Life cycle assessments of selected biofuels

For biofuels produced in Austria, this report presents the process steps (key process elements) that generate most greenhouse gas emissions. The effects of land use change were also examined and taken into account in the life cycle assessment. In the production of biodiesel from rapeseed, most greenhouse gases are emitted from the cultivation of rapeseed in the field (85 %). Bioethanol and biogas production generate most greenhouse gas emissions during the fermentation phase (fermentation 66 % for bioethanol, processing 88 % for biogas). If the effects of land use change are taken into account in the life cycle, biodiesel and especially biogas continue to result in greenhouse gas intake compared to fossil fuels. In the case of bioethanol, on the other hand, taking into account direct and indirect land-use change can reverse the greenhouse gas balance compared to petrol.