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FAQ

FAQ

The CARE-O-SENE research project is working on future-oriented technologies that are still largely unknown to many people. That is why we are giving you this overview. If you have any further questions, please use our contact form

SAF stands for Sustainable Aviation Fuels. . SAF refers to all sustainably produced aviation fuels, such as biogenic and synthetic fuels.

SAFs are divided into different generations. The first generation includes plant-based SAFs that are produced from vegetable oils. The second generation consists of SAFs produced from biomass, for example from waste and wood residues. Further generations consist of synthetic fuels. This is where something called the power-to-liquids (PtL) process comes into play.

For a fuel to be considered an SAF – and thus sustainable – the raw materials used are evaluated according to certain sustainability criteria. Criteria include whether there is competition with food production, how much drinking water is used and whether there is any destruction of ecosystems, for example through additional agricultural cultivation. 

The key of this technology is converting electric energy into liquid energy carriers (powerto-liquids; PtL). Sustainable aviation fuels (SAFs) are accessible via the PtL approach. One of the technologies used for this is the FischerTropsch(FT) process for converting hydrogen and carbon dioxide from sustainable sources into SAF. The resulting SAFs are not based on fossil fuels like conventional kerosene but on renewably generated electricity and carbon dioxide.

The Fischer-Tropsch process, unlike alternative power-to-liquid processes, is already established in the market. Sasol brings over 70 years of experience on Fischer-Tropsch catalysts to the table and is the technology leader in this field. Catalysts increase the efficiency of the chemical conversion processes. The new types of catalysts that are developed within the CARE-O-SENE project support the goal of decarbonising the aviation sector.

The Fischer-Tropsch process, unlike alternative power-to-liquid processes, is already established in the market. Sasol brings over 70 years of experience on Fischer-Tropsch catalysts to the table and is the technology leader in this field.

Due to global climate protection efforts and, in some cases, mandatory blending ratios for power-to-liquid kerosene, a strongly growing demand for sustainable aviation fuels is to be expected. Since green electricity and hydrogen will be relatively scarce commodities in the foreseeable future, it is essential to use these raw materials as efficiently as possible. CARE-O-SENE has, therefore, set itself the goal of increasing the process yield from 50 to 70 per cent to over 80 per cent, thanks to new catalysts. This means that significantly more fuel can be rendered usable with the same amount of resources. 

The aircraft would then no longer run on a fossil raw material but a synthetic alternative – that is a great advantage. Nevertheless, a combustion process still takes place – with carbon dioxide as an output. However, this carbon dioxide is returned to the cycle and used as a raw material. Depending on the CO2source, it is possible to produce partially or completely CO2-neutral kerosene. For example, this can be captured from industrial processes or waste incineration. With SAF produced in a CO2-neutral process like biogenic or direct air captured CO2 , no additional CO2 enters the atmosphere. 

No changes to existing aircraft or the supporting infrastructure are necessary to use Fischer-Tropsch derived SAF’s. However, the regulatory environment currently only allows a blending rate of 50%. SAF can be used as a so-called drop-in fuel for standard passenger aircraft. SAFs are already being added to conventional fossil fuels in small quantities. 

By circular carbon dioxide we mean CO2that has a biogenic origin or was directly captured from the air ("direct air capture"), then further processed in chemical processes and released again through combustion processes, as in the case of sustainable fuels.

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