Acetylene refers to unsaturated hydrocarbons . This compound, as well as its various homologues, serve as raw materials for the synthesis of a large number of chemical products.
Properties and acetylene production
Under atmospheric pressure and normal temperature, acetylene is a colorless gas. If the temperature drops to a value of -85 degrees and below, then this connection goes into another state - solid. In this case, crystals form. It should be noted that in the liquid and solid state, acetylene can easily explode under the influence of friction or upon impact (hydraulic or mechanical). It is this property that largely determines its scope. Acetylene combustion reactions occur in the presence of oxygen. As a result of this process, a flame occurs, characterized by the highest temperature (3150 degrees) compared with other types of fuel.
The main method for producing acetylene is a reaction in which calcium carbide and water interact. This process proceeds at temperatures of about 2000 degrees and is endothermic.
There is such a thing as acetylene yield. This is such an amount that is released as a result of decomposition of 1 kg of calcium carbide. GOST 1460-56 sets specific values for a given value, which is directly dependent on the degree of granulation of the starting material. Thus, a consequence of the relatively small particle size of calcium carbide is a decrease in the yield of acetylene.
This pattern is a consequence of the presence of impurities, for example, calcium oxide, in small carbide particles.
There are other, less cumbersome, expensive and energy-intensive methods for producing acetylene. For example, the reaction of thermooxidative pyrolysis of methane from natural gas; decomposition of oil, kerosene and other types of fuel by electropyrolysis.
Storage and transportation
All storage and transportation methods involve the use of cylinders. They are filled with a special mass of porous consistency. It is impregnated with acetone, which dissolves acetylene well. The use of this method can significantly increase the filling of an acetylene balloon and, importantly, reduces its explosiveness.
Prolonged contact of acetylene with metals such as copper and silver can increase its explosiveness. Therefore, the use of materials that may contain these metals, for example in valves, is unacceptable.
As a rule, cylinders should have special valves designed specifically for the storage of acetylene.
Full utilization of the entire container capacity can be achieved by storing empty containers so that acetone is distributed throughout the container. And this is possible only in a horizontal position. The filling of the balloon should be very slow, which is important for observing the conditions of the chemical reaction of the dissolution of acetylene in acetone, and in particular its speed.
Benefits of Dissolved Acetylene
The main advantage of dissolved acetylene over that obtained using portable generators of calcium carbide is that with the use of cylinders, welder labor is increased by about 20%, while acetylene losses are reduced by 25%. It should also be noted the increase in efficiency and maneuverability of the welding post, safety. Unlike the gas obtained from calcium carbide, dissolved acetylene contains significantly less foreign substances, that is, impurities, which allows it to be used in especially critical welding operations.
The main areas of application of acetylene
- Welding and cutting of metals.
- Use as a source of bright, white light. In this case, we are talking about acetylene obtained by the interaction of calcium carbide and water. In this case, autonomous lamps are used.
- Explosive production.
- Obtaining other compounds and materials, which are acetic acid, ethyl alcohol, solvents, plastics, rubber, aromatic hydrocarbons.
Acetylene: application in construction and industry
Autogenous and welding work accompany almost all stages of construction. It is in these types of work that acetylene is used. In a special device called a burner, gas mixing and the combustion reaction itself take place. The highest temperature of this reaction is achieved with an acetylene content of 45% of the total volume of the balloon.
The cylinders with this gas are marked as follows: they are painted white and the inscription “Acetylene” is applied in large red letters.
Construction work is carried out mainly in the open air. The use of acetylene and its homologs under these conditions should not take place under the influence of direct sunlight. Small breaks should be accompanied by shutting off the valves on the burner, and long breaks should be accompanied by shutting off the valves on the cylinders themselves.
In the chemical industry, acetylene is in great demand. Its use is the use of this substance in the process of obtaining organic synthesis products. These are synthetic rubber, plastics, solvents, acetic acid, etc.
Acetylene, being a universal fuel, is often used in processes accompanied by flame treatment. It is important that the use of acetylene in industry is only possible with safety measures, since it is an explosive gas.
Carbide lamps
The name "carbide lamp" is due to the use of an open flame stream of combustible acetylene as a light source. It, respectively, was obtained as a result of the interaction of calcium carbide with water.
Such lamps were widespread in the past. They could be seen on carriages, cars and even bicycles. In modern times, carbide lamps are used only in case of urgent need for a powerful stand-alone lamp. So, cavers often use them. Remote beacons provide exactly such lamps, because this type of lighting is much more profitable than the summing up of power lines. Quite widespread is the use of such lamps on long-range vessels.
Acetylene: use in medicine
How is the substance used in this area? General anesthesia involves the use of alkynes. Acetylene is one of those gases used in inhalation anesthesia. But its widespread use as such is a thing of the past. Now there are more modern and safer methods of anesthesia.
Although it should be noted that the use of acetylene did not pose a great danger, since before the value of its concentration in inhaled air reaches a dangerous limit, the lower combustibility threshold will be passed.
The most important condition for using this gas is compliance with safety measures. It is difficult to overestimate how dangerous acetylene is. Its use is possible only after conducting all the necessary briefings with employees of various fields in which it is used.