1 Emission Control Technology Emission Control Technology Highlights for Gasoline and Diesel Highlights for Gasoline and Diesel Engines Engines Rasto Brezny Manufacturers of Emission Controls Association June 2007 www.meca.org www.dieselretrofit.org MECA Background MECA Background Founded in 1976 to be The Technical Spokesperson for Our Industry 53 Member companies with over 30 years of experience in developing and manufacturing emission control technology. – Catalytic Converters (All Fuels) – Substrates and Diesel Particulate Filters – Sensors: Oxygen, NOx, Urea and Temperature – Thermal Management Strategies – Engine/Fuel System Management Technologies – Crankcase Emission Control Technology – Evaporative Emission Controls – Enhanced Combustion Technologies – UREA Suppliers – Fuel Cell Technology Components
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Emission Control Technology Highlights for Gasoline and ...zAdvanced emission control technologies can be combined with advanced engine controls to achieve ultra-low HC and NOx exhaust
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Emission Control Technology Emission Control Technology Highlights for Gasoline and Diesel Highlights for Gasoline and Diesel
Engines Engines
Rasto Brezny
Manufacturers of Emission Controls Association
June 2007
www.meca.org
www.dieselretrofit.org
MECA BackgroundMECA Background
Founded in 1976 to be The Technical Spokesperson for Our Industry53 Member companies with over 30 years of experience in developing and manufacturing emission control technology.– Catalytic Converters (All Fuels)– Substrates and Diesel Particulate Filters– Sensors: Oxygen, NOx, Urea and Temperature– Thermal Management Strategies– Engine/Fuel System Management Technologies– Crankcase Emission Control Technology– Evaporative Emission Controls– Enhanced Combustion Technologies– UREA Suppliers– Fuel Cell Technology Components
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Emission Control Systems forEmission Control Systems forSparkSpark--Ignited Vehicles & EnginesIgnited Vehicles & Engines
The Potential for Achieving Ultra Low Emissions The Potential for Achieving Ultra Low Emissions from Large Lightfrom Large Light--Duty Gasoline VehiclesDuty Gasoline Vehicles
• 38 different 2007 model PZEVs currently available4, 5, and 6 cylinder engines
• Heavier weight class LDTs currently limited to LEV II LEV or Tier 2, Bin 4 compliant models
NearNear--Zero Emission Systems IncludeZero Emission Systems IncludeAdvanced Engine Designs and Emission ControlsAdvanced Engine Designs and Emission Controls
Advanced Engine Technologies include:
– Improved fuel injectors
– Variable valve technology
– Lean start strategy with spark retard for fast catalyst heat-up
– Electrically controlled EGR valve
– Advanced control algorithms for precise A/F control
Perforated metal substrate with Integrated lambda sensor
SAE Paper No. 2007-01-1260
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Advanced Emission Technology DemonstrationAdvanced Emission Technology DemonstrationMECA Test Program: (SAE Paper 2007MECA Test Program: (SAE Paper 2007--0101--1261) 1261)
Goal – Ultra-low HC and NOx exhaust emissions on 2 large light-duty trucks:
Integration of advanced TWC systems with modified engine calibrations
FTP/SFTP Evaluations on “de-greened” and engine aged advanced emission systems
GMC Denali Fully Aged Advanced Emission System GMC Denali Fully Aged Advanced Emission System SFTP Performance SFTP Performance -- Below Current ARB 4K LimitsBelow Current ARB 4K Limits
SAE Paper No. 2007SAE Paper No. 2007--0101--12611261Summary and ConclusionsSummary and Conclusions
Advanced emission control technologies can be combined with advanced engine controls to achieve ultra-low HC and NOx exhaust emissions on heavy, light-duty gasoline vehicles
Tight air/fuel control is an important enabler to maintaining ultra-low exhaust emissions on gasoline vehicles
Emission performance would benefit from further improvements to thermal management and engine controls available to OEMs.
