http://www.independent.co.uk/news/science/scientists-predict-green-energy-revolution-after-incredible-new-graphene-discoveries-9885425.html

Story on the front page of today's Independent reporting on a study published in Nature that states that:

"Researchers have discovered that graphene allows positively charged hydrogen atoms or protons to pass through it despite being completely impermeable to all other gases, including hydrogen itself.

The implications of the discovery are immense as it could dramatically increase the efficiency of fuel cells, which generate electricity directly from hydrogen, the scientists said.

The breakthrough raises the prospect of extracting hydrogen fuel from air and burning it as a carbon-free source of energy in a fuel cell to produce electricity and water with no damaging waste products.

“In the atmosphere there is a certain amount of hydrogen and this hydrogen will end up on the other side [of graphene] in a reservoir. Then you can use this hydrogen-collected reservoir to burn it in the same fuel cell and make electricity,” said Professor Sir Andrei Geim of Manchester Univeristy."

Still only small scale and probably many years work involved in realising this on a commercial scale but it looks very positive.

Here is the Nature paper http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14015.html

Yes, graphene turns out to be permeable to H+ ions, and this might eventually lead to a new kind of fuel cell.

We have hydrogen fuel cells already. Graphene might make them lighter or safer or more reliable. Cool.

But the Indy piece implies that elemental hydrogen (H2) is abundant in the air. It ain't. Just lots of water (H2O). You can use wind energy to split water, and if you insist, that water could be extracted from the air by a big dehumidifier, though I think most engineers would just wait for it to rain.

Geim is a smart cookie, I think he has been misquoted by idiots.

how do stop the proton combining with oxygen before it passes through the membrane?

Posted By: tonyhow do stop the proton combining with oxygen before it passes through the membrane?

You make sure there is no oxygen on that side!

Posted By: Chris P BaconWhat happens if we start consuming hydrogen from air, does the concentration of 1 part in 2 million come back into balance naturally or will we end up depleting the available hydrogen?

That was my thought - yet another assumption that we can dump into or extract from the carefully balanced biosphere, which appears infinitely large, without unforseen consequences.

Second guessing the comment I linked above:

QJRMS: “The hydrogen content of atmospheric air at ground level”

http://onlinelibrary.wiley.com/doi/10.1002/qj.49708335808/abstract

0.6 parts per million. I assume that's of Hâ‚‚.

I calculate that if you burned all the hydrogen in the atmosphere in a year you'd be able to produce 244 GW. That might cover a couple of European countries, I suppose, but hardly a panacea. Dunno how fast the hydrogen would be replaced - there must be some sort of replacement process going on as hydrogen is lost to space being light enough to reach escape velocity from the upper atmosphere just due to thermal speeds.

But that's if you can get at all the molecular hydrogen (Hâ‚‚). I can't imagine there's much atomic ionised hydrogen around and what little there is must get reacted pretty quickly, I'd think.

What about just scrubbing mains gas at the point you wish to use a fuel cell, with the rest of the mains gas mix being put back into the pipe for other customers to use....

Posted By: Ed Daviesif you burned all the hydrogen in the atmosphere in a year you'd be able to produce 244 GW

So this 'harvesting energy from thin air' is a complete non starter. So what is the process good for - filtering pure hydrogen out of a hydrogen-rich mixed gas? Like natural gas - is that what ringi's suggesting?

Extracting hydrogen from methane, just like extracting it from water, takes big energy input to 'crack' the chemical bonds - in case of extracting from water, exactly same energy as is usefully released by subsequently burning it. Exactly zero nett energy gain - in fact considerable nett loss, due to the inefficiencies in the transactions.

So cracking methane or water to get hydrogen is totally negative as an energy source - unless the energy input is 'free' in some way, like solar, but even then that solar energy could have been used much more fruitfully. Or hydrogen as a waste by product of some other process - unlikely.

Hydrogen at best is only a tranformed form of some already existing energy. It is only justified, despite the energy-downgrade waste in its production by transformation, when the need for 'portable' fuel is paramount, in vehicles - when the only alternative is liquid fossil. Then, even worse in that use, powering a heat engine, the latter are inherently wasteful, converting at very best 50% (usually about 35%) of the fuel's energy to useful mechanical energy, the rest as heat, which goes to waste as it's hard to find useful use for that much un-storable lo-grade heat on board a vehicle.

Posted By: ringithe free Os

do you mean the free Cs? Is there a simple to understand energy flow diagram of this end to end process?

Posted By: Viking HouseDoes putting Hydrogen through a fuel cell instead of burning it prevent the creation of oxides of nitrogen?

As far as I know yes it does. Fuel cells are better than combustion in that respect.

Here is the E&T bit about it, probably a bit more realistic:
http://eandt.theiet.org/news/2014/nov/graohene-membrane-fuel-cell.cfm

Sorry fostertom , I did mean the fee Cs.

Methane is CH4,
So 2* CH4 is split in 4*H2 + 2C using steam and a catalyst
Add a O from the air to give 4*H2 + C2O + a little heat
Then add more 0 to give 2*H20 + electric output + more heat in the form of lots of stream
Some of the stream is fed back into the first step; hence this can work for CHP, but does not work well for producing H2 to store.

There is very long tern research into fuel cells that can run on methane or methanol directly, I don’t think hydrogen is a good option for transport as it is so hard to store.

Are you thinking about helium?

http://www.sciencedaily.com/releases/2014/03/140304094839.htm

"around four-fifths of all hydrogen released into the air is rapidly removed through soil activity,"

but where does that hydrogen come from? Is it created by radioactive rocks?