1,000 HOURS OF DURABILITY EVALUATION OF A PROTOTYPE 2007 DIESEL ENGINE USING B20 BIODIESEL FUEL

Transcription

1 1,000 HOURS OF DURABILITY EVALUATION OF A PROTOTYPE 2007 DIESEL ENGINE USING B20 BIODIESEL FUEL FINAL REPORT SwRI Project No Prepared For National Biodiesel Board 3337a Emerald Lane PO Box Jefferson City, MO Prepared By Michael D. Feist Imad A. Khalek, PhD September 2007 Revised June 2008

2 SOUTHWEST RESEARCH INSTITUTE P.O. Drawer Culebra Road San Antonio, Texas ,000 HOURS OF DURABILITY EVALUATION OF A PROTOTYPE 2007 DIESEL ENGINE USING B20 BIODIESEL FUEL FINAL REPORT SwRI Project No Prepared For National Biodiesel Board 3337a Emerald Lane PO Box Jefferson City, MO September 2007 Revised June 2008 Prepared by: Reviewed by: Michael D. Feist, Research Engineer Department of Engine and Vehicle Technology and Terry L. Ullman Assistant Director Department of Engine and Vehicle Technology Approved by: Imad A. Khalek, PhD Principal Engineer Department of Engine and Vehicle Technology Daniel W. Stewart, Director Department of Engine and Vehicle Technology ENGINE, VEHICLE, AND EMISSIONS RESEARCH DIVISION This report shall not be reproduced, except in full, without the written approval of Southwest Research Institute. Results and discussion given in this report relate only to the test it ems described in this report.

3 FOREWORD The work covered in this final report was performed for National Biodiesel Board (NBB) under Southwest Research Institute (SwRI ) Proposal A, dated January 17, The purpose of the program was to operate a 2007 Cummins ISL engine over a durability cycle for 1,000 hours using B20 biodiesel fuel. Emission measurements were performed at 125 and 1,000 hours of operation using ultra-low sulfur diesel (ULSD) fuel as well as B20 biodiesel fuel. Lube oil samples were extracted every 50 hours of accumulated durability operation and analyzed by SwRI. The lube oil analysis was funded by the Department of Energy National Renewable Energy Laboratory (DOE/NREL). Cummins Inc. provided a prototype 2007 model year, 8.9 liter, 330 hp, Cummins ISL diesel engine to SwRI for durability and emissions testing. A high-load durability cycle was performed for 1,000 hours using a B20 blend of soy-based biodiesel and commercially available ULSD fuel. Regulated emission measurements were performed at 125 and 1,000 hours of accumulated durability operation using emissions-grade B20 fuel as well as ULSD fuel which met the 2007 EPA specifications for emissions certification testing. Emissions testing was performed according to procedures outlined in the Code of Federal Regulations (CFR) Title 40 Part 86 Subpart N for heavy-duty on-highway engines. The test sequence for each fuel included one cold-start transient FTP test, three hot-start transient FTP tests, and one SET Ramped Modal Cycle (RMC). This project was performed by the Department of Engine and Vehicle Technology in the Engine, Vehicle, and Emissions Research Division of SwRI, under the supervision of Mr. Terry L. Ullman, Assistant Director and acting manager of the Diesel Technology Section. SwRI Project Manager was Dr. Imad A. Khalek, Principal Engineer, and SwRI Project Leader was Mr. Michael D. Feist, Research Engineer. The project was also supported by Mr. Matthew Marshell, Technician, Mr. Dan P. Marr, Staff Technician, and Mr. James E. Dittmar, Laboratory Supervisor. The sponsors representatives were Mr. Tom Verry from National Biodiesel Board, Ms. Jill Hamilton from Sustainable Energy Strategies, Mr. Michael O donnel and Mr. Edward Lyford from Cummins, and Mr. Robert McCormick from DOE/NREL. NBB funding for this project was provided by the Federal Transit Administration. SwRI Report ii

