[rfreytag]

I assume they are using renewable energy to reduce naturally-occurring iron oxide.

When the iron is burnt are they going to do with pure oxygen? Otherwise they'll get pollutants like nitrogen dioxide, possibly ozone. And the 0.5% not burnt will also become a pollutant unless carefully removed in some smokestack scrubber.

Or is this 'burning' to occur some kind of iron fuel cell? How would they liquidize the iron which is quite heavy?

Lastly, iron is heavy. Moving reduced iron could be expensive and dangerous.

Still, if sufficiently close to the renewable source this could provide much needed load leveling for intermittent sources.

[samus]

The article assumes the viability of a hydrogen-driven process to reduce the iron. The intention is to establish a circular economy of reducing iron oxidized by burning it in the proposed fashion.

The byproducts from burning iron are no more noxious than burning fossil fuels, possibly less so. Filtration technologies exist as well.

Of course this technology would have to compete with other technologies to make use of excess renewable energy, like liquid hydrogen storage and transport (which it has several advantages over), iron-based battery technologies, or green-produced carbon-based fuels. I guess it makes the most sense in applications where heat instead of electricity is required.

[_hypx]

> Of course this technology would have to compete with other technologies to make use of excess renewable energy, like liquid hydrogen storage and transport (which it has several advantages over), iron-based battery technologies, or green-produced carbon-based fuels. I guess it makes the most sense in applications where heat instead of electricity is required.

I'm going to come out and say those competing technologies are vastly more plausible and viable.