Climate issues in focus
Contents
Foreword by Leif Johansson
Renewable fuels – an overview
Seven alternatives – with different prerequisites
Climate impact
Energy efficiency
Land use efficiency
Seven alternatives
Fuel potential
Vehicle adaptation
Fuel cost
Fuel infrastructure
Holistic view and interaction – the keys to success
Overview / Detailed evaluation
Glossary
4–5
6–7
8–9
10 – 11
12 – 13
14 – 15
16 – 17
18 – 19
20 – 21
22 – 23
24 – 25
26 – 27
28 – 29
30 – 31
CO2-neutral vehicles are powered by fuels produced
from renewable raw materials, such as biomass.
Since these materials do not add carbon dioxide to
the ecosystem, they have no impact on our climate.
3
Climate issues are among the major challenges of our times. And their resolution will require
concerted effort on the part of the corporate sector, public agencies and individuals, calling for
collaboration across national boundaries and between different industries.
The transport industry plays a crucial role in the development of society
and its economy. Vehicles are used to build our roads, lay water pipes,
and create the foundations of our homes. Vehicles are used to transport
people and goods, and to facilitate trade and travel. Despite this, we
recognise that the transport sector accounts for a high proportion
of the emissions that have adverse effects on our climate. At present,
approximately 14 percent of all greenhouse gas emissions are generated
by transport of various kinds.
Concern for the environment has been a Volvo priority since 1972.
Because of this, we naturally feel a particular responsibility for climate
issues. We have no hesitation in admitting that we are part of the problem.
And we also recognise that we are part of the solution. This bold and
optimistic assertion is based on the advances that have been achieved
to date in the areas of energy efficiency, hybrid technology and
alternative fuels.
Leif Johansson
CEO Volvo Group
4
One of the major advantages of the diesel engine – one of the most
efficient energy converters available to us today – is that it does not
have to use conventional diesel oil or other fossil-based fuels.
With the aid of sophisticated engine technology and minor modifications,
the diesel can be adapted to run on a wide range of renewable fuels that emit
no excess carbon dioxide when used to power a vehicle, whether a truck, bus,
wheel loader or boat.
What is needed now is to undertake the production and distribution of renewable
fuels on a major scale. International coordination between producers and
legislators is also required to develop uniform fuel standards and stable, longterm regulations, since neither trucks nor buses – no more than climate issues –
are constrained by national boundaries. Broad consensus at the highest levels
is needed to ensure the successful development of CO2-neutral transport and
assist our endeavour to be part of the solution.
In this brochure, we compare a number of renewable fuels for which we have
developed functional CO2-neutral demonstration vehicles, specifically trucks.
The Volvo Group is prepared to meet the challenge.
CO2-neutral transport is not just a utopian dream!
5
Renewable fuels – an overview
CO2-neutral vehicles do not add to greenhouse effect.
CO2-neutral vehicles are powered by fuels produced from renewable
raw materials, such as biomass. Unlike fossil fuels, CO2-neutral fuels
add no excess carbon dioxide to the atmosphere. The combustion
process generates exactly the same amount of carbon dioxide as that
absorbed by the source material during its growth, and no increase
in atmospheric carbon dioxide will result provided that crop regrowth
matches the quantities harvested.
Three crucial factors make the changeover to renewable fuels more
urgent than ever:
• Climate change
Our use of fossil fuels contributes to global warming which, in the long
term, will certainly have dramatic and unpredictable consequences for
life on Earth.
• Increased energy demand
Rapid economic development in populous countries, such as India
and China, is increasing the pressure on the crude oil market, which is
now at the limit of its production and refining capacity.
• Decline in finite resources
The Earth’s reserves of oil and other fossil fuels will eventually be
exhausted – the only question is when – and some observers believe
that oil production has already peaked. The price of oil will increase in
the long term and will also become unstable due to geopolitical factors.
6
7
Seven alternatives – with different prerequisites
The Volvo Group is studying and evaluating
all renewable fuels with potential for use in
the Group’s products.
