Scientists Find New Way To Store Hydrogen Fuel

Science Daily ^ | 01-08-2004

[boris]

Source: University Of Chicago
Date: 2004-01-07

Scientists Find New Way To Store Hydrogen Fuel

University of Chicago scientists have proposed a new method for storing hydrogen fuel in this week's online edition of the Proceedings of the National Academy of Sciences.

The lack of practical storage methods has hindered the more widespread use of hydrogen fuels, which are both renewable and environmentally clean. The most popular storage methods-liquid hydrogen and compressed hydrogen-require that the fuel be kept at extremely low temperatures or high pressures. But the University of Chicago's Wendy Mao and David Mao have formed icy materials made of molecular hydrogen that require less stringent temperature and pressure storage conditions.

"This new class of compounds offers a possible alternative route for technologically useful hydrogen storage," said Russell Hemley, Senior Staff Scientist at the Geophysical Laboratory of the Carnegie Institution of Washington. The findings also could help explain how hydrogen becomes incorporated in growing planetary bodies, he said.

The father-daughter team synthesized compounds made of hydrogen and water, hydrogen and methane, and hydrogen and octane in a diamond-anvil cell, which researchers often use to simulate the high pressures found far beneath Earth's surface.

The hydrogen-water experiments produced the best results. "The hydrogen-water system has already yielded three compounds so far, with more likely to be found," said Wendy Mao, a graduate student in Geophysical Sciences at the University of Chicago.

The compound that holds the most promise for hydrogen storage, called a hydrogen clathrate hydrate, was synthesized at pressures between 20,000 and 30,000 atmospheres and temperatures of minus 207 degrees Fahrenheit. More importantly, the compound remains stable at atmospheric pressure and a temperature of minus 320 degrees Fahrenheit, the temperature at which liquid nitrogen boils.

"We thought that would be economically very feasible. Liquid nitrogen is easy and cheap to make," Wendy Mao said.

The hydrogen in a clathrate can be released when heated to 207 degrees Fahrenheit. The clathrate's environmentally friendly byproduct: water.

David Mao noted that while petroleum-based fuels will eventually run out, the supply of hydrogen is limitless. "Hydrogen is the most abundant element in the universe," said David Mao, a Visiting Scientist in Geophysical Sciences at the University of Chicago. If the new method of storing hydrogen fuel works as expected, "that's going to change everyone's life in a big way," he said.

The Maos have applied for a patent on their hydrogen clathrate synthesis technique, but one problem still remains: how to make the clathrates in quantities sufficient to power a car. "We've only made them in very small amounts in diamond-anvil cells," Wendy Mao said. The Carnegie Institution's Hemley noted that the clathrates can be produced in gas pressure devices as well as diamond-anvil cells.

In the realm of planetary science, the study helps explain how some of Jupiter's moons could have incorporated hydrogen during their formation. Scientists once thought that the moons were incapable of retaining hydrogen during their formation. Now it appears that Callisto, Ganymede and especially Europa contain large quantities of water ice, which would require the presence of hydrogen. The hydrogen clathrates that the Maos synthesized in the laboratory could have formed naturally under the temperature and pressure conditions expected to prevail inside these Jovian moons, Wendy Mao said.

--------------------------------------------------------------------------------

This story has been adapted from a news release issued by University Of Chicago.

[farmfriend]

Earlier Posting.

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[sourcery]

[The Duke]

Why do I believe that the *REAL* challenge is not STORING hydrogen, but rather PRODUCING it with less energy expendature than the energy it delivers.

[ClearCase_guy]

Yeah, I always feel dumb on that point, but it seems obvious.

Petroleum is in the ground. It's waiting to be "harvested", sure we have to refine it but it's there for us to grab. Hydrogen isn't like that. There are no hydrogen mines. You really have to extract hydrogen from something.

So, what's the "something" -- it seems like the "something" is a resource that must be harvested, so I'm not sure that's progress.
And then you have "extract" the hydrogen, and what is that process? I suspect it's more got an energy cost which is higher than refining petroleum, so I'm not sure we're making progress.
And then there's the problem with storage and transport. I suspect that's more costly than gasoline tanks and tanker trucks, so I'm not sure we're making progress.

