coal is formed when peat is altered physically and chemically. This process is called "coalification." During coalification, peat undergoes several changes as a result of bacterial decay, compaction, heat and time. Peat deposits are quite varied and contain everything from pristine plant parts (roots, bark, spores, etc.) to decayed plants, decay products and even charcoal if the peat caught fire during accumulation. Peat deposits typically form in a waterlogged environment where plant debris accumulated; peat bogs and peat swamps are examples. In such an environment, the accumulation of plant debris exceeds the rate of bacterial decay of the debris. The bacterial decay rate is reduced because the available oxygen in organic-rich water is completely used up by the decaying process. Anaerobic (without oxygen) decay is much slower than aerobic decay. For the peat to become coal, it must be buried by sediment. Burial compacts the peat and, consequently, much water is squeezed out during the first stages of burial. Continued burial and the addition of heat and time cause the complex hydrocarbon compounds in the peat to break down and alter in a variety of ways. The gaseous alteration products (methane is one) are typically expelled from the deposit, and the deposit becomes more and more carbon-rich as the other elements disperse. The stages of this trend proceed from plant debris through peat, lignite, sub-bituminous coal, bituminous coal, anthracite coal to graphite (a pure carbon mineral). Because of the amount of squeezing and water loss that accompanies the compaction of peat after burial, it is estimated that it took 10 vertical feet of original peat material to produce 1 vertical foot of bituminous coal in eastern and western Kentucky. The peat-to-coal ratio is variable and dependent on the original type of peat the coal came from and the rank of the coal.
Not sure if this will answer your question, but I'll give it a shot. It's less about the fact that is is coal and more about the fact that coal gives off heat. When coal was first being used as a heat source, it was cheaper than wood and there was a lot of it. So really the origin of the energy is in the heat that the coal generates when on fire and less about the coal itself.
how has coal mining changed over time
Zheng He was the one who had coal. He and his father, the emperor of China, and his uncle ,Samuel had created coal together on a farm in China.
Coal is not an invention, but rather the natural result of the fossilization of plants from the Carboniferous period.
coal in the western areas has a lower energy content
You can read about the history of coal miners from Wikipedia's official website. You can also read about the history of coal miners from Mining USA's official website.
Hands on History - 2001 Coal was released on: USA: October 2001
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Depending on what specific information you seek regarding coal plants, the best resources for learning about coal plants are from history and reference books. Websites such as UCS (Union of Concerned Scientists) have a website with information regarding coal including extraction, pollution and supply. Wikipedia also documents a brief history of coal mining. The Discovery site also offers an article about coal mining and coal plants.
Gerry Fanning has written: 'Oldham coal' -- subject(s): Coal mines and mining, History
E. A. Newell Arber has written: 'The natural history of coal' -- subject(s): Coal, Geology
it has changed the world
Donald F. Harker has written: 'Alaska coal mined land inventory' -- subject(s): Coal mines and mining, Abandoned coal mines, History
No, the ancient Egyptians did not have coal as it was not naturally found in Egypt. They primarily used wood and charcoal for their fuel needs. Coal mining and usage became prominent much later in human history.
For a time in the US history of coal mining, many of the miners lived on coal company property. This was especially true among the coal mining companies in West Virginia.
Jay Luke has written: 'When coal was queen' -- subject(s): Coal mines and mining, Pictorial works, History
Roger David Brown has written: 'Blood on the coal' -- subject(s): Coal mine accidents, History