Fossil Fuels :: Coal Petroleum Natural Gas

Part One - Introduction   Ã‚  Ã‚  Ã‚  Ã‚   Fossil Fuels are the most important energy sources in our world today. The overwhelming majority of the energy used in the world comes from the burning of three major fossil fuels: coal, petroleum, and natural gas. Fossil fuels are a non-renewable source of energy. They are formed over a very long period of time; the fossil fuels on earth today were formed from plants and animals that lived up to 300 million years ago. These fossil fuels are found in deposits deep beneath the earth. The fuels are burned to release the chemical energy that is stored within this resource. Energy is essential to modern society as we know it. Over 85% of our energy demands are met by the combustion of fossil fuels. Part Two – Formation   Ã‚  Ã‚  Ã‚  Ã‚   Going back to the earlier days of Earth, the plants and animals that lived then eventually died and decomposed. The majority of these life forms were ocean dwelling forms of plankton. When these ancient ocean dwellers died, they accumulated on the bottom of a seabed; this is how a good portion of our fossil fuel reserves began. The actual transformation process of these prehistoric creatures is not known, but scientists do know that the pressure, heat, and a great deal of time go into the making of fossil fuels. Geologists are fairly certain that the beds of organic remains mixed with silt and mud to form layers. Over time, mineral sedimentation formed on top of the organisms, effectively entombing them in rock. As this occurred, pressure and temperature increased, these conditions, and possibly other unknown factors, caused organic material to break down into the simpler form of hydrocarbons, which are chains of carbon and hydrogen ranging from simple configuration to complex compounds. Another affect of extreme pressure is that the oil and gas which are various mixtures of hydrocarbons raise upwards to the surface. Exactly when in the conversion process and the nature of this migration is not known and is subject to conjecture. Oil and gas are found in the ground, not freely drifting up through the earth. This is because the hydrocarbons come across rock formations that they are unable to penetrate. Complex rock structures that effectively trap gas and oil are formed by tectonic plate activity, the same forces that shift continents. The most common formation that accomplishes this is called an anticline, a dome or arched layer of rock that is impermeable by oil and gas.