# Hydrocarbon Composition of Gasoline Vapor Emissions from Enclosed Fuel Tanks

Draft

# EPA-420-D-10-001 January 2010 

# Assessment and Standards Division Office of Transportation and Air Quality

and

Human Exposure & Atmospheric Sciences Division Office of Research and Development

U.S. Environmental Protection Agency 

# Hydrocarbon Composition of Gasoline Vapor Emissions from Enclosed Fuel Tanks

Draft

NOTICE

This technical report does not necessarily represent final EPA decisions or positions. It is intended to present technical analysis of issues using data that are currently available. The purpose in the release of such reports is to facilitate the exchange of technical information and to inform the public of technical developments.

# Introduction

The purpose of this report is for EPA OTAQ (Offi ce of Transportation and Air Quality) to give an initial summary of EPA ORD (Office of Rese arch and Development) work on the composition of hydrocarbon emissions from gasoline, specifically the head space components above gasoline in an enclosed fuel tank. EPA ORD will formally publish this work in a scientific journal but, until that is done, this repo rt will provide details on that work since it is related to EPA regulatory packages such as ai r quality modeling done for the Renewable Fuel Standards and Light-Duty Vehicle Greenhouse Gas Standards.

Overview and Prior Work

Headspace vapors are those hydrocarbon compounds in gaseous form above a gasoline sample in an enclosed space such as a fuel tank, frequently a fuel storage tank used in the distribution for gasoline. Some of these vapors are emitted to the atmosphere in transport, storage, and utilization of gasoline. The numerous hydrocarbon compounds (about 120 individual hydrocarbons) represent the more volatile and lower molecular weight components of the gasoline. In recent years and even more so in the future, ethanol, as a renewable fuel component, is blended with gasoline generally at the 10% level, which results in 90% gasoline with 10% ethanol. This fuel mixture of 90% gasoline and 10% ethanol (in denatured form) will be referred to as E10 while 100% gasoline with no ethanol added will be referred to as E0. Also, blends of 85% ethanol and 15% gasoline (E85) can be used in specially de signed flexible-fueled vehicles but new headspace profiles with E85 have not yet been obtained in this project for E85.

There are, thus, the following three fuel blends of interest

100% gasoline E0 90% gasoline with 10% ethanol E10 85% ethanol with 15% gasoline E85

Originally, two profiles for headspace vapors for E0 and E10 were selected from the SPECIATE data base located at

http://www.epa.gov/ttn/chief/so ftware/speciate/index.html

These profiles were profile number 8737 and 8736 for E0 and E10 respectively. The profiles showed the following aromatic and olefin content for the headspace vapors.

Aromatics Olefins E0 blend 4% 13% E10 blend 2% 4%

1

# Since the use of ethanol, which has high octane pr operties, in gasoline would replace other high octane components such as aromatics, it is reasonab le to expect that the aromatic content of the headspace would decrease as these profiles show. It is not reasonable to expect that use of E10 would so markedly decrease olefin content. Gasoline composition varies widely in-use. The purpose of the air quality modeling using these profiles is to determine the air quality effects of adding ethanol to gasoline in an effort to ha ve the E0 and E10 samples reflect what happens when ethanol is added to gasoline rather thanusing profiles from samples where the widely varying composition of in-use gaso line obfuscates the results.

Initially, the two profiles from SPECIATE mentione d above were adjusted so that the olefin content of the E10 blend represen ted addition of 10% ethanol to the base gasoline (from splashblending). This adjustment was made by decreasing the olefin content of the E0 headspace profiles so that the total olefincontent would be about 4% an d increasing the other components including the aromatics to make up for the decreased olefin levels . The resulting profile (named 8737b) is shown in the attached table.

In addition to these calculations, measurements were done on an actual splash-blended E10 blend obtaining a speciation profile and comparing it to one obtained on the corresponding base gasoline. Gasoline/ethanol blends now generally utilize the higher octane of ethanol and, thus, as not splash-blended as occurred more in the past. Additional works should and will be done with these newer blends compared to a base ga soline. This future work though should be done on typical (average) E0 and E10 blends. Still, for this work, a base gasoline was used designed to be typical of in-use gasoline.

The base gasoline being used is that from an EPA in-use test program for emissions characterization. The gasoline/ethanol (E10) sample used for headspace analysis was splash blended. The base gasoline (E0) was shippe d in two canisters from the EPA Office of Transportation and Quality facility (OTAQ) in Ann Arbor, MI to the EPA Office of Research and Development (ORD) facility in Research Triangle Park, NC. That facility added 10% ethanol to a portion of the gasoline to create a 10% ethanol (E10) blend as described below. This gasoline has relatively low olefincontent (about 4%) but more typical aromatic content (about 26%).

Results

The impact on headspace vapors from the addition of 10% ethanol to the base gasoline in this study was to lower the % paraffins and %olefins, and slightly increase th e %aromatics. This is shown in the spreadsheet where the 86% paraffi ns, 7.6% olefins, and 5.1% aromatics in the headspace@25C for the base gasoline compares to 75.6% paraffins, 6.3% olefins, and 5.6% aromatics in the headspace with the added ethanol. Consequently the addition of 10% ethanol to the base fuel did decrease the % olefin content from 7.6 to 6.3% of total VOC observed in the headspace@25C. Note that these are percentages of the total VOC. This project did not measure how the total VOC emissions changed with addition of ethanol but only the percent change in the VOC itself. Generally, the addition of ethanol to a base gasoline increases the Reid Vapor Pressureof the resultant bl end and, thus, the total VOC emissions on a mass basis. Also note that isopentane is a major constituent of th e headspace vapors accounting

2

# for about 40% of the VOC while it accounts for about 10% of the composition of the b ase gasoline.

The results showed relatively similar aromatic levels for both E0 and E10 which the earlier profiles also showed. The results also showed relatively similar olefin levels for both fuels which the earlier profiles did not show.

These new profiles will be added to SPECIATE (as numbers 8762 and 8763).

Some smog chamber runs have been done with these samples and will be reported separately.



