With 9% of global emissions coming from the iron and steel industry, it is a major contributor to greenhouse gas emissions—mainly due to the fact that the manufacturing of steel in blast furnaces is inherently carbon-intensive, the most prevalent method at the moment.
Dr. Harriet Kildahl, who co-developed the method with Professor Yulong Ding, claims that the technology they have developed aims to transform this carbon dioxide into carbon monoxide that can be utilized in the iron ore reaction.
This is made possible by a thermochemical cycle, which uses temperature changes to carry out chemical reactions. In this manner, “an almost perfect closed carbon loop” is formed, transforming the typically harmful CO2 into a useful component of the reaction. The amount of coke (type of coal) required for this drastically reduces emissions, which in turn reduces steelmaking’s emissions by up to 90%.
According to the researchers, if this technique were applied to the final two blast furnaces in the UK, it could save £1.28 billion and reduce emissions overall by 2.9% over the course of five years.
“Current proposals for decarbonising the steel sector rely on phasing out existing plants and introducing electric arc furnaces powered by renewable electricity. However, an electric arc furnace plant can cost over £1 billion to build, which makes this switch economically unfeasible in the time remaining to meet the Paris Climate Agreement,” Professor Ding said. “The system we are proposing can be retrofitted to existing plants, which reduces the risk of stranded assets, and both the reduction in CO2, and the cost savings, are seen immediately.”
The system and its application in metal production are the subject of a patent application submitted by University of Birmingham Enterprise. It is currently seeking partners to participate in pilot studies and integrate this technology into the infrastructure that is already in place or to collaborate on further research to improve the process.