1Contents
Biofuel Cities – Technical guidance for biofuels
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Technical guidance for
biofuels Technical information concerning the application of biofuels
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Biofuel Cities – Technical guidance for biofuels
2 Imprint
Technical guidance to biofuels Publisher SenterNovem, formally represented by Rob Boerée, Managing Director Energy and Climate
Editors Kristina Birath, Haide Backman, Ulrika Franzén, Ulf Liljenroth (WSP Sweden AB), Per Godfroij, Bregje van Keulen (Senternovem)
Authors Kristina Birath, Haide Backman, Ulrika Franzén, Ulf Liljenroth (WSP Sweden AB)
Front page photos WSP Sweden AB
Layout and print SenterNovem and ICLEI European Secretariat
Copyright © 2008, SenterNovem, Utrecht, The Netherlands All rights reserved. No part of this publication may be reproduced or copied in any form or by any means without written permission of SenterNovem.
Acknowledgement
This publication is part of the activities of the Co-ordination Action Biofuel Cities European Partnership Consortium. The Coordination Action is funded by the Sixth Research Framework Programme of the European Union, under the Activity “Alternative Motor Fuels: Biofuel Cities”.
Legal notice Neither the European Commission nor the Co-ordination Action Biofuel Cities European Partnership Consortium nor any person acting on behalf of these is responsible for the use which might be made of this publication. The views expressed in this publication are the sole responsibility of the author specified and do not necessarily reflect the views of the European Commission nor the Co-ordination Action Biofuel Cities European Partnership Consortium.
Ethical issues The Co-ordination Action Biofuel Cities European Partnership Consortium undertakes to respect all basic ethical principles as outlined in the Charter of European Fundamental Rights, including human dignity; cultural, religious and linguistic diversity; equality and anti-discrimination; freedom of expression and of information; and respect for the environment.
The Biofuel Cities website can be accessed at: www.biofuel-cities.eu
A great deal of information on the European Union is available on the Internet. It can be accessed through the Europa server: http://europa.eu.int
Comments welcome!
The Biofuel Cities Consortium strives to provide relevant and user-friendly services and products, both in terms of quality and quantity of information design and of the actual information supplied. Please help us to improve our work and tailor it according to your needs and wishes! We will carefully evaluate and use all your comments and proposals, please send them to the address mentioned above.
3Contents
Biofuel Cities – Technical guidance for biofuels
Contents 1 Introduction 6
2 Bioethanol 8
2.1 Summary bioethanol 8
2.2 General fuel properties 9
2.3 Availability 11 2.3.1 Sources of bioethanol 11 2.3.2 Future availability 11
2.4 Use in vehicles 12 2.4.1 Vehicle technology 13 2.4.2 Exhaust gas emissions 16 2.4.3 User experience 18
2.5 Infrastructure requirements 22 2.5.1 Technical aspects of filling stations 22 2.5.2 Technical aspects of storage and transportation 23 2.5.3 Safety risks 25
2.6 Fuel quality standards 26
2.7 Production 28
2.8 Sustainability issues 29 2.8.1 GHG balance 29 2.8.2 Energy balance 32 2.8.3 Other sustainability issues 33
3 Biodiesel 40
3.1 Summary biodiesel 40
3.2 General fuel properties 41
3.3 Availability 42 3.3.1 Sources of FAME 42 3.3.2 Future availability 43
3.4 Use in vehicles 44 3.4.1 Vehicle technology 44 3.4.2 Exhaust gas emissions 47 3.4.3 User experience 48
3.5 Infrastructure requirements 49 3.5.1 Technical aspects of filling stations 49 3.5.2 Technical aspects of storage and transportation 49
3.6 Fuel quality standards 51
3.7 Production 52
3.8 Sustainability issues 54 3.8.1 GHG balance 54 3.8.2 Energy balance 56
Biofuel Cities – Technical guidance for biofuels
4 Contents
3.8.3 Other sustainability issues 57
4 Pure Plant Oil, PPO 63
4.1 Summary PPO 63
4.2 General fuel properties 64
4.3 Availability 65 4.3.1 Sources of PPO 65 4.3.2 Future availability 65
4.4 Use in vehicles 66 4.4.1 Vehicle technology 66 4.4.2 Exhaust gas emissions 68 4.4.3 User experience 68
4.5 Infrastructure requirements 69 4.5.1 Technical aspects of filling stations 69 4.5.2 Technical aspects of storage and transportation 70
4.6 Fuel quality standards 71
4.7 Production 71
4.8 Sustainability issues 72 4.8.1 GHG balance 72 4.8.2 Energy balance 73 4.8.3 Other sustainability issues 74
5 Biomethane 78
5.1 Summary biomethane 78
5.2 General fuel properties 79
5.3 Availability 81 5.3.1 Sources of biomethane 81 5.3.2 Future availability 81
5.4 Use in vehicles 82 5.4.1 Vehicle technology 82 5.4.2 Exhaust gas emissions 85 5.4.3 User experience 85
5.5 Infrastructure requirements 86 5.5.1 Technical aspects of filling stations 86 5.5.2 Technical aspects of storage and transportation 87
5.6 Fuel quality standards 88
5.7 Production 89
5.8 Sustainability issues 90 5.8.1 GHG balance 90 5.8.2 Energy balance 91 5.8.3 Other sustainability issues 92
6 Other biofuels 97
6.1 General fuel properties 97
5Contents
Biofuel Cities – Technical guidance for biofuels
Hydrogen 97 Electricity 97 DME 97
6.2 Availability 98 Hydrogen 98 Electricity 98 DME 99
6.3 Use in vehicles 99 Hydrogen 99 Electricity 99 DME 100
6.4 Infrastructure requirements 100 Hydrogen 100 Electricity 101 DME 101
6.5 Fuel quality standards 101 Hydrogen 101 Electricity 101 DME 102
6.6 Production 102 Hydrogen 102 Electricity 103 DME 103
6.7 Sustainability issues 104 Hydrogen 104 Electricity 104 DME 105
Biofuel Cities – Technical guidance for biofuels
6 1. Introduction
1 Introduction To combat climate change, protect the environment and improve
quality of life, emissions from the transport sector must be
reduced. The EU’s objective is to reduce greenhouse gas emissions
by 20% prior to 2020. Increased use of biofuels is one way to
achieve this objective. Others measures include increasing the use
and quality of energy efficient vehicles and changeover to cleaner
transport modes.
Many demonstration projects with biofuels, both on small and large
scale, have been performed in the EU during the last 15 years.
Biofuels have been introduced by fleet owners such as
municipalities, private companies and public transport companies.
These experiences have increased knowledge about the use of
biofuels.
The aim of this technical guide is to gather and collate knowledge
about the range of fuels that are currently in use. The target group
is fleet managers and purchasers with an interest in procuring
clean vehicles and fuels. The guide offers an overview of the
availability of vehicles and fuels; practical advice regarding
distribution and handling of fuels; information on fuel standards;
user experiences; and guidance on sustainability issues. However,
it should be noted that the guide only concerns biofuels for road
transport and that biofuels can be used in other transport
applications, such as ferries, trains, aeroplanes, etc.
The guide focuses on those biofuels which are available on a
relatively large scale today: bioethanol, biodiesel, Pure Plant Oil
and biogas. These fuels are likely to make a significant contribution
to EU target to reduce transport emissions by 20% before 2020.
The guide briefly addresses solutions – such as electricity,
hydrogen and DME – which may emerge on the market in the near
future and are anticipated to make a large contribution to the long-
term reduction of emissions from the transport sector.
Interviews with experienced users of biofuels, together with
literature studies, represent an important part of the background
material used to compile this guide. The aim of these interviews
71. Introduction
Biofuel Cities – Technical guidance for biofuels
was to identify users with in-depth knowledge of the functionality
of the vehicles and fuels. The users were located in Sweden,
Austria and Germany.
Each fuel is presented separately in the guide, together with a list
of references. Whilst the guide is best understood as an entity,
every effort has been made to ensure that each chapter can be
read, understood and utilised independently.
Biofuel Cities – Technical guidance for biofuels
8 2. Bioethanol
2 Bioethanol
2.1 Summary bioethanol
Bioethanol is used to substitute petrol around the world and is the
most commonly-used biofuel for this purpose1. Bioethanol can be
combined with petrol in any concentration up to pure bioethanol
(E100).
Bioethanol can be produced from any biological feedstock that
contains sugar or materials that can be converted into sugar such
as starch or cellulose.
First generation bioethanols are characterised by the fact that only
parts of the source plant are used for bioethanol production. The
next-generation (or second generation) bioethanols use nearly the
whole plant, including waste, for bioethanol production. The
process technology for second generation fuels is generally more
complex2.
The main crops used for the industrial production of bioethanol are
sugar cane, corn (maize), wheat and sugar beet3. The last two are
currently, and for the foreseeable future, the main sources of
bioethanol in Europe. Brazil is the world market leader in
bioethanol production.
High blend bioethanol can be used in adapted vehicles with petrol
engines and diesel engines. Bioethanol for adapted petrol engines,
E85, consists of 85% bioethanol and 15% petrol, which mitigates
against cold start problems. E85 is frequently used in Europe,
although pure bioethanol fuel, E100, can be used in warmer
climates where cold start problems are not a factor. Bioethanol
adapted diesel engines can run on ED95, a fuel consisting of 95%
hydrous bioethanol and 5% ignition improver.
1 2008. Sustainable Green Fleets website, www.sugre.info 2 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany 3 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commissions Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Biofuel Cities – Technical guidance for biofuels
92. Bioethanol
Bioethanol fuels Petrol engines Diesel engines
No changes 5-10% E-diesel 15%
Modified engines E85 ED95
Table 1 Functionality of bioethanol blends in petrol and diesel engines
E85 can be distributed and implemented in existing infrastructure
without major modifications, although - as E85 and petrol react
differently with certain plastic and rubber materials – some
materials in the infrastructure must be adjusted to ensure
compatibility with both fuels4.
Bioethanol can be manufactured from different sources and with
different processes. The environmental impact of bioethanol differs
according to the variations in the fuel’s life cycle, from the initial
source of production to use in a vehicle (the route from “well-to-
wheel”). Particularly important issues to consider are greenhouse
gas (GHG) balance and energy balance for the life cycle of the fuel.
2.2 General fuel properties
Bioethanol is a liquid that is soluble in petrol but has different
corrosive properties than petrol. Bioethanol can be used in different
blends as fuel to vehicles, from a small percentage of the fuel
content to 100% bioethanol. There is currently no international
standard for bioethanol, but many countries have their own
standards or guidelines for fuel content and properties. Some
comparisons have been made between different standards and
work is underway to create international quality specifications, in
order to increase the trading potential of bioethanol as fuel.
Bioethanol can be produced in two forms – hydrous (or hydrated)
and anhydrous. Bioethanol with water is hydrous (or hydrated)
bioethanol. Bioethanol with no water is anhydrous bioethanol.
Bioethanol is hydrophilic, meaning it attracts water.
Hydrous bioethanol typically has a purity of about 95% and has
been used in Brazil since the late 1970s. It has been used directly
4 2007, Logistics of fuel from ethanol producer to forecourt in Sweden and the Netherlands, BEST Deliverable D4.8, www.best-europe.org
Focus flexi fuel (Photo www.greenfleet.info)
Biofuel Cities – Technical guidance for biofuels
10 2. Bioethanol
as a motor fuel in adapted alcohol vehicles, with modified engines
that are able to use fuel with 95%+ bioethanol content. A second
stage process is required to produce high purity anhydrous
bioethanol for use in petrol blends. Most countries require industrial
bioethanol, whether hydrous or anhydrous, to be denatured (to
prevent oral consumption thereby differentiating it from potable
beverage alcohol for taxation purposes) by the addition of small
amounts (1% to 5%) of unpleasant or poisonous substances5.
The letter ‘E’ is used for fuels which contain bioethanol. For
example, the term E85 is used to designate a mixture of 85%
bioethanol and 15% petrol.
For heavy vehicles there is a bioethanol blending called bus fuel
ED95, which is developed for heavy-duty, bioethanol compression-
ignition engines. The trade name of the fuel is Etamax-D
as produced by SEKAB (Svensk Etanolkemi AB). Etamax-D has a
composition of (percentage by volume)6:
� 93.5 % bioethanol (hydrous 95 %)
� 3.6 % ignition improver
� 3.0 % denaturants (MTBE 2.5 % and iso-butanol 0.5 %
according to Swedish law)
� Corrosion inhibitor
The Etamax-D product for diesel is produced from SEKAB’s 95%
bioethanol. The 95% bioethanol specification is essentially the
same as the anhydrous 99.5% specification for petrol blending in
all respects except bioethanol and water content.
Despite the fact that bioethanol has a very low cetane number the
fuel has high qualities and also works well in a compression-ignition
engine. This property of the fuel is given by the ignition improver
additive.
5 2004, Setting a Quality Standard for Fuel Ethanol, IFQC, International Fuel Quality Center, Australia
6 2007, Experiences from introduction of ethanol buses and ethanol fuel stations, BEST Deliverable D2.1 and D2.2, www.best-europe.org
Ethanol bus in Madrid (Photo EMT Madrid)
Biofuel Cities – Technical guidance for biofuels
112. Bioethanol
2.3 Availability Bioethanol is the biofuel that is most commonly used worldwide for
substitution of petrol7. It can be combined with petrol in any
concentration up to pure bioethanol (E100).
Bioethanol can be produced from any biological feedstock that
contains sugar or materials that can be converted into sugar such
as starch or cellulose.
First generation bioethanols are characterised by the fact that only
parts of the source plant are used for bioethanol production. The
next-generation (or second generation) bioethanols use nearly the
whole plant, including waste, for bioethanol production. The
process technology for second generation fuels is generally more
complex.8
2.3.1 Sources of bioethanol
The main crops used for the industrial production of bioethanol are
sugar cane, corn (maize), wheat and sugar beet9. The last two are
currently, and for the foreseeable future, the main sources of
bioethanol in Europe. Large scale bioethanol production in Europe
would rely mostly on wheat. Brazil is the world market leader in
bioethanol production.
2.3.2 Future availability
Production of biomass for energy requires land use. This may
generate competition with crops normally used for food or
feedstock. Some potential sources of additional agricultural
capacity for growing bioethanol energy crops in ways that do not
compete with food production are described below10:
• The reduction of sugar subsidies is expected to reduce
sugar beet production, thereby releasing land currently
used for sugar beet where yields are poor. In high yield
7 2008, Sustainable Green Fleets website, www.sugre.info8 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany 9 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Biofuel Cities – Technical guidance for biofuels
12 2. Bioethanol
areas, however, some land is still expected to be used for
sugar production if there is a market for bioethanol.
• A steady increase of agricultural yields has been achieved
over the last decades and this trend is expected to
continue.
• Set-aside areas can in principle be used for non-food
production although it is difficult to make an accurate
estimate of land quality and therefore of yields.
• There is a large potential for collection and use of waste
woody biomass as well as straw for advanced bioethanol
fuels.
In recent years there has been great interest in processes to
convert ligno-cellulose into bioethanol via separation and
breakdown of the cellulose into fermentable sugars. Bioethanol
produced from ligno-cellulose is one of the so-called second
generation biofuels.
Ligno-cellulosic “wood” is considered here as a proxy for a range of
materials. The largest potential sources are farmed wood, perennial
grasses and wood waste from forestry.
At present, only small quantities of fuel are manufactured from
these sources, but the future potential is very large and a lot of
research is being devoted to developing such routes.
2.4 Use in vehicles High blend bioethanol can be used in adapted vehicles with petrol
engines and diesel engines. The fuels have different properties.
Bioethanol for adapted petrol engines, E85, consists of 85%
bioethanol and 15% petrol. In warmer climates E100 can be used,
but in Europe E85 is the most common available bioethanol fuel.
Bioethanol adapted diesel engines are dedicated to run on ED95, a
fuel consisting of 95% hydrous bioethanol and 5% ignition
improver.
10 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Biofuel Cities – Technical guidance for biofuels
132. Bioethanol
Bioethanol fuels Petrol engines Diesel engines
No changes 5-10% E-diesel 15 %
Modified engines E85 ED95
Table 2 Bioethanol blends usable in petrol and diesel engines
2.4.1 Vehicle technology
Light vehicles
Bioethanol can be used at a low blend, 5-10%, in all petrol vehicles
without modification. When bioethanol is blended into fuel at levels
above 10% of volume, some engine modifications may be
necessary. High blended bioethanol, E85, is used in adapted petrol
vehicles. These are flexifuel, which means that they can run on
either petrol or a blend of petrol and bioethanol up to 85 percent.
During the past few years, several major automobile manufacturers
have developed flexible fuel vehicles (FFVs). The main differences
between bioethanol FFVs and petrol vehicles are the materials used
in the fuel management system, metallic and rubber based
materials are replaced with bioethanol compatible substitutes.
Modifications to the engine calibration system are also made. The
corrosive effect of fuel rises when bioethanol content is increased.
15% petrol is added to the bioethanol fuel because bioethanol has
a lower vapour pressure than petrol at low temperatures, making
cold starts more difficult.
The bioethanol cars have only one fuel tank, which can be filled
with either E85 or petrol. The amount of bioethanol in the fuel is
detected by a sensor that analyses the content of the fuel tank
(mixture of bioethanol and petrol). The information is sent to the
engine and the fuel injection system is adjusted according to the
data.
Ford Focus ethanol car in Basque County, Spain
(Photo Kristina Birath)
Biofuel Cities – Technical guidance for biofuels
14 2. Bioethanol
A large variety of bioethanol cars are available on the European
market.
Ford: Focus, C-Max, S-max, Mondeo, Galaxy
Volvo: S40, V50 and C30, S80, V70
Saab: 9-5, 9-3
Renault: Megane
Peugot: 307 Bioflex
Skoda: Oktavia Flexifuel (1.6)
Volkswagen: Golf 1.6
Audi A3, A4,
Seat Leon and Altea,
Citroen C4 and C5
Table 3 Bioethanol cars available on the European market 2008
Other bioethanol fuel characteristics, including a high octane rating,
result in increased engine efficiency and performance. In
combination with turbo-technology, engine performance increases
when E85 is used.
Maintenance needs
Compared to conventional petrol cars, bioethanol cars need more
frequent service. The manufacturers recommend service every
10 000 km (or once a year), compared to every 20 000 km (or
once a year) for new petrol cars. The reason for this is that engine
oil and the oil filter have to be changed more often in a bioethanol
car, as the bioethanol fuel is not lubricating the engine as much as
petrol does and the oil gets worn out faster.
Driving range
Bioethanol fuel contains approximately 35% less energy compared
to petrol. This means that the consumption of bioethanol is higher
than petrol and thus the driving range is shorter. A bioethanol car
that uses 0.7 litres petrol/10 km needs 1.0 litre E85/10 km. The
bioethanol fuel has a higher octane number (104) and can be used
with a higher compression ratio, resulting in higher energy
efficiency. This means that engines optimised for bioethanol can be
Biofuel Cities – Technical guidance for biofuels
152. Bioethanol
more energy efficient than engines that are currently optimised for
petrol. As bioethanol has a higher octane number than petrol, it
offers increased torque and higher power, especially when used
in combination with turbo-technology.
Cost
Bioethanol cars can cost up to €800 more than a comparable petrol
model. However, some car manufacturers do not charge extra for
the bioethanol version. The additional cost includes the engine
heater which is standard equipment.
Cold start properties
Bioethanol cars can have cold start problems when the temperature
goes below -15ºC. From 5ºC use of engine heater is recommended.
Another reason for using the engine pre-heater is that the
emissions of hydrocarbons increase in cold weather. For these
reasons, bioethanol vehicles are equipped with an engine heater
when delivered.
Retrofitting
It is possible to retrofit a petrol car to operate on bioethanol, and
also to flexifuel E85-petrol. All parts in the fuel system must be
durable to bioethanol. When a car is retrofitted, the fuel injectors
are changed and the engine control plan has to be calibrated for
the new fuel. In Sweden, it is legal to retrofit petrol cars to
bioethanol cars since mid-2008. After conversion, the cars have to
be certified at the Swedish Motor Vehicle Inspection Company. The
car has to meet the emission standard it did prior to the retrofit.
Heavy duty vehicles
Heavy duty vehicles running on bioethanol are equipped with a
diesel engine adapted for bioethanol. At present, it is not possible
to retrofit diesel engines to enable bioethanol propulsion. The fuel
used consists of bioethanol and an ignition improver. Neat
bioethanol has a low cetane number and therefore the ignition
improver is required, together with increased compression ratio in
the engine.
Biofuel Cities – Technical guidance for biofuels
16 2. Bioethanol
Available vehicles
Today, bioethanol buses, waste trucks and distribution trucks are
available from Scania. The bioethanol bus is a standard city bus
with a compression-ignition engine modified for bioethanol fuel.
The main differences compared to a conventional diesel powered
engine are:
� Raised cylinder compression ratio
� Larger injector holes
� Modified injection timing
� Fuel pump with larger flow capacity
� Gaskets and filters in the fuel system exchanged to
materials more resistant to alcohol11
Maintenance needs
Bioethanol buses require as frequent maintenance as diesel buses
(every 10 000 km is the recommended frequency). However,
compared to diesel buses, bioethanol buses need more extensive
service each time and it is very important to keep the scheduled
service. The main service needs are change of motor oil and oil
filter. Change of fuel injectors is required at every second service,
as pollutants formed in the engine can get stuck in the fuel
injector, making the injection pressure fall. The cost for
maintenance of bioethanol buses is twice as high as for diesel
buses12.
Driving range
ED95 has about 60% lower energy content compared to diesel,
meaning that 60% more fuel is needed to drive a bioethanol bus
the same distance as a diesel bus. Both engines are as energy
efficient. Today’s bioethanol buses are equipped with a 500 litre
fuel tank in order to operate over the same distances as diesel
buses.
2.4.2 Exhaust gas emissions
There is no emission certification for flexifuel vehicles running on
E85, although this will become possible in the emission standard
for 2013. The emission test is thus made on petrol.
11 2007, Frequently asked questions on ethanol buses, www.ethanolbus.com 12 Interview with Per Wikström, Busslink, see Appendix IV.
Biofuel Cities – Technical guidance for biofuels
172. Bioethanol
Fuel/limits CO (g/km) HC (g/km) NOx (g/km)
E85 0,86 0,09 (a) 0,02
E5 petrol (b) 0,43 0,077 0,041
Limits (Euro 4) 1 0,1 0,08
(a) HC as measured by a FID instrument. The ethanol part of the organic gases
is some 30% to 40%.
(b) The 95 octane petrol in Sweden contains 5% ethanol since 2001.
Table 4 Average emissions from a car with 50 000 km aged catalyst (manual
transmission) (Source: Exhaust characterisation study, April 200813)
Emissions of HC increase when the temperature decreases. Tests of
cold start emissions were performed at +22ºC and -7ºC for E5 and
E8514. At +22ºC many emission components were lower for E85
than for E5 Aldehyde emissions increased due to the increase of
bioethanol in the fuel. During cold starts, the emissions of HC
increased substantially. Emissions of aldehydes (formaldehydes and
acetaldehydes) were generally higher for flexifuel vehicles running
on E85 compared to E5. The impact was more pronounced at -7ºC.
Therefore, car manufacturers recommend use of engine heater at
temperatures below+ 5ºC.