# Appendix

Sample Preparation

Both canisters (one for E0 and one for E10) were placed in a fuel shed maintained at 13 degrees C for storage. An approximate 1 liter aliquot of E0 was removed from one of the stored cans and placed in a stainless steel canister in the storage shed facility. The canister was removed from the shed, taken to the laboratory, and placed in a large storage cooler containing ice. After an approximate 2 hour cooling period a 225 ml samp le of the cooled gas was taken using a graduated cylinder, then placed ina 500ml stainless steel can th at contained 25 ml of 200 proof absolute ethanol. This can was closed, swirled mi xed, then placed into the storage cooler that contained the 1 liter can of gasoline (E0 designated as sample 41033). Both cans were stored for a period of about 90 minutes in the cooler. During this time period, and on 2 other occasions, the can containing the 90% gasolin e 41033 with 10% ethanol (E10) was swirl mixed for an approximate 15 second period.

Triply distilled water (70 ul) was injected into four recently cleaned and vacuum evacuated six liter SUMMA canisters to condition the canister surface. This small volume of water vaporizes to water vapor coating the intern al surfaces of the canister with a monolayer of water vapor to deactivate and condition active su rface sites allowing the storage of the hydrocarbons in the gasoline and gasoline head space at 25 degrees C. Without this deactivation, significant losses of hydrocarbon compounds from benzene to the high er molecular weight hydrocarbons would be observed during the sample storage period.

At the end of this process 25 ml aliquots of the E0 and E10 fuels were placed into 50 ml Erlenmeyer flasks then placed into a constant te mperature bath containing water and maintained at 25 o 

# C. After a 20 minute equilibration time 100 ul aliquots of the headspace vapors were taken from each flask and injected into the canisters wh ich were then filled to 40 psig with ultra high purity helium. The prepared canisters were al lowed to equilibrate for a 12 to 15 hour period before performing both GC/FID and GC/MS anal yses. Whole fuel samples were prepared by injecting 0.02ul aliquots of the cool ed liquid into canisters then filled to 40 psig using ultra high

3

# purity helium. More details of these procedures are published elsewhere. Li kewise more detailed concerning the GC/FID and GC/MS me thodology are published elsewhere. 1



# The results obtained for E0 sent to RTP for h eadspace analysis using GC/FID techniques are provided in the attached Excel spreadsheet. Inthe spreadsheet are the results for both the headspace at 25 degrees C and whole fuel analys es of E0 and E10. About 140 compound peaks are presented from the more than 200 compound peaks observed representing approximately 98% of total VOC concentration. The headspac e vapors for both E0 and E10 contain 6-7% olefins and about 5% aromatics. Compound name, VOC type, and RTINDEX 2 

# for each compound are provided in the first 3 columns to the left. Each sample analysis is identified by file name just above the identi fication of the sample. The column giving the quantitative levels (in ppb) is the observed peak c oncentration given as parts-per- billion-carbon (ppbC). At the bottom of the column is the sum of all the listedpeaks followed by the sum of all the more than 200 observed peaks. Below these 2 values is the ra tio that the sum of liste d peaks is of all the observed peaks. This value is typically 98 to 99% . In the rows below these values are the sum and % sum of the various compound groups to the total VOC. Ther e are pairs of these columns for each of the 4 canister sample results. For thos e 2 canister samples that contained ethanol, the concentration of ethanol was corrected for the reduced FID response due to the presence of the oxygen atom using published values. For ethanol, th e carbon atom attached to the hydroxyl (OH) group has about 50% reduced response with the FID compared to other carbon atoms in the compound. Consequently the correction for the 2 carbons in ethanol is given as 2/1.5 or 1.33.

The next column highlighted is the % that eachof the listed compounds is of total VOC, (the sum of the more than 200 observed peaks).

The next column highlighted is the ratio of the % of total VOC for each compound peak observed in the headspace@25C sample to that for the similar compounds observed in the whole gasoline analysis. As expected the more volatil e compounds contribute a larger % of total VOC in the headspace @25C than in the fuel. From the spreadsheet the ratio of 1.6 observed for ethanol indicates that this substituted hydrocarbon is less volatile than the hydrocarbon compounds, 3-methyl-1-butene and isopentane, eluti ng just before and after ethanol on the GC column.

Electronic copies of the chromatograms fo r all 4 samples are available if needed.

Precision and Accuracy of Results

1 

# Harley, R.A., S.A. McKeen, M.O. Rodgers, a nd W.A. Lonneman, Analysis of motor vehicle emissions during the Nashville/Middle Te nnessee Ozone Study, J. Geophys. Res., 106, 3559- 3567, 2001

2

## RTINDEX is a technique used to place the elution order and/or location of various VOCs on the GC column. The most common approach is to determine the retention times of a mixture of the C 2 

## -C 15 

## normal paraffins (i.e., ethane through pentadecane) then place other VO Cs by retention time were these co mpounds elute in reference to the normal paraffins. For example the retention time of benzene on an EPA GC column with an RTINDEX value of651.21 is about half way between the retention times of n-hexane with a defined RTINDEX value of 600.00 and nheptane with a defined RTINDEX value of 700.00.



# 4

# Over the years in past analyses of whole gasoline and gasoline headspace@25C sam ples, ORD has measured both precision and accuracy fo r these analyses. Repeats for instrumental precision are the more commonly performed with repeatability of 5% or better.

A National Institute of Standards and Technology Standard Reference Material (NIST/SRM) propane in air standard cylinder is used to determine accuracy. The assumption is made (as it is in EPA measurements of motor ve hicle exhaust) that a ll hydrocarbons respond in the flame ionization detector (F ID) with a uniform per carbon re sponse. However, ethanol, as well as any other oxygenated hydrocarbons in ga soline, does not respond in this way. As discussed earlier, an adjustmentwas made for the presence of oxygen in the FID response. In the case of ethanol, the presence of oxygen causes this 2 carbon compound to respond as if has only 1.5 carbons. Consequently, the observed measur ement for ethanol is adjusted using a 2/1.5 or 1.33 correction factor for this compound.

