EPA-AA-TEB-81-12
Evaporative and Exhaust Emissions of Two Automobiles
Fueled with Volatility Adjusted Gasohol
by
David C. Lawrence
Daniel J. Niemczak
December 1980
Test and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
U. S. Environmental Protection Agency
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Abstract
This paper presents the objectives and results of a vehicle emission test
program conducted by the U. S. Environmental Protection Agency (EPA) in
July, 1980. The program was designed to investigate the effects of using
various gasohol blends on vehicle evaporative and exhaust emissions.
Particular emphasis was directed towards a blended gasohol whose vola-
tility characteristics (ASTM distillation and Reid vapor pressure) were
adjusted to match as closely as possible those of a baseline gasoline.
Two vehicles received triplicate tests on each of four fuels: 1) a com-
mercial grade unleaded gasoline, 2) a blended gasohol containing 10%
ethanol with volatility characteristics similar to Fuel 1, 3) a mixture
of 10% ethanol and 90% Fuel 1, and 4) a mixture of 5% ethanol and 95%
Fuel 1. The analysis also included a gas chromatograph characterization
of the SHED vapors for ethanol concentrations and a comparison of carbon
balance fuel economy versus volumetric fuel economy.
Results indicate an overall increase in the total evaporative HC emis-
sions for all three gasohol fuels. Blended gasohol exhibited the lowest
increase of 41% while the 10% and 5% gasohol mixtures showed increases of
58% to 62%. Exhaust HC, CO and NOx were reduced with the blended gasohol
and 10% gasohol mixture when compared to the baseline gasoline. The 5%
gasohol mixture resulted in little or no change. For one test vehicle,
the volumetric and carbon balance fuel economy showed a decrease tor all
three gasohol fuels, while the other vehicle resulted in little or no
change. In comparing the two methods of fuel economy measurements
(carbon balance and volumetric) the volumetric method was consistently
0.6% higher.
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Intreduction '
As the production capabilities of ethyl alcohol and its use as a fuel
additive in the form of "gasohol" increase, continued research of its
effect on vehicle emissions is warranted. An earlier study conducted by
the U. S. Environmental Protection Agency (1)* showed that the largest
detrimental effect on emissions caused by the use of gasohol. was in the
area of evaporative hydrocarbon (HC) losses. This report stated that an
average increase of 49 - 62% could be expected using the current auto-
mobile fleet and method of gasohol production. Presently, commercial
gasohol is produced by "mixing" 10% (by volume) ethyl alcohol (or
ethanol) and 90% finished commercial gasoline. This addition of ethanol
drastically alters the volatility of the fuel which results in higher
evaporative emissions. One suggested solution to this problem is to
"blend" the gasohol at the refinery using heavier base stocks to end up
with a gasohol with volatility characteristics (ASTM distillation and
Reid vapor pressure) similar to commercial gasoline. As a result of this
concept, a test program was designed to investigate the effects of such a
gasohol on evaporative and exhaust emissions.
The program consisted of two late model passenger cars that received
triplicate evaporative tests using a commercial grade unleaded gasoline,
a special blended gasohol with modified volatility characteristics, and
two mixed gasohol fuels containing 5% and 10% ethanol. Secondary objec-
tives of the test program included an evaluation of exhaust emissions, a
comparison of volumetric and carbon balance fuel economy measurements and
gas chromatograph analysis of the SHED vapors for ethanol content.
The purpose of this report is to present the procedures, equipment and
results of this investigation.
Test Procedure i
The test procedure used in this program consisted mainly of the 1977
Federal Test Procedure (FTP) for evaporative and exhaust emissions (2).
Slight deviations from this procedure were introduced to accomodate addi-
tional data acquisition and instrument operation. However, these proce-
dures were usually introduced at times during the FTP which allowed
completion of the task while still following the FTP time constraints.
The deviations;from the FTP are listed belc; and a complete test sequence
is given in Appendix A.
The vehicle charcoal cannister was weighed before and after the
Diurnal Heat Build and the Hot Soak evaporative loss tests.
This was performed within the FTP time limits.
A volumetric flowmeter was connected in series between the
carburetor and the fuel pump. An electric fuel pump was
installed on each vehicle and used to prime the flowmeter and
float bowl prior to each driving cycle.
*Numbers in parentheses designate references at the end of the paper.
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A gas chromotograph was connected thru a sample port to the
SHED. A vacuum pump was used to inject the SHED vapor into the
column and it is estimated that about .5 liter was removed from
the SHED per injection.
Fuel density was measured immediately prior to each driving
cycle by means of an API hydrometer.
Engine parameters such as the water jacket, engine oil, and
carburetor bowl temperatures were recorded during the driving
cycle and Hot Soak loss portions of the FTP.
The original test plan called for triplicate tests to be run by each
vehicle using each tuel. However, due to void test make-up and a short-
age of test fuel, only duplicate tests were run by each vehicle on some
of the test fuels.
Test Fuels
The four fuels chosen for the program were tested in the following order:
i
Fuel 1: !A commercial grade unleaded gasoline used as the baseline
fuel.
