Today there is pervasive discussion, on how the world must transition smoothly, from the predominantly use of fossil fuels, to greener, more renewable sources of energy. Almost no one would argue, that it is a very necessary transition toward energy efficiency that must be made over the next century and beyond.
In this article we will take a more in depth look at the science behind what created our current fossil fuels, coal, oil, and natural gas deposits, the origins of how they were formed, what they were formed from, how long they take to accumulate, where they deposited, and why. It is hoped that this article will help to put the discussion of world energy source transition, into a more informed perspective for the reader.
In particular, we hope readers come to the realization (if they have not already,) that fossil fuels have been indispensable to the formation of mankind’s present technological development, and that they will continue to play an integral part in the future development of our world, for many centuries to come.
Moreover, that, rather than viewing fossil fuels in a hostile, or negative light, perhaps we should view their gradual replacement by greener, more renewable sources of energy, as a preservation of precious and irreplaceable natural resources, in the same manner, as we have come to see the world’s forest lands and waterways, as vital and irreplaceable natural resources, worthy of intelligent management and essential preservation.
Overview:
There are a number of popular misconceptions regarding the origins of oil, gas, and coal, the naturally occurring sources of energy we call fossil fuels.
Perhaps the most widely held misconception, is the popular belief that most fossil fuels were formed exclusively from the decomposition, and pressurization over time, of the remains of the largest classes of Dinosaurs (sauropods,) such as the species Brachiosaurus (now classified as Giraffatitan Brancai.)
The period in which the fossil fuels deriving from all dinosaurs could have begun accumulating, comprises around 160 to 185 million years. This is the entire span of the age of the Dinosaurs (i.e., the Mesozoic Era,) which started around 230 to 250 million years ago. However, firm dinosaur fossil evidence has only been uncovered from coal fossils, around the time of Tyrannosaurus Rex, during the Cretaceous Period, approximately sixty five million years ago.
The majority of naturally occurring fossil fuels, are now thought to come from fossilized plant and diatomic sea life including algae, over a much older, and longer span of time, from a “biogenic” process, similar to the one which formed the remains of dinosaurs into fossilized fuels.
The period of history in which plant and diatom (algae) based fossil fuels began accumulating spans the Paleozoic Era, which is about 300 to 350 million years in duration beginning about 600 million years ago. Moreover, scientific data suggests that the largest portion of plant based fossil fuels accumulated over the last period of this era, called the Carboniferous Period, lasting about 60 to 75 million years. The period derive its name from carbon, the element which comprises the bulk of the non-water content, of plants, animals, and sea life.
Another popular misconception, is that all naturally occurring oil comes from fossil fuels. In fact, some oil has been found to date, that originates from an “abiogenic” process, which does not involve the decomposition and transformation of either plant or animal life.
This type of petroleum is thought to form naturally, deep inside the Earth, seeping upward to more accessible depths. It is further thought by scientists, that if this “abiogenic” oil could be more readily discovered, it might also prove far more abundant not only on Earth, but on other planets in the Solar System.
Photo Source: http://en.wikipedia.org/wiki/File:Derrick.JPG
Petroleum Oil and Natural Gas:
Fossilized petroleum and natural gas, are thought to be formed primarily from plant and algae base life, beginning over 300 million years ago. Diatomic life (i.e., sea algae,) appears to comprise the greatest portion of these fossil fuels according to scientists. This follows naturally, as the land mass of our oceans is much greater than that of our continents, and the origins of sea life is generally older than land based forms of life.
Scientists believe that diatomic life died and fell to the floor of the seas. The dead algae was buried under sediment and rock. These sediment and rock layers then pressurized and heated the fossilized algae layer, until it formed into oil and natural gas. A similar process would occur on land, with plant and animal fossils forming peat which eventually formed into oil, gas, and coal.
The leading theory on the formation of petroleum oil and natural gas holds, that the first phase resulting from the heating and pressurization of fossil remains, involve the formation of a a dark organic layer called kerogen, which is waxy in nature.
The kerogen has a complex bond structure, which cracks and breaks down over time, into shorter molecules. These shorter, and consequently lighter structures, are composed primarily of the elements carbon and hydrogen. The resulting ratio of liquid and gas fractions in this mixture, results in either petroleum oil, or gas, or both depending on the ratio.