In the following pages, we will examine a number of renewable fuels
based on what we regard as the seven most important criteria:
1. Climate impact
2. Energy efficiency
3. Land use efficiency
4. Fuel potential
5. Vehicle adaptation
6. Fuel cost
7. Fuel infrastructure
In each case, the fuel will be rated on a descending scale of five (best)
to one (worst). Production is considered from a European perspective.
Biodiesel
Biodiesel is produced by the esterification of vegetable oils. Rapeseed oil
and sunflower oil are the most common feedstocks in Europe. Biodiesel
can be mixed with conventional diesel fuel. The hydrogenation of vegetable
oils is another promising method of producing fuel for diesel engines.
Synthetic diesel
Synthetic diesel is a blend of synthetically generated hydrocarbons
produced by the gasification of biomass. Synthetic diesel can be blended
with conventional diesel oil without problem.
DME – Dimethylether
A gas that is handled in liquid form at low pressure, dimethylether (DME)
is produced by the gasification of biomass.
Biogas
Biogas is a gaseous fuel consisting mainly of the hydrocarbon methane.
Biogas can be extracted from sewage treatment plants, refuse dumps
and other sources of biologically degradable material. The fuel can also be
produced by biomass gasification. Since biogas, in this case compressed
to 200 bar, must be burned in a spark-ignition engine, its energy efficiency
is lower.
Biogas + Biodiesel
Supplied by separate tanks and injection systems, biogas and biodiesel
are used in combination. A small percentage (10 percent) of biodiesel
(or synthetic diesel) is used to achieve compression ignition. In this option,
biogas is used in cooled, liquid form.
Hydrogen + Biogas
Methanol/Ethanol
Methanol is a product of biomass gasification, while ethanol is produced
by fermentation from crops with a high sugar or starch content. Research
into the production of ethanol from cellulose is under way at present.
Evaluation includes methanol/ethanol with an ignition additive.
8
Feedstock
Hydrogen gas can be mixed with biogas in low concentrations, in this
case 8 percent by volume. Higher concentrations are also possible.
Hydrogen gas can be produced by biomass gasification or electrolysis
of water using renewable electricity. A spark-ignition engine is required.
Process
Fuel
Esterification
Biodiesel
Wheat
Sugar beet
Straw
Hydrolysis &
fermentation
Ethanol
Waste wood
Gasification
Hydrogen
Rapeseed
Rapeseed oil
Sunflower
Sunflower oil
Farmed wood
Organic waste
Sewage
Dimethylether
Anaerobic
digestion
Manure
Methanol
Synthetic diesel
Biogas
Fuels available from different feedstocks.
Esterification is a chemical process in which the properties, particularly
the stability, of raw vegetable oils are improved.
Fermentation is a biological process in which material containing sugar
is broken down into ethanol and carbon dioxide. For use as a feedstock,
cellulose must first be hydrolysed into sugar using enzymes or acids.
Gasification means that organic material, such as biomass, is converted
into synthetic gas, which is a mixture of hydrogen gas and carbon monoxide.
The synthetic gas is then used to produce various synthetic fuel components.
Anaerobic digestion is a biological process in which organic material
is broken down, primarily into methane and carbon dioxide.
9
Climate impact
Carbon dioxide emissions for complete
‘well-to-wheel’ chain.
Although the calculations refer to fully renewable
raw materials, fossil fuels are currently used in
the cultivation and production.
In future, it will be possible to replace this fossil energy with renewable
energy, although at reduced efficiency.
Greenhouse gas emissions are reported as CO2 equivalents. In other words,
emissions of greenhouse gases other than carbon dioxide are converted to
the equivalent quantities of carbon dioxide.
The five-interval scale shows the reduction in CO2 emissions compared
with conventional diesel fuel. Non-fossil CO2 emissions are not included
since they do not produce a net increase in atmospheric carbon dioxide.
Biodiesel
Synthetic diesel
DME – Dimethylether
Methanol/Ethanol
Methanol/Ethanol
Biogas
Biogas+Biodiesel
Hydrogen+Biogas
Five of the options reduce the impact on the climate by over 90 percent.
In the case of methanol, gasification of black liquor is required to achieve
the highest rating.
In the case of biogas and hydrogen+biogas, biomass gasification is required
to achieve the highest rating. The lower rating applies if the biogas is produced
by anaerobic digestion of household waste.
