EPA-AA-TAEB 75-20
Evaluation of a PPG-Questor Prototype Vehicle
March 1975
Technology Assessment and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Environmental Protection Agency
-------
Background
Houston Chemical Division of PPG Industries developed a lead trap
to be used on a low pollutant emission vehicle which could be run on
leaded fuel. For the emission control system PPG • had Questor Corporation
equip the vehicle with a third generation Questor Reverter System. After
the vehicle had been tested by the California Air Resources Board and
showed promising results, the Emission Control Technology Division of
the Environmental Protection Agency requested testing of the vehicle.
The vehicle was delivered to the Motor Vehicle Emissions Laboratory in
Ann Arbor, Michigan on January 27, 1975.
The Environmental Protection Agency receives information about many
systems which appear to offer potential for emission reduction or fuel
economy improvement compared to conventional engines and vehicles.
EPA's Emission Control Technology Division is interested in evaluating
all such systems, because of the obvious benefits to the Nation from
the identification of systems that can reduce emissions, improve economy,
or both. EPA invites developers of such systems to provide to the
EPA complete technical data on the system's principle of operation,
together with available test data on the system. In those cases in
which review by EPA technical staff suggests that the data available
show promise, attempts are made to schedule tests at the EPA Emissions
Laboratory at Ann Arbor, Michigan. The results of all such test projects
are set forth in a series of Technology Assessment and Evaluation Reports,
of which this report is one.
The conclusions drawn from the EPA evaluation tests are necessarily
of limited applicability. A complete evaluation of the effectiveness
of an emission control system in achieving performance improvements
on the many different types of vehicles that are in actual use requires
a much larger sample of test vehicles than is economically feasible
in the evaluation test projects conducted by EPA. For promising
systems it is necessary that more extensive test programs be carried
out.
The conclusions from the EPA evaluation test can be considered
to be quantitatively valid only for the specific test car used,
however, it is reasonable to extrapolate the results from the EPA
test to other types of vehicles in a directional or qualitative manner,
i.e., to suggest that similar results are likely to be achieved on
other types of vehicles.
-------
System Description
The emission control system of the vehicle was developed by Questor
Corporation and is called the Questor Reverter System. The vehicle was
equipped with the latest third generation system and had accumulated
about 7000 miles of durability.
The Questor Reverter process is a three-step process which employs
both thermal oxidation and catalytic reduction. Replacing the conventional
exhaust manifold is a device which contains the three zones of operation.
Exhaust gas enters the first reaction zone called the limited oxidation
zone. In the vicinity of the exhaust ports air from an air pump is
injected, producing a thermal reaction which oxidizes a portion of
the hydrocarbons and carbon monoxide. The primary purpose of the
limited oxidation zone is to rapidly increase the temperature in the
emission control system, as well as maintain an abundance of carbon
monoxide at the entrance to the catalyst bed. Because the engine is
run richer than stoichiometric (air/fuel ratios of 12:1 {idle} to
13.5:1) an abundance of carbon monoxide is still present.
The partially oxidized exhaust gas then passes into the second
zone containing the reduction catalyst. The catalyst materials are
base metals impregnated on a stainless alloy screen. The catalyst
material on this vehicle is IN 1013, a copper-chromium-nickel composition,
impregnated on an Inconel 601 substrate. In this zone oxides of
nitrogen and carbon monoxide combine to form free nitrogen and
carbon dioxide.
In the third zone the balance of air from the air pump is injected
which oxidizes most of the remaining carbon monoxide and hydrocarbons.
A schematic of the Reverter System and description of the chemical
processes are shown on the following two pages.
Because of the high temperatures maintained, the Questor system
can be used with either leaded or unleaded gasoline. Lead passes
through the system in a vapor state which will not damage the catalyst.
This system did not utilize Transmission Controlled Spark or Exhaust
Gas Recirculation to control oxides of nitrogen (NOx) and the engine
had a higher compression ratio than standard (9.4:1 compared to 8.4:1)
for increased efficiency. Questor reports that current third generation
systems yield a 5 to 8% fuel economy penalty as compared to 1973
baseline vehicles.