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Light-Duty Vehicle Emission Technology DevelopmentsBeneficial to Full Range of Spark-Ignited Engine Applications
High Performance Aftermarket Converters
– CARB OBD-Compliant Aftermarket Converters
Medium & Heavy-Duty Engines
Motorcycles/Mopeds
– Closed-Loop TWC Systems for California/U.S. Motorcycles
Recreational Vehicles & Engines
– ATVs, Off-road Motorcycles, Marine engines
> 25 hp Off-Road Applications
– Advanced Closed-Loop TWCs to Achieve 2010 ARB Proposed Standards on Fork Lifts, GSE, Generator Sets
NOx solutions– SCR is commercial in Europe– NOx adsorber commercial on Mercedes E320, Med-duty Dodge
Ram pick-up.Integrated solutions– SCR/DPF are on vehicles– LNT/DPF is commercial with applications expanding– LNT/SCR gaining experience as passive solution– Retrofit options available for combined PM/NOx reductions
Developments Continue to Improve PM FiltersDevelopments Continue to Improve PM Filters
Porosity (%)Pore connectivity
02468
1012141618
200/19200/19
275/14
Pres
sure
Dro
p (k
Pa)
at 4
g/L
soo
t
Coated
BareOptimizedCell/Web
OptimizedPorosity
47++
47++
42+
•New materials, SiC, Al2TiO5, Mullite
•Good catalyzed backpressure characteristics
•Zone coating cuts NO2 emissions up to 50%
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FirstFirst--cost economics favor SCR for engines larger cost economics favor SCR for engines larger than about 2 liters. than about 2 liters.
Fixed urea system cost ~ $180
SCR increm. variable cost of $10-15 per liter displ.
LNT PGM incremental cost of $80-90 per liter displacement
Cos
t
Displacement
~2 literAssumptions:
•Substrate, can, and wash coating costs are the same for LNT and SCR
•SVR=0.8 assumed for LNT and SCR; NH3 slip catalyst SVR=0.25, PGM 30 g/cu.ft.; PGM LNT = 80 g/ft3;
•PGM at $40/g
SCR cheaper
LNT cheaper
Incremental Costs, LNT vs. SCR
~5 liter
50-70% PGM savings w/ mixed mode; LNT
Aggressive mixed mode and urea system (potential future systems) have breakeven at 5 liters displacement.
NOx Adsorber Catalyst Development Continues to Show Progress at Low Temperatures
Reference: SAE Paper No. 2006-01-1369
Note: first baseline LNT andadvanced LNT are Ba-based;Second baseline LNT is K-based
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NOx Adsorber Performance Window Stable after Multiple Sulfation and Desulfation Cycles
Low Temperature system has excellent activity window at low SV
NOx efficiency maintained through end-of-life simulation
Cycle NOx Performance of Low Temp LNT
0
10
20
30
40
50
60
70
80
90
100
150 200 250 300 350 400 450 500
Inlet Temperature (°C)
NO
x C
onv
(%)
after 20 DeSOxafter 55 DeSOx
60s L/ 3s R(0.27 g NO2/L flux/min)
35K VHSV
Reference: AVECC 2004
Zeolite SCR Catalysts Provide Performance Zeolite SCR Catalysts Provide Performance Advantages vs. Vanadia SCR CatalystsAdvantages vs. Vanadia SCR Catalysts
Zeolite SCR catalysts have broader temperature range Zeolite SCR catalysts are more tolerant of excess
NO2 than Vanadia systems.
Zeolite SCR catalysts have better HT durability than Vanadia catalysts. Aged 50 hours at 700C.
Source: SAE Gothenburg, 9/05
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Experience Growing in OnExperience Growing in On--Road SCR ApplicationsRoad SCR Applications
Urea Injection Systems Moving from Urea Injection Systems Moving from Air Assist to Airless DesignsAir Assist to Airless Designs
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Complete HD SCR System Complete HD SCR System Descriptions AvailableDescriptions Available
Reference: SAE Paper No. 2005-01-1860
Urea Quality Sensor
Advanced System Designs Emerging that Combine LNTs and SCR Catalysts
Advanced System Designs Emerging that Combine Advanced System Designs Emerging that Combine LNTs and SCR Catalysts: Mercedes E320 CDILNTs and SCR Catalysts: Mercedes E320 CDI
Reference: Mercedes Benz press release
Honda’s Advanced Clean Diesel Strategy Layers LNT and SCR Catalyst Functions on a Single Substrate
Reference: http://automobiles.honda.com
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2nd gen. NOx sensor introduced in mid 2005
NOx sensors recently completed 6000 h durability evaluationon heavy-duty diesel engine as a part of DOE’s APBF-DEC programWork underway on low NOx range/high accuracy sensor
Diesel Emission Control Technology Drives New Sensor Developments for NOx, NH3, urea
DPFs with Passive and Active Soot Regeneration DPFs with Passive and Active Soot Regeneration Strategies Available for RetrofitsStrategies Available for Retrofits
Passive systems rely on exhaust temperature and catalyst for regeneration
Active systems suited for on-and off-road applications with low exhaust temperatures including locomotives & marine engines
