emission control technology highlights for gasoline ..._diesel_12-05.pdf · emission control...
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Emission Control Technology Emission Control Technology Highlights for Gasoline & Diesel Highlights for Gasoline & Diesel
Engines Engines
December 2005
Manufacturers of Emission Controls Association
www.meca.orgwww.dieselretrofit.org
Gasoline Emission Control Technology: Extending Automotive Experience to All Gasoline Engines
Tier 2/LEV II automotive systems combine advanced TWCs with advanced engine controls to achieve near-zero exhaust emissions
Advanced catalysts can provide HC and NOx reductions for other gasoline engines:
– Aftermarket automotive converters
– Motorcycles
– Off-road applications: handheld equipment, non-handheld equipment, fork lifts, generators, marine engines, recreational equipment
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Reference: SAE 2000-01-0887
PZEVs Include State-of-the-Art Engine Controls, Integrated with Advanced Exhaust & Evaporative Emission Controls
Honda Accord PZEV SystemAir Intake HC Adsorber
High Cell Density, Thin Wall Substrate Utilization Increasing Worldwide to Meet Tighter Emission Standards
0
20
40
60
80
100
North America & WesternEurope
Japan
2003 2007Substrate Market Penetration, %
Reference: MECA 2003
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Engine
Zoned CC
1.3 L0.8 L
0.8 L 1.3 L
UB
900/2.5 400/6.5
Advanced TWCs & Substrates Focused on High Performance and Precious Metal Utilization
4.6 Liter Light Duty Truck Application:Pd concentrated in upstream zone for fast HC light off.Low loaded catalysts located downstream for NOx control.
Reference: SAE 2004-01-1271
4.6L V8
Total Catalyst Vol.:4.2 L
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
standard set 1 set 2
NM
HC
(g/m
i)
Bag 3Bag 2Bag 1
0.075 0.042 0.043
cc=96.9%ub=30.0% cc=96.9%
ub=23.9%
NMHC NOx
0
0.01
0.02
0.03
0.04
0.05
standard set 1 set 2
NO
x (g
/mi)
Bag 3Bag 2Bag 1
0.050.024
0.027
cc=94.4%ub=81.0%
cc=95.4%ub=79.6%
Advanced TWC Systems Achieved 50K mi. LEV II TargetsWith < 2 g of Precious Metals per Vehicle (< 15 g/ft3 on ave.)
1 : 4 : 10.141.24 + 0.422
1 : 4 : 20.271.24 + 0.421
PGM RatioUB PGM (g)CC PGM (g)Set
Reference: SAE 2004-01-1271
Catalysts Aged to 50K mi. Equivalent
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MECA PZEV Test Program Underway:Advanced Emission Technology Demonstration
Goal - PZEV/SULEV tailpipe emissions on two large light-duty trucks:
Integration of advanced TWC systems with modified engine calibrations– Baseline FTP testing of two test vehicles completed
– Advanced emission system design and build-up completed
– Initial cold-start calibration efforts initiated on first vehicle
– Completion targeted for first quarter 2006
2004 Ford F150, 5.4L Triton V8 2004 GMC Yukon Denali, 6.0L Vortec V8
Baseline FTP Emissions (4K mi, stock) and Program Emission Targets
0.30
0.25
0.20
0.15
0.10
0.05
0.06 0.04 0.02 0.00 1.0 2.0NMOG (g/mile) CO (g/mile)
NOx (g/mile)LEV-I ULEV (100k)
LEV-I ULEV (50k)
LEV II – ULEV (120k)
SULEV (120k)PZEV (150k)
F150F150DenaliDenali
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OBD-Compliant Aftermarket Converters Utilize Advanced TWC Materials for Improved Performance & Durability
1.91
1.67
4.16
0.16
0.16
0.090.17
0.21
0.20
0.000.501.001.502.002.503.003.504.004.50
NMHC CO/10 NOx
First Gen. CA AM CA OBD AM CA OBD AM - aged
FTP, g/mi
Test vehicle: 1997 Chevy Astro Van, 4.3 L
OBD Aftermarket Converters Superior PerformanceCan Also Provide Emission Benefits on Pre-OBD Vehicles
Next Generation Heavy-Duty CNG EnginesWill Use EGR + TWCs for Low NOx Emissions
0
0.049 0.0420.02
0.14
0.2
0.155
0.1
0.00
0.05
0.10
0.15
0.20
NMHC NOx CO/100 PM X 10
Stoich. CNG Engine with TWC EPA 2010 HD Diesel Stds.
