8 March 2004

Ethanol as Fuel for Recreational Boats

ENGS 190/ENGG 290 Final ReportSponsor: Professor Charles Wyman

Group Members:Erik Dambach, Adam Han, Brian Henthorn

www.dartmouth.edu/~ethanolboat

www.mercurymarine.com

Ethanol as Fuelfor Recreational Boats

Presentation Outline

• Need Statement and Background

• Engine Choice and Modifications

• Specifications and Testing

• Marketability

• Conclusions

• Acknowledgements

Ethanol as Fuelfor Recreational Boats

Need Statement

Due to the potential for environmental contamination by gasoline in recreational boating, fuel ethanol is a potential solution

to reduce pollution associated with recreational boating.

Ethanol as Fuelfor Recreational Boats

Why Ethanol?

• Recreational boating with gasoline as a fuel is a major source of pollution for both water and air

• Ethanol, unlike gasoline, is biodegradable and low in toxicity

• Ethanol is comprised of much fewer chemicals than gasoline

• As an additive, the use of ethanol as a fuel has the ability to allow for cleaner combustion and to lower air emissions

• Ethanol is a renewable source of energy

Ethanol as Fuelfor Recreational Boats

State of the Art

• The use of ethanol as a fuel has mainly been focused on the automotive industry

• There are limited studies of ‘alternative fuels’ in boating applications

• Fuel ethanol has never been researched for recreational boating

• Ethanol was investigated along with other ‘alternatives’ in use to strengthen fuel choice

Ethanol as Fuelfor Recreational Boats

Alternative Fuels for Gasoline Marine Engines

Ethanol as Fuelfor Recreational Boats

California Case Study

• US fuel prices and regulations vary by region

• Toughest emission regulations in country

• High price of gasoline• Supportive of alternative

fuel technology• Phase-out of MTBE

replaced with EtOH• 2nd most registered

number of boats in US• Discourages the use of

carbureted two-strokes

Ethanol as Fuelfor Recreational Boats

California Case StudyProjected Price Range* for Ethanol

Sale in California at Marinas Production Cost $1.020

Price Incentive $0.050

Transportation/handling costs $0.146 ─ $0.187

Excise Tax Rate $0.090

Mark-up $0.350

Projected California Price Range $1.656 ─ $1.697

Gasoline Equivalent Price Range $1.441 ─ $2.562

*Price per gallon of ethanol

Ethanol as Fuelfor Recreational Boats

Engine Overview

• 2000 Mercury 5 hp Four-Stroke Outboard

• Four-stroke for smaller needs (<90hp)

• Necessary Modifications– Materials Compatibility– A/F ratio– Cold-start

Ethanol as Fuelfor Recreational Boats

Materials Compatibility• Rubber Tubing, O-Rings

– Soaked in EtOH– Tubing replaced with

Viton B– O-rings replace with Butyl

Dupont Dow Elastomers Chemical Resistance Guide

Ethanol as Fuelfor Recreational Boats

Replacement of Rubberin Fuel System

Tubing

Drainage screw o-ring

Fuel pumpo-ring

Intake manifold o-ring

Ethanol as Fuelfor Recreational Boats

Materials Compatibility• Rubber Tubing, O-Rings

– Soaked in EtOH– Tubing replaced with

Viton B– O-rings replace with Butyl

• Fuel Filter– Soak in EtOH– Not needed to be replaced

• Metal Corrosion– Determine primary metal in

Fuel System using EDS on SEM

Dupont Dow Elastomers Chemical Resistance Guide

Ethanol as Fuelfor Recreational Boats

Energy-dispersive X-Ray Spectroscopy (EDS)

Main Jet - Brass Fuel Pump – Aluminum

Ethanol as Fuelfor Recreational Boats

Carburetor

Source: Mercury Service Manual, 4/5/6HP 4-Stroke

Ethanol as Fuelfor Recreational Boats

Carburetor Modifications• Enlarge Main Jet inner diameter by 20-40%

– (.033”, .036”,.039”)

