Production of biodiesel from feedstocks with high free fatty acids and its effect on diesel engine

252 Pages·2017·5.24 MB·English

by  Mustafa Canakci

Iowa State University Capstones, Theses and
Retrospective Theses and Dissertations
Dissertations
2001
Production of biodiesel from feedstocks with high
free fatty acids and its effect on diesel engine
performance and emissions
Mustafa Canakci
Iowa State University
Follow this and additional works at:https://lib.dr.iastate.edu/rtd
Part of theMechanical Engineering Commons
Recommended Citation
Canakci, Mustafa, "Production of biodiesel from feedstocks with high free fatty acids and its effect on diesel engine performance and
emissions " (2001).Retrospective Theses and Dissertations. 1100.
https://lib.dr.iastate.edu/rtd/1100
This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University
Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University
Digital Repository. For more information, please [email protected].
INFORMATION TO USERS
This manuscript has been reproduced from the microfilm master. UMI films
the text directly from the original or copy submitted. Thus, some thesis and
dissertation copies are in typewriter face, while others may be from any type of
computer printer.
The quality of this reproduction is dependent upon the quality of the
copy submitted. Broken or indistinct print, colored or poor quality illustrations
and photographs, print bleedthrough, substandard margins, and improper
alignment can adversely affect reproduction.
In the unlikely event that the author did not send UMI a complete manuscript
and there are missing pages, these will be noted. Also, if unauthorized
copyright material had to be removed, a note will indicate the deletion.
Oversize materials (e.g., maps, drawings, charts) are reproduced by
sectioning the original, beginning at the upper left-hand corner and continuing
from left to right in equal sections with small overlaps.
Photographs included in the original manuscript have been reproduced
xerographicaliy in this copy. Higher quality 6" x 9" black and white
photographic prints are available for any photographs or illustrations appearing
in this copy for an additional charge. Contact UMI directly to order.
ProQuest Information and Learning
300 North Zeeb Road, Ann Arbor, Ml 48106-1346 USA
800-521-0600

