SUPPLEMENTARY INFORMATION

Transcription

1 SUPPLEMENTARY INFORMATION DOI: /NCLIMATE1325 Increased estimates of air-pollution emissions from Brazilian sugar-cane ethanol Tsao, C.-C. 1, Campbell, J.E. 1*, Mena-Carrasco, M. 2, Spak, S.N. 3, Carmichael, G.R. 3, Chen, Y. 1 1 School of Engineering, University of California, Merced. 2 Department of Environmental Engineering, Universidad Andres Belo, Santiago. 3 Center for Global and Regional Environmental Research, University of Iowa, Iowa City. Supplementary Methods Monthly Allocation Factors (MAF) In the farming and field burning phases, MAF m,f is the monthly cultivation ratio of sugarcane crops, which is calculated by dividing the average sugarcane harvest in the next ten months by the total production due to the average 10-month-growth period of sugarcane. The monthly quantity of sugarcane harvested and crushed in Brazil is obtained from the USDA FAS 1. The activities of the burning and refinery phases follow the same temporal scaling. MAF m,t, the monthly ratio of ethanol distributed, is assumed to be evenly allocated over the 12 months in a year due to year-round demand. Emission Factors (EF) Emission factors (EF i,p ) of 6 regulated air pollutants in each phase of the sugarcane ethanol life-cycle are obtained from the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model 2. The formulation of emission factors (per Mg sugarcane yield) for the field burning phase in the GREET model are based on emission factors of biomass burning (per kg dried matter burned) synthesized from IPCC and Andreae et al. s work, and the estimation NATURE CLIMATE CHANGE 1

2 of sugarcane residue yield in an official report of sugarcane ethanol assessment prepared for Brazilian government 3. The residue yield is Mg dried matter of trash per Mg sugarcane produced with 80% of cane burned (resulting in Mg dried matter burned per Mg sugarcane). Mechanized harvesting of sugarcane in São Paulo state has allowed for a reduction in burning. Both agriculture survey data and Landsat studies for São Paulo state suggest that the use of burning as a management practice has been reduced to 50% of sugarcane cropland area in ,5. We apply the survey data for the burning practice rates in São Paulo state and assume 100% of the areas are burned in other states.

3 Supplementary Table S1. State-level life-cycle emission of ethanol in Brazil, 2008 (Unit: MT/yr) State VOC NOX PM10 PM2.5 SOX CO CO2 BC 1 OC 2 COS 3 ACRE , , RONDONIA , , AMAZONAS ,177 1,354, PARÁ 1,636 1, ,991 2,861, TOCANTINS , , MARANHÃO 2,434 1,758 1, ,459 2,809, , PIAUÍ 1, ,762 1,325, CEARÁ 1,403 1, ,940 2,899, R. G. NORTE 2,505 1,720 2,547 1, ,537 1,989, , PARAIBA 4,314 2,920 4,653 2, ,821 3,001, , PERNAMBUCO 13,365 8,969 14,891 7,363 1, ,905 8,529,385 1,831 8, ALAGOAS 17,773 11,700 21,210 10,483 2, ,840 9,076,521 2,638 12, SERGIPE 1,473 1,016 1, ,160 1,216, BAHIA 3,888 2,928 2,349 1, ,694 5,671, , MINAS GERAIS 30,003 20,139 33,389 16,509 3, ,715 19,208,958 4,104 19, ESPIRITO SANTO 3,310 2,255 3,474 1, ,992 2,455, , RIO DE JANEIRO 5,040 3,717 3,528 1, ,963 6,574, , SÃO PAULO 124, , ,221 76,555 22,434 1,512,931 91,561,414 16,726 79,994 1,576 PARANÁ 30,034 19,913 34,962 17,282 3, ,210 16,753,412 4,331 20, SANTA CATARINA ,773 2,052, R. G. SUL 1,733 1, ,255 3,629, MATO GROSSO 10,134 6,702 11,901 5,883 1, ,358 5,483,574 1,476 7, MATO GROSSO DO SUL 11,815 7,784 14,057 6,948 1, ,175 6,101,183 1,748 8, GOIÁS 19,971 13,276 23,032 11,386 2, ,767 11,487,701 2,848 13, Brazil (Total) 288, , , ,727 40,794 3,760, ,263,378 38, ,913 3,603 1 : Black carbon (BC) 2 : Organoc carbon (OC) 3 : Carbonyl Sulfide (COS)

