La Combustion Theory corresponds to a very complex process in the interaction of a fuel element and oxygen. After many years where scientists ignored what it really was, finally a Frenchman was able to give him the correct explanation.
What is Combustion Theory?
Let's start first with oxidation, which is a reaction by which some compound element interacts with oxygen, chemically speaking it is said that through this process the element loses electrons.
So we say that combustion is when this reaction occurs and the fuel that is involved releases heat energy creating a bright flame or a fleeting flare. Many times it may not even involve fire, it may just be gas that gives off heat.
Oxygen contributes to the reaction with an element called oxidizer, which is what allows oxidation to take place quickly and the fuel can release energy. The fuel must be under certain conditions in order to reach a point, which is called the flash point and for all fuels there are different conditions, all this in order to achieve this reaction.
Usually the fuel is of organic origin, they can come from animals or plants and are processed in different ways to become useful products to be used by man in his daily life.
You don't have to be a very intelligent person to know everything that fire represents in life, it is the element that enables many aspects of our daily life, such as transportation, cooking, the production of materials, it provides us with electricity and many other purposes that are of basic necessity for the preservation of life as it is today.
History of Combustion Theory
Historically the combustion theory It corresponds to a process that the primitives considered an enigma, after many centuries of studies, experiments and observations it was a source of controversy among the great scientists who tried to discover what the process behind this reaction was.
In the year 1718 a German gave name to an element that was supposedly the cause of this reaction, since he said that during this process the compound that is oxidized and was the source of the flame, contained the supposed element that was released upon contact. with oxygen, if the reaction lasted a short time it was because all the substance had already been released.
It was given the name of phlogiston and it was used in different proposals about the interaction of oxygen and other non-combustible elements, but which could also be oxidized. Many years later it was found that the proposal was wrong, however, a few scientists let it go unnoticed and raised arguments justifying the existence of phlogiston in fuels.
It was approximately in the year 1788 that Antoine Lavoisier, a French chemist, discarded the idea of phlogiston and proposed that among many Types of chemical reactions, when oxygen interacts with the element then a reaction called oxidation is provoked, on the other hand if the process was the other way around it was said to be reduction, where instead of losing electrons they were gained.
However, it seemed that at that time everyone was in favor of the phlogiston theory, so the Frenchman, in the company of a colleague, founded a magazine in which they published their research, it was that moment when everyone dismissed phlogiston as an element.
It was also that moment in which he was given the title of "father of modern chemistry", since with him all the elements in this science began to be valued.
Many scientists of the time ignored the importance of oxygen as an element, it was not until Antoine came to propose his theory on the oxidation of the elements, that many questions about previous theories (based on phlogiston) were dispelled.
Combustion Classes
Depending on the environment and the element that is involved in the combustion, this could be of three different classes, we will mention them all below:
incomplete combustion
It occurs when there is not enough oxygen in the reaction to cause the element to oxidize completely, for example; in the case of carbon, it will not be able to become carbon dioxide (which is what would happen if the oxidation is complete), but will remain as carbon monoxide.
It goes without saying that the element that is involved will be half burned, in such a way, it is considered to be at a midpoint and for that reason it is called incomplete combustion, the product that results from this reaction is called unburned, for obvious reasons.
Complete Combustion
Unlike incomplete combustion, in this case the oxidation process is completed successfully, all thanks to the fact that the fuel that was used allows it and that the environment is capable of sufficient oxygen, even surplus, since the Combustions that reach their maximum splendor and allow oxidation to occur throughout the composition of the element, if possible, not only in the fuel.
It is important that the air is a surplus factor so that this combustion can result, otherwise it would be halfway, as in an incomplete combustion.
Neutral or Stoichiometric Combustion
They can only be produced intentionally in an environment that is suitable for this process and it consists of testing the appropriate elements so that some characteristic of their composition is not exceeded and ends up becoming a complete combustion.
This, together with the right amount of oxygen, will be enough to produce a reaction that precisely oxidizes the elements, allowing a successful and not huge transformation.
Stages of Combustion Theory
As we mentioned before, combustion is actually a very fast reaction and it is strange to think that it has stages, but if it does, they just happen so fast that it is very difficult to assimilate it, they are only perceptible in a controlled environment and as an object of study.
The process of combustion theory is very complex from the first to the last stage, in those few seconds there are many chemical processes happening at the same time, however, these phases are Research objectives in many studies and the chemical reactions that are generated in this process, still continue to amaze the minds of many brilliant scientists.
The stages of the combustion theory are:
- pre-reaction: In this stage the radicals are formed by means of the dispersion of the hydrocarbon components, later they begin to interact with the oxygen. Radicals are very fluctuating units and in the process they tend to develop and disintegrate very quickly, if the combustion is very unstable and the speed with which the radicals are produced does not match that of the process, an explosion can occur.
- Second Stage: This is when all the parts of the process come together and give rise to oxidation, there is a massive exchange of electrons between the oxygen and the fuel. It is also the stage of combustion where more heat is generated, giving way to the formation of the flame.
- Final stage: Depending on the type of combustion, it will determine the end of it, but usually it is when the oxidation process is completed and gases are formed that are the effect of the reaction.
Combustion Theory Result
This type of reaction produces the formation of residues that are the effect of the oxidation of fuel elements, usually some of these are gases that are extremely harmful to the health of human beings, as well as polluting the air, also affecting animals and they move towards the atmosphere worsening the greenhouse effect, with this causing other complications for the environment.
This type of waste could be divided into two classes that we mention below:
- Gases: Outside of what the term represents for many, in reality some of these gases cannot even be noticed through the nose of man, but everything will always be according to the fuel that is involved in the reaction.
Among the gases that can be harmful is carbon monoxide, also known as the silent killer, since it is not perceptible to any sense and when this gas is inhaled in excess, it enters the lungs and then passes into the veins, replacing the oxygen in the blood, which for a long time causes death.
- Smoke: Smoke is a formation composed of different gases and elements that are involved in the combustion process, it also has some particles that are released from the fuel and dispersed in the air. The smoke is the result of incomplete combustion in which oxidation did not occur completely and the decomposition of the elements was dispersed in the air.
The color of the cloud can tell a lot about the composition of the gases that are dispersed, for example; If the color is light, that means that the most abundant element is oxygen and it is not toxic, but it can be very annoying for the nose and throat. On the other hand, if it is black or with different shades, you have to be careful, since that indicates that there is a combination of very harmful gases.
