As one of the world’s leading manufacturers of sustainable stainless steel, Outokumpu continues to search for opportunities to further minimise the effect the entire added value chain has on the climate. Replacing fossil coke with sustainable raw materials obtained from biomass is one of the most important measures to decrease direct emissions in steel works.
As part of Outokumpu’s strategy to strengthen their leadership role in the field of sustainability and to guarantee access to high quality raw materials, the company has decided to invest in a pelletising plant to produce bio-coke 1) at their site in Tornio, Finland. The cost of construction is approximately 30 million euros. Production is scheduled to start in mid-2025.
Timo Huhtala, General Manager for the bio-coke project at Outokumpu, says:
“Our decisive actions in the field of sustainability, for example ensuring a high rate of recycling and low-carbon energy sources, have already allowed us to provide stainless steel with the smallest carbon footprint in the entire industry. We are continuing work on our ambitious climate goal to lower the emissions from our entire added value chain by 42% by 2030, compared to the base year 2016.
Fossil coke is responsible for 50% of our direct emissions today. One concrete step to significantly reduce these direct emissions is, therefore, to replace fossil coke with bio-coke produced using waste material from the forestry and timber industries.”
In the past year, Outokumpu has examined the options for building their own production system for bio-coke on an industrial scale, and has developed a step-by-step plan to establish a supply of biomass-based raw materials for the future. This includes a mix of own production, external acquisition and partnerships.
The first step along the way is the investment made in a pelletising plant to produce bio-coke from externally acquired organic carbon2) at the site in Tornio with an annual capacity of 25,000 tonnes. This leads to a decrease of carbon emissions by 82,000 tonnes, which is the equivalent of the annual emissions of 8,000 Finnish citizens. Bio-coke is then used as a reduction agent in ferrochrome plants, as a substitute for fossil coke.
Bio-coke is currently the best available technology3) to replace fossil coke in ferrochrome production. The pilot plant in Tornio will allow Outokumpu to further develop the process and the product in order to facilitate future expansions.
Huhtala adds:
“The use of raw materials based on biomass offers interesting new opportunities to lower direct emissions. At the beginning of the year, with the successful testing of bio-coke, we reached an important milestone which gave us the confidence to take the next step and build our own pelletising plant.”
At the same time, Outokumpu has planned further investments into future production capacities for bio-coke. During the second phase, the concept for a pilot plant to produce bio-coke will be developed further, and will also address the question of how to make the most efficient use of the gases that are generated during the process. There are plans for further investment decisions in 2024, on the condition that financial feasibility can be guaranteed.
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1) Bio-coke is a renewable resource made from biomass from parallel material flows in the forestry and timber industries. In the first phase, the biomass is turned into bio-carbon using a pyrolytic procedure, and in the second phase, it can be processed/pelletised into bio-coke (i.e. compacted bio-carbon). Bio-carbon is used to smelt stainless steel and bio-coke is used to smelt ferrochrome as substitutes for fossil coal or coke.
2) Outokumpu is working on securing access to high quality bio-carbon through direct purchases and the development of partnerships. In November 2023, Outokumpu announced that it had become a shareholder of Envigas AB, the first major producer of bio-coal in the Scandinavian countries. The investment comes with a guaranteed right to 50% of the current and future production output of Envigas.
3) In contrast to the production of carbon steel, ferrochrome smelting cannot use hydrogen as a reduction agent because of the high temperatures that are required. In the long term, Outokumpu is investigating other potential technologies to replace fossil coke.
