Redacted for privacy - ir.library.oregonstate.edu · IV-4 Fuel Preparation 82 IV-5 Test Parameters 82 IV -6 Test Procedure 83 IV-7 Oil Test Analysis 84 IV -8 Ethanol and Water Vaporization

AN ABSTRACT OF THE THESIS OF

Gamaleldin A. Khalifa for the degree of Doctor of

Philosophy in Mechanical Engineering presented

on April 25, 1985

Title:

Effect of Hydrous Ethanol on Crankcase Oil Dilution

Abstract approved:Redacted for privacy

(I 14ight J. Bushnell

Adequate lubrication is of the utmost importance in

internal combustion engines. Low temperature operation

with low-proof alcohol may create some operational prob-

lems if alcohol and/or water accumulates in the crankcase

oil. Condensates of unburned alcohol and water may be

blown into the crankcase oil with blowby gases. These

condensates may form an emulsion with the crankcase oil

that may restrict the supply of oil for adequate lubrica-

tion. Three engine tests were performed to identify the

effect of low-proof ethanol fueling on crankcase oil dilu-

tion and degradation.

The first test was hydrous ethanol carburetion in a

2.3 liter, 4 cylinder, 1974 Ford gasoline engine. The

second test was a mixture of low-proof ethanol fumigation

and normal diesel fuel injection (at reduced rate) in an

Allis-Chalmers Model 2900 turbocharged diesel engine. The

third test was also a mixture of ethanol fumigation and

diesel injection in an Allis-Chalmers Model 2800 naturally

aspirated diesel engine.

Ethanol of 130 and 160 proof was used in these tests.

The duration of each test was six hours steady operation.

Independent parameters of crankcase oil temperature, en-

gine load and speed, percent of total energy in the form

of ethyl alcohol and proof of the ethyl alcohol were

considered and varied. After each test the oil was sam-

pled for American Society for Testing and Materials (ASTM)

laboratory tests for determination of flash points, fire

points, water by centrifuge, water by distillation, and

viscosity at room temperature.

Results for the first test indicate that the use of

ethanol of 130 proof or less may result in accumulation of

water in the crankcase oil that may be harmful to the

engine. In the second and third tests although there was

a decrease in fire and flash points as well as in the vis-

cosity of the oil, no appreciable amount of water or

alcohol was detected in the crankcase oil. It is impor-

tant to mention that there was a maximum alcohol fuel flow

rate beyond which the diesel engine starts to knock or

misfire.

Effect of Hydrous Ethanol on CrankcaseOil Dilution

by

Gamaleldin A. Khalifa

A THESIS

submitted to

Oregon State University

in partial fulfillment ofthe requirements for the

degree of

DOCTOR OF PHILOSOPHY

Completed April 25, 1985

Commencement June 1985

APPROVED:

Redacted for privacy

ProfiS-? MeChanical Engineering in charge of major

Redacted for privacypaHead of Mechan" 1 Engineering Department

Redacted for privacy

Dean of Gradu School

Date thesis is presented April 25, 1985

Typed by Sadie Airth for Gamaleldin A. Khalifa

ACKNOWLEDGEMENT

My most sincere appreciation goes to my major

Professor, Dr. Dwight J. Bushnell, for his unfailing moral

support, advice, patience and help.

I would also like to thank the other members of my

thesis committee, Professor Allan Robinson, Professor

Lorin Davis, Professor Larry Slotta and Professor John

Mingle for their kind help and assistance. I would like

to express special thanks to professor John Mingle for his

continuous help and availability. His help with the

experimentation equipments and particularly the emission

instruments is gratefully acknowledged and appreciated.

Funding for unsponsered research by OSU computer

science is acknowledged and appreciated.

Finally, I would like to thank my wife Azah, for her

understanding, support and help during the course of

study. To my daughter Ala and my new born son Ahmed who

made all this worth while, my thanks are due.

Finally my thanks to Sadie for typing this thesis.

TABLE OF CONTENTS

I. INTRODUCTION

Page

1

I-1 Problem Statement 31-2 Objectives 5

II. LITERATURE BACKGROUND 7

III.

II-1 Methanol Versus Ethanol11-2 Alcohols in S.I. Engines11-3 Alcohols in C.I. Engines

HYDROUS ETHANOL CARBURETION IN A SPARK

7

1730

IGNITION ENGINE 45

III-1 Introduction 45111-2 Engine and its Calibration 45111-3 Instrumentation 46111-4 Fuel Preparation 47111-5 Test Parameters and Scheduled Runs 48111-6 Test Procedure 49111-7 Oil Analysis 50111-8 Ethanol and Water Vaporization 51111-9 Results 54III-10 Conclusions 58

IV. ETHANOL FUMIGATION IN A TURBOCHARGEDDIESEL ENGINE 79

IV-1 Introduction 79IV-2 Engine and Fumigation Equipment 79IV-3 Instrumentation 80IV-4 Fuel Preparation 82IV-5 Test Parameters 82IV -6 Test Procedure 83IV-7 Oil Test Analysis 84IV -8 Ethanol and Water Vaporization 85IV-9 Results 85IV-10 Conclusions 88

V. ETHANOL FUMIGATION IN A NATURALLYASPIRATED DIESEL ENGINE 115

V-1 Introduction 115V-2 Engine and Fumigation System 115V-3 Instrumentation 116V-4 Fuel Preparation 117

Page

V-5 Test Parameters 117V-6 Test Procedure 118V-7 Oil Test Analysis 118V-8 Results 119V-9 Conclusions 122

VI. CONCLUSIONS AND RECOMMENDATIONS 149

VI-1 ConclusionsVI-2 Recommendations

REFERENCES CITEDAPPENDIX

1. Computer Program for Calculation ofEvaporation Rates of Alcohol andWater

149152

154

158

LIST OF FIGURES

Figure Page

2.1 Process schematic for ethanol productionfrom grain by fermentation 10

2.2 Process schematic for methanol productionfrom municipal solid waste 11

2.3 Effect of ethanol addition on the F-1octane number of unleaded gasoline fuel 20

2.4 Volume change of mixing for ethanol-gasoline blends 20

2.5 Distillation curve for gasohol andunleaded gasoline 21

2.6 Effect of temperature on relative fueleconomy of gasohol to unleaded gasoline 21

2.7 Water and methanol accumulation in theengine oil of a CLR engine 27

3.1 Ford distributor characteristics ModelNumber D4ZE 12127 KA 4E28 62

3.2 Performance on gasoline, full throttleFord 1974, 2.3 liter engine 63

3.3 Performacne on gasoline, Ford 19742.3 liter engine 64

3.4 Mixtures of ethyl alcohol and water byweight (U.S. Bureau of Standards) 65

3.5 Thermal efficiency versus scheduled testnumbers 66

3.6 Brake specific fuel consumption versusscheduled test numbers 67

3.7 Carbon monoxide content in the exhaustgas versus scheduled test numbers 68

3.8 Oxygen content in the exhaust gasversus scheduled test numbers 69

Figure

3.9

3.10

3.11

3.12

3.13

Volume of water accumulation in engineoil versus scheduled test numbers

Brookfield viscosity of engine oilversus scheduled test numbers

Flash point of oil versus scheduledtest numbers

Fire point of oil versus scheduledtest numbers

Sketch of Control Volume for Calculationof Evaporation Rates of Ethanol andWater

3.14 Percent of Alcohol Vaporized VersusPercent of Water Vaporized Prior to theIntake Manifold for 130-Proof Tests

3.15 Percent of Alcohol Vaporized VersusPercent of Water Vaporized Prior to theIntake Manifold for 160-Proof Tests

Page

70

71

72

73

74

75

76

3.16 Percent of Alcohol Vaporized VersusPercent of Water Vaporized Prior to theIntake manifold for 180-Proof Tests 77

4.1 Allis-Chalmers, Model 2900, turbochargeddiesel engine equipped with alcoholfumigation system 93

4.2 Shell and tube heat exchangers forcrankcase oil temperature control 94

4.3 External oil pump for crankcase oiltemperature control 94

4.4 Sketch of fumigation system controlvolume for calculation of evaporationrates of ethanol and water 95

4.5 Percent of diesel fuel relative tobaseline versus scheduled percent ofenergy as alcohol for 160-proof tests

4.6 Percent of diesel fuel relative tobaseline versus scheduled percent ofenergy as alcohol for 130-proof tests

96

97

Figure

4.7

4.8

4.9

4.10

4.11

4.12

4.13

4.14

4.15

4.16

4.17

4.18

4.19

4.20

Scheduled percent of alcohol versusreal percent of alcohol for 160-prooftests

Scheduled percent of alcohol versus realpercent of alcohol for 130-proof tests

Thermal efficiency percent as a functionof real percent alcohol

Carbon monoxide emission as a functionof real percent alcohol energy

Flash point of oil as a function ofreal percent alcohol for 160-proof tests

Flash point of oil as a function of realpercent alcohol for 130-proof tests

Fire point of oil as a function of realpercent alcohol for 160-proof tests

Fire point of oil as a function of realpercent alcohol for 130-proof tests

Brookfield viscosity of engine oil asa function of real percent alcohol for160-proof tests

Brookfield viscosity of engine oil asa function of real percent alcohol for130-proof tests

Volume of water as a function of realpercent of alcohol energy

Volume of ethanol as a function of realpercent of alcohol for 160-proof tests

Volume of ethanol as a function of realpercent of alcohol for 130-proof tests

Percent alcohol vaporized versus percentof water vaporized prior to intake mani-fold for 20% load and 160-proof alcoholtests

Page

98

99

100

101

102

103

104

105

106

107

108

109

110

ill

Figure Page

4.21 Percent alcohol vaporized versus percentof water vaporized prior to intake manifoldfor 80% load and 160-proof alcohol tests 112

4.22 Percent alcohol vaporized versus percent ofwater vaporized for 20% load and 130-proofalcohol tests

4.23 Percent alcohol vaporized versus percentof water vaporized for 80% load and 130-proof alcohol tests

5.1 Allis-Chalmers, Model 2800, naturallyaspirated diesel engine equipped withalcohol fumigation system

5.2 Percent of diesel fuel relative to baselineversus scheduled percent of alcohol energyfor 160-proof tests

113

114

126

127

5.3 Percent of diesel fuel relative to baselineversus scheduled percent of alcohol energyfor 130-proof tests 128

5.4 Scheduled percent alcohol as a function ofreal percent alcohol for 160-proof tests 129

5.5 Scheduled percent alcohol as a function ofreal percent alcohol for 130-proof tests 130

5.6 Thermal efficiency percent as a function ofreal percent alcohol 131

5.7 Carbon monoxide content in the exhaust gasas a function of real percent alcohol 132

5.8 Carbon dioxide content in the exhaust gasas a function of real percent alcohol 133

5.9 Flash point of engine oil as a function ofreal percent alcohol 134

5.10 Fire point of engine oil as a function ofreal percent alcohol for 20 % load 135

5.11 Fire point of engine oil as a function ofreal percent alcohol for 80% load 136

FigurePage

5.12 Brookfield viscosity of oil as a functionof real percent alcohol 137

5.13 Volume of water in engine oil as afunction of real percent alcohol 138

5.14 Percent of diesel fuel relative to baselineversus scheduled percent of energy asalcohol for 160-proof tests (comparison) 139

5.15 Percent of diesel fuel relative to baselineversus scheduled percent of energy asalcohol for 130-proof tests (comparison) 140

5.16 Thermal efficiency percent as a functionof real percent alcohol (comparison) 141

5.17 Flash point of oil as a function of realpercent of energy as alcohol for 130-proofalcohol tests (comparison) 142

5.18 Fire point of oil as a function of realpercent of energy as alcohol for 130-proofalcohol tests (comparison) 143

5.19 Flash point of oil as a function of realpercent of energy as alcohol for 160-proofalcohol tests (comparison) 144

5.20 Fire point of oil as a function of realpercent of energy as alcohol for 160-proofalcohol tests (comparison) 145

5.21 Percent alcohol vaporized versus percentwater vaporized prior to intake manifoldfor 160-proof alcohol

5.22 Percent alcohol vaporized versus percentwater vaporized prior to intake manifoldfor 130-proof alcohol

146

147

5.23 Comparison of evaporation rates betweenthe three different engines 148

Table

1.1

2.1

2.2

2.3

2.4

3.1

3.2

3.3

4.1

4.2

4.3

4.4

5.1

5.2

LIST OF TABLES

Page

Comparison of Latent Heat of Vaporizationand Boiling Point Temperatures of Waterand Ethanol 4

Properties of Ethanol, Methanol, Gasolineand #2 Diesel Fuels 12

Possible Potential Problems with Alcohols(Ethanol and Methanol) 16

Properties of Dilute Ethanol Fuel 31

Evaluation of Different Methods to Converta Diesel Engine for Alternative Fuels 44

Engine Specifications and CarburetorCalibration 59

Formula for Preparing Nominal ProofSolutions from 190-Proof DenaturedEthanol 60

Test Schedule Runs 61

Specifications for Allis-Chalmers,Model 2900 Diesel Engine 89

Specifications of Union 76 #2 Diesel Fuel 90

Fumigation-Diesel Test Schedule andSample Code Numbers 91

Specifications of Union 76 GuardolMotor Oil 92

Specifications for Allis-Chalmers,Model 2800 Diesel Engine 124

Alcohol Fumigation - Diesel TestSchedule and Codes 125

EFFECT OF HYDROUS ETHANOL ON CRANKCASEOIL DILUTION

CHAPTER I

INTRODUCTION

Indicators point to the fact that there will be

short fall of approximately 25% in crude oil supplies

relative to demand by the end of this century. Dwindling

fuel reserves and increasing fuel consumption are the main

factors. Politics as well as economics in both importing

and exporting countries plays a major role as to the use

of alternative fuels in internal combustion engines.

The use of alcohol fuels as a supplement to, or

replacement for, liquid fossil fuels in the transportation

and agricultural sectors has received significant atten-

tion. Special attention is given to ethanol and methanol

as fuel contenders in both spark ignition and compression

ignition engines. Extensive research has been carried out

on a variety of engines. Tests show that, in general,

spark ignition engines are capable of performing satisfac-

torily on mixtures of alcohol and gasoline or entirely on

alcohol. In the diesel engine area, engine configuration

as well as the method of utilizing the alcohol fuel,

complicates the picture.

2

In both types of engines there are problems that have

to be faced and addressed before alcohols can be consid-

ered a practical fuel for general consumer usage. One of

these problems is the lubricant-related one which has been

ignored or tolerated in a period of high demand to non-

petroleum based fuels.

One problem that has been identified is the

possibility of water and/or alcohol dilution of the crank-

case oil and the resulting degradation of the lubricating

ability of the oil. This is particularly important when

low proof alcohol, which can be manufactured from farm

products, is used. Emulsion of alcohol and/or water with

the oil are thought to cause two types of problems:

1. Droplets of alcohol and/or water in the

emulsion may flash to vapor upon contact

with hot surfaces leaving insufficient oil

in the lubricated area. This problem will

be more severe in boundary lubrication.

2. Alcohol may decrease the effectiveness of

oil additives, by reacting with them, or

merely by changing their chemical environ-

ment.

Because of these anticipated problems, three engine

tests were carried out to identify any water and/or alco-

hol being inducted in the crankcase oil. Tests performed

are:

3

1. Total replacement of gasoline fuel by low-

proof ethanol in a spark-ignition engine.

The alcohol carburetion fueling was achieved

by only enlarging the carburetor jets.

2. Fumigation of low-proof ethanol in a turbo-

charged diesel engine. Up to 80% of diesel

fuel, on an energy basis, was replaced by

ethanol fuel without engine modification.

3. Fumigation of hydrous ethanol in a naturally

aspirated diesel engine. Up to 30% diesel

fuel was replaced with ethanol fuel.

I.1 Problem Statement

Water included in the low proof-ethanol has favorable

as well as unfavorable effects on both spark ignition

(S.I.) and compression ignition (C.I.) engines. In S.I.

engines, water addition would be advantageous since this

would result in an increase of the knock-resistance of the

fuel as well as reduction in some gaseous exhaust emis-

sion, particularly nitric oxides (NOX). Water slows down

the reaction speed in the combustion chamber of the otto

type engine and therefore affects the reduction of combus-

tion peak temperature and pressure. More recently, water

addition has been investigated as an aid to diesel combus-

tion. A reduction in combustion temperature was achieved

4

with a corresponding reduction in NOX emission, smoke and

BSFC.

On the other hand water included in the fuel whether

being carbureted or fumigated may remain in the liquid

phase before entering the combustion chamber, especially

if the manifold temperature is low. The higher latent

heat and higher boiling point of water should favor a

fractional distillation of the ethanol up to the azetrope

point in the intake manifold. Table 1 shows this compari-

son.

Table 1.1

Comparison of Latent Heat of Vaporization andBoiling Point Temperatures of Water and Ethanol

Water Ethanol

Latent heat of vaporization (Btu/Lbm) 1000 361

Boiling point 0F 212 172

Any liquid phase inducted into the engine has the

opportunity to find it's way into the crankcase. This

occurs principally through blowby gases during the compre-

ssion stroke when cylinder temperature and pressure are

minimum. Oil dilution by water or alcohol will be harmful

to engine operation and may result in engine damage.

