Please Freep Mail me if you'd like on/off
Posted on 11/17/2007 12:44:57 AM PST by neverdem
If the hoped-for hydrogen economy is ever to become a reality, researchers must devise efficient ways to produce and store the gas. That will require a series of breakthroughs that have been slow in coming. But researchers in the United States have hit upon a material for storing hydrogen that could be far better than the competition--just the sort of break hydrogen researchers are looking for.
Hydrogen has long been seen as a potentially green alternative to gasoline, which is produced from fossil fuels and gives off the greenhouse gas carbon dioxide when burned. When piped through a fuel cell, hydrogen molecules (H2) combine with oxygen, producing only electricity and water. At room temperature, however, hydrogen is a gas, which makes it difficult to store enough of it on board a car to drive long distances. The gas can be compressed in high-pressure tanks or cooled to a liquid at ultracold temperatures. But both of those strategies require large amounts of energy themselves.
As an alternative, researchers have been searching for materials that can hold large amounts of H2 and release it on demand. But so far the best performers, which are known as metal hydrides, hold only about 2% of their weight in hydrogen at room temperature, well below what is needed for a practical gas tank. Other materials can get up to 7% but require either high or low temperatures, and thus added energy and cost.
Last year, however, researchers led by Taner Yildirim at the National Institute of Standards and Technology in Gaithersburg, Maryland, calculated that a material made from certain metals, such as titanium, and a small hydrocarbon called ethylene should form a stable complex that could bind up to 14% of its weight in hydrogen. Adam Phillips, a physicist and postdoc in the lab of Bellave Shivaram at the University of Virginia, Charlottesville, decided to give the proposal a try.
Phillips used a laser to vaporize titanium in a gas of ethylene. The combined material settled out of the gas and on to a substrate to form a film. When Phillips added hydrogen at room temperature and weighed the result, he found the 14% added weight, just as predicted. After running a series of successful control studies, Phillips and Shivaram reported their new material on Monday at the International Symposium on Materials Issues in a Hydrogen Economy in Richmond, Virginia.
The new result is "extremely interesting," says Gholam-Abbas Nazri, a hydrogen storage expert at the General Motors Research and Development Center in Warren, Michigan. However, Nazri adds, "we have to be very cautious." There have been numerous false starts in the field before, he says. And researchers still must make the material in bulk, demonstrate that it works in that form, and show that it will release hydrogen as easily as it sops it up.
Even with those caveats, George Crabtree, a physicist at Argonne National Laboratory in Illinois, says the result "is one of the most promising developments of the last few years."
Related site
Interesting.
The thing is, you need to make hydrogen more dense. Right now the easiest and cheapest way to do it is to super-cool it so it liquefies. Gaseous storage of hydrogen is a non-starter as far as technology goes, it’s flammable, high pressure and will diffuse through most steels making them brittle.
ping
Corrosive, too. An engineer friend of mine is working with a group that is developing hydrogen injection for gasoline engines. This method would inject a small amount of gaseous hydrogen into each intake cycle, boosting the "bang" and significantly increasing gas mileage as a result. They're having the same troubles, though. Difficulty in storage, the pressure issues and the effects of the hydrogen on the engine block and pistons. He says ceramics are the answer, but it sounds expensive to me.
The method in this story doesn't sound like a "break through" to me, though. 14% storage is double the previous methods, but it's still only 14% and IIRC, Russia has the world's largest reserves of titanium, which ain't cheap in it's own right.
A couple of points to consider about hydrogen:
1. Although burning hydrogen does not create carbon dioxide, it does create water vapor. Isn’t water vapor a green house gas?
2. There is a fundamental difference between the energy needed to extract and refine oil and the energy needed to create useable hydrogen. In the case of oil, there is a huge amount of energy already stored in the hydrocarbon molecules, and thus a big return on investment in terms of energy-in/energy-out. Hydrogen out in “the wild” represents no such stored-energy waiting to be tapped. To extract hydrogen from water, for example, you have to use at least as much energy as you will have available from the hydrogen that is your end product. In other words, a hydrogen economy depends on some primary energy source, such as nuclear power or an extremely vast array of solar power panels to make it work.
I’m not saying hydrogen is a bad idea, and i’m all for continued research. But it is by no means a “magic bullet”.
The thing with hydrogen is that it’s one of the most energetic fuels. But, most hydrogen is produced by cracking methane. Which requires a LOT of energy. Sure if you have a nuclear power plant you can use the electricity to electrolyze water, but why? It’s more efficient to just produce the electricity to feed the grid.
Unless we figure out how to run a pipeline to Jupiter and suck molecular hydrogen out of the atmosphere, we won’t be running on a “hydrogen economy” any time soon.
I can see some use for hydrogen. Not to produce electricity, since as you say it is much more efficient to use your primary energy source (solar, nuclear, etc) to produce the electricity directly rather than to waste energy extracting hydrogen to burn to produce electricity.
But imagine for a moment a sane US. I know, it’s impossible, but just imagine it. And imagine we had a very large number of nuclear reactors, and we extracted huge amounts of hydrogen from water or methane and used that hydrogen to power our cars.
Just think of all those useless and powerless ragheads sitting off in their deserts pounding sand up their butts. Isn’t that a dream worth working towards?
Please Freep Mail me if you'd like on/off
Don't let that bother you. Burning hydrocarbons (gasoline, diesel, ethanol, biodiesel, etc.) also produces - on average - one molecule of water for every molecule of carbon dioxide produced. Oxidation of any hydrogen containing molecule produces water. Water is oxidized hydrogen. Alternate oxidizers (fluorine, chlorine, sulfur, etc.) as well as the resulting oxidation products are highly toxic when compared to oxygen; so they cannot even be considered.
Honda is touting a new fuelcell Civic that emits only “clean water vapor” In the current state of the propaganda, water vapor is good.
Reality is irrelevant.
Oops! Virtually all methane is found in the form of natural gas. It is only coincidentally produced from oil refining. The “gas” in a gas stove is primarily methane.
The fuel cell Honda is the FCX, it is not a version of the Civic. It is a totally new design. If I lived in the Los Angeles area, I’d be signing up for one. I’ll just have to wait until they are available here (Naperville, Illinois).
Do you mean they are limited to California?
I was suprised to see it being advertised on TV
As you alluded in your post, going Nuclear "Big Time" would work well. I say we go nuke well over 100% of our current Electricity needs. Then we use the excess to "create" whatever fuel(s) we can.
Not all of California, only three Los Angeles area towns (Santa Monica, Torrence and Irvine) will have dealers supporting the initial rollout of the FCX. This is primarily due to the non-availability of hydrogen fueling stations.
Picture in your mind:
100 cars a minute pass a certain part of the road every 1 minute. The temperature is just below freezing. Each car is belching out steam and droplets of water. Black ice everywhere.
Black ice = evil.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.