Iron fuel shows its mettle • Hacker News Board

Re: Iron fuel shows its mettle

#21

Post by kinnth » Fri, Jun 23, 2023, 3:27 PM UTC

c0nsumer wrote: post #12

ermir wrote: post #6

Iron is not widely available in nature as a ready-to-use element, it must be processed into elemental iron, which takes a lot of energy as input. Therefore this can't be really considered as fuel, more like energy storage. You still need fossil fuels or nuclear power to turn iron ores into iron, then you have iron available for the process described in the article. I'm not criticizing the process, but it's not accura…

The article says this. It wraps up with: "If these problems can be overcome, you could use renewable electricity to produce iron, store it as long as necessary, transport it there and then burn it for power when needed, says Bergthorson. “Places that have excess energy could make iron, and others can buy it. This way, you could commodify renewable energy so it can be globally distributed without the need for transmis…

This is actually the same principle as BTC. High volume cheap electricity is used to process random numbers and the value is stored as BTC allowing it to be freely transferred once first mined.

The green economics of this need some serious consideration as i'd be really aware if you can reprocess it and get a second reaction for less energy than it cost you to turn the rust back into free iron metal.

Re: Iron fuel shows its mettle

#22

Post by droopyEyelids » Fri, Jun 23, 2023, 3:28 PM UTC

schwabacher wrote: post #4

Is iron a potential replacement for coal in steel and cement production?

it could be, but like other posters have mentioned, it takes a lot of energy to mine and refine the iron so it'd be in a usable state.

I think it's easiest to think of iron as another energy storage medium that could ease the peaks of renewable energy, by taking excess renewable energy to generate the iron, and oxidizing the iron for energy generation during peak demand periods with low renewable generation

It's like hydrogen in that way.

Re: Iron fuel shows its mettle

#23

Post by kinnth » Fri, Jun 23, 2023, 3:28 PM UTC

intothemild wrote: post #16

c0nsumer wrote: post #12

Earlier quoted context omitted.

The article says this. It wraps up with: "If these problems can be overcome, you could use renewable electricity to produce iron, store it as long as necessary, transport it there and then burn it for power when needed, says Bergthorson. “Places that have excess energy could make iron, and others can buy it. This way, you could commodify renewable energy so it can be globally distributed without the need for transmis…

Sure you could use renewables to make iron. But that thought process also extends to other methods too. You could use renewables to make other non renewable fuels. Why not just skip the middleman? Use renewables?

Renewables are exceedingly bad at storing energy for times when sun or wind isn't blowing so you always need a mix.

Re: Iron fuel shows its mettle

#24

Post by slashdev » Fri, Jun 23, 2023, 3:28 PM UTC

intothemild wrote: post #16

c0nsumer wrote: post #12

Earlier quoted context omitted.

The article says this. It wraps up with: "If these problems can be overcome, you could use renewable electricity to produce iron, store it as long as necessary, transport it there and then burn it for power when needed, says Bergthorson. “Places that have excess energy could make iron, and others can buy it. This way, you could commodify renewable energy so it can be globally distributed without the need for transmis…

Sure you could use renewables to make iron. But that thought process also extends to other methods too. You could use renewables to make other non renewable fuels. Why not just skip the middleman? Use renewables?

Because renewables are intermittent and unevenly located. This could potentially solve those problems.

There could be a space for it. Or maybe batteries will just always be better. Depends on the full costs of each and the use case. Burning fuel to make electricity is pretty inefficient, but burning fuel for heat compares better.

Re: Iron fuel shows its mettle

#25

Post by juujian » Fri, Jun 23, 2023, 3:29 PM UTC

obblekk wrote: post #14

> 0.3% of the Iron-oxide becomes nanoparticles which cannot be converted back into Iron. At that rate, 50% of the initial iron will be gone in 333 cycles of iron -> iron oxide -> iron. This a hard type of energy source to reason about: 1. It's not a pure fuel and acts like a battery most of the time, but it's also not renewable 2. Iron is extremely abundant on Earth, but it requires mining and processing to extract 3…

Might be possible to create a completely closed system to address the loss?

I am more concerned/confused by the fact that they use hydrogen to reduce the iron. That seems like a very convoluted process, why not use the hydrogen generate heat instead? Yes, it has much lower density, but it has advantages to make up for it, for instance the fact that you don't need to worry about evaporation, leakage, filters, all that at all.

