Fractional distillation

Question 1

What is crude oil?

Answer 1

A fossil fuel , formed from the remains of plants and animals, mainly plankton that died millions of years ago and were buried in mud, over millions of years with high temp and pressure, the remains turned into crude oil which can be drilled up from the rocks where its found

Question 2

examples of fossil fuels and what type of fossil fuels are they?

Answer 2

• coal ,oil and gas are called non- renewable fuels as they are used up quicker than they are being formed = they’re finite resources

Question 3

What is crude oil (technical ) and how are they separated?

Answer 3

• mixture of lots of different hydrocarbons most are alkanes.
  The different compounds in crude oil are separated using fractional distillation

Question 4

How does fractional distillation work? step 1-2

Answer 4

1) The oil is heated until most of it has turned into gas, the gas enters a fractionating column
2) In the column there’s a temperature gradient ( Hot at bottom , cooler at top)

Question 5

How does fractional distillation work? step 3-4

Answer 5

3) Longer hydrocarbon = higher bp so they condense back into liquid and drain out of column early on when they’re near bottom , Shorter hydrocarbons = lower bp ,They condense and drain out of column later on, near the top where its cooler.

4) You end up with crude oil mixture separated out into diff fractions. each fraction contains a mixture of hydrocarbons that all contain a similar number of carbon atoms = similar bp

Question 6

order from hot to cool ( bottom to top) with approx. number of carbons

Answer 6

Bitumen ( released from bottom ) 70+
crude oil
heavy fuel oil (40)
diesel oil (20)
Kerosene (15)
petrol (8)
liquified petroleum gas (contains mostly propane and butane and at top) (3)