Higher alkanes
As higher alkanes, alkanes are designated whose longest chain has at least nine carbon atoms. Nonane is the lightest higher alkane and has a flash point of 31 ° C. This is why it is no longer classified as highly flammable.
Use
As the number of carbon atoms, the viscosity of the materials is greatly increased, and therefore they are hardly available in gasoline. Instead, alkanes of up to a chain length of 16 atoms ( the hexadecane ) main component of diesel fuel and kerosene. These are therefore characterized by the cetane number, derived from the old name for hexadecane cetane. Due to the already high viscosity at room temperature, the use of these fuels at low temperature and in cold regions is problematic.
Higher alkanes from hexadecane are the main components of fuel oil, heavy oil, and many lubricating oils. The latter are often used because of their hydrophobic properties as corrosion protection. Since these alkanes are solid at room temperature and often, they are used in paraffin, for example for the production of candles.
Alkanes with a chain length from about 35 atoms find upwards in road construction as a natural asphalt (bitumen ) use. A majority of these alkanes, however, split into lower alkanes by cracking, as these have a greater value in the further processing.
Physical Properties
Nonane to hexadecane
Heptadecane to Tetracosan
Note: For Eicosan the material designation Icosan or Eikosan is in Beilstein and CAS Index continues to be used.