Description

This article is from the Gasoline FAQ, by Bruce Hamilton with numerous contributions by others.

4.4.1 Saturated hydrocarbons ( aka paraffins, alkanes )

- stable, the major component of leaded gasolines.
- tend to burn in air with a clean flame.
- octane ratings depend on branching and number of carbon atoms.

alkanes
normal = continuous chain of carbons ( Cn H2n+2 )
- low octane ratings, decreasing with carbon chain length.

    normal heptane	C-C-C-C-C-C-C                    C7H16

iso = branched chain of carbons ( Cn H2n+2 )
- higher octane ratings, increasing with carbon chain branching.

    iso octane =                       C   C   
    ( aka 2,2,4-trimethylpentane )     |   |
                                     C-C-C-C-C           C8H18   
                                       |
                                       C

cyclic = circle of carbons ( Cn H2n )
( aka Naphthenes )
- high octane ratings.

    cyclohexane  =                 C
                                  / \
                                 C   C
                                 |   |                   C6H12
                                 C   C
                                  \ /
                                   C

 

Continue to:

• prev: 4.4 What are the hydrocarbons in gasoline?
• Index
• next: 4.4.2 Unsaturated Hydrocarbons