Crude oil Flashcards
what is crude oil?
a complex mixture of hydrocarbon only
how are the molecules of crude oil?
it gas molecules in which carbon atoms are in chain or rings
why is crude oil an important substance?
because it is the fuels and feedstock for the petrochemical industry
is crude oil renewable?
no, it is a finite resource that will eventually run out one day
describe how the industrial process of fractional distillation separates crude oil into fractions
- oil is heated in the fractioning column and the oil evaporates and condenses at a number of different temperatures
- the many hydrocarbons in crude oil can be separated into fractions each which contains molecules with a similar number of carbon atoms
- the fractioning column works continuously. Heated oil is piped in at the bottom. The vaporised oil rises up the column and the various fractions are constantly tapped off at the different levels where they condense
- the fractions can be processed to produce fuels and feedstock for the petrochemical industry
what are the names of the main fractions obtained from crude oil?
- refinery gases
- gasoline/ petro
- kerosene
- diesel
- fuel oil
- bitumen
what is refinery gases used for?
domestic heating and cooking
what is gasoline/ petrol used for?
fuel for cars
what is kerosene used for?
fuel for aircraft
what is diesel used for?
fuel for some cars and trains
what is fuel oil used for?
fuel for large ships and in some power stations
what is bitumen used for?
surfaces roads and roofs
what properties influence crude oil’s influence as fuels?
some properties of hydrocarbon which depend on the size of their molecules
what properties influence crude oil’s influence as fuels?
-> the shorter the molecule
- the lower the temperature at which that fraction vaporises or condenses
- the lower its boiling point
- the less viscous it is
in longer molecules where are colours darker?
at the bottom fractions
what is fuel?
a substance that releases heat energy when burned
what is produced in complete combustion?
CO1 and H2O
what is produced in incomplete combustion?
if there is not enough oxygen some fuels don’t burn. Here carbon monoxide and unburnt fuels are released
why is carbon monoxide dangerous?
it prevents red blood cells carrying oxygen around the body. This can lead to breathing difficulties and eventually death
temperatures in car engines are reached high enough to allow what?
nitrogen and oxygen from air to reach forming oxides of nitrogen
what is produced when fuels are burnt?
the sulfur is oxidised to produce sulfur dioxide
what happens when sulfur and oxides of nitrogen are emitted into the atmosphere?
they react with rain water to create H+ acids
what happens when acid rain falls?
- the acid can ruin rocks and buildings
- can also alter the pH in soil or rivers which can affect an ecosystem
what are long chain alkanes converted to in cracking?
alkenes and shorter chain of alkanes