5

The amount of water and alcohol collecting in the

crankcase oil and the extent of oil dilution and degrada-

tion are expected to be a function of five independent

parameters:

1. Alcohol proof.

2. Crankcase oil temperature.

3. Engine speed and load (torque).

4. Air-fuel ratio in S.I. engines and alcohol

percent substitution (by energy basis) in

C.I. engines.

5. Running time on a given batch load of crank-

case oil.

1.2 Objectives:

1. To form a data base which could specify and

determine a functional relationship between

the independent parameters that cause oil

dilution.

2. Make use of the experimental data to calcu-

late the evaporation rates of alcohol and

water prior to the intake manifold of both

S.I. and C.I. engines.

The above objectives, if clearly determined, would

enhance the ability to specify optimal operating condi-

tions and reasonable periods between oil changes using

hydrous ethanol. This would promote the use of low-proof

6

ethanol without causing unnecessary engine damage or wear

due to oil dilution. This should be particularly impor-

tant under low temperature conditions of operation as is

the case in farm operations during winter time.

7

CHAPTER II

LITERATURE BACKGROUND

II.1 Methanol Versus Ethanol

Historically, the automotive and transportation

sectors has formed a large segment of the U.S. petroleum

consumption. Their combined demands comprise about 53% of

all U.S. petroleum requirements and almost 25% of the

total energy needs. (1)

Until recently, petroleum derived fuels; primarily

gasoline and diesel, have been preferred because they are

available and less expensive than any other forms of

fuels. Several factors will force consideration of other

types of non-petroleum alternative fuels, some of these

factors are:

1. Oil reserves are declining world wide.

2. Demand for oil is increasing.

3. Prices of oil are increasing with an increas-

ing rate relative to other forms of derived

fuels.

4. Political considerations may disrupt the

availability of petroleum fuels for some

importing countries.

The use of any other form of fuel in the automotive

and transportation sectors is governed by certain

8

criterias and must meet the following requirements.

1. Availability and abundancy of the source.

2. Technically known methods of production.

3. Economically feasible cost of utilization of

production methods.

4. Possible adaptability to existing types of

engines with or without minor modifications.

The most promising alternatives to gasoline and

diesel fuels are: liquid hydrocarbons from tar and oil

shale; synthetic fuels from natural gas and coal;

alcohols, particularly ethanol and methanol. (2,3)

Alcohol may not necessarily represent the most re-

source efficient or cost-effective use of available fuel

feed stock; however it is generally recognized that these

fuels are among only a very few alternative energy sources

which resemble current used petroleum fuels and permits

usage with minimal modifications.

Ethanol is produced by one of two processes:

1. Fermentation of grains and other sugar or

starch feed stocks.

2. Synthesis from ethylene. (4)

The first method could be utilized by farmers and

produce self sufficient fuels. The second method is from

a petroleum distillate and is not considered here as a

viable alternative. Distillation of ethanol is possible

9

and a final proof between 100 and 190 is generally attain-

able and generally is a function of distillation efficien-

cy. Beyond that, additional processing to obtain 200

proof ethanol is possible and usually involves a benzene

bond braking mechanism, which generally is expensive and

may be unwarranted.

Methanol can be produced from coal, natural gas and

waste wood. Its production involves a catalytic reaction

of carbon monoxide and hydrogen.

Figure 2-1 represents typical methods of producing

ethanol and Figure 2-2 represents that of methanol. (5)

Due to the vast availability of coal and natural gas;

methanol can be produced in far more large quantities than

ethanol; though ethanol can be produced in less larger

plants and can be termed the farm fuel.

To better understand the differences between ethanol,

methanol, gasoline and diesel fuel, Table 2-1 was con-

structed. (6,7,8)

It can be seen from Table 2-1 that ethanol and metha-

nol, unlike gasoline or diesel fuels, are single chemical

compounds with sharply defined boiling points. Their

molecular structure includes an (OH) or hydroxy radical

which gives them certain characteristics. Some of the

effects of alcohol fuels properties can be summarized as

follows:

ENZYME/YEASTCULTIVATION

GRINDINGAND

COOKING

CARBON DIOXIDE

GRAIN

FERMENTATIONETHANOL PURI-FICATION AND

DRYING

BY-PRODUCTRECOVERY

AND DRYING

HIGHER ALCOHOLS

ANHYDROUSETHANOL

CATTLEFEED

Figure 2-1. Process schematic for ethanol productionfrom grain by fermentation

SHREDDED

OXYGEN

IRON GAS ACID GASWASTES REMOVAL GASIFIER SCRUBBING REMOVAL

SLAGY

WASTE WATERTO TREATMENT

SULFURRECOVERY

CO-SHIFTCONVERSION

CO2REMOVAL

METHANOLSYNTHESIS

METHANOLPURIFICATION

Y

METHANOL

Figure 2-2. Process schematic for methanol productionfrom municipal solid waste

12

Table 2-1

Properties of Ethanol, Methanol,Gasoline and #2 Diesel Fuels

Property Ethanol Methanol Gasoline #2 Diesel

Formula C2H5OH CH3OH Mixtures of HydrocarbonMolecular weight 46.07 32.04 -- --Composition weight %

Carbon 52.20 37.50 85-88 87

Hydrogen 13.10 12.60 12-15 12.6Oxygen 34.70 49.90 0 0

Specific gravity 60°F/60°F .794 .796 .72-.78 .86Density lb/gallon 6.61 6.63 5.8-6.5 6.7-7.0Boiling point °F 172 149 80-437 363-652Flash point °F 55 52 -45 118-220Autoignition temp °F 793 867 495 --

Flammability Limits

Vol. % Lower 4.3 6.7 1.4 .6

Higher 19 361 7.6 6.5HHV Btu/lbm 12,800 9,750 20,260 19,550LHV Btu/lbm 11,600 8,600 18,900 18,500LHV Btu/gallon 76,700 57,000 130,000 128,000% of Gasoline LHV 61 46 100 98

Latent heat of vaporiza-tion Btu/lbm 36 474 170 250A/F Ratio Stochiometric 9.01 6.45 14.6 14.6Octane No. Research 111 112 91-100 --

Motor 92 91 82-92 --Cetan No. <15 <15 <15 40-60Vapor press (psi) at 100°F 2.25 4.6 9-13 .04

Energy Btu/ft (StandardStochio) 94.7 94.5 95.4 --

Solubility in water infinite infinite insoluble insolubleToxicity irritant,

toxiconly inlargedoses

irritant,cumula-tive

toxicant

moderateirritant

moderateirritant

13

A. The high octane number of alcohols makes them

inherently adaptable as fuels for conventional spark-

ignition engines.

B. The low cetane number makes them less adaptable

to compression-ignition engines. This seemingly formid-

able problem can be solved by the method of partial sub-

stitution of the fuel, by fuel additives or by some engine

modification such as start assisted diesel.

C. The high latent heat of vaporization of alcohol

normally has a cooling effect which reduces the charge

temperature and thus usually improves engine volumetric

efficiency. But on the other hand it will not evaporate

as readily without the increased addition of heat, especi-

ally at low ambient temperatures.

D. Difference in vapor pressure, volatility and boil-

ing point range will have a general effect on startabi-

lity, warm-up and acceleration, as well as the occurrence

of vapor lock.

E. Alcohol fuels have far less heating values com-

pared to petroleum fuels. Tank capacity should be

increased to attain the same distance travelled. The air-

fuel ratio will generally have an effect on engine power

output.

F. Safety problems must be addressed. Ethanol is

not as dangerous as methanol, which is a cumulative toxin.

14

G. Table 2-2 was constructed to show possible poten-

tial problems with alcohol fuels. They are divided into

six major parts: distribution and handling, compatability

with materials, vehicle performance, environmental ef-

fects, toxicity and economic factors. It could be seen

that many of the problems could be solved by engine or

fuel modifications. (6)

It could be generally stated that the technical

problems with ethanol are similar to that of methanol.

Most of the properties of ethanol are intermediate between

petroleum fuels and methanol. Those differences as well

as experience indicate that potential problems with the

use of ethanol would be less severe than those encountered

with methanol.

The main problem addressed here was the lubricant

compatability when low-proof ethanol was used. The effect

of alcohol fueling on exhaust gas emission and any effect

on engine wear was also noted.

It should finally be noted that the use of alcohol as

a motor fuel is expected to be a two-fold benefit:

1. Could save up to 50% of petroleum-derived

fuels and hence will reduce dependency on

foreign oil imports.

2. Better combustion quality with better en-

vironmental consequences. Lower emission of

15

certain gases into the atmosphere is ex-

pected - NOX to mention one.

16Table 2-2

Possible Potential Problems with Alcohols(ethanol and methanol)

ProbableProblems Occurrence

1. Distribution and Handling

A. Phase separation DefiniteB. Incompatability with fuel PossibleC. Hygroscopicity DefiniteD. Volume change in blending ProbableE. Storage stability Possible

2. Compatibility with Materials

A. Metal corrosion DefiniteB. Non-metal compatability DefiniteC. Lubricant compatability PossibleD. Internal engine wear and rust PossibleE. Fuel pump wear PossibleF. Dirt lossening and filter pluggings Probable

3. Vehicle Performance

A. Cold startability DefiniteB. Warm up derivability DefiniteC. Vapor lock ProbableD. Preignition PossibleE. Low cetane quality Definite

4. Environmental Effects

A. Vapor recovery in distributionsystem Unlikely

B. Environmental effects on spills DefiniteC. Exhaust Emissions

- unburned alcohol Definite- Aldehyde Definite- odor Probable

5. Toxicity and Safety Precautions

A. Toxicity DefiniteB. Vapor explosivity DefiniteC. Fire Problem Possible

6. Economic Factors

A. Economics relative topetroleum fuels Definite

17

11.2 Alcohols in S.I. Engines

Consideration of the use of alcohol fuels as an

automotive fuel is almost as old as the internal combus-

tion engine. The use of ethanol and methanol either

blended with gasoline or by themselves in automotive

engines for transportation purposes appears attractive for

the following reasons:

1. Feasibility of operating current automotive

engines with a minimum of design modifica-

tions.

2. Possibility of attaining modest improvements

in engine performance and exhaust emission.

3. Capability of alcohol manufacture from renew-

able resources.

Due to the high octane number of ethanol and metha-

nol, they are best suited for S.I. engines. For these

fuels to be used in current S.I. engines, they should

provide:

Acceptable performance, regarding cold

starting, warming up, hot driving and gene-

ral acceptable accelerations.

Acceptable fuel consumption and power output,

with the least emission possible.

Stable fuel composition under all climatic

conditions.

18

Compatability with normal production vehi-

cles, concerning materials used and engine

lubricating oil.

Acceptable availability of the fuel as well

as an economical production method.

In the process of solving these technical as well as

economical problems with alcohol fuels, not only the com-

bustion of the fuel must be considered but the effect of

the fuel on the remainder of the vehicle must be examined.

One of these areas is the compatibility between the fuel

used and the lubricating oil. Evidence also indicates

possible incompatibility with conventional lubricant addi-

tives due to the polar nature of alcohol fuels. Alcohols

accumulating in the crankcase through blowby gases are

expected to react with many of the lubricant's additives

and this interferes with the inhibitors normally available

to control engine deposits and wear. During low tempera-

ture operation when using methanol, Owens (9) observed an

increase rate of wear on piston rings and cylinder bore

and an alarming rate of accumulation of both water and

methanol in the engine crankcase oil.

To use alcohol fuels in S.I. engine different methods

have been suggested and used:

1. Blending with gasoline

2. Emulsion with gasoline

19

3. Dual fueling

4. Using straight alcohols

All of these methods use the carburetor of the engine

for introducing the fuel.

Blending with Gasoline

Ethanol and gasoline are miscible in all proportions.

Blends are normally sensitive to water and have very low

tolerance, although the water tolerance increases with

higher percent of ethanol concentration. At best anhy-

drous ethanol-gasoline blends should be used. This

restriction prevents the use of low proof alcohols without

the addition of stabilizing additives.

The best known blend is gasohol (10% anhydrous

ethanol + 90% gasoline). Figures 2-3, 2-4, 2-5 and 2-6

from Scheller (10) indicate the following:

Blends show an increase in octane number

Positive volume change was encountered

The distillation curve indicates good start-

ing, no vapor locks and improved performance,

especially during winter time. This is due

to the more volatile nature of the blend

between 10-60% distilled, giving more efficient

carburetion and more complete vaporization

with better distribution in the intake mani-

fold.

6

4

2

O0 2 4 6 8 10 12

LIQUID VOLUME % ETHANOL

20

Figure 2-3. Effect of ethanol addition on the F-1 octanenumber of unleaded gasoline fuel

0 2 4 6 8 10 12 14

LIQUID VOLUME % ETHANOL16

Figure 2-4. Volume change of mixing for ethanol-gasolineblends

400

300

200

100

0 20 40 60LV% DISTILLED

100

21

Figure 2-5. Distillation curve for gasohol and unleadedgasoline

40 60TEMPERATURE C'F)

80

Figure 2-6. Effect of temperature on relative fuel economyof gasohol to unleaded gasoline

22

Better miles/Btu and higher efficiency.

No unusual wear or deterioration of the

engine as a result of using gasohol.

Less Co emission and about equal NOX and

unburned hydrocarbons.

Lawrence (11) found the following comparison to gaso-

line when measuring emission from gasohol fueled vehicles:

Increased evaporative emissions by 50%.

Decreased exhaust hydrocarbon by 9%

Increased NOX by 7%.

Decreased CO by 35%.

Decreased fuel economy.

Other blends with more than 10% alcohol have been

used. In particular, Brazilian vehicles are calibrated to

accept either gasoline or 20% ethanol blend with no

adjustment. Chui's (12) findings were comparable to

Scheller (10):

Better miles/Btu

Hydrocarbon and CO emissions were reduced.

NOX emissions increased.

Derivability deteriorated. Slight surging

and hesitation of the vehicle were observed

during hot operation due to leaner equiva-

lence ratio. Note for the above test, the

calibration of the carburetor is a compro-

mise between gasoline and (20% ethanol

23

80% gasoline blend). Operation with gaso-

line is too rich and with the blend is close

to derivability limits.

Operation with higher blends requires carburetor

modification and a recalibration if gasoline alone is to

be used.

Cassells (13) used 15% methanol /85% gasoline blends

in a fleet test with generally a stable blend and better

specific fuel consumption.

Emulsion with Gasoline

The Ontario Research Foundation (ORF) has developed a

mechanical emulsification device using the vortex princi-

ple or the hydro shear concept compatible with installa-

tion in the fuel line of both diesel and spark ignition

engines. The main objective is to solve problems with

cold weather operation and avoid phase separation in

winter time as is the case with unemulsified blends.

Emulsification of blends of up to 80% alcohol and 20%

gassoline by volume was attempted by ORF. No data is

available for gasoline/ alcohol emulsification.

This method is presented here because low-proof

alcohol could be used in the blend.

24

Dual Fuel Operation:

Starke (15) investigated the addition of a second

fuel container, a second fuel pump as well as metering

instruments on a V.W. Scirocco equipped with a two step

register carburetor. Since this carburetor consists of

two separate floats; gasoline could be charged through one

while methanol/water mixture could be charged through the

other. Starke (15) recorded the following:

It is possible by means of the register

carburetor that has been installed in the

test car, to supply the engine at any time

with a fuel-air mixture of sufficient anti-

knock properties.

This method of dual operation allows the

addition of water to the alcohol fuel and up

to 30% water-methanol has been used.

The addition of water has the benefit of in-

creasing the knock-resistance above and over

that of pure methanol as well as reducing

(NOX) emission by slowing down the reaction

speed in the combustion chamber and hence

reducing peak combustion temperature and

pressure.

The register carburetor permits gasoline and

25

methanol/water mixture to be used at differ-

ent proportions.

The method has an advantage over pure gaso-

line, pure alcohol as well as normal blends.

Using Straight Alcohols:

S.I. engines can burn straight alcohol if properly

designed and calibrated for the fuel. Anhydrous or

water/alcohol mixture can be used and as low as 160 proof

has been attempted. The metering system for S.I. engines

can only be calibrated for one specific mixture. Changes

in water/alcohol concentrations can not be tolerated.

Modifications required to utilize alcohol fuels in

S.I. engines with best fuel economy are:

(1) Carburetor recalibration to produce and

maintain the required air-fuel ratio.

(2) Ignition advance needs to be modified.

(3) Some materials in the fuel system may need

to be changed due to the possible reaction

between these materials and the alcohol

fuel.

(4) Intake manifold needs to be heated to retain

good cylinder to cylinder distribution and

better evaporation of the alcohol fuel.

(5) Starting aid devices may be needed, especi-

ally at low ambient temperatures.

26

(6) Advantage of high octane number can be

utilized by increasing the compression ratio

(C.R.) for better fuel economy.

(7) Larger fuel tanks may be needed due to the

low heating values of alcohol fuels.

Many researchers used alcohol fuels in S.I. engines

by modifying the carburetor alone. The general perfor-

mance of the vehicle may not be adequate unless most of

the above mentioned modifications were used.