A lead trap developed by Houston Chemical Division of PPG Industries
for reduction of particulate emissions was included in the exhaust system.
-------
AIR
INJECTION
Reverter@ System
3rd Generation Device
/ EXHAUST
/ GAS
-' OUTLET
-------
OxidizepdrtiooofCO
ri. Maintain GO rich atmosphere
- .• -•:'•• ;--i ---v
^S^&^^^ad.^j^^
2NO-2co»N,'2C(VHeai • NO, reduced toN2 in presence ofcatelyst •
In presence dcopper 'Porfonof CO Oxidized to CO2 . ,|
•Catalyst is unaffected '•'_<
t • Predominaty CO and some HC passed tol
, . ^
• Final oxidation of remaining CO
>; ^ . ;^ 4HC'50J.4CO,.HJ0'Hea» • Oxidation continues in exhaust
REVERTER PROCESS
-------
The vehicle which was equipped with this system was a 1974 Ford
Pinto Squire Station Wagon with a 140 cubic inch (2300 cc) engine
and automatic transmission. A complete vehicle description is
given on the following page.
«
Test Procedure
Exhaust emissions tests were conducted according to the 1975 Federal
Test Procedure ('75 FTP), described in the Federal Register of November 15,
1972. Additional tests included the EPA Highway Cycle. All tests were
conducted using an inertia weight of 3000 Ibs. (1362 Kg) with a road
load setting of 10.3 horsepower (7.68 kW) at 50 miles per hour (80.5
km/hr).
Five '75 FTP's and five EPA Highway Cycles were run on the vehicle.
No calibration changes were made to the vehicle for the first four tests.
Results from these tests indicated that the fuel/air ratio had increased
during the test program. The idle CO had been set at about 6% prior
to delivery but read 7.8% after the fourth test. The idle rpm had
dropped to 620 and upon increasing it to 680 (the normal setting)
idle CO dropped to 5.7%. This was the calibration used for the fifth
test. Maintaining a consistent idle CO has reportedly been a continuing
problem with this system, no doubt because the carburetor was designed
to run much leaner than required by this system.
The fuel used for the first three tests (three each of '75 FTP's
and EPA Highway Cycles) was Indolene Clear, a standard unleaded test
fuel. Indolene 30, a standard leaded fuel, was used for the remaining
tests.
Test Results
Exhaust emissions data, summarized below, illustrate that the
PPG-Questor vehicle achieved the levels required by the 1978 Federal
emissions standards with no change in fuel economy compared to a 1974
Pinto wagon which was certified for sale in California (the test
vehicle was originally sold in California) .
'75
Composite Mass Emissions
grams per mile
(grams per kilometre)
HC
CO
NOx
PPG-Questor vehicle -
avg. of 5 tests
1974 Certification -
vehicle
1978 Federal emissions
standards
.10
(.06)
1.4
(.87)
.41
(.25)
2.62
(1.62)
35
(22)
3.4
(2.1)
.16
(.10)
1.7
(1.1)
.4
(.25)
1972 Procedure
Fuel Economy
(Fuel Consumption)
16.5 miles/gal
(14.3 litres/100 km)
16.6 miles/gal
(14.2 litres/100 km)
1975 Procedure
Fuel Economy
(Fuel Consumption)
17.1 miles/gal
(13.8 litres/100 km)
-------
TEST VEHICLE DESCRIPTION
Chassis model year/make - 1974 Pinto Squire
Emission control system - Questor Reverter System and PPG Lead Trap
Engine
type . . 4 stroke Otto Cycle, OHV, 4 cyl. in-line
bore x stroke 3.78 x 3.13 in/96.0 x 79.5 mm
displacement 140 in3/2300 cc
compression ratio . 9.4:1
maximum power @ rpm not available (NA)
fuel metering 2 barrel Holley carburetor
fuel requirement 91 RON
Drive Train
transmission type 3 speed automatic
final drive ratio 3.40:1
Chassis
type unitized construction, front engine, rear
wheel drive, 2 door station wagon
tire size 175 SR 13
curb weight NA
inertia weight 3000 lbs./1362 kg
passenger capacity 4
Emission Control System
basic type ... thermal reactor, reduction catalyst.
