Harnessing the Sun to Make Hydrogen Fuel - Can it Work?

If this technology is the real deal (and not the latest version of 'cold fusion') this would solve a whole boatload of problems.  Of course, there would likely be a new boatload of problems coming in to shore, but still ...

The latest edition of EETimes Online has the article, Nanotubes promise fuel from water.

More below ...

PORTLAND, Ore. -- Sandia National Laboratories recently demonstrated that hollow organic nanotubes, married to an inorganic catalyst, can harness sunlight to turn water into pure hydrogen and oxygen. By 2006, Sandia researchers hope to have prototypes from which a new kind of solar cell could be made that would convert water into fuel.

Such cells might replace fossil fuels in automobiles and thus reduce the United States' dependence on foreign oil.

Here's how they describe the mechanism. (It could be a routine by Groucho or Monty Python for all I understand of it.)

Organic nanotubes are used throughout nature to transport electrons and to convert light into energy. In humans, for example, porphyrin nanotubes provide the power by which hemoglobin forms new proteins. The Sandia researchers believe they can harness the same mechanism to power automobiles with water.

"Porphyrins serve in any function where energy has to be harvested," said Shelnutt. "The porphyrins themselves are well-understood, and there is even a chlorosomal rod [in nature that is closely related to porphyrin nanotubes]. It's a nanorod that acts as a light-harvesting agent in photosynthetic bacteria. So our device mimics that."

So how about it all you science types.  Sound promising?

•  Until Halliburton claims it owns sunlight

  
  yes it does- I can just see it now--

  Halliburton patents the sun-- we now have to pay a Sun User Fee of $2.14 a month to Halliburton.

  (actually, didn't Burns do this on the Simpsons?)

  by jgkojak on Mon Mar 28, 2005 at 02:08:58 PM PDT

  •  Can we delete that

    I don't want to give them ideas.

    by jgkojak on Mon Mar 28, 2005 at 02:09:21 PM PDT

    •  They may be evil, but they're smart

      Anything you've thought of, chances are they have a dozen people working on.

      And if it's not them, it would be Monsanto or GE or some other company . . .

      by Our Man In Redmond on Mon Mar 28, 2005 at 02:11:51 PM PDT

  •  more important: they own water

    the rethugs are trying to make government owned water supplies an illegal trading practice, because it subsidizes industry.  Kinda hard to turn water into hydrogen if you can't afford the water, now ain't it?

    Expect to be learning a lot more about cisterns and rainwater collection before long.  Some areas of the country already have a big industry in rainwater collection.

    by unterhausen on Mon Mar 28, 2005 at 02:32:44 PM PDT

•  Interesting, but

  I guess my big question would be how much output you could get from such a cell.

  What makes petroleum such a good energy source is that you get considerable bang for your buck, so to speak.  Other forms of energy are a lot more diffuse, so you need a lot of collectors to get the same amount.

  by Linnaeus on Mon Mar 28, 2005 at 02:15:19 PM PDT

•  Plausible...

  There's nothing wrong with the electrochemistry as spelled out.  It will bear watching, but we won't really know the economics of the thing vis-a-vis other photoenergetic technologies until it has been scaled up a little and some notions of what mass production involves have emerged.  

  by Faber on Mon Mar 28, 2005 at 02:17:28 PM PDT

•  yes

  It's called solar-power. nyuck nyuck

  by fitzov rules on Mon Mar 28, 2005 at 02:18:33 PM PDT

  •  Sounds more like photosynthesis

    artificial that is.  I don't think this would be a gas replacement, but still interesting.

    by ortsed on Mon Mar 28, 2005 at 02:35:32 PM PDT

    •  That's exactly what it is

      Water-splitting has been worked on for at least 25-30 years, but it's been really hard to get it to the practical stage.  The problem is that when sunlight hits a molecule, the molecule can do one of several things:

      • It can spit the energy right back out again.  This is fluorescence (That's why those day-glo markers seem to glow green - they really are glowing!).