Of major interest is the lubricant related problem

when using straight alcohols. Owens (9) reported an in-

creased wear on piston rings and lower areas of bearings

and the entire engine was coated with a stable yellowish

foam when using neat methanol fuel. The test was con-

ducted using simulated (ASTM) sequence II-C on a Coordi-

nated Lubricant Research (CLR) single cylinder engine.

This test is normally used to evaluate the rusting and

corrosion tendencies of motor oils in a test cycle de-

signed to relate to short-trip services under typical

midwestern states winter conditions. As can be seen in

Figure 2-7, an alarming rate of accumulation of both

unburned methanol and water in the engine oil were report-

ed by Owens (9).

Many other researchers investigated the use of

straight alcohol in S.I. engines.

30

25

20

15

10

40 Methanol concentration

m Water concentration methanol fuel

X Water concentration unleaded gasoline fuel

10 20 30 40 50 60

Engine Running Hours

Figure 2-7. Water and methanol accumulation in thecrankcase oil of CLR engine

28

Chui (12) enlarged the metering jets in the carbure-

tor to provide a comparable equivalence ratio, with the

following conclusions:

Cold staring is not possible on neat ethanol

at ambient temperatures below 5°C.

Adding 10% gasoline to ethanol fuel extended

cold startability down to 0 °C and improved

cold derivability.

NOX emission decreased.

Co emission remained the same.

Power and thermal efficiency increased.

The lean operation limit with alcohol fuel is

limited by the depressed intake temperature,

the low vapor/liquid ratio and the poor air-

fuel distribution.

Brinkman (16) changed the compression ratio (C.R.)

from 7.5 to 18 gradually and optimized the spark-timing

accordingly while providing heating of the incoming charge

in a single cylinder engine with the following observa-

tions:

Increasing the compression ratio and operat-

ing leaner with ethanol provides additional

thermal efficiency gains.

Generally, aldehydes and unburned HC tend to

increase.

NOX showed mixed variations

29

Co emission depends mainly upon the equiva-

lence ratio for that particular test.

Marabach (17) found that neat methanol greatly in-

creases engine wear rates while anhydrous ethanol and

alcohol gasoline blends do not increase wear rates over

that of unleaded gasoline. Engine wear rate was found to

be inversely related to engine oil temperature when using

methanol as a fuel. Adding water to ethanol increases

wear rate and causes oil lubricant dilution. (38)

Chui (18) believed engine wear in an alcohol fueled

engine stems from the following sources:

1. Alcohol and/or water emulsion with engine

oil may restrict boundary lubrication.

2. Alcohol and water droplets in the emulsion

may flash when contacting hot surfaces,

leaving insufficient amount of oil for lub-

rication.

3. Alcohol and its combustion products may

attack engine parts directly.

4. Abrasive metals already formed tend to in-

tensify wear.

Marbach (17), Chui (18 and 19) investigated different

oil additives with some ASTM tests modifications to con-

trol wear rates when using alcohol fuels.

Chaibongsai (20) defined two fully formulated oils

30

for use in a methanol fueled car and developed a screen-

ing test method for rapid evaluation of engine oil perfor-

mance and additive response to overcome the bore and ring

wear problems using a modified ASTM V-D test.

Generally the use of pure alcohol is favored as a

total replacement to petroleum-derived fuels. use of low-

proof alcohol can be facilitated if straight alcohol is

used. Water addition to alcohol generally changes their

physical and chemical properties, which affect carburetor

metering, evaporation in the intake manifold and combus-

tion energy. General properties of dilute ethanol are

listed in Table 2-3. Carburetor metering jets must be

enlarged. Theoretical calculations must be modified by a

flow coefficient which should be determined experimental-

ly. (37)

Straight low-proof ethanol was used in our S.I. en-

gine test. Carburetor calibration was the only engine

modification for that particular test.

11.3 Alcohols in C.I. Engines

Alcohols, whether being anhydrous or wet, are poor

diesel fuel. This is mainly due to the low cetane number

of the fuel which indicates a poor autoignition quality

and long ignition delay. Normally a minimum cetane number

of 40 is required by the ASTM test, while methanol and

ethanol have a cetane number of less than 15. (7, 21)

Table 2-3

Properties of Dilute Ethanol Fuel

i

Proof

AlcoholContent byVolume %

EthanolContent byWeight %

SpecificGravityat 60°F

Specific W9t.at 60°Flbs/gal

Lower HeatingValue Btu/lbm

of Fluid

Latent Heat ofVaporization

Btu/lbm

A/F Ratiolbm Air/lbm

Liquid

Intake Mani-fold Energy

Ratio

Calculated JetDia. Ratio:Ethanol & Water

Esperimen-tal Jet

Dia. RatioDia. Gasoline200 100 100.0 0.7939 6.54 11604 396 9.01 4.68 1.27 1.27190 95 92.3 0.8161 6.81 10710 440 8.32 5.63 1.31 --180 90 85.6 0.8339 6.95 9933 479 7.71 6.61 1.35 1.44160 80 73.4 0.8639 7.20 8517 549 6.61 8.84 1.45 1.75130 65 57.0 0.9021 7.52 6614 643 5.14 13.31 1.61 --100 50 42.4 0.9344 7.79 4920 727 3.82 20.25 1.87 --Purewater 0 0 1.0 8.34 0 970 -- -- -- --

32

The main difficulty with alcohol fuels is the initia-

tion of the flame. Other alcohol fuel problems in C.I.

engines is their poor lubricating ability in contrast to

diesel fuels. This is important when alcohol fuels are

injected through injectors in the combustion chamber as

this may normally cause injector tip wear. Due to the

high enthalpy of vaporization of alcohol fuels; a signifi-

cant cooling effect of the intake charge occurs. This

normally causes excessive ignition delay, quench or cold

starting problems. (33)

An important factor is the possible phase separation

if mixtures of ethanol and diesel fuel are used, particu-

larly if a small amount of water is present. The wider

flammibility range of alcohol fuels make them more hazar-

dous than normal diesel fuels.

To overcome some of these problems, different ap-

proaches of utilizing alcohol fuels in diesel engines have

been used. These methods can be divided into five classi-

fications.

I. Fuel modifications

2. Solutions

3. Emulsions

4. Engine modifications

a. spark-assisted diesel

b. surface ignition

c. twin injectors

33

5. Fumigation.

The percent of diesel fuel substitution when using

alcohol fuels as well as the power output, efficiency,

exhaust emission, phase separation, engine wear and lubri-

cants degradation were the focus of many investigators.

The effect of many parameters such as ignition delay,

compression ratio, injection timing and rate have also

been reported. Previous puplications when using alcohol

fuels in diesel engines are listed below, according to the

method of utilizing the alcohol fuel.

Fuel modifications

The only possible way to use alcohol fuels in C.I.

engines as a total replacement to diesel fuel without

engine modification is by using fuel additives. These

fuel additives should fulfill two objectives:

A. Improve the cetane quality of the fuel.

B. Enhance the lubricating ability of the fuel.

Ema (7) has shown that 1% of castor oil in the alco-

hol fuel is adequate for lubrication. Castor oil is

produced commercially in Brazil, though it is considered

to be toxic. About 20% of cetanox or 15% of hexyl nitrate

or Amyl nitrate is needed as a cetane improver. (7, 22)

The main drawback to this method is the expense of

the cetane improvers. Its advantage is that total substi-

tution of the diesel fuel by alcohols is possible and

34

considered the best of the alternatives, if it is economi-

cally viable.

Solutions

In S.I. engines gasohol, which is a solution of

unleaded gasoline and ethanol, is used. Similar mixtures

of diesel fuel and alcohol are not a viable alternative.

Methanol is completely insoluble in diesel fuels. Anhy-

drous ethanol is soluble in diesel fuels, but it's water

tolerance is extremely low and the mixture is generally

very unstable. Small amounts of water in the ethanol or

diesel fuel, or entering the tank through normal breathing

could cause phase separation.

Moses (23) used 50% by volume of anhydrous ethanol

and 50% of diesel fuel. The efficiency was found to be

almost the same as that of diesel fuel alone with virtual

elimination of smoke and particulates.

Hashimoto (24) employed up to 20% ethanol with no

appreciable oil degradation as a result. NOX emission, CO

emission and smoke were observed to decrease appreciably

for both pre-chamber and open chamber type diesel engines.

To date this method is not practical. Some expensive

stabilizing additives may be needed to make it otherwise.

Advantages of the method are that virtually no engine mod-

ification or extra tank is needed.

35

Emulsions

Emulsion as regarded here is the dispersion of small

droplets of alcohols into the diesel fuel. This emulsifi-

cation can be achieved either chemically by adding chemi-

cal stabilizers known as surfactants or mechanically by

using an emulsifier. Chemical stabilizers are expensive

and about 10% or more by volume is needed in the fuel.

(25)

Mechanical emulsification (with high turbulence mix-

ing devices) is normally unstable unless installed in line

with the injectors. The system is complicated by the fact

that a large portion of the fuel must be recirculated,

thus a separate pump and fuel cooler must be provided

along with the emulsifier. Up to 30% substitution of the

diesel fuel was possible and the method was best suited

for steady state, full load conditions. (14, 26).

Likos (27), using an emulsified fuel in a naturally

aspirated diesel engine concluded that using in-line emul-

sion systems are not recommended for utilizing low-proof

ethanol in a direct-injection (D.I.) diesel engine. Dam-

age was done to the injectors and injection pump and due

to the high makeup oil addition it can not be concluded if

the oil was degraded. Lawson (14) found that up to 20%

emulsion are possibly operable. The emulsion increases

water tolerance and can be formed stable or unstable.

Ecklund (21), Khan (28) noted that the chemical and

36

physical properties of the emulsion will affect fuel in-

jection quantity, spray pattern, penetration and the gen-

eral injection dynamics.

Engine modifications

Since alcohol burns readily when an ignition source

is supplied, several diesel engine concepts have been

reported.

Spark-Assisted. Foster (26) and Adelman (29) re-

ported the work of several authors. Investigators gener-

ally showed this method to be a technically feasible

method. Problems encountered using the spark-assisted

diesel engine are:

For the same diesel engine compression ratio,

high ignition voltage is required. It is

found difficult to achieve a satisfactory

level of reliability without the need of more

frequent services.

Lowering the compression ratio would result

in an increase in engine fuel consumption.

Placement of the spark plug in the engine is

a problem. If the injector is removed and

the spark plug is installed, a carburetor has

to be used. If the injector is left, the

spark location which gives the best

performance has to be found. In the latter

37

case some provision for lubrication must be

found.

Unlike the diesel engine, the multi-fuel cap-

ability is no longer available due to the

volatility requirements of the fuel as an

ignitable mixture.

The main advantage of this method is that pure alco-

hol could be used.

Surface Ignition. The main idea behind using the

surface ignition method is to initiate the flame by in-

jecting alcohol so that it impinges on a hot surface which

would result in ignition. This method is still experi-

mental and is done on a single cylinder engine. The hot

surface has to be heated externally to a temperature of

1000oC.

Nagalingam (30) reported that some engine modifica-

tion, combustion chamber configuration and a suitable

choice of material including the hot surface would need to

be chosen.

Results indicate that it could be a feasible, multi

fuel, alternative type of engine for alcohols as well as

gasoline and diesel fuels.

Twin Injectors. This is the idea for pilot in-

jection. The pilot, which is the diesel fuel, is injected

through one of the injectors while the alcohol fuel is

injected through the other injector. An engine with a

38

special head with two injectors is required. Pischinger

(31) and Holmer (32) built twin-injector engines and they

concluded the following:

Large substitution of the diesel fuel is

possible while obtaining reliable ignition

and knock-free combustion. The amount of

diesel fuel pilot needed is roughly that at

idle.

Efficiency is better or equivalent to that of

diesel fuel. alone.

Lower peak pressures and maximum rates of

pressure rise are achieved.

Very low smoke and the soot limit is non-

existent.

NOX emission is decreased appreciably.

He and Co emissions are the same or lower.

Thermal and mechanical stresses are reduced.

Compression ratio can be varied over a wide

range, from 14.5 to 19.3.

The main disadvantage of this method is its expense.

To utilize this method in existing types of engines, a

major modification to the engine must be done.

Fumigation

This is a process where part of the fuel is supplied

by alcohol through the engine air intake. The remaining

39

diesel fuel is delivered normally by a high pressure

injection system into the engine cylinder.

The alcohol injected in the intake air passage vapor-

izes and forms a combustible alcohol/air mixture. The

idea is to provide a lean alcohol fuel mixture which would

be ignited by the flame from the diesel fuel. In essence

this method of operating the engine is a combination of

premixed alcohol charge burning and diesel diffusive com-

bustion.

Normally a separate alcohol fuel system, including

fuel tank and delivery components, is required. Perfor-

mance of the alcohol injection system is very important.

Variables such as alcohol atomization, droplet size varia-

tion, fuel vaporization, intake manifold temperature de-

pression, alcohol-air mixture uniformity, engine volumet-

ric efficiency and cylinder to cylinder uniform distri-

bution is very important.

Due to the vaporization of the alcohol fuel and the

consequent temperature drop, a generally excessive igni-

tion delay and rapid rate of pressure rise were noted at

high alcohol fuel flow rates. (33)

Many systems for alcohol fumigation have been inves-

tigated. The two most commonly used are:

A. Alcohol carburetion

B. Air-assisted nozzles fumigation.

40

A. Alcohol Carburetion

Hardenberg (33) using a carburetor in a diesel

engine reported the following:

Advancing diesel injection timing to compen-

sate for the long ignition delay results in a

rapid pressure rise and in combustion noise.

Increasing the compression ratio was limited

by metallurgical cylinder pressures and

temperatures.

The engine tends to misfire for the optimized

diesel injection timing. Single injection

timing has not been satisfactory for the

entire load.

Ignition improvers showed moderate success in

shortening delay period.

Thermal efficiency for the diesel fuel engine

was slightly better at high load condition.

At part load, efficiency decreased signifi-

cantly. This was mainly due to quenching or

ignition delay effects and incomplete combus-

tion.

NOX emission was lower due to lower cycle

temperatures.

HC emission increased with the increase of

alcohol fuel flow rate.

CO emission was not significantly affected by

41

alcohol substitution of diesel fuel as long

as the fuel/air ratio was not too rich.

Smoke generally decreased.

At high load and low speeds, alcohol substi-

tution was limited due to rapid combustion

introducing knock. At high load and high

speed the alcohol fuel flow rate was limited

by flame quenching.

Generally the effect of excessive cooling and

ignition delay limit the substitution to less

than 35%.

B. Air-Assisted Nozzles

Likos (27 and 34), conducted an extensive research

with both methanol and ethanol fuels in both turbocharged

as well as naturally aspirated diesel engines. Dry metha-

nol and 160 proof ethanol tests were conducted for three

different engines. The duration of each test was about

500 hours of operation. The spray nozzles were located at

an elbow in the intake manifold and oriented to spray

counter to the air flow. This location has been found to

produce good distribution of the alcohol among cylinders.

The flow rate of alcohol fuel was held at 25% by volume of

the total fuel flows, although 50% and 75% ratios have

been conducted prior to starting the test. For all the

tests the engine was started and warmed up with diesel

42

fuel alone and the manufacturer's maximum engine rating

was never exceeded. The following were some of the con-

clusions reached.

Fumigation of dry methanol or 160-proof

ethanol can be utilized in a turbo-charged or

naturally aspirated direct or pre-chamber

diesel engine without incurring serious wear,

performance, emission or durability penal-

ties.

All of the engines did not show any lubricat-

ing oil degradation.

NOX emission decreased while both HC and Co

emissions increased.

Good alcohol fuel distribution among cy-

linders can be achieved by using systems such

as air assisted atomizing nozzles.

Chen (35) noted improved thermal efficiency at high

load and a reduction at low loads. Change of the proof of

ethanol from 200 to 160 produced no noticeable change in

engine performance. Ingition delay and rate of pressure

rise were observed to increase as well as HC and Co emis-

sions.

Heisey (4) has investigated alcohol as low as 140 -

proof with up to 50% of energy substitution by low proof

ethanol and concluded that increasing water percent in the

fuel, reduce NOX emission and lengthen the ignition delay.

43

Table 2-4, taken from Holmer (36), shows the relative

merits and shortcomings of the various methods listed.

Although the twin-injectors method appears to be attrac-

tive, it should be noted that this method is expensive and

is not readily adaptable to existing types of engines

without major modifications.

From those different methods outlined, it could be

seen that the air-assisted nozzles fumigation method ap-

pears to be the most attractive. This method could uti-

lize low proof alcohol with no fuel additives and almost

no engine modification. The alcohol fuel system is prac-

tical and generally less expensive than any other method.

