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| HYDROGEN POWER | |
October 20, 2003 |
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Hydrogen power, a prospective candidate in the race to find a non-fossil fuel source, has the potential to fuel vehicles for transportation and generate most of the world's electricity. Tom Bearden reports on the process of bringing hydrogen fuel from the laboratory to the showroom. The NewsHour Science Unit is funded, in part, by a grant from the National Science Foundation |
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What has a lot of people excited is that fuel cells don't burn anything. The devices combine hydrogen with oxygen, and the resulting electrochemical reaction produces electricity, heat, and water. That means the only thing that would come out of a fuel cell car's tailpipe would be water vapor; there'd be no pollution. At Rice University, Nobel Prize-winning physicist Richard Smalley thinks it's essential that a new source of energy be found. RICHARD SMALLEY: I believe it is the single most important problem facing humanity today: Energy. How are we going to get prosperous when oil and gas and coal are no longer enough? |
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| How quickly will the process happen? | ||||||||||||||||||||
| EXHIBITOR: So, this
is our show car.
TOM BEARDEN: These Denver-area students got a preview of the potential hydrogen future at a recent traveling exhibition of Ford Motor Company prototype cars and related technologies. EXHIBITOR: As the fuel cells become more reliable and we can use them in volume transportation, we replace the internal combustion engine and the transmission with a fuel cell and an electric motor to turn the wheels. MAN: That's tight. EXHIBITOR: Yeah. And it's coming, too. TOM BEARDEN: The question is, how fast are fuel cells coming? In his state of the union message, President Bush committed $1.2 billion over five years for basic scientific research into hydrogen power.
TOM BEARDEN: But there are enormous scientific challenges that must be surmounted before fuel cells will be practical for transportation. The first problem is getting enough pure hydrogen. Current technologies would require the construction of vast factories like this one. Even though hydrogen is the third most abundant element on earth, it takes a lot of energy to extract it because it exists in combination with other elements in the air, in water and in natural gas. And fuels cells will have to get a lot cheaper, more efficient, and produce a lot more electricity to be commercially viable. The short-term prospects are promising. Laptops, for example, don't require huge amounts of power. Neah power's chief technology officer, Leroy Ohlsen, says the key is to make a fuel cell small enough to fit in the same volume as an existing battery.
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| The challenge of storing hydrogen | ||||||||||||||||||||
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TOM BEARDEN: The prototype that Neah is developing and testing in the laboratory uses methanol as a source of hydrogen. Unlike batteries, fuel cells never have to be recharged. They're simply refueled. LEROY OHLSEN: Basically we have these ports, little tubes. And then what we do is, we flow methanol into the tube, it flows into the surface, goes through the pores, and out the middle chamber, which you can't see, and that would come out one of these tubes, essentially. And then on the other side, we flow in our oxidant. And then there will be a little pump that will pump the liquids through the tubes to the engine, and when you're ready for recharge ... in fact, you don't recharge at all, you just pull the cartridge off, you can either dispose it or recycle it, and then pop in a new cartridge, and you're ready to rock 'n' roll. TOM BEARDEN: But it's a long way from laptops to cars. Early hydrogen cars are operating now, but they're costly. This prototype cost half a million dollars. And they don't have the range to compete with a gasoline-powered car. A fuel-cell vehicle has to carry more hydrogen to go the same distance as a tank of gasoline, because hydrogen is a less concentrated source of energy. But current storage methods would require the fuel tank to be impractically large. In fact, the Department of Energy is now poring over applications for research grants to investigate that problem. The agency believes the storage challenge is so critical that it will award $150 million for basic scientific research.
TOM BEARDEN: Dr. Smalley thinks the solution lies in the black gunk in this jar. An electron microscope reveals that the gunk is really atomic-scale structures of carbon atoms linked together like chicken wire, and rolled into tubes. Smalley calls these "bucky tubes." They're an elongated version of "bucky balls," which he shared a Nobel Prize for discovering. He named them after Buckminster Fuller's geodesic domes. They're also called carbon nanotubes, "nano" because they're only one nanometer, one billionth of a meter, wide. One of the potentially useful properties of bucky tubes: they can attract molecules of hydrogen. DR. SMALLEY: So what we're looking for is something that the hydrogen molecules will love to sidle up against at near-liquid densities, but something that we can go into the gas station, connect up, and three minutes later we've got, you know, the equivalent of 20 gallons of gas. |
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| Could bucky tubes offer a solution? | ||||||||||||||||||||
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TOM BEARDEN: Smalley thinks it might be possible to make a fuel tank full of bucky tubes. They would concentrate the hydrogen and provide more storage in much less volume. The National Renewable Energy Laboratory in Golden, Colo., is also working with bucky tubes, and has applied for a DOE grant. Mike Heben says one of the biggest problems is how to get the hydrogen on and off the carbon. To be practical, the bond must be strong enough to hold the hydrogen, but not so strong that it would take high temperatures and pressures to release it when needed.
TOM BEARDEN: It sounds like you're talking about finding the most efficient sponge for hydrogen. MICHAEL HEBEN: That's exactly right. And the challenge is to discover if a sponge can be used, and what would that sponge look like, what are the properties of that sponge. TOM BEARDEN: And even if bucky tubes prove workable, scientists will still have to learn how to cheaply mass produce them. Today the National Renewable Energy Lab makes them by blasting a carbon target with a laser beam. The high temperatures create small batches of the material, which collect in cobweb-like strings. Bucky tubes produced by this process currently cost thousands of dollars a pound. Smalley is confident that one day they will be turned out as easily as petroleum products in a refinery.
TOM BEARDEN: Carbon is just one material whose properties will be investigated through the energy department grants. DOE hopes the money will allow some of the key questions to be answered in the very near term. TOM BEARDEN: It almost seems as if the government is trying to order up a breakthrough. MICHAEL HEBEN: No, I agree. They are trying to order up a breakthrough, and I agree that that's a difficult thing to do. But if the bar is not set high, I think scientists, like me, would perhaps not be challenged so strongly.
TOM BEARDEN: While some optimists see thousands of hydrogen fuel cell cars on the nation's highways within ten years, the Department of Energy's goal is more modest: to gather enough data in the next three years to know where the most promising avenues are for further investigation. |
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The NewsHour Science Unit is funded by a grant from: ![]() The National Science Foundation. Reports are produced solely by the NewsHour and do not necessarily reflect the views of the NSF. |