Crude Oil Flashcards
Explain why sulfur compounds found in crude oil should be removed from the fractions before they’re used for central heating?
In combustions SO2 is produced which can cause acid rain
How are large hydrocarbon molecules broken down?
The large hydrocarbon molecules are fed into an oxygen less (to prevent combustion of the hydrocarbon to H2O and CO2) steel chamber and heated to a high temperature and then passed over an aluminium oxide (Al2O3) catalyst
What are the two products formed in incomplete combustion
CO and H2O
What are the two products formed in complete combustion?
CO2 and H2O
How can you utilise SO2 that is produced as a waste product of combustion
You can react CaO which is basic with the SO2 acid in an acid neutralisation reaction which produces CaSO3 which can be further reacted to CaSO4 which can be used in plastering
What catalysts are used in a catalytic converter?
Pt or Rh
Why is a catalytic converter used
Because in combustion of nitrogen NO is produced which is very toxic, can cause respiratory problems as well as acid rain so a CC is used to break it down
Write 2 equations that display how a catalytic converter breaks down NO
2NO —> N2 + O2
2NO + 2CO —> N2 + CO2
What problems do unburnt hydrocarbons cause?
Respiratory problems
What is produced when a large hydrocarbon is cracked?
When a large hydrocarbon is cracked, a smaller alkane and one (or more) alkene molecules are formed
Name and define the two types of cracking
Thermal cracking requires high temperatures (up to 1000 oC) and high pressure (up to 70 atmospheres) and produces alkanes and a lot of alkenes
Catalytic cracking uses a lower temperature (around 450 oC) and slight pressure in the presence of a catalyst such as a zeolite or aluminium oxide to produce mainly aromatic hydrocarbons
Cracking is an __________ reaction
Endothermic
