Tag: petroleum and natural gas

In case of straight chain hydrocarbons, the octane number decreases with increase in the length of the chain.

The octane numbers of aromatic hydrocarbons are exceptionally high.

Introduction of double or triple bond increases the value of octane number.

$n$-nonane has an octane number of $-20$.

Compounds with more than 100 and less than 0 octane numbers are  also known. For example triptane has octane number of 125 and n -nonane has octane number of -45.

Branching of chain increases the value of octane number.

Cracking, alkylation and isomerization will increase the octane number of gasolines.

The addition of benzene, toluene and xylene will increase the octane number of gasoline.

During carbonization or destructive distillation of coal, bituminous coal is heated in iron or fireclay retorts to high temperature (1000-1400 deg C) in absence of air.

In propagation step of cracking process, a free radical removes a hydrogen atom from another molecule, turning the second molecule into a free radical.