FTP Transient Emissions, g/bhp-hr
Reference: DOE NGVTF September 2005 Project Report
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TWC Equipped Mufflers Successfully Demonstrated in ARB/MECA Small Engine Test Program
B&S #2
Kawasaki
Honda #2
Original Muffler
Muffler with Cat
Muffler with Cat
Original Muffler
Original Muffler Muffler with Cat
Catalyst Efficiency after Aging Remains High;TWCs Working in EPA Study with Similar Results
0
20
40
60
80
100
B&S#1 B&S#2 Tec. Hon.#1 Hon.#2 Kawa.
% E
ffic
ien
cy
0 hr 125 hr 250 hr 500 hr50% Target
Level
>80 cc - <225cc >225cc
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TWCs Significantly Reduce HC, CO, & NOx Emissions on Marine Engines - Good Durability after 480 hours of Operation
0.0
1.0
2.0
3.0
4.0
5.0
6.0
5.7 L 5.7 L 5.7 L 4.3 L
0 hour 480 hour
2007 ARB Standard
HC+NOx, g/kW-hr
*
•High HC+NOx emissions stem from engine compression loss
5.7 L Marine Engine with TWCs Installed
Diesel Emission Control Technology Is Making Significant Progress
General technology approaches to hitting the regulations
– Widespread filter usage in Japan, and SCR in Europe in 2005
– Filters provide PM control for U.S. HDE 2007
Filter technology
– Reliable regeneration
– Improved properties; ash storage/management
– Retrofit experience and options expanding
NOx solutions
– SCR is commercial
– NOx adsorbers under active development
Integrated solutions
– SCR/DPF are on vehicles
– LNT/DPF in commercial sales
– Retrofit options available for combined PM/NOx reductions
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DOCs and DPFs Form the Technology Base for Reducing PM Emissions from New and In-Use Diesel Engines
Diesel Particulate FiltersDiesel Oxidation Catalysts
Flow through monolithwith catalytic coating
COAldehydes
HCPAHSO2NOx
CO2H2OSO2 /SO3NOx
• Applicable to nearly all diesel engines;significant retrofit & OE experience base
• PM control through SOF oxidation –significant reduction of toxic HCs
• Standard on all on-road heavy-duty engines for 2007
• Significant experience base with LDDin Europe (> 1 million vehicles)
DOCs & DPFs can becombined with CrankcaseFilters for additional PMcontrol
DPF Substrate Design Optimization Includes Minimizing System Backpressure
RC200/19
02468
1012141618
200/19 200/19 275/14
Pres
sure
Dro
p (k
Pa)
at 4
g/L
soo
t
Coated
BareOptimizedCell/Web
OptimizedPorosity
Porosity (%)Pore connectivity
47++
47++
42+
Example: Cordierite DPF Substrate Designs
Reference: 2004 SAE Commercial Vehicle Congress; Highway Diesel Panel
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New DPF High Temperature Material Available
Reference: SAE 2005-01-0583
• Good catalyzedbackpressure characteristics
• Primary phase: aluminum titanate
• High volumetric heat capacity
• Monolithic fabrication
Engine Control Strategies Are Being Developed to Avoid Run-Away Filter Regenerations
Reference: SAE 2004-01-2657
p p g
Tem
pera
ture
s [d
egC
]
100
150
200
250
300
350
400
450
500
550 TS_0_5 TS_11_5 TS_22_5 TS_35_5 TS_52_5 TS_58_5 TS_66_5
Tem
pera
ture
gra
dien
ts [d
egC
/cm
]
-200
-150
-100
-50
0
50
tim e [second]0 200 400 600 800 1000 1200
TG _11_5TG _22_5 TG _35_5TG _52_5 TG _58_5TG _66_5
Time [seconds]
p p g
Tem
pera
ture
s [d
egC
]
100
150
200
250
300
350
400
450
500
550 TS_0_5 TS_11_5 TS_22_5 TS_35_5 TS_52_5 TS_58_5 TS_66_5
Tem
pera
ture
gra
dien
ts [d
egC
/cm
]
-200
-150
-100
-50
0
50
tim e [second]0 200 400 600 800 1000 1200
TG _11_5TG _22_5 TG _35_5TG _52_5 TG _58_5TG _66_5
Time [seconds]
Peak temp. @ filter exit500°C vs.
