Ethylene C2H4 Gas
Ethylene or ethene is a colourless flammable hydrocarbon gas. It has a slight “sweet musky” odor when pure.
The majority of this polyethene production is used for the manufacture of polyethene. Ethylene has also been used in agriculture as an important plant hormone.
DSW provides a wide range of speciality gases in various purities and concentrations, including ethylene, primarily for use in the chemical industry.
| Gas | Ethylene | Chemical Formula | C2H4 | |
| Einecs: | 200-815-3 | Molecular Weight: | 28.054 | |
| CAS: | 74-85-1 | Flammability range in air, [% volume]: | 2.7-36.0 | |
| Boiling Point: | at 1.013 bar [℃] | -103.68 | at 14.5 psi, [℉] | -154.60 |
| Density: | at 1.013 bar,15℃, [kg/m³] | 1.194 | at 1 atm., 70℉, [lb/ft³] | 0.073 |
Industrial Process
Several methods in the petrochemical industry produce ethylene. A primary way is steam cracking (SC), where hydrocarbons and steam are heated to 750-950 degC.
This process reduces the size of hydrocarbons and introduces unsaturation. Ethane is used as the feedstock and ethylene is produced.
Ethylene can be separated from the mixture using repeated compression and distillation.
It is also produced by passing ethyl alcohol vapours over dehydrating catalysts at 360-470 °C. It may also be produced by the pyrolysis of ethane.
The cracking of petroleum is another source.
Applications
Ethylene is the starting material for several industrial syntheses. It is employed as an intermediate in the chemical industry and for the production of plastics.
Ethylene C2H4 Gas is employed for the production of:
acetaldehyde
acetic acid
chloroethane
chloroethene (vinyl chloride)
dichloroethane
1,1-dichloroethene (vinylidene chloride)
epoxyethane (ethylene oxide)
ethanediol (ethylene glycol)
ethanol
ethoxyethane
ethylbenzene
phenylethene (styrene)
polychloroethene (polyvinyl chloride)
polyethene
propanoic acid
tetraethyl lead
trichloroethane
Ethylene is used as a component in calibration gases for the automotive, gas, oil as well and chemical industries.
C2H4 gas may be employed for welding and cutting but is not used for this purpose industrially.
Ethylene supplied in cylinders is used for controlled ripening of fruit, especially bananas. A concentration of a few ppm in the warehouse atmosphere is used. Because of flammability considerations, it is strongly recommended to use a mixture of ethene in nitrogen in this application
It has also been used in agriculture to promote crop growth: in this case, the gas is injected directly into the soil.
Ethylene is still used as an anaesthetic (in the US).
It is used as a refrigerant, especially in the petrochemical industry. It has the ASHRAE number R-1150.
