New Hydrogen Storage Technique

pwp writes to mention that researchers at the University of New Brunswick are reporting they have found a new method of storing hydrogen gas. The new method is able to condense hydrogen gas into a usable solid under mild conditions. "Hydrogen gas is typically stored under pressure in large metal cylinders, approximately four feet high. These cylinders are heavy and expensive to transport. Since they are under pressure, they also pose a safety hazard. 'We've reached a milestone with our ability to condense hydrogen into a usable solid,' said Dr. McGrady. 'The next step is to produce a safe, compact storage system for the compound that is both lightweight and affordable.' The research is expected to produce reversible hydrogen storage materials that can be processed into a powder for use in limitless commercial applications."

Comments

I want more.

[PrinceAshitaka]

This article has absolutly vague information on what research they are doing. Storing hydrogen as a solid, apparetly as a powder? What would be interesting is to see how much energy is lost in the chemical reactions of reacting hydrogen with whatever they react it with and then changing it back into hydrogen gas. I would also like to see how this compares to the energy required to compress hydrogen as it is currently done. This is what will determine this technologies usefulness in reality.

Only nine percent hydrogen by weight is success? How much fuel will it waste in transportation if there is nine times as much "pakaging" material as there is hydrogen. Yes the currently used hydrogen cylinders are heavy, but I do not believe they weigh nine times as much as they can carry.

Re:I want more.

[[Mobius]]

They bind it with aluminum to create a stable hydrogen/aluminum powder.

At least, that's what a local news report mentioned a few days back.

Re:I want more.

[Sockatume]

Of course, the real problem isn't just hydrogen density, the thermodynamics and kinetics of hydrogen uptake and release are important too. You want it to fall off in a nice controlled manner with very little energy: on the order of thermal energies so you can use waste heat from the fuel cell, or a simple heater, to get the hydrogen off. Likewise you want to be able to recharge it with hydrogen quickly and with small energy requirements. Many really great hydrogen storage solutions have run into problems at this end of the problem and need metal catalysts, which increases the weight and cost. Frankly, practical hydrogen fuel vehicles are still a couple of decades off. It's going to be cool, though. At the gas station, you won't have to go to the pumps, you'll just haul your "empties" out and swap them for reloaded cartridges. If you wanted to take extra fuel with you for a cross-country trip, you could just buy some spares. More expensive than jerry cans, but easier to swap in and out. Of course there's no particular reason for Audi's hydrogen cartridges to be same shape as BMW's, which could get "interesting".

Re:I want more.

[cupofjoe]

I agree that it would appear they could be talking about Alane (AlH3), which has a theoretical weight-density of about 10% hydrogen. Yes, 10% is good...but as folks in the hydrogen storage community would be quick to tell you, it's not unusual. For example, Lithium Borohydride (LiBH4) has a theoretical weight-density of almost 18.5% hydrogen! The key is simply to bind hydrogen with light elements in a stable configuration, right?

Wrong. That's not even the tip of the iceberg.

The real problem, as any hydride person would correctly point out, is not "theoretical storage fraction"; rather, it's REVERSIBLE storage fraction. It doesn't really matter, in the long run, if you can store 18%, or even 25% hydrogen by weight in a substance if the following are true:

1. it takes a LOT of energy to put it in (theormodynamically unfavorable hydrogenation reaction)
2. you can only get out a small fraction of what you put in under favorable conditions (non-reversibility)
3. the reaction doesn't move very quickly (unfavorable kinetics)

With these limitations, you face a severe energy penalty for trying to use the material as a hydrogen carrier, mostly because it's one-way. The keys to an inexpensive, efficient solid-state hydrogen storage material combine high storage fraction with a high level of reversibility: why bother using a material if you have to ship it back to the "refinery" when the hydrogen has been depleted? As an example, let me use the typical automotvie application to illustrate. (I know that TFA - which doesn't really say ANYthing, natch - doesn't explicitly state that their "revolutionary" material is for automotive applications, but that's where all the money is coming from these days.)

What I want to do is expose the dehydrogenated powder (it's usually a powder) to hydrogen gas at about 1 atmosphere (~15 psi), remove some heat of reaction (for later use, naturally) and go on with my business. Preferably at a "hydrogen filling station", whatever that ends up looking like. Oh, and refueling shouldn't take more than about 5 minutes. And once the tank is full, I should be able to drive 300 miles without filling up again.

Right now, there is NO material known on Earth that can fulfill these requirements and still be designed into a car.

The astute reader will notice immediately that I'm leaving out what might be the single-most crucial design driver: SAFETY. I don't know if everyone's been keeping up, but alane (and the alanate hydrides in general) are ROCKET FUELS. Personally, I don't want to drive around with 20kg of solid rocket fuel in my car's gas tank. In this case, safety will absolutely drive eventual adoption, even trumping reversible storage fraction.

For example, sodium alanate (NaAlH4) has a theoretical storage fraction of 5.6%, and the reversible fraction is starting to approach 4-5%, which is a very, very good track record. However, when it sees water (which it might, in a car accident) it EXPLODES. Well, deflagrates, but you get the point.

(rant on)

Don't get me wrong. I'm all about solid-state H2 storage, and the "H2 economy" in general, whatever that happens to be. I'm even a "real" materials engineer, working with hydrides. But I'm also all about reality, and hopefully trying to "drop the veil" of proprietary information wherever possible. We're working as a team, people. So, to the press folks at UNB: write better articles, publish some papers, or both.

(rant off)

-joe.

Sweet

[inviolet]

Assuming the energy needed to perform the condensation is not lossy, this technique is going to be da bomb. :)

Haha. But seriously, this is what the "hydrogen economy" needs. You could even grind the powder fine enough to be a slough, and 'pump' that into your vehicle's fuel tank.

When George Bush first proposed hydrogen as the solution to our fossil-fuel habit, everyone mocked him for failing to understand that hydrogen is just a storage medium, rather than an energy source. I suspect he knew that all along... but since most Americans don't know it, he persuaded them to (at least in principle) buy in to the idea.

Once there is enough interest in hydrogen, the "hydrogen economy" will indeed take off (e.g. today's breakthrough), and at that time we will be groping for a way to produce hydrogen in bulk. The optimal way to produce bulk hydrogen is of course a nuclear reactor. And so by this (alas necessarily) indirect route will Americans come to accept ubiquitous nuclear power. And that is exactly what Bush wanted (or at least should have wanted) all along.

If you'd settle for 2% then check this one

[ahfoo]

Home power has a cool PDF that describes how to create your own metal hydride based system. What's cool about their plans is they use bulk materials direct from the manufacturers and then show you how to prime your own system in a home lab if you're so inclined. I'd love to try it.

  Seems I read there was a similar system that is used in one version of the hydrogen powered car prototypes and they say they can get a hundred miles per tank on tanks about the size of a scuba tank.