The bioethanol compression ignition engine emits less particulate
matter (PM), and nitrogen oxide (NOX) compared to conventional
diesel engines. Tests have been performed on a bioethanol adapted
diesel engine with catalytic converter and EGR (exhaust gas
recirculation, system for NOX reduction)15. The emission tests show
that bioethanol buses meet the level for Euro 5 and EEV for both
NOX and particulates.
13 Westerholm R., et al, 2007, An exhaust characterisation study based on regulated and unregulated tailpipe and evaporative emissions from bi-fuel and flexi-fuel light-duty passenger cars fuelled by petrol (E5), bio-ethanol (E85) and biogas tested at ambient temperatures of +22ºC and -7ºC, Institution for Analytical Chemistry, Stockholm University, Sweden 14 Westerholm R., et al, 2007, An exhaust characterisation study based on regulated and unregulated tailpipe and evaporative emissions from bi-fuel and flexi-fuel light-duty passenger cars fuelled by petrol (E5), bio-ethanol (E85) and biogas tested at ambient temperatures of +22ºC and -7ºC, Institution for Analytical Chemistry, Stockholm University, Sweden 15 Egebäck, K-E., 2004, A clean ethanol fuelled compression ignition bus engine, Report for Bioalcohol Fuel Foundation (BAFF), Örnsköldsvik, Sweden
Biofuel Cities – Technical guidance for biofuels
18 2. Bioethanol
0
0,5
1
1,5
2
2,5
3
3,5
Scania DSI 9E med EGR 2) with catalytic converter and particulate filter
g/k
Wh
Nitrogen oxides (NOx) Level for Euro 4
Level for Euro 5 & EEV 1)
1) EEV = Enhanced Environmentally Friendly Vehicle2) EGR = Exhaust Gas Recirculation
0
0,5
1
1,5
2
2,5
3
3,5
Scania DSI 9E med EGR 2) with catalytic converter and particulate filter
g/k
Wh
Nitrogen oxides (NOx) Level for Euro 4
Level for Euro 5 & EEV 1)
1) EEV = Enhanced Environmentally Friendly Vehicle2) EGR = Exhaust Gas Recirculation
Figure 1 Emissions of NOX from an ethanol engine equipped with catalytic converter and EGR emission treatment system.
0,002
0
0,005
0,01
0,015
0,02
0,025
0,03
Scania DSI 9E med EGR 2) with catalytic converter and particulate filter
g/k
Wh
ParticulatesLevel for Euro 4 & 5
Level for Euro EEV 1)
1) EEV = Enhanced Environmentally Friendly Vehicle2) EGR = Exhaust Gas Recirculation
0,002
0
0,005
0,01
0,015
0,02
0,025
0,03
Scania DSI 9E med EGR 2) with catalytic converter and particulate filter
g/k
Wh
ParticulatesLevel for Euro 4 & 5
Level for Euro EEV 1)
1) EEV = Enhanced Environmentally Friendly Vehicle2) EGR = Exhaust Gas Recirculation
Figure 2 Emissions of PM from an ethanol engine equipped with catalytic converter and EGR emission treatment system
2.4.3 User experience
Bioethanol cars
Many actors have experiences of driving bioethanol cars,
particularly in Sweden where 160,000 bioethanol cars have been
sold.
Taxi Stockholm has many affiliated driving companies that use
biofuels in their vehicles. The main reason for using biofuels is the
economic advantage – fuel prices are lower, biofuelled taxis are
prioritised in many queues making waiting times shorter; and
customers demand environmentally adapted cars. It has not been
Want to know more? There is interesting information at www.baff.infowww.sugre.infowww.bioethanolcarburant.com
Biofuel Cities – Technical guidance for biofuels
192. Bioethanol
hard for car dealers to supply E85 vehicles to Taxi Stockholm. The
bioethanol cars need a little more maintenance, but not so much as
to make the cost a burden. Since E85 can be refuelled at almost
any fuel station, supply and availability of fuel does not present a
problem. Driving the cars is no different from driving diesel fuelled
taxi vehicles.
Within the EU-funded BEST project (Bioethanol for sustainable
transport) a survey of the attitudes among bioethanol car drivers
has been performed. The survey was done among drivers in the
BEST sites (see the number of respondents under the figure
below). The results are presented in a report “FFV driver attitudes -
Results from survey 2007”16. The drivers were asked about their
opinion on the performance of the cars. In Figure 3-5 the results
are presented. Total number of responses: Brandenburg 26,
Rotterdam 43, Madrid 13, Basque Country 14, Somerset 41,
BioFuelRegion (a part of Northern Sweden) 25, City of Stockholm
83, Stockholm - private 152, Stockholm - commercial 144.
Altogether 541 responses were included in the study.
Figure 3 Answers to the question: In your opinion, is an ethanol car worse or better than a conventional car in the following aspects:
8%
11%
15%
6%
88%
94%
78%
83%
94%
46%
51%
80%
96%
10%
6%
13%
10%
88%
43%
33%
14%
2%
2%
2%
1%
2%
9%
10%
92%
5%
4%
4%
2%
0% 20% 40% 60% 80% 100%
Passenger comfort
Driver comfort
Operation
Noise
Safety
Emissions
Smell
Accelleration
Speed
Braking
Range
Worse Equal Better
16 2007, FFV driver attitudes - Results from survey 2007, Input to the final report for the BEST project, intermediate report
Want to know more? Have a look at the website for the EU project BEST (Bioethanol for sustainable transport) www.best-europe.org
Biofuel Cities – Technical guidance for biofuels
20 2. Bioethanol
The drivers were also asked how satisfied or dissatisfied they were
with their bioethanol cars. Overall, 75% are satisfied, 18% are
neither satisfied nor dissatisfied and 7% are dissatisfied.
Figure 4 Answers to the question: In general, how satisfied or dissatisfied are you with your experience driving an ethanol car?
8%
7%
20%
5%
9%
7%
23%
21%
17%
24%
30%
14%
17%
18%
69%
86%
77%
71%
76%
56%
65%
76%
80%
75%
3%
7%
0%
15% 8%
14%
0% 20% 40% 60% 80% 100%
Brandenburg
Rotterdam
Madrid
Basque
Somerset
BFR
City of Sthlm
Sthlm - private
Sthlm - commercial
Total
Dissatisfied Neither dissatisfied nor satisfied Satisfied
The drivers were also asked if they would recommend bioethanol
cars to others. 83% said they would.
Figure 5 Would you recommend others to drive ethanol cars?
62%
83%
67%
78%
85%
83%
23%
29%
12%
21%
18%
11%
10%
13%
15%
9%
0%
5%
13%
5%
89%
71%
84%
100% 0%
7%
0%
3%
1%
4%
0% 20% 40% 60% 80% 100%
Brandenburg
Rotterdam
Madrid
Basque
Somerset
BFR
City of Sthlm
Sthlm - private
Sthlm - commercial
Total
Yes Uncertain No
Biofuel Cities – Technical guidance for biofuels
212. Bioethanol
Bioethanol buses
Stockholm Public Transport Authority, SL, introduced bioethanol
buses in the fleet in the beginning of 1990’s. The reason for the
change was mainly a need for better air quality in the city centre.
The bioethanol buses emit less NOX and PM. Busslink, a public
transport company, has been operating the bioethanol buses since.
SL owns and maintains the bioethanol fuel stations and Busslink is
responsible for operation and maintenance of the buses. The
bioethanol buses work well but they need frequent maintenance.
This is the most important lesson learned from the users. The
energy consumption is the same as for a diesel bus, but as the fuel
contains 60% less energy the buses need more fuel by volume.
This makes the refuelling takes some more time compared to
diesel. The buses also need larger fuel tanks in order to be able to
drive the same mileage as the diesel buses.
Within BEST a survey has been performed among drivers of
bioethanol buses. 54 drivers had been driving bioethanol buses
between 1–3 years in Stockholm, Sweden. They got questions
about the performance of the buses compared to diesel buses.
They were most positive to the lower emissions and the better
smell and most negative to the worsened acceleration and speed.
Figure 6 Ethanol bus drivers opinion on bus performance
In respect to the following statements, are ethanol buses in your
opinion better, equal or worse than conventional diesel buses
0 10 20 30 40 50
Comfort for passangers
Comfort for driver
Driving the vehicle
Effort, exhaustion of the driver
Safety
Pollution, exhaust emission
Smell
Acceleration
Speed
Brake
Number of drivers
BetterEqualWorseI don't knowNo answer
The drivers also got the question about their opinion towards
bioethanol buses and the majority of the drivers are positive.
Want to know more? You find information at: www.ethanolbus.com
Biofuel Cities – Technical guidance for biofuels
22 2. Bioethanol
What is your opinion to ethanol buses?
27
18
9
26
19
5
2 1 10
5
10
15
20
25
30
Verypositive
Ratherpositive
Neither/nor Rathernegative
Verynegative
No answer
Num
ber
ofdr
iver
s
BeforeNow
Figure 7 Ethanol bus drivers opinion on ethanol buses.
Diskteknik AB, in Sweden, has 13 cars available for their sales
people. These run on ethanol, E85. The vehicles are of the brands
Ford and Saab. Diskteknik has long experience with renewable
fuels as RME, biogas and now ethanol. The company has good
experiences with ethanol cars. These work just as well as
conventional vehicles and the drivers are very motivated to refuel
the vehicles with ethanol rather than petrol. At the moment it is
cheaper to drive on ethanol in Sweden.
2.5 Infrastructure requirements
It is important that proper fuel handling techniques are practiced to
prevent fuel contamination. Also choosing the right materials for
fuel storage and dispensing systems is crucial. Local and national
regulations and legislation applicable for fuel infrastructure must be
followed. These requirements can be different in individual regions
and countries.
2.5.1 Technical aspects of filling stations
Authorisation is required for the handling of flammables at petrol
stations. Authorisation granted for the handling of petrol does not
automatically apply to the handling of E85 or E9517. A petrol station
that sells petrol must, when wanting to sell E85/E95, also obtain
17 2007, Experiences from introduction of ethanol buses and ethanol fuel stations, BEST Deliverable D2.1 and D2.2, www.best-europe.org
Biofuel Cities – Technical guidance for biofuels
232. Bioethanol
authorisation for the handling of E85/E95. One important aspect is
that bioethanol and petrol have different explosive limits. This
means that an explosive gas atmosphere in an E85 storage tank
will exist across a wider temperature range than in a petrol storage
tank. Other aspects that could be included in legal requirements
are the increased risk of ignition, a recovery system for gases,
depth gauging and extinguishing agents.
E85 can be distributed and implemented in available infrastructure
without any major modifications18. E85 and petrol react differently
with some plastic and rubber materials. It is therefore important to
choose a material that is compatible with bioethanol for use in
pumps, pipes and tanks. Examples of materials that are suitable for
use with E85 are stainless steel, galvanised steel and bronze.
Materials that should not be used with E85 include zinc, brass, lead
and aluminium.
Since bioethanol is hydrophilic (it attracts water) it is important to
avoid water leakage in storage and distribution systems.
The bioethanol blend E85 is sold in two different kinds of pumps;
either a pump that is used only for E85 (a static pump) or a
flexifuel pump. An important benefit of the flexifuel pump is that it
can offer different blends of bioethanol and petrol, which
encourages the development of a flexible fuel market.
In Sweden there are examples of flexi-pumps where the client can
choose from E10, E25 or E85. More varieties are possible. For
example, in the future, both E85 and E100 could even be sold from
the same pump. The flexifuel pump is connected to two different
underground tanks – one with petrol and one with bioethanol.
2.5.2 Technical aspects of storage and
transportation
The technology for storing and dispensing petrol can be applied to
alcohol fuels such as E85/95 because alcohols and alcohol blends,
like petrol, are liquid fuels at ambient pressures and
18 2007, Logistics of fuel from ethanol producer to forecourt in Sweden and the Netherlands, BEST Deliverable D4.8, www.best-europe.org
Refuelling station for buses, Stockholm
(Photo Kristina Birath)
Biofuel Cities – Technical guidance for biofuels
24 2. Bioethanol
temperatures19. However, only E85/95-compatible materials should
be used in storage and dispensing systems. Most operating
problems with bioethanol-fuelled vehicles have been traced to
contaminated fuel. Consequently, choosing the right materials for
fuel storage and dispensing systems and following proper fuel
handling procedures are crucial for successfully operating
bioethanol-fuelled vehicles.
An example of the preparation and transport systems for
bioethanol fuel is given below where the situation in Sweden is
described:
The mixing of the different types of bioethanol fuels are performed
at designated sites20. These sites are preferably located close to
existing infrastructure like harbours, railways and roads. This will
facilitate the transport of raw material and fuels to and from the
mixing site.
At the mixing site there are storage tanks for the components in
the fuels; the size of these tanks depend on the volumes of fuels
produced at each specific site. From the storage tanks there are
pipe connections to the different means of transport so that raw
material and fuel can be pumped to and from the storage tanks.
The tanks are placed within an embankment which will collect any
leakages. This embankment must be able to collect the total
volume of the largest tank and also ten percent of the volume of all
tanks placed within the embankment. A spill collection system and
rain protection are required at the mixing site, as is a control
system that monitors the levels in the tanks, pumps and other
equipment associated with the mixing site.
From the mixing site the fuels are either transported by boat, train
or truck. For the product E5, dehydrated bioethanol is transported
to the oil companies’ own fuel preparation sites. E85 is produced at
the mixing sites and transported either directly to the filling
stations by truck or to fuel depots using all three modes of
19 2005, Storing and Dispensing E85 and E95, Experiences from Sweden and the US, BEST Deliverable D4.02A, www.best-europe.org
20 2007, Logistics of fuel from ethanol producer to forecourt in Sweden and the Netherlands, BEST Deliverable D4.8, www.best-europe.org
Refuelling station for cars, Stockholm
(Photo Kristina Birath)
Biofuel Cities – Technical guidance for biofuels
252. Bioethanol
transport. The ED95 (Etamax-D) is today mainly distributed directly
to the public transport companies by truck and used in buses.
2.5.3 Safety risks
E85
Bioethanol has a lower vapour pressure than petrol at low
temperatures. For example, E85 is more flammable than petrol at
0°C but at higher, normal, temperatures E85 is less flammable
because of the higher auto ignition temperature of 454°C21.
There is no increased risk associated with E85 compared with petrol
fuel when it comes to fire and safety aspects22. The risks with E85,
however, are different from petrol. Combustible vapours of E85 fuel
can occur in closed spaces (fuel tank in vehicles and at filling
stations) at higher ambient temperatures – and in a broader
temperature interval – than for conventional petrol fuels.
The advice and recommendations given by The Swedish Petroleum
Institute together with the special adaptations in today’s E85 cars
are sufficient to compensate for these risks.
E85 fires can be assessed to be less damaging to humans and
property and are less difficult to extinguish than petrol and diesel
fires. In Sweden no serious fire or explosion accidents have
occurred despite the fact that E85 is now widely used.
Filling stations for E85 are also modified in accordance with safety
recommendations from the Swedish Petroleum Institute. An
example of a measure is that the pistol valve on refilling pumps for
E85 should not be equipped with lock-up mechanism, because it
not should be possible to leave the pistol and build up static
electricity. With the exception of refilling of FFV cars as designed by
Saab, fuel vapours are emitted into open air by fuel refilling of E85
cars at Swedish filling stations. New regulations from the Swedish
Environmental Protection Agency are expected to address this issue
in the near future.
21 Green Fleets website, www.sugre.info
Want to know more? Information about fuel vapour composition and flammability properties of E85 can be found in SP Report 2008:15, available at www.sp.se/en/publications/Sidor/Publikationer.aspx
Biofuel Cities – Technical guidance for biofuels
26 2. Bioethanol
There are several benefits associated with E85 compared with
petrol, such as, slower fire propagation and less violent fires that
are easier to control than petrol fires.
E95
The bioethanol fuel for heavy-duty vehicles is explosive for a much
wider range of ambient temperatures than diesel. Several
measures have already been taken to reduce the risk for fire and
explosion in fuel distribution and refuelling. Recommendations
regarding E85 refuelling equipment have been issued by the
Swedish Petroleum Institute (SPI). For example a “spill-free” fuel
dispensing system reduces the risk of explosion during refuelling.
The vehicle manufacturers have also taken several measures to
increase safety. This is on-going work for E85 and the issue should
be addressed in more detail for bioethanol used in heavy-duty
vehicles as well23.
Besides the mentioned recommendations by SPI for refuelling,
some of the issues and conclusions for light-duty vehicles using
E85 also apply to heavy duty vehicles. For example, flame arresters
could be considered on heavy-duty vehicles. As for the tank at the
refuelling station, the air-fuel mixture in the vehicle tank is
explosive for a considerable range of temperatures and similar
precautions need to be taken into consideration.
Fires in the engine compartment have tended to be more frequent
in alcohol-fuelled buses in Sweden in comparison to diesel-fuelled
buses, although the statistic basis for such a conclusion is small.
2.6 Fuel quality standards There is currently no international standard for bioethanol as
vehicle fuel, but there is ongoing work in establishing standards
and agreements as an effect of the growing demand of biofuels.
22 2006, Safety aspects with E85 as a fuel for vehicles - Fire Safety Consideration, BEST Deliverable D4.02B, www.best-europe.org 23 Rehnlund, B., et al, 2007, Heavy-duty ethanol engines, BIOScopes EC project TREN/D2/44-LOT 2/S07.54739
Biofuel Cities – Technical guidance for biofuels
272. Bioethanol
Besides standards for the composition of the fuel there are a lot of
other regulations, or lack of regulations, that affects the use of
bioethanol as a vehicle fuel.
EU standards
CEN, the European Committee for Standardization, developed in
March 2005 a Workshop Agreement CEN CWA 15923 – Automotive
fuels – Ethanol E85 – Requirements and test methods. It is not a
standard, but lays down requirements for bioethanol-petrol blends
as delivered by the supplier for use in so-called flex-fuel vehicles.
The CWA has been prepared under a mandate given to CEN by the
European Commission. In the CWA all relevant characteristics,
requirements and test methods are specified. National adaptations
of the CWA may choose differently based on either local conditions
and/or updated knowledge24.
At the end of 2007 the European quality specification for bioethanol
as a blending component for petrol up to 5% in volume was
finalised. This activity was undertaken in response to a mandate to
CEN from the European Commission in support of its policy to
promote renewable fuels. The CEN technical commission (CEN/TC
19) accepted the EN 15376. Mixing was possible even before that,
but there was not a European standard drawn up containing
requirements for this blending component. Tax legislations allow
chemical substances in order to denature alcohol. Most of these
chemical substances are disadvantageous for car engines. In the
standard there is a strong advice written that no denaturant alcohol
is added to alcohol for fuel application. The maximal water content
is set at 0.3% (weight)25.
Current fuel specifications allow blending of up to 5vol% biodiesel
and bioethanol and up to 15% ETBE in the standard petrol and
diesel that is being sold. The 2007 proposal for changes to the Fuel
Quality Directive contains a proposal for specifications for the base
fuel for a 10% bioethanol blend26.
24 2005, I.S. CWA 15293:2005, Automotive fuels – Ethanol E85 – Requirements and test methods, NSAI (National Standards Authority of Ireland), Dublin
25 2007-11-09, European standard for ethanol in petrol finalized, Article from NEN, Centrum van Normalisatie, Delft, Netherlands
26 Verbeek, R., et al, 2008, Impact of biofuels on air pollutant emissions from road vehicles, TNO Science and Industrie Report report MON-RPT-033-DTS-2008-01737, Delft, Netherlands
Want to know more? The directive 2003/30/EC can be found at: http://ec.europa.eu/energy/res/legislation/doc/biofuels/en_final.pdf
Biofuel Cities – Technical guidance for biofuels
28 2. Bioethanol
2.7 Production The production process consists of conversion of biomass to
fermentable sugars, fermentation of sugars to bioethanol, and the
separation and purification of the bioethanol. Fermentation initially
produces bioethanol containing a substantial amount of water.
Distillation removes the majority of water to yield about 95% purity
bioethanol, the balance being water27.
In commercial bioethanol production, sugar can be obtained
directly from sugarcane (Brazil), sugar beet (Europe), or hydrolysis
of starch-based grains such as corn (USA) and wheat (Europe). In
the latter, the starch feedstock first needs to be ground to a meal
which is further hydrolysed to glucose by means of enzymes.
The mash is fermented using natural yeast and bacteria. Finally,
the fermented mash is separated into bioethanol and residues (for
feed production) via distillation and dehydration. The process
scheme for bioethanol production from starch is shown in the figure
below.
Figure 8 Process flow diagram for bioethanol production from starch28.
Besides sugar and starch, cellulose can also be converted into
ethanol, but the cellulosic biomass-to-ethanol production process is
more complicated than the sugar- or starch-to ethanol process29.
27 2008. Sustainable Green Fleets website, www.sugre.info28 Schwietzke, S., et al, 2008, Gaps in the Research of 2nd Generation Transportation Biofuels, IEA Bioenergy T41(2): 2008:01 29 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany
Biofuel Cities – Technical guidance for biofuels
292. Bioethanol
In the newest bioethanol production plant concepts, biogas is an
important by-product30. The biogas can be used, if necessary, for
the plants own energy needs, or sold as an “extra” commodity.
2.8 Sustainability issues Bioethanol can be manufactured from different sources and with
different processes. Depending on variations in the life cycle of a
particular bioethanol, from initial source to use in a vehicle, the
environmental impact will be different.
Below the important issues greenhouse gas (GHG) balance and
energy balance for different bioethanol fuels are explained and
presented. Also some other sustainability issues are highlighted,
however in more general terms.
2.8.1 GHG balance
Greenhouse gases are gases causing the greenhouse effect. The
greenhouse gases taken into account in this presentation are
carbon dioxide, CO2, nitrous oxide, N2O and methane, CH4.
The GHG balance for any biofuel is influenced by details like growth
location, use of fertilisers, use of agricultural machinery, production
processes, energy use, use of by products, transports etc. The GHG
balance will be different for different biofuels.
Greenhouse gas emission savings from biofuels are calculated as
the reduction of total emissions from the biofuel compared to the
total emissions from the fossil fuel comparator. These values in
table 5 originate from the Directive of the European Parliament and
of the Council on the promotion of the use of energy from
renewable sources, 2008/0016. How greenhouse gas emission
savings from biofuels are calculated is presented in Appendix I.
Typical values for different bioethanol used today, if produced with
no net carbon emissions from land use change are shown in Table
5. The emissions represent all emissions from well-to-wheel
30 2008, www.ber-rotterdam.com
Want to know more? Sustainability issues are not the focus in this report. Further information can be found at the website http://www.biofuel-cities.eu/index.php?id=6780.
Biofuel Cities – Technical guidance for biofuels
30 2. Bioethanol
(WTW), i.e. from extraction of raw materials to use of the fuel in
vehicles.
CO2 emissions from land use change: emissions of carbon
dioxide due to changes in land use mainly come from deforestation
for development of agriculture or built-up areas. When forested
areas are cut down, the land often becomes less productive and
has considerably less capacity to store CO2. This effect is not taken
into account.