Ethanol offers a reduction of 0 to 75 percent depending on the production method.
‘Well-to-wheel’ means that all relevant stages of the fuel chain
are considered. This includes the cultivation (including fertilisation)
and harvesting of the raw material, its transport to the fuel production
plant, production and distribution of the fuel to refuelling stations,
and its use in vehicles.
91-100% reduction
76-90% reduction
51-75% reduction
26-50% reduction
0-25% reduction
10
Source: EUCAR/CONCAWE/JRC and AB VOLVO
11
Energy efficiency
Total ‘well-to-wheel’ energy utilisation of a fuel.
In this instance, energy efficiency is rated on
a decreasing scale and is expressed as a
percentage indicating the proportion of energy
reaching the vehicle’s driven wheels.
For purposes of comparison, it may be noted that the fossil diesel oil used
today delivers an overall efficiency of approximately 35 percent. This relatively
high value is due to the fact that crude oil may be regarded as a ‘semi-finished’
product, making the production of diesel very energy-efficient.
The results for the same fuel may vary depending on the production
process used.
Biodiesel
Synthetic diesel
DME – Dimethylether
Methanol/Ethanol
Methanol/Ethanol
Biogas
Biogas+Biodiesel
Hydrogen+Biogas
DME and methanol are rated highest when produced from black liquor from
the wood pulp industry. The higher rating for synthetic diesel is also based on
the gasification of black liquor.
The ratings for biogas, biogas+biodiesel and hydrogen+biogas are based on
production by gasification and anaerobic digestion. However, the production
of biogas by black liquor gasification is not included.
The low rating of ethanol is due to the high energy utilisation in the cultivation
and fuel production processes.
Over 22%
20-22%
17-19%
14-16%
Under 14%
12
Source: EUCAR/CONCAWE/JRC and AB VOLVO
13
Land use efficiency
Scarcity of land resources makes the efficient use of land
a particularly important issue.
Efficient land use will be an increasingly
important factor in meeting the world’s
ever-growing demand for food and fuel.
Driving distance per hectare per year is a measure of the performance
of biofuel. The yield per hectare for each crop has been calculated using
figures for average yields from good quality land. The rating scale indicates
the distance per hectare that a heavy truck can cover annually.
Growth is based on Swedish conditions. Although crop cultivation in other
locations may yield different results, the relativities are more or less the same.
The quantity of fuel/energy used in harvesting, production, transport etc.
is subtracted from the quantity produced. Results for the same fuel may vary
depending on the production process used.
Biodiesel
Synthetic diesel
DME – Dimethylether
Methanol/Ethanol
Methanol/Ethanol
Biogas
Biogas+Biodiesel
Hydrogen+Biogas
DME and methanol based on black liquor gasification receive the highest
rating. Harvest yields are high, only small quantities of fossil fuels are required
and the fuels have a high energy efficiency.
Synthetic diesel also benefits from high harvest yields and low fossil fuel
consumption; however, its energy efficiency is lower and the selectivity in
production is limited.
Ethanol receives a low rating because of its limited energy efficiency and,
in certain instances, high fossil energy requirement.
Biodiesel is rated lowest due to low average harvest yields and very high fossil
energy utilisation.
Over 10 000 km
Biogas produced by black liquor gasification is not included.
7 501-10 000 km
5 001-7 500 km
2 500-5 000 km
Under 2 500 km
14
Source: EUCAR/CONCAWE/JRC, University of Lund, EU RENEW project and AB VOLVO
15
Fuel potential
The amount of fuel that can be produced varies
considerably depending on the particular option.
The availability of raw material and the choice
of production process determine the amount
of fuel that can be produced.
While some processes can use many different feedstocks and complete crops,
others are limited to parts of individual crops. Competition from food production
is a general problem with feedstocks derived from agricultural products.
According to a study by EUCAR/CONCAWE/JRC, the potential availability
of waste wood, farmed wood, and straw in the EU in 2012 will be approximately 700 TWh (Terawatt-hours) per year, while that of sunflower oil and
rapeseed oil will be an estimated 80 TWh per year. The amount of fossil
fuel that can be replaced by biomass varies depending on the efficiency
of the fuel production process and the end use.
