Alkanes from Crude Oil

Question 1

What is crude oil?

Answer 1

It is a fossil fuel - formed from the remains of marine organisms that lived millions of years ago (buried deep in the sea bed) and chemical reactions turned them into crude oil

Question 2

Crude oil renewability?

Answer 2

It is a finite resource (non-renewable) - being used up faster than it is being formed and will eventually run out

Question 3

How to make crude oil useful?

Answer 3

Complex mixture of hydrocarbons (mostly alkanes) - separated using fractional distillation (difference in boiling points)
Larger the molecules
Stringer the intermolecular forced
Higher the boiling point

Question 4

Process of fractionating column

Answer 4

Crude oil is heated and vapour piped into bottom of fractionating column - temperature gradient (hot at bottom and cold at top) and vapours cool as they rise through the column ; condense to a liquid state if they reach a part that is cool enough

Question 5

How do they leave the column?

Answer 5

Each separated part is called a fraction and each fraction contains many substances with similar boiling points : Bitumen has the highest boiling point (at bottom of column) and is in solid state at room temperature, refinery gases (methane, ethane, propane…) have lowest boiling point at top of column and leave without cooling enough to condense.

Question 6

Order of fractions - increasing boiling points

Answer 6

LPG
Petrol
Paraffin
Diesel
Heating oil
Fuel oil
Bitumen