1. Chapter 11 Fossil Fuels

2. Overview of Chapter 11  Energy Sources and Consumption  Energy Policy  Fossil Fuels  Coal  Oil and Natural Gas  Synfuels  ANWR

3. Energy Sources and Consumption  Energy sources were originally found locally and 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.  Per capita energy consumption of selected developed and developing countries Energy Sources and Consumption

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)  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 CO 2 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.  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?  Difficult to determine and estimates vary  Depends on:

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.  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  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)