Analysis of Octane Analysis of Octane Values Based on Values Based on

Gasoline Gasoline Components of Components of Various BrandsVarious Brands

Chris MonacoChris Monaco

Octane RatingOctane Rating

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

Octane RatingOctane Rating

Research Octane NumberResearch Octane Number Determined using a one cycle engineDetermined using a one cycle engine

Motor Octane NumberMotor Octane Number Run at higher temperatures and RPM’sRun at higher temperatures and RPM’s

Road Octane NumberRoad Octane Number Average of the research octane number Average of the research octane number

and the motor octane number. This is and the motor octane number. This is what is displayed on the gas pump.what is displayed on the gas pump.

Gas Chromatography/Mass Gas Chromatography/Mass Spectrometry Spectrometry

AnalysisAnalysis

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

87 Octane from Shell87 Octane from Shell

89 Octane from Shell89 Octane from Shell

93 Octane from Shell93 Octane from Shell

87 Octane from Thortons87 Octane from Thortons

89 Octane from Thortons89 Octane from Thortons

92 Octane from Thortons92 Octane from Thortons

Qualitative AnalysisQualitative Analysis

• Retention TimeRetention Time• Retention times of components of a Retention times of components of a

mixture can be compared to the mixture can be compared to the retention times for known samples if retention times for known samples if run under the same conditions.run under the same conditions.

• Mass/Charge RatioMass/Charge Ratio• Position of the peak on the graph Position of the peak on the graph

horizontally is equivalent to the horizontally is equivalent to the molecular mass of a component.molecular mass of a component.

Quantitative AnalysisQuantitative Analysis

Retention TimeRetention Time The area of the peak is measured by the The area of the peak is measured by the

equation: (height of peak/width of peak equation: (height of peak/width of peak at half height)at half height)

Mass/Charge RatioMass/Charge Ratio The height of the peak is measuredThe height of the peak is measured

Known Octane Values for Gasoline Known Octane Values for Gasoline ComponentsComponents

EthanolEthanol 107107

MethylcylcopentaneMethylcylcopentane 103103

BenzeneBenzene 9898

2,2,4-trimethylpentane2,2,4-trimethylpentane 100100

TolueneToluene 118118

P-xyleneP-xylene 136136

2-methylpentane2-methylpentane 7676

2,4-dimethylpentane2,4-dimethylpentane 8383

HexaneHexane 2525

2,3-dimethylpentane2,3-dimethylpentane 9494

MethylcyclohexaneMethylcyclohexane 104104

2,3,4-trimethylpentane2,3,4-trimethylpentane 9797

2,3,3-trimethylpentane2,3,3-trimethylpentane 102102

2-methylbutane2-methylbutane 9090

4-methylheptane4-methylheptane 3939

HeptaneHeptane 00

ShellShell87 octane87 octane 89 octane89 octane 93 octane93 octane

EthanolEthanol 11.3%11.3% 0%0% 10.2%10.2% 2-methyl-pentane2-methyl-pentane 8%8% 4.3%4.3% 4.5%4.5% HexaneHexane 3.7%3.7% 3.9%3.9% 0%0% MethylcyclopentaneMethylcyclopentane 0%0% 0%0% 0%0% BenzeneBenzene 0%0% 7.3%7.3% 7%7% 2,2,4-Trimethylpentane2,2,4-Trimethylpentane 0%0% 0%0% 0%0% TolueneToluene 6.3%6.3% 7.2%7.2% 8.2%8.2% P-xyleneP-xylene 0%0% 10.6%10.6% 0%0% 2,4-Dimethylpentane2,4-Dimethylpentane 2.8%2.8% 2.8%2.8% 0%0% 2,3-Dimethylpentane2,3-Dimethylpentane 7.8%7.8% 0%0% 0%0% 2,2,3,3-tetramethylbutane2,2,3,3-tetramethylbutane 5.8%5.8% 4.5%4.5% 0%0% 2,2,5-trimethylhexane2,2,5-trimethylhexane 0%0% 1%1% 4%4% 2,3,4-trimethylpentane2,3,4-trimethylpentane 4%4% 3.5%3.5% 2.5%2.5% 1,3-dimethylbenzene1,3-dimethylbenzene 10%10% 5.7%5.7% 21%21% HeptaneHeptane 0%0% 2.9%2.9% 0%0%

BPBP87 octane87 octane 89 octane89 octane 93 octane93 octane

EthanolEthanol 7.2%7.2% 0%0% 13.4%13.4% 2-methyl-pentane2-methyl-pentane 8.7%8.7% 7.9%7.9% 10.2%10.2% HexaneHexane 0%0% 3.4%3.4% 0%0% Methyl-cyclopentaneMethyl-cyclopentane 0%0% 4.7%4.7% 0%0% BenzeneBenzene 9.7%9.7% 0%0% 0%0% 2,2,4-Trimethylpentane2,2,4-Trimethylpentane 0%0% 0%0% 0%0% TolueneToluene 4.8%4.8% 4.5%4.5% 5.5%5.5% P-xyleneP-xylene 0%0% 1.9%1.9% 0%0% 2,4-Dimethylpentane2,4-Dimethylpentane 0%0% 0%0% 5.5%5.5% 2,3-Dimethylpentane2,3-Dimethylpentane 0%0% 8.1%8.1% 7%7% 2,2,3,3-tetramethylbutane2,2,3,3-tetramethylbutane 0%0% 8.8%8.8% 8%8% 2,2,5-trimethylhexane2,2,5-trimethylhexane 2.5%2.5% 0%0% 0%0% 2,3,4-trimethylpentane2,3,4-trimethylpentane 4.1%4.1% 5.8%5.8% 9%9% 1,3-dimethylbenzene1,3-dimethylbenzene 4.1%4.1% 2.8%2.8% 0%0% HeptaneHeptane 0%0% 0%0% 0%0%

