honours project 2014

0

An Investigation into the Potential

of Alternative Fuels to Replace

Fossil fuels in Road Transport

Lawrence Wright

BEng (Hon) Civil Engineering

40094914

Undergraduate Honours Project

CTR10114

Submission Date: 21st March 2014

Supervisor: Professor Wafaa Saleh

1

ABSTRACT

This honours project focuses on the investigation of future fuels expected to be developed

for road transport. The aim of the research is to evaluate the potential of alternative fuels to

replace fossil fuels by comparing them with each other in terms of cost, sustainability and

viability.

Three alternative fuels have been identified as the most environmentally friendly and realistic

options. These fuel types, biofuels, electric vehicles and fuel cell electric vehicles, are

researched in full to understand their properties, environmental impact and overall benefits.

Biofuels, in the form of bioethanol and biodiesel, are currently used as substitutes for petrol

and diesel. For this project laboratory tests were conducted to study the effects of mixing

ethanol with petrol in terms of performance and emissions. While these results are

favourable many other issues need to be taken into account. Examples include the fuel

versus food debate and overall sustainability.

Electric vehicles are presently widely available and the necessary infrastructure is in place.

However there are many drawbacks which result in a lack of public interest in purchasing

them. These include the price of the vehicle and the limitations of the batteries.

Fuel cell electric vehicles appear to be the most promising alternative. Unfortunately they are

currently the most underdeveloped of the alternative fuels considered. They have the

potential to eliminate emissions from road transport, however that depends on production

methods of the hydrogen used to fuel the vehicles. The cost of developing the infrastructure

and time necessary for their introduction is considerable.

While undertaking this project the future of fuels in road transport was always considered in

terms of the results. The results show that while electric vehicles and first generation biofuels

are adequate to reduce emissions in the short term, they may not be best suited for long

term use.

Overall fuel cell electric vehicles, in theory are the most feasible to completely replace fossil

fuels. However this will not be possible for decades.

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Table of Contents

Abstract 1

Table of Contents 2

List of Tables: 4

List of Figures: 4

Acknowledgements 5

Abbreviations ` 6

1 Introduction 7

2 Biofuels 9

2.1 Bioethanol 9

2.2 Biodiesel 10

2.2.1 Biodiesel Emission Results 11

2.3 Law 11

2.3.1 The Renewable Transport Fuel Obligation (RTFO) 12

2.3.2 EU Directives 12

2.4 Life cycle Environmental Analysis 13

2.5 Second generation biofuel 13

2.6 Biofuel Summary 14

3 Laboratory Report 15

3.1 Apparatus 15

3.2 Safety Precautions 17

3.3 Procedure 17

3.4 Calculations 18

3.5 Results 19

3.5.1 Fuel Consumption 19

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3.5.2 Emissions Produced 20

3.6 Laboratory Tests Conclusion 29

4 Electric Vehicles (EV) 30

4.1 Infrastructure 30

4.2 Cost 32

4.3 Range 32

4.4 Battery Packs 33

4.5 Hybrid Electric Vehicle (HEV) 33

4.6 Nissan Leaf 34

4.7 Electric Vehicles Summary 35

5 Fuel Cell Electric Vehicles (FCEV) 36

5.1 The California Example 37

5.2 Hydrogen Fuel Cell 37

5.3 Production of Hydrogen 38

5.4 Honda FCX Clarity 39

5.4.1 Home Energy Station 40

5.5 Timeframe 40

5.6 Fuel Cell Electric Vehicles Summary 41

6 Conclusions and Recommendations 42

References 43

Appendix A 46

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List of tables:

Table 2.1 Engine Emission Results from the University of Idaho 11

Table 3.1 Fuel Consumption 19

List of figures:

Figure 3.1. Honda CBF600 fixed on the Dyna Pro Dynamometer 15

Figure 3.2. Fuel measurement container connected to the motorbike and front monitor. 16

