Analysis of Octane Values Based on Gasoline Components of Various Brands Chris Monaco

Octane Rating An 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. An 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 Rating Research Octane Number Research Octane Number Determined using a one cycle engine Determined using a one cycle engine Motor Octane Number Motor Octane Number Run at higher temperatures and RPM’s Run at higher temperatures and RPM’s Road Octane Number Road Octane Number Average of the research octane number and the motor octane number. This is what is displayed on the gas pump. Average of the research octane number and the motor octane number. This is what is displayed on the gas pump.

Gas Chromatography/Mass Spectrometry

Analysis GC/MS is useful in determining the components of a mixture and the concentration of each component in a mixture. GC/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 Analysis Retention Time Retention Time Retention times of components of a mixture can be compared to the retention times for known samples if run under the same conditions. Retention times of components of a mixture can be compared to the retention times for known samples if run under the same conditions. Mass/Charge Ratio Mass/Charge Ratio Position of the peak on the graph horizontally is equivalent to the molecular mass of a component. Position of the peak on the graph horizontally is equivalent to the molecular mass of a component.

Quantitative Analysis Retention Time Retention Time The area of the peak is measured by the equation: (height of peak/width of peak at half height) The area of the peak is measured by the equation: (height of peak/width of peak at half height) Mass/Charge Ratio Mass/Charge Ratio The height of the peak is measured The height of the peak is measured

Known Octane Values for Gasoline Components Ethanol107 Methylcylcopentane103 Benzene98 2,2,4-trimethylpentane100 Toluene118 P-xylene136 2-methylpentane76 2,4-dimethylpentane83 Hexane25 2,3-dimethylpentane94 Methylcyclohexane104 2,3,4-trimethylpentane97 2,3,3-trimethylpentane102 2-methylbutane90 4-methylheptane39 Heptane0

Shell 87 octane89 octane93 octane Ethanol11.3%0%10.2% Ethanol11.3%0%10.2% 2-methyl-pentane8%4.3%4.5% 2-methyl-pentane8%4.3%4.5% Hexane3.7%3.9%0% Hexane3.7%3.9%0% Methylcyclopentane0%0%0% Methylcyclopentane0%0%0% Benzene0%7.3%7% Benzene0%7.3%7% 2,2,4-Trimethylpentane0%0%0% 2,2,4-Trimethylpentane0%0%0% Toluene6.3%7.2%8.2% Toluene6.3%7.2%8.2% P-xylene0%10.6%0% P-xylene0%10.6%0% 2,4-Dimethylpentane2.8%2.8%0% 2,4-Dimethylpentane2.8%2.8%0% 2,3-Dimethylpentane7.8%0%0% 2,3-Dimethylpentane7.8%0%0% 2,2,3,3-tetramethylbutane5.8%4.5%0% 2,2,3,3-tetramethylbutane5.8%4.5%0% 2,2,5-trimethylhexane0%1%4% 2,2,5-trimethylhexane0%1%4% 2,3,4-trimethylpentane4%3.5%2.5% 2,3,4-trimethylpentane4%3.5%2.5% 1,3-dimethylbenzene10%5.7%21% 1,3-dimethylbenzene10%5.7%21% Heptane0%2.9%0% Heptane0%2.9%0%

BP 87 octane89 octane93 octane Ethanol7.2%0%13.4% Ethanol7.2%0%13.4% 2-methyl-pentane8.7%7.9%10.2% 2-methyl-pentane8.7%7.9%10.2% Hexane0%3.4%0% Hexane0%3.4%0% Methyl-cyclopentane0%4.7%0% Methyl-cyclopentane0%4.7%0% Benzene9.7%0%0% Benzene9.7%0%0% 2,2,4-Trimethylpentane0%0%0% 2,2,4-Trimethylpentane0%0%0% Toluene4.8%4.5%5.5% Toluene4.8%4.5%5.5% P-xylene0%1.9%0% P-xylene0%1.9%0% 2,4-Dimethylpentane0%0%5.5% 2,4-Dimethylpentane0%0%5.5% 2,3-Dimethylpentane0%8.1%7% 2,3-Dimethylpentane0%8.1%7% 2,2,3,3-tetramethylbutane0%8.8%8% 2,2,3,3-tetramethylbutane0%8.8%8% 2,2,5-trimethylhexane2.5%0%0% 2,2,5-trimethylhexane2.5%0%0% 2,3,4-trimethylpentane4.1%5.8%9% 2,3,4-trimethylpentane4.1%5.8%9% 1,3-dimethylbenzene4.1%2.8%0% 1,3-dimethylbenzene4.1%2.8%0% Heptane0%0%0% Heptane0%0%0%