Measurements done by William Lonneman and Tad Kleindienst US Environment Protection Agency Office of Research and Development National Exposure Research Laboratory Research Triangle Park, NC 27711

5Gasoline # 41033 Headspace@25C and Whole Gas Analyses

Profile 8762 Profile 8763 Headspace Vapors E0 Headspace Vapors E10

NAME VOC type % of Total VO C Ratio HS to Whole Gasoline % of Total VO C Ratio HS to Whole Gasoline ppb ppb Propylene o 1.420 0.025 5.0 1.200 0.017 3.6 Propane p 3.090 0.054 8.9 2.740 0.038 6.2 Isobutane p 17.310 0.303 15.6 16.830 0.236 11.3 Butene-1 o 3.440 0.060 4.8 3.170 0.044 3.3 Isobutylene o 3.670 0.064 8.3 3.430 0.048 8.7 1,3-Butadiene o 0.580 0.010 2.5 0.340 0.005 1.0 n-Butane p 248.950 4.352 11.1 245.340 3.443 9.8 t-Butene-2 o 11.070 0.194 9.6 10.640 0.149 8.6 2,2-Dimethylpropane p 5.340 0.093 8.7 5.510 0.077 8.3 c-Butene-2 o 10.960 0.192 7.8 10.600 0.149 6.8 3-Methyl-1-Butene o 6.530 0.114 5.6 6.150 0.086 5.4 Ethanol ox 0.000 0.000 0.0 773.130 12.756 1.6 Isopentane p 2564.210 44.829 4.6 2600.840 36.495 4.2 Pentene-1 o 27.510 0.481 4.0 27.640 0.388 3.7 2-Methyl-1-Butene o 55.880 0.977 3.9 56.860 0.798 3.5 n-Pentane p 332.580 5.814 3.4 347.780 4.880 3.2 Isoprene o 1.020 0.018 3.3 0.930 0.013 3.1 trans-2-Pentene o 70.600 1.234 3.3 72.140 1.012 3.0 Unknown u 0.940 0.016 3.9 0.750 0.011 2.4 cis-2-Pentene o 38.470 0.673 3.3 38.880 0.546 3.0 2-Methyl-2-Butene o 103.970 1.818 3.0 104.510 1.466 2.7 2,2-Dimethylbutane p 26.870 0.470 2.2 28.860 0.405 2.1 Cyclopentene o 12.570 0.220 2.4 12.840 0.180 2.2 3-Methyl-1-pentene o 6.020 0.105 1.9 5.700 0.080 1.7 Cyclopentane p 19.610 0.343 2.0 20.620 0.289 1.9 2,3-Dimethylbutane p 264.190 4.619 1.6 285.050 4.000 1.6 2-Methylpentane p 216.080 3.778 1.5 235.960 3.311 1.5 3-Methylpentane p 124.530 2.177 1.3 137.510 1.930 1.3 2-Methyl-1-Pentene + Hexene-1 o 10.660 0.186 1.3 12.000 0.168 1.3 n-Hexane p 61.420 1.074 1.0 69.510 0.975 1.1 trans-3-Hexene o 5.980 0.105 1.1 6.530 0.092 1.1 trans-2-Hexene o 8.200 0.143 1.1 8.990 0.126 1.1 2-Methyl-2-Pentene o 12.760 0.223 1.1 11.130 0.156 1.1 cis-3-Hexene o 6.500 0.114 1.1 6.970 0.098 1.1 4-Methylcyclopentene o 1.500 0.026 1.2 1.480 0.021 1.2 cis-2-Hexene o 4.910 0.086 1.1 5.150 0.072 1.1 cis-3-Methyl-2-pentene o 8.770 0.153 0.9 9.740 0.137 1.0 2,2-DiMethylpentane p 3.410 0.060 0.8 3.850 0.054 0.9 Methylcyclopentane p 56.810 0.993 1.0 63.390 0.889 1.0 2,4-Dimethylpentane p 153.070 2.676 0.7 179.780 2.523 0.8 2,2,3-TriMethylbutane p 5.020 0.088 0.7 6.340 0.089 0.9 2,4-DiMethyl-1-Pentene o 0.390 0.007 0.8 0.400 0.006 0.7 1-Methylcyclopentene o 5.560 0.097 0.8 6.240 0.088 0.9 Benzene a 19.710 0.345 0.9 21.280 0.299 0.9 3,3-DiMethylpentane p 3.190 0.056 0.6 3.600 0.051 0.7 Cyclohexane p 9.350 0.163 0.8 10.650 0.149 0.8 4-Me-1-Hexene o 0.350 0.006 0.6 0.470 0.007 0.5 2-Methylhexane p 30.510 0.533 0.5 38.480 0.540 0.6 2,3-Dimethylpentane p 208.240 3.641 0.5 255.640 3.587 0.6 1,1-DiMeCyclopentane p 1.280 0.022 0.7 1.460 0.020 0.7 3-Methylhexane p 30. 730 0.537 0.5 38.420 0.539 0.5 5-Me-2-Hexene o 0.490 0.009 0.8 0.430 0.006 0.7 c-1,3-DiMeCyclopentane p 6.210 0.109 0.5 7.660 0.107 0.6 t-1,3,-DiMeCyclopentane p 8.120 0.142 0.5 10.310 0.145 0.6 2,2,4-TriMethylpentane p 297.780 5.206 0.4 384.850 5.400 0.5 3-Me-3-Hexene o 0.890 0.016 1.0 0.820 0.012 0.8 trans-3-Heptene o 1.230 0.022 0.8 0.900 0.013 0.6 n-Heptane p 16.330 0.285 0.4 21.620 0.303 0.5 trans-3-Heptene o 2.790 0.049 0.5 2.730 0.038 0.4 Unknown u 0.680 0.012 0.5 0.790 0.011 0.6 3-Ethyl-2-Pentene o 0.430 0.008 0.5 0.590 0.008 0.7 3-Methyl-2-Hextene o 0.630 0.011 0.4 0.870 0.012 0.5 2,4,4-TriMethyl-1-Pentene o 0.730 0.013 0.5 1.070 0.015 0.6 cis-2-Heptene o 0.570 0.010 0.4 0.660 0.009 0.5 MethylCyclohexane p 9.220 0.161 0.4 11.830 0.166 0.4 Unknown u 1.090 0.019 0.5 1.360 0.019 0.5 2,5-DiMethylhexane p 24.690 0.432 0.3 34.810 0.488 0.3 2,4-DiMethylhexane + EthylCyclopentane p 34.470 0.603 0.3 47.980 0.673 0.4 3,3-DiMethylhexane + 1,2,4-TriMeCyclopentane p 1.420 0.025 0.3 1.990 0.028 0.4 ctc-1,2,3-TriMeCyclopentane p 0.640 0.011 0.4 0.770 0.011 0.4



