C9 Crude Oils Flashcards
How is crude oils formed
50-100 million years ago tiny microorganisms living in warm seas died and sank to the seabed. Over time they were buried by layers of sediment. The sea evaporated, leaving layers of salt. Later more layers of sediment were departed, heat ans pressure turned the microorganisms into crude oils and nattual gases.
How do we extract crude oils
We drill dowm through layers of imperable sedement rock to reach the resevoirs of crude oils and natrual gas trapped in the rock beneath
What is crude oils a mixture of
Hydro cardbons
What is used to extract crude oil
Oil rigs
Finite
Resources that will eventually run out and will be unable to produce anymore
Biomass
A range of animals and plants that is an organic matter used for fuels
Mixture
Two or more substances that are placed together and can be physically seperated
Hydrocarbons
A compund of only hydrogen and carbon
How does fractional distilation seperate crude oils through fractions
The crude oil is heated to a vapour and pumped intona fractionating collumn which is hotter at the bottom and cool at the top. The hydrocarbons rise through the collumn and will cool and condense at the there respected boiling points.
What happens to the hydrocarbons as you go up the tower
The hydrocarbon length gets shorter
Shorter molecules
The shorter molecules means intermolecular forces have a lower boiling point and less viscous and more volitale and more flamable
Longer molecules
Longer molecules have longer molecular forces have a higher boiling point and are more viscous and less volitale and less flamable
What are alkanes
Alkanes are saturated hydrocarbons which has the maximum amount of carbons.
List the four alkanes
Methane CH4
Ethane C2H6
Propane C3H8
Butane C4H10
How to work out an alkane
Multiply the amount of carbons by 2 and then add 2
E.g. c30= 30x2+2=62 hydrogens
What are fractions produced to process
They are processed to produce fuels and feedstock
What happens during combustion
The carbon and hydrogen in the fuels are oxidised
What is combustion
The gaining of oxygen
What happens in incomplete combustion
If there is insufficent oxygen then incomplete combustion of a hydrocarbon produces carbon monoxide which is a toxig gas and water
What is the formula for insufficient combustion
CxHy+(x/2 + y/4)O2 ->xCO + y/2 H2O
What is catalytic cracking
Passing a vapour over a hot powered catalyst in catalytic cracking
What is steam cracking
Mixing the vapour with steam and heating to a high temperature which induces cracking in steam cracking
Why is steam and catalyric cracking happen
Cracking involves heating the hydrocarbon molecules to around 600-700 degrees to vapourise them. These processes break covalent bonds in tge molecules causing thermal decomposition reactions. The molecules are broken up in a random way which produces a mixture of smaller alkanes and alkenes.
What is the bromie water test
Alkane- no change in bromine water (stays brown and is saturated )
Alkene- the liquid changes to colourless (is not saturated)
What hydrocarbon is unsaturated
Alkene is the unsaturated hydrocarbon because it has a double hydrogen bond and the bond can split.
