For the life cycle assessment (LCA) of sustainable aviation fuels (SAF), new feedstocks of interest not currently covered by the CORSIA international aviation scheme were first identified by ALTERNATE. Life cycle inventory data were collected for these feedstocks. The methodology for LCA was also defined, designed to ensure compatibility with other international schemes for SAF such as CORSIA.
Alternative fuel production technologies for SAF have been selected, and the overall feedstock-to-fuel pathways have been determined.
Results indicate that SAF can provide between 21-85% GHG emissions benefits in comparison to fossil kerosene when emissions from land use change are not included. Main contributors to emissions are farming and fuel production steps. Parametric uncertainty can cause upto 28% variability in the GHG emission results. Emissions from land use change can negate potential savings from SAF, especially when forests or natural shrublands are lost. In addition, consequential LCA results indicated the importance of co-product modelling assumptions on induced land use change emissions.
With respect to the alternative aviation fuel composition requirements, a fuel database from the open literature has been created. Regarding the investigation on the drop-in fuel certification approach (tools & models), the objective is to highlight the fuel-dependent safety criteria. An analysis of the impact of fuel properties on aircraft operation (engine and fuel system) is underway.
Regarding the activity related to combustor and engine tests and models, an experimental data exploitation plan has been created.During the reporting period, the work planned included a laboratory study of emissions from different fuels using a liquid combustion standard generator (CAST).
Another important line of investigation concerns the utilization of sustainable fuel in commercial aviation and the airlines behavioural models. The work here has been concentrated in two areas: the descriptions of the different Market Based Measures (MBM) from a theoretical point of view and an exhaustive revision of the mechanisms to introduce sustainable fuels in commercial aviation, reviewing the regulations of the most active States in this field.
The last of the technical work packages is related to policy, regulations and operational optimization on the use of alternative fuel. The first part of this work package is the review of the present situation of the MBM application around the world, contained in a report already produced.
Finally, several dissemination and exploitation results have been achieved from early in the project development. The creation of the project website (www.alternateproject.com ) and its continuous update with relevant information related and about the project can be considered the most relevant one, but not the only one. On the other hand, the presence of the project on the Social Media, with an active account on Twitter and LinkedIn, is providing visibility to the project.