Since biomass potential in the EU in 2012 will not be sufficient to replace
fossil fuels, further initiatives and dedicated measures will be required to
increase the proportion. In the longer term, it will be possible to replace fossil
fuels in significant quantities provided that the right options are chosen.
Importing biomass from regions with better cultivation conditions is
a further possibility.
350-420 TWh
280-349 TWh
210-279 TWh
140-209 TWh
70-139 TWh
18
Biodiesel
Synthetic diesel
DME – Dimethylether
Methanol/Ethanol
Methanol/Ethanol
Biogas
Biogas+Biodiesel
Hydrogen+Biogas
The 350-420 TWh range is equivalent to approximately 10-12 percent of the
predicted demand for petrol and diesel in the EU in 2015.
DME, methanol, biogas, biogas+biodiesel and hydrogen+biogas receive
the highest rating.
Synthetic diesel, DME, methanol, and biogas can all be produced from complete
crops, wood feedstocks or other biological materials; however, synthetic diesel
has a lower energy efficiency and yields a lower proportion of fuel for vehicle use.
Household refuse and sewage can also be used in the production of biogas.
Ethanol can be produced from a number of feedstocks, including waste
wood and other biological materials containing cellulose, although at a relatively
low efficiency.
Biodiesel, which has the lowest rating, is produced from vegetable oils, such as
rapeseed oil and sunflower oil. Its availability is limited since rapeseed can only
be grown on the same land every fourth or sixth year, while only the oil in the
seeds can be used as fuel.
Source: EUCAR/CONCAWE/JRC and AB VOLVO
19
Vehicle adaptation
Different fuels require different types of vehicle adaptation.
The following is an overall assessment of the
technical complexity of adapting vehicles to use
the new fuels.
Assessment includes the effects of various parameters – such as maximum
engine performance, increased weight and range between refuelling – on
vehicle efficiency. The last of these, for example, may affect vehicle payload.
The complexity of adaptation includes factors that necessitate additional
fuel storage capacity, and require new and more expensive components,
as well as the technology needed to meet future emission standards.
As an example, some fuels require more advanced emission control
systems than others.
Biodiesel
Synthetic diesel
DME – Dimethylether
Methanol/Ethanol
Methanol/Ethanol
Biogas
Biogas+Biodiesel
Hydrogen+Biogas
Biodiesel and synthetic diesel receive the highest rating. Vehicles powered
by these fuels are essentially comparable with conventional diesels. However,
biodiesel necessitates more service and generates higher nitrogen oxide emissions.
Although the lower energy content of DME reduces vehicle range by 50 percent,
the fuel can still be used for long-haul transport. While it requires a unique and
advanced fuel system, DME also offers savings in terms of the cost and weight
of exhaust silencing and post-treatment systems.
Suitable for all heavy applications; no special vehicle
adaptation required.
The lower energy content of ethanol reduces the range of the vehicle by
30 percent per tank of fuel.
Suitable for most applications; no expensive or extensive
vehicle adaptation required.
Although biogas+biodiesel offers maximum engine performance, vehicle range
is cut by half if the gas is in liquid form. In addition, two separate fuel systems
are required.
Suitable for most applications; expensive and extensive
vehicle adaptation required.
Suitable for up to half of all applications; complex,
expensive and extensive vehicle adaptation required.
Biogas and hydrogen+biogas require an Otto engine, which limits power
output. The low energy density of the compressed gas limits the range of the
vehicle to approximately 20 percent of that of a diesel. Cost and weight are
increased by a complex fuel tank system.
Suitable for only a limited number of applications;
major, expensive and extensive vehicle adaptation required.
20
21
Fuel cost
‘Well-to-tank’ production cost.
Evaluation includes raw material costs, fixed
and variable production costs, transport and
infrastructural costs, and the cost of energy
utilisation in the distribution chain.
In general, future costs are difficult to predict due to fluctuations in raw
material prices and the rapid pace of technological development. In many
cases, the cost of producing a fuel is only a small element of the price
to the end user, due to taxes and other charges.
