Comparative environmental and energy profiles of potential bioenergy production chains in Southern Europe

Abstract

In this study, life cycle assessment (LCA) is used to assess and compare the environmental and energy profiles of three potential bioenergy production chains using different available feedstocks in Southern European countries. Two wastes, vineyard pruning and eucalypt logging residues, and a wooden energy crop, poplar, were examined in detail. The comparative LCA study showed that the use of poplar biomass for bioenergy production has a greater impact than the use of vineyard pruning and logging residues. The contribution from the poplar-cultivation-related activities considerably affected the results, as all the activities from field preparation to harvesting have been included within the system boundaries. In contrast, all the activities performed in the vineyard and forest prior to collection of the residues have not been computed in both scenarios since they have been allocated to the driving force of these stands: grapes and roundwood, respectively. The results support the idea that forest and agricultural waste would be an interesting and potential raw material for bioenergy purposes. However, further analysis should focus on these potential bioenergy sources, namely in terms of their availability and technical burning conditions, in order to meet energy requirements. Moreover, the environmental results were compared with others from literature corresponding to electricity production using alternative biomass sources and fossil fuels. In all the categories considered for comparison, environmental benefits were reported for the electricity production using a biomass source. However, these results must be carefully used since other issues - such as production costs, water availability and land use - should be considered.