(422e) Carbon Utilization Pathways for Steel Off-Gas CO?: A Techno-Economic and Environmental Perspective

As part of the global efforts to reduce greenhouse gas (GHG) emissions, the Republic of Korea has pledged to reduce its GHG emissions by 40% by 2030 compared to 2018 levels, as part of its Nationally Determined Contribution (NDC). Among major industrial sectors, the steel industry accounts for approximately 17% (115 million tons) of national GHG emissions, highlighting the need for targeted and economical mitigation pathways.

This study investigates and compares multiple carbon dioxide (CO₂) utilization pathways for converting steelmaking by-product gases into high-value fuels. Specifically, we focus on Finex Off-Gas (FOG) as the carbon source, with a processing scale of 10,000 tons per day of captured CO₂.

Multiple CO₂ conversion pathways are analyzed including (1) direct hydrogenation, (2) dry reforming of methane and (3) reverse water-gas shift. The study evaluates these pathways with the aim of producing key synthetic fuels, including methanol, methane, sustainable aviation fuel (SAF), and Fischer-Tropsch (FT) fuels. Each route is assessed in terms of process efficiency, GHG reduction, and integration potential within existing steel plant operations.

This study proposes a conversion product and pathway tailored to the South Korean steel industry, taking into account market scale and mitigation potential, based on Techno-Econmic Analysis(TEA) and Life Cycle Assessment(LCA) analyses. The promising products identified include methanol as a sustainable marine fuel and SAF as an eco-friendly aviation fuel.

By guiding product selection in line with Korea’s industrial and environmental priorities, this work supports the development of efficient and market-aligned carbon capture and utilization (CCU) systems.