Main JetMain Nozzle

Ethanol as Fuelfor Recreational Boats

Cold-start Solutions

Cold Start Method Portability Availability Fuel Cost Retrofit CostEffectiveness (single start) Repeatability

Environ. Impact Ease of Use TOTAL TOTAL weighted

Gasoline 5 5 3 4 4 1 8 4 34 77Propane 6 6 4 5 4 1 7 5 38 88Natural Gas 7 7 2 6 4 1 4 6 37 94Hydrogen Gas 1 1 0 8 1 1 3 7 22 66Diethyl Ether (EtOH) 1 1 0 7 2 1 5 7 24 68Diethyl Ether (Starting Fluid) 4 4 1 1 2 1 5 1 19 39Electric Heater (outlet) 8 8 0 2 7 1 1 1 28 74Electric Heater (battery) 1 3 0 3 7 7 1 1 23 66

Ethanol as Fuelfor Recreational Boats

Other Important Modifications

• Ignition Timing– Advance ignition timing for EtOH– Unfortunately, not possible with Mercury

outboard engine

• Compression Ratio – Increase (8.5:1~11:1)– Extremely expensive– Can only be drastically altered at production

stage

Ethanol as Fuelfor Recreational Boats

Target SpecificationsArea Quantification Justification Test

Environmental

NOx + HC emissions 1770.8 PPM 2008 CARB Exhaust Emissions Standard

Snap-on MT3505 Emissions Analyzer at Vermont Technical College

CO emissions 0.85% (reduction by 10%) The reduction is acceptable or ethanol to be preferred over gasoline.

Same as above

Performance

Horsepower 5 hp (100% of running on gasoline)

Maximum power output of gasoline engine

Torque, RPM, horsepower relationship

Efficiency At least 0.0140 gal/hr-hp (at least 66.7% of gasoline)

Energy content ratio of gasoline to ethanol

Run known volume of fuel until engine stopped

Cold-start Must start above 30°F Minimum starting temperature of gasoline engine

Start at cold temperature

Weight < 62.7 lbs. (110% of original engine weight)

According to Fairlee Marine Scale

Economics

Overall cost to retrofit (excluding labor)

$250 (25% of engine value maximum)

Alternative Fuel Data Center vehicle cost analysis

Economic analysis

Ethanol as Fuelfor Recreational Boats

Testing Methodology

Ethanol as Fuelfor Recreational Boats

Testing Methodology

Ethanol as Fuelfor Recreational Boats

Testing Setup

• Preparation for testing– Construct test stand– Break in engine

• Fuel Used– Gasoline: Shell 87 Octane

Unleaded– Ethanol: Ethanol with

Natural Gasoline Denaturant (2-5%)

• Testing Facilities– Emissions testing at

Vermont Technical College– Thayer School Ice Lab– Thayer School Loading

Dock

Ethanol as Fuelfor Recreational Boats

Emissions Testing

• Snap-on MT3505 Emissions Analyzer

• Emissions Analyzed– Hydrocarbons– NOx– CO

– CO2

• Tested at each throttle range (idle, mid, full)

• Tested at each jet size (.028”, .033”, .036”, .039”)

Ethanol as Fuelfor Recreational Boats

Emissions Testing Results

• Full and Mid-throttle testing– Idle is

independent of main jet size

• EtOH had dramatic reductions in emissions at .033” jet size

Hydrocarbon and NOx Emissions

3825

819.5

19532481

241.25 89.5314.25 403

0500

10001500200025003000350040004500

Gas EtOH (.033) EtOH (.036) EtOH (.039)

Fuel (Jet diameter in inches)

PP

M Full Throttle

Mid Throttle

Ethanol as Fuelfor Recreational Boats

Emissions Testing Results

• CO emissions– Increase using

EtOH

• Engine not optimized for EtOH combustion– Lower CO2 values

• .033” jet similar to gas emissions

CO and CO2 Emissions

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

14.00%

Gas EtOH(.033)

EtOH(.036)

