Carbon Capture, Utilization & Storage

Carbon Capture, Utilization, and Storage (CCUS) technology has the potential to transform the steel industry by addressing critical environmental challenges. As steel production generates significant carbon emissions, innovative solutions like Gas Fermentation and the KM CDR process are essential tools for any plausible path toward net-zero carbon emissions and enhancing economic competitiveness.

Gas Fermentation

Gas fermentation is a groundbreaking development in off-gas recycling. It addresses the need to reduce the steel industry's carbon footprint while enhancing economic competitiveness through the promotion of a circular economy. By recycling off-gases containing carbon monoxide (CO), carbon dioxide (CO₂), and hydrogen (H₂), gas fermentation converts these emissions into valuable fuels and chemicals.

The process involves microbial fermentation of carbon and hydrogen-rich offgases, such as coke oven gas, blast furnace top gas, direct reduction gas, and converter gas. This fermentation produces ethanol and other basic chemicals, significantly reducing CO₂ emissions while also lowering NO_X, SO_X, and particulate emissions. The fuels and chemicals produced offer superior economic returns, with greenhouse gas emissions from ethanol up to 80% lower compared to conventional gasoline.

Gas fermentation also delivers substantial economic benefits. The production cost per liter of ethanol can be up to 25% lower than conventional bio-ethanol processes. Developed by LanzaTech, this technology is implemented in the iron and steel industry through a partnership with Primetals Technologies.

Another key advantage of gas fermentation is its contribution to a closed-loop, zero-waste process. All process gases are recovered and reused, maximizing resource efficiency. This aligns with global sustainability goals by reducing reliance on fossil fuels. The ability to reduce CO₂ emissions per ton of produced ethanol further highlights its carbon capture value within the integrated iron and steelmaking process.

KM CDR Process

The CO₂ capture technology from Mitsubishi Heavy Industries is known as the KM CDR Process™. This amine-based CO₂ capture process uses a newly developed solvent called KS-21. The system is designed to capture 95% of the CO₂ from flue gas, compress it, and treat it to meet pipeline specifications.

The process has potential applications across various ironmaking and energy operations, including blast furnaces, dirct reduction plants, and power plants.

Benefits of Gas Fermentation

• Significant carbon footprint reduction: at least 2.3 t CO₂ per ton of produced ethanol
• Economic viability: the production cost per liter of ethanol is up to 25% lower than traditional bioethanol processes, enhancing profitability
• Resource conservation: gas fermentation utilizes 100% process gas recovery, ensuring no waste and maximizing resource utilization
• Sustainability: these technologies support the circular economy by converting waste gases into valuable products, reducing reliance on fossil fuels