Biofuel Cities – Technical guidance for biofuels
312. Bioethanol
Bioethanol production pathway
(CHP = Combined Heat and Power)
Typical greenhouse gas
emission saving
sugar beet bioethanol 48%
wheat bioethanol (process fuel not
specified) 21%
wheat bioethanol (lignite as process
fuel in CHP plant) 21%
wheat bioethanol (natural gas as
process fuel in conventional boiler) 45%
wheat bioethanol (natural gas as
process fuel in CHP plant) 54%
wheat bioethanol (straw as process fuel
in CHP plant) 69%
corn (maize) bioethanol, Community
produced (natural gas as process fuel in
CHP plant)
56%
sugar cane bioethanol 74%
Table 5 Typical greenhouse gas emission savings for different bioethanol fuels31.
Future bioethanol
Estimated typical values for future bioethanol that are not, or in
negligible quantities, on the market in January 2008, if produced
with no net carbon emissions from land use change are shown in
Table 6 below.
These fuels are typically produced from waste from agricultural or
forestry activities and have higher GHG saving potential than
bioethanol produced today.
31 21.1.2008, Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the promotion of the use of energy from renewable sources, Commission of the European Communities, 2008/0016, Brussels, Belgium
Biofuel Cities – Technical guidance for biofuels
32 2. Bioethanol
Bioethanol production pathway Typical greenhouse gas
emission saving
wheat straw bioethanol 87%
waste wood bioethanol 80%
farmed wood bioethanol 76%
Table 6 Typical greenhouse gas emission savings for different future bioethanol fuels32.
2.8.2 Energy balance
The fossil (non renewable) energy use for a biofuel over its life
cycle is an important sustainability factor.
The use of biofuels reduces the use of fossil energy. The energy
balance presented below includes both fossil and renewable (bio)
energy. Evidence of fossil energy savings does not automatically
mean that biofuel pathways are total energy (fossil and renewable)
efficient.
As with the greenhouse gas balance, the fossil energy savings of
biofuels are critically dependent on details like growth location, use
of fertilisers, use of agricultural machinery, production processes,
energy use, use of by products, transports etc. The energy use will
be different for different biofuels.
Taking into account the energy contained in the biomass resource,
one can calculate the total energy involved. The figure below shows
energy figures for different bioethanol fuels. Figures for fossil and
total (fossil and renewable bioenergy) well-to-wheel (WTW) energy
are presented. This represents the energy from well or source of
the biofuel to use of the fuel in the vehicle.
32 21.1.2008, Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the promotion of the use of energy from renewable sources, Commission of the European Communities, 2008/0016, Brussels, Belgium
Biofuel Cities – Technical guidance for biofuels
332. Bioethanol
Figure 9 WTW total versus fossil energy. For gasoline (petrol) total energy is equal to fossil energy. DDGS = Distiller’s Dried Grain with Solubles: the residue left after production of ethanol from wheat grain33.
2.8.3 Other sustainability issues
Soil quality/erosion
Soil erosion by water, wind and agricultural growth affects both
agricultural conditions and the natural environment.
Sugar beet can cause soil erosion, especially if grown on the light
soils of southern Europe. New techniques of inter-sewing between
cover crops can help the situation. However, sugar beet production
would probably not spread beyond areas of northern Europe with
heavy soils. In wet areas, the heavy machinery used for harvesting
sugar beet can cause soil compaction.
33 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commissions Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Biofuel Cities – Technical guidance for biofuels
34 2. Bioethanol
Continually removing straw instead of incorporating it in the soil
will decrease the soil’s organic content and may lead to reduced
moisture retention. This may be a larger problem in light southern
soils but probably does not represent a significant problem in the
prime cereals-growing areas of Northern Europe where a high
density of straw availability makes it most economic to site straw-
to-bioethanol fuel conversion plants34.
Acidification and Eutrophication
Acidification and eutrophication of ecosystems are two
environmental problems that to a great extent are caused by the
same pollutants.
The main cause of acidification is the airborne deposition of
sulphur. Nitrogen compounds (nitrogen oxides and ammonia) are
the dominant cause of eutrophication of many ecosystems, but also
contribute increasingly to acidification.
Acidification causes soil depletion, disappearance of plants and
animals as well as forest damage. The deposition of nitrogen
compounds favours forest growth, but at the same time leads to
the chemical disruption of a long list of ecosystems, and results in
decrease of biodiversity.
Because intensive agriculture using fertilisers tends to cause
eutrophication and acidification, increased crop production for
bioethanol fuels would tend to accelerate the problem. The driving
force for intensification is crop price: hence meeting biofuels
targets will probably cause intensification of oilseed (biodiesel)
production rather than of cereals (bioethanol) production.
Short rotation forest and other “advanced bioethanol fuels” crops
generally use less fertiliser than the other crops35.
34 2008, Sustainable Green Fleets website, www.sugre.info
Biofuel Cities – Technical guidance for biofuels
352. Bioethanol
Biodiversity
Biodiversity is the variety of life: the different plants, animals and
micro-organisms, their genes and the ecosystems of which they are
a part.
Growing energy crops instead of permanent crops and on “natural”
land now in voluntary set-aside areas would decrease biodiversity.
A European study concluded that the negative biodiversity impacts
are medium for sugar beet and low to medium for short rotation
forestry.36
The use of wood residues is considered to have no impact. Pesticide
use affects biodiversity negatively.
Large increases of pesticide applications are needed if the
frequency of sugar beet crops in a rotation is increased beyond
about one year in four. Sugar beet generally requires much more
pesticide than other crops.
Impact on ground water table
The increased growth of crops requiring extensive irrigation in arid
areas will put pressure on water resources. For example sugar beet
cultivation in Spain and Greece has a very high percentage of
irrigated area.
Increased cultivation of trees can also lead to a lowering of the
ground water table. Lowering of the water table can have
significant impact on the natural environment in the area
concerned.
Introduction of non-native species and GMOs
A genetically modified organism (GMO) is an organism whose
genetic material has been altered using genetic engineering
techniques.
35 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commissions Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 36 2006, How much bioenergy can Europe produce without harming the environment?, EEA Report No 7/2006, ISBN 92-9167-849-X, ISSN 1725-9177, Copenhagen, Denmark
Biofuel Cities – Technical guidance for biofuels
36 2. Bioethanol
There is some risk that non-native energy crops could spread in the
wild, because they lack natural predators. Using sterile varieties
(including GMOs) greatly reduce this risk. However, there are some
general concerns about the environmental and health impacts of
GMO crops.
Social impact, working conditions
In general, working conditions in relation to farm and agricultural
labour are regulated, particularly in the EU-27 and the US. In other
parts of the world the working conditions could be questioned.
However similar problems exist both for biofuel production and for
food and feed production.
Working conditions at sugar cane production sites in Brazil are
sometimes argued to be hard and to involve child workers. More
than 80% of the harvest is done by hand but the automatisation
rate is increasing37.
Competition with food production
Biomass for energy needs land and is therefore in competition with
other crops. A criticism raised against biomass, particularly against
large-scale fuel production, is that it could divert agricultural
production away from food crops, especially in developing
countries38.
The topic is complex and there are different opinions, pro and con,
from various stake holders.
37 Smeets, E., et al, 2006, Sustainability of Brazilian bio-ethanol, Copernicus Institute, Department of Science, Technology and Society Report NWS-E-2006-110, ISBN 90-8672-012-9, University of Utrecht, Netherlands 38 Peña, N., 2008, Biofuels for transportation: A climate perspective, Pew Center on Global Climate Change, Arlington, U.S.A.
Biofuel Cities – Technical guidance for biofuels
372. Bioethanol
Literature Bioethanol A clean ethanol fuelled compression ignition bus engine,
Egebäck, K-E., 2004
Report for Bioalcohol Fuel Foundation (BAFF), Örnsköldsvik,
Sweden
An exhaust characterisation study based on regulated and
unregulated tailpipe and evaporative emissions from bi-fuel
and flexi-fuel light-duty passenger cars fuelled by petrol
(E5), bio-ethanol (E85) and biogas tested at ambient
temperatures of +22°C and -7°C. Westerholm, R., et al,
2007
Institution for Analytical Chemistry, Stockholm University, Sweden
Biofuels for Transportation: A Climate Perspective, Peña, N.,
2008
Pew Center on Global Climate Change, Arlington, U.S.A.
Biofuel Technology Handbook, Rutz D., Janssen R., 2008
WIP Renewable Energies, München, Germany
DIRECTIVE 2003/30/EC OF THE EUROPEAN PARLIAMENT
AND OF THE COUNCIL of 8 May 2003, on the promotion of
the use of biofuels or other renewable fuels for transport,
2003
European Union, Brussels, Belgium
EU-27, Bio-fuels, Annual 2007
GAIN Report E47051, Washington, U.S.A.
European standard for ethanol in petrol finalised, 2007-11-
09
Article from NEN, Centrum van normalisatie, Delft, Netherlands
Experiences from introduction of ethanol buses and ethanol
fuel stations, 2007
BEST Deliverable D2.1 and D2.2, www.best-europe.org
Biofuel Cities – Technical guidance for biofuels
38 2. Bioethanol
FFV driver attitudes - Results from survey 2007
Input to BEST (Bio-Ethanol for Sustainable Transport) Final report,
intermediate report
Frequently asked questions on ethanol buses, 2007
www.ethanolbus.com
Gaps in the Research of 2nd Generation Transportation
Biofuels, Schwietzke, S., et al, 2008
IEA Bioenergy T41(2): 2008:01
Heavy-duty ethanol engines, Rehnlund, B. et al, 2007
BIOscopes, EC project TREN/D2/44-LOT 2/S07.54739
How much bioenergy can Europe produce without harming
the environment? 2006
EEA Report No 7/2006, ISBN 92–9167–849-X, ISSN 1725-9177,
Copenhagen, Denmark
I.S. CWA 15293:2005, Automotive fuels – Ethanol E85 –
Requirements and test methods, 2005
NSAI (National Standards Authority of Ireland), Dublin
Impact of biofuels on air pollutant emissions from road
vehicles, Verbeek, R. et al, 2008
TNO Science and Industrie Report MON-RPT-033-DTS-2008-
01737, Delft, Netherlands
Logistics of fuel from ethanol producer to forecourt in
Sweden and the Netherlands, 2007
BEST Deliverable D4.8, www.best-europe.org
Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT
AND OF THE COUNCIL on the promotion of the use of energy
from renewable sources, 23.1.2008
Commission of the European Communities, 2008/0016, Brussels,
Belgium
Biofuel Cities – Technical guidance for biofuels
392. Bioethanol
Safety aspects with E85 as a fuel for vehicles – Fire safety
consideration, 2006
BEST Deliverable D4.02B, www.best-europe.org
Setting a Quality Standard for Fuel Ethanol, 2004
IFQC, International Fuel Quality Center, Australia
Storing and Dispensing E85 and E95 – Experiences from
Sweden and the US, 2005
BEST Deliverable D4.02A, www.best-europe.org
Sustainable Green Fleets website, 2008
www.sugre.info
Sustainability of Brazilian bio-ethanol, Smeets, E., et al,
2006
Copernicus Institute, Department of Science, Technology and
Society Report NWS-E-2006-110, ISBN 90-8672-012-9, University
of Utrecht, Netherlands
Well - to - Wheels analysis of future automotive fuels and
powertrains in the European context, 2007
JRC/IES, European Commission Joint Research Centre, Institute for
Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Biofuel Cities – Technical guidance for biofuels
40 3. Biodiesel
3 Biodiesel
3.1 Summary biodiesel
In general discussions, the name biodiesel is used for many
different types of biofuels that could replace fossil diesel. However
in more detailed discussions it is wise to use more specific names,
as ‘biodiesel’ does not say something about the physical properties
of the fuel nor the quality, production process or feedstock used.
Different biofuels that can replace fossil diesel are: first generation
biodiesels: esterified plant oils and animal fats (FAME),
hydrotreated vegetable oils (HVO), pure plant oils (PPO – not
commonly named biodiesel, see chapter 4) and second generation
biodiesel: Fisher-Tropsch diesel (BTL- Biomass To Liquids),
produced by gasification of biomass and the production of synthetic
fuels via the chemical Fischer-Tropsch process. In this chapter,
FAME, HVO and BTL will be described.
First generation biodiesels are characterised by the fact that only
parts of the source plant are used for biodiesel production. The
next-generation (or second generation) biodiesels use nearly the
whole plant, including waste, for biodiesel production. The process
technology for second generation fuels is generally more complex.39
There are many options for utilising different sources for production
of the the first generation of biodiesels. Besides widely-used
dedicated oilseed crops such as rapeseed and soybean, animal fats
and waste oil can provide viable options for fuel production.
However, these feedstock types are not yet used on a large scale
today40. For BTL, all kinds of biomass can be used.
FAME is more commonly used in Europe than in other parts of the
world. In Central and Northern Europe the main crops are rapeseed
and, of less importance, sunflower is used in the south. Waste
cooking oils are also used to a limited extent.
39 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany 40 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany
Biofuel Cities – Technical guidance for biofuels
413. Biodiesel
FAME can be used in almost unmodified diesel-engines. B20 (20%
biodiesel blend in fossil diesel) and lower blends of biodiesel can be
used in most existing heavy duty vehicles without modifications.
B100, pure FAME, can only be used in vehicles when a warranty is
given by the car manufacturer. Synthetic diesel from biomass, BTL
and fossil based natural gas and coal, GTL and CTL, can be used in
diesel engines without modifications. Hydrated bio-oils, HVO, also
have the same characteristics as fossil diesel and can be used in
unmodified engines.
Fuel
Diesel engines
no changes
Modified diesel
engines Petrol engines
Biodiesel (FAME) B20 B100 X
BTL, (CTL, GTL) up to 100%
no change
needed X
Hydrated bio-oils
(HVO) up to 100%
no change
needed X
Table 7 Biodiesel and use in different kind of vehicles
The main difference between fossil diesel and FAME is that FAME is
more aggressive to elastomers so materials in the infrastructure
need to be compatible to both.
All kinds of biodiesels can be manufactured from different sources
and with different processes. Depending on circumstances in the
life cycle of a particular biodiesel from initial source to use in a
vehicle the environmental impact will be different. Particularly
important issues to consider are greenhouse gas (GHG) balance
and energy balance for the life cycle of the fuel.
3.2 General fuel properties Fatty acid methyl esters (FAME) is generally called biodiesel41 but
as there are many fuels that can replace fossil diesel FAME will be
used when oil based esters are discussed. FAME is used as fuel for
compression ignition. It is similar to fossil diesel fuel except that it
41 Verbeek, R. et.al., 2008, Impact of biofuels on air pollutant emissions from road vehicles, TNO Science and Industrie Report MON-RPT-033-DTS-2008-01737, Delft, Netherlands
FAME fuelled truck (Photo www.greenfleet.info)
Biofuel Cities – Technical guidance for biofuels
42 3. Biodiesel
is produced from renewable biomass42. B100 is pure FAME without
any blending of fossil diesel fuel. B99 is FAME that has been mixed
with a small amount of fossil diesel. This fuel mixing is also known
as “splashing.”
Biodiesel from vegetable oil can be used directly as a fuel with
minor engine modifications or blended up to 20% into petroleum
derived diesel fuel without modifications in areas of the world
where climate conditions permit the use of such a fuel. Today it is
possible to blend in up to 5% FAME in fossil diesel according to the
CEN standard EN 590.
FAME is practically immiscible with water, has a high boiling point,
a low vapour pressure and it is non-toxic and biodegradable43.
3.3 Availability
FAME is more commonly used in Europe than in other parts of the
world because Europe has a relative large diesel fleet.
There are many options for utilising different sources for FAME
production. Besides dedicated oilseed crops such as rapeseed and
soybean, animal fats and waste oil also provide viable options for
fuel production (although these feedstock types are currently not
used on a large scale).
First generation biodiesels are characterised by the fact that only
parts of the source plant are used for biodiesel production. The
next-generation (or second generation) biodiesels use nearly the
whole plant, including waste, for biodiesel production. The process
technology for second generation fuels is generally more complex44.
3.3.1 Sources of FAME
Biodiesel (fatty acid methyl esters, FAME) is usually derived from
vegetable oils and animal fats by a chemical process known as
42 2008-08-20, Properties of biodiesel, www.inforse.org/europe/dieret/altfuels/biodiesel.htm 43 Moura, L., 2007, User manual for fleet owners concerning AFVs, PROCURA Deliverable D2.4, Lisbon, Portugal 44 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany
Biofuel Cities – Technical guidance for biofuels
433. Biodiesel
transesterification, where a feedstock of oil reacts with methanol
and a potassium hydroxide catalyst45.
In addition, FAME may be produced by esterification of free fatty
acids with low molecular weight alcohols.
In Europe the main crops are rape (also known as colza) in the
centre and north and, of less importance, sunflower in the south.
Waste cooking oils are also used to a limited extent46.
3.3.2 Future availability
Biomass for energy needs land and could create competition with
crops for food or feed. The additional sources of agricultural
capacity for future growth of different biodiesel energy crops are
described below47:
• A steady improvement of agricultural yields has been
achieved over the last decades and this trend is expected to
continue.
• Set-aside areas can in principle be used for non-food
production although it is difficult to make an accurate
estimate of land quality and therefore of yields.
• There is a large potential for collection and use of waste
woody biomass for advanced, second generation, biodiesel
fuels, BTL.
Second generation biodiesel fuels are produced by using biomass-
to-liquid technologies. Using the so-called Gas-To-Liquid (GTL)
technology it is possible to produce liquid diesel fuels from
synthesis gas. This synthesis gas can be obtained by means of
gasification from a variety of feedstocks including coal (coal-to-
liquid, CTL), natural gas (GTL) and biomass (biomass-to-liquid,
BTL). Diesel is produced from the syngas using the Fischer-Tropsch
(FT) process.
45 Kousoulidou, M., 2008, Effect of biodiesel and bioethanol on exhaust emissions, Laboratory of applied thermodynamics, Mechanical engineering department, Report No.: 08.RE.0006.V1. Aristotle University Thessaloniki, Greece
46 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 47 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Rape seeds (Photo www.greenfleet.info)
Biofuel Cities – Technical guidance for biofuels
44 3. Biodiesel
NExBTL referred to as HVO (Hydro-treated Vegetable Oil) is
produced in a vegetable oil refining process, which entails direct
catalytic hydrogenation of plant oil. The resulting fuel has
specifications very close to that of fossil diesel, so that it requires
no modification or special precautions for the engine.
BTL diesel is chemically different from the methyl-ester biodiesel
produced from rapeseed or soybeans. It is likely that BTL will
receive the most attention over the next years, especially in
Europe48.
3.4 Use in vehicles
FAME can be used in almost all unmodified diesel-engines. B20
(20% FAME blend in fossil diesel) and lower blends of FAME can be
used in most existing heavy duty vehicles without modifications.
B100, pure FAME, can only be used in vehicles when a warranty is
given by the car manufacturer. Synthetic diesel from biomass, BTL
and fossil fuels as natural gas and coal, GTL and CTL, can be used
in diesel engines without modifications. Hydrated bio-oils also have
the same characteristics as fossil diesel and can be used in
unmodified engines.
Fuel
Diesel engines
no changes
Modified diesel
engines Petrol engines
Biodiesel (FAME) B20 B100 x
BTL, (CTL, GTL) up to 100%
no change
needed x
Hydrated bio-oils up to 100%
no change
needed x
Table 8 Use of biodiesel in different engines
3.4.1 Vehicle technology
Pure FAME (B100) is not compatible with natural rubber, which
may sometimes be found in older vehicles (before 1994). Because
48 Verbeek, R., et al, 2008, Impact of biofuels on air pollutant emissions from road vehicles, TNO Science and Industrie Report MON-RPT-033-DTS-2008-01737, Delft, Netherlands
Want to know more? Available vehicles
can be found at:
www.ufop.de
Biofuel Cities – Technical guidance for biofuels
453. Biodiesel
FAME functions as a solvent, it can degrade natural rubber hoses
and gaskets. FAME may also deteriorate polyurethane foam
materials. This is not usually a problem with B30 and lower
percentage FAME blends.
Availability of vehicles
UFOP (Union for the Promotion of Oil and Protein Plants) performed
a survey among car manufacturers in 2008. The survey shows that
use of pure FAME, B100, in the new Euro 4 cars with self-
regenerating particle filter system is not possible. The reason is
that the post-injection of FAME accelerates the dilution of the motor
oil. In older diesel cars from VW, Audi, Skoda and Seat B100 are
accepted49. Retrofitting with particle filters approved for FAME is a
way to use FAME in newer vehicles.
For heavy vehicles with Euro 4 and 5 engines, B100 is accepted by
Mercedes Benz, MAN, Scania and Volvo, as long as the FAME
complies with the European Biodiesel Standard EN 14214.
Maintenance
FAME is different from fossil diesel. If fossil diesel has been used, it
can be necessary to change the oil filter, before and occasionally
after a change to high blends of FAME. FAME has a solvent effect
that may release deposits accumulated on tank walls and pipes
from previous diesel fuel storage. The FAME works as a solvent and
can dissolve particulates, gum and other build-up in the engine
parts which initally leads to clogged filters. If FAME is used
continuously after that the filter does not have to be changed more
often compared to running on diesel.
For blends over B20 it is recommended to contact the original
equipment manufacturer to determine if seals, hoses, and gaskets
are compatible with the FAME blend being considered. Inspection
and replacement of degradable materials is wise.50 The
maintenance needed for heavy duty vehicles is motor oil change
every 30 000 km. No special motor oil is needed. The engine
49 2006, Status report regarding the granting of approval for operation with biodiesel as a fuel, UFOP Berlin, Germany 50 Moura, L., 2007, User manual for fleet owners concerning AFVs, PROCURA Deliverable D2.4, Lisbon, Portugal
Biofuel Cities – Technical guidance for biofuels
46 3. Biodiesel
abrasion is equal to diesel use. The buses have 5% higher
consumption than the diesel buses51.
Driving range
The energy content in B100 is about 92% of the energy content in
fossil diesel. The driving range is therefore shorter when driving on
FAME.
Cold start properties
The cloud point for FAME depends on which type of vegetable oil it
is based on. Palm oil based FAME has a cloud point at +12ºC,
compared with Canola-based FAME at –1ºC. B100 made from used
cooking oils performs well down to +4 ºC. In colder temperatures
the fuel is susceptible to gelling and may cause blockages in the
fuel system. Should colder weather occur, blending with petroleum
diesel is advised. Rape methyl ester (RME) made from fresh rape
oil is cold tolerant down to -6ºC.
Retrofitting
The material in the engine has to be compatible to FAME. It is
necessary to check with the manufacturer if it is possible to drive
on blends over B30 with a valid warranty. There are companies in
Germany which give warranty for FAME for all particle systems
according to the UFOP survey, “Status report regarding the
granting of approval for operation with biodiesel as a fuel”.
BTL, CTL and GTL
The synthetic diesel fuels from gasification of biomass and coal or
natural gas are very similar to the standard components in fossil
diesel and it is generally accepted that synthetic diesels have no
adverse effect on the engine52. GTL – gas-to-liquid diesel is used in
some extent in Europe. The energy content is the same as diesel
which means that the driving range is not affected. The large
difference between the fuels is the emissions of CO2, BTL is a
biofuel but CTL and GTL are fossil fuels.
