6.21 - Alkanes from crude oil

Question 1

What are the three main processes used to convert crude oil into fuels?

Answer 1

• Fractional distillation
• Cracking
• Reforming

Question 2

What is crude oil a mixture of?

Answer 2

Hydrocarbons of different chain lengths

Question 3

What is fractional distillation done in?

Answer 3

A distillation column

Question 4

What is the method for fractional distillation?

Answer 4

• Heat the crude oil to make it into a vapour
• Short chains will evaporate and condense first
• Allowing them to be collected separately to the other compounds

Question 5

Why is cracking done?

Answer 5

Because the demand is low for long-chain hydrocarbons but very high for shorter chains

Question 6

What is the process of cracking?

Answer 6

Splitting a long chain hydrocarbon into 2 smaller ones

Question 7

How is cracking carried out?

Answer 7

Passing the long-chain hydrocarbon over a heated catalyst, usually zeolite, causing it to split

Question 8

What is reforming?

Answer 8

The conversion of straight-chain hydrocarbons into branched-chain and cyclic hydrocarbons

Question 9

Why is reforming done?

Answer 9

Because straight-chains burn less efficiently than branched-chains and cyclic compounds