Background, aim, and scope
This paper presents the lifecycle assessment (LCA) of fuel ethanol, as 100% of the vehicle fuel, from sugarcane in Brazil. The functional unit is 10,000 km run in an urban area by a car with a 1,600-cm3 engine running on fuel hydrated ethanol, and the resulting reference flow is 1,000 kg of ethanol. The product system includes agricultural and industrial activities, distribution, cogeneration of electricity and steam, ethanol use during car driving, and industrial by-products recycling to irrigate sugarcane fields. The use of sugarcane by the ethanol agribusiness is one of the foremost financial resources for the economy of the Brazilian rural area, which occupies extensive areas and provides far-reaching potentials for renewable fuel production. But, there are environmental impacts during the fuel ethanol lifecycle, which this paper intents to analyze, including addressing the main activities responsible for such impacts and indicating some suggestions to minimize the impacts.
Materials and methods
This study is classified as an applied quantitative research, and the technical procedure to achieve the exploratory goal is based on bibliographic revision, documental research, primary data collection, and study cases at sugarcane farms and fuel ethanol industries in the northeast of São Paulo State, Brazil. The methodological structure for this LCA study is in agreement with the International Standardization Organization, and the method used is the Environmental Design of Industrial Products. The lifecycle impact assessment (LCIA) covers the following emission-related impact categories: global warming, ozone formation, acidification, nutrient enrichment, ecotoxicity, and human toxicity.
Results and discussion
The results of the fuel ethanol LCI demonstrate that even though alcohol is considered a renewable fuel because it comes from biomass (sugarcane), it uses a high quantity and diversity of nonrenewable resources over its lifecycle. The input of renewable resources is also high mainly because of the water consumption in the industrial phases, due to the sugarcane washing process. During the lifecycle of alcohol, there is a surplus of electric energy due to the cogeneration activity. Another focus point is the quantity of emissions to the atmosphere and the diversity of the substances emitted. Harvesting is the unit process that contributes most to global warming. For photochemical ozone formation, harvesting is also the activity with the strongest contributions due to the burning in harvesting and the emissions from using diesel fuel. The acidification impact potential is mostly due to the NOx emitted by the combustion of ethanol during use, on account of the sulfuric acid use in the industrial process and because of the NOx emitted by the burning in harvesting. The main consequence of the intensive use of fertilizers to the field is the high nutrient enrichment impact potential associated with this activity. The main contributions to the ecotoxicity impact potential come from chemical applications during crop growth. The activity that presents the highest impact potential for human toxicity (HT) via air and via soil is harvesting. Via water, HT potential is high in harvesting due to lubricant use on the machines. The normalization results indicate that nutrient enrichment, acidification, and human toxicity via air and via water are the most significant impact potentials for the lifecycle of fuel ethanol.
The fuel ethanol lifecycle contributes negatively to all the impact potentials analyzed: global warming, ozone formation, acidification, nutrient enrichment, ecotoxicity, and human toxicity. Concerning energy consumption, it consumes less energy than its own production largely because of the electricity cogeneration system, but this process is highly dependent on water. The main causes for the biggest impact potential indicated by the normalization is the nutrient application, the burning in harvesting and the use of diesel fuel.
Recommendations and perspectives
The recommendations for the ethanol lifecycle are: harvesting the sugarcane without burning; more environmentally benign agricultural practices; renewable fuel rather than diesel; not washing sugarcane and implementing water recycling systems during the industrial processing; and improving the system of gases emissions control during the use of ethanol in cars, mainly for NOx. Other studies on the fuel ethanol from sugarcane may analyze in more details the social aspects, the biodiversity, and the land use impact.
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Vinasse is the byproduct of the alcohol distillation that is recycled to the field.
Bagasse is the solid byproduct of the juice extraction that is used to produce energy.
