Acetylene production

Surely very many know that the very word - acetylene - is associated with the concept of "vinegar". But the fact that acetylene today is the only substance that can burn in the absence of air access, and which is widely used in industry, not everyone knows. Acetylene is dangerous, it is also emphasized by the fact that, for example, its burning in acid creates a flame with a temperature of up to 3100 ° C.

Edmund Davy was the first to receive acetylene in the distant year of 1836. Devi acted on potassium carbide with an ordinary aqueous solution, a reaction occurred , the equation of which can be written as: K2C2 + 2H2O = C2H2 + 2KOH. As a result, a gas was obtained, the formula of which is C2H2 and to which the scientist named bicarbonate hydrogen.

With the discovery of the doctrine of radicals, Justus Liebig called one of the groups of atoms (radicals) acetyl, although he considered a compound with the formula C2H3. The substance, which was received by Devi, began to be considered by chemists as a derivative of acetyl. Then, when the acquisition of acetylene was carried out by the Frenchman Marcelen Berthelot in several ways, the substance got its name, which is used in chemistry to this day. Berthelot considered the resulting compound as an acetyl molecule, from which a hydrogen atom was taken . Technologically, the production of acetylene Berthelot was the following process. He passed a pair of heated alcohols - methyl and ethyl - through a tube that had also been heated to a high temperature.

Somewhat later, in 1862, acetylene was synthesized by an electrochemical reaction, during which hydrogen was passed between electrodes made of carbon. These technologies at that time were very expensive and inefficient, and therefore could only be considered as a theoretical solution to the problem. Only at the very end of the century before last was invented a method that allowed to establish a more economical acquisition of acetylene. This method is based on calcining a mixture consisting of quicklime and coal. This allowed us to adjust the use of the connection as a gas for street lighting. The fact is that the gas, which contained about 92.3% of carbon, at a high temperature, gave off a huge amount of this substance in solid form. They give a bright enough light. In this case, the combustion temperature determines not only the burning brightness, but its color. The higher the temperature - the earlier is the color of the glow of carbon particles. Appeared heaters, filled with acetylene, could give light about fifteen times more than the then widespread gas lamps. Even when they were replaced by electric lighting, the use of acetylene for lighting continued in bicycle lanterns and omnibuses.

As the industry developed, more and more quantities of such a compound as acetylene were required. Getting it in industrial volumes began only in the last century. As a result of this "breakthrough" the connection was also used for technical needs. For building needs, acetylene was produced by quenching carbide with water. This product is widely known for its very unpleasant odor due to the impurities contained in it of ammonia and hydrogen sulphide. In fact, a chemically pure substance has a weakly expressed etheric smell. It is lighter than air, the molecular mass of acetylene is 26.038. The gas has no color, is readily soluble in many liquid solutions, and the solubility is determined by the temperature of the solution itself.

Modern technologies involve the production of acetylene from methane by means of electrocracking, a process in which methane gas is firstly passed between electrodes at a temperature not lower than 1600 ° C. Then, in order to prevent the decomposition of acetylene, the gas is rapidly quenched. Such a method is effective in that part of the heat generated by the combustion of a substance can be directed to heating the next reaction cycle, ensuring a continuous nature of its course.

Acetylene is widely used in welding and cutting metals, to produce very bright white light, for the production of explosive materials.