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Proposed Evaporative Emission Standards for Boats
Proposed Evaporative Emission Standards for Boats
Mike SamulskiOffice of Transportation and Air Quality
International Boat Builders’ Exhibition & Conference
Session 310: Boat Fuel SystemsOctober 11, 2007
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Outline
• Evaporative emission types
• Overview of proposed standards
• Rulemaking process
• Program details
• Questions
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Evaporative Emission Types
Refueling/spillage Venting emissions (diurnal, hot soak, running loss)
Permeation (fuel tank, hoses, other)
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Evap Standards
Three decades of automotive evaporative emission control(full vehicle test/standards)
Nonroad equipment are just now becoming
subject to evaporative emission control
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New Nonroad Standards
• Component based standards– Fuel and tank permeation– Component test for diurnal control– Design-based certification
• Existing standards– Large SI equipment (2007)– Recreational vehicles (2008)– Portable gas cans (2009)
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Proposed Standards
SI Marine• Portable tanks
– Tank permeation– Self-sealing vent
• Vessels– Hose and tank permeation– Diurnal emissions– Refueling spillage
Small SI as well– Hose and tank permeation– Running loss– Diffusion
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Marine Evap: NPRM Overview
Refueling Spillage: requested comment on potential for industry consensus standards (ABYC)
Standard/Category
Hose Permeation
Tank Permeation
Diurnal
Standard level 15 g/m2/day 1.5 g/m2/day 0.40 g/gal/day
Portable tanks 2009 2011 2009a
PWC 2009 2011 2009
Other tanks 2009 2012 2010b
a Design standard – self-sealing ventb Fuel tanks installed in nontrailerable boats (≥ 26 ft. in length) may meet a standard of 0.16 g/gal/day over an alternative test cycle
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Rulemaking Process
• gather information• meet with stakeholders• SBREFA
Pre-Proposal
NPRM(5/18/07)
PublicComment
(closed Aug 3)
ImplementFRM
(2008)
• public hearing
• written comment period
• address comments
• publish “Notice of Proposed Rulemaking”
• publish “Final Rulemaking”
• lead time• certification
YOU ARE HERE
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Small Businesses
• Small Business Regulatory Enforcement Fairness Act– Convened SBREFA Panels in 2001 and 2006– Representatives from engine, boat, tank, and hose
manufacturers
• Proposal includes all recommendations from panel report– Appropriate lead time– Broad definition of emission family– Compliance progress review for fuel tanks– Engineering design-based certification for tanks– Fuel tank credit program– Hardship provisions
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Program Details
HosePermeation
Diurnal
RefuelingSpillage
TankPermeation
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Proposed Diurnal Standards
• Portable fuel tanks– Self-sealing valve
• Installed tanks– Trailerable boats (<26 ft)
• 0.40 g/gal/day• 25.6-32.2°C
– Nontrailerable boats• 0.16 g/gal/day• 27.6-30.2°C
– Design-based certification• Seal tank up to 1.0 psi, or• Passive-purge carbon canister
• Tank manufacturer would certify
25.0
26.0
27.0
28.0
29.0
30.0
31.0
32.0
33.0
0 4 8 12 16 20 24
H ours
Fu
el T
emp
, Deg
rees
C
<26 ft
26 ft +
12
Diurnal: sealed tank with pressure relief
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26
31
36
0 4 8 12 16 20 24Hours
Deg
rees
C y = -0.42x + 1.5
R2 = 0.92
y = -0.47x + 0.81
R2 = 0.96
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0.0 0.5 1.0 1.5 2.0 2.5pressure relief setting [psi]
HC
[g
/ga
l/da
y]
22.2-35.6°C(72-96°F)
25.6-32.2°C(78-90°F)
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0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
0 5 10 15 20 25 30
Test Days
Ev
ap
ora
tiv
e H
C [
gra
ms
/ga
l/da
y]
Diurnal Emissions
Monday Outliers
Baseline Emission Level
Diurnal: passive carbon canister
Temp. Reduction72-96 F 64%78-90 F 68%81.6-86.4 F 71%
canister in boat
72-96°F
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Proposed Hose Standards
• Fuel line– 15 g/m2/day
• Fuel CE10, 23°C– Boat and engine hose
• Requested comment on more time for under cowl hose on outboards
– Primer bulbs• Vent and fill hose
– Standards do not apply unless hose will hold standing fuel
• Fuel line manufacturer would certify
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Hose: Low Permeation Materials
• Straight-run hose– Low permeation hose widely available– Fluoroelastomer/fluoroplastic barriers
• Molded hose and other rubber components– Fluroelastomer construction
rubber
barrier layerreinforcement
cover
SAE J1527Includes specificationFor 15 g/m2/day hose
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Proposed Tank Standards
• 1.5 g/m2/day– E10 fuel, 28°C– Preconditioning
• Fuel soak• Durability testing
• Design-based certification– Metal tanks– Automotive type multi-layer tanks
• Tank manufacturer would certify
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Tank Permeation: barrier treatment
• Fluorination– Expose tank surfaces to fluorine gas– Larger F molecules replace smaller H
molecules on surface
• Sulfonation– Expose tank surfaces to sulfur trioxide– Larger sulfonic acid groups form on surface
HC HC
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Tank Permeation: barrier treatment
Treatment Tank 1 Tank 2 Tank 3 Average
Baseline 11.5 11.4 11.2 11.4
Sulfonation% reduction
2.578%
2.776%
2.280%
2.578%
Fluorination% reduction
0.695%
0.695%
0.298%
0.596%
Treatment Tank 1 Tank 2 Tank 3 Tank 4 Avg.
