THE IMPACT OF BIODIESEL FUEL BLENDS ON AFTERTREATMENT DEVICE PERFORMANCE IN LIGHT-DUTY VEHICLES

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1 THE IMPACT OF BIODIESEL FUEL BLENDS ON AFTERTREATMENT DEVICE PERFORMANCE IN LIGHT-DUTY VEHICLES Matthew Thornton NREL, Marek Tatur and Dean Tomazic FEV Engine Technology Inc. National Biodiesel Conference & Expo 2008 February 5 th 2008

2 Disclaimer and Government License This work has been authored by Midwest Research Institute (MRI) under Contract No. DE-AC36-99GO10337 with the U.S. Department of Energy (the DOE ). The United States Government (the Government ) retains and the publisher, by accepting the work for publication, acknowledges that the Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work or allow others to do so, for Government purposes. Neither MRI, the DOE, the Government, nor any other agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe any privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the Government or any agency thereof. The views and opinions of the authors and/or presenters expressed herein do not necessarily state or reflect those of MRI, the DOE, the Government, or any agency thereof.

3 Project Overview One of several projects evaluating biodiesel future engine and emission control systems Collaboration between the National Biodiesel Board (NBB) and NREL (DOE) under a cooperative research and development agreement (CRADA) Evaluate the impact of biodiesel fuel blends on emission control system performance Includes two emission control systems and two fuel blends on a light-duty platform NAC/DPF and SCR/DPF systems 5% and 20 % biodiesel blends Optimization and performance over time CFD Modeling of SCR Engine teardown, oil dilution analysis, catalyst analysis Project duration approximately 2+ years

4 Fuel Comparison ULSD Base Fuel B20 Density (kg/dm 3 ) Cetane Number Carbon (wt%) Oxygen (wt%) Hydrogen (wt%) Kinematic Viscosity at 40 C [mm 2 /sec]

5 Hardware Overview SCR System

6 Hardware Overview NOx Adsorber System

7 Test Cell Set-up NOx Adsorber System DOC/NAC Engine Out Dual wall pipe DPF

8 Hardware Overview Test Vehicle Hardware

9 Hardware Overview Test Engine Hardware Power [kw] BMEP [bar] Speed [rpm] Torque [Nm] Smoke [FSN] Engine Power Peak torque Max engine speed Max. BMEP Number & Arrangement of Cylinders rpm rpm 4700 rpm 21 bar 4 cylinder inline Firing order Valve train Displacement 4 Valve DOHC 2.15 L Bore to stroke ratio Compression Ratio 18 Fuel injection system 2nd Generation Common- Rail DI

10 Engine-out Emission Optimization Base Euro 4 Calibration NEDC > 0.25 g/km NOx (0.4 g/mi) FTP75 < 0.7 g/mi NOx Replacement of stock ECU with development unit including RP capabilities Access to all engine/combustion parameters: Begin of injection, Pilot + Post injections, Railpressure, Boost pressure, EGR, Throttle, Swirl Steady-state optimization in 14 operating points Average reduction of all emissions over 50% Transient optimization in test cell and vehicle Average reduction of all emissions over 50% Implementation of emission control devices

11 Engine-out Emission Optimization Base calibration Optimized calibration NOx emissions comparison in 14 calibration modes 500 NOx [ppm] Engine speed [rpm] / BMEP [bar]

12 Engine-out Emission Optimization Smoke emissions in 14 calibration modes 6 5 Base calibration Optimized calibration 4 Smoke [FSN] Engine speed [rpm] / BMEP [bar]

13 Emissions Results NAC System

14 NMHC [g/mile] PM [mg/mile] Test Results Vehicle Emission Tests (at the U.S. EPA) Cold LA4 Hot LA4 Composite FTP 75 50,000 mile 120,000 mile NOx [g/mile] ,000 mile 120,000 mile CO [g/mile]

15 NMHC [g/mile] PM [mg/mile] Test Results Vehicle Emission Tests (at the U.S. EPA) Composite ULSD Composite B20 Composite B5 50,000 mile 120,000 mile NOx [g/mile] ,000 mile 120,000 mile CO [g/mile]

16 Test Results Vehicle Emission Tests (at the U.S. EPA) B20 = 11% ULSD = 10% B20 = 46% ULSD = 45% B20 = 43% ULSD = 45% Temperature [ C] Vehicle Speed [mph] Engine Out - B20 Tail Pipe Out - B20 Engine Out - ULSD Tail Pipe - ULSD B20 - Temperature upstream LNT ULSD - Temperature upstream LNT Time [s] Accumulated NOx [g]

17 Test Results Durability Testing Durability Cycle 700 Duration Duration completed 750 = 107% Number of Desulfurization completed Number of DPF regeneration completed Time [hr] DeSOx Avg Temp in DPF [deg C] DeSOx Avg Temp in NAC [deg C] DPF Regen Avg Temp in DPF [deg C] DPF Regen Avg Temp in NAC [deg C] OP2 Avg Temp in DPF [deg C] OP2 Avg Temp in NAC [deg C] OP1 Avg Temp in DPF [deg C] OP1 Avg Temp in NAC [deg C] Temperature [deg C]

18 NMHC [g/mile] PM [mg/mile] Test Results Durability Testing 0 hr - FTP 75 composite Intermediate life - FTP 75 composite Full usefull life - FTP 75 composite 50,000 mile 120,000 mile NOx [g/mile] ,000 mile 120,000 mile CO [g/mile]

19 NMHC [%] NMHC [%] Test Results Durability Testing Conversion Efficiency [%] NOx [%] Conversion efficiency target 120,000; 50,000 miles 0 hr FTP composite Intermediate life FTP composite CO [%]

20 Test Results Fuel Economy Impact Vehicle (FTP75) NOx [g/mile] B20 ULSD Fuel Economy [mpg] 0.0 Base EURO 4 T2B5 Feedgas T2B5 Tailpipe Base EURO 4 T2B5 Feedgas T2B5 Tailpipe 0.0

21 Test Results Fuel Economy Impact Vehicle (FTP75) B20 ULSD Fuel Economy [mpg] Base EURO 4 T2B5 Feedgas T2B5 Tailpipe 25

22 Summary and Conclusions Vehicle as well as test cell results indicate an increase in engine out NOx and decrease in PM using Biodiesel blends Tail pipe NOx emissions decreed using Biodiesel blends (for the NAC system which was calibrated for B20 operation) This NAC system achieved Tier 2 Bin 5 emission levels at simulated full useful life (120k mi) NOx adsorber regeneration control remains the same between petroleum based and Biodiesel blended fuel. Fuel economy impact using Biodiesel fuel was marginal using an integrated Tier 2 Bin 5 system. Durability investigations focusing on Biodiesel effects on engine and aftertreatment system are currently underway for the SCR system.

23 Acknowledgments DOE Office of FreedomCAR and Vehicle Technologies, Advance Petroleum Based and Non-Petroleum Based Fuels Activities: Stephen Goguen, Kevin Stork, and Dennis Smith, Technology Managers National Biodiesel Board: Steve Howell MECA: Joe Kubsh and Rasto Brezny EPA: Charles Schenk