Transcript Presentation to EPA on Ethanol Fuel Waiver August 31, 2005

Minnesota E-20 Fuel
Waiver Test Program
Technical Presentation
Dr. Ranajit (Ron) Sahu, Consultant
Phone: (626) 382 0001
[email protected]
Topics
• Off-Road Characteristics
– Equipment
– Engines
– Fuel Systems
• EPA’s Exhaust Regulations
– Impact on Air-Fuel Ratio Settings
• Summary of Existing E-20 Studies
2
Topics (cont.)
• General Testing Issues to Meet Waiver Criteria
– Creating technology categories to respond to
diversity
• Existing and newly regulated products
• Engine technologies/materials/components
– Statistically valid data
– Pass/Fail criteria
• Testing Evaluations/Criteria
– Impact on exhaust and evaporative emissions
– Impact on materials compatibility
– Impact on drivability/functionality
3
Topics (cont.)
• Illustrative Example – Handheld Engines
• Fuel Specification Issues
• Additional Technical Slides/Discussion
4
Off-Road Characteristics
Equipment
• Diversity
– Components, materials, and uses
• Key design issues differ by category
– Lawn and garden vs. snow vs. marine etc.
• Seasonal use
• Consumers
– Minnesotans own and rely on millions of off-road
engines, vehicles and equipment
– Exposed to potential hazards if engine/equipment
operates outside of normal expected conditions
6
Engines
• Air or Water Cooled
• Operator in Close Proximity to Hot
Engine/Exhaust System
• 2-Stroke and 4-Stroke – With Variations
• Various Fuel Introduction Technologies
– Mostly carbureted with variations
– Some fuel injected
7
Engines (cont.)
• Various Engine “Control” Technologies
– Mostly open loop with no feedback
– Few closed loop
• Various Emissions Reduction
Strategies/Technologies
8
Fuel Systems
• Wide variety of tank and hose materials
• Different evaporative control strategies
– Permeation, tank venting, etc.
• Multi-positional operational requirements
• Storage-stability issues due to seasonal usage
• Safety constraints
• EPA evaporative/permeation regulations
9
EPA’s Exhaust Regulations:
Impact on Air-Fuel Ratio Settings
Regulations Summary
EQUIPMENT/
ENGINE TYPE
CURRENT
EFFECTIVE
REGULATIONS
FUTURE
ADOPTED
STANDARDS
ANTICIPATED
FUTURE
REGULATIONS
Small Spark Ignition
• Lawn & Garden
• Other
Exhaust
Large Spark-Ignition
Engines
Exhaust / Evaporative
Exhaust/Evaporative
40 CFR Part 1048
2007
Exhaust / Evaporative
Exhaust / Evaporative
Exhaust / Evaporative
40 CFR Part 91
2006, 2007
Inboard / Stern-drive
Exhaust / Evaporative
Exhaust / Evaporative
40 CFR Part 1051
2006, 2007, 2008,
2010, 2012
Marine Engines
Recreational /
Vehicles
• Snowmobiles
• ATV’s
• Off-Road
Motorcycles
Revised Exhaust /
New Evaporative
40 CFR Part 90
11
Impact
• EPA’s exhaust emission regulations have
resulted in enleanment of the engine’s air-fuel
calibration to functional limits
• Fuel management systems cannot effectively
manage E0 through E20 fuels interchangeably
• Modification of existing fuel management
systems to operate on E-20 would require
tampering with an emission control device and
thus violate Federal Law
12
Limit for Acceptable
Operation
Limit for Emission
Compliance
Acceptable
Operating Range
Operation
on E20
Gasoline
Lean
Operation on
E10 Gasoline
Air:Fuel Ratio
Operation on
Neat Gasoline
Rich
13
Exhaust Gas Temperature vs. Fuel Change
1350
Exhaust Gas Temperature - Degrees F
1300
Change in CO for fuel change
from certification to E22 Engine M44
1250
CaRFG PH2
Fuel
1200
E22 Fuel
1150
1100
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
CO %
14
Summary of Existing E20
Experience and Studies
E-20’s Impact on Current, ExhaustEmission Compliant Small Engines
• Exhaust temperatures up 100°F
• Peak cylinder pressures higher
• Combustion deposits
• Cylinder head gasket burned & failed
• Exhaust valve burned
• Cylinder bore scored
– 25 hours light duty emissions testing
– Lost cylinder compression
– Lost 20% power
16
E-20 Implications on Engine Durability
Cylinder
head
gasket
burned
Lost seal
Exhaust
leak out
17
E-20 Implications on Engine Durability
Cylinder
head
gasket
burned
Lost seal
18
E-20 Implications on Engine Durability
Cylinder
Bore
scoring
Deposits
19
Engine Durability Implications with E-20
1
1
2
3
4
5
6
7
8
Head bolts discolored due to heat
and carbon build up from exhaust
gas blowing past bolt.
