The same oil we cook with can also be used as an alternative source of fuel to run a car engine.
Rudolf Diesel, Mechanical engineer
As early as 1900, Rudolf Diesel – designer of the diesel engine – proved his car engine could run on peanut oil at the Paris World Fair.
This is because all vegetable oils are made up of long chains of carbon atoms. A very similar molecular structure to diesel and gasoline.
Pure vegetable oil used as a fuel is known as SVO – Straight Vegetable Oil.
Straight vegetable oil = SVO
Normally, old vegetable oil is converted chemically into biodiesel. This is a renewable fuel that can be mixed with diesel, to give off safer emissions than diesel alone.
It is also possible to reuse pure vegetable oil for cooking, as long as you filter the oil first.
The main problem with both pure and mixed vegetable oils as fuels is that vegetable oil is very thick and viscous, and can damage the engine.
One solution is to use separate diesel and vegetable oil tanks. Once the engine has been warmed by diesel fuel it can then be switched over to the vegetable oil tank.
With both fuel types, burning the oil breaks the chemical bonds in the long chains of carbon atoms, and new bonds with oxygen are formed, which releases energy.
The engine needs to be switched back to diesel oil before it's turned off, so that the remaining oil doesn't clog up the engine.
More than 100 years on from Rudolf Diesel's discovery, we are still experimenting with using vegetable oils in the hunt to find a more efficient, renewable fuel.