51 Amtmann, G., January 2008, Our experiences with biodiesel – “From the frying pan into the tank“ Presentation by Amtmann at Grazer Stadtwerke AG 52 Verbeek, R., et al, 2008, Impact of biofuels on air pollutant emissions from road vehicles, TNO Science and Industrie Report MON-RPT-033-DTS-2008-01737, Delft, Netherlands
Biofuel Cities – Technical guidance for biofuels
473. Biodiesel
3.4.2 Exhaust gas emissions
Use of pure FAME leads to increase of NOX emissions for both
passenger cars and heavy duty vehicles. This is mainly an effect of
the higher cetane number, which leads to lower ignition delay
hence combustion advance and higher combustion temperature
and pressure. FAME has a higher oxygen content compared to
diesel which in combination with higher flame temperature may
lead to higher NOX. There can be up to 38% higher NOX emissions
according to experimental studies53. Tests by the US EPA show, in
Table 9, decreased emissions of emissions of HC and PM, more with
high blends than low-blends.
Emission Type B100 B20
Regulated
Emissions in relation
to conventional diesel
Total Unburned Hydrocarbons -67% -20%
Carbon Monoxide -48% -12%
Particulate Matter -47% -12%
NOx +10% +2%
Non-Regulated
Sulfates -100% -20% a
PAH (Polycyclic Aromatic Hydrocarbons) b -80% -13%
nPAH (nitrated PAH’s) b -90% -50% c
Ozone potential of speciated HC -50% -10%
a Estimated from B100 result.
b Average reduction across all compounds measured.
c 2-nitroflourine results were within test method variability.
Table 9 Average Biodiesel (B100 and B20) Emissions Compared to Conventional Diesel Heavy duty vehicles54
53 Kousoulidou, M., 2008, Effect of biodiesel and bioethanol on exhaust emissions, Laboratory of applied thermodynamics, Mechanical engineering department, Report No.: 08.RE.0006.V1. Aristotle University Thessaloniki, Greece
54 Testing was performed by the EPA. The full report titled "A comprehensive Analysis of Biodiesel Impacts on Exhaust Emissions" can be found at: www.epa.gov/otaq/models/biodsl.htm
Biofuel Cities – Technical guidance for biofuels
48 3. Biodiesel
3.4.3 User experience In order to gather information about experiences, several
interviews with users of biofuels have been performed. The
complete questions and answers can be found in Appendix IV.
The Public Transport Operator of the Town of Graz in Austria,
Grazer Verkehrsbetriebe, GVB, has used B100 in their bus fleet for
many years (since 1992). The FAME in Graz is made from collected
reused cooking oil. The procurement of the buses included a
requirement that the buses had to be adapted to FAME. This
includes exchange of fuel pipes and gaskets. The engine must be
capable to work with FAME (auxiliary heating systems, injection
pump, etc.). The experience from Graz is that if the requirement is
included already in the procurement the price for adapted buses is
not higher than for conventional diesel buses. There is no
difference in delivery time for the FAME adapted buses. There have
been no notable changes in the engine performance according to
GVB: “Our buses have very strong engines (more than 300 hp) and
nobody can notice a difference”. The fuel consumption increases by
5% and the need for maintenance increases slightly because it is
nesessary to change the oil filter and the engine oil in 30 000km
instead of 60 000km. The precise cost for this is not available.
The airport coaches, Flygbussarna, at Arlanda Airport in Sweden
have a fleet of approximately 50 vehicles. Five are run on 100%
RME. The others are diesel fuelled with 5% RME blending. The
B100 was introduced in April 2008. The five buses meet emission
standards Euro 3 and 4. In autumn 2008 another (sixth) bus was
bought which is Euro 5. The buses meet different emission
standards as part of a strategy to compare emissions from different
buses. All five buses are retrofitted and adapted to FAME. The
availability of vehicles on the market has been very limited and the
vehicle manufacturers leave much responsibility to the operator
after the vehicles have been retrofitted. Volvo is a partner in this
project. There are no ready for use FAME-adopted buses available
on the market, so work has to be done through projects and issues
such as guarantees must be solved seperately each time. So far
the project progresses well but there is still no experience from
cold weather/winter driving.
RME bus, Flygbussarna (Photo Agneta Weissglas)
Biofuel Cities – Technical guidance for biofuels
493. Biodiesel
3.5 Infrastructure requirements It is important that proper fuel handling techniques are practiced to
prevent fuel contamination. Also choosing the right materials for
fuel storage and dispensing systems is crucial. Local and national
regulations and legislation applicable for fuel infrastructure must be
followed. These requirements can be different in individual regions
and countries.
3.5.1 Technical aspects of filling stations
FAME filling stations need to fulfil largely the same legal
requirements as filling stations selling petroleum-based fuel.
Physically FAME is very similar to fossil diesel fuel. There has been
no proof that any of the metals currently used in the distribution,
storage, dispensing, or onboard fuel systems for diesel fuel would
not be compatible with FAME. The main difference between fossil
diesel and FAME is that the latter is more aggressive to the
elastomers that may be used in pumps and meters.55 Existing filling
stations and tanks can be used for FAME with only small
modifications. In order to prevent blockage in the pumps filter
systems, the storage tanks have to be cleaned thoroughly.
Dispensers used for diesel fuel can also be used for FAME, but
dispensers with elastomers in their composition may not be
compatible. The hose of the petrol pump has to be substituted for
one made of resistant FAME material. The petrol pump pistol has to
be checked accordingly to the specifications of the producer to
assure the FAME compatibility.
FAME spills should be cleaned up immediately. FAME is a very good
solvent and has thus the potential to damage paints and finish.
3.5.2 Technical aspects of storage and
transportation
FAME resistant storage tank materials include aluminium, steel,
fluorinated polyethylene, fluorinated polypropylene and Teflon.
Copper, brass, lead, tin, and zinc should be avoided. FAME can be
55 Moura, L., User manual for fleet owners concerning AFVs, PROCURA Deliverable D2.4, Lisbon, Portugal
Biodiesel fuelling station Graz Austria
(Photo www.greenfleet.info)
Biofuel Cities – Technical guidance for biofuels
50 3. Biodiesel
stored in above-ground or underground fuel tanks (same as
petroleum diesel). Conservation vents are not required since the
vapour pressure is very low, as for diesel fuel. The fuel should be
stored in a clean, dry, dark environment. The sealing surface
should be made of concrete.
The tank has to be cleaned every two years to avoid cases of
product liability and to retain permanently high quality of FAME.
Due to production and storage failures, FAME are frequently sold
out of their fuel specifications. Water and impurities in the fuel may
have impact on vehicle and engine performance and functionality.
The pipelines in the storing tank area are generally made of steel
(black or galvanised), fibreglass, or plastic suitable for fuel use.
Any built-in or added parts of nonferrous heavy metal (copper,
brass, bronze) or any zinc coated materials have to be substituted
by equivalent parts of steel or, if applicable, to be removed. These
measures avoid corrosion with a subsequent formation of metal
soaps which can deteriorate the quality of the FAME. All the joints
have to be tested for leaks, and a Teflon tape can be used as a
thread sealant (with the compatibility with FAME assured).
FAME is more susceptible to water contamination than petroleum
diesel. If there is water in the FAME fuel it can cause corrosion and
growth of micro-organisms. Large temperature swings in storage
tanks can promote moisture condensation on the inside.
Underground storage tanks are best at preventing condensation
because the fuel is kept at a relatively constant temperature, but
on the other hand an underground storage tank can have other
potential problems such as leakage56. Aboveground storage tanks
should be insulated (double wall) and shaded if possible to
moderate temperature swings. This will reduce the problem with
condensation.
Other techniques to prevent water contamination are to:
� Drain a small amount of fuel from the bottom of the storage
tanks every six months to remove any water that might have
accumulated in the tank.
Biodiesel tank (Photo www.greenfleet.info)
Biofuel Cities – Technical guidance for biofuels
513. Biodiesel
Want to know more? CEN, the European Committee for Standardization has an informative web page: www.cen.eu
� Avoid prolonged exposure of fuel to light which can cause algae
growth. Fibreglass tanks should be painted and/or placed in
shaded areas.
� If biological growth is a problem the same products that are
used with petroleum diesel can be used in FAME to “dry” the
fuel and clean up biological contaminants.
FAME should not be stored for more than six months without
antioxidant additive. Fuel aging and oxidants can lead to
heightened acid content, high viscosity and the formation of gums
and sediments that clog filters.
3.6 Fuel quality standards
In 1991, the first worldwide standard for rapeseed oil methyl ester
was published in Austria. In the following years, standards were
published in Germany and the Czech Republic (1994), Sweden
(1996), Italy and France (1997) and the U.S.A. (1999)57. National
standards of European countries were replaced by a common
European standard for biodiesel as automotive diesel fuel (EN
14214) and as heating fuel (EN 14213). There is also the European
diesel fuel specification, EN 590, which is applicable to biodiesel
blends up to 5% of FAME. EN 14214 includes specifications for fatty
acid methyl ester (FAME) fuel for diesel engines. B100 that meets
this standard can be used unblended in a diesel engine (if adapted
to B100) or blended with petroleum diesel fuel.
In Germany there is a DIN standard specifying requirements for
three varieties of FAME made of different oils: RME (rapeseed
methyl ester), PME (vegetable methyl ester, purely vegetable
products) and FME (fat methyl ester, vegetable and animal
products).
The standard EN 14214 thus specifies the requirements and test
methods for marketed and delivered fatty acid methyl esters,
FAME, to be used either as a sole automotive fuel for diesel engines
or as an extender for automotive fuel for diesel engines in
accordance with the requirements of EN 590.
56 Stombaugh, T., et al, 2006, Biodiesel FAQ, Issued 4-2206, Dep. of Biosystems & Agricultural Engineering, University of Kentucky, U.S.A. 57 2008-08-08, Fuel regulations, www.dieselnet.com
Biofuel Cities – Technical guidance for biofuels
52 3. Biodiesel
The European Commission intends to launch a wide debate in order
to modify the EN 14214 standard. Their aim is to enlarge the
number of raw materials that can be used to manufacture FAME,
making it possible to employ also soybean, sun, palm oil and other
fats such as UFO (used frying oil) and animal fats58.
Some national standards in EU countries allow FAME to be
distributed as a stand-alone fuel. The CEN is presently studying a
revised EN 590 specification for diesel fuel that will permit up to
and including 7% of biodiesel blend, instead of the present limit of
5%. There is also a proposal from the European Commission,
presented in January 2008 to introduce a binding 10% target for
biofuels in transport fuel by 2020. This is part of a long term
energy package which includes an overall binding 20% renewable
energy target, a 10% binding minimum target for transport fuels,
and a pathway to bring renewable energies in the fields of
electricity heating and cooling and transport to the economic and
political mainstream59.
3.7 Production
The feedstock for FAME can be vegetable oil, such as that derived
from oil-seed crops, used frying oil or animal fat. Soy is used in US
and mainly rapeseed and sunflower in Europe. Other feedstocks
include coconut and palm oils60.
The figure below illustrates the conversion of an oil-containing
feedstock into FAME. Prior to transesterification, the seed from
which the oil is extracted must be cleaned, dried, and hulled. The
oil can then be extracted by pressing or through solvent extraction.
The triglycerides in the extracted oil are transesterified in a reactor
with methanol and a base catalyst. Methanol and the base form an
alkoxide which then reacts with the triglycerides to produce an
58 Garofalo, R, 2006, Biodiesel Chains: Promoting favourable conditions to establish biodiesel market actions, EBB, European Biodiesel Board, EU-27 Biodiesel Report, Deliverable 7, Brussels, Belgium
59 2007, EU-27, Bio-fuels, Annual 2007, GAIN Report E47051, Washington, U.S.A. 60 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commissions Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Biofuel Cities – Technical guidance for biofuels
533. Biodiesel
intermediate, which then decomposes into the desired alkyl ester
(FAME).
In the subsequent steps, the products from the reactor, FAME and
glycerine, are neutralised, and the crude FAME phase can easily be
separated from the glycerine phase due to their large difference in
density. After separation, the excess alcohol is removed from both
the FAME and the glycerine via flash evaporation or distillation. The
methanol is then recycled to the beginning of the process, and the
glycerine can be further purified and sold as a by-product for other
industrial purposes.
Figure 10 Process flow diagram for FAME production61.
Second generation biodiesel fuels are based on biomass-to-liquid
technologies. The development of BTL-fuels is a relatively new
trend. BTL stands for Biomass-to-Liquid and like GTL (Gas-to-
Liquid) and CTL (Coal-to-Liquid) BTL-fuels belong to the group of
synthetic fuels.
Generally, the great advantage of second generation biodiesel is
that they can be produced from many different raw materials.
All three fuels, BTL, GTL and CTL, are characterised by similar
process steps, but only BTL is renewable. The transformation-
process of BTL-fuels has three main steps: gasification, gas
cleaning and synthesis62.
61 Schwietzke, S., et al, 2008, Gaps in the Research of 2nd Generation Transportation Biofuels, IEA Bioenergy T41(2): 2008:01 62 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany
Biofuel Cities – Technical guidance for biofuels
54 3. Biodiesel
3.8 Sustainability issues Biodiesel fuels can be manufactured from different sources and
with different processes. Depending on circumstances in the life
cycle of a particular biodiesel fuel, from initial source to use in a
vehicle, the environmental impact will be different.
In the following sections, the important issues greenhouse gas
(GHG) balance and energy balance for different biodiesel fuels are
explained and presented. Some other sustainability issues are
highlighted, albeit in more general terms.
3.8.1 GHG balance
Greenhouse gases are gases causing the greenhouse effect. The
greenhouse gases taken into account in this presentation are
carbon dioxide, CO2, nitrous oxide, N2O and methane, CH4.
The GHG balance for any biofuel is influenced by details like growth
location, use of fertilizers, use of agricultural machinery, production
processes, energy use, use of by products, transports etc. The GHG
balance will be different for different biofuels.
Greenhouse gas emission savings from biofuels are calculated as
the reduction of total emissions from the biofuel compared to the
total emissions from the fossil fuel comparator. These values in
Table 10 originate from the Directive of the European Parliament
and of the Council on the promotion of the use of energy from
renewable sources, 2008/0016. How greenhouse gas emission
savings from biofuels are calculated is presented in Appendix I.
Typical values for different biodiesels, if produced with no net
carbon emissions from land use change are shown in table 10
below. The emissions represent all emissions from well-to-wheel
(WTW), i.e. from extraction of raw material till use of the fuel in the
vehicle.
CO2 emissions from land use change: emissions of carbon
dioxide due to changes in land use mainly come from the cutting
down of forests and subsequent use of land for agriculture or built-
up areas, etc. When areas of forests are cut down, the land often
Want to know more? Sustainability issues are not the focus in this report. Further information can be found at the website http://www.biofuel-cities.eu/index.php?id=6780.
Biofuel Cities – Technical guidance for biofuels
553. Biodiesel
turns into less productive lands with considerably less capacity to
store CO2. This effect is not taken into account.
Biodiesels used today
Biodiesel production pathway typical greenhouse
gas emission saving
rape seed biodiesel 44%
sunflower biodiesel 58%
palm oil biodiesel (process not specified) 32%
palm oil biodiesel (process with no methane
emissions to air at oil mill)
57%
waste vegetable or animal oil biodiesel 83%
Hydrotreated vegetable oil from rape seed 49%
Hydrotreated vegetable oil from sunflower 65%
Hydrotreated vegetable oil from palm oil
(process not specified)
38%
Hydrotreated vegetable oil from palm oil
(process with no methane emissions to air at oil
mill)
63%
Table 10 Typical greenhouse gas emission savings for different biodiesel fuels63.
Future biodiesels
The table below shows estimated typical values for future biodiesels
that appear in negligible quantities or are not present on the
market in January 2008, assuming production with no net carbon
emissions from land use change.
These fuels are typically produced from waste from agricultural or
forestry activities and have higher GHG saving potential than the
FAME-based biodiesels produced today.
biofuel production pathway typical greenhouse
gas emission saving
waste wood Fischer-Tropsch diesel 95%
farmed wood Fischer-Tropsch diesel 93%
63 23.1.2008, Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the promotion of the use of energy from renewable sources, Commission of the European Communities, 2008/0016, Brussels, Belgium
Biofuel Cities – Technical guidance for biofuels
56 3. Biodiesel
Table 11 Typical greenhouse gas emission savings for different future biodiesel64.
3.8.2 Energy balance
The fossil (non renewable) energy use for a biofuel over its life
cycle is an important sustainability factor.
The use of biofuels reduces the use of fossil energy. The energy
balance presented below includes both fossil and renewable (bio)
energy. Fossil energy savings do not automatically mean that
biofuel pathways are entirely energy (fossil and renewable)
efficient.
As in the case with the greenhouse gas balance, the fossil energy
savings of biofuels are critically dependent on details like growth
location, use of fertilisers, use of agricultural machinery, production
processes, energy use, use of by products, transports etc. The
energy use will be different for different biofuels.
Taking into account the energy contained in the biomass resource
one can calculate the total energy involved. The figure below shows
energy figures for different biodiesel fuels. Figures for fossil and
total (fossil and renewable bioenergy) well-to-wheel (WTW) energy
are presented. This represents the energy from well or source of
the biofuel to use of the fuel in the vehicle.
64 23.1.2008, Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the promotion of the use of energy from renewable sources, Commission of the European Communities, 2008/0016, Brussels, Belgium
Biofuel Cities – Technical guidance for biofuels
573. Biodiesel
Figure 11 WTW total versus fossil energy: SME, sunflower methyl ester, REE, rapeseed ethyl ester, RME, rape methyl ester. For diesel the total energy is equal to fossil energy65.
3.8.3 Other sustainability issues
Soil quality/erosion
Soil erosion by water, wind and agricultural growth affects both
agricultural conditions and the natural environment66.
One FAME source with a potential for expansion are soybeans in
Brazil. These are typically grown close to the rainforest and the
existing high demand for soybeans is already suspected to
accelerate the destruction of the rainforest. Another major source
is palm oils from Malaysia and Indonesia: a rapid increase in
demand could be met by unsustainable production on rainforest
land. Sustainable certification could be considered as a solution.
65 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commissions Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 66 2008, Sustainable Green Fleets website, www.sugre.info
Biofuel Cities – Technical guidance for biofuels
58 3. Biodiesel
Acidification and Eutrophication
Acidification and eutrophication of ecosystems are two
environmental problems that to a great extent are caused by the
same pollutants.
The main cause of acidification is the airborne deposition of
sulphur. Nitrogen compounds (nitrogen oxides and ammonia) are
the dominant cause of eutrophication of many ecosystems, but also
contribute increasingly to acidification.
Acidification causes soil depletion, disappearance of plants and
animals as well as forest damage. The deposition of nitrogen
compounds favours forest growth, but at the same time leads to
the chemical disruption of a long list of ecosystems, and results in
decrease of biodiversity.
Because intensive agriculture using fertilisers tends to cause
eutrophication and acidification, increased crop production for
biofuels would tend to accelerate the problem. The driving force for
intensification is crop price: hence meeting biofuels targets will
probably cause more intensification of oilseed (FAME) production
than of cereals (bioethanol) production.
Sunflower, short rotation forest and other “advanced FAME fuels”
crops generally use less fertiliser than the other crops67.
Biodiversity
Biodiversity is the variety of life: the different plants, animals and
micro-organisms, their genes and the ecosystems of which they are
a part.
Growing energy crops instead of permanent crops and on “natural”
land in voluntary set-aside areas would decrease biodiversity.
A European study concluded that the negative biodiversity impacts
are high for rape and low to medium for short rotation forestry.68
67 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commissions Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Sunflower (Photo www.greenfleet.info)
Biofuel Cities – Technical guidance for biofuels
593. Biodiesel
The use of wood residues is considered to have no impact. Pesticide
use affects biodiversity negatively.
Increases of pesticide applications are needed if the frequency of
oilseed rape crops in a rotation is increased beyond about one year
in four.
Impact on ground water table
The increased growth of crops requiring extensive irrigation in arid
areas will put pressure on water resources.
Increased cultivation of trees can also lead to a lowering of the
ground water table. Lowering of the water table can have
significant impact on the natural environment in the area
concerned.
Introduction of non-native species and GMOs
A genetically modified organism (GMO) is an organism whose
genetic material has been altered using genetic engineering
techniques.
There is a risk that non-native energy crops could spread in the
wild, because they lack natural predators. Using sterile varieties
(including GMOs) greatly reduce this risk. However, many groups
and individuals remain concerned about the potential impacts of
GMOs.
Social impact, working conditions
In general, working conditions in relation to farm and agricultural
labour are regulated, particularly in EU-27 and the US. In other
parts of the world, working conditions could be questioned.
However similar problems exist both for biofuel production and for
food and feed production.
68 2006, How much bioenergy can Europe produce without harming the environment?, EEA Report No 7/2006, ISBN 93-9167-849-X, ISSN 1725-9177, Copenhagen, Denmark
Biofuel Cities – Technical guidance for biofuels
60 3. Biodiesel
Working conditions at palm oil farms in Asia are sometimes argued
to be hard and to involve child workers.
Competition with food production
Biomass for energy needs land and is therefore in competition with
other crops. A criticism raised against biomass, particularly against
large-scale fuel production, is that it could divert agricultural
production away from food crops, especially in developing
countries69.
The topic is complex and there are different opinions, pro and con,
from various stake holders.
69 Peña, N., 2008, Biofuels for transportation: A climate perspective, Pew Center on Global Climate Change, Arlington, U.S.A.
Biofuel Cities – Technical guidance for biofuels
613. Biodiesel
Literature Biodiesel A Comprehensive Analysis of Biodiesel Impacts on Exhaust
Emissions, 2002
Draft Technical Report EPA420-P-02-001, Assessment and
Standards Division, Office of Transportation and Air Quality, U.S.
Environmental Protection Agency, Washington, U.S.A.
Biodiesel FAQ, Stombaugh, T., et al, 2006
Issued 4-2206, Dep. of Biosystems & Agricultural Engineering,
University of Kentucky, U.S.A.
Biodiesel Chains: Promoting favourable conditions to
establish biodiesel market actions, Garofalo, R., 2006
EBB, European Biodiesel Board, EU-27 Biodiesel Report, Deliverable
7, Brussels, Belgium
Biofuels for Transportation: A Climate Perspective
Peña, N., 2008
Pew Center on Global Climate Change, Arlington, U.S.A.
