Hydrogen Storage - What's best?

I've read that there are three main ways to store and transport hydrogen:

1. Compressed gas: This is the most conventional way. Compressed hydrogen is kept in high pressure cylinders and that's all. Disadvantage: as you may know, hydrogen is highly explosive, and such way is dangerous in case of accidents. Also, the pressure vessels commonly used are made of low alloy steel, with high strengh. This kind of steel tends to suffer when exposed to hydrogen enriched environments (fragilization). Don't go into this trap. Ultimately, use composite pressure vessels. Contact some vendors to know the price and availability.

2. Water: A great way to do that is to obtain hydrogen directly from water electrolisis, on demand. YOu 'll find on the web a number of projects claiming for engine operation controlled by the amount of current used to generate hydrogen in the engine supply. Theoretically, all work fine, but I didn't see any mobile applications. There's a business in Europe intended to manufacture small power plants running on water, and obtaining the energy for the electrolisis from feedback, wind or solar panels. I dont know about efficiency and manufacture cost. Actually, in my oppinion, this is a great way of doing that, and I am personally planning to build something like this at home, even if only for fun. A reservoir to feed the engine may be small and typically done with ordinary PVC tube or similar, because you don't need to stand for so high pressures.

3. Dilution: The gaseous hydrogen is diluted, inside a pressure vessel at high pressure, in a mineral array acting like a spounge by combining itself with the gas(don't know the composition). It can store a really large amount of hydrogen. Disadvantage: weight. It's really heavy.

Do a google search, you'll be amazed on how many things you will discover.

"I've read that there are three main ways to store and transport hydrogen:"

4. Liquid hydrogen. Very cold. Lighter weight tanks for transport & storage as it is at atmospheric pressure. Costs more to liquify. Depends on end use and why you want to store or transport hydrogen.

5. Metal hydrides are a way of storing a lot of hydrogen at low pressure.

6. In a very hazardous airship. Look up the Hindenberg Disaster on the world-wide-wobble.

But the airship would make it easy to move around..

And it wouldn't take long to burn it off if you needed to dispose of it quickly..

Why are people afraid of Hydrogen? Because they do not know the facts:

The Hindenberg "Disaster" was not caused because of the hydrogen onboard. The ignition was due to an electrostatic charge of the material used for the mantle of the Zeppelin. If you look at the pictures, the Zeppelin is still in the air, while burning, meaning that H2 was still inside, not burning. Of course at the end all the H2 burned, it is a fuel. Also a H2-flame is invisible for the eye, so the flames that were seen came basically from the mantle material

Comparing H2 and gasoline: H2 is safer, even under pressure. State of the art tanks have shown that if there is a whole in the tank, the H2 will come out and if ignited, will burn pretty much like a flame for welding, the flame will not get "into" the tank and cause an explotion. In contrast to gasoline, where the liquid will go down and, in a car, the flame will ultimately reach all of the car. Also, if gasoline was not adopted in our society in a period of over 100 years, in parallel to the development of cars, I am sure HUGE concerns about its safety would arise now.

To store H2 at room temperature there are two ways:

Metalhydrides. The desorption of the hydrogen needs heat. Depending on MeH type, you can desorb it at room temperature or at higher temperatures. The typ of MeH will define the final weight and volume of the tank. i.e. state of the art technology: a 50 g H2 tank will weight at least 4 kg. Volume of about 2 Liters.

Pressure tanks: state of the art are 200 to 350 bar tanks (20 to 30 MPa). New developments of 70 MPa tanks are beeing carried out to store enough H2 to be able to compete with the range of gasoline cars (fuel cell cars).

if you have a specific question you can write me. I am in the field of fuel cell development. (sm@ceka.ch). Would be happy to help you, since I have collected a lot of information on companies since we are evaluating possibilities to store H2 for certain applications where we want to substitute batteries. If you use fuel cells, the main advantage is that you can decide the range or runtime of your electric motor just by the amount of H2 you can carry (store). In comparison to lead acid batteries and even to some of the newest Li ion batteries, the advantages would be of much less weight. Price could be an issue, if you compare to cheap lead acid batteries. But if Li ion batteries are the reference, the best with 200 Wh/kg energy density are quite expensive. So, if you want to f.ex. triple the energy , the price of 3 packs of Li ion batteries would be already comparable to the price of a fuel cell system. At least with our production technology for fuel cells (making a bit of marketing :-).

As a matter of fact, we will lunch a low cost fuel cell stack mid of this year. contact me if you are interested in any topic concerning Hydrogen and fuel cells.

hope to have helped.

hi,

we are trying to store hydrogen at high pressure ( @ 250PSI) which is produced from electrolysis of water, now while transfering from electrolyser to tank, we want to install a flame/flash arrester,which will quench the flame in the event of oxygen being mixed in the hydrogen stream ( which will trigger catalyst to react - H2 , O2 detector).

would you suggest what kind of flame arrester should be used ?

and what kind of catalyst or gas detector ?

any help would be highly appreciated!!

-kumar

I was going to suggest metal hydrides but you beat me to it!

The German AIP programme has been using this method for a while now for its submarine fuel cells. The following piece was taken from their info site.

