Acetylene refers to an unsaturated hydrocarbon series.This compound, and its various homologs serve as raw materials for the synthesis of large amounts of chemicals.
properties and obtaining acetylene
at atmospheric pressure and normal temperature Acetylene is a colorless gas.If the temperature is lowered to a value of -85 degrees or lower, this compound into another state - solid.In this form the crystals.It should be noted that in the liquid and solid phases can readily acetylene explode under the effect of friction or impact (mechanical or hydraulic).This property largely determines its scope.Acetylene combustion reaction occurs in the presence of oxygen.As a result of this process there is a flame, characterized by the highest rates of temperature (3150 ° C) as compared with other kinds of fuel.
The main method is the reaction of acetylene, which interact with calcium carbide and water.The process operates at conditions of temperature of about 2000 degrees and is endothermic.
There is such a thing as the output of acetylene.This is the amount that is released by the decomposition of 1 kg of calcium carbide.GOST 1460-56 establishes the specific values of this value, which is in direct proportion to the degree of granulation of the starting material.Thus, the consequence of the relatively small size of the particles of calcium carbide is a reduction in the yield of acetylene.
This pattern is a consequence of the presence in the small carbide particles of impurities, such as calcium oxide.
There are other, less bulky, expensive and energy-intensive processes for the preparation of acetylene.For example, the reaction thermooxidative pyrolysis of methane from natural gas;the expansion of oil, kerosene and other fuels by elektropiroliza.
Storage and transport
All storage and transportation methods involve the use of cylinders.They are filled with a special weight of porous consistency.It is impregnated with acetone, which is a good solvent for acetylene.The use of this method can significantly increase the occupancy of the acetylene cylinder and, more importantly, it reduces the risk of explosion.Prolonged contact
acetylene with metals such as copper and silver, may increase its explosivity.Therefore, impermissible use of materials which may contain these metals, such as valves.
Usually, cylinders must have special valves designed specifically for the storage of acetylene.
full use of the entire capacity of the container can be achieved by storing empty containers so that acetone was distributed throughout the volume of the cylinder.And this is possible only in a horizontal position.Filling the balloon should be done very slowly, which is important for compliance with the chemical dissolution reaction of acetylene in acetone, and in particular its speed.
Advantages dissolved acetylene
main advantage dissolved acetylene before, which are prepared using a portable generator of calcium carbide, it is that the application cylinder is an increase in labor welder approximately 20%, while the losses of acetylene thus reduced by 25%.It should also be mentioned the increase of the speed and maneuverability of the welding station, security.Unlike gas obtained from calcium carbide dissolved acetylene contains much less foreign matter, ie the impurities which allows to use it in particularly critical welding.
- acetylene welding and metal cutting.
- use as a source of bright, white light.In this case we are talking about the acetylene is produced by reacting calcium carbide and water.It uses self-contained luminaires.
- manufacturing explosives.
- Preparation of other compounds and materials which are acetic acid, ethyl alcohol, solvents, plastics, rubber, and aromatic hydrocarbons.
Acetylene: used in construction and industry
Autogenous welding and accompany almost all stages of construction.It is in these types of work used acetylene.In a special device called burner gases are mixed directly and combustion reaction itself.The highest temperature of the reaction is reached when the content of acetylene 45% of the total volume of the cylinder.
gas cylinders with this label as follows: painted in white color and are applied in big red letters the inscription: "Acetylene»
Construction works are carried out mostly in the open air.The use of acetylene and its homologues in these conditions should not take place under direct sunlight.Small breaks must be accompanied by overlapping valves on the burner, and the long - overlapping valves on the cylinders themselves.
The chemical industry is very in demand acetylene.Its application is the use of the substance during the preparation of organic synthesis.A synthetic rubber, plastics, solvents, acetic acid, etc.
Acetylene is a universal fuel, often used in processes involving flame treatment.Importantly, the use of acetylene in the industry is possible only with safety measures, because it is an explosive gas.
name "carbide lamp" due to the use as a light source open flame combustion of acetylene jet.It is accordingly obtained by reacting calcium carbide with water.
Such lamps were common in the past.They could be seen on the carriages, cars and even bicycles.In modern times carbide lamps use only in an emergency in a powerful stand-alone luminaire.For cavers often use them.Distant beacons supply such lamps is, in fact, this type of lighting is much better than the summing lines.Enough common is the use of such lamps on ships long voyage.
Acetylene: application in medicine
As used substance in this area?General anesthesia involves the use of alkyne.Acetylene is one of those gases, which are used in inhalation anesthesia.However, widespread use of it as such in the past.Now there are more modern and safe methods of anesthesia.
Although it should be noted that the use of acetylene is a great danger, as before the value of its concentration in the inhaled air reaches a dangerous limit, the lower limit of flammability is passed.
The most important condition is the use of gas safety measures.It's hard to overstate how dangerous acetylene.Its use is possible only after all the necessary instructions to the employees of the various areas in which it is used.