4.5.1 Crude oil Flashcards
Why does crude oil boil over a large range of temperature?
Different hydrocarbons in crude oil come in a huge variety of shapes and sizes.
What is crude oil?
Crude oil is a mixture of hydrocarbons, compounds of hydrogen and carbon only.
Why do we separate crude oil?
Most of the hydrocarbons are useful, but often for different purposes. We separate the oil into fractions which contain similarly used molecules.
What is a fraction of crude oil?
A mixture of similar hydrocarbons with similar boiling points.
As boiling points increase:
- Fractions get … in colour
- Fractions get … (like treacle)
… darker…
… more viscous …
What are properties and uses of refinery gases?
BP - low
Molecular Mass - low
Colour - light
Viscosity - low
Use - fuel for home cooking
What are properties and uses of gasoline?
BP - lowish
Molecular Mass - lowish
Colour - lightish
Viscosity - lowish
Use - fuel for cars
What are properties and uses of kerosene?
BP - medium
Molecular Mass - medium
Colour - medium
Viscosity - medium
Use - fuel for aircraft
What are properties and uses of diesel?
BP - medium
Molecular Mass - medium
Colour - medium
Viscosity - medium
Use - fuel for trains
What are properties and uses of fuel oil?
BP - highish
Molecular Mass - highish
Colour - darkish
Viscosity - highish
Use - fuel for ships
What are properties and uses of bitumen?
BP - high
Molecuclar Mass - high
Colour - dark
Viscosity - high
Use - making roads
What is fractional distillation?
Fractional distillation is a method to separate the components of crude oil. There is a fractional column that is hotter at the bottom and colder at the top.
How does fractional distillation work?
- Heated crude oil vapours enter the column.
- Vapours rise until they reach their boiling point, where they condense.
- Different vapours condense at different heights due to their different boiling points.
- Similar vapours condense together at a fraction.
Fractions are mixtures containing the hydrocarbons that boil in a particular temperature range.
What is the order of crude oil from the lowest boiling point?
Refinery gases
Gasoline
Kerosene
Diesel
Fuel oil
Bitumen
