Chapter 11 Fossil Fuels

Energy Sources and Consumption  Energy sources used to be local  Now they are worldwide  Developing vs. developed nations  20% of world’s population use 60% of the world’s energy sources

Energy Consumption in the US

US Energy Policy  Objectives:  1: Increase Energy Efficiency & Conservation  2: Secure Future Fossil Fuel Energy Supplies  3: Develop Alternative Energy Sources  4: Meet the First Three Objectives Without Further Damage to the Environment

Fossil Fuels  Combustible deposits in the Earth’s crust  Composed of the remains of prehistoric organisms Examples: coal, oil (petroleum), and natural gas  Non-renewable resource!

How Are Fossil Fuels Formed  Coal  Heat, pressure and time turned the plant material into carbon-rich rock (coal)  Oil  Sediment deposited over microscopic aquatic organisms  Heat pressure and time turned them into hydrocarbons (oil)  Natural Gas  Formed the same way as oil, but at temperatures higher than 100 °C

Coal  Most, if not all, coal deposits have been identified

Coal  US has 25% of world’s coal supplies  Known coal deposits could last 200 years  At present rate of consumption

2 Types of Coal Mining  Surface mining (right)  Subsurface mining

Mountain Top Removal

Case-In-Point Copper Basin, TN

Acid Mine Drainage  Pollution caused when sulfuric acid and dissolved lead, arsenic or cadmium wash out of mines into nearby waterways

Surface Mining Control and Reclamation Act (1977)  Requires filling (reclaiming) of surface mines after mining  Reduces Acid Mine Drainage  Requires permits and inspections of active coal mining sights  Prohibits coal mining in sensitive areas

Environmental Impacts of Burning Coal (besides mining)  Releases more CO 2 per heat energy produced  Releases other pollutants  Mercury  Sulfur oxides  Nitrogen oxides

Oil and Natural Gas  Oil and gas provide 60% of world’s energy  They provide 62% of US’s energy

Petroleum Refining  Numerous hydrocarbons present in crude oil (petroleum) are separated  Natural gas contains far fewer hydrocarbons than crude oil  Methane, ethane, propane and butane

Oil and Natural Gas Exploration  Oil and natural gas migrate upwards until they hit impermeable rock

Oil Reserves  Uneven distribution globally  More than half is located in the Middle East

Natural Gas Reserves  Uneven distribution globally  More than half is located in Russia and Iran

 Locating more deposits  Future extraction technologies  Changes in global consumption rates  Experts indicate there may be shortages in 21 st century How long will Supplies Last?  Depends on:

1989 Alaskan Oil Spill  Exxon Valdez hit a reef and spilled 260,000 barrels of crude oil into sound  Largest oil spill in US history  Led to Oil Pollution Act of 1990 Not any more!

Deepwater Horizon Oil Spill

Environmental Impacts of Oil and Natural Gas  Combustion  Increase carbon dioxide and pollutant emissions  Natural gas is far cleaner burning than oil  Production  Disturbance to land and habitat  Roads  Temporary jobs- leads to logging and cattle ranching  Transport  Spills - especially in aquatic systems  Ex: Alaskan Oil Spill (1989)

Case in Point - Arctic National Wildlife Refuge (ANWR)

Synfuel and Other Fossil Fuel Resources  Synfuel  Synthesized fuel from coal and other naturally occurring sources  Used in place of oil or natural gas  Include:  Tar sands  Oil shales  Gas hydrates  Liquefied coal  Coal gas (right)