Oil

An oil is any substance that is liquid at ambient temperatures and is hydrophobic but soluble in organic solvents. Oils have a high carbon and hydrogen content and are nonpolar substances. The general definition above includes compound classes with, and uses, including vegetable oils, petrochemical oils, and volatile essential oils. All oils can be traced back to organic sources.

Fuel

 * Main article: Petroleum

Almost all oils burn in aerosol form generating heat, which can be used directly, or converted into other forms of fuels by various means. The oil that is pumped from the ground is then shipped via oil tanker to an oil refinery. There, it is converted from crude oil to diesel fuel (petrodiesel), ethane (and other short-chain alkanes), fuel oils (heaviest of commercial fuels, used in ships/furnaces), gasoline (petrol), jet fuel, kerosene, and liquefied petroleum gas.

Electricity generation
Oil and any of its more refined products have been used to create electricity. This can be done by means of a steam engine, or by means of a turbine driven by exhaust gases. A steam engine turns the thermal energy into rotary motion, which can then be transformed into electricity, by means of a generator. In an exhaust gas turbine, the combustion products from burning the fuel expand, thereby turning a turbine. The turbine is coupled to an electric generator.

Lubrication
Due to their non-polarity, oils do not easily adhere to other substances. This makes oils useful as lubricants for various engineering purposes. Mineral oils are more suitable than biological oils, which degrade rapidly in most environmental conditions due to oxidation.