EtOH(.039)

Fuel (Jet diameter in inches)

%

Full Throttle CO%

Full Throttle CO2%

Mid Throttle CO%

Mid Throttle CO2%

Ethanol as Fuelfor Recreational Boats

Power Testing

• Power Calculated using:

• Torque = 4.22ft-lb at full throttle running on gasoline

• ~5 horsepower– .033” jet– .036” jet

Maximum Power Output

4.5

4.6

4.7

4.8

4.9

5

5.1

Gasoline EtOH - 0.028" diam. jet EtOH - 0.033" diam. jet EtOH - 0.036" diam. jet EtOH - 0.039" diam. jet

Fuel and Jet Size

hp

RPM

hplbfttorque

5252)(

Ethanol as Fuelfor Recreational Boats

Fuel efficiency testing

• Put in known amount of fuel (500 mL)

• Run until the engine stopped– Record run duration

time

• Measure amount of remaining fuel

Ethanol as Fuelfor Recreational Boats

Fuel Efficiency with Power

• Divide fuel efficiency by power output

• .036” jet size– closest to gasoline

efficiency

• .028” jet size (original optimized for gasoline)– Did not sustain

combustion of EtOH

Full-Throttle Efficiency with Power

0.093

0.1340.142

0.122

0.203

0

0.05

0.1

0.15

0.2

0.25

Gasoline EtOH - 0.028" diam. jet EtOH - 0.033" diam. jet EtOH - 0.036" diam. jet EtOH - 0.039" diam. jet

Fuel and Jet Size

gal

/hr-

hp

Ethanol as Fuelfor Recreational Boats

Cold-start Testing

• Gasoline Benchmark– Location: Cold room in ice lab, – Engine temperature monitored

with Fluke IR Thermometer– Cold room initially at 20°F– Warm cold room and engine

gradually

• Results– Below 30°F, engine did not

start– At 30°F, engine started with

much difficulty, requiring 15 pulls of recoil starter rope

• EtOH Testing– Location: Loading dock– Minimized difference between

• Results– Engine would not start at 30°F

without cold-start assist– Ether-assist achieved ignition

in four applications (pull of starter rope couple with ether spray into carburetor)

– EtOH engine with cold-start achieved ignition quicker than gasoline-powered engine

Ethanol as Fuelfor Recreational Boats

Determination of Optimal Jet Size

• .033” and .036” jet sizes determined optimal air-fuel ratio– .033” preferred due to reduced emissions,

slightly reduced efficiency

Jet Diameter (in.) Emissions Efficiency Power Total

0% (0.028) 4 4 4 12

20% (0.033) 1 2 1 4

30% (0.036) 2 1 1 4

40% (0.039) 3 3 3 9

Ethanol as Fuelfor Recreational Boats

Engine Economic Analysis

• Actual modification cost relatively minor– Rubber replacements

relatively inexpensive

• Labor costs significant, but within specification

• EtOH fuel costs for 60gal/yr increase from $101 to $141 compared to gasoline

Modification Cost without Labor Cost with Labor

Tubing $25.00 $25.00

O-ring $9.06 $9.06

Labor $0.00 $45.00

Jet Size $0.00 $0.00

Labor $0.00 $60.00

TOTAL $34.06 $139.06

Ethanol as Fuelfor Recreational Boats

Target vs. Actual SpecificationsArea Target Specification Actual Specification % Deviation from

Specification (if does not satisfy)

Environmental

NOx + HC emissions <1770.8 PPM 819.5 PPM

CO emissions <0.85% (reduction by 10%) 1.03% 21.2%

Performance

Horsepower >5 hp (100% of running on gasoline – no compression ratio change)

5.06 hp

Efficiency At least 0.140 gal/hr-hp (at least 66.7% of gasoline)

0.142 gal/hr-hp 1.4%

Cold-start Must start above 30°F Started above 30°F

Weight < 62.7 lbs. (110% of original engine weight)

57 lbs.