Biofuel Technology Handbook, Rutz D., Janssen R., 2008
WIP Renewable Energies, München, Germany
Effect of biodiesel and bioethanol on
exhaust emissions, Kousoulidou, M., 2008
Laboratory of applied thermodynamics, Mechanical engineering
department, Report No.: 08.RE.0006.V1, Aristotle University
Thessaloniki, Greece
EU-27, Bio-fuels, Annual 2007
GAIN Report E47051, Washington, U.S.A
Fuel regulations, 2008-08-08
www.dieselnet.com
Gaps in the Research of 2nd Generation Transportation
Biofuels, Schwietzke, S., et al, 2008
IEA Bioenergy T41(2): 2008:01
Biofuel Cities – Technical guidance for biofuels
62 3. Biodiesel
How much bioenergy can Europe produce without harming
the environment? 2006
EEA Report No 7/2006, ISBN 92–9167–849-X, ISSN 1725-9177,
Copenhagen, Denmark
Sustainable Green Fleets website, 2008
www.sugre.info
Impact of biofuels on air pollutant emissions from road
vehicles, Verbeek, R. et al, 2008
TNO Science and Industrie Report MON-RPT-033-DTS-2008-01737,
Delft, Netherlands
Our experiences with biodiesel – “From frying pan into the
tank, Amtmann, G., 2008
Presentation Presentation by Amtmann at Grazer Stadtwerke AG
Properties of biodiesel, 2008-08-20
http://www.inforse.org/europe/dieret/altfuels/biodiesel.htm
Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT
AND OF THE COUNCIL on the promotion of the use of energy
from renewable sources 23.1.2008
Commission of the European Communities, 2008/0016, Brussels,
Belgium
Status report regarding the granting of approval for
operation with biodiesel as a fuel, 2006
UFOP, Berlin, Germany
User manual for fleet owners concerning AFVs, Moura, L.,
2007
PROCURA Deliverable D2.4, Lisbon, Portugal
Well - to - Wheels analysis of future automotive fuels and
powertrains in the European context, 2007
JRC/IES, European Commission Joint Research Centre, Institute for
Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Biofuel Cities – Technical guidance to biofuel
634. Pure Plant Oil, PPO
4 Pure Plant Oil, PPO
4.1 Summary PPO
At present, PPO is produced mainly from plant sources which are
exclusively harvested for biofuel production. Typical dedicated
oilseed crops are sunflower, rapeseed and soybean. PPO from
rapeseed is by far the most-used crop for PPO initiatives in the
Netherlands and Germany70.
Pure Plant Oil can be used in modified diesel engines. This is due to
the higher viscosity and molecule weight, lower cetane number and
the higher flashpoint of the fuel, whereby ignition is more difficult.
These are also the most important differences with fossil diesel.
The viscosity of PPO (particularly at low temperatures) is much
higher than that of fossil diesel fuel. The fuel has to be heated to ca
60ºC before PPO can combust properly in a diesel engine. The
engines make less noise (due to the better lubrication of PPO), via
the glycerol present in the fuel. This better lubrication has a
positive effect on the lifespan of the engine caused by the presence
of glycerol in PPO. Glycerol, as a natural product, substitutes the
chemical and hazardous sulphur as found in diesel oil.
PPO Petrol engines Diesel engines
No changes x x
Modified engines x 100%
Table 12 PPO can be used in modified diesel engines.
In theory, PPO can be mixed at stations with fossil diesel – in any
ratio. However, a mixture of PPO and diesel is not desired by the
market because it can cause problems in vehicles that have not
been modified.
PPO can be manufactured from different sources and with different
processes. Depending on circumstances in the life cycle of a
particular PPO from initial source to use in a vehicle, the
environmental impact will be different. Particularly important issues
70 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany
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64 4. Pure Plant Oil, PPO
to consider are the greenhouse gas (GHG) balance and energy
balance for the life cycle of the fuel.
4.2 General fuel properties
Pure Plant Oil (PPO) is entirely made from plant materials and in
contrast to biodiesel it contains no methanol or other chemical
composites. Unlike biodiesel it is not allowed to use PPO for
blending in standardised fuels as an extender for automotive fuel
for diesel engines.
PPO can be referred to in several abbreviations. There are some
differences between the terms, although they are sometimes
slightly carelessly used and can refer to the same fuel. SVO
(straight vegetable oil) is usually new oil, fresh, uncooked and used
as diesel fuel. PPO (pure plant oils) is the same as SVO – PPO is the
term most often used in Europe. Other abbreviations are
occasionally used instead of PPO and can be misleading and
sometimes inaccurate. Such acronyms include WVO (waste
vegetable oil) which is used cooking oil, "grease", fryer oil,
probably including animal fats or fish oils from the cooking; and
another is UCO (used cooking oil) the same as WVO, but not
necessary vegetable.
The molecules of pure plant oil (just as animal fat and biodiesel)
vary, depending on the origin of the feedstock type, meaning the
characteristics of PPO are more variable than, for example, the
properties of bioethanol.
Compared to conventional fossil diesel the viscosity of PPO is up to
ten times higher, especially at cooler temperatures. This property
leads to technical challenges during winter operation and when cold
starting in conventional engines. PPO has a tendency to gum up at
colder temperatures and it has been difficult to blend it with fossil
diesel fuel. However, different types of plant oil have different
properties which affect engine performance. Some tropical oils with
more saturated, shorter-chained fatty acids, such as coconut oil,
can be blended directly with diesel fuel, offering the potential for
Want to know more? Information about laws, examples of publications and practical examples of PPO usage can be found at: http://www.ufop.de/english_news.php.
Biofuel Cities – Technical guidance for biofuels
654 Pure Plant Oil, PPO
the use of PPO-diesel blends in unmodified engines in tropical
locations71.
4.3 Availability
Vegetable oils, in general can be used as an alternative to diesel
oil. Depending on the molecular composition, the majority of
vegetable oils are known to be suitable for this purpose in their
‘pure origin”. Currently rapeseed, soy bean, sunflower, palm oil,
and jatropha, are well-known species.
Worldwide, some 450 cultivations of oil-containing plants are
available. However, more research is necessary to determine
ecological and economic benefits of these species.
PPO from rapeseed is by far the most-used crop for PPO initiatives
in the Netherlands, Germany, Austria, Belgium, France, Ireland,
United Kingdom and Denmark72.
4.3.1 Sources of PPO
Pure Plant Oil is a biofuel made of oil-based crops like rapeseed,
sunflower, soybean, jatropha or palm. Production is done by warm
– and cold pressing (crushing).
In terms of energy saving, cold pressing is the preferred method.
4.3.2 Future availability
Biomass for energy needs land and could therefore be in
competition with crops for food or feed. The additional sources of
agricultural capacity for growing energy crops are described
below73:
• A steady improvement of agricultural yields has been
achieved over the last decades and this trend is expected to
continue.
71 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany 72 2005, The road to pure plant oil?, SenterNovem, Report 2GAVE-05.05, Netherlands 73 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Want to know more? More information about jatropha can be found at the Centre for Jatropha Promotion http://www.jatrophabiodiesel.org.
Biofuel Cities – Technical guidance for biofuels
66 4. Pure Plant Oil, PPO
• Set-aside areas can in principle be used for non-food
production although it is difficult to make an accurate
estimate of land quality and therefore of yields.
4.4 Use in vehicles Pure Plant Oil can only be used in modified diesel engines. This is
due to its higher viscosity and molecule weight, lower cetane
number and the higher flashpoint of the fuel, whereby ignition is
more difficult. These are also the most important differences with
fossil diesel. The viscosity of PPO (particularly at low temperatures)
is much higher than that of fossil diesel fuel. The fuel has to be
heated to approximately 60ºC before PPO can combust properly in
a diesel engine. The engines make less noise (due to the better
lubrication of PPO), via the glycerol present in the fuel. This better
lubrication has a positive effect on the lifespan of the engine and is
caused by the presence of glycerol in PPO. Glycerol, as a natural
product, substitutes the chemical and hazardous sulphur as found
in diesel oil.
Sulphur in diesel oil also has a lubricating function. At the same
time sulphur is an environmentally dangerous product, as it binds
soot and particulate matter.
PPO Petrol engines Diesel engines
No changes x x
Modified engines x 100%
Table 13 PPO can be used in modified diesel engines.
4.4.1 Vehicle technology Availability - Retrofitting
All PPO driven vehicles are retrofitted. There are conversion
technologies available on the market. New, more advanced
systems are also being developed. The important modifications of a
standard vehicle are the following: modified atomisers are
generally used; a heat exchanger, thicker fuel lines and a fuel filter
(1 µm) are added. A number of electronic adjustments are also
made. Since PPO is pH-neutral, pipes and gaskets do not need to
be replaced.
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674 Pure Plant Oil, PPO
There are two modification systems available, a single-tank system
and a dual-fuel system74:
� Single-tank system
With a single-tank system, both PPO and diesel can be used in
the tank. A vehicle with a single-tank system has been fitted
with a pre-heating system, to improve the viscosity of the fuel
in cold weather. The engine management system also has to be
modified in a single-tank system. These are generally only
known to the car manufacturer, so this system is only used to a
limited extent.
� Dual-fuel system
With a dual-fuel system, the vehicle starts up using fossil
diesel, and the PPO is heated to around 60°C via a separate
fuel flow system. Once the PPO is up to temperature, after
around 15 minutes, a small onboard computer switches the
engine over to PPO. This system is fully automatic, with a small
display on the dashboard. Towards the end of the journey the
driver switches back to diesel, to ensure that there is no PPO
left in the fuel lines and to prevent startup problems and
blockages in the pipes and filters. This system uses ordinary
fossil diesel when starting and stopping the vehicle.
The dual-fuel system is the most common system. The engine
warranty is given by the conversion companies. The conversion kit
for a two tank system costs around €1 00075.
PPO fuels produce about the same power and torque as petroleum
diesel. Variations in power and emissions results may differ
according to engine technology, fuel quality and conversion kit
operating parameters76.
Maintenance
The quality of PPO is very important. The PPO has to comply with
the standard DIN 51605 in order to ensure vehicle functionality. It
has been shown that with insufficient refining of PPO there can be
74 2005, The road to pure plant oil?, SenterNovem, Report 2GAVE-05.05, Netherlands
75 2008, Elsbett OnlineShop, www.elsbett.com/gb/online-shop.html 76 2005, Pure Plant Oil Fuels: An Overview, Crude Country Biofuels Inc. May 20, 2005, Canada
Brökelmann PPO fuelled truck(Photo Brökelmann + co)
Biofuel Cities – Technical guidance for biofuels
68 4. Pure Plant Oil, PPO
problems with particles and carbon flakes that build up in the
combustion chamber and can damage the engine. It is also very
important to strictly follow the guidelines in the maintenance
manual, in order to avoid polymerisation (motor oil mixing with
PPO which causes disintegration of motor oil).
Driving range
The energy content in PPO is about 10% lower compared to diesel
which shortens the driving range by 10%.
Cold start properties
The viscosity of PPO is low which means that a supporting system
to heat the fuel is required even at normal temperatures and is
essential at low temperatures. It is always important to stop using
PPO (using diesel) before the trip ends, in order to clean the
system from PPO.
4.4.2 Exhaust gas emissions
Few studies on emissions from PPO use have been undertaken.
However, preliminary results show that PPO fuels have effect on
engine emissions. With an appropriate conversion kit and suitable
oils, airborne emissions from compression ignition engines using
PPO fuels are reduced in several key areas. Unburned hydrocarbons
(HC) are reduced by up to 60% or more. Volatile organics and
polycyclic aromatics (VOCs and PAH, respectively) are also
drastically reduced. At the tailpipe, particulate matter (PM), or
“black soot”, is reduced by 40% or more compared to petroleum77.
At the same time the emissions of NOX increases which is a result
of the low cetane number78.
4.4.3 User experience
In order to gather information about real operational experiences,
several interviews with users of biofuels have been performed. The
complete questions and answers can be found in Appendix IV.
77 2008, Emissions from combustion of Pure Plant Oil, PPO, http://www.folkecenter.dk/plant-oil/publications/PPO-emissions.htm
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694 Pure Plant Oil, PPO
Brökelmann & Co is an oil mill company which crushes and refines
oils for the food industry. They have nine trucks which use PPO as
a fuel. All trucks but one are converted with the 2-tank system. The
ninth truck uses a blend of 70% PPO and 30% diesel. They have
been using PPO since 2001. The main reasons for this are economic
and environmental. An exchange strategy for fossil fuelled vehicles
must be based on economic rationality. Brökelmann has not faced
any problems in vehicle acquisition or in delivery time. Additional
insurance has been given for the 2-tank system by the provider
Bioltec.
The operation of the vehicles – driving experiences and driving
characteristics – is not noticeably different from fossil fuelled
vehicles although the drivers feel good to drive biofuelled vehicles.
There is an additional maintenance cost due to tighter intervals for
exchanging engine oil (once every 50 000 km instead of once every
100 000 km). When it comes to oil supply in refuelling stations
Brökelmann comments that “Not all stations offer refined oils, some
have got cold pressed oils with high phosphorus content only.” The
overall difference in cost is to the advantage of PPO.
4.5 Infrastructure requirements
It is important that proper fuel handling techniques are being
practiced to prevent fuel contamination. Also choosing the right
materials for fuel storage and dispensing systems is crucial. Local
and national regulations and legislation applicable for fuel
infrastructure must be followed. These requirements can be
different in individual regions and countries.
4.5.1 Technical aspects of filling stations
Like any other 100% biofuel, public access to PPO at filling stations
is still in progress. In Germany and in the Netherlands there are
(independent) filling stations making PPO available. Most of these
filling stations are still owned by private and/or cooperative
organisations. Generally users of PPO have the PPO storage at their
own property or elsewhere in combination with other users of PPO.
78 Verbeek, R., et al, 2008, Impact of biofuels on air pollutant emissions from road vehicles, TNO Science and Industrie Report MON-RPT-033-DTS-2008-
Want to know more? More information about biodiesel fuelling stations can be found at www.procura-fleets.eu.
Brökelmann PPO fuelled trucks
(Photo Brökelmann + co)
Biofuel Cities – Technical guidance for biofuels
70 4. Pure Plant Oil, PPO
A special filling nozzle has been developed for filling points to
facilitate PPO to flow without spilling.
4.5.2 Technical aspects of storage and
transportation
Transport and storage of PPO should take place in accordance with
the regulations for edible oils. PPO is organic and should be treated
in accordance with “Material Safety Datasheet“ (EU-directive
91/155). Since PPO is a “non-hazardous” product, local and
national regulations do not form an objection or barrier for storage.
PPO should be stored in an oxygen-free, clean, dry, cool and dark
environment, and well protected against water leakage.
The transport equipment and storage tanks used for storage and
distribution should be made of stainless steel or any other material
suitable for storage of edible oils. For large-scale distribution
systems, the stocking of distribution locations will generally occur
in the same way as for fossil diesel. This means that the
distribution occurs from a central point and that refuelling stations
are regularly restocked from tanker lorries.
In theory, PPO can be mixed at refuelling stations with fossil diesel,
in any ratio. However, a mixture of PPO and diesel is not desired by
the market because it can cause problems in vehicles that have not
been modified79.
A quality reduction can occur through bacteriological deterioration
(PPO is actually a liquid that deteriorates easily), water intake and
oxidation. The last two mechanisms produce free fatty acids, which
can cause corrosion of the injector pumps and injectors during
direct injection into diesel engines.
PPO is a relatively unstable plant oil, but it is more stable than
biodiesel. PPO is less stable than fossil diesel. Adding an
antioxidant may help prevent the oil being degraded through
oxidation. When taking the regulations for storage into account,
01737, Delft, Netherlands
Want to know more? More information about transport and handling of biodiesel at refuelling stations can be found at www.agqm-biodiesel.de.
Biofuel Cities – Technical guidance for biofuels
714 Pure Plant Oil, PPO
PPO can be stored for at least 6-12 months, or even up to 5 years,
without the oil deteriorating. Practical experiences have however
indicated that there can be a considerable degradation of PPO when
stored for a long time80.
4.6 Fuel quality standards
There is a quality standard for PPO for the German market DIN V
51605 Fuels for vegetable oil compatible combustion engines - Fuel
from rapeseed oil - Requirements and test methods. The quality
demands are attainable for pure cold pressed rape seed oil, but
harder for some oils available on the market pressed at higher
temperatures. A larger scale adoption would require a market
separation of the different oils, to ensure a consistent quality81.
Practical tests in Germany show that in many cases PPO does not
meet the standard, particularly the variable characteristics are in
excess of the maximum value. The reasons for this are the low
seed quality, lack of refining steps and quality assurance
throughout the chain82.
4.7 Production
Plant oils are a fuel made by crushing and filtering oil-based crops
such as rapeseed, palm or nuts. The neat oil is then ready to be
used in some diesel engines. Pure plant oil was originally used by
Rudolf Diesel, back in 1912, in his first successful ignition engine,
which ran on peanut oil83.
Within European latitudes rape seed and sunflower seed are the
preferred agricultural products for the production of PPO. Most of
the oil containing seeds is pressed to cakes (feedstock) and oil.
79 2005, The road to pure plant oil?, SenterNovem, Report 2GAVE-05.05, Netherlands 80 2005, The road to pure plant oil?, SenterNovem, Report 2GAVE-05.05, Netherlands 81 Jensen, P., 27.01.2003, Short note on Pure Plant Oil (PPO) as fuel for modified internal combustion engines, European Commission, DG JRC/IPTS, The Institute for Prospective Technological Studies, Seville, Spain
82 2005, The road to pure plant oil?, SenterNovem, Report 2GAVE-05.05, Netherlands 83 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commissions Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
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72 4. Pure Plant Oil, PPO
An estimated 600 rural oil mills located close to the fields are
providing PPO to their customers. Some larger centrally located oil
mills tend to import seeds from abroad, and whilst the smaller oil
mills are using the so called “cold press” (crushing) method, the
larger mills generally use “hot press techniques”.
In terms of energy use, and the absence of any chemical aspect in
the processing, the cold process mills are favoured. As to output
and product consistency the larger mills prevail.
4.8 Sustainability issues
Biofuels can be manufactured from different sources and with
different processes. Depending on circumstances in the life cycle of
a particular biofuel, from initial source to use in a vehicle, the
environmental impact will be different.
4.8.1 GHG balance
Greenhouse gases are gases causing the greenhouse effect. The
greenhouse gases taken into account in this presentation are
carbon dioxide, CO2, nitrous oxide, N2O and methane, CH4.
The GHG balance for any biofuel is influenced by details like growth
location, use of fertilisers, use of agricultural machinery, production
processes, energy use, use of by products, transports etc. The GHG
balance will vary for different biofuels.
Greenhouse gas emission savings from biofuels are calculated as
the reduction of total emissions from the biofuel compared to the
total emissions from the fossil fuel comparator. These values in
Table 14 originate from the Directive of the European Parliament
and of the Council on the promotion of the use of energy from
renewable sources, 2008/0016. How greenhouse gas emission
savings from biofuels are calculated is presented in Appendix I.
Typical values for pure plant oil (PPO), if produced with no net
carbon emissions from land use change, are shown in Table 14.
Want to know more? Sustainability issues are not the focus in this report. Further information can be found at the website http://www.biofuel-cities.eu/index.php?id=6780.
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734 Pure Plant Oil, PPO
The emissions represent all emissions from well-to-wheel (WTW),
i.e. from extraction of raw material to use of the fuel in the vehicle.
CO2 emissions from land use change: emissions of carbon
dioxide due to changes in land use mainly come from the cutting
down of forests and subsequent use of this land for agriculture or
built-up areas, etc. When areas of forests are cut down, the land
often becomes less productive and has considerably less capacity
to store CO2. This effect is not taken into account.
Pure plant oil production pathway Typical
greenhouse gas
emission saving
pure vegetable oil from rape seed 57%
Table 14 Typical greenhouse gas emission savings for pure plant oil84.
4.8.2 Energy balance
The fossil (non renewable) energy use for a biofuel over its life
cycle is an important sustainability factor.
As in the case with the greenhouse gas balance, the fossil energy
savings of biofuels are critically dependent on details like growth
location, use of fertilisers, use of agricultural machinery, production
processes, energy use, use of bi products, transports etc. The
energy use will be different for different biofuels.
For rapeseed the following parameters have been published. From
field to tank: i.e. fossil fuel/electricity including agro activities as
well as processing - crushing /filtering, and distribution.
In an assessment to establish the energy input/output ratio for PPO
derived from rapeseed an average ratio is fixed to 1:6, i.e. 1 litre
diesel oil input generates 6 litre PPO output85.
Based on the assumption that fuel consumption for diesel and PPO
is similar in a vehicle energy use for transport, for processing
84 21.1.2008, Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the promotion of the use of energy from renewable sources, Commission of the European Communities, 2008/0016, Brussels, Belgium 85 2007, Ufop-Unilever report, Sustainable Rapeseed cultivation, Germany
Biofuel Cities – Technical guidance for biofuels
74 4. Pure Plant Oil, PPO
rapeseed and producing fertilisers the PPO-production related
consumption of fossil fuel can be estimated to approximately 35
MJ/100 km86.
4.8.3 Other sustainability issues
Soil quality/erosion
Soil erosion by water, wind and agricultural growth affects both
agricultural conditions and the natural environment.
One PPO source with a potential for expansion are soybeans in
Brazil. These are typically grown close to the rainforest and the
existing high demand for soybeans is already suspected of
accelerating the destruction of the rainforest.
Another major source is palm oils from Malaysia and Indonesia: a
rapid increase in demand could be met by unsustainable production
on rainforest land.
Sustainable certification could be considered as a solution87.
Acidification and Eutrophication
Acidification and eutrophication of ecosystems are two
environmental problems that to a great extent are caused by the
same pollutants.
The main cause of acidification is the airborne deposition of
sulphur. Nitrogen compounds (nitrogen oxides and ammonia) are
the dominant cause of eutrophication of many ecosystems, but also
contribute increasingly to acidification.
Acidification causes soil depletion, disappearance of plants and
animals as well as forest damage. The deposition of nitrogen
compounds favours forest growth, but at the same time leads to
the chemical disruption of a long list of ecosystems, and results in
decrease of biodiversity.
86 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commissions Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 87 2008, Sustainable Green Fleets website, www.sugre.info
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754 Pure Plant Oil, PPO
Because intensive agriculture using fertilisers tends to cause
eutrophication and acidification, increased crop production for
biofuels would tend to accelerate the problem. The driving force for
intensification is crop price: hence meeting biofuels targets will
probably cause more intensification of oilseed production (PPO)
than of cereals (bioethanol) production88.
Sunflower and rape crops generally use less fertiliser than the other
crops.
Biodiversity
Biodiversity is the variety of life: the different plants, animals and
micro-organisms, their genes and the ecosystems of which they are
a part.
Growing energy crops instead of permanent crops and on “natural”
land now in voluntary set-aside areas would decrease biodiversity.
A European study concluded that the negative biodiversity impacts
are high for rape.89
Large increases of pesticide applications are needed if the
frequency of sugar beet and to some extent oilseed rape crops in a
rotation is increased beyond about one year in four.
Impact on ground water table
The increased growth of crops requiring extensive irrigation in arid
areas will put pressure on water resources.
Introduction of non-native species and GMOs
A genetically modified organism (GMO) is an organism whose
genetic material has been altered using genetic engineering
techniques.
88 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 89 2006, How much bioenergy can Europe produce without harming the environment?, EEA Report No 7/2006, ISBN 92-9167-849-X, ISSN 1725-9177, Copenhagen, Denmark
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76 4. Pure Plant Oil, PPO
There is some risk that non-native energy crops could spread in the
wild, because they lack natural predators. Using sterile varieties
(including GMOs) greatly reduce this risk. However, some groups
and individuals are concerned about the overall impacts of GMOs.
Social impact, working conditions
In general working conditions in relation to farm and agricultural
labour are regulated, particularly in EU-27 and the US. In other
parts of the world, the working conditions could be questioned.
However similar problems exist both for biofuel production and for
food and feed production.
Working conditions at soy plantations in Brazil and palm oil farms
in Asia may involve child workers.
Competition with food production
Biomass for energy needs land and is therefore in competition with
other crops. A criticism raised against biomass, particularly against
large-scale fuel production, is that it could divert agricultural
production away from food crops, especially in developing
countries90.