4 EXECUTIVE SUMMARY One thousand hours of durability testing were run on a prototype model year 2007 Cummins ISL engine using B20 soy-based biodiesel blend with ultra low sulfur diesel (ULSD) fuel. The prototype engine was equipped with an aftertreatment system that consisted of a diesel oxidation catalyst (DOC) close-coupled to a diesel particulate filter (DPF) in a single body unit. Active regeneration of the DPF was accomplished via in-cylinder diesel fuel injection without any interference by the engine operator. Regulated emission measurements that included oxides of nitrogen (NO x ), total hydrocarbon (THC), carbon monoxide (CO), particulate matter (PM), along with carbon dioxide (CO 2 ), were performed after 125 hours and 1,000 hours of durability testing using one cold-start followed by three hot-start FTP transient runs and one run of the supplemental emission test (SET) ramped modal cycle (RMC). Emission testing was performed with two fuels; B20 and ULSD. Oil analyses were performed on a sample collected from the oil sump every 50 hours of engine operation, with an oil change interval occurring every 250 hours. The emissions of THC, CO, and PM were well below the 2007 standard with no statistical difference between B20 and ULSD. However, B20 resulted in about 6 to 6.5 percent higher NO x, and about 2.5 to 3.5 percent higher fuel consumption. The lube oil analysis showed an increase in soot mass and iron concentration by about one percent and 20 to 40 ppm, respectively, in 250 hours of engine operation prior to an oil change. Throughout the 1,000 hours of durability operation using B20, the engine ran successfully without problems, except for two instances at 150 hours and 950 hours of engine operation. At 150 hours, an engine fault was triggered due to excessive blow-by ventilation system backpressure. This problem was resolved by replacing the existing crankcase filter with a new production design. After replacement, no crankcase related problems were encountered for the remainder of the testing. At 950 hours, an engine surge problem was resolved by replacing the fuel filter. SwRI recognized that the fuel filter had not been replaced throughout testing, although the engine manufacturer recommended replacement every 250 hours of engine operation. Thus, with a current production crankcase ventilation filter and with routine fuel filter changes, no fuel-specific problems are expected to be encountered within 1,000 hours of durability operation using B20. SwRI Report iii

5 LIST OF ACRONYMS General: Charge Air Cooler Code of Federal Regulations Diesel Particulate Filter Brake Specific Fuel Consumption Environmental Protection Agency Exhaust Gas Recirculation Federal Test Procedure Heated Flame Ionization Detector National Biodiesel Board National Renewable Energy Laboratory Non-Dispersive Inferred Particulate Matter Ramped Modal Cycle Southwest Research Institute Ultra-Low Sulfur Diesel Variable Geometry Turbocharger Wide Open Throttle CAC CFR DPF BSFC EPA EGR FTP HFID NBB NREL NDIR PM RMC SwRI ULSD VGT WOT SwRI Report iv

6 TABLE OF CONTENTS Page FOREWORD... ii EXECUTIVE SUMMARY... iii LIST OF ACRONYMS...iv LIST OF FIGURES...vi LIST OF TABLES... vii 1.0 INTRODUCTION TECHNICAL APPROACH Test Engine Test Fuels Test Procedure RESULTS Durability Results Emissions Results SUMMARY Appendix No. of Pages A Test Fuel Properties...6 B Engine Lube Oil Analysis SwRI Report v

7 LIST OF FIGURES Figure Page 1 Cummins ISL Diesel Engine Operating in a Durability Test Cell Cummins ISL DPF Routing in a Durability Test Cell Cummins ISL Diesel Engine Installed in a Transient Test Cell Cummins ISL DPF and Blow-by Routing in a Transient Test Cell Emissions Measurement System Schematic Engine Lube Oil Analysis Results for Soot Mass, Viscosity, Inflect, and Buffer 10 7 Concentration of Select Lube Oil Elements Sampled During the 1,000 Hour Durability Testing Full Load Torque and Power Map for a 8.9 Liter Cummins ISL Diesel Engine When Operated With B20 Biodiesel Fuel at 125 Hours and 1,000 Hours of Accumulated Durability Operation SwRI Report vi

8 LIST OF TABLES Table Page 1 Test Fuel Titles, Fuel Codes, and Descriptions Select Fuel Properties Summary of Normalized Emission Results for a Cummins ISL Engine AFter 125 Hours of Durability Operation On B20 Fuel Summary of Normalized Emission Results for a Cummins ISL Engine AFter 1,000 Hours of Durability Operation on B20 Fuel SwRI Report vii

9 1.0 INTRODUCTION The National Biodiesel Board contracted SwRI to perform durability and emission testing with a prototype 2007 model year Cummins heavy-duty diesel engine using B20 biodiesel fuel. The objective of the program was to operate the Cummins engine over a 1,000-hour durability sequence using commercially available B20 biodiesel fuel. Regulated emissions were evaluated at 125 hours and 1,000 hours of operation using B20 fuel as well as ULSD fuel. Lube oil samples were taken every 50 hours of operation for analysis by SwRI. Cummins Inc. provided a 2007 model year, prototype, 8.9 liter, ISL diesel engine for the durability and emissions test work. Soy-based biodiesel fuel was blended with commercially available ULSD fuel for the durability-grade B20 fuel, which was provided by Sun Coast Resources. The same soy-based biodiesel was blended by SwRI with 2007 certification ULSD for the emissions-grade B20 fuel used during emission testing. The same 2007 certification ULSD fuel was also used for the ULSD emission testing. A proprietary, high load cycle was performed to accumulate 1,000 hours of durability testing. Regulated emission testing was performed at 125 and 1,000 hours of accumulated durability operation using emissions-grade B20 biodiesel fuel as well as emissions-grade ULSD fuel. Emission testing included one cold-start transient FTP test, three hot-start transient FTP tests, and one SET Ramped Modal Cycle (RMC). SwRI Report of 15

