Alkanes: Modification of Alkanes by Cracking Flashcards
1
Q
Why is cracking needed?
A
- There is a shortage of shorter chain fractions and a surplus of longer chain ones found in crude oil
- The longer chain fractions are in lower demand and are less economically valuable
2
Q
Define the term cracking
A
- A process where long chain hydrocarbons are broken into smaller chain hydrocarbons
- It involves breaking C-C bonds
3
Q
What are the two types of cracking?
A
- Thermal cracking
- Catalytic cracking
4
Q
What is thermal cracking?
A
- Requires high temperature (around 1200K)
- Requires high pressure (around 7000kPa)
- Produces a large proportion of alkenes and lower proportions of branched alkanes
5
Q
What is catalytic cracking?
A
- Requires relatively lower temperatures (around 700K)
- Requires only slight pressure.
- Produces a large proportion of arenes and branched alkanes needed to produce motor fuels
- Uses a zeolite catalyst