FOSSIL FUELS III Coal
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.
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.
Major Coal Forming Periods Carboniferous and Permian 360 to 250 MYA High quality bituminous and anthracite Upper Cretaceous to Miocene 100 to 5 MYA Low quality subbituminous and lignite coals Quaternary 2.6 MYA to present peat
Steps to becoming coal: Peat Lignite (brown coal) Subbituminous Bituminous Anthracite The major difference is the percentage of the coal that is carbon. Higher carbon concentration means better quality coal. (in general)
Coal progresses through the stages with increasing pressure and temperature. Type % Carbon Energy Content (MJ/kg) Lignite 30 11.6 – 16.3 Subbituminous 40 18.6 – 23.3 Bituminous 50 - 70 25.6 - 34.8 Anthracite 90 32.5 Oil 85 46
Coal Classification
Which type of coal provides the most energy/kg? Lignite Bituminous Anthracite
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+O2SO2 SO2 combines with water in atmosphere to form sulfuric acid. Limits the use of those coals Coal has uranium & thorium: radioactive Concentrated when coal is burned
Other contributions. Mercury Arsenic Selenium
Union Pacific Big Boy
Coal Mining Coal veins can be 1in to 400 ft thick. Must be at least 2 ft thick to make mining profitable. According to CNN, underground mining is the most dangerous occupation in America. Bureau of Labor Statistics underground mining is the second most dangerous occupation in America (by rate).
Coal Mining Tunneling – 40% Surface mining – 60% Removing overburden to get to coal Strip mining Mountaintop removal
Types of Coal Mining
Tunnel Mining
Strip Mining
Mountain Top Removal https://www.youtube.com/watch?v=p5RcbPZXUZo
Which type of coal mining is predominant? Tunnel mining Surface mining Placer mining
Should Mountain Top Removable be allowed in the U.S.? Yes No
US Coal Reserves by Type
Coal Reserves Sulfur Content
Coal Reserves Sulfur Content
World Coal Reserves
Coal Production
Which is the current high producer of coal? Russia China USA Germany
Chinese SY Mikado 2-8-2
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)
Donora 1948
Coal Consumption
Mix of Fuels in US
US Coal Production
Estimated that we have enough reserves for 200-300 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.
Should the use of coal in America be expanded? Yes No