Figure 3.3. Omniscan Gas Analyser 16

Figure 3.4. Exhaust Extractor Fan and Cooling Fan 17

Figure 3.5. 30mph Run AFR 20



Figure 3.8. 30mph run CO2 21



Figure 3.11. 30mph run CO 23



Figure 3.14. 30mph run HC 24



Figure 3.17. 30mph run NOX 26



Figure 3.20. 30mph run O2 27



Figure 4.1. Charging Point at Edinburgh Napier University Merchiston Campus 31

Figure 4.2. Nissan Leaf 34

Figure 5.1. Components of a FCEV 36

Figure 5.2. Honda FCX Clarity 39

Figure 5.3. Fuel Nozzle 39

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Acknowledgements

The completion of this Honours Project would not have been achieved without the kind

assistance of a few people. I would like to express my sincere appreciation firstly to my

project supervisor, Professor Wafaa Saleh. Throughout the process of producing this

dissertation her continued guidance and advice made the entire period, from start to finish

much easier and stress free. Anytime I needed assistance or feedback, Professor Saleh

kindly made herself available.

I would like to express my gratitude to the Engines Laboratory Technician Callum Wilson.

Over the two week period of conducting the laboratory tests he kindly donated his time to

teach me how to use the equipment and ensured the laboratory was open for me as often as

the schedule allowed. Furthermore he ensured the equipment was in proper working order at

all times. Without his generosity and patience the laboratory tests undertaken for the project

would not have been possible.

I would also like to thank Dr. Ravindra Kumar for his assistance and advice with regard to

the laboratory tests. His help was very valuable and his constructive observations were very

encouraging.

I must similarly direct my thanks to Shell UK customer care. Their response to my queries

were very helpful and they kindly provided me with more information than I had requested.

Finally I would like to thank the honours project leader Jonathon Cowie, library staff and

other university members of staff for helping me find material and making themselves

available to answer any questions.

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Abbreviations

United Kingdom - UK

European Union - EU

Nitrogen Oxides - NOX

Carbon Monoxide - CO

British Petroleum - BP

Greenhouse Gas - GHG

Hydrocarbons - HC

Renewable Transport Fuel Obligation - RTFO

Renewable Fuel Agency - RFA

European Commission - EC

Miles per Hour - mph

Millilitre - ml

Air to Fuel Ratio - AFR

Carbon Dioxide - CO2

Parts per Million - ppm

Oxygen - O2

Electric Vehicle - EV

Internal Combustion Engine - ICE

Ultra Low Emissions Discount - ULED

Lithium Ion - Li-ion

Hybrid Electric Vehicle - HEV

Kilowatt - kW

Fuel Cell Electric Vehicles - FCEV

California Hydrogen Highway Network - CaH2Net

California Fuel Cell Partnership - CaFCP

Water - H2O

Hydrogen - H2

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1 Introduction

The aim of this research project is to evaluate the potential of alternate fuels used in road

transport to replace fossil fuels. This is to be completed by investigating suitable alternative

fuels, analysing their properties and comparing them with fossil fuels. Issues to be

researched include price, environmental impact, energy output and infrastructure. It is hoped

that this project can be used to provide education on how best to introduce suitable

alternative fuels into the transport market.

According to the European Commission,

over-dependence of European transport on oil. Transport in Europe is 94 % dependent on

, 2013).

There are a number of reasons why it is now considered urgent. These include;

The need to reduce carbon emissions. Fossil fuels are burned sending high levels of carbon

emissions into the atmosphere. This is damaging to health and increases global warming.

Alternative fuels are the best hope to reduce the amount of greenhouse gases being

released from road transport. It is even possible that the right alternative will eventually

eliminate carbon emissions completely.

The shortage in long term availability of oil has made it necessary to explore other options.

At the moment it is envisaged that oil will begin to run out after about another 50 years

(Chapman, 2007). This will affect all aspects of life and suitable alternatives need to be

developed now to prevent the transport sector from shutting down should its supply come to

an end.

