United Kingdom – A revolutionary modification for current iron and steel furnaces created by University of Birmingham researchers has the potential to cut carbon dioxide (CO2) emissions from the steelmaking sector by over 90%.
A “closed loop” carbon recycling technology, which could replace 90% of the coke generally utilized in existing blast furnace-basic oxygen furnace systems and generates oxygen as a byproduct, is employed to achieve this dramatic reduction.
The system was created by Professor Yulong Ding and Dr. Harriet Kildahl from the School of Chemical Engineering at the University of Birmingham. It is described in a paper that was published in the Journal of Cleaner Production, and it shows that if it were implemented in the UK alone, it could save £1.28 billion in costs over the course of five years while lowering overall UK emissions by 2.9%.
Innovative recycling method
The majority of the steel used in the world is made in basic oxygen furnaces after being transformed from iron ore to steel in blast furnaces.
Because metallurgical coke, which is created by destructively distilling coal in a coke furnace, combines with the oxygen in the hot air blast to produce carbon monoxide, the process is inherently carbon intensive. CO2 is created when this interacts with the iron ore in the furnace. A hot stove is used to burn the nitrogen, CO, and CO2 that make up the top gas from the furnace, which is then blown into the furnace. The CO2 and N2 (which also contains NOx) are then released into the atmosphere.
The innovative recycling method uses a crystalline mineral lattice known as “perovskite” material to decrease the CO2 from the top gas to CO. The material was chosen because the reactions happen at temperatures (700–800 oC) that can be produced using heat exchangers linked to blast furnaces or powered by renewable energy sources.
The perovskite splits CO2 in conditions of high CO2 concentration into oxygen, which is taken up by the lattice, and CO, which is sent back into the blast furnace. In a chemical reaction that takes place in a low oxygen atmosphere, the perovskite can be transformed back into its original state. The created oxygen can be utilized to make steel in the standard oxygen furnace.
Fundamental sector
The production of iron and steel, which accounts for 9% of all worldwide emissions, is the fundamental industrial sector with the highest CO2 emissions. To keep global warming to 1.5°C by 2050, it is necessary to achieve a 90% decrease in emissions, according to the International Renewable Energy Agency (IRENA).
University of Birmingham Enterprise is seeking long-term partners to take part in pilot studies, deliver this technology to current infrastructure, or work together on additional research to develop the system. The company has filed a patent application covering the system and its use in the production of metal.
