The topic of alternative energies for vehicles

ABSTRACT The main objective of this thesis is to study about alternative energy sources used on internal combustion engines in order to reduce the engine's emission of pollutant gas and

MINISTRY OF EDUCATION AND TRAINING

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION

FACULTY FOR HIGH QUALITY TRAINING

GRADUATION THESIS AUTOMOTIVE ENGINEERING

Ho Chi Minh City, July 2023

THE TOPIC OF ALTERNATIVE ENERGIES FOR VEHICLES

NGUYEN MINH KHANG

S K L 0 1 0 7 7 3

ADVISOR : PhD NGUYEN VAN TRANG STUDENTS: NGUYEN MINH KHOA

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION

FACULTY FOR HIGH QUALITY TRAINING

Advisor: PhD NGUYỄN VĂN TRẠNG

Ho Chi Minh City, July 2023

THE SOCIALIST REPUBLIC OF VIETNAM

Independence – Freedom– Happiness

-

Ho Chi Minh City, July 1st, 2023

GRADUATION PROJECT ASSIGNMENT

Student name: NGUYỄN MINH KHOA Student ID: 19145193

Student name: NGUYỄN MINH KHANG Student ID: 19145188

Major: Automotive engineering technology

1 Project title: The topic of Alternative Energies for Vehicles

2 Content of the project:

-Chapter 1: Introduction

-Chapter 2: Hazard of pollution in internal combustion engine exhaust

-Chapter 3: Alternative fuels, advance additives and oil to improve environmental

performance of vehicles

-Chapter 4: Alternative and regenerate gas fuel to improve the environmental performance

of vehicles

-Chapter 5: Hybrid vehicle technologies

-Chapter 6: Battery technology for CO2 reduction

-Chapter 7: Conclusion and recommendation

3 Final product: 01 explanation book

CHAIR OF THE PROGRAM

(Sign with full name)

ADVISOR

(Sign with full name)

THE SOCIALIST REPUBLIC OF VIETNAM

Independence – Freedom– Happiness

-

Ho Chi Minh City, July 1st, 2023

ADVISOR’S EVALUATION SHEET

Student name: NGUYỄN MINH KHOA Student ID: 19145193

Major: Automotive engineering technology

Project title: The topic of Alternative Energies for Vehicles

Advisor: PhD NGUYỄN VĂN TRẠNG

EVALUATION

1 Content of the project:

2 Strengths:

3 Weaknesses:

4 Approval for oral defense? (Approved or denied)

THE SOCIALIST REPUBLIC OF VIETNAM

Independence – Freedom– Happiness

-

Ho Chi Minh City, July 1st, 2023 PRE-DEFENSE EVALUATION SHEET Student name: NGUYỄN MINH KHOA Student ID: 19145193 Student name: NGUYỄN MINH KHANG Student ID: 19145188 Major: Automotive engineering technology

Project title: The topic of Alternative Energies for Vehicles Name of Reviewer:

EVALUATION 1 Content and workload of the project

2 Strengths:

3 Weaknesses:

4 Approval for oral defense? (Approved or denied)

5 Overall evaluation: (Excellent, Good, Fair, Poor)

6 Mark:……….(in words: )

Ho Chi Minh City, … month, … day, … year

REVIEWER

(Sign with full name)

THE SOCIALIST REPUBLIC OF VIETNAM

Independence – Freedom– Happiness

-

Ho Chi Minh City, July 1st, 2023 EVALUATION SHEET OF DEFENSE COMMITTEE MEMBER Student name: NGUYỄN MINH KHOA Student ID: 19145193 Student name: NGUYỄN MINH KHANG Student ID: 19145188 Major: Automotive engineering technology

Project title: The topic of Alternative Energies for Vehicles Name of Defense Committee Member:

EVALUATION 1 Content and workload of the project

2 Strengths:

3 Weaknesses:

5 Overall evaluation: (Excellent, Good, Fair, Poor)

6 Mark:……….(in words: )

Ho Chi Minh City, … month, … day, … year

COMMITTEE MEMBER

(Sign with full name)

ACKNOWLEDGEMENT

With the assistance of the university, professors from the Faculty of High Quality Education, family, forebears, and coworkers, we studied and conducted research for our graduation thesis during that period We are deeply indebted to PhD Nguyen Van Trang, who encouraged and guided us during the graduation project

We would like to express our gratitude to the Ho Chi Minh City University of Technology and Education Board of Directors and the Faculty of Vehicle and Energy Engineering faculty for their support and direction during our academic careers We acquired a lot of new knowledge that will help us in the future, as evidenced by our graduation thesis Although there have been many efforts in the process of implementation time, due to limited professional knowledge and experience, the thesis still needs to improve, and we are looking forward to the valuable contributions of teachers and students Colleagues continue to exchange and contribute to helping us improve the thesis

Finally, we would like to thank our family, our friends and coworkers for their continuous support during the entire time we have studied at HCMUTE

Best regards!

ABSTRACT

The main objective of this thesis is to study about alternative energy sources used on internal combustion engines in order to reduce the engine's emission of pollutant gas and the risk of exhausting traditional fuel sources The thesis explores different sources of clean fuels with great potential in future applications Analyze and compare advantages and disadvantages for current traditional fuels such as gasoline and diesel Provide practical application evidence to see the potential for emissions and renewables Explain the production and transportation of alternative fuels Thereby showing the essential need of alternative energy sources in the future There are 7 chapters in the thesis:

We provide justifications and arguments for selecting the topic in the first chapter, which serves as an introduction to the thesis implementation technique The current environmental imperatives and the need for alternative fuels are then covered in chapter 2

It is becoming more and more concerning that exhaust gas pollution and traditional fuel sources are running out

We started looking at alternative fuels that may be used in today's automobiles, including those in liquid and gaseous forms Three potential liquid fuels for automobiles are ethanol, biodiesel, and methanol They carry the promise of a future replacement for conventional energy sources like gasoline and oil thanks to their better environmental emissions and strong vehicular application qualities Gaseous fuels like natural gas, biogas, propane, or hydrogen are also excellent answers to the world's fuel shortage There has been widespread use of these traits and advantages in the contemporary reality around the world The aforementioned alternative fuels will help the environment and move us closer to our goal of having no emissions by 2050 since they will reduce carbon emissions somewhat The thesis also demonstrates how much hybrid electric vehicles contribute to environmental issues Learn about the many hybrid electric car models available today and battery technology that lowers CO2 emissions

