Cycling UK Forum

Hydrogen can be stored in many forms, as upthread.

In current (!) hydrogen powered cars it's stored as a gas.

Jonathan

PS: And Calor gas is different from hydrogen, not least in its boiling point.

Mick F wrote: 2 Aug 2021, 5:10pm Not suggesting anything.

I'm saying that hydrogen is compressed into cylinders and forms a liquid.
Insufficiently compressed, no doubt it remains a gas.
It's not the hydrogen that's heavy of course, but the container to hold it.

Pick up a full calor gas cylinder and give it a shake. Heavy!
There's liquid in there.

Calor gas is not hydrogen.

Here is what the manufacturers of the refilling station which is pictured in Jonathan's photo, up thread, have to say.

"Today, most car manufacturers have opted for the solution that consists in storing hydrogen in the gaseous form, at high pressure."

"Hydrogen turns into a liquid when it is cooled to a temperature below -252,87 °C."

"Currently, storing hydrogen in the liquid form is being reserved for certain special applications, in high-tech areas such as space travel. "

Source: https://energies.airliquide.com/resourc ... gen-stored

I'm glad Jonathan posted that picture of a hydrogen car. By doing a quick bit of googling I've learnt a few things.

Volkswagen consider the overall cost of running an EV to be more or less the same as that of running a similar ICE.

https://www.volkswagen.co.uk/electric/s ... ectric-car

Hydrogen is the lightest element. The atoms are so small they can pass through some plastic materials. Potentially very dangerous stuff.

Al

al_yrpal wrote: 2 Aug 2021, 6:34pm Hydrogen is the lightest element. The atoms are so small they can pass through some plastic materials. Potentially very dangerous stuff.

Comparison with petrol upthread... do you think that hydrogen is more dangerous than petrol?

Thanks

Jonathan

PS: In the conditions of interest hydrogen is usually a diatomic molecule.

PPS: Carbon dioxide molecules can pass through many plastics, and they're a lot bigger than hydrogen.

Jdsk wrote: 2 Aug 2021, 6:39pm

al_yrpal wrote: 2 Aug 2021, 6:34pm Hydrogen is the lightest element. The atoms are so small they can pass through some plastic materials. Potentially very dangerous stuff.

Comparison with petrol upthread... do you think that hydrogen is more dangerous than petrol?

Isn't the internet a wonderful thing?

https://blog.ballard.com/hydrogen-safety-myths
https://www.nrdc.org/experts/christian- ... -clear-air
https://www.hydrogenfuelnews.com/hydrog ... s/8538722/
https://hydrogen.wsu.edu/2017/03/17/so- ... ogen-fuel/

biketips666 wrote: 2 Aug 2021, 5:46pm
"Hydrogen turns into a liquid when it is cooled to a temperature below -252,87 °C."

Hydrogen turns into a liquid when it is compressed.

The containers in which it is stored are explosive, that's why they are thick solid steel.
Maybe this is why hydrogen is stored as a gas for vehicle use.

Mick F wrote: 2 Aug 2021, 7:12pm

biketips666 wrote: 2 Aug 2021, 5:46pm "Hydrogen turns into a liquid when it is cooled to a temperature below -252,87 °C."

Hydrogen turns into a liquid when it is compressed.

It is impossible to compress hydrogen from gas to liquid above 33 K.
https://en.wikipedia.org/wiki/Liquid_hydrogen

Jonathan

Mick F wrote: 2 Aug 2021, 7:12pmThe containers in which it is stored are explosive, that's why they are thick solid steel.
Maybe this is why hydrogen is stored as a gas for vehicle use.

It's mostly to avoid lugging a cryogenic cooling system around.

Jonathan

Strange how I know that our cylinders had liquid in them when full eh?
Damed heavy things.

Mick F wrote: 2 Aug 2021, 7:30pm Strange how I know that our cylinders had liquid in them when full eh?
Damed heavy things.

If you know how to liquefy hydrogen at room temperature I suggest letting Stockholm know as soon as possible.

Jonathan

Mick F wrote: 2 Aug 2021, 7:12pm

biketips666 wrote: 2 Aug 2021, 5:46pm
"Hydrogen turns into a liquid when it is cooled to a temperature below -252,87 °C."

Hydrogen turns into a liquid when it is compressed.

I'm sure you are correct, you seem to know a lot about so many different subjects.

But for the purpose of accuracy, the quote that you attribute to me, was actually a re-quote from a company that seems to specialise in the distribution of energy products, including Hydrogen:

https://energies.airliquide.com/resourc ... gen-stored

Mick F wrote: 2 Aug 2021, 5:10pm Not suggesting anything.

I'm saying that hydrogen is compressed into cylinders and forms a liquid.
Insufficiently compressed, no doubt it remains a gas.
It's not the hydrogen that's heavy of course, but the container to hold it.

Pick up a full calor gas cylinder and give it a shake. Heavy!
There's liquid in there.

Calor isn't H2, Critical point of H2 is ~33K, so you can't compress H2 to a liquid.

One reason the H2 containers are so heavy is that they need to be big and very strong to hold a useful amount of such a low density gas.

As is usual this thread took on a life of it's own - mainly about the pro's and con's of electric vehicles.
I started the thread because whatever low carbon solutions will be used for our heating and transport it will inevitably have to come from the electrical supply.
I'm concerned that we are nowhere near being able to supply the large increase in demand that this entails.
I've yet to see any projections as to the likely demand by 2040.

Nor does there seem to be any ambition of the this government or any alternative to provide a solution.
The dithering about Nuclear power has gone on for decades.

ANTONISH wrote: 3 Aug 2021, 4:23pmI've yet to see any projections as to the likely demand by 2040.

"Updated energy and emissions projections 2019"
https://assets.publishing.service.gov.u ... s-2019.pdf


https://www.icaew.com/insights/viewpoin ... rojections

Jonathan