Recyclable Hydrogen Fuel Tanks

hydrogen gusher:

at room temp aluminum and water react to form aluminum oxide plus hydrogen (very quickly), when a small amount of surfactant (e.g. gallium element) is added.

http://www.fuelcellsworks.com/Supppage7355.html

http://www.physorg.com/news98556080.html

same reaction occurs with other metals at temperatures similar to internal combustion engines, magnesium is example.
http://www.techbriefs.com/component/content/article/3498


so we can produce hydrogen on demand as the car drives without storing more than a small amount for startup, by investing the energy in recycling the spent oxides in cars to turn back into the metal, which is of course the energy that powers the vehicle using this arrangement. 

It lends itself to similar energy densities as fossil fuels, no storage degradation like batteries have, losing energy over time.  

it has the convenience of filling stations that would be very easy to implement to dispense metal pellets and water.  Much easier than recycling whole gas tanks or battery packs, waiting 8 hours for your car to charge (what if is an emergency?) or other strange ideas people are grasping at.

is safer than storing hydrogen gas, which by the way is safer than storing gasoline in cars as it quickly evaporates UPWARD in a crash, not pooling along the freeway underneath your burning engine as gasoline does.

infrastructure is already in place to refine aluminum, it's called ALCOA and other large aluminum companies, tho presumably if used in cars, the locations would be moved around to optimize.

the fueling stations could, probably less efficiently, than trucking it in like gasoline in tankers, or maybe the stations would have a thermal solar modular dish or two and could produce some themselves.


additional benefits: 

a car using fuel cells can run on the metal produced by any electric source including renewable so we can transition transparently for the driver to less polluting energy sources.

a car using fuel cell plus electric motors is simpler mechanically so would likely cost less to maintain

electric cars like this could be designed with the powertrain flat like a sandal and arbitrary body on top, limited only by wheel spacing.  (this idea was elaborated in the futurecar episode last year on disovery channels)

fuel cells are twice as efficient converting energy to motion so the would cost less than half per mile for equivalent fuel inputs.

we need some kind of chemical powered locomotion.  batteries, despite advances are wimpy and wear out much quicker than an internal combustion engine.  if we can get fuel cells to the same lifetimes we should be in good shape.  This should be theoretically easy as they are just a mix of molecular membranes and chemicals. 

A similar material, reverse osmosis membranes were very expensive and now are churned out by the mile in petrochemical plants.

of course the water is available, covering 70% of our planet.  even put thru a reverse osmosis filter, which cleans it better than triple distilled water, is twenty five cents a gallon in front of every grocery store and drugstore in the US.

Aluminum is the seventh most abundant element in the earth's crust.

there you go,  the pig has lipstick, and it FLYs!
(presuming that flying car guy ever gets into production)

The hydrogen is an energy storage medium, so I don't quite get what you mean by "sink". All storage takes energy to maintain. You can say it's not an efficient storage medium and then we could argue.  I'd like to see what the total efficiency would be for solar or nuclear energy used to split water for hydrogen and then the energy to combine the hydrogen into and out of the chemical store.  I suspect it's not great right now and swapping whole takes is kind of stupid -- people will run out of fuel trying to milk the whole tank. I like the idea of metal pellets much better.