Table 2-4

Evaluation of Different Methods to Converta Diesel Engine for Alternative Fuels

DifferentMethods

Alternative Fuels ReplacedDieselFuel

Effici-ency

FuelExpense

Easy toConvert

Relia-bility

Dura-bility

Methanol Ethanol

Cetane numberincreasingadditive

1 2 3 3 1 3 3 1

Emulsion die-sel alterna-Live fuel

2 2 1 3 2 2 1 2

2

1

CarburetorAll fuel,.spark

Part of fueldiesel

2 2 3 1 2 1 2

1 1 1 3 2 2 2

Sp6rkigniteddiesel

2 2 3 3 2 1 1

Two separateinjectionsystems

3 3 2 3 2 2 2 1-3

1. III s to Inc in proved.2. Acceptable.3. Excellent.

45

CHAPTER III

HYDROUS ETHANOL CARBURETIONIN A SPARK IGNITION ENGINE

III.1 Introduction

Low-proof ethanol was carbureted in a 1974 Ford, 2.3

liter, 4 cylinder, gasoline engine. Tests were conducted

to evaluate any excessive oil dilution caused by water or

alcohol or both. The carburetor was calibrated for each

alcohol proof and load. Air-fuel ratio carburetion was

adjusted to yield a maximum of 1.0% carbon monoxide in the

exhaust. Material, data and results of this chapter are

reported from Mingle and Boubel. (38)

111.2 Engine and its Calibration

A 1974 Ford, 2.3 liter, 4 cylinder, overhead cam

engine with no emission control hardware was used. Ap-

proximately 200 hours of operation were conducted on this

engine prior to this test. For each alcohol proof and

load, a different carburetor calibration was required.

Table 3-1 shows the engine specification and carburetor

calibration. Note for 130 proof, the largest size jet

possible was 0.144 inches and that the air bleed orifices

for both primary and secondary were restricted. Note,

46

also, that the secondary system was required to obtain 75%

load for 130-proof alcohol.

Figure 3-1 shows the spark advance characteristics of

the distributor, determined on a Sun Distributor Testor.

Figures 3-2 and 3-3 show the performance of the engine on

gasoline as determined by actual testing.

111.3 Instrumentation

Engine speed and load were regulated by an Eaton

Dynamatic Dynamometer, Model 1014 WIG. Fuel flow rate was

determined by timing the flow of 100 grams of fuel using a

pan balance.

The air flow rate was determined by connecting an

ASME flow nozzle system to a small plenum which replaced

the air cleaner at the entrance to the carburetor.

Temperature measurements were made using chromel-

alumel, type K, thermocouples connected to an Esterline-

Angus, Model PD 2064, Data Acquisition and Recording Unit.

Oil temperatures in and out of the oil cooler, exhaust gas

temperatures at the outlet of the manifold, water tempera-

tures at the outlet of the manifold, and water tempera-

tures in and out of the intake manifold required shielded

couples. Ambient air temperature, intake manifold metal

temperature, and the mixture temperature in the front

manifold leg required only small arced beads.

47

The exhaust gas analysis was determined using Beckman

IR-15A nondispersive infrared analyzers for carbon mon-

oxide (CO) and carbon dioxide (CO2). Oxygen (02) analysis

was made using a Scott, Model 150, paramagnetic oxygen

analyzer.

111.4 Fuel Preparation

The ethyl alcohol used for the test was purchased

from Van Waters & Rogers Company, listed under their trade

name of VANZOL 190 A-1 (SD-3A). This product began as

190-proof ethyl alcohol and was denatured as shown in

Table 3-2. When adding water to reduce the nominal proof

to 180, 160 and 130, respectively, the effect of the

denaturing fluids upon specific gravity was ignored. Each

batch of fuel, blended in individual 55-gallon drums, was

adjusted to certain specific gravity value set forth by

the U.S. Bureau of Standards for pure ethyl alcohol and

water. These specific gravity values as a function of

temperature are shown in Figure 3-4 and were plotted from

data tables in Handbook of Physics and Chemistry, 42nd

edition, Chemical Rubber Publishing Company. Table 3-2

shows the quantities of water and denatured alcohol blend-

ed to obtain the desired specific gravity values, and the

error involved in ignoring the denaturing fluids. The

error appears to be 2 weight percent alcohol for 180 proof

and reduces to 0.9 weight-percent for 130 proof.

48

111.5 Test Parameters and Scheduled Runs

24-tests were scheduled with the following indepen-

dent variables:

1. Proof of alcohol. 130, 160 and 180 proof

ethanol was used.

2. Air fuel ratio was adjusted to yield a maxi-

mum of 1.0% carbon monoxide in the exhaust.

Two additional tests were made to explore

the gross effect of air-fuel ratio.

3. Crankcase oil temperature: 130°F and 180°F

4. Intake manifold temperature: 130oF and

180 °F.

These temperatures were chosen to pro-

vide one temperature above and one tempera-

ture below the ethanol-water azeotrope

point.

5. Engine speed and load (torque). Engine load

was 35% and 75% of rated load at 2500 rpm.

The load was selected mainly on the basis of

carburetor performance. At 35% load, the

primary main jet was fully functioning, and

the idle jet was also functioning to the

extent that precise air-fuel ratio control

was possible. At 75% load, the primary

49

throttle plate was nearly wide open and the

secondary throttle plate was closed.

6. Running Time - Six hours maximum. However,

tests were stopped at any time that water

sufficient to discolor the oil was evident.

Table 3-3 shows the test scheduled runs.

111.6 Test Procedure

Prior to the beginning of each test, the crankcase

oil and engine oil filter were replaced with new products.

Eight quarts of Havoline 10W-40 super premium (SE or SF)

was used, distributed as follows: 4-quarts in engine pan,

one quart in filter, and three quarts in oil cooler. Oil

was continuously circulated from the pan through the tube

side of the cooler at a constant rate of 4 gpm. Water was

circulated with manual control through the shell side of

the cooler at the rate necessary to achieve the proper

degree of cooling for the target temperature.

To achieve intake manifold water temperature control,

the cooling water passage between manifold and engine

block was sealed with a blank-off plate. Hot water leav-

ing the head was piped to the rear side (adjacent to the

block) of the manifold water passage. Water from the

front side of the passage was piped to the suction side of

the engine water pump. Cold water with manual control was

50

mixed with the hot water (from the head) to produce the

desired temperatures.

The engine was started and allowed to warm up at 2500

rpm to the selected load and test conditions for ten

minutes. Then, the first data readings were observed and

recorded. For an additional six hours; data were observed

and recorded each hour until the end of the sixth hour,

after which the engine load was reduced to a minimum for 5

minutes for a cooling-off period before stopping.

For a test where a large quantity of water was anti-

cipated to accumulate in the crankcase oil, the engine was

started as above, but was stopped briefly after one hour

to observe the color of the crankcase oil and also the

level of the oil dipstick. If there was an increase in

the level of one quart or more and the color was creamy,

the test was stopped. Otherwise, the test was continued

for another hour.

Immediately after the conclusion of the test, one

gallon of oil or mixtures were pumped from the system into

a glass jar for observation and laboratory testing. The

remainder of the crankcase oil was pumped from the system

and discarded.

111.7 Oil Analysis

The following ASTM standard test were conducted:

1. ASTM D-88, viscosity in Saybolt Universal

51

seconds (SUS) at 100°F, 140, 180 and 210°F.

2. ASTM D-96, water determination using a cen-

trifuge.

3. ASTM D -95, water determination by distilla-

tion.

4. ASTM D-92, flash and fire point determina-

tion.

5. ASTM D-287, gravity by hydrometer.

6. Another test to obtain the kinematic visco-

sity of the samples at 72°F using a Brook-

field Viscosimeter was conducted. Although

this test is not a standard ASTM method, it

was found to yield very indicative results.

111.8 Ethanol and Water Vaporization

A computer program (Appendix 1) was developed to

calculate the expected vaporization rates of alcohol and

water prior to entering the intake manifold. Figure 3-13

shows the inlet and outlet states. Assumptions are:

1. Steady flow process

2. Control volume is adiabatic

3. Effect of air velocity, swirl droplet size

or spray formation is not considered

4. Ideal solutions

5. No chemical reactions

52

6. Although the time and distance involved does

not allow for thermodynamic equilibrium to

hold, nevertheless, local thermodynamic

equilibrium was assumed.

The amount of energy needed to heat and vaporize a

liquid mixture from T2to T

3can be calculated given a

knowledge of the enthalpies of vaporization of the pure

components, the heat capacities of the pure components in

vapor and liquid states, and the enthalpies of mixing of

vapor and liquid phases. If a liquid mixture containing

mole fraction 'Yi is heated and vaporized completely be-

tween T2

and T3, then

T3

= :Y.(CP3/P)Required .C1171

T2

+ LHm,v (I; ,P) - LHM,L

(772,2)

Due to the small variations of the enthalpies of

mixing in the liquid and vapor states, the mixing enthal-

pies terms were assumed to cancel each other. The speci-

fic heats were assumed constant for the temperature range

used. The energy from the moist air was utilized to heat

and vaporize the low proof alcohol.

53

Conservation of Mass:

. .

RWV(1) RWL(2) RW3 RWV(3) RWL(3)

REL(2) RE(3) REV(3) REL(3)

RAIR(1) = R

AIR(3)

Energy Balances:

Energy given by the dry air

QAIR = R

AIR(1) CpAIR (T1

Energy given by the water vapor in the air

(2a)

awv(i) = Rwv(i)EAHwv(i) + Cpw (T1 - T3) (2b)

This total energy was given to heat both water and

ethanol to temperature T3 and vaporizes part of them at

T3. Condition 3 was normally a two phase region.

Note that temperature (T2) is the temperature of the

low-proof alcohol and is normally taken as the room

temperature. Temperature (T3) is the intake manifold

temperature. Temperature (T1) is the air temperature and

for the turbocharged engine case, it is the temperature

after the turbocharger.

Q AIR QWV (1) = RE(3)E[CPEL (Tx T2) XE (41/E(3)

CPEV (Tx T2)) 4. (1-XE) CPEL (Tx T3)]3

+ Rw(3)E[Cpwr., (Tx - T2) +X (dB_

-w(3)

+ Cpwv (Tx - T3)) + (1 - Xw) Cpwl, (Tx - T3)i]

54

Tx is the boiling point of ethanol at the intake

manifold pressure. Since no superheating is expected

under those temperature operation, T3 is assumed to be the

boiling point of ethanol. The above equation will reduce

to the following.

. . .

= _ Cp (T - T (TQAIR + QWV(1) RE(3) E 3 2) + Rw Cp

(3) W (T3 - T2).

+ xEE(3)46'HE(3) w w(3) '6`1.1W(3)

+ X_ R_ (2c)

The computer program will first assume 100% of etha-

nol (anhydrous) vaporized and calculate the corresponding

amount of water vaporized, from equation (2c). Then, less

than 100% ethanol vaporization was assumed with a corre-

sponding water vaporized calculation from equation (2c).

Figure 3-14, 3-15 and 3-16 show the plots of the amount of

alcohol vaporized versus that of water vaporized. Com-

plete vaporization of water and ethanol is important in

the distribution of the alcohol fuel from cylinder to

cylinder as well as for the overall performance of the

engine.

111.9 Results

It should be noted that sometimes the desired oil

temperature and manifold temperature were not maintained

exactly at the desired values. However those variations

should not alter the validity of the tests.

55

The 35% load test with 130 and 160 proof fuel at

180oF oil and 180oF manifold temperatures were deleted

because it was apparent that no oil dilution would occur.

These correspond to tests number 8 and 16. Tests number

1, 2, 3 and 4 were stopped by the second hour of testing

due to the formation of a milky water-oil emulsion and

the accumulation of more than one quart of water in the

oil as observed on the dipstick. These were the only

tests that had an appreciable water accumulation.

The correlation between the kinematic viscosity at

room temperature using the Brookfield Viscometer and the

water accumulation measured by either the centrifuge or

distillation methods was found to be good. This indicates

that the Brookfield kinematic viscosity test is a quick

and a fairly accurate test.

The thermal efficiency tends to increase at high load

with the 160 and 180 ethanol proof; however for the 130

proof a reduction of efficiency is evident as shown in

Figure 3-5.

The Brake Specific Fuel Consumption (BSFC), Figure 3-

6, tends to increase especially for the case of 130-proof

at 35% load. This general increase is due to increased

mass flow rates of ethanol fuel to produce a comparable

energy input as that of gasoline because of the different

heating values.

56

Figure 3-7 shows the carbon monoxide (Co) emission

behavior. Alcohol fuels tend to decrease (Co) emission

considerably. Lower (Co) emission at 130 proof and 35%

load was probably due to a leaner equivalence ratio.

Figure 3-9 shows the water accumulation in the crank-

case oil. For the 130 proof ethanol and 75% load, the

accumulation was especially high; particularly for the

case of low oil temperature and/or manifold temperature.

Similar trends can be seen in Figure 3-10 for the kine-

matic viscosity, where the viscosity tends to increase in

proportion with water accumulation.

Note that no measurable water accumulated for the 160

and 180 proof ethanol cases.

Figure 3-11 and Figure 3-12 for the flash and fire

point did not predict any appreciable change, since the

variation is within the repeatability of the method. The

flash point was never below 395°F, indicating absence of

ethanol fuel in the oil.

Figures 3-14, 3-15 and 3-16 show the vaporization

rates of alcohol and water prior to the intake manifold

generated by the computer program. General conclusion can

be summarized as follows:

The vaporization rates were generally very

low. The low intake air temperatures and

the somewhat low air flow rates did not help

the vaporization process.

57

The vaporization rates decreased with a re-

duction in the alcohol proof.

For the same alcohol proof, the vaporization

decreased with increased load.

The lowest vaporization rates were for the

130-proof and 75% load tests. These are the

cases where excessive oil dilution was de-

tected.

The maximum amount of water in the fuel

occurs with the 130-proof and 75% load

cases. Low vaporization rates indicate

significant amount of water was inducted in

the liquid phase. For the above mentioned

cases only about 40% of the anhydrous

ethanol vaporized, while almost all the

water was inducted in the intake manifold as

liquid. This indicates that the above tests

are the most likely to cause oil dilution,

which was found to be the case.

For the 160 and 180-proof alchol cases;

although the vaporization rates are general-

ly low; yet the water in the fuel is lower

than the 130-proof alcohol cases.

The crankcase oil dilution tends to occur

when very low vaporization rates are coupled

58

with high amount of water in the fuel as is

the case for the 130-proof and 75% load

tests.

111.10 Conclusions

High water flow rates in the fuel and low vaporiza-

tion rates were found to be the major factors that causes

oil dilution. At an alcohol proof of 130 or less more

than 20% of water by volume could accumulate in the crank-

case of a spark ignition engine in less than two hours.

Although a study of water-oil emulsion effect on engine

wear, performance or durability was not carried out, it is

generally believed that more than 1% of water in the

crankcase oil will be harmful to the engine. An accumula-

tion of 20% by volume will definitely have an adverse

effect on engine operation over a long period and will

surely damage the engine.

Table 3-1

Engine SpecificationsCarburetor Calibration

ENGINE: 1974 Ford,

CARBURETOR: Holley 5200

and

2.-3 liter, 4 cylinder OIIC

Model D 42EP-GA

MEASURED DIAMETER, INCHESGASOLINE 180 Pr. 160 Pr. 130 Pr.

FUEL LOAD ALL 35% 75% 35% 75% 35% 75%

Pri. Idle Jet (1) 0.7 .056 .056 .063 .063 .086 .086

Pri. Idle Air Bleed 1.80 MM (.071) .071 .071 .071 .071 .071 .071Pri. Idle Jet 1.32 MM (.052) .082 .093 .104 .120 .136 .144Pri. Main Air Bleed 1.70 MM (.067) .067 .067 .067 .067 .067 .063

Sec. Idle Jet 0.5 MM (.020) .081Sec. Idle Air Bleed 0.7 MM (.029 NOT NOT NOT NOT NOT .029Sec. Main Jet 1.40 MM (.055) OPEN OPEN OPEN OPEN OPEN .144Sec. Main Air Bleed 1.95 MM (.076) .071

DISTRIBUTORIGNITION TIMING:OIL COOLER

NOTE: (1) For 35%desired

(2)

D4ZE 12127 KA 4E286° BTC (Idle No Vacuum)Ross, "BCF" Cooler, Shell and Tube, Oil on Tube Side,Capacity 3 Quarts.

load, the tapered, idle adjusting needle was used to achieveCO concentration in exhaust gas.

Largest size possible without exposing thread roots

Compression Pressures @ Cranking rpm

Cyl. No. Pressure, psig

1

2

3

4

148150144146

(2)

Table 3-2

Formula for Preparing Nominal ProofSolutions from 190-Proof

Denatured Ethanol

NOMINAL PROOF

Water added, lbm

190 Proof DenaturedEthanol, lbm

60

180 160 130

33.5 86.7 156.5

322.0 301.8 242.0

Total Weight, lbm 355.5

Total Water in Mik, lbm 48.3

Total Alcohol, lbm 297.2

Wt. % Water 16.4(14.4) (3)

Wt. % Alcohol 83.6(85.6)

Sp. Gr. @ 77°F (2)0.827

338.5

110.0

278.5

28.3(26.6) (3)

71.7(73.4)

0.855

398.5

175.1

223.4

43.9(43.0) (3)

56.1(57.0)

0.892

NOTE: (1) Purchased from Van Waters & Rogers as VANZOL 190 A-1(SD-3A)

SD-3A Base100 gal. ethyl alcohol, 190 proof

5 gal. methanol

VANZOL 190100 gal. SD-3A10 gal. isopropyl alcohol1 gal. methyl isobutyl ketone

(2) VANZOL 190 A-1 (SD-3A), Sp. Gr. @ 77°F = 0.804

(3) Numbers in parentheses refer to the percentagesif no denaturant were present

61

Table 3-3

Test Schedule Runs

RunNo. Alcohol Proof

Engine Load %of Rated

Oil Temp°F

Manifold Temp°F

130 1301 130 75 (39.7 BHP)2 130 75 130 1803 130 75 180 1304 130 75 180 180

5 130 35 (18.6 BHP) 130 1306 130 35 130 1807 130 35 180 1308 130 35 180 1809 160 75 130 130

10 160 75 130 18011 160 75 180 13-012 160 75 180 180

13 160 35 130 13014 160 35 130 18015 160 35 180 13016 160 35 180 18017 180 75 130 13018 180 75 130 18019 180 75 180 13020 180 75 180 18021 180 35 130 13022 180 35 130 18023 180 35 180 13024 180 35 180 180

C0

"0

L00.

