Hacker News Reader

Comment by aurelwu | Hacker News Reader

Direct reduction of iron ore with Hydrogen can eliminate most of the process emissions of smelting: https://en.wikipedia.org/wiki/Direct_reduced_iron . Production of secondary steel (recycled steel) using electric arc furnaces also barely has process emissions.

View on HN

I've never heard of this before, so correct me if I'm wrong, but that wikipedia article makes it look like 2Fe2O3 + 6H2 -> 2Fe + 6H2O. Commercially hydrogen is produced via CH4 + 2H2O -> CO2 + 4H2.

Combined you're just converting methane into CO2 and H2O as if you burnt it? Is it actually the case that this ends up needing less hydrocarbons than other routes for some reason?

If carbon emissions were heavily taxed, it would be cheaper to generate the hydrogen from water electrolysis.

In the US, no new blast furnaces have been built in decades; they’re all mini mills and/or direct reduction furnaces and yeah, the latter use natural gas. But again, you could use electrolytically producers hydrogen. There’s no reason to use steam reformed hydrogen except it’s currently cheaper.

You might be interested in the direct reduced iron process.

https://en.wikipedia.org/wiki/Direct_reduced_iron

I think[1] typical plants steam reform natural gas to CO and H2 and use that to reduce iron ore below the melting temperature of iron. Which makes it energy efficient.

[1] I think == don't quote me

Reply on news.ycombinator.com