To meet the Swedish climate target of net-zero greenhouse gas (GHG) emissions by 2045, it has become more and more urgent for the aviation sector to reduce its climate footprint. However, this represents a challenge for the non-commercial part of the aviation sector such as the air borne search-and-rescue services, as their activities cannot be compromised by the climate target. Increased use of sustainable aviation fuels (SAF) is a way to achieve the climate target, while still not compromising the mission for this part of aviation.
However, due to a high demand on SAF, their availability and possibility to supply the aviation sector in Sweden as well as their environmental impact in relation to the climate target is still somewhat uncertain.
This report aims to increase the understanding in these issues by first reviewing the domestic feedstock availability and calculating the SAF production potential within Sweden. Thereafter, an assessment was done on how the aviation fuel market could vary in Sweden by 2045 due to the strength of the GHG reduction mandate and the dependence or independence of fuel from outside Sweden.
This was done through 4 different future scenarios based on a mathematical model. Finally, the environmental impact of selected SAFs was evaluated by life cycle assessment (LCA) following the method described in the recast of the Renewable Energy Directive (REDII). The assessment was done based on the currently available data. Thus, the future change in the technology and other circumstances were not taken into account.
The current and future (2045) Swedish production potential of jet fuel was investigated via 4 different pathways, i.e., Hydroprocessed Esters and Fatty Acids (HEFA) from biogenic waste oils, Gasification-based Fischer-Tropsch (G-FT) from forest residues, Hydrothermal Liquefaction (HTL) from forest residues and Power-to-Liquid (PtL) from biogenic captured CO2 and H2 from electrolysis via Fischer-Tropsh (FT).
The pathways, of the assessed ones, having the highest current and future potential considering feedstock supply are G-FT and HTL. The results were however considerably affected by the assumptions made on process yield. The production potential of PtL was not as high as the other pathways due to low availability of feedstock. Finally, HEFA was the pathway with the lowest potential due to the low availability of domestic raw material.
Based on the scenario analysis, the future of fossil free jet fuel is highly dependent of the price of fuel as well as the maximum allowed blending ratio of fossil free jet fuel. In this particular scenario analysis, domestic ATJ and HEFA was favored by the model thanks to their low production costs and avoided import costs, since the fuel is produced in Sweden. However, although the production plants used in the model will be constructed within Swedish borders, it is unlikely that domestic HEFA feedstock would be sufficient to supply them and there would likely be an import of waste oils to meet the demand of the plants.
The environmental assessment was done on UCO-based HEFA and PtL. HEFA was assessed as it is the fuel that the Search and Rescue fleet used during the pilot phase of this project. PtL was assessed for the sake of comparison and also because most data for PtL production was already available. Both HEFA and PtL show the potential of reducing the fossil GHG emissions up to 70 and 77%, respectively. However, with the technical and legislative limitations, it is not yet possible to use pure SAF in the aviation sector. This leads to the potential emission reduction of the greenhouse gases being lower than 42%. SAF production and transportation of feedstock are one of the main contributors to the emissions.
In general, HEFA production has higher climate impact than the production of PtL. In addition, UCO which is the feedstock for HEFA was assumed to be collected in China. This gives a significantly higher impact compared to the PtL-process where all activities were assumed to take place in Sweden. This implies that the climate impact of HEFA can be reduced if the UCO can be collected domestically. However, as the assessment shows, the climate target will be difficult to achieve when using HEFA or PtL.
The challenge lies on the upstream processes of these two SAF which currently are still fossil-based. For HEFA, it is common that H2 is produced from natural gas while for PtL, the production of raw materials used in electrolysis and carbon capture process such as chemicals and catalysts contribute to fossil emissions.