chapter 18 fossil fuels and the environment. fossil fuels forms of stored solar energy created from...

Chapter 18

Fossil Fuels and the Environment

Fossil Fuels

Forms of stored solar energy created from incomplete biological decomposition of dead organic matter

Buried (swamp-like environment) and oxidized

• Crude Oil• Natural Gas• Coal

Crude Oil• Crude Oil

– Naturally occurring petroleum, normally pumped from wells in oil fields (primary production)

• secondary production: steam or CO2 injected to push oil up

– Refinement of crude oil produces most of the petroleum products we use today

Natural Gas

• Natural Gas– Naturally occurring

gaseous hydrocarbon generally produced in association with crude oil or from gas wells

– An important efficient and clean burning fuel (cleaner than oil) commonly used in homes and industry

Oil in the 21st Century

• The U.S has an energy problem caused by dependence on fossil fuels, especially oil

• Maximum global production is expected between 2020 and 2050

• The challenge is to plan for the decline in oil supply and shift to alternative energy sources

Methane Hydrates

• White ice-like compound made up of molecules of methane gas

• Trapped in “cages” of frozen water in the sediments of the deep seafloor or within areas of permafrost

• “transitional” fuel source– combustion produces less CO2 than

conventional fossil fuels

• Coal-bed methane

Environmental Effects of Oil and Natural Gas

• Recovery: damage to fragile ecosystems, water and air pollution, land subsidence, and waste disposal

• Refining: soil, water and air pollution• Delivery and Use: energy to power

automobiles, produce electricity, etc.

Arctic National Wildlife Refuge

• Pristine wilderness area in Alaska with large oil reserve

• Favor of:– oil is needed– create jobs– new tools and

drilling practices means less impact

Arctic National Wildlife Refuge

• Against drilling:– should remain as a

wilderness– ice roads require

much water from ponds

– heavy vehicles will scar the open tundra

Coal

• Solid, brittle, carbonaceous rock that is one of the world’s most abundant fossil fuels.

• Classified according to energy content as well as carbon and sulfur content– low sulfur coal emits less sulfur dioxide, so

more desirable– high sulfur coal: acid rain (burned) and acid

mine drainage (water in mines)

Coal Mining and the Environment

• Strip Mining– A surface mining

process in which the

overlying layer of

soil and rock is

stripped off to reach

the coal-acid mine drainage

-erosion

-sediment pollution

• Underground Mining– Associated with environmental problems

including acid mine drainage, land subsidence and coal fires

- spoil piles

- mine collapse

- mine fires

• Transport of Coal– freight trains; coal-slurry pipelines

• The Future of Coal– 90% of fossil fuel reserves– Scrubbing: removes sulfur dioxides; lower

temperature (reduce air pollution)

• Allowance Trading– Reduces pollution– EPA grants utility companies tradable

allowances for polluting

Oil Shale and Tar Sands

• Oil Shale– A fine-grained sedimentary rock– exceeds global reserves of oil– The oil is a synfuel– requires much energy to extract and make

usable; not competitive with cost of crude oil or other conventional fossil fuels

• Tar Sands– Sedimentary rocks or sands impregnated with

tar oil, asphalt or bitumen