Environmental Engineering Reference
In-Depth Information
Ideally, such oil alternatives should reduce (or even remove) the dependence of
oil as well as contributing as much as possible to meet the GHG emissions target.
However, it is also widely accepted that joint efforts from politics, regulators, sci-
entists and consumers will be needed to support an independent oil/GHG controlled
scenario in the future.
On the view of the predictions, the need for a secure energy supply for trans-
portation make essential to explore biofuels as alternative to mineral oil based
fuels addressing and evaluating socio-economic and environmental consequences
originated in their implementation.
From a wider context, there are three main drivers for the promotion, develop-
ment and implementation of biofuels in our society. In principle, these are energy
independence, climate change and rural development [3]. The political motivation
to support biofuels arises from each individual driver or combinations of them.
The main theoretical reasons for the promotion of biofuels can be summarised as
follows:
1.
Biofuels can improve independence and energy security
. Local, national or
global production of energy can avoid the reliance on politically and/or socially
unstable energy suppliers [7]. In addition, the global oil demand is increasing
exponentially and there is a need to find alternatives to fossil fuels derived from
petroleum.
2.
Biofuels may contribute to a reduction in carbon emissions (aka climate change
mitigation).
They have been often considered a solution to climate change. In
fact, net emissions from biofuels have been reported to be remarkably lower
than those generated from the combustion of fossil fuels [8, 9]. Nevertheless,
the GHG emissions from the production of biofuels are a key issue that needs
careful attention as they arise from every single stage in the supply chain from
feedstock production and transport to conversion, biofuels distribution and end
use (Fig. 8.2). Recently, some studies point out the CO
2
reduction may be
far less than originally thought due to the inclusion of crop production costs
including fertilisers, machinery, etc. as well as harvesting, transformations and
distribution [3].
3.
Biofuels can help to increase farm income and contribute to rural development.
With a growing biofuels market, many countries will be able to grow more type
of crops to cover national or foreign demands on energy crops. The increasing
demand for agriculture due to the labour-intensive plant derived technologies
[10] is expected to improve farm income, which in countries with oversupply
can also help to reduce the need for subsidies. Traditionally deprived rural areas
could experience a renaissance through the implementation of biofuels and biore-
fineries. In addition, there is also a lot of controversy over food vs fuel and the
growth of specific crops to be transformed into biofuels. The resolution of this
process will necessarily take place on the basis of very different variables over
time [11].
With a wide array of potentially renewable energy resources, the concept and
proposed benefits evolving from the use of biofuels are inspiring; therefore they