TABLE OF CONTENTS

GRADUATION PROJECT ASSIGNMENT i

ADVISOR’S EVALUATION SHEET ii

PRE-DEFENSE EVALUATION SHEET iii

EVALUATION SHEET OF iv

DEFENSE COMMITTEE MEMBER iv

ACKNOWLEDGEMENT v

ABSTRACT vi

TABLE OF CONTENTS vii

LIST OF FIGURES xi

LIST OF TABLES xvii

LIST OF ABBREVIATION xix

CHAPTER 1 INTRODUCTION 1

1.1 Reasons for choosing the topic 1

1.2 Need for Alternative Fuel 1

1.3 Research purposes 2

1.4 Object and scope of the study 2

1.5 Situation of biofuel research abroad 2

1.6 Research situation in Vietnam 5

CHAPTER 2: HAZARD OF POLLUTION IN INTERNAL COMBUSTION ENGINE EXHAUST 7

2.1 Introduction 7

2.2 The state of global air pollution 7

2.3 Mechanism of formation of harmful substances in exhaust gases of internal combustion engines 12

2.3.1 Mechanism of formation of Nitrogen Oxide 12

2.3.2 Formation of nitrogen dioxide 12

2.3.3 Formation of nitrogenous protoxide 13

2.3.4 Mechanism of formation of unburnt hydrocarbon HC 13

2.3.5 Mechanism of PM formation in the combustion of Diesel engines 13

2.4 Harm of pollutants in engine exhaust 14

2.4.1 For human health 14

2.4.2 For the environment 15

CHAPTER 3: ALTERNATIVE FUELS, ADVANCE ADDITIVES AND OIL TO

IMPROVE ENVIRONMENTAL PERFORMANCE OF VEHICLES 17

3.1 Biodiesel 17

3.1.1 Introduction 17

3.1.2 Biodiesel production 18

3.1.3 Biodiesel Properties 23

3.1.4 Transportation and Storage of Biodiesel 24

3.1.5 Engine Tests 25

3.1.6 Challenges for Biodiesel 31

3.2 Methanol 31

3.2.1 Introduction 31

3.2.2 Methanol Properties 32

3.2.3 Potential of Methanol 35

3.2.4 Methanol Benefits and Challenges 36

3.2.5 Engine Tests 37

3.3 Ethanol 45

3.3.1 Introduction 45

3.3.2 Ethanol Production 46

3.3.3 Ethanol Properties 47

3.3.4 Ethanol–Gasoline Engine Tests 49

3.3.5 Flexible Fuel Vehicles 59

Flex Fuel: Benefits and Disadvan 60

3.3.6 Ethanol Opportunities and Challenges 60

CHAPTER 4: ALTERNATIVE AND REGENERATE GAS FUEL TO IMPROVE THE ENVIRONMENTAL PERFORMANCE OF VEHICLES 62

4.1 Fossil natural gas 62

4.1.1 Introduction 62

4.1.2 Natural Gas Composition 63

4.1.3 Natural Gas Properties 63

4.1.4 Fossil natural gas production, transmission and distribution 66

4.1.5 Advantages and disadvantages of NG 66

4.1.6 Natural gas safety 68

4.1.7 Test with CNG-DI engine 70

4.1.8 Challenges for CNG 79

4.2.2 Biogas production 81

4.2.3 Biomethane distribution and storage 83

4.2.4 Advantages and disadvantages when using biogas as fuel for engines 84

4.2.5 The Benefits of Biogas Upgrade to Biomethane 84

4.2.6 SWOT Analysis of Biogas and Biomethane 86

4.2.7 Performance 87

4.2.8 Gas vehicles 88

4.3 Liquid petroleum gas (LPG) 89

4.3.1 Introduction 89

4.3.2 LPG Production, distribution and storage 90

4.3.3 Properties of LPG 91

4.3.4 Water in fuel 93

4.3.5 LPG Merits and Demerits 94

4.3.6 LPG Safety Aspects 95

4.3.7 LPG Conversion Systems 96

4.3.8 LPG in Gasoline Engine Applications 99

4.3.9 LPG in Diesel Engine Applications 101

4.4 Hydrogen 105

4.4.1 Introduction 105

4.4.2 Hydrogen production 108

4.4.3 Hydrogen properties 112

4.4.4 Hydrogen Storage and Transportation 117

4.4.5 Hydrogen Benefits 120

4.4.6 Hydrogen Safety 121

4.4.7 Hydrogen impact on economic growth 123

4.4.9 Hydrogen in Fuel Cells 124

4.4.8 Impact of Hydrogen Fuels on the Performance of Internal Combustion (IC) Engine 126

4.4.9 Impact of Hydrogen Fuels on Emissions of Internal Combustion (IC) Engines 130

CHAPTER 5: HYBRID VEHICLE TO PROCTECT ENVIRONMENT 135

5.1 Introduction 135

5.2 Hybrid Vehicle Configurations 136

5.3 Hybrid Vehicle Classification 138

5.4 Hybrid Vehicle Operations 139

5.4.1 Series Hybrid Operation 139

5.4.2 Parallel Hybrid Operation 140

5.4.3 Series–Parallel Hybrid Operation 141

5.4.4 Complex Hybrid Operation 143

5.4.5 ISG System Operation 145

5.5 Hybrid Vehicle Benefits 146

5.5.1Energy Benefit 146

5.5.2 Environmental Benefit 148

5.6 The challenges of hybrid vehicle design 150

CHAPTER 6: BATTERY TECHNPLOGY FOR CO 2 REDUCTION 153

6.1 Introduction 153

6.2 CO 2 reduction opportunities of using batteries 154

6.2.1 Introduction 154

6.2.2 Review of passenger car driving cycles 154

6.2.3 Summary 164

6.3 Battery functionality and chemistries for vehicle applications 164

6.3.1 Cell functionality 164

6.3.2 Performance metrics 166

6.3.3 Chemistries 166

6.3.4 Cost 171

6.4 Lithium ion cells 172

6.4.1 Lithium ion cell construction 172

6.4.2 Lithium ion cell safety 172

6.4.3 Lithium ion cell life 173

6.5 Battery management systems 173

6.5.1 Introduction 173

6.5.2 Cell voltage measurement and control 174

6.5.3 Contactor control 174

6.5.4 Isolation monitoring 175

6.5.5 Temperature control 175

6.5.6 State of charge/health calculation 175

6.5.7 Communication 176

CHAPTER 7: CONCLUSION AND RECOMMENDATION 177

REFERENCES 178

LIST OF FIGURES

Figure 1 1 Government goals and polices of some Southeast Asian countries to the

biofuel development 6

Figure 1 2 Total energy consumption for vehicles in some countries area area Winter Male Asian (IEA 2008) 6

Figure 2 1 Annual variation of air pollutant concentration on China between 2015 and 2018 8

Figure 2 2 Emission rates of gaseous pollutants in Ibadan [4] 9

Figure 2 3 Seasonal average values of PM2.5 concentrations from 2017 to 2020 10

Figure 2 4 Carbon dioxide emissions in Japan in fiscal year 2020, by sector 11

Figure 2 5 Carbon dioxide emissions from energy consumption in the United States from 1975 to 2021 11

Figure 2 6 Greenhouse effect 16

Figure 3 1 US Biodiesel Production, Exports, and Consumption 17

Figure 3 2 Schematic of Biodiesel Production Path 18

Figure 3 3 Transesterification equation 19

Figure 3 4 Acid esterification equation 19

Figure 3 5 Mechanism of acid catalyzed transesterification of vegetable oils 20

Figure 3 6 Ester conversion with respect to molar ratio 20

Figure 3 7 Supercritical methanolysis process 21

Figure 3 8 Schematic diagram of the experimental setup 26

Figure 3 9 NOx emission vs engine load at constant engine speed of 1500 rpm 27

Figure 3 10 CO emission vs engine load at constant engine speed of 1500 rpm 28

Figure 3 11 CO2 emission vs engine load at constant engine speed of 1500rpm 29

Figure 3 12 HC emission vs engine load at constant engine speed of 1500 rpm 30

Figure 3 13 Global methanol demand between 2018 and 2022 32

Figure 3 14 Methanol production from natural gas 34

Figure 3 15 Biomass (Wood) to methanol process 35

Figure 3 16 The schematic diagram of the chassis dynamometer CFV = critical flow venturi; HEPA = high efficiency particulate air filter; OVN = oven type heated analyzer 37

Figure 3 17 Effects of different methanol blending ratios on fuel consumption at

different vehicle speeds 39

Figure 3 18 Effects of different methanol blending ratios on CO2 emissions at different vehicle speeds 41

