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Powerpaste, a hydrogen technology for small vehicles

fraunhofer.de

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Re: Powerpaste, a hydrogen technology for small vehicles

#51

Post by sfifs »

coryrc wrote: post #49
tomas789 wrote: post #8

Solving hydrogen storage has great implications. Hydrogen has high gravimetric energy density (1 kWh worth of H2 is light) but very low volumetric density (1 kWh takes up a large volume). Easy solutions are compressed hydrogen (H2 is a small molecule and easily escapes even through a material, steel embrittlement and energy for compression are big issues), cryogenic cooling (energy intensive and cryocoolers have sign…

You don't need hydrogen, you need electrons. I prefer to store my electrons directly in atomic element 3, so I can fill it directly with electrons and get them back out, at much higher efficiencies than this process.

In all energy storage tech, you're trading off energy density (eg. energy per kilogram) against power rating (energy per second that you can transfer). Then you have trade-off considerations like safety, emissions (which have a value - see Tesla P/L), production cost, supply chain etc. For different use cases, different trade-offs may work out.

Lithium battery tech typically trades off power rating and energydensity (Earlier - how much acceleration and range, nowadays with better batteries - how fast you can fill up) for other benefits.

This tech prioritises safety and power rating at some production cost and supply chain.

Gasoline gives emissions and engine complexity vs other conveniences

Rockets prioritize both power and energy density over everything else and uses LH2 and LOX dealing with cryo complexity

Re: Powerpaste, a hydrogen technology for small vehicles

#52

Post by DaniFong »

amluto wrote: post #3
h2odragon wrote: post #2

> Onboard the vehicle, the POWERPASTE is released from a cartridge by means of a plunger. When water is added from an onboard tank, the ensuing reaction generates hydrogen gas in a quantity dynamically adjusted to the actual requirements of the fuel cell. In fact, only half of the hydrogen originates from the POWERPASTE; the rest comes from the added water OK sounds great! so this stuff is more sensitive to moisture…

Sodium is boring. Potassium is much better! Seriously, though, this sounds like a horrible technology. Synthesize fancy goo that is unstable when wet. React with water to make hydrogen (itself moderately dangerous). Produce some kind of slush containing magnesium hydroxide (presumably) and miscellaneous organic crud as waste. What, exactly, happens with the waste? At least magnesium hydroxide is not as nasty as sodiu…

"miscellaneous organic crud" i figure you would recycle all of it in an environment where the slurry is saturated with hydrogen gas at high temperature and pressure, and what happens is the water reacts to make magnesium oxide, back to hydride

Re: Powerpaste, a hydrogen technology for small vehicles

#53

Post by ChuckMcM »

Ah chemistry is pretty neat. Presumably there is a process to take the left over magnesium hydroxide and convert it back into metallic magnesium? Their explainer[1] doesn't say much about that part of the process. (note it looks like you can bake it at 332 degree C to get magnesium oxide. (can you tell I'm not a chemist?) I think it would be helpful to have the entire fuel cycle laid out somewhere.

That said, the operational infrastructure requirements for this seem to be much easier to satisfy with off the shelf technology than hydrogen storage which, frankly, is really really hard.

[1] https://www.zess.fraunhofer.de/content/dam/ikts/zess/documen...

Re: Powerpaste, a hydrogen technology for small vehicles

#54

Post by pfdietz »

jbay808 wrote: post #17
NickM wrote: post #13

Earlier quoted context omitted.

or direct air capture (expensive and inefficient) The big question in my mind is whether direct air capture is inherently expensive and inefficient...or if this is just a chicken/egg problem where we haven't invested time and money in making it cheaper because it's expensive, and it's expensive because we haven't invested time and money in making it cheaper. I don't know enough about physics and chemistry to answer t…

It's inherently expensive, because you have to undo the entropy loss of letting the CO2 diffuse into the atmosphere. It basically means running an expensive molecule sorting operation, whose cost has a floor set by the laws of thermodynamics, in advance of whatever else you wanted to do with the CO2.

That entropy loss is not that large (it's logarithmic in the dilution). A bigger problem is simply the cost of handling a lot of air.

Re: Powerpaste, a hydrogen technology for small vehicles

#55

Post by Hypx »

coryrc wrote: post #49
tomas789 wrote: post #8

Solving hydrogen storage has great implications. Hydrogen has high gravimetric energy density (1 kWh worth of H2 is light) but very low volumetric density (1 kWh takes up a large volume). Easy solutions are compressed hydrogen (H2 is a small molecule and easily escapes even through a material, steel embrittlement and energy for compression are big issues), cryogenic cooling (energy intensive and cryocoolers have sign…

You don't need hydrogen, you need electrons. I prefer to store my electrons directly in atomic element 3, so I can fill it directly with electrons and get them back out, at much higher efficiencies than this process.