The topic is complex and there are different opinions, pro and con,
from various stake holders.
90 Peña, N., 2008, Biofuels for transportation: A climate perspective, Pew Center on Global Climate Change, Arlington, U.S.A.
Biofuel Cities – Technical guidance for biofuels
774 Pure Plant Oil, PPO
Literature Pure Plant Oil, PPO Biofuel Technology Handbook, Rutz D., Janssen R., 2008
WIP Renewable Energies, München, Germany
Biofuels for Transportation: A Climate Perspective, Peña, N.,
2008
Pew Center on Global Climate Change, Arlington, U.S.A.
Elsbett OnlineShop, 2008
www.elsbett.com/gb/online-shop.html
Emissions from combustion of Pure Plant Oil, PPO, 2008
www.folkecenter.dk/plant-oil/publications/PPO-emissions.htm
How much bioenergy can Europe produce without harming
the environment?, 2006
EEA Report No 7/2006, ISBN 92–9167–849-X, ISSN 1725-9177,
Copenhagen, Denmark
Pure Plant Oil Fuels: An Overview, 2005
Crude Country Biofuels Inc. May 20, 2005, Canada
Short note on Pure Plant Oil (PPO) as fuel for modified
internal combustion engines, Jensen, P., 27.01.2003
European Commission, DG JRC/IPTS, The Institute for Prospective
Technological Studies, Seville, Spain
The road to pure plant oil? 2005
SenterNovem, Report 2GAVE-05.05, Netherlands
Well - to - Wheels analysis of future automotive fuels and
powertrains in the European context, 2007
JRC/IES, European Commission Joint Research Centre, Institute for
Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
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78 5. Biomethane
5 Biomethane
5.1 Summary biomethane
Methane mainly consists of methane with the molecule formula
CH4. The molecule is identical for both natural gas and biomethane
only with the difference that the atoms originates from a bio source
or a fossil source. The name biogas is commonly used to indicate
biomethane. One should keep in mind that ‘biogas’ is also used for
low(er) quality gasses, e.g. direct products of a fermentation
process. Therefore the term biomethane is used in this report to
indicate the upgraded vehicle fuel.
Biomethane is a renewable alternative fuel, which is produced by
breaking down organic matter by a process of microbiological
activity. The origin of biomethane can vary, ranging from livestock
waste, manure, harvest surplus, to vegetable oil residues.
Dedicated energy crops are becoming more and more common as a
feedstock source for biomethane production.
Another feedstock source is the collection of biomethane from
landfill sites. In Germany biomethane is produced in agricultural
facilities, mainly by the fermentation of manure and maize silage.
Recently, wastewater sludge, municipal solid wastes and organic
wastes from households have been introduced as a source for
biomethane91.
Biomethane is used in petrol engines, with bi-fuel technology
meaning that the vehicle can run on both biomethane and petrol,
or as dedicated biomethane vehicles. The bi-fuel vehicles have two
different tank systems and the driver can chose when to drive on
biomethane or petrol. The vehicles are of the same type as vehicles
used for natural gas, which means that there is a large range of
light and heavy duty biomethane vehicles available.
91 Rutz D., Janssen R., 2008, Biofuel Technology Handbook, WIP Renewable Energies, München, Germany
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795. Biomethane
It is also possible to use biomethane in diesel engines, using dual-
fuel technology. This is relatively new and is done by retrofitting of
diesel vehicles (mainly heavy duty).
Biomethane Petrol engines Diesel engines
No changes x x
Dual fuel 100%
100% (diesel
ignition)
Table 15 Biomethane use in different engines
Gaseous energy sources are far more difficult to store and
transport than liquid fuels and require more storage space due to
their substantially lower energy density. For storage and transport
purposes biomethane must be stored in specially installed high
pressure tanks.
Biomethane can be manufactured from different sources and with
different processes. Depending on circumstances in the life cycle of
a particular biomethane from initial source to use in a vehicle, the
environmental impact will be different. Particularly important issues
to consider are the greenhouse gas (GHG) balance and energy
balance for the life cycle of the fuel.
5.2 General fuel properties
Biomethane and natural gas mainly consists of methane with the
molecule formula CH4. The molecule is identical for both gases only
with the difference that the atoms originate from a bio source or a
fossil source.
There are different names used for biomethane, e.g. renewable
methane, methane gas, Compressed Methane Gas, CMG, Green
Gas, biogas. The term biogas is also used for other products with
lower quality which often is burned to produce heat and electricity.
These different products do not necessarily have the same quality
(e.g. purity of the gas; methane content).
When biomethane is used as vehicle fuel the raw gas must be
upgraded and thus receive a higher caloric value and a more
constant gas quality. By purifying the gas from substances like
The simple structure of a methane molecule, CH4
Picture from www.wikipedia.se
Biofuel Cities – Technical guidance for biofuels
80 5. Biomethane
hydrogen sulphide, ammonia and water it does not enhance
corrosion. Mechanically damaging particles are removed and by
holding the water content at a low level, the biomethane does not
freeze. Afterwards the biomethane has a methane content above
95vol%92. As a comparison it can be mentioned that, before
upgrading, natural gas from e.g. the North sea has a methane
content of approximately 87% and Dutch natural gas has a
methane content of approximately 81%93, although methane gas
(whether natural gas or biomethane) upgraded to vehicle fuel
always have a higher methane content.
If biomethane quality varies too much it can be detrimental to the
vehicle engine performance. One of the major concerns in
reciprocating engines is engine knock. The anti-knock property can
be expressed as methane number and is analogous to octane rating
of petrol. Low methane number is usually the result of the presence
of heavy hydrocarbons in the fuel. In addition to the methane
number, the Wobbe index is also an important parameter for gas
engines as it determines both the power and equivalence ratio and
changes that might result in poor operational and environmental
performance94.
Biomethane has clean burning qualities. Because of the gaseous
nature of the fuel, it must be stored onboard a vehicle in either a
compressed form like compressed methane gas (CMG) at 200-240
atmospheres or as liquefied form such as liquefied methane gas
(LMG) at typically 1,4 - 10 atmospheres.
Biomethane is combustible in mixture with air. The flammability
limits of biomethane in air depend on the methane content in the
gas.95
92 2008, Biogas as a vehicle fuel, http://engva.eu/Content.aspx?PageID=190
93 Persson, M., 2006, Biogas Upgrading to Vehicle Fuel Standards and Grid Injection, IEA Bioenergy Task 37, Aadorf, Switzerland 94 2006, Biogas as a transport fuel, NSCA, the National Society for Clean Air and Environmental Protection, ISBN 978 0 903 47461 1, England
95 2007, Basic data on biogas – Sweden, Swedish Gas Centre, Malmö, Sweden
Want to know more? Interesting information can be found at www.biogasmax.eu
Biofuel Cities – Technical guidance for biofuels
815. Biomethane
5.3 Availability Biomethane is a renewable alternative fuel, which is produced by
breaking down organic matter by a process of microbiological
activity.
The origin of biomethane can vary, ranging from livestock waste,
manure, harvest surplus, to vegetable oil residues. Dedicated
energy crops are becoming more and more common as feedstock
source for biomethane production.
Another feedstock source is the collection of biomethane from
landfill sites. In Germany biomethane is produced in agricultural
facilities, mainly by the fermentation of manure and maize silage.
Recently, wastewater sludge, municipal solid wastes and organic
wastes from households have been introduced as a source for
biomethane8.
5.3.1 Sources of biomethane
Rotting municipal waste, food waste or sewage (both human and
animal) is turned into gas by means of "anaerobic conversion" in a
digester. Farmed organic crops like switch grass can also
potentially be used to produce biomethane96.
5.3.2 Future availability
Biomass for biomethane needs land and could therefore be in
competition with crops for food or feed. The additional sources of
agricultural capacity for growing energy crops are described
below97:
• A steady improvement of agricultural yields has been
achieved over the last decades and this trend is expected to
continue.
• Set-aside areas can in principle be used for non-food
production although it is difficult to make an accurate
estimate of land quality and therefore of yields.
96 2008, Sustainable Green Fleets website, www.sugre.info97 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
Biofuel Cities – Technical guidance for biofuels
82 5. Biomethane
• Finally some additional organic waste (domestic waste,
manure, dairies, fish farms, slaughterhouses etc) is
available for the production of biomethane. In order to
arrive at a realistic potential for biomethane many factors
must be considered.
Although there is a lot of suitable biomass feed around, the first
option is not to turn it into biomethane. For example farmed crops
can potentially be used to produce biomethane. However the high
cost of such feedstocks is likely to make this option uneconomic
compared to other alternatives, unless the price on crops as wheat
decrease. Municipal waste or sewage can play some role in
biomethane production, but the main future potential feedstock is
manure.
5.4 Use in vehicles
Biomethane is used in petrol engines, with bi-fuel technology
meaning that the vehicle can run on both biomethane and petrol,
or as dedicated biomethane vehicles. The bi-fuel vehicles have two
different tank systems and the driver can chose when to drive on
biomethane or petrol. The vehicles are the same type as vehicles
used for natural gas which means that there is a large range of
light and heavy duty biomethane vehicles available.
It is also possible to use biomethane in diesel engines with dual-
fuel technology. This is relatively new and is done by retrofitting of
diesel vehicles (mainly heavy duty).
Biomethane Petrol engines Diesel engines
No changes x x
Dual fuel 100%
100% (diesel
ignition)
Table 16 Biomethane use in different engines
5.4.1 Vehicle technology
There is a wide variety of available vehicles. Over 40 manufacturers
worldwide provide methane vehicles, which can run on either
Want to know more? Overviews of available
vehicles can be found at:
www.miljofordon.se
http://www.e-mobile.ch/
Biofuel Cities – Technical guidance for biofuels
835. Biomethane
biomethane or natural gas, including Citroën, Fiat, Mercedes, Opel,
Ford and Volkswagen. In a number of countries customers are also
offered retrofitted vehicles. The light-duty vehicles are mostly bi-
fuel but the heavy duty vehicles as buses and trucks are generally
dedicated to biomethane. The heavy duty vehicles have a spark-
ignition engine. Examples of manufacturers which offer heavy duty
biomethane vehicles are MAN, Volvo, Iveco and Mercedes.
Dual-fuel (biomethane/diesel) vehicles are retrofitted. The diesel is
used for the first ignition then the biomethane ignites.
Heavy duty biomethane vehicles often reduce noise levels, as the
spark-ignition engine is less noisy compared to the diesel engine.
The drawback of this technology is that the engine’s energy
efficiency and torque are substantially lower than a comparable
diesel engine.
If the car runs out of biomethane it automatically changes fuel. In
some models the driver needs to push a button to change to petrol.
The vehicles do not need to stop and the change of fuel does not
affect the driving98
Maintenance
The biomethane vehicles are very sensitive to the quality of the
fuel and the biomethane has to be kept at the same quality as
natural gas.
Biomethane vehicles are maintained with the same frequency as
petrol cars. The fuel tanks have to be inspected regularly in order
to check that it doesn’t leak. The fuel tank does not have to be
emptied for regular service but for certain repairs in the fuel
system the tank has to be emptied for safety reasons.
The heavy duty vehicles running on biomethane have the same
service intervals as diesel engines. The experience from
biomethane buses is that it is important to follow the scheduled
maintenance. The spark plugs have to be changed, otherwise the
catalytic converter can be affected.
Want to know more? Interesting information about methane gas fuelled vehicles can be found at http://engva.eu/
Biofuel Cities – Technical guidance for biofuels
84 5. Biomethane
Driving range
Biomethane is sold in normal cubic meters, Nm3, and one Nm3 is
about 1 litre of petrol, the energy content of 1 Nm3 biomethane is
7% higher than 1 litre of petrol. A full tank of biomethane equals
about 200-400 km in a light vehicle, then the driver can switch to
the petrol.
Today the heavy duty biomethane vehicles have a spark ignition
engine which means that the consumption of biomethane increases
by about 20% in a biomethane bus compared to a diesel bus. The
reason is mainly the change from a diesel engine to a less energy
efficient petrol engine and does not depend on the biomethane
fuel.
Cost
The cost for biomethane passenger vehicles is between 5–20%
higher than conventional petrol cars.
The heavy vehicles producers add about €40 000-50 000 to the
price of a conventional truck or bus for the biomethane version.
Safety issues
The biomethane fuel tanks are placed in well protected locations in
the car. They are made of very durable materials and the cars are
tested as other cars in the EuroNCAP tests. Biomethane is lighter
than air and if there is a leakage of biomethane it dissipates quickly
in well-ventilated areas. There are also safety valves that can be
released if it is needed. The situation is the same for heavy duty
vehicles.
Natural gas
Natural gas is the same molecule as biomethane but has a fossil
origin. All information concerning natural gas is the same as for
biomethane. The difference is the result on emissions of CO2. A
change from diesel to natural gas increases the emissions of CO2 by
up to about 20%. The reason is the change from diesel engine to
the less efficient petrol engine.
98 2008, www.miljofordon.se
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855. Biomethane
Retrofitting
Petrol and diesel vehicles can be converted to biomethane. It is a
two tank system. A fuel tank system for biomethane is installed in
the vehicle. The electronic system in the engine has to be adapted
to biomethane and petrol/diesel99. The dual-fuel
(diesel/biomethane) engines are not available on the market so the
vehicles have to be retrofitted. The cost is around €10 000100.
5.4.2 Exhaust gas emissions
Biomethane use has a positive effect on regulated emissions.
Biomethane and natural gas have the same properties so the data
can be used for both fuels.
Emission petrol diesel
NOx 55% 80%
CO 55% 50%
PM x 98%
HC 80% 80%
Ozone formation 65% 85%
Table 17 Reductions of toxic emissions (in %) from biomethane combustion in comparison with petrol and diesel101
5.4.3 User experience
Stockholm Public Transport Authority, SL, introduced biomethane in
the end of the 1990s. The buses in the fleet are from Volvo as well
as MAN. The biomethane bus fleet is about 51 buses and will
increase to about 120 in the coming years.
The main lesson learned is that the quality of the biomethane is
vital to the function of the buses, together with a well kept
maintenance schedule. Because the buses have a petrol-engine
(spark ignition) they lose some torque compared to the diesel
buses. This has led to higher noise compared to diesel buses, as
well as higher fuel consumption, but on the whole the biomethane
buses work well. The main price difference compared to diesel
99 2008, Konvertering till gasdrift, Brochure from Tekniska Verken and Svensk Biogas, Linköping, Sweden 100 Tekniska verken, Linköping, Sweden as above
101 Rutz D., Janssen R., Biofuel Technology handbook, WIP Renewable Energies, München, Germany
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86 5. Biomethane
buses is the additional cost for the bus and also the fuel station,
which is much more expensive compared to diesel. Training of the
personnel that will drive, maintain and refuel the buses has been
important to ease introduction of the vehicles.
Taxi Stockholm has many affiliated driving companies that use
biofuels for their vehicles. One reflection made by the companies is
that it is hard to get gas vehicles. Without special connections in
the business it is mostly used cars that are available. The number
of, and distance to, refuelling stations in Stockholm is acceptable as
long as they are not out of order. In the past there have been
problems with fuel supply to the stations, but these have mostly
been solved. The main reason for using biofuels is the economic
advantages – to shorten the waiting time for the taxis and to be
prioritised by customers demanding environmental adapted cars.
The downside with biomethane vehicles is the very increased
refuelling interval – instead of once every other day its four times a
day.
5.5 Infrastructure requirements It is important that proper fuel handling techniques are being
practiced to prevent fuel contamination. Also choosing the right
materials for fuel storage and dispensing systems is crucial. Local
and national regulations and legislation applicable for fuel
infrastructure must be followed. These requirements can be
different in individual regions and countries.
The use of gaseous fuels needs new infrastructure in the form of
filling stations adapted for gaseous fuels instead of liquid fuels. The
construction of a biomethane pump costs much more than the
construction of a conventional pump for liquid fuels.
5.5.1 Technical aspects of filling stations
Fuelling a methane vehicle is, from the consumer’s perspective, a
procedure not much more complicated than fuelling liquid petrol or
diesel. Fast-fill dispensing takes only slightly longer than fuelling
petrol. Slow fill systems, normally associated with fleet
applications, are used when a fleet is parked in a depot overnight.
Several varieties of slow-fill home compressors (vehicle refuelling
Taxi queue at Arlanda airport Biofuelled cars, and cars that fulfil the requirements of the eco taxi definition set up by Stockholm City, are prioritised in the queue at Arlanda airport, and thus have shorter waits.
Photo Kristina Birath
Want to know more? Information regarding gas filling stations in Europe: www.erdgasfahrzeuge.de (Germany) www.guidametano.com (Italy) www.erdgastanken.ch (Switzerland) www.erdgasautos.at (Austria) www.gazdefrance.fr (France) www.ngva.co.uk (Great Britain) www.dutchfour.com (the Netherlands)www.cng.cz (the Czech Republic)
Biofuel Cities – Technical guidance for biofuels
875. Biomethane
appliances –VRAs) are available so that individual commuter cars
can be refuelled at home102.
5.5.2 Technical aspects of storage and
transportation
There are several ways of distributing natural gas or biomethane to
the customer, either to fuelling stations or to a fleet depot. The gas
can be compressed and piped through a pipeline that was designed
specifically for this purpose or it can be introduced into the existing
natural gas grid. Alternatively it can be liquefied or compressed
and, afterwards, trucked to a fuelling station.103
Biomethane can be injected and distributed through the natural gas
grid since biomethane - like natural gas - mainly consists of
methane104. Sweden, Switzerland, Germany and France have a
standard for injecting biomethane into the natural gas grid. The
standards have been set to avoid contamination of the gas grid or
end use. In the standards there are limits on certain components
for instance sulphur, oxygen, particles and water dew point. These
demands are in most cases possible to achieve with existing
upgrading processes. In some cases landfill gas can be difficult to
upgrade to sufficient quality due to large content of nitrogen.
Introduction of biomethane into the natural gas grid is subject to
some restrictions:
� The biomethane has to be compressed to a pressure equal to
that of the natural gas in the grid
� The biomethane should be odorised with the same substance as
the natural gas
� In places where the natural gas has a high energy content, e.g. in
Sweden, a small amount of propane needs to be mixed into the
biomethane to achieve the same energy content as the natural gas.
Where this is not the case, e.g. in the Netherlands or France, such
measures are not needed. If no pipeline network exists, the gas
102 2008, Decision Makers’ Guide - how to implement a biomethane project, Biogasmax, www.bigasmax.eu
103 2008, Decision Makers’ Guide - how to implement a biomethane project, Biogasmax, www.biogasmax.eu104 Persson, M., 2006, Biogas Upgrading to Vehicle Fuel Standards and Grid Injection, IEA Bioenergy Task 37, Aadorf, Switzerland
Want to know more? Interesting information about technical aspects of biomethane fuelling stations can be found at www.procura-fleets.eu
Refuelling station for biogas, Söderhallen Bus Depot, Stockholm
Photo Kristina Birath
Biofuel Cities – Technical guidance for biofuels
88 5. Biomethane
can be compressed into CNG storage tanks on-board specially
designed trucks and brought to a fuelling station where it can be
distributed into vehicles.
Methane that is not immediately dispensed into a vehicle needs to
be stored on site. Gas that is transported by truck, grid or pipeline
will be compressed and stored in high-pressure (250 bar) cylinders
at the fuelling station e.g. in the case of large bus fleets or public
fuelling stations. Liquid natural gas (LNG) is stored in bulk-storage
cryogenic tanks and then vaporised prior to dispensing into
vehicles.
Biomethane is lighter than air, so that any gas leaking will rise
upwards. Biomethane also has a higher temperature of ignition
than either petrol or diesel. This means that the risk of fire or
explosion in traffic accidents is smaller for biomethane than for
petrol or diesel.
5.6 Fuel quality standards
Within the framwork of IEA Bioenergy, Task 37 - Energy from
Biogas and Landfill Gas, a report on standards for biomethane has
been produced105. It states that there are no European standard
for biomethane for fuel but national standards for biomethane in
all countries where biomethane is used. In Switzerland where
biomethane is injected into the natural gas grid at several
places in there are two different quality standards. The Swiss
regulation (G13) is gas for limited injection and gas for unlimited
injection. There are more restrictions for unlimited injection are
higher than for limited.
Germany has a standard for biomethane injection (G262),
developed in cooperation between German Water and Gas
Association and the German Biogas Association. The standard is
based on the German standard for natural gas, DVGW G260. The
105 Biogas Upgrading to Vehicle Fuel Standards and Grid Injection, Persson, M.,
2006 IEA Bioenergy Task 37, Aadorf, Switzerland
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895. Biomethane
standard allows injection of two types of gas: for limited injection
and unlimited injection. The German standard also requires the
biomethane producer to present at safety data sheet that describes
any health hazards in connection to the handling of the
biomethane.
In France, Gaz de France has produced a standard for biomethane
injected in the natural gas grid. This standard has more restricted
limits for oxygen content and for heavy metals and halogens than
other standards In Sweden, all biomethane used as vehicle fuel
follows the Swedish standard, SS 15 54 38, Motor fuels – biogas as
a fuel for high-speed Otto engines). In Appendix II some details of
this standard are shown106.
5.7 Production
Biogas production starts from a fossil-carbon-free biomass waste
product and uses part of the biogas to fuel the process. The
production occurs through a fermentation process without oxygen
present (anaerobic). The result is low graded biogas which can be
burned to create electricity and heat. Cleaning and upgrading of
the gas is required, to remove various impurities and the bulk of
the CO2 is needed o reach fuel quality. Such plants already exist in
Scandinavia107.
Most biogas production installations have so far have geared to
production of heat and power, concepts for fuel production plants
have been developing with a view to produce a gas that can be
used in combination with, or as an alternative to, natural gas as
automotive fuel (Compressed Biogas or CBG).
In the newest bio-ethanol production plant concepts, biogas is an
important by-product108, produced through fermentation of the rest
product. The biogas can also be used, if really necessary, for the
plant’s own energy needs or sold as an “extra” commodity.
106 Basic data on biogas, Svenska gasföreningen, Swedish Gas Association, 2007 107 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 108 2008, www.ber-rotterdam.com
Want to know more? IEA Bioenergy Task 37 focus on Energy from Biogas and Landfill gas. Read more at: http://www.iea-biogas.net/
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90 5. Biomethane
5.8 Sustainability issues Biomethane can be manufactured from different sources and with
different processes. Depending on circumstances in the life cycle of
a particular biomethane from initial source to use in a vehicle, the
environmental impact will be different.
Below the important issues of greenhouse gas (GHG) balance and
energy balance for different biomethanes are explained and
presented. Also some other sustainability issues are highlighted,
however in more general terms.
5.8.1 GHG balance
Greenhouse gases are gases causing the greenhouse effect. The
greenhouse gases taken into account in this presentation are
carbon dioxide, CO2, nitrous oxide, N2O and methane, CH4.
The GHG balance for any biofuel is influenced by details like growth
location, use of fertilisers, use of agricultural machinery, production
processes, energy use, use of by products, transports etc. The GHG
balance will be different for different biofuels.