Speedway 87 octane89 octane93 octane Ethanol13.2%11.5%12.1% Ethanol13.2%11.5%12.1% 2-methyl-pentane6%5.5%4.5% 2-methyl-pentane6%5.5%4.5% Hexane3.9%2.8%2.1% Hexane3.9%2.8%2.1% Methyl-cyclopentane0%4%0% Methyl-cyclopentane0%4%0% Benzene0%0%0% Benzene0%0%0% 2,2,4-Trimethylpentane9.2%0%0% 2,2,4-Trimethylpentane9.2%0%0% Toluene4.8%4.7%3.7% Toluene4.8%4.7%3.7% P-xylene7.2%0%0% P-xylene7.2%0%0% 2,4-Dimethylpentane0%0%4% 2,4-Dimethylpentane0%0%4% 2,3-Dimethylpentane7.7%7.3%6% 2,3-Dimethylpentane7.7%7.3%6% 2,2,3,3-tetramethylbutane0%0%0% 2,2,3,3-tetramethylbutane0%0%0% 2,2,5-trimethylhexane0%0%5% 2,2,5-trimethylhexane0%0%5% 2,3,4-trimethylpentane2.9%4.5%6% 2,3,4-trimethylpentane2.9%4.5%6% 1,3-dimethylbenzene4%7%7.5% 1,3-dimethylbenzene4%7%7.5% Heptane0%0%0% Heptane0%0%0%

Thortons 87 octane89 octane93 octane Ethanol11%11%10.1% Ethanol11%11%10.1% 2-methyl-pentane6%5.3%4.7% 2-methyl-pentane6%5.3%4.7% Hexane3.7%3.2%2.2% Hexane3.7%3.2%2.2% Methyl-cyclopentane4.7%0%0% Methyl-cyclopentane4.7%0%0% Benzene0%0%0% Benzene0%0%0% 2,2,4-Trimethylpentane0%0%0% 2,2,4-Trimethylpentane0%0%0% Toluene5.4%5.5%6% Toluene5.4%5.5%6% P-xylene6.6%0%0% P-xylene6.6%0%0% 2,4-Dimethylpentane0%4%4% 2,4-Dimethylpentane0%4%4% 2,3-Dimethylpentane8.2%7.5%7% 2,3-Dimethylpentane8.2%7.5%7% 2,2,3,3-tetramethylbutane8.2%8%7% 2,2,3,3-tetramethylbutane8.2%8%7% 2,2,5-trimethylhexane0%2.4%2% 2,2,5-trimethylhexane0%2.4%2% 2,3,4-trimethylpentane3.9%4.8%4.5% 2,3,4-trimethylpentane3.9%4.8%4.5% 1,3-dimethylbenzene4%7.8%16% 1,3-dimethylbenzene4%7.8%16% Heptane0%0%0% Heptane0%0%0%

Phillips octane89 octane93 octane Ethanol5.1%6.1%5.3% Ethanol5.1%6.1%5.3% 2-methyl-pentane7.2%7.7%7.5% 2-methyl-pentane7.2%7.7%7.5% Hexane4.2%5.1%4.4% Hexane4.2%5.1%4.4% Methyl-cyclopentane4.4%5%4.5% Methyl-cyclopentane4.4%5%4.5% Benzene0%0%0% Benzene0%0%0% 2,2,4-Trimethylpentane0%0%0% 2,2,4-Trimethylpentane0%0%0% Toluene5.6%5.9%6% Toluene5.6%5.9%6% P-xylene0%8.5%0% P-xylene0%8.5%0% 2,4-Dimethylpentane0%0%0% 2,4-Dimethylpentane0%0%0% 2,3-Dimethylpentane8.1%8.2%8.5% 2,3-Dimethylpentane8.1%8.2%8.5% 2,2,3,3-tetramethylbutane7.7%7.9%8% 2,2,3,3-tetramethylbutane7.7%7.9%8% 2,2,5-trimethylhexane0%0%1% 2,2,5-trimethylhexane0%0%1% 2,3,4-trimethylpentane2.8%3%3% 2,3,4-trimethylpentane2.8%3%3% 1,3-dimethylbenzene7.8%4.1%13% 1,3-dimethylbenzene7.8%4.1%13% Heptane0%0%0% Heptane0%0%0%

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

Further Analysis If 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 Cited Data Collected at USF by: Data Collected at USF by: Bettylou Wahl – BS, Biology/Chemistry, USF 2004 Bettylou Wahl – BS, Biology/Chemistry, USF 2004 Ken Hutchinson – BS, Environmental Science, USF 2004 Ken Hutchinson – BS, Environmental Science, USF 2004 References: References: