Analysis of Values Based on Components-Naphtha

Analysis of Octane Values Based on Gasoline Components of Various Brands

Chris Monaco

Octane RatingAn octane rating refers to the measure of the maximum compression ratio at which a particular fuel can be utilized in an engine without some of the fuel /air mixture "knocking" or self igniting.

Octane RatingResearch Octane NumberDetermined using a one cycle engineMotor Octane NumberRun at higher temperatures and RPMsRoad Octane NumberAverage of the research octane number and the motor octane number. This is what is displayed on the gas pump.

Gas Chromatography/Mass Spectrometry

AnalysisGC/MS is useful in determining the components of a mixture and the concentration of each component in a mixture.

87 Octane from Shell

89 Octane from Shell

93 Octane from Shell

87 Octane from Thortons

89 Octane from Thortons

92 Octane from Thortons

Qualitative AnalysisRetention TimeRetention times of components of a mixture can be compared to the retention times for known samples if run under the same conditions.Mass/Charge RatioPosition of the peak on the graph horizontally is equivalent to the molecular mass of a component.

Quantitative AnalysisRetention TimeThe area of the peak is measured by the equation: (height of peak/width of peak at half height)Mass/Charge RatioThe height of the peak is measured

Known Octane Values for Gasoline ComponentsEthanol107Methylcylcopentane103Benzene982,2,4-trimethylpentane100Toluene118P-xylene1362-methylpentane762,4-dimethylpentane83Hexane252,3-dimethylpentane94Methylcyclohexane1042,3,4-trimethylpentane972,3,3-trimethylpentane1022-methylbutane904-methylheptane39Heptane0

Shell87 octane89 octane93 octaneEthanol11.3%0%10.2%2-methyl-pentane8%4.3%4.5%Hexane3.7%3.9%0%Methylcyclopentane0%0%0%Benzene0%7.3%7%2,2,4-Trimethylpentane0%0%0%Toluene6.3%7.2%8.2%P-xylene0%10.6%0%2,4-Dimethylpentane2.8%2.8%0%2,3-Dimethylpentane7.8%0%0%2,2,3,3-tetramethylbutane5.8%4.5%0%2,2,5-trimethylhexane0%1%4%2,3,4-trimethylpentane4%3.5%2.5%1,3-dimethylbenzene10%5.7%21%Heptane0%2.9%0%

BP87 octane89 octane93 octaneEthanol7.2%0%13.4%2-methyl-pentane8.7%7.9%10.2%Hexane0%3.4%0%Methyl-cyclopentane0%4.7%0%Benzene9.7%0%0%2,2,4-Trimethylpentane0%0%0%Toluene4.8%4.5%5.5%P-xylene0%1.9%0%2,4-Dimethylpentane0%0%5.5%2,3-Dimethylpentane0%8.1%7%2,2,3,3-tetramethylbutane0%8.8%8%2,2,5-trimethylhexane2.5%0%0%2,3,4-trimethylpentane4.1%5.8%9%1,3-dimethylbenzene4.1%2.8%0%Heptane0%0%0%

Speedway87 octane89 octane93 octaneEthanol13.2%11.5%12.1%2-methyl-pentane6%5.5%4.5%Hexane3.9%2.8%2.1%Methyl-cyclopentane0%4%0%Benzene0%0%0%2,2,4-Trimethylpentane9.2%0%0%Toluene4.8%4.7%3.7%P-xylene7.2%0%0%2,4-Dimethylpentane0%0%4%2,3-Dimethylpentane7.7%7.3%6%2,2,3,3-tetramethylbutane0%0%0%2,2,5-trimethylhexane0%0%5%2,3,4-trimethylpentane2.9%4.5%6%1,3-dimethylbenzene4%7%7.5%Heptane0%0%0%

Thortons87 octane89 octane93 octaneEthanol11%11%10.1%2-methyl-pentane6%5.3%4.7%Hexane3.7%3.2%2.2%Methyl-cyclopentane4.7%0%0%Benzene0%0%0%2,2,4-Trimethylpentane0%0%0%Toluene5.4%5.5%6%P-xylene6.6%0%0%2,4-Dimethylpentane0%4%4%2,3-Dimethylpentane8.2%7.5%7%2,2,3,3-tetramethylbutane8.2%8%7%2,2,5-trimethylhexane0%2.4%2%2,3,4-trimethylpentane3.9%4.8%4.5%1,3-dimethylbenzene4%7.8%16%Heptane0%0%0%

Phillips 6687 octane89 octane93 octaneEthanol5.1%6.1%5.3%2-methyl-pentane7.2%7.7%7.5%Hexane4.2%5.1%4.4%Methyl-cyclopentane4.4%5%4.5%Benzene0%0%0%2,2,4-Trimethylpentane0%0%0%Toluene5.6%5.9%6%P-xylene0%8.5%0%2,4-Dimethylpentane0%0%0%2,3-Dimethylpentane8.1%8.2%8.5%2,2,3,3-tetramethylbutane7.7%7.9%8%2,2,5-trimethylhexane0%0%1%2,3,4-trimethylpentane2.8%3%3%1,3-dimethylbenzene7.8%4.1%13%Heptane0%0%0%

Further AnalysisThe sample could be run longer so components with longer retention times would register.

Further AnalysisIf the concentration of every component of the gasoline and the octane rating for each components were known an octane rating for the mixture could be calculated and compared to the one generated by testing the mixture as a whole.

Works CitedData Collected at USF by:Bettylou Wahl BS, Biology/Chemistry, USF 2004Ken Hutchinson BS, Environmental Science, USF 2004References:http://www.refiningonline.comhttp://jr.stryker.tripod.com/physchem/gc_ms.html