20
Engine material compatibility
Implications with E-20
Bowl gasket
swelled & lost
seal.
Carburetor
bowl mounting
screw gasket
attacked by
E20 in few
hours. Fuel
containment
seal.
21
Engine material compatibility
Implications with E-20
Carburetor welch plug epoxy attacked by
E20 in 17 wks. Fuel containment seal.
22
Engine material compatibility
Implications with E-20
Fuel Cap
gasket swelled
& warped by
E20 in 1 wk.
Fuel
containment
seal & tank
venting.
23
Brazilian Experience
• During 1970s and 1980s, blends ranging from E14 – E24
used in Brazilian fuel supply (pre-emission compliant
products)
• OPEI Member Experience (2-Stroke engines)
– Lean air fuel ratio delivery resulting in
•
•
•
•
higher engine temperatures
engine seizures
Poor acceleration performance
Cold start problems
– Phase-separation due to water uptake leading to water in
carburetor
– Formation of deposits blocking carburetor nozzles
– Corrosion of engine parts, crankcase, bearings, crankshaft, etc.
– Had to develop unique products with different carburetor
settings, fuel system materials, etc.
24
Orbital 2002 and 2004; NREL 2002
• E20 requires resizing/recalibration of existing open loop
engines (i.e., changed A/F ratio) to prevent
– enleanment, resulting in temperature increase, and engine
malfunctions
– detrimental impacts on safety
• Detrimental impacts of phase-separation due to
presence of water in E-20 – potential engine stall – esp.
at cold temperatures
• Poor (Cold) Start performance (esp. important for handstart engines)
• Hot and Cold performance degraded
25
Publication SAE 920164
• Concluded that ethanol has an adverse
effect on evaporative permeation
emissions from current fuel tanks and
hoses
26
Summary of E-20 Studies
• Causes corrosion of metals and resulting impacts on
engine components
• Distorts elastomers and causes resulting impacts on fuel
system components
• Causes loss of lubricity due to “cylinder wall wash”
• Loosens deposits in existing equipment – leading to
plugged fuel filters etc.
• Damage to painted parts
• Adverse impact on exhaust and evaporative emissions
and on engine/equipment performance
27
General Testing Issues
to Meet Waiver Criteria
Waiver Issues and Test Criteria
1.
2.
3.
4.
Exhaust emissions
Evaporative emissions
Materials compatibility
Drivability/Operational Performance and “Tampering”
Risk
•
EPA must determine whether and when new fuels could cause
“failures” in each of these categories
Data must be derived from unmodified engines, vehicles, and
equipment that are EPA-certified, as applicable
Waiver applicant must evaluate carbureted-engine configurations
with their existing air:fuel ratios set for EPA certification fuels
•
•
29
Testing - Product Categories
• Since emissions regulations are changing,
off-road engines/equipment groups to be
tested should include mix of:
– Existing, pre-compliant equipment
– Existing, EPA compliant equipment
• New
• In-use
– Future, prototypical new equipment designed
to meet EPA evaporative and exhaust
regulations anticipated before 2015
30
Testing - Representativeness Via
Technology Categories
• Need to identify and test “representative”
mix of engines/equipment
• Must test different “Technology
Categories”, based on
•
•
•
•
•
Engine combustion cycle (2 Stroke and 4 Stroke)
Fuel delivery / control systems
Exhaust emission controls/strategies
Evaporative emissions controls/strategies
Equipment use profile
31
Technology Categories - Fuel
Delivery Systems
• Carburetion
– Float type
– Diaphragm type
– Single vs. multi-circuit
• Fuel Injection
– Open loop
– Closed loop
32
Technology Categories – Exhaust
Emissions Controls / Strategies
• Various Engine Designs and Modifications
– 2 Cycle vs. 4 Cycle
– Side vs. overhead valve configurations
