Scientists find safer way to store hydrogen Australian scientists have come up with a clever way of storing hydrogen that they feel could make it a viable portable fuel source. Hydrogen is abundant: pass a current through water and you'll make some. Hydrogen-powered fuel cells have therefore been advanced as a potential replacement for the internal combustion engine and …
Half their cars, eh? That's super. How about all their heavy freight vehicles? How about their trains? Hell, how about their aircraft, whilst I'm at it? I'll bet they don't have a whole load of ethanol driven cargo ships either. I stated that running an industrial nation on ethanol was impractical. Don't cherrypick, please.
There are also some issues involved with scaling Brazil's solution to the rest of the world. How much ethanol-brewing feedstock might one grow in the UK, for example? Now contrast with how much hydrogen cracking you could get out of a brace of modern nuclear reactors.
Again, my point was that this is not next-gen technology, it could be done now if needs be, with existing nuclear and solar tech. Converting all of the world's arable land into biofuel generation would work too, but there may be issues with that, like being able to eat...
...which means you need to invent a solar cell that's better than 15% efficient, which means -- you guessed it -- back to the drawing board!
Something which seems to escape the green campaigners, I think because they're by and large not actually technical people or involved in technical industries: Any plan, which depends on fifty years of inventing things which don't exist yet, is not a good plan. That's one of the major reasons I'm so hot (if you'll pardon the expression) on nuclear fission and water cracking: these are things which we already know how to do.
...which means you need to invent a solar cell that's better than 15% efficient, which means -- you guessed it -- back to the drawing board!
Completely wrong. For solar electricity, the energy source is inexhaustible in human terms and has zero cost. It beomes a matter of economics: the cost of making solar cells and the cost of the real estate on which you put them. At present the real estate cost is close to zero (no-one much wants the vast tracts of near-lifeless desert that exist) but the cost of the solar cells is rather high compared to the cost of generating the same electricity from fossil fuels.
Raising the efficiency of the solar cells is one way to improve this. Making them much more cheaply is another. If we could make a plastic sheet that generated electricity as cheaply as we make polythene sheets, it would not need to be even 5% efficient to revolutionise the world.
(Nature did this a long time ago. It's called a plant. Conversion efficiency of solar energy to hydrocarbons rarely better than 1%, but a very low production cost in human terms because to a large extent, they grow themselves into useful products, and make their own seeds. If only they didn't need so much water to grow! )
"Huge natural supply of hydrogen": how's about the world's oceans?
Yes, I know you said "hydrogen gas". Thing is though, cracking water into H2 and O2 is well understood, and the technology to do it is a *lot* less hassle than the big dangerous refineries needed to turn crude oil into kerosene, gasoline, diesel, fuel oil, etc..
It would also be an incredibly nifty adjunct to any power station. Regular power stations assume near-constant load, and renewables have a hugely variable generating capacity. Neither of these will match the national grid's demands very well, so a hydrogen electrolysis plant would provide a perfect sink for any excess juice when the lights get turned off. Also, currently there's a lot of fun and games trying to match power demands, but if you can permanently run all your power stations at 10% (say) above the worst-case demand and instantaneously reduce/cut power to the electrolysis plant when you're hit by a peak, then life would become a lot easier for national grids.
The problem with hydrogen has always just been storage and distribution. If they've truly sorted this (and see Nigel11's comment above about energy density), then the game is on.
1. Convert the huge container ships that bring all those goods from China to use nuclear engines with water cracking plants.
2. Allocate some of the ships' space to carry empty container sized batteries, depending on the length of the voyage.
3. Fill the empty batteries en route.
4. Profit.
Can I have my Nobel prize now please?
See frank ly's post above. To get the hydrogen to fill up your tank, you need to obtain the hydrogen. To get it from the sea, you need to supply the energy necessary to pry the H2 loose from the O (which is all you'll get back when you burn it), plus enough to cover the inefficiencies of the process.
How much better just to take said energy supply and send it directly to the vehicle, cutting out the middle-hydrogen? And we don't need to spend massive amounts to build a hydrogen-distribution network and hydrogen-storage stations---we've already got a reasonably-good one for transmitting energy in the form of electricity.
Since burning/fuel-celling H2 is better than petrol for on-street pollution prevention, we could even set up fueling stations supplied with water and electricity, and crack it there to fill a car's hydrogen tank. That way we avoid all those nasty hydrocarbons out the tailpipe, and the cost of distributing hydrogen qua hydrogen. I hope we can build a fossil-fueled electric plant with better efficiency than internal combustion.
when you look at all combustion fuels the best bet is actually diesel. Its probably the most compact per unit energy, its relatively high flashpoint, and its well known.
LIQUID hydrogen scores only on weight. Its light which is why its useful in rockets but as the odd shuttle disaster shows, its not something you want to be sitting on if it gets ignited all at once....