This has also contributed to the rapid price rise of fuels. Increasing taxes combined with

higher costs to oil companies supplying fuel has seen the price for consumers multiply in

recent years. As a result ordinary people have had to spend more and more on transport

costs. It is hoped that suitable alternatives will reduce fuel prices in the long term.

In this project three viable alternative are being investigated and analysed in detail. These

are, biofuels, electric vehicles and fuel cell electric vehicles.

Biofuels are fuels that are produced from renewable energy sources, such as sugarcane or

other similar crops. The main biofuels are bioethanol and biodiesel. These are currently

mixed at low levels in the fuel in almost all vehicles today. Biofuels are a relatively new

prospect which has a big potential to improve and expand its use in road transport. Because

it is so new it has many issues which it has yet to overcome. In this honours project biofuels

are investigated fully to discover their impact and viability. This includes laboratory tests

which were conducting in the Engines Laboratory in order to understand biofuels better.

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Electric vehicles are currently the most common and most developed alternative to fossil

fuels on the road s there are major drawbacks

which reduce their desirability to most people. Some problems include the price of the cars,

the limited range and the long-term energy levels of the battery packs, among others. All

these issues are investigated in this report with what can be expected in the future.

Constantly improving technology can help expand the use of electric vehicles. A profile is to

be conducted of the most popular electric car at the moment which is the Nissan Leaf.

The introduction of fuel cell technology is an exciting prospect. Fuelled by hydrogen, it has

the potential of producing zero carbon emissions. However this is currently the least

developed of the alternatives. As it stands it may not be until the middle of this century

before hydrogen fuelled vehicles may begin to take a foothold in the transport sector. The

main issue effecting the long term commercialisation of these vehicles is the cost and lack of

infrastructure, along with methods of producing hydrogen.

Although the three alternative options investigated in this project are very different, they each

provide a great deal of promise with regards to replacing fossil fuels as the most common

road transport fuel in the long term. They are each renewable energy sources which is very

important. Continued research and improvements are vital in the search to replace oil. While

today it is still early in the quest to achieve this goal, it is hoped that this research project can

have a small role to play.

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2 Biofuels

Biofuels are fuels which are created from renewable energy sources. They are produced

from organic matter, with most coming from crops. The two main types of biofuels are

biodiesel and bioethanol. Biofuels currently play an important role in reducing carbon

emissions and preserving the dwindling supply of oil.

Because they are liquid fuels like petrol or diesel, they are seen as a suitable substitute for

combustion engines. While biofuels could be used as a fuel in their own right they are

generally mixed with petrol or diesel at moderately low levels. At high levels modifications

may be needed to the engines to prevent damage. Under the current law in the UK and the

EU Directives every fuel supplier has to comply with legislation which has been introduced to

promote biofuels and increase renewable energy use in the transport sector.

Currently there appears to be a basic lack of knowledge among the general public about the

overall effects of using biofuels, whether beneficial or damaging. They may have the

potential to be a good long term alternative to oil however biofuels are a reasonably new

commercial concept. Concerns exist about the carbon balance of biofuels when all aspects

of their use and production are taken into account. At the moment all biofuels being

produced are in the first generation of this fuel range and so have many issues to overcome

before they can develop.

Some of these concerns include compatibility with car engines, overall environmental

benefits and the excessive amount of land needed to produce these fuels. There is also

believed to be less energy created or power discharged from biofuels than petrol and diesel,

this results in a higher fuel consumption per distance travelled.

2.1 Bioethanol

Ethanol is an alcohol made by the fermentation of carbohydrates in feedstock. These

typically are sugar in crops such as maize or sugarcane and starch in wheat or barley. It can

also be used as a fuel in its pure form but is generally mixed with petrol.

While ethanol has been around with over a century, it only started to become a viable

alternative fuel in the 1970s due to an oil crisis (Solomon et al, 2007). Since then its

popularity has grown worldwide. However there has been limited improvements in its

composition.

