Hydrogen and biomass-based carbon source integration for iron and steel manufacturing: A systematic review of Life Cycle Assessment studies

Iron and steel manufacturing is a material-intensive, energy-intensive, and emission-intensive process that is focused on attaining carbon neutrality. An important step towards decarbonizing iron and steel manufacturing is quantifying the environmental impacts associated with its potentially sustainable emerging technologies. In this study, we conducted a systematic review of 21 Life Cycle Assessment (LCA) studies that integrated hydrogen and/or biomass in iron and steel production. We categorized various technologies following an LCA approach, focusing on the technological and regional definition of goal and scope and impact categories of Global Warming Impact (GWI), Terrestrial Acidification (TA), Fossil Resource Scarcity (FRS), Mineral Resource Scarcity (MRS), and Fine Particulate Matter Formation (FPMF). According to the findings, GWI of steel ranges from -845 kg CO ₂ eq. to 2287 kg CO ₂ eq. per ton of steel and the GWI of iron ranges from -41kg CO ₂ eq. to 2799 kg CO ₂ eq. per ton of iron. Furthermore, the integrated technologies also have corresponding average approximate TA, FPMF, MRS, and FRS of 11 kg SO ₂ eq., 3 kg PM 2.5 eq., 83 kg CU eq., and 304 kg oil eq. per ton of iron. The variations in these results are highly dependent on technological and regional differences of the goal and scope of the studies. This study reinforces the significance of exploring hydrogen and/or biomass integration methodologically, linking results to various LCA choices. Additionally, the results derived from this review also aim to emphasize the need for technological and region specific modelling, data and methodological standards, transparent reporting in conducting LCA in integrating hydrogen and/or biomass into the iron and steel industry.