In general, this study confirms the knowledge already gained in several LCA studies of biofuels. The type of biomass input and the conversion rate to the final fuel are quite important with respect to the environmental evaluation of all types of biofuels. Direct emissions of the conversion plant and transport issues are less relevant, as long as legal limits are maintained and biomass is not transported over very long distances of >150 km.
The European residue and energy crop biomass potential was assessed under the frame conditions of unaffected food, animal fodder and fibre production. This means
•that energy crops were considered to be grown only on surplus land, including fallow land and/or land released due to increased production efficiency,
•that the straw used e.g. for animal bedding and fodder was subtracted from the total production and
•that no wood needed for the wood processing industry is used for bioenergy generation.
The WtT LCA analysis includes the production of biomass, transports to the production plant, conversion processes and fuel distribution to the filling station.
The main conclusions which can be drawn from the well-to-tank LCA of BtL-production can be summarized as follows:
•The environmental performance of BtL production is determined by the biomass production, except for the category summer smog which is determined by the onversion process itself
•The estimated N2O emissions linked to fertilizer production and usage are contributing to the global warming potential of BtL production in the range of 12-35%.
•Environmental improvement potentials for BtL production are:
-Improved technology of biomass production with reduced fertilizer application and increased biomass yields.
-Increased energy efficiencies for the conversion processes.
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