Figure 3 19 Effects of different methanol blending ratios on NOx emissions at different vehicle speeds 42

Figure 3 20 Effects of different methanol blending ratios on CO emissions at different vehicle speed 43

Figure 3 21 Effects of different methanol blending ratios on THC emissions at different vehicle speeds 44

Figure 3 22 Greenhouse gas emission reduction potential with respect to source 45

Figure 3 23 Global Ethanol Production by Country or Region 47

Figure 3 24 Effective torque vs RPM for different ethanol-gasoline blends and octane levels 52

Figure 3 25 Effective power vs RPM for various ethanol-gasoline blends and octane levels 53

Figure 3 26 Specific consumption vs RPM for various gasoline-ethanol blends and octane levels 54

Figure 3 27 Effective performance vs RPM for different ethanol-gasoline blends and octane levels 55

Figure 3 28 Carbon monoxide vs RPM for different concentrations of ethanol-gasoline and octane levels 56

Figure 3 29 Nitrogen oxides vs RPM for different ethanol-gasoline blends and octane levels 57

Figure 3 30 Carbon dioxide vs RPM for different ethanol-gasoline blends and octane levels 58

Figure 4 1 The applications of NG 62

Figure 4 2 Estimated technically recoverable shale gas reserves (tcm) 63

Figure 4 3 Various Combustion Systems for CNG fuel 70

Figure 4 4 Schematic Diagram of the Experimental Set-Up 71

Figure 4 5 Brake Power Versus Engine Speed at WOT 74

Figure 4 6 Brake Torque Versus Engine Speed at WOT 75

Figure 4 7 Brake Specific Fuel Consumption Versus Engine Speed at WOT 75

Figure 4 8 Unburned Hydrocarbon Versus Engine Speed at WOT 76

Figure 4 9 Oxides of Nitrogen Versus Engine Speed at WOT 77

Figure 4 10 Carbon Monoxide Versus Engine Speed at WOT 78

Figure 4 11 Biomethane supply chains (a) landfill gas pathways and (b) anaerobic digestion (AD) pathways 81

Figure 4 12 Schematic of a generic anaerobic digestion process 82

Figure 4 13 Conversion routes to produce liquefied/compressed biomethane 82

Figure 4 14 Typical biogas production by feedstock (m3 /ton) 82

Figure 4 15 SWOT analysis of biogas 86

Figure 4 16 SWOT analysis of biomethane 87

Figure 4 17 Global LPG consumption from 2002-2012 89

Figure 4 18 Route of LPG from production to the end-consumer 90

Figure 4 19 The vehicle LPG fuel tank and its design parameters 95

Figure 4 20 Mechanically controlled LPG carburetion system used (first generation) 97

Figure 4 21 Microprocessor-controlled LPG system (second generation) 97

Figure 4 22 Sequent LPG vapor injection system (third generation) 98

Figure 4 23 Brake thermal efficiency variations with engine speed for various water/fuel mass ratios of water injection 100

Figure 4 24 BSFC variations with engine speed for variations water/fuel mass ratios of water injection 101

Figure 4 25 Histogram of maximum combustion pressure for diesel and dual fuel engine 102

Figure 4 26 Effect of equivalence ratio on ignition delay of propane diesel/air mixture 103

Figure 4 27 Effect of engine load on pressure rise rate for diesel and dual fuel engine 103

Figure 4 28 Schematic diagram of EGR system for dual fuel engine 104

Figure 4 29 Fuel conversion efficiency and bsfc as a function of load at N = 1500 rpm 104

Figure 4 30 Variation of NOx concentration and exhaust gas temperature with engine load 105

Figure 4 31 Depiction of grey, blue and green hydrogen production 107

Figure 4 32 Other Colors of Hydrogen 108

Figure 4 33 Hydrogen production costs using natural gas in selected regions, 2018.[38] 109

Figure 4 34 Coal-based hydrogen production [30] 111

Figure 4 35 Microbial electrolysis cells [35] 112

Figure 4 36 Combustion chamber volumetric and energy comparison for gasoline and hydrogen fueled engines 116

Figure 4 37 Hydrogen storage 120

Figure 4 38 HYSAFE activity matrix 123

Figure 4 39 Current policy support for hydrogen deployment, 2018 123

Figure 4 40 Schematic of fuel cell 125

Figure 4 41 Fuel cell vehicle with on-board storage 126

Figure 4 42 Volumetric efficiency changes with different percentages of hydrogen in the CI engine [51] 127

Figure 4 43 Volumetric efficiency changes with different percentages of hydrogen in the SI engine [79] 127

Figure 4 44 Brake power and brake torque changes with different percentages of hydrogen in the CI engine [51] 128

Figure 4 45 Brake thermal efficiency with different percentages of hydrogen in the CI engine [51] 128

Figure 4 46 Brake thermal efficiency with different percentages of hydrogen in the SI engine [48] 129

Figure 4 47 Brake thermal efficiency with different percentages of hydrogen in the SI engine [51] 129

Figure 4 48 Reducing of CO emissions using hydrogen fuel in diesel engines [51] 130

Figure 4 49 Reducing of CO emissions using hydrogen fuel in gasoline engines [79].131 Figure 4 50 Reducing CO2 emission using hydrogen fuel in diesel engines [51] 131

Figure 4 51 Reducing CO2 emission using hydrogen fuel in gasoline engines [48] 132

Figure 4 52 Increase of NOx emissions using hydrogen fuel in diesel engines [51] 132

Figure 4 53 Increase of NOx emissions using hydrogen fuel in gasoline engines [85] 133

Figure 5 1 Classification of vehicles 135

Figure 5 3 Classification of HEVs 138

Figure 5 4 Series hybrid operating modes 140

Figure 5 5 Parallel hybrid operating modes 141

Figure 5 6 Engine-heavy series–parallel hybrid operating modes 142

Figure 5 7 Motor-heavy series–parallel hybrid operating modes 143

Figure 5 8 Dual-axle (front-hybrid rear-electric) complex hybrid operating modes 144

Figure 5 9 Separated-starter-generator system for conventional ICEVs 145

Figure 5 10 Integrated-starter-generator system for HEVs 145

Figure 5 11 Power generations of electricity for two types of HEVs—PHEV and REV 147

Figure 5 12 Energy conversions for various EVs 148

Figure 5 13 Energy savings by regenerative braking 148

Figure 5 14 Global warming potential related to the entire lifecycle of the three reference vehicles 149

Figure 5 15 Comparison of vehicle noises 150

Figure 6 1 Growth in light-duty plug-in electric vehicle sales globally since 2011 153

Figure 6 2 US federal test procedure (FTP) 72 driving cycle 155

Figure 6 3 US highway driving cycle 156

Figure 6 4 US 06 driving cycle 156

Figure 6 5 Illustration of idle time during US FTP 72 driving cycle 159

Figure 6 6 Per cent of US FTP 72 driving cycle that can be completed versus power delivered to the road for several vehicle classes Graph does not go through origin due to idling time 160

Figure 6 7 Per cent of US 06 driving cycle that can be completed versus power delivered to the road for several vehicle classes Graph does not go through origin due to idling time 161

Figure 6 8 Peak acceleration power requirements by drive cycle and vehicle size 161

Figure 6 9 Peak braking power requirements by drive cycle and vehicle size 162

Figure 6 10 Maximum energy content of single braking event by drive cycle and vehicle size 163