900oC w/o strategy
Peak temp. gradient:- 160°C/cm vs.
- 600oC/cm w/o strategy
Development of a strategy to avoid uncontrolled filter regeneration during engine deceleration to an idle condition
Implementation of additional regeneration control measures:
– Control of the amount of post injection
– Temperature compensation to fine tune the filter inlet temperature
– Adjustment of the mass flow
– Torque compensation
Soot loading = 14 g/liter
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Zone-Coated DPFs Can Be Used to Optimize Precious Metal Content and Limit NO2 Emissions
CDPF with normal coating CDPF with zone coating, 65% less PGM
NO2 emissions cut by more than 50% with zone coating
Diesel Particulate Filters (DPF) for Retrofits
200,000+ retrofits worldwide
Many regions are mandatingtheir use
Variety of technologies for a variety of applications
Not universally applicable, but expanded applicationsand technologies developing
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“Flow-Thru” or “Partial” Filter Technologies Emerging for Diesel Retrofits
• Potential for 50-75% PM reduction
• Can be catalyzed, usedwith a DOC, or a fuel-borne catalyst
• Has applicability on olderengines, light-duty vehicles
• Filtering achieved with sinteredmetal sheets or wire meshes
• Resistant to plugging
Metal Substrate with SinteredMetal Sheets
Active DPF Types Available for Low Temperature Exhaust Applications
Passive DPFs with Electric Assist– Uses on-board heaters intermittently in combination with
catalyst-based filters or fuel borne catalysts
Electrically-Heated Active DPFs– Regenerated on-board at stand-still or off-board / exchange
Fuel Burner / Thermal Regeneration
Air Management with Active Air Intake Throttling to Raise Exhaust Gas Temperature
Diesel Fuel Injection with a DOC or Catalyst-Based DPF– Can be combined with thermal management, adjustable filter
volume, and/or fuel borne catalysts
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Fuel Injection Active Filter Regeneration Systems for Retrofit Mimic Future HD OEM Active DPF Systems
DPF
Exhaust gas
Diesel vapor
DOC
Fuel Injection Unit
Diesel fuel provides regeneration heat source
Preferred regeneration characteristics– Faster, more uniform heat up of DPF
– Quick and efficient regenerations
– Uniform temperature distribution in DPF
Compatible with NOx Systems
Dedicated controller with diagnostic functions Heat
HDD DPF/LNT Demonstrates 90% NOx Efficiency after 2000 Hours of Aging
23 desulfations at 675 C and λ<0.9 for 30-60 minutes; 4.5% cycle average fuel penalty; 15 ppm sulfur fuel (Reference: DEER 2004)
15 liter 475 hp 2004 Cummins engine. SVR DPF = 3.5; SVR LNT = 2.9
FT P Composite NOx
0.00.51.01.52.02.5
0 250 500 750 1000 1250 1500 1750 2000
Age (hours)
NO
x (g
/bhp
-hr)
NOx Mean Desulfation
Engine-out Level
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LD/MD DPF/LNT Systems Demonstrate High NOxEfficiency After 2000-2200 Hours of Aging
Reference: DEER 2005
PC in-linesystem:LNT SVR = 2
MD pick-updual-legsystem:LNT SVR = 2
0.24
0.38
0.27 0.
30
0.430.
48
0.450.
