Meeting on Biofuel Technologies and Environmental Impacts Atibaia, August Luiz A Martinelli (CENA/USP)

Transcription

1 Meeting on Biofuel Technologies and Environmental Impacts Atibaia, August 2009 Ethanol from Sugar Cane in Brazil: Water Use and Impacts on Water Research Luiz A Martinelli (CENA/USP)

2 Source: FAOSTAT and CANASAT (INPE)

3 Brazil North 3% Northeast 20% Center-West 9% 63% Southeast South 8% 0% 8% 9% 20% Source: Locatel & Azevedo, 2008 Federal University of Sergipe, Brazil 63% North Northeast Southeast South Center-West

4 Source: CANASAT -

5 Before Source: CANASAT -

6 2008 Source: CANASAT -

7 WATER USE Martinelli & Filoso, 2008 Ecological Applications 18(4): Feedstock production (sugar cane) Industrial use (sugar cane to ethanol)

8 Feedstock production (sugar cane) Green water: evapotranspiration - water footprint Brazil more than 75% of sugar cane is rainfed Irrigation Rainfed Gerbens-Leenes et al. (2008) de Faiture and Berndes (2009)

9 Feedstock production (sugar cane) Green water: evapotranspiration - water footprint Brazil more than 75% of sugar cane is rainfed de Faiture and Berndes (2009)

10 Industrial use (sugar cane to ethanol) Blue water: rivers, streams, lakes, groundwater Data source Department of Water and Energy of the State of São Paulo (DAEE) (responsible for grant water withdraw permission to industrial activities in the State of São Paulo) A total of 183 mills that renewed their licenses between million of m 3 of water per year 240 days of ethanol production: 30 m 3.s -1 (20% of the industrial water use of 2000) CONAB (2008): São Paulo State 340 million ton of sugar cane 900 million of m 3 /340 million ton of sugar cane = 2.7 m 3 /ton (Elia Neto, 2008: 40 mills = 1.8 m 3 /ton) 70 s: 15 m 3 /ton 90 s: 5 m 3 /ton Now: 2-3 m 3 /ton Future: 0 m 3 /ton

11 Irrigation (green water) Rainfed (green water) Industrial (blue water)

12 Energy water footprint (m3/gj) 1,2 Industrial (blue water) 1,0 0,8 0,6 0,4 0,2 0,0 Wind Natural gas Nuclear Coal Solar Ethanol Crude oil

13 Water sources Number Percent river 1 st order % river 2 nd order 56 18% river 3 rd order 35 11% river 4 th order 14 5% Reservoirs 50 16%

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17 Seven major watersheds of the State of São Paulo 35% of the area of the State 75% of the riparian forest were replaced by pasture or sugar cane. 12% 16% 40% 27% 6% 20% 22% From: Silva et al., Scientia Agricola, 2007

18 WATER QUALITY Martinelli & Filoso, 2008 Ecological Applications 18(4): Soil erosion (control) Riparian forests (loss of) Pesticides (contamination) Biodiversity (loss and habitat change) Water pollution (industrial effluents)

19 20% bare soils 80% good cover

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21 27 ton/ha.yr surface erosion 3 ton/ha.yr gully (?) erosion

22 Fine suspended solids (mg/l) Amazon Ji-Paraná Piracicaba Mogi Cabras Pisca

23 Bryconamericus iheringii 100% 80% 60% Aquatic insect Detritus/sediments 40% Algae 20% 0% Floresta Ripária Vegetação Mista Pastagem Intact Riparian Forest Degraded Forest Replaced DET ALG VTR PEI IVT IVA ITR IAQ

24 Industrial effluents from the sugar cane/ethanol industry Sugar cane washing (2.58 m 3 of water/ton): 0.18 a 0.50 kgbod/m 3 of effluent Effluent from the industry (1 m 3 of water/ton): 1.50 kgbod/m 3 of effluent Vinasse (10-13L of vinasse per L of ethanol): kgbod/m 3 of vinasse

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27 State of São Paulo (2008): 14 million m 3 of ethanol 14 million m 3 of ethanol x 10 L vinasse/l of ethanol = 140 million m 3 of vinasse 8 kg million of BOD per day Urban inhabitant generates kg of BOD per day Equivalent organic load produced by 150 million inhabitants (4 x population of the State of São Paulo)

28 Vinasse 10-13L/L of ethanol ph 4.1 Temperature (C) 90.0 BOD (kg/m 3 ) 17.0 Nitrogen (kg/m 3 ) 0.36 Phosphorus (kg/m 3 ) 0.06 Potassium (kg/m 3 ) m3/ha (12-15% sugar cane area) Vinasse 10-13L/L of ethanol ph 4.1 Temperature (C) 90.0 BOD (kg/m 3 ) 17.0 Nitrogen (kg/ha) 90.0 Phosphorus (kg/ha) 15.0 Potassium (kg/ha) Elia Neto (2008) www. apta.sp.gov.br/cana

29 Source: Sergio Antonio Veronez de Souza

30 Photos: Sergio Antonio Veronez de Souza

31 Photos: Sergio Antonio Veronez de Souza

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33 Strategies to reduce impacts on water resources Control use of herbicides, pesticides and other chemicals on sugarcane crops. Avoid expansion of sugarcane crops to areas devoid of riparian buffers. Monitor use of water resources and impacts to water quality. Promote industrial practices that reduce use of water and recycle. (e.g. Project for water use reduction in the sugarcane industry created by the Sugarcane Technology Center (CTC) Sao Paulo Brazil and more recently Dedini Company). Implement public policies to promote reduction in water use (e.g, charging for water use in the state of Sao Paulo is showing positive results). Enforce laws to protect and restore riparian buffers.

34 Strategies to reduce impacts of waste production Reduce production of vinasse by using less water in the industrial process and by improving fermentation technologies (e.g. Fermentec, Inc.). Full treatment of water waste to reduce organic matter content and nutrient concentrations. Enforce laws banning discharge of vinasse into rivers and streams. Maximize use of sugarcane by-products: increase biomass-to-electricity efficiency in production of energy for mills. Utilize vinasse to produce biogas. Utilize bagasse and agricultural residues to produce 2 nd generation biofuels (e.g. bio-oil).

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41 30% of the sugar cane cultivated area has mechanized harvesting. Social problem: unemployment but can we call sugar cane cutting of a descent job?