Fuel 2: A blended gasohol containing 10% ethanol and 90% unleaded
gasoline having volatility characteristics similar to that
of Fuel 1.
Fuel 3: A mixture (by volume) of 10% ethanol and 90% Fuel 1.
Fuel 4: A mixture (by volumeJ of 5% ethanol and 95% Fuel 1.
The test fuels were selected to investigate two suggested methods of
reducing evaporative hydrocarbon emissions trom gasohol fuelea vehicles.
The first method is that of blending the gasohol to have lower volatility
by using heavier base stocks and adding ethanol. The secona method was
to reduce the concentration of the ethanol to 5%.
The volatility match between Fuel 1 and Fuel 2 turned out to be very
difficult to obtain within the original specifications of identical Reid
vapor pressure (RVP) and ASTM distillation curves within +_5°F of each
other. The fuel finally purchased from the Amoco Oil Company in
Naperville, Illinois was within 0.1 psi RVP and +20°F ASTM distillation.
Fuel 3 is a mixture of 10% ethanol and 90% Fuel 1. This fuel represents
a typical gasohol currently on the commercial market.
Fuel 4 is also a mixture with 5% ethanol and 95% Fuel 1. This fuel was
used to investigate the effects of a lower concentration of ethanol.
The fuel characteristics for all four fuels are shown in Table 1 ana a
comparison of the ASTM distillation data is displayed in Figure 1. The
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test fuels were stored in sealed drums until testing started on that
particular fuel. They were then tranferred to a vented, chilled fuel
cart and kept at 48 - 52°F.
The fuels were tested in the specified numerical order except that the
baseline fuel (Fuel 1) was repeated at the end of the test sequence to
confirm that the baseline results did not shift.
Table 1
Fuel Inspection Data
Fuel 1 Fuel 2 Fuel 3 Fuel 4
ITEM Baseline Gasoline Blended Gasohol 10% Gasohol 5% Gasohol
1. API Gravity 54.9 49.2 54.2 54.6
2. Sp. Gravity .759 .783 .762 .760
3. R.O.N. 95.2 99.4
4. M.O.N. 84.3 87.2
5. RVP, PSI 9.3 9.4 10.2 10.4
6. ASTM Dist.
IBP 95°F 102°F 92°F 97°F
10% 120 128 118 116
20% ; 143 147 133 129
30% 173 160 146 146
40% 208 194 156 186
50% 240 258 210 226
60% 267 278 251 257
70% 294 301 281 286
80% 320 321 311 314
90% 354 350 345 348
EP 432 434 425 424
Analysis
Performed: Amoco Oil Co. Amoco Oil Co. Ethyl Corp. Ethyl Corp.
by
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450
average carb. bowl temperature
for all fuels
Fuel 1: Baseline Gasoline (RVP=9.3.)
Fuel 2: "Blended Gasohol" (9.4)
Fuel 3: 10% ethanol & 90% Fuel 1 (10.2)
Fuel 4: 5% ethanol & 95% Fuel 1 (10.4)
r
20
-i
30
r
40
r-
50
r
60
i
70
I
80
r~
90
100
Percent Evaporated
Fig. 1 - ASTM Distillations for Test Fuels
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-7-
Test Vehicles
The two test vehicles used were a 1979 Buick Regal and a 1979 Chrysler
LeBaron. Vehicle specifications for these cars can be found in Appen-
dix B.
Prior to testing, the vehicles were inspected and adjusted to meet manu-
facturer's specifications and the mechanical fuel pump was bypassed with
an electical pump. This pump was necessary to prime the volumetric flow-
meter and float bowl prior to each test.
Instrumentation of the vehicles included bare-bead, type J tnermocouples
located in the fuel tank, carburetor bowl, engine oil pan, and in the
engine water jacket. The engine parameters were measured as indicators
of test condition and load repeatability and the fuel parameters were
correlated back to the evaporative emission results.
Fuel flow was also measured volumetrically using a flowmeter which was
placed between the fuel pump and the carburetor. The same flowmeter was
used for both cars and was connected and primed before each test. Fuel
density was also measured at this time using an API hydrometer.
Gas Chromatograph Analysis
The gas chromatograph analysis of the SHED vapors was used to quantita-
tively determine the concentration ot ethanol vapors in the evaporative
emissions. The gas chromatograph (G.C.) used was a Perkin-Elmer Model
3920 witn dual FID detectors. The column consisted of ten feet of 1/8
inch O.D. tubing packed with tris (cyano ethoxy) propane. The column
temperature was kept at 50°C which resulted in the ethanol peaking at 15
minutes. A sample pump (from a Philco Ford CVS) was used to inject the
vapor into the column and the G.C. response was traced on a strip chart
recorder. The peak widths were assumed to be relatively constant and no
effort was-made to integrate the peak areas.
The G.C. was calibrated prior to the program using the following proce-
dure: After stabilizing the instrument at the indicated temperature and
purging the column (for three days) a small petri dish containing anhy-
drous ethanol was left partially uncovered on a balance in the SHED.
