Reviewed by Lexie CornerJul 29 2024
Recent research by Heriot-Watt University’s Research Centre for Carbon Solutions suggests that by combining carbon capture technologies with financial incentives, the steel industry can reduce its carbon footprint and become profitable using lower-grade iron ore. This approach could potentially address the issue of dwindling high-grade ore reserves and create a more sustainable steel production process. These findings were published in the Journal of Cleaner Production.
Slag deposit at Scunthorpe Steel Work. Image Credit: Phil Renforth
The steel industry, responsible for 5-8 % of global carbon dioxide emissions, has seen its total emissions rise over the past decade, driven by increased demand.
According to the International Energy Agency, there is "limited" potential to reduce emissions without innovation. Commercializing novel zero-emission production techniques is, therefore, essential.
In the study, Professor Phil Renforth and colleagues explain how significant emissions reduction in the steel sector, when paired with financial levers, might make steel carbon negative and enable the use of lower-grade iron ore.
This could be the cherry on the cake for the steel industry and open up new opportunities for investment in the UK. 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, biomass-based reductants, and carbon capture and storage, as they’ve been identified as the most likely net zero pathways by the International Energy Agency.
Phil Renforth, Professor, Research Centre for Carbon Solutions, Heriot-Watt University
Professor Phil Renforth adds, “The UK has around 180 million tons 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 gigaton of carbon dioxide per year by 2050."
This would need to be supported by strong government incentives—around 200-500 USD per ton. Decarbonizing will drive up the cost of steel, so there has to be a driver for change. Also, these are nascent technologies that require significant investment if they’re to be implemented on any meaningful scale. Adding an incentive for carbon removal may offset the cost of decarbonization.
Phil Renforth, Professor, Research Centre for Carbon Solutions, Heriot-Watt University
One significant surprise for the carbon researchers came from Renforth's model.
“Surprisingly, the model shows that once financial incentives and carbon removal technologies are in place, lower-grade ores become commercially viable,” notes Phil Renforth.
Current production favors higher purity ore, which is cheaper to use because it requires less energy and materials. The UK doesn’t have any commercial-grade 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.
Phil Renforth, Professor, Research Centre for Carbon Solutions, Heriot-Watt University
Phil Renforth concludes, “This is a critical step in addressing climate change while supporting industrial growth.”
Journal Reference:
Renforth, P., et al. (2024). Carbon dioxide removal could result in the use of lower-grade iron ore in a decarbonized net-negative emission steel industry. Journal of Cleaner Production. doi.org/10.1016/j.jclepro.2024.142987.