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 5th 2008

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.

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

Fuel Comparison

12.5912.92Hydrogen (wt%)

2.742.28

Kinematic Viscosity at 40°C [mm2/sec]

2.37

85.04

43.2

0.853

B20

0.00Oxygen (wt%)

87.08Carbon (wt%)

42.0Cetane Number

0.846Density (kg/dm3)

ULSDBase Fuel

Hardware Overview – SCR System

Hardware Overview – NOx Adsorber System

Dual wall pipe

DOC/NAC

DPF

Engine Out

Test Cell Set-up – NOx Adsorber System

Hardware Overview – Test Vehicle Hardware

Hardware Overview – Test Engine Hardware

Po

wer

[kW

]

102030405060708090

100110120

Torq

ue [

Nm

]

100

150

200

250

300

350

400

BM

EP

[bar]

468

10121416182022

Sm

oke [

FS

N]

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Speed [rpm]

500 1000 1500 2000 2500 3000 3500 4000 4500 5000

Engine Power 113 kW @ 4000 rpm

Peak torque 360 Nm @ 2000 rpm

Max engine speed 4700 rpm

Max. BMEP 21 bar

Number & Arrangement of Cylinders

4 cylinder inline

Firing order 1 - 3 - 4 - 2

Valve train 4 Valve DOHC

Displacement 2.15 L

Bore to stroke ratio 1.0034

Compression Ratio 18

Fuel injection system2nd Generation Common-

Rail DI

Engine-out Emission Optimization

Base Euro 4 CalibrationNEDC > 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, Rail-

pressure, 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

Engine-out Emission Optimization

NOx emissions comparison in 14 calibration modes

0

100

200

300

400

500

600

700

800

650

0.00

1000

1.80

1200

3.02

1425

1.61

1615

3.07

1750

6.30

2000

4.00

2060

6.40

2300

4.05

2050

1.46

2250

8.16

2650

6.69

1450

4.59

1750

4.59

Engine speed [rpm] / BMEP [bar]

NO

x [

pp

m]

Base calibration

Optimized calibration

Engine-out Emission Optimization

Smoke emissions in 14 calibration modes

0

1

2

3

4

5

6

650

0.00

1000

1.80

1200

3.02

1425

1.61

1615

3.07

1750

6.30

2000

4.00

2060

6.40

2300

4.05

2050

1.46

2250

8.16

2650

6.69

1450

4.59

1750

4.59

Engine speed [rpm] / BMEP [bar]

Sm

oke [F

SN

]

Base calibration

Optimized calibration

Emissions ResultsNAC System

PM [mg/mile]

0123456789

1011

NOx [g/mile]

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

120,000 mileStandard

50,000 mileStandard

Cold LA4 Hot LA4 Composite FTP 75

NMHC [g/mile]

0.000

0.025

0.050

0.075

0.100

CO [g/mile]

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

120,000 mileStandard50,000 mile

Standard

Test Results – Vehicle Emission Tests (at the U.S. EPA)

Test Results – Vehicle Emission Tests (at the U.S. EPA)

PM [mg/mile]

0123456789

1011

NOx [g/mile]

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

120,000 mileStandard

50,000 mileStandard

Composite ULSD Composite B20 Composite B5

NMHC [g/mile]

0.000

0.025

0.050

0.075

0.100

CO [g/mile]

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

120,000 mileStandard50,000 mile

Standard

Test Results – Vehicle Emission Tests (at the U.S. EPA)

Veh

icle

Speed [

mph]

0

10

20

30

40

50

60

B20 = 11%ULSD = 10%

B20 = 46%ULSD = 45%

B20 = 43%ULSD = 45%

Acc

um

ula

ted N

Ox

[g]

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5 Engine Out - B20 Tail Pipe Out - B20 Engine Out - ULSD Tail Pipe - ULSD

Tem

pera

ture

[°C

]

050

100150200250300350400450500

Time [s]