Immediately after the SHED was sealed, an initial sample was injected
into the G.C, and the digital balance reading recorded. Then, at a
frequency determined by the G.C. sampling rate, additional samples were
injected and weights recorded as the ethanol slowly evaporated. This
procedure was repeated once and the data reduced to a grams ETOH versus
G.C. response curve. A linear regression revealed a linear relationship
(coefficient of determination, R^ = .9939) and a SHED volume correction
factor was introduced to account for a vehicle in the SHED. However, no
corrections were made for barome,tric pressure or ambient temperature
variat ions.
Test Results
EVAPORATIVE EMISSION RESULTS - The evaporative HC emission test results
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for each vehicle are presented in Table 2. The average results for the
program are presented in Table 4 arid displayed graphically in Figure 2.
These results demonstrate several noticeable trends.
Considering the blended gasohol (Fuel 2) first, the total vapor generated
(vehicle canister weight gain plus ShED evaporative results) using this
fuel was 3% less than the total vapor generated by the baseline gasoline
which would be expected because of the lower front end volatility of the
blended fuel (see Table 4). However, the total SHED test emissions were
41% higher than the baseline gasoline. Breaking this down into the
Diurnal Breathing Loss (DEL) and the Hot Soak Loss (HSL) portions of the
SHED test, shows that most of the evaporative emissions increase came
from the HSL test where a 21% increase in the vapor generated was
observed. This can be explained by examining the distillation curves for
both these fuels and noting that the highest achieved carburetor bowl
temperatures during the HSL tests were above 150°F where the blended
gasohol is more volatile than the baseline fuel (all the gasohol fuels
had carburetor bowl temperatures of about 153°F and the baseline gasoline
had a carburetor bowl temperature of about 156°F).
The total vapor generated during the DEL test dropped by about 13% when
using blended gasohol, however the evaporative losses rose by 6%. This
indicates an effect on the trapping efficiency of the canister charcoal
by the alcohol. This efficiency loss was 1% (not statistically signifi-
cant) for the LeBaron and 4% for the Regal. It is hard to determine if
the alcohol is being preferentially absorbed by the charcoal since the
gas chromatograph data varied widely for each test vehicle. The
LeBaron1s ethanol emissions accounted for 12% of the total losses when
using blended gasohol, while the Regal"s ethanol loss accounted for only
2%. The gas chromatograph data is presented in Appendix C.
In comparing the 10% ethanol - 90% baseline fuel mixture (Fuel 3) to the
baseline fuel, a 24% increase in the total vapor generated and a 58%
increase in the total evaporative losses can be seen (see Table 4).
Again, the increased volatility of the mixture is the primary reason for
these increases, but compounding this is the trapping efficiency decrease
(about 3% average) of the charcoal canister. The fuel mixture containing
5% ethanol and 95% baseline gasoline (Fuel 4) exhibited similar evapora-
tive emission results as did Fuel 3. The total vapor generated rose to
25% compared to the baseline fuel resu^-, and the total evaporative
losses rose 62%. This fuel had the highest Reid vapor pressure and low
end volatility which caused the Diurnal losses to increase 106%. The Hot
Soak losses rose 20% which was the lowest of the three gasohol fuels
tested.
EXHAUST EMISSION RESULTS - The exhaust emission results for each vehicle
are presented in Table 3. The average results for the program are
presented in Table 5 and displayed graphically in Figure 3.
In comparing the blended gasohol and the 10% gasohol mixture to the base-
line gasoline rwe find a significant decrease in the exhaust HC, CO and
NOx emissions. HC decreased by 8% for the blended gasohol and 23% for
the 10% gasohol mixture, while CO decreased 35% and 40% respectively.
NOx emissions were reduced 22% for the blended gasohol and 3% for the 10%
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gasohol mixture. This can be explained by noting the leaning effect the
ethanol has on the air/fuel ratios. NOx emissions may have been affected
by cylinder temperature variations due to the presence of ethanol.
However, for the 5% gasohol mixture, the leaning effect is not as
apparent since the exhaust emission results closely resemble those of the
baseline fuel.
FUEL ECONOMY RESULTS - For this test program tne EPA city fuel economy
was measured by both the carbon balance method and using a volumetric
flowmeter. However, due to a lack of availability of the flowtneter
Fuel 4 was not measured volumetrically. The average results for the
program are presented in Table 5 and displayed graphically in Figure 3.
Figure 4 provides a comparison of the carbon balance method versus the
volumetric measurement.
For all the gasohol fuels tested, a slight decrease in the average fuel
economy was observed for both the carbon balance method and the volu-
metric measurement when compared to the baseline gasoline (one vehicle
showed a decrease while the other vehicle showed little or no change).
The 10% gasohol mixture produced the largest decrease of 2%. These
results are expected since the energy content of gasohol is known to be
below that of gasoline. However, other sources have shown that ethanol
burns more efficiently in the combustion chamber thereby minimizing the
effect of a lower energy density.
In comparing the volumetric measurement to the carbon balance method, the
volumetric measurement was consistently 0.6% higher. A summary of the
calculations used for the carbon balance method is given in Appendix P.
