摘要

A commonly agreed methodology for weighting the relative importance of different environmental impacts in Life Cycle Assessment (LCA) is lacking, although it is becoming a typical phase in LCA. Multi-Criteria Decision Analysis (MCDA) provides an avenue to develop weighting tools applicable in LCA. The purpose of this paper is to describe a process of assessing environmental impacts of two alternative raw materials and to present the problems related to it. A panel which includes experts in measuring the environmental impacts of biomass production was requested to identify and weight impact categories to assess environmental impacts of biomass production. The panelists identified new environmental impacts (such as biodiversity) not included to the standard LCA. The highest weights were given by the panelists to climate change, natural land use change and biodiversity. The environmental impacts were analyzed for four case biomass production chains producing biodiesel and pulp in Finland. In case chains, the raw material for biodiesel is Asian palm oil or Finnish rapeseed oil, while the raw material for pulp is South American eucalyptus or Finnish birch. The calculations of the LCA impacts were limited to the impact categories for which inventory data were available. In calculations, different types of normalization procedures were tested to receive information on their effects on the LCA results. According to the results, in some cases normalization have considerable impact on the magnitude of the results. In general, the results imply that biomass imported from developing countries has less environmental impacts compared to the local forest and field biomass produced in Finland. However, due to the several sources of uncertainties included in the results, they are only to be used for illustrative purposes. In the future, applying the MCDA in LCA may deepen the applicability of the analyses, if valid and reliable data is available.

  • 出版日期2012-7