New Steelmaking Process Could Save Money and Reduce Emissions

British researchers have found a way to reduce emissions of planet-warming carbon dioxide from steelmaking, while also saving money. This is a significant breakthrough that could help to reduce the impact of climate change.

Steel production is responsible for a significant portion of the world's carbon emissions. However, decarbonizing the steel industry is difficult due to its reliance on coking coal to produce raw iron.In a paper published in the Journal of Cleaner Production this month, scientists at the University of Birmingham in England proposed using a form of the mineral perovskite to recycle the carbon dioxide that steelmaking blast furnaces produce. If they can make it work at a large scale, the process could drastically cut the industry's emissions, without the need for expensive new equipment or machinery.

"We can almost completely close the loop," said Harriet Kildahl, lead author of the study. "All of those harmful gases that were being released into the atmosphere are now being used for something useful, just recycled within the system."

Hydrogen-based steelmaking is seen as a potential alternative to traditional steelmaking methods. Hydrogen is produced with renewable electricity and can be used to turn iron ore into iron. This process has been known for decades, but steelmakers are only now beginning to invest in it due to its high costs.

The perovskite mineral the researchers examined can turn carbon dioxide back into carbon monoxide, which can be used as an alternative to coking coal in a blast furnace. This would substantially reduce the cost of the process, making it cheaper than hydrogen-based processes.

The technology can also be retrofitted onto existing blast furnaces, cutting emissions by about 90% and avoiding the need for huge new investments in hydrogen-based steelmaking. This is a crucial advantage, as it allows steelmakers to reduce emissions without incurring significant additional costs.

A perovskite is a type of crystal made from niobium, calcium carbonate, iron ore and barium carbonate. Perovskites have also been proposed as new forms of fuel and solar cells.

Niobium is a critical mineral that is only mined in Brazil and Canada. This leaves major countries like the US and China reliant on imports. Niobium is used in steel alloys, which helps to make cars lighter and more fuel-efficient.

"This approach will be much faster and more cost-effective than other methods for reducing stranded assets," said Yulong Ding, a professor at the University of Birmingham and co-author of the paper.

The method has been demonstrated on a small scale in a laboratory, but it has not yet been proven commercially. This will be critical to demonstrating its viability. Challenges include finding a material that can replace coking coal's structural role in the blast furnace. The authors said that commercial demonstration plants could be possible within five years.