IIRC BMW were working on this. I think I read it in one of their magazines.
The problem is that hydrogen atoms are so small that they pass easily through the intersticial spaces of a metal crystal lattice. This means that storing hydrogen in a conventional pressurised cylinder is problematic – the stuff just leaks out and at quite a rapid rate.
BMW’s idea was to turn this negative into a positive. That is, to actually store the hydrogen within the matrix of the metal. I don’t know if they were considering a foam or a solid block of metal, but the general idea was that your “tank” is not actually hollow in the conventional sense. They had some kind of mechanism for allowing the hydrogen to diffuse in in a controlled manner during filling and also to diffuse out when in use. They considered it a comparatively safe way of handling a volatile material – not just security against explosions that might be experienced with a tank of liquid H2, but also hazards during the refuelling. process.
Wiki says not in practice:
The british TV show Top Gear helped to spread a lot of these misconceptions.
They described hydrogen as basically free energy with the only downside being it needed to be “scraped off” other things. When of course this “scraping”, if we insist on calling it that, costs energy, and it’s recombining hydrogen which nets us the energy to use for the motor.
Also, they described a hydrogen fuel cell as a portable power station. “You’re actually generating your own electricity!”.
By this definition, I have lots of little cylindrical “power stations” around my home…Do you think they’re a terrorist target? :eek:
Sorry for not reading any posts in this thread. My contribution in short: in nanoscale you can store both electricity and hydrogen in capacitors. When they can do them both in one capacitor efficiently mileage problems are history.
Problems:
Any gas - hdrogen, methane, propane - is hard to contain. The convenience of handling a simple liquid like gasoline should not be underestimated.
Storage is an isue - you can either pressrize it, so you are driving around with a bunch of welding tanks in your vehicle; or you can have a giant thermos and liquid hydrogen (totally impractical and even more dangerous). Hydrogen is not very dense, oddly enough for something used to make Hindenburgs float in air. The volume (size) of the tank compared to an equivalent gasoline tank is much larger. Storage in a metal matrix is a good idea - I went to a lecture about it in 1985 - but again, we’re talking about a lump of metal pretty close to the size of a gas tank; even if it were foamy or steel wool, it’s still significant added weight.
Electrolyzing water to make hydrogen is not extremely efficient. Keep adding the inefficiencies together and you have to have a lot of power to generate that H2. The advantage is that if your electricity is solar or wind, you have a storage medium.
The ideal use for hydogen would be in jet aircraft. They use huge quantities of fuel at a time; they fly (usually) to a very limited number of destinations, so it would be simpler to install the infrastructure to handle it. The problem is - to carry enough fuel, part of the fuselage would have to be turned into a giant thermos bottle - but you would have to put it in the centre for balance. This would mean the people by the wing would be sitting on top of a container of supercooled liquid - one bad crack-up and it would turn them to popsicles in a second.
I read something in Scientific American quite a few years ago where they were designing a system that used liquid hydrogen produced at nuc plants. The idea was to pipe liquid hydrogen through special power lines. The liquid H2 cooled the power lines and reduced line losses and could then be used at the end-point for fueling a vehicle or cooking or whatever. I can’t recall whether they wanted to use an actual superconductor for the lines or just very cold normal conductors.
If this had worked, or could be made to work, it would have solved or ameliorated several problems
a) cut down line loses in electrical distribution,
b) fueled your home for cooking/heating/barbecuing and given you a fuel source in your garage.
c) Allowed placement of nuc plants out in a desert somewhere, leaving the hysterical anti-nuc people somewhat less to whine about.
An intermediate scenario was to put an H2 filling station at the end of every major power line that would become your corner gas station.
It was a thought provoking article and it would be interesting to know whether anyone actually tried this. Since I haven’t noticed any H2 powered cars or very cold power lines, I assume the plan ran aground on some engineering practicalities.
Regards
Testy
To all, thank you for your replies.
I’m certainly much better informed about the pitfalls of utilizing hydrogen in this any.
I think they were using an aluminum foam.
I don’t expect to see hydrogen powered cars.
Hydrogen can be stored with nanotechnology, but it is not stored in a capacitor. The two technologies are not related. Carbon nanotube capacitors are likely to become the state of the art very soon. This will be a great advancement in high density energy storage, but it will be used in electric vehicles, not hydrogen powered vehicles.
A lithium hydride cell is also not hydrogen storage, that is simply a battery. Nanotechnology based lithium batteries are also likely to become the state of the art soon.
Does anybody else read the OP in an old Jewish mans accent?
Yeah, I only said when…
Anyways a little reading related to the OP
http://www.ak-tremel.chemie.uni-mainz.de/literature/10.1038_35104634.pdf