Ethylene (C2H4) is a colorless and sweet-smelling gas. It occurs naturally in plant tissue, but for industrial purposes, it is obtained by thermal cracking of naphtha or low alkanes. It forms an explosive and flammable mixture with air at low to medium concentrations.
It is used in the petrochemical and polymer industries as a raw material. The principal reactions include polymerization (production of polyethylene), oxidation (production of ethylene oxide, ethylene glycol, acetylaldehyde, etc.), halogenation (production of halogenated ethylenes), alkylation (production of ethylbenzene, ethyltoluene, etc.) and hydration (production of ethanol). It is also used in agriculture for ripening fruits.
Some of its physical properties are:
|Molecular weight: 28.054||Critical temperature: 282.35 K|
|Melting point: 104 K||Critical pressure: 5.0408 MPa|
|Normal boiling point: 169.35 K||Critical density: 214.2 kg/m3|
|Normal vapor density: 1.26 kg/m3||(@ 273.15K; 1.0135MPa)|
Table 1. Ethylene: Values of thermodynamic, transport and surface tension properties of the saturated liquid and vapor
The values of thermodynamic properties are from Jacobson et al. (1988), transport properties from Holland et al. (1983) and surface tension from Beaton and Hewitt (1989). A correlation of the viscosity and thermal conductivity data of gaseous and liquid ethylene.
Beaton, C. F. and Hewitt, G. F. (1989) Physical Property Data for the Design Engineer, Hemisphere Publishing Corporation, New York. DOI: 10.1016/0300-9467(89)80011-5
Holland, P. M., Heaton, B. E., and Hanley, H. J. M. (1983). A correlation of the viscosity and thermal conductivity data of gaseous and liquid ethylene. J. Phys. Chem. Ref. Data. 12: 917.
Jacobson, R. T. et al. (1988) International Thermodynamic Tables of the Fluid State, 10. Ethylene. Blackwell Scientific Publications, Oxford.