All renewable fuels bear the "bio" label. However, having taken a closer look
at such fuels, DaimlerChrysler researchers have discovered that the designation
"bio" alone is inadequate.
So can biofuels help to significantly reduce CO2 emissions from motor
vehicles?
"Use of such fuels could turn out to be a big success, but this won’t
necessarily be the case," says Stefan Keppeler, a fuel specialist at
DaimlerChrysler Research. According to Keppeler, the designation "bio" is not in
itself an indication of quality with regard to climate protection.
Keppeler and his colleagues have taken a very close look at biofuels, and
what they’ve found gives them reason to be cautious. A completely objective
examination of these fuels, for example, reveals an extraordinary range of
ecological effects, whereby not every fuel with the "bio" label makes an
appropriate contribution to climate protection.
Keppeler and his colleagues found that increased use of biogenic fuels will
only noticeably improve the CO2 balance if the "right" biofuels are selected. In
turn that requires combining the most suitable organic material with the most
effective procedures for producing fuels of the highest quality.
Conversely, those who view the organic origin of a plant by itself as a
guarantee of environmental friendliness may find that they have grossly
miscalculated the ecological value of the resulting fuel.
Second-Generation Renewable Fuels
Although it hasn’t received much attention, the family of biofuels has
expanded significantly over the past few years: "Classic" fuels such as
biodiesel (widely available in Germany) and bioethanol (used in Brazil and North
America) have been joined by new types of renewable fuel, including synthetic
biomass-to-liquid (BTL) fuels and ethanol made from lignocellulose.
The newcomers, which are commonly referred to as "second-generation"
biofuels, are quite different from their predecessors.
Biodiesel, for example, is the result of chemical esterification of rapeseed
oil, and bioethanol is made in Brazil using sugar from sugar cane; in the United
States, it is made mainly from corn and soybeans.
Ethanol made from biomass (actually straw) is produced in a completely
different manner, however. This fuel is created through a complex two-stage
process in which the straw’s fibre material - consisting mainly of lignin
and cellulose - is initially transformed into sugar. A relatively simple
second process step then converts the sugar to ethanol.
BTL production also involves a two-step process: Here, the base
biomass - in the form of forestry thinnings or fuel crops - is
carbonized at a low temperature to form synthesis gas, which basically consists
of carbon monoxide and hydrogen. This gas can then be converted to a liquid fuel
(at present usually diesel) in a special reactor.
There are other major differences between the two generations of
biofuels:
1) The processes for making biodiesel and bioethanol - the
first-generation biofuels - utilize only a relatively small part of the
plant in question, such as the oil pressed out of the tiny black rapeseed (taken
from a plant that measures one metre high or more), or starchy buds taken from
wheat and rye. On the other hand, second-generation biofuels make use of the
entire plants - in other words, every fibre and cell, from the stem to the
flower, or from the tree root all the way to the very uppermost leaves. Because
of this difference, second-generation biofuels yield much more fuel per area of
cultivation than was possible with their predecessors.
2) First-generation renewable fuels also display a relatively poor CO2
balance, which is far removed from the theoretical maximum of 100 percent CO2
savings (also known as CO2 neutrality). The figure for biodiesel made from
oilseed rape doesn’t exceed 50 percent; for bioethanol, it can even be
significantly lower depending on the source plant. But with BTL diesel fuel it
is possible to reduce greenhouse gas emissions by as much as 95 percent. BTL
fuel is not entirely CO2-neutral, though. This is because energy from fossil
sources is still required for essential products like fertilizers and
pesticides, while fossil fuels are also needed for the transport of BTL fuels.
Nevertheless, the fuel comes very close to the ideal in terms of CO2
neutrality.
So why aren’t we seeing widespread use of second-generation biofuels? The
problem has to do with the state of development of the manufacturing processes
involved. Production techniques for first-generation biofuels are well advanced.
In Germany, for example, oilseed rape is being grown on an area totalling more
than one million hectares - all for the express purpose of producing energy. The
biodiesel produced as a result of these efforts accounts for 5.6 percent of
total diesel sales. But most experts believe that this figure will remain more
or less stagnant, because the area available for cultivation of the plant cannot
simply be expanded at will.
The situation is markedly different with regard to manufacturing processes
for second-generation biofuels. None of these fuels is available yet on the
market, at least not in any quantity worth mentioning. In addition, the
facilities needed to produce them are all demonstration or pilot plants. Due to
the limited production capacities involved, these facilities are a long way from
being economically feasible.