Greenhouse gas emission savings from biofuels are calculated as
the reduction of total emissions from the biofuel compared to the
total emissions from the fossil fuel comparator. These values in
table 18 originate from the Directive of the European Parliament
and of the Council on the promotion of the use of energy from
renewable sources, 2008/0016. How greenhouse gas emission
savings from biofuels is calculated is presented in Appendix I.
Typical values for different biomethane, if produced with no net
carbon emissions from land use change are shown in table 18
below. The emissions represent all emissions from well-to-wheel
(WTW), i.e. from extraction of raw material till use of the fuel in the
vehicle.
CO2 emissions from land use change: emissions of carbon
dioxide due to changes in land use mainly come from the cutting
down of forests and subsequent use of land for agriculture or built-
up areas, etc. When areas of forests are cut down, the land often
Want to know more? Sustainability issues are not the focus in this report. Further information can be found at the website http://www.biofuel-cities.eu/index.php?id=6780
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915. Biomethane
becomes less productive and has less capacity to store CO2. This
effect is not taken into account.
Biomethane production pathway Typical greenhouse
gas emission saving
biomethane from municipal organic waste as
compressed natural gas 81%
biomethane from wet manure as compressed
natural gas 86%
biomethane from dry manure as compressed
natural gas 88%
Table 18 Typical greenhouse gas emission savings for different biomethane
fuels109.
5.8.2 Energy balance
The fossil (non renewable) energy use for a biofuel over its life
cycle is an important sustainability factor.
The use of biofuels reduces the use of fossil energy. The energy
balance presented below includes both fossil and renewable (bio)
energy. Fossil energy savings do not automatically mean that
biofuel pathways are total energy (fossil and renewable) efficient.
As in the case of greenhouse gas balance, the fossil energy savings
of biofuels are critically dependent on details like growth location,
use of fertilisers, use of agricultural machinery, production
processes, energy use, use of by products, transports etc. The
energy use will be different for different biofuels.
Taking into account the energy contained in the biomass resource
one can calculate the total energy involved. The figure below shows
energy figures for different biomethane fuels. Figures for fossil and
total (fossil and renewable bio energy) well-to-wheel (WTW) energy
are presented. This represents the energy from well or source of
the biofuel to use of the fuel in the vehicle.
109 23.1.2008, Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the promotion of the use of energy from renewable sources, Commission of the European Communities, 2008/0016, Brussels, Belgium
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92 5. Biomethane
Figure 12 WTW (WTT and TTW) energy requirement for compressed biomethane (CBG). The black bars indicate the span of uncertainties in the values110.
5.8.3 Other sustainability issues
Biogas is mainly produced when rotting municipal waste, food
waste or sewage (both human and animal) is turned into gas by
means of "anaerobic conversion" in a digester. Farmed organic
crops can also be used. For farmed organic matter the following
sustainability issues should be observed.
Soil quality/erosion
Soil erosion by water, wind and agricultural growth affects both
agricultural conditions and the natural environment.
Continually removing waste straw instead of incorporating it in the
soil will decrease the soil organic content and may lead to poorer
moisture retention111.
110 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 111 2008, Sustainable Green Fleets website, www.sugre.info
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935. Biomethane
Acidification and Eutrophication
Acidification and eutrophication of ecosystems are two
environmental problems that to a great extent are caused by the
same pollutants.
The main cause of acidification is the airborne deposition of
sulphur. Nitrogen compounds (nitrogen oxides and ammonia) are
the dominant cause of eutrophication of many ecosystems, but also
contribute increasingly to acidification.
Acidification causes soil depletion, disappearance of plants and
animals as well as forest damage. The deposition of nitrogen
compounds favours forest growth, but at the same time leads to
the chemical disruption of a long list of ecosystems, and results in
decrease of biodiversity.
Because intensive agriculture using fertilisers tends to cause
eutrophication and acidification, increased crop production for
biofuels would tend to accelerate the problem112.
Biodiversity
Biodiversity is the variety of life: the different plants, animals and
micro-organisms, their genes and the ecosystems of which they are
a part.
Growing energy crops instead of permanent crops and on “natural”
land now in voluntary set-aside areas would decrease biodiversity.
Impact on ground water table
The increased growth of crops requiring extensive irrigation in arid
areas will put pressure on water resources.
Introduction of non-native species and GMOs
A genetically modified organism (GMO) is an organism whose
genetic material has been altered using genetic engineering
techniques.
112 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
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94 5. Biomethane
There is some risk that non-native energy crops could spread in the
wild, because they lack natural predators. Using sterile varieties
(including GMOs) greatly reduce this risk. However, some
stakeholders are concerned about the wider impacts of GMOs.
Social impact, working conditions
In general, working conditions in relation to farm and agricultural
labour are regulated, particularly in EU-27 and the US. In other
parts of the world, the working conditions could be questioned.
However similar problems exist both for biofuel production and for
food and feed production113.
The topic is complex and there are different opinions, pro and con,
from various stake holders.
113 Peña, N., 2008, Biofuels for transportation: A climate perspective, Pew Center on Global Climate Change, Arlington, U.S.A.
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955. Biomethane
Literature Biomethane
Basic data on biogas – Sweden, 2007
Swedish Gas Centre, Malmö, Sweden
Biofuel Technology Handbook, Rutz D., Janssen R., 2008
WIP Renewable Energies, München, Germany
Biofuels for Transportation: A Climate Perspective, Peña, N.,
2008
Pew Center on Global Climate Change, Arlington, U.S.A.
Biogas as a vehicle fuel, 2008
http://engva.eu/Content.aspx?PageID=190
Biogas as a road transport fuel, 2006
NSCA, the National Society for Clean Air and Environmental
Protection, ISBN 0 903 47461 1, ISBN 978 0 903 47461 1, England
Biogas Upgrading to Vehicle Fuel Standards
and Grid Injection, Persson, M., 2006
IEA Bioenergy Task 37, Aadorf, Switzerland
Decision Makers’ Guide – how to implement a biomethane
project, 2008
Biogasmax, www.biogasmax.eu
DIRECTIVE 2003/30/EC OF THE EUROPEAN PARLIAMENT
AND OF THE COUNCIL of 8 May 2003, on the promotion of
the use of biofuels or other renewable fuels for transport,
2003
European Union, Brussels, Belgium
Konvertering till gasdrift, 2008
Brochure from Tekniska Verken and Svensk Biogas, Linköping,
Sweden
Biofuel Cities – Technical guidance for biofuels
96 5. Biomethane
Kvalitetskrav på biogas som fordonsbränsle, 2001
Swedish Gas Centre, Demosheet 29, Malmö, Sweden
Well - to - Wheels analysis of future automotive fuels and
powertrains in the European context, 2007
JRC/IES, European Commission Joint Research Centre, Institute for
Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
www.miljofordon.se, 2008
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976 Other biofuels
6 Other biofuels
In this chapter, a range of other biofuels – Hydrogen, electricity
and DME - are briefly described. These fuels are relevant to
mention but outside the scope of this guide.
6.1 General fuel properties
Hydrogen
Hydrogen fuel, H2, consists of two hydrogen atoms in one molecule.
Hydrogen is an energy carrier. Hydrogen can be burned in a
combustion engine or be chemically converted to electricity and
water in a fuel cell. The energy content of hydrogen is low on a
volume basis. Hydrogen is a gas at ambient temperature and
pressure and needs to be liquefied to be stored in a vehicle.
Electricity
Electricity is an energy carrier. Conventional electricity, 220 V, can
be used to charge batteries in electric vehicles or plug-in hybrids.
The electric engine is more efficient compared to the combustion
engine, reaching about 80 % efficiency compared to the
combustion engine’s 25-30 percent. The diesel engine reaches
about 43 % efficiency.
DME
DME (dimethyleter) has a boiling point of -25°C114, It can be
liquefied at a pressure of 0.6 MPa at normal temperatures. DME
can be used as fuel for diesel engines as the cetane rating is 55-60.
It has a low heat value of approximately 29 MJ/kg. The fuel is more
corrosive, flammable, and volatile than fossil diesel. Using pure
DME in vehicles requires pressurisation to several atmospheres,
similar to LPG. The energy content of DME is half that of diesel,
which means that motorist needs to refuel more often, or install a
larger fuel tank.
114 2008-09-02, Japan DME Forum – about DME, www.dmeforum.jp/about/index_e.html
Want to know more? There is interesting information at www.dmevehicle.eu
Want to know more? There is interesting information at www.h2moves.eu and www.hfpeurope.org
Biofuel Cities – Technical guidance for biofuels
98 6 Other biofuels
6.2 Availability
Hydrogen
In principle, hydrogen can be produced from virtually any primary
energy source. Although it is the most widespread element in the
universe, free hydrogen does not occur in nature. It needs to be
“extracted” from compounds such as hydrocarbons and of course
water, by using energy.
This can be done via gasification of a hydrocarbon or organic
feedstock and via splitting of water or through electricity via
electrolysis of water115. However, the use of electricity for
production of hydrogen is less efficient compared to the use of
electricity in battery or plug in vehicles.
A lot of hydrogen can theoretically be produced both from fossil
sources (natural gas and coal) and renewable sources (biomass).
The gasification route produces syngas from which other fuels as
DME, methane, ethanol, methanol and synthetic diesel can be
produced. For example, both coal and natural gas based production
plants are being built in China and South Africa. Production
methods for hydrogen from syngas based on biomass are being
developed in Europe by Choren.
Electricity
Electricity is not a fuel as such, but an energy carrier. Electricity
can be produced in a number of different ways and using different
sources: nuclear, wind, water, coal, biomass etc116. The emissions
from an electric vehicle depend entirely on how the electricity is
produced.
Electricity is widely available in society and is easy to access.
Electric vehicles can be charged at home, during the night or during
the day at recharging sites. There are both fast charging and
normal charging techiques. The available electric vehicles, such as
115 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu).
116 Birath, K., Sjölin, L., 2007. Clean vehicles and alternative fuels - Trends and visions, NICHES Consortium, Stockholm, Sweden
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996 Other biofuels
the two-seater car produced by Norwegian manufacturer Think,
have a range of 180 km in one charge117.
DME
DME has been used for decades in the personal care industry
(aerosol propellant), and for the production of ultra-pure glass
(because DME burns without soot formation), and is now
increasingly being exploited for use as a clean burning alternative
to LPG (liquefied petroleum gas), diesel and petrol118. However, at
present there are only a few test vehicles running on DME.
The most likely feedstock in the short term is natural gas and coal.
Wood can also be envisaged. The black liquor (biomass produced
within the chemical pulp industry) production route is also suitable
for DME (or methanol)119.
6.3 Use in vehicles
Hydrogen
Hydrogen can be used as a fuel in spark ignition engines and in fuel
cells. Almost all vehicle manufacturers are involved in fuel cell
research but most believe fuel cell technology will not become
widely available before 2020.
Fuel cell and hydrogen adapted vehicles are being produced but
mainly for demonstration projects. One example is the 27 fuel cell
buses that run within the EU-demonstration project CUTE120 .
Electricity
In the 1990s many manufacturers such as Citroen, Ford, Honda,
GM, Peugeot and Toyota had electric vehicle programmes and a
number of models were introduced on the market. Despite the
large research effort, the driving range of available cars remained
too short, up to 100 km at the most. Many of the manufacturers
117 2008, www.think.no 118 2008, International DME Association, www.aboutdme.org119 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 120 2008, The Fuel Cell Bus Club, www.fuel-cell-bus-club.com
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100 6 Other biofuels
began to focus on hybrid technology, where the efficient electricity
engine can be used within the conventional system. However, a
number of car manufacturers have now developed a renewed
interest in electric vehicles, due to the development of better and
more promising battery technologies (Li-ion) and super capacitors.
As large efforts are invested in climate efficient technology, many
manufacturers are interested in electric drives. The electric engine
is much more energy efficient compared to the combustion engine
and needs about 1.5-2 kWh to run 10 km. If 1 million electric
vehicles ran 10000 km per year on electricity, 1.5 TWh electricity
would be needed121. The combination of batteries and combustion
engine, plug-in technology, is very promising. Most large vehicle
manufacturers are currently involved in projects to develop plug-in
vehicles. Pure electric vehicles are sold by Think. Nissan and
Renault are involved in an electric vehicle project in Israel.
DME
DME (di-methyl ether) is mainly suitable as a diesel fuel and can be
one of the fuels that replace fossil diesel in the future. At the
moment the focus is to develop an efficient production of the fuel.
There are no vehicles commercially available and there is very little
experience from use so far.
6.4 Infrastructure requirements
Hydrogen
Hydrogen fuelling stations can provide hydrogen fuel for vehicles in
different ways. Stations can be designed to produce hydrogen on-
site, or to have hydrogen fuel delivered from centralised production
plants in liquid or gaseous form.
Hydrogen can be stored as a gas, a cryogenic liquid, using a solid,
or with a carbon-based medium, such as methanol or hydrocarbon
fuels. Boil-off is a specific problem with liquid hydrogen122. Storage
121 Plugged in . the end of the oil age, Gary Kendall, WWF 080403 122 Nylun, N-O., et al, 2008, Status and outlook for biofuels, other alternative fuels and new vehicles, VTT RESEARCH NOTES 2426, ISBN 978-951-38-7196-3, ISSN 1455-0865, Espoo, Finland
Electric hybrid bus in London
Photo Kristina Birath
Biofuel Cities – Technical guidance for biofuels
1016 Other biofuels
of hydrogen (on board) is still one of the mayor research topics
within the field of hydrogen vehicles.
Electricity
Electricity is supplied by the electric mains. For the normal charging
one needs an ordinary outlet. Connecting an electric vehicle to a
charging post necessitates the use of a cable and plug.123 With
normal charge, one hour of charge corresponds to 15-20 km of
driving. Full charge depends on the size of the battery and can take
between 8-12 hours. Fast charge is 2-3 times faster than normal
charging. The
The big plus for electricity is of course that it can be transported on
long distances in a relative cheap and simple way. It is also widely
available but an infrastructure easily accessible for cars is needed.
Recharge points are often available at home or the office but not
always available at public parking facilities and fuel stations.
DME
Transport, storage and distribution of DME is the same as for LPG.
DME is stored under 9 bar pressure. At the moment the focus is to
develop an efficient production of the DME fuel. There is very little
experience from use so far.
6.5 Fuel quality standards
Hydrogen
For hydrogen there is an ISO standard ISO/TS 14687-2:2008,
Hydrogen fuel - Product specification - Part 2: Proton exchange
membrane (PEM) fuel cell applications for road vehicles, which
specifies the quality characteristics of hydrogen fuel when used as
a fuel for road vehicles.
Electricity
The electricity has to be standard European 230 V/16 Ampere.
123 2008, The European Association for Battery, Hybrid and Fuel Cell Electric Vehicles, www.avere.org/what_are_evs.htm#how
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102 6 Other biofuels
DME
For DME there is not yet an international standard for the fuel.
6.6 Production
Hydrogen
Hydrogen is already produced in significant quantities, mostly for
industrial applications. Oil refineries, in particular, are large
hydrogen consumers.
The most widespread hydrogen production process is steam
reforming of natural gas (essentially methane). The catalysed
combination of methane and water at high temperature produces a
mixture of carbon monoxide and hydrogen (known as “syngas”).
The “CO-shift” reaction then combines CO with water to form CO2
and hydrogen. The process is technically and commercially well-
established and natural gas is a widely available and relatively
cheap feedstock124. Coal based production is also common but
needs to be combined with carbon capture and sequestration, in
order not to increase the emissions of CO2 more than conventional
fossil fuels. Carbon sequestration concepts and technologies are
relatively new and there is no long-term test evidence that these
technologies will be successful.
Steam reforming of heavier hydrocarbons is also possible but rarely
applied in practice, because the process equipment is more
complex and the potential feedstocks such as LPG or naphtha have
a higher alternative value. Electrolysis uses electricity to split the
water molecule. This is a well established technology both at large
and small scale.
Direct solar energy can also be used to produce hydrogen either by
thermal splitting of water into hydrogen and oxygen or electrolysis
through photovoltaic electricity125. Biomass can be converted in a
controlled atmosphere to methane, which is then steam reformed
to separate the Hydrogen for use. Both the raw methane and
124 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
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1036 Other biofuels
cleaned hydrogen can be used to fuel a generator which can supply
the power to run the system. The cleaned hydrogen can be used
for hydrogen vehicles.
Electricity
Electricity is not a fuel per se, but an energy carrier. Electricity can
be produced in a number of different ways: nuclear, wind, water,
coal, biomass etc126. In recent years the use of “internal power
plants” in conventional petrol vehicles has become more and more
common, utilising energy that would otherwise go to waste as heat.
This principle is more commonly known as electric hybrid or hybrid
electric.
Biomass is used to generate electricity. Both dedicated biomass
and biomass co-firing are used in the electricity generation sector.
Biomass co-firing involves combining biomass material with coal in
existing coal-fired boilers. Biomass is supplied from various sources
like: agricultural residues, energy crops, forestry residues and
urban wood waste/mill residues.
DME
DME can be produced from a variety of sources, including natural
gas, coal, waste from pulp and paper mills, forest products,
agricultural by-products, municipal waste and dedicated fuel crops
such as switch grass127.
World production today is primarily by means of methanol
dehydration, but DME can also be manufactured directly from
synthesis gas produced by the gasification of coal or biomass, or
through natural gas reforming128.
Among the various processes for chemical conversion of natural
gas, direct synthesis of DME is the most efficient.
125 2008, Sustainable Green Fleets website, www.sugre.info126 Birath, K., Sjölin, L., 2007. Clean vehicles and alternative fuels - Trends and visions, NICHES Consortium, Stockholm, Sweden 127 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 128 2008, International DME Association, www.aboutdme.org
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104 6 Other biofuels
6.7 Sustainability issues Sustainability issues are not the focus in this report. Further
information can be found at the website: http://www.biofuel-
cities.eu/index.php?id=6780.
Hydrogen
Some obvious advantages for hydrogen are near-zero well-to-
wheel emissions when using wind or solar generated electricity to
produce hydrogen and zero-emission driving, for a hydrogen
vehicle equipped with a fuel cell (FC) as it only emits water
vapour129. When other feedstocks are used for generating
electricity, this means emissions of CO2, NOx, PM, see Electricity
below.
Hydrogen can be produced from a number of primary energy
sources. As there are many possible routes to a “hydrogen
alternative” there are also a wide range of energy usage and
greenhouse gas (GHG) emissions alternatives.
Using the WTW (well-to-wheel) approach for hydrogen it is clear
that a large part of the energy usage and all of the GHG emissions
occur at the production stage130.
Electricity
Electric vehicles (EVs) produce zero tailpipe emissions, which
makes them a particularly attractive for busy urban areas where
poor air quality often leads to health problems. Although using
electricity results in no air pollution, its production process often
results in substantial emissions131. On the other hand however, it is
also possible to produce electricity from very clean and sustainable
sources.
A full WTW analysis of EVs’ environmental benefit must consider
the emissions associated with the production and supply of the
129 2008, Sustainable Green Fleets website, www.sugre.info130 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu) 131 Birath, K., Sjölin, L., 2007. Clean vehicles and alternative fuels - Trends and visions, NICHES Consortium, Stockholm, Sweden
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1056 Other biofuels
electricity used to recharge vehicles as well as the potential
environmental burden due to battery production and recycling. In
many countries it is easy to calculate for GWP (Greenhouse
Warming Potential) since figures are available for the average GWP
produced per kWh of electricity delivered132.
Batteries can have a high environmental impact due to the energy
required to produce them and because of the potential for
contamination of land or groundwater upon their disposal.
However, the most popular EV batteries until now (lead-acid and
Ni-MH) are both readily recyclable, so is the most promising
alternative from now on, the Li-ion battery. Moreover, the EC End
of Life Vehicle Directive (2000/53/EC) dictates that these batteries
must be recycled.
DME
DME can be produced from biomass as well as second generation
biodiesel fuels, BTL (biomass to liquid).
The higher efficiency of the synthesis process gives DME a slight
advantage over the synthetic diesel fuel from the same bio source.
As a result of this DME has a better energy and GHG result than
other BTL fuels133.
132 2008, Sustainable Green Fleets website, www.sugre.info133 2007, Well - to - Wheels analysis of future automotive fuels and powertrains in the European context, JRC/IES, European Commission Joint Research Center, Institute for Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
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106 6 Other biofuels
Literature Other biofuels Clean vehicles and alternative fuels - Trends and visions,
Birath, K., Sjölin, L., 2007
NICHES consortium, www.niches.org
International DME Association, 2008
www.aboutdme.org
Japan DME Forum – about DME, 2008-09-02
www.dmeforum.jp/about/index_e.html
Plugged in. the end of the oil age, Gary Kendall, 2008.
WWF
Status and outlook for biofuels, other alternative fuels and
new vehicles. Nylund, N-O., et al, 2008
VTT RESEARCH NOTES 2426, ISBN 978-951-38-7196-3, ISSN
1455-0865, Espoo, Finland
Sustainable Green Fleets website, 2008
www.sugre.info
The Fuel Cell Bus Club, 2008
www.fuel-cell-bus-club.com/
The European Association for Battery, Hybrid and Fuel Cell
Electric Vehicles 2008
www.avere.org/what_are_evs.htm#how
Well - to - Wheels analysis of future automotive fuels and
powertrains in the European context, 2007
JRC/IES, European Commission Joint Research Centre, Institute for
Environment and Sustainability, Italy (ies.jrc.ec.europa.eu)
www.think.no
2008
Biofuel Cities – Technical guidance for biofuels
107Glossary
Glossary Anhydrous alcohol
Alcohol that is free of water and at least 99% pure
CHP
Expression for the Combined Heat and Power process.
CEN
The European Committee for Standardizsation.
CO2
Carbon dioxide. CO2 can be of fossil origin, and thus have a
negative effect on global warming, or of renewable origin and not
have an effect on global warming.
CWA
A CEN Workshop Agreement.
DDGS
Distiller’s Dried Grain with Solubles: the residue left after
production of ethanol from wheat grain.
Denaturisation
To prevent oral consumption and thereby differentiating ethanol as
vehicle fuel from potable beverage alcohol for taxation purposes,
by adding of small amounts of unpleasant or poisonous substances
- denaturants.
First generation biofuels
These fuels are characterised by the fact that only parts of the
source plant are used for biofuel production. The next-generation
(or second generation) biofuels use nearly the whole plant,
including waste, for biofuel production. The process technology for
second generation fuels is generally more complex.
Biofuel Cities – Technical guidance for biofuels
108 Glossary
Fischer-Tropsch process (or Fischer-Tropsch
Synthesis)
A catalysed chemical reaction in which synthesis gas (syngas), a
mixture of carbon monoxide and hydrogen, is converted into liquid
hydrocarbons of various forms. Biodiesel is one example.
GHG balance
Green house gases are gases causing the greenhouse effect. The
greenhouse gases taken into account in this report are carbon
dioxide, CO2, nitrous oxide, N2O and methane, CH4.
GMO
A genetically modified organism
Hydrophilic
The chemical property to attract water. The opposite, to reject
water, is called hydrophobic.
Hydrous alcohol
Alcohol that contains some water and usually has a purity of 96%
PM
Particulate Matter, which has a negative effect on health when
inhaled into the body.
Syngas (from synthesis gas) The name given to a gas mixture that contains varying amounts of
carbon monoxide and hydrogen generated by the gasification of a
carbon-containing fuel to a gaseous product with a heating value.
