EPA-AA-TAEB 76-16
Durability of Dana Retronox
EGR and UOP Oxidizing Catalyst Retrofit
Ford F-250 Truck
April 1976
Technology Assessment and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Environmental Protection Agency
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Background
In a cooperative program with Dana Corporation and Universal Oil
Products (UOP), the Emission Control Technology Division (ECTD), previously
tested a retrofitted medium duty truck. _!/ In those tests the system
achieved substantial reductions in hydrocarbon and carbon monoxide
emissions and small reduction in oxides of nitrogen emissions. The
durability portion of that test program was terminated due to diminished
interest by Dana in a retrofit EGR system.
Recently, UOP contacted ECTD to ascertain if EPA would conduct
emission tests on one of those vehicles. Since ECTD was interested in
evaluating the durability of a retrofit EGR - oxidation catalyst system,
EPA agreed to a short test program.
The Environmental Protection Agency receives information about many
devices for which emission reduction or fuel economy improvement claims
are made. In some cases, both claims are made for a single device. In
most cases, these devices are being recommended or promoted for retrofit
to existing vehicles although some represent advanced systems for
meeting future standards.
The EPA is interested in evaluating the validity of the claims for
all such devices, because of the obvious benefits to the Nation of
identifying devices that live up to their claims. For that reason the
EPA invites proponents of such devices to provide to the EPA complete
technical data on the device's principle of operation, together with
test data on the device made by independent laboratories. In those
cases in which review by EPA technical staff suggests that the data
submitted hold promise of meeting the claims made for the device,
confirmatory tests of the device are scheduled at the EPA Emissions
Laboratory at Ann Arbor, Michigan. The results of all such confirmatory
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 confirmatory tests are neces-
sarily of limited applicability. A complete evaluation of the effective-
ness of an emission control system in achieving its claimed 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 confirmatory test projects conducted by EPA. 2] For
promising devices it is necessary that more extensive test programs be
carried out.
!_/ TAEB Report 75-6 "Exhaust Emissions from Two Medium Duty Trucks Equipped
with the Dana UOP Truck Retrofit System."
2/ See Federal Register 40 FR 3495, 1/22/75, for a description of the
test protocols proposed for definitive evaluations of the effective-
ness of retrofit devices.
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The conclusions from the EPA confirmatory tests can be considered
to be quantitatively valid only for the specific type of vehicles used
in the EPA confirmatory test program. Although it is reasonable to
extrapolate the results from the EPA confirmatory 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,
tests of the device on such other vehicles would be required to reliably
quantify results on other types of vehicles.
In summary, a device that lives up to its claims in the EPA confir-
matory test must be further tested according to protocols described in
footnote 2] to quantify its beneficial effects on a broad range of
vehicles. A device which when tested by EPA does not meet the claimed
results would not appear to be a worthwhile candidate for such further
testing from the standpoint of the likelihood of ultimately validating
the claims made. However, a definitive quantitative evaluation of its
effectiveness on a broad range of vehicle types would equally require
further tests in accordance with footnote 2j.
System Description
The Dana Retronox system employs an EGR system controlled by engine
speed and ported carburetor vacuum, and a vacuum cut-off controlled by
engine speed. Both EGR and relative spark timing retard have been shown
to be effective in reduction of total oxides of nitrogen. The Retronox
system is installed typically as shown in Figure 1. The EGR valve is
controlled by ported vacuum assuming the engine speed is above the set
point of the ignition operated speed-sensing valve. The recirculated
exhaust gas is introduced into the intake system via the existing PCV
plumbing. The distributor vacuum advance is connected downstream of the
speed-sensing valve. Thus, as with the EGR, vacuum advance can be
activated only above the speed-sensing valve set point.
In typical installations the engine speed-sensing valve opens at
1250 rpm and the vacuum operated EGR valve closes at approximately 3 in.
