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.

[Sergio]

I think this is great news, however I don't know enough about the subject to say anything else. I do have some questions however, and I'm not being a wet blanket, I want something like this work.

1. Would the system only use distilled (pure water)? If not, how would additonal contaminats, minerals, particals in the water be dealt with?

2. How would we deal with areas of the country like the South West that has very high mineral content in the water to begin with and where, due to population influx, will in 20 to 30 years have a critical water shortage? Do we drink the stuff of put it in our transportation?

Best Regareds

Sergio

[Naspino]

There's certainly no law of physics preventing cheap hydrogen - there's always nuclear-powered hydrolysis.

The laws of physics prevent me from responding to you.

[demnomo]

Someone just corrected me. "The Water Engine" was a 1992 movie, not a novel, written by David Mamet.

[myself6]

I would think that you would need to keep the hydrogen and oxygen in a stable state (water) until the "last minute" (just before it is used as fuel for combustion). This way, if anything unplanned were to happen, there would be a minimal amount of combustible material to fuel an explosion.

Therefore to make this possible a technology to "instantly" convert water to hydrogen and byproducts would be needed. I dont know if this is possible with current technology or EVER possible. I do think that researching this is a good idea though.

[js1138]

The laws of physics show that it will never be possible to get cheap hydrogen and therefore it is a waste of time to even look for a solution.

The laws of physics do not prohibit solar energy, and that is what this is. Whether it will be practical is undecided.

[Ff--150]

btttrl

[Gorjus]

I would think that you would need to keep the hydrogen and oxygen in a stable state (water) until the "last minute.

Now this would be a challenge for the physics. Regardless of how you do it, if you're going to get energy out of recombining hydrogen and oxygen, you need to put in the energy to split them apart in the first place (and a bit more, since there are always losses). A plant catalyst gets the energy from sunlight. It may be more efficient than previous methods, but it still won't produce more energy than the incident sunlight provides. "There ain't no such thing as a free lunch."

So, converting then unconverting at the last minute seems like a pretty tough challenge.

However, all it not lost. I'm sure we'll be able to work out the storage/safety things, and so we can separate the hydrogen out ahead of time - preferably in clean, non-polluting nuclear power stations. Or perhaps we'll all grow solar panels on the roof of our cars, and they'll simmer away like teakettles during the day, busily using sunlight to convert water to hydrogen for the drive home. If we get the conversion efficiency high enough, you might get Yugo performance for about $40k per car.

[Still Thinking]

As I have said before on similar threads; hydrogen separation is not a "source" of energy, just a transport vehicle. It is because the H2O atom is the lower energy state of the hydrogen and oxygen atoms involved that burning hycrogen releases heat energy. This is what happens when hydrogen is burned: it combines with atmospheric or other oxygen to form water vapor and release energy. So if we start with water and end up with hydrogen and oxygen, we have to provide the same amount of energy to separate the h2 and o2 as is released when they combine.

When plants perform this transformation, they must in some way be using solar power (in addition to the catalyst mentioned) to effect the change. If this is the case, and we could copy and scale the process, it COULD appear to be almost free because there is so much solar energy available and because present solar systems are so innefficient, that this method would appear to be free by comparison.

Another poster was correct in noting that nuclear separation could appear to be very cheap. You would just have to account for the cost of the electricity which would otherwise be sold. The energy involved is not coming from the hydrogen but from the nuclear fuel, which was an original "source", because the potential energy was already in it when we dug it out of the ground.

[Still Thinking]

Do we drink the stuff of put it in our transportation?

Hey a twofer! Drink the water, then put it in the car!

[E.G.C.]

BTTT!!!!!

[Some hope remaining.]

The problem is in the storage and transport of H2; current estimates are that 15% - 20% of all hydrogen leaks out through tank walls, hoses, and seals.

Indeed. I remember reading an article not too long ago more specifically about the transportation issue. I think the point was that compared to gasoline, the energy density of compressed hydrogen is pretty low. The gist was that if you had to deliver compressed hydrogen by tanker truck, for example, you'd actually be burning as much or more energy (IIRC) to drive the truck than you'd deliver in the hydrogen. Pipelines would be much better but you can't have pipelines to every rural filling station.

So unless you can generate it locally, which maybe they will be able to do ultimately, it didn't make a lot of sense.

Even transporting in the form of water, though, may or may not have as much energy density as gasoline. I don't remember.

[Sacajaweau]

Excellent for "the boys". Cap the lid when you're done.

[narby]

Another wonder of science that emerged out of the slime. The intense and infinitely complex nature of the simplest parts of nature continue to strengthen my in intelligent creation by the God I know

I just love it when creationists accept some parts of science, but reject others.

Apparently when it comes to creation, everything can be explained by looking at a few hundred words in Genesis. If it isn't in there, then it didn't happen. Sure, that makes a lot of sense.

Genesis didn't say anything about Dinosaurs. It didn't say anything about 90 some percent of the creatures of the earth going extinct, yet their bones are here.

Can't you creationists just get it through your heads that God only gave you a really really really abrieviated story of Creation in Genesis, and there's plenty of room to drive truck loads of Evolution between those few hundred words.

[keithtoo]

Storage is still a tough nut to crack. because...
Hydrogen is up there as the first element for a reason. It is the smallest and it has a tendency to seep out of whatever storage container it is put into.

[Still Thinking]

Like Hank Hill, I regularly perform the miracle of turning beer into water.

[TBall]

A longer shelf life is one of the advantages of Millennium Cell's technology in which hydrogen stored in sodium borohydride solution.

[Ichneumon]

Isn't evolution wonderful?

Yes it is.

I'm with you. How can people think such things "just happened" by chance?

Because we have a good understanding and personal knowledge of how complex solutions can "just happen" using evolutionary processes. Evolution as a process is a fantastically efficient explorer of the vast range of possible solutions to a problem.

The whole field of "genetic programming" is based on harnessing evolution's power for the task of finding solutions to problems that are too complex or poorly understood for solving by the usual methods (including the application of human brainpower).

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.

Drug companies harness evolution in order to develop microbes that can produce desired drugs, and to search for new drugs which couple to specific chemicals.

Yes, Virginia, evolution actually *works*.

[myself6]

I agree, the physics would be tough if even possible. Its the only way I would consider driving a hydrogen power car though. I simply would not be to excited about driving a potential bomb around. The problem of the physics may preclude any attempt at SAFE and efficient hydrogen powered cars. Like I said though, I have no objection to research in this area.

My personal opinion is that a real source of alternative power will be the derivative of the research we put into the "dry wells" of hydrogen, solar, wind, etc. Combine that research with the efforts in quantum physics, super conduction and "happy accidents", we will probably be close to another power source that will allow us to expand our technology.

BTW, none of this will happen if the government continues to regulate every aspect of life in this country. We will be stuck with current technology until the power sources required to run them dries up. Innovation requires freedom and freedom requires being left alone by regulators and government.

[Carry_Okie]

I wonder how much water and acreage they would need?

[templar]

It is the smallest and it has a tendency to seep out of whatever storage container it is put into.

There is a time factor as well as a seepage factor to consider here. The storage need not be for extremely long periods (gasoline aslo has a tendency to go 'bad' over a period of time). The Hydrogen only needs to be stored in a manner that will minimize loss during the period from manufacture to use. This could mean only a few weeks of actual containment without significant loss is needed.