Are you saying that hydrogen is more or less efficient used as a fuel compared to hydrocarbons such as petrol, diesel or LPG?
The basic science says:
Hydrogen by weight contains approximately 3 time’s the usable energy compared to petrol or diesel.
Hydrogen when consumed in a fuel cell produces approx 2 times the electrical energy converted to mechanical energy, when compared to the energy converted from a similar weight of petrol in a standard internal combustion engine powered motor vehicle. EG Honda Clarity H2 vehicle, output energy measured at the wheels.
Note:
I’ve suggested the following as a short read on the energy transfers and other aspects of the redox reactions involved in combining hydrogen and oxygen.
From Scientific American and two MIT chemists. The reference is a little dated, but I suspect the chemistry had not changed in that time.
That’s all I can say on this for now. Three replies around the one should have covered enough.
I reckon the Government could be keen on Hydrogen because it is something we can export to other countries, and would give some credibility with greenhouse gas reduction. Not easy to export electricity across oceans, no matter how green it has been produced.
Hydrogen is not the panacea for the future that some think. It has some serious issues. From Wikipedia.
Properties
The product of its combustion with oxygen alone is water vapor (although if its combustion is with oxygen and nitrogen it can form toxic chemicals), which can be cooled with some of the liquid hydrogen. Since water is often considered harmless to the environment, an engine burning it can be considered “zero emissions”. In aviation, however, water vapor emitted in the atmosphere contributes to global warming (to a lesser extent than CO2).[6] Liquid hydrogen also has a much higher specific energy than gasoline, natural gas, or diesel.[7]
The density of liquid hydrogen is only 70.99 g/L (at 20 K), a relative density of just 0.07. Although the specific energy is more than twice that of other fuels, this gives it a remarkably low volumetric energy density, many fold lower.
Liquid hydrogen requires cryogenic storage technology such as special thermally insulated containers and requires special handling common to all cryogenic fuels. This is similar to, but more severe than liquid oxygen. Even with thermally insulated containers it is difficult to keep such a low temperature, and the hydrogen will gradually leak away (typically at a rate of 1% per day[7]). It also shares many of the same safety issues as other forms of hydrogen, as well as being cold enough to liquefy, or even solidify atmospheric oxygen, which can be an explosion hazard.
We buy fuel by volume, in which case hydrogen has lower energy content than hydrocarbons. The degree depends on the pressure if it is a gas. When liquified this is still true due to the low density of hydrogen in all its forms. I am not sure that the measurement of energy content by either weight or volume is a useful measure of efficiency in this context.
Sticking to road vehicles, electric vehicles are more efficient than hydrogen in the sense that there are fewer steps (with losses) between the origin of the energy and the road. To me this is a better measure of efficiency. But EVs currently have less range than those that carry liquid fuel. Some take this to mean that hydrogen will solve the range problem.
However that involves building a network of hydrogen service stations and dealing with the storage and energy conversion issues on the vehicle. I think investing in better battery technology and building a better network of charging stations is going to prove to be the better solution to the range problem and EVs will get up over HVs.
There is also the VHS vs Beta question. Getting to market first may be the decider rather than pure technical merit.
Whether hydrogen is useful and sufficiently efficient for bulk transport of energy is a moot point. Selling renewably sourced energy overseas instead of hydrocarbons sounds like a nice option. Whether sending tankers of hydrogen to (say) SE Asia is profitable remains to be seen.
These include science kits for education through to small scale commercialised fuel cells and electrolysers. All pricing in USD.
Anyone tempted is advised to check on what may or may not be permitted in a residential location. The developers of the Lavo hydrogen based competitor to the a Tesla PowerWall and similar all in one Storage systems may have this all sorted for Australia?
Hi @Fred123, the link brings up an advert by Dick Smith promising to make me rich in months and a disgusting colour shot of ear wax in various forms.
What’s not evident until you read the article. The waste product is CO. There is no explanation of what to do with this gas. It’s not clear the discovery changes anything.IMO the reforming of methane is not a solution to GHG emissions, unless it converts the carbon content to an easily managed solid form. Diamond dust would be useful.
Methane reforming? There is no recycling of methane, as suggested in the attached article. It’s a one way trip with CO2 the byproduct. It’s just one way of producing hydrogen from natural gas (methane) obtained from drilling gas fields or fracking.
P.S.
The following might be a more useful link, assuming there is no need to for earwax treatments or instant wealth. Yes, there are promotions, but more in keeping with the topic.
I search if possible for alternate sources of the same content to avoid the peripheral garbage adverts. Most genuine items of scientific endeavour have a website connected to the original source or topic specific web sources. Most of whom realise earwax and fake Dick Smith advertising is a turn off.
Mirage News is as per it’s literal meaning, not to be relied upon.
That Bitcoin scam was not there when I posted it but it is there now so I have asked Google to shut it down.
That is the first Goocle ad for the scam that I have seen since 05.09.2020 so it appears that along with the 2 different ones I saw in the past few days, these grubs must be crawling out from under their rocks again.
Reality is ammonia is an everyday chemical, transported by road and rail in bulk. It does have a hazardous goods classification, standards for safe transport and safety management.
It’s potential for use as a convenient and safer way to store or use hydrogen would see it more widely used. The risks however remain the same as currently regulated. It’s worth pointing out that aside from the pungent odour, it may best be a fuel restricted to managed environments, and not the average back yard.
Victoria does the dirty work in producing a clean energy source for another country. Where does the CO2 produced by this pilot plant go? Straight into the atmosphere, that’s where.
In the future, in large-scale production, where is it proposed to go?
Well that old boondoggle of ‘carbon capture and storage’ under Bass Strait.
Never been demonstrated to be practical or even doable on a large scale.
Hey, if you want Hydrogen, just produce it from renewable electricity and water. No CO2 produced at all.
