PetroleumChapter 10

Notes

Petroleum• Fossil fuel

–Formed hundreds of millions of years ago from dead plants & animals which were subjected to great heat and pressure

–Found buried in layers of clay, mud, silt, or sand, often at the bottom of water (which may be gone now)

Petroleum

• Fuels made from petroleum provide nearly half the energy used in the world

• Petroleum is also responsible for the production of thousands of products we use in our everyday lives

Petroleum

• Non-renewable resource

• Cannot be replaced at the rate at which it is being used

Petroleum• Petroleum is sometimes found as a

solid in rocks & sand, but more often it is in liquid form

• This liquid can come in a variety of colors (black, dark brown, green, red, yellow, even colorless)

• It also has a variety of thicknesses that control its viscosity – the rate at which it flows

• These depend on the substances that make up the petroleum

One form of petroleum, CRUDE OIL, cannot be used right from ground.

• Petroleum must first be separated into its useful parts by fractional distillation

Fractional Distillation:

–Liquid is heated until it vaporizes (changes into a gas)

–Then the gas is cooled until it condenses (changes back into a liquid)

–Since different parts or fractions boil at different temperatures, each fraction will vaporize & thus condense at a different time

• Fractional distillation (a.k.a. refining) occurs in fractionating towers

• At the refinery, towers may rise up to 30 meters tall and be heated to 385o C – the temp. at which petroleum vaporizes

FractionatingTower

1. Hydrocarbons have different boiling points according to the number of carbon atoms and how they are arranged

2. The crude oil is heated and the resultant vapors rise up the tower

The Process

3. The vapors cool as they rise and condense onto trays

4. The lightest compounds condense at the top of the tower and are taken off as LPG (liquefied petroleum gas)

Products from distillation

• Liquid gas

• Gasoline, jet fuels, diesel fuel

• Fuel oil, kerosene

• Chemical petroleum – plastics, fabrics

• Lubricants

• Wax

• Asphalt