Figure 6 11 Theoretical braking energy available by vehicle speed and vehicle size 163

Figure 6 12 Battery processes during discharge 165

Figure 6 13 Battery processes during charge 166

Figure 6 14 2008 Toyota Prius NiMH battery pack 168

Figure 6 15 2010 Honda Insight NiMH battery pack 168

Figure 6 16 Lithium ion cell construction 172

LIST OF TABLES

Table 3 1 Comparison of Biodiesel Production Methods 22

Table 3 2 Biodiesel's Physical Characteristics 23

Table 3 3 Measured properties of D100, B10, B20 and B30 25

Table 3 4 The Yanmar TF-M diesel engine specifications 26

Table 3 5 Properties of Methanol 33

Table 3 6 Main parameters of the GDI engine 37

Table 3 7 Main properties of methanol and gasoline 38

Table 3 8: Ethanol Fuel Properties in Comparison with Gasoline and Diesel 47

Table 3 9: Biodegradability of Selected Fuels 49

Table 3 10 Main characteristics of the engine used in the tests 50

Table 3 11 Physicochemical properties of gasoline and anhydrous ethanol 50

Table 3 12 Volumetric concentrations of the fuels involved in the tests 51

Table 4 1: Natural gas composition 63

Table 4 2: Compering of Natural Gas with Gasoline and Diesel 64

Table 4 3: Safety’s properties of NG compare with Petrol and Diesel 69

Table 4 4 Test Engines Specifications 72

Table 4 5 Natural gas composition 73

Table 4 6: Selected properties and constituents of biogas, biomethane and fossil natural gas 79

Table 4 7 European biogas feed-in projects as of May 2010 83

Table 4 8 Typical ranges and differences in the composition of raw biogas, biomethane, and natural gas as reference 85

Table 4 9: Energy content of biogas and some other fuels 88

Table 4 10: The composition of LPG for different countries 91

Table 4 11: LPG Properties Compared to Gasoline and Diesel Fuels 92

Table 4 12: Physical Properties of Hydrogen 113

Table 4 13: Fuel Properties of Hydrogen 114

Table 4 14: Ignition and Flammability Properties of Hydrogen in Comparison with Other Fuels 115

Table 4 15: Comparison of Energy Content of Various Fuels 116

Table 4 16 Classification of fuel cell systems based on the employed membrane 125

Table 6 1: Summary of key statistics of common global driving cycles 155

Table 6 2: USABC battery goals 157

Table 6 3: Start stop metrics for US and select international driving cycles 158

LIST OF ABBREVIATION

NG: Natural Gas

CNG: Compressed natural gas

LNG: Liquefied natural gas

USEPA: The US Environmental Protection Agency

ENTSOG: European Network of Transmission System Operators for Gas

LVH: Lower heating value

EIA: International Energy Agency

US: United State

UK: United Kingdom

WOT: Wide open throttle

RNG: Renewable natural gas

AD: Anaerobic digestion

MSW: Municipal solid waste

BLEVE: Boiling liquid expanding vapor explosion

UVCE: Unconfined vapor cloud explosion

BSFC: Brake specific-fuel consumption

H2-ICEs: Hydrogen-fueled internal combustion engines

ICE: Internal combustion engine

FCEVs: Fuel for fuel cell electric vehicles

LDVs: Low voltage differential signaling

POX: Partial oxidation

ATR: Autothermal reforming

SOEC: Solid Oxide Electrolysis Cells

EFI: Electronic fuel injection

DI: Direct injection

HCNG: Hydrogen–CNG Engines

PEVs: Plug-in electric vehicles

BEVs: Battery electric vehicles

PHEVs: Plug-in hybrid electric vehicles

USCAR: United States Council for Automotive Research

USABC: United states Advanced Battery Consortium

EVS: Electric vehicles

HEVs: Hybrid electric vehicles

BMS: Battery management system

HVIL: High Voltage Interlock

SOC: State of charge

SOH: State of health algorithm

DC: Direct current

HFRR: High frequency reciprocating rig

FFA: Free fatty acids

RVP: Reid Vapor Pressure

DME: Dimethyl ether

MTBE: Methyl tertiary-butyl ether

DMC: Dimethyl carbonate

BTE: Brake thermal efficiency

MON: Motor octane number

AFR: Air-fuel ratio

FFV: Flexible fuel vehicle

ZEV: Zero-emission vehicle

SULEVs: Super ultra-low emission cars

REV: Range-extended electric vehicles

ISG: Integrated starter generator

ECVT: Electronic continuously variable transmission

SRM: Switched reluctance motor

PFC: Power factor corrector

IGBT: Insulated-gate bipolar transistor

OEMs: Original equipment manufacturers

CHAPTER 1 INTRODUCTION

1.1 Reasons for choosing the topic

Today, along with the strong development of economy and society, there is a rapid increase

in means of transportation and propulsion equipment equipped with internal combustion engines As a result, fuel consumption is increasing, especially traditional fossil fuels gasoline and diesel This is causing the risk of rapid depletion of traditional fuel sources and serious environmental pollution due to toxic emissions of the engine

Vietnam is a developing country, so it is not outside the general development rules of the world The shortage of fuel and environmental pollution caused by exhaust from traditional fuel-powered engines are at an alarming rate Therefore, the problem is that it is necessary

to research and use alternative fuels with low toxic emissions to reduce environmental pollution on the one hand, and on the other hand can partially compensate for the shortage

of transmission fuel system The preferred alternative fuels are those with low toxic emissions, large reserves, low cost, and can be easily used in existing engines without much need to be changed about texture Some typical alternative fuels can be mentioned such as hydrogen, liquefied petroleum gas, compressed natural gas (Compressed Natural Gas - CNG), biomass gas

According to the forecast of the US Department of Energy, by 2030, the proportion of traditional fossil energy in total energy use will remain high, over 86%, renewable energies will only increase insignificantly, about 8.1% In addition, environmental pollution and the greenhouse effect pose many difficult challenges for humans That has prompted scientists

to research more economical methods of using fuel (using fuel-saving additives, using high-efficiency thermal equipment and engines ) and developing alternative fuel sources, new and renewable fuel sources, reducing environmental pollution emissions Therefore, our group chose the topic ‘The topic of Alternative Energy for Vehicle''

1.2 Need for Alternative Fuel

• Diminishing Reserves of Conventional Fuels

The traditional fuels including petroleum would be depleted after some time Because they are not renewable

• To reduce environmental pollution

The use of alternative fuels significantly harmful exhaust emissions as well as ozone- producing emissions

• To protect against Global Warming

According to a commonly accepted scientific theory, burning fossil fuels was causing temperatures to rise in the earth's atmosphere Although global warming continues to be just a theory, a lot of people across the globe are of the belief that discovering sources of cleaner burning fuel is an essential step towards enhancing the quality of our environment

• To reduce import cost and improve nation's economy

The majority of oil fields are located in the Middle East and the majority of OPEC countries are associated with problems – both political and economic So, the production rate in uncertain and may not meet demand This causes a rise in price abruptly On the other hand, the feedstock for alternative fuels are renewable and can be produced locally with

• Meeting the current global energy demand

Every day increasing demand of energy has created a large gap between demand and supply

1.3 Research purposes

Research and use alternative fuels with low toxic emissions to reduce environmental pollution on the one hand, and on the other hand can partially compensate for the shortage

of traditional fuels Analyze and statistics data specifically on emission factors produced

in alternative fuel sources Realize the benefits and limitations of alternative fuels Shows

us the urgency of environmental problems and the depletion of traditional fuel sources Understand the alternative renewable fuel sources, understand the different types of alternative fuels available as of today Know the chemical properties of alternative fuel