– Ignition timing changes
– Air/Fuel preparation and delivery systems
• Stratification
• Compression wave technology
• Catalysts
• Hybrids (2/4 Strokes)
33
Illustration of 2005 Exhaust Diversity –
EPA Non-Road Small SI Engines
[Additional Illustrations at End of Presentation]
Category
Non-Road SI (Handheld and Ground Supported)
Emission Classes
I-A, I-B, I, II, III, IV, V
Displacement (cc)
20 - 1000
Useful Life
Engine Cycle
50-1000 hrs
2S, 4S
Fuel Introduction
2S
Carbureted, EFI, SFI
4S
Carbureted, EFI, SFI
Control
Open Loop, O2S/ECM
Valve Location
2S
Piston Port (most), Reed
4S
Side Valve, Overhead Valve
Emissions Reduction
Phase 1, Phase 2
2S
EM, EM/TWC, OC, OC-2, TWC, TWC/OC
4S
EM, ECM, ECM/O2S, EM/TWC, TWC
34
Technology Categories –
Evaporative Materials
• Permeation from
– Fuel Tanks made of:
•
•
•
•
•
•
•
Metal
HDPE
Barrier Treated HDPE (fluorinated, sulfonated)
Selar
Nylons (various grades)
Coextruded (various types)
Other materials
– Fuel Hoses made of:
• NBR
• FKM
• Other materials
• Venting Emissions from
– Uncontrolled venting systems
– Carbon Canisters
35
Testing – Statistically Valid Data
• EPA will consider the data’s statistical validity
and how well the program represents the
product universe
– How many different products should be tested?
– How many replicate products and repeat
measurements?
– How will test data quality be controlled?
– Which data points provide statistically significant
results? Which are outliers?
– Which statistical tests should be used? etc.
• Statistical expertise helpful in designing the test
program and analysis of the results
36
Testing Evaluations/Criteria
Testing – Pass/Fail Criteria
• How will pass/fail criteria be established?
– Comparison with EPA standards and
procedures
• exhaust emissions
• evaporative emissions
– Criteria need to be developed for:
• materials compatibility tests
• drivability/operability tests
38
Testing Exhaust and Evaporative
Emissions
• Goal – Evaluate E-20’s impacts on compliance
with emissions standards:
– Criteria pollutants (NOx, HC, CO, PMx)
• Test Protocols
– EPA exhaust emission test protocols
– EPA evaporative emission test protocols
– EPA durability/aging provisions
• Pass/Fail criteria – compliance with EPA
compliance levels
• Air toxics
– e.g, aldehydes, etc.
39
Testing Materials Compatibility
•
Goal – Assess Short and Long Term E-20 compatibility with
– Metals
• Zinc, brass, cast iron, lead, aluminum, magnesium, nickel, etc.
– Non-metallics
• NBR, polyurethane, nylons, Viton, Teflon, nitrile, mylar, silicon sealants, felt, etc.
– Adhesives used for labels and decals
•
Test Protocols – Need to be developed for various test types below:
– Coupon tests
– Engine/equipment soak tests under non-operational conditions
– Durability tests under nominal operating conditions
• Laboratory (bench) tests
• Field tests
– Durability tests under off-nominal operating conditions
•
Pass/Fail Criteria – Need to be developed for tests above.
40
Testing “Drivability”
• Goal - How does E-20 impact normal operation or
expected normal operation? Specifically, tests should
examine
–
–
–
–
–
–
–
–
Cold start ability (in all applicable ambient environments)
Load pickup
Acceleration
Hot restartability
Vapor lock
Maximum power operation
Fuel switching: from E-20 to Baseline fuel and vice versa
Impact on safe equipment operation
• Test Protocols – Need to be developed
• Pass/Fail Criteria – Need to be developed
41
Illustrative Example:
Handheld Engines
Test Categories
Engine/Control
Technology
(current and future)
Product Type
Blower
Pro
Trimmer/
Brushcutter
Chainsaw
Consumer
Farmer
Y
Y
N
N
Y
N
Stratified w/cat
N
Y
N
N
Compression Wave
Y
N
Y
N
2S w/cat
Y
Stratified
Y
4S
Y
2S w/tuned exhaust
Y
Pro
Y
N
Pro
Farmer
Y
Y
43
