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Iron fuel shows its mettle

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Re: Iron fuel shows its mettle

#121

Post by samus »

chasil wrote: post #64
Tade0 wrote: post #50

> “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 transmission lines. Metals can solve a big problem in the renewable energy transition: long-duration energy storage.” My gut feeling is that transmission lines would still be cheaper. That being said long-term storage seems to be the value prop…

"Altiro gets around this problem by adding a little natural gas to ignite the iron powder when the boiler first starts up." You will also need a very specialized furnace, and supplies of CH4.

The demand for natural gas is probably minuscule compared to the total heat output of a burning cycle. Also, thanks to the war in Ukraine, demand for natural gas might decline in the long term if European countries switch to alternative, hopefully greener, energy sources.

Re: Iron fuel shows its mettle

#122

Post by Animats »

GlibMonkeyDeath wrote: post #87

Sounds like one of the least efficient energy storage ideas I've heard in a long time, I wonder how this is getting funded? Hmm, let's check to see who is behind this...the founding professor https://www.tue.nl/en/research/researchers/philip-de-goey/ is a fellow/awardee of the Combustion Institute, gets funding from ERC, etc. OK, so I guess all that European taxpayer money won't spend itself, and if you have a hammer…

Yes, this is a strange approach. Separate iron from iron oxide, which is energy intensive. That's what blast furnaces did, or do, and it's a messy and energy-intensive process. Burn iron to get heat and iron oxide. Repeat.

Are there numbers on the energy efficiency and costs of this process? This seems very strange. Batteries are above 90% round-trip efficiency now. This has to be lower.

Re: Iron fuel shows its mettle

#123

Post by ben_w »

Tade0 wrote: post #50

> “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 transmission lines. Metals can solve a big problem in the renewable energy transition: long-duration energy storage.” My gut feeling is that transmission lines would still be cheaper. That being said long-term storage seems to be the value prop…

Yeah.

Article says energy density of 11.3 kWh/litre.

WolframAlpha says using that for all global electricity for a day is 33e9 kg iron: http://www.wolframalpha.com/input/?i=2%20TW%20%2A%201%20day%...

Some estimates I did a while back and then wrote up nicely with ChatGPT said a global power grid would use about x100 that much iron: https://github.com/BenWheatley/Studies-of-AI/blob/main/Globa...

So the cut off between them is that if you use this for more than about four (/eight) months, the grid was cheaper.

That said, while I personally love the idea of a global grid, geopolitics rather than technical merit is likely to be the dominant constraint for any solution, as everything[0] is cheap enough that cost doesn't matter.

Also, possibly still useful for shipping? Possibly? I assume they'd prefer synthetic oil, but I don't claim any real knowledge, that's just my uninformed guess.

[0] Well, almost everything — concrete-based gravity batteries produce too much CO2 so they're expensive with current production methods just in a non-monetary sense, and antimatter production is so inefficient it's not viable, but those are the only two exceptions I know about.

Re: Iron fuel shows its mettle

#124

Post by samus »

bbojan wrote: post #116

The elephant in the room are, as always, nitrous oxides (NOx). Whenever you burn something in a nitrogen atmosphere, NOx are created. They contribute to acid rain and the formation of smog, and are a trigger for asthma.

While certainly being an issue, they are a far smaller problem than emissions of greenhouse gases by fossil power sources. It is a greenhouse gas itself, but most human emissions come from agriculture. Moreover, there are technologies to reduce the emission of NOx'es from burning processes.

Re: Iron fuel shows its mettle

#125

Post by thsksbd »

13of40 wrote: post #51
thsksbd wrote: post #30

Earlier quoted context omitted.

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

Not sure why this is dead, but AFAIK magnetism in iron and steel is dependent on "domains" of iron molecules that are aligned in a crystal structure so the magnetic effect isn't just scattered to all directions. That's why some kinds of stainless steel aren't magnetic - the adulturant elements break up the crystal structure. In this case I think the question would be whether these particles are big enough to form a "…

at nanoscale many (all?) iron oxides become super-paramagnetic. If anything, they're even more attracted to magnetic fields.

Re: Iron fuel shows its mettle

#126

Post by samus »

hankman86 wrote: post #112

Or you just use the iron to build more towers for wind turbines. Or transmission lines to send renewable electricity to where it is needed.

There is no shortage of iron, while this is another way to make usage of abundant renewable energy. Especially when at the destination actually heat is required. Apart from that, neither wind turbines nor more transmission lines help with the problem of making excess energy available for future use.

Re: Iron fuel shows its mettle

#127

Post by AlbertCory »

__MatrixMan__ wrote: post #109
AlbertCory wrote: post #76

There's an experiment in here where Theodore Gray "burns" iron: https://www.youtube.com/watch?v=NMJtieqVUc4 I hosted this. Getting permission from the Building department to have fire indoors was lotsa fun.

The lecture looks interesting, but if you want to skip to the burning stuff part: https://youtu.be/NMJtieqVUc4?t=2587 I learned that stainless steel burns the hard way. You can use stainless steel scrubby pads as a heat sink to vaporize DMT in a contraption called "the machine". Naively, I thought steel wool would work instead of the scrubby pad. It doesn't. The fibers are too small and it ignites--pretty much exactl…

Pro tip: do Show Transcript to skip around a YT video. Find the words you want, then click it.

Re: Iron fuel shows its mettle

#130

Post by chasil »

Animats wrote: post #122
GlibMonkeyDeath wrote: post #87

Sounds like one of the least efficient energy storage ideas I've heard in a long time, I wonder how this is getting funded? Hmm, let's check to see who is behind this...the founding professor https://www.tue.nl/en/research/researchers/philip-de-goey/ is a fellow/awardee of the Combustion Institute, gets funding from ERC, etc. OK, so I guess all that European taxpayer money won't spend itself, and if you have a hammer…

Yes, this is a strange approach. Separate iron from iron oxide, which is energy intensive. That's what blast furnaces did, or do, and it's a messy and energy-intensive process. Burn iron to get heat and iron oxide. Repeat. Are there numbers on the energy efficiency and costs of this process? This seems very strange. Batteries are above 90% round-trip efficiency now. This has to be lower.

According to the source below, aluminum has higher energy density than iron (23.5kWh/L versus 16.7kWh/L).

The entry for iron in the link below is also higher than the iron energy density reported in the parent link (11/3 kWh/L).

https://onlinelibrary.wiley.com/doi/full/10.1002/ente.202000...

Of course, aluminum used in this way is the classic thermite reaction; I conjecture that the iron reaction is also.

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

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