Management of Water Resources in the Sugarcane Agro- Industry in Brazil

Transcription

1 Workshop on Examples of Positive Bioenergy and Water Relationships Royal Swedish Academy of Agriculture and Science (KSLA) Stockholm, August 2015 Management of Water Resources in the Sugarcane Agro- Industry in Brazil André Elia Neto Environmental and Water Resources Consultant

2 ABOUT UNICA UNICA The Brazilian Sugarcane Industry Association is the largest association of producers of sugar and bioethanol in Brazil. It was created in 1997 with the merger of several industry organizations. With more than 120 members, it represents more than 50% of the ethanol and 60% of the sugar produced in Brazil. It is also responsible for around 70% of bioelectricity from sugarcane, marketed in the country

3 BRAZILIAN SUGARCANE SECTOR Number of mills Sugarcane growers 70,000 Sugarcane area 9.5 million ha (in 2014) Sugarcane Processed 650 million tons (2014/2015) 6 Electricity to power grid 20.8 TWh (in 2014) Direct employments 1.2 million² Sector Revenue US$ billion 3 Foreign Revenue (Exports): US$ 16 billion (2011/12) % Energy matrix 15.7% (2 nd source, > hydro) CO 2 reductions emission > 600 million tons (since 1975) 1 st SUGAR PRODUCER IN THE WORLD 4 Sugar production = 37.7 million t/year (5) 2 nd ETHANOL PRODUCER IN THE WORLD 4 Ethanol production = 25.6 million m 3 /year (5) 22% of world production 22% of world production 45% of world exports 36% of world exports Elaboration: UNICA. Note ¹ Data from Oct / 2012; ² Data from RAIS; 3 Neves, Trombin and Consoli. The sugar-energy map of Brazil, In: Ethanol and Bioletricity. 4 Source: LMC (Fourth Quarter 2012). 5 Source: UNICADATA safra 2013/14. (6) CONAB

4 Million Hectares Total Area LAND USE IN BRAZIL Update in Percentages refer to the Brazilian territory. Native Vegetation Land in Current Use Other Uses % 65% 30% 5% Conservation Units and ILs Permanent Protected Areas Other Native Vegetation % % % Pastures Crop Land % 7% Sugarcane 9.5 1% Sugarcane FOR ETHANOL % Others crops (million hectares) 21 2,9 3,8 9,5 14,4 Source: ICONE, IBGE (PAM 2010 and Censo Agropecuário), MMA, INPE (TerraClass), Agricultural Land Use and Expansion Model Brazil Ag-LUE-BR (Gerd Sparovek, ESALQ/USP). Compiled by: UNICA and Cosan. Note: ILs = Indigenous Lands. Other Native Vegetation include Legal Reserves (RLs)

5 Ethanol-Sugar Mills Location in Brazil In Brazil there are two sugarcane areas: in the North-Northeast at about 12% of the production area of sugarcane (a part with irrigation) and the Center-South with the remaining 88% (essentially rainfed production) In the Center-South, the harvest takes place from April to December The North-Northeast harvest begins in September, ending the following year in March. Source: NIPE-Unicamp, IBGE e CTC

6 Area and Productivity increse area stable area drought

7 Use and reuse water and wastewater in the sugarcane industry It is difficult to dissociate the production of bioethanol and sugar in Brazil, most of sugarcane mills produce both products. The average use of water in industry, with a production mix of 50% of sugarcane for sugar and 50% for ethanol production, results in about 22 m3 / t of processed cane (as we can see in the following table)