# 6Gasoline # 41033 Headspace@25C and Whole Gas Analyses (continued)

Profile 8762 Profile 8763 Headspace Vapors E0 Headspace Vapors E10

NAME VOC type % of Total VO C Ratio HS to Whole Gasoline % of Total VO C Ratio HS to Whole Gasoline ppb ppb ctc-1,2,3-TriMeCyclopentane p 0.640 0.011 0.4 0.770 0.011 0.4 2,3,4-TriMethylpentane p 100.690 1.760 0.3 142.440 1.999 0.3 Toluene a 189.470 3.312 0.3 255.930 3.591 0.3 2,3-DiMethylhexane p 19.740 0.345 0.3 28.230 0.396 0.3 2-Methylheptane p 4.200 0.073 0.2 6.000 0.084 0.3 4-MeHeptane p 1.920 0.034 0.2 2.810 0.039 0.3 3,4-DiMethylhexane p 3.740 0.065 0.2 5.310 0.075 0.3 3-Methylheptane p 5.220 0.091 0.2 7.280 0.102 0.3 ctc-1,2,4-TriMeCyclopentane p 1.300 0.023 0.4 1.560 0.022 0.4 t-1,4-DiMeCyclohexane p 0.000 0.0 0.000 0.0 Unknown u 26.500 0.463 0.2 40.450 0.568 0.2 1,1-DiMethylcyclohexane p 0.600 0.010 0.3 0.650 0.009 0.2 Unknown u 0.360 0.006 0.3 0.400 0.006 0.3 2,2,4-TriMethylhexane p 0.530 0.009 0.2 0.950 0.013 0.3 Unknown u 0.000 0.0 0.000 0.0 n-Octane p 2.520 0.044 0.2 3.940 0.055 0.2 cis-2-Octene o 0.590 0.010 0.2 1.320 0.019 0.3 Isopropylcyclopentane p 0.000 0.0 0.000 0.0 2,3,5-TriMethylhexane p 4.650 0.081 0.2 6.910 0.097 0.2 2,4-DiMethylheptane p 1.190 0.021 0.3 1.950 0.027 0.4 2,6-DiMethylheptane p 0.900 0.016 0.2 1.800 0.025 0.4 1c2-DiMethylcyclohexane n-Propylcyclopentane p 0.000 0.0 0.000 0.0 2,5-DiMeHeptane p 1.770 0.031 0.2 2.680 0.038 0.2 Unknown u 0.830 0.015 0.5 0.840 0.012 0.4 1,1,4-TriMeCyclohexane p 0.000 0.0 0.440 0.006 0.6 Ethylbenzene a 8.630 0.151 0.2 12.820 0.180 0.2 ctt-1,2,4-TriMeCyclohexane p 0.960 0.017 0.2 1.370 0.019 0.2 m-& p-Xylene a 27.440 0.480 0.1 40.450 0.568 0.2 3-Methyloctane p 1.180 0.021 0.2 1.610 0.023 0.2 ctc-1,2,4-TriMeCyclohexane p 1.700 0.030 0.1 2.790 0.039 0.1 3,3-DiEthylpentane p 0.450 0.008 0.1 0.810 0.011 0.2 o-Xylene a 5.670 0.099 0.1 8.430 0.118 0.2 Nonene-1 o 1.540 0.027 0.1 2.700 0.038 0.2 1,1,2-TriMeCyclohexane p 1.540 0.027 0.1 2.700 0.038 0.2 Nonane p 0.380 0.007 0.1 0.720 0.010 0.2 trans-2-Nonene o 0.880 0.015 0.1 1.620 0.023 0.1 Isopropylbenzene a 1.280 0.022 0.1 2.180 0.031 0.1 3,5-DiMethyloctane p 0.490 0.009 0.4 0.110 0.002 0.1 2,6-DiMethyloctane p 0.350 0.006 0.1 0.490 0.007 0.1 n-Propylbenzene a 3.140 0.055 0.1 4.210 0.059 0.1 m-Ethyltoluene a 8.750 0.153 0.1 12.220 0.171 0.1 p-Ethyltoluene a 3.990 0.070 0.1 5.480 0.077 0.1 1,3,5-TriMethylbenzene a 4.520 0.079 0.1 5.790 0.081 0.1 3-Methylnonane p 0.120 0.002 0.1 0.170 0.002 0.1 o-Ethyltoluene a 3.180 0.056 0.1 4.280 0.060 0.1 1,2,4-TriMethylbenzene a 10.910 0.191 0.1 15.640 0.219 0.1 n-Decane p 0.340 0.006 0.1 0.720 0.010 0.1 Isobutylbenzene + 1-Me-2-Propylcyclohexane a 0.210 0.004 0.1 0.450 0.006 0.1 sec-Butylbenzene a 0.270 0.005 0.1 0.430 0.006 0.1 m-Cymene a 0.320 0.006 0.1 0.410 0.006 0.1 1,2,3-TriMethylbenzene a 2.090 0.037 0.1 2.650 0.037 0.1 Indane n 0.650 0.011 0.1 0.790 0.011 0.1 m-Diethylbenzene a 0.000 0.000 1,Me-3-n-Propylbenzene a 0.640 0.011 0.0 0.960 0.013 0.0 n-Butylbenzene a 0.850 0.015 0.1 1.520 0.021 0.1 1-Me-2-n-Propylbenzene a 0.750 0.013 0.1 0.950 0.013 0.1 1,4-DiMe-2-Ethylbenzene a 0.680 0.012 0.1 0.420 0.006 0.0 Unknown u 0.000 0.0 0.490 0.007 0.1 1,2-DiMe-4-Ethylbenzene a 0.680 0.012 0.1 0.990 0.014 0.1 1,3-DiMe-2-Ethylbenzene a 0.000 0.0 0.000 0.0 n-Undecane p 0.520 0.009 0.4 0.330 0.005 0.1 1,2-DiMe-3-Ethylbenzene a 0.000 0.0 0.000 0.0 1,2,4,5-Tetra-Me-Benzene a 0.400 0.007 0.1 0.280 0.004 0.0 Unknown u 0.790 0.014 0.1 0.510 0.007 0.0 Unknown u 0.000 0.0 0.210 0.003 0.0 Methylindane n 0.350 0.006 0.2 0.000 0.0 n-Pentylbenzene + t-1-Me-2-(4MP)cyclohexane a 0.000 0.0 0.000 0.0 Unknown u 0.000 0.0 0.000 0.0 t-1-But-3,5-DiMeBenzene a 0.000 0.000 Naphthalene n 0.000 0.000 0.0 0.180 0.003 0.0 n-Dodecane p 0.310 0.005 0.3 0.000 0.0



