Possible Breakthrough In Hydrogen Energy 326
destinyland writes "MIT researchers have developed a method of splitting a water molecule by emulating the way blue-green algae separates oxygen from hydrogen. One chemistry professor called it 'an extremely clever piece of work' that addresses 'the nanoscale organization of the components.' Using sunlight rather than electricity to make hydrogen from water could greatly improve the efficiency of the process. The hydrogen can be stored for generating electricity or burned as fuel for cars. The project is being led by the winner of a 2004 MacArthur Foundation genius grant, who uses genetically engineered viruses as templates for nanoscale electronic components. 'Suddenly, I wondered, what if we could assemble materials like the abalone does — but not be limited to one element?'" Here is the press release from MIT; the research paper is available only to subscribers of Nature Nanotechnology (or those willing to part with $18).
Efficiency doesn't matter (Score:3, Interesting)
This could be a winner even if efficiency isn't great.
Yes, there are nightmare problems handling hydrogen (invisible flame, leaks through many materials)
BUT - provided it's durable and cheap you have Solar power that works 24 hours/day. Turn electricity to hydrogen by day, burn hydrogen or run a fuel cell by night.
Re:which is better (Score:5, Interesting)
Who says we have to restrict ourselves to the surface?
Re:it's nothing, kapitalist dogs! (Score:2, Interesting)
Re:Nanoscale Viruses? (Score:1, Interesting)
Unless, of course, these viruses escape and replicate. Imagine the scientist's surprise when 70% of his body is decomposed into hydrogen and oxygen! I'm also fond of the 3/4 of the Earth's surface.
I'm only half joking.
Re:efficiency (Score:5, Interesting)
I should probably start logging in at some point so that people actually read my comments. A shame I can't be bothered to remember my password.
Yes you should. This is very very interesting that someone who works on thermochemical reads slashdot!!! Are you on the CR5 at Sandia? I'm a highschool student who spent a lot of spare time looking at various thermochemical schemes. Trying to understand the chemical engineering behind them. You can read my conclusions if you want. Please keep in mind that I have no real lab and haven't done any experiments.
In the end, I came to the conclusion that I liked FeO/Fe2O3 the best. The problem I saw was passivation of the iron oxide. So I looked many ways to get rid of this problem. By either misting molten FeO, grinding FeO into smaller particles, reaction with acids, etc. But one I found that I think has not been considered is the disproportion of the FeO. FeO disproportionate at temps below about 500 C as 4FeO -> Fe + Fe3O4. I have no idea what the resulting mixture looks like mechanically when this happens, but according to stuff I read it does indeed happen. Thermodynamic calculations with NIST data show that the reaction is favorable. Metalic iron reacts much better with steam than FeO, AFAIK.
The next cycle I liked was the ISPRA mark 2 sodium manganese cycle:
1. Na2O.MnO2 + H2O -> 2NaOH(a) + MnO2 at 100 C
2. 4MnO2(s) -> 2Mn2O3(s) + O2(g) at 487 C
3. Mn2O3 + 4NaOH -> 2Na2O.MnO2 + H2(g) + H2O at 800 C
This seemed quite good except for that high temperature NaOH.
This weird cycle came up in one of Ken Schultz's papers and I found it quite interesting. It's all liquid, and it seems quite strange. Could it work? I have no idea. There could be corrosion problems, with the KOH.
1. K2O2 + H2O -> 2KOH + O2 at 100 C
2. 2KOH + 2K -> 2K2O + H2 at 725 C
3. 2K2O -> 2K + K2O2 at 850 C
Another idea I had was what I call the thermoelectrochemical engine. Here's how it works. You have two metals, A and B. A can be smelted from it's oxide by hydrogen or CO, and B can reduce water or CO2. There is a non-trivial potential difference between the two metals. For example, A = iron, and B = tin. I'm guessing you can see where this is going.
1. 2Fe + SnO2 -> 2FeO + Sn + 0.5ish V in aqueous electrolyte
2. Sn + 2H2O -> SnO2 + 2H2 at some slightly elevated temperature.
3. 2FeO + 2H2 -> 2Fe + 2H2O at some elevated temperature
There are probably better metals than iron and tin but I picked them because I'm pretty sure they'd work.
Thanks for reading. I'm thinking that FeO is better than sulfur-iodine because there's no high temp separation, and no corrosives running around at high temperature.
Re:Efficiency doesn't matter (Score:2, Interesting)
wonder how many current (global/giant/energy) firms will be trying (very VERY hard) to clobber this ... starting with large advertising campaigns aka "this will not work blah blah blah"! I have got solar power on my roof and I hear a lot of people saying "not efficient enough" ... well bugger them, at the current rate I will have paid this off in 5 years time and from then onwards ...
Re:which is better (Score:4, Interesting)
I'd take Cuba, at least they have universal healthcare.
Re:Isn't electrolysis 60+% efficient? (Score:5, Interesting)
Also, you don't want methane. You want gasoline. By the time you end up with methane, you have gasoline. Baking soda is a carbon dioxide capture system. We pretty much already have the technology, and I wish someone with a real lab (not me) would do a tech demo.
Re:which is better (Score:3, Interesting)
The surface area of the Earth is finite. Our appetite for energy is not.
Don't take infinity so lightly. Our current appetite for energy is definitely finite. If you intended to say that from an infinite timeframe point of view, many things are infinite, and while humanity's appetite for energy in an infinite timeframe is possible to be infinite, it’s improbable, as it's over optimistic to assume we are going to exist forever.
Re:which is better (Score:1, Interesting)
I think it would be better for the long term survival of the species if we ran out of cheap, easy energy sources for several generations, and we designed new culture based on long term sustainability instead of constant growth
Yeah, that worked out so well in Mad Max. Great idea.
Re:Efficiency doesn't matter (Score:3, Interesting)
Ahh, but how long until you have the unsubsidized price paid off?
It might be good for *you* because other people are paying for it, but it's not as good for *everyone*.
Re:which is better (Score:5, Interesting)
In a way that relates to long term survival of mankind, I have to look at the consequences of this when it has replaced about 95% of the petro-crap we use now to run everything. That could happen as the petro becomes ever harder to extract in a safe mode, which as we are seeing, doesn't seem to be the case for deep sea drilling.
Hydrogen, once split, is a very small molecule, and like helium, is hard to store in a pressure vessel because it will slowly walk right through the walls of the vessel, even Monel metal ones. Since the other side of the vessel wall is at local atmospheric pressure, and hydrogen, being even lighter than helium, will head skyward as fast as its weight difference can make it go in the presence of the viscosity of the air. And AFAIK, it never stops, escaping into space because we don't have gravity sufficient to retain it by a factor of 20+.
Why is this important? Simple, really. Eventually we will run out of the raw material to make water, and since we are breaking it down to make this fuel, if this leakage is not being re-combusted, therefore giving the planet back its water, there will come a time when water will become scarce. Fresh water for human consumption already is a problem in some locales.
Since hydrogen can be stored in a manner similar to the acetone soaked foam filling in a bottle of welding acetylene, at very low pressures compared to direct storage as a compressed gas, such storage should be mandated from the gitgo as it will reduce this loss by 95+%...
I don't see us running out of water nearly as quickly as we have run out of petro stuffs, but in the Lazarus Long view, it may well happen. We will have made a replica of the planet Dune and I don't think that is what the folks promoting this envision. Too many will see this as a short term profit generator, and will not care what happens 100k years in the future, its not their watch. Those folks should not be trusted with your investment dollars.
--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)