1.4 Object and scope of the study

The object and scope of this study is renewable and abundant energy sources today in order

to overcome the shortage of traditional energy and the pollution problem in engine exhaust The scope of the study focuses on the theoretical basis, statistics and practical comparisons

on many aspects of alternative raw materials compared to gasoline and diesel such as engine performance, emissions, cost, etc

1.5 Situation of biofuel research abroad

Biofuels in solid form have been used since man-made discovery fire Wood was the first form of biofuel used even by ancient people for cooking and heating With the discovery

of electricity, man discovered one way awake other to history use the course birth? learn Biofuel study has been used use the word one time very long to produce power output In this form, it is possible to see the detected fuel even before it is detected fossil fuels Due

to exploratory developments in the field of fossil fuels The appearance of fossil fuels such

as gas, coal, and oil has seriously affected the production and biofuel use With its advantages, fossil fuels have become popular, special bye is in countries play develop Research using biofuel is typical Nikolaus August Otto Rudolf Diesel is the German inventor of the diesel engine He designed the diesel engine to run in peanut oil and then, Henry Ford was car design Model T was produced 1903-1926 This vehicle is completely designed to use fuel biofuel derived from hemp for fuel With the development of science and technology techniques in the exploration, exploitation and processing of fossil fuels, the "ancient" fuel dictionary" with cheap and abundant cost has led to difficulties for the development of product technology export also like app use give course Whether born learn

However, after the severe oil crisis in 1973 and in 1979, research on biofuel production was focused again And since 2000, countries around the world actually complied with the Rio de Janeiro Compromise (1992), then Kyoto (1997), find techniques to limit greenhouse gas (CO2, methane, N2O, etc.) classic fuel, replaced by green energy (green energy like solar energy) weather, wind, hydroelectricity, etc.) In the past two decades, it is expected

that at a rate of Exploiting and consuming as today, fossil fuels such as coal and crude oil will be exhausted depleted in the next few decades, and at the same time the perception of greenhouse effect caused by the use of Using fossil fuels, biofuels are once again of interest and it became an important goal in the program of sustainable economic development for the Country family

Currently, in the world, there are more than 50 countries that have conducted research and production put into use biofuel Biofuels are used as fuel in the transport sector including clean vegetable oils, ethanol, biodiesel, dimethyl ether (DME), ethyl tertiary butyl ether (ETBE) and products thereof According to statistics, for biofuels bioethanol, in 2003 the total ethanol production was 38 billion liters, by 2006, the whole world had produces about

50 billion liters of ethanol of which about 75% is used as fuel According to it is expected that in 2012, ethanol fuel output will reach about 80 billion liters For fuel biodiesel, in

2005 produced 4 million tons of biodiesel (B100), in 2010 it will increase about above 20 million ton

One of the first countries to use bioethanol fuel on a public scale business is Brazil Since

1970, research on the use of biofuels has been invested On a national scale, in 1975 all gasoline was blended with 25% (E25) Each year Brazil period sword about 2 billion dollar

is the word question topic import password oil mine

One of the largest bioethanol producers and users of biofuel best right tell arrive to be America Year 2006, product export bioethanol obtains near the 19 billion liters, in there than 15-billion-liter okay history use do course whether, accounting for near the 3% market school course whether gasoline According to It is predicted that in 2012, this country will provide over 28 billion liters of ethanol and biodiesel, accounting for 3.5% of the amount of petroleum used To encourage the use of clean fuels, the Government Satisfied real presently job reduce tax 0.50 USD/gallon ethanol and first USD/gallon diesel born At the same time, the US government always has policies to support small and medium enterprises small in the field of biofuel production The head of the White House has vowed to bring water The US got rid of its dependence on foreign oil, by investing heavily in R&D to create labor turmeric new product productivity quantity clean and biofuel

China with the leading population characteristics in the world, every year needs to use 2.5 million barrels of oil, of which 50% must be imported from abroad So, to deal with an energy shortage, on the one hand, China invests heavily outside its territory to exploit Oil extraction, on the other hand, focuses on exploiting and using renewable energy, investing

2.4-in scientific basis for research on biofuels That's why accord2.4-ing to the statistics of inventions in production technology as well like the application of biofuels, now China is the country leading in the world Early 2003 gasoline E10 (10% ethanol and 90% gasoline) Satisfied main awake Okay history use live 5 wall cities big and about to next will open

increase over 2 billion liters by 2010, about 10 billion liters by 2020 (in 2005 it was 1.2 billion liters) At the end of 2005, the factory produced producing fuel ethanol with a capacity of 600,000 tons/year (the largest in the world) has come into operation move at Sand Lam- Central Country

Similar to China, fuel consumption in India is about 2-million-yen bin oil mine /day, although of course, have next 70% quantity pepper tree This Right import export Main government India has a plan to invest 4 billion USD in renewable fuel development, every year product export about 3- b i l l i o n - l i t e r ethanol From month 1/203, 9 bang and 4 pee region Satisfied history use E5 gasoline, next time will be used in the remaining states, then used in the whole country To develop biodiesel for public transport, the government plans to plant the oil plants, especially attend 13 planting project million hectares of trees Jatropha curcas /physic nut (tree fence post, tree oil sesame) to year 2010 replace position about ten% diesel oil mine

In Southeast Asia, the development of research into the production and use of fuel biological materials have been interested and developed since more than 10 years Since

1985, Thailand has mobilized dozens of leading scientific agencies to implement the Royal project develop efficient technology to produce ethanol and biodiesel from palm oil Year

2001, The country has established a National Fuel Ethanol Commission (NEC) chaired by the Minister of Industry and Trade responsible for administering the biofuel development program In 2003, there was stock Dozens of E10 petrol stations in Bangkok and surrounding areas Government insists E10 and B10 will Okay history use in chief water enter head ten century next With Malaysia, commission oil rub MPOB give know, arrive year 2015, this will have 5 home machine product export diesel born learned from palm oil, with a total capacity of nearly 1 million tons for domestic use and export to the EU Indonesia strives to use B5 widely throughout the country by 2015 Outside oil rub, will head private plant ten million ha tree Jatropha curcas take oil do diesel born learn

In addition, some other countries such as Mexico have strategies to develop palm oil and Jatropha curcas to bow grant diesel born learn to use give luck load labor add live prime minister dollar and region shallow village Colombia has enacted a law that requires cities with more than 500,000 inhabitants to use E10 Argentina approved the Biofuel Law (April 2006) regulating 2010 oil refinery mixing 5% ethanol and 5% biodiesel in gasoline for sale

in the market school Costa Rica, Philippines even have reveal submit history use diesel born learn from oil rub, oil coconut European countries have biofuel programs such as: Germany, UK, France, West Spain, Italy, Netherlands, Sweden, Portugal, Switzerland, Austria, Bulgaria, Poland, Hungary, Ukraine, Belarus, Russia, Slovakia Even in Laos, they are also building factories biodiesel production on the outskirts of the capital Vientiane Some African countries like Ghana also in progress next near to the biofuel

1.6 Research situation in Vietnam

Also like the water above position gender and the water in area, research rescue

product export and biofuel application in Vietnam has been proposed for more than