      • It can hold onto the energy for awhile, and then spit it back out as light later, which is called phosphorescence.  This is how those Halloween toys that glow for a few hours after you put them under a lamp work. The light emisssion is delayed for reasons I won't go into except to say that the energy exchange is something called a "forbidden transition," which means it can't happen as easily as fluoresence, which is an "allowed transition."

      • It can vibrate away the energy it absorbed as heat.  This was the big problem I ran into in grad school {in 1983 :-( } working on tying these light absorbing molecules onto polymers, since they're usually as expensive as all get out and you want to make sure you don't lose any of the material (imagine if your catalytic converter in your car gradually lost all its platinum in the exhaust).

      • It can do useful work, like splitting water into hydrogen and oxygen.

      The other problem is that the systems, even if they work well, are expensive.  One of the systems I worked on used the metal ruthenium, a relative of platinum.  One problem with it was that the only known sources of ruthenium were in the USSR [Ruthenia is an old name for Russia, in fact] and South Africa, and in the early 1980s we didn't want to do business with either place if possible.  One of the major news magazines did a story on this at the time, and pointed out this problem.

      So, what's a young chemist concerned about the environment to do?  I got into the environmental cleanup field instead, but that's a story for another day...

      by Dem in Knoxville on Mon Mar 28, 2005 at 03:59:36 PM PDT

•  Nope

  by SW on Mon Mar 28, 2005 at 02:19:23 PM PDT

  •  Just kidding

    Of course it works.  But it isn't the most efficient way to use solar radiation to create hydrogen, just the one that is currently the most in vogue because it has the prefix "nano" attached to it.

    by SW on Mon Mar 28, 2005 at 02:26:14 PM PDT

•  It works.

  I don't understand this particular process, but getting hydrogen out of water using sunlight can be done.  The question is how efficiently can you do it.

  The current process is chemistry set stuff.  Use a solar cell for electricity, and then run that through water to break up the water into hydrogen and oxygen.

  If this process is more efficient, that would be great.

  by A Citizen on Mon Mar 28, 2005 at 02:21:27 PM PDT

•  we'd be running everything on solar

  if they had found a way to put a meter on the sun.

  by rasbobbo on Mon Mar 28, 2005 at 02:37:12 PM PDT

•  Monty Porphyrin (nerd alert)

  This is what a porphyrin looks like:

  

  It's all carbon and hydrogen atoms, except in the middle, which has some nitrogen atoms as well.  The nitrogen atoms in the middle of that ring like to bind metal atoms (iron, for instance), and those metal atoms in turn can carry electrical energy.  A little more precisely, they can (depending on the details) either pick up electrons from, or deliver electrons to, other chemicals somewhere else.

  Your body uses similar compounds all the time.  Hemoglobin, the oxygen carrier in the blood, has a similar structure --it's got an iron atom in the middle -- as do the active regions of some of the enzymes that control metabolism and energy transfer in cells.

  And -- believe it or not -- these guys have their very own Web site.

  by ColoRambler on Mon Mar 28, 2005 at 02:46:58 PM PDT

•  Not a panacea.

  Sure, you could do it, but would you want to?

  This sounds to me like a pretty expensive way to generate motor vehicle fuel.  It comes down to efficiency.  Which is cheaper?  Growing corn or rape seeds for biofuels, or creating your own quasi-photosynthesis, or using conventional photovoltaics for electrolysis?

  There are lots of ways to generate alternative vehicle fuels.  The question is, at what price.  You have a very different economy is the answer is $4 per gallon equivalent than you do if the answer is $16 per gallon equivalent.

  by ohwilleke on Mon Mar 28, 2005 at 02:49:32 PM PDT

•  Isn't there a finite amount of water on Earth?

  I've been led to believe that all the water on Earth has always been here and always will be, constantly recycled through the evaporation-precipitation process.

  So, how does it help us if we solve the oil crisis by using up our water?

  Forgive me if this is scientifically ignorant, I admit I am a liberal arts guy.

  by jetfan on Mon Mar 28, 2005 at 03:05:59 PM PDT

  •  The Cycle would be a Closed Loop

    In other words, you split H20 into H2 and O.