10 2.0 TECHNICAL APPROACH 2.1 Test Engine A prototype 2007 model year Cummins ISL engine, shown in Figure 1, was provided by Cummins Inc. for the biodiesel durability and emissions test program. The 8.9 liter heavy-duty, on-highway diesel engine produced a 268 kw on emissions-grade B20 fuel. The inline 6- cylinder engine had a rated speed of 2100 rpm and peak torque of 1708 N m at 1400 rpm with emissions-grade B20 fuel. The engine was equipped with a diesel oxidation catalyst (DOC) followed by a catalyzed diesel particulate filter (DPF) that use diesel fuel post injection (incylinder) for active regeneration. The engine had a variable geometry turbocharger (VGT) and a high-pressure exhaust gas recirculation (EGR) with an EGR cooler. FIGURE 1. CUMMINS ISL DIESEL ENGINE OPERATING IN A DURABILITY TEST CELL SwRI Report of 15

11 2.2 Test Fuels The neat soy-based biodiesel used for blending the durability and emission test fuels was procured from Sun Coast Resources, Inc. out of Houston, Texas. The B100 met the fuel quality specifications listed in ASTM D b. The durability test fuel was a B20 blend of the neat soy-based biodiesel and a commercially available ULSD fuel. The durability fuel was blended by Sun Coast Resources and delivered to SwRI. Approximately 17,000 gallons of durability B20 biodiesel fuel was used during the 1,000-hours of durability testing. SwRI also procured eight 55-gallon drums of the neat biodiesel from Sun Coast Resources. The drummed biodiesel was blended by SwRI with an emissions grade 2-D, ultralow sulfur diesel fuel which met the 2007 EPA specifications for emissions certification testing. This emissions-grade B20 biodiesel fuel was used only during emissions testing. In addition to the emissions-grade B20 fuel, emissions testing was also performed with straight 2007 certification ULSD fuel. The 2007 certification fuel used for blending and testing was obtained from Haltermann Products, batch number VC3021LS10, and internally identified at SwRI as EM-6328-F. Table 1 summarizes the fuels used during the program, and Table 2 provides information on some selective fuel properties while detailed fuel analyses can be found in Appendix A. Fuel analyses were performed by SwRI for fuels EM-6353-F, EM-6365-F, and EM-6354-F, while the Certificate of Analysis from Haltermann Products was included for EM-6328-F. TABLE 1. TEST FUEL TITLES, FUEL CODES, AND DESCRIPTIONS Fuel Title SwRI Fuel Code Description Neat Biodiesel EM-6353-F B100 used to blend durability and emissions B20 test fuels 2007 Cert. ULSD EM-6328-F Used during emissions testing and to blend EM F Durability-Grade B20 EM-6365-F Blended with EM-6353-F and commercially available ULSD fuel -- used during durability operation Emissions-Grade B20 EM-6354-F Blended with EM-6353-F and EM used during emissions testing SwRI Report of 15

12 TABLE 2. SELECT FUEL PROPERTIES B20- Emission- Grade B20- Durability- Grade B100 ULSD 1 ASTM Test Test Property / Description Units EM-6354-F EM-6365-F EM-6353-F EM-6328-F D2500 Cloud Point Deg C C N/A D deg C cst N/A D482 Ash Content mass % <0.001% <0.001% N/A D4951 Phosphorus ppm <5 <5 <5 N/A D5453 Total Sulfur ppm D613 Cetane Number D86 Distillation IBP deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C N/A 20% Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C FBP deg C Fuel analysis as supplied by Fuel Supplier 2.3 Test Procedure Durability operation was performed at SwRI in a steady-state durability test cell. Figure 1 shows the Cummins ISL engine during durability operation, while Figure 2 shows the DPF installation in the durability test cell. SwRI Report of 15

13 DPF Turbocharger Outlet FIGURE 2. CUMMINS ISL DPF ROUTING IN A DURABILITY TEST CELL Prior to durability operation, the ISL engine s turbocharger assembly was replaced due to a damaged impeller and a final calibration update was performed. The intake air restriction, exhaust restriction, charge air cooler (CAC) restriction, CAC outlet temperature, and engine coolant outlet temperature were set according to the engine manufacturer s specifications. The engine was operated at rated power and peak torque to verify engine performance. While operating in the durability test cell, a number of engine and test cell parameters were monitored. A limited number of key engine parameters were recorded at 1 Hz, whereas, all monitored engine and test cell data were recorded hourly. The durability test cell was computer controlled and incorporated a number of automated safety functions that allowed the test cell to operate continuously. The engine was shut down every 25 hours to check engine lube oil levels and test cell hardware. The engine lube oil and lube oil filter were changed every 250 hours of accumulated durability operation, while lube oil samples were taken every 50 hours of durability operation During durability testing, the engine was operated over a proprietary high-load, accelerated durability cycle. Approximately 60 percent of the cycle was at rated power, 15 SwRI Report of 15

