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 –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 –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 21 st 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