Fossil fuels are often spoken of as a type of negative, polluting energy, harmful to the environment. Fossil fuels are considered a non-renewable energy source due to the difficulty of regeneration.
Currently, fossil fuels are the most widely used energy source in the world. It is used to generate electrical energy but above all it is also used to generate mechanical energy (cars, heat engines, etc.)
The theory that fossil fuels formed from the fossilized remains of dead plants by exposure to heat and pressure in the earth's crust for millions of years was first introduced by Andreas Libavius ââ"in his Alquemia of 1597" and later by Mikhail Lomonosov "from 1757 and certainly for 1763". The first use of the term "fossil fuel" was by the German chemist Caspar Neumann, in an English translation in 1759.
What are fossil fuels?
Fossil fuels are a series of substances and gases formed from decomposed remains of animals and plants that are generated in certain layers of soil, serving as a type of non-renewable energy.
The fuels come from a process of partial decomposition of the organic material. These fuels are originated by a transformation process of millions of years of plants and vegetables (cases of oil, coal and natural gas).
These are primary energy sources since they can be obtained directly without transformation.
Formation of fossil fuels
Fossil fuels are formed by a process of partial decomposition of organic matter. It is a transformation process of millions of years due to the pressure and temperature that several layers of sediment exert on organic matter.
They have originated naturally by a process of fossilization in environmental anoxia (lack of oxygen): the organic matter has not been degraded by microorganisms (which can not live), but remains in the form of more complex, solid organic molecules ( coal ), liquid (oil) or gas (natural gas). The energy of these molecules is what is released in using them as fuel.
This process of millions of years is what converts fossil fuels into a non-renewable energy source, since it is consumed much faster than it is not generated.
Importance of fossil fuels
Fossil fuels have a high calorific value that makes them a very important source of useful energy to generate thermal energy.
The use of fossil fuels has allowed the great economic and demographic growth linked to the industrial revolution of the 19th century. At present they are fundamental for our economy. In 2007, the combustion of coal, oil and natural gas accounted for 86.4% of the world's primary energy.
Consequences of the use of fossil fuels
Fossil fuels are highly unpopular for environmental groups. Its combustion generates a lot of gases. These gases become one of the main sources of air pollution because they contribute to increasing the greenhouse effect and, consequently, to global warming.
Today, the use of fossil fuels is an important sustainability problem, both for environmental and economic reasons (the planet's resources are limited and will one day be exhausted).
Types of fossil fuels
Oil is a mineral oil, constituted by hydrocarbons, contained in large pockets to the upper strata of the earth's crust.
This fossil fuel, once refined, gives a large number of products used as a source of energy, especially in the automotive and thermal engines. These products include gasoline, diesel, fuel, etc. They can also be used as raw material for the petrochemical industry.
Most of this source of non-renewable coal was formed during the Carboniferous period (from 359 to 299 million years ago).
Natural gas is a source of fossil energy, as are coal or oil. It is constituted by a mixture of hydrocarbons, molecules formed by carbon and hydrogen atoms. Its calorific value varies greatly according to its composition, but the highest are between 8,500 and 10,200 kilocalories per cubic meter of gas.
It is the cleanest fossil energy in terms of waste and atmospheric emissions, and the most efficient fuel for obtaining electricity in thermal power plants, with a total efficiency of 50.7% compared to 25.7% of fuel, 26.1% of the uranium (nuclear power plant) and 26.8% of the coal.
Natural gas can be used directly without having to previously transform it into electricity. This feature allows it to have a much higher efficiency of 91.2%. Its storage is cheaper and easier than coal and petroleum products.
It began to be used from the 60s as the preferred fuel except in transport, where oil continues to predominate. In addition to being a non-renewable source of energy, it is also used as a raw material for many chemical products.
Last review: June 12, 2019