Source: https://senecalearning.com/en-gb/definitions/cracking/

# Cracking

Cracking is the process of converting alkanes into alkenes and shorter alkanes. We crack alkanes because the shorter chain alkanes are more valuable (they are used as fuel).

## Thermal cracking

- Thermal cracking uses harsh conditions like high temperature and high pressure.
- It breaks the alkanes into a high percentage of alkenes and comparatively few alkanes.
- Thermal cracking is done at about 1,000 degrees Celcius and 70 atm pressure.

## Catalytic cracking

- Using a catalyst allows you to lower the temperatures and pressures needed for the reaction. This reduces costs and makes the reaction faster.
- Catalytic cracking is done at 450 degrees Celcius and only just above atmospheric pressure.
- The catalyst we use is called a zeolite. This is an ionic compound containing aluminium, silicon, and oxygen.
- You tend to get molecules containing benzene rings and short hydrocarbons.