Background, aim and scope
Climate change is a subject of growing global concern. Based on International Energy Agency (IEA 2004) research, about 19% of the greenhouse gas emissions from fuel combustion are generated by the transportation sector, and its share is likely to grow. Significant increases in the vehicles fleets are expected in particular in China, India, the Middle East and Latin America. As a result, reducing vehicle fuel consumption is most essential for the future. The reduction of the vehicle weight, the introduction of improved engine technologies, lower air friction, better lubricants, etc. are established methods of improving fuel efficiency, reducing energy consumption and greenhouse gas emissions. Continued progress will be required along all these fronts with light-weighting being one of the most promising options for the global transport sector. This paper quantifies greenhouse gas savings realised from light-weighting cars with aluminium based on life cycle assessment methodology. The study uses a pragmatic approach to assess mass reduction by comparing specific examples of components meeting identical performance criteria. The four examples presented in this analysis come from practical applications of aluminium. For each case study, the vehicle manufacturer has supplied the respective masses of the aluminium and the alternative component.
Material and methods
A full life cycle assessment with regards to greenhouse gas emissions and savings has been carried out for different aluminium applications in cars as compared to the same applications in steel or cast iron. The case studies reference real cases, where aluminium is actually used in series production. The studies are based on a greenhouse gas lifecycle model, which has been developed following the ISO standard 14040 framework. For each component, sensitivity analysis is applied to determine the impact of lifetime driving distance, driving characteristics (impact of air friction) and recycling rate.
Life cycle results show that in automotive applications, each kilogram of aluminium replacing mild steel, cast iron or high strength steel saves, depending on the specific case (bumper and motor block of a compact car, front hood of a large family car, body-in white of a luxury car), between 13 and 20 kg of greenhouse gas emissions.
The performed sensitivity analysis finds that even with ‘worst case’ scenarios savings are still significant.
The results not only demonstrate significant benefits of aluminium with regard to greenhouse gas savings but also show that these are very sensitive to variations of the recycling rate, the life-time driving distance and the driving behaviour.
Recommendations and perspectives
Good care is needed to gather life-cycle data and to make informed estimates, where no data are available. Furthermore, greenhouse gas savings for additional components should be calculated using this life cycle model to sustain the findings.
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Atherton J (2007) Declaration by the metals industry on recycling principles. Int J Life Cycle Assess 12(1):59–60
Boin UMJ, Bertram M (2005) Melting standardized aluminium scrap: a mass balance model for Europe. JOM 57(8):26–33
Buxmann K (2002) Treatment of aluminium recycling in life cycle assessments. Paper presented at the International Automobile Recycling Congress, March 13–15, Geneva
Buxmann K, Kistler P, Rebitzer G (2009) Independent information modules—a powerful tool for life cycle management. Int J Life Cycle Assess, Special Issue 14(1)
Ducker Research (2006) Aluminum content for light non-commercial vehicles to be assembled in North America, Japan and the European Union in 2006
EAA (2008) Environmental profile report for the European Aluminium Association—life cycle inventory data for aluminium production and transformation processes in Europe, www.eaa.net
Helms H, Lambrecht U (2004) Energy savings by light-weighting—part II. IFEU Institute for Energy and Environmental Research, Heidelberg
Helms H, Lambrecht U (2007) The potential contribution of light-weighting to reduce transport energy consumption. Int J Life Cycle Assess 12(2):58–64
Helms H, Lambrecht U, Höpfner U (2003) Energy savings by light-weighting—part I. IFEU Institute for Energy and Environmental Research, Heidelberg
IAI (2007) Life cycle assessment of aluminium: Inventory data for the primary aluminium industry—year 2005. Update, www.world-aluminium.org
IAI (2008) Improving sustainability in the transport sector through weight reduction and the application of aluminium-model, www.world-aluminium.org
IEA (International Energy Agency) (2004) CO2 emissions from fuel combustion. OECD, Paris
IFEU (Institute for Energy- and Environmental Research) (2001) Transport emission estimation model (TREMOD). Software tool developed by IFEU for the ‘Umweltbundesamt’ (German environmental agency), vers Nov 2001
IISI (2006) Internal document. IISI, Brussels
Julius J, Mutz S (2008) Automotive recycling-aluminium recovery from end-of-life vehicles. RWTH Aachen University, Aachen, EAA internal document prepared by: Chair of Processing and Recycling (I.A.R.)
Schmidt W, Dahlqvist E, Finkbeiner M, Krinke S, Lazzari S, Oschmann D, Pichon S, Thiel C (2004) Life cycle assessment of lightweight and end-of-life scenarios for generic compact class passenger vehicles. Int J Life Cycle Assess 9(6):405–416
Werner F, Richter K (2000) Economic allocation in LCA: A case study about aluminium window frames. Int J Life Cycle Assess 5(2):79–83
White M (2006) Cans or cars—aluminium & the automotive industry a JLR light vehicle strategy. Aluminium 2006: 21st International Aluminium Conference, Moscow
We thank J. Hannagan and P. Morton for helpful discussions and B. Gilmont, K. Martchek, and G. Rebitzer for assistance in the research.
Special Issue “Life Cycle Performance of Aluminium Applications”
This paper only covers two impact categories and has not undergone a critical review procedure as specified in ISO 14044. Therefore, it does not intend to make a comparative assertion, i.e. state the overall environmental superiority of one alternative versus another, nor should it be used by others for comparative assertions.
Responsible editors: Gerald Rebitzer, Jörg Schäfer
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Bertram, M., Buxmann, K. & Furrer, P. Analysis of greenhouse gas emissions related to aluminium transport applications. Int J Life Cycle Assess 14, 62–69 (2009). https://doi.org/10.1007/s11367-008-0058-0
- Climate change
- Greenhouse gas emissions
- ISO standard 14044
- Transport sector