Iron and steel plants are ripe for upgrades that could have a serious impact on carbon emissions.
That’s the consensus from UCL researchers, who determined that upgrading, or retrofitting, global iron and steel processing plants could cut roughly two years’ worth of global carbon emissions, or up to 70 gigatonnes by 2050. Overall, iron and steel contribute 7% of the world’s total carbon emissions.
Researchers actually found that the upgrades to the processing facilities would reduce 58.7 gigatonnes of carbon emissions between 2020 and 2050. However, moving forward those upgrades and retrofits and upgrades by five years would increase the emissions reduction to nearly 70 gigatonnes by 2050.
The study determined this schedule by creating a database of 19,678 individual processing units located in 4,883 individual iron and steel plants around the world. Researchers then inventoried the plants’ characteristics, such as location, processing technologies, operating details, status, and age. They also realized that most steel processing plants are only upgraded with newer technologies that require less carbon-intensive processes when the units are at the end of their operational life. And currently, as of 2019, nearly 75% of the world’s steel was produced in coal powered plants with high emissions. In addition, refining takes a toll on equipment, requiring periodic retrofitting.
Overall, 43.2% of global iron and steel plants have been retrofitted with new technologies or have otherwise enhanced their processes to extend their operating lifetime. Retrofits typically occur after 15 to 27 years of use, depending on the technique used and age. Based on that range, researchers found that upgrading operating processing units to incorporate low-emissions technology at their predicted time of retrofit would achieve emissions reductions on the lower end. However, moving the refits and upgrades and completing them five years earlier would increase those carbon emissions reductions by 16% by 2050.
“Our results lend vivid background to the possibility of achieving net-zero carbon emissions in iron and steel production in the future,” said Senior Author Professor Dabo Guan (UCL Bartlett School of Sustainable Construction). “By retrofitting existing plants with low-carbon technologies, and improving scrap collecting and recycling, the iron and steel sector can dramatically reduce its carbon emissions. This study sheds light on the specific emissions reductions that are possible within the iron and steel industry.”
However, the researchers also pointed out that retrofitting and upgrading the overall steel and iron industry is dependent on individual plants. In addition, there’s no one-size-fits-all approach to retrofitting the industry, because plants and facilities have their own processes and technologies.
“About 63% of the world’s steel production is from some type of blast oxygen furnace, while most of the remaining capacity is produced by electric arc furnaces,” researchers summarized in an accompanying article to their study. “Upgrading the global inventory of blast oxygen furnaces will yield the greatest net carbon savings, about 74% of the total projected carbon savings. Upgrades to electric arc furnaces would account for the second highest net carbon savings, at about 16% of the projected whole, though this may be limited by the total amount of stock scrap available worldwide as the technique is dependent on recycling existing metals.”
Researchers also noted that their database should provide some greater understanding of the production methods used in the steel and iron industry. In addition, the research could help policymakers create a “roadmap” of when and how to target the industry for emissions reductions goals.
“Our study presents various CO2 emissions mitigation pathways at the plant level, optimizing when and how to retrofit each plant based on processing routes, latest retrofitting year and operating lifetime, stressing the importance of early retrofitting with deep decarbonization technologies for achieving net-zero carbon emissions by 2050,” said PhD student Tianyang Lei of Tsinghua University.
Researchers published their study in the journal Nature.