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Table 2 - Evaporative HC Emission Results for Individual Vehicles
1979 LeBaron
Vehicle Canister
Weight Gains (gm)
SHED Results
Fuel N
Fuel 1 5
Fuel 2 3
Fuel 3 3
Fuel 4 2
1979 Regal
Fuel N
Fuel 1 5
Fuel 2 3
Fuel 3 3
Fuel 4 2
Notes: 1.
2.
3.
Diurnal Hot Soak
mean 1 .34
s.dev 0.25
mean 1.50
s.dev 0.04
% ch 11.9
me an 1.81
s.dev 0.09
% ch 35.1
mean 2.64
s.dev 0.66
% ch 97.0
SHED
Diurnal
mean 3.34
s.dev 0.79
mean 3.44
s.dev 0.65
% ch 3.0
mean 5.78
s.dev 0.80
% ch 73.1
me an 6.97
s.dev 1.33
% ch 108.7
HC results
% ch is re
To t a 1 v a po
2.46
0.20
3.67
0.35
49.2
3.36
0.17
36.6
3.33
0.40
35.4
(gm)
Total
3.80
0.16
5.17
0.36
36.1
5.17
0.08
36.1
5.97
0.27
57.1
Results (gm).
Hot Soak
2.45
0.74
4.95
0.35
102.0
4.17
0,14
70.2
2.60
0.04
6.1
Total
5.79
0.71
8.39
0.95
44.9
9.95
0.92
71.8
9.57
1.29
65.3
are not corrected
ferenced to Fuel 1
r generated = SHED
Total Vapor
Generated (gm)
Diurnal
24.50
1.84
20.80
1.73
-15.1
25.03
1.69
2.2
30.20
0.99
23.3
Hot Soak
9.58
0.54
9.67
0.50
0.9
16.17
3.34
68.8
12.55
0,07
31.0
Vehicle Canister
Weight Gains (gm)
Diurnal
21.84
0.53
18.47
0.84
-15.4
22.43
0.96
2.7
21.85
2.05
0.04
Hot Soak
7.70
0.75
8.67
0.23
12.6
12.20
2.21
58.4
11.70
0.14
51.9
Diurnal Hot
25.84
1.62
22.30
1.71
-13.7
26.84
1.67
3.9
32.84
0.33
27.1
Soak Total
12.04
0.66
13.34
0.75
10.8
19.53
3.18
62.2
15.88
0.47
31.9
37.88
2.09
35.64
2.02
-5.9
46.37
4.08
22.4
48.72
0.79
28.6
Total Vapor
Generated (gm)
Diurnal Hot Soak
25.18
0.48
21.91
1.39
-13.0
28.21
0.24
12.0
28.82
0.72
14.5
10.15
0.38
13.62
0.54
34.2
16.37
0.18
61,3
14.30
0.18
40.9
Total
35.33
0.56
35.53
1.58
0.6
44.58
0.91
26.2
43.12
0.91
22.0
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Til-
lable 3 - Exhaust Emissions and Fuel Economy Results for Individual Vehicles
1979 LeBaron
Fuel N
Fuel 1 4
Fuel 2 3
Fuel 3 3
Fuel 4 1
1979 Regal
Fuel
Fuel 1
Fuel 2
Fuel 3
Fuel 4
Notes: 1,
2.
3.
FTP Results (gm/mi)
HC CO NOx
mean 0.70 13.55 1.82
s.dev 0.02 0.58 0.12
mean 0.54 7.67 1.65
s.dev 0.05 0.86 0.29
% ch -22.9 -43.4 -9.3
mean 0.55 8.13 1.84
s.dev 0.03 0.23 0.02
% ch -21.4 . -40.0 1.1
mean 0.68 12.10 1.88
% ch -2.9 -10.7 3.3
FTP Results (gm/mi)
N HC CO NOx
4 mean 1.02 7.33 3.01
s.dev 0.16 0.71 0.13
3 mean 1.04 5.97 2.13
s.dev 0.06 0.67 0.51
% ch 2.0 -18.6 -29.2
3 mean 0.77 4.50 2.86
s.dev 0.02 0.10 0.11
% ch -24.5 -38.6 -5.0
1 mean 1.08 7.90 3.06
% ch 5.9 . 7.8 1.7
MPG
C.
C02 F.
533. 16
0.82 . 0.
535. 16
2.08 0.
0.4 1
- 523. 16
3.21 0.
-1.9 0
521. 16
-2.3 0
C02
469.
7.04
483.
2.65
3.0
472.
6.24
0.6
474.
1.1
HC results are not corrected for the ethanol
% ch is referenced to Fuel 1.
C.B.F.E. = Carbon Balance Fuel
Economy.
B.
E.
.4
05
.6
10
.2
.4
12
.0
.5
.6
C.B.
F.E.
18.9
0.24
18.4
0.06
-2.6
18.3
0.25
-3.2
18.3
-3.2
Vol.
F.E.
16.4
0.07
16.5
0.06
0.6
16.4
- 0.15
0.0
~
MPG
Vol.
F.E.
19.1
0.15
18.6
0.07
-2.6
18.5
0.10
-3.1
_
response of i
Vol. F.E. = Volumetric Fuel Economy.