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400

B20 - Temperature upstream LNT ULSD - Temperature upstream LNT

Test Results – Durability Testing

750

700

0 100 200 300 400 500 600 700

Duration completed

Durability Cycle

Duration

Time [hr]

311

28

0 50 100 150 200 250 300 350

Number of DPF

regeneration

completed

Number of

Desulfurization

completed

= 107%

750

700

0 100 200 300 400 500 600 700

Duration completed

Durability Cycle

Duration

Time [hr]

311

28

0 50 100 150 200 250 300 350

Number of DPF

regeneration

completed

Number of

Desulfurization

completed

= 107%

503

468

471

460

628

612

651

625

0 100 200 300 400 500 600 700 800

OP1 Avg Temp in NAC [deg C]

OP1 Avg Temp in DPF [deg C]

OP2 Avg Temp in NAC [deg C]

OP2 Avg Temp in DPF [deg C]

DPF Regen Avg Temp in NAC [deg C]

DPF Regen Avg Temp in DPF [deg C]

DeSOx Avg Temp in NAC [deg C]

DeSOx Avg Temp in DPF [deg C]

Temperature [deg C]

750

700

0 100 200 300 400 500 600 700

Duration completed

Durability Cycle

Duration

Time [hr]

311

28

0 50 100 150 200 250 300 350

Number of DPF

regeneration

completed

Number of

Desulfurization

completed

= 107%

750

700

0 100 200 300 400 500 600 700

Duration completed

Durability Cycle

Duration

Time [hr]

311

28

0 50 100 150 200 250 300 350

Number of DPF

regeneration

completed

Number of

Desulfurization

completed

= 107%

503

468

471

460

628

612

651

625

0 100 200 300 400 500 600 700 800

OP1 Avg Temp in NAC [deg C]

OP1 Avg Temp in DPF [deg C]

OP2 Avg Temp in NAC [deg C]

OP2 Avg Temp in DPF [deg C]

DPF Regen Avg Temp in NAC [deg C]

DPF Regen Avg Temp in DPF [deg C]

DeSOx Avg Temp in NAC [deg C]

DeSOx Avg Temp in DPF [deg C]

Temperature [deg C]

Test Results – Durability Testing

PM [mg/mile]

0.00

2.00

4.00

6.00

8.00

10.00

12.00

NOx [g/mile]

0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080

120,000 mileStandard

50,000 mileStandard

0 hr - FTP 75 composite Intermediate life - FTP 75 composite Full usefull life - FTP 75 composite

NMHC [g/mile]

0.000

0.025

0.050

0.075

0.100

CO [g/mile]

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50

120,000 mileStandard50,000 mile

Standard

Test Results – Durability Testing

Conversion Efficiency [%]

94

96

98

100

102

50 60 70 80 90 100NOx [%]

NM

HC

[%

]

90

92

94

96

98

100

102

50 60 70 80 90 100CO [%]

NM

HC

[%

]

0 hr FTP composite

Intermediate life FTPcomposite

Conversion efficiency target 120,000; 50,000 miles

Test Results – Fuel Economy Impact Vehicle (FTP75)

NO

x [

g/m

ile]

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Ba

se

EU

RO

4

T2

B5

Fe

ed

ga

s

T2

B5

Ta

ilpip

e

0.74

0.34

0.03

0.72

0.31

0.05

B20 ULSD

Fu

el E

co

no

my [

mp

g]

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

Ba

se

EU

RO

4

T2

B5

Fe

ed

ga

s

T2

B5

Ta

ilpip

e

35.3

31.8 30.734.8

30.7 30.1

Test Results – Fuel Economy Impact Vehicle (FTP75)

Fu

el E

co

no

my [

mp

g]

25

26

27

28

29

30

31

32

33

34

35

36

37

Ba

se

EU

RO

4

T2

B5

Fe

ed

ga

s

T2

B5

Ta

ilpip

e

35.3

31.8

30.7

34.8

30.730.1

B20 ULSD

• 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.

Summary and Conclusions

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