Energy generation from Aluminium and Water: Feasible or snake oil?

[Nivee~]

I found this article about generating hydrogen by treating water with aluminium. Can anyone here prove if it's really feasible in the long term?

https://timesofindia.indiatimes.com/people/this-delhi-boy-is-trying-to-disrupt-the-energy-industry/articleshow/67923808.cms

[sevenperforce]

7 minutes ago, Nivee~ said:

I found this article about generating hydrogen by treating water with aluminium. Can anyone here prove if it's really feasible in the long term?

https://timesofindia.indiatimes.com/people/this-delhi-boy-is-trying-to-disrupt-the-energy-industry/articleshow/67923808.cms

Yes, it's real.

https://phys.org/news/2007-05-hydrogen-aluminum-alloy-fuel-cells.html

It's not currently economical because the aluminum and gallium you need cost too much. If we can figure out a way to cheaply recycle aluminum oxide and gallium (saltwater electrolysis might work) then it would end up working much better.

[HebaruSan]

6 minutes ago, sevenperforce said:

Yes, it's real.

So once you've got the hydrogen, you put it into a fuel cell (right?), which produces water vapor as exhaust. Can that be piped back into the aluminum-gallium system, in effect making it a closed system with respect to the water?

[Nivee~]

15 minutes ago, HebaruSan said:

So once you've got the hydrogen, you put it into a fuel cell (right?), which produces water vapor as exhaust. Can that be piped back into the aluminum-gallium system, in effect making it a closed system with respect to the water?

Yeah, but aluminium is oxidized in the first reaction, so it needs to be removed (no closed system, I am afraid..). Gallium however, does not react, so it can be reused. 

And whatever happens to the Alumina waste? Is it reduced back to aluminium? Or dumped?

[HebaruSan]

5 minutes ago, Nivee~ said:

Yeah, but aluminium is oxidized in the first reaction, so it needs to be removed (no closed system, I am afraid..). Gallium however, does not react, so it can be reused. 

Right, I'm mainly trying to determine whether you'd need to fill a water tank.

5 minutes ago, Nivee~ said:

And whatever happens to the Alumina waste? Is it reduced back to aluminium? Or dumped?

Yes, the article said, "However, the cost of aluminum could be reduced by recycling it from the alumina using a process called fused salt electrolysis. The aluminum could be produced at competitive prices if the recycling process were carried out with electricity generated by a nuclear power plant or windmills." So that's the energy input for the overall system.

[kerbiloid]

So, they should use electricty to extract aluminium from aluminium oxide and hydrogen from hydrogen oxide to use them as fuel to produce electricity?

Isn't it like a wind generator powered by a fan powered from the outlet powered by this wind generator?

P.S.
They can just store small amounts of energy this way. 

Edited February 24, 2019 by kerbiloid

[Starman4308]

That's not going to work except for energy storage. You need to pump a huge amount of energy into alumina to refine it to metallic aluminum, more than you'll get back from the hydrogen.

[StrandedonEarth]

It basically amounts to a complicated way to produce hydrogen for fuel cells. Probably not any more efficient than straight electrolysis 

[sevenperforce]

2 minutes ago, StrandedonEarth said:

It basically amounts to a complicated way to produce hydrogen for fuel cells. Probably not any more efficient than straight electrolysis 

It's a carbon-neutral way to produce hydrogen. That's all.

Also, if the reaction can be catalyzed properly, it's a VERY dense hydrogen storage mechanism. You could fill your tank with water and change out an aluminum powerpack as needed.

[Scotius]

3 minutes ago, sevenperforce said:

It's a carbon-neutral way to produce hydrogen. That's all.

Also, if the reaction can be catalyzed properly, it's a VERY dense hydrogen storage mechanism. You could fill your tank with water and change out an aluminum powerpack as needed.

True, that. Still, for hybrid cars it might work out. Someday, after a big company throws a billion or two at the problem.

[Shpaget]

TANSTAAFL.

You're not getting free energy from this. It can work as a primary cell battery, but recycling the materials will always require more energy than you get out.

[StrandedonEarth]

47 minutes ago, Shpaget said:

TANSTAAFL.

*buys a BEvERage* Can I get my free lunch now?

Yeah, it's a roundabout way of converting an energy source to hydrogen, carbon-free (once you have the energy). In this carbon-emission-reduction world. nuclear would be a great energy source, once the reactor plant is built and the fissiles are mined and processed (and how much carbon emissions does that produce anyways?). But the enviropeeps apparently don't want nuclear to be a solution.

[Shpaget]

4 minutes ago, StrandedonEarth said:

nuclear would be a great energy source, once the reactor plant is built and the fissiles are mined and processed (and how much carbon emissions does that produce anyways?).