The main issue restricting mixing ethanol with petrol at higher percentages is its high

corrosive level. Car engines older than ten years old are in danger of being damaged from

high percentage mixes of ethanol in petrol.

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Bioethanol also produces only two thirds the energy of petrol. This can be attributed to the

presence of a high level of oxygen. However this also improves combustion and is

responsible for lower levels of nitrogen oxides (NOX) and carbon monoxide (CO) among

other carbon emissions (Balat et al, 2008). This is evident in the laboratory tests which were

undertaken for this honours project. The laboratory report is included in the next chapter.

Brazil is the major producer of bioethanol from sugarcane, the United States is the major

producer of bioethanol from corn. Together they produce more than

bioethanol (Wheals et al, 1999) which is where most bioethanol in the UK is imported from.

Most ethanol produced in Europe is made from wheat or sugar beet.

The policy changes of many governments worldwide over the last decade has made

investing in biofuels an attractive prospect for most large oil companies. Modern fuel often

has to have a certain percentage of biofuel or a cap on the amount of emissions allowable. A

joint venture between shell and Brazilian firm Cosan produces more than 2 billion litres of

ethanol a year from sugar cane in Brazil (Shell Global, 2013). BP has also invested in

producing biofuels from sugar cane in Brazil with the view of increasing the quantity rapidly

over the next few decades.

2.2 Biodiesel

Biodiesel is made from vegetable oils and animal fats. It is produced through a process of

refining. It can be used as a fuel for vehicles in pure form but is usually mixed with diesel.

When originally designing the diesel combustion engine, Rudolf Diesel used vegetable oil as

fuel. Eventually as crude oil became more accessible, the diesel engine evolved to be fuelled

by petroleum diesel, only reverting back to biodiesel during times of shortage, such as during

the Second World War (Ma et Hanna, 1999).

Recently along with the renewed attention on bioethanol, there has been a big increase in

the production of biodiesel from vegetable oil and animal fats. The most popular vegetable

oils used to make biodiesel include sunflower oil or rapeseed oil. These are much more

commonly used than animal fats as they are much more widely available and easier to

produce.

In Europe biodiesel is by far the most popular biofuel, where it is produced most by

Germany. Here the fuel is commonly used without mixing with diesel. This is because it has

better lubrication (Bozbas, 2008). In cold weather it may not work effectively, however

additives can be easily used to improve its structure.

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2.2.1 Biodiesel Emission Results

Current biodiesel made from vegetable oils produce very favourable results. Most studies

show there is very little or even no reduction in the output of energy from biodiesel than

petroleum diesel. However a lower heating value means it sometimes generates slightly less

power. This is minimal. Overall it is believed to reduce greenhouse gas (GHG) emissions by

a total of about 41% (Hill et al, 2006). This is much better than ethanol.

Table 2.1 Engine Emission Results from the University of Idaho (Bozbas, 2008)

Emission 100% Ester fuel (B100)

(%) 20/80 Mix (B20)

(%)

Hydrocarbons -52.4 -19.0

Carbon monoxide -47.6 -26.1

Nitrous oxides -10.0 -3.7

Carbon dioxide 0.9 0.7

Particulates 9.9 -2.8

Unfortunately it was not possible to conduct emission tests in the Engines Laboratory for this

project as the motorbike only runs on petrol and the equipment can only measure emissions

from petrol motors. However table 2.1 shows the results of such tests conducted by the

University of Idaho in the United States.

It can be seen in the table hydrocarbons (HC) and carbon monoxide (CO) show a sharp

decrease. This can be attributed to high oxygen content in the biofuels which provides a

more economical combustion. Similarly nitrous oxides (NOX) emissions also show a

reduction. Unfortunately carbon dioxide (CO2) emissions show a minor increase. This is a

setback for biodiesel. CO2 is the most important emission which needs to be reduced.

Overall the results show there is much less emissions produced from biodiesel than diesel.

2.3 Law

As the popularity of biofuels has grown, legislation in the UK and the EU has been

introduced. This is to ensure that the quality of biofuels is properly controlled and their use is

promoted. It has also been recognised as a way to reach international goals set out to

reduce carbon emissions, such as those from the Kyoto protocol.

