C.9 Crude oil and fuels EOY10 Flashcards
(17 cards)
What is crude oil
- finite resource found in rocks
-remains of an ancient biomass consisting mainly of plankton that was buried
in mud - mostly hydrocarbons
What is a hydrocarbon
A substance made up of hydrogen and carbon atoms only
Steps to fractional distillation of crude oil
- Crude oil is heated to vaporise it
- Vapour passed into fractionating column
- Top of column cooler than bottom
- fractions separated by b.p as they condensed at different temperatures
- low boiling fractions at the top
- high boiling point at bottom
Are alkanes saturated
Yes
-single covalent bonds
- As many hydrogens as possible
First 4 alkanes
Methane
Ethane
Propane
Butane
What type of hydrocarbons are mostly found in crude oil
alkanes
general formula for alkane
CnH2n+2
What length of hydrocarbon are the most useful
Short chain
Short chain hydrocarbon properties
Boiling point: Low
Volatility: High
Viscosity: Low
Flammability: High
Long chain hyrdocarbon properties
Boiling point: High
Volatility: Low
Viscosity: High
Flammability: Low
Complete Combustion Vs Incomplete
Complete
- Fully oxides carbon and hydrogen (enough oxygen)
- Produces water + CO2
Incomplete
- Not fully oxides (not enough O2)
- Product water + CO / C
Why is cracking done
- Large molecules are less useful and not in as much demand
- Cracking them turns them into shorter molecules
- More useful and in more demand
what are the two types of cracking
steam and catalytic
Steam cracking conditions
-High temp (750)
- Steam (H2O gas)
Catalytic Cracking conditions
- Zeolite catalyst
- High temp (lower than steam)
What is an alkene
- Unsaturated Hydrocarbon
- General formula: CnH2n
Products of cracking
Smaller alkanes and alkenes
