1. Introduction
Many factors determine gasoline quality. One of the key
specifications of gasoline is the octane number, which is
related to the fuel knocking (self-igniting) property in internal
combustion engines. High octane numbers correspond
to a low knocking intensity that is related to good engine
performance.
In general, branched paraffins have higher octane numbers
than their corresponding linear paraffins (Table 1).
For instance, linear hexane has an octane number equal
to 25, while 2,2-dimethylbutane, an hexane isomer, has
an octane number equal to 92. For that reason, isomerization
of linear paraffins, a process in which straight-chain
hydrocarbon molecules rearrange to form branched hydrocarbons
[1], is used to improve gasoline quality.