Nonrenewable Energy Sources

Transcription

1 Nonrenewable Energy Sources Fossil Fuels and Nuclear Energy This Photo by Unknown Author is licensed under CC BY-SA

2 Nonrenewable Energy Fossil Fuels coal, oil, natural gas Nuclear Fuels Uranium-235, Plutonium-239

3 Energy Use Commercial Energy Sources Those that are bought and sold Examples: coal, oil, natural gas Subsistence Energy Sources Those gathered by individuals for their own use Examples: wood, charcoal, animal waste This Photo by Unknown Author is licensed under CC BY-SA This Photo by Unknown Author is licensed under CC BY-SA

4 Process of Electricity Generation 1. Burning fuel transfers energy to water which is heated to steam 2. Kinetic energy contained within the steam is transferred to the blades of a turbine 3. As the turbine is turned by the steam, the shaft in the center of the turbine turns a generator 4. This mechanical motion generates energy

5 Process of Energy Use This Photo by Unknown Author is licensed under CC BY-NC-SA

6 Energy Efficiency Most coal burning power plants are about 35% efficient Cogeneration: using a fuel to generate electricity and produce heat If steam is used for industrial purposes or to heat buildings it is diverted to turn a turbine first Improves efficiency to as high as 90%

7 Fuel Efficiency of Cars

8 Coal Solid fuel formed primarily from the remains of trees, ferns, and other plant material that were preserved million years ago. 4 types of coal, ranked from lesser to greater in age, exposure to pressure, and energy content Lignite, Sub-bituminous, Bituminous, Anthracite Largest coal reserves are in the United States, Russia, China, and India This Photo by Unknown Author is licensed under CC BY-NC

9 Advantages Energy dense Plentiful Easy to exploit by surface mining Technological demands are small Economic costs are low Easy to handle and transport Needs little refining Disadvantage Contains impurities Release impurities into air when burned Trace metals like mercury, lead, and arsenic Combustion leads to increased levels of sulfur dioxide and other air pollutants Ash Carbon dioxide is released into the atmosphere which contributes to climate change

10 Petroleum Mixture of hydrocarbons, water, and sulfur that occurs in underground deposits Oil and gasoline made this ideal for mobile combustion, such as vehicles Formed from the remains of ocean-dwelling phytoplankton that dies million years ago Largest deposits of petroleum are Saudi Arabia, Russia, United States, Iran, China, Canada, Mexico This Photo by Unknown Author is licensed under CC BY-SA

11 Advantages Convenient to transport and use Relatively energy-dense Cleaner-burning than coal Disadvantages Releases carbon dioxide into the atmosphere Possibility of leaks when extracted and transported Releases sulfur, mercury, lead, and arsenic into the atmosphere

12 Natural Gas Component of petroleum in the ground as well as in gaseous deposits separate from petroleum Contains 80-95% methane and 5-20% ethane, propane, and butane Advantages Contains fewer impurities and therefore emits almost NO sulfur dioxide or particulates Emits only 60% as much carbon dioxide as coal Disadvantages When unburned, methane escapes into the atmosphere (greenhouse gas) Exploration of natural gas has the potential of contaminating groundwater

13 Other Fossil Fuels Oil Sands: slow-flowing, viscous deposits of bitumen mixed with sand, water, and clay Bitumen (tar or pitch)- degraded type of petroleum This Photo by Unknown Author is licensed under CC BY

14 The Future of Fossil Fuel Use If current global use continues, we will run out of conventional oil in less than 40 years. Coal supplies will last for at least 200 years, and probably much longer Hubbert Curve- a graph that shows the point at which world oil production would reach a maximum and the point at which we would run out of oil This Photo by Unknown Author is licensed under CC BY-SA

15 Nuclear Energy Nuclear power plants world by using heat from nuclear fission to heat water Fission- nuclear reaction in which a neutron strides a relatively large atomic nuclease, which then splits into two or more parts. This process releases heat and more neutrons which then strike additional nuclei, continuing the process. The heat us used to create steam which turns a turbine, which turns a generator to produce electricity. This Photo by Unknown Author is licensed under CC BY-NC

16 This Photo by Unknown Author is licensed under CC BY-SA

17 Fuel Rods- cylindrical tubes that house the nuclear fuel used in a nuclear power plant Control Rodscylindrical devices that can be inserted between the fuel rods to absorb excess neutrons. These are used to slow or stop the fission reaction. This Photo by Unknown Author is licensed under CC BY-SA

18 Advantages No air pollution is produces Countries can limit their need for imported oil Disadvantages Possibility of accidents Disposal of the radioactive waste

19 Radioactive Waste At some point the nuclear fuel can not produce enough heat to be used in a power plant but is still emitting radioactivity. Waste must be stored in special, highly secure locations. High-Level Radioactive Waste: the form used in fuel rods. Low-Level Radioactive Waste: the protective clothing, tools, rages, and other items used in routine plant maintenance.

20 Fusion The reaction that powers the sun and other stars. Lighter nuclei are forced together to produce heavier nuclei. Heat is released Fusion is a promising, unlimited source of energy in the future, but so far scientists have had difficulty containing the heat that it produces. This Photo by Unknown Author is licensed under CC BY-SA