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Chapter 17 Non-renewable energy
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Natural resources: the fuels we use to run cars, ships, planes, factories, etc….
Fossil fuels: the remains of ancient organisms that changed into coal, oil, or natural gas (we use the most out of all the natural resources). Two main problems with fossil fuels The supply is limited Obtaining and using them has environmental consequences. Fuels are used for 4 main purposes. Transportation Manufacturing Heating and cooling buildings For generating electricity.
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Fuels is typically converted into a “more convenient” form.
Electricity is a big one!!! How is electricity generated? Electric generator: a machine that converts mechanical energy into electrical energy. Most use a turbine Steps of a coal powered plant Burning fossil fuel releases heat, which boils water to produce steam Steam is directed against the blades of a turbine, which turns Turbine is connected to an electric generator with then turns generating electricity. Steam is then directed to a condenser where it cools and becomes a liquid again.
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Btu: British Thermal unit, one Btu is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. One wooden kitchen match can produce about 1 Btu. Average candy bar produces about 1000 One pound of coal produces about 15000 The US uses more energy per person than any other country (except Canada and UAE). Breakdown: 19% residential, 16% commercial, 27% transportation, 38% industrial. - US and Canada have the lowest gas taxes in the world….what does this mean for our conservation of gas practices?
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Fossil fuel deposits Coal Formed from the remains of plants that lived in swamps 100’s of millions of years ago. Found mainly in the eastern US 300 to 250 MYA, most of Eastern US was swamp, and was repeatedly covered with sediment as the ocean rose and fell. This compressed the remains Heat and pressure caused the coal to form Coal deposits out west formed the same way, but much younger Coal mining Effects of mining, COVERED. Two major advantages to coal: relatively inexpensive and needs little refining after being mined.
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NOT IN YOUR TEXT BOOK Types of coal Peat: lowest quality, very easy to find. Lowest amount of Carbon (means low energy output).. Lignite: next up in quality, mined, is about 67% carbon. Bituminous: third best quality, mined, is about 83% carbon. Anthracite: highest quality, mined, about 94% carbon, most valuable, hardest to get, and cleanest burning.
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Oil and Natural Gas formation
Result from the decay of tiny marine organisms that accumulated on the bottom of the ocean millions of years ago. Heated until they became energy rich carbon molecules These particles migrated into the porous rock. Most of the US oil and nat. gas are located in Alaska, texas, California, and the gulf of Mexico. Electricity sources in the US coal: 57% Oil 2% Hydroelectric 8% Natural gas 10% Nuclear 23%
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Petroleum “Texas T” “Black Gold”….oil!!
Oil that is pumped from the ground, also called crude oil or petroleum Petroleum products: fuels, chemicals, plastics, etc… Accounts for 45% of the worlds commercial energy use. Found around geological features that tend to trap is as it moves in the earths crust. Most of the worlds reserves are located in the Middle East Most be transported to a refinery.
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Environmental effects of using oil
When burned they release pollutants (like sulfur) which can lead to smog Believed that it also contributes to global warming Oil spills can be expensive to clean and have a huge impact on organisms (think BP oil spill in the GOM)
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Natural Gas Methane (CH4) About 20% or worlds energy comes from this Previously thought of as a nuisance and burned off Produces fewer pollutants Fossil fuels future Estimated by 2050 world energy demand will have doubled (I believe this is a low number) No large reserves have been discovered since 2000. Much of the oil in the deep ocean is still inaccessible
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Oil refinery NOT IN YOUR TEXT BOOK!!!!!
Step 1 fractional distillation. You basically heat crude oil up, let it vaporize and then condense the vapor. Step 2 conversion. Chemical processing, for example, can break longer chains into shorter ones. This allows a refinery to turn diesel fuel into gasoline depending on the demand for gasoline. Step 3 Refineries must treat the fractions to remove impurities Step 4 Refineries combine the various fractions (processed, unprocessed) into mixtures to make desired products. For example, different mixtures of chains can create gasolines with different octane ratings
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Nuclear energy Based on the energy with in the nucleus of an atom Nuclear fission: based on the principal of splitting atoms Nuclear fusion: based on the principal of combing 2 atoms Both release massive amounts of energy The basics (fission) The nuclei of uranium atoms are bombarded with neutrons. These cause the nuclei to split. These new particles collide with more uranium. Expands exponentially If left uncontrolled = atomic bomb.
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How a nuclear power plant works.
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The basics Step 1: Energy is released by the nuclear reaction heating water to very high pressure/temp Step 2: superheated water is pumped to heat exchanger. Water in second pipe flashes to high pressure steam Step 3: steam turns turbine, which turns electric generator Step 4: steam is cooled, (second pipe) waste heat is released as steam.
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Advantages Very concentrated source of energy Do not produce air polluting gases If done properly, very low levels are radiation are released Disadvantages Expensive to build Radioactive wastes Nuclear meltdown (bad boom) Chernobyle
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Wastes Finding a safe place to store nuclear waste is a huge issue Can remain dangerously radioactive for 1000’s of years Mining for uranium creates radioactive waste as well All the used fuels, liquids, and equipment are hazardous waste. Storage facility's must be geologically stable for more than 10,000 years. Safety concerns Worlds worst nuclear accident: Chernobyl in 1986. Lots of things went wrong. 350,000 people were displaced 1000’s died of radioactive poisoning In the US, most serious was Three Mile Island in Pennsylvania.
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