14 percent of the cycle was at peak torque, and 25 percent of the cycle was at low and high idle. The cycle was repeated for the duration of the 1000 hr durability test. After 125 hours and again after 1,000 hours of accumulated durability operation, the Cummins ISL engine was removed from the durability test cell and installed in a transient emissions test cell. Figure 3 shows the test engine installed in the transient cell during the 125- hour emissions testing. FIGURE 3. CUMMINS ISL DIESEL ENGINE INSTALLED IN A TRANSIENT TEST CELL Figure 4 shows the DPF and blow-by routing in the transient test cell. The DPF inlet was approximately 1 meter from the outlet of the turbocharger. Because the Cummins ISL engine used an open crankcase ventilation system, the blow-by gases were routed into the engine s exhaust pipe, after the DPF. A heated, stainless steel pipe was used to route the blow-by from the crankcase ventilation filter to the exhaust pipe. To prevent condensation and artificial cooling, the blow-by pipe temperature was maintained at the maximum blow-by gas temperature observed during operation at rated power and peak torque of 54 C. SwRI Report of 15

15 Heated Stainless Steel Blow-by Pipe FIGURE 4. CUMMINS ISL DPF AND BLOW-BY ROUTING IN A TRANSIENT TEST CELL The engine was tested according to procedures outlined in the Code of Federal Regulations (CFR) Title 40 Part 86 Subpart N for heavy-duty on-highway engines. The test sequence conducted on the engine included one cold-start transient FTP test, three hot-start transient FTP tests, and one SET Ramped Modal Cycle (RMC). This sequence of tests was performed using both the emissions-grade B20 biodiesel fuel as well as the 2007 certification ULSD fuel. All measurements were made using dilute sampling techniques with a full flow CVS dilution tunnel. A schematic of the emissions sampling system is shown in Figure 5. SwRI Report of 15

16 Positive Displacement Pump (PDP) Dilution Air Filter Pack Mixing Orifice Exhaust Pipe 10 Diameters Sample Zone Horiba MEXA 7200 (HC, CO, CO2, NOx) Heat Exchanger CO, CO2, HC, and NOx Background Bag Particulate Filter Sample PM Gas Meter Pump Bag Sample Gas Analyzer Engine Sample Line Heated Line 90mm PM Filters FIGURE 5. EMISSIONS MEASUREMENT SYSTEM SCHEMATIC Regulated emissions of total hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NO x ), and particulate matter (PM) were measured for each test. The total hydrocarbons were measured using continuous sampling techniques with a heated flame ionization detector (HFID). The NO x levels were measured continuously using a chemiluminescent analyzer. Carbon monoxide (CO) and carbon dioxide (CO 2 ) were measured continuously using NDIR analyzers. The PM level for each test was determined using a type PM dilute sampling system that collected particulate matter on 47 mm Teflo filter media. Each filter was weighed before and after sampling to establish the mass accumulated for the given emissions test. SwRI Report of 15

17 3.0 RESULTS 3.1 Durability Results The 1,000-hour durability testing with soy-based B20 biodiesel fuel was successful. Other than the exceptions listed below, the engine showed no significant changes in operation or performance throughout the test. With the high load durability cycle, DPF regeneration was not a problem. At 150 hours of durability operation, the engine began leaking lube oil from the filler cap on the valve cover. It was also observed that there was no blow-by flow from the open crankcase ventilation system even at high load operation; while blow-by flow had been evident earlier in the program. Furthermore, an engine fault code related to the crankcase pressure became active. Removal of the crankcase ventilation system filter remedied the problems described above. According to Cummins, the maintenance interval for replacement of the crankcase ventilation filter was 80,000 miles or 2,000 hours of field operation. Due to the acceleration factor of the durability cycle, Cummins did not expect to replace the filter until 975 hours of durability operation. A new replacement crankcase ventilation filter was supplied by Cummins and installed on the engine. According to Cummins, the new replacement filter is the one used in current production engines and the failed filter was an old design. The new replacement filter had several additional passages as well as a spring loaded bypass port, compared to the older version. SwRI was not able to independently confirm whether or not the problem encountered with the blow-by filter was fuel-specific. However, the new replacement filter was used throughout the rest of the project for over 850 hours without any crankcase related problems. At approximately 950 hours of accumulated durability operation, the engine began surging when operated at rated speed and full load. An engine fault code also activated stating the injector metering pressure was below normal. After several days of interaction with Cummins, the problem remained unresolved. SwRI finally recognized that the fuel filter had not been changed during the project. Although not communicated to SwRI prior to the filter failure, the Cummins specified maintenance interval for the fuel filter replacement is 500 hours of field operation. Due to the acceleration factor of the durability cycle, the fuel filter should have been replaced every 250 hours. After replacing the fuel filter, the engine resumed normal operation and the active engine fault cleared. SwRI was not able to independently confirmed whether or not this problem was fuel-specific. Engine lube oil analysis was performed by SwRI on samples collected every 50 hours of durability operation. As mentioned previously, the lube oil and lube oil filter was replaced every 250 hours of durability operation. Approved by Cummins, the engine lube oil used during the program was Valvoline Premium Blue, SAE 15W-40, API Services CJ-4, CI-4, CH-4, and DF/SL. A comprehensive summary of the lube oil analysis is included in Appendix B. SwRI Report of 15

