A decarbonised steel industry that includes carbon dioxide removal techniques in its net zero arsenal could use lower-grade iron ore, according to a new study.
Steel accounts for 5-8% of carbon dioxide emissions globally, and its total emissions have risen over the past decade due to increased demand.
The International Energy Agency has stated that, without innovation, the scope to limit emissions is ‘limited’.
Therefore, the commercialisation of new zero-emission production processes, such as lower-grade iron ore, is critical.
Identifying pathways to net zero
Professor Phil Renforth and team describe in the study how deep emissions mitigation in the steel industry, combined with financial levers, could not only result in steel becoming carbon negative – it could also make the use of lower-grade iron ore feasible.
Professor Renforth said: “We developed a bespoke techno-economic model that stimulates scenarios where steel production is enhanced with climate change interventions.
“We focused on measures like directly reduced iron ore, biomass-based reductants, and carbon capture and storage, which the International Energy Agency has identified as the most likely net zero pathways.
The team developed a bespoke techno-economic model that stimulates scenarios where steel production is enhanced with climate change interventions.
It focused on measures like directly reduced iron ore, biomass-based reductants, and carbon capture and storage, which the International Energy Agency has identified as the most likely net zero pathways.
Offsetting the cost of decarbonisation
The UK has around 180 million tonnes of slag byproduct from steel production.
If the industry used this material to capture atmospheric carbon dioxide, for example, coupling direct air capture with a mineral reaction system, it could remove up to one gigatonne of carbon dioxide per year by 2050.
Decarbonising will drive up the cost of steel, so there has to be a driver for change.
“These are nascent technologies that require significant investment if they’re to be implemented on any meaningful scale,” Renforth explained.
“Adding an incentive for carbon removal may offset the cost of decarbonisation.”
Making the use of lower-grade iron ore feasible
Renforth’s model threw up one big surprise for the carbon researchers.
Surprisingly, the model shows that once financial incentives and carbon removal technologies are in place, lower-grade iron ore becomes commercially viable.
Current production favours high-purity ore, which is cheaper to use because it requires less energy and materials.
Renforth said: “The UK doesn’t have any commercial-grade iron ore, and it’s becoming incredibly hard to find around the world. That’s a problem that’s not going away.
“Our model shows that by integrating advanced emission reduction technologies and using lower-grade iron ore, we can create a sustainable, economically viable path towards a carbon-negative steel industry.”
He concluded: “This is a critical step in addressing climate change while supporting industrial growth.”
