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DEER Conference – August 2003
Urea SCR and DPF System for Diesel Sport Utility Vehicle Meeting
Tier II Bin 5DOE and Ford Motor Company Advanced CIDI
Emission Control System Development Program(DE-FC26-01NT41103)
Diesel Engine Emission Reduction ConferenceAugust 2003
2
DEER Conference – August 2003
Presentation Overview
• DOE Program Overview• Vehicle Results• SCR Functional Improvements• Exhaust Gas Sensor Development• CDPF Strategy Development• Urea Program• Future Work
3
DEER Conference – August 2003
Urea SCR and DPF System for Diesel Sport Utility Vehicle Meeting
Tier II Bin 5
Program Overview
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DEER Conference – August 2003
Phase I - Initial build/test phase (12 mos.)Establish baseline emission control systemDeliver engine dynamometer NOx and PM test resultsDemonstrate and deliver prototype vehicle NOx and PM test resultsDeliver urea delivery (infrastructure) prototype
Phase II - System/component optimization phase (18 mos.)Define final system hardware componentsDeliver NOx and PM performance dataDemonstrate emission control system (includes NOx and PM data)
Phase III - Durability/Demonstration phase (18 mos.)Definition of durability test procedureFinal NOx and PM emission levels Define fuel sulfur limits for emission control systemFinal report for the completed program
DOE Ultra-Clean Fuels ProgramOutline of Ford’s program to achieve Tier II emissionstandards for 2007 using low sulfur diesel fuel as an enabler for a high efficiency aftertreatment system.
Primary Contractor
Subcontractors
Catalyst Suppliers
5
DEER Conference – August 2003
FEV ProgramConcept Design• CFD Modeling including urea injection
Engine Dynamometer• Baseline and rapid warm-up testing• Urea SCR/CDPF optimization• Transient FTP/US06 testing
Emission Control System Durability• 5000 hours (~120k miles)
6
DEER Conference – August 2003
ExxonMobil ProgramIntellectual property discussion delayed program for 9 months; program was then accelerated to contain original objectives.
SCR urea catalyst development• Durable, high NOx conversion from 150° to
600°C with low N2O make.Urea program• Co-fueling concept• Low temperature urea solution• Infrastructure studiesFuel development• Make and use fuel, which will be typical of 2007
production with 15 ppm sulfur cap.
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DEER Conference – August 2003
Urea SCR and DPF System for Diesel Sport Utility Vehicle Meeting
Tier II Bin 5
Vehicle Results
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DEER Conference – August 2003
aqueousurea
DOC
Turbo
NOx sensor
Spray Deflector
Flow mixing plate
SCRCatalyst
DOC
LDT Exhaust System
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DEER Conference – August 2003
Diesel Fuel Properties• ExxonMobil blended 14,000 gallon batch to represent
typical 2007 ULSD.– Uniform fuel over program duration.– Stored and dispatched in drums.
Estimated Proposed Program Proposed‘06 Diesel DOE Program Fuel 2007
Fuel Property Properties Min/Max Delivered Cert. FuelSulfur, ppm 15* 10 / 15 12.5 7 / 15Density, kg/m3 850 820 / 850 841.1 839 / 865Aromatics, vol. % 32 25 / 32 29.5 27 minPolyaromatics, wt. % 10 6 / 11 11.0 no specCetane number 46 44 / 48 44.9 40 / 50T50, C 267 250 / 280 249 243 / 282T90, C 306 300 / 320 307 293 / 332
* As delivered to the vehicle
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DEER Conference – August 2003
LDT Temperatures and Space VelocityFTP-75 Test
0
50
100
150
200
250
300
350
400
0 500 1000 1500 2000
Time (seconds)
Tem
pera
ture
(°C
)
0
20000
40000
60000
80000
100000
120000
140000
160000
Spac
e Ve
loci
ty (h
r-1)
Turbo Out DOC in SCR in SCR out Space Velocity
urea on
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DEER Conference – August 2003
Weighted FTP-75 Emissions
