrogen mitigation.