EVALUATION OF GHG EMISSIONS AND ENERGY BALANCES OF INNOVATIVE AVIATION BIOFUEL PATHWAYS

This study aimed to analyse and assess the GHG emissions reduction potential of alternative fuels for aviation; and provide insights on the GHG emissions profiles and the energy efficiency of representative options for the provision of alternative aviation fuels. Such insights are critical for the biofuel market players in making investment decisions and for policy makers when defining regulatory measures, including support mechanisms. To date, there is a variety of pathways that have been defined and approved to produce alternative jet fuels from bio-based and waste materials with several options for conversion technologies. Some waste or a residue pathways do not require land for feedstock production, others use bio-based feedstocks that do not compete with food production. It is important to consider whether the energy efficiency of each alternative fuel option is justified by the benefits in terms of emissions. reductions. The analysis is focused on alternative drop-in jet fuels, e.g. non-fossil hydrocarbon fuels characterized by the same chemical structure as conventional jet fuel. Fuels made from wastes and residues exhibit lower GHG emissions per MJ of final fuel compared to aviation fuels produced from the vegetable oils analyzed. However, the effect which the methodological rules for allocating inputs have on emissions and energy balance can be more pronounced than the consideration of whether the feedstock is a waste or not.