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Table 4 - Average Evaporative HC Emission Results for Test Program
Shed Results (gm)
Vehicle Canister
Weight Gains (gm)
Total Vapor
Generated (gm)
Fuel
Fuel 1
Fuel 2
Fuel 3
Fuel 4
Notes :
Table
Notes :
N Diurnal Hot Soak Total Diurnal Hot Soak Total Diurnal
10 mean 2.34 2.46 4.80 23.17 8.64 31.81 25.51
6 mean 2.47 4.31 6.78 19.63 9.17 28.80 22.10
%.ch. 5.6 75.2 41.3 -15.3 6.1 -9.5 -13.4
6 mean 3.80 3.77 7.57 23.73 14.18 37.91 27.53
% ch. 62.4 53.3 57.7 2.4 64.1 .' 19.2 7.9
4 mean 4.81 2.96 7.77 26.02 12.13 38.15 30.83
% ch. 105.6 20.3 61.9 12.3 40.4 19.9 20.9
1. HC results are not corrected for the ethanol response of the FID.
2. % ch is referenced to Fuel 1.
3. Total vapor generated = SHED results + vehicle canister weight gain
5 - Average Exhaust Emissions and Fuel Economy Results for Test Program
FTP Results (gm/mi) MPG
C.B. Vol.
Fuel N HC CO NOx C02 F.E. F.E.
Fuel 1 8 mean .86 10.44 2.41 501. 17.6 17.7
Fuel 2 6 mean .79 6.82 1.89 509. 17.4 17.5
% ch -8.1 -34.7 -21.6 1.6 -i.l -1.1
Fuel 3 6 mean .66 6.32 2.35 497. 17.3 17.4
% ch - 23.3 -39.5 -2.5 -.8 -1.7 -1.7
Fuel 4 2 mean .88 10.00 2.47 498. 17.4
% ch 2.3 -4.2 2.5 -.6 -1.1
1. HC results are not corrected for the ethanol response of the FID.
2. % ch is referenced to Fuel 1.
3. C.B. F.E. = Carbon Balance Fuel Economy.
Hot Soak Total
11.10 36.61
13.48 35.58
21.4 -2.8
17.95 45.48
61.7 24.2
15.09 45.92
35.9 25.4
Vol. F.E. = Volumetric Fuel Economy.
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SHED RESULTS
6.0 -i
4.5 H
to
§3.0 -\
o
1.5 H
Diurnal
105.
62.4%
?.:.«*
2 3
Fuels
6.0 -
4.5 -
S 3.0 H
M
O
i.s H
Hot Soak
75.;
20.3%
234
Fuels
Total
10.0 -j
7.5 -
5.0 -
2.5 -
0
57.7% 61-
41.3% pg;l
Fuels
40 -
30 -
20 -
10 -
VEHICLE CANISTER WEIGHT GAIN
Diurnal
0 J
2.4%
12.
234
Fuels
Hot Soak
CO
s
M
u
20
15 -
10 -
5 -
n -
64 . 1%
:::::::$8
A 1 y :::-SH::::
,.:.H %m
SSSS: ::::::&:
lil ilil
iiiiii li
S;5p |S^
1234
Fuels
Total
60 -i .
45 H
c.
30 -|
15 H
-9.5%
19.2% 19
2 3
Fuels
60 -
45 -
| 30 -|
j
15 H
VAPOR GENERATED
Diurnal
0
7.9%
-13.4%
20.9%
1234
Fuels
* percent change from Fuel 1
32 1
24 -
Hot Soak
61.7%
1 2 3
Fuels
Fig. 2 - Evaporative HC emission results (average of 2 vehicles)
Total
m
1
^t
e.
64 -
48 -
32 -
16 -
n
24.2% 25.4%
-
::-::.:;.: »
-2-8Z III I
::::?:: SS?:$ xjj
111 11 1
HI ||
1 ''''''' -is*:-:1:-: ffifij
^
1
i
1
1
1
^L
23
Fuels
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-14-
2.0 -!
1.5
1.0
.5 -
HC
-8.1%
2.3%
-23.3%
2 3
Fuels
NO,,
5.0 -,
3.75 -
2.50 -
1.25 -
0
-2.5%
-^1.6%|||f
llli
2.5%
1234
Fuels
* percent change from Fuel 1
20 -I
15 -
10 -
5 -
CO
-4.2%
-34.7% -39.5%i
2 3
Fuels
F.E.
19 -i
18 -
17 H
16 -
15
234
Fuels
Fig. 3 - FTP exhaust emissions and fuel economy results (average of 2 vehicles)
20-1
19-
j | Carbon Balance Fuel Economy
Volumetric Fuel Economy
17 -
16 -
Y//////S
'///////A
|
1 2 3
Fuels
* percent change from carbon balance method
Fig. 4 - Carbon balance versus volumetric fuel economy
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-15-
Conclusions
Based on the findings of this test program several conclusions can be
made concerning the emissions effect of "blended" gasohol and "mixed"
gasohol fuels:
1) Blended gasohol exhibited approximately 41% greater evapora-
tive HC emission losses than the base fuel.
2) The presence of ethyl alcohol caused about a 1-3% loss in the
trapping efficiency of the canister.
