FOSSIL FUELS: NON-RENEWABLE ENERGY RESOURCES

Fossil Fuels

•Fossil fuels are organic compounds•They are high energy

• Have obtained energy from photosynthesizing organisms that lived millions of years ago

•Consist primarily of compounds called hydrocarbons (hydrogen & carbon)

Coal!

• Produced from remains of plants millions of years ago in anaerobic environments such as swamps

• Much of coal was formed during the Pennsylvanian era

• Created under specific conditions• Organic material trapped under water• Heat and pressure applied very slowly over a long period of time

Creating Coal….

Coal…depending on heat & pressure!

Types of Coal – Peat

• Partial decomposition of plant remains• Produces brownish-black material

Types of Coal - Lignite

•Peat deposits covered by layers of sediment

•The weight of overlying sediments squeezes out water & gases from the peat

•Lignite is less dense than peat

Types of Coal – Bituminous Coal

• Known as soft coal• More sediments deposited & further compresses lignite

• Bituminous coal is the most abundant type of coal• Has a shiny luster, more so than lignite

Types of Coal - Anthracite

• The hardest of all coal types• Formed because of extremely high temperatures and pressures due to the folding of Earth’s crust• Bituminous coal anthracite coal

Energy from Coal

•When bituminous coal and anthracite coal are burned, they produce a lot of energy

•Bonds in hydrocarbons are high energy, so breaking them releases it

Petroleum & Natural Gas• Formed mostly from microorganisms that lived in oceans

or large lakes millions of years ago• Petroleum (oil) is made of hydro carbons in the liquid form• Natural gas is also made of hydrocarbons, in the gaseous

form

Petroleum Formation• Microorganisms die in shallow oceans or lakes• Remains of these organisms accumulate on ocean floor & in lake sediments• Is this environment aerobic or anaerobic?• ANAEROBIC

Petroleum Formation

• Organic remains buried by sediment• Limited oxygen supply needed for decomposition

• Prevention of OXIDATION• Decomposition does not occur.

• As more sediments accumulate, heat & pressure on organic remains increases

• When the heat & pressure is great enough, chemical changes occur to the molecules and convert the organic material in petroleum or natural gas

Oil Traps

• Oil collects between interconnected rock particles of sedimentary rocks (these are permeable)

• The weight of overlying rocks forces water & hydrocarbons out of pores and up through layers of permeable rock

• This flow continues upward until they meet an impermeable rock – called a cap rock, usually shale

Oil Reservoirs

• Hydrocarbons that accumulate beneath cap rocks form a reservoir of oil by saturating all spaces between the rock particles

• Petroleum is less dense than water, so what happens to it if it is mixed with water?• It floats on top of it!

• Natural gas is less dense than petroleum so it floats on top of petroleum

Natural Gas

• Primarily composed of methane (CH4)

• Other components include:• Carbon dioxide• Nitrogenous compounds• Hydrogen sulfide

• Burns cleaner than other petroleum products• Releases less carbon dioxide than oil or coal

• Also produces less secondary pollutants than oil or gas

Renewable Resources

•Wind•Hydroelectric Power (HEP)

•Dam it

•Solar Power•Wave Power•Geothermal energy•Biomass energy