Circulating Fluidized Bed Technology

The CFB Advantage: Why This Technology Matters

Traditional steelmaking through blast furnaces operates at temperatures exceeding 1500°C and relies heavily on coking coal, making it one of the most carbon-intensive industrial processes. CFB technology offers several compelling advantages:

Lower Operating Temperatures: CFB processes operate at temperatures below 700°C when using hydrogen as a reductant. This dramatic temperature reduction not only prevents particle sticking but makes the entire process easier to control and significantly more energy-efficient.

Direct Fine Ore Processing: Unlike shaft furnaces that require expensive pelletizing or sintering operations, CFB processes can directly handle iron ore fines (0.03-1mm). This eliminates an entire energy-intensive pre-processing step, reducing both capital expenditure and operational costs.

Superior Environmental Performance: By enabling the use of hydrogen as a reducing agent and integrating with renewable electricity for heating, CFB processes can achieve near-zero CO2 emissions – a stark contrast to the 2+ tonnes of CO2 per tonne of steel produced in traditional routes.

Commercial CFB Technologies Leading the Charge

The market currently offers limited proven CFB solutions:

Circored™ (Metso): The most established commercial CFB technology, featuring a two-stage reactor configuration with typical plant capacities of 1.25 million tonnes per year. The process can operate on natural gas or 100% hydrogen, providing flexibility during the energy transition.

Circofer™ Process: Utilizing a combination of circulating and stationary fluidized beds, this technology offers another pathway for CFB-based iron production.

Calix ZESTY™: An emerging hydrogen-based process, although not strictly a CFB processes, however has similar benefits, that uniquely separates the heat source from the reaction, enabling easy hydrogen recycling and promising near-zero emissions intensity.

The Integration Opportunity: Transforming Existing Steel Plants

CFB technology has the potential for brownfield integration. Rather than requiring complete plant reconstruction, CFB processes can be strategically integrated into existing integrated steel plants through several approaches:

Blast Furnace Replacement: CFB-based DRI plants can directly replace aging blast furnaces while utilizing existing downstream infrastructure, power systems, and material handling equipment.

Hybrid Production Systems: CFB processes can complement existing operations, allowing for gradual transition strategies that align with equipment replacement cycles and capital planning.

EAF Integration: The DRI and HBI produced by CFB processes integrate seamlessly with Electric Arc Furnaces, enabling steel producers to leverage existing or expanded EAF capacity.

This integration capability is particularly valuable given the massive infrastructure investments already made in integrated steel plants. Rather than stranding these assets, CFB technology offers a pathway to transform them into green steel production facilities.

Challenges and Considerations

The transition to CFB-based green steel production isn't without challenges. The hydrogen infrastructure requirements are substantial – a one million tonne annual DRI plant would require approximately 3,200 MW of photovoltaic capacity for full hydrogen integration. This highlights the critical need for coordinated development of renewable energy infrastructure alongside steel production facilities.

Additionally, the timing of integration typically aligns with major plant renewal cycles, often at the 25-year mark for existing facilities. This creates a strategic window for planning and executing CFB integration projects.

Looking Ahead: The Strategic Imperative

As the steel industry faces increasing carbon pricing, regulatory pressure, and customer demands for green steel, CFB technology represents more than just an alternative production route – it's a strategic necessity. Early movers who begin planning CFB integration now will be best positioned to capture the growing premium for low-carbon steel while maintaining competitiveness in an evolving market.

The question isn't whether the steel industry will adopt CFB technology for green steel production, but how quickly steel producers can execute this transformation while maximizing the value of their existing assets.

For steel industry leaders, the time to act is now. CFB technology offers a clear pathway to decarbonization that can leverage existing infrastructure investments while positioning companies for the green steel future that customers and stakeholders increasingly demand.