I used to work for an idiot that wanted to do something similar. He was not happy to find out that the total efficiency of using electricity to split water molecules into hydrogen and oxygen gas and then run the stuff through a fuel cell was only about 60% efficient. And when I say "not happy" what I mean is that he thought the university perfessers were conspiring against him to keep him from making huge piles of money.
Most energy generated by wind farms is made off peak. Anyone could set up a simple wind powered rotor. Just cutting a drum in half and welding the halves side to side would make a pelton wheel that could draw enough power from the wind at the corners of a building to supply hydrogen and oxygen from water.
Presumably the oxygen could be stored in the air for later reuse whilst the hydrogen could be gathered into a replacement vehicle fuel tank.
At the moment the idea of having a fuel tank that isn't integral to the vehicle seems to be the biggest problem. When you consider that integral tanks also mean small tanks, you have to wonder why it's taken so long to rethink that idea. (Not that petrol tanks haven't always been sufficiently large for the journeys the vehicles they are designed for.)
But if all you require are drop tanks then all you need acquire are drop tanks. That will hurt the tax office though. And the petrol companies, so there are likely to be health and safety issues to keep the status quo.
Methane is easier to manufacture and store than hydrogen, not to mention cheaper, easier and safer.
So why is it there's never any news about development of it as an alternative fuel for vehicles? Is it public perception (who wants to drive a "fartmobile?, or is there some major downside to its use that I'm not aware of?
No, seriously, this puzzles me.
If your just going to burn it, might as well use Natural Gas. Natural Gas cars are available, they are not great...
They are working on fuel cells for Methane but they are not as advanced as Hydrogen full cells.
Methane is currently cheap because it's mostly made from Natural Gas or coal, you can make it from rotting garbage but not enough for more then some local heating.
If you have extra electricity off peak it can be used to split water to hydrogen, when used it's back to water.
Not sure if there's any one reason. When you say methane, you're basically saying natural gas (90%+ methane), which is just another limited resource that we might arguably be trying to rely less on. And, if there's any desire to curb CO2 production, that isn't it. You can cultivate methane from pig farms and such, but I don't know it that has infrastructure level prospects.
I don't think hydrogen makes a lot of sense, but I'm glad that there's R&D effort in the background seeing what can come of it. As a fuel source with any remote chance of replacing gasoline/petrol, I can't ever see hydrogen taking lead. You lose so much energy electrolyzing or gas reforming the stuff into existence. It's only advantage over battery storage is that you could potentially "fill up the tank" much quicker than a battery recharge. I say potentially, because I don't know of any safe, standardized hydrogen deployment system ready for everyday use, with which to quote against.
isnt methanethe single biggest contributer to AWG on the whole planet, ie, if we stopped eating cows and drinking Milk, then killed them all off, there would actually be a significant change in GW gasses rather than pissing about with a gas that has drastically less effect and much harder to change.
perhaps im wrong but i could have swarn someone said cows are far more effective at warming things up then cars are.
I remember reading somewhere that we could cut CO2 emissions by switching from eating beef to eating kangaroo as apparently kangaroo's don't produce methane.
I was never convinced by this article as the details were a bit vague; are they trying to claim that kangaroo's don't fart or that kangaroo farts don't contain methane?
Kangaroos live where they have evolved so eat what they're used to.
Cows are fed grass and dead cows and all sorts of shit that they're probably not used to but make economic 'sense' for us to feed to them now. This isn’t the ideal food for them and makes them fart. God knows what they're ideal diet is. My ancient local breed of cow survives in the field all year round with no additives but modern breed will point their hoofs skywards without shed loads of nutrients added to their diet.
Kangaroos will produce 3-5 times the same amount of meat as sheep will on the same land in australia if left to there own devices - if the sheep are left to their own devices they will die, cows produce less than 1/2 the meat the sheep do.
At the moment cows pay better than sheep and hardly anyone eats roo but if food does become scarce I can see that changing.
Cows release methane not by farting, but from their mouths. It is produced by the bacteria in one of their stomachs. Kangaroos are not ruminants and therefore don't have the same structured digestive system. Plus kangaroo is tastier and lower in fat.
Methane is anout 15 times more potent as a greenhouse gas than CO2, true, but it has a short half-life in the atmosphere (about 10 years from memory). It gets broken down by UV and recombines with oxygen as CO2 and water. Incidentally water vapour is an even more potent greenhouse gas than methane, but the atmosphere is naturally pretty much saturated with the stuff. If it weren't for global warming caused by water vapour, the planet would mostly be too cold for life.
Anyway: methane does not accumulate long-term in the atmosphere, whereas CO2 (probably) does. Which is why the focus is on the CO2.
