Refractory behaviour in hydrogen atmospheres: insights for decarbonized direct reduction processes

In response to the environmental challenges facing the 21st century, the direct reduction of iron (DRI) technology is projected to gain space in steel production, initially with the use of natural gas as reducing agent but with progressively higher amounts of H2 added to the reducing gas, possibly up to 100%. As there is only limited precedent of industrial applications where refractories are exposed to atmospheres with such high levels of hydrogen content, the implications of these process changes for the durability of the refractory lining are still not fully comprehended. This work takes an experimental bottom-up approach to tackle this question, using high-temperature, multi-day hydrogen exposure tests under laboratory conditions to investigate the kinetics of reduction of ceramic oxides by hydrogen and provide mechanistic insights into corrosion. By identifying the key factors driving material degradation, this research will contribute to ensuring the reliability of refractories in hydrogen-based DRI for sustainable steel production.