(i)

15

00

0 107.11

-XL00.

I0-

5

0

25-

20-

5 10 15 20Vacuum, in Ha

1000 2000 3000 4000

Engino RPM

5000

62

Figure 3-1. Ford distributor characteristics Model NumberD4ZE 12127 KA 4E28

7

X

L

NE

-J

41)%

. 44

01:4

30

L.

E_ct- J

15

11. CO201 I O-

E5 - 114.s.

0 -CO0

03

, 0a. 60-

O 0c4

030 = 40 -

0

20-

100-

BO-

0

hp

Bhp

Mc

Mt

F hp

(CALCULATED)

0 1000 2000 3000 4000 5000

Engin© RPM

63

Figure 3-2. Performance on gasoline, full throttle Ford1974, 2.3 liter engine

0

L.

120- FULL BMEP

FULL TORQUE0 100 ->

BO -El-

1

60

0O. 40-

0

LaQ.

720L

- 0E 0

OEs.

r-

40-

30-

20-1

I 0 -

0

0.700

E Q, 0.500

coc.5 00

L.0.400

co

64

FULL VOLUMETRICEFFICIENCY

FMEP(CALCULATED)

FULL LOADHALF LOAD

HALF LOADFULL LOAD

1000 3000

Engine Speed, RPM

4000 5000

Figure 3-3. Performance on gasoline, Ford 1974, 2.3 literengine

90 80 70 60

Weight-Percent Ethanol

15°C

20°C25°C.

65

Figure 3-4. Mixtures of ethyl alcohol and water by weight(U.S. Bureau of Standards)

>-u

(1,1

tf-LIJ

0EL.

0-CI-

30

20

10 0

G

X

130-Proof Alcohol

160-Proof Alcohol

180-Proof Alcohol

1

4 6 8 10 12 14 16 18 20 22 24Scheduled Test Numbers

Figure 3-5. Thermal efficiency versusscheduled test. numbers

1.2

e 130-Proof Alcohol

m 160-Proof AlcoholX 180-Proof Alcohol

F---i2 4 6 8 10 12 14 16 18 20 22 24

Scheduled Test Numbers

Figure 3-6. Broke specific fuel consumpElon

versus scheduled numbers

2.50 130-Proof Alcohol' 160-Proof Alcohol

x 180-Proof Alcohol

1.5

I I 1----1---- I 1 1----I4 6 8 10 12 14 16 18 20 22 24Scheduled Test Numbers

Figure 3-7. Carbon monoxide emission versusscheduled test numbers

0 130-Proof Alcohol

0 160-Proof AlcoholX 180-Proof Alcohol

1.5

6 8 10 12 14 16 18 20 22 24Scheduled Test Numbers

Figure 3-8. Oxygen content in the exhaust gasversus scheduled numbers

25 0 130-Proof Alcohol

a 160-Proof AlcoholX 180-Proof Alcohol

20

0 2 4 8 10 12 14 16 18 20 22 24Scheduled Test Numbers

Figure 3-9. Percent volume of water accumulation inengine oil versus scheduled test numbers

320

300

280

260

240

220

200

180

160

140

120

0 130-Proof Alcohol

Q 160-Proof AlcoholX 180-Proof Alcohol

1000 2 4 6 8 10 12 14 16 18 20 22 24

Scheduled Test Numbers

Figure 3-10. Brookfield viscosity of engine oilversus scheduled test numbers

450

430

410

390

370

350

O 130-Proof Alcohol

m 160-Proof AlcoholX 180-Proof Alcohol

0 6 8 10 12 14 16 18 20 22 24Scheduled Test Numbers

Figure 3-11. Flash point of oil versusscheduled test. numbers

0

500

480

1/4/

460

00-

440L

420

400

O 130-Proof Alcohol

Q 160-Proof AlcoholX 180-Proof Alcohol

0 11111F-11116 8 10 12 t4 16 t8 20 22 24

Scheduled Test Numbers

Figure 3-12. Fire point of oil versusscheduled test numbers

I

74

I. Inlet Air

. Inlet Low-proofAlcohol

3. Outlet, Air, Water, Alcohol, Mixtures.Two Phase.

Figure 3-13. Sketch of control volume for calculationof evaporation rates of ethanol and water

0

0

60

50

40

30

20

le

Load X 010r Him (TO r

0 76 120.6 02

x7676

1411.8

187.80007

76 187.8 7035 134.5 67

a 26 145.8 CO35 175.5 60

10 15 20

Water Vaporized (%)

25 30

Figure 3-14. Percent of alcohol vaporized versus percentof water vaporized prior to the intakemanifold for 130-proof tests

0

00

00

50

40

30

20

10

Load X 011°F mik(r3)*r11 .....11.0.111.

0 75 147.0 seci 76 160.0 01X 76 174.0 690 76 178.6 680 36 130.6 63A 36 148.0 60

SS 173.6 62

I I I10 15 20 25 30 35

Water Vaporized a)

Figure 3-15. Percent of alcohol vaporized versus percentof water vaporized prior to the intakemanifold for 160-proof tests

0_c0

60

50

40

30

20

10

Load x oiler tilka3>er11........

0 76 148.6 68o 76 164.0 01X 76 176.0 68* 76 170.6 62A 36 141.0 680 36 146.6 66

36 188.6 6136 178.6 66

I

10 20 30 40Wo Eor Vaporized a)

50 60

Figure 3-16. Percent of alcohol vaporized versus percentof water vaporized prior to the intakemanifold for 180-proof tests

78

List of Symbols

C = Specific heat

/01 = enthalpy of vaporization

p = pressure

Q = Energy

Energy rate

mass flow rate

T = temperature

X = mass fraction

Y = mole fraction

Subscripts

E = ethanol

i = component

L = liquid phase

m = mixture

V = vapor phase

W = water

79

CHAPTER IV

ETHANOL FUMIGATION IN A TURBOCHARGEDDIESEL ENGINE

IV.1 Introduction

Low-proof ethanol, 130 and 160 proof was fumigated

into the intake manifold of a turbocharged diesel engine.

The diesel fuel was injected normally at a reduced rate.

No engine modification was done other than installing a

fumigation system between the turbocharger and the intake

manifold. The objective of the study was to determine any

oil dilution or degradation caused by the fumigation of

the low proof ethanol. Material, data and results of this

chapter are reported from Mingle and Bushnell. (39)

IV.2 Engine and Fumigation Equipment

Testing was performed on an Allis-Chalmers, Model

2900, 6-cylinder diesel engine with no modifications ex-

cept for the installation of the alcohol fumigation equip-

ment (Figure 4-1). The fumigation system was fashioned

after a design of Dr. James Smith, Colorado State Univer-

sity. The atomizing nozzles are from Spray Systems Com-

pany and are made up of a No. 11 spray set with a 1/4 JN

nozzle body and an external mixing cap. Spray nozzles

were mounted in a cone that was installed in the air

80

intake system between the turbocharger and the intake

manifold. Three nozzles were mounted at 120-degree inter-

vals around the cone, with the alcohol stream spraying

across the air stream at a 30-degree angle. The atomizing

air was controlled by a pressure regulator while the

liquid flow could be controlled by a needle valve on the

nozzle body or by varying the pressure on the liquid.

Liquid pressures were provided by a magnetic-drive air

motor gear pump (Cole-Palmer No. C-7002-88). An internal

loop was used to recirculate part of the alcohol and to

stabilize the pump pressure and fluid flow (for engine

specifications see Table 4-1).

Engine oil cooling/heating was accomplished by using

two shell and tube heat exchangers and an external oil

pump (Figures 4-2 and 4-3). To maintain the oil at a

temperature of 60°C (140°F) required the use of both cool-

ers with the cooling water on the shell side of the ex-

changer. Maintaining the 104°C (220 °F) oil temperature

required the passage of steam through the shell side of

both exchangers. All other oil temperatures could be

achieved by using cooling water on the shell side of the

exchanger.

IV.3 Instrumentation

Engine speed and load were controlled by an Eaton

Dynamatic dynamometer, Model 1014 WIG. Diesel fuel flow

81

rates were determined by timing the flow of 227 grams (1/2

lbm) of fuel using a pan balance. Alcohol mixture flow

rates were measured using a calibrated rotometer, and a

check was provided by timing 100 grams of alcohol using a

pan balance.

Air flow rates were determined by connecting an ASME

flow nozzle system to a small plenum that replaced the air

cleaner at the entrance to the turbocharger.

Exhaust gas analyses were determined using Beckman

IR-15A nondispersive infrared analyzers for carbon monox-

ide (CO) and carbon dioxide (CO2). Oxygen (02) analysis

was made using a Scott, Model 150, paramagnetic oxygen

analyzer.

Temperature measurements were made using chromel-

alumel, type K, thermocouples connected to a 10-point

digital readout. Oil temperatures in and out of the oil

cooler; and exhaust gas temperatures at the outlet of the

exhaust manifold and at the outlet of the turbocharger

were recorded. Also recorded were the water-in and water-

out temperatures. Inlet air temperatures were recorded

before and after turbocharging and also after alcohol

fumigation.

Pressures of intake and exhaust manifolds and pres-

sure from the turbocharger exhaust were measured using

mercury or water manometers. Pressures of alcohol atom-

82

izing air and alcohol liquid pressure were measured on 0-

60 psi pressure gauges made by Marsh Instrument Company.

IV.4 Fuel Preparation

The ethyl alcohol used for the test was purchased

from Van Waters and Rogers Company and listed under the

trade name of VANZOL 190 A-1 (SD-3A). The product was

denatured 190-proof ethyl alcohol which was further

diluted with water to 160 and 130 proof.

The diesel fuel was from Union 76 Oil Company with

specifications as in Table 4-2.

IV.5 Test Parameters

The following five independent parameters were varied

as shown:

1. Ethanol proof; 130 and 160

2. Crankcase oil temperature; 140, 180 and

220oF. Note that the crankcase oil tempera-

tures were chosen to provide temperatures

above and below the azetrope point. When

temperatures are above the azetrope point,

little or no condensation of ethanol is

expected.

3. Engine speed and load (torque). Load was

set at 20% and 80% of rated load at 2000

rpm.

83

4. Alcohol inducted as percentage of total

energy; 40%; 60% and 80% were used.

5. A six hour duration running time on a given

batch load of crankcase oil. It is assumed

that the relationship between oil dilution

and time would be direct and linear, pro-

vided other variables are held constant.

The schedule test with those different parameters is

shown in Table 4-3.

IV.6 Test Procedure

Before each test the crankcase oil and the engine oil

filter were replaced with new products. The initial

charge of oil was two and a half gallons (9.5 liters) of

Union Guardol, SAE 30, with specifications as in Table 4-

4. The oil was circulated continuously from the oil pan

through the two oil coolers by an oil pump, while the

cooling water was circulated through the shell side of the

coolers. The water flow was controlled manually and, in

one series of tests, was replaced by steam such that the

oil could be maintained at the required 104°C (220°F).

The engine cooling-water temperature was manually control-

led to 82°C (180°F) for all tests.

For a full 6-hour test, the engine was started and

allowed to warm up at 1,800 rpm on diesel fuel only. At

the end of the warm-up period, the predetermined flow rate

84

of the alcohol/water mixture was initiated through the

fumigation system. The engine rpm was then set on the

dynamometer control, and the diesel fuel flow rate was in-

creased or decreased until the desired load was achieved.

The engine was then left to stabilize until data taken at

5-minute intervals varied less than 2 percent. When the

engine reached this stable condition, the 6-hour run was

started with data taken at 60-minute intervals until the

end of the sixth hour. An appropriate cool-down of 15

minutes was allowed at the conclusion of each test.

Immediately after the conclusion of the test, one

gallon of oil was drained from the crankcase. An addi-

tional small sample was taken for processing by the

Department of Energy's Bartlesville (Oklahoma) Energy

Technology Center (BETC). The remainder of the oil was

discarded.

IV.7 Oil Test Analysis

The following laboratory tests were performed on the

oil samples:

1. ASTM-92 flash point, C° (F°)

2. ASTM-92 fire point, C° (F°)

3. ASTM-95 water by distillation, %

4. ASTM-96 water and sediment by centrifuge, %

5. Brookfield Viscosity; centipoise at room

temperature.

85

Also, water and ethanol concentrations in the lubri-

cating oil was analyzed by Bartlesville Energy Technology

Centre. Ethanol was measured by a gas chromatograph,

while water was measured by a photo volt Aquatest II

method.

IV.8 Ethanol and Water Vaporization

The computer program (Appendix 1) was used to calcu-

late the vaporization rates of alcohol and water prior to

entering the intake manifold. Figure 4-4 shows the inlet

and out let states for the diesel engine cases.

For the turbocharged diesel engine, the temperature

of the air after the turbocharger is relatively high,

which enhances the vaporization process considerably.

Figures 4-20, 4-21, 4-22 and 4-23 show the plots of the

amounts of alcohol vaporized versus that of water vapor-

ized.

IV.9 Results

Figures 4-5 and 4-6 show the percent of diesel fuel

consumed to the scheduled percent of fumigated alcohol

fuel. At 20% load an apparent and clear deviation from

the perfect line of correlation can be seen. When using

130-proof ethanol at low loads and high alcohol fuel flow

rates; the same amount of diesel fuel is needed as that of

the baseline. That indicates you can shut down the

86

alcohol fuel and the engine will maintain the same rpm and

produce the same output.

The deviation of the real percent alcohol from the

scheduled percent alcohol is plotted in Figures 4-7 and 4-

8. A great departure from the perfect line of correlation

is apparent at 20% load and 130-proof alcohol.

Thermal efficiency decreases steadily with increasing

alcohol flow rate, especially at 20% load as is apparent

in Figure 4-9.

Carbon monoxide (CO) in the exhaust gas tends to

increase with increased alcohol fuel flow rate (Figure 4-

10). This is probably due to increased quenching, rather

than 02

starvation; because of the high excess 02

in the

exhaust gas and the low intake manifold temperatures.

The laboratory test results on the used oil indicate

the following:

A slight decrease in both flash and fire point with

an increase flow rate (Figures 4-11 through 4-14.)

Figures 4-15 and 4-16 show Brookfield Viscosity (CPS)

as a function of real % of energy as alcohol. The corre-

lation is not clear; particularly for the 130 proof alco-

hol.

The amount of water and alcohol accumulated in the

crankcase oil is shown in Figures 4-17 through 4-19.

These amounts are very small and normally are within the

87

repeatability of the experiment. The correlations in

general are difficult to recognize.

Figures 4-20 through 4-23 show the % of alcohol

vaporized versus the % of water vaporized. The outputs

are from the computer program. Because of the high tempe-

rature from the turbocharger, appreciable amounts were

vaporized. Results can be summarized as follows:

1. More vaporization at 160 proof than at 130

proof.

2. The amount of vaporization decreased with

an increased alcohol flow rates.

3. Higher carnkcase oil temperature, especially

the 220°F has a significant effect on vapor-

ization, especially at low flow rates.

4. The vaporization rate does not show a signi-

ficant difference between the 20% and 80%

load for the same alcohol proof.

In general the vaporization rate was found to be a

function of alcohol proof, alcohol fuel flow rate, air

temperature and engine oil temperature. The worst pre-

dicted vaporization rates were for 130-proof 80% load

(Figure 4-23). For the case of 130-proof, 80% load and

220°F oil temperature, if 80% alcohol is assumed to be

vaporized, only about 42% of water may vaporize. The 58%

of liquid water entering the combustion chamber may either

evaporate due to high temperatures, or it may be blown

88

into the engine crankcase oil. Since no water accumulated

in the engine oil, it is believed that most of the water

evaporated in the combustion chamber and is either

exhausted with the exhaust gases or vented through the

breather tube. This identifies the importance of the

crankcase ventilation system. Effective ventilation aids

in removing condensibles that would otherwise accumulate

in the oil.

IV. 10 Conclusions

It can be concluded that, for this particular turbo-

charged engine, no material damage will result from the

use of alcohol as a dual fuel with diesel if the alcohol

fuel is fumigated.

For this particular test no problem with lubricating

oil dilution was detected.

At low loads and low temperatures a fumigation of

more than 60% energy by alcohol is not beneficial. More

diesel will be consumed with corresponding reduction in

thermal efficiency.

