Energy from Organic Fuels

1. Energy from Organic Fuels F2 Coal

2. Coal • Millions of years ago, many parts of Earth that are now dry land were covered by swamps. • Warm, humid climate – ideal for plant growth. • As these plants died, their remains accumulated and, in time, were covered by sediments. • Heat and pressure produced by the weight of these sediments caused chemicalchanges to occur within the plant matter. • At the same time, water was forced out. • These processes changed the plant material into a solidrock called coal

3. Coal Formation • Coal Formation – occurs in stages over millions of years • At each stage, the plant matter loses more hydrogen and oxygen • The remaining carbon becomes more concentrated • As the carbon concentration increases, so does the amount of energy given off by burning it

4. Stages of Coal Formation • Peat– a brittle, brown plantmaterial containing a great deal of water and a low percentage of carbon • Not a form of coal • Is the firststage in the formation of coal • Compacted mass of twigs, leaves, and branches that resembles decaying wood • Located at or near Earth's surface • Gives off a large amount of smoke because of its high percentage of water and impurities

5. Stages of Coal Formation • Lignite– The second stage in coal formation • A soft, brown coal composed of about 40percent carbon • Layers of sediment are deposited on top of bedsofpeat • The heat and pressure caused by the weight of these sediments compress the peat • Forces the waterout • Burns quickly and gives off very little smoke • Located below Earth's surface and must be mined

6. Stages of Coal Formation • Bituminous Coal – a purer form of coal • A soft coal composed of about 85percent carbon • Forms deep in Earth's crust • Most abundant type of coal mined in the US • Less water and fewer impurities than lignite • Burns hotter and with even less smoke • Widely used in industry • Used by many powerplants to produce the energy needed to heat water and convert the water into steam that generates electricity. • Subbituminous Coal – a classification used for coal between the lignite stage and bituminous stage

7. Stages of Coal Formation • Anthracite Coal– Shiny, black rock with about 95percent carbon • As more sediments are added to bituminous coal, there is more heat and pressure • The pressure and heat change the sedimentary bituminous coal into a metamorphic rock • Bituminous Coal

8. Stages of Coal Formation • Anthracite Coal– Shiny, black rock with about 95percent carbon • As more sediments are added to bituminous coal, there is more heat and pressure • The pressure and heat change the sedimentary bituminous coal into a metamorphic rock • Located deeper in the ground than any of the other forms of coal • Has the least water, fewest impurities, and highest carbon content • Burns the hottest with the least amount of smoke • Most expensive form or coal

9. The Need for Energy

10. Section Review • Complete the questions in the section review