10 years, there have been many research projects on production and testing of

biofuels live some Institutes and universities, investment and development

projects resource extraction raw materials for biofuel production such as biogas,

bioethanol and biodiesel of enterprises Karma Until now, however, the context for

fuel production and application Vietnam's biology is still very bleak, and the main

reason is the Vietnamese government There is no specific long-term strategic

policy to support the application biofuel For biogas fuels, up to now, the

development model is mostly automatic development of people and small and

medium-sized enterprises and the application of fuel This owner weak give

machine play electricity

Studies bioethanol born, development strong from few years or more come here,

when Main Cover Vietnamese Male Satisfied topic go out the chapter submit

push strong history use course born studied and developed national technical

standards on gasoline, diesel fuel and biofuels QCVN1:2009/BKHCN, at present,

there are more than 04 production plant projects ethanol production from tapioca

starch with a scale of around 100 million liters/year, of which, 01 project has been

put into operation, 01 project is about to be completed and the remaining 02

projects are in progress construction process There are also several other projects

According to estimates, with output supply of the above factories and projects,

besides supplying to the domestic market, ethanol Fuel needs to be exported to

foreign countries because the reserves are too large compared to domestic demand

water If taking according to the national gasoline consumption data in 2007

(7,148,000 tons/year), then if phase E5, then the factory project volume meets

adequate response However, the construction massive production projects of

ethanol fuel from cassava (tapioca) will cause great impacts on events play trine

are not weigh opposite to in to submit product export quantity real in Vietnamese

This will lead to an unsustainable development of agriculture Up to now,

deploying the application in the early stages with only E5 is still very slow and has

many problems There are gaps in the technical standards for storage,

transportation, and need to be improved and maintained guess the queen fruit

difficult measure will happen go out when history use fuel born learn

For biodiesel fuel, there have also been many research works and pilot production,

however, to date, many development projects produce type this fuel has to be stopped, the experimental research studies only stop at degree in room then test or tissue image (QCVN1:2009/BKHCN)

comprehensive picture of biofuel development in Vietnam According to research

by experts from the IEA (International Energy Agency), a comparison of goals

and policies for the development of fuel production and use biology in some

Southeast Asian countries shows, figure 1.1, the level of interest of government

to biofuels in the medium level, while policy for chapter love play development

of energy in Thailand be considered heart very high

Figure 1 1 Government goals and polices of some Southeast Asian countries to the

Figure 1 2 Total energy consumption for vehicles in some countries area Southeast

Asian (IEA 2008) [9]

CHAPTER 2: HAZARD OF POLLUTION IN INTERNAL COMBUSTION

ENGINE EXHAUST

2.1 Introduction

Gas pollution is an important environmental problem facing people today Gas is emitted from sources such as vehicles, factories, agriculture and other fossil energy sources Gas contains many pollutants such as greenhouse gases, nitrogen oxides and harmful gases Air pollution can cause many adverse effects on human health and the environment Headaches, shortness of breath, and serious effects on the respiratory system can occur in people exposed to the gas for long periods of time At a more serious level, pollutants in gas can cause climate change and add to global warming

For internal combustion engines, the operation is due to combustion through the combustion of fuel in the cylinder Combustion of a mixture of hydrocarbons and air under ideal conditions will only produce CO2, H2O and N2 However, because of the heterogeneity of the mixture and the complexity of the combustion process, the exhaust gases from the engine always contain harmful substances such as nitrogen oxides (NO, NO2, N2O – collectively known as NOx), carbon monoxide (CO), unburnt hydrocarbons (HC) and solid particles, especially PM The ratio of all these pollutants depends on the type of engine and how it is operated For example, in a Diesel engine, the CO concentration is very low and accounts for an insignificant proportion, the HC concentration is only about 20% of that of a gasoline engine, but the NOx concentration in these two types of engines has similar values equivalent In contrast, PM is an important pollutant in diesel engine exhaust, but it is insignificant in gasoline engine exhaust

The level of pollution generated by the engine will be lower when operating with poor fuel mode However, the concentration of HC will increase because of the low combustion rate and the disengagement of the engine due to the poor combustion mixture [8]

The maximum temperature of the combustion process is also an important factor affecting the composition of pollutants because it strongly affects the reaction kinetics, especially the reactions that generate NOx and PM

In general, all structural or operating parameters of the engine that affect the mixture composition and combustion temperature have a direct or indirect influence on the formation of pollutants in the exhaust gas

Emission standards for cars are applied by different countries around the world with the aim of reducing harmful emissions from cars and protecting the environment Starting in

1992, the Euro I emission standard was applied in the European Union (EU) and has now reached Euro VI In Vietnam, the Euro V emission standard has been officially applied since January 1, 2022 Vin Fast is the leader in applying Euro emission standards to the products it manufactures Vin Fast’s gasoline-powered cars all focus on environmental factors, ensuring emission standards from level 5 (Euro 5) or higher

2.2 The state of global air pollution

Air pollution is becoming a worrying threat to the living environment and human health These pollution sources range from industrial activities and transportation to agriculture, road construction and energy sources Most cities around the world do not comply with World Health Organization (WHO) standards for air quality Figures show that air

developing world In addition to health problems, air pollution also causes harm to the environment, affecting other organisms on the planet Therefore, addressing this issue is urgent and should be a worldwide priority

We can refer to the following definition given by the European Community in 1967: "Air

is said to be polluted when its composition is changed or when foreign substances are present that cause harmful effects scientifically proven harm or cause discomfort to humans"

Accordingly:

− Pollutants can cause harm to nature and humans that science at the time recognized

or simply cause discomfort such as odors, colors

− The list of pollutants as well as their permissible concentration limits in emission sources may change over time

To date, air pollutants have been identified, most of which are present in the exhaust gases

of internal combustion engines

Figure 2 1 Annual variation of air pollutant concentration on China between 2015 and

2018

Sources of air pollution are very diverse As for the air environment in urban areas, pollution is mainly caused by transportation, construction, industry, residential activities and waste In which, the highest pollution source accounts for 70% from means of transport (Ministry of Transport 2010)

Considering the emission sources of polluting gases throughout our country, it is estimated that traffic activities emit nearly 85% of CO, 95% of VOCs

Transport is the biggest source of air pollution in urban areas, especially the emission of

CO, VOC, NO2 Emissions of these gases increase each year with the development of more and more vehicles On average, each car emits 4 times more pollution than motorbikes

Figure 2 2 Emission rates of gaseous pollutants in Ibadan [4]

Figure 2.2 shows that the usage of gasoline was responsible for around 96% and 62%, respectively, of CO and NOx emissions Diesel, with values ranging from around 62 to 97% of the total for each pollutant, is the main source of CO2, PM10, and SO2 emission Likewise, the use of wood was responsible for almost 95% of N2O and CH4 emissions With a large density of vehicles, degraded quality of vehicles and poor road system, the amount of air pollution from traffic is at an alarming rate Cars and motorbikes in

Vietnam include many types, many of which have been used for many years, so they have low technical quality, high fuel consumption and concentration of toxic substances

in exhaust gas, and noise big Even in big cities, the percentage of cars that have been used for many years is still quite high

Construction activities of urban technical and social infrastructure, including water

supply and drainage, transport and housing projects are taking place at a very high rate However, air pollution due to dust from construction sites remains a dilemma Although there are regulations on dust shielding at construction sites, vehicles transporting

materials and waste are required to wash their vehicles before leaving the site, and

spraying of road cleaners is allowed The implementation of these regulations is still limited

Therefore, dust emission from construction, moving and transportation activities still contributes significantly to urban air pollution Regulations on dust protection need to be improved and stricter to ensure the construction of social infrastructure that leaves a beautiful appearance for the city but also ensures the health and living environment for the urban community

