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Iron fuel shows its mettle

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Re: Iron fuel shows its mettle

#201

Post by bioemerl »

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…

What if the place with excess energy is America in the place was not enough is Europe?

Re: Iron fuel shows its mettle

#202

Post by DennisP »

rbanffy wrote: post #190
coryrc wrote: post #180

Earlier quoted context omitted.

In winter cloudy conditions solar PV produces 10-15% power. Assuming some hydro storage, that's 4x overbuild. Not cost effective. Europe all gets winter at the same time. If you've got a cold snap for three weeks with low wind, the only plan is reliance on massive fossil fuel backup. The cost of keeping that capacity for only using a week a year isn't priced into solar either. The CO2-intensity of electricity generat…

> In winter cloudy conditions solar PV produces 10-15% power Depends on the latitude and these numbers seem to be for very high ones close to the polar circles. > Not cost effective. Are we pricing in the societal collapse due to climate change? I’d suspect a 4x overbuild would be quite cheap against that. OTOH, keeping some natgas capacity for when a freakish cold snap with no wind hits seems kind of OK.

GP is clearly talking about cost-effectiveness compared to other solutions, such as France's approach and seasonal storage.

Re: Iron fuel shows its mettle

#203

Post by DennisP »

hankman86 wrote: post #114
SmooL wrote: post #71

Earlier quoted context omitted.

> My gut feeling is that transmission lines would still be cheaper Transmission lines are great for moving electricity, but only if there's demand for that electricity _right now_. Otherwise, you have to store it - which is a problem, because battery tech right now isn't great (or rather, it's not good enough for grid-scale requirements) . This iron powder could be thought of as a "battery". It might be harder to mov…

But isn’t that the point of transmission lines - match supply and demand? Given a large enough region, there is going to be a place where renewable electricity can be produced. Case in point being offshore wind turbines where there are almost always strong winds to spin these. Moving this electricity to where it is consumed is a huge issue though. Existing power grids were created with centralised power stations in m…

In the US we're especially bad at building new long-distance transmission. Some projects have languished for decades.

There are probably other places where it's difficult to get that large-enough region, for geographic or geopolitical reasons.

Re: Iron fuel shows its mettle

#204

Post by DennisP »

onlyrealcuzzo wrote: post #146
jerf wrote: post #61

Earlier quoted context omitted.

To a first approximation, Earth is a big ball of iron, so losing 50% of the iron in 333 cycles doesn't seem like that big a deal. Getting more iron is an energy issue rather than an availability issue. I'm also somewhat concerned about the nanoparticle's effect on living things. It is likely that it is only a question of local exposure, as in general once they get out they should still rust in some relatively short p…

> so losing 50% of the iron in 333 cycles doesn't seem like that big a deal. Where does the Iron go??? It's not like Fission or Fusion is happening, right?!

Per the article, it goes into the HEPA filter. After that, recover it or dispose of it as you see fit.

Re: Iron fuel shows its mettle

#205

Post by SV_BubbleTime »

chewbacha wrote: post #102
howlin wrote: post #100

I don't really understand why iron is being considered over aluminum. Is aluminum production from ore too complex compared to iron? I would have to imagine burning metallic aluminum produces much more energy per gram.

My gut is to assume that aluminum isn't as viable because it does _not_ oxidize as readily as iron does.

Aluminum definitely oxidizes extremely well. Most of the aluminum you come in constant with is oxidized intentionally (anodizing).

It’s just a ridiculously expensive metal to make.

Look up how much alumina is minded all over the world, how it’s shipped to Iceland for processing because of their cheap geothermal electricity, then shipped to China to processing, then shipped back around the world to final destination. It’s crazy.

Re: Iron fuel shows its mettle

#206

Post by ben_w »

burmanm wrote: post #194
rbanffy wrote: post #190

Earlier quoted context omitted.

> In winter cloudy conditions solar PV produces 10-15% power Depends on the latitude and these numbers seem to be for very high ones close to the polar circles. > Not cost effective. Are we pricing in the societal collapse due to climate change? I’d suspect a 4x overbuild would be quite cheap against that. OTOH, keeping some natgas capacity for when a freakish cold snap with no wind hits seems kind of OK.

> Depends on the latitude and these numbers seem to be for very high ones close to the polar circles. No, those values are far from polar circle. I'm guessing closer to central Europe, since for example in Finland the PV produces 0% during the winter months. 10-15% would be insane to get here, but there simply isn't any energy in the sun (and closer to the polar circle you get - there's no sun at all during winter) a…

Finland (the south of it anyway) has about a gigawatt of HVDC lines connecting it to other countries, about 200W/capita.