WTW
Abbreviation for well-to-wheel, i.e. the life cycle of a fuel. WTW is
equal can be expressed as WTT plus TTW (well-to-tank and tank-
to-wheel).
Biofuel Cities – Technical guidance for biofuels
109Glossary
SME
Sunflower methyl ester
REE
Rape seed ethyl ester
RME
Rape seed methyl ester
Biofuel Cities – Technical guidance for biofuels
110 Appendix I
Appendix I
Methodology to calculate
greenhouse gas, GHG,
reductions 1. 1. Greenhouse gas emissions from the production and
use of transport fuels, biofuels and other bioliquids shall
be calculated as134:
E = eec + el + ep + etd + eu – eccs - eccr – eee,
where
E = total emissions from the use of the fuel;
eec = emissions from the extraction or cultivation
of raw materials;
el = annualised emissions from carbon stock
changes caused by land use change;
ep = emissions from processing;
etd = emissions from transport and distribution;
eu = emissions from the fuel in use;
eccs = emission savings from carbon capture and
sequestration;
eccr = emission savings from carbon capture and
replacement; and
eee = emission savings from excess electricity
from cogeneration.
Emissions from the manufacture of machinery and
equipment shall not be taken into account.
2. Greenhouse gas emissions from fuels, E, shall be
expressed in terms of grams of CO2 equivalent per MJ of
fuel, gCO2eq/MJ.
3. In exception to paragraph 2, for transport fuels, values
calculated in terms of gCO2eq/MJ may be adjusted to
134 21.1.2008, Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on the promotion of the use of energy from renewable sources, Commission of the European Communities, 2008/0016, Brussels, Belgium
Biofuel Cities – Technical guidance for biofuels
111Appendix I
take into account differences between fuels in useful
work done, expressed in terms of km/MJ. Such
adjustments shall only be made where evidence of the
differences in useful work done is provided.
4. Greenhouse gas emission savings from biofuels and
other bioliquids shall be calculated as:
SAVING = (EF – EB)/EF,
where
EB = total emissions from the biofuel or other
bioliquid
EF = total emissions from the fossil fuel
comparator.
5. The greenhouse gases taken into account for the
purposes of paragraph 1 shall be CO2, N2O and CH4. For
the purpose of calculating CO2 equivalence, these gases
shall be valued as follows:
CO2: 1
N2O: 296
CH4: 23
Biofuel Cities – Technical guidance for biofuels
112 Appendix II
Appendix II
Standard for biofuels – standard and properties for Pure Plant Oil, PPO
The flashpoint of PPO is significantly higher than that of fossil
diesel. It lies at around 240 °C and is therefore particularly safe in
storage and transport and easy to handle. Consequently, in
Germany for example, PPO is not included in any hazard classes
according to the “Ordinance for Flammable Liquids”. PPO is
biodegradable in a short time in soil and waters and e.g. in
Germany, it is not classified in any water hazard class. Parameters
of PPO in comparison with fossil diesel are shown in Table 19,
below.
Source:
Rutz D., Janssen R., January 2008,
Biofuel Technology Handbook, 2nd Version,
WIP Renewable Energies, Germany
Density
[kg/l]
Viscosity
[mm²/s]
Flashpoi
nt [°C]
Caloric
value [at
20°C
MJ/kg]
Caloric
value
[MJ/l]
Cetane-
number
Fuel-[l]
Diesel 0.84 5 80 42.7 35.87 50 1
PPO -
Rapeseed
oil
0.92 74 317 37.6 34.59 40 0.96
Table 19 Parameters of PPO in comparison with fossil diesel
Standard for PPO from rapeseed oil, DIN 51 605 - German
Rapeseed Oil Fuel Quality Standard is shown in Table 20.
Source:
2008-08-28,
Biodiesel standards,
http://www.biofuelsb2b.com/useful_info.php?page=Biofuels_Stand
Biofuel Cities – Technical guidance for biofuels
113Appendix II
Limiting Value Testing Method Properties /Contents Unit min. max.
Density (15ºC) kg/m3 900 930 DIN EN ISO 3675 DIN EN ISO 12185
Flash Point by P.-M.
ºC 220 - DIN EN 22719
Calorific Value kJ/kg 35000 - DIN 51900-3
Kinematic Viscosity (40ºC)
mm2/S - 38 DIN EN ISO 3104
Low Temperature Behaviour - - -
Rotational Viscometer (testing conditions will be developed)
Cetane Number - - - Testing method will be reviewed
Carbon Residue Mass-% - 0.40 DIN EN ISO 10370
Iodine Number g/100 g 100 120 DIN 53241-1
Sulphur Content mg/kg - 20 ASTM D5453-93
Variable properties
Contamination mg/kg - 25 DIN EN 12662
Acid Value mg KOH/g - 2.0 DIN EN ISO 660
Oxidation Stability (110ºC)
h 5.0 - IS0 6886
Phosphorus Content
mg/kg - 15 ASTM D3231-99
Ash Content Mass-% - 0.01 DIN EN ISO 6245
Water Content Mass-% - 0.075 pr EN ISO 12937
Table 20 DIN 51 605 - German Rapeseed Oil Fuel Quality Standard
Biofuel Cities – Technical guidance for biofuels
114 Appendix II
Standards for biofuels –standard for biomethane
Biogas type A concerns biogas for engines without lambda
regulation, that is ’lean-burn’ engines used in heavy vehicles such
as trucks and buses. Type B concerns biogas for engines with
lambda regulation used in stochiometric combustion, for example in
private cars, although most heavy vehicles also have lambda
regulation today. Details from the Swedish standard for biogas for
vehicle fuel use, SS 15 54 38, is shown in Table 21. Other standards
around Europe can be found at http://www.iea-biogas.net/.
Source:
2007,
Basic data on biogas,
Svenska gasföreningen, Swedish Gas Association, Sweden
Property Unit Biogas, type
A
Biogas, type
B
Wobbe index MJ/Nm3 44.7 – 46.4 43.9 – 47.3
Methane content vol-% * 97±1 97±2
Water dew point at the highest
storage pressure (t = lowest
average daily temperature on a
monthly basis)
°C t - 5 t - 5
Water content, maximum Mg/ Nm3 32 32
Maximum carbon dioxide +
oxygen + nitrogen gas content, of
which oxygen, maximum
vol-% vol-
%4.0 1.0 5.0 1.0
Total sulphur content, maximum mg/ Nm3 23 23
Total content of nitrogen
compounds (excluding N2)
counted as NH3, max.
mg/ Nm3 20 20
Maximum size of particles µm 1 1
* at 273.15 K and 101.325 kPa
Table 21 Details of the Swedish standard for biogas as vehicle fuel, SS 15 54 38
Biofuel Cities – Technical guidance for biofuels
115Appendix II
Regulations for biomethane
injection Source for following information and quotes:
Polman, E.A., 21st September 2007,
Quality Aspects of Green Gas,
SenterNovem, Netherlands,
www.senternovem.nl/duurzameenergie/publicaties/publicaties_bio-
energie/kwaliteitsaspecten_groen_gas.asp
In 2003 an EU directive regarding biofuels (2003/55/EC) was
drawn up. In article 24 the following is noted:
“Member States should ensure that, taking into
account the necessary quality requirements, biogas
and gas from biomass or other types of gas are
granted non-discriminatory access to the gas
system, provided such access is permanently
compatible with the relevant technical rules and
safety standards. These rules and standards should
ensure, that these gases can technically and safely
be injected into, and transported through the
natural gas system and should also address the
chemical characteristics of these gases.”
Thus, there must be regulations drawn up in order to enable biogas
injection into the existing gas network. And several countries have
directives for biogas quality when blending it into the natural gas
network. The limit values for the contaminants are for the most
part comparable, but for some components e.g. CO2 and halogen
hydrocarbons there are significant differences in the limit values.
The injection of biogas derived from landfill gas is prohibited in
Switzerland, Austria and Germany. In Switzerland the addition of
LPG to biogas is also forbidden. In France, a special regulation is in
force through which an investigation into the health risks can be
requested by the authorities before biogas is allowed to be
injected. The limit of 6% for CO2 in the Dutch legislation is higher
than in the other countries. Outside the limits set by the Wobbe
index, it appears that there is absolutely no restriction to raising
Biofuel Cities – Technical guidance for biofuels
116 Appendix II
the level of 6%. This would give the biogas injectors more
possibilities in the separation of methane/ CO2 mixtures.
Biofuel Cities – Technical guidance for biofuels
117Appendix III
Appendix III
Comparison of standards –
comparison of bioethanol
standards Source for following information and tables:
December 31, 2007,
White paper on internationally compatible biofuels
standards,
Tripartite task force Brazil, European Union & United States of
America,
http://ec.europa.eu/energy/res/biofuels_standards/international_bi
ofuels_ standards.htm
During 2007 a tripartite task force consisting of representatives
from Brazil, EU and U.S. worked together and compared standards
for biofuels in order to reduce the potential handicap that lack of or
to differing standards for biofuels would be. Existing documentary
standards for biofuels would be reviewed and identification of areas
where greater compatibility could be achieved in the short and long
term would be made. The standards to be considered were those
produced by ABNT (Associação Brasilieira de Normas Téchicas),
ANP (Agência Nacional do Petróleo, Gás Natural e Biocombustíveis),
CEN and ASTM International and in effect before the end of 2007.
The Biodiesel Tripartite Task Force and the Bioethanol Tripartite
Task Force both comprised of representatives from the private and
public sectors. Below the U.S. and Brazilian standards are only
briefly described as a comparison to the EU documents.
U.S. The U.S. industry standard for bioethanol is “ASTM D 4806
Standard Specification for Denatured Fuel Ethanol for Blending with
Petrol for Use as Automotive Spark Ignition Engine Fuel.” The ASTM
has followed the premise that the only bioethanol to be used in the
marketplace as a petrol extender will be denatured, and hence the
specification D 4806 is for denatured fuel bioethanol. A separate
ASTM specification “ASTM D 5798 Specification for Fuel Ethanol
Biofuel Cities – Technical guidance for biofuels
118 Appendix III
(Ed75-Ed85) for Automotive Spark-Ignition Engine Fuel” is for fuel
bioethanol to be used in specially designated vehicles as a petrol
substitute. This Ed75-Ed85 fuel bioethanol is produced from
denatured bioethanol complying with the ASTM D 4806 standard,
and contains additional specifications for parameters applicable to
vehicles designed to operate with high percentages of bioethanol in
their fuel.
Brazil The most recent Brazilian standard for hydrous and anhydrous
bioethanol is Resolução ANP no. 36/2005. The use of bioethanol as
a blending component with petrol at high levels (20-25 vol %) or
as pure fuel (E100) in the domestic market for more than thirty
years has led to the development of materials compatible with their
characteristics, but has also determined the need for additional
controls in the specification, particularly on pH, ions and metals
which are reflected in the current specifications.
PROPERTY US Brazil EU
D 4806 D 4806 Undenatured Anhydrous Hydrous prEN 15376
Color
Dye Allowed, but not mandated
Dye Allowed, but not mandated
Dye mandated for in country, but not for export.
Dye prohibited for in country
Dye Allowed, but not mandated
Ethanol Content, vol %, min. 92.1 93.9 99.6(3) -- [96.8]
Ethanol + C3-C5 sat. alcohols, vol %, min -- [98.4](2) -- -- 98.8
Total Alcohol, vol %, min. -- [98.95] 99.6 95.1 [99.76]
C3-C5 sat. alcohols, vol %, max -- (1) [4.5] -- -- 2.0
Water content, vol %, max 1.0 1.05 [0.4] [4.9] 0.24
Density at 20C, kg/m3, max -- -- 791.5 807.6 --
Methanol, vol %, max 0.5 0.53 -- -- 1.0
Denaturant, vol %, min/max
1.96 / 5.0 No Denaturant
No Denaturant
No Denaturant
Set By Country 0/1.3
Biofuel Cities – Technical guidance for biofuels
119Appendix III
Hydrocarbons, vol %, max -- -- 3(4) 3(4) --
Solvent-washed gum, mg/100 mL, max 5.0 5.3 -- -- --
Gum or Resid by Evap, mg/100ml, max
5(washed gum) 5.3 (washed gum) --
5(unwashed)(5)
10 (unwashed)(5)
Electrical Conductivity, uS/m, max -- -- 500 500 --
Sulfate, mg/kg, max* 4 4.2 -- 4 Working
Inorganic Chloride, mg/kg, max 40. 42.1 -- 1 25
Copper, mg/kg, max 0.1 0.105 0.07 -- 0.1
Sodium, mg/kg, max -- -- -- 2 --
Iron, mg/kg, max -- -- -- 5 --
Acidity, mass % (mg/L), max
0.007 (56) 0.0074 (58.9)
0.0038 (30) 0.0038 (30) 0.007
pHe 6.5 – 9.0 6.5 – 9.0 -- 6.0 – 8.0 Dropped
Phosphorus, mg/L, max -- -- -- -- 0.5
Sulfur, mg/kg, max. 30. 5 -- -- 10
Appearance Clear & Bright Clear & Bright
Clear & No Impurities
Clear & No Impurities
Clear & Bright
(1) Not specified by can be calculated for US. (Heavy alcohol content = 100 - bioethanol content - methanol content - water content)
(2) Numbers in [ ] are calculated estimates and not specified limits
(3) Limit only applies to bioethanol not produced by fermentation from sugarcane or bioethanol contaminated by other types of alcohol
(4) Applies only to imported bioethanol
(5) Procedures are likely different.
Table 22 Bioethanol Specifications for U.S., Brazil and EU
The Bioethanol Tripartite Task Force considered relevant standards
and specifications, documents on the parameters and methods, and
commentaries on the similarities or differences of the
specifications. The U.S. denatured bioethanol standard was
converted to an undenatured basis so comparison could be made
with the undenatured standards of the EU and Brazil.
Biofuel Cities – Technical guidance for biofuels
120 Appendix III
Since bioethanol is a pure substance, the specifications are largely
about controlling the contaminants. There are some variations
among the specifications on the contaminants due to the differing
bioethanol levels in blended petrol. The three current specifications
have many similarities. A significant difference among the three
sets of standards is water content, which is set at different levels
primarily due to the varying bioethanol concentrations permitted in
petrol and the petrol distribution differences. For bioethanol, the
Task Force concluded that there is no technical specification that
constitutes an impediment to trade given the current situation. It is
recognised that additional drying and testing will be required by
Brazil and U.S. exporters wishing to supply the EU-market.
Biofuel Cities – Technical guidance for biofuels
121Appendix III
Comparison of standards –
comparison of biodiesel
standards Source for following information and tables:
December 31, 2007,
White paper on internationally compatible biofuels
standards,
Tripartite task force Brazil, European Union & United States of
America,
http://ec.europa.eu/energy/res/biofuels_standards/international_bi
ofuels_ standards.htm
During 2007 a tripartite task force consisting of representatives
from Brazil, EU and U.S. worked together and compared standards
for biofuels in order to reduce the potential handicap that lack of or
to differing standards for biofuels would be. Existing documentary
standards for biofuels would be reviewed and identification of areas
where greater compatibility could be achieved in the short and long
term would be made. The standards to be considered were those
produced by ABNT (Associação Brasilieira de Normas Téchicas),
ANP (Agência Nacional do Petróleo, Gás Natural e Biocombustíveis),
CEN and ASTM International and in effect before the end of 2007.
The Biodiesel Tripartite Task Force and the Bioethanol Tripartite
Task Force both comprised of representatives from the private and
public sectors. Below the U.S. and Brazilian standards are only
briefly described as a comparison to the EU documents.
Major differences between the standards are that the biodiesel
standards in Brazil and the U.S. are applicable for both fatty acid
methyl esters (FAME) and fatty acid ethyl esters (FAEE) and the
current European biodiesel standard is only applicable for fatty acid
methyl esters (FAME). The standards for biodiesel in Brazil and the
U.S. are used to describe a product that represents a blending
component in conventional hydrocarbon based diesel fuel, but the
European biodiesel standard describes a product that can be used
either as a sole diesel fuel or as a blending component.
Biofuel Cities – Technical guidance for biofuels
122 Appendix III
The present Brazilian biodiesel specification (Resolution ANP n°
42/04), released to support the preliminary activities of the
National Biodiesel Programme, was elaborated taking into account
the wide variety of feedstocks expected to be used in Brazil, as well
as the existing international experience and specifications (ASTM
D6751 and EN 14214). Several properties listed in the provisional
Brazilian specification still do not have established limits, but must
have values reported. Others have more flexible limits, to
accommodate feedstock diversity.
The first national biodiesel specification in the U.S. has been the
ASTM standard D 6751, “Standard Specification for Biodiesel Fuel
(B100) Blend Stock for Distillate Fuels, adopted in 2002, according
to www.dieselnet.com (2008-08-08). The D 6751 standard covers
biodiesel (B100) used as a blending component with petroleum
diesel fuels. No standards currently exist in the USA that would
cover neat biodiesel (B100) or biodiesel blends for use as
automotive fuels.
The tripartite task force found several parameters which differed so
much between the standards that they were categorised as
fundamental differences and was presumed not to be possible to
achieve a technical alignment of. Examples of those parameters are
sulphur content, cetane number, density and mono, di-, tri-
acylglycerides.
Biofuel Cities – Technical guidance for biofuels
123Appendix III
Comparison of standards –
comparison of biogas standards
Quality Requirements for Biogas in France, Austria, Switzerland,
Sweden, Germany and the Netherlands as presented in:
Polman, E.A., 21st September 2007,
Quality Aspects of Green Gas,
SenterNovem, Netherlands,
www.senternovem.nl/duurzameenergie/publicaties/publicaties_bio-
energie/kwaliteitsaspecten_groen_gas.asp
Physical Properties F A CH S D NL Unit
Calorific Upper Value 38.5 –
46.1
(H)
34.2 –
47.8
(L)
38.5 –
46.1
38.5 –
47.2
39.6 –
43.2
30.2 –
47.2
31.6 –
38.7
MJ/
m3n
Wobbe-index 49.1 –
56.5
(H)
43.2 –
46.8
(L)
47.9 –
56.5
47.9 –
56.5
45.4 –
48.6
37.8-
46.8
(L)
46.1-
56.5
(H)
43.46
–
44.41
MJ/
m3n
Qualities
Water dew point < -5 < -8
(40
bar)
60%
humidi
ty
< -60 Ground
temp.
< -10
(8 bar)
ºC
Water <32
mg/(n)
m3
Temperature (in the
injection gas)
-20 -
+20
0 – 40 ºC
Sulphur (in total) 30 10 30 23 30 45 mg/
m3n
Anorganically bonded
sulphur (H2S)
5 5 5 10 5 5 mg/
m3n
Biofuel Cities – Technical guidance for biofuels
124 Appendix III
Mercaptans 6 6 15 10 mg/
m3n
Odorant level (THT) 15-40 15-25 good > 10.
nomin
al 18
mg/
m3n
Ammonia none 20 3 mg/
m3n
Chlorine containing
Compounds
1 none none 50 mg/
m3n
Fluorine containing
compounds
10 none geen 25 mg/
m3n
Hydrogen Chloride (HCl) none 1 ppm
Hydrogen cyanide (HCN) none 10 ppm
Mercury 1 µg/ m3
Carbon monoxide (CO) 2 1 mol%
CO2 in dry gas networks
(max)
2.5 3 6 3 6 6 mol%
CO2 in wet gas networks n.a. Mol%
BTX (Benzene. Toluene.
Xylene)
500 ppm
Aromatic hydrocarbons 1 mol%
oxygen in dry gas
networks
0.01 0.5 0.5 1 0.5 0.5 mol%
oxygen in wet gas
networks
n.a.
Hydrogen 6 4 5 0.5 5 12 mol%
Methane number > 80
Methane >96 >96 >97 - mol%
Dust Techn.
free
< 1µm Techn.
free
Techn.
free
Siloxans < 10
(mg/m
3)
5 ppm
Table 23 Quality Requirements for Biogas in France, Austria, Switzerland,
Sweden, Germany and the Netherlands
Biofuel Cities – Technical guidance for biofuels
125Appendix IV
Appendix IV
Interviews Notes from interviews with users of biofuelled vehicles
Biofuel Cities – Technical guidance for biofuels
126 Appendix IV
Biofuel Cities – Technical guidance for biofuels
127Appendix IV
Biofuel Cities – Technical guidance for biofuels
128 Appendix IV
Biofuel Cities – Technical guidance for biofuels
129Appendix IV
Biofuel Cities – Technical guidance for biofuels
130 Appendix IV
Biofuel Cities – Technical guidance for biofuels
131Appendix IV
Biofuel Cities – Technical guidance for biofuels
132 Appendix IV
Biofuel Cities – Technical guidance for biofuels
133Appendix IV
Biofuel Cities – Technical guidance for biofuels
134 Appendix IV
Biofuel Cities – Technical guidance for biofuels
135Appendix IV
Biofuel Cities – Technical guidance for biofuels
136 Appendix IV
Biofuel Cities – Technical guidance for biofuels
137Appendix IV
Biofuel Cities – Technical guidance for biofuels
138 Appendix IV
Biofuel Cities – Technical guidance for biofuels
139Appendix IV
Biofuel Cities – Technical guidance for biofuels
140 Appendix IV
Biofuel Cities – Technical guidance for biofuels
141Appendix IV
Biofuel Cities – Technical guidance for biofuels
142 Appendix IV
Biofuel Cities – Technical guidance for biofuels
143Appendix IV
Biofuel Cities – Technical guidance for biofuels
144 Appendix IV
Biofuel Cities – Technical guidance for biofuels
145Appendix IV
Biofuel Cities – Technical guidance for biofuels
146 Appendix IV
Biofuel Cities – Technical guidance for biofuels
147Appendix IV
Biofuel Cities – Technical guidance for biofuels
148 Appendix IV
Biofuel Cities – Technical guidance for biofuels
149Appendix IV
Biofuel Cities – Technical guidance for biofuels
150 Appendix IV
Biofuel Cities – Technical guidance for biofuels
151Appendix IV
Technical guidance for biofuels Many demonstration projects with biofuels, both small and large
scale, have been performed in the EU in the last 15 years. Biofuels
have been introduced by fleet owners as municipalities, private
companies and public transport companies. This has lead to
increased knowledge about the use of biofuels. The aim of this
guide is to gather the knowledge about fuels that are used today.
The target group for the technical guide is interested fleet
managers and actors purchasing vehicles. The guide gives practical
and straight forward information on availability of fuels and
vehicles and knowledge on handling and distribution of the fuels. It
also includes user experiences, information on fuel standards and
sustainability issues.
The focus is on the biofuels available on a relatively large scale
today: bioethanol, biodiesel, Pure Plant Oil and biogas. Future
solutions as electricity, hydrogen and DME are covered briefly.
The Biofuel Cities European
Partnership is a forum for
the application of biofuels.
Open to all stakeholders in
the area of biofuels for
vehicles, it offers:
• www.biofuel-cities.eu -
your one-stop shop for
information on biofuels
application;
• online facilities, workshops
and study tours to
exchange and network with
your peers and learn from
experts;
• news, publications and
tools to provide
information, guidance and
support.
European Partnership
participants have full access to
all features. Participation is free
Join Biofuel Cities!
To join, register at
www.biofuel-cities.eu
or write to
for more information.