Plants Give Up Secret Of Splitting Water

IOL ^ | 2-6-2004

[blam]

Plants give up secret of splitting water

February 06 2004 at 07:21AM

Washington - Researchers said on Thursday they had taken another step toward understanding how plants split water into hydrogen and oxygen atoms - which may provide a cheap way to produce clean-burning hydrogen fuel.

Producing hydrogen from water is the stuff of science fiction - and some comments by US President George Bush. But the team at Imperial College London and Japan Science and Technology Corp. in Yokohama said they had taken the best pictures yet of the plant structures that do it every day.

They used high-resolution x-ray crystallography to make an image of the tiny atomic splitter that separates the two hydrogen atoms from an oxygen atom in a water molecule.

"Results by other groups, including those obtained using lower resolution x-ray crystallography at 3.7 angstroms have shown that the splitting of water occurs at a catalytic center that consists of four manganese atoms," said So Iwata of Imperial's Department of Biological Sciences.

'Together this arrangement gives strong hints about the water-splitting chemistry'

"We've taken this further by showing that three of the manganese atoms, a calcium atom and four oxygen atoms form a cube-like structure, which brings stability to the catalytic center," Iwata added in a statement.

"Together this arrangement gives strong hints about the water-splitting chemistry."

Writing in the journal Science, Iwata and colleagues said they looked at a plant bacterium called Thermosynechococcus elongatus. "Without photosynthesis life on Earth would not exist as we know it," Jim Barber of Imperial's Department of Biological Sciences said in a statement.

"Oxygen derived from this process is part of the air we breathe and maintains the ozone layer needed to protect us from ultraviolet radiation.

"Now hydrogen also contained in water could be one of the most promising energy sources for the future. Unlike fossil fuels it's highly efficient, low-polluting and is mobile so it can be used for power generation in remote regions where it's difficult to access electricity."

Water has always seemed a logical source for hydrogen but the only known feasible method to separate it, electrolysis, costs ten times as much as natural gas, and is three times as expensive as gasoline, Barber said.

[Gorjus]

[Gasoline as a bomb] Only if mixed with an oxidizer (air.)

Yup. Also true for hydrogen. Yes, hydrogen mixes easier. But that's (as I see it) more on the order of a leak issue. A problem to be careful about, but not necessarily a bomb. Nonetheless, it is certainly true that tanks for hydrogen fuel would need to be sealed much better than those for gasoline. It's just that keeping the hydrogen from getting out is enough of a problem that keeping air from getting in is relatively easy.

[Dementon]

Holy cow, I sure look forward to the day I can fill up my tank with a garden hose.

I filled up my dads tank with the garden hose once...

He was not very happy with me.

[Dead Dog]

They're like that yah know. That why it's important to eat a salad every now and then. Let them know where they are in the food chain.

[js1138]

So you are saying solar energy and solar electric cells are impossible according to the laws of physics? And plants themselves are impossible, and the creation of food by plants is impossible?

[Flightdeck]

"Let' start woth the first law:

the total energy of the system plus the surroundings is constant

If you can violate that one we are rich!"


The first law of..physics? You mean Newton's first law? You must mean the first law of thermodynamics, based on the second line. Okay, no one is talking about violating conservation of energy. There is inherent, internal energy in every molecule. Simply stated, the first law you are referring to is:

Rate of energy out of a system = Rate of energy into a system + Rate of change of energy within the system.

Notice that if the third term is positive (and it usually is), the energy output is greater than the energy input, dependent on the efficiency of the process.

None of this has to do with it being "cheap" as myself6 put it, which is wholly irrelevant to the "laws of physics". Following your logic, it would be pointless to go chop some wood, because burning them for heat in the fireplace violates the laws of physics. Well, there happens to be energy IN the wood.

[Flightdeck]

myself6, sorry I was confused by an earlier post to you, when I referred to you in the last post, I meant to refer to Naspino

[chaosagent]

Yes but the amount of energy has to be equivalent. That's why a hydrogen-powered car has to carry more fuel than a conventional one.

Gasoline is hard to beat in the mass-to-energy department. That's why nothing has replaced it yet. And the same reason propane/LNG powered cars have to have larger fuel tanks to travel the same distance.

[CougarGA7]

Just think of what the drivers seat in cars would look like if we do that. :)

[TBall]

While I do not currently own this stock in this company, but I do think there work is very interesting and addresses many of the concerns brought up in this thread.

http://www.millenniumcell.com/index.pl

[CougarGA7]

An explosion is just something that burns REALLY FAST.

[Lee'sGhost]

"Now to overcome the Hindenberg effect."

Easy -- don't coat the skin of your Zeppelin with the equivelent of rocket fuel and everything will be just fine.

[Lee'sGhost]

"Hey, the Europeans and Japanese pay way more than the US does for gasoline."

Horse pucky. We just pay in other ways.

[Nov3]

You need to reread my post - I said nothing of the sort.

[Lee'sGhost]

"You already do that with gasoline."

The most frustrating aspect of this topic from otherwise seemingly intelligent people -- the so called "Hindenberg effect." 1) Duh -- you already drive a bomb around, and 2) hydrogen is a lot safer than gasoline to haul around. Number 2 is somewhat understandable, number 1 is just stupid.

[Still Thinking]

What are you talking about? Laquer or something similar?

[js1138]

I read what you said and it is irrelevant. You said cheap energy is impossible due to the laws of physics. This is not a decided issue. Plants convert solar energy to a commercially usable form every day. And do it cheaply.

Solar electric panels may or may not be cost effective in the future. We have no ideas what breakthroughs might occur in materials and manufacture.

You have no way of judging whether artifical photosynthesis might become commercially viable.

I'm sure your opinion is reasoned, but it is not necessarily correct.

[Nov3]

Breaking water into its constituents is an endothermic process. The energy has to come from somewhere. I really don't think you are equipped for this discussion.

Notice that if the third term is positive (and it usually is)

We really don't need to go any farther into this discussion.

[Constantine XIII]

It is SO obvious why heavier-than-air craft will never fly. I mean, they're heavier than air! DUH!

[Nov3]

You said cheap energy is impossible due to the laws of physics.

No I said FREE energy is impossible. It has to come from somewhere. This may be a more viable form of solar energy but a lot of the discussion on this thread seems to ignore the realities of thermodynamics.

[Constantine XIII]

No joke. If gasoline get up over $3 a gallon, the market will become much more welcoming to hydrogen-fueled cars.

Once we pass pricing parity, we can leave the crazies to play in their sandbox.