[coloradan]

A great way to store hydrogen i sto chemically combine it with oxygen. The hydrogen thus stored is nontoxic* and nonflammable, and can easily be liberated by the simple addition of elemental sodium, an element in non-toxic* table salt.

*Dihydrogen monoxide has been linked to deaths by inhalation, and salt has been linked to heart disease.

[gaijin]

Dihydrogen monoxide

Oooh, yikes! That sounds like nasty stuff! ;)

[Phsstpok]

Petroleum is in the ground. It's waiting to be "harvested"

Um, I don't know about you, but I don't use petroleum, even as a jelly. I use gasoline. producing gasoline from raw petroleum (assume sweet crude) is a intensive process requiring lots of energy.

There are no hydrogen mines. You really have to extract hydrogen from something.

Well, there are a few naturally occuring Hydrogen deposits that can be tapped in the same manner as tapping into petroleum, and that would be pretty pure hydrogen, but it's not available in commercially desirable quantities in gaseous form.

There are ton's and tons of hydrogen stored in naturally occuring hydrates in various locations and you have to work at it to keep it from escaping once you remove it from the rather extreme conditions under which it forms (usually as methane hydrate under the ocean floor). But you don't even have to go that far. There's lots of relatively easy ways to get hydrogen out of perfectly mundane stuff for less energy input (compared to gasoline/petroleum) than you get back.

So far as I know it's never been an energy budget problem, but always a storage problem.

[Mr. Quarterpanel]

Why do I believe that the *REAL* challenge is not STORING hydrogen, but rather PRODUCING it with less energy expendature than the energy it delivers.

Actually, it is both. Having said that, the problem of storage is the more vexing of the two. There are solar panels that can extract hydrogen from water directly, which solves your problem, sort of. Not perfect, but it goes that direction.

My thoughts are the storage aspect. Hydrogen storage has to have low loss and relatively safe handling in order to provide an acceptable fuel. While I think that diamond anvils are not practical, this will certainly give those researcher a good starting point.

[trebb]

Dropping some lye and some aluminum foil into the Dihydrogen monoxide will also liberate the Hydrogen. The biggest problem is for wicked witches who will be unable to safely work at the factories as exposure to Dihydrogen monoxide has been known to melt witches.

[ffusco]

Universal solvent?
; )

[antiRepublicrat]

Why do I believe that the *REAL* challenge is not STORING hydrogen, but rather PRODUCING it with less energy expendature than the energy it delivers.

Hydrogen in this use is all about making energy portable, not making it in the first place. The important thing is that you're left with something that can power a car around with sufficient power and range.

The idea of a hydrogen fuel cell car is amazing. The fuel cells can produce enough electricity to power a high-performance car with perfect quiet and only water vapor as the emissions. The only technical problem is the high-pressure hydrogen tanks you'd be hauling around. With something like this, you can have such a car just running off a couple of unpressured thermos bottles in the back.

Then we can generate our electricity through hydroelectric, coal, nuclear, solar, wind and domestic natural gas, bottle it up for cars, and tell the Arabs to go screw themselves on the majority of oil we import. Terrorist funding would take a major hit.

This is a Good Thing^TM.

[boris]

"A great way to store hydrogen i sto chemically combine it with oxygen. The hydrogen thus stored is nontoxic* and nonflammable, and can easily be liberated by the simple addition of elemental sodium, an element in non-toxic* table salt."

The problem is that the energy cost of making Na is greater than that recovered from burning the H2 evolved. Again a big storage battery. The interesting aspect to me is that density is a huge problem with H2; even as a liquid it is 11 times less dense than gasoline. In fact, it liberates less energy per unit mass than gasoline (but more per pound). So if H2 could be stored at densities approaching that of water or water ice, it may open up some applications.

--Boris

[boris]

"Earlier Posting."

I did a search on "hydrogen", "clathrates", etc, and came up with nothing.

--Boris

[Visalia]

...the supply of hydrogen is limitless.

So what? It takes electricity to produce hydrogen. That's what oil is for.

[coloradan]

I think you mean, it liberates less energy per unit volume but more per unit mass (~ pound).

[farmfriend]

IT happens. I just remembered seeing it so I cut and pasted the title into the search feature and it came up.

[boris]

"I think you mean, it liberates less energy per unit volume but more per unit mass (~ pound)."

Yeah; fingers ahead of brain.