Ford/DOE SCR Program Update Christine Lambert Diesel Exhaust Aftertreatment Ford Research Laboratories June 17, 2004 C. Lambert
Seventh CLEERS Workshop 6/17/2004
DOE Ultra-Clean Fuels Program Outline of Ford’s program to achieve Tier 2 emission standards for 2007 using low sulfur diesel fuel as an enabler for a high efficiency aftertreatment system. Primary Contractor
Subcontractors
Catalyst Suppliers
Phase I - Initial build/test phase (July01-July02) Establish baseline emission control system Deliver engine dynamometer NOx and PM test results Deliver prototype vehicle NOx and PM test results Deliver urea delivery (infrastructure) prototype Phase II - System/component optimization phase (July02-July04) Define final system hardware components Deliver NOx and PM performance data from fresh system Phase III - Durability phase (July04-July05) Definition of durability test procedure Final NOx and PM emission levels Final report for the completed program
C. Lambert
Seventh CLEERS Workshop 6/17/2004
Introduction • Tier 2 Bin 5 standards represent 90-95% NOx and PM reduction from today’s Tier 1 standards for diesels. Standard Tier 1 (100k mi) Tier 2 Bin 5 (120k mi)
NOx (g/mi) 1.25 0.07
PM (g/mi) 0.10 0.01
• NOx and PM control remain a challenge for diesels. • Choices for PM include fuel additive/filter and catalyzed filter. • Choices for NOx include HC SCR, NOx Adsorber, & NH3 SCR.
C. Lambert
Seventh CLEERS Workshop 6/17/2004
Comparison of NOx Reduction Technologies 100 90 80 70
HC SCR
60
Urea SCR
50
LNT
40 30 20 10
US06
FTP-75
0 100
200
300
400
Catalys t Te mpe rature (°C)
C. Lambert
Seventh CLEERS Workshop 6/17/2004
500
600
FTP Fuel Economy Penalty Comparison FTP NOx Conversion (%)
(estimated using 2.5L York Transit feedgas)
100 90 80 70 60
Urea SCR + filter
3% Fuel Penalty from PM Filter
50 40 30 20 10 0 0
2
LNT + filter
HC SCR + filter
4
6
8
FTP Fuel Economy Penalty (%) C. Lambert
Seventh CLEERS Workshop 6/17/2004
10
Use of Modeling for Improved SCR Function • Predict system performance ¾ Predict NOx conversion levels ¾ Predict fuel economy impact ¾ Provide direction for system design
• Evaluate system performance ¾ Diagnose problems with system hardware/strategy ¾ Provide direction for future system testing
C. Lambert
Seventh CLEERS Workshop 6/17/2004
Cu mulative NOx (% of en gine out)
Prediction of FTP Performance 100
Engine out out Engine
90
System A
80
Urea
70 60
Target 90% Conv.
50 40
E
System AA Tailpipe Tailpipe System
T
PM Filter Filter SiC
System B
System B Tailpipe Tailpipe System B
30 20
Urea E
10
System B Tailpipe Tailpipewith withrapid rapidwarm-up warm-up System B
0 0
200
400
600
800
1000 1200 1400
FT P Cycle T im e (seconds)
Rapid warm-up = extra 50°C ramped in over first 30s of test. C. Lambert
SCR
Seventh CLEERS Workshop 6/17/2004
T
DOC
SCR
SiC Filter PM Filter
LDT Exhaust System (NOx) Turbo
Spray Deflector
DOC
SCR Catalyst
DOC
NOx sensor
aqueous urea
C. Lambert
Flow mixing plate
Seventh CLEERS Workshop 6/17/2004
160000
350
140000
300
120000
250
100000
200
80000
150
60000
100
40000
50
20000
-1
400
Space Velocity (hr )
Temperature (°C)
LDT Temperatures and Space Velocity on FTP LDT Temperatures and Space Velocity (without rapid warm-up strategy) FTP-75 Test
0
0
0
500
1000
1500
Time (seconds) Turbo Out
C. Lambert
DOC in
SCR in
SCR out
Space Velocity
Seventh CLEERS Workshop 6/17/2004
2000
Weighted FTP-75 Emissions
(Without Rapid Warm-up Strategies, September 2003) 0.25
0.42
Bag 3 emissions Bag 2 emissions 0.20
0.208 (82%)
Bag 1 emissions Tier II Bin 5 Stds, 120k mi
0.067 (79%)
grams/mile
( ) Catalyst efficiency 0.15
0.033 (94%)
0.10
0.088 (82%) 0.062 (93%)
0.05
0.007 (96%) 0.015 (97%)
0.107 (52%)
0.042 0.004 0.006
0.041 (82%)
0.032
THC
NMHC
0.082 (52%)
0.00
C. Lambert
CO/10
Seventh CLEERS Workshop 6/17/2004
NOx
}
Current range of TP NOx with rapid warm-up strategies
Importance of Urea Mixing (Transient Vehicle Results)
100
Poor mixing Improved mixing
Cumulative TP NOx (% EO NOx)
90 80 70 60 50 40 30 20 10 0 0
250
500
750
1000
1250
test time (s)
C. Lambert
Seventh CLEERS Workshop 6/17/2004
1500
1750
2000
Importance of NO2/NOx Ratio on Aged Catalyst Performance 100 90
NOx Conversion (%)
80 70 60 50 40
HT aged, NO only
30
HT aged, 1:1 NO:NO2
20
sulfated, NO only
10
sulfated, 1:1 NO:NO2
0 150
200
250
300
350
400
450
Catalyst Temperature (°C)
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Seventh CLEERS Workshop 6/17/2004
500
550
600
Impact of HC on SCR performance 100
20
NOx Conversion (%)
80 70 60 50 40 30 20
Degreened Activity (250°C, 20% NO2 in feed) Start HC Addition
18
Activity Regained
16 14 12 10 8
500°C, 10 min
6 % NOx Conv. Cum. HC's
4
10
2
0
0
C. Lambert
Seventh CLEERS Workshop 6/17/2004
Cumulative HCs (g/l catalyst)
End HC Addition
90
Urea Program Prototype Urea Co-fueling System Status • Co-axial nozzle design chosen and improved for durability and reliability. • Urea pumping unit designed and feasible for modern dispenser. • Prototype system being built to evaluate cofueling, including low temp. • Vehicle modified with compatible fill-neck and urea storage for demo.
C. Lambert
Seventh CLEERS Workshop 6/17/2004
Future Work • • • • •
Finalize rapid warm-up strategy Choose final catalyst formulations Aging cycle development – 120k mi NOx and NH3 sensor development Complete urea infrastructure investigation
C. Lambert
Seventh CLEERS Workshop 6/17/2004
Acknowledgements Ford Brendan Carberry, Dick Chase, Bob Hammerle, Dave Kubinski, Paul Laing, Christine Lambert, Mike Levin, Cliff Montreuil, Rick Soltis, Devesh Upadhyay, Michiel van Nieuwstadt, Scott Williams FEV Erik Koehler, Dean Tomazic Exxon Mobil Joan Axelrod, Jeff Beck, Bill Blazowski, Owen Feeley, Rich Grosser, Mike Kerby, Marcus Moore, Mike Noorman, Charlie Schleyer
C. Lambert
Seventh CLEERS Workshop 6/17/2004