# 7

## Summary Statistics on Headspace Profiles

GasE0 HS@25C GasE10 HS@2 

## NAME Sum of GC Peaks 5,698 7,000 Sum of ALL GC Peaks 5,720 7,032

%Sum of Peaks are of Total HC 99.610 99.545

Sum of Parafins 4,936.64 5,339.24 % of Total 86.303 75.925

Sum of Aromatics 293.58 397.77 % of Total 5.132 5.656

Sum of Olefins 435.40 443.35 % of Total 7.612 6.304

% Ethanol is of Total HC 0.000 10.994 % Ethanol adjusted for FID Response is of Total HC 12.757

Sum of Unknowns 31.19 45.80 % of Total 0.545 0.651

Sum of Fused Rings 1.00 0.97 % of Total 0.017 0.014



# 8Gasoline # 41033 Headspace@25C and Whole Gas Analyses Whole Gasoline Analysis

E0 Gasoline E10 Gasoline NAME VOC type % of Total VOC % of Total VOC ppb ppb Propylene o 0.550 0.005 0.490 0.005 Propane p 0.680 0.006 0.640 0.006 Isobutane p 2.170 0.019 2.160 0.021 Butene-1 o 1.396 0.012 1.380 0.013 Isobutylene o 0.870 0.008 0.575 0.006 1,3-Butadiene o 0.450 0.004 0.490 0.005 n-Butane p 43.790 0.391 36.360 0.351 t-Butene-2 o 2.248 0.020 1.800 0.017 2,2-Dimethylpropane p 1.202 0.011 0.970 0.009 c-Butene-2 o 2.760 0.025 2.270 0.022 3-Methyl-1-Butene o 2.300 0.021 1.650 0.016 Ethanol ox 0.000 0.000 601.970 7.731 Isopentane p 1085.710 9.704 903.320 8.723 Pentene-1 o 13.330 0.119 10.770 0.104 2-Methyl-1-Butene o 28.050 0.251 23.520 0.227 n-Pentane p 192.770 1.723 160.060 1.546 Isoprene o 0.600 0.005 0.430 0.004 trans-2-Pentene o 42.090 0.376 35.140 0.339 Unknown u 0.470 0.004 0.460 0.004 cis-2-Pentene o 23.140 0.207 19.120 0.185 2-Methyl-2-Butene o 68.840 0.615 56.350 0.544 2,2-Dimethylbutane p 24.150 0.216 19.820 0.191 Cyclopentene o 10.240 0.092 8.360 0.081 3-Methyl-1-pentene o 6.350 0.057 4.890 0.047 Cyclopentane p 19.010 0.170 15.520 0.150 2,3-Dimethylbutane p 322.610 2.884 258.910 2.500 2-Methylpentane p 290.040 2.592 232.290 2.243 3-Methylpentane p 188.070 1.681 150.340 1.452 2-Methyl-1-Pentene + Hexene-1 o 16.370 0.146 13.650 0.132 n-Hexane p 115.050 1.028 91.870 0.887 trans-3-Hexene o 10.440 0.093 8.310 0.080 trans-2-Hexene o 15.100 0.135 12.000 0.116 2-Methyl-2-Pentene o 23.100 0.206 14.750 0.142 cis-3-Hexene o 11.860 0.106 9.430 0.091 4-Methylcyclopentene o 2.440 0.022 1.870 0.018 cis-2-Hexene o 8.810 0.079 6.820 0.066 cis-3-Methyl-2-pentene o 18.110 0.162 14.140 0.137 2,2-DiMethylpentane p 8.580 0.077 6.470 0.062 Methylcyclopentane p 114.310 1.022 90.990 0.879 2,4-Dimethylpentane p 416.280 3.721 328.280 3.170 2,2,3-TriMethylbutane p 13.600 0.122 10.100 0.098 2,4-DiMethyl-1-Pentene o 0.900 0.008 0.780 0.008 1-Methylcyclopentene o 14.230 0.127 10.460 0.101 Benzene a 43.490 0.389 36.140 0.349 3,3-DiMethylpentane p 9.730 0.087 7.950 0.077 Cyclohexane p 23.880 0.213 19.510 0.188 4-Me-1-Hexene o 1.240 0.011 1.430 0.014 2-Methylhexane p 121.640 1.087 97.660 0.943 2,3-Dimethylpentane p 781.810 6.988 622.010 6.006 1,1-DiMeCyclopentane p 3.800 0.034 3.030 0.029 3-Methylhexane p 127. 490 1.140 102.130 0.986 5-Me-2-Hexene o 1.270 0.011 0.950 0.009 c-1,3-DiMeCyclopentane p 24.060 0.215 19.220 0.186 t-1,3,-DiMeCyclopentane p 33.910 0.303 27.110 0.262 2,2,4-TriMethylpentane p 1454.670 13.002 1163.680 11.237 3-Me-3-Hexene o 1.790 0.016 1.450 0.014 trans-3-Heptene o 2.890 0.026 2.330 0.022 n-Heptane p 83.300 0.745 68.520 0.662 trans-3-Heptene o 11.360 0.102 8.960 0.087 Unknown u 2.440 0.022 2.010 0.019 3-Ethyl-2-Pentene o 1.560 0.014 1.220 0.012 3-Methyl-2-Hextene o 3.090 0.028 2.560 0.025 2,4,4-TriMethyl-1-Pentene o 3.140 0.028 2.720 0.026 cis-2-Heptene o 2.500 0.022 1.942 0.019 MethylCyclohexane p 47.670 0.426 38.930 0.376 Unknown u 4.420 0.040 3.620 0.035 2,5-DiMethylhexane p 177.140 1.583 146.080 1.411 2,4-DiMethylhexane + EthylCyclopentane p 238.440 2.131 194.880 1.882 3,3-DiMethylhexane + 1,2,4-TriMeCyclopentane p 9.740 0.087 7.990 0.077 ctc-1,2,3-TriMeCyclopentane p 3.490 0.031 2.840 0.027



