Blood Protein Used to Split Water

brian0918 writes "The Imperial College in London is reporting that genetically-engineered blood protein can be used to split water into oxygen and hydrogen. The abstract can be viewed for free from the Journal of the American Chemical Society." From the article: "Scientists have combined two molecules that occur naturally in blood to engineer a molecular complex that uses solar energy to split water into hydrogen and oxygen. This molecular complex can use energy from the sun to create hydrogen gas, providing an alternative to electrolysis, the method typically used to split water into its constituent parts. The breakthrough may pave the way for the development of novel ways of creating hydrogen gas for use as fuel in the future."

Comments

Energy output = input?

[Disoriented]

Now we just have to figure out if the amount of energy needed to synthesize the blood protein (say, X liters of hydrogen in a fuel cell) is less than
the energy of the hydrogen produced from this process... :)

--
Rare 680X0 and PowerPC posters!

Re:Energy output = input?

[Chris Burke]

I'd be willing to bet that this compound can be used to break multiple water molecules, just like our hemoglobin can carry another oxygen molecule after it drops one off. The source of energy that allows continued hydrogen production is the sun.

In which case, the main question is the rate at which you can produce hydrogen. How much of the substance do you need, and how much solar energy, to produce how much hydrogen over what period of time? That is what will define whether or not this is a practical method of producing hydrogen. One obvious point of comparison would be an equal-sized photovoltaic solar cell and water electrolysis machine. If it doesn't do better than that, it's pretty worthless. On the other hand it might be a very efficient way to convert solar energy into hydrogen gas for fuel cells, which would be sweet.

Not to mention the other possibilities it opens up in biochemistry. These proteins are fascinating, as is the idea of swapping out the bound metal atom to get different effects.

Re:Energy output = input?

[jcr]

What really matters is how much this process drops the cost of separating water, not the energy efficiency.
-jcr

Re:Energy output = input?

[Tumbleweed]

Now we just have to figure out if the amount of energy needed to synthesize the blood protein (say, X liters of hydrogen in a fuel cell) is less than
the energy of the hydrogen produced from this process... :)

This statement _really_ old, and completely misses the point.

It takes more energy to find, drill for, pump, process, and ship oil, than you ever get out of it. That ain't the point, either.

The POINT is to have a MOBILE fuel (or energy transfer medium, or whatever you want to call it; it's semantics at this point). Energy you can use to move your butt from one place to another in a vehicle.

Laptop computers aren't as powerful as desktop computers, AND they're a lot more expensive as well. That doesn't mean they're worse than desktop computers, just that that is how MOBILE computers work. Same thing with oil/hydrogen/what-have-you.

We expend energy to have a fuel (oil, hydrogen, natural gas) that we can take with us. No, it's not as energy efficient as plugging into the electric grid, but then again, I don't have an extension cord that long. :)

I'm sure it won't be less than the energy of the hydrogen produced by the process, but, what SHOULD we be comparing it to?

How much energy does it take to produce hydrogen via cracking natural gas?
How much energy does it take to produce hydrogen via electrolysis?
How much energy does it take to produce hydrogen via splitting water with a high-temp gas cooled nuclear reactor?
How much energy does it take to produce hydrogen via some genetically-engineered seagrass or other plant?

The efficiency of whatever hydrogen fuel cell or Hydrogen internal combustion engine is another part of the 'efficiency' equation, but then you get to compare that to a fossil-fuel ICE and get to take into account the efficiencies and hard dollar costs of removing pollution from the exhaust, and from pollution mitigation efforts of the stuff that makes it out of the tailpipe, anyway.

Please, everyone, just stop it with the 'will it take more energy to get it into a portable form than you get from the portable energy'? Yes, it will always take more energy to put the energy source into a portable form. It's worth it because YOU'RE PUTTING IT IN A PORTABLE FORM.

Ahem. Hopefully I haven't been too obnoxious here, but this is just really getting old and tired (just like me).

And now I'm hungry.

Re:efficiency

[TubeSteak]

Regardless, if you put in 2.7 units of energy and get out 0.000057 units... that seems really (s)low

Even if your math is off, it might not matter if the process can be scaled up, since solar power is cheap/free.

The important question is how cheaply can they synthesize the needed protein.

Re:efficiency

[Anonymous Coward]

I'd think that the amount of sun in isn't really relevant to how useful this will be. It would be more interesting to know whether there's any maintenance associated with the protein... How long can the protein go on breaking down water/taking in sunlight before it needs to be replaced with more protein?

