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.

[yhwhsman]

I myself have used genetic programming to produce results, and evolution almost always does so far faster than I had expected, and the solutions are always elegant and surprising.

But is this truly evolution? You (god) are doing the manipulating on whatever you're producing (creation).

[chaosagent]

Ah, but the hydrogen is compressible and the gasoline is not.

The amount of energy in 20 gallons of gasoline doesn't change.

The amount of energy in a 20 gallon tank of hydrogen depends how much pressure it's under.

It's best to talk about the mass (weight) of the two.

20 gallon of gasoline weighs about 125 pounds.

125 pounds of hydrogen (however much it's compressed) does not contain near the energy that 125 pounds of gasoline does.

[StriperSniper]

Invest in manganese.

;-)

[JoeGar]

Producing hydrogen from water is the stuff of science fiction - and some comments by US President George Bush.

Er, doesn't just sticking two electrodes in water do the trick? Oxygen collects at one electrode and hydrogen at the other?

[myself6]

The point is that it is a gas and under pressure. I have no idea how much hydrogen it would take to give a car enough mileage to make it feasible but it must be quite a bit. If the tank were ruptured during an accident the pressurized gas would expand at a terrible rate. If ignited, this rapidly expanding gas would explode (rapidly expand)with a concussive force grater than gasoline. Most hydrocarbons burn rather than explode because the oxidizer takes time to diffuse into the liquid. pressurized hydrogen gas wouldnt have this problem

There are many factors that determine the force of an explosion besides the amount of potential energy stored in the substance. For example, why do you think they don't allow smoking in grain elevators? Those are some HUGE explosions!

[Doctor Stochastic]

An explosion is just something that burns REALLY FAST.

Ok as far as it goes, but somewhat incomplete. A low explosive burns really fast; a high explosive burns faster than the speed of sound in the material.

In an automobile engine, one wants really fast; faster than sound forms a shock which acts like a hammer and punched holes in pistons.

[Doctor Stochastic]

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

But we know the maximum energy from sunlight. For the nonce, the Sun isn't going to get hotter; this sets an upper limit on the energy/acre extracted from sunlight by any means.

[js1138]

But we have a lot of sunlit areas on earth not being used for much else. not to mention a lot of inhabited areas that could use air conditioning. I suppose solar will never supply all of anyone's energy needs, but it could be part of the mix.

[Doctor Stochastic]

Solar is good for streetlights, sheep tank pumps, and other small uses. It would be hard to power a city.

On the other hand, simple solar heaters do well in heating water for home use. The Department of Energy doesn't like this; they only seem to go for 100% rather than 80% savings.

[#3Fan]

Australia a supplier of manganese. Cool!

[CougarGA7]

True. I was only putting it in the most general form.