The Kyoto protocol is a United Nations agreement which set international binding emission

reducing targets. It was adopted in 1997 and came into effect in 2005. The protocol was

renewed in 2012. Current stipulations requires countries to reduce emissions by at least 18%

from 1990 levels. It is to be completed or renewed again by 2020.

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2.3.1 The Renewable Transport Fuel Obligation (RTFO)

The Renewable Transport

principle legislation for the regulation of biofuel

for Transport, 2012).

The RTFO means that fuel suppliers of at least 450,000 litres of fuel a year must ensure 5%

comes from renewable sources. This means that most fuels now contains 5% biofuel. If the

necessary amount of biofuel is not met the alternative is to buy out of the obligation. This is

controlled by the Renewable Fuel Agency (RFA) who as part of the RTFO were set up to

oversee its application (Department for Transport, 2012).The regulation is processed using a

certificate system.

In 2011 the RTFO was updated to ensure a minimum GHG saving can be achieved and

proper land use is controlled so as to reduce the production of carbon emissions when

growing and harvesting the biofuel.

There has been suggestion that the 5% level may in time be increased to 10% in line with

EU targets, but currently there are no plans to do this. The main reason for this is the

expected maintenance and performance issues with engines in cars more than ten years

old, should this be applied.

2.3.2 EU Directives

The first EU biofuels directive was published in May 2003, Directive 2003/30/EC. This

directive issued a target of replacing fossil fuels in transport with 5.75% biofuels by 2010.

Biofuels were firmly regarded as the most important type of alternative fuel in transport at the

time.

However environmental and social concerns meant it was subsequently replaced by

Directive 2009/28/EC, The Renewables Directive. The purpose of this directives was to

promote the use of all alternative fuels in transport such as electricity and hydrogen along

with biofuels. The 2009 directive set a new target requiring 10% renewable energy in

transport by 2020.

In the directive strict sustainability standards for biofuels are outlined in Article 17

Bio liquids (European Parliament, 2009).The aim in

this article is to ensure biofuels achieve a clear and significant GHG saving.

The Fuel Quality Directive, Directive 2009/30/EC, which replaced Directive 98/70/EC, is

responsible for setting standards for petrol and diesel. The directive also introduces Article

7a, enforcing reductions in GHG emissions in road transport on fuel suppliers. In regard to

biofuels the directive issues sustainability measures. This is to help apply article 7a and

ensure the process overproducing biofuels also minimises the level of emissions released

13

into the atmosphere. Some measures include restrictions on land which can be used. To

help protect soil quality, forests and vulnerable species of plants are protected (European

Parliament, 2009).

2.4 Life cycle Environmental Analysis

One major drawback with the production of biofuels is the insufficient availability of land to

grow the feedstock. This has created a food versus fuel debate. With the world population

continually growing, more food needs to be produced. In the next 50 years demand for food

is expected to double while transport fuel demand will increase even faster. With the growing

demand for biofuels as a possible supply of fuel many of these crops are used as feedstock

to produce fuel instead. This will impact the price in food as it becomes more valuable. It will

also curtail the market percentage biofuels can gain in the transport sector (Hill et al, 2006).

There are further issues relating to the amount of carbon emissions produced while growing

the crops. When growing the feedstock, carbon dioxide is taken in and replaced with oxygen.

However this does not make it carbon neutral. Large machinery are needed to set, irrigate

and harvest the crops, producing carbon emissions. Fertilizers and pesticide further

contribute to the negative environmental impact. The effect this has on water resources has

also been scrutinised. Transport of the feedstock again produces

environmental benefits of biofuels.

Overall though despite these negative effects, biofuels are shown to provide a significant

reduction in carbon emissions and fuel price.

2.5 Second generation biofuel

All biofuels currently being produced are regarded as the first generation of biofuels. The

potential accessibility problems with biofuels due to the restrictions of feedstock availability

raises question marks over it sustainability.

