Retaining the BF–BOF Core While Closing the Carbon Loop

Retaining the BF–BOF Core While Closing the Carbon Loop CRT allows BF–BOF steel plants to retain their core process while closing the carbon loop: off-gas carbon is recycled into fuel, enabling zero-emission operation and surplus power generation, without disrupting continuous steelmaking. For most integrated steel producers, the greatest barrier to deep decarbonisation is not ambition, but risk. Blast furnaces and basic oxygen furnaces are capital-intensive, long-life assets designed for continuous operation. Any pathway that requires dismantling, wholesale replacement, or prolonged shutdown is economically and operationally unattractive. CRT addresses this reality directly. Rather than attempting to replace the BF–BOF route, CRT is designed to wrap around the existing process, treating steel off-gases not as waste to be flared or diluted, but as recyclable carbon streams. Carbon monoxide and carbon dioxide contained in blast furnace gas, converter gas, and associated flue gases are captured within the system boundary and converted into reusable fuel. This approach preserves what already works: • the metallurgical function of the blast furnace, • the productivity and reliability of the BOF, and • the continuous nature of steelmaking operations. At the same time, it fundamentally changes the role of carbon. Instead of leaving the plant as an emission, carbon is retained inside the system and recycled repeatedly as an energy carrier. A key advantage of this architecture is that thermal and power demands are addressed together. Recycled fuel produced via CRT can be used to meet internal steel plant heat requirements first — hot blast stoves, reheating, and auxiliary loads — ensuring process stability. Where recycled fuel production exceeds internal heat demand, the surplus can be used to generate dispatchable baseload power via gas turbines or combined-cycle systems. The carbon dioxide from that power generation is then captured and returned to the CRT loop, maintaining a closed system. The result is not just lower emissions, but a structural shift in plant energy balance: • emissions are internalised, • fuel security is improved, and • power becomes a by-product of decarbonisation rather than an external dependency. Critically, this is achieved without interrupting steel production. CRT does not require changes to burden chemistry, furnace operation, or steel quality. It is implemented as an integrated energy-carbon platform operating alongside existing assets, allowing staged deployment and risk-managed scaling. For BF–BOF operators, this reframes the decarbonisation question. It is no longer about abandoning proven processes or waiting for uncertain alternatives to mature. It becomes a matter of closing the carbon loop around assets already in place, transforming emissions into value while maintaining operational continuity. In this sense, CRT is not a transition away from BF–BOF steelmaking. It is a pathway to make existing steel plants compatible with a zero-emissions future — while delivering additional power, resilience, and optionality along the way.