André Elia Neto
Environmental and Water Resources Consultant
Management of Water Resources in the Sugarcane Agro-
Industry in Brazil
Workshop on “Examples of Positive Bioenergy and Water Relationships”
Royal Swedish Academy of Agriculture and Science (KSLA)
Stockholm, 25-26 August 2015
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
ABOUT UNICA
Number of mills 4011
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$ 28.15 billion3
Foreign Revenue (Exports): US$ 16 billion (2011/12)
% Energy matrix 15.7% (2nd source, > hydro)
CO2 reductions emission > 600 million tons (since 1975)
Elaboration: UNICA. Note ¹ Data from Oct / 2012; ² Data from 2010. RAIS; 3Neves, Trombin and Consoli. The sugar-energy map of Brazil, 2010. In: Ethanol
and Bioletricity. 4 Source: LMC (Fourth Quarter 2012). 5 Source: UNICADATA safra 2013/14 . (6) CONAB
2nd ETHANOL PRODUCER IN THE WORLD4
Ethanol production = 25.6 million m3/year(5)
22% of world production
36% of world exports
1st SUGAR PRODUCER IN THE WORLD4
Sugar production = 37.7 million t/year(5)
22% of world production
45% of world exports
BRAZILIAN SUGARCANE SECTOR
4.6
0.5%
Million Hectares
LAND USE IN BRAZIL
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)
Total Area Native Vegetation Land in Current
Use Other Uses
851 554 258 38
100% 65% 30% 5%
Pastures Crop Land
Sugarcane
9.5
1%
60
7%
198
23% Sugarcane
FOR ETHANOL
204
24%
Conservation
Units and ILs
135
16%
Permanent
Protected Areas
215
25%
Other Native
Vegetation
2.9 3.8
9.5 14.4
21
Others crops (million hectares)
Update in 2012. Percentages refer to the Brazilian territory.
Source: NIPE-Unicamp, IBGE e CTC
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.
Area and Productivity
stable area
increse area
drought
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)
Process water
Sector Finality Specific Use
Average Use
[m3/t cane] [%]
Feeding, preparation and extraction (grinding and difusion)
Sugar cane washing 2.200 m3/t cane total 2.200 9.9
Imbibition 0.250 m3/ t cane total 0.250 1.1
Bearing cooling 0.035 m3/ t cane total 0.035 0.2
Cooling oil 0.130 m3/ t cane total 0.130 0.6
Subtotal 2.615 11.8
Juice
treatment
Cooling at sulphiting (*1)
0.100 m3/t cane sugar 0.050 0.2
Preparation of lime mixture 0.030 m3/t cane total 0.030 0.1
Preparation of polymer (*1)
0.015 m3/t cane sugar 0.008 0.0
Heating juice for sugar (*1)
160 kg steam/t cane sugar 0.080 0.4
for ethanol (*2) e (*4)
50 kg steam/t cane ethanol 0.025 0.1
Filter imbibition 0.030 m3/ t cane total 0.030 0.1
Filter condensers 0.300 a 0,350 m3/t cane total 0.350 1.6
Subtotal 0.573 2.6
Sugar mills (*1)
Steam for evaporation 0.414 t/t cane sugar 0.207 0.9
Condensers/multijets evaporation
4 a 5 m3/t cane sugar 2.250 10.2
Steam for cooking 0.170 t/t cane sugar 0.085 0.4
Condensers/multijets cookers 8 a 15 m3/t cane sugar 5.750 26.0
Molasses dilution 0.050 m3/t cane sugar 0.030 0.1
Delay cooking 0.020 m3/t cane sugar 0.010 0.0
Sugar washing (1/3 water e 2/3 steam)
0.030 m3/t cane sugar 0.015 0.1
Retainer of powdered sugar 0.040 m3/t cane sugar 0.020 0.1
Subtotal 8.367 37.8
Fermentation (*2)
preparation of the fermentation mixture
0 a 10 m3/m
3 ethanol residual 0.100 0.5
Juice cooling 30 m3/m
3 ethanol 1.250 5.6
Treatment of yeast 0.010 m3/m
3 ethanol 0.001 0.0
Washing gases CO2 fermentation
1.5 a 3.6 m3/m
3 ethanol 0.015 0.1
Fermentation cooling 60 a 80 m3/m
3 ethanol 3.000 13.6
Subtotal 4.366 19.7
Table – Averages rates of water uses in the sugar and ethanol mills in Brazil
Souce: ELIA NETO et al., 2009 – Manual de Conservação e reuso de Água na Agroindústria Sucroenergética . UNICA, FIESP, CTC e ANA
Process water
Ethanol distillation
(*2)
Heating (steam) 3.5 a 5 kg/m3 ethanol 0.360 1.6
Cooling condensers 80 a 120 m3/m
3 ethanol 3.500 15.8
Subtotal 3.860 17.4
Power
generation
Steam production 400 a 600 kg/t cane total 0.500 2.3
Desuperheating steam 0.030 l/kg steam 0.015 0.1
Whashing gas from the chimney of the boiler.
