Sugarcane ethanol: Contributions to climate change - BAFF

Mitigation of GHG emissions using sugarcane bioethanol
�e GHG emissions associated with direct land use change (LUC) are estimated separately
in the next section, where the possible indirect impacts of land use change (ILUC) are also
discussed for the speci�c case of the expansion of ethanol production in Brazil. �e energy
use/conversion for 2006 and for each 2020 Scenario is presented in Table 4.
�e corresponding GHG emissions for are in Table 5. Note that the di�erences in total
emissions are strongly dependent on the co-products credits. �e large di�erence between
2006 and the 2020 Electricity Scenario is due to an actual increase in the system energy
e�ciency (much larger energy output). An analogous increase in energy output occurred
between 2006 and the 2020 Ethanol Scenario, but note that the change is an increase in
ethanol output (rather than in electricity) and also the emissions are presented in kg CO 2
eq/m 3 ethanol. In the 2020 Ethanol Scenario the volume of ethanol produced/unit area (or
ethanol/ t cane) is 1.4 times larger than in the 2020 Electricity Scenario.
It is important to remember that the 2006 data (and results) correspond to the average
values of the parameters; even for a homogeneous set of producers (Brazil Center South
region) di�erences in processes (agricultural and industrial) impact energy �ows and
GHG emissions. For the sample used, the variation of main production parameters and the
Table 4. Energy balance in anhydrous ethanol production (MJ/t cane).
2006 2020 electricity 2020 ethanol
Energy input 235 262 268
Agriculture 211 238 238
Cane production 109 142 143
Fertilizers 65 51 50
Transportation 37 45 45
Industry 24 24 31
Inputs 19 20 25
Equip./buildings 5 4 6
Energy output 2,198 3,171 3,248
Ethanol a 1,926 2,060 2,880
Electricity surplus b 96 1,111 368
Bagasse surplus a 176 0.0 0.0
Energy ratio 9.4 12.1 12.1
a Based on LHV (Low Heating Value).
b Considering the substitution of biomass-electricity for natural gas-electricity, generated with 40%
(2006) and 50% (2020) efficiencies (LHV).
Sugarcane ethanol 99