Not much if your mining and processing equipment is electrical powered by nuclear.

[StrandedonEarth]

3 minutes ago, Shpaget said:

Not much if your mining and processing equipment is electrical powered by nuclear.

I considered that, but there's manufacturing the steel and concrete as well. At least smelting aluminum can be carbon-free.

Graphite rods are a carbon sink woot!

[Shpaget]

Electric arc furnace for steel can be powered by nuclear.

Cement is also produced by baking stuff, which doesn't really demand burning fossil fuels. It could nuclear. Hypothetically, you don't even need the electrical energy step.

[StrandedonEarth]

9 minutes ago, Shpaget said:

Electric arc furnace for steel can be powered by nuclear.

Cement is also produced by baking stuff, which doesn't really demand burning fossil fuels. It could nuclear. Hypothetically, you don't even need the electrical energy step.

Hmmm, nuclear power plants and materials produced with nuclear power.... I like it!

[sevenperforce]

1 hour ago, Shpaget said:

TANSTAAFL.

You're not getting free energy from this. It can work as a primary cell battery, but recycling the materials will always require more energy than you get out.

I don't see anyone suggesting this is a free lunch. But it could be a way of generating energy from scrap aluminum (if you recycle only the gallium) or a fast way to turn electricity into hydrogen (if you recycle both) or a fantastic way of powering hydrogen fuel cells (if you put it in a car).

[Starman4308]

4 hours ago, sevenperforce said:

I don't see anyone suggesting this is a free lunch. But it could be a way of generating energy from scrap aluminum (if you recycle only the gallium) or a fast way to turn electricity into hydrogen (if you recycle both) or a fantastic way of powering hydrogen fuel cells (if you put it in a car).

The issue with the notion of using this to deal with scrap aluminum is that, unless possibly you are dealing with very low-grade scrap aluminum, it's much better just to recycle the aluminum, which skips the expensive hassle of separating aluminum from the oxygen that loves it so very much.

[sevenperforce]

15 minutes ago, Starman4308 said:

The issue with the notion of using this to deal with scrap aluminum is that, unless possibly you are dealing with very low-grade scrap aluminum, it's much better just to recycle the aluminum, which skips the expensive hassle of separating aluminum from the oxygen that loves it so very much.

It may be that the cost of low-grade scrap aluminum is low enough that the process is an affordable means of generating hydrogen without using fossil fuels; the alumina would just be scrapped. Heat could probably be used to separate out the gallium.

 

[StrandedonEarth]

What would be low-grade scrap aluminum? Back in high school we threw old scrap soffits (building material) and pop cans into the crucible and cast it into new shapes (an owl in my case, not sure what happened to that. Wish I still had it)

[YNM]

I think that any power source sourced from hydrolysis is just power storage really. It's not like burning coal or oil, nor is it like harnessing wind power, geothermal, solar energy or even nuclear power.

But it might be a better (read : denser) way to store energy than batteries.

Edited February 25, 2019 by YNM

[kerbiloid]

11 hours ago, sevenperforce said:

It's a carbon-neutral way to produce hydrogen.

If they had not to spend a lot of carbon electrodes to produce aluminium.

[DDE]

1 hour ago, kerbiloid said:

If they had not to spend a lot of carbon electrodes to produce aluminium.

That, and the involvement of large amounts of acid can be a bigger problem than carbon emissions.

1 hour ago, YNM said:

I think that any power source sourced from hydrolysis is just power storage really.

You need not dress this as an opinion. It’s a fact, one that passing audiences weren’t quite aware of during the hydrogen craze about a decade ago (subjectively, we’ve been hearing less and less about hydrogen as simple electric-powered cars surged all the way to the Asteroid Belt, pun intended).

[YNM]

36 minutes ago, DDE said:

simple electric-powered cars surged all the way to the Asteroid Belt, pun intended.

In all fairness, it was boosted with 480 tonnes of kerosene at the start.

[Orc]

Greetings all

 

Aluminium is super expensive to refine in the first place. If I remember my numbers right about 20 kwh of electricity per kg, which is why aluminium smelters are always next to big hydroelectric dams or have their own coal or gas burning power station. Aluminium's value is derived from its lightness (for a given strength) and its recycling cost. Recycling used aluminium (still aluminium metal, not oxides) is super cheap.

This leads me to believe that the process described above is at least snake oil, and at worst out-right fraud attempting to part fools with their money.

 

If you want an example of aluminium and water yielding a lot of energy look up ALICE (https://en.wikipedia.org/wiki/ALICE_(propellant). I am sure this is something Kerbals would do.

 

Regards 

Orc