Fuel is material that can produce heat while being consumed, by burning, for example. Fossil fuels, also called mineral fuels, are combustible materials that are organic, having derived from remains of living beings. They include coal, lignite, natural gas, peat, and oil. Artificial fuels, such as gasoline and kerosene, are made from these natural fuels. Fossil fuels can take a number of forms: methane is a gas, oil a liquid, and coal a solid.
Types of Fossil Fuels
Some fossil fuels are referred to as carbonaceous fuels, which derive from plant waste. The carbonaceous fuel with the lowest carbon content is peat, which is estimated to cover about 2% of the Earth's land in wetlands known variously as bogs, mire, moors, swamps, and peatlands. Fuel peat is different than moss peat, which is used in agriculture.
Lignite is the carbonaceous fuel with the next highest amount of carbon. Also called brown coal, is brownish or yellowish and has more moisture than coal. It is found in North America and Germany.
Coal, which has the highest carbon content, still has a range among its five types. They are, in increasing order, black lignite or subbituminous coal, bituminous coal, semibituminous coal, semianthracite, and anthracite. Note that semibituminous coal is high-grade bituminous coal, while semianthracite is low-grade anthracite coal. Of these, anthracite is most nearly pure carbon.
Natural gas is composed of gaseous hydrocarbons mixed with other components. Its main component is methane, which makes of 80–95% of its content. Other gases included may be butane, ethane, and propane. It is found both near deposits of petroleum, as well as separately.
Crude oil, or petroleum, is another of the fossil fuels. It is found in deposits in rock formations within the Earth and extracted for use as fuel oil, gasoline, and other products such as wax, manufacturing of plastics, lubricants, and sulfuric acid, among others. Saudi Arabia is both one of the largest producers and largest exporters of crude oil in the world.
Formation of Fossil Fuels
Petroleum, coal, and natural gas are by-products of geological processes deep in the Earth. Coal is created in swamps, where plant sediment gathers over vast periods of time and slowly turns into peat and finally to coal. Petroleum and gas tend to form in the depths of the ocean, where the Earth cooks deeply buried organic material over millions of years to form oil.
The creation of fossil fuels used today began over 300 million years ago, according to some experts.
Historical Use of Fossil Fuels
Fossil fuels used throughout history show a growing trend of importance, tied greatly to human scientific understanding of energy and burning power. Fossil fuels for powerful fires date back to ancient China, where there is evidence that coppersmiths used coal in their forge fires. Oil may be the oldest of the fossil fuels used as a type of petrochemical; the ancient Egyptians used oil for medical treatments and possibly cosmetics. Native Americans, too, had fossil fuels for waterproofing and sometimes also for medical purposes.
Until the late 19th century, whaling provided the majority of oil used for lamps and lighting fixtures. With the devastation of the whale population, due to whaling, the price of whale oil increased dramatically, leading many to search for alternative lamp fuel. Petroleum, which is relatively cheap and seemed at the time to be a boundless resource, quickly became the leading fuel for lights.
Fossil fuels used for power dates back to the Chinese coppersmiths, and throughout the Industrial Revolution, the smoky and smoggy skies were the result of coal-powered factories. Yet not until the development of automobiles and aircraft did fossil fuels used for power gain their true power over the world. Since the early 20th century, almost all transportation methods have been powered by natural gas.
Uses of Fossil Fuels
In 2006, world energy consumption was 86% fossil fuels or their derivatives. This included 36.8% petroleum, 26.6% coal, and 22.9% natural gas. The remaining energy was supplied by non-fossil fuel such as hydroelectric, nuclear energy, geothermal energy, and energy generated by solar power, tides, and wind. World energy consumption rises yearly.
Petroleum and natural gas power homes, factories, and transportation, but also make their way into the daily life of nearly everyone through petrochemicals. These refined components of oil are used in thousands of household products, from plastic items, to clothing, to medicine and cosmetics. Any product that contains propylene, vinyl, ethanol, glycol, butadene, or ingredients that end in xylene is a petrochemical derived from fossil fuels.
Environmental Concerns and Depletion of Fossil Fuels
Because there is a finite amount of fossil fuels available, their depletion is a source of concern. As science has discovered, the Earth is rapidly running out of fossil fuels; a prospect which could be devastating to all facets of modern existence.
The fact that these fuels release pollutants, such as carbon monoxide, when burned is another source of concern. Fossil fuels do heavy damage to the environment and are a main culprit in the case of human-caused global warming. Although they have powered the world almost exclusively for a century and contributed to human society for long before, it appears that fossil fuels will someday need to be replaced by other energy sources.
The possibility that their burning contributes to global climate change or global warming has been the subject of heated debate.