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 ------- 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. ------- 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. ------- 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 ------- 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. ------- 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 ------- 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. ------- 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. ------- 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 ------- |