Hg vacuum. The truck was also retrofitted with a UOP pellet-type, noble
metal oxidizing catalyst. An air pump was required.
The system was installed on a 1973 Ford F-250 truck (the vehicle is
described in detail on the following page). The vehicle had accumulated
8300 miles since EPA last tested the vehicle.
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TEST VEHICLE DESCRIPTION
Chassis model year/make - 1973 Ford F-250
Emission control system - EGR, oxidation catalyst>vacuum
advance cut-off
Engine
type 4 stroke Otto cycle, OHV, V-8
bore x stroke 4.05 x 3.5 in. (102.9 x 88.9 mm)
displacement 360 cu. in. (5899 cc)
compression ratio 8.00:1
maximum power @ rpn
fuel metering single 2 barrel carburetor
fuel requirement . . . . . . ... regular unleaded (tested with
indolene HO, unleaded)
Drive Train
transmission type 3 speed automatic
final drive ratio 3.73:1
Chassis
type frame, front engine, rear drive
tire size 800 x 16.5
curb weight 4300 pounds
inertia weight 5500 pounds
passenger capacity 3
Emission Control System
basic type ~ Dana Retronox exhaust gas recir-
culation controlled by engine speed
and ported carburetor vacuum
- UOP oxidation catalyst.pellet-type,
noble metal
durability accumulated on svstem
- engine speed controlled cut-off
of the distributor vacuum advance
9400 miles
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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 except that no evaporative emissions tests were
conducted and an altered road load setting was used. In addition the
vehicle was tested for emissions and fuel economy by using the EPA
Highway Fuel Economy Test (HFET), described in the Federal Register,
Volume 39, Number 200, October 15, 1974.
These tests are conducted on a chassis dynamometer and employ the
Constant Volume Sampling (CVS) procedure, which gives exhaust emissions
of HC, CO, NOx and C0« in grams per mile. Fuel economy is calculated by
the carbon balance method. The fuel used was Indolene unleaded 96 RON
gasoline. All tests were conducted at an inertia weight of 5500 pounds
(2495 kg) with a road load setting of 22.7 horsepower (16.9 kW) at 50
miles per hour (80.5 km/hr).
The proposed light duty FTP specifies 22.7 horsepower at 5000
pounds (2268 kg). However, the procedures used during the previous
testing specified 22.7 horsepower and 5500 pounds. Therefore, so the
results would be comparable, this value of inertia weight was used.
The vehicle was tested in three modes: baseline vehicle, vehicle
with Retronox, vehicle with Retronox and oxidation catalyst.
Test Results
Exhaust emission data, summarized below, showed that the system was
functioning properly. Detailed results appear in a table at the back of
this report.
'75 FTP Composite Mass Emissions
grams per mile
(grams per kilometre)
(one test each)
Baseline vehicle
with Retronox
with Retrono^ and
UOP catalyst
HC
CO
CO,
2.99 58.21 784
(1.86) (36.17) (487)
3.21 59.60 807
(1.99) (37.04) (501)
1.28 17.50 858
(.80) (10.87) (533)
Fuel Economy
NOx (Fuel Consumption)
5.20 10.0 miles/gal.
(3.23) (23.6 litres/100 km)
3.03 9.7 miles/gal.
(1.88) (24.3 litres/100 km)
3.88 10.0 miles/gal.
(2.41) (23.6 litres/100 km)
Vehicle had 2 false starts and 2 stalls when cold.
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Carburetor
Ported Vacuum
Speed
Sensing
Valve
7/t.
a
Coil
Distributor
PCV Line
Vacuum controlled
valve
Exhaust pipe
DANA RETRONOX EGR SYSTEM
INSTALLATION
Figure 1
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For comparison results from the previous tests (with 500 miles on
the system) were:
'75 FTP Composite Mass Emissions
grams per mile
(grams per kilometre)
(3 tests each con-
figuration)
Baseline
with Retronox
with Retronox and
UOP catalyst
HC
CO
CO,
4.47 98.0 803
(2.77) (60.7) (498)
2.84 49.3 865
(1.76) (30.6) (536)
.56 13.5 973
(.35) (8.4) (603)
Fuel Economy
NOx (Fuel Consumption)
5.72 9.0 miles/gal.
