Comparative energy, emissions and economic assessment of low-carbon iron and steel making processes using imported liquid organic hydrogen carrier options

Hydrogen (H₂)-based steel making is expected to become a major driver of intercontinental low-carbon H₂ imports. Eight H₂ supply scenarios based on either local H₂ production at major steel producing locations (Germany/Japan), or liquid H₂ carrier (dibenzyltoluene/perhydrodibenzyltiluene, DBT/PDBT) import from the United Arab Emirates, and their integration with H₂ direct reduced iron (H-DRI) and electric arc furnace (EAF) processes, are investigated using process modeling. Solar energy-based PDBT import using surplus heat for dehydrogenation is the most cost-competitive H₂ import scenario in Germany's case (levelized steel production cost, ∼685 $/tLS, with carbon emissions, ∼237 kgCO₂/tLS). In Japan's case this scenario is the most economically favorable of all scenarios (∼736 $/tLS), with emissions (∼350 kgCO₂/tLS) comparable to natural gas-DRI-EAF with 50% carbon capture. Steam methane reforming with carbon capture-based PDBT import is neither environmentally nor economically viable. PDBT-based H-DRI-EAF production cost is sensitive to electricity, H₂ production, dehydrogenation energy, and carbon costs.