I think the answer to your question is in the video.
if it was easy and cheap to transport hydrogen in bulk, why did they set up a fuelling station that produced hydrogen on site?
The simple answer is that although hydrogen has a much higher energy density than petrol, hydrogen is so light compared to petrol that you need to compress hydrogen to a very high pressure to get any decent amount of energy out of it.
Note that in the video the hydrogen used to refuel cars is stored at 10000psi. and goes into the vehicle and is stored in the vehicle at 7500psi
That's a lot of pressure!!!
To make a large containment vessel such as would be needed on a fuel tanker that could safely hold a flammable gas at 10000 psi would be prohibitively expensive.
I dread to think what would happen if a tanker full of hydrogen at 10000 psi were to be involved in an accident and rupture
Also, because hydrogen is the smallest atom in the periodic table, leakage- particularly when stored at high pressure is also a significant problem.
At the moment there are a total of 11 hydrogen refuelling stations in the UK and AFAIK all produce hydrogen on site
Cheers
Bruce
It is still early days for hydrogen as a road fuel. Lots of pilot projects, but potentially could be useful.
As I see it, at the moment, there are two ways of making the stuff. Steam reformation of methane (natural gas), which is done on a massive industrial scale, where the hydrogen is needed for industrial chemical processes. A big one being to make nitrogen fertilisers, ammonia, nitric acid etc. The by product being CO2. Some of which is valuable for other things, such as making fizzy drinks, beer, even keeping our aging nuclear gas cooled (by CO2) reactors gassed up.
Keeping this on topic, nitric acid is fundamental to making shooting powders and other explosives, which was the original impetus for Fritz Haber to invent the process, during WWI, to keep Germany supplied.
You might recall a recent crisis where the main fertilizer plants in the UK were switched off due to being uneconomic to operate with current soaring gas prices. The knock on effect of basically switching off UK CO2 production for other uses requiring the Government to step in and subsidise them. And possibly also worried about fertiliser shortages going forward. Ultimately from taxpayers money of course.
There is talk of "greening" this by carbon capture and storage, (injecting it into old oil wells and forgetting about it) but despite a lot of talk about that, its not being done yet AFAIK. Nor is it ever likely to be done for coal or gas fired power stations despite a lot of studies.
This stuff is often called "blue" hydrogen. There is even talk, and some pilot studies, about using it to replace, in whole or in part, our domestic gas supplies. Which makes little sense to me. Reforming methane to hydrogen is an inefficient process.
Then there is electrolysis. To make "green" hydrogen. A lot of work on these, some big ones are approaching 80% efficiency in turning kWh of electricity into kWh of hydrogen. Whilst also producing oxygen which might have a value too. Potentially this could be a great way of storing surplus wind energy, hydro from other countries, or delivered from them by pipeline, even solar. Or, dare I say it, from Nuclear.
Large scale storage in cryogenic liquid form, tankered or shipped around. Boiled up again and compressed to say 350 or 700 BAR for road fuel or other uses. Some analysis of the efficiency of that:
https://www.hydrogen.energy.gov/pdfs/9013_energy_requirements_for_hydrogen_gas_compression.pdf
But then how to use the hydrogen to power vehicles ? Basically expensive fuel cells, or burn it in an adapted internal combustion engine. Both have inefficiencies, and seem to me to be broadly comparable in real world use, at the moment. And burning hydrogen can create a lot of NOx, that has to be dealt with, maybe by straightforward catalytic convertors, or "AdBlue" urea injection approaches, now well proven.
Or, green hydrogen can be combined with CO2 from other sources to make synthetic liquid fuels, for aviation or even road use. Nearly carbon neutral.