(3.54) (26.1 litres/100 km)
4.29 9.1 miles/gal.
(2.65) (25.8 litres/100 km)
5.18 8.6 miles/gal.
(3.21) (27.2 litres/100 km)
A comparison of the test results shows the same trend noted in the
previous tests: "Very substantial reductions in hydrocarbon and carbon
monoxide emissions and small, but significant reductions in oxides of
nitrogen emissions." However a larger test sample would be required to
completely evaluate the system effectiveness and its deterioration.
On the Highway Fuel Economy Test (HFET) the results were:
HFET Mass Emissions
grams per mile
(grams per kilometre)
Baseline vehicle
with Retronox
with Retronox and
UOP catalyst
HC
.99
(.62)
Fuel Economy
CO CO NOx (Fuel Consumption)
13.86 652
(8.61) (405)
.91 17.03 663
(.57) (10.58) (412)
7.05 13.1 miles/gal.
(4.38) (18.0 litres/100 km)
5.54 12.8 miles/gal.
(3.44) (18.4 litres/100 km)
.26 1.57 667 5.69 13.2 miles/gal.
(.16) (.98) (414) (3.54) (17.9 litres/100 km)
No Highway Fuel Economy Tests were conducted during the previous
test series since the test cycle had not been developed at that time.
Conclusions
The Dana Retronox EGR/UOP oxidizing catalyst retrofit system
demonstrated continued substantial reductions in hydrocarbon and carbon
monoxide emissions and a small reduction in oxides of nitrogen emissions
compared to baseline. There was no fuel penalty incurred by this system.
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Because of normal test-to-test variability one should be cautious
in drawing conclusions from a single test in each configuration. However
a comparison of '75 FTP data for the configurations "Baseline" and "with
Retronix and UOP catalyst," before and after 9400 accumulated miles,
indicates that the catalyst lost oxidizing effectiveness, which is not
an unusual occurrence for a new catalyst. The effectiveness of the
Retronox system in controlling NOx, however, appears to have improved.
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Baseline
with Retronox
with Retronox and
UOP catalyst
Table 1
175 FTP Mass Emissions
grains per mile
Test Number HC
77-245 3.98
77-7 4.03
77-246 3.42
Baseline
with Retronox
with Retronox and
UOP catalyst
Baseline
with Retronox
with Retronox and
Bag 1 Cold Transient
CO CO NOx
106.40 838
115.21 828
73.04 901
Test Number
77-245
77-7
77-246
Test Number
77-245
77-7
77-246
5.00
3.62
3.64
'75
HC
2.99
3.21
1.28
EPA
HC
.99
.91
.26
Fuel
Economy
MPG HC
8.7 2.88
8.7 3.66
8.6 .58
Bag 2 Hot Stabilized Bag 3 Hot Transient
Fuel Fuel
Economy Economy
CO C00 NOx MPG HC CO C00 NOx MPG
53
58
2
FTP Composite Mass
grains per mile
CO C00
58.21
59.60
17.56
Highway Cycle
grams per
CO
13.86
17.03
1.57
784
807
858
Mass
mile
co2
652
663
667
.00 780
.19 917
.72 874
Emissions
NOx
5.20
3.03
3.88
Emissions
NOx
7.05
5.54
5.69
i,
4.26 10.2 2.45 31.83 751 7.14 11.0
3.51 8.7 2.44 31.83 760 2.34 10.8
2.97 10.1 .99 4.08 796 5.80 11.0
Fuel Economy
MPG
10.0
9.7
10.0
Fuel Economy
MPG
13.1
12.8
13.2
UOP catalyst
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