Hydrogen Direct Reduction: History and Pathways for Cost Reduction

ABSTRACT The steel industry, a critical pillar of global economic development, is highly energy‐intensive, accounting for approximately 7%–9% of global energy‐related CO 2 emissions. The transition from traditional carbon‐intensive metallurgy to hydrogen‐based metallurgy represents a pivotal pathway for the green and sustainable development of the steel industry. This review elaborates on the evolution of hydrogen direct reduction technologies, highlighting early pilot‐ and commercial‐scale plants that primarily utilized fluidized bed reactors with natural gas reforming or ammonia plant exhaust gases as reducing agents. These early efforts demonstrated the feasibility of hydrogen reduction but could not achieve long‐term stable operation. The urgent need for decarbonization has resulted in renewed focus on research and development in hydrogen direct reduction, with steel companies proposing diverse technological solutions and advancing industrial demonstrations globally. Despite significant progress, the cost of hydrogen production has become a significant barrier to its widespread adoption. Strategies to lower costs include enhancing the reaction efficiency, integrating green electricity to supply heat, utilizing low‐grade ores, and leveraging renewable, off‐peak, and surplus electricity for hydrogen production. As the price of hydrogen is 0.7 ¥·Nm −3 (Standard volume), the cost of the hydrogen direct reduction–electric arc furnace process is comparable to that of the blast furnace–basic oxygen furnace process. Hydrogen direct reduction is expected to gradually replace the conventional blast furnace ironmaking method, which is emerging as a mainstream steel production process that underpins the green, low‐carbon, and sustainable development of the global steel industry.