Green H o take (optional)
Green power
Green H
Battery limit
e-
Linde Electrolysis
Power system
Reheat furnace
Vent
EAF
DRI
Linde O compression/ treatment
Green O
Linde Cojet System H burners
Linde REBOX Hyox H burners
Green O o take (optional)
Linde technology
For full decarbonisation of 2 Mt/y steel plant with 100% DRI:
DRI Total H and O consumption per tonne of rolled steel EAF Reheat
H and O production
1.1 GW
Electrolyser capacity
H , kg/t
63
3
9
75
H production
210,000 Nm /h
O , kg/t
0 - 55
45
40
85 - 140
O production
100,000 Nm /h
30% of electrolyser O production is used, 70% potentially for other o takers
Figure 4 Integrated green steel production ecosystem
as a fuel. As the electrolyser produces both hydrogen and oxygen, we would then have a complete integrated system. However, such a plant can also serve in a hub where additional production of hydrogen and oxygen are supplied to neighbouring off-takers. Summary The steel industry can decarbonise significantly with hydrogen steelmaking or CO₂ capture and sequestration where feasible. However, these approaches are longer-term (beyond the year 2030) solutions that are not sustainable today due to the capital and operating cost impacts on steelmakers. For them to become sustainable or viable, we need a combination of higher costs of CO₂ emissions, plus a well-developed infrastructure to supply low-cost renewable power and hydrogen at a very large scale.
Steelmakers can take short-term steps with incremental and stepwise sustainable decarbonisation approaches that are affordable today. Energy efficiency improvements with oxyfuel combustion – with fossil fuel savings of 20-60% – offer immediate CO₂ reductions with low Capex commitments on several unit processes. Proven oxyfuel-based solutions can reduce the steel industry’s CO₂ emissions by 200 Mt/a. Integrated steel mills can decarbonise by raising blast furnace tuyere injectant levels using external gasification, increasing the scrap ratio in converters, and charging DRI/HBI produced by the gasification of low carbon footprint feedstocks and alternate fuels such as coke oven gas.
Joachim von Schéele joachim.von.scheele@linde.com
www.decarbonisationtechnology.com
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