Total volume of Reverter System approx-
imately 280 in3/4590 cc. Replaces
exhaust manifold.
reduction catalyst location . . . Reverter
substrate Inconel 601
loading IN 1013
thermal reactor location Reverter
air injection Stock
size pump NA
drive ratio NA
location exhaust ports
additional features . . lead trap, Safe Guard System, Normal
Operating Temperature Control
durability accumulated on system . 7000 miles/11,300 km
-------
EPA Highway Cycle Mass Emissions
grams per mile
(grams per kilometre)
Fuel Economy
HC CO NOx (Fuel Consumption)
PPG-Questor Vehicle - .00 .50 .89 23.2 miles/gal
average of 5 tests (.00) (.31) (.55) (10.1 litres/100 km)
On the '75 FTP CO emissions were above the standards once, on the
fourth test; after the calibration change CO was again below the
standards. Fuel economy declined during each of the tests until the
calibration change was made; then it increased to a level of the average
of the first four tests (17.1 mpg). HC and NOx emissions were well
below the standards on all tests. All results are presented in the
Appendix of this report.
The vehicle stalled once shortly aft'er the initial start of the
first '75 FTP. It was restarted and performed satisfactorily for the
remainder of the test. On the next four '75 FTP's the vehicle did not
stall, but the driver had to give extra gas to keep it running during
the first few seconds. Driveability was poor until after the first
acceleration of each test; after that it was acceptable.
Conclusions
The PPG-Questor vehicle, with 7000 miles accumulated, met the
1978 Federal emission standards with no loss in fuel economy compared to
1974 models. The system would have to undergo further durability testing
to determine if it is capable of meeting the standards at 50,000 miles,
which would be necessary for certification.
Questor has been able to improve the fuel economy of the Reverter
System during the past two years from an original 20% loss to the
present state which shows no loss in fuel economy compared to a 1974
system. With further improvements in the NOx catalyst, heat management,
and fuel metering more improvements in fuel economy are expected. The
two major problem areas are in air management and fuel metering. The
present system uses a stock air pump and carburetor, neither of which
was designed for this system.
-------
Appendix
Table I
'75 FTP Composite Results
Mass emissions, grams per mile
Fuel economy, miles per gallon
Test No.
19-7586
9-7634
9-7648
19-7695
9-7747
HC
.09
.03
.15
.16
.08
CO
2.35
1.56
2.86
3.52
2.79
C00
z.
496
509
515
542
516
NOx
.16
.15
.15
.19
.17
Fuel Ecor
17.7
17.3
17.1
16.2
17.1
-------
Table II
Bag 1 Cold Transient
'75 FTP Individual Bag Results
Mass emissions, grams per mile
Fuel economy, miles per gallon
Bag 2 Hot Stabilized
Bag 3 Hot Transient
Test Number
19-7586
9-7634
9-7648
19-7695
9-7747
HC
.51
.21
.69
.55
.37
CO
8.07
4.23
7.42
11.33
9.06
C00
520
550
549
577
547
NOx
.35
.34
.34
.45
.39
Fuel
Economy
16.6
15.9
15.8
14.9
15.8
HC
.00
.00
.00
.04
.00
CO
.71
.89
1.69
1.00
1.09
C00
492
505
518
538
513
NOx
.05
.06
.05
.05
.06
Fuel
Economy
18.0
17.5
17.1
16.4
17.3
HC
.07
.04
.07
.12
.08
CO
1.15
.83
1.66
2.41
1.29
C00
486
486
484
523
497
NOx
.23
.19
.20
.25
.22
Fuel
Economy
18.2
18.2
18.2
16.8 ,
i
17.8
-------
.11
Table III
EPA Highway Cycle
Emissions results and fuel economy
Mass emissions, grams per mile
Fuel economy, miles per gallon
Test No. HC CO C00 NOx Fuel Economy
19-7586
9-7634
19-7648
19-7695
9-7747
.00
.00
.00
.02
.00
.17
.44
.38
1.05
.45
tr
370
383
340
430
388
.78
.66
.55
1.80
.64
24.0
23.1
26.1
20.6
22.8
------- |