18 Figure 6 shows the soot mass, viscosity, inflect, and buffer lube oil results measured during the 1,000-hour durability testing, while Figure 7 shows the concentration of select elements measured in the lube oil. A fresh lube oil sample was analyzed at 0 hours of testing. Oil changes occurred at 250, 500, and 750 hours of durability operation after the lube oil samples were collected. Although an oil change occurred at 250 hours, an oil sample was not collected at 250 hours of operation. Soot mass in the lube oil increased by about one percent and iron increased by about 20 to 40 ppm after 250 hours of engine operation. During the first 250 hours of engine operation, copper increase was also observed. Soot mass % Oil Change Viscosity cst Inflect mg KOH/g Buffer mg KOH/g Fresh Oil at 0 Hours 18 Soot Mass [%] Viscosity [cst] and Inflect, Buffer [mg KOH/g] Oil Sample [hours] FIGURE 6. ENGINE LUBE OIL ANALYSIS RESULTS FOR SOOT MASS, VISCOSITY, INFLECT, AND BUFFER SwRI Report of 15

19 Cu, Fe, Si Concentration [ppm] Fresh Oil at 0 Hours Cu ppm Fe ppm Si ppm Oil Change Ca ppm Mg ppm P ppm Zn ppm Ca, Mg, P, Zn Concentration [ppm] Oil Sample [hours] FIGURE 7. CONCENTRATION OF SELECT LUBE OIL ELEMENTS SAMPLED DURING THE 1,000 HOUR DURABILITY TESTING 3.2 Emissions Results After installation in a transient emissions test cell, the engine settings were verified and a power validation procedure was performed by operating the engine at full load and at rated speed and peak torque speed using emissions-grade B20 biodiesel fuel. Using an 8 rpm per second speed sweep, a full load torque map was generated. Figure 8 shows the full load torque and power maps for the Cummins ISL engine when operated on emissions-grade B20 fuel at the 125- hour and 1,000-hour test intervals. As shown from the torque and power traces, engine performance was essentially the same when tested at 125 and 1,000 hours of accumulated durability operation. The B20, 125-hour, full load torque map was used to generate the transient FTP test cycle and the ramped modal cycle (RMC) test cycle. In order to keep testing consistent between fuels and between the 125-hour and 1,000-hour test intervals, the command cycles generated with the emissions-grade B20 fuel at the 125-hour test were used throughout the program. After performing emission tests with emissions-grade B20, the test fuel was changed to 2007 EPA certification ULSD. The fuel change was performed by removing the fuel supply and return hoses from the engine and purging the system with ULSD fuel. Engine and laboratory fuel filters were also replaced. After reassembling the fuel system, the engine was operated at rated power for approximately one hour with ULSD fuel to further purge the system. SwRI Report of 15

