Conclusion

Due to the numerous environmental advantages that biodiesel

have over petroleum-based fuels, biodiesel production is
growing rapidly worldwide. However, in order to replace
conventional diesel and gasoline fuels, biodiesel as an
alternative liquid fuel should not only have superior
environmental benefits but also be economically competitive,
have relevant resources to meet energy demands, and have a
positive net energy balance ratio. This review shows biodiesel
as a cost-effective alternative to conventional diesel fuel with
the added environmental and performance benefits. Biodiesel
environmental impact depends on many production factors like
type of natural resources, type of technology applied,
operational practices, or methods of waste management.
Hence, good management of these factors is needed in order to
improve overall environmental impact of biodiesel. In order to
avoid unwanted environmental consequences, biodiesel
production should be sustainable, thus requiring the fulfillment
of certain environmental criteria like high GHG reduction
potential, good energy balance, higher crop yield per hectare,
and low water demand. However, ensuring environmentally
sustainable biodiesel production primarily requires that
sustainability standards cover direct and indirect effects on the
environment. From a practical point of view, air, water, soil and
crop protection, management of energy, water, nutrients and
agrochemicals, conservation of biodiversity and landscape, crop
cultivating, harvesting, processing and distribution, etc. are
points of interest where good environmental practices are
needed to address sustainable biodiesel production and its
further development. Finally, an important role in facilitating
environmentally sustainable biodiesel production have
provisions of laws, regulations, and other relevant documents
designed to ensure that production of biodiesel is
environmentally sustainable and produces real savings in GHG
and other emissions, to ensure the protection of biodiversity,
and to meet other sustainability requirements.
In addition to the substitution of bioethanol for gasoline,
replacing fossil diesel with biodiesel is currently the major
avenue for complying with the indicative EU targets that
demand biofuel shares of 2% in 2005 and 5.75% by 2010.The
rationale for these targets are potentially positive
environmental impacts, most notably the mitigation of climate
change through GHG abatement, con-servation of fossil fuels
and, hence, aspects of energy supply security, as well as
positive employment effects in the agricultural sector. At
present, however, neither bioethanol nor biodiesel are
competitive to conventional fuels in Europe. In many Member
States, therefore, tax exemption sand reductions are granted
for these biofuels in order to reach the indicative, yet not
mandatory, EU targets. In this paper, we have analysed the
environmental and economic aspects of rapeseed-based
biodiesel as a substitute for fossil diesel. First, a thorough
energy balance based on a variety of recent empirical studies
indicates that biodiesel does conserve part of the energy
contained in the replaced fossil diesel– but only by about two-
thirds, not 100%. Second, our net GHG balances
demonstratethatGHGsavingsfromusingbiodieselinsteadoffossild
ieselare around 60%. In fact , policy makers’ frequent positive
assessment of biodiesel appears to be mainly the result of the
strong emphasis on climate protection in today’s environmental
policy. The overall environmental balance of the substitution of
biodiesel for fossil diesel, however, is far from being
unequivocally positive, most notably due to laughing gas
emissions contributing to ozone depletion. In line with
politicians’ most important concern, we have focused on the
issue of climate change mitigation, rather than providing an
exhaustive cost-benefit analysis, which is an important
challenge for future research given the difficulty in quantifying
all environmental and economic impacts. Our major finding is
that biodiesel is far from being a cost-efficient emission
abatement strategy . Infact , with current GHG abatement cost
of about 200¤/t, biodiesel will not be fostered by the recently
launched European emission trading system, the primary and
widely accepted instrument for providing cost-efficient climate
protection. Therefore, biodiesel needs promotion measures
such as tax exemptions, which are perfectly in accord with
Directive 2003/96/EC. In 2004,total tax losses due to tax
exemptions for biodiesel in the
EU25wereashighas736Mill.¤,withGermanycontributingabout50
0Mill.¤. We have gauged that the EU25 tax losses may easily
increase up to 5 Bn ¤ by 2010. Furthermore, it has been
demonstrated that acreage requirements for biodiesel and
bioethanol production clearly exceed the available amount of
set-aside land in the EU25. The scarcity of arable land will
inevitably lead to increased competition for acreage. It appears
to be obvious that biofuel production will thus compete with
agricultural feedstock cultivation for food purposes. As a
consequence, prices of both rape oil and derived food products
may rise if rapeseed supply does not accelerate accordingly.
Therefore, we have suggested a variety of more efficient
alternatives for the abatement of GHG based on both
renewable and conventional technologies. Electricity
generation on the basis of fast-growing plants, such as poplar
and reed grass, for example, might be both a relatively cheaper
alternative in terms of abatement cost and an alternative
income source and employment support measure for the
agricultural sector. Limiting this kind of agricultural cultivation
precisely to the mandatory share of EU set-side land of 10%
would help to, first, avoid competition for acreage and, second,
contribute to the 22% share of renewable energy technologies
in electricity generation that is demanded by the European
Commission by 2020. However, supporting both biomass-based
electricity generation via feed-in tariffs and biofuels via tax ex
emptions at the same time, a sit is currently the case in
Germany, could lead to unnecessary competition for acreage
because of the fact that biomass based electricity and biofuel
generation are competing for the same biomass resources
(VIEWLS 2005:1). Rather than incurring substantial further
increases in tax losses up to 5 Bn ¤ due to the promotion of
biofuels in 2010, any government would be well advised to
spend only part of that amount of money in there search and
development (R&D) of future technologies, such as the Fischer
Tropsch synthesis, which would open the scope of raw
materials .Eventually ,successful R&D endeavors and high crude
oil prices may render advanced biofuels (BtL) a serious and
competitive option for Europe, whose CO2 emission reduction
potential also much higher than that of conventional biofuels,
amounting to 90% compared to replaced fossil fuels (VIEWLS
2005: 3)
The properties of biodiesel could be affected by seven
major factors, including (i) oxidation, (ii) thermal
decomposition or thermal fluctuations, (iii) water
absorption, (iv) biodegradation or microbial growth, (v)
exposure to sunlight/photo oxidation, (vi) metal
contamination and (vii) presence and absence of additives,
etc. Although the properties of as-received biodiesel meet
the given standard, many properties can deviate from the
standard once biodiesel is degraded.
• Although almost all types of vegetable oils can be used
to replace the diesel oil, however the rapeseed oil and
palm oil can be the most suitable oils which can be
used as diesel fuel extender.
• (2)
Vegetable oils alone can be used only for small
engines for a short-term period. For long-term use
and for heavy/big engines, blend of diesel and
vegetable oils is recommended.
• (3)
These vegetable oils should be used after proper
filtration, deguming and dewaxing. Proper quantities
of other chemicals.