What’s more, the complex technology for converting lignocellulose into starch
or sugar is still in its infancy.
In other words, second-generation biofuels will not be able to play the role
their undisputed benefits warrant until the technologies for their production
can be applied on a major scale, and in a manner that yields financial returns.
This will require a tremendous amount of investment in research and development.
Biofuels at a Crossroads
Keppeler’s team examined two different renewable-fuel development strategies
for the period between now and 2030 - and the possible effects they might
have if implemented. Both of the scenarios assume similar basic conditions with
regard to the amount of land available for plant cultivation and set a European
Union biofuel share of 15 percent by 2030.
The difference between the two scenarios has to do with the underlying
assumptions regarding how biofuels will be further developed in Germany and in
other countries in Europe. The researchers presented two alternatives:
Scenario 1 assumes a gradual expansion of first-generation biofuels,
while second-generation fuels would receive comparatively lower levels of
funding, thereby ensuring a substantial time lag until they would be able to
take on a more important role.
Scenario 2 is much more ambitious: it suggests that governments and the
industrial sectors involved would significantly increase their commitment to,
and investment in, the development of economical methods for producing
second-generation renewable fuels. This would lead to a situation in which
second-generation fuels would account for a growing proportion of total biofuel
production, beginning around 2010. At the same time, Scenario 2 is based on the
assumption that the significance of first-generation biofuels would stagnate
over time, or in fact even decline.
A careful comparison of the two scenarios leads to three essential
conclusions.
1. As far as Scenario 1 is concerned, the intermediate objectives up to 2030
could only be achieved in Germany and other European countries for fuels
suitable for gasoline engines. The targets would be beyond reach for diesel
fuel. In particular, it wouldn’t be possible to achieve the long-term target of
producing 15 percent of diesel in Germany and throughout the entire European
Union from renewable resources. In fact, due to the limited land available, it
would be almost impossible to achieve a share of biodiesel greater than ten
percent.
2. The more ambitious Scenario 2 shows that consistent development of the
technologies for producing second-generation biofuels actually offers the
potential to significantly exceed the study’s targets. Based on their
calculations, the DaimlerChrysler researchers believe that if all the land now
available for biomass cultivation was used, it would be possible to achieve a
market share of slightly more than 20 percent for renewable fuels in the EU by
2030. In Germany, that figure would be even higher at 28 percent. This estimate
even takes into account the intense competition for biomass that is likely to
emerge as use of organic materials for generating electricity and heat continues
to increase.
3. The benefits offered by Scenario 2 are even more dramatic in terms of CO2
reductions, which would be double the reductions of Scenario
1.
But it’s a Big Investment
The indisputable benefits of the new biofuels do have their price - as
the DaimlerChrysler researchers found out. That’s because the investment that
would be required to make Scenario 2 a reality in Germany would total an
estimated 17.7 billion euros between now and 2030, compared to the 5.5 billion
euros that would have to be spent on biofuel production in line with Scenario
1.
As Keppeler is quick to point out, however: "The doubling of CO2 reductions
is just one benefit offered by second-generation biofuels. In addition, the
consistent use of renewable fuels is one of the few feasible approaches at the
moment that will enable us to break free of our nearly total dependence on crude
oil as the sole source of energy for our mobility."
Summarizing the main lesson learned from the scenarios, Keppeler says:
"Investment in the development of biofuels must be carried out with an open mind
toward the technologies employed. The criteria defining the energy policy goals
in relation to the fuel market should be clear. However, it’s crucial that no
single type of fuel is favoured."
Keppeler also believes there should be a level playing field with regard to
funding and tax policies throughout Europe. "My biggest nightmare would be
individual national regulations for 27 different types of fuels or fuel mixtures
in 27 different countries," he says.
Keppeler would also like to see tight controls on "bio" labelling.
"You can’t have a situation where rainforests are chopped down in Indonesia
so that we can produce biofuels here in Europe," he says.
According to Keppeler, DaimlerChrysler is working with the United Nations
Environment Program (UNEP) and the Worldwide Fund For Nature (WWF) to ensure
that such a situation never arises. The aim is to draw up sustainability
criteria governing the cultivation of biomass to be used in biofuels. These
criteria would then form the foundation for future biofuel certification
processes - and thus help to prevent "bio" labelling fraud.
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