Increased carbon monoxide in the exhaust with in-

creased alcohol % is apparent.

Due to high temperatures after the turbocharger, sig-

nificant vaporization of alcohol and water occurred, which

enhanced the combustion process, and decreased the possi-

bility of oil dilution considerably.

Table 4-1

Specifications for Allis-Chalmers,Model 2900 Diesel Engine

A. Engine Data and Characteristics

Number of cylinders 6 1.Sore 3.875 in. (98.42 mm)Stroke 4.250 in. (207.95 mm)Total displacement. 301 cu. in. (4933 cm3)Crankshaft rotation (viewed from

fan end) clockwiseNumber of main bearings 7

Compression ratio (nominal).... 16.25:1Compression pressure (minimum) at sea 2.

level 600 rpm hot. 500 psi (35.15kg/cm2)

Firing order 1-5-3-6-2-4Minimum stabilized water

temperature 180° F (82°C)Maximum permissible exhaust

restriction 1 in. Ng (25.4 mm)

B. Fuel Injection

Nozzle holder assembly manufacturer:Allis-Chalmers

Fuel injection pump manufacturer:Roosa Master

Nozzle type...spring loaded, 4-hole orificesfices

Opening pressure ,2900 psi (203 kg/cm 2)

Orifice size 0.32 mm (0.0126 in.)Fuel pump timing to engine, static...20°Fuel oil filter combination, primary

and secondaryFuel injection pump speed (ratio tocrankshaft) 5.1

C. Valve Data and Timing

Valve Lash AdjustmentIntake valve clearance:

015 in.018 in.

Exhaust valve clearance:015 in..018 in.

(0.381 mm) hot(0.457 mm) cold

(0.381 mm) hot(0.457 mm) cold

Valve TimiplExhaust valve (with .01.95 in. - 0.495 mmtappet clearance):

Opens BBDC 56°Closes AIDC 16°Duration 252°

Intake valve (with .0195 in.-0.495 mm tap-pet clearance):.

Opens BTDC 20°Closes ABDC 48°Duration 248°Overlap 36°

D. Lubrication

Type full pressureLubricating oil filter full flowLubricating oil specifications:

"Service DS" or "Series 3"Oil pump speed (ratio to crankshaft)... 5:1

90

Table 4-2

Specifications of Union 76#2 Diesel Fuel

Density gm/cm3 at I5°C.8597

Gravity, °API33.5

Flash Point, °C (°F)

Distillation °C (°F) at % recovered

86 (186)

Initial boiling point 184 (363)

10228 (442)

50273 (522)

90316 (600)

End point344 (652)

Cetane number44

Viscosity

SUS at 100°F37.9

CSt at 40°C03.4

Sulfur, Wt. %00.14

Carbon residue (Rams) on 10% bottoms,wt %

00.12

Cloud point, °C 1°F) -10 (14)

Pour point, °C (°F) -18 (0)

Color, ASTM00.5

Corrosion, Cu strip, 3 hr at 100 °C(212 °F)

la

Ash, Wt. %< .01

Table 4-3

Fumigation-Diesel Test Scheduleand Sample Code Numbers

I. 160-proof Ethanol II.

A. 20 pct rated load @ 2,000 rpm (19.6 Bhp)

1. 140° F oil temp. Zero alcohol2. 140° F oil temp. 40% 11

3. 140° F oil temp. 60%114. 140° F oil temp. 80%II5. 180° F oil temp. 40%

6. 180° F oil temp. 60%117. 180° F oil temp. 80%1115. 220° F oil temp. 40%

16. 220° F oil temp. 60%17. 220° F oil temp. 80%

130-proof Ethanol

A. 20 pct rated load @ 2,000 rpm (19.6 Bhp)

1. 140° F oil temp. 40% alcohol2. 140° F oil temp. 60% "3. 140° F oil temp. 80%

%I4. 180° F oil temp. 40%5. 180° F oil temp. 60%6. 180° F oil temp. 80%

1113. 220° F oil temp. 40%1114. 220° F oil temp. 60%

15. 220° F oil temp. 80%

B. 80 pct rated load @ 2,000 rpm (78.5 Bhp)

8. 140° F oil temp. Zero alcohol9. 140° F oil temp. 40% "

10. 140° F oil temp. 60%11. 140° F oil temp. 80%

1112. 180° F oil temp. 40%1113. 180° F oil temp. 60%

14. 180° F oil temp. 80%II18. 220° F oil temp. 40%1119. 220° F oil temp. 60%

20. 220° F oil temp. 80%

B. 80 pct rated load @ 2,000 rpm (78.5 Bhp)

7. 140° F oil temp. 40% alcohol8. 140° F oil temp. 60% "

9. 140° F oil temp. 80%1110. 180° F oil temp. 40%

11. 180° F oil temp. 60%12. 180° F oil temp. 80%16. 220° F oil temp. 40%17. 220° F oil temp. 60%18. 220° F oil temp. 80%

92

Table 4-4

Specifications of Union 76Guardol Motor Oil

SAE Grade 30

Gravity, API° 25.3

Density g/cm3 at 15°C 00.9020

Color 7.0

Flash point, °C (°F) 230 (446)

Fire point, °C (°F) 250 (482)

Pour point, °C (°F) -18 (0)

Viscosity

SUS at 100°F 597

SUS at 210°F 67.5

CSt at 40°C 113.9

CSt at 100°C 11.95

Viscosity index

Foam test

Total base number ASTM

Ash, sulfated, Wt. %

Zinc, Wt. %

2896

93

Pass

7

0.98

0.143

rut4)tr.

RS

O 0

O 4

rcl 0

4.)

c)-1

or-13

Nrd

Hw a,

rcia,

o"H

(1)ai

4-)(I)

u)

(1)

"H0)0

a)

I1-1

RS

to N by

tor-1

KC

"CI 1-k

94

Figure 4-2. Shell and tube heat exchangers for crankcaseoil temperature control

Figure 4-3. External oil pump for crankcase oiltemperature control

1. Inlet Air

95

2. Inlet LOw-proofAlcohol

1 t

3. Outlet, Air, Water, Alcohol, Mixtures.Two Phase.

Figure 4-4. Sketch of fumigation system control volumefor calculation of evaporation rates ofethanol and water

120

00

1000

80

60

40

20

160-Proof Alcohol0 20% Loadw 80% Load

0

Line of PerfectCorrelation

01

0 10 20 30 40 50 60 70 80 90Scheduled (X) of Alcohol Energy

Figure 4-5. Percent of diesel fuel relative to baselineversus scheduled percent of energyas alcohol for 160-proof tests

o

120

CCI 100

o

.80

60

LL.

40

20

130-Proof Alcohol

0 20% LoadW 80N Load

0

0

GI

Lino of PerfectCorrelation

I 1 I I 1 I I 1

10 20 30 40 50 60 70

Scheduled (%) of Alcohol Energy

80 90

Figure 4-6. Percent of diesel fuel relative to baselineversus scheduled percent of energy

as alcohol for 130-proof tests

80-

70-0A=0

...0 60-U)O

50-rn

Ili 40-4-0

30-0:5 20--0a)

0(I) 1 0

IGO Proof Alcohol

line of perfectCorrelation

20% load

80% load

oil lernp., C

60°0 82°* 104°

60°

Ia1 104°

-- 82°

0 10 20 30 40Real % of Energy as Alcohol

50 60 70

Figure 4-7. Scheduled percent of alcohol versus realpercent of alcohol for 160-proof tests

80

80--

70-0.1=00 60-QU)

50-cp

Wc 40-

15.2 30-o

ID

20-I)

0W 10-

130 Proof Alcohol

max. liquidflow

line of perfect111)

cormlufkm

oil temp. , C

60°20% toad 82°

* 104°60°

80% load °

104°

0 10 20 30 40Real % of Energy as Alcohol

50 60 70

Figure 4-8. Scheduled percent of alcohol versus realpercent of alcohol for 130-proof tests

80

50_

40_

80 % load

20 % loud

I)

onlemp. C

fb 60°160 proof o 82°

104°

60°130 proof 4 82°

* 104°

10 20 30 40 50 60 70 80

Real % of Energy as Alcohol

Figure 4-9. Thermal efficiency percent as a functionof real percent alcohol

0.6 -

0.5 -

0.4 -

(12

--- 0.3 -

0

0.2

0 20 % loud

0

(-) 0.1 -

80 % load

0

10 20 30 40

Real % of Energy as Alcohol

';`,(,*n°

50

160 proof

130 proof

60

()

oil lemp., CGO°

o- 82°

_ 104°

60°

*- 82°

*- 104 °

70

Figure 4-10. Carbon monoxide emission as a functionof real percent alcohol energy

80

250-

100-O

160 Proof Alcohol

*-EP* cry

0

20 % load 0

*

oil temp., C60 °

82 °

104°

10 20 30 40 50

Real % of Energy as Alcohol

80 % loud

60

D-- 60°82 °

* --104°

70

Figure 4-11. Flash point of oil as a function of realpercent alcohol for 160-proof tests

80

250-00

o 200-a_

0CA: 150-

130 Proof Alcohol

----6100_6k to **

10 20 30 40 50Real % of Energy as Alcohol

0*

20% loud

80 % load

60

oil lemp.,C

60 °O 82 °* - -104°D_ 60°* 82 °* --104°

70

Figure 4-12. Flash point of oil as a function of realpercent alcohol for 130-proof tests

80

160 Proof Alcohol

2501

C)0

200_c

O

a)

ISO-

100-0

*

10 20 30 40

Real % of Energy as Alcohol

13t(**

oil lernp.,C

60°20% loud o 82

* 104°

0 60 °

80% loud 82 °

* 104°

50 60 70 80

Figure 4-13. Fire point of oil as a function of realpercent alcohol for 160-proof tests

250-

130 Proof Alcohol

.0 No_o

10 20 30 40

Real % of Energy as Alcohol50

20% loud

80% load

60

oil temp., C

60 °

o 82°

* 104°

0 60°82 °

* 104°

70

Figure 4-14. Fire point of oil as a function of realpercent alcohol for 130-proof tests

80

270-

260-

>, 250

240--(1

.454-

00

03 230-

220-0

160 Proof Alcohol

807. loud

oil lemp., C

60°

o 82°104°0 60°

* 82 °* 104°

10 20 30 40Real% of Energy as Alcohol

50 60 70

Figure 4-15. Brookfield viscosity of engine oil as afunction of real percent alcohol for160-proof tests

80

270- 130 Proof Alcohol

260-

U)0U

240--00.

l`z2

0

tD 230-

220 -

0

... ...0.11.

oll lemp., C

60 °

20% load 0 82 °

* 104°

o 60 °80 % load * 82 °

* 104 °

10 20 30 40Real % of Energy as Alcohol

50 60

Figure 4-16. Brookfield viscosity of engine oil as afunction of real percent alcohol for130-proof tests

70 80

2000-

1600-

2; 1200a.

a)15 800

Oa)E 400o-6

20% load., 160 proof alcohol

80 %load 130 proof alcohol

oil lemp.,C60*

* 82 0

* 104°

10 20 30 40 50 60 70 80Real % of Energy as Alcohol

Figure 4-17. Volume of water as a function of realpercent of alcohol energy

200-

160-

0.c 80-

4-0a)E 40-D0

160 Proof Alcohol

20 % load

80 % load

oil temp., C

60 °o 82°* 104°o-- 60°* 82°* 104°

0

0 10 20 30 40 50 60 70 80Real % of Energy as Alcohol

Figure 4-18. Volume of ethanol as a function of realpercent of alcohol for 160-proof tests

130 Proof Alcohol

20 % load

80 % loud

oll I emp.,C

60°

o 82

* 104°

o 60°* 82°* 104°

0 10 20 30 40 50Real % of Energy as Alcohol

60 70

Figure 4-19. Volume of ethanol as a function of realpercent of alcohol for 130-proof tests

80

/I

I

N

o

0-C0

120-

100

t ,

I

80-

60--

40-

20-

188-Proof 2ex Local,

Ala S Lood x Gorr 13°:IS\\s.........._

83.2

81.6

71.382.477.9

72.7

70.8

70.7

83.3

79.2

70.6

..---. .....____ ...._____

40 163.8 129.6

0 60 168.8 130.9

X 76 162.9 125.9

49 183.6 123.8

0 60 183.7 128.8

A76 178.3 129.6

80 149.3 122.7

0 80 169.2 122.2

CI 40 220.0 132.93

* ee 220.2 133.6

ee 228.0 136.4

Figure

I I

20 40

4-20. Percent

I I

60 80 100

Water Vapor i zed

alcohol vaporized

120 140 160

(%)

ve. percent watervaporized prior to the intake manifold for 20 %

load and 160-proof alcohol teats

120

n 100X%.* \\

189-Proof , 80 X Load

13 \

N0 80 -Ala X 01 1 r Ts'r T3'r

11. p.m wse........11M41,x.,

0 00. -60 0

X

- - CI40<>

o-C

8

20 -

A

.:(

01

49 138.7 176.6 97.049 141.6 160.1 06. 688 137.4 181.7 89.460 137.7 194.6 86.660 139.2 192.2 87.240 164.0 167.9 98.800 166.9 192.4 96.789 170.8194.8 86.340 229.9 188.2 88.860 220.0 166.2 66.689 220.3 192.2 86.8

1 I I

0 20 40 60I80 100 120 140

Water Vaporized 0)

Figure 4-21. Percent alcohol vaporized ve. percent watervaporized prior to Eh intake manifold for

80% load and 180-proof alcohol toots

120

e-% 100

%,

N

lo 80 138 -Preof 28X Load

0Ala X 011F 7:r

600 0 40 100.0 121.0 74.1

> 0 80 148.4 122.1 71.8

X OS 148.4 128.0 70.8

O0 40 --49 177.4 122.11 70.4

IG 0 SS 170.0 120.1 71.2

A 410 190.2 138.1 73.8

48 221.4 133.3 01.8

20 so 220.1 131.9 70.4

O So 228.1 136.2 77.2

20 40 60 80

Water Vaporized (%)

100 120

Figure 4-22. Percent alcohol vaporized vs. percent water

vaporized prior to the intake manifold

for 20X load and 130-proof alcohol tests

120

100

80N

60

0

a

'40

20

130-Proof , sex Load

Ala X 011 ir 711r

MC 4 170.7 MO$34.0 MC 4 06.0MC 3 MC0 $7.e

101.5 MC I 04.2

10e.1 01.5 00.6I 7C 0 015.2 80. 0221.3 MC I 08.3228 .8 105.2 00.0210.0 107.4 00.1

0 40o esx es* 48O 01A OS

4080es

20 40 50 80

Water Vaporized (X)

100 120

Figure 4-23. Percent alcohol vaporized vs. percent watervaporized prior to the intake manifold for

80 X load and 130-proof alcohol teat.

115

CHAPTER V

ETHANOL FUMIGATION IN A NATURALLYASPIRATED DIESEL ENGINE

V.1 Introduction

130 and 160 low proof ethanol was fumigated into the

inlet manifold of a naturally aspirated diesel engine.

The diesel fuel was injected normally at a reduced rate.

Except for the installation of the fumigation system be-

fore the intake manifold, no engine modification was done.

The objective of the study was to determine any oil

dilution or degradation caused by the fumigation of the

low proof ethanol.

Since the engine is a non-turbocharged engine, the

inlet air temperatures are low compared to the tempera-

tures out of the turbocharger for a turbocharged engine.

The evaporation of the low proof ethanol will cause the

inlet charge temperature to drop even lower. This is

expected to affect engine performance as well as oil

dilution. Some comparison between the turbocharged diesel

engine and the naturally aspirated engine is included.

V.2 Engine and Fumigation System

An Allis-Chalmers, Model 2800, naturally aspirated, 6

cylinder diesel engine with specification as in Table 5-1

116

was used for this test. The fumigation system (Figure 5-

1) was installed between the air intake and the inlet

manifold, without any other engine modifications. The air

assisted nozzles and the cone are the same as that of the

previous experiment.

Engine oil cooling was accomplished by using a shell

and tube heat exchanger and an external oil pump. The

cooling water was passed through the shell side of the

heat exchanger, while the crankcase oil passage was

through the tube side. Continuous recirculation of the

crankcase oil was provided by the pump, while that of the

water was controlled and regulated manually by a valve.

V.3 Instrumentation

Engine speed and load were controlled by an Eaton

Dynamatic dynamometer, model 1014 WIG. Diesel fuel flow

rates were determined by timing the flow of 100 grams of

fuel using a pan balance. Low proof alcohol flow rates

were measured using a calibrated rotometer.

Air flow rates were determined by connecting an ASME

flow nozzle system to a small plenum that replaced the air

cleaner at the entrance to the intake manifold. The air

stream passes through the cone, delivering with it the

atomized low proof ethanol before entering the intake

manifold.

117

Carbon monoxide (CO) and carbon dioxide (CO2) were

analyzed by a Beckman IR-I5A nondispersive infrared anal-

yzer. Oxygen (02

) analysis was made using Westinghouse

Hagan model 209 oxygen monitor.

