In the relentless pursuit of carbon neutrality, the steel industry—a titan of global carbon emissions—is undergoing a significant transformation. Researchers, led by Jing Wei from the College of Architecture and Environment at Sichuan University, are making strides in carbon capture, utilization, and storage (CCUS) technologies, offering a beacon of hope for a greener future. Their work, published in *Energy Environment Protection*, provides a comprehensive overview of the current state of crude steel production, its associated carbon emissions, and the innovative technologies emerging to mitigate these impacts.
The steel industry is a major contributor to global carbon emissions, primarily due to the traditional blast furnace-basic oxygen furnace (BF-BOF) processes. However, driven by the imperative of carbon capture, researchers and industry stakeholders are developing technologies that facilitate a transition to hydrogen-based metallurgy. “The steel industry is at a crossroads,” says Wei. “We are witnessing a shift from conventional methods to more sustainable practices, and CCUS technologies are at the heart of this transition.”
Common carbon capture technologies employed in steel plants include liquid absorption, solid adsorption, and membrane separation methods. Each of these technologies has its principles, benefits, and drawbacks. For instance, chemical absorption using monoethanolamine (MEA) can achieve a CO2 capture rate of 90%, but it requires high regeneration energy consumption of 4 − 5 GJ/t CO2. In contrast, ammonium hydroxide absorption processes can reduce energy consumption to 1.5 GJ/t CO2.
International demonstration projects, such as the Japanese COURSE50 project, have achieved a 30% reduction in CO2 emissions per ton of crude steel. Similarly, BaYi Iron & Steel has upgraded its molten reduction ironmaking furnace to a European smelting furnace, attaining a CO2 capture rate of over 97%. However, the global average cost of CO2 capture remains high, presenting significant challenges for widespread adoption.
One of the key challenges is the increased energy consumption associated with carbon capture technologies, ranging from 2.5 − 4.0 GJ per ton of steel. Additionally, infrastructure limitations, such as the lack of CO2 pipeline networks in 80% of steel plants, pose a significant hurdle. Insufficient carbon pricing coverage, accounting for only 30% − 40% of the capture costs, further complicates the economic viability of these technologies.
Looking ahead, technological advancements in novel phase-change absorbents, such as eutectic solvents, and metal-organic framework (MOF) adsorption materials are expected to significantly reduce capture costs by 2030 and beyond. These innovations require overcoming challenges associated with the collaborative integration of steel plants, chemical industrial parks, and storage sites.
The “hydrogen-carbon co-production” model, a collaboration between HBIS Group and Shell, exemplifies this integrated approach. This model utilizes captured CO2 for microalgae cultivation and enhanced oil recovery (EOR), establishing a carbon-negative value chain. “The future of the steel industry lies in collaborative innovation and policy-driven initiatives,” Wei emphasizes. “By leveraging CCUS technologies and fostering partnerships across the value chain, we can accelerate the transition towards carbon neutrality.”
As the global push for carbon neutrality intensifies, the industrialization of CCUS in the steel sector must rely on policy-driven initiatives and collaborative innovation. This review offers a theoretical foundation and practical insights to guide the development of economically viable CCUS pathways, accelerating the steel industry’s transition towards a sustainable future. With the advancement of global carbon neutrality initiatives, the steel industry is poised to embrace a new era of innovation and sustainability, driven by the relentless pursuit of a greener tomorrow.