[ TECHNOLOGY ] and similar mechanical properties are close to zero . So , the case for steel is clear . The future of iron and steelmaking can therefore be nothing other than green .
Flue gas flaring or power and heat recovery
Iron and steelmaking generate many thousands of tonnes of carbon dioxide ( CO 2
) annually . The emissions predominantly come from blast furnace gas ( BFG ) and basic oxygen furnace gas ( BOFG ). These flue gases contain carbon monoxide ( CO ), hydrogen , and methane . Methane is a potent greenhouse gas and CO is poisonous .
To avoid CO and CH 4 emissions , BFG and BOFG can be flared to convert these gases to CO 2 and water vapour . In some facilities , BFG and BOFG are utilized by feeding them to a gas engine which generates heat and power for the facility . In this case , the exhaust from the gas engine will be rich in CO 2 and water vapour , but the heat and power generation will avoid the use of some of the fossil fuel .
CO 2 capture using modern solvents
Many iron and steel producers are piloting processes for decarbonisation with emerging
Steel is the backbone of every industrialized nation . The energy transition cannot take place without it .
technology providers . For example , ArcelorMittal is using the patented DMX™ solvent-based
CO 2 capture technology in the 3D Project , or DMX Demonstration Dunrkirk . The Project will capture
CO 2 from blast furnace flue gases .
CO 2 is produced when coke is used to reduce iron ore to iron .
Decarbonisation pathway
Replacement of blast furnace with DRI using blue hydrogen
Replacement of blast furnace with DRI using green hydrogen
Application in iron and steelmaking
Ironmaking
Ironmaking
CO 2 emissions avoidance route
CO 2 capture during hydrogen production
Renewable or nuclear power for water electrolysis to hydrogen
Substitution of fossil coke / coal in the existing blast furnace with biocarbon
Ironmaking Sustainable biogenic CO 2 emissions *
Increased use of electric arc furnaces
Steelmaking , scrap re-processing
Renewable or nuclear power for the electric arc furnace
Plasma decomposition of CO 2 to syngas |
Iron and steelmaking |
Renewable or nuclear power for the |
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electrical plasma |
Reheating using electricity , blue or green hydrogen
Fermentation of BFG , BOFG to ethanol and then synthetic fuels production
BFG , BOFG combustion for heat and power
BFG , BOFG conversion to hydrogen using Water Gas Shift
Iron oxide chemical looping BFG , BOFG flue gas conversion to hydrogen
Steel processing
Iron and steelmaking
Iron and steelmaking
Iron and steelmaking
Iron and steelmaking
Displacement of fossil fuel in steel reheating furnace
Avoidance of CO 2 emissions from flue gas combustion *, substitution of fossil fuel by ethanol-derived fuels
Avoidance of CO 2 emissions from fossil fuel combustion for heat and power *
Avoidance of CO 2 emissions from fossil fuel use in hydrogen production *
Avoidance of CO 2 emissions from fossil fuel use in hydrogen production *
* CO 2 emissions can be further reduced if CO 2 from these processes is captured .
Green Steel World | Issue 10 | February 2024 39