Retrofitting Blast Furnaces for Producing Green Steel and Green Urea

This paper proposes a process to produce green steel, green slag cement, and green urea by retrofitting the existing blast furnaces for using torrefied biomass, biochar, and bio-coke derived from carbon-neutral biomass. Top gas recovery is proposed to extract hydrogen and carbon dioxide, with 100 percent oxygen replacing air by converting the blast furnace into an oxygen blast furnace. No internal modifications are required to the existing blast furnace, including the blast furnace stoves. Only associated auxiliary systems are modified or added. The modified blast furnace is highly flexible in its raw material quality and product mix, without sacrificing overall productivity and thermal efficiency. For every tonne of rated production capacity of an existing blast furnace, nearly 0.50 tonne of green urea can be produced at attractive economics. India can become self-sufficient in urea production without relying on imports by retrofitting most of its operating blast furnaces. It is a bioenergy carbon capture and storage method in which the generated green carbon dioxide gas is sequestered, leading to negative carbon emissions. The air pollution from the oxygen blast furnaces is completely avoided except for excess green carbon dioxide, if not sold or sequestered.