20 Torque [N-m] Torque 125-Hour Torque 1000-Hour Power 125-Hour Power 1000-Hour Power [kw] Speed [rpm] FIGURE 8. FULL LOAD TORQUE AND POWER MAP FOR A 8.9 LITER CUMMINS ISL DIESEL ENGINE WHEN OPERATED WITH B20 BIODIESEL FUEL AT 125 HOURS AND 1,000 HOURS OF ACCUMULATED DURABILITY OPERATION 0 Prior to the commencement of the project, an agreement between the National Biodiesel Board and Cummins Inc. was reached regarding the presentation of the emission results. Per the agreement, SwRI was only permitted to release normalized emission results. Furthermore, emission results from the 125-hour and 1,000-hour testing were to be isolated, showing no comparison between the initial and final testing. With those limitations, the only evaluations performed were between the B20 biodiesel fuel and ULSD fuel at the 125-hour and 1,000-hour emission tests. Table 3 shows the normalized emission results for the 125-hour emissions testing. The emission results were normalized using the 125-hour ULSD hot-start mean emission value for each pollutant. With the use of a DPF, the HC, CO, and PM emission levels were all well below the regulatory standards, causing increased measurement variability. A t-test comparison was performed on the B20 and ULSD hot-start tests to determine if the mean values were equal. Hotstart t-test values less than 0.05 indicated there was a 95 percent chance or greater that the mean values were distinct. Due to the higher variability for the low levels of HC, CO, and PM measurements, the B20 and ULSD hot-start mean values were not significantly different at the 5 percent significance level. However, the hot-start mean NO x, CO 2, and brake-specific fuel consumption (BSFC) values were significantly different at the 5 percent significance level. NO x levels increased 5.9 percent with the emissions-grade B20 biodiesel fuel as compared to the ULSD fuel over the hot-start triplicate testing. Carbon dioxide increased 0.5 percent and BSFC increased 2.6 percent with B20 fuel over hot-start testing. The increase in fuel consumption with SwRI Report of 15

21 the B20 was expected due to the lower energy content of B20 fuel compared to that of ULSD. Reported on a mass basis, BSFC differences were inline with typical energy differences between ULSD and B20 fuel. The increase in NO x was also expected due to the presence of oxygen in the fuel that promotes the formation of NO x in internal combustion engines. TABLE 3. SUMMARY OF NORMALIZED EMISSION RESULTS FOR A CUMMINS ISL ENGINE AFTER 125 HOURS OF DURABILITY OPERATION ON B20 FUEL Test Normalized Brake-Specific Emissions Results 2 Description Test Name HC 1 CO 1 NOx PM 1 CO2 BSFC Cold Start Hot Start Hour Hot Start B20 Hot Start RMC C/H Composite Hot Start Ave Hot Start COV 75% 33% 0.6% 5.3% 0.2% 0.2% Cold Start Hot Start Hour Hot Start Cert. ULSD Hot Start RMC C/H Composite Hot Start Ave Hot Start COV 120% 24% 0.3% 31% 0.2% 0.2% RMC 29% -13% 4.4% 32% -0.2% 1.9% % Difference C/H Composite -93% -28% 4.7% 74% 0.3% 2.4% (B20-ULSD)/ULSD Hot Start Ave. -6.1% -21% 5.9% 39% 0.5% 2.6% Hot Start t-test BSHC, BSCO, and BSPM are well below the regulatory standards. 2 Test results were normalized using the ULSD hot start average emission values. 3 Values less than 0.05 indicate hot start mean values are significantly different at the 5 % significance level. Table 4 shows the normalized Cummins ISL 1,000-hour emission results. The results were normalized using the 1,000-hour ULSD hot-start mean emission value for each pollutant. Similar to the 125-hour test results, it is difficult to quantify a change in HC, CO, and PM emission results due to the very low emission levels and higher variability of the data. For the 1,000-hour test, the mean hot-start NO x level increased 6.5 percent with B20 fuel as compared to the ULSD test results. The mean hot-start BSFC increased 3.4 percent and CO 2 increased 1.7 percent with B20 biodiesel fuel as compared to the straight ULSD fuel. SwRI Report of 15

22 TABLE 4. SUMMARY OF NORMALIZED EMISSION RESULTS FOR A CUMMINS ISL ENGINE AFTER 1,000 HOURS OF DURABILITY OPERATION ON B20 FUEL Test Normalized Brake-Specific Emissions Results 2 Description Test Name HC 1 CO 1 NOx PM 1 CO2 BSFC Cold Start Hot Start Hour Hot Start B20 Hot Start RMC C/H Composite Hot Start Ave Hot Start COV 20% 7% 0.8% 15.3% 0.1% 0.1% Cold Start Hot Start Hour Hot Start Cert. ULSD Hot Start RMC C/H Composite Hot Start Ave Hot Start COV 170% 29% 1.1% 18% 0.2% 0.2% RMC -40% 4.1% 6.7% -80% 0.5% 2.2% % Difference C/H Composite N/A -57% 7.6% -24% 1.4% 3.1% (B20-ULSD)/ULSD Hot Start Ave. 3400% -56% 6.5% -22% 1.7% 3.4% Hot Start t-test BSHC, BSCO, and BSPM are well below the regulatory standards. 2 Test results were normalized using the ULSD hot start average emission values. 3 Values less than 0.05 indicate hot start mean values are significantly different at the 5 % significance level. As specified in the agreement between NBB and Cummins, no comparison was made between the 125-hour and 1,000- hour emission test results. SwRI Report of 15