Temperature measurements were made using chromel-

alumel, type K, thermocouples connected to a 10-point

digital readout. Water inlet and outlet temperatures, oil

inlet and outlet temperature, air inlet temperature, inlet

manifold temperature and exhaust temperatures were mea-

sured. Pressures were measured using mercury or water

manometers.

V.4 Fuel Preparation

The ethyl alcohol used was from Van Waters and Rogers

Company listed as VANZOL 190 A-1 (SD-3A). It was dena-

tured and diluted to 160 and 130 proof.

V.5 Test Parameters

The following variables were varied independently:

1. Ethanol proof; 130 and 160

2. Crankcase oil temperature; 140° and 1800 F

3. Engine speed and load. Load was set at 20%

and 80% of rated load at 2000 rpm.

4. Alcohol inducted as % of total energy; 20%

and 30%. Higher % of alcohol on energy

basis were attempted, but failed. At 80%

118

load engine starts to misfire, and at 20%

load excessive diesel fuel consumption oc-

curred.

5. Running time. Six hour duration period on a

given batch load of crankcase oil.

Table 5-2 shows tests schedule.

V.6 Test Procedure

Before each test the crankcase oil and the engine oil

filter were replaced with new products. The engine was

started and allowed to warm up with diesel fuel only. A

predetermined flow rate of low proof ethanol was then

fumigated and the diesel fuel flow rate was adjusted

according to the load. After a stabilizing time of about

15 minutes, the 6 hour test was started. Data was taken

at one hour interval time, until the end of the sixth

hour.

Immediately after the conclusion of the test, one

gallon of oil was drained from the crankcase. The remain-

der of the oil was discarded.

V.7 Oil Test Analysis

The following laboratory tests were performed on the

oil samples:

(1) ASTM-92 Fire and Flash Point

119

(2) ASTM-95 Water by Distillation

(3) ASTM-96 Water and Sediment by Centrifuge

(4) Brookfield Viscosity; Centipoise at room

temperature.

V.8 Results

Figures 5-2 and 5-3 show an apparent diesel fuel con-

sumption increase with an increase in the alcohol fuel

flow rates for the 20% load. At 80% load the alcohol fuel

will improve the combustion process, as evidenced by ther-

mal energy gains, until about 28% energy of alcohol, after

which the flame will be quenched and the engine starts to

misfire.

Figures 5-4 and 5-5 show the deviation between the

scheduled alcohol energy % and the real alcohol energy %.

The deviation is higher for the 130 proof alcohol at 20%

load tests.

The thermal efficiency (Figure 5-6) shows a steady

reduction at 20% load and a small or no change at 80%

load.

The general trend for the carbon monoxide is a steady

increase as shown in Figure 5-7, while changes in carbon

dioxide emission (Figure 5-8) are very small.

No appreciable change in the fire and flash points

(Figures 5-9, 5-10 and 5-11), while Brookfield viscosity

shows a decrease at high alcohol energy % (Figure 5-12).

120

Figure 5-13 is the volume of water collected from

the crankcase oil. The amounts are generally very small

and no higher than that found in a diesel fuel operation

alone.

At one test (number 12), when both the oil and air

temperature were low and the inlet manifold mixture tem-

perature was higher than normal an appreciable amount of

water was vented through the breather tube. However, for

this test no excessive accumulation of water was detected

in the crankcase oil. This fact stresses the importance

of the crankcase ventilation system and its ability to

vent some of the condensibles in the engine oil.

Figures 5-14 through 5-20 show the comparison between

the turbocharged diesel engine and the naturally aspirated

diesel engine.

Figures 5-14 and 5-15 show the deviation from the

perfect line of correlation to be more pronounced for the

naturally aspirated diesel engine particularly for the 20%

load cases. The thermal efficiency (Figure 5-16) was less

for the naturally aspirated engine for all cases and

decreases more rapidly for the 20% load. The fire and

flash points (Figures 5-17 through 5-20) show a rapid

decrease for the naturally aspirated diesel engine cases.

Note that the alcohol fuel substitution was limited

to 30% energy basis for the case of the naturally

121

aspirated diesel engine, while the substitution was up to

80% energy basis for the turbocharged diesel engine.

Figure 5-21 and 5-22 were plotted from the computer

program output (Appendix 1). Results and conclusions from

these plots can be summarized as follows:

1. Due to the relatively low air and manifold

temperatures; the vaporization rates of both

alcohol and water prior to the intake mani-

fold were found to be low.

2. Although the % of the fumigated alcohol fuel

on an energy basis was not more than 30%,

complete vaporization did not occur.

3. The vaporization rates were generally lower

for the 130-proof and 80% load especially

for the high alcohol fuel flow rates. These

conditions explain why the engine tends to

misfire at high load and suggests flame

quenching as a possible source, particularly

when the intake manifold temperature gets

very low. Note that the manifold tempera-

ture drops as low as 46°F.

4. The lowest vaporization rate were found to

be for the cases of 130-proof alcohol and

80% load when the engine oil temperature was

low. For the case of 130-proof, 80% load

and 28% alcohol energy, Figure 5-22, only

122

about 50% of water vaporized when 80% alco-

hol ethanol vaporization was assumed. Al-

though the low-proof alcohol fuel flow rate

is relatively low, the engine tends to mis-

fire for any alcohol fuel flow rate in-

crease.

5. In general, any amount of liquid water in-

ducted into the engine combustion chamber

was presumed to be evaporated at high engine

cycle temperature and exhausted with the

exhaust gases. Any small amount of water

vapor blown into the engine crankcase was

presumed to be vented through the breather

tube.

Figure 5-23 shows the evaporation rates comparison

between the three engine tests. The figure suggests why

oil dilution occured in the S.I. engine case.

V.9 Conclusions

It can be concluded that for this particular

naturally aspirated engine, no oil dilution

or degradation will result from the use of

low proof ethanol; if the alcohol fuel is

fumigated into the engine in a dual fuel

operation.

123

The low-proof alcohol fumigation is limited

to about 30% energy basis. At high loads

the engine tends to misfire and at low loads

excessive diesel fuel consumption will

occur.

Due to low intake charge temperatures, the

vaporization rates were generally low. How-

ever, due to the low % alcohol substitution

and the consequent low water mass flow rates

in the fuel; no oil dilution was detected.

Thermal efficiency increased slightly at

high loads and decreased appreciably at low

loads.

Table 5-1

Specifications for Allis-Chalmers,Model 2800 Diesel Engine

A. Engine Data and Characteristics

Number of cylinders 6

Sore 3.815 in. (98.42 mm)Stroke 4.250 in. (707.95 mm)Total displacement. 301 cu. in. (4933 cm3)Crankshaft rotation (viewed from

fan eel) clockwiseNumber of main bearings 7

Compression ratio (nominal).... 16.25:1Compression pressure (minimum) at sea 2

level 600 rpm hot. 500 psi (35.15kg/cm2)

Firing order 1-5-3-6-2-4Minimum stabilized water

temperature 180° F (82°C)Maximum permissible exhAust

restriction 1 in. Hy (25.4 mm)

C. Valve Data and Timing

1. Valve Lash AdjustmentIntake valve clearance:

015 i n. (0.381 nun) hot018 in. (0.457 mm) cold-

Exhaust valve clearance:015 in. (0.381 mm) hot018 in. (0.457 mm) cold

B. Fuel Injection

Nozzle holder assembly manufacturer:Allis-Chalmers

Fuel injection pump manufacturer:Roosa Master

Nozzle type...spring loaded, 4-hole orillies[ices

Opening pressure...2900 psi (203 kg/em'Orifice size 0.32 mm (0.0126 in.)Fuel pump timing to engine, static' ?0°Fuel oil filter combination, primaryand secondary

Fuel injection pump speed (ratio tocrankshaft) c.1

Valve TimingExhaust valve (with .0195 in. - 0.495 mmtappet clearance):

Opens BBDC 56°Closes A1DC 16°Duration 252°

Intake valve (with .0195 in. -0.495 mm tap-pet clearance) :

Opens BTDC 20°Closes ABDC 48°Duration 248°Overlap 36°

D. Lubrication

Type full pressureLubricating oil filter full flowLubricating oil specifications:

"Service DS" or "Series 3"Oil pump speed (ratio to crankshaft)... 5:1

Table 5-2

Alcohol Fumigation - DieselTest Schedule and Codes

Alcohol Proof160 130

% Rated loadat 2000 RPM 20% load (19.4 BHP) 80% (77.6 BBB) 20% 80%

of total energyin form ofalcohol

Crankcaseoil temperature °F

0% 20% 30% 0% 20% 30% 20% 30% 20% 30%

140°F (1) (2) (3) (6) (7) (8) (11) (12) (15) (16)

180°F(4) (5) (9) (10) (13) (14) (17) (18)

Figure 5-1. Allis-Chalmers, Model 2800, naturallyaspirated diesel engine equipped withalcohol fumigation system

C120

0

0100

0

800

80 line of perfect

correlation

30

40 --160-Proof

IA_ 0 20 Percent Load

0 80 Percent Load20

0 10 20 30

Scheduled X Alcohol Energy

I40

Figure 5-2. Percent of diesel fuel relative to baselineversus scheduled percent of alcohol energy

for 160-proof tests

0C

0

0

1000

80.44

0

O 80

120

O40

130-Proofk. 0 20 Percent Load

O a 80 Percent Load20

line of perfect

correlation

0

x.,

1 1 1 1

v 0 10 20 30 40

Scheduled % Alcohol Energy

Figure 5-3. Percent of diesel fuel relative to baseline

versus scheduled percent of alcohol energy

for 130-proof tests

0

0

30

25

20

15

10

160-Proof AlcoholO 20% Loadw 80% Load

Line of PerfectCorrelation

10 15 20 25 30 35Real (X) Alcohol Energy Basis

Figure 5-4. Scheduled percent alcohol as a function ofreal percent alcohol for 160-proof tests

300

25 130-Proof Alcohol0 20% Load

0111 80% Load

20

Q

0

15

10 Line of PerCorrelation

10 15 20 25

Real (X) Alcohol Energy Basis'

30 35

Figure 5-5. Scheduled percent alcohol as a function ofreal percent alcohol for 130-proof tests

0EL

.0

30

2520

15--

10--

O 160-Proof ,

130-Proof ,

160-Proof

0

X 130-Proof ,

I I

x

20% Load20% Load80% Load80% Load

0 5 10 15 20 25 30 35Real (X) Alcohol Energy Basis

Figure 5-6. Thermal efficiency percent as a function ofreal percent alcohol

.18

.06

.03--

e15

X

160-Proof ,

130-Proof ,

160-Proof ,

130-Proof ,

20%20%80%80%

LoadLoadLoadLoad

5 10 IS 20 25 30 35Real CIO Alcohol Energy Basis

Figure 5-7. Carbon monoxide content in the exhaustgas as a function of real percent alcohol

76 X

5

4

2-- e 160 -Proof , 20 Loadm 130-Proof , 20% Load1 160-Proof , 80% LoadX 130-Proof , 80% Load

I I 1 1 i I

5 10 15 20 25 30Real (%) Alcohol Energy Basis

I

35

Figure 5-8. Carbon dioxide cas a function of real percent alcohol

L

480 0 160-Proofw 130-Proof

450o

420

390

360

330

0

300 I I 1 I I I I

0 5 10 15 20 25 30 35

Real (X) Alcohol Energy Basis

Figure 5-9. Flash point of engine oil as a functionof real percent alcohol

S00160-Proof , 80% Load

Q 130-Proof , 80% Load

480

a

460

0

440

420

4000 S 10 IS 20 25 30 35

Real CIO Alcohol Energy Basis

0

0

Figure 5-10. Fire point of engine oil as a functionof real percent alcohol for 20% load

0

500--

480

440

4204-

e 160-Proof , 80% LoadIs 130-Proof , 80X Load

4000 5 10 15 20 25 30 35

Real (X) Alcohol Energy Basis

Figure 5-11. Fire Point of engine oil as a functionof real percent alcohol for 80% load

300--0 160-Proof , 20% Loadm 130-Proof , 20% Load

280 -- A 160-Proof , 80% Loadx 130-Proof , 80% Load x

220

200 1 1 1 1 1

0 5 10 15 20 25 30 35Real CO Alcohol Energy Basis

Figure 5-12. Brookfield viscosity of oil as a functionof real percent alcohol

tn,

.06--

.05-- A

.04

.03--

.02--

.01

0 160-Proof , 20% Load130-Proof , 20% Load160-Proof , 80% Load130-Proof , 80% Load

5 10 IS 20 25 30 35Real (%) Alcohol Energy Basis

Figure 5-13. Volume of water in engine oil as a functionof real percent alcohol

(1)

C

0

C4

4,

3

120

100

80

60

40

20

Turbocharged

--- Naturally Aspirated

0

160-Proof Alcohol

e 20% Load

m 80% Load Line of PerfectCorrelation

I I- I I I I

10 20 30 40 50 60 70

Scheduled Cl.) of Alcohol .Energy

I I

80 90

Figure 5-14. Percent of diesel fuel relative to baselineversus scheduled percent of energyas alcohol for 160proof tests

120

(a0

1000

80

0

60

' Turbocharged

Naturally Aspirated

0

130-Proof Alcohol

040

20% Load

LL. m 80% Load Line of Perfect

20Correlation

OI 1 F I I 1I

80 9010 20 30 40 50 60 70

Scheduled (X) of Alcohol Energy

Figure 5-15. Percent of diesel fuel relative to baseline

versus scheduled percent of energy

as alcohol for 130-proof tests

40_

80 % loud

.---19111--..4---.100

20 % load

TurbochargedNatural ly Asp !rated

01 temp. G

60°

160 proof o 82°* 104°

60°

130 proof * 82°* 104°

* *

cit,,4-)

10 20 30 40 50 60 70 80Real % of Energy as Alcohol

Figure 5 -16. Thermal efficiency percent as a functionof real percent alcohol

250(30

200-[0

1-1- 150-

100

TurbocharGed130 Proof Alcohol Naturally Aspirated

oz - z -----610._ toEl**

0**111 0* oil lempIC

60 °20 % load 0 82 °

* 104

0 60°80 7. load 82°

* 104°

0 10 20 30 40 50

Real % of Energy as Alcohol

60 70

Figure 5-17. Flash point of oil as a function of realpercent alcohol for 130-proof tests

80

250

Turbocharged130 Proof Alcohol ....4 Natural ly Aspirated

C)

200-ECL

1:1: 150-

10 20 30 40

Real % of Energy as Alcohol

50

20 % load

80% load

60

oil lemp.,C

60 °

o 82 °* 104°

60 °

* 82°* 104°

70

Figure 5-18. Fire point of oil as a function of realpercent alcohol for 130-proof tests

80

250-

C)o 200

E

tZ15

150-wa

100-0

160 Proof Alcohol.0,4

TurbochargedNaturally Aspirated

E

oil temp., C60 °

20 % load o 82 °

* 104°0 60 °

A-80 % load 82 °

* 104°

10 20 30 40 50

Real % of Energy as Alcohol60 70

Figure 5-19. Flash point of oil as a function of realpercent alcohol for 160-proof tests

80

160 Proof Alcohol

250

C)0

.- 200-'50

0U: 150-

100

TurbochargedNatural ly Aspirated

* Ott

20 % load

80% load

oil lernp.,C

60 °

o 82 °

104°

60°

* 82 °

* 104 °

0 10 20 30 40 50

Real % of Energy as Alcohol

60

Figure 5-20. Fire point of oil as a function of realpercent alcohol for 160-proof tests

70 80

120

100

80N

0a.

180-Proof

Ala X Load X (Her 73 r60 .--- 41.0.4.

> 0 20 20 130.1 63.6_ a 28 20 141.3 49.0o 40 X 30 20 138.6 61.0X0o <> 20 20 179.8 48.7

0 20 80 139.6 61.4<t 20 A 28 80 148.3 61.6

28 80 177.8 66.9

I

20 40 60 80 100Water- Vaporized (X)

120

Figure 5-21. Percent alcohol vaporized versus percentwater vaporized prior to intake manifoldfor 160-proof alcohol

140

N

0

120--

100

80130-Proof

60Ala X Load ourr .13IMenewOrms

40 0 280 30

X 3820 _ 40. 28

0 29A es

411.20 140.020 138.829 130.180 141.480 141.160 138.8

I I20 40

83.849.461.967.047.8

I60 80 100 120

Water Vaporized (X)

Figure 5-22. Percent alcohol vaporized versus percentwater vaporized prior to intake manifold

for 130-proof alcohol

120

100

0 80

060

0 400U

20

11111111111111111111111111111:111111111111TimmimmeeimiImmisammiUMIumummumuumw1111111111111111111111111111011111111

111111111111111111111111111111111111111

111111111111111114)11111111111141.

111111111111111111111111V1111111111111111MINUIN

INITAMMIt.111111111n11

1111111111111111M111111rpm!dialm

TurbochargedC.I. Engine

NaturallyAspirated C.I.