"One solution is to carry the hydrogen in metal hydride accumulators, at low pressure and ambient sea temperature. (A metal hydride is a solid compound of hydrogen and metallic alloy, in which individual hydrogen atoms occupy interstitial positions in the host metal's crystalline lattice. By manipulating temperature and pressure, hydrogen gas can be absorbed or released at will.) Another, less efficient, approach is to generate gaseous hydrogen from a stored liquid hydrocarbon such as diesel fuel, kerosene, or methanol. This requires an auxiliary device called a "reformer," in which a mixture of hydrocarbon and water is vaporized and superheated under pressure to yield a mixture of hydrogen and carbon dioxide."

One pro-hydrogen site I looked at was talking about new evidence that laid the blame for the Hindenburg disaster on the paint that they used on the outer skin. Obviously the Hydrogen joined in when the paint caught fire but it apparently allowed the burning wreckage to descend slowly enough to allow the passengers who stayed aboard to get off...?

Drew

Ok, I must be clear in my statement: 3 ways to store hydrogen at room temperature.

"YOu 'll find on the web a number of projects claiming for engine operation controlled by the amount of current used to generate hydrogen in the engine supply. Theoretically, all work fine, but I didn't see any mobile applications. There's a business in Europe intended to manufacture small power plants running on water, and obtaining the energy for the electrolysis from feedback, wind or solar panels."

Why in the world use electricity to separate hydrogen from water to run and control an engine, when it is far more efficient to simply supply the electricity to an electric motor???

As to running a power plant on water? Another inefficient Rube Goldberg contraption!

And then to obtain the energy for the electrolysis from the output of the power plant? Or even solar or wind: Much more efficient to use the electricity from these sources directly!

Hint: It takes more energy to separate the water than you can possibly get from recombining it, burning the hydrogen in air, or any scenario you can come up with.

This is perpetual motion all over again ... does it never stop?

Greg

Well, actually, it is not a perpetual motion because you're actually injecting energy to keep it running. No physical barriers for this.

The reason why some people claim for water electrolysis is safety and convenience. As I said, they claim for it... I didn't say it works.

I think about it as some way to store energy from renewable sources, not as the approach like burning fossile fuel. Ok, you may need to use more power

After all, almost every single research to build hybrid vehicles in the world use the concept of fuel cell, much safer, reversible, and works. Sometime in the near future, I think, it will be possible to remove the combustion engine already present in hybrids. I personally think that they are in the right way to go. It's not an approach of a new solution for an old concept (using alternative engines to burn... water!), but a hole new concept. Just like changing from magnectic tape to CD, not only building a better tape record.

I'm getting old. Did they invent the reversible fuel cell now?

What I know from hybrid technology is that they work with a ICE at the utmost efficacy, driving a generator. Then a set of batteries is used to store, give energy.

It are the batteries that do the reversing.

Why don't you make heat with the energy that is generated to much? and store some of it in batteries to enable you to drive to your work and back each day.

Yes, there are fuel cells that are reversible. That's really new technology, not yet implemented. But this is one of the cutting edges of development.

There are many more systems to store H₂.

H₂ is a small molecule, so small that there is nothing that can stop it, even no metal container can prevent that H2 is leaking through the metal atoms and surely no composite will be able to prevent this.

You tickled a sore spot on the Hydrogen business: how to store it.

Did you google a bit? You will find that where H₂ is used in chemical processes the H₂ is made on the spot and fed directly in the process. No process plant owner is going to be so stupid to start storing H₂ unless it is to sell it.

to store hydrogen in the form of solid by taking advantage of Nanotechnology.They tried to store hydrogen in nanoporous material. A very large surface area is enfolded to a extremely small space. They yet to make progress enough to store hydrogen on board of vehicle -- a viable future of hydrogen economy much depend on it.

If you are thinking of storing liquid hydrogen, you might ask your suppliers what they use. A dewar (Thermos bottle) of the appropriate size is the usual solution.You can find suppliers on Google. Before you even decide that you WANT to store it, though, I suggest that you read Air Products Safetygram Number 9 at: http://www.airproducts.com/nr/rdonlyres/780e8a00-f1bf-435c-8219-6601da6632f0/0/safetygram9.pdf I have seen a result of violating minimum distances between liquid hydrogen tanks and other substances and I suggest following the rules. DickL

Read this for another set of ideas.

http://www.switch2hydrogen.com/h2.htm

Well then. Problem solved! Using actually available products, all you have to do is put on your United Nuclear T-Shirt, connect your Poly fuel line to your $2,125 bank of Solar Panels, and.......?

H storage is very difficult and the main reason this energy source hasn't taken off. You need very high pressure and/or very cold temps. Both present a significant problem with safety and efficiency.

In addition the energy density of H₂ is very low compared to liquid hydrocarbons such as diesel fuel, or gasoline, but also very low compared to any of the hydrocarbon gases.

Not only is it difficult to store, you need to store so much of it for a given amount of energy.

H₂ in comparison with the energy storage of other fuels:

Gasoline 34MJ/l, Diesel 39MJ/l, LPG 24MJ/l, Ethanol 22MJ/l, Methanol 16MJ/l, Liquid H2 8MJ/l, 700atm H2 5MJ/l, 350atm H2 3MJ/l, 1atm H2 0.01MJ/l.

Greg