Biodiesel
Synthetic diesel
DME – Dimethylether
Methanol/Ethanol
Methanol/Ethanol
Biogas
Biogas+Biodiesel
In these examples, the cost of the particular fuel is compared with that
of conventional diesel oil, assuming a crude oil price of USD70 per barrel
(excluding taxes). Comparison is made on a per-litre equivalent basis.
This means that over a litre of fuel is required in some cases to obtain
the same energy content as a litre of diesel.
DME and methanol receive the highest rating. These are already cost-competitive
when produced from black liquor; however, production by gasification of forest
products or farmed wood is more expensive.
The results for the same fuel may vary depending on the feedstock used.
Biodiesel is about 60 percent more expensive than conventional diesel.
Hydrogen+Biogas
In the case of biogas and hydrogen+biogas, biogas based on waste materials
is the most cost effective, due mainly to low feedstock cost.
In the case of biogas+biodiesel, biogas in liquid form is approximately 25 percent
more expensive than compressed biogas.
Biogas produced by gasification of black liquor is not included in the summary.
Cheaper than diesel from crude oil.
0 to +19% more expensive.
+20 to +59% more expensive.
Synthetic diesel is the most expensive fuel due to high capital costs and
the relatively low energy efficiency of production.
Ethanol is generally expensive to produce. Production from forest products
is the most expensive process.
+60 to +99% more expensive.
+100 to +140% more expensive.
22
Source: EUCAR/CONCAWE/JRC and AB VOLVO
23
Fuel infrastructure
Handling and distribution.
Infrastructure is an important criterion in terms
of how quickly and easily a new fuel can be
introduced and integrated with existing systems.
As such, it is often regarded as the greatest
challenge to the introduction of an alternative fuel.
Biodiesel
Synthetic diesel
DME – Dimethylether
Methanol/Ethanol
Methanol/Ethanol
However, it should be noted that since the infrastructure for conventional
fuels is also in need of major investment, infrastructure is a secondary issue
in the longer term.
Biogas
This evaluation also takes into account the safety and environmental
aspects of handling the fuel within the infrastructure.
Hydrogen+Biogas
Biogas+Biodiesel
Synthetic diesel receives the highest rating. The fuel can easily be mixed
with conventional diesel oil without compromising established standards and
specifications. Specific measures are required in the case of biodiesel due
to the lower stability of the fuel in storage.
When used in pure form, methanol and ethanol require corrosion-resistant
materials, additional fire safety measures and a separate infrastructure.
Due to the significant health hazards involved, methanol should be handled
in completely closed systems.
No changes (liquid fuel).
Minor changes (liquid fuel).
Major changes (liquid fuel).
Gas handled in liquid form at low pressure.
DME is a gas at room temperature and atmospheric pressure. In a vehicle,
the fuel is used as a liquid at a pressure of 5 bar. The distribution infrastructure
for DME is similar to that of liquefied petroleum gas (LPG). DME is heavier
than air and can accumulate in the event of leakage, creating a fire hazard.
Biogas is handled at high pressure (200 bar) and requires the same infrastructure
as that currently used to distribute natural gas.
The infrastructure required for hydrogen is the most expensive and complex
of all since hydrogen must be handled at an even higher pressure than biogas.
Gas handled under high pressure or in
liquid form at low temperature.
24
25
Holistic view and interaction – the keys to success
This brochure emphasises the importance of a holistic view, and of interaction between
the various players involved in the analysis and selection of the biofuel of the future.
All renewable fuels have the potential to reduce climate emissions from
the transport industry by a significant amount. As one of the world’s leading
manufacturers of heavy trucks, buses, construction machines and diesel
engines, Volvo is willing and able to shoulder its share of responsibility
for climate issues by developing engines designed to use renewable fuels.
As outlined in these pages, all renewable fuels have their advantages
and disadvantages and, as a vehicle manufacturer, we would encourage
joint evaluation in choosing the fuel of the future.
One aspect of renewable fuel production not discussed in this brochure is
how the necessary crops are cultivated – a conscious omission since this
is a general criterion that does not apply to specific fuels. However, this is
not to suggest that it is unimportant – quite the opposite. It is very important
that the methods used to grow biomass for renewable fuels are sustainable
in the long run, otherwise the advantages may be lost. It is also important
that our common interest in developing CO2-neutral transport does not
interfere, for example, with food production.
