Iron Powder Passes First Industrial Test as Renewable, Carbon Dioxide-Free Fuel
spectrum.ieee.org
spectrum.ieee.org
Gas? Shut it off. Wood and coal? Water. Oil? Fine water mist or co2.
But iron oxide? An out of control fire can burn for days and most fire departments aren't equipped to handle it. The byproduct is a magma that destroys anything it touches and if water contacts an iron fire it will result in an explosion.
None of the websites I can find mention iron as an example of a metal fire when talking about the dangers of using water on them. Metals like magnesium and lithium yes. But not iron: https://www.isystemsweb.com/metal-fires/
This source talks about the use of water firefighting at steel mills. That's not quite the same thing as powdered metal. But still illustrative: https://firesafeworld.com/fire-safety-in-iron-and-steel-indu...
As you'd expect, water on hot metal will lead to steam explosions. But from the sounds of it, the simplest solution to that problem is keep your distance, and keep putting water on the fire until it overwhelms the heat capacity of the molten metal.
Steam explosions which kick up more metal in air. But I think typical firefighting foam would easily help with that, much less water but still deprives fire of oxygen.
If you asked me to fight such a fire, I'd setup some unmanned nozzles, retreat, turn on the pumps slowly, and just wait it out. Probably will be an expensive total loss. But no-one gets hurt, and the burning iron doesn't itself release particularly toxic fumes, so no long term harm. Not that bad really for an industrial fire.
Sounds like a good candidate for grid storage if it can be reversed somewhat efficiently, the weight isn't as big a deal in grid, especially if it is compact.
The high weight could probably be used to store gravitational potential energy as well in hilly areas.
However, if we had a crapton of iron, it would probably be better to seed plankton.
As a battery, a box full of iron has a lot of drawbacks - it has low specific energy (you need a lot of iron to store your energy), it's heavy (it costs a lot to transport from the refinery to the place the energy is being used), and it's inneficient (burning iron to generate steam to drive a turbine might get you 40% efficiency at best, and removing the oxygen again later has its own issues).
The one application that this makes sense is for generating process heat - you can slowly store energy by electrolysis and then release it as a very high temperature heat source. In most cases hydrogen would make more sense: it's simpler to electrolyze and burns hotter, but it's difficult to handle and store which might be important for the application.
Say a 20 MW solar plant, works for 6 months to generate powdered iron. Then start the 10 MW companion thermal plant, burn the iron powder instead of coal, generate electricity as a base load plant. Meanwhile the rust ash from the thermal plant is the new fodder for the solar plant.
I can see that the overall cyclic efficiency can be lower than existing plants, but definitely carbon neutral.
In theory, you want an abundant substance which takes up oxygen, produces solid waste, which is easy to clean up, raw material which is stable in outdoor conditions (if spilled) and non-toxic to your skin in either form.
I read through the literature after seeing a NewAtlas article a couple of weeks ago [1] & [2].
> Nitrogen? Sulfur?
Gases are harder to take to recycling.
> Sodium?
Can't touch it without gloves or sneeze around it (the problem is H2 gas, not the sodium itself).
There was a memorable sodium leak in a Kalpakkam nuclear power plant in India that I remember, where the issue was the H2 from the sodium + water lines breaking.
> Aluminum?
Aluminium would be easier to mine out of the ground than Fe, but Al02 to Al is a harder conversion to do already in terms of energy efficiency.
And as someone who's burned through a crucible and the floor with Thermite & spent time cleaning it up, the real value of iron oxide is that it doesn't get "harder by burning" (AlO2 is HARD) & produces a fragile and flaky waste product which is easy to clean off the equipment.
[1] - https://newatlas.com/energy/bavarian-brewery-carbon-free-ren...
I found the question equally intriguing.
This is still an energy storage medium, so think of it like a very energy dense battery rather than a true fuel & today it is produced by burning carbon in coal/coke.
That aside, for a solid powder fuel, pretty much yes.
That 2nd article lists out why it is most likely the best choice, but to collect everything I read together.
2nd most abundant (Al is more), powder burns into powder oxide which can be separated easily (not corundum glass), production capacity exists across the world (not exotic material), the waste product will dissolve in acidic water (for cleaning), but isn't a "heavy heavy" metal (we can excrete iron through our kidneys), decent flame capacity (magnesium would burn hotter, maybe), very shelf stable, degrades into the final product (it rusts, but then you dump it the same way), won't catch fire by itself (not like the alkali metals or sulfur/phosphorus)
Eventually, there's just a few non-carbon elements which even hit a part of those - Al, Si and Fe. And the other two make it one-use only with glassy (literally) oxides.
Where can I read more about AlO2?
A quick Google search is unhelpful. Is it also called "alluminum peroxide oxide"?
Sorry, bad typo for the oxide - Al has many oxides. I meant Al2O3, not Al2O (or AlO2)
https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth...
Also, I'm no chemist but I imagine it's a lot easier to strip an oxygen atom or two off of an iron oxide molecule than to string together a bunch of water and atmospheric CO2 molecules into a complex hydrocarbon. So we can convert the combustion byproducts back into fuel much more easily with iron.