Thank you!

[mapkinase]

I would like to praise the submitter for providing a link to a peer-reviewed article. Does not happen very often, worth mentioning.

Next:

[jafac]

We'll need one of these that can split Oxygen and Carbon.

(ie - remove Carbon Dioxide from the atmosphere, and plant the Carbon somewhere safe - like maybe in empty petroleum resevoirs, where it came from).

Problem with large scale use?

[The Step Child]

From the abstract:

In the presence of the colloidal PVA-Pt as a catalyst and triethanolamine (TEOA) as a sacrificial electron donor, the photosensitized reduction of water to H2 takes place.

My chemistry knowledge isn't really up to the point where I can fully understand the whole abstract, but it sounds like we still need triethanolamine as a source of electrons in order to reduce water to H2. So the energy needed to produce more triethanolamine could put a big dent in the net energy gained from the H2 produced when we're talking about the practical large-scale usefulness of this. Maybe one day we could use another (renewable) electron donor like NADPH, so that we can couple it to another biochemical process like photosynthesis in order to renew our electron donors :)

Re:Splitting CO2

[noigmn]

Yeh was thinking the same. If we could break down carbon and sulphur compounds in the air, it would be a big step forward in fixing global warming. And also in atmospheric engineering, which we might need if we decide to create an atmosphere on Mars.

Imagine if photosynthesis could work with whatever compound we wanted. We could have it on space ships to break the CO2 breathed out back into O2 to rebreath also. Might also work for divers.

Re:Desalinization

[oni]

Actually, I thought the abstract said that the compound used is oxidized, meaning that the oxygen is captured and only the hydrogen is released. If I read the abstract wrong, please correct me.

My (admittedly layman's) understanding is thus: they have a molecule that sticks to oxygen. Put the molecule into water and it grabs the oxygen away from H2O, releasing H2. That by itself is not very impressive. Sodium does something similar. So here's the cool part, when exposed to sunlight, the molecule releases its oxygen - thus the process will go on so long as you have sunlight and water. This is only interesting because the molecule works like a catalyst.

IF it really works (I am cautiously optimistic) this could be the biggest discovery in the history of the world. It could mean that our civilization is no longer on the road to oblivion. It could mean no more energy wars (but don't worry, we'll still have to fight the United Atheist Alliance).

Our Machine Overlords

[sylvainsf]

So scientists have invented a way for the machines to get cheap hydrogen power FROM OUR BLOOD?

check your physics, spoilsport

[bodrell]

Hydrogen is a non-starter, even with this technology. Why? Simple physics: it takes more energy to unbond water than you get back from burning the hydrogen and thusly re-bonding it back into water. Period, end of story. It's a little thing called the Second Law of Thermodynamics. Deal.

Hydrogen is a Really Bad Idea.

Nothing can contain it, storing it (as a supercold liquid) takes enormous amounts of energy, and, at root, it's got negative ER/EI. I don't care if it's in a portable form - IT'S NOT A SUSTAINABLE TECHNOLOGY. PERIOD.

I suggest bicycles.

Refuting your points, one-by-one:

1) Energy doesn't come from out of the ether; even oil comes from sunlight's energy, ultimately. All organic matter is fuel, and it took a lot more energy (from the sun) to produce that fuel than will be obtained from burning it. That would be the case even if extraction and separation were free, which is far from reality. It takes a LOT more energy to vaporize water into steam than is obtained from the mechanical energy in steam. Even a Carnot engine is less than 40% efficient. But guess what? That lack of efficiency doesn't matter when the heat is free, from geothermal to solar sources. Are you going to tell me geothermal is a "non-starter" because of the difference in energy input vs. output? Didn't think so.

2) I think you mean the First Law of Thermodynamics, conservation of energy. The Second Law simply states that the entropy of the universe will continue to increase.

3) Hydrogen need not be stored as cold liquid in a tank. The focus of hydrogen technology right now is matrices that can absorb hydrogen at one pressure / temperature, then release it with a pressure / temperature swing in a controllable fashion. Other ideas involve chemically releasing hydrogen (from ammonia, for example) as needed. No one said gaseous hydrogen was the be-all end-all.

4) Bicycles are great, but we should be riding those regardless of what fuel goes in the gas tank. It's also difficult to, say, move furniture with a bicycle.