Fuels Flashcards
What are hydrocarbons?
Compounds that contain hydrogen and
carbon atoms only.
What is crude oil?
- Acomplex mixture of hydrocarbons.
- Contains molecules with rings or chains of carbon
atoms. - An important source of useful substances like fuels
and feedstocks for the petrochemical industry. - Afinite resource.
Where can crude oil be found?
Under the sea and ground.
What does it mean when crude oil is described as
‘finite’?
It will run out.
How can crude oil be separated?
Fractional distillation
How does the process of fractional distillation work
to separate crude oil?
- Crude oil is vaporised before it enters a fractionating column.
- The fractionating column is hotter at the bottom than at the
top. The vapours rise up and condense at different fractions
depending on their boiling points. - Hydrocarbons with low boiling points will be tapped off the
top of the column and hydrocarbons with high boiling points
will be tapped off the bottom of the column
Why is crude oil separated?
Unseparated crude oil isn’t very useful
but the separated products (such as
petrol) are very useful
Refinery gas is a fraction of crude oil. What are its
common uses?
Heating and cooking
Which fraction of crude oil is used as fuel in cars?
Petrol (gasoline).
Diesel is also less commonly used
Kerosene is a fraction of crude oil. What is a
common use of kerosene?
Aircraft fuel
Diesel oil is a fraction crude oil. What is it commonly
used for?
Fuel for some cars and trains.
Which fraction of crude oil is used for road surfacing
and roofs?
Bitumen
Fuel oil is a fraction of crude oil. What is it commonly
used for?
Fuel for large ships and in some power
stations.
How do the hydrocarbons at each faction differ?
- Boiling points.
- Ease of ignition.
- Viscosity.
- The number of hydrogen and carbon atoms their molecules have
Where in the fractionating column do hydrocarbons with the highest viscosity condense?
Viscosity is how thick and sticky a substance is.
The hydrocarbons with the highest viscosity
(like bitumen) are collected at the bottom of the
fractionating column.
What are the properties of hydrocarbons that are
tapped from the top of the fractionating column, like
petrol and refinery gas?
- Low boiling point.
- Highly volatile.
- Easily ignited.
- Shorter carbon chains (small molecules).