Steel is a critical component of nearly every aspect of life, forming our infrastructure and influencing our industries and economy. However, the traditional methods of steel production, which follow the linear ‘take, make, dispose’ model, are increasingly under scrutiny for their environmental impact, particularly the amount of waste that is generated at various stages of production.
In 2023, researchers from Birmingham University proposed an innovative solution for blast furnace steelmaking which they believe could almost completely decarbonise the steel industry (1). Their system consists of a closed-loop recycling method, which could be retrofitted to existing steelmaking facilities and replace up to 90% of the coke typically used in current steel production(2).
But just how feasible is their proposal? Let’s look at the principles of closed-loop manufacturing and its potential for implementation into the steel industry.
What is Closed-loop Manufacturing?
Unlike linear manufacturing, closed-loop manufacturing focuses on creating a circular system where waste is not only minimised but also repurposed and reintegrated into the production process. For resource-intensive industries like steel, this method would mean a complete shift in how industries approach production. In closed-loop systems, products are designed and manufactured with the entire lifecycle in mind, meaning that they are intended to be recycled, repurposed or returned to the manufacturing process after their initial use. Given that steel is a 100% recyclable material, however, the steel industry has an advantage over other sectors, with the potential to eliminate or significantly reduce the need for new raw materials and waste generation.
Implementation In the Steel Industry
To effectively decarbonise blast furnace steelmaking, the Birmingham research team created a system which captures the CO2 from the top gas in blast furnaces, using a lattice made from crystalline perovskite, a calcium titanium oxide mineral with unusual properties such as superconducting electricity, high thermopower and extreme magnetoresistance(3). The perovskite lattice splits out CO2 and absorbs the remaining oxygen, while the CO2 is fed back into the blast furnace. The absorbed oxygen is then released from the perovskite and returned to the furnace to produce steel, which has the added effect of regenerating the perovskite material.
The researchers claim that this model could be retrofitted to existing steelmaking facilities and save over £1.28 billion over the course of five years. With 90% of coking products made redundant through this process, the closed-loop system could effectively reduce the UK’s overall emissions by 3%(2).
This process presents an innovative alternative to current decarbonisation plans, which typically involve the construction of electric arc furnaces (EAF) to replace blast furnaces. Since an EAF plant can cost more than £1 billion to build, a switch to closed-loop manufacturing would be more financially viable to introduce and eliminate the need to shut down existing plants while new ones are built. Tata Steel UK most recently faced this issue with the shut down of blast furnace no.5 and no.4 in their Port Talbot facility to prepare for their £1.25 billion EAF transformation(5). The closure has resulted in the loss of thousands of jobs, strikes and industrial action, in addition to halted steel production.
Challenges and Barriers to Adoption
As this closed-loop model is a relatively new concept, one of the main challenges to its adoption is further testing and development of the system to ensure that it is viable for mass implementation. Although retrofitting a blast furnace is significantly cheaper than building an EAF, the cost of installing this system may still be a barrier, particularly for smaller steelmaking companies. The need for continuous research and development to refine this technology can add to the financial burden, making it challenging for some steel manufacturers to justify the investment without clear long-term economic returns. Additionally, demand for low-or-zero carbon steel must be strong enough to support the closed-loop system and provide incentive for manufacturers to adopt this model.
Another barrier to implementation is a potential lack of policy support. For closed-loop steel production to be feasible, government policies must be introduced to incentivise sustainable practices and provide clear guidelines for implementation. This may include financial incentives, such as tax breaks or subsidies, for companies that invest in this technology. Without this support, the transition to closed-loop steel production may be slow and uneven, limiting its potential impact on decarbonisation.
Despite these challenges, the rise of Industry 4.0, or the digitalisation of manufacturing processes, is likely to further enhance the concept of closed-loop steel production and the Birmingham research team’s proposal provides a cost-effective and innovative solution to decarbonisation that may be significantly more feasible to achieve. With the appropriate backing and development, their system may be the key to achieving the 95 percent reduction target by 2050, minimising disruptions to production, while providing widespread sustainability benefits.
Author: Shirley Carruthers - Content Creator at ParkerSteel
References:
Are Closed-Loop Systems the Future of Waste-Free Steelmaking?
First published on 23/08/24