Fuels

1
Fuels

• LO I understand what is meant by a fuel and
  combustion.

2
A fuel is a substance that reacts with
(burns) releasing energy.
oxygen
heat

• Another word for burning is .

combustion
Burning in a plentiful supply of oxygen is called
combustion.
complete
Combustion is an , reaction
(gives out heat).
exothermic
LO I understand what is meant by a fuel and
combustion.
3
Fossil Fuels

• LO I understand how the main fossil fuels are
  formed.

4
The three main fossil fuels are

• Fossil fuels are made from the dead remains of
  animal and plant material that lived
  of years ago.

millions

• coal

• crude oil

• natural gas

Fossil fuels are a resource.
finite
One day they will run out.
LO I understand how the main fossil fuels are
formed.
5
Coal is formed from the dead remains of
, that grew in prehistoric swamps.
Formation of Coal
trees
The dead trees fell into the swamp and were
covered in .
mud
heat
pressure
millions

• The action of and over
  of years turned the remains into coal.

LO I understand how the main fossil fuels are
formed.
6
Oil is formed from microscopic plants and animals
( ) that lived in ancient oceans.
Formation of Oil
plankton
The plankton died, fell to the seabed and was
covered in layers of .
sand
heat
pressure
millions

• The action of and over
  of years turned the remains into oil.

oil
Natural gas is formed at the same time as
and sits on top of the oil trapped under a layer
of rock.
LO I understand how the main fossil fuels are
formed.
7
Global Warming

• LO I know what is meant by global warming.

8
The Greenhouse Effect
sun
All of the heat on the planet comes from the
.
This heat energy is held around the planet by the
.
atmosphere
greenhouse
This is called the effect.
cold
Without it the planet would be too at
night for life to exist.

• LO I know what is meant by the greenhouse
  effect.

9

• LO I know what is meant by the greenhouse
  effect.

10
Greenhouse Gases
Greenhouse gases trap energy.
heat
Some trap more heat than others

• water vapour

- evaporation of water.

• carbon dioxide

- breathed out by living things.
- burning of fossil fuels.

• methane

- decomposition of dead material by bacteria.

• ozone

- formed in the upper atmosphere .

• LO I know what is meant by the greenhouse
  effect.

11
average
In recent years, the temperature of the
Earth has been increasing.
This is Global Warming
What is causing this?

• LO I know what is meant by global warming.

12
Possible Reasons for Global Warming

• LO I know some possible reasons for global
  warming.

13
Carbon Dioxide
Global temperatures and carbon dioxide levels in
the atmosphere have been linked together.
higher
The higher the level of carbon dioxide, the
the temperature.
However, what is happening here?

• global warming is causing more CO2 in the air

• more CO2 in the air is causing global warming

• LO I know some possible reasons for global
  warming.

14
Global Warming Effect (Natural)
sea
Most of the Earths CO2 is dissolved in the
.
less
The higher the temperature the soluble
the CO2 becomes.
Increased solar activity is making sea
temperatures .
rise
Dissolved CO2 is coming out of the and
into the .
sea
air

• LO I know some possible reasons for global
  warming.

15
CO2 Effect (Man-made)
carbon dioxide
Burning fossil fuels produces .
Increased CO2 in the atmosphere increases the
effect.
greenhouse
Global temperatures .
rise

• LO I know some possible reasons for global
  warming.

16
Possible Consequences ofGlobal Warming

• LO I know some possible consequences of global
  warming.

17
Global warming may lead to

• more violent weather systems

- hurricanes, tornadoes, storms.

• drought

- desert areas are expanding

• flooding of coastal areas

- caused by melting ice at the poles.

• more forest fires

- due to drier, hotter conditions.
habitats
All of these effects destroy and may cause
some species to become .
extinct

• LO I know some possible consequences of global
  warming.

18
Hydrocarbons

• LO I understand what is meant by a hydrocarbon.

19
Hydrocarbons
The substances which make up oil and natural gas
are mainly .
hydrocarbons

• A hydrocarbon is a substance made from
  and only.

hydrogen
carbon
mixture
Oil as it comes from the ground is a
of different hydrocarbons.
crude
It is known as oil.
LO I understand what is meant by a hydrocarbon.
20
Extracting Oil

• LO I know how crude oil is extracted from the
  ground.

21
Crude oil forms in a layer of . rock.
porous

• The oil travels upwards until it becomes trapped
  under some
• rock.

non-porous
drilling
The oil is released by a hole through
this rock.
pressure
The crude oil is under and flows
to the surface.
More oil can be forced to the surface by pumping
or into the rock.
water
steam
LO I know how crude oil is extracted from the
the ground.
22
Separating Crude Oil

• LO I understand how the hydrocarbons in crude
  oil are separated.

23
Separating Crude Oil
Different hydrocarbons have different
points.
boiling

• The differences in the boiling points can be used
  to separate the hydrocarbons.

The crude oil is separated into parts with
boiling points within a particular range -
.
fractions
fractional
distillation
This is done using
.
LO I understand how the hydrocarbons in crude
oil are separated.
24
The Fractionating Tower

• Refinery gas

The gases rise up the tower and condense at
different levels depending on the boiling point.
Petroleum
Naphtha
Kerosene
Fuel Oil
350C
Residue
LO I understand how the hydrocarbons in crude
oil are separated.
25
The Fractions
Fraction Number of C atoms Boiling range (C) State

• Refinery gas

1-4
-160 to 20
gas
liquid
Petroleum
5-6
20 to 65
Naphtha
6-11
65 to 180
liquid
Kerosene
9-15
180 to 250
liquid
liquid
Fuel Oil
15-25
250 to 350
Residue
25
350
solid
LO I understand how the hydrocarbons in crude
oil are separated.
26
Trends in the Fractions

• LO I understand how the carbon chain length
  affects the properties of fractions.

27
As the chain length increases

• the boiling point .

increases

• the ease of evaporation .

decreases

• the flammability .

decreases

• the viscosity (thickness) .

increases
LO I understand how the carbon chain length
affects the properties of fractions.
28
Uses of Fractions

• LO I know some examples of the uses of
  fractions.

29
Most crude oil fractions are used as fuels

• Refinery gas - .

heating

• Petroleum - fuel for .

cars

• Naphtha - fuel for cars,
  .

consumer
products

• Kerosene - fuel for .

aircraft

• Fuel oil - fuel for and .

ships
lorries

• Residue - oil, and
  for roads.

lubricating
wax
tar
LO I know some examples of the uses of
fractions.
30
Pollution

• LO I understand how pollution can be caused by
  burning fossil fuels.

31
When fossil fuels are burned
sulphur dioxide

• is produced from the
  sulphur present in coal.

nitrogen oxides

• are produced in petrol
  engines.

Both of these gases dissolve in rain water
making .
acid rain
Carbon dioxide is also produced which contributes
to warming.
global
LO I understand how pollution can be caused by
burning fossil fuels.
32
Incomplete Combustion

• LO I understand how incomplete combustion
  occurs.

33
Fossil fuels burning in a limited supply of
oxygen (poor ventilation) produce

• , a toxic gas.

carbon monoxide

• , turning everything black.

soot
This is known as combustion.
incomplete
LO I understand how incomplete combustion
occurs.
34
Reducing Pollution

• LO I understand how to reduce pollution.

35
Car exhaust systems contain catalytic convertors
which

• turn harmful gases like
  and
• into less harmful
  ones.

carbon monoxide
nitrogen oxides

• contain metal catalysts.

transition
There are also lean burn engines which mix more
with the fuel.
oxygen
petrol cuts down on toxic lead.
Unleaded

• LO I understand how to reduce pollution.