Possible Breakthrough In Hydrogen Energy

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).

Comments

efficiency

[wizardforce]

This is from what I've read on the subect, quite impressive in terms of how it works however, this isn't a technology that is very likely capable of exceeding the efficiency of a few other methods of producing Hydrogen. 10% solar => Hydrogen efficiency would be impressive for a biological system but well within reach of other technologies like solar thermal + water thermochemical cracking This technology might be of use if alternatives remain comparatively expensive.

Re:efficiency

[Anonymous Coward]

As someone who both worked on this biological route and saw this thesis defense (FYI, this is a dupe of an earlier story), and someone who is now working on the solar thermal route, I agree so heartily I was amazed to actually read this comment here. This is exactly the correct analysis -- extremely cool science, brilliant work, but no chance of being an actual engineering solution. As far as "comparitively expensive", the solar thermal routes we work on use metal oxides like FeO/Fe2O3 which is completely recovered while the biological route we use incorporates IrO2... and degenerates after 4-5 cycles. This seems like a no-brainer to me. However, the quantum efficiency trends due to cross coupling, the gel method of suspending wires, etc were all absolutely fascinating ideas.

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.

Re:efficiency

[Black Gold Alchemist]

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:which is better

[init100]

If discover or invent an even cheaper, easier way to get energy out of water now, we'll have another "industrial revolution" type of growth, and come to an even worse dead-end when that runs out too.

Except sunlight isn't expected to run out in a timeframe that humanity can fathom.

Re:which is better

[cgenman]

Considering that all life on this planet has a tendency to expand to consume all available resources, I wouldn't count on a cultural change to rectify the consumptionist problem.

But don't cry a tear for poor H20. The water is not consumed when you create Hydrogen; when recombined with Oxygen it forms water again. You're not getting energy "out" of water. You're getting energy out of solar radiation. The water is merely a temporary medium to be broken apart to store energy, and re-combined to release it.

Dupe! And Unobtianium Alert!!!

[Black Gold Alchemist]

This story appears to be a dupe.

Iridium, a form of unobtainium, is used. This costs upwards of $13,000 per kg. About 3 tons are produced a year.

Over-rated

[Anonymous Coward]

Some genuinely incredible work has come out of the labs at MIT; however, the work described in this article is pedestrian. Frankly, Prof. Belcher is a seriously over-rated, one-trick pony. Don't get me wrong, it's a hugely impressive trick - essentially directed evolution of viruses to get their capsid (i.e., proteinaceous component) to selectively bind to [whatever], but she applies it to whatever the current hot topic is, such as the photocatalytic splitting of water, and has absolutely done it to death. It's her hammer for the world of research nails.

Some of you may recall one of her papers a few years ago on virus-based lithium ion batteries. That work was also Belcher's brainchild, used the exact same techniques as are found in this Nature Nanotech paper, and was also ridiculously over-rated.

The problem with MIT is shameless self-promotion - and it's self-perpetuating because people (even the MIT professors spouting their own greatness) believe it. Another example is Robert Langer, whose work is fine but unremarkable. However, because he's so well known and great at self-promotion, he gets papers in Science/Nature/etc. As a result, his fame continues and the accolades continue to pour in.

It's frustrating to watch, knowing that fame and accolades are often undeserved when brilliant work from lesser known researchers goes unnoticed, but there's really no solution other than to point out when particular academics get more recognition than they deserve and hope that others reading agree and spread the word.

Re:Over-rated

[rubies]

Thanks Sheldon, say hi to Penny for me.

Re:Not so fast . . .

[BluBrick]

Wait, what? The pond scum is not the lawyer?

Hydrogen == Battery

[Anonymous Coward]

You're not getting energy "out" of water. You're getting energy out of solar radiation.

Yup, hydrogen is just a battery: you charge it by removing the oxygen, then discharge it by burning it (which recombines the oxygen atoms and reforms water).

(unless, of course, you're doing fusion, then hydrogen IS a power source)

Re:Isn't electrolysis 60+% efficient?

[Black Gold Alchemist]

Yes, electrolysis is 70%+ efficient. But, it first must go through that pesky and pricey 20% efficient solar panel, so you get %14 solar to hydrogen. Wouldn't it be great if we could skip that solar panel and all the associated pricing, and go right to hydrogen? That's what this is about.

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:What happens at night?

[feepness]

What happens if I run out of hydrogen at night?

