Comparative life cycle assessment of rapeseed oil and palm oil
Schmidt J (2010)
International Journal of Life Cycle Assessment 15 (2):183-197
Background, aim and scope
The environmental effect of globalisation has been debated intensively in the last decades. Only few well-documented analyses of global versus local product alternatives exist, whilst recommendations on buying local are vast. At the same time, the European Environmental Agency’s Third Assessment concludes that the resource use within the EU is stabilising at the expense of increased resource use for import of products to the EU. Taking its point of departure in vegetable oils, this article compares rapeseed oil and palm oil as a local and a global alternative for meeting the increasing demand for these products in the EU. By using detailed life cycle assessment (LCA), this study compares the environmental impacts and identifies alternative ways of producing rapeseed oil and palm oil to the EU market in order to reduce environmental impacts.
Materials and methods
The consequential approach for system delimitation is applied (Ekvall and Weidema 2004; Weidema 2003; Schmidt 2008a; Schmidt and Weidema 2008). This approach differs from the attributional approach in a way that the actual affected suppliers and technologies are modelled instead of averages. In addition, co-product allocation is avoided by system expansion. The method for life cycle impact assessment (LCIA) is EDIP97 updated (LCA-Center 2007). In addition, land use and the associated impacts on biodiversity are assessed using the LCIA method described in Schmidt (2008b).
The characterised results of the LCA show that palm oil is environmentally preferable to rapeseed oil within ozone depletion, acidification, eutrophication, photochemical smog and land use, whilst the differences within global warming and biodiversity are less clear. The most significant process contributing to global warming from rapeseed oil is the cultivation of rapeseed, whilst the oil palm cultivation and the palm oil mill (effluent treatment) are equally important. Regarding land use and biodiversity for rapeseed oil, the avoided production caused by system expansion has a major role, whilst system expansion has only limited effect on the results of palm oil.
Alternative cultivation practices and technologies are assessed. The findings for rapeseed oil are that local expansions of the cultivated area on set-aside area is preferable to displacement of crops which are compensated for by increased agricultural production abroad and that the full press technology in the oil mill is preferable to solvent extraction. Concerning palm oil, cultivation on peat increases the contribution to global warming significantly with a factor of 4–5 compared to cultivation on the current mix of soils types. The other hotspot related to global warming (effluent treatment) can be markedly reduced by installation of digester tanks and subsequent utilisation of biogas.
The results of the scenarios show that the approach to system delimitation matters. When the consequential approach to system delimitation is applied in the agricultural stage, uncertainties show to be significant. These uncertainties are mainly related to the determination of how increased production is achieved, increased cultivated area and/or increased intensification. Overall, palm oil tends to be environmentally preferable to rapeseed oil within all impact categories except global warming, biodiversity and ecotoxicity where the difference is less pronounced and where it is highly dependent on the assumptions regarding system delimitation in the agricultural stage.
Recommendations and perspectives
Since the environmental performance of rapeseed oil and palm oil is a result of the current applied technologies and since improvement options exist in both product systems, it may be more relevant for decision makers to focus on requirements on the applied technologies in the product systems rather than preferring the one oil over the other.
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