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Powerpaste, a hydrogen technology for small vehicles

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Re: Powerpaste, a hydrogen technology for small vehicles

#11

Post by hannob »

Nasrudith wrote: post #10
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…

Why not just use a closed loop hydrocarbon from electricity system as a shipping fuel if you have excess power and a need for transit? The main theoretical point of hydrogen is very high specific energy per mass but it is essentially purest acidic gas and a pain. Bonding it to something else mitigates it so why 3 H per N instead of 4 H per C? Both are toxic gases at this point leaving ammonia's main advantage in the…

The problem with every hydrocarbon-based fuel is that you need the carbon.

You get that from CO2. But then you need to get the CO2. Where do you get it from? From a fossil-based plant? Well, ideally you'd want to get rid of those, not exactly smart to create incentives to keep them running. The alternative is either biomass (problematic) or direct air capture (expensive and inefficient). (Some insightful discussion on green methanol: https://www.youtube.com/watch?v=jXACyUxxBts )

With non-carbon based fuels like hydrogen or ammonia you skip that problem (air is 78% nitrogen, much easier to extract).

Re: Powerpaste, a hydrogen technology for small vehicles

#12

Post by zhengyi13 »

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 gas to feed to your fuel cell.

The racket it made, with a loud kerchunk splitting the balls, and the hissing immediately following, was just slightly terrifying.

This paste seems a good deal saner in comparison.

Re: Powerpaste, a hydrogen technology for small vehicles

#13

Post by NickM »

hannob wrote: post #11
Nasrudith wrote: post #10

Earlier quoted context omitted.

Why not just use a closed loop hydrocarbon from electricity system as a shipping fuel if you have excess power and a need for transit? The main theoretical point of hydrogen is very high specific energy per mass but it is essentially purest acidic gas and a pain. Bonding it to something else mitigates it so why 3 H per N instead of 4 H per C? Both are toxic gases at this point leaving ammonia's main advantage in the…

The problem with every hydrocarbon-based fuel is that you need the carbon. You get that from CO2. But then you need to get the CO2. Where do you get it from? From a fossil-based plant? Well, ideally you'd want to get rid of those, not exactly smart to create incentives to keep them running. The alternative is either biomass (problematic) or direct air capture (expensive and inefficient). (Some insightful discussion o…

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 the question on what the theoretical lower bound on cost might be.

Re: Powerpaste, a hydrogen technology for small vehicles

#14

Post by zdragnar »

WJW wrote: post #7
amluto wrote: post #3

Earlier quoted context omitted.

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…

It's not like petroleum is all that nice though, it's just that the handling around it has been pretty much perfected over the decades. You can collect spent sludge at the same place a scooter has to come anyway to refill and then re-hydrogenate the sludge into fresh paste.

The big difference, of course, is that petroleum doesn't explode or combust when rained on. Aside from sparks or ignition sources, it can sit in a bucket or puddle and be happy staying put.

Re: Powerpaste, a hydrogen technology for small vehicles

#15

Post by choeger »

I know this sounds awfully complicated to handle (and recharge), but I think the market for practical applications of H fuel is existing, so these ideas can be evaluated in practice.

Also, not every invention has to save the world. So this paste might become useful for drones or in spacecraft. Depending on the energy density it might even be very usable for electrified air travel.

Re: Powerpaste, a hydrogen technology for small vehicles

#16

Post by ksdale »

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…

Not that internal combustion engines are the model to aspire to... but they're just a metal contraption full of explosions. Being terrifying isn't necessarily a disqualifier, haha.

Re: Powerpaste, a hydrogen technology for small vehicles

#17

Post by jbay808 »

NickM wrote: post #13
hannob wrote: post #11

Earlier quoted context omitted.

The problem with every hydrocarbon-based fuel is that you need the carbon. You get that from CO2. But then you need to get the CO2. Where do you get it from? From a fossil-based plant? Well, ideally you'd want to get rid of those, not exactly smart to create incentives to keep them running. The alternative is either biomass (problematic) or direct air capture (expensive and inefficient). (Some insightful discussion o…

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.

Re: Powerpaste, a hydrogen technology for small vehicles

#18

Post by WJW »

zdragnar wrote: post #14
WJW wrote: post #7

Earlier quoted context omitted.

It's not like petroleum is all that nice though, it's just that the handling around it has been pretty much perfected over the decades. You can collect spent sludge at the same place a scooter has to come anyway to refill and then re-hydrogenate the sludge into fresh paste.

The big difference, of course, is that petroleum doesn't explode or combust when rained on. Aside from sparks or ignition sources, it can sit in a bucket or puddle and be happy staying put.

Neither does this substance though. It releases hydrogen when in contact with water, not explode or combust. It might, of course, explode if sparks are introduced but the same thing can happen to hydrocarbon based fuels.

In any case, what a substance does when rained on is not very relevant for a fuel that is kept in a fuel tank at all times. By the time it's exposed to the weather, the vehicle must have crashed and in such a circumstance most safety guarantees are out of the window anyway.

Re: Powerpaste, a hydrogen technology for small vehicles

#20

Post by JoeAltmaier »

WJW wrote: post #18
zdragnar wrote: post #14

Earlier quoted context omitted.

The big difference, of course, is that petroleum doesn't explode or combust when rained on. Aside from sparks or ignition sources, it can sit in a bucket or puddle and be happy staying put.

Neither does this substance though. It releases hydrogen when in contact with water, not explode or combust. It might, of course, explode if sparks are introduced but the same thing can happen to hydrocarbon based fuels. In any case, what a substance does when rained on is not very relevant for a fuel that is kept in a fuel tank at all times. By the time it's exposed to the weather, the vehicle must have crashed and…

No hydrocarbon fuels aren't oxygenated. Put a spark plug in your gas tank, run it day and night - nothing. Has to be oxygen in there.
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