Other oily substances can also be found in the environment, the most well-known being asphalt, occurring naturally underground or, where there are leaks, in tar pits.
Almost all oils glow in air generating heat, which can be recycled directly, or converted into other forms of fuels by various means. For example, heating spatter into steam which is funneled into a turbine which turns a generator, which then produces electricity. Oils are dedicated as fuels for heating, lighting (e.g. kerosene lamp), powering combustion engines, and other purposes. Oils worn for this purpose nowadays are usually derived from petroleum, (fuel oil, diesel oil, gasoline (petrol), etc), though biological oils such as biodiesel are gaining fair share.