    Then you burn it back into water.

    No water is lost.

    LL

    by LeftyLimblog on Mon Mar 28, 2005 at 03:12:40 PM PDT

•  Three problems with Hydrogen

  that need to be addressed before it is useful for large-scale use:

  1. Production. No such thing as a hydrogen mine, and the closest thing to that is stripping the protons off of natural gas. Sadly, that does absolutely nothing to address the fossil fuel issue. Splitting water into H and O, which is what the technique described above does, is promising, but there are daunting efficiency issues that need to be solved for it to be economical.

  2. Storage. Gasoline has a very high energy density, both in energy/weight and energy/volume. Getting hydrogen packed densely enough to have comparable energy storage capability has also proven to be difficult. Compressed gas is straightforward, but the pressures you need are alarmingly high. Liquefication requires a hefty energy cost to cool the gas down to 20 Kelvin, and also has high losses (due to evaporation). Most of the current research is in developing solid materials which can absorb large quanities of H and then release it on demand.

  3. Use. Fuel cells are great: clean, efficient, effective. Sadly, they also cost an arm, a leg, and a foot. Getting fuel cells to cost a reasonable amount of money is nontrivial. Getting the efficiency higher is also an area of active research, since that will help with problems 1 & 2.

  If you talk to people in the field, they will say that these problems are all solvable, but that we're probably talking a couple of decades for a complete systemic solution.

  (Not original to me; most of this cribbed from a colloqium I went to a couple of months ago entitled "The Hydrogen Economy".)

  -dms

  by dmsilev on Mon Mar 28, 2005 at 03:10:46 PM PDT

  •  But it is so important to push on this.

    The prospect of limitless, clean burning energy should be pursued with all the vigor of the Manhattan Project. It is the most vitally important work we could undertake; the fate of humankind almost certainly depends on it.

    Plants seem to be fairly efficient at turning sunlight, CO2 and water into energy. If plants can do it, so can we.

    If the US fails to lead here, Europe, Japan or China will do it instead. Last summer was the hottest in Europe in 500 years - 30,000 people died. They know that Global Warming is real and they are not beholden to the Saudis.

    Americans hate science but they get body counts. When a series of major weather disasteres kills 10 of thousands in the US, Democrats must be ready to use it as a cudgle to beat BushCo into oblivion.

    by BartBoris on Mon Mar 28, 2005 at 03:25:22 PM PDT

    •  I agree...

      ...a Manhattan Project or Space Race like effort should be initiated. With many estimates of peak oil having been reached or reached soon, and with China and India quadrupling their automobile capacity by 2050, we're going to have an serious energy crisis long before any Social Security crisis. Perhaps this is the only way to shorten the 2-decade forecast from the above post.

      But don't look for any far reaching vision from our current Oil Pimp Bush. But maybe he'll surprise us. One issue is that most politicians have become so short sighted that they can't think beyond the end of their term - a Manhattan Project maynot come to fruition in their political lifetime. We need someone with the balls/vision of JFK to generate an 'energy race'.

      We're currently losing the race. My next car is a Honda Civic hybrid, screw the US automakers for dragging their heels.

      by philo on Mon Mar 28, 2005 at 03:53:53 PM PDT

•  The Trick Is Where to Introduce It

  Well, I looked at the linked paper, and it seems that all they've done is just proof-of-concept. They don't actually have a cell that will produce gasses yet, not even a benchtop demo. But it's exciting--the article says they expect to have a demonstration cell this year or next.

  I think, as a general rule, any radical new energy source will be applied to cars last. The problem is that we have a huge global infrastructure for mining, refining, shipping, storing and delivering petro fuel to vehicles. Hydrogen seems to me to be pretty different from gasoline in its requirement for storage and handling. Think missiles.

  I've seen it suggested for example that fuel cells might first be installed on buildings, because the present models are large and heavy, which doesn't matter for buildings. This expands the market which drives more innovation until the technology becomes light and efficient enough to warrant rolling out infrastructure to support vehicles.
  

  by Gooserock on Mon Mar 28, 2005 at 03:19:23 PM PDT