8 Process water Table Averages rates of water uses in the sugar and ethanol mills in Brazil Sector Finality Specific Use Average Use Feeding, preparation and extraction (grinding and difusion) Juice treatment [m 3 /t cane] [%] Sugar cane washing m 3 /t cane total Imbibition m 3 / t cane total Bearing cooling m 3 / t cane total Cooling oil m 3 / t cane total Subtotal Cooling at sulphiting (*1) m 3 /t cane sugar Preparation of lime mixture m 3 /t cane total Preparation of polymer (*1) m 3 /t cane sugar Heating juice for sugar (*1) 160 kg steam/t cane sugar for ethanol (*2) e (*4) 50 kg steam/t cane ethanol Sugar mills (*1) Fermentation (*2) Filter imbibition m 3 / t cane total Filter condensers a 0,350 m 3 /t cane total Subtotal Steam for evaporation t/t cane sugar Condensers/multijets evaporation 4 a 5 m 3 /t cane sugar Steam for cooking t/t cane sugar Condensers/multijets cookers 8 a 15 m 3 /t cane sugar Molasses dilution m 3 /t cane sugar Delay cooking m 3 /t cane sugar Sugar washing (1/3 water e 2/3 steam) m 3 /t cane sugar Retainer of powdered sugar m 3 /t cane sugar Subtotal preparation of the fermentation mixture 0 a 10 m 3 /m 3 ethanol residual Juice cooling 30 m 3 /m 3 ethanol Treatment of yeast m 3 /m 3 ethanol Washing gases CO 2 fermentation 1.5 a 3.6 m 3 /m 3 ethanol Fermentation cooling 60 a 80 m 3 /m 3 ethanol Subtotal Souce: ELIA NETO et al., 2009 Manual de Conservação e reuso de Água na Agroindústria Sucroenergética. UNICA, FIESP, CTC e ANA

9 Process water Ethanol Heating (steam) 3.5 a 5 kg/m 3 ethanol distillation (*2) Cooling condensers 80 a 120 m 3 /m 3 ethanol Power generation Subtotal Steam production 400 a 600 kg/t cane total Desuperheating steam l/kg steam Whashing gas from the chimney of the boiler. 2.0 m 3 /t steam Clean ashtrays boiler 0500 m 3 /t steam Cooling oil and air from the turbo Water towers of condensation (*3) 15 l/kw m 3 /t steam 6.0 (*3) 27.1 Subtotal Others Cleaning floors and equipment m 3 /t cane total Use drinking 70 l/ employee days Subtotal Total Note (* 1) items that do not participate in the process of ethanol; (* 2) those who did not participate in the process of sugar; (* 3) those who participate only in the case of production of surplus energy is not computed in the sums; (* 4) recovering the heat of the hot juice for ethanol Souce: ELIA NETO et al., 2009 Manual de Conservação e reuso de Água na Agroindústria Sucroenergética. UNICA, FIESP, CTC e ANA

10 Process water - Distribution Average Distribution of Water Uses in Sugar Ethanol Sugarcane Industry Gas scrubber 5% Ethanol condeser cooling 16% Other 14% Fermentation cooling 19% Washing sugarcane 10% Juice evaporation 10% Sugar concentratio n 26% The two major uses are for cooling water, with: 36% for sugar factory and 35% for ethanol production. There are still: 10% for sugarcane washing and 5% for cleaning emission from boilers. These are the 4 points where it can act more readily to obtain results with reduced water intake, with the circuit closing, in a program of Management of Water Resources in the Sugarcane Agro-Industry Source: ELIA NETO, A. Gestão dos Recursos Hídricos na Agroindústria Canavieira. UNICA, 2014

11 Water catchment rate (m 3 /t). Taxa de Captação [m3/t.cana] 22 DECREASE WATER CATCHMENT Curva de Tendência da Taxa de Captação de Água na Indústria Canavieira Trend curve of the water catchment rate in the sugar cane industry Management of Water Resources in the Sugarcane Agro-Industry Average catchment Environmental Protocol, 2014 Goal of sector Source: adapted from ELIA NETO, A. et al., 2009 Manual de Conservação e reuso de Água na Agroindústria Sucroenergética. UNICA, FIESP, CTC e ANA The water catchment, was 15 to 20 m3 per ton of cane about 4 decades ago. It has been minimized with the closing of the water systems to reuse. On average, the catchment water for industry, is about 2 m3 / ton of cane (data from 2005) The self-imposed target is 1 m3 per ton of cane

