An Integrated Techno-Economic and Environmental Assessment of Ammonia as a Reductant in Green Steel Manufacturing

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Provides kinetic correlations and an LSPC model that can be used for further optimization of ammonia-based steelmaking.

🏢実務担当者:Offers cost and emissions benchmarks for green steel using ammonia, valuable for corporate strategy on alternative reductants.

🏛政策担当者:Highlights the need for policies to reduce green ammonia costs and support supply-chain decarbonisation for steel.

This paper presents the first integrated technical, economic, and environmental assessment of ammonia as a reductant for green steel production. Decarbonising primary iron and steelmaking is critical for meeting global climate‑mitigation goals, as the sector contributes ~7% of global direct CO₂ emissions and remains reliant on carbon‑intensive reductants. Hydrogen‑based direct reduced iron (H₂‑DRI) is currently the leading low‑carbon pathway, yet its large‑scale adoption is limited by the high cost of green hydrogen and challenges associated with storage, transport, and long‑term handling. Ammonia has emerged as a promising alternative or complementary reductant due to its higher volumetric energy density, mature global transport infrastructure, favourable safety profile, and potential for cost‑effective production from renewable electricity. Despite growing interest, the techno‑economic and environmental implications of direct ammonia utilisation remain poorly understood. This study addresses that gap through the first integrated assessment of ammonia‑based reduction. Part A develops and validates kinetic correlations for hematite reduction in ammonia and hydrogen using 198 experiments conducted at 600-800°C, supplemented by additional literature data. Results show that ammonia reduction proceeds via mixed direct and indirect pathways, with utilisation maximised at ~800°C and 30 min residence time. Part B incorporates these utilisation figures into a Levelized Steel Production Cost (LSPC) model across 22 scenarios in the USA, Australia, and India, demonstrating that reductant price is the dominant cost driver and that green ammonia must fall to ~$150-200/t to reach parity with NG‑DRI under current energy prices. Part C evaluates Scope 1-3 emissions, showing that although ammonia‑ and hydrogen‑based routes nearly eliminate plant‑level emissions, lifecycle emissions depend strongly on upstream energy sources. Overall, the study concludes that ammonia, particularly low‑cost green ammonia, can be a viable reductant for green steelmaking, contingent on improved utilisation, supply‑chain decarbonisation, and advances in renewable ammonia production.

• openaire https://doi.org/10.2139/ssrn.6253382first seen 2026-05-14 21:13:15