Originally Posted by Michael2 View Post
I saw a video on the www a couple of years ago, but haven't been able to find it since.
There was a small motor (lawn mower motor I think) that was powered by hydrogen gas. The motor drove an alternator which powered a small welder and it turned an aluminium drum. The drum was submerged in a tank of water and the welder electrode touched the aluminium drum and arced. The spinning drum stopped the electrode from sticking to the aluminium. The arc bound O2 to the aluminium, falling to the bottom of the tank as an aluminium oxide residue, and the liberated hydrogen bubbled to the top and powered the motor.
Was it real? I don't know.
It is quite real.
There is a patent on this and apparently BMW did some experiments to look at feasibility (BMW since went on to develop cars with high-pressure hydrogen storage instead - so that should say something).
Hydrogen supply unit - US Patent 4702894
Hydrogen supply unit - US Patent 4702894
Quote:
A unit substantially as shown in the drawings has been used to drive a 500 cc motor cycle engine. The wire 22 had a diameter of 1,6 mm and was of commercial purity (98% Al). The unit produced over 1000 cc of hydrogen a minute, with an aluminium
wire consumption rate of 140 to 180 cm per minute. The rate of deposition of aluminium oxide was about 4 kilograms per 500 kilometers travelled.
Conventional modifications were made to the carburettor to enable the engine to run on a mixture of hydrogen and air.
The wire 22 carries a voltage of about 18000 volts with a current of about 1 amp.
The invention may equally be used to power stationary industrial engines, as well as motor vehicle engines.
Taking those claims at face value, the system requires 18kW of electrical energy, to power a 500cc (petrol) engine.
An average 500cc motorbike engine back then could be expected to produce a maximum of about 36kW of power. However, running on hydrogen produces about a 20% loss of power (based on real-world data). For simplicity, lets say 8kW are lost.
So it takes 18kW of energy to run an engine that produces 28kW. So assuming your alternator and drivetrain are 100% efficient, you now have a maximum of 10kW at the wheels, instead of 36.
Now with a rate of aluminium MIG wire consumption of 180 cm/min (or 108m/hr). What's the best price you can get a 7kg roll of 1mm mig wire for? $150ish? So that means just under $5/hr to run at current prices.
If the same engine averages 3l/100km, it would also cost about $5/hr to run, but you would have 3.5* the power at the wheels.
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