Recycling Process for Net-Zero CO₂ Emissions in Steel Production

Abstract

The iron and steelmaking industry must focus on neutralizing CO₂ emissions. One solution involves using hydrogen as a reducing agent for iron ore. However, carbon is an essential element as primary steel is produced by refining molten carbon-saturated iron (hot metal). Ironmaking processes applying CO₂ capture and utilization have been suggested; however, they are limited to the reduction process. To satisfy the demand for primary steel production with net-zero CO₂ emissions, a new carbon recycling ironmaking process capable of producing hot metal must be considered. This study proposes a carbon recycling ironmaking process using deposited carbon-iron ore composite (CRIP-D). In the CRIP-D process, hot metal is produced by using the solid carbon recovered by reforming exhaust gas as reducing and carburizing agents. Moreover, using the recovered solid carbon, iron oxides are reduced more rapidly, and reduced iron is melted at a lower temperature than that using fossil fuel-derived carbon. This means carbon-neutral steel can be produced more efficiently than conventional ironmaking processes. Using proven technologies, following hot metal production, primary steel can be produced while minimizing the burden on the steel mills for converting equipment. Thus, true carbon-neutral primary steel is feasible using the proposed CRIP-D process.