CHEM 1106 Lecture Notes - Lecture 8: Anthracite, Bioenergy, Nimby
3 Apr 2016
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Document Summary
Gasoline is a lighter fraction from crude oil. There are more than 150 compounds in the mixture. The gasoline fraction that comes from a distillation column is called straight-run gasoline and it does not perform well in modern high-compression automobile engines. Octane ratings measures the fuel"s ability to resist knocking, decreasing fuel eiciency. Knocking occurs when the fuel combusts before the spark plug ires. Isooctane is very resistant to knocking so it is assigned the octane rating of 100. Gasoline with an octane rating of 90 performs the same as a mixture of 90% isooctane and 10% heptane. Chemists can convert straight chain alkenes with branched ones and combine hydrocarbons with 3 or 4 carbon atoms to products with 7 or 8 carbons, which are more useful as auto fuel. Octane ratings can be improved in many ways, one being catalytic reformation of the low octant alkanes into cyclic alkanes with higher octane ratings.