Uncatalyzed wall-flow filter with electrical or fuel burner regeneration
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Euro 4 Application with Flow-Thru FilterDemonstrates 60-70% PM Reduction
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
ETC ESC
Engine-out Tailpipe
PM Emissions, g/kW-hr
Euro 4/5 Limit
Euro 4/5 Limit
Source: MAN
Integrated Solutions for Combined PM/NOx Reductions Integrated Solutions for Combined PM/NOx Reductions Available for RetrofitAvailable for Retrofit
Experience with Diesel RetrofitsExperience with Diesel RetrofitsSpans a Variety of OnSpans a Variety of On--Road Vehicle ApplicationsRoad Vehicle Applications
Retrofit Experience is Expanding to Retrofit Experience is Expanding to OffOff--Road Vehicle ApplicationsRoad Vehicle Applications
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OffOff--Road Retrofit Installations of NOx Catalysts + Filter Road Retrofit Installations of NOx Catalysts + Filter SystemsSystems
SCR
Cat
alys
ts
DPF Filter
UreaUrea--SCR System Retrofit Applied to NYC FerrySCR System Retrofit Applied to NYC Ferry
90+% NOx efficiency under normal cruise conditions
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Challenges for OffChallenges for Off--Road RetrofitsRoad Retrofits
More diverse engine/equipment application space than on-road
– Skewed toward older equipment
– Proper engineering judgment applied to heat shielding and mounting locations
– Maintaining driver visibility
– Can require extensive use of high grade vibration isolators especially in track drive equipment
Lack of preventative equipment maintenance
– Especially air filters, injectors and turbochargers
– Basic inspection and maintenance of installations
User interference with the installation process
– Taking short cuts to get machines done now
Conclusions
All Major Regulations Moving to Tight PM and NOx Emission Standards for Diesel Engines
Technology Forcing Standards are an Important Driver for Continued Emission Control Innovations and Investments
Continued Development of Advanced Diesel Engine Combustion Strategies will have a Significant Impact on the Overall Emission System Designs Required to Meet Future Regulatory Standards
A Variety of Technologies Are Available and Emerging for PM, NOx, and Toxic HC Emission Control for Both Light-Duty and Heavy-Duty Diesel Vehicles
On-Road Diesel Technologies Will Migrate into Nonroad Diesel Applications including Locomotive and Marine diesels.
Retrofit NOx Technologies Expected to Expand in the Near Term toInclude HC- and urea-SCR options for on-road and off-road applications
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www.dieselretrofit.org –
your retrofit resource on the web
• Technology descriptions• Contacts for retrofit suppliers• Case study reports
BackBack--up Slidesup Slides
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Baseline Vehicle Configurations & Test DetailsBaseline Vehicle Configurations & Test Details
Exhaust emissions characterized in most cases using triplicate FTP testing
California Phase III RFG with 17 ppm S used throughout the test program (mileage break-in, emissions testing, engine aging of emissions systems)
Denali calibration was modified for improved cold-start and hot-start performance.
Systems aged using accelerated fuel cut aging for 220 hrs.
Advanced Emission Systems Aged for 220 hours Advanced Emission Systems Aged for 220 hours Using an Accelerated Engine Aging ProtocolUsing an Accelerated Engine Aging Protocol
800
820
840
860
880
900
920
940
960
980
1000
0 10 20 30 40 50 60
Time, sec.
Tem
pera
ture
, deg
. C
Cat Bed Temperature
AFR=Stoichiometric (40 sec.) AFR=Rich (6 sec.)AFR=Rich w/ Air
Inj. (10 sec.)
AFR=Stoich w/ Air Inj. (4 sec.)
0
50000
100000
150000
200000
250000
300000
Tim
e, S
ec
800 820 840 860 880 900 920 940 960 980 1000Catalyst Bed Temperature, deg. C
Left Bed HistogramRight Bed Histogram
Denali System Aging History
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Tight AirTight Air--Fuel Control Important for Achieving and Fuel Control Important for Achieving and Maintaining Low Exhaust EmissionsMaintaining Low Exhaust Emissions
F150 Baseline Calibration vs. Denali Final Calibration
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20
0 100 200 300 400 500
Time, seconds
Engi
ne-o
ut A
ir/Fu
el R
atio
FB DG EODF DG EODenali engine-out AFR
varies from approx. 14.5 to 13.8 during first 100 sec. compared to 15.8 to 12 for the F150.
After temperature stabilization,Denali AFR is very stable, but F150 still varies significantly
Denali Catalyst System FTP Conversion Efficiencies Denali Catalyst System FTP Conversion Efficiencies Remain High After 220 h of Aging Remain High After 220 h of Aging