Over the next two decades it is expected that second generation biofuel will become

available. This is a liquid fuel produced from plant biomass known as lignocellulose material.

Lignocellulose matter is the most profoundly available and underutilized raw material which

is mostly wasted when producing current biofuels (Sims et al, 2010). This makes it very

cheap.

Second generation biofuel, which does not have to come from food crops, would convert all

the plant into fuel, ensuring minimum waste. Plant biomass, such as wood or straw is often

used as fuel by simply burning it. This creates heat or

create liquid biofuel could make it an ideal source of alternative fuel in road transport.

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Currently the majority of biomass produced across the world is wasted. When it is harvested,

it is left to rot on the ground.

is another added advantage.

Presently second generation biofuels are being tested with positive results. A lower carbon

emissions rate and better level of sustainability has the potential to make them carbon

neutral. The main reason why it is not yet commercial is the lack of infrastructure. Bio

refineries are needed to produce this advanced biofuel (Naik et al, 2010). A lot of work is

needed to create these bio refineries where the biomass is produced and converted to fuel.

2.6 Biofuel Summary

Current available biofuels on first sight do achieve their purpose of reducing carbon

emissions. However when all environmental aspects of their production are taken into

account, there is only a modest overall improvement. While it is also likely that it will reduce

the price of fuel and increase the availability of petrol or diesel. It is a benefit for today.

However in the long term it will not be enough, due to the limitations of its production

capacity.

The potential that second generation biofuels show is much more promising. It eliminates

many of the drawbacks of the first generation biofuel. However with it not becoming available

for the next two decades, first generation biofuels will have to suffice for the immediate

future. A significant effort will be needed to develop the infrastructure needed to proceed with

the commercialization of second generation biofuels.

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3 Laboratory Report

As part of this honours project laboratory tests were undertaken to investigate the impact of

mixing ethanol with petrol. The tests were completed over two weeks in the Engines

Laboratory. Ethanol was mixed with petrol at different percentages ranging from 5% to 20%,

it was then used in the motorbike and run at different speeds with the results being recorded.

The results measured fuel consumption per distance travelled and the range of emissions

produced through the exhaust. They were then analysed and compared together to see how

they changed. All results are included in this report with the conclusions stating the effects of

ethanol on reducing emissions and increasing fuel consumption.

3.1 Apparatus

The motorbike used in the engines laboratory is a 2004 Honda CBF 600. This was securely

placed upon a Dyna Pro Dynamometer. The back wheel of the motorbike was on the roller

which would record speed and distance travelled while the motorbike was running. These

were displayed on a computer screen in front of the motorbike. The dynamometer could only

record for a maximum run of 3 minutes and only when the motorbike was travelling over

5mph. As a result it was decided in these tests each run should be about 2 minutes and 30

seconds in length. Recording generally started at 7 or 8mph and ended when the motorbike

decelerated below 5mph.

Figure 3.1. Honda CBF600 fixed on the Dyna Pro Dynamometer

The fuel used was Shell Unleaded Petrol. This already contains 5% ethanol due to the

Renewable Transport Fuel Obligation (RTFO). This was stored in fuel cans.

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Different measuring containers were used to mix the fuel. A container was also used to

measure the fuel used. This was connected to the engine in the motorbike. This meant

instead of filling the fuel tank, this container could be filled with the fuel used recorded after

each run on the motorbike.

Figure 3.2. Fuel measurement container connected to the motorbike and front monitor.

An Omniscan Gas Analyser was used to measure the emissions from the motorbike. A

probe was connected to the inside of the exhaust pipe. This recorded the emissions being

released and saved them on the machine. These results could then be exported onto the

computer to be analysed.

Figure 3.3. Omniscan Gas Analyser

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3.2 Safety Precautions

All necessary safety precautions were adhered to while conducting the tests in the Engines

Laboratory.