Alves IT (1991) Environmental Impact Assessment of the Pilões Distillery (in Portuguese). Environmental impact report. Environmental Office of the State of Sao Paulo. Environmental Planning Coordination, Araraquara
COPERSUCAR (1989) Environmental Impact Study: Destilaria Batatais S.A. (in Portuguese). Environmental Office of the State of Sao Paulo. Environmental Planning Coordination, Piracicaba
EMBRAPA (1997) Greenhouse gas emissions from the burning of sugarcane (in Portuguese), technical report. Ministry of Agriculture and Supply. The Brazilian Agricultural Research Corporation, Brasilia
Factor G, Longin E, Mengiardi J, Teljigovic M, Villanueva A, Welton C (1998) Lifecycle Assessment of Sugar Production: cane sugar versus beet sugar. Technical University of Denmark (DTU): Report. 80410, Denmark
Hauschild MZ, Bachmann TM, Huijbregts M, Jolliet O, Köhler A, Larsen HF, Margni M, McKone T, MacLeod M, Van de Meent D, Schuhmacher M, Rosenbaum RK (2007) International consensus model for comparative assessment of chemicals - USEtox. Proceedings of the SETAC Europe 17th Annual Meeting, 20-24 May 2007, Porto, Portugal
Hauschild MZ, Wenzel H (1998) Environmental assessment of products, vol 2: Scientific background. Chapman & Hall, Cambridge
ISO (1997) ISO 14040: Environmental management–Lifecycle assessment–Principles and framework. International Organization for Standardization, Geneva
ISO (2006) ISO 14044: Environmental management–Lifecycle assessment–Requirements and guidelines. International Organization for Standardization, Geneva
Kulay LA (2000) Development of life-cycle analysis model suitable to Brazilian conditions: application to the simple superphosphate case (in Portuguese), Dissertation. University of Sao Paulo, Sao Paulo
Macedo IC, Leal MRLV, Silva JEAR (2004) Report of greenhouse effect gas emissions in the production and use of ethanol in Brazil (in Portuguese). Environmental Office of the State of Sao Paulo, Sao Paulo
Ministry of Agriculture, Livestock and Supply (2007) Evolution of the Sugarcane Productivity in Brazil. Office for the Production and Agroenergy Department for SugarCane and Agroenergy, Brazil http://www.agricultura.gov.br, accessed 1.5.2007
Ministry of Mines and Energy (2007) National Energy Accounting, Final Report. EPE, Rio de Janeiro
Ocean Studies Board and Water Science and Technology Board (2000) Clean coastal waters: understanding and reducing the effects of nutrient pollution. Commission on Geosciences, Environment, and Resources, National Research Council, Washington
Shigaki F (2006) Transport of phosphorus in surface runoff depending on the type of P source and rainfall intensity: Relevance to environmental management in Brazilian production systems (in Portuguese), PhD thesis. University of Sao Paulo, Piracicaba
SimaPro Database (2003) Inventory Database—SimaPro software. Technical University of Denmark (DTU). EDIP, Denmark
Stranddorf HK, Hoffmann L, Schmidt A (2005) Update on impact categories, normalisation and weighting in LCA: selected EDIP97 data. Environmental project no. 995. Danish Ministry of Environment, Copenhagen
Wenzel H, Hauschild MZ, Alting A (1997) Environmental Assessment of Products, vol 1: Methodology, tools and case studies in product development. Kluwer, Dordrecht
The authors wish to thank State of São Paulo Research Foundation and Institute Factory of Millennium for inspiring and funding the research.
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Roberto Ometto, A., Zwicky Hauschild, M. & Nelson Lopes Roma, W. Lifecycle assessment of fuel ethanol from sugarcane in Brazil. Int J Life Cycle Assess 14, 236–247 (2009). https://doi.org/10.1007/s11367-009-0065-9
- Fuel ethanol
- Global warming
- Human toxicity
- Lifecycle assessment (LCA)
- Nutrient enrichment
- Ozone formation
- Renewable energy
- Environmental impacts