Test Parameters To Be Measured
•
•
•
•
Startability
Multipositional stability (@idle, @WOT)
Acceleration
Emissions (new and deteriorated)
– Exhaust
– Evaporative/Permeation (Tanks, Lines)
•
•
•
•
•
Power and Torque
Fuel consumption
Plug Seat Temperatures
Exhaust Temperatures
Materials Compatibility Indicators
–
–
–
–
•
Crankshaft assembly (Corrosion)
Cylinder (Corrosion)
Carburetor components (Corrosion/Distortion)
Fuel tanks / Fuel lines / Seals (Distortion)
Safety Feature Performance
44
Fuel Specification Issues
Testing – Fuel Specifications
• The exact composition of E20 needs to be
defined across all appropriate parameter
ranges (e.g., ethanol content)
• The exact choices for baseline fuels need
to be defined
46
Additional Technical Slides
(future discussion)
2005 Diversity - Snowmobiles
Category
Recreation Vehicle - Snowmobile
Emission Classes
-
Displacement (cc)
120 - 1500
Useful Life
Engine Cycle
400 hrs // 5 yrs // 8000 km
2S, 4S
Fuel Introduction
2S
Carb, TBI, Indirect Inj
4S
Carb, TBI, Indirect Inj, Port Fuel Inj., EC
Control
Open Loop
Valve Location
2S
Reed (most), Piston Ported
4S
OHV
Emissions Reduction
2S
EM
4S
EM
48
2005 Diversity – ATV’s
Category
Recreational Vehicle - ATV
Emission Classes
Displacement (cc)
Useful Life
Engine Cycle
50-800
1000 hrs, 10000 km, or 5 years
2S, 4S
Fuel Introduction
2S
Carb
4S
Carb, Inj
Control
Open Loop
Valve Location
2S
Reed, Piston Ported
4S
OHV
Emissions Reduction
2S
EM
4S
EM
49
2005 Diversity – Off Road MC’s
Category
Recreational Vehicle – Off Road Motorcycle
Emission Classes
Displacement (cc)
Useful Life
Engine Cycle
50-650
Earlier of 10000 km or 5 yrs
2S, 4S
Fuel Introduction
2S
Carb
4S
Carb
Control
Open Loop
Valve Location
2S
Reed Valve, Piston Port
4S
OHV
Emissions Reduction
2S
EM
4S
EM
50
2005 Diversity - Marine
Category
Marine
Emission Classes
-
Displacement (cc)
60 - 3600
Useful Life
Engine Cycle
PWC/Outboard – 350 hrs/10 yrs, Inboard/Stern Drive – 480 hrs/10 yrs
2S, 4S
Fuel Introduction
2S
Carb, DI, DI/EC, Indirect Inj/EC, TBI, MPI
4S
Carb, Carb/EC, DI, MPI, MPI/EC, Indirect Inj.
Control
Valve Location
2S
Reed, PP
4S
OHV
Emissions Reduction
2S
EM, DFI, Cat, ECM/DFI
4S
EM, ECM, SFI, MFI, Cat
51
2005 Diversity – Large SI
Category
LSI
Emission Classes
-
Displacement (cc)
1000 - 6000
Useful Life
Engine Cycle
7 yrs / 5000 hrs
4S
Fuel Introduction
2S
n/a
4S
Carb, TBI, MPI
Control
Open loop, closed loop
Valve Location
2S
n/a
4S
OHV
Emissions Reduction
2S
n/a
4S
EM, TWC
52
Specific Test Issues For Fuel
Specification
• What is the specification for E-20?
– Ethanol should meet ASTM 4806
– Fuel as a whole should meet ASTM 4814
– Additional denatured ethanol standards (presumably
like CA) need to be met (per RFA)
– Specific denaturant specs need to be met
(presumably like CA, per RFA)
– Additives should be specified: ignition improvers,
detergents, corrosion inhibitors, anti-foaming agents,
demulsifiers, lubricity additives, biocides, etc.
– Finally, certain additional specs (RVP?, distillation
curve?, octane?) may need to be met
53
Fuels – Baseline Testing
• What Baseline fuel(s) should be used?
– Seasonal/regional baseline fuel blends?
– Emissions and emission control systems tests
need to use EPA certification fuels.
– For determination of “drivability” and
operability differences, tests need to use E10
as baseline fuel.
54
Fuel Test Specifications
• Fuel Characteristics (all Baseline fuels and E-20)
–
–
–
–
–
–
–
–
–
–
–
Ethanol concentration
RVP, boiling curve, Drivability Index
Mixability of oil in fuel
Gum formation
Water content, Corrosion
Octane (RON, MON)
Storability
Autoignition temperature, flash point
Flammability limits
All properties per ASTM 4806 and ASTM 4814
All additional specifications per CARB (and MN, if applicable)
55