My Hindi newspaper of 28th had an amusing and amazing story. A Pak engineer, Waqar Ahmad, recently demonstrated his Water-Fuelled engine before a gathering of politicians, government officials, scientists (?) and students, etc.
I got curious and searched the internet for more about the news. I got some links to the said item, which I give here:
The Pak Government is very happy. An engine running on Water as fuel! All energy problems will get solved! Water being available in abundance, humanity shall have unlimited energy to consume. The engineer is now to go ahead with govt. support.
Rejoicing! Hurrah!! Energy problem no more!!!
For a physicist like me, that is a pure HOAX, unfortunately. Water as fuel in place of petrol/diesel in an internal combustion engine? 100 per cent impossible. Why? Simply because the known laws of nature (physics) do not permit that.
What is the mechanism of getting energy out of noncombustible water? The news items does not make things clear. What I could understand is this: water would be subjected to electrolysis to produce hydrogen, which would act as fuel in place of petrol/diesel. That is fine; nothing wrong.
But it is not explained how that electrolysis would be effected. Electrolysis necessarily means use of electricity! Is the engineer using a storage battery to have continuous supply thereof to decompose water into its chemical constituents, one of them being hydrogen to be used as fuel? To run an engine, you would need a continuous supply of hydrogen. And that would demand a continuous process of electrolysis, which in itself implies a continuous supply of electricity.
This electric power supply is the ultimate source of energy. I reiterate that the news does not clarify if an electric supply is being used for the said engine. What else is the mechanism of electrolysis?
If this much is true then what you are actually doing is this:
electric source (electricity) →convert to chemical energy (electrolysis) → hydrogen (source of chemical energy) → convert to heat energy (hydrogen as fuel) → convert to mechanical energy (rotational motion produced) → use
this to drive a vehicle etc.
Now if this is the trick being followed, without disclosing the hidden use of an electric power supply, then a question deserves to be answered: Why not use that electricity to run an electric motor directly, which would drive the desired machinery.
electric source (electricity) → convert to mechanical energy (drive an electric motor to get rotational motion) → use this to drive a vehicle etc.
This is the principle of battery-driven cars/bikes available in the market.
Any student of thermodynamics can understand well that the first approach would be necessarily less efficient than the second, because at every step of converting one form of energy into another involved unavoidable loss of energy.
So a million dollar question is how water can act as a fuel? (I am talking of chemical fuel and not nuclear fuel!)