Volvo has already demonstrated its ability to develop vehicles for all of
the renewable fuel options discussed here. However, the development of
carbon dioxide-neutral transport will not happen of its accord – nor can we
do it alone. Making CO2-neutral transport a reality will require the active
participation of politicians, government agencies and fuel producers.
Politicians and government agencies must take international decisions,
at European level or higher, to enable stable, long-term regulations to be
implemented, while fuel producers must provide the answers as to when
production and distribution can begin.
The availability of biofuels is another crucial factor. Even if current
production resources are expanded rapidly, availability will be limited for
a number of years to come. For this reason, the best and most logical
solution in the short term is to blend the biofuels now available with today’s
fossil fuels. This can be initiated immediately, does not call for extensive
technical modifications or a new infrastructure, and offers immediate
environmental benefits.
26
In the longer term, the feasibility of developing CO2-neutral transport will be
influenced greatly by ongoing efforts to improve energy efficiency, the introduction of hybrid technology on a wide scale and technological advances in
fuel production. Neither we in the Volvo Group nor anybody else knows with
certainty when or in what quantities CO2-neutral fuels will become available;
nevertheless, we feel that there is reason for optimism.
In the company’s experience, developments that appear impossible at a
given point in time often become a reality several years later. Since this has
been the case in other environment-related areas, such as exhaust gas
emission control, energy efficiency and hybrid technology, the Volvo Group
is fully confident that developments in CO2-neutral transport will ultimately
prove successful.
27
Overview and detailed evaluation
Detailed evaluation of fuels
Summary of results for different criteria and fuels.
Detailed summary of figures used to evaluate
fuels in accordance with specified criteria.
Climate
impact
Energy
efficiency
Land use
efficiency
Fuel
potential
Vehicle
adaptation
Fuel
costs
Fuel
infrastructure
Climate impact
Energy efficiency (well-to-wheel)
Index
Efficiency
Production is considered from a European
perspective.
Biodiesel
Methanol/Ethanol
+
Bi
od
ie
H
se
yd
l
ro
ge
n+
Bi
og
as
Bi
og
as
Bi
og
as
Et
ha
no
l
M
et
ha
no
l
Bi
od
H
ie
yd
se
ro
l
ge
n+
Bi
og
as
Bi
od
ie
se
Sy
l
nt
he
tic
D
di
M
es
E
el
–
Di
m
et
hy
le
th
er
Methanol/Ethanol
Bi
og
as
Typical value
+
Worst case
Bi
og
as
Best case
Et
ha
no
l
DME – Dimethylether
Co
nv
en
tio
na
ld
ie
se
l
Bi
od
ie
Sy
se
nt
l
he
tic
D
M
di
E
es
–
el
Di
m
et
hy
le
th
er
M
et
ha
no
l
Synthetic diesel
Land use efficiency
Fuel potential (EU 2012)
Fuel cost relative to fossil diesel
Km/hectare/year
TWh
Cost increase
Biogas
Biogas + Biodiesel
28
*Ignition additive not included
+
Bi
od
ie
H
se
yd
l
ro
ge
n+
Bi
og
as
Bi
og
as
Bi
og
as
Et
ha
no
l*
Bi
od
ie
se
Sy
l
nt
he
tic
D
di
M
es
E
el
–
Di
m
et
hy
le
th
er
M
et
ha
no
l*
Bi
od
ie
H
se
yd
l
ro
ge
n+
Bi
og
as
Bi
og
as
+
Bi
og
as
Et
ha
no
l
M
et
ha
no
l
Bi
od
ie
se
Sy
l
nt
he
tic
D
di
M
es
E
el
–
Di
m
et
hy
le
th
er
+
Bi
od
ie
H
se
yd
l
ro
ge
n+
Bi
og
as
Bi
og
as
Bi
og
as
Et
ha
no
l
M
et
ha
no
l
Bi
od
ie
se
Sy
l
nt
he
tic
D
di
M
es
E
el
–
Di
m
et
hy
le
th
er
Hydrogen+Biogas
29
Glossary
Anaerobic digestion
A biological process in which organic material
is broken down, mainly into methane and carbon
dioxide.
