1. Results of Research Engine and Vehicle Drive Cycle Testing during Blended Hydrogen/Methane Operation Thomas Wallner, Henning Lohse-Busch, Henry Ng Argonne National Laboratory Robert Peters University of Alabama at Birmingham NHA Annual Hydrogen Conference 2007 San Antonio/Texas March 19 th – 22 nd 2007 DOE-Sponsors: Lee Slezak, Gurpreet Singh

2. 2 Government license The submitted manuscript was developed by the UChicago Argonne LLC as Operator of Argonne National Laboratory (“Argonne”) under Contract No. DE-AC-02-06CH11357 with DOE. The U.S. Government retains for itself, and others acting on its behalf, a paid-up, nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.

3. 3 Outline Motivation for blend testing Argonne’s Hydrogen Engine Approach Comparison of fuel properties Research engine testing –Test setup –Combustion analysis –Efficiency evaluation –NO x emissions results Vehicle Drive-Cycle testing –Vehicle specifications –Fuel economy comparisons –Emissions results Summary and conclusions

4. 4 Motivation for blend testing Pros and cons Blending hydrogen with methane reduces the demand for hydrogen Hydrogen offers unique combustion properties even in blended operation Improved on-board storage density Addition of methane causes formation of greenhouse gas emissions (CO 2 ) Running on hydrogen/methane blends results in formation of regulated emissions other then NO x

5. 5 Argonne’s Hydrogen Engine Approach Moving from Single-Cylinder Research to On-Road Application  DOE-Targets: 45 % BTE 0.07 g/mile NO x

6. 6 Comparison of fuel properties Liquid versus gaseous fuels HGHG ParameterSymbolUnitDieselGasolineMethaneH2H2 Density  kg/m 3 830 I 730-780 I 0,72 I 0,089 I 71 II,III Stoichiometric air demand L St kg air /kg fuel 14,514,717,234,3 Lower heating value HuHu MJ/kg Kst 42,543,550120 Mixture calorific value V HGHG MJ/m 3 3,83 3,82 3,4 3,76 3,2 4,53 Boiling temperature III T Boiling °C180-36025-215-162-253 Ignition limits IV Vol-% 0,6-5,5 0,5-1,3 1,0-7,6 0,4-1,4 5,3-15 0,7-2,1 4-76 0,2-10 Minimum ignition energy III,IV,V E Ignition mJ0,24 0,290,02 Self-ignition temperature T Ignition °Capprox. 250approx. 350595585 Diffusion coefficient I,IV Dm 2 /s--1,9x10 -6 8,5x10 -6 Quenching distance III,IV,VI mm22,030,64 Laminar flame speed IV,V v lam cm/s40-80 40200 Carbon contentCMass-%86 750 I at 1,013 bar und 0 °C II at –253°C III at 1,013 bar IV in air V =1 VI at 20°C

7. 7 Comparison of fuel properties Liquid versus gaseous fuels HGHG ParameterSymbolUnitDieselGasolineMethaneH2H2 Density  kg/m 3 830 I 730-780 I 0,72 I 0,089 I 71 II,III Stoichiometric air demand L St kg air /kg fuel 14,514,717,234,3 Lower heating value HuHu MJ/kg Kst 42,543,550120 Mixture calorific value V HGHG MJ/m 3 3,83 3,82 3,4 3,76 3,2 4,53 Boiling temperature III T Boiling °C180-36025-215-162-253 Ignition limits IV Vol-% 0,6-5,5 0,5-1,3 1,0-7,6 0,4-1,4 5,3-15 0,7-2,1 4-76 0,2-10 Minimum ignition energy III,IV,V E Ignition mJ0,24 0,290,02 Self-ignition temperature T Ignition °Capprox. 250approx. 350595585 Diffusion coefficient I,IV Dm 2 /s--1,9x10 -6 8,5x10 -6 Quenching distance III,IV,VI mm22,030,64 Laminar flame speed IV,V v lam cm/s40-80 40200 Carbon contentCMass-%86 750 I at 1,013 bar und 0 °C II at –253°C III at 1,013 bar IV in air V =1 VI at 20°C On-board storage Lean operation Combustion speed Emissions

8. 8 Effect of blending hydrogen with methane Fuel properties 020406080100 Volume fraction of CH 4 in H 2 [Vol-%] Mass fraction CH 4 in H 2 Lower heating value Stoichiometric air demand 0 20 40 60 80 100 120 Mass fraction of CH 4 in H 2 [Mass-%] Lower heating value [MJ/kg] 0 10 20 30 40 50 60 Stoichiometric air demand [kg air /kg fuel ]

9. 9 Experimental setup Single cylinder research engine 0.5 liters displacement Bore / stroke: 89 / 79.6 mm Max. speed: 6000 RPM 4-valve DOHC configuration External supercharger and air-heater Hydrogen fueling modes: –Port injection –Direct injection

10. 10 Test program Single cylinder research engine Fuels tested –Pure hydrogen (H 2 ) –5% methane in hydrogen (5% CH 4 ) –20% methane in hydrogen (20% CH 4 ) Speeds tested –2000 RPM –4000 RPM Loads tested –2, 4 and 6 bar IMEP –Unthrottled (lean) operation 4000 Speed [RPM] 2000 Load [bar] 4 6 2 Fuel [-] H2H2 5% CH 4 20% CH 4

