Reducing the Energy Carbon Content - Energy and Climate: How to Achieve a Successful Energy Transition - page 79

Biomass energy and biofuels: potentialities and risks

Biomass is a renewable energy source, which presents the advantage of
storing energy.
We can expect to see an increase in the role of biomass for energy
production in the future. Biomass offers the advantage of being a renew-
able energy which is also storable. In the European Union, energy from
biomass reached 61Mtoe in 2006, an increase of 3.1Mtoe comparedwith
2004. In the world, biomass represents the main source of renewable
energy, amounting to 1186Mtoe in 2006 [1, 66].
The production of heat by combustion represents themain energy use of
biomass, wood being the primary renewable energy source in Europe.
Wood can be burnt in individual or collective boilers. It can also be used to
produce steam, generate electricity as well as heat in cogeneration.
Anaerobic methane fermentation in the presence of waste rich in

organic matter produces biogas. At least some of the methane produced
can also be recovered in open refuse tips by fermentation. The

main disadvantage of the biogas produced in this way is that it contains
numerous contaminants, and in particular highly corrosive acid com-
pounds. In general therefore, biogas requires intensive treatment. Biogas
can also be used as a compressed gas fuel (NGV). Although this applica-
tion is faced with the difficulty of distributing a gaseous fuel, it offers a
highly interesting environmental balance.
Production of biofuels currently represents the main alternative to
petroleum fuels in the field of transport. The production of biofuels has
grown very rapidly, generating strong controversies about its negative
impact on food supply. The world production in 2006 reached 24.4Mtoe,
as compared with 10.3Mtoe in 2000.
Biofuels offer the advantage of reducing the dependence of the con-
sumer countries on oil while at the same time improving the CO 2 balance.
The CO 2 emitted by combustion of biomass is seen as neutral with respect
to the greenhouse gas balance since it can be considered as being recycled
during photosynthesis, as indicated earlier. We must nevertheless take
into account all emissions generated during the production, transport and
transformation of biomass (life cycle analysis), which may in some cases
significantly reduce, or even completely cancel out, this advantage.
The European Union member states have set an initial goal of incorpo-
rating at least 5.75% of biofuels in 2010 and 10% by 2020 in the fuels of
fossil origin (gasoline and diesel). Within the present context of economic
crisis and controversy about the role of biofuels, these figures might be
revised.

aerobic