1. Biodiesel and 2010 Engine After­
Treatment Technology
Steve Howell
Technical Director
National Biodiesel Board
Presented at Alternative Fuels &
Vehicles National Conference and Expo
Tuesday, April 21, 2009

2. Biodiesel and Advanced Emission
Controls
• Thanks to Bob McCormick and Aaron Williams of NREL for
much of the content of these slides
­2010

3. How will the 2010 standards be met?
• Introduction of ultra­low sulfur diesel fuel in October 2006
• October 2008 ASTM approves up to 5% biodiesel as D975 fuel
• B6 to B20 ASTM standard also approved by ASTM: D7467
• Intermediate EPA emissions standard for 2007:
• 0.01 g/bhp­h for PM, 1.2 g/bhp­h for NOx
• Diesel particle filters (DPF), un­burned diesel fuel for regeneration
• Increased levels of exhaust gas recirculation (EGR) and higher fuel
injection pressures
• Full EPA emissions standard in 2010:
• 0.01 g/bhp­h for PM, 0.20 g/bhp­h for NOx
• DPF, EGR, high pressure fuel injection
• Exhaust catalysts for NOx reduction
•NOx adsorber catalysts, unburned diesel fuel for operation
•Selective catalytic reduction (SCR)
•Diesel Exhaust Fluid (DEF) needed for SCR operation

4. Diesel Particle Filters
• Exhaust flows through porous wall­flow elements
– PM is trapped on the walls of the filter
• When exhaust temperature is high enough, PM is burned off
– In most cases, unburned diesel fuel is injected to accomplish this
• Precious metal is loaded onto filter walls to lower the
temperature required for regeneration
• Issues:
– Regeneration at low temperatures/duty cycles
– Plugging with incombustible materials like lube oil ash

5. Catalytic Control of NO Emissions
x
•NO Adsorber Catalyst (or lean NO
x x
trap –LNT)
– Catalyst converts all NO to NO , adsorbent
x 2
bed “traps” NO 2
– When bed is saturated, exhaust is forced
“rich”
– NO is released and converted to N2
2
– Bed also traps SO , but doesn’t release it
2 NO adsorber catalyst (NAC) is also
• Near sulfur free exhaust is needed x
known as a lean­NO trap (LNT)
• Higher temps, longer time needed to x
release sulfur
– 90%+ conversion is possible
•Selective Catalytic Reduction (SCR)
NOx + NH3
Sensor
– Used for industrial NO control for many
x
years
– Requires a supplemental “reductant”
– Typically ammonia, derived from urea SCR
• “Diesel Exhaust Fluid”
– 80­90% reduction efficiency
Injection
Urea
– Generally sulfur tolerant

6. NBB 2007/2010 OEM Program
Objective: Investigate the impact of B20 and
lower biodiesel blends on 2007 and later fuel
system, engine, and emission control technology
• Major NBB/DOE Collaboration via CRADA
• Ongoing program areas:
– Light­duty diesel vehicle testing with DPF and NO x
control
– Medium­duty engine testing with DPF and NO control
x
– Heavy­duty vehicle testing with active regen DPF
• Ongoing and future program areas include
additional MD and HD testing with DPF and NOx
control systems, off­highway systems

7. Biodiesel Testing with DPF – MD Engine
• Cummins ISB 300
– 2002 Engine, 2004 Certification
– Cooled EGR, VGT
• Johnson Matthey CCRT
– 12 Liter DPF
– Passively Regenerated System
– Pre Catalyst (NO Production)
2
• Fuels: ULSD, B100, B20, B5
• ReFUEL Test Facility
– 400 HP Dynamometer
– Transient & Steady State Testing
• Cummins
– Soot Characterization
– Significant financial support for
testing

8. B20 Testing with DPF – HD FTP
B20 results in substantial PM reduction even with DPF
(data for 2003 Cummins ISB with Johnson Matthey CCRT on HD FTP)
Reduction with DPF ranges
from 20% to 70%, depending
on basefuel, test cycle, and
other factors
• Reduction in sulfate
emissions
• Increased PM reactivity
Williams, et al., “Effect of Biodiesel Blends on Diesel Particulate
Filter Performance” SAE 2006­01­3280