Figure 2 3 Seasonal average values of PM2.5 concentrations from 2017 to 2020

From 2018 to 2019, the concentration of PM2.5 dust tends to increase more than the period from 2010 to 2017 Compare the monitoring results of PM2.5 dust concentration in the past months from 2013 - 2019 shows that, from September to mid-December 2019, the concentration of PM2.5 dust increased sharply compared to the previous months and increased compared to the same period of the years from 2015 to 2018 The period from

2019 had many maxima in air pollution in the Northern area from September to December

In several major places, like Hanoi and Ho Chi Minh City, the air quality index has frequently been at a poor level, with the AQI index ranging from 150 to 200, occasionally even reaching 200, which is equal to a very poor level The most harmful type of fine dust

is PM2.5 (under 2.5 micrometers), which, when inhaled through the respiratory system, has the potential to induce a number of disorders that have a negative impact on one's health

Figure 2 4 Carbon dioxide emissions in Japan in fiscal year 2020, by sector

Figure 2 5 Carbon dioxide emissions from energy consumption in the United States

from 1975 to 2021

From January 1, 2020, to April 10, 2020, air quality in our nation will likely be better than

it was during the same time last year [10] According to the AQI calculation's findings, the

kept at excellent to moderate levels Particularly, the levels of PM2.5 and CO parameters were substantially lower than the time starting in the second half of March 2020, which included the time when the entire country adopted social isolation to prevent the Covid 19 epidemic the same time period in prior years Additionally, compared to the period beginning in February 2020, these are the periods when fewer automobiles are involved in traffic in the inner city districts, which forced many socioeconomic activities to stop or scale back This demonstrates that the impact of emission sources, including traffic and factory operations, has a major impact on urban air quality, which is particularly obvious

in Ho Chi Minh City and Hanoi throughout the specified time period Additionally, the above frequently improves on the preceding instance

2.3 Mechanism of formation of harmful substances in exhaust gases of internal combustion engines

2.3.1 Mechanism of formation of Nitrogen Oxide

In the NOx family, NO accounts for the largest proportion NOx is mainly generated by N2

in the intake air of the engine Gasoline or Diesel fuel contains very little nitrogen, so their effect on NOx concentration is negligible Heavy fuels used in low-speed marine engines contain a few parts per thousand nitrogen (mass ratio) and can generate small amounts of NOx in the exhaust gas The formation of NO by oxidation of nitrogen in the air can be described by the Zeldovich mechanism Under conditions of an air residue factor of approximately 1, the main reactions for NO formation and decomposition are:

O + N2 ↔ NO + N (1.1)

N + O2 ↔ NO + O (1.2)

N + OH ↔ NO + H (1.3) Reaction (1.3) occurs when the mixture is very rich NO is formed in the flame film and in the combustion products behind the flame film In the engine, combustion takes place under high pressure conditions, the reaction zone is very thin (about 0.1mm) and the burning time is very short; In addition, the pressure in the cylinder increases during combustion, which makes the temperature of the pre-combustible part higher than the temperature reached immediately after leaving the flame zone, so most of the NO is formed

in the combustion zone after the fire NO formation is strongly temperature dependent The NO generation reaction has a much lower rate than the combustion reaction NO concentration is also strongly dependent on oxygen concentration Therefore, in conditions

of high temperature and high O2 concentration, the NO concentration in the combustion product is also large

2.3.2 Formation of nitrogen dioxide

The concentration of NO2 can be neglected compared with NO if calculated according to equilibrium thermodynamics under normal flame temperature conditions This result can

be approximated in the case of spark ignition engines For Diesel engines, up to 30% of NOx is found in the form of NO2 Nitrogen dioxide NO2 is formed from nitrogen monoxide

NO and intermediates of combustion products according to the following reaction:

NO + HO2 ↔ NO2 + H (1.4) Under high temperature conditions, the NO2 formed can decompose according to the reaction:

NO2 + O ↔ NO + O2 (1.5)

In case the NO2 generated in the flame is immediately cooled by a low-temperature medium, the reaction (1.5) is controlled, that is, NO2 continues to exist in the combustion product Therefore, when the gasoline engine works for a long time at no-load, the concentration of NO2 in the exhaust gas will increase Similarly, when the Diesel engine works at low load, the reverse reaction to convert NO2 into NO is also controlled by low-temperature air regions Nitrogen dioxide also forms in the discharge line when the discharge rate is low and oxygen is present NO2 is the most toxic gas in the NOx family,

so it is important to organize the combustion process well to reduce the reaction rate of formation and speed up the decomposition reaction of this pollutant

2.3.3 Formation of nitrogenous protoxide

Nitrogen protoxide N2O mainly forms from the intermediates NH and NCO when they react with NO:

NH + NO ↔ N2O + H (1.6)

N2O is mainly formed in the oxidizing region with a high concentration of H atoms, and hydrogen is the substance that causes the strong decomposition of nitrogen protoxide according to the reaction:

N2O + H ↔ NH + NO (1.8) N20 + H ↔ N2 + OH (1.9) Therefore, N2O only accounts for a very low proportion in the exhaust gas of an internal combustion engine (about 3 ÷ 8ppmV)

2.3.4 Mechanism of formation of unburnt hydrocarbon HC

The generation of unburnt hydrocarbon HC, or more generally, the formation of organic products, is due to incomplete combustion or due to part of the mixture located outside the flame spread area This occurs due to the heterogeneity of the mixture or to the extinguishing of the flame film in the vicinity of the wall or in the dead spaces, i.e in the low temperature region, which is different from the CO and NOx formation taking place out in a homogeneous phase in areas of high temperature HC includes very different hydrocarbon components, with different toxicity to human health as well as different reactivity during chemical transformation in the atmosphere Usually HC contains a large fraction of methane In addition, they also have more reactive oxygen-containing components such as aldehydes, ketones, phenols, alcohols, etc If the carbon-containing component accounts for only a few percent of the HC of the spark ignition engine, the aldehyde is can reach up to 10% in Diesel engine HC and of these aldehydes, formaldehyde accounts for 20% of total carbon-containing components

2.3.5 Mechanism of PM formation in the combustion of Diesel engines

PM formation in a diffuse flame is primarily fuel dependent The higher the C component fuel, the higher the PM concentration

The second factor affecting PM concentration is fuel concentration and oxygen

concentration Indeed, PM formation is mainly due to incomplete combustion of the fuel When the mixture is poor and uniformly distributed, the PM concentration is so small

formed, which in turn also affects the final PM concentration present in the combustion product

The third factor affecting PM formation is the temperature distribution in the flame High temperatures in fuel-rich regions favor PM formation On the contrary, the high

temperature in the area of excess oxygen will favor the oxidation of PM The

concentration of PM released from the diffuser flame is the difference between the

amount of PM formed and the amount of PM oxidized

In summary, the concentration of PM present in the combustion gas after exiting the diffuse flame depends on four basic factors: fuel composition, fuel concentration, oxygen concentration and temperature distribution in fire

2.4 Harm of pollutants in engine exhaust

2.4.1 For human health

− CO: Carbon Monoxide is a colorless, odorless and tasteless gas produced by the incomplete oxidation of carbon in fuel in the absence of an oxygen supply [8]

