There is a clear trend that the European steel industry is changing from the BF-BOF route to EAF based steelmaking to reduce its direct and indirect CO2 emissions. The target is to cut CO2 emissions by 80-95% in 2050 compared to 1990 levels. This transformation causes a lot of changes in the steelmaking industry in the future. The overall transformation can be reached with hydrogen-based steelmaking, Carbon Capture and Utilization (CCU), and increased recycling of steel scrap and steel by-products (European Steel Association 2019). In addition, there are also other emerging trends of EAF steelmaking that are already showing their first signs.
This article is a summary of Prof. Timo Fabritius’ presentation “Rising Trends of EAF Steelmaking” in the joint webinar “Future Challenges in EAF Steelmaking” by Luxmet and the University of Oulu. The article discusses the main points of the presentation and gives an overview of the trends and future of EAF steelmaking.
Low carbon roadmap in Europe
The European steel industry has an ambition to reduce CO2 emissions by 80-95% before the year 2050. Forecasts are based on assumptions that there will be several solutions to decrease CO2 emissions significantly. Figure 1 presents the various pathways for emissions reduction between 1990 and 2050. In 1990, crude steel production in Europe was 197 Mt, which meant 298 Mt of CO2 emissions. In 2015, the crude steel production was 166 Mt and the CO2 emissions produced were 221 Mt. The estimation for 2050 is that the production of crude still will increase to the level of 200 Mt, which would mean 266 Mt of CO2 emissions. If the emissions are to be reduced by 80-95% this would mean that the crude steel production in 2050 would produce 62-15 Mt of CO2 emissions after the reductions (Figure 1).
Figure 1. Different pathways for emissions reduction between 1990 and 2050, including use of CO2-free energy (Amended from European Steel Association 2019).
There are various pathways to reduce CO2 emissions. Scenario A in Figure 1 assumes that there will be no new innovations, the production mix remains the same and, the projected demand will be met with the existing capacity. However, this scenario is not realistic as it does not take into account ongoing development projects. Scenario B will continue the retrofitting of existing steel plants while keeping the EAF share constant. Scenario C describes current projects that use low CO2 energy. This pathway would reduce emissions by 74% compared to 1990 levels. Scenarios D (upper boundary) and E (lower boundary) describe alternative pathways with low CO2 energy to reduce emissions.
These scenarios would use scrap-based EAF as well as the lowest emission technology. Scenario F in Figure 2 presents current projects with CO2-free energy. This would make it possible to reduce emissions by 86%. The last scenarios G (upper boundary) and H (lower boundary) presents alternative pathways to reduce emissions with CO2-free energy. (European Steel Association 2019)
The rise of the Electric Arc Furnace route
In the upcoming years, both BF-BOF and EAF based process routes are used, but to decrease CO2 emissions, but the portion of EAF based process route needs to be increased. This means that in the future, renewable electricity and hydrogen will play a major role. When the use of electric arc furnaces increases, it will also increase the energy demand. The required additional energy will be approximately 400 TWh CO2-free energy per year. Only with these changes is it possible to reduce the CO2 emissions produced by the steel industry by 80-95%.
Figure 2. Precentages of global steelmaking processes.
The replacement of the BF-BOF route with EAFs will increase operating costs by 10 to 35% depending on the used raw material and electricity price. Therefore, the development of new processes, such as CCU (Carbon Capture and Utilization), should be started soon as the investment cycle is long.
In 2019, approximately 70% of steel was produced with the commercial BF-BOF route. In the future, it is estimated that EAF based products will increase their share from 20% to almost 60%. Emission-free electricity will also play a major role in the future when switching to EAF based production.
Slag and side streams will also change in the future. The transition from the BF-BOF process route to an EAF utilizing hydrogen-reduced iron will significantly change the composition of slag and other side streams (dust, sludge) generated at steel plants. In the future, EAF will be the main unit to be used for the internal circulation of slags, dust, and spent refractories. More slag is generated, and the specific energy consumption is increased compared to traditional scrap-based EAF if:
- DRI is used and/or
- Low-quality scrap is changed and/or
- EAF is used as an internal recycling unit
This means that the development of the EAF process and monitoring methods are needed in the future. In addition, it would enable the EAF process to be more flexible with different raw materials and energy sources.
The transition from the BF-BOF route to EAF based steelmaking is needed to decrease the CO2 emissions. The EAF process must be developed and optimized further and a variety of monitoring methods should be used as it would allow, for example, more flexible use of energy sources, continuous charging, and optimal arc length. This could be done for example with the ArcSpec system.
In order to achieve these emissions targets, it is important to act now. Contact us to find out how you can make your EAF more environmentally friendly.
Also, be sure to read our article series “Pathways to Decarbonization of Steel Industry”. Click here to read the first part.
References:
European Steel Association 2020. Low Carbon Roadmap [online]. Brussels: EUROFER. Available at: https://www.eurofer.eu/assets/Uploads/EUROFER-Low-Carbon-Roadmap-Pathways-to-a-CO2-neutral-European-Steel-Industry.pdf [Accessed 15 February 2021]