You have to make H while the sun shines.

Re:Isn't electrolysis 60+% efficient?

[Ihlosi]

Yes, electrolysis is 70%+ efficient. But, it first must go through that pesky and pricey 20% efficient solar panel,

True. But there are other renewable source with intermittent output that can be used for electrolysis, like wind power. And where I live, the potential power from wind is about five times that of solar.

Also, you don't want methane. You want gasoline. By the time you end up with methane, you have gasoline.

Yeah, yeah, I know. I'd be happy with methane first, since it's already much easier to handle than plain hydrogen. Synthesizing longer chain hydrocarbons might make the fuel more convenient, but also requires more effort.

Baking soda is a carbon dioxide capture system.

The problem with CO2 is that you'll need _lots_ for the industrial process, and there's only very little of it air (300-something ppm). Extracting that is a major pain in the rear (i.e. requires lots of energy).

Re:which is better

[Bongo]

Would it be better to find new and amazing ways to create energy from resources now, or would it be better for humanity to first learn to live within our means as oil runs out?

Humans have shown over and over that in large groups we use all the resources available, don't slow or restrain ourselves in time to save ourselves, and unless there are consistent, strict rules and provisioning in place, we exhaust available resources.

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. If discover or invent an even cheaper, easier way to get energy out of water now, we'll have another "industrial revolution" type of growth, and come to an even worse dead-end when that runs out too.

I also think it would be better if children skipped ages 1 to 12 and started life as 13 year olds. No even better, as 21 years olds.

Whilst it would be nice to imagine a new culture which transcends material growth, our development thus far has come along side material growth. The material side is related to the cultural side. It is no accident that the most underdeveloped cultures (female genital mutilation, widespread corruption as a daily fact of life, religious intolerance, deep racism and sexism) are all places that are materially poor. Like, green grass is a luxury. Clean water is a luxury.

So when you champion "living within our means", you're talking about your current cushy oil based lifestyle. If you took that away, how do you know that the next generation won't develop a harder culture? In history, men and women segregated because life was dangerous and the men were sent to do the most dangerous jobs. In South Africa, Apartheid started because the white poor miners were on the verge of losing their jobs to even poorer native Africans. In Zambia, my own mum couldn't get a driving license because the "driving test" was dinner with the examiner. In Pakistan, life is still essentially feudal today, with forced arranged marriages and family members being disowned for not following the strict traditional rules. I mean, there's places where it is not so bad, and some are more progressive, but my point is, it is easy to forget how tenuous is our hold on rational liberal secular humanistic culture.

it is not that those other cultures are "bad", they are just the best that ordinary humans can manage when the living conditions are harder.

The way to sustainability is better technology that can do more. Anything else is stagnation and eventual devolution to death.

If we fail to invent that new technology, we will fail to progress culturally beyond nation states and dogma.

There is a line in Pygmalion where the well-to-do gentleman asks the thief, "have you no morals man??"

And the thief replies, unashamed, "can't afford them."

Re:What happens at night?

[jonnat]

The energy density of hydrogen as compared to liquid hydrocarbons is pathetic. The best use of hydrogen would be to to synthesize hydrocarbons, of course at that point you'd wonder why you bothered with hydrogen at all instead of just making biodiesel from algae.

First time I hear of a molecular property being described as pathetic.

Nonetheless, you are wrong. Wikipedia (http://en.wikipedia.org/wiki/Energy_content_of_biofuel) is kind enough to show us that the specific energy density of hydrogen (120-140 MJ/kg) is much higher than that of hydrocarbons (55 MJ/kg, Methane). The low density of hydrogen makes it less energetic only in volumetric terms

Furthermore, the crucial advantage of hydrogen is the lack of carbon atoms, its combustion (or catalyzed oxidation, as in a fuel cell) resulting only in water.

Re:which is better

[Almost-Retired]

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)

Re:What happens at night?

[networkBoy]

I already do this.
I story my hydrogen in a liquid for ease of use. This way I can use hoses to get it to my engine where I then allow it back into a vapor form (by pushing it through small nozzles at about 135 bar.
My storage method is really cool:
I stick 34 hydrogen atoms onto a chain of 16 atoms of element 6.
Best thing is that this method of storage is nearly explosion proof, even with a 20% oxygen atmosphere around my fuel storage, I can put a lit match out in it while it is in it's liquid state. It is only under extreme pressure that it detonates, and that is how I drive my car.