0.0060.004
0.107(52%)
0.082(52%)
0.0320.041(82%)
0.033(94%)
0.015 (97%)
0.067(79%)
0.007 (96%)
0.00
0.05
0.10
0.15
0.20
0.25
THC NMHC CO/10 NOx
gram
s/m
ileBag 3 emissionsBag 2 emissionsBag 1 emissions
Tier II Bin 5Stds, 120k mi
( ) Catalyst efficiency
0.062 (93%)
0.208 (82%)
0.088 (82%)
0.042
0.42
12
DEER Conference – August 2003
Urea SCR and DPF System for Diesel Sport Utility Vehicle Meeting
Tier II Bin 5
SCR Functional Improvements
13
DEER Conference – August 2003
Importance of NO2/NOx Ratio on Degreened Catalyst Performance
0
10
20
30
40
50
60
70
80
90
100
150 200 250 300 350 400 450 500 550 600
Catalyst Temperature (°C)
NO
x C
onve
rsio
n (%
)
NO only1:1 NO:NO2
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DEER Conference – August 2003
Importance of NO2/NOx Ratio on Aged Catalyst Performance
0
10
20
30
40
50
60
70
80
90
100
150 200 250 300 350 400 450 500 550 600
Catalyst Temperature (°C)
NO
x C
onve
rsio
n (%
)
HT aged, NO only
HT aged, 1:1 NO:NO2
sulfated, NO only
sulfated, 1:1 NO:NO2
15
DEER Conference – August 2003
Impact of Sulfur and Regeneration on SCR Performance
0
10
20
30
40
50
60
70
80
90
100
150 200 250 300 350 400 450 500 550 600 650Catalyst Temperature (°C)
NO
x co
nver
sion
(%)
degreened
120k mi sulfated
after regen at 650°C
16
DEER Conference – August 2003
0
10
20
30
40
50
60
70
80
90
100
NO
x C
onve
rsio
n (%
)
0
2
4
6
8
10
12
14
16
18
20
Cum
ulat
ive
HC
s (g
/l ca
taly
st)
% NOx Conv.Cum. HC's
Impact of HC on SCR performance
DegreenedActivity(250°C,
20% NO2in feed)
Start HCAddition
500°C,10 min
ActivityRegained
End HCAddition
17
DEER Conference – August 2003
Importance of Urea Mixing(Steady-State Engine Dyno Results)
0
10
20
30
40
50
60
70
80
90
100
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
NH3 / NOx Ratio [molar]
NO
x C
onve
rsio
n [%
]
0
10
20
30
40
50
60
70
80
90
100
NH
3 Sl
ip /
Engi
ne O
ut N
Ox
[%]
target 25 mm
target 150 mm
mesh downstream
mesh upstream
target 25 mm slip
target 150 mm slip
mesh downstream slip
mesh upstream slip
System A conv
System B conv
System C convSystem D convSystem A slip
System B slip
System C slipSystem D slip
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DEER Conference – August 2003
Importance of Urea Mixing(Transient Vehicle Results)
0
10
20
30
40
50
60
70
80
90
100
0 250 500 750 1000 1250 1500 1750 2000test time (s)
Cum
ulat
ive
TP N
Ox
(% E
O N
Ox)
Poor mixingImproved mixing
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DEER Conference – August 2003
Importance of Rapid Warmup
0
5
10
15
20
25
30
0 250 500 750 1000 1250 1500test time (s)
Cum
ulat
ive
TP N
Ox
(% E
O N
Ox)
ModelModel w/rapid warmup
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DEER Conference – August 2003
Urea SCR and DPF System for Diesel Sport Utility Vehicle Meeting
Tier II Bin 5
Exhaust Gas Sensor Development
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DEER Conference – August 2003
S(NO) > S(NH3) > S(NO2)
sensitivity
C3H6 (ppm)0 200 400 600 800 1000 1200
V
0.25
0.30
0.35
0.40
0.45
0.50
0.55
0.60
100 ppm NO
baseline
100 ppm NO2
100 ppm NH3
(~1cm DIA tube)
NOx sensor (NGK):• Laboratory data: • Vehicle data:
• For this test, the sensor was located downstream of SCR catalyst. As expected, the sensor responded to both NO and NH3. Also, the tailpipe NOx was all NO.
time (sec))0 200 400 600 800 1000 1200
ppm
0
100
200
300
400
500
600
NO (FTIR)NO2 (FTIR)NH3 (FTIR)Sensor (ppm_NO)
2_06_03: 112:bags1_2
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DEER Conference – August 2003
Vehicle test: Comparison of NH3 measured at the tailpipe using FTIR with
that predicted by the sensor (after
compensating for water)
NH3 Sensor:• Prototype sensors are under development by automotive
suppliers.• Vehicle data from one such sensor shown below (composition
proprietary) :– Selective NH3 response. Some sensitivity to H2O.
