71-16
Exhaust Emissions From A Passenger Car Equipped With
A Universal Oil Products Catalytic Converter
December 1970
John C. Thomson
Division of Motor Vehicle Research and Development
. Air Pollution Control Office
ENVIRONMENTAL PROTECTION AGENCY
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Vehicle Tested
In order to evaluate the Universal Oil Products catalytic
reactor UOP supplied APCO with a converted vehicle. For
this test, a 1970 Volkswagen Squareback with electronic
fuel injection was used. This vehicle is equipped with
a 9B cubic inch opposed four cylinder engine and automatic
transmission. The stock fuel injection system was modi-
fied to prevent cutoff of fuel during deceleration and the
catalyst unit was installed in place of the standard muf-
fler. The vehicle was first delivered to APCO for test
in August 1970. However, exhaust leaks made the results
of that test questionable and the vehicle was returned to
UOP for repairs. The vehicle was returned to APCO in De-
cember 1970 for the further testing described in this re-
port. All tests were run on Indolene clear fuel.
Tests Conducted
The following tests were performed on the vehicle:
1. Standard 1970 Federal test procedure for exhaust
emissions (Table 1).
2. Closed, constant volume sampling technique using
9 repeats of the seven mode 1970 Federal emissions
test cycle (Table 2).
3. Standard 1972 Federal test procedure using the
LA4-S3 driving cycle with constant volume sampling
(Table 3).
For the 1970 Federal test procedure oxides of nitrogen were
analyzed using a continuous non-dispersive infrared technique
in addition to the specified instrumentation. For the constant
volume sampling tests oxides of nitrogen were measured using
both the wet chemical modified Saltzman technique and the
electrochemical "NOx Box". Carbon monoxide was measured
using non-dispersive infrared and hydrocarbons were determined
using a flame ionization detector.
Emission Results
In Table I comparisons are made between two identical tests
uslng the 1970 Federal test procedure. In order to emphasize
the effectiveness of the exhaust catalyst, the results from
the first (cold) cycle is separated from the seventh (hot)
cycle. The very significant effect qf the combination warm
up of the engine and the catalyst show an order of magnitude
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reduction from the cold condition to the hot condition. The
effect of this device on all three pollutants is quite evident.
For reference the emission standards for 1970 are hydrocarbons
2.2 gpm and carbon monoxide 23 gpm.
In Table 2 constant volume tests run simultaneously with the
1970 Federal test are shown. During these tests, the exhaust
pipe temperature was high enough to ruin the rubber coupling.
In order to prevent contamination of the exhaust with burned
rubber products, an asbestos sleeve with aluminum cover was
used between the test pipe and rubber coupling.
The 1972 Federal test procedure results are reported in Table
3. Test #1 was run on the first day of testing and test #2
was run on the last day. The UOP -representative reported that
the differences in these tests was possibly due to the effect
of conditioning. After long periods of high speed steady load
operation, emissions tend to be higher but tend to drop after
a period of operation at lower speeds and varying load. The
proposed emission standards for 1975 are hydrocarbons 0.5 gpm,
carbon monoxide 11 gpm and oxides of nitrogen 0.9 gpm. This
vehicle came quit~ close to meeting these standards. It
would appear that the standards could be met on this vehicle
if the emissions during the first 40 seconds of start up and /
warm up could be reduced.
An attempt was made to measure particulates, but the high
exhaust temperature caused significant amounts of the rubbe~r
coupling to be burned off and collected as particulate.
Driveability of the vehicle was acceptable although the use
of an engine of this size caused a considerable amount of full
throttle operation during the emission tests.
Conclusions
\
1. The vehicle supplied by UOP for evaluation showed quite
low exhaust emissions.
2. There appears to be an adverse effect on the early results
caused by the conditioning of the vehicle prior to testing.
3. The vehicle failed to meet the 1975 exhaust emission
standards.
4. The driveability of the vehicle as converted was accept-
able.
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TABLE 1
1970 Federal Test Procedure" Replicate Tests
First Cycle
Seventh Cycle
Composite
Hydrocarbons
279 ppm
279 ppm
32
18
0.4
0.4
ppm
ppm
gpm
gpm
Carbon
Monoxide
3.
3.
0.
0.
0 %
1 %
62 %
32 %
10 gpm
8 gpm
Oxides of
Nitrogen
784 ppm
643 ppm
28
0
0.5
0.4
ppm
ppm
gpm
gpm
PPM indicates concentration in parts per million.
GPM indicates calculated mass in grams per mile.
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TABLE 2
Constant Volume Sampling Using 1970 Driving Cycle
Test 1 Test 2
Hydrocarbons 1. 1 gpm 1.2 gpm
Carbon Monoxide 14 gpm 14 gpm
Carbon Dioxide 403 gpm 386 gpm
Oxides of Nitrogen* 1.2 gpm 1.2 gpm
Oxides of Nitrogen** 0.8 gpm 0.9 gpm
* NOx Box results reported as N02.
** Saltzman results reported as N02.
GPM indicates grams per mile.
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TABLE 3
1972 Federal Test Procedure
Test 1 Test 2
Hydrocarbons 2.3 gpm 1.4 gpm
Carbon Monoxide 32 gpm 10 gpm
Carbon Dioxide 444 gpm 431 gpm
Oxides of Nitrogen* 1.3 gpm 1.1 gpm
Oxides of Nitrogen** 0.6 gpm 0.8 gpm
* NOx Box results reported as N02-
** Saltzman results reported as N02•
GPM indicates grams per mile.
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