Comparative life cycle assessment of biodiesel and fossil diesel fuel

Biofuels offer clear advantages in terms of greenhouse gas emissions, but do they perform better when we look at all the environmental impacts from a life cycle perspective. In the context of a demonstration project at the Flemish Institute for Technology Research (VITO) on the use of rapeseed methyl ester (RME) or biodiesel as automotive fuel, a life cycle assessment (LCA) of biodiesel and diesel was made. The primary concern was the question as to whether or not the biodiesel chain was comparable to the conventional diesel chain, from an environmental point of view, taking into account all stages of the life cycle of the two products. Additionally, environmental damage costs were calculated, using an impact pathway analysis. This paper presents the results of the two methods for evaluation of environmental impacts of RME and conventional diesel. Both methods are complementary and share the conclusion that although biodiesel has much lower greenhouse gas emissions, it still has significant impacts on other impact categories. The external costs of biodiesel are a bit lower compared to fossil diesel. For both fuels, external costs are significantly higher than the private production cost. (Author)