Petroleum

Petroleum, (from Greek πέτρα - rock and έλαιο - oil) also called crude oil, is a thick and black liquid. It is a natural material mainly made of hydrocarbons. The hydrocarbons came from many billions of ancient phytoplankton. When they died, their bodies sank to the bottom. This formed basins of oil in many parts of the world.

Most petroleum is found by drilling down through rocks on land or off-shore on the continental shelf. Major producers are in the Middle East, the Americas, and Russia. It is the most important world fuel source. It supplies 38% of the world's energy and is also used to make petrochemicals.

Crude oil is a mixture of many different chemicals (mostly hydrocarbons), most of which burn well. It is separated into simpler, more useful mixtures by fractional distillation in oil refineries to give separate chemicals such as gasoline (or petrol) for cars, kerosene for airplanes and bitumen for roads. The bitumen gives crude oil its dark black color; most of the other chemicals in crude are slightly yellow or colorless.

Petroleum can be easily transported by pipeline and oil tanker. Refined petroleum is used as fuels; mainly gasoline (petrol) for cars, diesel fuel for diesel engines used in trucks, trains and ships, kerosene fuel for jets and as lubricants.

Petrochemicals:

• alcohols
• antiseptics
• artificial rubber
• detergents
• drugs
• explosives
• food additives
• insecticides
• perfumes
• plastics
• textile fiber