James Burgett of computer recycling fame
shows me his test setup at ACCRC
for running his Lincoln on aluminum soda cans.
They threw this rig together quickly to test the concept.
The concept works.
Here's how it works.
Soda cans are dumped into a tank of Lye (sodium hydroxide and water).
The sodium hydroxide peels off the aluminum oxide surface from the aluminum allowing water to come into contact with aluminum metal. The aluminum immediately oxidizes, ripping the water's oxygen atoms away to make aluminum oxide. That releases the hydrogen which bubbles out to be burned in the Lincoln's engine.
Here's the reaction: H2O + Al -> AlO2 + H2 + heat