3) Reducing the concentration of ethanol from 10% t.o 5% does not
reduce evaporative HC emissions. The two mixed gasohol fuels
(10% gasohol mixture and 5% gasohol mixture) increased evapo-
rative HC emissions by an average of 60%.
4) The blended gasohol decreased exhaust HC by 8% and the 10%
gasohol mixture decreased exhaust HC by 23%. The 5% gasohol
mixture increased exhaust HC by 2%.
5) Exhaust CO decreased 4-40% with all the gasohol fuels.
6) NOx emissions decreased 22% with the blended gasohol and 3%
with the 10% gasohol mixture. NOx emissions increased 3%
with the 5% gasohol mixture.
7) Fuel economy (by carbon balance and volumetrically) decreased
about 1-2% with all the gasohol fuels. (One test vehicle
showed a decrease while the other vehicle showed little or no
change).
8) The volumetric fuel economy measurement was 0.6% higher than
the carbon balance method.
References
1. Richard Lawrence, "Gasohol Test Program," EPA Report 79-4, December,
1978.
2. Federal Register, Vol. 41, No. 164, August 23, 1976
3. California Air Resources Board, "Testing of Three Caltrans Gasohol
Fueled Vehicles," Project 2F80E2, May, 1980.
-------
-16-
Appendix A
Test Procedure
-------
-17-
Gasohol Test Sequence
1. Drain and refuel to 20% tank capacity
2. Run 1 LA-4 driving cycle
3. Hot soak one hour
4. Drain and refuel to 40% tank capacity
5. Run 1 LA-4 driving cycle
6. Soak 12 - 24 hours at 68 - 75°F ambient temperature
7. Run 1 FTP with SHED:
a. Diurnal Heat Build:
- drain and refuel to 40% tank capacity (leave fuel cap off)
- move vehicle to SHED
- weigh vehicle canister and check canister lines
- move vehicle into SHED
- at 58°F fuel temperature, install fuel cap and seal enclosure
doors
- take gas chromatograph sample (at 60°F)
- perform one hour diurnal heat build (at 60°F)
- take gas chromatograph sample (at 84°F)
- immediately weigh vehicle canister and check canister lines
b. Run 3-bag FTP emissions test within 60 minutes of end of diurnal
test
c. Hot Soak:
- immediately after 3-bag emissions test, move vehicle to SEED
- weigh vehicle canister and check canister lines
- move vehicle into SHED and seal enclosure doors
- take gas chromatograph sample and perform one hour soak test
- after one hour, take gas chromatograph sample
- immediately weigh vehicle canister and check canister lines
8. Precondition for the next test
a. If using the same fuel, go to step 5
b. If switching fuels, go to step 1
-------
-18-
Appendix B
Test Vehicle Specifications
-------
OYNO SJTE:D005 TEST » 80-4176
PROCESSED* .09J49130 JUL 8t
MANUFACTURER
VEHICLE SPECIFICATION REPORT -(LO TESTING)- DATE OF ENTRY t 6/35/80
VEHICLE SPECIFICATIONS
VEHICLE ID / VER REPRESENTED CAHLINE MODEL CODE
DRIVE CODE
SOURCE
CHRYSLER
VMX-253
SEDAN
REAR DRIVE STR. LEFT
OTHER
DRIVE AXL WTS EOUIV.
VEHICLE MODEL. ACTIVE FULL EMPTY CURB INRTIA TEST 0/D ACTUAL
TYPE ACTUAL VEHICLE MODEL YEAR YEAR TANK TANK WEIGHT CLASS WEIGHT CODE DYNO HP
RUNNING CHG
NUMBER
NON-CER LEBARON
79
79
4000P 4000P 11.9
TIRE - SPECIFICATIONS
PRIMARY DURABILITY VEHICLE ID Ok ASSIGNED OF
ALT. MANUFACTURER
TIRE Si RIM
SIZES
MFR
SWL BLT PSI
CONSTR N M N M FT RR
ENGINE SPECIFICATIONS
DISPLACEMENT BORE
318. E
IGNITION
TIMING 1
IGNITION
TIMING 2
RATED
STROKE HP
TIM.
TOL.
TIMING
HPM
ENGINE
TYPE
ENGINE NO. NO.
CONFIGURATION CYL. CARBS
OTTO SPARK V-BLOCK
RPM
TQL.
TIM.
GEAR
f. CO
LEFT
% CO
RIGHT
* CO
COMH.
H
CO
TOL.
1
IDLE
RPM
TOTAL
# BBLS
?
IDLE
TOL.
FUEL SYSTEM FUEL COMP. COAST-
MFR/MOOEL INJCT? TURBO? RATIO DOWN TM
IDLE
GEAR
NO NO .
