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How to save two years’ worth of net global CO2 emissions

Stephen Cousins

Low-carbon upgrades to iron and steelworks could remove nearly 60 gigatonnes of carbon from the world’s atmosphere, although cost and other factors challenge its practicality

Credit: iStock | Elena-Bionysheva-Abramova

Building low-emissions technology into scheduled refits of iron and steel works could cut global carbon emissions by the equivalent of two years’ worth of net global CO2 emissions, the latest research has revealed.

The study, published in the journal Nature, was led by UCL in collaboration with Tsinghua University, Peking University and King's College London.

Researchers compiled a comprehensive database of 19,678 processing units in 4,883 individual iron and steel plants around the world and found that if all currently operating units had a low-carbon upgrade at their predicted time of refit, total emissions from the sector could be reduced by 58.7 gigatonnes between 2020 and 2050.

Furthermore, if the refits were completed five years early, total carbon savings would increase 16%, to 69.6 gigatonnes, said researchers.

The study notes that, as of 2019, the last year that data is available, 74.5% of the world’s steel was produced in coal powered plants that release ‘considerable’ carbon emissions. Refits to individual processing units, needed to prolong their operational life, typically occur after 15 to 27 years of use, depending on the techniques used and age.

Upgrading the global inventory of blast oxygen furnaces, used in steel production, was found to yield the greatest projected net carbon savings, accounting for about 74% of overall savings. Upgrades to electric arc furnaces came second, covering about 16% of overall carbon savings.

However, the team warned that effective decarbonisation requires mitigation measures at every plant and ‘the complexity and variety of methods involved in steel production’ means there is ‘no one-size-fits-all decarbonisation technology or solution for the entire sector’.

Furthermore, retrofitting low carbon technology remains expensive and difficult to finance under current market conditions. Professor Dabo Guan, senior author of the study at UCL Bartlett School of Sustainable Construction, said: ‘Iron and steel represents a stable business operation, it would require very strong motivation, usually an order from above, to carry out low carbon retrofitting. Investors usually aren’t interested in doing this as it has either a very long, or non-existent, profit return period.’

Researchers hope the findings presented in the report will help policymakers create a more realistic roadmap for when and how iron and steel plants should be upgraded to meet emissions reduction targets. The research includes an inventory of the technical characteristics of all processing units, including locations, processing technologies, operating details, status and age.

Effective policy should take into account daily operations in processing units on the ground to be effective, added Guan: ‘Policy makers talk about low carbon development, whereas a plant manager is concerned about operation safety and benefits to employees. Retrofitting or upgrading units would mean temporarily ending production, meaning less employment. Effective policy needs to click with what’s needed at the bottom level.’


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