# 9Gasoline # 41033 Headspace@25C and Whole Gas Analyses (continued) Whole Gasoline Analysis

E0 Gasoline E10 Gasoline NAME VOC type % of Total VOC % of Total VOC ppb ppb 2,3,4-TriMethylpentane p 775.810 6.934 639.310 6.173 Toluene a 1339.630 11.974 1109.480 10.713 2,3-DiMethylhexane p 153.750 1.374 133.550 1.290 2-Methylheptane p 36.440 0.326 30.590 0.295 4-MeHeptane p 15.540 0.139 13.350 0.129 3,4-DiMethylhexane p 31.520 0.282 26.630 0.257 3-Methylheptane p 46.520 0.416 39.710 0.383 ctc-1,2,4-TriMeCyclopentane p 6.940 0.062 6.150 0.059 t-1,4-DiMeCyclohexane p 1.700 0.015 1.640 0.016 Unknown u 282.200 2.522 237.980 2.298 1,1-DiMethylcyclohexane p 4.290 0.038 3.940 0.038 Unknown u 2.630 0.024 2.290 0.022 2,2,4-TriMethylhexane p 6.200 0.055 5.300 0.051 Unknown u 0.990 0.009 0.910 0.009 n-Octane p 29.350 0.262 24.980 0.241 cis-2-Octene o 6.710 0.060 5.740 0.055 Isopropylcyclopentane p 1.040 0.009 0.900 0.009 2,3,5-TriMethylhexane p 50.700 0.453 44.620 0.431 2,4-DiMethylheptane p 7.980 0.071 6.930 0.067 2,6-DiMethylheptane p 7.970 0.071 6.930 0.067 1c2-DiMethylcyclohexane n-Propylcyclopentane p 2.090 0.019 1.820 0.018 2,5-DiMeHeptane p 21.030 0.188 18.550 0.179 Unknown u 3.310 0.030 2.780 0.027 1,1,4-TriMeCyclohexane p 1.270 0.011 1.110 0.011 Ethylbenzene a 106.170 0.949 95.190 0.919 ctt-1,2,4-TriMeCyclohexane p 11.070 0.099 10.030 0.097 m-& p-Xylene a 368.860 3.297 335.120 3.236 3-Methyloctane p 11.280 0.101 10.340 0.100 ctc-1,2,4-TriMeCyclohexane p 29.860 0.267 27.520 0.266 3,3-DiEthylpentane p 6.450 0.058 6.140 0.059 o-Xylene a 85.590 0.765 79.320 0.766 Nonene-1 o 26.390 0.236 23.810 0.230 1,1,2-TriMeCyclohexane p 26.390 0.236 23.810 0.230 Nonane p 7.090 0.063 6.900 0.067 trans-2-Nonene o 17.540 0.157 16.400 0.158 Isopropylbenzene a 24.030 0.215 23.670 0.229 3,5-DiMethyloctane p 2.150 0.019 2.500 0.024 2,6-DiMethyloctane p 6.550 0.059 6.450 0.062 n-Propylbenzene a 61.570 0.550 64.280 0.621 m-Ethyltoluene a 203.520 1.819 214.260 2.069 p-Ethyltoluene a 87.280 0.780 93.290 0.901 1,3,5-TriMethylbenzene a 111.050 0.993 119.840 1.157 3-Methylnonane p 1.900 0.017 2.550 0.025 o-Ethyltoluene a 73.670 0.658 79.500 0.768 1,2,4-TriMethylbenzene a 285.760 2.554 321.300 3.103 n-Decane p 10.610 0.095 11.860 0.115 Isobutylbenzene + 1-Me-2-Propylcyclohexane a 5.960 0.053 6.870 0.066 sec-Butylbenzene a 5.280 0.047 5.990 0.058 m-Cymene a 7.010 0.063 8.510 0.082 1,2,3-TriMethylbenzene a 51.460 0.460 61.020 0.589 Indane n 14. 230 0.127 16.620 0.160 m-Diethylbenzene a 0.000 0.000 1,Me-3-n-Propylbenzene a 44.380 0.397 57.420 0.554 n-Butylbenzene a 31.470 0.281 42.860 0.414 1-Me-2-n-Propylbenzene a 18.940 0.169 24.990 0.241 1,4-DiMe-2-Ethylbenzene a 9.310 0.083 13.290 0.128 Unknown u 8.680 0.078 12.220 0.118 1,2-DiMe-4-Ethylbenzene a 15.070 0.135 22.170 0.214 1,3-DiMe-2-Ethylbenzene a 1.190 0.011 1.910 0.018 n-Undecane p 2.300 0.021 4.290 0.041 1,2-DiMe-3-Ethylbenzene a 4.320 0.039 6.220 0.060 1,2,4,5-Tetra-Me-Benzene a 7.150 0.064 11.130 0.107 Unknown u 10.320 0.092 15.920 0.154 Unknown u 3.870 0.035 6.550 0.063 Methylindane n 2.960 0.026 4.600 0.044 n-Pentylbenzene + t-1-Me-2-(4MP)cyclohexane a 2.610 0.023 4.350 0.042 Unknown u 1.750 0.016 2.920 0.028 t-1-But-3,5-DiMeBenzene a 0.000 0.000 Naphthalene n 4.500 0.040 9.120 0.088 n-Dodecane p 2.220 0.020 3.890 0.038



# 10

# Summary Statistics on Whole Gasoline Profiles

GasE0 Whole GasE10 Whole 

# NAME Sum of GC Peaks 11,038 10,039 Sum of ALL GC Peaks 11,189 10,221

%Sum of Peaks are of Total HC 98.654 98.221

Sum of Parafins 7,295.60 5,950.96 % of Total 65.203 58.224

Sum of Aromatics 2,994.77 2,838.12 % of Total 26.765 27.768

Sum of Olefins 405.26 329.93 % of Total 3.622 3.228

% Ethanol is of Total HC 0.000 5.890 % Ethanol adjusted for FID Response is of Total HC 7.264

Sum of Unknowns 321.08 287.66 % of Total 2.870 2.814

Sum of Fused Rings 21.69 30.34 % of Total 0.194 0.297



# 11

### Calculated Profile for E0 Gasoline H eadspace Based on E10 Profile Compound Profile 8737B Compound (CONTINUED) Profile 8737 B