CO has the ability to affect the transport of red blood cells in the blood, making parts of the body not enough oxygen If the concentration of CO in the air is greater than 1000 ppm, about 70% of the red blood cell count will be suppressed, which can be fatal to people exposed to CO However, even at lower concentrations, CO can cause long-term health problems in humans When more than 20% of the red blood cell count is controlled, the victim may experience headaches, dizziness, nausea, and when this ratio reaches 50%, the function of the human brain will be drastically affected Therefore, controlling the production, storage, transportation and use of fuel is very important to minimize the effects of CO on health and the environment

− NOx: NOx is a group of nitrogen oxides, in which NO accounts for a large proportion NOx is produced when the combustion gas consisting of N2 and O2 reacts at high temperatures (above 1100°C) Nitrogen monoxide (x=1) is not very dangerous but is the basis for making nitrogen dioxide (x=2) NO2 is a pinkish gas with a rather characteristic odor, detectable when its concentration in the air reaches about 0.12 ppm NO2 is not easily soluble in water, so it can go deep into the lungs when inhaled, causing inflammation and damage to the cells of the respiratory organs Victims will have insomnia, cough, difficulty breathing because of the influence of NO2 Nitrogen Protoxide N2O is the basis for creating ozone in the atmosphere

− Hydrocarbon: Hydrocarbon (HC) is an ingredient in the exhaust gas that is a product

of incomplete combustion in the presence of a rich mixture or when a fault occurs during combustion They can be harmful to human health, especially aromatic hydrocarbons Benzene is one of these substances The role of benzene has long been identified in blood cancer when its concentration is greater than 40 ppm or causing nervous system disorders when the concentration is greater than 1 g/m3, sometimes even causes of liver diseases Therefore, controlling the production, transportation and use of fuels to minimize the production of hydrocarbons is essential to protect human health and the environment

− SO2: Sulfur oxide is a highly hydrophilic substance, so it is very soluble in nasal

secretions They are then oxidized to sulfuric acid (H2SO4) and ammonium salts, and then travel through the respiratory tract deep into the lungs Sulfur dioxide (SO2)

is another substance that is potentially harmful to human health, not only causing respiratory inflammation, but also reducing the body's resistance and increasing the harmful effects of pollutants another infection to an infected person Controlling the production, transportation and use of fuel is very important to minimize the generation of sulfur oxides and SO2, in order to protect human health and the environment

− PM: PM is a particularly important pollutant in the exhaust gas of Diesel engines

It exists as solid particles with an average diameter of about 0.3mm, so it is easy to penetrate deep into the lungs when inhaled PM poses a danger to human health by interfering with the respiratory organs and is one of the causes of cancer due to cyclic aromatic hydrocarbons (HAPs) adsorbed on their surface in formation process Minimizing the production of PM and other pollutants in diesel engine exhaust is essential to protect human health and the environment

− Lead: Lead in the engine exhaust appears due to the use of the additive Tetraethyl lead Pb(C2H5)4 to increase the anti-knock properties of gasoline fuel The mixing of this substance into gasoline is still the subject of controversy in the scientific community Lead in exhaust gas exists in the form of very small particles, very small

in diameter, so it is easy to enter the human body through the skin or inhalation Then, about 30 to 40% of the lead will enter the bloodstream The presence of lead can affect ion exchange in the brain, interfere with the synthesis of enzymes to form red blood cells and more specifically, affect the nervous system and slow down intellectual development in the brain children Lead begins to pose a danger to humans when blood lead levels exceed 200 to 250 mg/litre [8] However, to protect human health, minimizing the use of the additive Tetraethyl lead Pb(C2H5)4 is essential, which requires the cooperation of scientists and governments

2.4.2 For the environment

Along with the growth in the number of cars, a contradiction arising in the development of society is the problem of environmental pollution due to harmful emissions from the engines of cars and motorbikes released into the surrounding air ta This source of pollution becomes the main threat to human life, especially in cities with high motor vehicle density, the greater this danger

Figure 2 6 Greenhouse effect

− Atmospheric temperature change: With the current rate of increase in CO2 in the air, scientists predict that by the middle of the twenty-first century, the concentration of CO2 in the air could double At that time, the temperature is expected to increase by 2-3oC, causing many serious impacts on the environment Part of the ice in the Arctic and Antarctic will melt, increasing sea level and causing saltwater intrusion Changes in rainfall patterns will affect drought in already at-risk areas and increase desertification on Earth In addition, crop growing conditions will also be affected

by climate change that is likely to cause landslides, land occupation and reduced crop yields Therefore, reducing CO2 emissions is necessary to protect the environment and have a better future for people and our planet

− Effects on ecology: An increase in NOx levels, especially nitrogen protoxide N2O, has the potential to cause negative impacts on the environment and human health

In particular, when the amount of NOx and N2O increases, they will increase the destruction of the ozone layer in the upper atmosphere - a layer of gas that is extremely necessary to filter ultraviolet rays emitted from the sun The impact of ultraviolet rays not only causes skin cancer and biological mutations for humans, but also destroys the life of organisms on earth, disrupts the rhythm of life and leads

to the spread of strange diseases Currently, conditions on Mars are already similar

to those on Earth, when there are no longer many layers of protection and life on this planet has undergone a lot of negative changes Therefore, reducing the emission of NOx and N2O is essential in protecting the environment and the health

of people and species living on earth

On the other hand, acidic substances such as SO2, NO2, are oxidized to sulfuric acid, nitric acid dissolved in rain, snow, fog, etc., which destroys vegetation on earth (acid rain), and causes food poisoning wear on metal structures

CHAPTER 3: ALTERNATIVE FUELS, ADVANCE ADDITIVES AND OIL TO IMPROVE ENVIRONMENTAL PERFORMANCE OF VEHICLES

3.1 Biodiesel

3.1.1 Introduction

An alternative fuel called biodiesel is made from animal and vegetable fats It can be made

by trans esterifying animal or vegetable lipids with alcohol, either with or without a catalyst Large, branching triglyceride molecules of vegetable oils and fats are chemically changed into smaller, straight chain molecules that are almost identical in size to the molecules of the species found in diesel fuel The reaction rate and process yield are enhanced by the employment of catalysts Because the transesterification process is reversible, more alcohol is needed to tip the balance of the reaction toward the products Transesterification uses alcohols like ethanol, methanol, or butanol as well as catalysts like base, acid, and lipase

Without major or moderate engine system modifications, biodiesel can be used in diesel engines Diesel-biodiesel blends of 5% and 100% (or neat) biodiesel content are referred

to as B5 and B100, respectively Commercial success has been achieved in recent years with the usage of biodiesel-diesel blends (B5-B20) in diesel engines To increase the lubricity of diesel fuel, biodiesel is blended with diesel in small amounts (up to 2%) Fuel lubricity is influenced by the type of additives used, the crude source, and the sulfur content reduction method The lubricity of fuel depends on crude source, refining process to reduce the sulfur content and the type of additives used Ball on cylinder lubricity evaluator and high frequency reciprocating rig (HFRR) are used to evaluate the lubricity of fuel For diesel, the HFRR technique suggests a wear scar diameter (WSD) cap of 460 m WSD drops to 325 m even when 2% biodiesel is blended with diesel Oil firms reduce sulfur levels to comply with Euro IV/V requirements; the loss brought on by the reduction in sulfur level can be made up for by adding biodiesel to diesel The lubricity-related issues can be solved by adding even 2% biodiesel to fuel

Figure 3 1 US Biodiesel Production, Exports, and Consumption

This Figure 3.1 shows trends in U.S biodiesel production, exports, and consumption from

2001 to 2021 Exports of biodiesel peaked in 2008 primarily because of an unintended