Fractional Distillation and Cracking
- Created by: Chloe Trotter
- Created on: 19-04-16 19:39
View mindmap
- Fractional Distillation and Cracking
- Crude oil is a mixture of mainly different sized alkane hydrocarbons
- Different fractions condense at different temperatures
- This can be used to separate the different chains
- In a fractional distillation unit
- Oil is preheated and passed into a column
- Fractions will condense at different heights
- Temperature of the column decreases upwards
- Separation depends on boiling point
- Small molecules condense at the top
- Lower temperatures
- Large molecules condense at the bottom
- Higher temperatures
- Small molecules condense at the top
- In a fractional distillation unit
- Boiling point depends on the size of the molecules
- This can be used to separate the different chains
- Different fractions condense at different temperatures
- Vacuum distillation
- Lowers the pressure to lower the boiling point
- Means the heavy substances from the fractionating column can be distilled further
- Done without higher temperatures
- Lowers the pressure to lower the boiling point
- Thermal cracking
- High pressure
- 7000 kPa
- High temperatures
- 400-900
- Bonds broken anywhere in the molecule
- Happens by C-C and C-H fission
- Produces mostly alkenes
- Produces Hydrogen
- Used in the Habour process
- High pressure
- Catalytic Cracking
- Slight pressure
- Cheaper than thermal cracking
- High temperature 450
- Cheaper than thermal cracking
- Zeolite catalyst
- Crystalline aluminosilicates, clay like substances
- Produces branched and cyclic alkanes and aromatic hydrocarbons
- Used for producing motor fuels
- Slight pressure
- Cracking
- Breaking up large alkane molecules
- Into smaller alkanes and alkenes
- C-C and C=C
- C-C
- Into smaller alkanes and alkenes
- Done because the demand for smaller alkanes is higher than the supply
- Larger alkanes have a big supply
- Saves from having to extract crude oil to preserves the stock
- Breaking up large alkane molecules
- Crude oil is a mixture of mainly different sized alkane hydrocarbons
Comments
No comments have yet been made