60
suitable for temperate regions. Yields of the crops per unit of land area also differ
between regions.
GHG emissions from the soil, such as emissions of nitrous oxide from the applied
nitrogen fertilizers and the release of carbon dioxide from peat are affected by the
soil of an agricultural area. Furthermore, utilization of agricultural residues as
energy source or fertilizer depends on the technologies employed in the region.
The replaced energy sources by the residue vary by region. GHG reduction
through this replacement is larger in coal-dependent area than oil-dependent area.
This difference in energy sources is most remarkable in the replacement of electric
power generation. In mainland China, where coal-fired power stations are dominant, the carbon emission factor is about 1.1 kg CO 2 /kWh (Department of Climate
Change, National Development and Reform Commission, China 2008). In the
Tokyo region of Japan, the carbon emission factor in 2010 was about 0.4 kg CO 2 /
kWh (Ministry of Environment 2010), only one-third as much. This means that
replacement of power generation would have a large CO 2 reduction effect in China
and a small effect in the Tokyo region. The amounts would be even smaller in a
region that uses hydroelectric power, such as Brazil (0.2 kg CO 2 /kWh) (Portugal
2011).
The TTW stage is not affected by the production region but by local characteristics of regions in which a biofuel is consumed. Large amounts of biofuel are distributed internationally. Average lifespan and performance of vehicles and atmospheric
pollution standards differ greatly between countries. Mixing ratios for biofuels and
conventional fuels also vary between countries. For instance, in Brazil, ordinary
gasoline (commonly referred to as gasohol) is blended with 18–25% (v/v) of anhydrous ethanol (MAPA 2011b), whereas in Japan the legal limit of ethanol blends is
3% (v/v) (Fukuda et al. 2006).
These points show that, when evaluating the GHG reduction effect of biofuels,
LCA must be carried out considering the local characteristics of the producing
regions and consuming regions.
6.3 Sugarcane Ethanol Production in Brazil
As stated earlier, LCA is a useful tool to evaluate the climate change mitigation
potential of biofuels. Yet, it is also a source of controversy as LCA results are significantly dependent on local conditions of production and utilization, and options
made by practitioners when selecting system boundaries, allocation procedures, and
the functional unit of the system, among others. Thus, the truthful GHG and fossil
fuel resource savings from biofuel life cycle and uncertainty factors behind LCA
results are yet to be surely understood. To clarify these matters, a LCA has been
conducted to evaluate the GHG emission and nonrenewable energy (NRE) consumption of sugarcane ethanol production in the South-Center region of Brazil and
its application in the Brazilian national passenger vehicles. The analysis is focused
on current practices, taking as reference the base year 2008 (the latest year for which
K. Hanaki and J. Portugal-Pereira
suitable for temperate regions. Yields of the crops per unit of land area also differ
between regions.
GHG emissions from the soil, such as emissions of nitrous oxide from the applied
nitrogen fertilizers and the release of carbon dioxide from peat are affected by the
soil of an agricultural area. Furthermore, utilization of agricultural residues as
energy source or fertilizer depends on the technologies employed in the region.
The replaced energy sources by the residue vary by region. GHG reduction
through this replacement is larger in coal-dependent area than oil-dependent area.
This difference in energy sources is most remarkable in the replacement of electric
power generation. In mainland China, where coal-fired power stations are dominant, the carbon emission factor is about 1.1 kg CO 2 /kWh (Department of Climate
Change, National Development and Reform Commission, China 2008). In the
Tokyo region of Japan, the carbon emission factor in 2010 was about 0.4 kg CO 2 /
kWh (Ministry of Environment 2010), only one-third as much. This means that
replacement of power generation would have a large CO 2 reduction effect in China
and a small effect in the Tokyo region. The amounts would be even smaller in a
region that uses hydroelectric power, such as Brazil (0.2 kg CO 2 /kWh) (Portugal
2011).
The TTW stage is not affected by the production region but by local characteristics of regions in which a biofuel is consumed. Large amounts of biofuel are distributed internationally. Average lifespan and performance of vehicles and atmospheric
pollution standards differ greatly between countries. Mixing ratios for biofuels and
conventional fuels also vary between countries. For instance, in Brazil, ordinary
gasoline (commonly referred to as gasohol) is blended with 18–25% (v/v) of anhydrous ethanol (MAPA 2011b), whereas in Japan the legal limit of ethanol blends is
3% (v/v) (Fukuda et al. 2006).
These points show that, when evaluating the GHG reduction effect of biofuels,
LCA must be carried out considering the local characteristics of the producing
regions and consuming regions.
6.3 Sugarcane Ethanol Production in Brazil
As stated earlier, LCA is a useful tool to evaluate the climate change mitigation
potential of biofuels. Yet, it is also a source of controversy as LCA results are significantly dependent on local conditions of production and utilization, and options
made by practitioners when selecting system boundaries, allocation procedures, and
the functional unit of the system, among others. Thus, the truthful GHG and fossil
fuel resource savings from biofuel life cycle and uncertainty factors behind LCA
results are yet to be surely understood. To clarify these matters, a LCA has been
conducted to evaluate the GHG emission and nonrenewable energy (NRE) consumption of sugarcane ethanol production in the South-Center region of Brazil and
its application in the Brazilian national passenger vehicles. The analysis is focused
on current practices, taking as reference the base year 2008 (the latest year for which
K. Hanaki and J. Portugal-Pereira