Unless you're thinking of a hybrid supercapacitor, you're still going to need a chemical reaction first.

Re: Powerpaste, a hydrogen technology for small vehicles

#56

Post by mensetmanusman »

Used to work at the Leibniz institute in Dresden, near where this research at the Fraunhofer institute on POWERPASTE is happening.

Not sure why they are trying to brand in all caps, but highly recommend adding Dresden to your bucket list post Covid. Most beautiful city I have experienced.

Re: Powerpaste, a hydrogen technology for small vehicles

#57

Post by kaliszad »

tomas789 wrote: post #8

Solving hydrogen storage has great implications. Hydrogen has high gravimetric energy density (1 kWh worth of H2 is light) but very low volumetric density (1 kWh takes up a large volume). Easy solutions are compressed hydrogen (H2 is a small molecule and easily escapes even through a material, steel embrittlement and energy for compression are big issues), cryogenic cooling (energy intensive and cryocoolers have sign…

Well, I don't think hydrogen is the answer for all these reasons. It seems, that sodium (Na) can under certain conditions (very thin film, e.g. when applied to a surface with great speed of 10s of m/s) react directly with water and produce stable electric current. That is not so hard to do, e.g. hard disks, regular turbines etc. pretty much would provide such conditions :-) The patents for such use in Lockheed-Martin rockets expired long ago but it seems based on the details, that it worked reasonably well.

Sodium is very easy to handle. There is no need for large pressure or any bonding elements. The hydroxide can be turned into sodium again by well known processes that were used on industrial scale more than 100 years ago already. This process and the "burn" of sodium with water both release hydrogen as a by-product. This could solve the winter energy storage issue. Also you could quite likely safely transport sodium in former oil tankers or by pipe if heated to a bit more than 100 °C/ or in the form of concentrated hydroxide (the "waste")... so the infrastructure is mostly there. As you all well know, original sodium can be extracted from regular NaCl salt that we have plenty of in sea water and salt mines.

Best of all, sodium reacts so rapidly, it could under minor adjustments replace diesel in +- regular engines too. (That is also the contents of one of the patents.) That is of course not so efficient, but there is a large installed base.

Re: Powerpaste, a hydrogen technology for small vehicles

#58

Post by kaliszad »

zhengyi13 wrote: post #12

In '99, while working at a solar hydrogen startup as a recent grad, I was exposed to a fellow who proposed to transport H in the form of H2O, and his solution for cracking it was to make purple ping pong balls filled w/ Na. He'd deliver a hopper of Na ping pong balls, and a machine filled with water. Feed balls into the machine, which would then use a ram to split the balls underwater, and siphon off the resulting H2…

It would be lot easier to just use sodium directly and have hydrogen as a by-product. (See my other comment.)

Re: Powerpaste, a hydrogen technology for small vehicles

#59

Post by kaliszad »

corty wrote: post #9
hannob wrote: post #5

Earlier quoted context omitted.

Ammonia is currently considered as one of the more promising options for future shipping fuels. There are a number of projects planning to create green ammonia at scale, e.g. this: https://asianrehub.com/ Ammonia is already made from hydrogen today, making that green is pretty straightforward, you just need enough clean electricity. Just get the hydrogen from electrolysis, the ammonia synthesis process itself is well…

Ammonia is one of the less pleasant chemicals one could use. I'd rather have Hydrogen-exuding paste than Ammonia in an accident. The Hydrogen might explode. But the Ammonia definitely will hurt you.

Ammonia is quite ok. You can smell it :-) You can put it into water, where it is quite stable. We know how to handle it at industrial scale because of fertilizers.

Re: Powerpaste, a hydrogen technology for small vehicles

#60

Post by mojomark »

hinkley wrote: post #24
zhengyi13 wrote: post #12

In '99, while working at a solar hydrogen startup as a recent grad, I was exposed to a fellow who proposed to transport H in the form of H2O, and his solution for cracking it was to make purple ping pong balls filled w/ Na. He'd deliver a hopper of Na ping pong balls, and a machine filled with water. Feed balls into the machine, which would then use a ram to split the balls underwater, and siphon off the resulting H2…

There was another group during that era doing something similar with sodium hydroxide, which is a little less... violent. Not quite sure I recall how that chemistry worked, but I think the idea is 'find something where the hydrogen bonds are easier to crack than H2O'. Now there are other groups trying to figure out if they can increase the power capacity of batteries by replacing the electrolyte. Which sounds like a…

Aluminum oxidation.
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