Atmospheric pressure
Normal air pressure at sea level (approx. 1 bar).
Biomass
Biological material from which energy can be
extracted.
Black liquor
A high-energy residual product of chemical paper
pulp manufacture whose energy content is normally recovered by burning.
Carbon dioxide-neutral
transport
CO2-neutral transport is achieved by means of vehicles powered by fuels produced from renewable
feedstocks, such as biomass, that add no excess
carbon dioxide to the atmosphere.
Cellulose
The principal component of plant cell walls.
Approx. 40-50 percent of wood consists of cellulose.
Climate impact
Activities that affect the climate; in this context,
mainly greenhouse gas emissions.
CO2
Carbon dioxide.
CO2 equivalents
The result of conversion of a greenhouse gas into
the equivalent amount of carbon dioxide with the
same greenhouse effect.
Compressed biogas
Biogas compressed to approx. 200 bar.
Compression ignition
The process in which the fuel in a diesel engine
is ignited by the high temperature – produced by
compression in the cylinder.
30
Diesel engine
An engine in which the air/fuel mixture self-ignites
under high compression.
Electrolysis
The breakdown of a substance using electrical
current; in this context, the breakdown of water
into hydrogen and oxygen.
Energy efficiency
In this context, the proportion of the input energy
that reaches driven wheels of the vehicle.
Esterification
A chemical process in which raw vegetable oils are
converted into esters and given enhanced physical
properties, particularly greater stability.
EUCAR/CONCAWE/JRC
Fermentation
EUCAR – European Council for Automotive
Research and Development
CONCAWE – Oil Companies´ European
Organisation for Environment, Health and Safety
JRC – Joint Research Center of the European Commission. http://ies.jrc.cec.eu.int/index.php?id=346
A biological process in which a material with a
sugar content is broken down into ethanol and
carbon dioxide. When cellulose is used as a feedstock, decomposition (hydrolysis) into sugar must
first be carried out using enzymes or acids.
Gasification
A process in which an organic material, such
as biomass, is converted into synthetic gas,
a mixture of hydrogen gas and carbon monoxide.
The synthetic gas can then be used to produce
various synthetic fuel constituents.
Ignition improver
A fuel additive that improves the compression
ignition in a diesel engine.
Liquid biogas
Biogas liquefied by cooling to approx. -165ºC.
Gasification of
black liquor
Black liquor from pulp mills can be gasified and
used to produce synthetic vehicle fuels such as
methanol, DME and synthetic diesel. In the pulp
mill, the energy content of the black liquor is replaced
using low-grade biomass, which is burned.
Methane (CH4)
The simplest type of hydrocarbon, and the primary
constituent of biogas and natural gas.
Otto engine
An engine in which the air/fuel mixture is ignited
by a spark plug.
Renewable electricity
Greenhouse effect
Long-wave radiation is prevented from escaping
the Earth’s atmosphere by greenhouse gases,
contributing to higher temperatures on the planet’s
surface.
Electricity produced from a renewable energy
source, primarily hydro, biomass and wind.
Renewable fuel
A fuel produced from a renewable source,
such as biomass, hydro, wind or solar energy.
Well-to-wheel
A concept in which all relevant stages of the fuel
chain are considered. This includes the cultivation
(including fertilisation) and harvesting of the raw
material, its transport to the fuel production plant,
production and distribution of the fuel to refuelling
stations, and its use in vehicles.
Greenhouse gases
Gases that contribute to the greenhouse effect;
in this context, primarily carbon dioxide of fossil origin.
Hybrid technology
Propulsion technology for vehicles based on
two different energy converters, such as a diesel
engine and an electric motor. Braking energy can
be stored and returned to the electric motor.
Hydrocarbon
A chemical compound of carbon and hydrogen.
Fossil energy
Non-renewable energy from earlier geological
periods, primarily oil, coal and natural gas.
Hydrogenation
The treatment of plant oils or animal fats, primarily
with hydrogen gas in a refining process, for the
production of synthetic hydrocarbons.
Fossil fuels
Fuels based on fossil energy, primarily oil, coal
and natural gas.
Hydrolysis
A chemical process in which a molecule is broken
down following the addition of a water molecule.
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