1
VO
ENGINE FAMILY ENGINE CODE '
168
AXLE
RATIO
N/V
RATIO
ODOMETER
730
A/C
INSTALLED
DRIVE TRAIN ANO CONTROL SYSTEM SPECIFICATIONS
EXHAUST TYPE
CRANKCASE
SYSTEM
TRANSMISSION
CONFIGURATION CODE
EVAPORATION
SYSTEM
FUEL TYPE
MAIN-TANK
CAPACITY VOLUME
YES SINGLE RIGHT REAR CLOSED A-3
SHIFT SPEED
AUX.-TANK
CAPACITY VOLUME
CANISTER
EVAPORATIVE EMISSION
FAMILY CODE
UNLEADED (AT EPA-IND HO)
SALES CLASS
18. G
7.2G
EXHAUST RECYCLE
OXIDATION CATALYST
CONTROL SYSTEM TYPES
OTHER
VEHICLE SPECIFICATION COMMENTS
7344 0
DYNO SITE»D005 TEST » 80-4178
-------
OYNO SITEtDOOS TEST * 80-^224
PROCESSED*
JUL 8t 1980
MANUFACTURER
VEHICLE SPECIFICATION REPORT -
-------
-21-
Appendix C
Gas Chromatograph Raw Data
-------
-22-
Gas Chromatograph Raw Data of Ethanol Vapors
Vehicle
BDB
ADB
BHS
AHS
DDE
DHS Total
Test
Regal Blended #1
Blended #2
Blended #3
Mean
S.D.
10% #1
10% #2
10% #3
Mean
S.D.
5% #1
LeBaron Blended #1
Blended #2
Blended #3
Mean
S.D.
10% #1
10% #2
10% #3
Mean
S.D.
5% #1
def. gms.
2.2 .055
2.0 .050
4.5 .120
0.1 0.0
0.6 .010
0.2 0.0
1.6 0.38
2.0 .050
0.7 .013
0.2 .0
0.3 .002
0.6 0.10
def. gms.
7.8 .213
4.0 .106
5.8 .157
1.9 .047
2.0 .050
1.3 .030
16.8 .466
10.7 .295
12.0 .331
1.4 .033
2.2 .055
1.8 .044
def. gms.
5.8 .157
2.8 .072
3.7 .097
0.1 0.0
0.1 0.0
0.0 0.0
0.2 0.0
3.4 .089
5.4 .145
8.7 .221
0.0 0.0
0.1 0.0
0.0 0.0
def. gms.
9.1 .249
5.6 .151
6.1 .165
0.9 .019
5.0 .134
1.9 .047
4.2 .111
15.1 .418
13.7 .379
14.1 .390
4.1 .109
4.9 .131
4.9 .131
gms. gras. Test
.158 .092 .250
.056 .079 .135
.107 .086 .193
.072 .009 .081
.037 .068 1.05
.047 .019 .066
.040 .040 .080
.041 .042 .084
.005 - .020
.030 .047 .077
.111
.428 .329 .757
.245 .234 .479
.337 .225 .618
.109 .197
.318 .169 .487
.033 .109 -14z
.053 .131 .184
.135 .136 .271
.030
.034 .131 .165
Notes: 1. BDB = before diurnal test
ADB = after diurnal test
BHS = before hot soak test
AHS = after hot soak test
DDB = A diurnal test (ADB - BDB)
DHS = £ hot soak (AHS - BHS)
-------
-23-
Appendix D
Carbon Balance Fuel Economy Calculations
-------
-24-
Carbon Balance Fuel Economy Calculations
The carbon balance formula is used to calculate the fuel economy of a
vehicle from the exhaust emission data gathered during the 1975 Federal
Test Procedure. This equation is in the following general form:
MPG = grams of carbon/gallon of fuel
grams of carbon in exhaust/mile
From this general Lui.uiua.ci, uuc C4ua
of a vehicle using indolene fuel is:
formula, the equation for calculating the fuel economy
indolene fuel is:
MPG =
0.866 (.2798)
0.866[EHC] + .429[ECO]
where: 2798 = density of indolene fuel (g/gal)
E = exhaust emissions ( g/j&i )
.866, .429 and .273 are the carbon weight frac-
tion of HC, CO and CC>2 respectively
Since the fuel properties of the baseline gasoline and gasohoi fuels used
in this test program differ from indolene, the carbon balance equation
had to be modified to compensate for these differences. As a result, the
carbon balance formula was reduced to the following form:
MPG =
D(W)
F[EHC] + .429[ECO] + .273[EC02]
where: D = fuel density (g/gal)
V/ = carbon weight fraction of fuel
F = carbon weight fraction of exhaust HC
E = exhaust emissions ( S'1.)
The values of D, W and F
tabulated below:
D
for the four fuels tested in this program are
W
D(W)
Fuel 1
Fuel 2
Fuel 3
Fuel 4
2867.12
2957.78
2878.45
2870.90
0.8702
0.8400
0.8341
0.8527
0.8702
0.8764
0.8702
0.8702
2494,97
2484.54
2400.92
2448.02
The following section provides a brief summary of the equations or
methods used in determining the above values of D, W, and F for the
various fuels. It should be noted that the carbon weight fractions of
the base gasoline (Fuel 1) and the blended gasohoi (Fuel 2) were supplied
by Amoco Oil Company. As a result, the equation to determine the carbon
weight fraction of the fuel was only applied to the 10% and 5% mixtures
of gasohoi (Fuel 3 and Fuel 4). These equations are as follows:
-------
-25-
A. Calculation of fuel density:
fuel density = specific gravity A2_J X density of water
at 60°F 60°
B. Calculation of carbon weight fraction of the fuel (3):
Carbon weight fraction = A(W) D + B(K) £
where: A = volume percent of gasoline used in fuel mixture
W = carbon weight fraction of gasoline used in fuel mixture
Dg = density of gasoline used in fuel mixture (g/gal)
Df = density of gasohol fuel (g/gal)
B = volume percent of ethanol used in fuel mixture
K = carbon weight fraction of ethanol used in fuel mixture
= .5214
De = density of ethanol used in fuel mixture = 2979.18
(g/gal)
C. Calculation of carbon weight fraction of exhaust HC :
1) This calculation involves no equations only 2
assumptions.