Before starting the motorbike the fans had to be switched on. One fan was placed over the

exhaust pipe of the motorbike to extract the fumes. To supplement this, a fan blowing fresh

air into the room was turned on. Two fans were also placed in front of the dynamometer

which had to be turned on when the bike was running. The purpose of these were to blow air

at the bike to prevent it from overheating. When all the equipment was turned on ear

protectors had to be worn as it created a lot of noise.

Figure 3.4. Exhaust Extractor Fan and Cooling Fan

Further precautions meant no loose clothing could be worn while on the motorbike. Goggles

were worn while mixing the fuel to prevent it from splashing into the eyes. It was also

important to ensure the straps holding the motorbike in place were tightly secured before

each run.

3.3 Procedure

Tests were conducted for fuel mixtures containing 5%, 10%, 15% and 20% ethanol. For

each of these mixtures, runs were completed at 30mph, 45mph and 60mph.

Each run consisted of the first 45 seconds gradually accelerating to the target speed of either

30, 45 or 60mph. It would then stay at that speed for 1 minute, before gradually decelerating

for 45 seconds until it stopped. Each individual run was repeated 3 to 5 time to get the most

consistent results.

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In advance of conducting the tests, the fuel was mixed and prepared for use, the

dynamometer and gas analyser were turned on and prepared to record the results.

Before recording the results the bike had to be driven for 3 to 4 minutes to get it up to the

right temperature. At this stage everything was ready to start recording the results.

After each run the results were saved and exported to excel on the computer where they

were analysed and all the necessary graphs were produced and studied.

3.4 Calculations

As there was 5% ethanol in the petrol at the start, the amount of ethanol need to be added to

get 10%, 15% and 20% had to be calculated. The calculations are shown as follows;

10% Mixture

50ml ethanol +Xml ethanol / 1000ml + X = 0.10

50 + X = 100 + 0.1X

0.9X = 50

X = 55.56ml

56ml of ethanol should be added to every litre of petrol which already contains 5% ethanol to

make it 10%.

15% Mixture

50ml ethanol + Xml ethanol / 1000ml + X = 0.15

50 + X = 150 + 0.15X

0.85X = 100

X = 117.65ml

118ml of ethanol should be added to every litre of petrol which already contains 5% ethanol

to make it 15%.

20% Mixture

50ml ethanol + Xml ethanol / 1000ml + X = 0.20

50 + X = 150 + 0.2X

0.8X = 150

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X = 187.5ml

188ml of ethanol should be added to every litre of petrol which already contains 5% ethanol

to make it 20%.

After each run, the amount of litres consumed per mile was calculated.

For this the fuel used in litres was divided by the distance travelled in miles to get how much

fuel was used in a mile, - e.g. 0.102 litre / 1.3 miles = 0.078 litres per mile

3.5 Results

Results were recorded and analysed to show two outcomes of increasing the mixture of

ethanol in petrol. The first shows how the fuel consumption increased and the second

outcome shows in detail how much the production of emission decreased.

3.5.1 Fuel Consumption

Table 3.1. Fuel Consumption

Speed

Fuel Mix

Distance

(Mile)

Fuel Used

(Litre) Litre/Mile

30mph

5% 0.67 0.068 0.101

10% 0.68 0.07 0.103

15% 0.67 0.071 0.106

20% 0.69 0.074 0.107

45mph

5% 0.92 0.081 0.088

10% 0.94 0.086 0.091

15% 0.94 0.087 0.093

20% 0.93 0.087 0.094

60mph

5% 1.3 0.102 0.078

10% 1.28 0.101 0.079

15% 1.27 0.103 0.081

20% 1.3 0.107 0.082

Table 3.1 shows the average distance travelled and amount of fuel used for each run. It can

be seen the higher percentage of ethanol in the fuel gradually increases the amount of fuel

needed per distance travelled. For each 5% increase of ethanol, there is an increased fuel

consumption of just over 1%. This is very low.

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It can also be seen that at higher speeds, less fuel is consumed per mile. This may be

different in real road transport situations with more accelerating and decelerating, using

much more fuel at higher speeds.

