How to get acetylene from methane

Acetylene is a substance belonging to the class of alkynes. In other words, it is a hydrocarbon that has a triple bond in each molecule. In this case, the chemical formula of acetylene is as follows: C ₂ H ₂ . In itself, this substance is a colorless gas, which is much lighter than air. Get acetylene from methane. The substance is chemically active and explosive.

How to Get Acetylene

From methane at home, it's very difficult to get acetylene. The simplest method of extracting this gas is the reaction of water with calcium carbide. Many of you probably remember how to throw puddles of this substance into puddles and what was the reaction. At the same time, a rapid hiss was noted. As for calcium carbide, it gradually melted, forming a large amount of foam. A similar reaction can be written as follows:

CaC ₂ + 2H ₂ O = C ₂ H ₂ + Ca (OH) _2.

Many use technical calcium carbide, which contains a large amount of impurities. As a result, during the reaction with water, the substance gives off an unpleasant odor. It arises because of the formation, along with acetylene, of a small amount of vapors of toxic gases. Most often it is phosphine, hydrogen sulphide and so on. This method is considered the most common, because you can get acetylene from methane only with the help of special equipment.

Obtaining in industry

How do they get acetylene from methane in industrial conditions? Currently, only one method is used - cracking. In the process of obtaining acetylene , the -C-C bonds are broken. This occurs in the presence of catalysts and when exposed to sufficiently high temperatures. Methane - natural gas is used for production. It is inexpensive and easily available raw materials. It is for this reason that cracking is the most reasonable method, both economically and technically.

How is cracking carried out?

Conversion of "methane - acetylene" can be done in several ways. In the first case, natural gas is passed through pre-heated electrodes. The temperature can reach up to 1600 ° C. After heating, there is rapid cooling. The second method is based on the use of heat, which is formed as a result of partial combustion of acetylene.

The equations of the reactions "methane-acetylene" are written as follows:

1. In the I case: 2CH ₄ = C ₂ H ₂ + 3H ₂ .

1. In the second case: 6CH ₄ + 4O ₂ = C ₂ H ₂ + 8H ₂ + 3 CO + CO ₂ + 3H ₂ O.

Experts do not recommend the use of acetylene cylinders equipped with valves made of bronze. After all, the composition of this alloy includes copper. Since acetylene is chemically active, it can react with the metal. As a result, explosive salts are formed.

The use of acetylene

Acetylene is a substance that is widely used in various industrial branches. Most often this gas is used in the manufacture of ethyl alcohol as the main raw material. In addition, acetylene is used to produce certain types of rubber, acetic acid and plastic.

This gas is also actively used when welding, as well as cutting various metals. It is worth noting that the oxidation of oxygen with acetylene produces a strong flame. The gas is a source of sufficiently bright light in the luminaires of an autonomous type. On the basis of acetylene, explosives are produced , which are subsequently used as detonators.