So this could potentially work, because aluminum is a cheap and plentiful resource. At the moment they%26#039;re only trying to use this technology in small engines (like lawnmowers) to see if it works. If it does, they%26#039;ll try to scale it up to larger engines for cars, and you%26#039;ll have an environmentally friendly source of hydrogen. There are some issues with the amount of heat produced during the the reaction between the water and aluminum alloy, so it%26#039;s not sure to work, but it%26#039;s fairly promising.
Bottom line is that hydrogen cars won%26#039;t be available for probably at leat 20 years. In the meantime we should be focusing on development of hybrids and electric cars. Joseph Romm%26#039;s %26#039;The Hype About Hydrogen%26#039; 0% 0 Votes
http://www.commutercars.com/h2/ 14% 1 Vote
Hydrogen can be extracted from water, when hydrogen burns, it also produces water as a byproduct. 0% 0 Votes
Hydrogen ICEs can burn at a temperature below the point that creates nitrogen oxides.
Hydrogen ICEs are very efficient.
Hydrogen fuel cell cars will be very efficient.
NOTE: Hydrogen is an energy Carrier! Not a fuel source. We cannot drill, mine, or gather hydrogen. It must be made from natural gas, electolysis of water, or various other ways. More than likely, coal power plants will produce hydrogen through electrolysis with the electricity they produce at night when few use it. The power companies might pipeline it into town where it could be sold at an Exxon or Shell station.
Just my prediction.
What do I know, I%26#039;m 13 0% 0 Votes
Hydrogen has a very low energy density per unit volume unless you crank the pressure way up (~5000PSI for the tank design Bosh were advertising a few years back), or go cryogenic which does bad things to the energy efficiency as you need something of the order of the same energy given by burning the hydrogen to liquefy the stuff (meaning 50% efficiency before you even get an engine involved). Then you have the issues of transporting a bulky flammable gas (or cryogenic liquid at a few kelvin) from where it is produced to the cars and devising a safe filling mechanism...
There has been some work done on metal hydrides as storage, but the density really is not there.
Now there has been work done on reforming methanol (gives H2, CO2, CO and H20) on the vehicle and using the H2 to run a fuel cell, but that technology has some fairly nasty issues (cost of the cell stack first and foremost, also startup time and inefficiency for short trips (You have to heat the cell stack to ~80C before it starts producing useful power)), it might some day become sane for long haul trucking and possibly for trains where electric railways cannot be directly used for whatever reason, but I really don%26#039;t see it for passenger cars.
Look into the %26#039;think%26#039; project done by IIRC Ford and GM, for the gory details. It was an open secret that this was done, not because it was going to give us workable hydrogen cars, but as a sop to the Californian government (It was easier then buying the politicians).
Hydrogen is at best (if they manage to solve the storage and transport issues) a somewhat more portable intermediate step between large electrical generators/chemical plants and the prime mover on the vehicle (but every conversion costs you overall efficiency).
Now, a thermal power station is somewhere between (~40% (nuclear) and 55% (state of the art gas)) efficient, so anything you do with electricity has to allow for the fact that you are starting off with ~50% of the energy you put into the system... So for a gas fired plant, and assuming that the production, transport, and compression for the cars tank do not require any energy input (ha!), the cars engine would have to be around twice as efficient running hydrogen then running propane before you see any net benefit. Now liquefied propane gas is mature technology and could be a reasonable place to go.
The fuel cell might one day replace the IC engine as it bypasses the thermodynamic efficiency limit of the Carnot cycle, but I would bet it runs on methanol rather then H2 (much easier to handle and store).
I would raise serious doubts about your underlying assumption that hydrogen cars are %26#039;the next thing%26#039;. Getting US diesel (and diesel engines) dragged kicking and screaming into the 21st century would be my bet for the next thing.
Regards, Dan. I used to work on the control systems for this stuff. 14% 1 Vote