23 4.0 SUMMARY SwRI performed durability and emissions test work for the National Biodiesel Board using a prototype, 2007 model year Cummins ISL diesel engine. The Cummins engine performed 1,000 hours of durability operation using soy-based B20 biodiesel fuel. Emission testing was performed at 125 and 1,000 hours of durability operation. Emissions testing included one cold-start transient FTP test, three hot-start transient FTP tests, and one SET Ramped Modal Cycle (RMC). The Cummins ISL engine completed the 1,000-hour durability with no significant change in engine performance or operation. A crankcase ventilation filter backpressure problem occurred at 150 hours of engine operation. The problem was resolved for the remainder of testing by replacing the crankcase filter with a current production replacement filter that was provided by Cummins. Replacement of the fuel filter resolved an engine surge problem that occurred at 950 hours of durability operation. Although the manufacturer recommended fuel filter changes every 250 hours of engine operation, a single filter was used through 950 hours of operation. Both the 125-hour and 1,000-hour emission results showed an increase in NO x and BSFC on emissions-grade B20 biodiesel fuel as compared to ULSD fuel. On B20 and ULSD fuels, emission of HC, CO, and PM were similar and well below the applicable emission standards with the use of a DPF exhaust aftertreatment device. SwRI Report of 15

24 APPENDIX A TEST FUEL PROPERTIES

25 SPECIFICATION FOR BIODIESEL (B100) ASTM D b March 2007 Biodiesel is defined as the mono alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, for use in compression-ignition (diesel) engines. This specification is for pure (100%) biodiesel prior to use or blending with diesel fuel. # Property ASTM Method Limits Units Calcium & Magnesium, combined EN max ppm (ug/g) Flash Point (closed cup) D min. Degrees C Alcohol Control (One of the following must be met) 1. Methanol Content EN Max % volume 2. Flash Point D Min Degrees C Water & Sediment D max. % vol. Kinematic Viscosity, 40 C D mm 2 /sec. Sulfated Ash D max. % mass Sulfur S 15 Grade S 500 Grade D 5453 D max. (15) 0.05 max. (500) % mass (ppm) % mass (ppm) Copper Strip Corrosion D 130 No. 3 max. Cetane D min. Cloud Point D 2500 Report Degrees C Carbon Residue 100% sample D 4530* 0.05 max. % mass Acid Number D max. mg KOH/g Free Glycerin D max. % mass Total Glycerin D max. % mass Phosphorus Content D max. % mass Distillation, T90 AET D max. Degrees C Sodium/Potassium, combined EN max ppm Oxidation Stability EN min hours Workmanship Free of undissolved water, sediment, & suspended matter BOLD = BQ-9000 Critical Specification Testing Once Production Process Under Control * The carbon residue shall be run on the 100% sample. A-1

26 ASTM Test B20-Emission B20-Durability-Grade B100 EM-6354-F EM-6353-F Results EM-6365-F Results Results Test Property / Description Units D2 blend Requirement D130 Copper Corrosion Strip Rating 3 max. 1B 1A 1A D2274 Accelarated Stabilitity Filterable Insoluble mg/100ml N/A Adherent Insoluble mg/100ml N/A Total Insolubles mg/100ml 10 max N/A D2500 Cloud Point Deg C Note C D2709 Water & Sediment 0.05 max. Total Volume Vol% Description Clear & Bright Clear & Bright Clear & Bright D deg C cst 1.9~ D482 Ash Content mass % 0.01 max. <0.001% <0.001% D4951 Phosphorus ppm % max. <5 <5 <5 Ramsbottom Carbon on 10% distillation wt% 0.35 max N/A D524 D5453 Total Sulfur ppm D6079 Lubricity by HFRR 46 max. Major Axis mm N/A Minor Axes mm N/A Wear Scar Diameter mm N/A Wear Scar Description lightly abraded oval lightly abraded oval N/A Fuel Temperature degc N/A D613 Cetane Number 43 min D Free Glycerin wt% N/A N/A <0.005 Total Glycerin wt% N/A N/A Monoglyceride wt% N/A N/A Diglyceride wt% N/A N/A Triglyceride wt% N/A N/A A-2

27 D664 Inflection Point mg KOH/g N/A N/A 0.09 Buffer End Point mg KOH/g <0.05 < D7111 Alkali metals Sodium (Na) ppm Nd <1 <1 <1 Potassium (K) ppm Nd <1 < Alkaline metals Magnesium (Mg) ppm Nd <1 < Calcium (Ca) ppm Nd < D874 Sulfated Ash wt% <0.001 D93 Flash Point Deg F Flash Point Deg C 52 min EN14112 Rancimat Run 1 hours >12 hrs Run 2 hours >12 hrs Average hours >12 hrs D86 Distillation IBP deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C % Evaporated deg C FBP deg C Recovered ml % A-3