Production of biodiesel from feedstocks with high free fatty acids and its effect on diesel
engine performance and emissions
by
Mustafa Canakci
A dissertation submitted to the graduate faculty
in partial fulfillment of the requirements for the degree of
DOCTOR OF PHILOSOPHY
Major: Mechanical Engineering
Major Professor: Jon H. Van Gerpen
Iowa State University
Ames, Iowa
2001
UMI Number: 3016766
UMf
UMI Microform 3016766
Copyright 2001 by Bell & Howell Information and Learning Company.
All rights reserved. This microform edition is protected against
unauthorized copying under Title 17, United States Code.
Bell & Howell Information and Learning Company
300 North Zeeb Road
P.O. Box 1346
Ann Arbor, Ml 48106-1346
ii
Graduate College
Iowa State University
This is to certify that the Doctoral dissertation of
Mustafa Canakci
has met the dissertation requirements of Iowa State University
Signature was redacted for privacy.
Major Professor
Signature was redacted for privacy.
or the Major Pr am
Signature was redacted for privacy.
For th G aduate College
iii
TABLE OF CONTENTS
LIST OF FIGURES vii
LIST OF TABLES x
ABSTRACT xiv
1. INTRODUCTION 1
2. REVIEW OF LITERATURE 6
2.1. Vegetable Oils 6
2.2. T ransesteri fication 7
2.3. The Tr ansesteri fication of Oils and Fats with High Free Fatty Acids 16
2.4. Pilot Plant Scale Transesterification 26
2.5. Waste Restaurant Grease and Animal Fat in the United States and Iowa 32
2.6. Chemical Analysis of Unprocessed Restaurant Grease and Animal Fat 37
2.7. Diesel Engine Emissions Fueled with Vegetable Oil Esters 41
2.8. Diesel Engine Emissions Fueled with Restaurant Waste Oils 47
2.9. Diesel Engine Emissions Fueled with Waste Vegetable Oil Esters 49
3. EXPERIMENTAL METHODS AND APPARATUS 53
3.1. Test System Setup for Small Scale Biodiesel Production 53
3.2. Diesel Engine Setup and Test Schedule 54
3.3. Data Acquisition System and Emission Measurement Equipment 56
4. DATA ANALYSIS AND CALCULATION 58
4.1. Data Analysis 58
4.1.1. Exhaust Emissions 58
4.1.2. Humidity Correction Factor for NO 61
x
4.2. Analysis of Injection Pressure Cylinder Pressure and Ignition Delay 63
4.3. Heat Release Analysis and Cylinder Pressure Smoothing Technique 66
4.4. Statistical Analysis 73
5. BIODIESEL PRODUCTION FROM HIGH FFA FEEDSTOCKS 74
5.1. Preparation of Methyl Ester with Sulfuric Acid Catalyst 75
5.1.1. Effect of Molar Ratio 77
5.1.2. Effect of Reaction Temperature 79
5.1.3. Effect of Catalyst Amount 79
5.1.4. Effect of Reaction Time 81
5.1.5. Effect of Alcohol Type 82
IV
5.1.6. Effect of Water 83
5.1.7. Effect of Free Fatty Acids 85
5.1.8. Summary of the Acid Catalysis Study 87
5.2. Preparation of Methyl Ester from Material with High FF A 88
5.2.1. Process Development 89
5.2.1.1. Effect of Catalyst Amount and Reaction Time on the Acid Value of
the Synthetic Mixture 90
5.2.1.2. Effect of FFA Level 91
5.2.1.3. Effect of Alcohol Type 94
5.2.2. Development of 2-Step Pretreatment Process 95
5.2.2.1. Effect of Molar Ratio, Catalyst Amount, and Reaction Time in First Step. 98
5.2.2.2. Effect of Molar Ratio, and Reaction Time in Second Step 99
5.2.2.3. Effect of Acid Value on Alkaline-Catalyzed T ransesteri fication 105
5.2.3. Summary of the Preparation of Methyl Ester from Material with High FFA.. 107
5.3. Preparation of Methyl Esters from Yellow Grease 108
5.3.1. Effect of Molar Ratio and Reaction Time on the Acid Value of
Yellow Grease in First Step and Second Step 109
5.3.2. Effect of Different Alkaline Catalysts on Tr ansesteri fication 112
5.3.3. Summary of the Preparation of Methyl Esters from Yellow Grease 114
5.4. Preparation of Methyl Esters from Brown Grease 115
5.4.1. Effect of Catalyst Amount on the Acid Value of Brown Grease 116
5.4.2. Effect of Different Alkaline Catalyst and Amounts on Transesterification 117
5.4.3. Yield Analysis of the Methyl Esters Produced from Feedstock with
High FFA 119
5.4.3.1. Effect of Pretreatment Step Number and Alkaline Catalyst on
the Methyl Ester Yield 119
5.4.3.2. The Effect of Solubility of Methanol in the Oils and Methyl Ester 121
5.4.4. Summary of the Preparation of Methyl Esters from Brown Grease 123
5.5. Soap and Catalyst Analysis in Washing Process of the Methyl Esters 124
5.6. Test System Setup for Pilot Plant Scale Biodiesel Production 126
5.6.1. Pretreatment Unit in the Pilot Plant 126
5.6.2. Tr ansesteri fication (Main) Unit in the Pilot Plant 131
5.7. Pilot Plant Operation and Analysis 133
5.7.1. Large Scale Biodiesel Production from Soybean Oil (Case Study 1) 133
5.7.2. Large Scale Biodiesel Production from Yellow Grease (Case Study 2) 136
5.7.3. Effect of Mixing 142
5.7.4. Effect of Washing Number 142
5.7.5. Large Scale Methyl Ester Production from Brown Grease (Case Study 3) 143
5.7.6. Soap and Catalyst Analysis in Pilot Plant Methyl Ester Production 147
5.7.7. Summary of the Pilot Plant Operation and Analysis 149
5.8. Economic Analysis of the Methyl Esters Produced in the Pilot Plant 150
5.8.1. Cost Analysis of the Methyl Esters Produced in the Pilot Plant 150
V
5.8.2. Comparison of the Costs of the Methyl Esters Produced in the Pilot Plant 153
6. ENGINE TEST RESULTS AND DISCUSSION 158
6.1. Properties of the Fuels Used in Engine Test 158
6.2. Performance and Emissions of the Diesel Engine Fueled with Biodiesel 161
6.2.1. Engine Performance 161
6.2.2. Engine Emissions 166
6.2.2.1. Comparison of CO Emissions 167
6.2.2.2. Comparison of CO% Emissions 168
6.2.2.3. Comparison of Unbumed HC Emissions 169
6.2.2.4. Comparison of NO Emissions 171
x
6.2.2.5. Comparison of Bosch Smoke Numbers (SN) 173
6.2.2.6. Summary of Exhaust Emissions Results 175
6.3. Combustion Characteristics of the Fuels Tested in the Diesel Engine 175
6.3.1. Comparison of the Start of Fuel Injection 175
6.3.2. Comparison of the Start of Combustion and Fuel Burning Rate 179
6.3.3. Comparison of the Ignition Delay 181
6.4. Observed Trends in Engine Emissions and Combustion Characteristics 183
6.4.1. Effect of the Fuels on the Pressures in the Injection Line 184
6.4.2. Effect of Ignition Delay on Unbumed HC and CO Emissions 186
6.4.3. Effect of Start of Fuel Injection on Smoke Number 188
6.4.4. Effect of Start of Fuel Injection and the Start of Combustion on
NO Emissions 188
x
7. CONCLUSIONS AND RECOMMENDATIONS 192
7.1. Process Development 192
7.2. Pilot Plant Development 196
7.3. Engine Performance and Emissions Evaluation 197
7.4. Recommendations for Future Work 198
APPENDIX A: AOCS OFFICIAL METHOD CA 14-56 FOR TOTAL, FREE AND
COMBINED GLYCEROL TEST 200
APPENDIX B: AOCS OFFICIAL METHOD CD 3A-63 FOR ACID VALUE TEST.. 209
APPENDIX C: SOAP AND CATALYST TEST IN ESTER, WASH WATER, AND
GLYCERIN 211
APPENDIX D: CALIBRATIONS OF THE PRESSURE TRANSDUCERS 213
APPENDIX E: CALIBRATION CURVES OF THE EMISSION ANALYZERS 215
APPENDIX F: ANOVA TABLES 218
APPENDIX G: RAW DATA COLLECTED FOR ENGINE TEST 221
REFERENCES
ACKNOWLEDGMENTS