time (sec))0 200 400 600 800 1000 1200 1400
ppm
-20
0
20
40
60
80
100
120
140
FTIRsensor
6_03_03: 561:bags1_2
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DEER Conference – August 2003
Urea SCR and DPF System for Diesel Sport Utility Vehicle Meeting
Tier II Bin 5
CDPF Strategy Development
24
DEER Conference – August 2003
Future LDT Exhaust System
aqueousurea
DOC
Turbo
NOx sensor
Spray Deflector
Flow mixing plate
SCRCatalyst
DOC
aqueousurea
DOC
Turbo
NOx sensor
Spray Deflector
Flow mixing plate
SCRCatalyst
DOC
CDPF
25
DEER Conference – August 2003
Temperatures during DPF Regeneration
2
34
5
6
7
8
9
1
9” dia x 10” L(229 x 254 mm)
L from rearof filter grid
T# (mm) type1 175 complete2 125 complete3 50 complete4 175 cent. side5 125 cent. side6 50 cent. side7 175 corner8 125 corner9 50 corner
0 5 10 15 20 25 30 35 40 45 50 55200
300
400
500
600
700
800
900
Exha
ust T
empe
ratu
re [°
C]
Time [min]
TBDPF TDPF6 TDPF1 TDPF7 TDPF2 TDPF8 TDPF3 TDPF9 TDPF4 TADPF TDPF5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Fue
l Flo
w [k
g/h]
Fuel Flow
26
DEER Conference – August 2003
Temperatures during DPF Regeneration
0 2 4 6 8 10 12 14 16200
300
400
500
600
700
800
900
Exh
aust
Tem
pera
ture
[°C
]
Time [min]
T_BDPF T_DPF1 T_DPF2 T_DPF3 T_DPF4 T_DPF5 T_DPF6 T_DPF7 T_DPF8 T_DPF9 T_ADPF
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Fuel
Flo
w [k
g/h]
Fuel Flow
2
34
5
6
7
8
9
1
9” dia x 10” L(229 x 254 mm)
L from rearof filter grid
T# (mm) type1 175 complete2 125 complete3 50 complete4 175 cent. side5 125 cent. side6 50 cent. side7 175 corner8 125 corner9 50 corner
27
DEER Conference – August 2003
Urea SCR and DPF System for Diesel Sport Utility Vehicle Meeting
Tier II Bin 5
Urea Program
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DEER Conference – August 2003
Urea ProgramPrototype 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 co-fueling, including low temp.• Vehicle modified with compatible fill-
neck and urea storage for demo.
29
DEER Conference – August 2003
Urea ProgramLow Temperature Urea Solution
• Use of aqueous urea can cause difficulty in cold climates.
• Urea at 32.5 wt% has the lowest freeze point at 12°F(-11°C) of any blend in water.
• Potential freeze point depressants investigated, but found to cause negative catalyst impact at Ford.
Conclusion: Heated systems will be needed for colder climates.
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DEER Conference – August 2003
Urea ProgramStudy of Urea Supply Scenario
• Meeting with key urea suppliers to understand supply chain from production to service station.
• Using A. D. Little Study as baseline. • Determining optimum supply case.
- forecast urea volumes- estimate urea cost per gallon
31
DEER Conference – August 2003
Urea SCR and DPF System for Diesel Sport Utility Vehicle Meeting
Tier II Bin 5
Future Work
32
DEER Conference – August 2003
Future Work
• Rapid warm-up strategy• Choose final catalyst formulations/configuration• Aging cycle development – 5000 hrs• Sensor development• Continue urea infrastructure investigation
33
DEER Conference – August 2003
Acknowledgements
FordBrendan Carberry, Dick Chase, Bob Hammerle, Dave Kubinski,Paul Laing, Christine Lambert, Mike Levin, Cliff Montreuil,Rick Soltis, Devesh Upadhyay, Michiel van Nieuwstadt,Scott Williams
FEVErik Koehler, Dean Tomazic
Exxon MobilJoan Axelrod, Jeff Beck, Bill Blazowski, Owen Feeley, Rich Grosser, Mike Kerby, Marcus Moore, Mike Noorman, Charlie Schleyer
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