12 Management of Water Resources in the Sugarcane Agro-Industry Strategy: minimum water catchment and zero discharge reduction of use, and practice of water reuse closed circuit Effluent sent to the sugarcane fields Reuse Efficiency 95%, relative to the goals Average Distribution of Water Uses in Sugar Ethanol Sugarcane Industry Gas scrubber 5% Other 14% Washing sugarcane 10% Juice evaporation 10% Goals for water management Catchment (m 3 /t.cane) 1.0 Ethanol condeser cooling 16% Fermentation cooling 19% Sugar concentratio n 26% Consumption (m 3 /t.cane) 1.0 Wastewater to river (m 3 /t.cane) zero Average use= 22 m 3 /t.cane (in mill) There are mills that water catchment smaller than the goal (with 0.7 m 3 / t cane and even less)

13 WATER BALANCE Losses: Average = 0.9 m3/t.cane Goal = 0.9 m3/t.cane Catchment: Average = 2 m 3 /t.cane Goal = 1 m 3 /t.cane Cane s water: Average = 0.7 m 3 /t.cane 16 L/kg 8 L/kg 23 L/L 12 L/L Use and reuse 22 m 3 /t.cane Reuse Index: 91% (goal 95%) ~18 L/kWh Agronomic s Reuse Average = m 3 /t.cane Goal = 1.8 m 3 /t.cane Wastewater Average = m 3 /t.cane Goal = 0 m 3 /t.cane Global average water balance in the sugarcane mills with the mix of production from 50% sugar and 50% ethanol. Souce: Elia Neto, A. et all Manual da Conservação e Reúso de Água na Agroindústria Sucroenergética, Versão revisada 13

14 The Good Industry Practices cooling spray pond water tower of cooling water

15 The Good Industry Practices decanter of sugarcane washing water dry cleaning sugarcane 15 cleaning of the boiler gases decanter of efluent

16 Irrigation with effluents Rescue irrigation (*): To plant sugarcane: mm To ratoon cane: mm Productivity average gains (*): Sugarcane plant 12 to 20% Ratoon cane 6 to 12% Reuse: reduces the need for new sources of water for irrigation. (*) Source: Rosenfeld, U. Irrigação e Fertirrigação nas Sub Regiões de SP e GO. Palestra; Simpósio de Tecnologia de Produção de Cana-de-Açúcar, GAPE/FEALQ, Piracicaba, 04/07/2003

17 Main drivers for implementing the practice The greatest motivation for the practice is to make available water for the other sectors, especially during the dry season. For example in the São Paulo state (the countrys largest sugarcane producer): Licensed water catchment distribuition in São Paulo' state (source: PERH ) industry 28% urban 40% rural and other 32% Total demand = 304,5 only in the harvest period

18 FINAL REMARKS Main challenges: the cost The self-imposed goals of the sector are voluntary, since there is no restriction on the use of water when used correctly. These goals have become standards of some certifications (such as Bonsucro and Green Ethanol in Sao Paulo). The level of investment required is about 2 million dollars per plant, with treatment and complete closure of the water systems. In order to achieve the lowest levels of 0.5 cubic meter per ton the water inside the sugarcane, should be reused. In order to do this, the technological level required is much larger and more expensive (investment of at least 20 million dollars per plant)

19 Advantage : Non irrigation FINAL REMARKS The cane planting in Brazil is essentially rainfed as opposed to several countries, This is another great benefit of sustainability in the production of sugarcane. Normally ferti-irrigation and rescue irrigation occur with effluent reaching up to 1/3 of the sugar cane area with very low water layer (60 to 120 millimeters). In the Northeast there is a bigger use of water resources for irrigation due to water deficit, using supplemental irrigation (200 to 400 millimeters per year), even then only in a part of the plantation, Intended mainly to productivity similar to Central-South region of 90 tons per hectare, much higher than the average in the region, in which rainfed production is below 50 tons per hectare.

20 thanks (tack)