EPA-AA-TSS-PA-84-5
Technical Report
Evaporative Emissions of Methanol
Blend Fueled Vehicles
Project Officer
Craig A. Harvey
November 1984
NOTICE
Technical Reports do not necessarily represent final EPA
decisions or positions. They are intended to present
technical analysis of issues using data which 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 which may form the basis for a final EPA
decision, position or regulatory action.
Technical Support Staff
Emission Control Technology Division
Office of Mobile Sources
Office of Air and Radiation
U. S. Environmental Protection Agency
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SOUTHWEST RESEARCHINSTITUTE
POST OFFICE OHAWEH 28S10 • 8220CULEBRA ROAO • SAN ANTONIO. TEXAS. USA 78284 -1512) 684-5) 11'TELEX 78-7367
September 28, 1984
TO: Mr. Craig A. Harvey, Project Officer
Environmental Protection Agency
2565 Plymouth Road
Ann Arbor, MI 48105
FROM: Harry E. Dietzmann
Department of Emissions Research
Southwest Research Institute
6220 Culebra Road
San Antonio, TX 78284
SUBJECT: Final Data Report on Tasks 1 and 2 of Work Assignment No. 4,
Contract 68-03-3192, "Gasoline Volatility Analysis," SwRI
Project 03-7774, Phases -104 and -204.
I. INTRODUCTION
This Work Assignment is made up of four individual Tasks, each of which
has its own objectives. Task 1, "Matched Gasoline Preparation," is included
to formulate test gasolines for use in Task 2, "Vehicle Evaporative Emission
Testing." Task 2 uses a 14-car fleet under test for DOE to gain information
on changes in evaporative emission performance due to the use of methanol
blends. Task 3, "Vehicle Fuel Volatility Trends," is an attempt to determine
how gasolines with a range of front-end volatilities "weather" in the fuel
tank during normal consumer use. Task 4, "Gasoline Volatility Control Study,"
uses refinery modeling to determine the costs (to the refiner) associated
with volatility control as a method to reduce evaporative emissions. The
Final Data Report presents data and results of Tasks 1 and 2. Separate
Final Data Reports will be submitted on Tasks 3 and 4 .
II. SUMMARY
Evaporative emission tests were conducted on a 14-vehicle DOE fleet
currently under test at SwRI. Seven vehicles were accumulating mileage on
an unleaded control fuel (EM-601-F), and seven vehicles were accumulating
mileage on an alcohol blend (EM-602-F) containing 4 percent methanol, 2
percent ethanol and 2 percent t-butyl alcohol (TBA). Alcohol speciation
of evaporative emission hydrocarbons was conducted on selected tests using
the alcohol-containing fuel. In addition, a "matched-blend" gasoline
(EM-603-F) was prepared so that the front-end volatility index (FEVI) was
equivalent to the FEVI of the control fuel.
Exhaust emissions datawerenot collected during the complete test matrix,
but rather only on the DOE blend vehicles operating on the blend fuel,and
the DOE control vehicle operating on the control fuel. The CO, HC, and
NOx emission rates were quite close for the two vehicle-fuel combinations.
SAN ANTONIO, TEXAS
WITH orncu IN HOUSTON. TEXA:
ANO WASHINGTON.
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-2-
Based on the data generated in this study, the following
items appear pertinent.
1. Hydrocarbon evaporative emissions of the blend
vehicles tested on the control fuel averaged 5.55
g/test compared to 2.50 g/test for the control
vehicles tested on the control fuel (EM-601-F).
2. Hydrocarbon evaporative emissions from the blend
vehicles on the blend fuel (EM-602-F) increased
significantly to 23.62 g/test for the seven
vehicles. This is not surprising, since the RVP
of the blend fuel (EM-602-F) was 12.3 psi compared
to the RVP of 9.1 psi of the control fuel.
3. Evaporative emission testing of both vehicle
groups with the matched blend fuel (EM-603-F)
produced evaporative emissions only slightly
higher than the 2.0 g/test for the control
vehicles. Differences between the control
vehicles tested on EM-601-F and EM-603-F (i.e.,
fuels with the same FEVI) showed essentially no
difference in evaporative emissions, i.e., 2.50
g/test with EM-602-F compared to 2.23 g/test with
EM-603-F. However, when the blend vehicles were
tested with EM-601-F, evaporative emissions were
5.50 g/test compared to 2.37 g/test with the
matched blend fuel, EM-603-F.
4. In general, methanol accounted for about four
percent of the ppmC in the SHED evaporative
emission tests. Ethanol generally accounted for
less than one percent of the SHED ppmC and TBA
accounted for less than 0.5 percent of the SHED
ppmC.
III. RESULTS
A. Task 1 - Matched Blend preparation
Preparation of the "matched blend" gasoline
(EM-603-F) has been completed and fuel inspection data are
presented in Table 1. This fuel was prepared to have a front
end volatility equivalent to the DOE unleaded control fuel
(EM-601-F). Approximately 450 gallons of the "matched blend"
fuel were prepared and about 200 gallons were used during the
emission testing of the DOE vehicles under this work
assignment, leaving about 250 gallons for testing at the end
of the DOE vehicle mileage accumulation, scheduled for
FY'85. It is anticipated that mileage accumulation on the
DOE vehicles will be completed in late November.