9. Balance Point Temperature/Regeneration
Rate Results
BPT • BPT is 40ºC lower for B20
ULSD 360ºC • Soot is more easily burned off of filter
B20 320ºC • B20 can be used for lower temperature duty cycle
B100 250ºC
• Regeneration rate increases with
increasing biodiesel content
• Even at 5%, biodiesel PM measurably
oxidizes more quickly

10. Biodiesel and DPF operation
• Biodiesel is compatible with Diesel Particulate
Filters, and has some distinct advantages:
– Lowers regeneration temperatures
– Less engine out particulate matter
– May provide increased performance and decreased
maintenance vs. ULSD alone
– May provide increased fuel economy
• Regeneration mode is important
– Late in­cylinder injection may cause increased fuel
dilution of engine oil and limit the level of biodiesel
that can be used (i.e. B20 or B5)
– Most US heavy duty applications use exhaust
stream fuel injection which is compatible with B20,
perhaps higher blends
– NBB is working closely with OEM’s in this area

11. Biodiesel Testing with LD Emission Control Systems
• Includes two emission control systems and two fuel blends
on a light­duty platform
– NAC/DPF and SCR/DPF
– 5% and 20 % biodiesel blends
• Performance, optimization and durability
– Aging to represent 2100 hours of operation (approximately 120,00
miles or full useful life) for B20
– Emissions evaluations over UDDS, US06, and HFET –conducted
by EPA
– Perform engine and fuel component teardown at end of aging
Engine: DCX OM646 Vehicle: Mercedes C200 CDI
Vehicle: Mercedes C200 CDI

12. Test Results – EPA Chassis Dynamometer
NOx Adsorber Catalyst (NAC)
11
B20 10
PM [mg/mile]
9 Cold LA4 50,000 mile 120,000 mile
8 Hot LA4 Standard
7 Standard
6 Composite FTP75
5
4
3
2
1
0
0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08
NOx [g/mile]
11
10
ULSD
PM [mg/mile]
9 Cold LA4 50,000 mile 120,000 mile
8 Hot LA4 Standard
7 Standard
6 Composite FTP75
5
4
3
2
1
0
0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08
NOx [g/mile]

13. Experimental Setup and Objectives: SCR
Diesel Particulate Filter
Diesel Particulate Filter
§ Compare SCR catalyst performance §
§ JM CCRT (12 Liters)
JM CCRT (12 Liters)
with ULSD and Soy B20 through §
§ Passively Regenerated
Passively Regenerated
engine testing §
§ Pre Catalyst for NO 2 Production
Pre Catalyst for NO Production
2
§ Measure relative importance of catalyst
de­NOx Aftertreatment
de­NOx Aftertreatment
temp, exhaust chemistry and catalyst § JM Zeolite SCR (15.5 Liters)
§ JM Zeolite SCR (15.5 Liters)
space velocity § Urea Injection (air assisted)
§ Urea Injection (air assisted)
§ Measure B20’s impact on these §
§ NH3 Slip Catalyst
NH3 Slip Catalyst
system variables and overall NOx
conversion Diesel Engine
Diesel Engine
§
§ 2002 Cummins ISB (300 hp)
2002 Cummins ISB (300 hp)
§ Focus on Steady­State Modal Testing § 2004 Emissions Cert
§ 2004 Emissions Cert
§
§ Cooled EGR, VGT, HPCR
Cooled EGR, VGT, HPCR
Urea Injection
Diesel Selective NH3
DOC Particulate Catalytic Slip
Filter Reduction Cat

14. ULSD vs B20 – SCR Overall NOx Conversion
§ No statistical difference in NOx Conversion with B20

15. Conclusions:
• NBB, the US Department of Energy, and the
engine and vehicle manufacturers are
expending significant resources to understand
how biodiesel blends interact with new diesel
emission controls
• Detailed testing thus far indicates B20 and lower
blends are compatible with both diesel and NOx
after treatment
– Provides benefits in some cases
• B5 is now just part of normal D975 diesel fuel
• Additional study is underway
– Quantify long term benefits of biodiesel blends
– Late in­cylinder injection may cause fuel dilution
– NBB is encouraging OEM’s to publicly support B20