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A comment on A new way to make steel could cut 5% of CO2 emissions at a stroke. Parent comment

Re:A new way to make steel could cut 5% of CO2 emissions at ... by Hextinium on Tuesday November 06, 2018 @03:19AM (#18389250)
Blast furnaces do not need fuel to create iron, the process in which iron oxide is converted to iron is endothermic but the coke itself is the fuel in the furnace. It actually is necessary to do this to produce carbon monoxide which reacts with the iron oxide.
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Re:A new way to make steel could cut 5% of CO2 emissions at ... by bigger_cheese on Tuesday November 06, 2018 @06:05PM (#18395681)
It can get very complicated. There are a few different reactions which occur in a Blast Furnace some are exothermic some are endothermic.

BF is very simplistically a giant counter current reactor. Ore and Coke (the reactants) are added at the top at room temperature and hot gas (the "blast") is injected at the bottom and they flow past each other.

CO is not the only reductant that plays a role Hydrogen primarily from the humidity contained within injected gas also plays a role in the heat balance of the furnace.

Hydrogen is actually very efficient at reducing iron and avoids the CO2 byproduct. I know in the past some alternative ironmaking methods have looked into using things like hydrogen gas and natural gas (CH4) to directly reduce iron ore using a process abbreviated as DRI (Direct Reduced Iron) and for a while in the '90's this was marketed as a Blast Furnace alternative I haven't really kept up with technology.

I started my career as a Metallurgist (Materials Engineer) working at a Blast Furnace they are hugely complicated beasts.

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Re:A new way to make steel could cut 5% of CO2 emissions at ... by SomeAmerican on Tuesday November 06, 2018 @01:02PM (#18393334)
"Blast furnaces do not need fuel to create iron"

Blast furnaces need fuel to raise the temperature of the blast furnace input to speed up stripping what becomes slag and the oxygen from the iron oxide in the iron ore. Carbon monoxide is what is able to penetrate the iron ore at the high temperatures.

My previous comment is criticizing the author for suggesting that yet another fuel produces the heat for the blast furnace.

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