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TABLE 1. TASK 1 FUEL INSPECTION DATA
Fuel Code
Specification ASTM
API Gravity @ 60 °F D-287
Distillation, °F . D-86
IBP
10%
50%
90%
EP
Recovery, %
Residue, %
Loss, %
% Evaporated @ 158°F
RVP, psig D-323
Water, ppm D-1533
V/L @ 20°F D-439
b
Water tolerance
FEVIC
EM-601-F
59.5
87
119
207
341
409
98.0
1.0
1.0
28.0
9.1
158
137.3
— — —
12.7
EM-602-F
58.8
89
111
18t)
336
402
98.0
1.0
1.0
40.5
12.3
587
119.9
pass
17.6
EM-603-F
101
125
212
339
393
98.0
1.0
1.0
32.5
8.6
— — —
12.8
Additional fuel inspection data will be
included as they are received.
ASTM information document on Gasohol,
_ASTM Section 5, Volume 05.01 (Appendix).
"Front end volatility index, FEVI = RVP -t-0,13 (% Evap @ 158°F)
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-4-
The remaining 250 gallons are stored in securely sealed
drums in a "cold box" until the vehicles are ready for
testing. Sufficient quantities of the unleaded control fuel
and alcohol blend have been drummed and are also stored for
testing in November or December.
B. Task 2 - Vehicle Evaporative Emission Testing
Emission tests on the 14 DOE vehicles have been
completed and results are presented in Table 2. All of the
control fuel vehicles were tested first with the control fuel
and then the matched blend. For five of the blend vehicles
the test sequence was first the control fuel, then the DOE
blend, and finally the matched blend. The other two blend
vehicles (102 and 107) were tested first on the DOE blend,
then the matched blend, and finally the control fuel. As can
be seen from the odometer readings in Table 2, the mileage
between each test ranged from a few hundred to a few thousand
miles. All of the mileage accumulation was done by lending
the vehicles to employees to use in their normal driving. As
preconditioning prior to the start of the SHED test each
vehicle was run on the test fuel using one LA-4 dynomometer
driving cycle and overnight soak as in the standard EPA
certification procedure.
Evaporative emission results for the DOE vehicles operating
on three fuels are summarized in Figure 1. Total .evaporative
emissions of the seven DOE blend vehicles tested on the
control fuel (5.55 g/test) were about double those from the
seven DOE control vehicles (2.50 g/test). Most of this
difference was due to the greater diurnal emissions of the
blend vehicles, which was statistically significant at a 95
percent confidence level. When tested on the blend fuel
(EM-602-F) the"evaporative emissions of the seven DOE blend
vehicles increased dramatically. An increase in evaporative
emissions with EM-602-F is not unexpected, since the RVP of
the fuel is 12.3 psi compared to the control fuel (EM-601-F)
RVP of 9.1 psi. No significant difference in total
evaporative emission results was observed when the blend and
control vehicles were tested with the matched blend fuel,
EM-603-F, but the diurnal emissions of the blend vehicles
were significantly greater than the control vehicles at a 95
percent confidence level.
During the evaporative emission tests with the blend and
matched blend fuels, samples were obtained to quantitatively
determine the amount of methanol, ethanol and t-butyl alcohol
(TEA) in selected SHED tests. These results are presented in
Table 3. In general, methanol was the only alcohol to
account for more than one percent of the total hydrocarbons
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TABLE 2. EMISSIONS RESULTS FROM DOE VEHICLES
Fuel Code Vehicle^ Odometer
EM-601-F
DOE
Control
Fuel
EM-601-F
DOE
Control
Fuel
EM-602-F
DOE
Blend
Fuel
EM-603-F
EPA
Matched
Blend
Fuel
EM-60 3-F
EPA
Matched
Blend
Fuel
101
102
103
104
105
106
107
Avg
201
202
203
204
205
206
207
Avg
101
102
103
104
105
106
107
Avg
101
102
103
104
105
106
107
Avg
201
202
203
204
205
206
207
Avg
3,455
15,5 32
12,656
16,222
9,905
9,706
9.614
11,727
9,916
15,265
14,136
17,326
11,165
11,205
9,236
12,607
FTP Emission Rate
CO
a
MR
MR
MR
MR
MR
MR
MR
2.99
3.65
3.15
5.37
5.92
3.05
2.44
3.80
3.56
4.12
2.98
4.57
4.81
1.75
4.02
3.68
MR
MR
MR
MR
MR
MR
MR
NR
MR
MR
NR
MR
NR
MR
HC
MR
MR
MR
MR
MR
MR
MR
0.32
0.33
0.45
0.62
0.33
0.40
0.39
0.41
0.46
0.63
0.51
0.56
0.51
0.41
0.40
0.48
MR
MR
NR
NR
MR
NR
MR
NR
NR
MR
MR
MR
NR
MR
g/mi
NO,,
MR
MR
NR
NR
NR
MR
NR
0.57
0.47
0.50
,0.52
0.46
0.70
0.60-
0.55
0.67
0.58
0.66
0.49
0.72
1.09
0.55
0.63
MR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
SHED Evap. HC r g
Diuraal Hot SoaK
Total
1.31
8.53
,34
1.33
not run
Orr
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24
22
20
18
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6.0
5.5
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en
.2 4.5
en
en
•^
w 4.0
S
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.U
2 3.5
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8 2.5
2
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*^^
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1.5
1.0
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•
m
mm
mm
r
*
••
)
••
•*
•m
-
-
-
-
-
-
-
-
vehicles accumulatin
mileage on EM-601-F
(200 series) ^
/•
r
t
NOT]
EM-
EM-
EM-
Vehicles accumulatin
mileage on EM-602-F
(100 series)
EM-601-F is control fuel
EM-602-F is blend fuel
EM-603-F is "matched blen
EM-601-F EM-602-F EM-603-F
Evaporative Emission Test Fuel
Figure 1. Comparison of Evaporative Emission Results from
DOE vehicles tested with three fuels
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Legend
Hot Soak
EM-602-F
EM-603-F
Figure 2.