1-METHYLPROPYLBENZENE 0.012% 2,5-DIMETHYLHEXANE 0.227% 2-METHYLPROPYLBENZENE 0.009% 2,6-DIMETHYLHEPTANE 0.028% 1,1,2-TRIMETHYLCYCLOPENTANE 0.000% 2,6-DIMETHYLOCTANE 0.053% 1,1,3-TRIMETHYLCYCLOPENTANE 0.000% 2-BUTYNE 0.000% 1,1-DIMETHYLCYCLOHEXANE 0.002% 2-ETHYL-1-BUTENE 0.000% 1,1-DIMETHYLCYCLOPENTANE 0.002% 2-METHYL-1-BUTENE 0.478% 1,2,3,4-TETRAMETHYLBENZENE 0.000% 2-METHYL-1-PENTENE 0.090% 1,2,3,5-TETRAMETHYLBENZENE 0.000% 2-METHYL-2-BUTENE 0.833% 1,2,3-TRIMETHYLBENZENE 0.066% 2-METHYL-2-HEXENE 0.000% 1,2,3-TRIMETHYLCYCLOPENTANE 0.000% 2-METHYL-2-PENTENE 0.117% 1,2,4,5-TETRAMETHYLBENZENE 0.012% 2-METHYL-2-PROPENAL 0.000% 1,2,4-TRIMETHYLBENZENE 0.267% 2-METHYL-3-ETHYLPENTANE 0.001% 1,2,4-TRIMETHYLCYCLOPENTANE 0.019% TRANS-2-METHYL-3-HEXENE 0.000% 1,2-DIETHYLBENZENE 0.000% 2-METHYLHEPTANE 0.174% 1,2-DIMETHYL-3-ETHYLBENZENE 0.008% 2-METHYLHEXANE 0.807% 1,2-DIMETHYL-4-ETHYLBENZENE 0.039% 2-METHYLOCTANE 0.043% PROPADIENE 0.000% 2-METHYLPENTANE 4.607% 1,3,5-TRIMETHYLBENZENE 0.091% 3,3-DIMETHYL-1-BUTENE 0.000% 1,3-BUTADIENE 0.001% 3,3-DIMETHYLHEPTANE 0.000% CYCLOPENTADIENE 0.000% 3,3-DIMETHYLHEXANE 0.055% 1,3-DIETHYLBENZENE 0.017% 3,3-DIMETHYLPENTANE 0.079% 1,3-DIMETHYL-2-ETHYLBENZENE 0.000% 3,4-DIMETHYLHEPTANE 0.000% 1,3-DIMETHYL-4-ETHYLBENZENE 0.000% 3,4-DIMETHYLHEXANE 0.045% 1,3-DIMETHYL-5-ETHYLBENZENE 0.000% 3,5-DIMETHYLHEPTANE 0.000% 1,4-DIETHYLBENZENE 0.057% 3,5-DIMETHYLOCTANE 0.003% 1,4-DIMETHYL-2-ETHYLBENZENE 0.025% 3,6-DIMETHYLOCTANE 0.003% 1-BUTENE 0.082% 3-ETHYL-2-PENTENE 0.000% 1-BUTYNE 0.000% 3-ETHYLHEXANE 0.000% 1-ETHYL-TERT-BUTYLETHER 0.000% 3-ETHYLPENTANE 0.235% 1-HEPTENE 0.000% 3-METHYL-1-BUTENE 0.114% 1-HEXENE 0.043% 3-METHYL-1-HEXENE 0.000% 1-METHYL-2-ETHYLBENZENE 0.070% 3-METHYL-1-PENTENE 0.058% 1-METHYL-2-ISOPROPYLBENZENE 0.000% CIS-3-METHYL-2-HEXENE 0.000% 1-METHYL-2-N-BUTYLBENZENE 0.001% 3-METHYL-CIS-2-PENTENE 0.000% 1-METHYL-2-N-PROPYLBENZENE 0.025% CIS-3-METHYL-3-HEXENE 0.000% 1-METHYL-2-TERT-BUTYLBENZENE 0.000% 3-METHYL-TRANS-2-PENTENE 0.000% 1-METHYL-3-ETHYLBENZENE 0.189% 3-METHYL-TRANS-3-HEXENE 0.000% 1-METHYL-3-ISOPROPYLBENZENE 0.018% 3-METHYLCYCLOPENTENE 0.002% 1-METHYL-3-N-PROPYLBENZENE 0.037% 3-METHYLHEPTANE 0.194% 1-METHYL-4-ETHYLBENZENE 0.073% 3-METHYLHEXANE 0.794% 1-METHYL-4-ISOPROPYLBENZENE 0.010% 3-METHYLNONANE 0.017% 1-METHYL-4-NPROPYLBENZENE 0.000% 3-METHYLOCTANE 0.052% 1-METHYLCYCLOPENTENE 0.045% 3-METHYLPENTANE 2.510% 1-NONENE 0.000% 4,4-DIMETHYL-2-PENTENE 0.000% 1-OCTENE 0.000% 4,4-DIMETHYLHEPTANE 0.004% 1-PENTENE 0.270% 4-METHYL-1-HEXENE 0.007% 1-PROPYNE 0.000% 4-METHYL-1-PENTENE 0.000% 2,2,3-TRIMETHYLBUTANE 0.039% 4-METHYL-CIS-2-PENTENE 0.000% 2,2,3-TRIMETHYLPENTANE 0.000% 4-METHYL-TRANS-2-PENTENE 0.000% 2,2,4-TRIMETHYLHEXANE 0.036% 4-METHYLHEPTANE 0.083% 2,2,4-TRIMETHYLPENTANE 2.542% 4-METHYLOCTANE 0.000% 2,2,5-TRIMETHYLHEXANE 0.000% TRANS-5-METHYL-2-HEXENE 0.000% 2,2-DIMETHYLBUTANE 1.383% ACETALDEHYDE 0.000% 2,2-DIMETHYLHEXANE 0.000% ACETONE 0.000% 2,2-DIMETHYLOCTANE 0.000% ACETYLENE 0.000% 2,2-DIMETHYLPENTANE 0.072% ACROLEIN 0.000% 2,2-DIMETHYLPROPANE 0.025% BENZALDEHYDE 0.000% 2,3,3-TRIMETHYLPENTANE 0.000% BENZENE 1.202% 2,3,4-TRIMETHYLPENTANE 0.723% N-BUTYRALDEHYDE 0.000% 2,3,5-TRIMETHYLHEXANE 0.034% C10H20 0.000% 2,3-DIMETHYL-2-BUTENE 0.000% C11H16 0.000% 2,3-DIMETHYLBUTANE 1.667% UNIDENTIFIED C9-C12+ 0.000% 2,3-DIMETHYLHEPTANE 0.000% CIS,TRANS-1,2,4-TRIMETHYLCYC L 0.001% 2,3-DIMETHYLHEXANE 0.203% CIS-1,2-DIMETHYLCYCLOHEXANE 0.025% 2,3-DIMETHYLPENTANE 0.597% Cis-1,3-DIMETHYLCYCLOHEXANE 0.000% 2,4,4-TRIMETHYL-1-PENTENE 0.014% CIS-1,3-DIMETHYLCYCLOPENTAN E 0.174% 2,4,4-TRIMETHYL-2-PENTENE 0.000% 1-CIS,2-TRANS,3-TRIMETHYLCYC L 0.005% 2,4-DIMETHYL-1-PENTENE 0.005% CIS-1,TRANS-2,4-TRIMETHYLCYC L 0.008% 2,4-DIMETHYLHEPTANE 0.032% CIS-1,TRANS-2,TRANS-4-TRIMET H 0.003% 2,4-DIMETHYLHEXANE 0.413% 1-CIS-2-DIMETHYLCYCLOPENTAN 0.000% 2,4-DIMETHYLOCTANE 0.000% CIS-1-ETHYL-3-METHYLCYCLOPE N 0.000% 2,4-DIMETHYLPENTANE 0.650% CIS-2-BUTENE 0.208% 2,5-DIMETHYLHEPTANE 0.063% Cis-2-HEPTENE 0.009%