Re: Iron fuel shows its mettle

#26

Post by TheGeminon » Fri, Jun 23, 2023, 3:29 PM UTC

intothemild wrote: post #16

c0nsumer wrote: post #12

Earlier quoted context omitted.

The article says this. It wraps up with: "If these problems can be overcome, you could use renewable electricity to produce iron, store it as long as necessary, transport it there and then burn it for power when needed, says Bergthorson. “Places that have excess energy could make iron, and others can buy it. This way, you could commodify renewable energy so it can be globally distributed without the need for transmis…

Sure you could use renewables to make iron. But that thought process also extends to other methods too. You could use renewables to make other non renewable fuels. Why not just skip the middleman? Use renewables?

I think this is likely more of an energy storage project, rather than an energy production one (which seems to be the stance the article takes).

At grid-level, battery tech is challenging, requiring technologies like pumped storage that require particular environments (e.g. damming a river) and can't really be transported.

If this works out you could use excess solar during the day to deoxidize the rust produced, and then run the iron reactor overnight, or on cloudy, windless days.

Re: Iron fuel shows its mettle

#27

Post by juujian » Fri, Jun 23, 2023, 3:29 PM UTC

proto-n wrote: post #20

obblekk wrote: post #14

> 0.3% of the Iron-oxide becomes nanoparticles which cannot be converted back into Iron. At that rate, 50% of the initial iron will be gone in 333 cycles of iron -> iron oxide -> iron. This a hard type of energy source to reason about: 1. It's not a pure fuel and acts like a battery most of the time, but it's also not renewable 2. Iron is extremely abundant on Earth, but it requires mining and processing to extract 3…

Is iron oxide magnetic in nanoparticle size? Because if it is, then we can probably very efficiently filter it before releasing it into the atmosphere.

The article mentions a HEPA filter.

Re: Iron fuel shows its mettle

#28

Post by olau » Fri, Jun 23, 2023, 3:29 PM UTC

j-a-a-p wrote: post #10

Looks like the same thing as Form Energy provides. They are selling plants at MW level (article is about a small brewery at kW level) https://formenergy.com/

Form Energy is a bit light on details, but it looks like they are using a water based electrolyte, add oxygen, get electric power and rust when discharging, then add electric power and get iron and oxygen when charging.

The project mentioned here is setting the iron powder on fire and need to use a steam turbine to get electric power out of it. So different tech.

Re: Iron fuel shows its mettle

#29

Post by balaga01 » Fri, Jun 23, 2023, 3:30 PM UTC

intothemild wrote: post #16

c0nsumer wrote: post #12

Earlier quoted context omitted.

The article says this. It wraps up with: "If these problems can be overcome, you could use renewable electricity to produce iron, store it as long as necessary, transport it there and then burn it for power when needed, says Bergthorson. “Places that have excess energy could make iron, and others can buy it. This way, you could commodify renewable energy so it can be globally distributed without the need for transmis…

Sure you could use renewables to make iron. But that thought process also extends to other methods too. You could use renewables to make other non renewable fuels. Why not just skip the middleman? Use renewables?

Well, it ties into the storage issue that we see with renewable. We still need energy when there is no wind at night. Burning iron at night and regenerating during the day could be a solution. It needs to prove that it can be competitive with the other methods (compressed air, li-ion batteries, flow batteries, molten salts, flywheels...).

Re: Iron fuel shows its mettle

#30

Post by thsksbd » Fri, Jun 23, 2023, 3:30 PM UTC

proto-n wrote: post #20

obblekk wrote: post #14

> 0.3% of the Iron-oxide becomes nanoparticles which cannot be converted back into Iron. At that rate, 50% of the initial iron will be gone in 333 cycles of iron -> iron oxide -> iron. This a hard type of energy source to reason about: 1. It's not a pure fuel and acts like a battery most of the time, but it's also not renewable 2. Iron is extremely abundant on Earth, but it requires mining and processing to extract 3…

Is iron oxide magnetic in nanoparticle size? Because if it is, then we can probably very efficiently filter it before releasing it into the atmosphere.

iron oxide magnetic properties depend on its oxidation state, temperature and particle size.