a) For gasoline, the carbon weight fraction of the
exhaust HC is the same as the carbon weight frac-
tion of the fuel.
b) For gasohol, the fraction of ethanol contained in
the exhaust is minimal (it is less than .1% of
the measured exhaust hydrocarbons (3)). Thus,
the carbon weight fraction of the exhaust HC for
.' ' gasohol will be the same as the carbon weight
fraction for the gasoline used in the fuel mix-
ture.
-------
-26-
Appendix E
Individual Test Results
-------
Individual Test Data
1979
Fuel Test Date
R>E£.l
Fuet£
FOa.3
FUEL 4-
FuEiJ.
/i
£
3
.1
a
3
A
£
3
J.
a
j.
2.
^2/80
t/25/ao
6/26/80
7/6/^0
7/7/50
7/"?/(9o
T//5/09
7A7/90
r//?/9c
rfeo/eo
7/22/eo
7 /&/80
7/24/&0
FTP (gm/mi)
HC CO NOX CO 2
.7^
.69
.72.
.48
.3-8
.55
.52
.58
.55
.68
,68
/3.7
/2.8
/f.2
7.5"
6.?
a 6
ao
8.4
8.0
12.1
/3.^
/.76
A 68
A87
A 33
/-87
/.76
1.85
1,85
I.&2.
1.88
135
53^
53Z-
533.
533-
531.
537.
524.
5fr
5^5
52/-
53$.
mpg
C.B. Vol.
16,4
\6.S
\t>A
/6.7
/ 6. 6
\(oS
16.3
\b5
J&3
16.5
/6.4
/6.4
/6^5
I6,5~
/6.5
16,4
16.4-
|6.6
/6.3
-
SHED (gm)
DEL HS Total
1.78
I./9
l.lt
l,5/
/.53
1^5
1.82.
1.72.
I.Jo
2.17
3.11
1.22
/.Iff
ZJ5
a..^
2.^3
3.30
4-. oo
3.71
3AI
3.5-0
3- /6
3.61
3,05"
2.5"?
£.5-7
3.93
355-
3.9*
4.8/
5:53
51/6
3T23
5:.2a
3:08
5:78
6./6
379
3.75"
Can. Wt. (gm)
DEL HS
ai-4-
24.3
£5:a
183
21. ^
£2.3
23./
26, a
25". 8
3a ?
2?. 5"
26.0
25: £
9.3
9,3
/a a
96
10.2
?.2.
14.6
13.9
2o.b
/2.6
/££"
/a/
9,o
Tot. Vap. (gm)
DEL HS Total
23.18
25:49
26. 5"/
£0.41
22.73
23.75'
24.72
27.92
27.70
33,07
32.61
27.21
24.7£
//.45~
\\.bto
£.83
(2.9o
14.20
I2.^/
/ao/
/?.4o
2a/a
/6.2/
&&>'
/2.67
//o'?
34.^3
37./3"
3^3f
33. 3 /
36. ?3
36. ^6
42. -?3
457 3£
50. BB
4?. 28
4^./6
3^.89
3535'
Key: C.B.= FTP Carbon Balance Fuel Economy
Vol.= Volumetric Fuel Economy
DBL = Diurnal Breathing Loss
HS = Hot Soak
Can. Wt. = Canister Weight Gain
Tot. Vap. = Total Vapor Generated
-------
Individual Test Data
1979 RE6-/U.
Fuel Test Date
FuELl
Fl'GL *2
F^'Et- 3
FUE*. 4
F^l
1
e
3
1
a
3
J.
2.
3
.1
a
i
/a
6/a;/Bo
6/30/ao
7/2/80
r/b/so
7/7/80
7/7/60
7//5/8C'
7/17/80
7//8/80
r/2i/ao
7/22/80
*7 1^180
7/£4/#0
FTP (gm/mi)
HC CO NOV CO 2
/.GO
,9/
'?/
i
£.(*$
£86
3.32
4, /4
6.55
^6>3
4.96
7.9/
6,e>3
4-40
3.3o
^.^
3.00
3,03
4.^
4.^
57^3
4>24-
4,27
4,o/
2^7
2.63
/.7*
I.S4-
5o
5.71
271 .
7.18
9.47
70.79
10.10
897
10 AS
& 66
6./4
4.6'f
Can. Wt. (gm)
DBL HS
an
^2.$
^^~l
/7.5"
/f.o
td.1
&\.+
az.
------- |