BIOFUEL - THE FUEL OF THE FUTURE
First
Generation Biofuels
The first generation biofuels refer to the fuels that have
been derived from sources like starch, sugar, animal fats
and vegetable oil. The oil is obtained using the
conventional techniques of production. Some of the most
popular types of first generation biofuels are:
Biodiesel: This is the most common type of biofuel
commonly used in the European countries. When biodiesel is
mixed with mineral diesel, the mixture can be used in any
diesel engine. A large number of vehicle manufacturers
recommend the use of 15% biodiesel mixed with mineral
diesel. In Europe, a 5% biodiesel blend is generally used at
gas stations. This type of biofuel is mainly produced using
a process called transesterification. This fuel if very
similar to the mineral diesel and is chemically known as
fatty acid methyl. This oil is produced after mixing the
biomass with methanol and sodium hydroxide. The chemical
reaction thereof produces biodiesel.
Vegetable oil: Vegetable oil is used in several old
diesel engines that have indirect injection systems. This
oil is also used to create biodiesel, which when mixed with
conventional diesel fuel is compatible for most diesel
engines. Used vegetable oil is converted into biodiesel.
Sometimes, water and particulates are separated from the
used vegetable oil and then this is used as a fuel. These
kinds of oil can be either used for cooking purpose or even
as fuel. The main fact that determines the usage of this oil
is the quality. The oil with good quality is generally used
for cooking purpose. In most of the countries, vegetable oil
is mainly used for the production of biodiesel.
Biogas: Biogas is mainly produced after the anaerobic
digestion of the organic materials. Biogas can also be
produced with the biodegradation of waste materials which
are fed into anaerobic digesters which yields biogas. The
residue or the by product can be easily used as manure or
fertilizers for agricultural use. The biogas produced is
very rich in methane which can be easily recovered through
the use of mechanical biological treatment systems. A less
clean form of biogas is the landfill gas which is produced
by the use of naturally occurring anaerobic digesters, but
the main threat is that these gases can be a severe threat
if escapes into the atmosphere.
Bioalcohols: These are alcohols produced by the use
if enzymes and micro organisms through the process of
fermentation of starches and sugar. Ethanol is the most
common type of bioalcohol whereas butanol and propanol are
some of the lesser known ones. Ethanol fuel is the most
commonly used biofuel in the world and particularly in
Brazil. Ethanol can be put to use in petrol engines as a
substitute for gasoline. Also, it can be mixed with gasoline
in any ratio. The contemporary automobile petrol engines can
work on mixtures of gasoline and ethanol that have 15%
bioethanol. This mixture of gasoline and ethanol has more
quantity of octane. The Ethanol fuel has less British
Thermal Unit energy content. Thus, to drive the same
distance, more fuel is required. Also ethanol has a
corrosive effect on combustion chambers, aluminum, rubber
hoses and gaskets and fuel systems. Biobutanol is sometimes
also referred to as a direct replacement of gasoline because
it can be directly used in the various gasoline engines.
Butanol is produced using the process of ABE fermentation,
and some of the experiments have also proved that butanol is
a more energy efficient fuel and can be directly used in the
various gasoline engines.
Syngas: This is a gas that is produce after the
combined process of gasification, combustion and pyrolysis.
Biofuel used in this process is converted into carbon
monoxide and then into energy by pyrolysis. During the
process, very little oxygen is supplied to keep combustion
under control. In the last step known as gasification the
organic materials are converted into gases like carbon
monoxide and hydrogen. The resulting gas Syngas can be used
for various purposes.
Besides first generation biofuels, some second generation
biofuels that are being developed are Fischer-Tropsch
diesel, bio-DME, DMF, biomethanol, biohydrogen, wood diesel,
mixed alcohol and biohydrogen diesel. Algae fuel is a third
generation biofuel derived from algae. This is also called
as oilgae.