1. Chapter 10 Fossil Fuels

2. Overview of Chapter 10 Energy Sources and Consumption Energy Policy
Fossil Fuels
Coal
Oil and Natural Gas
Synfuels
ANWR

3. Energy Sources and Consumption
Energy sources used to be local
Now they are worldwide
Fossil fuels
Nuclear energy
Electricity
Energy consumption is different between developing and developed nations
20% of world’s population use 60% of the world’s energy sources

4. Energy Sources and Consumption
Energy density
Amount of energy contained in a given volume or mass of an energy source
Energy efficiency
A measure of the fraction of energy used relative to the total energy available in a given source

5. Energy Sources and Consumption
Per capita energy consumption of selected developed and developing countries

6. Energy Consumption in the US

7. US Energy Policy
Objective 1: Increase Energy Efficiency and Conservation
Requires many unpopular decisions
Examples
Decrease speed limit to conserve fuel
Eliminate government subsidies
Objective 2: Secure Future Fossil Fuel Energy Supplies
2 oppositions: environmental and economic

8. US Energy Policy Objective 3: Develop Alternative Energy Sources
Who should pay for this? Gas taxes?
Objective 4: Meet the First Three Objectives Without Further Damage to the Environment

9. Fossil Fuels Combustible deposits in the Earth’s crust
Composed of the remnants (fossils) of prehistoric organisms that existed millions of years ago
Includes coal, oil (petroleum) and natural gas
Non-renewable resource
Fossil fuels are created too slowly to replace the reserves we use

10. How Are Fossil Fuels Formed?
300 million years ago
Climate was mild
Vast swamps covered much of the land
Dead plant material decayed slowly in the swamp environment

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

12. Coal Most, if not all, coal deposits have been identified
Occurs in different grades - based on variations in heat and pressure during burial

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

14. 2 Types of Coal Mining Surface mining (right) Subsurface mining
Chosen if coal is within 30m of surface
Subsurface mining
Extraction of mineral and energy resources from deep underground deposits

15. Environmental Impacts of Mining Coal
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

16. Mountain Top Removal

17. Environmental Impacts of Burning Coal
Releases large quantities of CO2 into atmosphere
Greenhouse gas
Releases other pollutants into atmosphere
Mercury
Sulfur oxides
Nitrogen oxides
Can cause acid precipitation

18. Making Coal Cleaner
Scrubbers
Fluidized Bed Combustion (below)

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

20. Petroleum Refining
Numerous hydrocarbons present in crude oil (petroleum) are separated
Based on boiling point
Natural gas contains far fewer hydrocarbons than crude oil
Methane, ethane, propane and butane

21. Oil and Natural Gas Exploration
Oil and natural gas migrate upwards until they hit impermeable rock
Usually located in structural traps

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

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

24. How long will Supplies Last?
Difficult to determine and estimates vary
Depends on:
Locating more deposits
Future extraction technologies
Changes in global consumption rates
Experts indicate there may be shortages in 21st century

25. 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
Transport
Spills - especially in aquatic systems
Ex: Alaskan Oil Spill (1989)

26. 1989 Alaskan Oil Spill

27. 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

28. Case in Point - Arctic National Wildlife Refuge (ANWR)

29. Synfuel and Other Fossil Fuel Resources
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)