fossil fuels

how old is earth?

4.56 Ga

examples of fossil fuels

coal, oil, natural gas

are fossil fuels renewable or nonrenewable

nonrenewable

nonrenewable

consumed by humans faster than they can be replenished through geological processes

renewable energy sources

biomass, hydroelectric, solar, wind, tidal and wave, geothermal

why is nuclear energy not renewable

it relies on finite resources like uranium

hydrocarbon

organic chemicals that consist of chain or ring like polymers made of carbon and hydrogen atoms

short polymer chains

less viscous and more volatile, gas

long chains

more viscous and less volatile, solid

intermediate chains

liquid

beginning of oil formation

organic material is well preserved, lithified, warms up, chemical reactions take place (kerogen)

at 90C…

kerogen molecules break into smaller oil and natural gas molecules

at 160C…

any remaining oil breaks down into natural gas

above 225C…

organic matter loses all its hydrogen and transforms into graphite

oil window

narrow range of temperatures (90-225 C) that forms oil

oil trap

migration of oil into reservoir rock

porosity

the overall amount of open space in a rock

permeability

degree to which pores or cracks connect to each other

rocks with […] make the best reservoir rocks

high porosity and permeability

how easy is it to extract oil?

relatively easy

best source rocks

organic rich, often black shales

best reservoir rocks

high porosity, high permeability, highly fractured

best seal rocks

impermeable, non fractured

three types of coal

low, intermediate, high rank

how does lignite form?

during burial at temperatures of less than 100C

rank of lignite

low rank, 60-70% carbon

how does bituminous coal form?

during burial, at temperatures between 100-200C

what rank is bituminious coal

intermediate, 70-80% carbon

how does anthractie form?

during burial, at temperatures between 201-300C

rank of anthracite

high rank, 90% carbon