Economics

Overall cost to retrofit (excluding labor)

<$250 (25% of engine value maximum)

$34.06

Ethanol as Fuelfor Recreational Boats

Engine Marketability

“The buying public always looks towards mainstream success for their purchasing decision. If a product has had success and proven to perform at or near that of a

gasoline powered engine, they will most certainly consider it. “

-Randy Stratton, The Stratton Group

Although there are a lot of environmentally-conscious people, they are often unwilling to pay anything extra.

-Chris Virgo, mechanic at North Tahoe Marina

Ethanol as Fuelfor Recreational Boats

Timeline for ENGS 190  TASKS 1 2 3 4 5 6 7

Environmental              

  Background Research              

  Investigate fate and transport for gasoline and ethanol              

  Investigate effects of gasoline and ethanol in lakes              

  Investigate regulations              

Economic Case Study              

  Background Research              

  Determine most applicable location              

  Investigate infrastructure for introducing fuel ethanol              

  Investigate cost associated with infrastructure              

  Determine retail cost of ethanol on lakes              

Technical              

  Background Research              

  Determination of engine type for modification              

  Investigate adaptation of engines for ethanol              

  Investigate cold start technologies              

Evaluate literature research              

Search for and secure an engine              

Written Proposal              

Oral Proposal              

Written Progress Report              

Oral Progress Report              

Ethanol as Fuelfor Recreational Boats

Timeline for ENGG 290TASKS 1 2 3 4 5 6 7 8

Pre-testing procedure and preparation                

Design retrofit for engine                

Benchmark testing for gasoline                

Materials acquisition for retrofit                

Construct prototype for ethanol                

Test ethanol prototype for performance                

Test ethanol prototype for emissions                

Cost analysis of retrofitted engine                

Investigate marketability of engine                

Investigate implementation of engine                

Implementation report via website              

Oral Progress Report                

Written Final Report                

Oral Final Report                

Ethanol as Fuelfor Recreational Boats

Project Conclusions

• Ethanol was found to out-perform gasoline environmentally for water and air pollution in recreational boating applications

• Ethanol as a fuel has high potential given the infrastructure, fuel cost, and environmental policy trends

• A four-stroke outboard engine was successfully modified to run on ethanol fuel

• Testing of the engine running on ethanol showed similar performance in terms of power, varied for emissions, and decreased fuel efficiency

• Website: www.dartmouth.edu/~ethanolboat

Ethanol as Fuelfor Recreational Boats

Recommendations

• Obtain dynamometer for engines of low hp to strengthen existing data

• Determine optimal jet size between 20% and 30%

• Alter compression ratio/timing to further optimize the engine at manufacturer level

• Research effects of ethanol materials and potential long-term replacements to increase longevity of engine

• Use findings to further ethanol-fueled engine research

Ethanol as Fuelfor Recreational Boats

AcknowledgementsAt Thayer School:Prof. Charles WymanProf. John CollierProf. Robert GravesDoug FraserGary DurkeeThayer School Instrument RmThayer School Machine ShopPaula BergProf. Benoit Cushman-RoisinProf. Horst RichterJoan LevyCathy FollensbeeWilliam CoteBin YangDaniel IliescuDaniel Cullen

Outside sources:Fairlee Marine Betsy Dorries and Steve Belitsos at Vermont

Technical CollegeRoberta NicholsTerry Jaffoni and Jackie Fee of CargillMichael O'Keefe and Professor Phil Malte at

University of WashingtonDon Mathey at Donlee Pump Company California Air Resources BoardEnvironmental Protection Agency (especially Stout

Alan)Edward Nelson at Wisconsin Department of Natural

ResourcesTom Durbin at University of California RiversideWarren H. Hunt of the Aluminum AssociationGarland Lewis at TohatsuJohn Cruger-Hansen Jeff Schloss at University of New HampshireJack Hull at Rainbow Rubber ExtrusionsJay Kidwell at The Carburetor Shop, Inc. and Mile

High PerformanceBones Gate FraternityZeta Psi Fraternity