Agriculture Reference
In-Depth Information
Keywords:
Bioethanol, sugar beet, environment, health, food
I
NTRODUCTION
Energy sources in history of mankind have been changing due to exploration, technology
and development. Some evidences exists that mankind learned to control fire more than
500,000 years ago. In early 1600`s people in Europe discovered how useful coal for heating is
and after 1850, when steam engine was discovered, the coal consumption increased
exponentially. In the 1900`s so called age of the combustion engine that is based on petrol
extensive consumption began [1-3]. The need upon quick changes has crucial importance for
direct problems: increase of oil prices, limited of reserves [2, 4] and political instability in the
main oil producers‟ countries and also indirect problems that are shown as impact on the
climate and environment. These impacts to the environment are consequence of releasing
large amount of emissions of greenhouse gases (GHG) into the atmosphere [5-8].
The mobility has crucial importance in our modern industrialized society [9]. Apart from
a few exceptions, the transport of people and goods is sustained by liquid fuels. Despite the
known fact, of limited petroleum resources, the consumption is still growing. Therefore a
number of various studies put the date of the global peak in oil production between 1996 and
2035 [10-13]. The transport sector accounts for more than 30% of final energy consumption
in the European Union (EU) and is expanding, along with carbon dioxide (CO
2
) emissions.
The main source is road transport, which accounts for 84 % of those CO
2
emissions.
Additionally, the transport sector depends to 98 % on fossil oil [14, 15].
On the other hand, the world population keeps growing and improving the standard of
living, are the facts that lead to a significant increase of energy consumption [16].
Renewable energy sources, unlike fossil fuels, can be used without ever being used up.
By that it is important to point out that the renewable energy sources release the equal amount
of CO
2
when being burned as it is used in process of photosynthesis [17-20]. Promoting the
use of biofuels together with sustainable agriculture and forestry practices laid down in the
rules governing the common agricultural policy could create new opportunities for
sustainable rural development in a more market orientated common agriculture policy and to
respect for flourishing country life and multifunctional agriculture, and could open a new
market for innovative agricultural products with regard to present and future [7].
Nevertheless, renewable energy sources represent only 13.6% of the global energy
production. By that biomass, feedstock for liquid biofuels presents only 0.4% [21].
A variety of common sugar crops can be used as the feedstock for producing ethanol fuel,
including sugar cane stalks, sugar beet tubers and sweet sorghum stalks, all of which contain
a large portion of simple sugars. Once these sugars have been extracted they can be fermented
easily into ethanol [22]. Although several microbial hosts have been investigated for ethanol
production, S. cerevisiae,
E. coli
and
Z. mobilis
remain the most mature platforms. With
multiple steps distillation the necessary fortification of the ethanol to a purity level of 96%
can be achieved [23]. The remaining wash consists of water and organic materials [12, 24].
First generation biofuels like bioethanol, the current potential candidate as a petroleum
replacement for internal combustion engines, is a fuel generally derived from food crops such
as sugar beet [25].