28 Residue ml % Loss ml N/A Pressure corrected IBP deg C N/A Pressure corrected 10% deg C N/A Pressure corrected 50% deg C N/A Pressure corrected 90% deg C 343 max N/A Pressure corrected FBP deg C N/A EN14078 FAME Content vol% +/- 2% N/A NOTES 1 ASTM D-6584 is not applicable to vegetable oil methyl esters obtained from lauric oils (e.g. coconum, palm oil) 2 ASTM D-7111 (ICP) is substituted. A-4

29 A-5

30 A-6

31 APPENDIX B ENGINE LUBE OIL ANALYSIS

32 Property Result Rep# Fixed RecvDate 5/11/ :49 5/17/ :00 5/17/ :00 6/13/ :22 WrkSheet ProjName OB OB OB OB LabNum SOilCode 0Hr 50Hr 100Hr 150hr SampTag CEC Soot Soot mass % D c Viscosty cst D4739 TBN Inflect mg KOH/g Buffer mg KOH/g D5185 Al ppm Sb ppm Ba ppm B ppm Ca ppm Cr ppm <1 < Cu ppm Fe ppm Pb ppm Mg ppm Mn ppm <1 <1 1 2 Mo ppm Ni ppm <1 <1 <1 13 P ppm Si ppm Ag ppm Na ppm 5 <5 5 8 Sn ppm <1 <1 <1 6 Zn ppm K ppm <5 <5 <5 <5 Sr ppm V ppm Ti ppm Cd ppm B-1

33 Property Result Rep# Fixed RecvDate WrkSheet ProjName LabNum SOilCode SampTag CEC Soot Soot mass % D c Viscosty cst D4739 TBN Inflect mg KOH/g Buffer mg KOH/g D5185 Al ppm Sb ppm Ba ppm B ppm Ca ppm Cr ppm Cu ppm Fe ppm Pb ppm Mg ppm Mn ppm Mo ppm Ni ppm P ppm Si ppm Ag ppm Na ppm Sn ppm Zn ppm K ppm Sr ppm V ppm Ti ppm Cd ppm /13/ :22 6/18/ :40 6/25/ :58 6/25/ : OB OB OB OB hr 300hr 350hr 400hr <1 <1 < <1 <1 < <1 <1 < <5 <5 <5 <1 1 <1 1 B-2

34 Property Result Rep# Fixed RecvDate WrkSheet ProjName LabNum SOilCode SampTag CEC Soot Soot mass % D c Viscosty cst D4739 TBN Inflect mg KOH/g Buffer mg KOH/g D5185 Al ppm Sb ppm Ba ppm B ppm Ca ppm Cr ppm Cu ppm Fe ppm Pb ppm Mg ppm Mn ppm Mo ppm Ni ppm P ppm Si ppm Ag ppm Na ppm Sn ppm Zn ppm K ppm Sr ppm V ppm Ti ppm Cd ppm /25/ :58 6/25/ :58 7/2/ :43 7/2/ : OB OB OB OB hr 500hr 550hr 600hr /26/2007 6/28/ < <1 < <1 < <5 < <5 <5 <5 <5 B-3

35 Property Result Rep# Fixed RecvDate WrkSheet ProjName LabNum SOilCode SampTag CEC Soot Soot mass % D c Viscosty cst D4739 TBN Inflect mg KOH/g Buffer mg KOH/g D5185 Al ppm Sb ppm Ba ppm B ppm Ca ppm Cr ppm Cu ppm Fe ppm Pb ppm Mg ppm Mn ppm Mo ppm Ni ppm P ppm Si ppm Ag ppm Na ppm Sn ppm Zn ppm K ppm Sr ppm V ppm Ti ppm Cd ppm /2/ :43 7/2/ :43 7/9/ :50 7/9/ : OB OB OB OB hr 700hr 750hr 800hr 6/30/2007 7/2/2007 7/4/2007 7/8/ < <1 1 2 < < <5 <5 <5 <5 B-4

36 Property Result Rep# Fixed RecvDate WrkSheet ProjName LabNum SOilCode SampTag CEC Soot Soot mass % D c Viscosty cst D4739 TBN Inflect mg KOH/g Buffer mg KOH/g D5185 Al ppm Sb ppm Ba ppm B ppm Ca ppm Cr ppm Cu ppm Fe ppm Pb ppm Mg ppm Mn ppm Mo ppm Ni ppm P ppm Si ppm Ag ppm Na ppm Sn ppm Zn ppm K ppm Sr ppm V ppm Ti ppm Cd ppm /20/ :11 7/20/ :11 8/14/ :44 8/14/ : OB OB OB OB hr 900hr 950hr 1000hr 7/10/2007 7/12/ <1 < < <5 <5 5 5 <1 <1 1 1 B-5