Images Dated 19th January 2006

Oil barrels

Oil barrels. Oil products are obtained from crude oil, which is oil from the ground before it has been refined. It contains a varied mixture of hydrocarbons, and is heated to separate it into parts called fractions. Fractions obtained from crude oil include bitumen, fuel oil, lubricating oils, diesel, jet fuel, petrol, and petroleum gases. The fractions are used as aircraft, motor vehicle and heating fuels, as industrial fuels and lubricants, and to make products such as plastics in the chemical industry. These barrels carry the logos of ExxonMobil, Royal Dutch Shell, and BP, three of the world's largest oil companies

© PAUL RAPSON/SCIENCE PHOTO LIBRARY

Vacuum pipestill at an oil refinery

Oil refinery. This is a vacuum pipestill, a distillation tower (still) where the high-boiling point part of crude oil is refined into parts (fractions) such as fuel oil and bitumen. The crude oil, a mixture of hydrocarbons, is heated to around 400 degrees Celsius and piped into the bottom of this tower in a vacuum. This lowers the boiling point of the fractions. Hydrocarbon gases from the boiling oil rise up the tower towards the coolest area at the top. Different fractions are collected at different levels, depending on their boiling point. Fuel oil is collected at a higher level than bitumen. The low-boiling point part of crude oil is refined earlier in an atmospheric pipestill. Photographed at ExxonMobil's Fawley Oil Refinery, Hampshire, UK

© PAUL RAPSON/SCIENCE PHOTO LIBRARY

Pipestills at an oil refinery

Oil refinery. Atmospheric pipestill (right) and a vacuum pipestill (left). These are distillation towers (stills) where hot crude oil is separated into parts called fractions. The crude oil, a mix of hydrocarbons, is heated to around 400 degrees Celsius and piped into the base of the atmospheric pipestill. Hydrocarbon gases from the boiling oil rise up the tower towards the coolest area at the top. The fractions are collected at different levels, depending on their boiling points. Ones with a low boiling point (petroleum gases, petrol) rise towards the top of the tower. Ones with a higher boiling point (jet fuel, diesel) condense lower down. The part that doesn't boil is sent to the vacuum pipestill, where vacuum boiling yields parts such as fuel oil and bitumen. Photographed at ExxonMobil's Fawley Oil Refinery, Hampshire, UK

© PAUL RAPSON/SCIENCE PHOTO LIBRARY