Expediting the Use of Clean-Diesel Engines with Retrofit Emission Control Technologies Air Quality...
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Expediting the Use of Clean-Diesel Expediting the Use of Clean-Diesel Engines with Retrofit Emission Control Engines with Retrofit Emission Control
Technologies Technologies
Air Quality Conference for Local Elected Air Quality Conference for Local Elected OfficialsOfficials
May 10-11, 2001May 10-11, 2001Sacramento, CASacramento, CA
Presentation OutlinePresentation Outline
Introduction
Background
Retrofit Control Technologies
Elements of a Retrofit Program
Cost Estimates
Conclusion
IntroductionIntroduction
Diesel Engines Are a Major Source of NOx, PM, and Toxic Emissions
Even with the Prospect of Tighter Emission Standards in the Future, Existing, High-Emitting Diesel Engines Will Be in Use for the Next 10 to 20 Years
Retrofitting Existing Diesel Engines with Exhaust Control Technologies or Converting Diesel Engines to Natural Gas Are Available Strategies to Reduce Emissions and Expedite Clean-Vehicle Deployment
A Successful Retrofit Program Must Be Properly Designed and Implemented
Available Retrofit TechnologiesAvailable Retrofit Technologies
PM, CO, HC and Toxics
– Diesel Oxidation Catalysts (DOC)
– Diesel Particulate Filters (DPF)
– Enhanced Combustion Modifications (e.g., cams, coatings, superchargers)
– Crankcase Emission Controls
Available Retrofit Technologies (cont.)Available Retrofit Technologies (cont.)
NOx
– Selective Catalytic Reduction
– Lean NOx Catalyst Technology
– Systems Strategies (e.g., engine modifications to reduce NOx plus PM exhaust controls)
– EGR
Retrofit ExperienceRetrofit Experience
Mining
Materials Handling
Truck and Bus
Marine Vessels and Locomotives
Stationary Diesel Engines
Overview of Retrofit ProgramsOverview of Retrofit Programs
The Number and Scope of Retrofit Programs Is Rapidly Growing
– North America (California, New York, New England, Mexico, and elsewhere)
– Europe (Austria, Finland, France, Germany, Sweden, Switzerland, and United Kingdom)
– Asia (Hong Kong, Korea, Japan, and Taiwan)
– Latin America (El Salvador and Nicaragua)
Diesel Oxidation CatalystsDiesel Oxidation Catalysts
Carbon
SOF
NOx
CO
HC
Carbon
NOx
Water
Oxidation Catalysts Oxidize CO, HC, and SOF to Reduce PM, CO, HC, and Toxic Emissions.
Diesel Oxidation Catalysts Are Efficient and Diesel Oxidation Catalysts Are Efficient and ProvenProven
Oxidation Catalyst Control Capabilities– PM -- 20-50% Reduction
– CO and HC -- >90%
– Toxic HCs -- >70%
DOCs Destroy Large Fractions of Toxic EmissionsDOCs Destroy Large Fractions of Toxic Emissions
1.290.8
1.86
9.41
11.36
0.560.10.2
2.8
6.8
0
2
4
6
8
10
12
Formal
dehyd
e
Aceta
ldeh
yde
Acrolie
n
1,3
Butadie
ne
PAHs
Before After
Toxic Hydrocarbon Compounds Reduced by 68%
PAH Emissions Reduced by 56%
Greater Reductions Possible with Low Sulfur Fuel
mg/bhp-hr
Source: MECA 1999
Diesel Particulate FiltersDiesel Particulate Filters
Trapped PMCell Plugs
Exhaust(PM, CO, HC)Enter
Ceramic HoneycombWall
Exhaust (CO2, H2O)Out
Diesel Particulate Filters Are Efficient and Diesel Particulate Filters Are Efficient and Are Developing an Impressive Track RecordAre Developing an Impressive Track Record
Filter Control Capabilities– PM -- 80%->90% Reduction
– CO and HC -- >90%
– Toxic HCs -- >90% Reduction
ARB/ARCO/CEC Retrofit Demonstration ARB/ARCO/CEC Retrofit Demonstration Program Program
0
0.5
1
1.5
2
2.5
CO NOx/10 HC PM
Control (CARB)
Test (CARB)
Test (EC-D)
Test (EC-D, filter)
Source: SAE 2000-01-1854
undetectable
Filters Destroy Large Fractions of Toxic EmissionsFilters Destroy Large Fractions of Toxic Emissions
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Before After
PAH Emissions Reduced by 89%
PAH, mg/bhp-hr
Source: MECA 1999
1.2
0.14
Recent Data Reports nitro-PAH Are Decreased with Recent Data Reports nitro-PAH Are Decreased with FiltersFilters
Octel, SAE TopTec 9/00
Filters Are Very Effective in Reducing Ultra-Fine Filters Are Very Effective in Reducing Ultra-Fine ParticlesParticles
Post filtered gas has the same particulate concentrations as the dilution air
Carbon-Based Ultra-Fine Particles Reduced by in Excess of 99.99 %
Peugeot SAE 2000-01-0473
Diesel Particulate Filter Retrofit DurabilityDiesel Particulate Filter Retrofit Durability
VehicleApplication
Engine Displacement (l) and Power (hp)
Accumulated Distance (mi)
PM Reduction Efficiency (%)
Euro ESC1 US FTP2
Intercity Train 14 430 372,902 89 99
Airport Bus 10 292 357,531 80 n.a.
Express Bus 10 368 304,598 94 94
Mail truck 7 236 294,469 78 93
City Bus 11 260 142,205 93 98
Refuse Truck 7 235 128,342 93 n.a.
Refuse Truck 7 235 65,743 92 n.a.
