4b Flashcards
1
Q
Crude oil
A
Mixture of hydrocarbons
2
Q
Crude oil separation
A
- It is heated, vaporised in a fractional distillation tower (hotter at the bottom, cooler at the top)
- Gases travel until the temperature is lower than the boiling point, then they turn into a liquid
(except natural gases, which stay as gases and bitumen that comes off at the bottom and never turns into a gas)
The boiling point and viscosity decrease as you go down
Flammability increases as you go up
3
Q
Crude oil fractions
A
- Natural gases
- Petrol / Gasoline
- Kerosine
- Diesel
- Fuel oil
- Bitumen
4
Q
Natural gases
A
Home heating
5
Q
Petrol / Gasoline
A
Car fuel
6
Q
Kerosene
A
Plane fuel
7
Q
Diesel
A
Bus/Lorrie fuel
8
Q
Fuel oil
A
Boat/Power station fuel
9
Q
Bitumen
A
Roads
10
Q
Fuel
A
A substance that releases energy when burnt
11
Q
Nitrogen oxide formation
A
- In car engines
- If the temperature is high enough, Nitrogen in the air reacts with oxygen to form nitrogen oxygen
12
Q
Sulfur dioxide formation
A
- Fuels can contain impurities such as sulfur
- When these impure fuels are burnt, sulfur dioxide is produced
13
Q
Cracking
A
Spliting larger alkanes(less value) into smaller alkanes(more value) and alkenes (and/or hydrogen)
Requires: Heat(600-700 ºC), Catalyst(silica or alumina)
Longer alkane –> Shorter Alkane + Alkene
14
Q
Why is cracking useful
A
- Produces smaller, more valuable in demand hydrocarbons.
- Less demand for longer alkanes
- That are used for fuels or polymers
