Chapter 15 “Organic Fuels”

1. Chapter 15 “Organic Fuels” Mrs. Paul Environmental Science Pgs 234 - 249

2. “The Need for Energy” • Many forms of energy to meet the needs of people on Earth. • Heat, light, energy, mechanical energy, chemical energy, nuclear energy. • Energy cannot be created or destroyed, only changed from one form to another.

3. Example: • Energy from the sun converted to chemical energy stored in plants. • When you eat, the stored energy is converted to heat, mechanical energy, and chemical energy used to carry out life processes. • Food is a form of fuel that your body uses for energy.

4. Fuels from Organisms • Called organic fuels. • Contain carbon-based molecules formed by living things as well as carbon. • Hydrocarbon: compound made of only carbon and hydrogen. • Example: methane, ethane, octane • Many organic fuels contain other chemicals as well (considered to be impurities in fuel).

5. Fuel: any substance from which energy can be obtained. • Fossil fuel: remains of ancient organisms that changed into coal, oil, or natural gas. • Central to life in modern societies. • 2 main problems: • 1. supply of fossil fuel is limited. • 2. obtaining and using them causes environmental problems.

6. 5 main purposes of fuels: • 1. cooking • 2. transportation • 3. manufacturing • 4. heating and cooling buildings • 5. generating electricity to run appliances. • How suitable the fuel is depends on: • Energy content, cost, availability, safety, and byproducts of use.

7. Electricity-Power on Demand • Energy in fuel often converted into electrical energy to power machines. • More convenient to use than coal, etc. • How is electricity generated? • Electric Generator: machine that converts mechanical energy (motion) into electrical energy. • Do this by moving electrically conductive material inside a magnetic field.

8. Most electric generators convert the movement of a turbine into electrical energy. • Turbine: wheel that changes the force of a moving gas or liquid into energy that can do work. • Usually, steam turns the turbine.

10. Coal fired power plant

11. Energy Use • World Patterns • People in developed societies use more energy than people in developing countries. • Differences within developed countries too. • Ex: Canada/US uses 2x that of Japan or Switzerland. • Energy Use in the United States • Uses more energy than all except Canada and United Arab Emirates. • Uses more than 25% to transport goods and people by truck and personal vehicle. • Lowest fuel cost = little incentive to conserve. • Japan and Switzerland have minimal fossil fuel and supplement with other energy sources.

14. Check for Understanding: Give 2 reasons why the United States uses more energy per person compared with most other countries.

15. How Fossil-Fuel Deposits Form Not distributed evenly.

16. Coal Formation • Forms from remains of plants that lived in swamps • Much in US formed 320 to 300 million years ago (vast swampland covered eastern US). • Coal in western US only 100 – 40 million years ago. • Ocean levels rose and fell = swamps covered with sediment. • First forms Peat: brittle, brown plant material containing a great deal of water and low percentage of carbon. • Layers of sediment compress the peat into lignite: soft, brown coal composed of about 40% carbon; it burns quickly and gives off little smoke. • Sediment compressed plant remains and heat and pressure within Earth’s crust caused coal to form.

17. Peat

18. Lignite

19. Oil and Natural Gas Formation • Result from decay of tiny marine organisms that accumulate on bottom of ocean millions of years ago. • Remains buried by sediments and heated = became complex energy-rich carbon-based molecules. • Molecules migrated into porous rocks.

22. Coal • Most of fossil fuel reserves made of coal. • ½ of electricity in US comes from coal fired plants • Advantages: • Inexpensive • Need little refining after mining.

23. Coal Mining and the Environment • Underground = minimal effect at surface. • Surface mining • Remove top of entire mountain to reach coal. • Toxic chemicals can leach into nearby water sources. • Air Pollution • High grade coal produces less pollution and more heat. • Ex: bituminous coal: soft coal located deep in Earth’s crust • Anthracite coal: metamorphic rock made when extreme pressure and heat act on bituminous coal. Clean-burning and almost smokeless; fewest impurities of all coal. • Low grade coal produces more pollution and less heat • Ex: lignate

24. Sulfur found in coal = pollution

25. Petroleum • Petroleum: oil that is pumped from the ground, aka crude oil. • Petroleum product: anything made from crude oil. • Ex: fuels, chemicals, plastics • Accounts for 45% of world’s commercial energy use. • Nonrenewable resource.

26. Locating Oil Deposits • Found in and around geologic features (folds, faults, salt domes) that trap oil as it moves in Earth’s crust. • Exploration wells drilled to determine volume and availability of deposit. • Wells drilled and oil pumped or flows to surface. • Oil transported to refinery to convert to fuel and other petroleum products.

27. Natural Gas • 20% of nonrenewable energy comes from natural gas. • Methane • Recovered from many oil wells. • Produces fewer pollutants than other fossil fuels.

28. Fossil Fuels and the Future • Fossil fuels supply 90% of the energy used in developed countries. • It is projected that by 2050, our energy needs will have DOUBLED. • Predicting Oil Production • Still increasing, but slowly. • Factors considered in oil predictions: • Oil Reserves: oil deposits that can be extracted profitably at current prices using current technology.

29. Some oil deposits have not been discovered or become commercial. • Changes in technology to allow more oil to be extracted. • Relative cost of obtaining oil. • Future Oil Reserves • Geologists predict that oil production from fields accessible from land will peak in 2010. • Additional oil under ocean floor = more expensive.

30. The Environmental Effects of Using Oil • Pollution released into the air. • Contribute to formation of smog and cause health problems. • Carbon Dioxide released may contribute to global warming. • Oil spills

31. Biomass Fuels • Biomass Fuels: a fuel formed from the products of living organims. • Ex: wood, garbage, methane, alcohol. • Renewable resources • Garbage • The materials you throw away; composed mostly of organic material. • 2/3 of material in it can be burned; some cities burning garbage to generate electricity.

32. Methane • Swamp gas produced in swamps from decaying plants. • A naturally produced form of methane. • Alcohol • Bioconversion: conversion of organic materials into fuels. • A hydrocarbon in which one of the hydrogens is replaced with an oxygen-hydrogen group.