Hydrogen fueled vehicle using Mg?
Hydrogen fueled vehicle using Mg?
(OP)
Interesting article on a hydrogen fueled vehicle...
http://www.isracast.com/tech_news/231005_tech.htm
Thoughts?
http://www.isracast.com/tech_news/231005_tech.htm
Thoughts?





RE: Hydrogen fueled vehicle using Mg?
RE: Hydrogen fueled vehicle using Mg?
RE: Hydrogen fueled vehicle using Mg?
RE: Hydrogen fueled vehicle using Mg?
One of the problems with hydrogen seems to be space needed to store it. I think we have all seen the pictures of vehicles with a fuel cell at one end, hydrogen tanks at the other, and not much in between.
I can therefore understand the logic of generating hydrogen in the vehicle rather than carrying the hydrogen around. However, if something like aluminium is going to be used as the source of power for a vehicle, why bother to generate hydrogen and then burn the hydrogen in a combustion engine or fuel cell.
When I first did some investigation to find out what fuel cells are, I didn't come across hydrogen fuel cells and automotive applications. Nowadays one has to sift through things to read anything else, but at the time, the information I found on fuel cells, was aluminium fuel cells to provide power to telephone exchanges in the event of failure of mains electric power.
=
I have a little digital clock at home. Two electrodes are plugged into a potato from the garden, an apple off the tree, or whatever else happens to be in season. It appears to many that the clock is powered by the apple. However, over time, the zinc on the zinc electrode [I assume that's what it is] is eaten away, and really the clock is running as a fuel cell with the fuel being the zinc electrode which will need replacing from time to time.
I would be surprised if [i]creating hydrogen and then using it[/] proved to be more energy efficient than a fuel cell directly powered by aluminium, or magnesium, or whatever these guys decide to use as their fuel.
=
Last month the rage was the Russian scientists that have persuaded the UK government to part with some cash in the hope that spinning water inside a vehicle can generate the hydrogen required to power it - a sort of perpetual motion idea, as the hydrogen gets turned back into water!
=
Fuel cells are just batteries that don't get recharged. If I keep replacing the lead and sulphuric acid in a lead acid battery (and clearing out the waste, eg lead sulphate) then I have a lead and acid powered fuel cell.
Without any calculations to back it up, I intuitively feel that lead would be more effciently used this way, than somehow trying to generate hydrogen from it and then trying to use the hydrogen, and the same would apply to magnesium, aluminium, etc.
I'd need a good explanation to be convinced that what they are proposing has any real merit, but I'm a hydrogen sceptic anyway - at least until most houses are running off electricity from non-hydrocarbon sources.
RE: Hydrogen fueled vehicle using Mg?
1 kg of Al reacted with water will produce at best 0.11 kg of hydrogen (some hydroxide is formed which will reduce the yield)
because
3H20+2 Al= Al 2 O 3+ 3H2
AW 1 16 27
MW 18 27
N 3 2 1 3
RW 54 54 6
so we burn 1 kg of Aluminium ot get 0.11 kg of hydrogen
And when we burn the hydrogen at say 60% efficiency (ie equal to the best practical fuel cell seen) we'd get 0.11*120 MJ*.6= 8 MJ of useful work
So, we're putting in 56 MJ of electrical energy and getting 8 back.
Are these guys lying scumbags or just incredibly incompetent?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Hydrogen fueled vehicle using Mg?
The Mg + H2O reaction is exothermic. I've seen lab demo of burning Mg underwater. I've not seen this for Al. The heat from the exothermic reaction creates steam and this was also going to be used in conjunction with the reburn of hydrogen as shown in the isracast schematic.
As a comparison what does the conversion of crude oil at 1000 ft. down into IC engine shaft output look like:
energy in->->->->energy out ?
RE: Hydrogen fueled vehicle using Mg?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Hydrogen fueled vehicle using Mg?
$180 for a tank of "fuel"!
.....I have some prime swamp land for sale!
Stupidity is the basic building block of the universe. F.Z.
RE: Hydrogen fueled vehicle using Mg?
RE: Hydrogen fueled vehicle using Mg?
However, this does not square very well with claims that only 50% of the oil pumped up is actually useable as liquid fuel, the rest gets used as asphalt etc.
Farming is a very fuel intensive business, I am not surprised to hear that if you grow the biomass on a typical first world farm then it ends up energy negative. Biomass should be generated from unusable by-products, not as the primary crop (hello sugar farmers).
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Hydrogen fueled vehicle using Mg?
http://www.keralanext.com/news/index.asp?id=409921
RE: Hydrogen fueled vehicle using Mg?
RE: Hydrogen fueled vehicle using Mg?
h
RE: Hydrogen fueled vehicle using Mg?
RE: Hydrogen fueled vehicle using Mg?
In my humble opinion these studies give a far better picture of future fuel systems than I’ve seen.
http://www.dotynmr.com/PDF/Doty_FutureFuels.pdf
http://www.dotynmr.com/PDF/Doty_H2Price.pdf
http://w
RE: Hydrogen fueled vehicle using Mg?
RE: Hydrogen fueled vehicle using Mg?
RE: Hydrogen fueled vehicle using Mg?