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
Step 1: Lye Tank and Water Bubbler
Here's James with the lye tank. The aluminum cans go in here.
His left hand is on the hydrogen vent hose. The gas that bubbles out of it is hot and steamy and has a fair amount of powdery white aluminum oxide in it. So next it goes into a pipe to the bottom of the white bubbler tank, where it bubbles through water. That makes it cool and clean.
Just like in a hookah or bong.
Step 2: Storage Bag
From the water bubbler bong the hydrogen goes into this black garbage bag for storage.
The reaction can take place at high pressures, so in future the lye tank and other parts of the gas generator will be pressure vessels leading into a high pressure storage tank.
Step 3: Engine Air Intake Duct
From the storage bag the hydrogen goes to the car's air intake.
James has gotten the car to run on hydrogen concentrations between 5% and 70%, so
the mix is pretty forgiving. Here it's controlled by a tuna can resting on top of the aluminum duct tee.
In the future setup it'll be replaced by a proper butterfly valve to set the mixture to some optimum.
Step 4: Soda Cans and Lye in Action
Here's what it looks like when cans dissolve in lye.
The white powdery stuff is mostly aluminum oxide with a bit of sodium hydroxide.
The water has to be replenished often as it gets cracked away to oxidize the aluminum and release hydrogen.
The lacquer and labels on the cans are a bit of a nuisance, they block the lye from getting to the outside of the cans. Shredded cans might be better.
If you want to make your own sodium hydroxide, you can leach it out of ashes.