Comparison of percent methanol in SHED hydrocarbons
DOE blend vehicles tested'wi'th two fuels (Blend,
EM-602-F and matched blend, EM-603-F)
from three
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TABLE 3. ALCOHOL SPECIATION OF SHED HYDROCARBONS FROM THREE
DOE BLEND VEHICLES OPERATING ON TWO FUELS
EM-602-F
EM-603-F
Alcohol
Vehicle Species Cone.
104 CH OH ppm
ppmC
ug/m3
% THC
C2H OH ppm
ppmC
ug/m3
% THC
TBA ppm
ppmC
ug/m3
% THC
105 CH OH ppm
ppmC
ug/m3
% THC
C^OH ppm
ppmC
ug/m3
% THC
TBA ppm
ppmC
Ug/m 3
% THC
Diurnal
26.2
20.7
34,958
4.2
1.80
3.1
3446
0.6
0.44
1.7
1369
0.3
13.65
10.8
18,191
4.8
1.05
1.8
2015
0.8
0.07
0.27
196
0.1
Hot Soak
53.6
42.3
71,451
4.2
6.74
11.4
12,906
1.1
2.65
10.1
8163
1.0
7.02
5.5
9361
1.8
1.24
2.1
2378
0.7
0.18
0.69
480
0.2
Back-
around
0.3
0.2
362
0.5
ND
ND
ND
ND
ND
ND
ND
ND
0.22
0.2
2177
1.0
0.03
0.05
48 >
0.3
ND
ND
ND
ND
Diurnal
4.48
3.54
5970
3.6
0.55
0.94
1050
0.9
0.13
0.50
393
0.5
4.17
3.29
5560
3.6
0.02
0.03
39
:.V-.. xo'.i
' .'0.04
0.15
124
0.2
Hot Soak
2.83
2.24
3870
3.4
0.37
0.63
708
1.0
0.07
0.27
224
0.4
2.85
2.25
3790
3.6
0.41
0.70
775
1.1
0.07
0.27
208
0.4
3ack-
ground
0.16
0.13
252
0.7
0.01
27.4
— — —
0.01
0.04
34
0.2
0.21
0.17
278
0.8
0.03
0.05
65
0.2
ND
ND
ND
ND
101
CH3OH
C H OH
TBA
ppm
ppmC
ug/m3
% THC
ppm
ppmC
Ug/m 3
% THC
ppm
ppmC
ug/m3
% THC
17.26
13.6
23,001
4.1
1.36
2.3
2598
0.7
0.06
0.23
148
0.1
3.64
2.9
4852
2.9
0.79
1.3
1517
1.3
0.13
0.50
361
0.5
0.50
0.4
662
0.2
0.05
0.09
104 •
0.5
ND
ND
ND
ND
VOID
VOID
VOID
VOID
0.05
0.09
105
0.2
ND
ND
ND
ND
3.14
2.5
4170
3.9
ND
ND
ND
ND
0.11
0.42
339
0.6
0.13
0.10
173
0.8
0.04
0.07
71
0.4
ND
ND
ND
ND
ND - not detected
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-9-
in the evaporative emissions. The percent methanol in SHED
evaporative emissions of the DOE vehicles was generally about
4 percent of the total hydrocarbons in the SHED, as
illustrated in Figure 2. Methanol was blended at four
percent, ethanol was blended at two percent, and TBA was
blended at two percent. Ethanol averaged about 0.7 percent
of the SHED hydrocarbons, while TBA accounted for less than
0.4 percent of the SHED hydrocarbons.
Prepared by:
t.
Harry^E. Dietzmann
Manager, Chemical Analysis
Department of Emissions Research
Reviewed by:
Submitted by:
Charles T. Hare'
Manager, Advanced Technology
Department of Emissions Research
Karl J./,Sprinaer
Director ^
Department of Emissions Research
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