honours project 2014
TRANSCRIPT
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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
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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 3.6. 45mph Run AFR 20
Figure 3.7. 60mph Run AFR 21
Figure 3.8. 30mph run CO2 21
Figure 3.9. 45mph run CO2 22
Figure 3.10. 60mph run CO2 22
Figure 3.11. 30mph run CO 23
Figure 3.12. 45mph run CO 23
Figure 3.13. 60mph run CO 24
Figure 3.14. 30mph run HC 24
Figure 3.15. 45mph run HC 25
Figure 3.16. 60mph run HC 25
Figure 3.17. 30mph run NOX 26
Figure 3.18. 45mph run NOX 26
Figure 3.19. 60mph run NOX 27
Figure 3.20. 30mph run O2 27
Figure 3.21. 45mph run O2 28
Figure 3.22. 60mph run O2 28
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
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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
Figure 3.6. 45mph Run - AFR
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(m
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)
AF
R
Time (Seconds)
45mph Run - AFR
AFR 5% AFR 10% AFR 15% AFR 20% speed
-
21
Figure 3.7. 60mph Run - AFR
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
0
10
20
30
40
50
60
12
14
16
18
20
22
24
26
28
30
32
34
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
5
10
15
20
25
30
35
4
5
6
7
8
9
10
11
12
13
14
15
16
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
Sp
eed
(m
ph
)
CO 2
(%)
Time (Seconds)
30mph Run - CO2
CO2 5% CO2 10% CO2 15% CO2 20% speed
-
22
Figure 3.9. 45mph run CO2
Figure 3.10. 60mph run CO2
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
10
15
20
25
30
35
40
45
50
4
5
6
7
8
9
10
11
12
13
14
15
16
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
Sp
eed
(m
ph
)
CO 2
(%)
Time (Seconds)
45mph Run - CO2
CO2 5% CO2 10% CO2 15% CO2 20% speed
0
10
20
30
40
50
60
4
5
6
7
8
9
10
11
12
13
14
15
16
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
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
Figure 3.12. 45mph run CO
0
5
10
15
20
25
30
35
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
Sp
eed
(m
ph
)
CO
(%
)
Time (Seconds)
30mph Run - CO
CorrectedCO 5% CorrectedCO 10% CorrectedCO 15%
CorrectedCO 20% speed
0
5
10
15
20
25
30
35
40
45
50
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
Sp
eed
(m
ph
)
CO
(%
)
Time (Seconds)
45mph Run - CO
CorrectedCO 5% CorrectedCO 10% CorrectedCO 15%
CorrectedCO 20% speed
-
24
Figure 3.13. 60mph run CO
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
10
20
30
40
50
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
CorrectedCO 5% CorrectedCO 10% CorrectedCO 15%
CorrectedCO 20% speed
0
5
10
15
20
25
30
35
-300
200
700
1200
1700
2200
2700
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
Sp
eed
(m
ph
)
HC
(p
pm
)
Time (Seconds
30mph Run - HC
HC 5% HC 10% HC 15% HC 20% speed
-
25
Figure 3.15. 45mph run HC
Figure 3.16. 60mph run HC
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.
0
5
10
15
20
25
30
35
40
45
50
-200
300
800
1300
1800
2300
2800
3300
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
Sp
eed
(m
ph
)
HC
(p
pm
)
Time (Seconds)
45mph Run - HC
HC 5% HC 10% HC15% HC 20% speed
0
10
20
30
40
50
60
0
500
1000
1500
2000
2500
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
Sp
eed
(m
ph
)
HC
(p
pm
)
Time (Seconds)
60mph Run - HC
HC 5% HC 10% HC 15% HC 20% speed