11. 11 Pressure traces and rate of heat release Lower flame speed of methane causes longer combustion duration -30-1501530456075 Crank angle [deg CA] 0 10 20 30 40 50 Cylinder pressure [bar] 0 10 20 30 40 50 ROHR [J/deg CA] 100% H2 5% CH4 20% CH4 n=2000 RPM IMEP=6 bar IT=10 degCA BTDC

12. 12 Pressure traces and rate of heat release Partially compensate able by earlier spark timing -30-1501530456075 Crank angle [deg CA] 0 10 20 30 40 Cylinder pressure [bar] 0 5 10 15 20 ROHR [J/deg CA] 100% H 2 5% CH 4 20% CH 4 n=2000 RPM IMEP=4 bar IT=MBT

13. 13 2000RPM Research engine results Indicated efficiency -55152535455565 Spark timing [deg CA BTDC] 18 20 22 24 26 28 30 32 34 Indicated efficiency [%] 6 bar IMEP 2 bar IMEP 100% H 2 20% CH 4 5% CH 4 4 bar IMEP

14. 14 2000RPM Research engine results NO x emissions -20-10010203040 Spark timing relative to MBT spark timing [deg CA] 1 10 100 1000 10000 NO x emissions [ppm] 6 bar IMEP 5% CH 4 100% H 2 20% CH 4 2 bar IMEP 4 bar IMEP

15. 15 Hydrogen/methane blend vehicle testing Vehicle details on the eTec / Roush H 2 Silverado Standard features Seat positions6 Engine6.0l V8 Transmission4 speed automatic Drive2 wheel Vehicle modifications Supercharged and intercooled Powertrain control system custom calibrated for H2 Fuel Compressed Hydrogen with electronic fuel injection Three 150 liter tanks Type 3 (aluminum lined, carbon-fiber reinforced) 350 bar (5000 psi) storage pressure 10.5 kg (10.5 gge) usable fuel Standard 350 bar fueling nozzle (SAE J2600) Weight and dimensions Curb Weight (est.)6,625 lbs. GVWR8,600 lbs. Wheelbase153 in

16. 16 Hydrogen/methane blend vehicle testing Comparison of storage capability 11% increase in stored energy with 5% methane in hydrogen 46% increase in stored energy with 20% methane in hydrogen H2H2 5%CH 4 20%CH 4 0 50 100 150 200 250 300 Vehicle range [miles]

17. 17 Test program Hydrogen/methane blend vehicle testing Engine calibration –Constant air/fuel ratio (Φ~0.5) Fuels tested –Pure hydrogen (H 2 ) –5% methane in hydrogen (5% CH 4 ) –20% methane in hydrogen (20% CH 4 ) Drive cycles FTP-72 (UDDS) –12.07 km (7.5 mi) –frequent stops –maximum speed 91.2 km/h (56.7 mi/h) –average speed 31.5 km/h (19.6 mi/h) 0200400600800100012001400 Time [s] 0 10 20 30 40 50 60 Speed [mph]

18. 18 Hydrogen/methane blend testing Vehicle results – Fuel consumption Fuel economy in operation on pure hydrogen slightly higher (due to optimization and faster combustion) 0.12 mpMJ equals to about 19 mpg gasoline equivalent 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 Fuel economy [mpMJ] H2H2 5%CH 4 20%CH 4

19. 19 Hydrogen/methane blend testing Vehicle results –CO 2 Virtually no carbon dioxide emissions in pure hydrogen operation Even 20% blend almost meets 2012 Kyoto Target 0 50 100 150 200 250 CO 2 emissions [g/mi] H2H2 5%CH 4 20%CH 4 2012 Kyoto Target

20. 20 Tier II Bin 5 120 k Tier II Bin 5 50 k Hydrogen/methane blend testing Vehicle results – Limited emissions NO x emissions are virtually the only limited emissions component in pure hydrogen operation NO x emissions decrease with increased amount of methane in the mixture (as seen in engine experiments) CO in the range of federal regulations No catalyst used H2H2 NO x emissions [g/mi] 00.020.040.060.080.1 5% CH 4 20% CH 4 CO emissions [g/mi] 0 1 2 3 4 5

21. 21 Hydrogen/methane blend testing Vehicle results – Limited emissions Hydrocarbon emissions increase dramatically with increased amount of methane in the blend –NMHC (calculated) close to zero No catalyst used 0 0.5 1 1.5 2 2.5 3 THCCH4 Raw emissions [g/mi] H2H2 5% CH 4 20% CH 4

22. 22 Summary and conclusion Blending hydrogen with methane can effectively reduce the hydrogen demand Slower combustion speed of blends compared to pure hydrogen can be partially compensated for with spark timing adjustment Blending significantly increases the vehicle range Reduction of NO x emissions with increased amount of methane in the blend Tier II Bin 5 emissions regulations can be met without aftertreatment

23. Results of Research Engine and Vehicle Drive Cycle Testing during Blended Hydrogen/Methane Operation Thomas Wallner, Henning Lohse-Busch, Henry Ng Argonne National Laboratory Robert Peters University of Alabama at Birmingham NHA Annual Hydrogen Conference 2007 San Antonio/Texas March 19 th – 22 nd 2007 DOE-Sponsors: Lee Slezak, Gurpreet Singh