Averages: 194,456 88 96
SCR
SCR ApplicationsSCR Applications
SCR Has Been Used Successfully on Stationary SCR Has Been Used Successfully on Stationary Sources and Is Now Used for Mobile SourcesSources and Is Now Used for Mobile Sources
SCR Control Capabilities– PM – 30-50% Reduction
– CO and HC -- >80%
– Toxic HCs – >80%
– NOx – 60 - >80%
SCR Test Results in European & US Steady State Test SCR Test Results in European & US Steady State Test CycleCycle
0
500
1000
1500
2000
2500
1 2 3 4 5 6 7 8 9 10 11 12 13mode
NO
x [g
/h]
NOx before catalyst: 6.79 g/bhphr NOx after catalyst: 1.34 g/bhphr
NOx conversion: 80%
Integrated System Using a DOC, DPF, and SCRIntegrated System Using a DOC, DPF, and SCR
Engine
Catalyst/Filter SCR Oxidation Cat
Removal of HC, CO, PM
Removal of NOx
Removal of NH3 slip if required
4-way conversion
Urea
Integrated System – Lean NOx Catalysis + Integrated System – Lean NOx Catalysis + FilterFilter
Integrate heat transfer and chemistry Integrate heat transfer and chemistry for simultaneous reduction of for simultaneous reduction of NOx, CO, HC, & PMNOx, CO, HC, & PM
LNCLNC(NOx reduction)(NOx reduction)
DPFDPF(CO, HC, and(CO, HC, andPM oxidation)PM oxidation)
DirtyDirtyExhaustExhaust
InIn
Clean AirClean AirOutOut
GainGainHeatHeat
LoseLoseHeatHeat
RecuperatorRecuperator
SupplementaSupplementary HC ry HC
InjectionInjection
Elements of a Proper Retrofit Control ProgramElements of a Proper Retrofit Control Program
The Condition of the Engine Is an Important Factor in Making a Decision Whether to Retrofit Control Technology
For Filter Retrofit, Vehicle Application, Exhaust Temperature (Duty Cycle), and Fuel Sulfur Level Must Be Properly Matched
Elements of a Proper Retrofit Control Program (cont.)Elements of a Proper Retrofit Control Program (cont.)
Retrofit Technology Check List
– Size
• Properly Sized Control Technologies Ensure Low Back Pressure and Maximum Performance
– Vehicle Integration
• An Important Aspect of Control Technology Retrofit, but Has Been Successfully Accomplished on Both On- and Off-Road Vehicles (muffler replacement or in-line installation)
Elements of a Proper Retrofit Control Program (cont.)Elements of a Proper Retrofit Control Program (cont.)
Retrofit Technology Check List (cont.)
– Fuel Quality
• For PM Control, <15 ppm Allows for Maximum Emission Control Performance and Best Filter Regeneration Characteristics
• Oxidation Catalysts Can Be Formulated to Minimize Sulfation, but at the Expense of Some Reduced Emission Control Performance
• Some Technologies Can Be Applied to Certain Applications Using Fuels with Higher Sulfur Levels
– Maintenance
• Vehicles to Be Retrofitted Should Be Properly and Regularly Maintained
• Retrofit Technology Should Be Maintained per Manufacturer’s Recommended Procedures
Filter System Retrofitted to a BusFilter System Retrofitted to a Bus
Filter System Retrofitted to a BusFilter System Retrofitted to a Bus
Filter System
Filter System Retrofitted to a Refuse TruckFilter System Retrofitted to a Refuse Truck
Filter System
Direct Fit In-line ConverterDirect Fit In-line Converter
Catalyst
Integrated Converter MufflerIntegrated Converter Muffler
Muffler Replacement
Central Artery/Tunnel Project (Big Dig)Central Artery/Tunnel Project (Big Dig)
Filter System
Current Cost Current Cost
Filter Technology
– Depends on Engine Size – Approximately $3000 - $5500 per Vehicle Depending on Type of Vehicle Integration
– 2-4 Hours for Installation
– Ash Removal at ~60,000 Miles
Oxidation Catalyst Technology
– Approximately $500 - $1800 per Vehicle Depending on Type of Vehicle Integration
– 2 Hours for Installation
– Maintenance – Periodic Inspection and Cleaning if Necessary
Current Cost (cont.)Current Cost (cont.)
SCR
– Approximately $15,000 - $50,000 per Vehicle Depending on Type of Vehicle
– 2 Days for Installation
– Reagent Consumed at 6% of Fuel Consumption (depending on conversion efficiency, engine type, etc.)
Lean-NOx/Filter Technology
– $5,000 - $10,000 per Vehicle Depending on Type of Vehicle
Costs for Retrofit Control Technologies Will Decrease as Sales Volumes Increase and Systems Are Fully Optimized
Stationary Engine Urea SCR Cost Effectiveness Stationary Engine Urea SCR Cost Effectiveness (2000 hp Diesel Engine)(2000 hp Diesel Engine)
400 hrs/yr 8000 hrs/yr
NOx removed 11.3 TPY 225 TPY
Reagent usage 22.6 TPY 450 TPY
Capital recovery factor .20 .26
Reagent, $/ton $ 400 $ 200
Annual cost: Capital 17,800 24,960
Reagent 9,040 90,000
Total $26,840 $115,160
Cost/ton NOx removed $ 2,375 $ 512
ConclusionsConclusions
A Variety of Demonstrated Retrofit Technologies Are Available to Significantly Reduce PM, NOx, HC, CO, Toxic, Smoke, and Odor Emissions from Existing HDDEs
A Growing Number of Retrofit Programs Are Being Successfully Implemented
A Properly Designed and Implemented Program Can Achieve Important Diesel Exhaust Emission Reductions and Expedite the Use Of Clean-Diesel Engines
Active Participation by All Interested Parties Will Be A Key Element in a Successful Program