GHG balance of ethanol production in Brazil (J. Seabra

GHG balance of ethanol production in Brazil
Joaquim E. A. Seabra
[email protected]
Analysis for sugarcane
products
The main objective of the work was the assessment of life cycle
energy use and greenhouse gas (GHG) emissions related to cane
sugar and ethanol, considering bagasse and electricity surpluses
as coproducts.
GREET 1.8c.0 model was used to evaluate energy use and GHG
emissions in the ethanol life cycle, with recent production
parameters of the Brazilian Center-South Region.
Some default parameters were changed to better reflect Brazilian
conditions.
Parameters based on the CTC database (2008/2009 season).
Database
Pathways
ATR mix
Chemicals
By-products
Sugar
production
ATR eq
SUGAR
Agr. chemicals
Fuels
Chemicals
Sugarcane production
- Farming
- Harvesting
- Transport
By-products
Hydrous etOH
production
Chemicals
By-products
Anhydrous etOH
production
Seabra et al. (2011)
ATR eq
Fuel
HYDROUS
ETHANOL
Ethanol
T&D
ATR eq
Fuel
ANHYDROUS
ETHANOL
Ethanol
T&D
Fuel use
Fuel use
ATR balance
Seabra et al. (2011)
Coproducts
Bagasse surplus displancing fuel oil
Electricity surplus displacing NG thermoelectricity
Coproducts
Brazilian SIN Operating Margin in 2008
100%
Average fuel mix
80%
60%
Other*
Diesel
40%
Coal
Nuclear
20%
0%
Natural gas
Results
Sugar
Sugarcane farming
Trash burning
Field emissionsa
Agr. inputs production
Sugarcane transportation
Sugarcane processing
Ethanol T&D
Tailpipe emissions
Credits
Electricityb
Bagassec
Total
Seabra et al. (2011)
Ethanol
Fossil energy use
GHG emissions
Fossil energy use
GHG emissions
(kJ/kg)
(g CO2eq/kg)
(kJ/MJ)
(g CO2eq/MJ)
1,109
88
508
237
37
85
48
85
48
18
31
6.8
3.8
6.7
3.8
1.4
2.6
1.8
0.8
-754
-416
-46
-35
-60
-33
-3.7
-2.7
721
234
80
21.3
40
19
4
22
Sugar
Seabra et al. (2011)
Emissions savings
Sensitivity
Different methods to allocate
sugarcane emissions between sugar
and ethanol.
Seabra et al. (2011)
Different methods to deal with sugar
and ethanol coproducts allocation
(electricity and bagasse surplus).
Uncertainty analysis
Uncertainty analysis
Seabra et al. (2011)
Sugarcane biorefinery
Juice
processing
Cane juice
Steam
Ethanol
Electricity
Cane trash
Bagasse
Mill’s power
plant
Electricity
Adjacent plant
Bagasse
surplus
Electricity option:
Power plant
Electricity
OR
Ethanol option:
Biochem. conversion
plant
Seabra and Macedo (2010)
Ethanol
Electricity
GHG emissions balance
Ethanol LC emissions (g CO2eq/MJ)
Seabra and Macedo (2010)
-19
5
Sensitivity
Lifecycle emissions for gasoline and marginal electricity to yield equal net avoided emissions.
Seabra and Macedo (2010)
Forthcoming
Silva et al. (2011)
Forthcoming
Silva et al. (2011)
Ethanol-Biodiesel integration
Façon system
Soja
Óleo
Eletricidade
Cana
Bioetanol
Usina integrada
Seabra and Souza (2011)
Biodiesel
Ethanol-Biodiesel integration
Fossil energy consumption
150
100
Produção do etanol
Transporte
50
kJ/MJ
Insumos agrícolas
Emissões do solo
0
Queima da palha
Cultivo da cana
Créditos
-50
Total
-100
Referência
Sistema integrado
Ethanol-Biodiesel integration
GHG emissions
25
20
Produção do etanol
Transporte
g CO2 eq/MJ
15
Cultivo da cana
10
Queima da palha
Emissões do solo
5
Insumos agrícolas
Créditos
0
Total
-5
Referência
Sistema integrado
Thank you
Joaquim E. A. Seabra
[email protected]