BI 105A Environmental Biology

1. BI 105AEnvironmental Biology Professor Jill Nissen Montgomery College Fall 2006

2. Chapter 11 Fossil Fuels

3. Energy use in highlydeveloped countries • Only 20% of the world’s population lives in highly developed countries • These people use 60% of the world’s commercial energy • Each person in highly developed countries uses 8 times as much energy as each person in a developing country!

4. Energy in U.S. • U.S. has 4.6% of world population; uses 24% of the world’s commercial energy; • 86% from nonrenewable fossil fuels (63% oil & natural gas, 23% coal); • 8% from nuclear power; • 6% from renewable sources (hydropower, geothermal, solar, biomass).

5. Energy in U.S. • In 1973, 35% of the oil used in the U.S was imported • Today, U.S. imports 55.5% of its oil (12.9% from the Persian Gulf region) • The U.S Department of Energy estimates that by 2015, 100% of our oil will be imported

6. Changes in U.S. Energy Use Fig.19–4, p. 499

7. Coal formed from partially decomposed plant material exposed to heat and pressure for aeons

8. Sources & Uses • Most of the world's coal reserves are in the Northern Hemisphere, mainly the U.S.(25%), Russia, China, Australia, India, Germany, and South Africa. • Supplies 24% of world's commercial energy (23% in U.S.); • China largest user; U.S. second largest user.

9. Advantages and Disadvantages of Using Coal Advantages • most abundant fossil fuel; • major U.S. reserves, could last more than 200 years at current consumption rates; • high net energy yield; Disadvantages • dirtiest fuel, highest carbon dioxide; • Pollutants in coal are major threats to human health • Mining coal causes major environmental degradation, and there are significant human safety and health risks in the mining process

10. Making Coal a Cleaner Fuel • Scrubbers – chemicals in scrubber react with pollutants in exhaust to remove 98% of sulfur and 99% of particulate matter • Fluidized-bed combustion – as the coal burns, limestone neutralizes most of the SO2 in the coal

11. Oil and Natural Gas formed from large numbers of microscopic aquatic organisms that died and settled in oxygen-deficient sediments

12. Extraction & Processing Crude oil and natural gas are often trapped together Extraction: • primary - drill & pump • secondary - inject H2O • tertiary - inject steam or CO2 • refine to separate components based on different boiling points (Fig. 11-9) • transport by tanker, truck, pipeline

13. Oil • petroleum, or crude oil is acomplex liquid mixture of hundreds of hydrocarbon compounds, with small amounts of S, O, N impurities; • Supplies 61.5% of the energy used in the world (63% in U.S.);

14. Advantages and Disadvantages of Using Conventional Oil Advantages • low cost • high net energy yield • easily transported Disadvantages • Production is declining, and the supply will be depleted within 50–100 yrs • pollution & environmental degradation.

15. Natural Gas • mixture of only a few different hydrocarbons: mostly methane with smaller amounts of ethane, propane, and butane; • propane & butane are removed asliquefied petroleum gas (LPG) • Use of natural gas is increasing in 3 main areas – generation of electricity, transportation, and commercial cooling

16. Advantages and Disadvantages of Using Natural Gas Advantages • low cost; • reserves 65–80 yrs for U.S., 125 years for world at current consumption rates; • easy to transport by land via pipelines; Disadvantages • transport difficult (must be converted to LNG); • pollution & environmental degradation.

17. Oil in U.S. • Has 2.3% of world reserves, but • Uses nearly 30% of world reserves; • 65% for transportation; • increasing dependence on imports.

18. Sources • Organization of Petroleum Exporting Countries (OPEC) -- 13 countries have 65% world reserves: Algeria, Ecuador, Gabon, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates, & Venezuela • Almost half the recoverable reserves are in 2 countries, Russia and Iran

19. Global Oil Demand and Supply

20. Synfuels Naturally occurring liquid or gaseous fuels that substitute for oil or natural gas • Tar sands, also known as oil sands • Oil shales • Gas hydrates, methane hydrates • Coal liquefaction • Coal gasification Problem: these all still produce CO2

21. A National Energy Strategy Needed because: • The supply of fossil fuels is limited • The production, transport, and use of fossil fuels pollute the environment • Our heavy dependence on foreign oil makes us economically vulnerable

22. A National Energy Strategy Must have the following objectives: • Increase energy efficiency and conservation • Secure future fossil fuel energy supplies • Develop alternative energy sources • Accomplish the first three objectives without further damaging the environment

23. Current National Energy Policy Developed by President Bush (p. 250) 5 components: • Modernize conservation • Modernize energy infrastructure • Increase energy supplies • Accelerate the protection and improvement of the environment • Increase our nation’s energy security

24. Review Objectives Energy Consumption • Compare per capita energy consumption in highly developed and developing countries. Fossil Fuels • Define fossil fuel, and distinguish among coal, oil, and natural gas. • Describe the processes that formed coal, oil, and natural gas. Coal • Discuss the advantages and disadvantages, including environmental problems, of using coal. • Explain how scrubbers and fluidized-bed combustion make coal a cleaner fuel. Oil and Natural Gas • Discuss the advantages and disadvantages, including environmental problems, of using oil and natural gas. • Briefly describe U.S. dependence on foreign oil. Synfuels and Other Potential Fossil Fuel Resources • Define synfuel and list the five kinds of synfuels. • Briefly consider the environmental implications of using synfuels. The U.S. Energy Strategy • Relate three reasons the U.S. needs a comprehensive national energy strategy. • Briefly describe the National Energy Policy of the George W. Bush administration.