There IS a clear and present danger of a runaway warming event caused by the thawing of methane hydrates of natural orogin currently trapped in permafrost across the world's Northern tundras. If the permafrost thaws, lots of methane is released, causing increased global temperatures, causing more thawing and more methane. A positive feedback loop until all the arctic has thawed. The fossil record shows that this has happened several times in recent geological time, without human causation. A very sudden thaw, followed by a gradual cooling. To my mind, this is the key reason why we should be VERY bothered about human CO2 emissions.
OTOH, if you reduce CO2 in the atmosphere, plants will grow much less efficient (and also require more water). Or if you reduce the temperature just a little bit and we might end up starving because food plants won't grow very well.
Better then to figure out how to keep the temperature up when the gradual cooling sets in.
Better then to figure out how to keep the temperature up when the gradual cooling sets in.
Methinks that's a long-term problem, after dealing with the runaway thawing of the arctic and consequent temperature and sea-level rises. (The cooling after that is inevitable, once there's no longer any supply of short-lived methane into the atmosphere from thawing permafrost. The methane converts to CO2, and plants once again start trapping the CO2, and the ice once again starts to creep down from the pole, once again locking up the methane from decomposing vegetation as methane hydrates ... repeat many times, until continental drift does away with the Arctic ocean.)
"Incidentally water vapour is an even more potent greenhouse gas than methane, but the atmosphere is naturally pretty much saturated with the stuff."
The atmosphere's capacity for water vapour depends on temperature; increasing atmospheric water vapour due to warming is one of the positive feed back effects that make CO2 emissions so concerning.
With no positive feedbacks, you can compare the mean temperatures of the moon, Mars and Venus and get 0.7C per doubling of CO2 concentration, which would mean we'd be looking at less than 2C between 1900 and 2100. But there are positive feedbacks, lots of them.
Actually Methane is already out there. Cars can be converted to run on CNG (compressed natural gas) as well as LPG (Liquid petroleum gas, better remembered as low pressure gas).
The problem is that to get enough range out of a reasonably sized tank, a very high pressure is needed. The potential for explosions if the tank is badly maintained is high (far higher than for a tank of gasoline). Also refilling is not nearly as simple as pumping a liquid, or plugging in an electric cable (and not as fast as the former, though faster than recharging a battery).
For these reasons the general public are not in general offered CNG vehicles. You'll find it used for running taxis and public transport in some cities. If oil runs out and gas (shale gas) does not, that might yet change.
Depending on what sort of performance one wants (optimize weight, volume, pressure, temperature, etc.) there are a number of technologies (see http://en.wikipedia.org/wiki/Hydrogen_storage).
Perhaps the best would be some sort of liquid hydrocarbon, formed with the hydrogen to be stored and carbon extracted from combustion processes or the atmosphere. At least it would be carbon neutral. And we know how to pump, store and burn hydrocarbons.
"once the mercury hits 350 that the hydrogen really starts to flow" I have a little bottle of mercury and I can use it to hit a sign that has the number 350 on it and everything should be good!
Or is this just a really bad example of journalism where they use mercury to mean TEMPERATURE! And if so what units, K, C or F! 350 K is easy to hit (77 C), 350 F is also easy to hit (162 C). 350 C is a bit more difficult.
I think it's incorrect because 'abundant' to me means lying around everywhere ready for the picking. Given that the article talks about 'fuel source' I think it's very reasonable to question the word 'abundant'.
Hydrogen is not a fuel source on this planet. Never will be. It might be a useful energy transportation medium one day but never a source.
Oxy-Acetylene welding kits were very dangerous to use a hundred years ago... the Acetylene was made with a water activated carbide generator can... if any pressure built up, the Acetylene exploded, messing up the shop...
It was found that liquid acetone filled tanks would absorb a really large volume of Acetylene and be stable...
Looks like someone did the same for Hydrogen gas... this is actually a very good thing...
However methinks they can't get storage at a scale to work powering a 60-100 Kw fuel cell for any length of time...
Acetylene tanks can only be pumped up to 10 atmospheres, or 150 psi before the become unstable...
dkyd's post of the properties of the inert filler sez it all = yet again another scheme that, ultimately fails...
Well worth pointing out that the Hindenburg was actually a good demonstration of the relative safety of Hydrogen! The majority of its passengers survived the disaster. Those that didn't mostly jumped from too great a height or were crushed by falling structural components. It was the aluminium-paint skin that started the disaster, and the hydrogen burned harmlessly up into the sky, being so much lighter than air.
From an old book about rocketry (published in 1972), begining of the chapter "Exotics":
Fifteen years ago people used to ask me "What is an exotic fuel anyway?" and I would answer "It's expensive, it's got boron in it, and it probably doesn't work."
(the book is Ignition! by John D. Clark)
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