Abstract
Despite periods of enthusiasm and numerous announcements of large-scale projects, electrolytic hydrogen has not yet been widely deployed in commercial-scale industrial applications. Hydrogen is still considered an important mitigation tool, given its potential to decarbonize heavy transport, chemical feedstocks, and hard-to-abate industries. Metallurgical processes are among the most difficult to decarbonize sources of greenhouse gas emissions: high temperature requirements can make electrification impractical or impossible, carbon-based reducing agents are frequently required, and novel process technologies can take decades to commercialize. In this context, hydrogen is distinct in its ability to replace both carbon-based fuels and reductants, especially for processes with commercial precedents or analogues.
Iron ore is readily reduced to iron using hydrogen, and the principal ironmaking processes have used hydrogen produced from natural gas as a complementary reductant for over 60 years. Despite this experience, barriers to hydrogen adoption remain, including hydrogen plant costs, clean power costs, firm power availability, and lack of electrical infrastructure, among other often overlooked factors. To put these challenges in context, the breakeven cost for hydrogen ironmaking is estimated for representative blast furnace and direct reduced ironmaking process configurations. The technoeconomics of these configurations are compared to hydrogen production costs at the scale required for ironmaking in a North American context. The gap between profitable ironmaking and hydrogen costs is discussed to illustrate factors that could enable competitive hydrogen-based ironmaking in future. Additional commentary on hydrogen’s decarbonization potential is also provided for other applications in metals and mineral processing.