fractional distillation of petroleum

1. Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Petroleum and Natural Gas
Many items that we use in our daily life are
actually organic compounds. These include
plastics, food, fuels, soaps, disinfectants and
even drugs!
Most of these are manufactured from
petroleum. In fact, petroleum is a mixture of
alkanes.

2. Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
How are petroleum and natural gas
formed?
Millions of years ago, tiny sea creatures and plants
sank to the sea bed when they died.
Heat and pressure acted on these organisms over
millions of years, eventually producing petroleum
and natural gas.
Petroleum and natural gas are often found
thousands of metres below the surface of the
earth. Deep wells have to be drilled to get
them out.

3. Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Petroleum
Petroleum (also called crude oil) is a dark brown,
foul-smelling liquid.
It is a mixture of different hydrocarbons.
Petroleum must be separated into fractions (or parts)
before it can be useful.
When we refine oil, we separate petroleum into
useful fractions.

4. Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Fractional Distillation of Petroleum
Petroleum can be separated by
fractional distillation in an oil refinery.
A hydrocarbon with more carbon
atoms has a higher boiling point
than one with fewer carbon atoms.
Each petroleum fraction is a
mixture of hydrocarbons which
boils over a certain temperature
range.

5. Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Fractional Distillation of Petroleum
Smaller hydrocarbons have
lower boiling points and are
collected at the top of the
fractionating column.
The bigger hydrocarbons are
collected at the lower sections of
the column.

6. Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
What happens in an oil refinery?
3. Hot vapour rises up the column
and begins to cool down.
The smaller hydrocarbons are
collected at the top of the
fractionating column as gases.
The bigger hydrocarbons are
collected at the lower sections of
the fractionating column.
1. In the furnace at the bottom of the
fractionating column, petroleum is
heated into a vapour.
2. The vapour is pumped into a huge
fractionating column.

7. Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
What happens in an oil refinery?
This fraction has the
highest range of boiling
points. It is the residue
at the bottom of the
fractionating column.
This fraction has the lowest
range of boiling points and is
distilled over first.
Petroleum gas is a mixture of
gases including methane,
propane and butane.

8. Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
The Uses of Petroleum Fractions
Ar of S = 32
Mr of MgSO4 = 24 + 32 + (16 x 4) = 120
Ar of O = 16

9. Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.
Comparison of Fuels