2. The fossil fuels
• Coal, oil, and gas are fossil fuels.
• Remains of plants and animals that lived
million of years ago.
• They are all from organic compounds – C.
• Give plenty of heat when burned – fuel!
• Ex. methane + oxygen carbondioxide + water + energy
(CH4 + 2O2 CO2 + H2O + energy)
3. Coal
• Dead vegetation collects on the bottom of a swamp.
• Decay stops – microbes need oxygen –oxygen
depleted.
• Vegetation buried under debris.
• Thousands of years.. Sediment piles up. Peat!
• Peat gets buried further down, more pressure, more
temp! COAL!
• The more pressure, the more temp the harder
coal!
5. Oil & gas
• Formed from the soft remains of sea plants
and animals that form on the sea floor.
• Similar stages as in the coal process.
• Oil – less dense, migrates up through rock into
oil trap.
Ocean
gasImpermeable rock
Oil
7. Fractional destillation
• Crude oil pumped in at
base.
• Compounds boil.
• Smallest compounds boil
first – rise to the top.
• Other compounds rise
part of the way.
• Heaviest stay at the
bottom.
• All depending on different
boiling points.
• The larger molecules –
less flammable, less
runny.
8. Further pocessing!
• Clean impurities – sulphur compounds.
• Some fractions devided into smaller groups –
methane, ethane, prophane…
• Cracking:
turns longer molecules into smaller
ex. have alot of naphtha but less gasoline, break
naphtha into smaller molecules!
it always procuces ethene and propene - plastics!