20 40 60 80 100

Water Vaporized C%)120 148

Figure 5-23. Comparison of evaporation rates betweenthe three different engines

149

CHAPTER VI

CONCLUSIONS AND RECOMMENDATIONS

The objective of the work described in this thesis is

to determine any oil dilution or degradation caused by

utilizing low-proof alcohol fuels in both spark ignition

and compression ignition engines. The evaporation rates

of both ethanol and water prior to entering the intake

manifold of the engine were calculated and a correlation

was found to exist between the evaporation rates and oil

dilution. Tests were conducted for one gasoline engine

and two diesel engines. This chapter summarizes the con-

clusions of these tests and gives recommendations for

future work.

VI-1 Conclusions

For S.I. engines; excessive oil dilution may

occur when low-proof ethanol is carbureted

in the engine. At 130-proof and 75% load,

more than 20% of water by volume accumulated

in the engine crankcase oil in a matter of a

few hours. This rate of accumulation will

have an adverse effect on engine operation

over a long time period and will damage the

engine.

150

The evaporation rates of ethanol and water

prior to the intake manifold in the case of

the S.I. engine were found to be very low.

Almost none of the water in the alcohol fuel

evaporated, especially at high load and 130 -

proof alcohol. The water was blown into the

crankcase oil, causing its dilution. For

160 and 180 alcohol proof, no appreciable

oil dilution was detected.

For the turbocharged diesel engine, the

temperature of the air after the turbo-

charger is relatively high. The high tem-

perature enhances the evaporation rates of

ethanol and water considerably. Most of the

alcohol fuel and the water in the fuel eva-

porated before entering the combustion cham-

ber, even for the case of high alcohol fuel

flow rate and 130-proof. Any small amounts

of water blown into the crankcase oil were

presumed to evaporate at high cycle tempera-

tures and are either exhausted with the

exhaust gases or vented through the breather

tube.

For this particular turbocharged diesel

engine, no lubricating oil dilution was de-

tected and no material damage to the engine

151

is expected if the low alcohol proof fuel is

fumigated in a dual fuel operation.

Maximum amount of the diesel fuel substitu-

tion by the low proof alcohol is governed at

low load conditions by excessive diesel fuel

consumption and at high loads by engine

misfire. Generally more than 60% substitu-

tion on an energy basis is not recommended.

For the case of the naturally aspirated

diesel engine, the vaporization rates of the

alcohol fuel and water prior to entering the

combustion chamber were low. This is parti-

cularly important if we considered that the

amount of low-proof alcohol fuel substitu-

ting the diesel fuel was generally low. No

more than 30% substitution was used compared

to 80% substitution when using the turbo-

charged diesel engine. The engine intake

air temperature is relatively low and does

not enhance the vaporization of ethanol and

water. The liquid water entering the com-

bustion chamber is believed to evaporate at

high engine cycle temperatures and either

was exhausted or vented through the breather

tube.

152

Fumigation of the low-proof alcohol fuel is

a viable alternative in this type of engine.

The amount of diesel fuel substitution is

limited at low loads by increased diesel

fuel consumption and at high loads by flame

quenching and engine misfire. More than 25%

substitution is not recommended for this

type of engine.

No oil dilution was detected and no engine

damage is expected if the alcohol fuel is

fumigated in a dual fuel operation.

Generally; the crankcase oil dilution tends

to occur when very low vaporization rates

are coupled with high water flow rates in

the fuel.

VI-2 Recommendations:

For S.I. engines, a study of the mechanism

of gas blowby when using low-proof alcohol

fuel is warranted. The effect of the piston

and ring pack design configuration to con-

trol gas-blowby needs more investigation.

More research as to the effect of water and

alcohol dilution of the crankcase oil on

engine durability and life expectancy is

153

needed.

A study of the effects of alcohol fueling on

crankcase engine oil additives is recom-

mended.

A study of practical methods to vaporize the

low-proof alcohol fuel before entering the

combustion chamber will be beneficial and

will allow higher % of alcohol fuel to be

used.

154

REFERENCES CITED

(1) U.S. National Alcohol Fuels Commission; Fuel Alcohol:An Energy Alternative for the 1980s, Final Report.

(2) Thring, R. H.; "Alternative Fuels for Spark IgnitionEngines," SAE 831685.

(3) Bro, Klaus and Pedersen, P. S.; "Alternative DieselEngine Fuels: An Experimental Investigation ofMethanol, Ethanol, Methane and Ammonia in a D.I.Diesel Engine with Pilot Injection". SAE 770794.

(4) Heisey, J. B. and Lestz, S. S.; "Aqueous AlcoholFumigation of a Single Cylinder D.I. Diesel Engine,"SAE 811208.

(5) Wagner, T. 0.; Gray, D. S.; Zarah, B. V. andKozinski, A. A.; "Practicality of Alcohols as MotorFuel," SAE 790429.

(6) U.S. DOE, July 1979; Ethanol Fuel Modification forHighway Vehicle Use; ALO- 3683 -T1. pp. 4 & 10.

(7) Alternative Fuels Committee of the Engine Manufac-turers Association;" A Technical Assessment ofAlcohol Fuels," SAE 820261.

(8) Wilhoit, R. C. and Zwolinski, B. J., "Physical andThermodynamic Properties of Aliphatic Alcohols,"Journal of Physical and Chemical References Data,Volume 2, 1973. Supplement No. 1.

(9) Owens, E. C.; "Methanol Effects on Lubrication inEngine Wear," International Symposium on Alcohol FuelTechnology Methanol and Ethanol. Wolfsburg, Germany,Nov. 1977.

(10) Scheller, W. A.; "Test on Unleaded Gasoline Contain-ing 10% Ethanol-Nebraska Gasohol," InternationalSymposium on Alcohol Fuel Technology Methanol andEthanol. Wolfsburg, Germany, Nov. 1977.

(11) Lawrence, R. D.; "Emission from Gasohol Fueled Vehi-cles," Third International Symposium Alcohol FuelsTechnology. Asilomar, California, May 1979.

(12) Chui, G. K.; Anderson, R. D. and Baker, R. E.; "Bra-zilian Vehicle Calibration for Ethanol Fuels," ThirdInternational Symposium Alcohol Fuels Technology.Asilomar, California, May 1979.

155

(13) Cassels, G. R.; Dyer, W. G. and Roles, R. T.; "BP-New Zealand Experience with Methanol/GasolineBlends," Third International S osium Alcohol FuelsTechnology. Asilomar, California, May 1979.

(14) Lawson, A. and Last, A. J.; "Development of on-boardMechanical Fuel Emulsifier for Utilization ofDiesel/Methanol and Methanol/Gasoline Fuel Emulsionsin Transportation," Third International SymposiumAlcohol Fuels Technology. Asilomar, California, May1979.

(15) Slarke, K.; "Fueling the S.I. Engine with Gasoline/Methanol Water Blends," International Symposium onAlcohol Fuel Technology Methanol and Ethanol.Wolfsburg, Germany, Nov. 1977.

(16) Brinkman, N.D.; "Ethanol Fuel - A Single CylinderEngine Study of Efficiency and Exhaust Emission,"SAE 810345.

(17) Marbach, H. W.; Grame, E. A.; Owens, E. C. andNaegeli, D. W.; "The Effects of Alcohol Fuels andFully Formulated Lubricants on Engine Wear,"SAE 811199.

(18) Chui, G. K. and Millard, D. H. T.; "Development andTesting of Crankcase Lubricatns for Alcohol FueledEngines," SAE 811203.

(19) Chui, G. K. and King, E. T.; "Modified Sequence V-DTest with Two Engines Using Alcohol Fuels," SAE830239.

(20) Chaibongsai, S.; Howlett, B. J. and Millard, D. H.T.; "Development of an Engine Screening Test toStudy the Effect of Methanol Fuel on CrankcaseOils," SAE 830240.

(21) Ecklund, E. E.; Bechtold, R. L.; Timbario, T. J. andMcCallum, P. W.; "State of the Art Report on the Useof Alcohols in Diesel Engines," SAE 840118.

(22) Holmer, E.; "Methanol as a Substitute Fuel in theDiesel Engine," International Sumposium on AlcoholFuel Technollgy Methanol and Ethanol. Wolfsburg,Germany, Nov. 1977.

(23) Moses, C.; Naegeli, D.; Owens, E. and Tyler, J.;"Engine Experiments of Alcohol/Diesel Fuel Blends,"Third International Symposium Alcohol Fuels Tech-nology. Asilomar, California, May 1979.

156

(24) Hashimoto, I.; "Diesel-Ethanol Fuel Blends for HeavyDuty Diesel Engines: A Study of Performance andDurability," SAE 820497.

(25) Baker, Q. A.; "Use of Alcohol in Diesel Fuel Emul-sions and Solutions in a Medium-speed DieselEngine," SAE 810254.

(26) Foster, D. E.; "A Survey of Proposed Methods ofBurning Alcohol in Diesel Engines," CONF-8006185-1.

(27) Likos, W. E. and Moses, C. A.; "Effect of Low-proofAlcohol Utilization to Supplement Diesel Fuel onEngine Life Expectancy,". DOE/BC/10467. FinalReport.

(28) Khan, N. and Gollahalli, S. R.; "Performance andEmission Characteristics of a Diesel Engine BurningUnstabilized Emulsions of Diesel Fuel with Water,Methanol, and Ethanol," SAE 811210.

(29) Adelman, H.; "Alcohols in Diesel Engine - A Review,"SAE 79095.

(30) Nagalingam, B.; Sridhar, B. L.; Panchapakesan, N.R.; Gopalakrishnan, K. V. and Murthy, B. S.; "Sur-face Ignition Initiated Combustion of Alcohol inDiesel Engines - A New Approach," SAE 800262.

(31) Pischinger, F. F.; "A New Way of Direct Injection ofMethanol in a Diesel Engine," Third InternationalSymposium Alcohol Fuels Technology. Asilomar,California, May 1979.

(32) Holmer, E.; "The Utilization of Different Fuels in aDiesel Engine with Two Separate Injection Systems,"Third International Symposium Alcohol Fuels Tech-nology. Asilomar, California, May 1979.

(33) Harderiberg, H. 0. and Ehnert, E. R.; "IgnitionQuality Determination Problems with AlternativeFuels for Compression Ignition Engines," SAE 811212.

(34) Likos, W. E.; "The Effect of Alcohol Fueling onDiesel Engine Durability," SAE 841384.

(35) Chen, J.; Gussert, D.; Gao, X.,; Gupta, C. andFoster, D.; "Ethanol Fumigation of a TurbochargedDiesel Engine," SAE 810680.

157

(36) Holmer, E.; Berg, P. S. and Bertilsson, B. I.; "TheUtilization of Alternative Fuels in a Diesel EngineUsing Different Methods," SAE 800544.

(37) Mingle, John, G. - Oregon State University - Privatecommunications.

(38) Mingle, J. G. and Boubel, R. W.; "Effect of Low-Proof Fuel Alcohol on Crankcase Oil Dilution in anOtto-Cycle Engine," Final report DOE/BC/10343-1

(39) Mingle, J. G. and Bushnell, D. J.; "Effect of Low-Proof Alcohol Fumigation-Fueling on Crankcase OilDilution in a Diesel-Cycle Engine," Final reportDOE/BC/10449-1

APPENDIX

158

APPENDIX 1

Computer Program for Calculation of

Evaporation Rates of Alcohol and Water

GET,EVAPOR/COPY,EVAPOR

PROGRAM EVAPOR(INPUTIOUTPUT)

C** THIS PROGRAM UTILIZES FIRST LAW ANALYSIS (ENERGY BALANCES) TOC** DETERMINE THE EVAPORATION RATES OF ALCOHOL AND WATER IN A DUAL -

C -- FUELED DIESEL ENGINE CYCLE BEFORE ENTERING THE COMBUSTION CHAMBERC-- (AT THE INLET MANIFOLD). EXPERIMENTAL VALUES OF ALCOHOL,WATERC -- AND AIR FLOW RATES ARE TO BE USED.

REAL MASSALC,MASSAIR,RHUMID,ALCHSP1,ALCHSP2,ALCOHPRREAL AIRTEMP,CONTEMP,MANTEMP,WCHART,CPAIR,CPALCOHREAL HFGALC,HFGWAT,AIRMOIS,HYDALCH,OATMASS,TOTLWATREAL ENTOAL,ENTOWT,TOTLGIV,VAPALC,VAPWAT,DPR,PRESSREAL AA(11),BB(11),AABB,AIRENGY,MOSENGY,TOTLENGINTEGER I,N

C** READING INPUT DATA AND PRINTING IT.

PRINT*,'YOU NEED TO ENTER 5 DATA PER LINE TOTAL OF 3 LINES'

READ*, N,DPR,PRESS,MASSALC,WCHARTREAD*, ALCOHPROIRTEMP,CONTEMP,MANTEMPOLCHSP2READ*, CPAIRICPALCOH,HFGALC,HFGWAT,HFGWAT2

WHILE (NAT.()) DO

MASSAIR = 2530.36*SORT(DPR*PRESS/(460.0+AIRTEMP))

C** CALUATION OF WATER VAPOR IN AIR, WATER IN ALCOHOL,AND MASS FLOWC-- RATES OF HYDROUS ETHANOL.

AIRMOIS = MASSAIR*WCHARTHYDALCH = (MASSALC*0.78737*ALCOHPR)/(200kALCHSP2)WATMASS = MASSALC-HYDALCHTOTLWAT = AIRMOIS+WATMASS

C** CALCULATION OF ENERGY AMOUNTS AND ENERGY BALANCES. FIRST ENERGYC-- GIVEN BY AIR AND MOISTURE IN AIR ASSUMED TO BE CONDENSED.

159

AIRENGY = MASSAIR*CPAIR*(CONTEMP-MANTEMP)

MOSENGY = AIRMOISOFGUAT+AIRMOIS*(CONTEMP-MANTEMP)TOTLENG = AIRENGY+MOSENGY

C** ENERGY GIVEN TO ALCOHOL AND WATER IN ALCOHOL TO BE HEATED (OR)-C-- COOLED TO MANIFOLD TEMPERATURE.

ENTOAL = HYDALCH*CPALCOH*(MANTEMP-AIRTEMP)

ENTOWT = WATMASS*(MANTEMP-AIRTEMP)TOTLGIV = ENTOAL+ENTOWTAVAILB = TOTLENG-TOTLGIV

C** CALCULATE AMOUNT OF ENERGY NEEDED TO VAPORIZE ALCOHOL AND WATER

C-- AT THE MANIFOLD TEMPERTAURE.

VAPALC = HFGALC*HYDALCHVAPWAT = HFGWAT2*TOTLWAT

C** TO DETERMINE X OF ALCOHOL AND WATER VAPORIZED, FIRST ASSUME 100%C-- ALCOHOL VAPORIZATION AND CORRESPONDING WATER FROM ENERGY BALANCE.

C-- THEN DECREASE X OF ALCOHOL GRADUALLY.

DO 30, 1=1,11AA(I)=110-I*10

AABB = AVAILB-(AA(I)*VAPALC)/100BB(I)= AABB*100/VAPWAT

30 CONTINUE

C** PRINTING CALCULATED OUTPUT AND READ OUTS.

PRINT 80, (N,DPR,PRESS,MASSALC,WCHART)PRINT 90, (ALCOHPR,AIRTEMP,CONTEMP,MANTEMP,ALCHSP2)PRINT 90, (CPAIR,CPALCOH,HFGALC,HFGWAT,HFGWAT2)

80 FORMAT(1H1,1X,I7,4(3X,F8.3))90 FORMAT(1X,5(F8.3,3X))

PRINT*,

PRINT*,'MASS OF AIR CALCULATED BTU/HR =1, MASSAIR

PRINT*,'ENERGY GIVEN BY AIR AND MOISTURE BTU/HR =',TOTLENG

PRINT *,'ENERGY GIVEN TO HEAT TO MANIFOLD BTU/HR =',TOTLGIV

PRINT *,'AVAILAB ENERGY FOR VAPORIZATION BTU/HR =',AVAILB

PRINT*,

PRINT*,' X ALCOHOL X WATER VAPORIZED'

DO 40, I=1,11

PRINT 60, AA(I),BB(I)

60 FORMAT(1X,2X, F6.2,6X, F6.2)

40 CONTINUE

160

READ*, N, DPR,PRESS,MASSALC,WCHART

READ*, ALCOHPR,AIRTEMP,CONTEMP,MANTEMP,ALCHSP2READ*, CPAIR,CPALCOH,HFGALC,HFGWAT,HF6WAT2

ENDWHILE

STOP

END

GETOUT/COPY,OUT

YOU NEED TO ENTER 5 DAT. PER LINE TOTAL OF 3 LINES

1 1.140 30.000 10.450 .008

160.000 79.800 120.500 83.200 .854

.240 .580 400.000 1025.400 1046.500

MASS OF AIR CALCULATED DTU/HR 636.9112595069

ENERGY EVEN BY AIR AND MOISTURE DTU/HR = 11116.39435893

ENERGY GIVEN TO NEAT TO MANIFOLD BTU/HR = 24.52334126229

AVAILAB ENERGY FOR VAPORIZATION BTU/HR = 11091.87101707

% ALCOHOL Z WATER VAPORIZED

100.00 97.64

90.00 101.40

80.00 105.16

70.00 108.72

60.00 112.63

50.00 116.44

40.00 120.20

30.00 123.96

20.00 127.72

10.00 131.47

0 135.23