Biocoal in the blast furnace for reduced climate impact
31 August, 2017
Use of biocoal in blast furnace-based steelmaking could reduce fossil carbon dioxide emissions by as much as 30 percent in the short to medium term. In a recently started research project under the direction of Swerea MEFOS the methods will be developed and tested at SSAB.
Ore-based steelmaking generates large carbon dioxide emissions, since the blast furnace process uses reduction agents from fossil sources – coal and coke. Limiting these carbon dioxide emissions is now the greatest challenge facing the steel industry. While SSAB's blast furnaces in Oxelösund and Luleå are among the world's most energy efficient, they account for Sweden's largest emissions of carbon dioxide.
"We are adopting both a short-term and a long-term perspective in our work to reduce fossil carbon dioxide emissions. The biocoal project is an excellent initiative for further reduction of C02 levels using today's blast furnace technology. If the tests are successful, some of the coal and coke that is currently used can be replaced with biocoal, without any need for major investments, resulting in even more fossil-free production," explains Era Kapilashrami Production Director Metallurgy, in Oxelösund.
The aim of the research project is to demonstrate the possibilities for industrial-scale use of biocoal, a renewable reduction agent and energy resource, in Swedish blast furnaces to reduce carbon dioxide emissions from the process over the short term. When fully developed, installed and implemented, the technology could reduce fossil carbon dioxide emissions arising from blast furnace-based steel making by about 30 percent.
“Estimates based on data from previous projects that we have conducted indicate that there is good potential for reducing fossil carbon dioxide emissions by using biocarbon," says Professor Lena Sundqvist Ökvist, project manager at Swerea MEFOS. “Now we have a unique opportunity to test this is practice. Industrial-scale trials will show both how application of biocarbon works in existing systems and which impact it has on the blast furnace process and overall carbon dioxide emissions.”
The project will involve close collaboration with the forest industry and developers of biocarbon technology. The results will subsequently be applied by both steelmakers and biocarbon producers. Eventually, it may also be possible to transfer the technology to other metal producers, for example, in the non-ferrous, iron powder and ferro-alloy industries.
Project funding mounting to 5.4 million kronor is being provided by the Swedish Energy Agency. The project partners are Swerea MEFOS, Luleå University of Technology and SSAB.
The reducing agents used in the blast furnace process consist of fossil carbon (approx. 70% coke and 30% pulverized coal). The project will demonstrate the replacement of a portion of the pulverized coal and/or coke with climate-neutral biocarbon. Biocarbon can be charged to the blast furnace in various ways; for example, via injection in powder form, or as charcoal via the top of the blast furnace. It is theoretically possible to demonstrate the potential of biocarbon in full-scale trials without the need for extensive changes in either process or plant. There is no appreciable effect on total energy use. The positive outcome is reduced emissions of fossil carbon dioxide.