Decarbonization of the Iron and Steel Industry with Direct Reduction of Iron Ore with Green Hydrogen

TLDR

Iron and steel production accounts for 7 % of global GHG emissions, and incremental changes in current primary technologies are insufficient to meet emission reduction targets. The study proposes replacing coke with hydrogen produced by water electrolysis to substantially lower emissions from iron and steel production. A Python‑based mass and energy flow model was developed to assess the feasibility of hydrogen direct reduction of iron ore coupled with electric arc furnace for carbon‑free steel production, excluding pellet making and steel finishing. Modeling shows HDRI‑EAF could cut EU steel emissions by over 35 % at current grid levels, with energy use of 3.72 MWh/tls slightly higher than the 3.48 MWh for BF‑BOF, and identifies electrolyzer efficiency and grid emission factor as key drivers.

Abstract

Production of iron and steel releases seven percent of the global greenhouse gas (GHG) emissions. Incremental changes in present primary steel production technologies would not be sufficient to meet the emission reduction targets. Replacing coke, used in the blast furnaces as a reducing agent, with hydrogen produced from water electrolysis has the potential to reduce emissions from iron and steel production substantially. Mass and energy flow model based on an open-source software (Python) has been developed in this work to explore the feasibility of using hydrogen direct reduction of iron ore (HDRI) coupled with electric arc furnace (EAF) for carbon-free steel production. Modeling results show that HDRI-EAF technology could reduce specific emissions from steel production in the EU by more than 35 % , at present grid emission levels (295 kgCO2/MWh). The energy consumption for 1 ton of liquid steel (tls) production through the HDRI-EAF route was found to be 3.72 MWh, which is slightly more than the 3.48 MWh required for steel production through the blast furnace (BF) basic oxygen furnace route (BOF). Pellet making and steel finishing processes have not been considered. Sensitivity analysis revealed that electrolyzer efficiency is the most important factor affecting the system energy consumption, while the grid emission factor is strongly correlated with the overall system emissions.