C14 Crude oil and fuels Flashcards
What is a hydrocarbon?
Compound containing only hydrogen and carbon
How is crude oil formed?
Over millions of years from the remains of ancient biomass
What are the alkanes?
Hydrocarbons that only have single bonds
How does the boiling point of a hydrocarbon depend on chain length?
Longer chain, higher boiling point
How does viscosity depend on chain length?
The longer the chain the higher the viscosity
How can different alkanes in crude oil be seperated?
Fractional distillation
Name 5 useful fuels produced from fractional distillation
Petrol
Diesel
Kerosene
Heavy fuel oil
Liquefied petroleum gases
What is kerosene used for?
Airplane fuel
What is the most viscous remaining oil found at the bottom of a distillation tower used for?
This residue is used for making roads and roofs
What is diesel used for?
Fuels for vans, trucks and larger cars
How does the fractional distillation process work?
- Crude oil is vapourised
- Hydrocarbon gases
enter column - Hydrocarbon gases rise
rise up in the column - Hydrocarbon gases
condense at the
different temperatures - Product is collected
What is cracking?
Breaking down a hydrocarbon with long chains in to smaller more useful ones
What are the two methods of cracking?
Steam cracking
Catalytic cracking
What are the products of cracking?
Short chain alkanes and alkenes
What are alkenes?
Hydrocarbons with one double bond
What are alkenes used for?
Formation of polymers
Describe the reactivity of alkenes compared to alkanes
alkenes are much more reactive
How can you test for alkenes?
Alkenes turn orange bromine water colourless
How does catalytic cracking work?
Vaporise the hydrocarbons then pass them over a hot catalyst
How does steam cracking work?
Mix the hydrocarbons with steam at a very high temperature
What are the products of complete combustion?
Carbon dioxide and water
What conditions are needed for cracking
High temp from 300° to 900°
Steam or a catalyst