2.0 m3/t steam 1.000 4.5
Clean ashtrays boiler 0500 m3/t steam 0.250 1.1
Cooling oil and air from the turbo
15 l/kW 0.500 2.3
Water towers of condensation (*3)
38 m
3/t steam 6.0
(*3) 27.1
Subtotal 2.265 10.2
Others Cleaning floors and equipment 0.050 m3/t cane total 0.050 0.2
Use drinking 70 l/ employee days 0.030 0.1
Subtotal 0.080 0.4
Total 22.126 100
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
Process water - Distribution
Average Distribution of Water Uses in Sugar
Ethanol Sugarcane Industry
Gas scrubber
5%
Other
14%
Fermentation
cooling
19%
Sugar
concentratio
n
26%
Juice
evaporation
10%
Washing
sugarcane
10%
Ethanol
condeser
cooling
16%
Source: ELIA NETO , A. Gestão dos Recursos Hídricos na Agroindústria Canavieira . UNICA, 2014
• 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”
Curva de Tendência da Taxa de Captação de Água na
Indústria Canavieira
0
2
4
6
8
10
12
14
16
18
20
22
19 70 19 8 0 19 9 0 2 0 0 0 2 0 10 2 0 2 0
Taxa
de
Cap
taçã
o [m
3/t.c
ana]
DECREASE WATER CATCHMENT
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
Environmental Protocol, 2014
Goal of sector
Management of Water
Resources in the Sugarcane
Agro-Industry
Trend curve of the water catchment rate in the sugar cane industry.
Wa
ter
ca
tch
me
nt
rate
(m
3/t
).
Average catchment
Average Distribution of Water Uses in Sugar
Ethanol Sugarcane Industry
Gas scrubber
5%
Other
14%
Fermentation
cooling
19%
Sugar
concentratio
n
26%
Juice
evaporation
10%
Washing
sugarcane
10%
Ethanol
condeser
cooling
16%
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
Goals for water management
Catchment (m3/t.cane) 1.0
Consumption (m3/t.cane) 1.0
Wastewater to river (m3/t.cane) zero Average use= 22 m3/t.cane (in mill)
There are mills that water catchment smaller
than the goal (with 0.7 m3 / t cane and even
less)
Reuse Efficiency 95%,
relative to the goals
13
WATER BALANCE
Souce: Elia Neto, A. et all “Manual da Conservação e Reúso de Água na Agroindústria Sucroenergética, 2009. Versão revisada
Catchment:
Average = 2 m3/t.cane
Goal = 1 m3/t.cane
Cane’s water:
Average = 0.7
m3/t.cane
Wastewater
Average = 0 - 1.8 m3/t.cane
Goal = 0 m3/t.cane
Agronomic’s Reuse
Average = 0 - 1.8 m3/t.cane
Goal = 1.8 m3/t.cane
Losses: Average = 0.9 m3/t.cane
Goal = 0.9 m3/t.cane
Use and reuse
22 m3/t.cane
Reuse Index:
91% (goal 95%)
23 L/L
12 L/L
16 L/kg
8 L/kg
~18 L/kWh
Global average water balance in the sugarcane mills with the mix of production from 50%
sugar and 50% ethanol.
tower of cooling water
cooling spray pond water
The Good Industry Practices
15
decanter of sugarcane washing water dry cleaning sugarcane
cleaning of the boiler gases decanter of efluent
The Good Industry Practices
(*) 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
“Rescue” irrigation (*):
To plant sugarcane: 80-120 mm
To ratoon cane: 40-60 mm
Irrigation with effluents
Productivity average gains (*):
Sugarcane plant 12 to 20%
Ratoon cane 6 to 12%
Reuse: reduces the need for new sources of water for irrigation.
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):
urban 40%
rural and other 32%
industry 28%
Licensed water catchment distribuition in São Paulo' state
(source: PERH-2012-21015)
Total demand = 304,5 only in the
harvest period
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)
FINAL REMARKS
Advantage : Non irrigation
• 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.