6.5 Fossil Fuels

Fossil fuel combustion

Reaction with oxygen & fossil fuels that release energy as heat & produces them as products

BURNING

Hydrocarbons

Fossil fuels are burned to release energy & the carbon stored in them reacts with O2 to form CO2

Fossil fuels (hydrocarbons that release energy in the same way:

-methane

-gas

-propane

-butane

-coal

-wood & biomass work the same

Fossil fuels to generate electricity

Coal is 1 source, natural gas is 2nd

Steps of electricity generated

Heat → water into steam → steam to turbine → turbine powers generator → generator produces electricity

-coal, oil, natural gas, biomass, trash all burned to create energy

-most of energy is lost or not converted into electricity escapes as heat

Environmental consequences of coal

-Habitat destruction to clear land for mining

-producers pollutants & releases CO2 (GHG)

-release PM → irritate respiratory

Cogeneration

When heat produced from electricity generation is used to provide heat to a building

-CHP (combined heat & power) system are more efficient & better than coal or natural gas

Environmental consequences with tar sands

-habitat destruction to clear land for roads (drilling/ dogging thorough ground → biodiversity loss)

-ground or surface water depletion (H2O needed for steam & for washing impurities)

-water contamination (tailing ponds can runoff to surface water or leach into groundwater)

-CO2 released by machinery

Environmental consequences from crude oil/ petroleum

Possibility of spill (tanker ships or pipelines breaking

-spills in water → clogs fish gills → fish dies or stick to bird feathers

-spills on land → toxic to plant roots, surface or groundwater contamination

-habitat loss or fragmentation when land is cleared for roads, drilling equipment, pipelines