4 Supplementary Table S2. Summary of emissions and emission ratio from 5 life-cycle phases for São Paulo State, 2008 (Unit: MT/yr) Unit Life-cycle Farming Field Burning Refinery T/D Vehicle VOC 2,293 (1.8%) 101,204 (81.4%) 13,384 (10.8%) 1,055 (0.8%) 6,448 (5.2%) 124,383 NO X 15,449 (13.7%) 36,144 (32.2%) 31,724 (28.2%) 23,772 (21.2%) 5,307 (4.7%) 112,396 PM 10 PM 2.5 1,466 (0.9%) 112,769 (72.2%) 40,151 (25.7%) 753 (0.5%) 1,081 (0.7%) 156, (1.0%) 56,388 (73.7%) 18,341 (24.0%) 527 (0.7%) 555 (0.7%) 76,555 SO X 3,676 (16.4%) 5,786 (25.8%) 1,487 (6.6%) 11,415 (50.9%) 69 (0.3%) 22,434 CO 5,577 (0.4%) 1,330,114 (87.9%) 31,724 (2.1%) 4,483 (0.3%) 141,033 (9.3%) 1,512,931 Supplementary Table S3. Major municipalities of field burned in São Paulo state, 2008 by this approach and CANASAT data. This Study CANASAT a Municipality Burned area (ha) % of São Paulo burned area Burned area (ha) % of São Paulo burned area Ribeirão Preto 695,274 31% 530,637 28% Bauru 283,853 13% 203,435 11% São José do Rio Preto 242,585 11% 312,643 16% Araraquara 201,022 9% 153,529 8% a: Data based on Rudorff et al. (2010) 5

5 IPCC GFEDv3.1 d FINN e Supplementary Table S4. Emission factors (g emitted/ kg DM) of sugarcane or agriculture biomass burning applied in this study and in satellite based approaches. This study a Jenkins b Andrea and Merlet. c CO ± NOx ± ± SOx f g PM e 6.9 PM VOC OC BC ± COS ± a : Emission factors from GREET are based on Andrea and Merlet (2001). b : Emission factors from sugarcane burning experiments 6. c : Emission factors for biomass burning from agriculture open burning 7. d : Based on Andreae and Merlet (2001) and personal communication 8. e : Based on Dennis et al. (2002), Andreae and Merlet (2001), Jenkins (1996), and EPA AP-42 document (1995) 9. f : as SO 2 g : as TPM

6 Supplementary Figure S1. Emission of PM 2.5 and CO in different phases for July 2008 including (a) Field burning (b) Farming (c) Refinery (d) Transportation and distribution (e) Vehicle combustion phase.

7 Supplementary Figure S2. Emission of 5 air pollutants (a) VOC (b) NO X (c) PM 10 (d) PM 2.5 (e) SO X (f) CO in January and July, 2008.

8 Supplementary Figure S3. Comparison of monthly PM2.5 emission in August 2008 (a) Sugarcane field burning emissions estimated by our bottom-up approach; (b) FINN; (c) GFEDv3.1; and (d) GFEDv3.1-Ag. Supplementary Figure S4. Difference of bottom-up and other emission estimates in August 2008: (a) bottom-up minus GFEDv3.1; (b) bottom-up minus FINN.

9 References 1 Barros, S. Brazil Sugar Annual Report No. BR9004, (USDA, 2009). 2 Wang, M., Wu, M., Huo, H. & Liu, J. H. Life-cycle energy use and greenhouse gas emission implications of Brazilian sugarcane ethanol simulated with the GREET model. Int. Sugar J. 110, (2008). 3 Macedo, I. d. C., Leal, M. R. L. V. & Silva, J. E. A. R. d. Assessment of greenhouse gas emissions in the production and use of fuel ethanol in Brazil. (Government of the State of São Paulo, 2004). 4 Macedo, I. C., Seabra, J. E. A. & Silva, J. Green house gases emissions in the production and use of ethanol from sugarcane in Brazil: The 2005/2006 averages and a prediction for Biomass Bioenerg. 32, (2008). 5 Rudorff, B. F. T. et al. Studies on the Rapid Expansion of Sugarcane for Ethanol Production in São Paulo State (Brazil) Using Landsat Data. Remote Sensing 2, (2010). 6 Jenkins, B. M. Atmospheric pollutant emission factor from open burning of sugar cane by wind tunnel simulations. (University of California, Davis, Davis, CA, 1994). 7 Andreae, M. O. & Merlet, P. Emission of trace gases and aerosols from biomass burning. Glob. Biogeochem. Cycle 15, (2001). 8 van der Werf, G. R. et al. Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires ( ). Atmos. Chem. Phys. 10, (2010). 9 Wiedinmyer, C. et al. The Fire INventory from NCAR (FINN) a high resolution global model to estimate the emissions from open burning. Geosci. Model Dev. Discuss. 3, (2010).