The first thing, before determining the meaning of the term coal, is to know its etymological origin. In this case, we can establish that it comes from the Latin, exactly from “carbo”, which refers to the black matter that remains as a result after burning the wood.
Therefore, a fossil substance resulting from the decomposition process of a woody material is called carbon. Coal, which is used as fuel, is a non-renewable resource: it cannot be regenerated or produced to sustain its consumption.
Composed of sulfur, nitrogen, hydrogen, oxygen and other elements, coal mainly arose in the so-called Carboniferous Period, which ended about 300 million years ago. The geological process that converted plant-type organic substances into carbon is called carbonization.
The development of coal begins with the accumulation of vegetables in shallow marine or marshy regions. The remains of these plants are deposited at the bottom and, when covered by water, are protected from the air. Over time, anaerobic bacteria transform the substances, which begin to enrich themselves in carbon and become covered with clay and sand.
When used as a fuel, coal can be used to produce electrical energy. Coal is also used in the steel industry and in cement production, for example.
It is known as charcoal to dark material, solid fuel and color arises from the incomplete combustion or distillation of plant residues and wood. It is a substance with a high percentage of carbon.
In the same way, we cannot ignore that there is also what is called activated carbon or activated carbon. It is a highly crystalline and porous material that is used both to purify drinking water and to purify glycerin, as well as to shape gas masks.
The process to obtain this material is carried out using materials such as coconut shell, palm trees, walnuts or wood. These are then subjected to two types of procedures such as thermal activation and chemical activation.
According to DigoPaul, the animal charcoal, meanwhile, is obtained similarly to the process of charcoal, but from bones of animals. In this case, the percentage of carbon is lower. Animal charcoal is used as a bleach.
In the same way, within the field of gastronomy, and more specifically pastry, there is what is known as sweet coal. It is a very typical sweet of the Christmas holidays in Spain. Yes, because it is considered that it is the present that the Magi leave, instead of good gifts, to children who have not behaved well during the year.
Visually it resembles mineral coal as it is black in color, has a hard consistency and its appearance is rocky. It is very rich in sugar and is obtained from it and from water.