# 12

### Compound Profile 8737B Compound Profile 8737 B

Cis-2-OCTENE 0.002% TRANS-4-OCTENE 0.000% CIS-2-PENTENE 0.327% HEXALDEHYDE 0.000% CIS-3-HEXENE 0.055% VALERALDEHYDE 0.000% CROTONALDEHYDE 0.000% P-METHYLSTYRENE 0.000% CYCLOHEXANE 0.228% NONANAL 0.000% CYCLOHEXENE 0.000% OCTANAL 0.000% CYCLOPENTANE 0.577% 1-UNDECENE 0.004% CYCLOPENTENE 0.119% 1-BUTENE+ ISOBUTENE 0.000% ETHANE 0.056% 1,3-HEXADIENE (TRANS) 0.000% ETHANOL 0.124% 3-METHYL-2-PENTENE 0.097% ETHYLBENZENE 0.273% PROPYLTOLUENE 0.000% ETHYLCYCLOHEXANE 0.000% O-TOLUALDEHYDE 0.000% ETHYLCYCLOPENTANE 0.000% ISOPROPYLCYCLOPENTANE 0.000% ETHYLENE 0.000% C11H14 0.000% FORMALDEHYDE 0.000% 3-ETHYLPENTENE 0.050% INDAN 0.037% DANITOL 0.049% ISOBUTANE 5.357% 2-BUTENE 0.192% 2-METHYLPROPENE (ISOBUTYLENE) 0.090% METHYLINDANE 0.031% M-& P-XYLENE 0.997% CIS-2-NONENE 0.000% 2-METHYLBUTANE (ISOPENTANE) 27.821% T-1-BUTYL-2-METHYLBENZENE 0.000% ISOPRENE 0.022% 2,5-DIMETHYLBENZALDEHYDE 0.000% 2-PROPANOL 0.000% P-DIETHYLBENZENE &N-BUTYLB E 0.003% ISOPROPYLBENZENE (CUMENE) 0.046% 4-METHYLCYCLOPENTENE 0.004% ISOPROPYLCYCLOHEXANE 0.000% C10H12 0.000% ISOVALERALDEHYDE 0.000% C11H24 0.000% METHANE 0.000% C12H26 0.000% METHANOL 0.000% 2-OCTENE 0.000% MEK 0.000% C-3-HEXENE 0.000% O-METHYLSTYRENE 0.000% UNIDENTIFIED C6 0.000% MTBE 0.000% C6H8 0.000% METHYLCYCLOHEXANE 0.298% UNIDENTIFIED C7 0.000% METHYLCYCLOPENTANE 1.150% C7H14 0.000% N-BUTANE 22.649% C8H14 0.000% N-BUTYLBENZENE 0.000% C9H18 0.000% N-BUTYLCYCLOPENTANE 0.000% 1,5-DIMETHYLCYCLOPENTENE 0.000% N-DECANE 0.063% ETHYLCYCLOPENTENE 0.000% N-DODECANE 0.023% ISOBUTYRALDEHYDE 0.000% N-HEPTANE 0.494% CAMPHENE 0.000% N-HEXANE 1.684% METHYLBENZALDEHYDE 0.000% N-NONANE 0.073% METHYLCYCLOHEXENE 0.000% N-OCTANE 0.153% PENTADIENE 0.000% N-PENTANE 7.187% PIPERYLENE 0.000% N-PENTYLBENZENE 0.000% 1-TERT-BUTYL-3,5-DIMETHYLBEN Z 0.001% N-PROPYLBENZENE 0.067% UNKNOWN 0.000% N-TRIDECANE 0.000% N-UNDECANE 0.040% NAPHTHALENE 0.027% O-XYLENE 0.312% C10H22 0.000% C7H12 0.000% C8H16 0.000% PROPANE 0.342% PROPIONALDEHYDE 0.000% PROPYLCYCLOHEXANE 0.004% N-PROPYLCYCLOPENTANE 0.001% PROPYLENE 0.013% STYRENE 0.000% TOLUALDEHYDE 0.000% TOLUENE 2.918% TRANS-1,2-DIMETHYLCYCLOHEXANE 0.000% TRANS-1,2-DIMETHYLCYCLOPENTANE 0.000% TRANS-1,3-DIMETHYLCYCLOHEXANE 0.000% TRANS-1,3-DIMETHYLCYCLOPENTANE 0.016% TRANS-1,3-PENTADIENE 0.000% TRANS-1,4-DIMETHYLCYCLOHEXANE 0.003% TRANS-1-ETHYL-3-METHYLCYCLOPENTANE 0.000% TRANS-2-BUTENE 0.043% TRANS-2-HEPTENE 0.000% TRANS-2-HEXENE 0.099% TRANS-2-OCTENE 0.003% TRANS-2-PENTENE 0.641% TRANS-3-HEPTENE 0.013% TRANS-3-HEXENE 0.081% TRANS-3-NONENE 0.000%



# 13