[vdblnkr34 (OP)]

Hi.

Is it safe to transport hydrogen gas compressed into water tank?

[Bored chemist]

It is impossible to answer that question.
water tanks look  something like this.
Most
CWT.JPG (26.66 kB . 683x585 - viewed 3111 times)

so I would say probably not.

One possibly useful piece of information is that you almost certainly won't get insurance cover for doing it.

[Origin]

Is it safe to transport hydrogen gas compressed into water tank?

The quick answer is no.  Water tanks are not designed to hold compressed hydrogen.

[vdblnkr34 (OP)]

Is it safe to transport hydrogen gas compressed into water tank?

The quick answer is no.  Water tanks are not designed to hold compressed hydrogen.

Oops, sorry. I didn't think to mention that it would be especially designed water tank, to hold huge amount of pressure.

No plastic containers.

[Bored chemist]

If it is designed to contain hydrogen, then it is not a water tank.

[Bored chemist]

No plastic containers.

High pressure hydrogen tanks are sometimes made from glass reinforced plastic.
They are less dangerous in the event of a fire.
When the plastic gets got it softens and is forced out through the gaps between the glass fibres. That vents the tank relatively slowly.
Obviously, that is not great, but it is better than the violent bursting of a metal tank.

[vdblnkr34 (OP)]

I didnt get to the part what to use to build it. The idea to compress hydrogen into water as a preventative matter. And bigger the capacity.

[Petrochemicals]

There is a reason pressurised containers are the shape they are.

[Bored chemist]

There is a reason pressurised containers are the shape they are.

Yes

Tyre.JPG (25.1 kB . 478x495 - viewed 3157 times)

[Bored chemist]

I didnt get to the part what to use to build it. The idea to compress hydrogen into water as a preventative matter. And bigger the capacity.

Filling the tank with water leaves less room for hydrogen and makes it heavier.

[Origin]

I didnt get to the part what to use to build it. The idea to compress hydrogen into water as a preventative matter. And bigger the capacity.

Are you saying you want to dissolve hydrogen into the water?

[evan_au]

The idea to compress hydrogen into water

Solubility of Hydrogen in water at normal room conditions is about 0.00016, which sounds rather low.
- Compared to Carbon dioxide at 0.169, which is 1000x higher
- You would get somewhat more dissolved under pressure (just like a soda siphon), but it's not very effective.

Or do you mean that water is a very compact (denser) way of transporting Hydrogen?
- Unfortunately, once Hydrogen is combined with Oxygen to make water, it is useless as a fuel.

[vdblnkr34 (OP)]

I didnt get to the part what to use to build it. The idea to compress hydrogen into water as a preventative matter. And bigger the capacity.

Filling the tank with water leaves less room for hydrogen and makes it heavier.

Not really. Water doesn't get compressed, gas does Basically you can inject any amount of gas into the water tank, as long as it can hold that pressure. The reason to use water is to make hydrogen less dangerous during transportation. Can be used something else.

[chiralSPO]

Water doesn't get compressed

not really (Water is compressible—not much, but enough. Also, I'm not sure why you would say this, as it means that there is less room for added gas—a more compressible liquid would "make room" for the added gas as the pressure increases...)

you can inject any amount of gas into the water tank, as long as it can hold that pressure.

not really (at some point the pressure is high enough that it will liquify, and then there is less compressibility)

The reason to use water is to make hydrogen less dangerous during transportation

How? I can't think of any benefit from adding water. It just means that higher pressures will be needed to store the same amount of hydrogen (which is more dangerous), and more mass being carried (requiring more energy). If the hydrogen catches fire, the water won't do anything to stop it...

[alancalverd]

People get overexcited about hydrogen fires, thanks to the Hindenburg disaster. But if you look at the film, the dangerous fire was of the envelope, which destroyed the rigid structure and ignited the cabins. The hydrogen gas rose away from the aircraft (which is why it was there in the first place) and burned fairly harmlessly above it.   

[Bored chemist]

Not really.

Yes. Really.

[vdblnkr34 (OP)]

one trailer can carry up to 1000kg of hydrogen, is not enough. need to carry more, like 40000kg

[vdblnkr34 (OP)]

CaH2

[vdblnkr34 (OP)]

20 tons of this CaH2 will give enough hydrogen to make almost 200,000 litters of water. Not bad.

[Bored chemist]

20 tons of it will require at least 40 tons of water to release the hydrogen contained in it.
You could burn that hydrogen and get 20 tons of water.

So what?
20 tons of CaH2 will react with water to give a few tons of hydrogen (and a lot of corrosive sludge).

If you want to use a hydride to transport hydrogen, try ammonia.
https://www.energy.gov/sites/prod/files/2015/01/f19/fcto_nh3_h2_storage_white_paper_2006.pdf