Today oil and natural gas are found underground, on both land and sea. The points of discovery occur in areas where the rock is porous, and within the rocks themselves (e.g., shale oil found in the Northwest US and Canada), as well as between folds of rock.
One of the most important areas of commercially applied Geology, involves the systematic study and mapping of the Earth’s rock tables, layers, and the various strata of rock formations, in order to optimize the search for commercially accessible quantities of petroleum oil and natural gas.
Oil and natural gas seep or leak naturally from the oceans’ floors. This seepage is thought to greatly exceed the quantities spilled or leaked, in man made recovery operations or fuel transportation every year.
Man has used oil petroleum products for roughly six thousand years, beginning with
ancient Babylonians, Assyrians, and Sumerians, who used pitch from the Euphrates River for various medicinal and industrial uses. The Dead Sea, was once named Lake Asphaltites. Asphalt like globs of petroleum still wash ashore today, from underwater seepage of oil pitch.
The uses of petroleum oil are seeming innumerable, the refined derivatives are found in fuels, lubricants, construction materials, plastics, and medicines to name a few. [1],[ 3]
Photo Source: http://en.wikipedia.org/wiki/File:NaturalGasProcessingPlant.jpg
Coal:
Coal forms from fossilized plants and animals, in a similar manner to that of petroleum oil and natural gas. Coal sediment is thought to comprise roughly one percent of all sedimentary rock formations, i.e., of the sedimentary rock record.
Coalification is the process of transforming the first phase of decomposition of fossilized plants and animals, which is called peat, into the rock like material, we know as the fuel coal.
The most consistent theory, and the fossil data which supports it, regarding this metamorphosis, holds that coal is formed primarily from heating peat, formed from both plant and animal decomposition. The historical process is also marked by transportation processes during the transformation into coal, as evidenced by signs of microlamination, and the presence of boulders in coal formations, and the absence of soil layers under coal formations.
Said another way, coalifaction may occur during and after natural transportation of coal forming peat under high heat conditions, rather than taking place at the original site of the fossil, and or peat formation.
The support for heat being the most important element in the coalification of peat includes experiments in which anthracite materials (i.e., synthetic forms of coal,) have been generated from heating cellulosic materials in a matter of minutes.
Natural coal classifications or types include, lignite, bituminous, and anthracite, ranging from softest to hardest respectively. Coal is comprised of carbon, hydrogen, oxygen, nitrogen and some sulphur. Anthracite coal being the hardest and most shiny in appearance of all the three types of coal, contains the highest percentage of carbon, and is the most energy dense (i.e., yields the most amount of energy per weight.)
Coal was first used in the smelting of metals in ancient China. This is no doubt due to the higher temperatures that could be achieved by using coal instead of wood.
Coal is mined throughout the world, through various methods, including digging in underground coal mine shafts, and strip mining the sides of open coal formations such as hills and mountains. The coal is transported to the point of use via trains, ships, and as water/ coal slurries in pipelines.
Coal powers roughly 60% of the electrical power plants in the United States. Petroleum oil and gas, hydroelectric, geothermal, biomass and alternative energies such as wind, and solar also contribute power to the electrical grids in the US. [1],[ 2]
Photo Source: http://en.wikipedia.org/wiki/File:NaturalGasProcessingPlant.jpg
Conclusions:
Our modern society is at present, wholly dependent on the use of fossil fuels. It is a finite resource that took millions of years to form, which cannot be replaced once it is depleted. Therefore, we should treat fossil fuels as we do our forest lands, and waterways, as precious resources that absolutely must be preserved, and used sparingly for only the most essential of our needs. One such example, for which we currently do not have viable alternative technology, are plastics and some lubricants.
However, for our energy needs, we do have many viable alternatives to fossil fuels, which should be perfected, refined, and integrated as rapidly as possible into our economy, so that we can preserve our fossil fuel resources to the largest extent possible. As we move toward energy efficiency in green homes, energy-saving transportation alternatives, and other areas of our lives, we are getting closer to the preservation of earth’s fossil fuels.
1: http://www.energyquest.ca.gov/story/chapter08.html
2: http://www.icr.org/article/origin-coal/
3: http://www.livescience.com/environment/051011_oil_origins.html
4: http://dinosaurs.about.com/od/dinosaurbasics/a/dinosaurages.htm
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