Global steel companies are actively combating climate change by reducing carbon emissions.
Traditional steel production, using the blast furnace (BF) – basic oxygen furnace (BOF) process,
heavily depends on coal and emits substantial CO2. To mitigate this, companies are transitioning to
the more eco-friendly DRP (direct reduction plant) – EAF (electric arc furnace) process, which lowers
CO2 emissions. This study quantitatively evaluates the impact of increased hydrogen consumption
on the carbon footprint of product (CFP) through an analysis of direct reduction process heat and
mass balances. The study prioritises a comprehensive material balance based on mass
conservation principles. The heat balance is calculated using differences in enthalpy through state
energy properties, avoiding heat consumption. Validation using operational data from Hyundai Steel
Dangjin works’ blast furnaces shows close alignment between calculated results and actual data,
with less than 1 per cent error. This methodology facilitates a detailed analysis of the direct reduction
process, offering insights into its feasibility and efficiency. Analysis of the operational impact by
increasing the hydrogen ratio demonstrates reduced CO2 emissions and increased heat
requirements due to the endothermic nature of hydrogen reduction, in contrast to the exothermic CO
reduction. Possible solutions include raising reducing gas temperature or enhancing flow rate. The
study effectively utilises designed heat and mass balances to assess material quantities and thermal
balance under different operational conditions. It lays the foundation for the initial direct reduction
process design, aiding in deriving and optimising operational parameters. Additionally, it provides
valuable insights into the challenges of increased hydrogen, contributing to the production of greener
steel by addressing these issues.