Re: Iron fuel shows its mettle

#207

Post by rsaesha »

dredmorbius wrote: post #200
rsaesha wrote: post #72

Earlier quoted context omitted.

>Earth is a big ball of iron. No it's not. Inside the crust both Si and Al are more common. There is plenty of Fe, which is all in oxide form. Mining and processing required.

Shrug. Iron is abundant on Earth, including within the crust, where it's the fourth most abundant element (after Oxygen, silicon, and aluminium), roughly 5% by mass. And yes, considerably more prevalent in the core. Iron and oxygen account for roughly 32% of Earth's total mass, each, the largest proportion of any element. https://en.wikipedia.org/wiki/Earth_mass > Sure, not as abundant as silicates. But nowhere near…

Let's be reasonable here, mantle and nucleus iron don't matter to this analysis.

Crust iron is all oxide. Fe at 5% average. In some locations obviously more concentrated up to 90% ore. Not all sites are viable for mining, and this is very important to understand. Just because there is plenty of iron out there doesn't mean all of it is commercial grade.

This means energy input to turn iron oxide into iron, which the article claims could be used as fuel and/or long term energy storage.

-Fuel I don't believe for a second.

-Energy storage it's a maybe. It needs to commercially beat plenty of options. Which to me seems unlikely since the path still includes heat and steam engine which would incurr at a cicle loss of at least 50%. And this being conservative etc. Would mean a steam engine operated in a very narrow power band - which would mean a baselevel powerplant not a peaker powerplant. And didn't yet consider other possible losses, as for one, the Fe degradation over time. Energy cycles that count on heat and engine are wasteful. Could this waste be compensated by a much cheaper capex and/or opex relative to Li or similar batteries? That's a big Maybe.

I myself want to believe there is a solution to renewables intermittency. But on this one in particular, I'm quite bearish for the reasons above.

Re: Iron fuel shows its mettle

#208

Post by dredmorbius »

MagicMoonlight wrote: post #129

Comparing petrol with iron based on volume rather than weight seems highly misleading. I’m assuming that actual energy density is much worse with iron right?

It really depends, principally on what your extant constraints are.

For some applications, mass is a critical concern (e.g., powered aircraft). For others, it's volume, say, powerplant + fuel stores aboard a marine vessel.

As I'm understanding this proposal, the iron is largely recycled, so transport of iron is relatively minimised. The concern is how much iron is required on site, and what the plant-sizing characteristics are given that.

Though of course, in any public communication of novel research and technological proposals, there's a significant amount of PR, spin, and narrative-spinning, so it's fair to be skeptical.

Re: Iron fuel shows its mettle

#209

Post by dredmorbius »

samus wrote: post #124
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.

From a global-warming perspective, NOx also has a fairly short residency-time, as I understand.

Yes, it's an environmental concern for other reasons, but focusing on greenhouse considerations is fairly reasonable.

Re: Iron fuel shows its mettle

#210

Post by dredmorbius »

rsaesha wrote: post #207
dredmorbius wrote: post #200

Earlier quoted context omitted.

Shrug. Iron is abundant on Earth, including within the crust, where it's the fourth most abundant element (after Oxygen, silicon, and aluminium), roughly 5% by mass. And yes, considerably more prevalent in the core. Iron and oxygen account for roughly 32% of Earth's total mass, each, the largest proportion of any element. https://en.wikipedia.org/wiki/Earth_mass > Sure, not as abundant as silicates. But nowhere near…

Let's be reasonable here, mantle and nucleus iron don't matter to this analysis. Crust iron is all oxide. Fe at 5% average. In some locations obviously more concentrated up to 90% ore. Not all sites are viable for mining, and this is very important to understand. Just because there is plenty of iron out there doesn't mean all of it is commercial grade. This means energy input to turn iron oxide into iron, which the a…

The proposal is clearly for energy storage, not as a primary energy source.

To that extent, it resembles other synfuel concepts. The principle difference being that iron-as-energy-storage entails reduction rather than synthesis, in the chemical sense, for hydrocarbon synfuels.

There's a lot to be said for options which provide long-term, "shelf-stable", environmentally-benign, high-volume energy storage with convenient storage, handling, and utilisation characteristics. I've looked with interest on petroleum-analogue hydrocarbon synthesis (Fisher-Tropf) and alcohol (Sabattier) processes for some years. Both have long (multi-decadal, approaching a century) of established use. Yes, the overall process is lossy (as little as 15% net energy recovery), but there are applications for which there are very few alternatives: powered heavier-than-air flight, marine transport, mobile use, off-grid primary or back-up power systems, heating, and industrial applications.

I think I'd made abundantly clear that the abundance question is pedantry.

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