Water Use in Sugar and Ethanol Industry in the State of São Paulo (Southeast Brazil)

Abstract

Brazil is the largest producer of ethanol from sugarcane in the world. While the ethanol industry is economically important to Brazil for several reasons, it also has a significant impact on the environment. Here we analyze the water consumptive use in the transformation of the feedstock (sugarcane) . Although the water used by sugarcane mills has decreased in recent decades, it is still possible to further decrease the amount of water used by ethanol production. This would decrease the pressure on 1st order streams of the state from which most water is withdrawn. In addition, the enormous volume of vinasse production must be reduced because it exerts constant pressure on aquatic ecosystems, soil and groundwater due to the constant increase in the potassium (K) concentration in areas where it is used as a fertilizer.

Sugarcane water footprint under different management practices in Brazil: Tietê/Jacaré watershed assessment

“…5) was calculated, considering that one ton of processed cane produces 85 L of ethanol (Hernandes et al, 2013), while each litre of ethanol generates 12 L of vinasse (Martinelli et al, 2013).…”

“…To a certain extent, this solution has helped to protect aquatic ecosystems. Since the 1980s, this practice has brought economic benefits in replacing part or all of the mineral fertilizer, improving the physical and chemical characteristics of the soil, increasing agricultural productivity and reducing the immediate problem of water ecosystems pollution (Martinelli et al, 2013).…”

Impacts of Bio-Based Energy Generation Fuels on Water and Soil Resources

“…Use per tonne of feedstock has decreased dramatically for both corn and sugarcane ethanol. For instance, the consumptive water use of ethanol-sugar mills in Southeast Brazil has decreased from 15 m 3 Mg −1 of sugarcane bagasse prior to 2008 to <3 m 3 Mg −1 in 2008 [35].…”

Assessing potential impacts of sugarcane production on water resources: A case study in Brazil

“…Water withdrawal by sugarcane mills has decreased along the years. Between 1970 and 1990 water withdrawal was reduced from 15–20 to 5.6 m 3 t −1 of sugarcane processed, and reached 1.5 m 3 t −1 in 2008 or even less than 1 m 3 t −1 in some areas of São Paulo . This has been possible due to the optimization of some industrial processes and water reuse in industry .…”

“…Between 1970 and 1990 water withdrawal was reduced from 15-20 to 5.6 m 3 t -1 of sugarcane processed, 21 and reached 1.5 m 3 t -1 in 2008 or even less than 1 m 3 t -1 in some areas of São Paulo. 22,23 Th is has been possible due to the optimization of some industrial processes and water reuse in industry. 21 Also, over the years, the application of waste water and vinasse, both industrial effl uents, in the sugarcane fi eld (mainly aft er harvesting) has become common.…”