47
0.00
0.10
0.20
0.30
0.40
0.50
200 h 2000 h 4000 h 6000 h
g/bh
p-hr
NO
x
33
5
2
4
3 3
5
0
2
4
6
200 h 2000 h 4000 h 6000 h
mg/
bhp-
hr P
M
System A System B
INTAKE MANIFOLD
MANIFOLD
ATA
A
FTER
CO
OLE
R
C12 DIESEL ENGINE
EXHAUST
AIR FILTER
FLOW BALANCING
VALVES
EXHAUST
EXHAUST FLOW
SENSORS
CB-DPF AR
CB-DPF AL
SCR AL
SCR AR
UREA INJECTION
UREA INJECTION
EXHAUST DAMPER
CLEANUP CATALYST
LPL EGR PICKUP
INTA
KE
TH
RO
TTLE
T (IMP)
N
TPS
PRESSURE CONTROL
UREA PUMP
UREA INJECTION CONTROLUREA
EGR COOLER
EGR VALVE
LPL EGR
INTAKE MANIFOLD
MANIFOLD
ATA
A
FTER
CO
OLE
R
C12 DIESEL ENGINE
EXHAUST
AIR FILTER
FLOW BALANCING
VALVES
EXHAUST
EXHAUST FLOW
SENSORS
CB-DPF AR
CB-DPF AL
SCR AL
SCR AR
UREA INJECTION
UREA INJECTION
EXHAUST DAMPER
CLEANUP CATALYST
LPL EGR PICKUP
INTA
KE
TH
RO
TTLE
T (IMP)
N
TPS
PRESSURE CONTROL
UREA PUMP
UREA INJECTION CONTROLUREA
EGR COOLER
EGR VALVE
LPL EGR
DPF/SCR Systems Maintain High Efficiencies after 6000 Hours of Aging
Transient FTP Emission Results
Reference: DEER 2005
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Reference: SAE Paper No. 2004-01-1289
DPF+SCR Systems Are On the Road
• 10 trucks operated for more than2 million cumulative miles (2 refuse,8 tractors; 3 emission tested)
• 45 liters of SCR cats./engine (200 cpsi)
Reference: SAE Paper No. 2005-01-1861
15 L Engine: 74-82% NOx Reduction thru 75,000 mi
12 L Engine: 81-91% NOx Reduction thru 2 years of operation
12V version (1st gen. sensor) is in serial production
since mid 2002
2nd gen. sensor introduced in mid 2005
12V version (2nd gen. sensor)
12V version (1st gen. sensor)24V version (2nd gen. sensor)
NOx sensors recently completed 6000 h durability evaluationon a heavy-duty diesel engine (SAE paper no. 2005-01-3793)Work underway on low NOx range/high accuracy sensor
NOx Sensors in Production – Active Development Focused on Diesel Applications
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Integrated Solutions for Combined PM/NOx Reductions Available for Retrofit
Emulsified Diesel Fuel + DOC or DPF– 15-40% NOx reduction
Low Pressure EGR + DPF – 40-60% NOx reduction
Lean NOx Cat. + DPF or DOC – 25-35% NOx reduction
SCR catalyst
Pre-catalyst
Slipcatalyst
NH3 injection
Exhaustgases
DOC + SCR – 70-80% NOx reduction
www.dieselretrofit.org
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Future Diesel Engines Will Include High Performance Emission Systems Integrated with Advanced Engine Combustion
Technologies
SAE Paper No. 2005-01-1091
• Dual loop EGR is used to stabilize low load lean combustion.
• Highly-premixed rich combustion is used for LNT regen.
• Tier 2, Bin 3 potential (0.035 g/mi NOx estimate for FTP)
Summary
Technology Forcing Standards are an Important Driver for Continued Emission Control Innovations and Investments
Tailpipe And Evaporative Emission Technologies Developed for Light-Duty Gasoline Vehicle Applications Provide Solutions for the Full Range of Spark-Ignited Engines
A Variety of Technologies are Available and Emerging for PM, NOx, and Toxic HC Emission Control for New Diesel Engines
Retrofit Experience Is Growing Worldwide with a Variety of Technology Options Available for Controlling PM and NOx Emissions from On- and Off-Road Diesel Engines
The Ultimate Solution to Reducing Emissions from Mobile Sources Requires a Systems Approach Utilizing Advanced Engine Designs, Advanced Integrated Emission Control Technology, and Low Sulfur Fuels