Baseline 7.5 8.5 -- -- 8.0
Sulfonation% reduction
7.39%
7.82%
7.210%
7.74%
7.56%
Fluorination% reduction
5.729%
5.037%
6.223%
4.642%
5.433%
HDPE Blow-Molded Fuel Tanks [g/m2/day]
Crosslink PE Roto-Molded Fuel Tanks [g/m2/day]
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Tank Permeation: barrier platelets
% BarrierPermeation[g/m2/day]
2%4%4%6%6%
3.01.92.01.41.4
HC
HDPE/EVOH Blow-Molded Fuel Tanks [E10]
Nanocomposite Fiberglass [E10]
Tank Size[gallons]
Permeation[g/m2/day]
14 1.0
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Tank Permeation: continuous barrier
Soak Period Tank 1 Tank 2
27 weeks 0.15 0.05
35 weeks 0.07 0.09
44 weeks 0.11 0.04
Average 0.11 0.06
HDPE
HDPE
adhesive
EVOH
adhesive
IXEF
XLPE
Thermoformed HDPE/EVOHFuel Tanks [g/m2/day] 29°C, E10
HDPE/IXEF Blow-moldedTest Bottles [g/m2/day] 29°C, E10
Bottle Permeation
1 0.3
2 0.7
3 0.4
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Tank Permeation: continuous barrier
PA 11
XLPETank
OuterShell
Permeation
1 MDPE 0.7
2 XLPE 0.8
Roto-Molded PE/PA11Fuel Tanks [g/m2/day] 29°C, E10
CBT
XLPE
Roto-Molded PE/CBT“Single-Shot” Fuel Tanks
Manufacturer testing on 5 gallon tanks showed
permeation results well below proposed standards
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Tank Permeation: barrier coating
• Epoxy coatings applied to XLPE tanks• Adhesion treatment (light fluorination)
CoatingSoak Period
E10Permeation
g/m2/day
None 29 weeks7.58.5
InsideThermocured 15 weeks
0.60.021.0
OutsideThermocured* 15 weeks
1.93.33.3
OutsideUV cured
additional6 weeks
0.4
* Inspection showed uneven application of the coating which likely affected permeation results
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Tank Permeation: alternative materials
Tank Material Permeation
g/m2/day, 29°C, E10
V1 thermoplastic polyester 5.6
C10C11C13
impact toughenedacetal copolymer*
0.80.50.6
Vandar Celcon
Alternative MaterialFuel Tanks [g/m2/day] 29°C, E10
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Refueling
• Spillage control– Design filler neck for nozzle with automatic shut off, or– Filler neck orientation to cause fuel flow-back into tank
• Approaches– Redesign of fuel system– Automatic fuel shut-off before overflow– Fuel/air separator in vent line
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System Integration
• Industry consensus standards– SAE J1527 addresses hose permeation– ABYC H24 potential vehicle for spillage control
• Working with NMMA/ABYC/USCG– Industry is developing canister installation
specifications in context of EPA & USCG standards– ABYC is assessing fuel/air separators and fuel
system designs for spillage control– NMMA certification