SpeedwaySpeedway87 octane87 octane 89 octane89 octane 93 octane93 octane

EthanolEthanol 13.2%13.2% 11.5%11.5% 12.1%12.1% 2-methyl-pentane2-methyl-pentane 6%6% 5.5%5.5% 4.5%4.5% HexaneHexane 3.9%3.9% 2.8%2.8% 2.1%2.1% Methyl-cyclopentaneMethyl-cyclopentane 0%0% 4%4% 0%0% BenzeneBenzene 0%0% 0%0% 0%0% 2,2,4-Trimethylpentane2,2,4-Trimethylpentane 9.2%9.2% 0%0% 0%0% TolueneToluene 4.8%4.8% 4.7%4.7% 3.7%3.7% P-xyleneP-xylene 7.2%7.2% 0%0% 0%0% 2,4-Dimethylpentane2,4-Dimethylpentane 0%0% 0%0% 4%4% 2,3-Dimethylpentane2,3-Dimethylpentane 7.7%7.7% 7.3%7.3% 6%6% 2,2,3,3-tetramethylbutane2,2,3,3-tetramethylbutane 0%0% 0%0% 0%0% 2,2,5-trimethylhexane2,2,5-trimethylhexane 0%0% 0%0% 5%5% 2,3,4-trimethylpentane2,3,4-trimethylpentane 2.9%2.9% 4.5%4.5% 6%6% 1,3-dimethylbenzene1,3-dimethylbenzene 4%4% 7%7% 7.5%7.5% HeptaneHeptane 0%0% 0%0% 0%0%

ThortonsThortons87 octane87 octane 89 octane89 octane 93 octane93 octane

EthanolEthanol 11%11% 11%11% 10.1%10.1% 2-methyl-pentane2-methyl-pentane 6%6% 5.3%5.3% 4.7%4.7% HexaneHexane 3.7%3.7% 3.2%3.2% 2.2%2.2% Methyl-cyclopentaneMethyl-cyclopentane 4.7%4.7% 0%0% 0%0% BenzeneBenzene 0%0% 0%0% 0%0% 2,2,4-Trimethylpentane2,2,4-Trimethylpentane 0%0% 0%0% 0%0% TolueneToluene 5.4%5.4% 5.5%5.5% 6%6% P-xyleneP-xylene 6.6%6.6% 0%0% 0%0% 2,4-Dimethylpentane2,4-Dimethylpentane 0%0% 4%4% 4%4% 2,3-Dimethylpentane2,3-Dimethylpentane 8.2%8.2% 7.5%7.5% 7%7% 2,2,3,3-tetramethylbutane2,2,3,3-tetramethylbutane 8.2%8.2% 8%8% 7%7% 2,2,5-trimethylhexane2,2,5-trimethylhexane 0%0% 2.4%2.4% 2%2% 2,3,4-trimethylpentane2,3,4-trimethylpentane 3.9%3.9% 4.8%4.8% 4.5%4.5% 1,3-dimethylbenzene1,3-dimethylbenzene 4%4% 7.8%7.8% 16%16% HeptaneHeptane 0%0% 0%0% 0%0%

Phillips 66Phillips 6687 octane87 octane 89 octane89 octane 93 octane93 octane

EthanolEthanol 5.1%5.1% 6.1%6.1% 5.3%5.3% 2-methyl-pentane2-methyl-pentane 7.2%7.2% 7.7%7.7% 7.5%7.5% HexaneHexane 4.2%4.2% 5.1%5.1% 4.4%4.4% Methyl-cyclopentaneMethyl-cyclopentane 4.4%4.4% 5%5% 4.5%4.5% BenzeneBenzene 0%0% 0%0% 0%0% 2,2,4-Trimethylpentane2,2,4-Trimethylpentane 0%0% 0%0% 0%0% TolueneToluene 5.6%5.6% 5.9%5.9% 6%6% P-xyleneP-xylene 0%0% 8.5%8.5% 0%0% 2,4-Dimethylpentane2,4-Dimethylpentane 0%0% 0%0% 0%0% 2,3-Dimethylpentane2,3-Dimethylpentane 8.1%8.1% 8.2%8.2% 8.5%8.5% 2,2,3,3-tetramethylbutane2,2,3,3-tetramethylbutane 7.7%7.7% 7.9%7.9% 8%8% 2,2,5-trimethylhexane2,2,5-trimethylhexane 0%0% 0%0% 1%1% 2,3,4-trimethylpentane2,3,4-trimethylpentane 2.8%2.8% 3%3% 3%3% 1,3-dimethylbenzene1,3-dimethylbenzene 7.8%7.8% 4.1%4.1% 13%13% HeptaneHeptane 0%0% 0%0% 0%0%

Further AnalysisFurther Analysis

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

Further AnalysisFurther Analysis

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

Works CitedWorks Cited

Data Collected at USF by:Data Collected at USF by: Bettylou Wahl – BS, Biology/Chemistry, Bettylou Wahl – BS, Biology/Chemistry,

USF 2004USF 2004 Ken Hutchinson – BS, Environmental Ken Hutchinson – BS, Environmental

Science, USF 2004Science, USF 2004 References:References:

http://www.refiningonline.comhttp://www.refiningonline.com http://http://

jr.stryker.tripod.com/physchem/gc_ms.hjr.stryker.tripod.com/physchem/gc_ms.htmltml