FOSSIL FUELS III. Coal

Transcription

1 FOSSIL FUELS III Coal

2 Formed from ancient plants. Coal beds were prehistoric swamps. Can be considered to be stored solar energy. Photosynthesis: CO2 + H20 + solar energy carbohydrates + O2 We can also run the process backwards and burn carbs to get energy, water and carbondioxide. Audio Link

3 Normally when a plant dies it decomposes. If there is not enough Oxygen, it can t completely decompose, thus we get a slow accumulation of energy. In a swamp, the bacteria that decompose the plants also use up the Oxygen. Coal found today formed between 1 and 440 million years ago.

4 Steps to becoming coal: Peat Lignite Subbituminous Bituminous Anthracite The major difference is the percentage of the coal that is Carbon. Higher Carbon concentration means better quality coal. (in general)

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6 Coal progresses through the stages with increase pressure and temperature. Type % Carbon Energy Content (Btu/lb) Lignite Subbituminous Bituminous Anthracite

7 The largest amount of US coal is Bituminous. Approximately 1% is Anthracite. (Found in Pennsylvania.) Many coal veins have a high sulfur content. Significant contributor to acid rain. S+O2 SO2 SO2 combines with water in atmosphere to form sulfuric acid. Limits the use of those coals

8 Coal Mining Coal veins can be 1in to 400 ft thick. Must be at least 2 ft thick to make mining profitable. Two basic ways to get to it Tunnels (deep reserves) (40%) Strip mining (near surface) (60%)

9 Tunnel Mining Tunnel Mining Video

10 Strip Mining

11 Mountain Top Removal

12 Should mountain top removal be removed? 1. Yes 2. No

13 US Coal Reserves by Type

14 Coal Reserves Sulfur Content

15 World Coal Reserves

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17 Proved Coal Reserves (2006) Brazil Poland Kazakhstan Ukraine South Africa Australia India China Russia United States TOTAL (million tonnes (teragrams)

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20 Coal Production in the U. S. Since 1950

21 Coal production for the five largest state producers

22 Coal consumption Great Britain plans to stop using coal for electric generation in 2025.

23 A thick shroud of haze lingers over China, turning the sky an opaque grey. Beijing, China's capital, is situated under the densest portion of the smog layer. The aerosol pollution can be seen blowing eastward across the Bo Hai Bay and Yellow Sea reaching as far as North and South Korea and the islands of Japan. (NASA)

24 Coal Consumption

25 Mix of Fuels in US

26 Coal use in perspective Source: U.S. Energy Information Administration, Monthly Energy Review

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28 Production of Coal 2006 Total World Poland Indonesia Germany South Africa Russia Australia India USA China Expected Life of Reserves

29 Estimated that we have enough reserves for years at current production rates. Use may be expanded Replace aging oil/natural gas/nuclear electric plants More demand for electrical energy Alternative uses such as coal gasification but on the decline in the U.S.

30 Coal Gasification Coal gasification can be used to produce syngas, a mixture of carbon monoxide (CO) and hydrogen (H2) gas. This syngas can then be converted into transportation fuels like gasoline and diesel. Alternatively, the hydrogen obtained from gasification can be used for various purposes such as powering a hydrogen economy, making ammonia, or upgrading fossil fuels.

31 Adverse Effects of Coal Millions of tons of waste products Acid rain from high sulfur coal Interference with groundwater Impact of water use on flows of rivers and consequential impact on other land-uses Coal-fired power plants without effective fly ash capture are one of the largest sources of humancaused background radiation exposure Coal-fired power plants shorten nearly 24,000 lives a year in the United States, including 2,800 from lung cancer[44] Coal is the largest contributor to the human-made increase of CO2 in the air[46]

32 Should the use of coal in America be expanded? 1. Yes 2. No