3.5.2 Emissions Produced

Air to Fuel Ratio (AFR)

Figure 3.5. 30mph Run - AFR


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Figures 3.5, 3.6 and 3.7 show the results for the air to fuel ratio (AFR). In the combustion

process the fuel has a chemical reaction with the gases in the air. Higher levels of ethanol

effects this reaction. It can be seen in the graphs that the AFR increases. This is a positive

which results in less carbon gases being released from the exhaust. This happens because

of a better combustion, reducing carbon emissions and increasing the release of oxygen.

Carbon Dioxide (CO2)

Figure 3.8. 30mph run CO2

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0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160

Sp

eed

(m

ph

)

AF

R

Time (Seconds)

60mph Run - AFR

AFR 5% AFR 10% AFR 15% AFR 20% speed

0

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30

35

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Sp

eed

(m

ph

)

CO 2

(%)

Time (Seconds)

30mph Run - CO2

CO2 5% CO2 10% CO2 15% CO2 20% speed

22



Figures 3.8, 3.9 and 3.10 show the results for carbon dioxide (CO2) emissions. This is the

most well-known carbon gas and has had a big effect on global warming. It can be seen in

the results that high levels of it are being released. It is obvious that higher percentages of

ethanol significantly reduce the amount of the gas being released into the atmosphere. This

is important as it proves the benefits of increased levels of ethanol in petrol.

0

5

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50

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Sp

eed

(m

ph

)

CO 2

(%)

Time (Seconds)

45mph Run - CO2

CO2 5% CO2 10% CO2 15% CO2 20% speed

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60

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Sp

eed

(m

ph

)

CO 2

(%)

Time (Seconds)

60mph Run - CO2

CO2 5% CO2 10% CO2 15% CO2 20% speed

23

Carbon Monoxide (CO)

Figure 3.11. 30mph run CO


0

5

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30

35

0

0.1

0.2

0.3

0.4

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Sp

eed

(m

ph

)

CO

(%

)

Time (Seconds)

30mph Run - CO

CorrectedCO 5% CorrectedCO 10% CorrectedCO 15%

CorrectedCO 20% speed

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eed

(m

ph

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CO

(%

)

Time (Seconds)

45mph Run - CO



24


Carbon monoxide (CO) is a very toxic and harmful gas. It is made up of carbon and oxygen.

In figures3.11, 3.12 and 3.13 it can be seen that it is released at much lower levels than CO2.

It can also be seen that ethanol has a huge effect in decreasing its levels. In figure 3.13 the

gas peaks at 1.4% in the 5% run while in the 20 % run the level at the same point is only

0.2%. Higher levels of ethanol changes the amount CO being released. When the speed is

constant, it goes from increasing in the 5% run to steadily decreasing in the 20% run.

Hydrocarbons (HC)

Figure 3.14. 30mph run HC

0

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30

40

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60

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160

Sp

eed

( m

ph

)

CO

(%

)

Time (Seconds)

60mph Run - CO



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1700

2200

2700

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160

Sp

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(m

ph

)

HC

(p

pm

)

Time (Seconds

30mph Run - HC

HC 5% HC 10% HC 15% HC 20% speed

25



Hydrocarbon (HC) are made up of hydrogen and carbon. The results show that at steady

speeds levels are very low, however during accelerating and especially decelerating very

high levels are released. This is because the unburnt gas is being released through the

exhaust when the gears are changed and the revs are higher. In these tests it appears that

the ethanol does not make much of a difference in reducing the levels. Instead the best way

to reduce it is through a more efficient driving style.

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Sp

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(m

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HC

(p

pm

)

Time (Seconds)

45mph Run - HC

HC 5% HC 10% HC15% HC 20% speed

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0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160

Sp

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(m

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HC

(p

pm

)

Time (Seconds)

60mph Run - HC

HC 5% HC 10% HC 15% HC 20% speed

honours project 2014

Documents